Planification optimisee des reseaux electriques par la methode des ...

African Journals Online (AJOL)

In this paper, the insertion of renewable power sources (wind, solar photovoltaic, hydroelectric) in an existing electrical system was planned by the method of genetic algorithms in real coding. The main objective of this planning is the optimization of production costs of these renewable energy sources and electric power ...

Physics experiments in graphite lattices (1962); Experiences sur les reseaux a graphite (1962)

Energy Technology Data Exchange (ETDEWEB)

Bacher, P; Cogne, F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1962-07-01

A review is made of the various experimental methods used to determine the physics of graphite, natural uranium lattices: integral lattice experiments; both absolute and differential, effective cross section measurements, both by activation methods and by analysis of irradiated fuels, fine structure measurements. A number of experimental results are also given. (authors) [French] On decrit les differentes methodes experimentales utilisees pour determiner les parametres physiques de reseaux a uranium-graphite. Il s'agit d'experiences globales: mesures absolues et relatives de laplaciens, mesures de sections efficaces effectives par activation et par analyses de combustibles irradies, mesures de structures fines. Un certain nombre de resultats experimentaux sont communiques. (auteurs)

The effect of an alternating electric field on a totally ionised plasma; Action d'un champ electrique alternatif sur un plasma totalement ionise

Energy Technology Data Exchange (ETDEWEB)

Baglin, H; Brin, A; Ozias, Y; Salmon, J [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Delcroix, J L [Ecole Normale Superieure, 75 - Paris (France)

1960-07-01

The equation giving the distribution function of the electrons in a steady-state, for a fully ionized plasma in an a.c. field, are provided from the Fokker-Planck equation. The electric conductivity is complex and depends on the frequency. (author) [French] L'equation qui donne la fonction de distribution des electrons dans un etat stationnaire pour un plasma totalement ionise dans un champ electrique alternatif est fournie par l'equation de Fokker-Planck. La conductibilite electrique est complexe et depend de la frequence. (auteur)

Sealed coupling for an electrical heating conductor with coaxial sheath (pattern 1964); Raccord etanche pour conducteur electrique chauffant a gaine coaxiale (type 1964)

Energy Technology Data Exchange (ETDEWEB)

Arragon, Ph; Aubert-Chevallier, R; Gentil, J; Seguin, M; Vilcot, M; Villiers, J [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1965-07-01

Many irradiation devices call for supplementary electrical heating which can provide a constant temperature. We describe a coupling whose high performance makes it possible for the sheathed electrical resistance to provide maximum power. Since this coupling is sealed and does not require special cooling, it may be placed in any position on the irradiation device. (authors) [French] De nombreux dispositifs d'irradiation necessitent un chauffage electrique d'appoint capable d'assurer une temperature constante. Nous decrivons un raccord dont les bonnes performances permettent a la resistance electrique gainee de dissiper une puissance elevee. Etant etanche et n'ayant pas besoin d'un refroidissement special, ce raccord peut etre place dans n'importe quelle partie d'un dispositif d'irradiation. (auteurs)

Integral measurements of lattice properties in the natural uranium-graphite critical facility Marius; Mesures globales de reseaux a graphite dans l'empilement critique marius

Energy Technology Data Exchange (ETDEWEB)

Cogne, F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

A systematic study of natural uranium-graphite lattices has been undertaken in the critical facility MARIUS, which was built in 1959 in Marcoule. Integral measurement of lattice properties are carried out by the progressive replacement method. This report describes the experimental methods, the analysis of the experiments and the results obtained for lattices with pitches ranging from 192 to 317 mm and fuel elements with cross sections ranging from 6 to 20 cm{sup 2}. The principles of correlation of the results are also outlined. Additional experimental results are also given, pertaining to the determination of the anisotropy, of both the axial and the radial migration areas, and of the age in graphite. (author) [French] L'empilement critique MARIUS, construit en 1959 a Marcoule, a ete utilise pour l'etude systematique des reseaux a graphite-uranium naturel. Les mesures globales de reseaux sont faites par la methode de remplacement progressif. On decrit ici les methodes experimentales utilisees pour ces mesures globales, les principes du depouillement et les resultats obtenus pour des pas de 192 a 317 mm et des combustibles de 6 a 20 cm{sup 2} d'uranium naturel. On donne d'autre part le principe de correlation des mesures. Un certain nombre de resultats experimentaux complementaires sont donnes, en permettant de determiner l'anisotropie, les aires de migration axiale et radiale, l'age dans le graphite. (auteur)

Sealed coupling for an electrical heating conductor with coaxial sheath (pattern 1964); Raccord etanche pour conducteur electrique chauffant a gaine coaxiale (type 1964)

Energy Technology Data Exchange (ETDEWEB)

Arragon, Ph.; Aubert-Chevallier, R.; Gentil, J.; Seguin, M.; Vilcot, M.; Villiers, J. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1965-07-01

Many irradiation devices call for supplementary electrical heating which can provide a constant temperature. We describe a coupling whose high performance makes it possible for the sheathed electrical resistance to provide maximum power. Since this coupling is sealed and does not require special cooling, it may be placed in any position on the irradiation device. (authors) [French] De nombreux dispositifs d'irradiation necessitent un chauffage electrique d'appoint capable d'assurer une temperature constante. Nous decrivons un raccord dont les bonnes performances permettent a la resistance electrique gainee de dissiper une puissance elevee. Etant etanche et n'ayant pas besoin d'un refroidissement special, ce raccord peut etre place dans n'importe quelle partie d'un dispositif d'irradiation. (auteurs)

Diffusion, electrical mobility and ionic interactions in molten Salts; Diffusion, mobilite electrique et interactions ioniques dans les sels fondus

Energy Technology Data Exchange (ETDEWEB)

Lantelme, F. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-05-01

The diffusion and the electrical migration of ions in the molten alkali nitrates LiNO{sub 3}, NaNO{sub 3} and KNO{sub 3} and in their mixtures have been examined using stable or radio-active isotope indicators. This experimental works shows that there are large differences in the diffusion coefficients and the electric mobilities when they are compared using the Nernst-Einstein formula. An interpretive model has been put forward which shows the role played by poly-ionic displacements: in a salt AC the particles moving are not only the free ions A{sup -} and C{sup +} but also the groups [A{sub n}C{sub m}]{sup (m-n)+}... These results confirm the importance of electrostatic attraction and of the polarizability of the ions. This mechanisms, furthermore, explains the inversions of electrical mobilities often observed in liquid ionic media. (author) [French] La diffusion et la migration electrique des ions dans les nitrates alcalins fondus LiNO{sub 3}, NaNO{sub 3} et KNO{sub 3} et dans leurs melanges ont ete examinees a l'aide d'indicateurs isotopiques stables et radioactifs. Cette etude experimentale fait apparaitre des ecarts importants entre les coefficients de diffusion et les mobilites electriques compares au moyen de la formule de Nernst-Einstein. Un modele d'interpretation a pu etre propose mettant en evidence l'existence de deplacements polyioniques: dans un sel AC les particules en mouvement sont non seulement les ions libres A{sup -} et C{sup +} mais aussi des groupes [A{sub n}C{sub m}]{sup (}m{sup -n)+}. Ces resultats precisent l'importance des attractions electro-statiques et de la polarisabilite des ions. D'autre part, ce mecanisme permet de rendre compte des renversements des mobilites electriques souvent observes en milieu ionique liquide.

Diffusion, electrical mobility and ionic interactions in molten Salts; Diffusion, mobilite electrique et interactions ioniques dans les sels fondus

Energy Technology Data Exchange (ETDEWEB)

Lantelme, F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-05-01

The diffusion and the electrical migration of ions in the molten alkali nitrates LiNO{sub 3}, NaNO{sub 3} and KNO{sub 3} and in their mixtures have been examined using stable or radio-active isotope indicators. This experimental works shows that there are large differences in the diffusion coefficients and the electric mobilities when they are compared using the Nernst-Einstein formula. An interpretive model has been put forward which shows the role played by poly-ionic displacements: in a salt AC the particles moving are not only the free ions A{sup -} and C{sup +} but also the groups [A{sub n}C{sub m}]{sup (m-n)+}... These results confirm the importance of electrostatic attraction and of the polarizability of the ions. This mechanisms, furthermore, explains the inversions of electrical mobilities often observed in liquid ionic media. (author) [French] La diffusion et la migration electrique des ions dans les nitrates alcalins fondus LiNO{sub 3}, NaNO{sub 3} et KNO{sub 3} et dans leurs melanges ont ete examinees a l'aide d'indicateurs isotopiques stables et radioactifs. Cette etude experimentale fait apparaitre des ecarts importants entre les coefficients de diffusion et les mobilites electriques compares au moyen de la formule de Nernst-Einstein. Un modele d'interpretation a pu etre propose mettant en evidence l'existence de deplacements polyioniques: dans un sel AC les particules en mouvement sont non seulement les ions libres A{sup -} et C{sup +} mais aussi des groupes [A{sub n}C{sub m}]{sup (}m{sup -n)+}. Ces resultats precisent l'importance des attractions electro-statiques et de la polarisabilite des ions. D'autre part, ce mecanisme permet de rendre compte des renversements des mobilites electriques souvent observes en milieu ionique liquide.

Comparison between IEEE and CIGRE Thermal Behaviour Standards and Measured Temperature on a 132-kV Overhead Power Line

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Alberto Arroyo

2015-12-01

Full Text Available This paper presents the steady and dynamic thermal balances of an overhead power line proposed by CIGRE (Technical Brochure 601, 2014 and IEEE (Std.738, 2012 standards. The estimated temperatures calculated by the standards are compared with the averaged conductor temperature obtained every 8 min during a year. The conductor is a LA 280 Hawk type, used in a 132-kV overhead line. The steady and dynamic state comparison shows that the number of cases with deviations to conductor temperatures higher than 5 ∘ C decreases from around 20% to 15% when the dynamic analysis is used. As some of the most critical variables are magnitude and direction of the wind speed, ambient temperature and solar radiation, their influence on the conductor temperature is studied. Both standards give similar results with slight differences due to the different way to calculate the solar radiation and convection. Considering the wind, both standards provide better results for the estimated conductor temperature as the wind speed increases and the angle with the line is closer to 90 ∘ . In addition, if the theoretical radiation is replaced by that measured with the pyranometer, the number of samples with deviations higher than 5 ∘ C is reduced from around 15% to 5%.

Two rice GRAS family genes responsive to N -acetylchitooligosaccharide elicitor are induced by phytoactive gibberellins: evidence for cross-talk between elicitor and gibberellin signaling in rice cells.

Science.gov (United States)

Day, R Bradley; Tanabe, Shigeru; Koshioka, Masaji; Mitsui, Toshiaki; Itoh, Hironori; Ueguchi-Tanaka, Miyako; Matsuoka, Makoto; Kaku, Hanae; Shibuya, Naoto; Minami, Eiichi

2004-01-01

In this study, we present data showing that two members of the GRAS family of genes from rice, CIGR1 and CIGR2 (chitin-inducible gibberellin-responsive), inducible by the potent elicitor N -acetylchitooligosaccharide (GN), are rapidly induced by exogenous gibberellins. The pattern of mRNA accumulation was dependent on the dose and biological activity of the gibberellins, suggesting that the induction of the genes by gibberellin is mediated by a biological receptor capable of specific recognition and signal transduction upon perception of the phytoactive compounds. Further pharmacological analysis revealed that the CIGR1 and CIGR2 mRNA accumulation by treatment with gibberellin is dependent upon protein phosphorylation/dephosphorylation events. In rice calli derived from slender rice 1, a constitutive gibberellin-responsive mutant, or d1, a mutant deficient in the alpha -subunit of the heterotrimeric G-protein, CIGR1 and CIGR2 were induced by a GN elicitor, yet not by gibberellin. Neither gibberellin nor GN showed related activities in defense or development, respectively. These results strongly suggested that the signal transduction cascade from gibberellin is independent of that from GN, and further implied that CIGR1 and CIGR2 have dual, distinct roles in defense and development.

Les reseaux de politique publique comme facteur d'influence du choix des instruments de politique energetique canadienne a des fins environnementales de 1993 a nos jours

Science.gov (United States)

Fathy El Dessouky, Naglaa

Au cours de la derniere decennie, les modes de la gouvernance ont pris place dans un contexte totalement different de celui qu'ils avaient auparavant. Les gouvernements modernes se rendent compte qu'ils perdent de plus en plus leur capacite a elaborer et a gerer les changements d'une maniere autonome. Ainsi, les fonctions et les activites traditionnellement accomplies exclusivement par le gouvernement engagent de nos jours une gamme d'acteurs etatiques et non etatiques. A l'encontre du concept traditionnel de l'Etat controleur, la gouvernance contemporaine est ainsi devenue moins une question d'offre de service et davantage une gestion indirecte des reseaux de politique publique. Dans cette entreprise, les gouvernements contemporains, cherchant plus d'information, de soutien et de legitimite en matiere de formulation des decisions, ont besoin d'etablir des relations avec les divers groupes d'interet qui, a leur tour, voulaient plus de promotion et de protection en faveur de leurs interets a travers leur implication au processus de l'elaboration et de la mise en oeuvre des politiques publiques. Ainsi, l'approche des reseaux de politique publique represente aujourd'hui un courant considerable au sein du champ d'analyse des politiques publiques. Toutefois, les preoccupations des chercheurs pour cette approche, dans le domaine des politiques energetiques a des fins environnementales, semblent recentes, et les etudes realisees sont encore trop peu nombreuses. Au Canada, au debut des annees 1990, le gouvernement ainsi que plusieurs groupes d'interets, des differents secteurs energetique, industriel et environnemental, ont commence a intensifier leurs efforts pour s'attaquer au probleme du changement climatique d'origine energetique, genere surtout par le secteur de l'industrie. Au cours de la derniere decennie, la question touchant plutot le sujet du developpement energetique durable represente le plus important domaine des politiques publiques ayant surgi recemment dans

Controlled Operation of the Islanded Portion of the International Council on Large Electric Systems (CIGRE Low Voltage Distribution Network

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Ghullam Mustafa Bhutto

2017-07-01

Full Text Available In islanding, a portion of the power network, comprised of the loads and distributed generation (DG units, is isolated from the rest of the power grid and forms a micro grid (MG. In this condition, it becomes essential for the islanded MG to operate in a stable and controlled manner by providing ancillary services. When the MG is cut off from the main grid, the islanding must be detected by the DG units. In this condition it is essential that one of the controllers should be switched to the voltage-frequency (VF control mode. In islanding, the network loses it slack reference and this reference is established by a VF controller. The voltage and the frequency of the islanded MG deviate when disconnected from the transmission grid and these deviations are caused by the load-generation imbalance. The voltage and the frequency of the islanded MG can be restored to the permissible limits if the desired/exceeded amount of active and reactive power is injected/absorbed by the locally available sources in islanded MG. This paper proposes a control strategy which can compensate the voltage and the frequency deviations in the islanded portion of the International Council on Large Electric Systems (CIGRE low voltage distribution network by using advanced power electronics devices such as STATCOMs for Photovoltaic (PV Units and Battery Energy Storage Systems (BESS STATCOMs (for battery units. The selection of the VF controller for the most suitable DG unit of this test network is also presented in this paper, and the effectiveness of the controllers is verified by presenting simulation results using DIgSILENT (DIgSILENT GmbH, Gomaringen, Germany power factory software version 15.0.

Validity of the electrical model representation of the effects of nuclear magnetic resonance (1961); Validite de la representation par modele electrique des effets de resonance magnetique nucleaire (1961)

Energy Technology Data Exchange (ETDEWEB)

Bonnet, G [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1961-07-01

When studying the behaviour of a magnetic resonance transducer formed by the association of an electrical network and of a set of nuclear spins, it is possible to bring about a representation that is analytically equivalent by means of an entirely electrical model, available for transients as well as steady-state. A detailed study of the validity conditions justifies its use in most cases. Also proposed is a linearity criterion of Bloch's equations in transient state that is simply the prolongation of the well-known condition of non-saturation in the steady-state. (author) [French] L'etude du comportement d'un transducteur a resonance magnetique forme de l'association d'un reseau electrique et d'un ensemble de noyaux dotes de spin, montre qu'il est possible d'en deduire une representation analytiquement equivalente au moyen d'un modele entierement electrique utilisable pour un regime transitoire aussi bien que pour un regime permanent. Une etude detaillee des conditions de validite permet d'en justifier l'emploi dans la majorite des cas. On propose enfin un critere de linearite des equations de Bloch en regime transitoire, qui constitue un prolongement de la condition connue de non-saturation en regime stationnaire. (auteur)

Towards the development of a regional electricity market in Central Africa: Issues and Challenges; Vers la realisation d'un marche regional de l'electricite en Afrique Centrale: Enjeux et defies

Energy Technology Data Exchange (ETDEWEB)

Veilleux, Rheaume; Mbadinga, David; Kitoko Senghi, Laurent

2010-09-15

This article gives a short description of the African continent. It then describes the 5 energy pools covering 54 countries: COMELEC, SAPP, WAPP, PEAC, EAPP. More specifically, the article looks at the main strategies and methods to be put in place in order to implement the electricity market, in particular the regional market of Central Africa. The current interconnecting projects and studies between different African countries, made by RSW international in collaboration with different partners, are presented, and in a more comprehensive way, the one related to the Interconnexion of the electrical networks of the member countries of the ECCAS. [French] Cet article presente une courte description du continent africain. Par la suite, on decrit les 5 pools energetiques couvrant les 54 pays : COMELEC, SAPP, WAPP, PEAC, EAPP. Plus specifiquement, on aborde les principales strategies et moyens a mettre en place pour implanter et developper le marche de l'electricite, plus particulierement le marche regional de l'Afrique centrale. Les projets ou etudes d'interconnexion en cours entre differents pays de l'Afrique, realises par RSW International de concert avec differents partenaires, sont presentes et, de facon plus exhaustive, celle relative au projet de l'Interconnexion des Reseaux Electriques des Pays Membres de la CEEAC.

Electrical conductivity of air under the action of a shock wave; Conductivite electrique de l'air sous l'action d'une onde de choc

Energy Technology Data Exchange (ETDEWEB)

Thouvenin, Jacques [Commissariat a l' energie atomique et aux energies alternatives - CEA (France)

1960-07-01

A method is described for the measurement of the electrical conductivity of a shock wave in air. The results reveal the preponderant part played by the NO molecule. Reprint of a paper published in Comptes rendus des seances de l'Academie des Sciences, t. 250, p. 302-304, sitting of 11 January 1960 [French] On decrit un procede de mesure de la conductivite electrique d'une onde de choc dans l'air. Les resultats font apparaitre le role preponderant joue par la molecule NO. Reproduction d'un article publie dans les Comptes rendus des seances de l'Academie des Sciences, t. 250, p. 302-304, seance du 11 janvier 1960.

On a non-linear problem posed by the temperature determination in an electrically heated plate; Sur un probleme non lineaire pose par la determination de la temperature dans une plaque chauffee electriquement

Energy Technology Data Exchange (ETDEWEB)

Gerber, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

Let us consider a flat plate, electrically heated, with one face thermally insulated and the other face isothermal. It is shown that a two-dimensional perturbation of the insulated face has no influence on the temperature of this face. (author) [French] Soit une plaque plane, chauffee electriquement, dont une face est isolee thermiquement et l'autre face isotherme. On montre qu'une perturbation bidimensionnelle de la face isolee est sans influence sur la temperature de cette face. (auteur)

Câbles electriques - Calcul du courant admissible - Partie 1: Equations de l'intensité du courant admissible (facteur de charge 100%) et calcul des pertes - Section 2: Facteurs de pertes par courants de Foucault dans les gaines dans le cas de deux circuits disposés en nappe

CERN Document Server

International Electrotechnical Commission. Geneva

1993-01-01

Câbles electriques - Calcul du courant admissible - Partie 1: Equations de l'intensité du courant admissible (facteur de charge 100%) et calcul des pertes - Section 2: Facteurs de pertes par courants de Foucault dans les gaines dans le cas de deux circuits disposés en nappe

Systematic study of the use of electrical fields for improving heat exchange in boiling liquids; Etude systematique de l'utilisation de champs electriques pour l'amelioration des echanges thermiques dans des liquides bouillants

Energy Technology Data Exchange (ETDEWEB)

Bochirol, L; Bonjour, E; Lagnier, R; Verdier, J; Weil, L [Commissariat a l' Energie Atomique, Grenoble (France).Centre d' Etudes Nucleaires

1961-07-01

We have studied, at the boiling point, for liquids with various electrical properties (hexane, benzene, trichloroethylene, demineralized water, acetone, methyl-ethyl-ketone, etc...) the effect of the application of electric fields on the exchange coefficients and on the maximum dissipative powers before calefaction. We have given the mechanism of the significant improvements obtained (multiplication by a factor of 2 to 10): - in the natural convection zone by showing the role played by the dielectric properties of the liquids under study; - in the zone of nuclear boiling by analysis of the forces acting on the boiling nuclei. Finally we give some experimental results concerning measurements made under pressure until local boiling occurred: they show the possibility of some interesting applications of the method. (author) [French] On a etudie, a l'ebullition, sur des liquides de caracteristiques electriques diverses (hexane, benzene, trichlorethylene, eau demineralisee, acetone, methylethylcetone, etc...) les effets de l'application de champs electriques sur les coefficients d'echanges et les puissances maximales dissipables avant calefaction. On a precise le mecanisme des ameliorations importantes obtenues (multiplication par un facteur 2 a 10): - dans la zone de convection naturelle en mettant en evidence le role des caracteristiques dielectriques des liquides etudies; - dans la zone d'ebullition nucleaire par analyse des forces mises en jeu sur les noyaux d'ebullition. On donne enfin des resultats experimentaux sur des mesures effectuees sous pression jusqu'a l'ebullition locale: ils illustrent des possibilites d'applications interessantes du procede. (auteur)

Gases e ruídos em edificações para suínos: aplicação das normas NR-15, CIGR e ACGIH Gases and noise level in swine housing: application of the NR-15, CIGR and ACGIH norms

Directory of Open Access Journals (Sweden)

Carlos A. de P. Sampaio

2005-04-01

finishing. The results showed that the continuous noise level were below the one found in the standards, however there were observed differences (P < 0.05 in relation to the noise level measured in piglet's nursing cages and in semi-slatted floor. The respective concentrations of hydrogen sulfide and methane were less than 1 ppm and less than 0,1% by volume, which was lower than the recommended limits in NR-15, CIGR and ACGIH. The oxygen level was 21% in average.

Contribution to the theoretical study of order-disorder phenomena in the electrical properties of alloys (1963); Contribution a l'etude theorique des phenomenes d'ordre dans les proprietes electriques des alliages (1963)

Energy Technology Data Exchange (ETDEWEB)

Beal, M T [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1963-07-01

We have study theoretically the ordering of alloys and its influence an electrical resistivity. We have looked at the cases of concentrated, non magnetic alloys such as Cu Zn {beta} or Cu{sub 3}Au and of diluted, magnetic alloys such as noble matrix with rare earth impurities. In both cases, a simple method of molecular field with nearest neighbour interactions is used. Scattering cross sections are calculated with free electrons and Born approximation. The electrical properties are described with a good accuracy by single diffusions on each center (long range order). But some anomalies near to the ordering temperature are caused by double diffusions on pairs of interacting atoms or spins (local order). (author) [French] On presente une etude theorique des phenomenes d'ordre et de leur influence sur les proprietes electriques des alliages. Deux cas sont envisages: celui des alliages non magnetiques concentres, tels que Cu Zn {beta} ou Cu{sub 3}Au et celui d'alliages magnetiques tres dilues du type matrice noble impuretes de terres rares. Dans les deux cas on utilise une methode simple de champ moleculaire avec interactions entre plus proches voisins seulement. Les sections efficaces de diffusion sont calculees dans un modele d'electrons libres et dans l'approximation de Born. Les proprietes electriques sont decrites en premiere approximation par les diffusions simples sur chaque atome ou spin (ordre a longue distance). Mais elles presentent des anomalies a la temperature d'ordre dues aux diffusions doubles sur des paires d'atomes ou de spins plus proches voisins (ordre local). (auteur)

Contribution to the theoretical study of order-disorder phenomena in the electrical properties of alloys (1963); Contribution a l'etude theorique des phenomenes d'ordre dans les proprietes electriques des alliages (1963)

Energy Technology Data Exchange (ETDEWEB)

Beal, M.T. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1963-07-01

We have study theoretically the ordering of alloys and its influence an electrical resistivity. We have looked at the cases of concentrated, non magnetic alloys such as Cu Zn {beta} or Cu{sub 3}Au and of diluted, magnetic alloys such as noble matrix with rare earth impurities. In both cases, a simple method of molecular field with nearest neighbour interactions is used. Scattering cross sections are calculated with free electrons and Born approximation. The electrical properties are described with a good accuracy by single diffusions on each center (long range order). But some anomalies near to the ordering temperature are caused by double diffusions on pairs of interacting atoms or spins (local order). (author) [French] On presente une etude theorique des phenomenes d'ordre et de leur influence sur les proprietes electriques des alliages. Deux cas sont envisages: celui des alliages non magnetiques concentres, tels que Cu Zn {beta} ou Cu{sub 3}Au et celui d'alliages magnetiques tres dilues du type matrice noble impuretes de terres rares. Dans les deux cas on utilise une methode simple de champ moleculaire avec interactions entre plus proches voisins seulement. Les sections efficaces de diffusion sont calculees dans un modele d'electrons libres et dans l'approximation de Born. Les proprietes electriques sont decrites en premiere approximation par les diffusions simples sur chaque atome ou spin (ordre a longue distance). Mais elles presentent des anomalies a la temperature d'ordre dues aux diffusions doubles sur des paires d'atomes ou de spins plus proches voisins (ordre local). (auteur)

Experimental study of the effect of an electric field on thermal exchanges under forced convection with gaseous carbon anhydride in presence of the radiation of the Melusine pile; Etude experimentale de l'effet d'un champ electrique sur les echanges thermiques en convection forcee avec l'anhydride carbonique gazeux en presence du rayonnement de la pile Melusine

Energy Technology Data Exchange (ETDEWEB)

Perroud, P.; Rebiere, J.; Verdier, J.

1961-01-21

Previous studies showed that, under free or forced convection, the application of a non-uniform electric field with a sufficient intensity at the neighbourhood of the heating elements resulted in a significant improvement of the thermal exchange coefficient under some flow rate and pressure conditions. But these improvements first required the creation of ions in the gas (shock ionization and existence of a corona effect above a sufficient voltage). This document therefore report further studies performed at the neighbourhood of the Melusine atomic pile which would provide ionizing radiations of much greater intensity. The objectives were, on the one hand, a global verification of work hypotheses imagined for the exchange improvement mechanism, and, on the other hand, to obtain data on the conditions under which this exchange improvement mechanism could be used in channels of a reactor. The authors present the instrumentation (measurement cells, gas circuit, heating circuit, high voltage circuit), describe how physical values are measured (pressure, gas flow rate, temperature of the heating element, gas temperature, high voltage). They describe how they compare powers exchanged under forced convection between dioxide carbon and a heated wire with or without external ionizing radiations, and report the various performed calculations (power supplied to the gas, temperature shift, Nusselt and Reynolds numbers). They report and discuss experimental results obtained outside the pile without ionizing radiations, and within the pile in presence of a ionizing radiation [French] Les essais ont ete effectues dans les conditions suivantes: nombres de Reynolds variant de 20.000 a 80.000, pression de 11 a 21 kg/cm{sup 2}, temperatures moyennes de l'element chauffant de 200 a 600 deg. C, tension electrique de 0 a 30 kV eff et intensite maximum du rayonnement γ, 3x10{sup 7} roentgen/h. On a confirme, hors pile, que l'augmentation de la puissance echangee, au dessus du seuil d

Smart electric grids in the United Kingdom energy strategy; Les reseaux electriques intelligents dans la strategie energetique du Royaume-Uni

Energy Technology Data Exchange (ETDEWEB)

Gloaguen, Olivier [Ambassade de France au Royaume-Uni, Service de presse, 58 Knightsbridge, London SW1X 7JT (United Kingdom); Dreyfus, Charles-Antoine [Ecole des Mines de Paris - MINES Paris Tech, 60, Boulevard Saint-Michel 75272 Paris cedex 06 (France)

2011-09-15

This study first gives an overview of the current status and limitations of the British power grid. It indicates the British energy mix, describes the network structure and its economic operation (gross and retail market with the bid and offer system, role of the System Operator, ways to increase the electricity production). It presents the energy policy and its regulation framework, outlines the current limitations and challenges (ageing grid, power crunch, de-carbonation challenges). It presents the development of a smart grid as a solution to economy de-carbonation challenges: definition of the 'smart grid concept', smart grid development planning (from 2010 to 2050), technological transition associated with smart electric grid development (a cleaner but more intermittent and random electricity production, better use of fossil fuels, electric energy storage, consequences for the grid, introduction and effects of smart meters). It describes the new associated economic model: evolution of the value chain, financial challenges (required investments, expected benefits, subsidies), new regulation system. It addresses the strategic challenges and the various uncertainties (notably in terms of consumption, privacy issue in relation with the use of smart meters, and project implementation).

Solution des systemes de controle de grandes dimensions basee sur les boucles de retroaction dans la simulation des reseaux electriques

Science.gov (United States)

Mugombozi, Chuma Francis

The generation of electrical energy, as well as its transportation and consumption, requires complex control systems for the regulation of power and frequency. These control systems must take into account, among others, new energy sources such as wind energy and new technologies for interconnection by high voltage DC link. These control systems must be able to monitor and achieve such regulation in accordance with the dynamics of the energy source, faults and other events which may induce transients phenomena into the power network. Such transients conditions have to be analyzed using the most accurate and detailed hence, complex models of control system. In addition, in the feasibility study phase, the calibration or the setup of equipment as well as in the operation of the power network, one may require decision aid tools for engineers. This includes, for instance, knowledge of energy dissipated into the arresters in transient analysis. These tools use simulation programs data as inputs and may require that complex functions be solved with numerical methods. These functions are part of control system in computer simulator. Moreover, the simulation evolves in a broader context of the development of digital controller, distributed and parallel high performance computing and rapid evolutions in computer (multiprocessor) technology. In such context, a continuing improvement of the control equations solver is welcomed. Control systems are modelled using ax=b simultaneous system of equations. These equations are sometimes non-linear with feedback loops and thus require iterative Newton methods, including the formation of a Jacobian matrix and ordering as well as processing by graph theory tools. The proposed approach is based on the formulation of a reduced rank Jacobian matrix. The dimension is reduced up to the count of feedback loops. With this new approach, gains in computation speed are expected without compromising its accuracy when compared to classical full rank Jacobian matrix representation. A directed graph representation is adopted and a proper approach for detecting and removing cycles within the graph is introduced. A condition of all zero eigenvalues of adjacency matrix of the graph is adopted. The transformation of the graph of controls with no cycle permits a formulation of control equations for only feedback points. This yields a general feedback interconnection (GFBI) representation of control, which is the main contribution of this thesis. Methods for solving (non-linear) equations of control systems were deployed into the new GFBI approach. Five variants of the new approach were illustrated including firstly, a basic Newton method (1), a more robust one, the Dogleg method (2) and a fixed-point iterations method (3). I. The presented approach is implemented in Electromagnetic Transient program EMTP-RV and tested on practical systems of various types and levels of complexity: the PLL, an asynchronous machine with 87 blocks reduced to 23 feedback equations by GFBI, and 12 wind power plants integrated to the IEEE-39 buses system. Further analysis, which opens up avenues for future research includes comparison of the proposed approach against existing ones. With respect to the sole representation, it is shown that the proposed approach is equivalent to full classic representation of system of equations through a proper substitution process which complies with topological sequence and by skipping feedback variable identified by GFBI. Moreover, a second comparison with state space based approach, such as that in MATLAB/Simulink, shows that output evaluation step in state-space approach with algebraic constraints is similar to the GFBI. The algebraic constraints are similar to feedback variables. A difference may arise, however, when the number of algebraic constraints is not the optimal number of cuts for the GFBI method: for the PLL, for example, MATLAB/Simulink generated 3 constraints while the GFBI generated only 2. The GFBI method may offer some advantages in this case. A last analysis axis prompted further work in initialization. It is shown that GFBI method may modifies the convergence properties of iterations of the Newton method. The Newton- Kantorovich theorem, using bounds on the norms of the Jacobian, has been applied to the proposed GFBI and classic full representation of control equations. The expressions of the Jacobian norms have been established for generic cases using Coates graph. It appears from the analysis of a simple case, for the same initial conditions, the behaviour of the Newton- Kantorovich theorem differs in both cases. These differences may also be more pronounced in the non-linear case. Further work would be useful to investigate this aspect and, eventually, pave the way to new initialization approaches. Despite these limitations, not to mention areas for improvement in further work, one notes the contribution of this thesis to improve the gain of time on simulation for the solution of control systems. (Abstract shortened by UMI.).

Special metallurgy - the electrical butt-welding by flashing of sintered magnesium-magnesium oxide composites (1963); Metallurgie speciale - le soudage electrique en bout par etincelage du composite fritte magnesium-magnesie (1963)

Energy Technology Data Exchange (ETDEWEB)

Charleux, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

Electrical resistance welding has become quite important since World War II because of the need of a high yield in aeronautical production. Progress has been due in particular to the improvements made in electronically controlled apparatus making possible the automatic control of welding. For the butt-welding of sections requiring either a high production rate or a high quality weld, the flash butt-welding system has been very much developed these last few years. The use of this welding method is of great importance in the field of the bonding of oxidisable metals such as magnesium or aluminium and its alloys, because the welded joint is free from oxides. This study consists of general considerations on the flash-welding process with regard to temperature distribution in the parts during welding, and to electrical phenomena connected with flashing. Besides this general or theoretical section, we have applied the welding process to the bonding of sintered magnesium, a magnesium-magnesium oxide composite, whose use as a structural element in nuclear reactors is considered. (author) [French] Le soudage electrique par resistance a pris un essor important depuis la derniere guerre mondiale a cause du besoin de haut rendement pour la production aeronautique. Les progres ont ete possibles surtout par l'amelioration des appareils de commande electronique qui permettent un controle automatique de la soudure. Pour le soudage bout a bout de profiles, demandant soit un haut debit de fabrication, soit une haute qualite du joint soude, le procede de soudage en bout par etincelage a ete tres developpe ces dernieres annees. Ce mode de soudage a un domaine d'utilisation important dans la liaison des metaux oxydables tels le magnesium ou l'aluminium et ses alliages, du fait de la proprete du joint soude exempt d'oxydes. Cette etude comporte une consideration generale du processus de l'etincelage, quant a la repartition de la temperature dans les pieces pendant le soudage et aux

Special metallurgy - the electrical butt-welding by flashing of sintered magnesium-magnesium oxide composites (1963); Metallurgie speciale - le soudage electrique en bout par etincelage du composite fritte magnesium-magnesie (1963)

Energy Technology Data Exchange (ETDEWEB)

Charleux, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

Electrical resistance welding has become quite important since World War II because of the need of a high yield in aeronautical production. Progress has been due in particular to the improvements made in electronically controlled apparatus making possible the automatic control of welding. For the butt-welding of sections requiring either a high production rate or a high quality weld, the flash butt-welding system has been very much developed these last few years. The use of this welding method is of great importance in the field of the bonding of oxidisable metals such as magnesium or aluminium and its alloys, because the welded joint is free from oxides. This study consists of general considerations on the flash-welding process with regard to temperature distribution in the parts during welding, and to electrical phenomena connected with flashing. Besides this general or theoretical section, we have applied the welding process to the bonding of sintered magnesium, a magnesium-magnesium oxide composite, whose use as a structural element in nuclear reactors is considered. (author) [French] Le soudage electrique par resistance a pris un essor important depuis la derniere guerre mondiale a cause du besoin de haut rendement pour la production aeronautique. Les progres ont ete possibles surtout par l'amelioration des appareils de commande electronique qui permettent un controle automatique de la soudure. Pour le soudage bout a bout de profiles, demandant soit un haut debit de fabrication, soit une haute qualite du joint soude, le procede de soudage en bout par etincelage a ete tres developpe ces dernieres annees. Ce mode de soudage a un domaine d'utilisation important dans la liaison des metaux oxydables tels le magnesium ou l'aluminium et ses alliages, du fait de la proprete du joint soude exempt d'oxydes. Cette etude comporte une consideration generale du processus de l'etincelage, quant a la repartition de la temperature dans les pieces

Study of heterogeneous multiplying and non-multiplying media by the neutron pulsed source technique; Etude des milieux heterogenes multiplicateurs et non-multiplicateurs par la technique de la source pulsee de neutrons

Energy Technology Data Exchange (ETDEWEB)

Deniz, V [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1968-06-01

The pulsed neutron technique consists essentially in sending in the medium to be studied a short neutron pulse and in determining the asymptotic decay constant of the generated population. The variation of the decay constant as a function of the size of the medium allows the medium characteristics to be defined. This technique has been largely developed these last years and has been applied as well to moderator as to multiplying media, in most cases homogeneous ones. We considered of interest of apply this technique to lattices, to see if useful informations could be collected for lattice calculations. We present here a general theoretical study of the problem, and results and interpretation of a series of experiments made on graphite lattices. There is a good agreement for non-multiplying media. In the case of multiplying media, it is shown that the age value used until now in graphite lattices calculations is over-estimated by about 10 per cent. [French] La technique de la pulsation neutronique consiste essentiellement a envoyer dans le milieu a etudier une courte bouffee de neutrons et a determiner la constante de decroissance asymptotique de la population engendree. La variation de cette constante de decroissance en fonction des dimensions du milieu permet de determiner ses caracteristiques. Cette technique a connu ces dernieres annees un grand essor et a ete appliquee a des moderateurs et des milieux multiplicateurs. Il s'agissait dans la plupart des cas de milieux homogenes. Il nous a semble interessant de l'utiliser dans le cas des reseaux, afin de voir si ces experiences peuvent fournir des renseignements utiles aux calculs. Nous presentons ici une etude theorique generale du probleme, ainsi que les resultats et l'interpretation d'une serie d'experiences faites sur des reseaux a graphite. L'accord est bon dans le cas des reseaux non-multiplicateurs. Dans le cas des reseaux multiplicateurs, on montre que la valeur de l'age utilisee jusqu'ici dans les calculs

Improvement of heat transfer to gases by mean of electric fields (1962); Etude de l'amelioration des echanges de chaleur dans les gaz au moyen de champs electriques (1962)

Energy Technology Data Exchange (ETDEWEB)

NONE

1962-07-01

The effects of electric fields on heat transfer to the following gases: air, argon, nitrogen, carbon dioxyde, helium, hydrogen, were studied in an annular channel, the inner part of which is the heating element. Experiments were made both in free convection and forced convection, the latter case with and without an external source of ionisation. Two causes of improvement of heat transfer were found: electro-convection and ionic convection; the influence of various parameters (electric fields, current of ionisation, temperatures, pressures, flow rate, etc...) is also investigated. Increasing of exchanged power was measured: in free convection this increasing reached 400 per cent and, in forced convection, it was found to be mainly dependent on stream velocity, decreasing from 300 per cent at Re = 6000 to few per cent for Re {>=} 30000 for a given gas pressure. Experiments in pile have shown that the use of an external source of ionisation allowed to obtain the same order of improvement as above but with a voltage much lower. This fact would make easier the use of this process of heat transfer in a channel of a reactor. (authors) [French] On a etudie l'action du champ electrique sur les echanges de chaleur dans les gaz suivants: air, argon, azote, anhydride carbonique, helium, hydrogene, avec un element chauffant cylindrique dans un canal concentrique. Des experiences ont ete effectuees en convection libre et en convection forcee en l'absence et en presence d'une source exterieure d'ionisation. On a distingue deux sortes de mecanismes d'accroissement des echanges, l'un d'electroconvection proprement dite et l'autre de convection ionique, et on precise l'influence des divers parametres (champ electrique, courant d'ionisation, temperature, pression, debit, etc...). On a pu chiffrer les ordres de grandeur des accroissements d'echanges observes qui, en convection libre, atteignent 300 a 400 pour cent et, en convection forcee, dependent beaucoup de la vitesse d

Calculation of the anti-trap factor in heavy water lattices; Calcul du facteur antitrappe dans les reseaux a eau lourde

Energy Technology Data Exchange (ETDEWEB)

Naudet, R; Mougey, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-07-01

The calculation of the anti-trap factor of a lattice is complex when a large fraction of captures occurs in a range of energies where the spectrum in the fuel is considerably different from the simple dE/E law. This is particularly true for heavy water lattices in which the distances. between the bars are generally fairly large with respect to the slowing-down length. In order to take into account this effect it is necessary both to know the constitution of the effective resonance integral as a function of the energy, and to be able to calculate the distribution in the fuel. This report is devoted to these two problems. An improved method of treating the statistical domain makes it possible to plot the curves of the cross-sections per unit lethargy for various shapes of the fuel. Furthermore, the slowing-down of the neutrons is studied using a Monte-Carlo method which makes it possible in particular to take into account the perturbations caused by the non-moderating rods. A study is also made of the problem of shielding effects due to the captures themselves. (authors) [French] Le calcul du facteur antitrappe dans un reseau est complique lorsqu'une fraction importante des captures a lieu dans un domaine d'energie ou le spectre dans le combustible s'ecarte sensiblement de la loi simple en dE/E. Ceci est particulierement vrai pour les reseaux a eau lourde dans lesquels les distances entre barres sont en general assez grandes vis-a-vis de la longueur de ralentissement. Pour tenir compte de cet effet il faut connaitre d'une part la decomposition de l'integrale de resonance effective en fonction de l'energie, d'autre part savoir calculer le spectre dans le combustible. Le rapport est consacre a ces deux problemes. Un traitement ameliore du domaine statistique permet de tracer des courbes de sections de capture par unite de lethargie pour differentes geometries de barreaux. D'autre part le ralentissement des neutrons est etudie par une methode de Monte Carlo, qui permet

Improvement of the heat exchanges by application of an electric field in the boiling freon 12; Amelioration des echanges thermiques par application d'un champ electrique dans le freon 12 bouillant

Energy Technology Data Exchange (ETDEWEB)

Bonjour, Emmanuel; Verdier, Jacques; Weil, Louis [Commissariat a l' energie atomique et aux energies alternatives - CEA, Centre d' Etudes Nucleaires de Grenoble (France)

1960-07-01

lt was already known that the heat exchanges by simple convection are considerably improved by the application of an electric field, but no study about the effect of this field when there is ebullition has been issued until now. The authors indicate the result of their experimental investigations which present a very great interest for the increase of the efficiency of the refrigeration cycles. Reprint of a paper published in Revue generale du froid, Sep 1960 [French] On savait deja qu'il etait possible d'ameliorer sensiblement les echanges thermiques dus a la simple convection par l'application d'un champ electrique, mais jusqu'a present, il n'existait pas de resultats concernant l'effet de ce champ en presence d'ebullition. Les auteurs indiquent les resultats de leur investigation experimentale qui presente un tres grand interet pour l'accroissement de l'efficacite du cycle de refrigeration. Reproduction d'un article publie dans Revue generale du froid, Sep 1960.

Agreement ''power networks and environment'' 2001-2003; Accord ''reseaux electriques et environnement'' 2001-2003

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-01-01

This agreement, discussed between the French government and Electricite de France (EdF) group, proposes some engagements for the 2001-2003 era for a better environmental integration of power transmission and distribution networks. The agreement is made of two parts: 1 - public distribution networks: realization of new workmanship (medium and low voltage power lines, new lines in dense urban areas), actions on existing workmanship (consequences of December 1999 storms, aesthetical aspects, burial of the main overhead lines in wooded areas, reinforcement of EdF's environmental commitment, remedial actions for environmental 'black points'), general measures of implementation (increasing network safety, protection of birds fauna, coordination of works); 2 - public transportation network (RTE): development and safety improvement of the public transportation network (reinforced arrangement for the establishment of regional development schemes, development of international interconnections, safety improvement of the public transportation network, RTE's environmental plan); line projects (arrangements during projects elaboration, accompanying program); long lived RTE's commitment (environmental management and ISO-14001 certification, vigilance with respect to electromagnetic fields, R and D). (J.S.)

Proprietes optiques dans l'infrarouge lointain et de transport electrique de systemes electroniques a basse dimensionalite

Science.gov (United States)

Lefebvre, Jacques

Cette these presente une etude experimentale de deux systemes ayant des proprietes physiques particulieres decoulant de leur caractere anisotrope. Le premier systeme est un conducteur organique quasi-unidimensionnel, le sel de Bechgaard (TMTSF)sb2ClOsb4. Le second est un systeme mesoscopique base sur une heterostructure a base de GaAs/Alsb{x}Gasb{1-x}As pour lequel la dimensionalite peut etre variee continuement entre deux et un. En dimension un, ce systeme porte le nom de fil quantique. Pour le sel de Bechgaard (TMTSF)sb2ClOsb4, une mesure de la photoconductivite dans l'infrarouge lointain a permis d'identifier une resonance dans la phase onde de densite de spin sous champ magnetique (ou ODSIC). Cette resonance, visible dans la gamme de longueurs d'onde entre 410 et 599 mum, se deplace vers les forts champs magnetiques avec l'augmentation de l'energie du photon. Malgre qu'elle s'apparente a une resonance cyclotron, un calcul theorique du coefficient d'absorption a montre qu'elle est intimement liee a la phase ODSIC et que son energie est donnee par sqrt{4deltasbsp{N}{2}+omegasbsp{c}{2}} avec deltasb{N}, l'amplitude de la bande interdite ODSIC au niveau de Fermi et omegasb{c}, l'energie cyclotron. Le gaz d'electrons dans une heterostructure a base de GaAs/Alsb{x}Gasb{1-x}As a ete etudie dans les regimes dimensionnels entre deux et un (de 2D a quasi-1D en passant par quasi-2D). En combinant des mesures de transport electrique a des mesures de transmission optique dans l'infrarouge lointain obtenues quasi-simultanement sur un meme echantillon, plusieurs conclusions emergent. Entre autres, trois regimes de modulation sont identifies et a leurs frontieres, des signes distinctifs apparaissent autant dans les mesures de transport que dans les mesures de la transmission optique. Une analyse globale permet de degager une vue coherente des modes collectifs dans les differents regimes dimensionnels.

Electric space heating scheduling for real-time explicit power control in active distribution networks

DEFF Research Database (Denmark)

Costanzo, Giuseppe Tommaso; Bernstein, Andrey; Chamorro, Lorenzo Reyes

2015-01-01

This paper presents a systematic approach for abstracting the flexibility of a building space heating system and using it within a composable framework for real-time explicit power control of microgrids and, more in general, active distribution networks. In particular, the proposed approach...... is developed within the context of a previously defined microgrid control framework, called COMMELEC, conceived for the explicit and real-time control of these specific networks. The designed control algorithm is totally independent from the need of a building model and allows exploiting the intrinsic thermal...... inertia for real-time control. The paper first discusses the general approach, then it proves its validity via dedicated simulations performed on specific case study composed by the CIGRE LV microgrid benchmark proposed by the Cigré TF C6.04.02....

Natural uranium-graphite system. Critial experiments on the G1 reactor; Systeme uranium naturel-graphite. Experiences critiques sur le reacteur G1

Energy Technology Data Exchange (ETDEWEB)

Schmitt, A P; Tanguy, P; Teste du Bailler, A; Zaleski, C P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

A number of experiments have been performed during the start up period of the G1 (1956) and G2 (1958) reactors in Marcoule, both on their lattices and on different lattices (hollow rods, clusters, under moderated lattices). The first chapter gives a thorough description of the two reactors. The second chapter deals with buckling measurements, both absolute (flux plots) and relative by the method of progressive substitution. The experimental results are summarised in Table VI. The third chapter contains a number of other measurements performed on G1. (author)Fren. [French] Le demarrage des reacteurs G1 (1956) et G2 (1958) de Marcoule nous a permis d'effectuer une serie d'experiences tant sur les reseaux de ces piles que sur des reseaux differents (elements tubulaires ou divises, reseaux sous-moderes, etc...). Dans une premiere partie, nous donnons une description detaillee des deux reacteurs. Dans la deuxieme partie, relative aux mesures de laplaciens, nous decrivons d'abord les mesures absolues de laplaciens (cartes de flux), puis les mesures relatives effectuees par la methode originale de remplacement progressif. Les resultats experimentaux sont rassembles dans le tableau VI. Dans la troisieme partie, nous rappelons un certain nombre d'autres mesures effectuees sur G1. (auteur)

A new temperature effect in ionized media in the presence of heavy negative electrical charges; Sur un nouvel effet de temperature dans des milieux ionises en presence de charges electriques negatives lourdes

Energy Technology Data Exchange (ETDEWEB)

Klein, S [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-12-01

A relatively large electromotive force appears between two electrodes having different temperatures in an atmosphere of ionized vapours. The theoretical interpretation of this phenomenon is based essentially on the one hand on the massive formation of heavy negative electrical charges near the 'cold' electrode and on the other hand, in the case of flames, on the existence of an electronic temperature much higher than that predicted by conventional theory. This temperature effect makes it possible to convert the ionizing energy directly into electricity. (author) [French] Une force electro-motrice relativement importante apparait dans des vapeurs ionisees entre deux electrodes maintenues a des temperatures differentes. L'interpretation theorique, de ce phenomene est essentiellement basee, d'une part sur la formation massive de charges electriques negatives lourdes pres de l'electrode ''froide'' et, d'autre part, dans le cas des flammes sur l'existence d'une temperature electronique beaucoup plus elevee que celle prevue par la theorie classique. Cet effet de temperature permet de convertir directement l'energie ionisante en electricite. (auteur)

Protection of Distribution Systems with Distributed Energy Resources

DEFF Research Database (Denmark)

Bak-Jensen, Birgitte; Browne, Matthew; Calone, Roberto

of 17 months of work of the Joint Working Group B5/C6.26/CIRED “Protection of Distribution Systems with Distributed Energy Resources”. The working group used the CIGRE report TB421 “The impact of Renewable Energy Sources and Distributed Generation on Substation Protection and Automation”, published...... by WG B5.34 as the entry document for the work on this report. In doing so, the group aligned the content and the scope of this report, the network structures considered, possible islanding, standardized communication and adaptive protection, interface protection, connection schemes and protection...... are listed (chapter 3). The first main part of the report starts with a summary of the backgrounds on DER and current practices in protection at the distribution level (chapter 4). This chapter contains an analysis of CIGRE TB421, protection relevant characteristics of DER, a review of current practices...

Heavy water reactors physics; Physique des reacteurs a eau lourde

Energy Technology Data Exchange (ETDEWEB)

Girard, Y; Lourme, P; Naudet, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

An important research programme on heavy water reactor physics has been carried out in France for quite a few years. The decision to build the EL 4 prototype and so to choose the heavy water gas cooled type has renewed the interest in this programme and at the same time given to it a more specific orientation A summary of the results gained in this field is presented in this paper. In the first part are described the experimental investigations, most of them were carried out in the criticality facility AQUILON II. The experiments are grouped in four parts - Systematic studies of lattices Buckling measurements. - Specific studies of gas-cooled lattices. - Fine structure, spectral indices measurements etc... - Measurements on lattices or samples containing Uranium of various enrichment or Plutonium. The second part is devoted to a summary of the theoretical studies. The whole results have allowed an improvement of the calculation methods, have led to a better understanding of the neutron balance in lattices, and have permitted the establishment of a set of formula to predict not only the clean fuel conditions but also the evolution of the nuclear properties with irradiation. Some specific studies on power reactor are quoted. (authors) [French] Un important programme d'etudes sur la physique des reacteurs a eau lourde est mene en France depuis assez longtemps. La decision de construire le prototype EL 4 et de s'engager ainsi dans la filiere des reacteurs a eau lourde refroidis par gaz a redonne un nouvel interet a ce programme et l'a en meme temps oriente dans une direction plus particuliere. La presente communication, rassemble les resultats des etudes faites dans ce domaine depuis la derniere conference de Geneve. Dans la premiere partie on decrit les etudes experimentales dont la plupart ont ete effectuees dans la pile d'experiences critiques Aquilon II. Les experiences sont groupees en quatre ensembles: etude systematique de reseaux (mesures de laplaciens) etudes

The development of an electrically compensated differential calorimeter for the measurement of in-pile heat evolution (1962); Etude et realisation d'un calorimetre differentiel a compensation electrique pour la mesure des echaufpements en pile (1962)

Energy Technology Data Exchange (ETDEWEB)

Ayela, F; Derrien, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1962-07-01

It has been possible with the calorimeter of which we give the principle and details in the present report, to determine the calorific power produced by nuclear radiation in a given sample using simple electrical measurement. It also renders unnecessary all absolute measurements of temperature, all possible calibration, and the use of the thermal or thermoelectric constants of the constituent elements. The possible uses of the apparatus are fairly varied, as shown by the first in-pile experiments which we have carried out and for which we give results. (authors) [French] Le calorimetre, dont nous decrivons le principe et les details dans le present rapport, nous permet de determiner, par de simples mesures electriques, la puissance calorifique liberee par les rayonnements nucleaires dans un echantillon donne. Il nous affranchit aussi, de toute mesure absolue de temperature, de tout etalonnage prealable, et de l'utilisation des constantes thermiques ou thermoelectriques de ses elements constitutifs. Les possibilites d'emploi de l'appareil sont assez variees comme nous le montrent les premiers essais que nous avons effectues en pile et dont nous donnons les resultats. (auteurs)

Contribution to the study of the structure of silver krypton solid solutions; Contribution a l'etude de la structure des solutions solides argent-krypton

Energy Technology Data Exchange (ETDEWEB)

Levy, V; Tullairet, J; Delaplace, J; Antolin-Baudier, J; Adda, Y [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

The silver-krypton solid solutions formed by electrical discharge have been studied by X-rays, electrical resistivity and electronic transmission microscopy. The crystalline parameter and residual resistivity measurements have shown that the krypton atom behaves very differently to those of other elements of the periodic classification when dissolved in silver. The recovery of the crystalline parameter and of the electrical resistivity has been studied as a function of temperature. (authors) [French] Les solutions solides argent, krypton, realisees par decharges electrique ont ete etudiees par Rayons X, resistivite electrique et microscopie electronique en transmission. Les mesures de parametre cristallin et de resistivite residuelle ont montre que le comportement de l'atome de krypton est tres different de celui des autres elements de la classification periodique en solution dans l'argent. La restauration du parametre cristallin et de la resistivite electrique en fonction de la temperature a ete etudiee. (auteurs)

Use of a Monte-Carlo method for studying the statistical distribution of electric fields around an ion in a one-component plasma; Etude, par une methode de Monte-Carlo de la repartition statistique des champs electriques au niveau d'un ion, dans un plasma a une composante

Energy Technology Data Exchange (ETDEWEB)

Rossignol-Guzzi, D [Commissariat a l' Energie Atomique, 94 - Limeil-Brevannes (France). Centre d' Etudes Nucleaires

1968-11-01

A Monte-Carlo simulation has been made of the equilibrium configurations taken by a plasma of equally charged punctual ions, immersed in a uniform neutralizing background of electrons. The statistical repartition of the electric field acting on one ion, needed to obtain Stark effect, was specially obtained. Comparison for dense plasmas, was made with the former works of Holtzmark, Mayer, Broyles. (author) [French] On simule sur ordinateur, suivant une methode de Monte-Carlo, les configurations prises a l'equilibre thermodynamique par un plasma d'ions ponctuels et de meme charge, places dans un milieu d'electrons uniformement distribues. On etudie, en particulier, la repartition statistique des champs electriques au niveau d'un ion, utilisee dans les calculs d'effets Stark. On compare, dans le cadre des plasmas denses, les resultats obtenus aux travaux precedents de Holtzmark, Mayer, Broyles. (auteur)

Percolation dans des reseaux realistes de nanostructures de carbone

Science.gov (United States)

Simoneau, Louis-Philippe

versatility in the choice of network components that can be simulated. The tools we have developed, grouped together in the RPH-HPN software Reseaux percolatifs hybrides - Hybrid Percolation Networks, construct random networks, detect contact between the tubes, translate the systems to equivalent electrical circuits and calculate global properties. An infinity of networks can have the same basic characteristics (size, diameter, etc.) and therefore the properties of a particular random network are not necessarily representative of the average properties of all networks. To obtain those general properties, we simulate a large number of random networks with the same basic characteristics and the average of the quantities is determined. The network constituent elements can be spheres, rods or snakes. The use of such geometries for network elements makes contact detection simple and quick, and more faithfully reproduce the form of carbon nanotubes. We closely monitor the geometrical and electrical properties of these elements through stochastic distributions of our choice. We can choose the length, diameter, orientation, chirality, tortuosity and impenetrable nature of the elements in order to properly reproduce real networks characteristics. We have considered statistical distribution functions that are rectangular, Gaussian, and Lorentzian, but all other distributions that can be expressed mathematically can also be envisioned. During the creation of a particular network, we generate the elements one by one. Each of their properties is sampled from a preselected distribution. Efficient algorithms used in various fields were adapted to our needs to manage the detection of contacts, clusters and percolation. In addition, we model more realistic contact between rigid nanotubes using an original method used to create the network that does not require a relaxation phase. Finally, we use Kirchhoff's laws to solve the equivalent electrical circuit conventionally. First, we evaluated

Theoretical study of the influence on surface temperature of a geometrical perturbation of wall of an electrically heated channel (1960); Etude theorique de l'influence, sur la temperature de surface, d'une perturbation geometrique de la paroi d'un canal chauffe electriquement (1960)

Energy Technology Data Exchange (ETDEWEB)

Gerber, R [Commissariat a l' Energie Atomique, Section des Transferts Thermiques, Grenoble (France).Centre d' Etudes Nucleaires; Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

In experiments on forced convection heat transfer in an electrically heated channel, the temperature of the channel face in contact with the fluid is generally calculated from the measured temperature of the isolated face. A process for measuring this temperature leads to the study of the theoretical influence of a local perturbation of the wall thickness on the temperature distribution in this wall. Various problems at the limits, posed by this question of measurement, are dealt with. (author) [French] Dans les experiences de transfert thermique en convection forcee, dans un canal chauffe electriquement, la temperature de la face du canal en contact avec le fluide, est generalement calculee a partir de la temperature mesuree de la face isolee. Un procede de mesure de cette temperature conduit a etudier l'influence theorique d'une perturbation locale de l'epaisseur de la paroi sur la repartition de la temperature dans cette paroi. Divers problemes aux limites, posees par cette question de mesure, sont traites. (auteur)

Transient Monitoring Function–Based Fault Detection for Inverter-Interfaced Microgrids

DEFF Research Database (Denmark)

Sadeghkhani, Iman; Esmail Hamedani Golshan, Mohamad; Mehrizi-Sani, Ali

2018-01-01

One of the major challenges in protection of the inverter-interfaced islanded microgrids is their limited fault current level. This degrades the performance of traditional overcurrent protection schemes. This paper proposes a fault detection strategy based on monitoring the transient response......-domain simulation case studies using the CIGRE benchmark low voltage microgrid network....

Optimal Selective Harmonic Mitigation Technique on Variable DC Link Cascaded H-Bridge Converter to Meet Power Quality Standards

DEFF Research Database (Denmark)

Najjar, Mohammad; Moeini, Amirhossein; Dowlatabadi, Mohammadkazem Bakhshizadeh

2016-01-01

In this paper, the power quality standards such as IEC 61000-3-6, IEC 61000-2-12, EN 50160, and CIGRE WG 36-05 are fulfilled for single- and three-phase medium voltage applications by using Selective Harmonic Mitigation-PWM (SHM-PWM) in a Cascaded H-Bridge (CHB) converter. Furthermore, the ER G5/...

The influence of the form of the cells on the buckling and fine structure of the thermal flux in a heterogeneous pile; Influence de la forme des cellules sur le laplacien et structure fine du flux thermique dans une pile heterogene

Energy Technology Data Exchange (ETDEWEB)

Bailly du Bois, B [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1957-07-01

The elementary diffusion equation and the age equation have been solved for lattices assumed, to be infinite and periodic. In this way the influence of the form of the cells on thermal captures and resonance captures is determined. The solutions obtained are expressed by means of tabulated functions which can be used in the analysis of the f factor measurements. The case of mixed lattices in which different types of rods are regularly arranged is also foreseen. (author) [French] L'equation elementaire de la diffusion et l'equation de l'age ont ete resolues pour des reseaux supposes infinis et periodiques. On determine ainsi quelle est l'influence de la forme des cellules sur les captures thermiques et les captures de resonances. Les solutions obtenues s'expriment au moyen de fonctions tabulees qui peuvent etre utilisees dans le depouillement des mesures du facteur f. Le cas des reseaux mixtes dans lequels des barreaux de types differents sont disposes regulierement est egalement envisage. (auteur)

L'interdisciplinarite en sciences sociales pour l'etude du contact des langues (Interdisciplinarity in Social Sciences of the Study of the Relationships of Languages). Proceedings of a Colloquium of the International Center for Research on Bilingualism and the Institute for Interethnic and Intercultural Studies and Research (2nd, Quebec City, Quebec, Canada, October 1-5, 1984).

Science.gov (United States)

Prujiner, Alain, Ed.

Papers given at an international conference applying the social sciences to the study of the relationships of languages include the following: "Reseaux sociaux et comportements langagiers en milieu de contact des langues" ("Social Networks and Language Behaviors in a Language Contact Setting") by M. Blanc and J. Hamers, with…

The accelerator tube of ions of the generator Van de Graaff of the CEA. Survey of development. First results; Le tube accelerateur d'ions du generateur van de graapp du commissariat. Etude de developpement. Premiers resultats

Energy Technology Data Exchange (ETDEWEB)

Bruck, H; Prevot, F [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

1953-07-01

Rare are the Van de Graaff supplies whose tube doesn't collapse electrically to tensions and currents very lower to those that the generator can provide. We chose the general measurements: length and diameter, and put the accent on the survey of the individual element, so much to the mechanical viewpoint (installation, solidity, tightness and degassing), that to the electric viewpoint (to increase the electric rigidity of it). After modification the breakdown voltage as well as the performances of the tube have been improved greatly. (M.B.) [French] Rares sont les machines de Van de Graaff dont le tube ne s'effondre pas electriquement a des tensions et des courants bien inferieurs a ceux que le generateur peut fournir. Nous avons choisi les dimensions generales: longueur et diametre, et mis l'accent sur l'etude de l'element individuel, tant au point de vue mecanique (montage, solidite, etancheite et degazage), qu'au point de vue electrique (pour en augmenter la rigidite electrique). Apres modification la tension de claquage ainsi que les performances du tube ont ete grandement ameliorees. (M.B.)

Controle optique de qubits lies a des centres isoelectroniques d'azote dans le GaAs

Science.gov (United States)

Ethier-Majcher, Gabriel

Le traitement de l'information quantique est un domaine de recherche actuellement en pleine effervescence car il laisse entrevoir une revolution dans notre facon de traiter et d'echanger de l'information. D'une part, l'ordinateur quantique promet de resoudre des problemes comme la factorisation d'un polynome de facon beaucoup plus efficace qu'un ordinateur classique. D'autre part, les communications quantiques promettent l'echange d'information de facon fondamentalement inviolable. Afin de tirer pleinement profit de ces nouvelles technologies, il sera avantageux de construire des reseaux quantiques. Dans un tel reseau, des processeurs quantiques, les noeuds, seront connectes par des photons voyageant dans des fibres optiques. Les reseaux quantiques permettront de deployer les communications quantiques a grande echelle et de creer des super-ordinateurs quantiques. La realisation de reseaux quantiques necessitera des interfaces optiques pouvant echanger l'information de facon coherente entre un qubit (bit d'information quantique) et un photon. L'implementation de telles interfaces dans un systeme physique s'avere un important defi scientifique et technologique. Or, les systemes actuellement envisages a cette fin souffrent d'un faible couplage avec la lumiere ou encore de grandes inhomogeneites, constituant des obstacles a la realisation de reseaux a grande echelle. Dans cette these, le potentiel des centres isoelectroniques pour realiser des interfaces optiques est evalue. Deux types de qubits lies a des paires d'azote dans le GaAs sont consideres : les qubits excitoniques et les qubits de spin electronique, controlables par l'intermediaire d'excitons charges. Le controle optique complet des qubits excitoniques est demontre, ce qui constitue la premiere realisation du genre dans les centres isoelectroniques. L'observation d'excitons charges dans ce systeme, liant a la fois des trous lourds et des trous legers, laisse entrevoir de nouvelles possibilites afin de

CNE'96: National Energy Conference 'Improving Energy Efficiency in a Transition Economy'. Proceedings

International Nuclear Information System (INIS)

Petrescu, M.; Balan, Gh.; Zlatanovici, D.

1996-01-01

Every two years a national conference on energy is held in Romania under the auspices of Romanian Electricity Authority (RENEL). The CNC'96 Conference entitled 'Improving Energy Efficiency in a Transition Economy' has taken place in the Black Sea resort Neptun-Olimp, on September 1-5, 1996. The conference was divided in 8 sections covering the subjects: 1) Energy policies and strategies - Financing of refurbishment and development; 2) Clean and efficient technologies of the fossil fuels - Renewable energy sources; 3) Rehabilitation - Retrofitting of power facilities; 4) Nuclear Power; 5) Predictive and preventive maintenance technologies; 6) Management and process information systems; 7) Environment conservation and mitigating measures; and 8) Energy end-use. An opening talk was given by V.Romert, the Director General of RENEL, and keynote addresses were presented by I.Lindsay, WEC Secretary General (Energy in an era of change and the WEC within it), by J.E.Gray, Vice Chairman of the Atlantic Council of the United States (Global Energy Outlook), and by F.Meslier, Director of the EDF East Energy Unit, Ile de France and Chairman of the 37 Study Committee of CIGRE (Quelques evolutions recentes de la CIGRE et de son Comite 37). (M.C.)

Displacements and intensities of the components of hydrogenic lines of the helium atom in the presence of exterior uniform electrical and magnetic fields; Deplacements et intensites des composantes des raies hydrogenoides de l'atome d'helium en presence de champs exterieurs electrique et magnetique uniformes

Energy Technology Data Exchange (ETDEWEB)

Deutsch, C; Herman, L; Nguyen, H [Laboratoire de Recherches Physiques, 75 - Paris (France); Drawin, H W [Commissariat a l' Energie Atomique, Association Euratom-CEA, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1967-07-01

The Waller-Foster method for hydrogenic lines of neutral helium is extended in order to take into account an external magnetic field (vector K) having an arbitrary angle with an external constant electric field (vector F). The diagonal correction has been evaluated numerically taking into account recent experimental data. A Fortran IV program written for the CDC 3600 computer allows to calculate the displacements and the intensities for any hydrogenic transition. Special attention is given to the {l_brace}2-4{r_brace} transitions in neutral helium. (authors) [French] La methode de perturbation de Waller et Foster est generalisee afin de tenir compte d'un champ magnetique exterieur (vecteurK) faisant un angle quelconque avec un champ electrique exterieur (vecteurF). La correction diagonale des matrices de perturbation est evaluee numeriquement a l'aide des donnees atomiques les plus recentes. Un programme ecrit pour l'ordinateur CDC 3600 permet le calcul des deplacements et des intensites pour des transitions hydrogenoides quelconques. Les transitions [2-4]d'helium neutre ont ete etudiees plus particulierement. (auteurs)

Study of the electrical conductivity of lithium fluoride; Etude de la conductibilite electrique du fluorure de lithium

Energy Technology Data Exchange (ETDEWEB)

Adam-Benveniste, M [Commissariat a l' Energie Atomique, 91 - Saclay (France). Centre d' Etudes Nucleaires

1967-06-01

We studied the electrical conductivity of LiF crystals doped with positive divalent ions. The current carriers are the positive ion vacancies created either by thermal agitation or in compensation for charge excess of a M{sup 2+} in substitution. The vacancies displacement is represented by: {mu} K'/NeT exp(- u/kT), where K' and u are constants. The concentration of free carriers equals that of the M{sup 2+} impurity only at high temperature. The M{sup 2+} ions are slightly soluble and form either precipitates of MF{sub 2} or dipole agglomerates. In these states, the M{sup 2+} ions do not contribute to the conductivity. The vacancies induced by the isolated M{sup 2+} ions are not totally free but are in equilibrium with electrically neutral dipoles: M{sub dipole} [+] {r_reversible} M{sup 2+} + [+]{sub porteur}, and follow: p/(1-p){sup 2} = Z c exp H/kT, where p is the degree of association of vacancies, Z is the number of equivalent positions of a complex, H its binding energy. The analogy with concentrated electrolyte permits to adapt Debye-Huckel theory to the crystals. In our case H varies with concentration between 0.38 and 0.07 eV. This explains both association degree equals unity at low temperature and complete dissociation for high concentration at high temperature. (author) [French] Nous etudions la conductibilite electrique des monocristaux de LiF dopes en ions divalents positifs. Le porteur de courant est la lacune de lithium creee soit par agitation thermique, soit pour compenser l'excedent de charge d'un ion M{sup 2+} en substitution. Le deplacement des lacunes se traduit par: {mu} = K'/NeT exp(- u/kT), ou K' et u sont des constantes. La concentration des porteurs n'est egale a celle des impuretes M{sup 2+} qu'a haute temperature. Les ions M{sup 2+} sont peu solubles et forment soit des precipites de MF{sub 2}, soit des agglomerats de dipoles. Dans ces etats, les M{sup 2+} ne participent plus a la conductibilite. Les lacunes induites par les ions M

The accelerator tube of ions of the generator Van de Graaff of the CEA. Survey of development. First results; Le tube accelerateur d'ions du generateur van de graapp du commissariat. Etude de developpement. Premiers resultats

Energy Technology Data Exchange (ETDEWEB)

Bruck, H.; Prevot, F. [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

1953-07-01

Rare are the Van de Graaff supplies whose tube doesn't collapse electrically to tensions and currents very lower to those that the generator can provide. We chose the general measurements: length and diameter, and put the accent on the survey of the individual element, so much to the mechanical viewpoint (installation, solidity, tightness and degassing), that to the electric viewpoint (to increase the electric rigidity of it). After modification the breakdown voltage as well as the performances of the tube have been improved greatly. (M.B.) [French] Rares sont les machines de Van de Graaff dont le tube ne s'effondre pas electriquement a des tensions et des courants bien inferieurs a ceux que le generateur peut fournir. Nous avons choisi les dimensions generales: longueur et diametre, et mis l'accent sur l'etude de l'element individuel, tant au point de vue mecanique (montage, solidite, etancheite et degazage), qu'au point de vue electrique (pour en augmenter la rigidite electrique). Apres modification la tension de claquage ainsi que les performances du tube ont ete grandement ameliorees. (M.B.)

Use of superconductors for storage and discharge of electrical energy; L'utilisation des supraconducteurs pour le stockage et la decharge de l'energie electrique

Energy Technology Data Exchange (ETDEWEB)

Sole, J [Commissariat a l' Energie Atomique, Limeil-Brevannes (France). Centre d' Etudes

1968-07-01

stockage et la decharge de l'energie electrique. (auteurs)

Micro-striction 1 and 2 (1961); Microstriction 1 and 2 (1961)

Energy Technology Data Exchange (ETDEWEB)

Alddieres, M; Aymar, R; Jourdan, P; Samain, A [Association Euratom-CEA Cadarache, 13 - Saint-Paul-lez-Durance (France)

1961-07-01

A certain quantity of gas is enclosed between two co-axial glass tubes (diameters 67 and 87 mm). In this annular space thus formed exists a permanent magnetic configuration, whose lines of force are perpendicular to the surface of the tubes (0-500 gauss). An electric field is then produced by induction such that its lines of force are circles whose axis coincides with that of the tubes (200 V/cm). The electric field lasts for 0.5 {mu}s. This field ionises the gas and causes an electric current to flow perpendicularly to the magnetic field. The corresponding Laplacian force accelerates the plasma along the axis of the tubes. In a first series of measurements, the discharge characteristics in the absence of a permanent field were studied. It is, in particular, convenient to group together all the irreversible phenomena which occur by assuming the existence of an electrical discharge resistance. The plasma movement in the permanent magnetic field induces in this latter a back-e.m.f. By taking into account the discharge resistance, the electric current and the forces tending to accelerate the plasma can be evaluated. The efficiency of the acceleration process has been measured. It passes through a maximum for a certain value of the permanent magnetic field. The experimental results have been compared with the simple model described above. (authors) [French] Une certaines quantite de gaz est enfermee entre deux tubes en verre de meme axe (diametres 6V et 87 mm). L'espace annulaire ainsi defini est le siege d'une configuration magnetique permanente, dont les lignes de force sont perpendiculaires a la surface des tubes (0-500 gauss). On fait apparaitre par induction un champ electrique dont les lignes de force sont des cercles dont l'axe coincide avec l'axe des tubes (200 V/cm). Ce champ electrique persiste pendant 0,5 {mu}s. Ce champ electrique ionise le gaz et fait circuler un courant electrique perpendiculaire au champ magnetique. La force de Laplace correspondante

Utility communication networks and services specification, deployment and operation

CERN Document Server

2017-01-01

This CIGRE green book begins by addressing the specification and provision of communication services in the context of operational applications for electrical power utilities, before subsequently providing guidelines on the deployment or transformation of networks to deliver these specific communication services. Lastly, it demonstrates how these networks and their services can be monitored, operated, and maintained to ensure that the requisite high level of service quality is consistently achieved.

MVAC Submarine cable, impedance measurements and analysis

DEFF Research Database (Denmark)

Arentsen, Martin Trolle; Expethit, Adrian; Pedersen, Morten Virklund

2017-01-01

influence the losses. Secondly, cable parameters such as component impedances, positive-, zero-sequence impedances and losses are measured for varying currents and frequencies. Zero sequence is measured for two setups, one with armour grounded, and with armour open to match CIGREs formula assumption......-sequence impedance is found between the measurements and the CIGRÉ formulas. It is concluded that the formulas are not accurate for the specific cable under test....

Measurements of integrated components' parameters versus irradiation doses gamma radiation (60Co) dosimetry-methodology-tests

International Nuclear Information System (INIS)

Fuan, J.

1991-01-01

This paper describes the methodology used for the irradiation of the integrated components and the measurements of their parameters, using Quality Insurance of dosimetry: - Measurement of the integrated dose using the competences of the Laboratoire Central des Industries Electriques (LCIE): - Measurement of irradiation dose versus source/component distance, using a calibrated equipment. - Use of ALANINE dosimeters, placed on the support of the irradiated components. - Assembly and polarization of components during the irradiations. Selection of the irradiator. - Measurement of the irradiated components's parameters, using the competences of the societies: - GenRad: GR130 tests equipement placed in the DEIN/SIR-CEN SACLAY. - Laboratoire Central des Industries Electriques (LCIE): GR125 tests equipment and this associated programmes test [fr

Electrohydrodynamics: a high-voltage direct energy conversion process; L'electrohydrodynamique: Un procede de conversion directe d'energie a haute tension

Energy Technology Data Exchange (ETDEWEB)

Brun, S [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1967-04-15

This analysis consists of a theoretical and practical study of a high-tension electrical power generator based on the Van de Graaff generator principle, the main difference being that the charges produced are transported by a gas in motion and not by a belt. The electrical and thermal properties of such a generator are studied, as well as the difficult problem of the production of the ionised particles used in the conversion. A certain number of results already published on this process for converting kinetic energy into electrical energy is given, as well as some possible applications in the field of space technology. (author) [French] Cette analyse est une etude theorique et pratique d'un generateur de puissance electrique a haute tension, base sur le principe du generateur Van de Graaff, la difference principale etant que les charges produites sont transportees pur un gaz en mouvement et non par une courroie. Les proprietes electriques et thermiques d'un tel generateur sont etudiees ainsi que le probleme delicat de la production des particules ionisees utilisees dans la conversion. Un certain nombre de resultats publies sur ce procede de conversion d'energie cinetique en energie electrique sont reproduits, ainsi que les applications possibles aux problemes spatiaux. (auteur)

Phase and group refractive index curves for electromagnet waves moving in an ionised medium (1962); Courbes des indices de phase et de groupe d'ondes electromagnetiques se propageant dans un milieu ionise (1962)

Energy Technology Data Exchange (ETDEWEB)

Consoli, T [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1962-07-01

The family of curves presented in this table give the phase and group refractive indexes of plane electromagnetic waves propagating along and across a static magnetic field in a plasma. (author) [French] Les courbes presentees sous formes de reseaux donnent les indices de phase et de groupe d'ondes electromagnetiques planes se propageant longitudinalement ou transversalement dans un plasma en presence d'un champ magnetique statique. (auteur)

Proceedings 2001. Networks. Section 3. Book 4

International Nuclear Information System (INIS)

Shukleva, Eva; Taleski, Rubin

2001-01-01

The holding of this Symposium was initiated by MAKO CIGRE - Macedonian Committee on Large High Voltage Systems, in compliance with its determination to raise competent discussions on current issues. The 3 sections of the conference were entitled: (1) power plants facilities, (2) power transmission lines, (3) networks. The forth volume includes the following topics: STK 36 - electromagnetic compatibility; STK 37 - planning and development of the power systems; STK 38 - power systems analysis and STK 39 - power systems control. Papers relevant to INIS are indexed separately

Asset management trends and challenges

Energy Technology Data Exchange (ETDEWEB)

Rijks, E. [Continuon, Arnhem (Netherlands); Ford, G.L. [PowerNex Associates Inc., Toronto, ON (Canada); Sanchis, G. [Reseau de Transport d' Electricite, Paris (France)

2007-07-01

Recent business and regulatory changes in the electric power industry have affected the operation of electric utilities. Most have accepted competition and commercialization. Various strategies have emerged as companies strive to improve performance and retain profitability in an environment where competition or regulatory pressure is reducing revenues at a time when customer expectation is increasing. As focus shifts away from engineering excellence towards commercial performance, the new business ideology for electric utilities is to optimize asset management. This paper identified asset management technology trends, opportunities and challenges. Although many utilities are currently comfortable with their existing asset management processes, regulators are increasingly scrutinizing utilities as they seek approval for rates and investments in aging infrastructure. Much more rigorous financial analysis methods are needed to justify the large investments that are needed. In addition, the credibility of the processes and methods used by utilities will be increasingly questioned. In recognition of the growing importance of asset management, several initiatives have been launched to provide forums for sharing information and to provide a unifying force to asset management methods. The International Council on Large Electric Systems (CIGRE) was one of the first to recognize the importance of asset management. This paper summarized recent CIGRE activities as well as the developments of publicly available specification (PAS) 55 in the United Kingdom. It was concluded that utilities that adopt standardized approaches will be more credible in the eyes of regulatory authorities. 3 refs., 4 figs.

Congestion management in a market environment. 2. CIGRE/PES Symposium

International Nuclear Information System (INIS)

2005-01-01

With the opening of electricity markets and changes in the power flows, the issue of available transmission capacity is of more and more importance. Market orientated answers and real-time solutions are implemented or under consideration; diligent management of existing assets and timely investment decisions to increase capacity and to improve the management systems are fundamental. This Symposium discusses the congestion management issue for internal and cross border exchanges, covering six subject areas: international Practices for Congestion Management, tariffs and Pricing, operations for Congestion, information Technology Issues, experiences with Congestion Management, tools for Congestion Management. (author)

Networks Within Cities and Among Cities: A Paradigm for Urban Development and Governance

OpenAIRE

Pompili, Tomaso

2006-01-01

Networks and networking have become fashionable concepts and terms in regional science, and in particular in regional and urban geography in the last decade: we speak about network firms, network society, network economy but also network cities, city-networks, reti urbane, reseaux de villes. Only catch-words for somebody; a true new scientific paradigm according to others. Our opinion is that in fact we are confronted with a new paradigm in spatial sciences, under some precise conditions: - t...

SEE electric systems. The electricity market opens up. New challenges in metering; SEE reseaux electriques. L'ouverture du marche de l'electricite. Un nouveau defi pour le comptage

Energy Technology Data Exchange (ETDEWEB)

Bergerot, J.L. [Electricite de France (EDF), 75 - Paris (France); Doulet, A.; Delorme, G. [EDF-GDF Services, 33 - Bordeaux (France). Groupe d' appui et d' assistance gaz] [and others

2001-07-01

The application of the European Directive on the opening up of the energy market redefines the role of companies involved in the production, transmission and distribution of electricity so that eligible customers can henceforth take advantage of the opportunities presented by a genuine market. During this conference managers of transmission and distribution networks will explain the actions they intend to put into place to fulfill their mission. Eligible customers will express their expectations in terms of the market transparency, real prices and contract periods as well as explaining their requirements relating to the quality of electricity and service. Electricity suppliers will indicate the fields in which they aim to differentiate their offer, starting with a product which until now seemed banal. A foreign network manager will share his recent experiences, as regards all of these points. Finally, the constructors will show how traditional metering will evolve to become the management tool to monitor the complex relationships between all the players in the electricity market. (authors)

Protection of Multi-Terminal VSC-HVDC Grids Based on the Response of the First Carrier Frequency Harmonic Current

DEFF Research Database (Denmark)

Ashouri, Mani; Khazraj, Hesam; Silva, Filipe Miguel Faria da

This paper investigates the response of first carrier frequency harmonic (FCFH) current for designing a protection algorithm for multi-terminal Voltage source converter-based HVDC (VSC-MTDC) transmission grids. This transient harmonic current has been used before, to discriminate external AC faults...... various kinds of faults with different locations and resistances. This paper will also consider half-bridge MMC instead of two-level VSCs to test the sensitivity of the FCFH based algorithm for lower harmonic values. A modified meshed version of CIGRE DC model has been used in PSCAD and the signal...

Reliability analysis of HVDC grid combined with power flow simulations

Energy Technology Data Exchange (ETDEWEB)

Yang, Yongtao; Langeland, Tore; Solvik, Johan [DNV AS, Hoevik (Norway); Stewart, Emma [DNV KEMA, Camino Ramon, CA (United States)

2012-07-01

Based on a DC grid power flow solver and the proposed GEIR, we carried out reliability analysis for a HVDC grid test system proposed by CIGRE working group B4-58, where the failure statistics are collected from literature survey. The proposed methodology is used to evaluate the impact of converter configuration on the overall reliability performance of the HVDC grid, where the symmetrical monopole configuration is compared with the bipole with metallic return wire configuration. The results quantify the improvement on reliability by using the later alternative. (orig.)

The judgement of simultaneous commutation failure in HVDC about hierarchical connection to AC grid

Science.gov (United States)

Li, Ming; Song, Xinli; Huang, Daoshan; Liu, Wenzhuo; Zhao, Shutao; Ye, Xiaohui; Meng, Hang

2017-09-01

The hierarchical connection to AC grid at inverter sides in UHVDC has been take in several projects. This paper introduced the frame of the connection mode in hierarchical access system and compared it with the traditional one at the case of HVDC-Cigre. Then the criterion of commutation failure according to the same valves current was deduced. In order to verify the accuracy of the criterion, this paper used PSD-BPA (Bonneville Power Administration) to simulate the setting voltage drop in the East China power grid and certified the correctness of the formula.

Pop / Priit Hõbemägi

Index Scriptorium Estoniae

Hõbemägi, Priit, 1957-

2008-01-01

Heliplaatidest: Tony Joe White "Deep Cuts", Ray LaMontagne "Gossip In The Grain", Mogwai "The Hawk Is Howling", Kaiser Chiefs "Off With Their Heads", Static-X "Cannibal Killers Live", Hector Zazou "Corps Electriques", Hector Zazou & Swara "In the House of Mirrors", "Ladyhawke", "Friendly Fires"

activit secondaire* du programme acca la cdp 12, cdp/rdp 2

International Development Research Centre (IDRC) Digital Library (Canada)

freelance

5.3. But et objectifs spécifiques de la stratégie de Partage des Risques ... EEEAO : Echange d'Energie Electrique en Afrique de l'Ouest. FAO: Food and Agriculture ...... 95 000 pour son noyau central) sur les deux rives du Delta du fleuve.

High security ion-lithium batteries with rapid recharge for the terrestrial transport and energy storage; Batteries de type ion-lithium de haute securite a recharge rapide pour le transport terrestre et le stockage d'energie

Energy Technology Data Exchange (ETDEWEB)

Zaghib, Karim; Dontigny, M.; Charest, P.; Guerfi, A.; Trotier, J.; Mathieu, M.C.; Zhu, W.; Petitclerc, M.; Veillette, R.; Serventi, A.; Hovington, P.; Lagace, M.; Trudeau, M.; Vijh, A.

2010-09-15

Electrical terrestrial transport is today a hub of innovation and growth for Hydro-Quebec. In the perspective of electrification of terrestrial transports, battery remains the critical factor of future success of rechargeable electrical vehicles. For nearly 20 years, Hydro-Quebec, via its research institute, has worked at developing battery material for the lithium-ion technology. Two types of Li-ion batteries have been developed: the energy battery and the power battery. [French] Le transport terrestre electrique est aujourd'hui un pole d'innovation et de croissance pour Hydro-Quebec. Dans la perspective de l'electrification des transports terrestres, la batterie demeure le facteur critique du succes futur des vehicules electriques rechargeables. Depuis pres de 20 ans, Hydro-Quebec, par le biais de son Institut de recherche, travaille au developpement de materiaux de batteries destinees a la technologie lithium-ion. Deux types de batteries Li-ion ont ete mises au point : la batterie d'energie et la batterie de puissance.

Journal des Sciences Pour l'Ingénieur - Vol 12 (2010)

African Journals Online (AJOL)

DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. M Pasquinelli, D Maestre, K Lagha, D Barakel, J Le Rouzo, C Alfonso, O Palais ... Modele electrique d'une pile a combustible « pem » pour utilisation electronique de puissance · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

Power system harmonics and passive filter designs

CERN Document Server

Das, J C

2015-01-01

J.C. Das is a consultant of electrical power systems at Power Systems Studies, Inc., USA. He is Life Fellow of IEEE (UK), Fellow of IET (India), and has authored approximately sixty technical papers and published 190 study reports of real-world power systems. He is the author of three books including ARC Flash Hazard Analysis and Mitigation. He is a registered P.E. in the states of Georgia and Oklahoma, C.Eng. in UK, and Eur Ing in Europe. J. C. Das is also a member of CIGRE, Federation of European Engineers, and other technical associations and organizations.

HVDC: A key solution in future transmission systems

Energy Technology Data Exchange (ETDEWEB)

Heyman, Olof H.; Weimers, Lars; Bohl, Mie-Lotte

2010-09-15

With the transition of power grids, based on sustainable generation, HVDC is a key technology with new applications. This includes connection of remote wind parks and strengthening of existing AC grids. In addition, traditional applications, such as bulk hydropower transfer and interconnections between regions, play a major role in our transition to sustainable generation and the associated grids. The technology for regional grids with a limited number of nodes is already in place and commercial projects are commissioned. For extensive grids, development and verification are ongoing in parallel to industry standards being discussed in groups such as ENTSO-E and CIGRE.

Preliminary tests to determine the fatigue curve of the Ibis ACSR (Aluminum Cable Steel Reinforced) conductor; Ensaios preliminares para determinacao da curva de fadiga do cabo condutor ACSR Ibis

Energy Technology Data Exchange (ETDEWEB)

Rosa, Daniel M. [Universidade de Brasilia (UnB-Gama), DF (Brazil)], E-mail: danielrosa@unb.br; Fadel, Aida A.; Araujo, Jose Alexander; Ferreira, Jorge Luiz A.; Henriques, Antonio Manoel D. [Universidade de Brasilia (EnM/UnB), DF (Brazil). Dept. de Engenharia Mecanica], Emails: aida@unb.br, alex07@unb.br, jorge@unb.br, Henriques@unb.br; Hortencio, Tania M.O.S. [Companhia Energetica de Goias Distribuicao S.A. (CELG D), Goiania, GO (Brazil)], E-mail: tania.hortencio@celg.com.br

2009-07-01

The aim of this work was to present a fretting fatigue experimental rig for overhead conductors and to carry out a set of experiments to obtain life estimative for a standard Ibis ACSR, Aluminium Conductor Steel Reinforced. A preliminary S-N (Wohler) Curve was obtained in the medium high cycle fatigue regime. Experiments considered the occurrence of at least two wire breaks to obtain each point of the S-N curve, which was compared to CIGRE's Safe Border Line (CSBL). The experimental results showed five to ten times large lives than the ones provided by CSBL adoption. (author)

Current status of research on power-frequency electric and magnetic fields of research

International Nuclear Information System (INIS)

Anon.

1991-01-01

Recent scientific literature has suggested a number of possible human health effects which might be associated with exposure to power frequency electric and magnetic fields. Several authoritative reviews of this subject have been published. currently, the major uncertainty and the major research effort is directed to the issue of these fields and cancer. Therefore, this review will be limited to examining the evidence relating prolonged power-frequency electric and magnetic field exposure to cancer in human populations. This paper reports that the CIGRE expert Group has assessed the research literature in the following areas: epidemiological evidence, animal studies, cellular effects, knowledge of mechanisms

High-voltage test and measuring techniques

CERN Document Server

Hauschild, Wolfgang

2014-01-01

It is the intent of this book to combine high-voltage (HV) engineering with HV testing technique and HV measuring technique. Based on long-term experience gained by the authors as lecturer and researcher as well as member in international organizations, such as IEC and CIGRE, the book will reflect the state of the art as well as the future trends in testing and diagnostics of HV equipment to ensure a reliable generation, transmission and distribution of electrical energy. The book is intended not only for experts but also for students in electrical engineering and high-voltage engineering.

Results and interpretation of spectral indices measurements made with AQUILON; Resultats et interpretation de mesures d'indices de spectre dans aquilon

Energy Technology Data Exchange (ETDEWEB)

Frichet, J P; Mougey, J N; Naudet, R; Taste, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-07-01

This report deals with a set of spectral indices measurements made in the heavy water reactor Aquilon on lattices constituted by massive fuel elements of dia. 29,2 mm. The fuel elements were made either of natural uranium or of slightly depleted or slightly enriched uranium, or of an uranium-plutonium alloy. The measurements were carried out for various lattice pitches (square pitch from 110 to 210 mm) and in certain cases for various temperatures (from 20 to 80 deg. C). The results are compared to calculated values obtained by using the latest advances of the thermalization theory developed at Saclay applied to the moderation by heavy water. (authors) [French] Ce rapport est consacre a un ensemble de mesures d'indices de spectre realisees dans la pile a eau lourde Aquilon sur des reseaux d'elements combustibles pleins, de 29,2 mm de diametre. Ces combustibles se composaient ou bien d'uranium naturel, ou bien d'uranium tres legerement appauvri ou enrichi, ou bien d'un alliage uranium plutonium. Les mesures ont ete effectuees pour toute une serie de pas de reseaux (pas carre 110 a 210 mm), certaines d'entre elles a plusieurs temperatures (20 a 80 deg. C). Les resultats des mesures sont compares a des valeurs calculees obtenues en utilisant les plus recents developpements de la theorie de la thermalisation mise au point a Saclay, appliques au cas de la moderation par l'eau lourde. (auteurs)

Estimation of the energy needs; Estimation des besoins energetiques

Energy Technology Data Exchange (ETDEWEB)

Ailleret, [Electricite de France (EDF), Dir. General des Etudes de Recherches, 75 - Paris (France)

1955-07-01

The present report draws up the balance on the present and estimable energy consumption for the next twenty years. The present energy comes mainly of the consumption of coal, oil products and essentially hydraulic electric energy. the market development comes essentially of the development the industrial activity and of new applications tributary of the cost and the distribution of the electric energy. To this effect, the atomic energy offers good industrial perspectives in complement of the energy present resources in order to answer the new needs. (M.B.) [French] Le present rapport dresse le bilan sur la consommation energetique actuelle et previsionnelle pour les vingt prochaines annees. L'energie actuelle provient principalement consommation de charbon, de produits petroliers et d'energie electrique essentiellement hydraulique. l'evolution du marche provient essentielement du developpement l'activite industriel et de nouvelles applications tributaire du cout et de la distribution de l'energie electrique. A cet effet, l'energie atomique offre de bonne perspectives industrielles en complement des sources actuelles energetiques afin de repondre aux nouveaux besoins. (M.B.)

Production of nuclear graphite in France; Production de graphite nucleaire en France

Energy Technology Data Exchange (ETDEWEB)

Legendre, P; Mondet, L [Societe Pechiney, 74 - Chedde (France); Arragon, Ph; Cornuault, P; Gueron, J; Hering, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1955-07-01

The graphite intended for the construction of the reactors is obtained by the usual process: confection of a cake from coke of oil and tar, cooked (in a electric oven) then the product of cook is graphitized, also by electric heating. The use of the air transportation and the control of conditions cooking and graphitization have permitted to increase the nuclear graphite production as well as to better control their physical and mechanical properties and to reduce to the minimum the unwanted stains. (M.B.) [French] Le graphite destine a la construction des reacteurs est obtenu par le procede usuel: confection d'une pate a partir de coke de petrole et de brai, cuisson de cette pate (au four electrique) puis graphitation du produit cuit, egalement par chauffage electrique. L'usage du transport pneumatique et le controle des conditions cuisson et de graphitation ont permit d'augmenter la production de graphite nucleaire ainsi que de mieux controler ses proprietes physiques et mecaniques et de reduire au minimum les souillures accidentelles. (M.B.)

Superconducting superlattices. Les super reseaux de supraconducteurs

Energy Technology Data Exchange (ETDEWEB)

Triscone, J M; Fischer, O [Geneva Univ. (Switzerland)

1993-03-01

By piling up ultra-thin layers of discrete materials, physicists now have a choice method for the study of superconductivity at high temperature. These superlattices are prepared by successive layers of YBaCuO and PrBaCuO deposited by cathode sputtering to study the variation of superconductivity with layer thickness. The transition temperature decreases rapidly when the distance between two layers increases. Current vortices are created, without a magnetic field, widening the transition temperature. The variation of resistivity near critical temperature in a magnetic field shows that the energy required to displace vortices is increasing with the thickness of the YBaCuO layer, with thin layers anisotropy is high and energy dissipation is important. (G.R.). refs., figs.

Diagnóstico de averías de un cambiador de tomas en carga mediante redes neuronales

OpenAIRE

Piñas García, Miguel Ángel

2010-01-01

Un cambiador de tomas en carga por sus siglas en español CTC u OLTC por sus siglas en inglés (“On-Load Tap Changer”) es la única parte con movimiento en un transformador. Su Misión es realizar la operación de cambio de una toma a otra del devanado de regulación, modificando el número de espiras en uno de los devanados, en respuesta a un cambio de tensión en la red debido a variaciones en la carga. De acuerdo a una encuesta internacional realizada por el CIGRE el 40% de los fallos del transfor...

A Current Limiting Strategy to Improve Fault Ride-Through of Inverter Interfaced Autonomous Microgrids

DEFF Research Database (Denmark)

Sadeghkhani, Iman; Esmail Hamedani Golshan, Mohamad; Guerrero, Josep M.

2017-01-01

With high penetration of distributed energy resources (DER), fault management strategy is of great importance for the distribution network operation. The objective of this paper is to propose a current and voltage limiting strategy to enhance fault ride-through (FRT) capability of inverter...... for both four- and three-wire configurations. The proposed strategy provides high voltage and current quality during overcurrent conditions, which is necessary for sensitive loads. Several time-domain simulation studies are conducted to investigate the FRT capability of the proposed strategy against both...... asymmetrical and symmetrical faults. Moreover, the proposed method is tested on the CIGRE benchmark microgrid to demonstrate the effectiveness of the proposed limiting strategy....

Nuclear magnetic resonance of iron-57 nuclei in local fields in yttrium and iron garnets; Resonance magnetique nucleaire des noyaux du fer 57 dans les champs locaux du grenat d'yttrium et de fer

Energy Technology Data Exchange (ETDEWEB)

Robert, C. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1961-07-01

We have demonstrated the nuclear resonance of {sup 57}Fe nuclei in the local field of each of the two magnetic sub-lattices of yttrium and iron garnets. The resonance frequencies and the relaxation times have been measured as a function of the temperature. (author) [French] Nous avons mis en evidence la resonance nucleaire des noyaux de {sup 57}Fe dans le champ local de chacun des deux sous-reseaux magnetiques du grenat d'yttrium et de fer. Les frequences de resonances et les temps de relaxation ont ete mesures en fonction de la temperature. (auteur)

Study of current instabilities in high resistivity gallium arsenide; Etude des instabilites de courant dans l'arseniure de gallium de haute resistivite

Energy Technology Data Exchange (ETDEWEB)

Barraud, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1968-07-01

We have shown the existence and made a study of the current oscillations produced in high-resistivity gallium arsenide by a strong electric field. The oscillations are associated with the slow travelling of a region of high electrical field across the whole sample. An experimental study of the properties of these instabilities has made it possible for us to distinguish this phenomenon from the Gunn effect, from acoustic-electric effects and from contact effects. In order to account for this type of instability, a differential trapping mechanism involving repulsive impurities is proposed; this mechanism can reduce the concentration of charge carriers in the conduction band at strong electrical fields and can lead to the production of a high-field domain. By developing this model qualitatively we have been able to account for all the properties of high-resistance gallium arsenide crystals subjected to a strong electrical field: increase of the Hall constant, existence of a voltage threshold for these oscillations, production of domains of high field, low rate of propagation of these domains, and finally the possibility of inverting the direction of the propagation of the domain without destroying the latter. A quantitative development of the model makes it possible to calculate the various characteristic parameters of these instabilities. Comparison with experiment shows that there is a good agreement, the small deviations coming especially from the lack of knowledge concerning transport properties in gallium arsenide subjected to high fields. From a study of this model, it appears that the instability phenomenon can occur over a wide range of repulsive centre concentrations, and also for a large range of resistivities. This is the reason why it appears systematically in gallium arsenide of medium and high resistivity. (authors) [French] Nous avons mis en evidence et etudie des oscillations de courant qui se produisent a champ electrique eleve dans l'arseniure de

Gestion des déchets d'équipements électriques et électroniques ...

African Journals Online (AJOL)

La gestion des Déchets d'Equipements Electriques et Electroniques (DEEE) est un défi pour le Sénégal. Leur quantité augmente rapidement et leur gestion informelle expose l'environnement et les acteurs aux risques liés aux substances toxiques qu'ils contiennent. L'étude vise à déterminer les caractéristiques des ...

Kinetics of heterogeneous systems; La cinetique des milieux heterogenes

Energy Technology Data Exchange (ETDEWEB)

Deniz, V [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-07-01

In this report, a general transport theory treatment is presented for the kinetics study as applied to finite heterogeneous systems. The theory is applicable to experiments near the critical point as well as to pulsed neutron experiments on multiplying or non-multiplying lattices. The general method is also applied to exponential experiments on infinite non-diverging lattices. The particularity of the present study is the explicit introduction of heterogeneity in the formulation and the search for the dependence of the parameters on the buckling of the finite medium. As a result of this, the finite medium parameters are in the first place expressed in terms of the corresponding infinite medium ones through the buckling and the anisotropic migration areas, and in the second place all the parameters are expressed as integrals only over an unit cell instead of over the whole pile. A preliminary less detailed study is first made in order to distinguish clearly between what are called 'dynamic parameters' and 'static parameters', and to define the meanings given in this report to these two terms. In the appendices are given approximate one-group treatments for the study of the dynamic fine structure, the time constant in infinite lattices, and the anisotropic diffusion coefficients in non-multiplying lattices. (author) [French] On presente dans ce rapport une methode generale, utilisant la theorie du transport pour l'etude de la cinetique des milieux finis heterogenes. La theorie est applicable aussi bien aux experiences pres de la criticite qu'aux experiences par sources pulsees de neutrons sur des reseaux multiplicateurs ou non-multiplicateurs. La methode generale est aussi appliquee aux experiences exponentielles sur des reseaux infinis non-divergents. La particularite de l'etude est l'introduction explicite de l'heterogeneite dans la formulation et la recherche de la dependance des parametres par rapport au laplacien du reseau fini. Il en resulte d'une part que les

Reconnection of the islanded portion of the CIGRE low voltage distribution network

DEFF Research Database (Denmark)

Bhutto, G.M.; Bak, Claus Leth; Somro, Duur M.

2016-01-01

Islanding is phenomena in which a part of the distribution grid is electrically disconnected from the main transmission system. Islanded operation is encouraged in order to operate the electrical power networks in reliable manners. However, the reliability of the small networks operating is island...... is less as compared to that of the grid connected system. The islanded portion of the distribution network can be reconnected to the transmission grid if the voltage magnitudes, voltage phase angles and the frequencies of the two systems are synchronized. The main objective of this paper is to facilitate...

Cycle for fuel elements. Uranium production, programs for nuclear power stations and capital expenditure involved; Cycles de combustibles. Production d'uranium, programme de centrales electriques et effort financier correspondant

Energy Technology Data Exchange (ETDEWEB)

Andriot, J; Gaussens, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

naturel-graphite, - filiere uranium naturel-eau lourde, - filiere uranium enrichi-eau legere pressurisee. Tout programme apparaitra donc comme une combinaison des trois programmes simples precedents. On s'est attache en outre a examiner les consequences du recyclage du plutonium dans les diverses filieres. Les puissances electriques installees et les capacites des usines situees en amont ou en aval etant ainsi calculees, on a essaye ensuite de chiffrer le montant des investissements qui serait necessaire pendant les quinze annees en cause pour mettre en place les programmes envisages. Les resultats sont presentes sous la forme d'un echeancier d'investissements. Cette presentation nous semble en effet interessante compte tenu des disponibilites non illimitees en capitaux de la France dans les prochaines annees. (auteur)

Study on AC loss measurements of HTS power cable for standardizing

Science.gov (United States)

Mukoyama, Shinichi; Amemiya, Naoyuki; Watanabe, Kazuo; Iijima, Yasuhiro; Mido, Nobuhiro; Masuda, Takao; Morimura, Toshiya; Oya, Masayoshi; Nakano, Tetsutaro; Yamamoto, Kiyoshi

2017-09-01

High-temperature superconducting power cables (HTS cables) have been developed for more than 20 years. In addition of the cable developments, the test methods of the HTS cables have been discussed and proposed in many laboratories and companies. Recently the test methods of the HTS cables is required to standardize and to common in the world. CIGRE made the working group (B1-31) for the discussion of the test methods of the HTS cables as a power cable, and published the recommendation of the test method. Additionally, IEC TC20 submitted the New Work Item Proposal (NP) based on the recommendation of CIGRE this year, IEC TC20 and IEC TC90 started the standardization work on Testing of HTS AC cables. However, the individual test method that used to measure a performance of HTS cables hasn’t been established as world’s common methods. The AC loss is one of the most important properties to disseminate low loss and economical efficient HTS cables in the world. We regard to establish the method of the AC loss measurements in rational and in high accuracy. Japan is at a leading position in the AC loss study, because Japanese researchers have studied on the AC loss technically and scientifically, and also developed the effective technologies for the AC loss reduction. The JP domestic commission of TC90 made a working team to discussion the methods of the AC loss measurements for aiming an international standard finally. This paper reports about the AC loss measurement of two type of the HTS conductors, such as a HTS conductor without a HTS shield and a HTS conductor with a HTS shield. The AC loss measurement method is suggested by the electrical method..

Candidacy of a chitin-inducible gibberellin-responsive gene for a major locus affecting plant height in rice that is closely linked to Green Revolution gene sd1.

Science.gov (United States)

Kovi, Mallikarjuna Rao; Zhang, Yushan; Yu, Sibin; Yang, Gaiyu; Yan, Wenhao; Xing, Yongzhong

2011-09-01

Appropriate plant height is crucial for lodging resistance to improve the rice crop yield. The application of semi-dwarf 1 led to the green revolution in the 1960s, by predominantly increasing the rice yield. However, the frequent use of single sd1 gene sources may cause genetic vulnerability to pests and diseases. Identifying useful novel semi-dwarf genes is important for the genetic manipulation of plant architecture in practical rice breeding. In this study, introgression lines derived from two parents contrasting in plant height, Zhenshan 97 and Pokkali were employed to locate a gene with a large effect on plant height by the bulk segregant analysis method. A major gene, ph1, was mapped to a region closely linked to sd1 on chromosome 1; the additive effects of ph1 were more than 50 cm on the plant height and 2 days on the heading date in a BC(4)F(2) population and its progeny. ph1 was then fine mapped to BAC AP003227. Gene annotation indicated that LOC_OS01g65990 encoding a chitin-inducible gibberellin-responsive protein (CIGR), which belongs to the GRAS family, might be the right candidate gene of ph1. Co-segregation analysis of the candidate gene-derived marker finally confirmed its identity as the candidate gene. A higher expression level of the CIGR was detected in all the tested tissues in tall plants compared to those of short plants, especially in the young leaf sheath containing elongating tissues, which indicated its importance role in regulating plant height. ph1 showed a tremendous genetic effect on plant height, which is distinct from sd1 and could be a new resource for breeding semi-dwarf varieties.

Diverse Secreted Effectors Are Required for Salmonella Persistence in a Mouse Infection Model

Energy Technology Data Exchange (ETDEWEB)

Kidwai, Afshan S.; Mushamiri, Ivy T.; Niemann, George; Brown, Roslyn N.; Adkins, Joshua N.; Heffron, Fred

2013-08-12

Salmonella enterica serovar Typhimurium causes typhoid-like disease in mice and is a model of typhoid fever in humans. One of the hallmarks of typhoid is persistence, the ability of the bacteria to survive in the host weeks after infection. Virulence factors called effectors facilitate this process by direct transfer to the cytoplasm of infected cells thereby subverting cellular processes. Secretion of effectors to the cell cytoplasm takes place through multiple routes, including two separate type III secretion (T3SS) apparati as well as outer membrane vesicles. The two T3SS are encoded on separate pathogenicity islands, SPI-1 and -2, with SPI-1 more strongly associated with the intestinal phase of infection, and SPI-2 with the systemic phase. Both T3SS are required for persistence, but the effectors required have not been systematically evaluated. In this study, mutations in 48 described effectors were tested for persistence. We replaced each effector with a specific DNA barcode sequence by allelic exchange and co-infected with a wild-type reference to calculate the ratio of wild-type parent to mutant at different times after infection. The competitive index (CI) was determined by quantitative PCR in which primers that correspond to the barcode were used for amplification. Mutations in all but seven effectors reduced persistence demonstrating that most effectors were required. One exception was CigR, a recently discovered effector that is widely conserved throughout enteric bacteria. Deletion of cigR increased lethality, suggesting that it may be an anti-virulence factor. The fact that almost all Salmonella effectors are required for persistence argues against redundant functions. This is different from effector repertoires in other intracellular pathogens such as Legionella.

Electronic analogue simulator of radio cardiograms; Simulateur analogique electronique de radiocardiogrammes

Energy Technology Data Exchange (ETDEWEB)

Roux, G; Lansiart, A; Vernejoul, P de; Kellershohn, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-07-01

The various parameters of the heart pump and of the blood circulation can be determined by radio-cardio-graphical techniques. The curves thus obtained can be more easily used in radiocardiography if the electronic analogue simulator described here is employed. The experimental and simulated radio-cardiograms are made to coincide by varying the electrical parameters of the simulator. Using simple charts it is possible to obtain directly the actual original physiological parameters from these electrical parameters. Some examples are given showing the excellent accuracy obtained in the determination of ejection indices by the simulator. (authors) [French] Les differents parametres de la pompe cardiaque et de la circulation sanguine peuvent etre determines par les techniques de radiocardiographie. L'exploitation des courbes obtenues en radiocardiographie est rendue plus aisee par l'utilisation du simulateur analogique electronique presente ici. Le radiocardiogramme experimental et le radiocardiogramme simule sont superposes en agissant sur les parametre electriques du simulateur. Par l'utilisation d'abaques simples, ces parametres electriques permettent de retrouver directement les parametres reels d'origine physiologique. Quelques exemples sont donnes montrant l'excellente precision obtenue dans la determination des indices d'ejection a l'aide du simulateur. (auteurs)

In-pile experimental device for Sirene thermionic converters; Dispositif d'experimentation en pile des convertisseurs thermoioniques sirene

Energy Technology Data Exchange (ETDEWEB)

Bliaux, J; Durand, J; Lazare-Chopard, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1969-07-01

The irradiation device described here, was built for in pile life tests of 100 We SIRENE converters. The nuclear converter is located in a sealed vacuum chamber, which is plugged at the lower end of a coaxial tubing acting as electrical leads. The output power is available on a variable resistive load on the bank of the reactor pool. Thermal, electrical and neutronic parameters of the converter are recorded. Since 1967, two permanent devices allowed five experiments in the swimming pool TRITON (CEN-FAR) and the results, obtained till now, are presented. (authors) [French] Le dispositif d'irradiation SIRENE decrit ici a ete concu en vue d'une etude statistique de performances de convertisseurs thermoioniques nucleaires de puissance unitaire 100 We. Le dispositif doit assurer la bonne marche du convertisseur en pile, permettre le changement de la position verticale du convertisseur dans le coeur, sortir du coeur la puissance electrique convertie sans degradation notable et enregistrer les differents parametres thermiques, electriques et neutroniques du convertisseur. Depuis 1967, deux dispositifs fonctionnent en permanence et ont permis de faire cinq experiences dans le reacteur piscine TRITON du CEN-FAR. Les resultats obtenus jusqu'a present, sont presentes. (auteurs)

Design and study of the performance of a Raman lidar model, combining a pulsed laser source and a holographic grating double monochromator; Realisation et etudes des performances d'une maquette de lidar Raman combinant une source laser impulsionnelle et un double monochromateur a reseaux holographiques

Energy Technology Data Exchange (ETDEWEB)

Nacass, Philippe

1976-03-16

Raman sont ensuite decrites. L'originalite de cette derniere reside dans l'utilisation de monochromateurs a reseaux holographiques et dans la simplicite du systeme d'obtention des resultats. Avec ce montage, la mesure in-situ de la retrodiffusion Raman de N{sub 2}, O{sub 2}, H{sub 2}O de l'atmosphere et CO{sub 2} en forte concentration, faite a une distance de 30 a 40 m, permet une estimation raisonnable de la sensibilite et de la portee d'un montage definitif plus performant. (auteur)

Data acquisition and processing on T.F.R. using a minicomputer

International Nuclear Information System (INIS)

Hennion, F.; Idmtal, J.; Touche, J.

1975-01-01

Certain experimental TFR data are digitalized and may be acquired by a Telemecanique Electrique T 2000 computer. These data are stored on magnetic tapes and can be treated on line. The signals from direct measurements or calculation results are plotted on a visual display screen located on the experimental site, which means that the main parameters of the experiment can be known immediately after the collision [fr

Reseaux de conception innovante et formes de proximites

Directory of Open Access Journals (Sweden)

Bénédicte Serrate

2010-08-01

Full Text Available La conception, appelée « design » dans les entreprises industrielles, représente dans le processus d’innovation une étape essentielle pourtant peu étudiée encore par les économistes. Elle mobilise pour aboutir à des innovations de plus en plus jugées essentielles à la compétitivité de l’entreprise, quantité d’acteurs internes et externes selon une logique de réseau sans cesse renouvelée. A partir de l’observation de cas empiriques, nous avons tenté dans cet article de comprendre comment s’organisaient ces réseaux innovants. Aujourd’hui dans la plupart des pays qui pratiquent des politiques de développement économique local, il semble établi qu’il faille construire des proximités géographiques entre acteurs pour que se développent des relations industrielles favorisant la dynamique d’innovation et le transfert des connaissances. L’abondance des « clusters » et des « pôles de compétitivité » partout dans le monde témoigne de ce postulat. En analysant les modes d’organisation des réseaux de conception nous avons donc cherché à vérifier si la proximité géographique constituait encore un ressort essentiel et si la globalisation des entreprises ne laissait pas apparaitre d’autres formes de proximités.

Browse Title Index

African Journals Online (AJOL)

Vol 1, No 1 (2001), Mise en évidence d'un optimum de fines dans les sables ô béton: Exemple d'un sable des dunes de la région de Dakar ( Sénégal), Abstract. IK Cissé, M ... Vol 12 (2010), Modele electrique d'une pile a combustible « pem » pour utilisation electronique de puissance, Abstract. I Sadli, S Raël, B Davat, ...

Study of transient states in thermo-ionic converters; Etude des regimes transitoires des convertisseurs thermoioniques

Energy Technology Data Exchange (ETDEWEB)

Landrot, J [Commissariat a l' Energie Atomique, 91 - Saclay (France). Centre d' Etudes Nucleaires

1968-07-01

In order to control a thermo-ionic reactor, it is necessary to know the dynamic influence of four fundamental parameters: the injected thermal power, the electrical charge resistance, the temperature of the cesium and the thermal exchange coefficient of the collector cooling circuit. The principles of the thermo-ionic converter are briefly exposed. The over-riding influence of the first two parameters is shown with the help of experimental static readings. These two parameters are then made to vary in turn. The laws of variation as a function of the time, of the electrical power produced and of the temperature of the various parts of the converter are deduced. (author) [French] Pour envisager le controle et la regulation d'un reacteur thermoionique, il est necessaire de connaitre l'influence dynamique de quatre parametres fondamentaux: puissance thermique injectee, resistance electrique de charge, temperature de cesium et coefficient d'echange thermique du circuit de refroidissement du collecteur. On rappelle brievement les principes du convertisseur thermoionique. A l'aide de releves statiques experimentaux, on montre l'influence preponderante des deux premiers parametres. On fait ensuite varier successivement ces deux parametres. On met en evidence les lois de variation en fonction du temps de la puissance electrique produite et de la temperature des differents points du convertisseur. (auteur)

The electric comfort; Le confort electrique

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

In the framework of the public information on the electric power utilization in the household, Electricite De France presented on april-may at Paris Meeting, the possibilities and the advantages of the electric comfort. The concerned domains are: the electric cheating, the air-conditioning, the hot water, the lighting and the electric household appliances. Information on prices and statistical data on electric heating are also provided. (A.L.B.)

Evaluation electric bicycles; Evaluation velos electriques

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-10-01

Leovelo service is the first measure in favor of the bicycle to control the air pollution and to conserve energy. It provides in the city of Clermont-Ferrand (France) a service of bicycle hiring. This document evaluates the project after two years of operating. It provides a technical evaluation (maintenance, equipment, financing) and also the socio-economic impacts. (A.L.B.)

Workshop on Design Loads for Advanced Fighters: Meeting of the Structures and Materials Panel of AGARD (64th) Held in Madrid (Spain) on 27 April-1 May 1987.

Science.gov (United States)

1988-02-01

artificial intelligence system. It is posited that combining such a system, referred to informally as "Guardian", with a system incorporating aircraft...Proceedings of the Aerospace Medical Association Annual Scientific Meeting, 1976. 13. Van Patten, R. E. Current research on an artificial intelligence ...avions qui l’ont suivi (MIRAGE 4000, MIR. III NG et RAFALE) avec leur syst~me de commande de vol electrique et leur stabilite artificielle , a achev

Cycle for fuel elements. Uranium production, programs for nuclear power stations and capital expenditure involved; Cycles de combustibles. Production d'uranium, programme de centrales electriques et effort financier correspondant

Energy Technology Data Exchange (ETDEWEB)

Andriot, J.; Gaussens, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

'une des trois filieres suivantes: - filiere uranium naturel-graphite, - filiere uranium naturel-eau lourde, - filiere uranium enrichi-eau legere pressurisee. Tout programme apparaitra donc comme une combinaison des trois programmes simples precedents. On s'est attache en outre a examiner les consequences du recyclage du plutonium dans les diverses filieres. Les puissances electriques installees et les capacites des usines situees en amont ou en aval etant ainsi calculees, on a essaye ensuite de chiffrer le montant des investissements qui serait necessaire pendant les quinze annees en cause pour mettre en place les programmes envisages. Les resultats sont presentes sous la forme d'un echeancier d'investissements. Cette presentation nous semble en effet interessante compte tenu des disponibilites non illimitees en capitaux de la France dans les prochaines annees. (auteur)

Experimental Determination of the Neutron Characteristics of UO{sub 2}-PuO{sub 2}-H{sub 2}O Lattices; Determination Experimentale Des Caracteristiques Neutroniques De Reseaux UO{sub 2}-PuO{sub 2}-H{sub 2}O

Energy Technology Data Exchange (ETDEWEB)

Debrue, J.; Fabry, A.; Leenders, L.; Motte, F.; Van Den Broeck, H. [Centre d' Etude de l' Energie Nucleaire, Mol (Belgium)

1967-09-15

combustibles mixtes UO{sub 2}-PuO{sub 2} enrichis respectivement a 3% {sup 235}U- 1% Pu fissile et 2% {sup 235}U-2% Pu fissile, et d'un combustible UO{sub 2} enrichi a 4% {sup 235}U; les teneurs isotopiques en {sup 240}Pu des deux combustibles mixtes sont en outre nettement differentes, respectivement 7 et 17%. Dans une premiere partie du programme, on etudie des reseaux reguliers dans des coeurs a deux zones cylindriques coaxiales, une zone UO{sub 2}-PuO{sub 2} et une zone UO{sub 2} ; on s'attache particulierement a explorer, de part et d'autre de la frontiere commune a ces deux zones, la region de transition dans laquelle le spectre neutronique evolue entre les distributions energetiques caracteristiques de chacun des deux reseaux. Les resultats experimentaux sont destines a l'etalonnage des methodes de calcul. Dans une seconde partie du programme, on simulera des portions du coeur du reacteur de la centrale SENA afin d'etudier les problemes particuliers au rechargement d'un tiers de ce coeur par du combustible mixte UO{sub 2}-PuO{sub 2}. Parmi les techniques experimentales mises en oeuvre a l'occasion de ces differentes experiences, on met en evidence celles qui sont les plus specifiques de la presence du plutonium: mesure de la densite de fission par comptage direct des produits de fission formes par irradiation dans le combustible mixte, mesure d'indices de spectre au moyen de detecteurs fissiles et de detecteurs presentant des resonances voisines de celles des isotopes du plutonium. Les conditions optimales d'application de ces techniques sont presentees; l'incidence des incertitudes affectant les resultats experimentaux des indices de spectre (rapports de sections efficaces) sur le cycle du combustible est discutee. Enfin, on presente brievement un programme d'essais sous-critiques conduit jusqu'a present sur deux lots de crayons combustibles UO{sub 2} enrichi a 5 et 1% {sup 235}U, dans le but d'etudier les possibilites des methodes consistant a exciter un reseau sous

Study of transient states in thermo-ionic converters; Etude des regimes transitoires des convertisseurs thermoioniques

Energy Technology Data Exchange (ETDEWEB)

Landrot, J. [Commissariat a l' Energie Atomique, 91 - Saclay (France). Centre d' Etudes Nucleaires

1968-07-01

In order to control a thermo-ionic reactor, it is necessary to know the dynamic influence of four fundamental parameters: the injected thermal power, the electrical charge resistance, the temperature of the cesium and the thermal exchange coefficient of the collector cooling circuit. The principles of the thermo-ionic converter are briefly exposed. The over-riding influence of the first two parameters is shown with the help of experimental static readings. These two parameters are then made to vary in turn. The laws of variation as a function of the time, of the electrical power produced and of the temperature of the various parts of the converter are deduced. (author) [French] Pour envisager le controle et la regulation d'un reacteur thermoionique, il est necessaire de connaitre l'influence dynamique de quatre parametres fondamentaux: puissance thermique injectee, resistance electrique de charge, temperature de cesium et coefficient d'echange thermique du circuit de refroidissement du collecteur. On rappelle brievement les principes du convertisseur thermoionique. A l'aide de releves statiques experimentaux, on montre l'influence preponderante des deux premiers parametres. On fait ensuite varier successivement ces deux parametres. On met en evidence les lois de variation en fonction du temps de la puissance electrique produite et de la temperature des differents points du convertisseur. (auteur)

Study of the thermoelectric properties of Pb{sub (1-x)} Sn{sub x} Te; Contribution a l'etude des proprietes thermoelectriques de solutions Pb{sub (1-x)}Sn{sub x} Te

Energy Technology Data Exchange (ETDEWEB)

Borde, D [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-04-15

The present work concerns the study of the electrical properties (thermoelectric power, electrical resistivity and Hall coefficient) of PbTe and SnTe crystals and of solid polycrystalline solutions of Pb{sub 1-x} Sn{sub x} Te (0.1 < x < 0.6) between 80 and 800 deg. K. From the temperature dependence of these properties and the effect of the addition, it has been possible to characterize the semiconductor nature of these solutions, and to approach their band structure; in particular the forbidden gap behaviour in these solutions has been analyzed and evidence for the existence of a double valence band has been obtained. (author) [French] Le present travail est relatif a l'etude des proprietes electriques, en particulier du pouvoir thermoelectrique de la resistivite electrique et du coefficient de Hall, de cristaux PbTe et SnTe, et de solutions solides polycristallines Pb{sub 1-x} Sn{sub x} Te (0,1 {<=} x {<=} 0,6) entre 80 et 800 deg. K. La variation de ces proprietes avec la temperature, ainsi que l'effet de l'addition de Sn sur celles-ci, ont permis de preciser le caractere semiconducteur de ces solutions, et contribue a la determination de leur structure de bandes, en particulier le comportement de la bande interdite dans ces solutions a ete analyse et l'existence d'une double bande de valence mise en evidence. (auteur)

Fabrication et applications des reseaux de Bragg ultra-longs

Science.gov (United States)

Gagne, Mathieu

This thesis presents the principal accomplishments realized during the PhD project. The thesis is presented by publication format and is a collection of four published articles having fiber Bragg gratings as a central theme. First achieved in 1978, UV writing of fiber Bragg gratings is nowadays a common and mature technology being present in both industry and academia. The property of reflecting light guided by optical fibers lead to diverse applications in telecommunication, lasers as well as several types of sensors. The conventional fabrication technique is generally based on the use of generally expensive phase masks which determine the obtained characteristics of the fiber Bragg grating. The fiber being photosensitive at those wavelengths, a periodic pattern can be written into it. The maximal length, the period, the chirp, the index contrast and the apodisation are all characteristics that depend on the phase mask. The first objective of the research project is to be able to go beyond this strong dependance on the phase mask without deteriorating grating quality. This is what really sets apart the technique presented in this thesis from other long fiber Bragg grating fabrication techniques available in the literature. The fundamental approach to obtain ultra long fiber Bragg gratings of arbitrary profile is to replace the scheme of scanning a UV beam across a phase mask to expose a fixed fiber by a scheme where the UV beam and phase mask are fixed and where the fiber is moving instead. To obtain a periodic index variation, the interference pattern itself must be synchronized with the moving fiber. Two variations of this scheme were implanted: the first one using electro-optical phase modulator placed in each arm of a Talbot interferometer and the second one using a phase mask mounted on a piezo electric actuator. A new scheme that imparts fine movements of the interferometer is also implemented for the first time and showed to be essential to achieve high quality ultra long fiber Bragg gratings. High quality theory matching ultra long fiber Bragg gratings up to 1 meter long are obtained for the first time. The possibility of fabricating high quality ultra long fiber Bragg grating of more than 10 cm (approximately the maximal phase mask length) opens a variety of new applications otherwise impossible with short fiber Bragg grating technology. Ultra long fiber Bragg gratings have unique characteristics such as high reflectivity, high dispersion and ultra narrow bandwidth. Those characteristics can be used to do advanced signal processing, non linear propagation experiments, distributed feedback fiber lasers and dispersion compensator for telecommunication or optical tomography. The second objective of this project is to use these ultra-long fiber Bragg gratings as an optical cavity for fiber lasers. Alot of research in the past years have been concentrated on those lasers, particularly on distributed feedback fiber lasers where the gratings spans all the gain media. A new random fiber laser configuration is presented. It is based on passive or active insertion of phase shifts along the Bragg grating to obtained a phenomenon called light localization which is the optical equivalent of Anderson localization. This complex wave phenomenon has the unique property to mimic the reflection of a uniform photonic crystal with the random diffusion of light among the elements of a random media. Being commonly obtained in fine powders which must respect a certain set of rules, the realization of 1D structures is vastly simplified in optical fibers. Two random fiber laser schemes based on light localization, one using erbium dopant and the other one Raman scattering, are demonstrated for the first time and compared to traditional distributed feedback fiber lasers.

Converters and electric machines. Solid insulating materials. Electrical characteristics; Convertisseurs et machines electriques. Materiaux isolants solides. Caracteristiques electriques

Energy Technology Data Exchange (ETDEWEB)

Anton, A. [Institut National Superieur de Chimie Industrielle, 76 - Rouen (France)

2003-08-01

The aim of this article is to allow a preselection of a solid insulating material using the most common electrical characteristics: tangent of the loss angle, relative permittivity, dielectric rigidity, superficial resistivity, transverse resistivity, resistance to high voltage creeping spark currents, index of creeping resistance. The characteristics of the main solid insulating materials are presented in tables for: thermoplastics, thermosetting materials, natural insulating materials, mineral insulating materials, rubber and synthetic elastomers, stratified insulating materials, thermoplastic films, composite synthetic papers. A comparison is made between the different materials using the three properties: tangent of the loss angle, relative permittivity and resistance to HV spark creeping currents. (J.S.)

Structure of simple liquids; Structure des liquides simples

Energy Technology Data Exchange (ETDEWEB)

Blain, J F [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1969-07-01

The results obtained by application to argon and sodium of the two important methods of studying the structure of liquids: scattering of X-rays and neutrons, are presented on one hand. On the other hand the principal models employed for reconstituting the structure of simple liquids are exposed: mathematical models, lattice models and their derived models, experimental models. (author) [French] On presente d'une part les resultats obtenus par application a l'argon et au sodium des deux principales methodes d'etude de la structure des liquides: la diffusion des rayons X et la diffusion des neutrons; d'autre part, les principaux modeles employes pour reconstituer la structure des liquides simples sont exposes: modeles mathematiques, modeles des reseaux et modeles derives, modeles experimentaux. (auteur)

PROCEDE DE GESTION DENERGIE DUN VEHICULE ELECTRIQUE

OpenAIRE

Granato , Giovanni; Zidani , Hasnaa

2013-01-01

L'invention se rapporte à un procédé de gestion d'énergie pour un véhicule électrique, comprenant un calculateur, un moteur électrique, une batterie électrique et un moteur thermique d'appoint utilisant un carburant et conçu pour aider la batterie à faire fonctionner ledit moteur électrique. La principale caractéristique d'un procédé selon l'invention est qu'il comprend les étapes suivantes : - une étape de sélection d'un trajet compris entre un point de départ et un point de destination, - u...

Computing Services and Assured Computing

Science.gov (United States)

2006-05-01

fighters’ ability to execute the mission.” Computing Services 4 We run IT Systems that: provide medical care pay the warfighters manage maintenance...users • 1,400 applications • 18 facilities • 180 software vendors • 18,000+ copies of executive software products • Virtually every type of mainframe and... chocs electriques, de branchez les deux cordons d’al imentation avant de faire le depannage P R IM A R Y SD A S B 1 2 PowerHub 7000 RST U L 00- 00

Increasing the electrical discharge endurance of acid anhydride cured DGEBA epoxy resin by dispersion of nanoparticle silica. High Perform. Polym. 11 (1999) pp 281-296 by IOP Publishing Ltd

DEFF Research Database (Denmark)

Henk, Peter O; Kortsen, T.W.; Kvarts, T.

1999-01-01

combinations were used: (a) fumed nanoparticle silicon dioxide referred to as Aerosil, (b) equal volumes of Aerosil and nanoparticle anatase, and (c) Aerosil plus anatase in combination with coarse-particle filler grade calcium-magnesium carbonate dolomite. A test for endurance using the CIGRE method II...... electrode arrangement was applied, the test comprising the establishment of partial discharges running perpendicularly onto one face of a plate specimen for a period measured until breakdown.Our results show that the endurance of the pure polymer is low. Increased loading with Aerosil increases...... the endurance by a factor of up to 20 as the Aerosil content goes from zero to 5.4 vol%. Aerosil mixed with anatase has a similar effect. The high level of endurance is maintained with an additional high-volume (35 vol.%) filling of coarse-particle dolomite to an epoxy system already containing Aerosil...

Development of a new loss allocation method for a hybrid electricity market using graph theory

International Nuclear Information System (INIS)

Lim, Valerie S.C.; McDonald, John D.F.; Saha, Tapan K.

2009-01-01

This paper introduces a new method for allocating losses in a power system using a loop-based representation of system behaviour. Using the new method, network behaviour is formulated as a series of presumed power transfers directly between market participants. In contrast to many existing loss allocation methods, this makes it easier to justify the resulting loss distribution. In addition to circumventing the problems of non-unique loss allocations, a formalised process of loop identification, using graph theory concepts, is introduced. The proposed method is applied to both the IEEE 14-bus system and a modified CIGRE Nordic 32-bus system. The results provide a demonstration of the capability of the proposed method to allocate losses in the hybrid market, and demonstrate the approach's capacity to link the technical performance of the network to market instruments. (author)

Site selection of active damper for stabilizing power electronics based power distribution system

DEFF Research Database (Denmark)

Yoon, Changwoo; Wang, Xiongfei; Bak, Claus Leth

2015-01-01

electronics based power device, which provides an adjustable damping capability to the power system where the voltage harmonic instability is measured. It can stabilize by adjusting the equivalent node impedance with its plug and play feature. This feature gives many degrees of freedom of its installation......Stability in the nowadays distribution power system is endangered by interaction problems that may arise from newly added power-electronics based power devices. Recently, a new concept to deal with this higher frequency instability, the active damper, has been proposed. The active damper is a power...... point when the system has many nodes. Therefore, this paper addresses the proper placement of an active damper in an unstable small-scale power distribution system. A time-domain model of the Cigre benchmark low-vltage network is used as a test field. The result shows the active damper location...

Control and Automation Systems at the TSO/DSO interface

DEFF Research Database (Denmark)

Silvestro, F.; Pilo, F.; Mauri, G.

2017-01-01

(Distribution Network Operator) have to assure a secure reliable and good power quality, without taking into consideration any real-time operation of the active components present in their systems. In order to accomplish their missions, DNOs will have to exploit the support of control and automation systems...... and protection systems, but also “external inputs” coming from the Transmission Networks (operated by the Transmission System Operator) and the forthcoming “smart world” (i.e. smart cities, smart transports, smart industries, smart customers etc.). The processing of all such inputs will still have...... to be subordinated to the possibility for Distribution Companies to operate their network under their ultimate responsibility (DSO – Distribution System Operators). This paper presents an overview of the activities of CIGRE C6.25 Working Group (JWG), focusing on the control and automation systems for the future...

Managing high penetration of renewable energy in MV grid by electric vehicle storage

DEFF Research Database (Denmark)

Kordheili, Reza Ahmadi; Bak-Jensen, Birgitte; Pillai, Jayakrishnan Radhakrishna

2015-01-01

This paper proposes an intelligent algorithm for dealing with high penetration of renewable energy sources (RESs) in the medium voltage by intelligently managing electric vehicles (EVs), as one of the grid flexible loads. The MV grid used in this work is a CIGRE benchmark grid. Different...... residential and industrial loads are considered in this grid. The connection of medium voltage wind turbines to the grid is investigated. The solar panels in this study are residential panels. Also, EVs are located among the buses with residential demand. The study is done for different winter and summer...... scenarios, considering typical load profiles in Denmark. Different scenarios have been studied with different penetration level of RESs in the grid. The results show the capability of the proposed algorithm to reduce voltage deviations among the grid buses, as well as to increase the RES penetration...

Effect of a non lethal whole-body gamma irradiation on the spontaneous and evoked electroencephalographic activities of the adult rabbit; Effets d'une irradiation gamma globale non letale sur les activites electroencephalograpiques spontanees et evoquees du lapin adulte

Energy Technology Data Exchange (ETDEWEB)

Court, L [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1969-07-01

The whole of the experimental methods described (animal preparation, achievement of a precise physiological technique, dosimetry, biological information processing) allowed us to follow the changes for 15 days in the spontaneous and evoked electroencephalogram activities of rabbits submitted to a non-lethal 400 rads whole-body gamma-irradiation. Behavioural troubles, changes in the arousal state and the spontaneous electrical activity of the neo-cortex and hippocampus were noticed constantly together with an enhanced cortical excitability, and the appearance of elements of the paroxystic series sometimes in contrast with a general decrease in amplitude. After a visual stimulus the general morphology of evoked activities at the level of the primary visual areas and hippocampus was unchanged, but enhanced latencies and delays, less systematic modifications in amplitudes seemed to show out a direct effect of radiations on the nervous system and sensorial activities; these troubles seemed to occur independently from the basic electrical activity. As a whole, the changes observed were usually transitory and varied with each individual. Finally an assumption is made to explain the mechanism of arousal troubles and the general evolution of spontaneous electrical activity in the brain. (author) [French] 'L'ensemble des methodes experimentales decrites (preparation des animaux, mise au point d'une technique physiologique precise, dosimetrie, traitement de l'information biologique) a permis de suivre, pendant 15 jours, chez le lapin soumis a une irradiation gamma globale non letale de 400 rads, les modifications des activites electroencephaliques spontanees et evoquees. De facon constante, on note des troubles du comportement, des modifications de la vigilance et de l'activite electrique spontanee du neo-cortex et de l'hippocampe, ainsi qu'une augmentation de l'excitabilite corticale, l'apparition d'elements de la serie paroxystique contrastant parfois avec une diminution

Improvements in the electromechanical conversion of energy using shock waves; Contribution a la conversion d'energie electromecanique par onde de choc

Energy Technology Data Exchange (ETDEWEB)

Landure, Yves

1971-10-21

This report concerns the electrical mechanical conversion. In this study it was obtained by the depolarization of a ferroelectric ceramic. We are particularly interested by the high electrical horse-power. Shock wave which produces depolarization is created by a gun powder. The speed of the projectile is measured and the pressures generated in the ceramic is determined graphically. The energy freed is released on a linear resistive load. We were able to prove by different parameters how to obtain the maximum electrical energy. On a resistive load of 26 ohms, it was freed 0,91 J/cm{sup 3} in less than 0,5 μs corresponding to an electrical horse-power superior to 2 MW/cm{sup 3}. (author) [French] Ce rapport concerne la conversion d'energie electro-mecanique. Dans cette etude elle est obtenue par la depolarisation d'une ceramique ferro-electrique. Nous nous sommes interesses tout particulierement aux fortes puissances. L'onde de pression produisant la depolarisation est creee par l'impact d'un projectile lance par un canon a poudre. La vitesse du projectile est mesuree et la pression engendree dans la ceramique est determinee graphiquement. L'energie liberee est recueillie sur une impedance de charge lineaire. On a pu mettre en evidence differents parametres permettant d'obtenir l'energie electrique maximale. Sur une charge resistive de 26 ohms, il a ete libere 0,91 j/cm{sup 3} en moins de 0,5 μs, soit une puissance superieure a 2 MW/cm{sup 3}. (auteur)

DISCRETION MAGNETIQUE DES MACHINES ELECTRIQUES DE PROPULSION NAVALE

OpenAIRE

Froidurot , Benoît

2002-01-01

For about ten years, electrical machines have been commonly used in naval propulsion systems for civilian applications. This is mainly due to new magnetic materials (magnets...) and power drive electronic, which increase the performances of the machines. This kind of propulsion is planed to be implemented on military ships. However, some constraints of discretion make this propulsion require specific systems for the ship security. This study is then dedicted to the magnetic discretion of nava...

Les brulures electriques chez les voleurs de cuivre

Science.gov (United States)

Belmir, R.; Fejjal, N.; Achbouk, H.; El Mazouz, S.; Gharib, N.; Abassi, A.; Belmahi, A.

2011-01-01

Summary Les vols de biens fabriqués avec le cuivre semblent en hausse depuis un certain temps du fait de son prix élevé de revente, ce qui est à l’origine d’une augmentation du nombre d’accidents électriques par haut voltage (AEHV) qui sont graves du fait des brûlures profondes qu’elles provoquent le long des axes vasculo-nerveux. Les Auteurs rapportent une série de neuf cas d’AEHV traités au service de chirurgie plastique et de brûlés de l’Hôpital Ibn Sina de Rabat, Maroc, à travers laquelle ils étudient les caractéristiques épidémiologiques, cliniques et thérapeutiques. La population intéressée était jeune et active. Les brûlures étaient secondaires à un contact avec des câbles à haute tension lors de tentatives de vol par arrachement de conducteurs en cuivre dans les transformateurs dans 67% des cas, et lors de tentatives de coupure de caténaires alimentant les trains électriques sur le réseau ferroviaire dans 33% des cas. Le traitement des lésions électrothermiques a nécessité des interventions itératives avec amputation et désarticulation des segments de membres nécrosés dans 66% des cas, dont les suites étaient marquées par des séquelles fonctionnelles invalidantes. La prévention de ce type d’AEHV reste fondamentale. PMID:22262961

Electrical properties of airborne nanoparticles produced by a commercial spark-discharge generator

Energy Technology Data Exchange (ETDEWEB)

Bau, S., E-mail: sebastien.bau@inrs.fr; Witschger, O. [Laboratoire de Metrologie des Aerosols, Institut National de Recherche et de Securite, INRS (France); Gensdarmes, F. [IRSN, Laboratoire de Physique et de Metrologie des Aerosols, Institut de Radioprotection et de Surete Nucleaire (France); Thomas, D. [LSGC/CNRS, Nancy Universite, Laboratoire des Sciences du Genie Chimique (France); Borra, J.-P. [Equipe Decharges Electriques et Procedes Aerosols, Laboratoire de Physique des Gaz et des Plasmas (France)

2010-08-15

A nanoparticle generator based on the principle of electrical discharge (PALAS GFG-1000) was used to produce nanoparticles of different chemical natures. The fractions of electrically neutral particles were then measured by means of a Spectrometre de Mobilite Electrique Circulaire (SMEC, i.e. radial-flow mobility analyzer) for different operating conditions. The experimental results were compared with the theoretical values calculated from the Fuchs extended charge equilibrium model for spherical particles and agglomerates. For the smallest particles (below 20 nm), the deviations observed remain below 10%, and tend towards 20% for larger particles (over 35 nm).

Effect of a non lethal whole-body gamma irradiation on the spontaneous and evoked electroencephalographic activities of the adult rabbit; Effets d'une irradiation gamma globale non letale sur les activites electroencephalograpiques spontanees et evoquees du lapin adulte

Energy Technology Data Exchange (ETDEWEB)

Court, L. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1969-07-01

The whole of the experimental methods described (animal preparation, achievement of a precise physiological technique, dosimetry, biological information processing) allowed us to follow the changes for 15 days in the spontaneous and evoked electroencephalogram activities of rabbits submitted to a non-lethal 400 rads whole-body gamma-irradiation. Behavioural troubles, changes in the arousal state and the spontaneous electrical activity of the neo-cortex and hippocampus were noticed constantly together with an enhanced cortical excitability, and the appearance of elements of the paroxystic series sometimes in contrast with a general decrease in amplitude. After a visual stimulus the general morphology of evoked activities at the level of the primary visual areas and hippocampus was unchanged, but enhanced latencies and delays, less systematic modifications in amplitudes seemed to show out a direct effect of radiations on the nervous system and sensorial activities; these troubles seemed to occur independently from the basic electrical activity. As a whole, the changes observed were usually transitory and varied with each individual. Finally an assumption is made to explain the mechanism of arousal troubles and the general evolution of spontaneous electrical activity in the brain. (author) [French] 'L'ensemble des methodes experimentales decrites (preparation des animaux, mise au point d'une technique physiologique precise, dosimetrie, traitement de l'information biologique) a permis de suivre, pendant 15 jours, chez le lapin soumis a une irradiation gamma globale non letale de 400 rads, les modifications des activites electroencephaliques spontanees et evoquees. De facon constante, on note des troubles du comportement, des modifications de la vigilance et de l'activite electrique spontanee du neo-cortex et de l'hippocampe, ainsi qu'une augmentation de l'excitabilite corticale, l'apparition d'elements de la serie

Influence of Nanosilica Filler Content in LDPE Composites on Partial Discharge Characteristics

Institute of Scientific and Technical Information of China (English)

Z. Abdul-Malek; A.M. Azzin; Y.Z. Ariel; Aulia; K.Y. Lau; M. Jaafar

2011-01-01

Partial discharges （PDs） due to artificial void in samples of LDPE nanocomposite sheet have been investiga- ted in this work. PDs may cause the degradation of insulating materials and may affect the lifetime of high-voltage ap- paratus. An experimental work using sphere ball-plane electrode system （CIGRE Method II） and a 1.0 mm LDPE composite sheet was carried out. Different weight percentages of nanosilica （0%, 2%, 4%, 6% and 8%） were used. PD experimental results, such as PD magnitude and PD number （both PD pulse polarities）, as functions of the ap- plied stress duration at a specified applied voltage were compared. The surface morphology of specimens was also presented and this conforms to the PD findings. The experimental results show that the PD characteristics of the LDPE generally improve with the introduction of nanosilica, the composite with the highest content of filler, namely the 8% （wt） nanosilica sample has the least partial discharge activities.

Power system technical performance issues related to the application of long HVAC cables

DEFF Research Database (Denmark)

Wiechowski, on behalf of Cigre WG C4.502, W.; Sluis, L. V. der; Ohno, Teruo

2011-01-01

This paper reports the progress of work of Cigre Working Group C4.502 “Power system technical performance issues related to the application of long HVAC cables”. The primary goal of the WG C4.502 is to write a technical brochure that will serve as practical guide for performing studies necessary...... for assessing the technical performance of HV/EHV systems with large share of AC cable lines. This paper besides providing a background for formulation of WG C4.502 and its overall aim, describes the tasks that were accomplished before the interim report was submitted to Study Committee C4 System Technical...... Performance in August 2010. The work in the WG is ongoing and final report will be ready according to the time schedule in 2012. The focus of this paper is in particular to show all issues related to system technical performance with assigned weights in terms of their importance and/or uniqueness for cable...

Pay-as-bid based reactive power market

International Nuclear Information System (INIS)

Amjady, N.; Rabiee, A.; Shayanfar, H.A.

2010-01-01

In energy market clearing, the offers are stacked in increasing order and the offer that intersects demand curve, determines the market clearing price (MCP). In reactive power market, the location of reactive power compensator is so important. A low cost reactive producer may not essentially be favorable if it is far from the consumer. Likewise, a high cost local reactive compensator at a heavily loaded demand center of network could be inevitably an alternative required to produce reactive power to maintain the integrity of power system. Given the background, this paper presents a day-ahead reactive power market based on pay-as-bid (PAB) mechanism. Generators expected payment function (EPF) is used to construct a bidding framework. Then, total payment function (TPF) of generators is used as the objective function of optimal power flow (OPF) problem to clear the PAB based market. The CIGRE-32 bus test system is used to examine the effectiveness of the proposed reactive power market.

Pay-as-bid based reactive power market

Energy Technology Data Exchange (ETDEWEB)

Amjady, N. [Department of Electrical Engineering, Semnan University, Semnan (Iran, Islamic Republic of); Rabiee, A., E-mail: Rabiee@iust.ac.i [Center of Excellence for Power System Automation and Operation, Department of Electrical Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Shayanfar, H.A. [Center of Excellence for Power System Automation and Operation, Department of Electrical Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of)

2010-02-15

In energy market clearing, the offers are stacked in increasing order and the offer that intersects demand curve, determines the market clearing price (MCP). In reactive power market, the location of reactive power compensator is so important. A low cost reactive producer may not essentially be favorable if it is far from the consumer. Likewise, a high cost local reactive compensator at a heavily loaded demand center of network could be inevitably an alternative required to produce reactive power to maintain the integrity of power system. Given the background, this paper presents a day-ahead reactive power market based on pay-as-bid (PAB) mechanism. Generators expected payment function (EPF) is used to construct a bidding framework. Then, total payment function (TPF) of generators is used as the objective function of optimal power flow (OPF) problem to clear the PAB based market. The CIGRE-32 bus test system is used to examine the effectiveness of the proposed reactive power market.

Applications of electrical resistivity measurements to research into the purification of uranium using floating molten zone by electronic bombardment; Applications des mesures de resistivite electrique a l'etude de la purification de l'uranium par fusion de zone flottante par bombardement electronique

Energy Technology Data Exchange (ETDEWEB)

Pascal, J L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-02-01

un examen micrographique, des mesures de microdurete et des essais de recristallisation secondaire, a permis d'apprecier le nouveau degre de purete de l'uranium obtenu. L'examen de ce degre de purete a ete poursuivi par des mesures de resistivite electrique a 20 deg. K. Mais on a du tenir compte dans l'interpretation de ces mesures, de l'anisotropie de resistivite de l'uranium {alpha} a 20 deg. C et de l'influence de l'etat structural sur la resistivite residuelle. Ces mesures ont conduit, en determinant les resistivires de monocristaux d'uranium {alpha}, a distinguer les resistivites principales suivant les axes [100] et [010]. (auteur)

Possibility of using radioactivity control measurements for determining contamination paths in nutritional vectors; Etude des possibilites d'utilisation des resultats de la surveillance de la radioactivite pour la recherche des trajectoires d'evolution de la contamination des vecteurs alimentaires

Energy Technology Data Exchange (ETDEWEB)

Garnier, A [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1966-07-01

The object of the report is to study the possibility of using results of radioactivity controls for determining the paths followed by contamination in nutritional vectors; these are necessary for calculating protection norms. Radioactive contamination of a nutritional vector is expressed in terms of parameters which suggest that a certain number of criteria may be used for choosing the results which are to be exploited. An actual example of a 'vertical' study based on results of measurements made purely for control purposes shows the difficulties which may be encountered. A list of the results obtained by the control networks set up in the Community Countries, either for the atmosphere, for milk, or for other foodstuffs, shows that these networks are not at the present organised in such a way as to make such a study possible. It appears desirable that a large part of the work carried out by the control Services be oriented in such a way as to yield the complementary information required for experimental studies of radioactive contamination transfers. (author) [French] L'objet du rapport est l'examen des possibilites d'utilisation des resultats de la surveillance de la radioactivite pour la recherche des trajectoires d'evolution de la contamination des vecteurs alimentaires, necessaires au calcul des niveaux de protection. La contamination radioactive d'un vecteur alimentaire s'exprime en fonction de parametres, qui suggerent de retenir un certain nombre de criteres pour la selection des resultats a exploiter. Un exemple concret d'etude 'verticale' basee sur des resultats de mesures faites uniquement dans un but de controle met en evidence les difficultes rencontrees. L'inventaire des resultats obtenus par les reseaux de controle des differents Pays de la Communaute, soit pour l'atmosphere, soit pour le lait, soit pour d'autres aliments, montre que ces reseaux ne sont pas actuellement organises de facon a permettre de telles etudes, Il parait souhaitable qu

Prediction du profil de durete de l'acier AISI 4340 traite thermiquement au laser

Science.gov (United States)

Maamri, Ilyes

Les traitements thermiques de surfaces sont des procedes qui visent a conferer au coeur et a la surface des pieces mecaniques des proprietes differentes. Ils permettent d'ameliorer la resistance a l'usure et a la fatigue en durcissant les zones critiques superficielles par des apports thermiques courts et localises. Parmi les procedes qui se distinguent par leur capacite en terme de puissance surfacique, le traitement thermique de surface au laser offre des cycles thermiques rapides, localises et precis tout en limitant les risques de deformations indesirables. Les proprietes mecaniques de la zone durcie obtenue par ce procede dependent des proprietes physicochimiques du materiau a traiter et de plusieurs parametres du procede. Pour etre en mesure d'exploiter adequatement les ressources qu'offre ce procede, il est necessaire de developper des strategies permettant de controler et regler les parametres de maniere a produire avec precision les caracteristiques desirees pour la surface durcie sans recourir au classique long et couteux processus essai-erreur. L'objectif du projet consiste donc a developper des modeles pour predire le profil de durete dans le cas de traitement thermique de pieces en acier AISI 4340. Pour comprendre le comportement du procede et evaluer les effets des differents parametres sur la qualite du traitement, une etude de sensibilite a ete menee en se basant sur une planification experimentale structuree combinee a des techniques d'analyse statistiques eprouvees. Les resultats de cette etude ont permis l'identification des variables les plus pertinentes a exploiter pour la modelisation. Suite a cette analyse et dans le but d'elaborer un premier modele, deux techniques de modelisation ont ete considerees, soient la regression multiple et les reseaux de neurones. Les deux techniques ont conduit a des modeles de qualite acceptable avec une precision d'environ 90%. Pour ameliorer les performances des modeles a base de reseaux de neurones, deux

Study of the injection of plasma into a magnetic field of double curvature geometry; Etude de l'injection de plasma dans un champ magnetique a double courbure

Energy Technology Data Exchange (ETDEWEB)

Lasry, J [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1967-06-15

An hydrogen plasma puff is injected along the lines of a magnetic field with a double curvature geometry. The plasma is produced by a coaxial gun with an annular preionization system. It is shown theoretically that the electric drift of the plasma can be cancelled if a depolarizing current flows along the field lines towards a region of good transverse conductivity. The experiment shows that in these conditions the curvature drift of the ions of the plasma may be used as a very efficient process to purify the fast component of the plasma puff. The depolarizing electron currents are measured and the mutual cancellation of the electric fields developing into the oppositely curved region is demonstrated to be possible. The current densities agree with the values deduced of the curvature drift of the ions. (author) [French] Un plasma d'hydrogene est injecte le long des lignes de force d'un champ magnetique a double courbure. Le plasma est produit par un canon coaxial a preionisation annulaire. Il est montre theoriquement que la derive electrique du plasma peut etre annulee si un courant de depolarisation circule le long des lignes de force vers une region de conductivite transversale elevee. L'experience montre que dans ces conditions, la derive de courbure des ions peut etre utilisee comme un moyen efficace de purification de la composante rapide du plasma. Les courants electroniques de depolarisation sont mesures et l'annulation mutuelle des champs electriques se developpant dans les regions de courbures opposees est demontree. Les densites de courant sont en accord avec les valeurs deduites de la derive de courbure des ions. (auteur)

An intense plane-beam ion source (1963); Source d'ions intense a faisceau plan (1963)

Energy Technology Data Exchange (ETDEWEB)

Deicas, R; Valckx, F P.O. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1963-07-01

Experiments are described carried out on the cross-section of a Penning type ion source which is a prototype of the annular ion source intended for the M.M.I.I. device at the Fontenay-aux-Roses Nuclear Research Centre. It is shown that the existence or absence of a very strong concentration depends in particular on the magnetic geometry. With a suitable magnetic and electrical geometry it is possible to concentrate the discharge towards the slit and thus to increase considerably the electrical yield and the gas yield. In pulsed conditions, the current derived from this source can exceed 100 mA with a slit 20 cm long and 0.2 mm wide. The gas yield can attain 20 per cent. The main characteristics of the discharge and of the beam are examined. (authors) [French] On decrit les experiences faites sur une section droite d'une source d'ions type Penning, qui est un prototype pour une source d'ions annulaire, destine au dispositif M.M.I.I. au Centre d'Etudes Nucleaires de Fontenay-aux-Roses. On montre que l'existence ou non d'un regime intense depend surtout de la geometrie magnetique. Avec une geometrie magnetique et electrique convenables on peut concentrer la decharge vers les levres et ainsi augmenter considerablement le rendement electrique et le rendement en gaz. En regime pulse le courant extrait de cette source peut depasser 100 mA avec une fente de 20 cm de long et 0. 2 mm de largeur. Le rendement en gaz peut atteindre 20 pour cent. On etudie les principales caracteristiques de la decharge et du faisceau. (auteurs)

Analysis of resonances due to 'S' neutrons in experiments on transmission by time-of-flight. 1. without the interference term; Analyse des resonances dues aux neutrons 'S' dans les experiences de transmission par temps de vol. 1. sans terme d'interference

Energy Technology Data Exchange (ETDEWEB)

Corge, C R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

Various methods of transmission resonance analysis for 's' wave neutrons in time of flight experiments are described in this report. Only the case when the interference term can be neglected is treated in this first part. Results are given relative to a more complete partial area method and also to a new method so-called the width at half depth method. (author) [French] Le present rapport est consacre a l'expose de differentes methodes d'analyse des resonances dues aux neutrons d'ondes 's' dans les experiences de transmission par temps de vol, cette premiere partie traitant uniquement le cas ou l'on peut negliger le terme d'interference. Y figurent en particulier sous forme de reseaux de courbes, les resultats relatifs a une methode des aires partielles amelioree et ceux relatifs a une nouvelle methode dite de la largeur a mi-profondeur. (auteur)

Presentation of RTE results 2003; Bilan electrique francais 2003

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

In 2003, RTE recorded a clear improvement in its financial results, and continued its debt reduction programme. The financial year 2003 was marked by a clear improvement in RTE's financial performance: results exceeded objectives, with turnover growing strongly, net income reached levels almost three times higher than those recorded in 2002, the economic rate of return rose to 7.1%, and debt was reduced by 470 Meuros. These results are explained by the substantial improvement in productivity, which has risen by 5% per year on average over the last three years. Net income has almost tripled due to RTE's improved productivity completed by a significant rise in its turnover and stabilizing operating costs RTE's finances therefore remain healthy, enabling the company to continue its debt reduction programme. Satisfactory economic and financial rates of return. Deadlines facing RTE in 2004: in application of the second European Directive, adopted on 26 June 2003, RTE faces two major deadlines in 2004: - the implementation of the 2. phase in the process of opening up the French electricity market, - its legal independence. On 1 July 2004, the market will be opened up to competition for all professional customers. At that date RTE, like all other electricity transmission system operators (TSOs) in the European Union, should be a legally independent body. The new central role of TSOs in Europe: how are electricity transmission system operators in other EU countries organised?.

Models for the control of electric actuators (EGEM, electrical engineering series); Modeles pour la commande des actionneurs electriques (Traite EGEM, serie Genie electrique)

Energy Technology Data Exchange (ETDEWEB)

Louis, J.P.

2004-07-01

The modeling of a system to be automatized is a key step for the determination of the control laws because these laws are based on inverse models deduced from direct models. The ideal example is the DC actuator, the simpleness of which allows to directly shift from the modeling to the control law. For AC actuators, the modeling tools are based on the classical hypotheses: linearity, first harmonics, symmetry. They lead to very efficient models which allow to study the properties in dynamical and permanent regime of the most important actuators: synchronous motors, asynchronous motors, voltage inverters. Some extensions to other kind of machines which does not fulfill the classical hypotheses are also proposed: synchronous machines with non-sinusoidal field distribution and asynchronous machines in saturated regime. (J.S.)

Optimum input leads for cryogenic apparatus; Optimisation des descentes de courant dans des enceintes cryogeniques

Energy Technology Data Exchange (ETDEWEB)

Der Nigohossian, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-02-15

The electrical leads used to introduce a current into a cryostat cause a heat influx due to thermal conduction and to Joule heating. It is very important to be able to minimize this flux. Theoretical calculation of optimized leads takes into account the varying heat and electrical conductivities of the leads as well as the heat exchange coefficient with the effluent gas. Practical results have been summarized in different tables which permit for a specific material i.e. copper, aluminium, brass, stainless steel with the intensity and end temperatures being known (i.e. 4,2 or 18,5 deg. K at the cold end; 77,295 or 320 deg. K at the warm end) to deduce the minimum heat flow and the length-cross section ratio of the optimized leads. A general method is indicated, which would allow to solve the same problem for other materials. (author) [French] Les conducteurs electriques assurant la liaison d'appareillages situes dans des cryostats apportent tant par effet Joule que par conductibilite thermique une certaine quantite de chaleur qu'il est tres important de pouvoir minimiser. L'etude theorique de l'optimisation des descentes de courant tient compte des variations des conductibilites thermique et electrique ainsi que de l'influence des echanges avec le gaz. Pratiquement les resultats ont ete resumes dans differents tableaux ce qui permet, pour un materiau donne tel que cuivre, aluminium, laiton, acier inoxydable, connaissant l'intensite et les temperatures d'extremites 4,2 et 18,5 deg. K d'une part, et 77,295 et 330 deg. K d'autre part, de deduire la consommation minimale et le rapport longueur-section d'un conducteur optimise. Une methode generale est indiquee, qui permet de resoudre le probleme pour d'autres materiaux. (auteur)

A Framework for Network Visualisation (Un Cadre Pour la Visualisation des Reseaux)

Science.gov (United States)

2010-02-01

Consider, for example, the passenger transportation network. Two hundred years ago it had no railways and what little intercity travel there was went by...road; one hundred years ago most intercity travel was by a vast rail network, and there was no air traffic; starting perhaps fifty years ago, rail...archaeological interest, and so forth. Exactly where between towns a road is laid may make no difference to a traveller , but it does make a difference to the

Interactive Visualization of Network Dynamics (Visualisation interactive de la dynamique des reseaux)

Science.gov (United States)

2014-06-01

colour coding. The group factor f determines the structure of the hypernode and must be set with careful consideration in respect to the...reference. In experimental psychology it is a well accepted procedure to divide the frames of references into two categories: An egocentric reference...there is almost no colour contrast. For this reason the curvature and feature edges of a surface are harder to recognize and a matching between the

Graphite reactor physics; Physique des piles a graphite

Energy Technology Data Exchange (ETDEWEB)

Bacher, P; Cogne, F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Noc, B [Electricite de France (EDF), 75 - Paris (France)

1964-07-01

physique des piles de puissance a graphite et uranium naturel se poursuit depuis parallelement au developpement de ce type de piles. L'etude systematique des proprietes des reseaux en fonction du pas, de la geometrie du combustible et du diametre des canaux de refroidissement a pu etre entreprise a partir de 1960 grace a l'empilement critique MARIUS. Cette etude a permis de couvrir un domaine tres etendu: pas variant de 19 a 38 cm, barreaux et tubes d'uranium dont les sections droites vont de 6 a 35 cm{sup 2}, canaux dont le diametre est compris entre 70 et 140 mm. On a pu ainsi verifier, et au besoin adapter, les methodes de calcul de reseaux. Le fonctionnement des piles de Marcoule, ainsi que les experiences effectuees sur ces piles au cours des dernieres annees, ont apporte des renseignements precieux sur l'evolution globale des proprietes neutroniques du combustible en fonction de l'irradiation. Des experiences plus precises ont egalement ete faites dans MARIUS avec des combustibles contenant du plutonium (combustibles irradiee ou reconstitues), et seront entreprises des le debut 1965 en temperature dans l'empilement critique CESAR, dont la construction s'acheve a Cadarache. Les analyses des combustibles irradies permettent de completer ces resultats et de faciliter leur interpretation. Il sera ainsi possible de verifier dans tout le domaine utile de temperature les theories de thermalisation et de spectres developpees en France. L'efficacite de barres de controle en fonction de leurs dimensions, des materiaux les constituant, et des reseaux les environnant a ete mesuree dans MARIUS, et les resultats ont ete confrontes d'une part avec le calcul, d'autre part avec les mesures effectuees dans EDF 1. Les etudes du controle proprement dit des piles a graphite ont porte essentiellement sur les risques d'instabilites spatiales, et sur les moyens de les deceler et de les combattre, ainsi que sur les deformations du flux provoquees par les barres de controle. (auteurs)

Developpement d'une methode calorimetrique de mesure des pertes ac pour des rubans supraconducteurs a haute temperature critique

Science.gov (United States)

Dolez, Patricia

Le travail de recherche effectue dans le cadre de ce projet de doctorat a permis la mise au point d'une methode de mesure des pertes ac destinee a l'etude des supraconducteurs a haute temperature critique. Pour le choix des principes de cette methode, nous nous sommes inspires de travaux anterieurs realises sur les supraconducteurs conventionnels, afin de proposer une alternative a la technique electrique, presentant lors du debut de cette these des problemes lies a la variation du resultat des mesures selon la position des contacts de tension sur la surface de l'echantillon, et de pouvoir mesurer les pertes ac dans des conditions simulant la realite des futures applications industrielles des rubans supraconducteurs: en particulier, cette methode utilise la technique calorimetrique, associee a une calibration simultanee et in situ. La validite de la methode a ete verifiee de maniere theorique et experimentale: d'une part, des mesures ont ete realisees sur des echantillons de Bi-2223 recouverts d'argent ou d'alliage d'argent-or et comparees avec les predictions theoriques donnees par Norris, nous indiquant la nature majoritairement hysteretique des pertes ac dans nos echantillons; d'autre part, une mesure electrique a ete realisee in situ dont les resultats correspondent parfaitement a ceux donnes par notre methode calorimetrique. Par ailleurs, nous avons compare la dependance en courant et en frequence des pertes ac d'un echantillon avant et apres qu'il ait ete endommage. Ces mesures semblent indiquer une relation entre la valeur du coefficient de la loi de puissance modelisant la dependance des pertes avec le courant, et les inhomogeneites longitudinales du courant critique induites par l'endommagement. De plus, la variation en frequence montre qu'au niveau des grosses fractures transverses creees par l'endommagement dans le coeur supraconducteur, le courant se partage localement de maniere a peu pres equivalente entre les quelques grains de matiere

Evaluation experimentale et theorique du comportement a la flexion de nouveaux poteaux en materiaux composites

Science.gov (United States)

Metiche, Slimane

La demande croissante en poteaux pour les differents reseaux d'electricite et de telecommunications a rendu necessaire l'utilisation de materiaux innovants, qui preservent l'environnement. La majorite des poteaux electriques existants au Canada ainsi qu'a travers le monde, sont fabriques a partir de materiaux traditionnels tel que le bois, le beton ou l'acier. Les motivations des industriels et des chercheurs a penser a d'autres solutions sont diverses, citons entre autre: La limitation en longueur des poteaux en bois ainsi que la vulnerabilite des poteaux fabriques en beton ou en acier aux agressions climatiques. Les nouveaux poteaux en materiaux composites se presentent comme de bons candidats a cet effet, cependant; leur comportement structural n'est pas connu et des etudes theoriques et experimentales approfondies sont necessaires avant leur mise en marche a grande echelle. Un programme de recherche intensif comportant plusieurs projets experimentaux, analytiques et numeriques est en cours a l'Universite de Sherbrooke afin d'evaluer le comportement a court et a long termes de ces nouveaux poteaux en Polymeres Renforces de Fibres (PRF). C'est dans ce contexte que s'inscrit la presente these, et notre recherche vise a evaluer le comportement a la flexion de nouveaux poteaux tubulaires coniques fabriques en materiaux composites par enroulement filamentaire et ce, a travers une etude theorique, ainsi qu'a travers une serie d'essais de flexion en "grandeur reelle" afin de comprendre le comportement structural de ces poteaux, d'optimiser la conception et de proposer une procedure de dimensionnement pour les utilisateurs. Les poteaux en Polymeres Renforces de Fibres (PRF) etudies dans cette these sont fabriques avec une resine epoxyde renforcee de fibres de verre type E. Chaque type poteaux est constitue principalement de trois zones ou les proprietes geometriques (epaisseur, diametre) et les proprietes mecaniques sont differentes d'une zone a l'autre. La difference

Variable speed electrical driving systems; Entrainements electriques a vitesse variable

Energy Technology Data Exchange (ETDEWEB)

Bonal, J. [ESE, Promethee, Groupe Schneider (France)

1997-12-31

This book is the first of a series of 3 volumes which synthesize the most recent knowledge on variable speed electrical driving systems. It is devoted to electronic and electromechanical engineers and technicians and to manufacturers of electrical equipments involving such systems. after a recall of basic electrotechnical and mechanical notions, this book focusses on the functionalities and criteria of definition of driving systems, and shows the interactions between the different parts of these equipments. It develops a methodological approach of the choice for the most suitable technology with respect to the application under consideration. Various industrial sectors are concerned and a particular attention is paid to the driving of receptive turbo-machineries which play a major role in the energy balance sheet of the industrial electrical power force. (J.S.) 28 refs.

Electrical energy in France 2002; Energie electrique en France 2002

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-12-01

This report presents the provisional results of power flows on the French power system (RTE) in 2002: generation, national consumption, physical exchanges with foreign countries (instantaneous exchange balances measured by metering on each interconnection line, recorded as imports or exports, depending on the sign), adjusted consumption (for climate contingencies and leap years), energy balance (generated and imported, consumed), noteworthy data (all flows on the RTE network as well as generation auto-consumed by the industrial customers connected to this network), electricity market (contractual exchanges with foreign countries, base load blocks exchanged between balance responsible entities), power facilities (thermal, hydro-, transmission lines), main transmission facilities commissioned during the year (interconnections between France and Spain, Italy, Germany and Belgium). (J.S.)

Electrical equipment service. 1997-1998; Service materiel electrique. 1997-1998

Energy Technology Data Exchange (ETDEWEB)

1997-12-31

This brochure edited by the electrical equipment service from the direction of studies and researches (DER) of Electricite de France (EdF) presents some of their remarkable realizations in the domain of energy, their expertise activity in attendance on electricity producers, forwarders and distributors, their expertise activity in attendance on industrialists, and the know-how of their testing laboratories in attendance on designers and operators. (J.S.)

Electric-powered vehicles in Italy; Les vehicules electriques en Italie

Energy Technology Data Exchange (ETDEWEB)

Bordel, St.; Carles, R.

2003-09-01

The aim of this study is to make a synthesis about the development of electric-powered vehicles, in particular in Italy. After a brief historical review of this type of propulsion system, a state-of-the-art review is made which allows to show up the different existing architectures and their characteristic specificities. This review allows to identify the key scientific and technical domains in the existing research programs in progress in order to make these 'alternative' transportation systems economically viable. The second part of the study explains the situation of Italy with respect to these propulsion systems. The political commitments are analyzed first and then some of the university and industry centers of competences for these key domains are presented. Finally, some trans-national collaborations in progress are shown. (J.S.)

Of floating-zone uranium; Sur l'uranium de zone flottante

Energy Technology Data Exchange (ETDEWEB)

Clottes, G [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1965-01-01

to 30 ppm of soluble impurities in the refined metal. (author) [French] La methode de la zone flottante a ete choisie pour purifier l'uranium. Les differents parametres qui interviennent dans cette technique de purification ont ete etudies par des considerations theoriques et technologiques. On montre que la vitesse la plus rentable de deplacement de zone fondue est de 0,7 cm par heure, que le sens de deplacement ne peut etre que de bas en haut, et que la fusion doit s'effectuer sous des pressions de l'ordre de 10{sup -7} Torr. Outre ces problemes relatifs a la purification, l'etude de la stabilite de la zone flottante nous a conduits a definir un domaine de variations des diametres et hauteurs de gouttes, repondant aux conditions d'Heywang d'une part, et d'autre part, compatible avec une fusion a coeur du barreau. Ce domaine montre que la zone flottante est facilement applicable a des barreaux dont le diametre est compris entre 5 et 10 mm, et qu'elle est inapplicable si le diametre est superieur a 21 mm. L'appareillage, constitue par un dispositif de chauffage par bombardement electronique sous ultra-vide, est conditionne par les differents parametres etudies. A defaut de bons resultats d'analyse, l'uranium ainsi traite a ete caracterise par des tests metallurgiques et physiques: des examens micrographiques, des mesures de microdurete, de resistivite electrique a basse temperature, ont montre une purification sensible en tete du barreau; ces resultats ont ete confirmes part l'abaissement a 270 C de la temperature de recristallisation et l'aptitude marquee du metal raffine au phenomene de polygonisation. Les mesures de resistivite electrique a basse temperature constituent un moyen simple et quantitatif pour rendre compte de la purete du metal. L'influence d'une impurete sur la resistivite electrique de l'uranium a ete etudiee a l'aide d'alliages U-Au a faibles concentrations en or. Il ressort de ces experiences les deux points importants suivants: 1 - les mesures de

Photovoltaic production and distribution network; La production photovoltaique et les reseaux de distribution

Energy Technology Data Exchange (ETDEWEB)

Fraisse, J.L. [ERDF, 75 - Paris (France)

2010-04-15

The rapid development of photovoltaics boosted by attractive feed-in tariffs caused a sharp increase in requests for connection to public distribution grids, which were originally designed to serve consumers. ERDF, main distribution network operator in France, is facing a challenge in terms of capacity for handling requests for connection and in terms of public distribution network operation and management. (author)

A study of uranium-thorium mixed lattices; Etude de reseaux mixtes uranium - thorium

Energy Technology Data Exchange (ETDEWEB)

Bacher, P; Eckert, R; Mazancourt, R de [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1957-07-01

Some subcritical experiments have been carried out during the charging of the pile G1 by introducing thorium bars in a regular lattice into the pile. The spreading out of these experiments over a period of three months has permitted: a) work on a pile gradually increasing in size and b) measurements on comparable charges in so far that they have either the same number of bars of thorium, or the same concentration of thorium. From the measurements at constant charge and at constant concentration, it is possible by extrapolation to determine the critical charges and concentrations. The values obtained have showed that the material Laplacian of the lattice depends linearly on the thorium concentration and must cancel out for a concentration T = 8.8 {+-} 0.3 per cent by volume. These results have been found, to a very good approximation, by a simple calculation. (author) [French] Des experiences sous-critiques ont ete effectuees au cours du chargement de la pile G1 en introduisant des barres de thorium reparties suivant un reseau regulier dans la pile. L'etalement de ces experiences sur trois mois a permis d'operer sur une pile de plus en plus grosse et de faire un grand nombre de mesures sur des chargements comparables par le fait qu'ils avaient soit le meme nombre de barres de thorium, soit la meme concentration en thorium. A partir des mesures a chargement constant et a concentration constante, il a ete possible de determiner par extrapolation les chargements et concentrations critiques. Les valeurs obtenues ont montre que le laplacien matiere moyen du reseau dependait lineairement de la concentration en thorium, et devrait s'annuler pour une concentration T = 8,8 {+-} 0,3% en volume. Ces resultats ont ete retrouves avec une tres bonne approximation par un calcul elementaire. (auteur)

DC Voltage Control and Power-Sharing of Multi-Terminal DC Grids Based on Optimal DC Power Flow and Flexible Voltage Droop Strategy

Directory of Open Access Journals (Sweden)

F. Azma

2015-06-01

Full Text Available This paper develops an effective control framework for DC voltage control and power-sharing of multi-terminal DC (MTDC grids based on an optimal power flow (OPF procedure and the voltage-droop control. In the proposed approach, an OPF algorithm is executed at the secondary level to find optimal reference of DC voltages and active powers of all voltage-regulating converters. Then, the voltage droop characteristics of voltage-regulating converters, at the primary level, are tuned based on the OPF results such that the operating point of the MTDC grid lies on the voltage droop characteristics. Consequently, the optimally-tuned voltage droop controller leads to the optimal operation of the MTDC grid. In case of variation in load or generation of the grid, a new stable operating point is achieved based on the voltage droop characteristics. By execution of a new OPF, the voltage droop characteristics are re-tuned for optimal operation of the MTDC grid after the occurrence of the load or generation variations. The results of simulation on a grid inspired by CIGRE B4 DC grid test system demonstrate efficient grid performance under the proposed control strategy.

SLC summer 2011 university - What energy model for Europe in 2030? Proceedings

International Nuclear Information System (INIS)

2011-09-01

This document brings together the available presentations given at the summer 2011 university of the SLC (save the climate) organization on the topics of the energy model for Europe in 2030. Ten presentations (slides) are compiled in this document and deal with: 1 - The Negatep (France) scenario - extrapolation to Europe (Pierre Bacher, Claude Acket, Gerard Pierre); 2 - Renewable energies, potentialities and constraints (Jean-Louis BAL); 3 - Biomass availability for energy valorizations at the 2050 sights (Henry-Herve Bichat); 4 - Nuclear risk and nuclear safety control (Marie-Pierre Comets, ASN); 5 - The new horizons of nuclear energy (S. David, CNRS/IN2P3, IPN Orsay); 6 - A sustainable low carbon economy? EU Energy Policy in making... 2020... 2050... (Marc Deffrennes, DG ENERGY D2 Euratom Nuclear Energy); 7 - CO 2 capture and sequestration techniques (B. Durand); 8 - Climate change and its timelines (Sylvie Joussaume, CNRS, Pierre Simon Laplace Institute - IPSL, Laboratory of climate and environmental Sciences - LSCE); 9 - The Europe of electricity and the strategic role of grids (Andre Merlin, CIGRE); 10 - How to reduce to 50% the electricity share of nuclear origin? (Herve Nifenecker)

Development of ultracold neutron detectors and a polarization analyzing system for the measurement of the neutron electric dipole moment; Developpement de detecteurs de neutrons ultra-froids et d'un systeme d'analyse de polarisation pour la mesure du moment electrique dipolaire du neutron

Energy Technology Data Exchange (ETDEWEB)

Rogel, Gwendal

2009-10-29

This thesis was performed in the context of a project aiming to measure the electric dipole moment (EDM) of the neutron at the Paul Scherrer Institute. Two aspects have been studied: The detection and the polarization analysis of ultracold neutrons. Three types of detectors have been tested at the Institut Laue-Langevin (ILL): The Cascade-U (GEM technology), the {sup 3}He gas detector and {sup 6}Li-doped glass scintillators (GS family). Their detection efficiency and their background sensitivity have been measured. The GS10 scintillator is competitive with the {sup 3}He gas detector under the conditions realized with the EDM spectrometer. A GS3/GS20 scintillator stack has enabled to improve the neutron/gamma discrimination. It has been found 20% less efficient than the {sup 3}He gas detector under the EDM spectrometer. The Cascade-U detector has been observed to be 20% less efficient than a 500 microns thick GS10 glass as confirmed by simulations. A new system for simultaneous spin analysis is presented. It consists of two independent detection systems (arms) which are each made of an adiabatic spin flipper, a spin analyzer, and a detector. The arms detect opposite spin components, allowing the simultaneous counting of both neutron spin orientations. A prototype mounted in horizontal configuration has been tested at ILL. The analyzing power of both arms has been measured to be 80%. The transmission of the system without spin analyzers has been found to be 50%. (author) [French] Cette these s'inscrit dans un nouveau projet de mesure du moment dipolaire electrique (EDM) du neutron a l'institut Paul Scherrer. Deux aspects ont ete etudies ici: la detection et l'analyse de polarisation de neutrons ultra-froids. Trois types de detecteurs ont ete testes a l'Institut Laue-Langevin (ILL): le Cascade-U (technologie GEM), le compteur a gaz {sup 3}He et des scintillateurs dopes au {sup 6}Li (type GS). Leur efficacite de detection ainsi que leur sensibilite au bruit de fond ont

Study and realisation of a high frequency analyzer; Etude et realisation d'un analyseur de signaux a haute frequence

Energy Technology Data Exchange (ETDEWEB)

Bourbigot, J [Commissariat a l' Energie Atomique, Fontenay aux Roses (France). Centre d' Etudes Nucleaires

1966-07-01

This device is designed for the amplitude and frequency analysis of electric or electromagnetic signals in the frequency range of 0 to 55 MHz. The frequency spectrum of a preset bandwidth is displayed on the screen of an oscilloscope. Conceived to analyse the electromagnetic oscillations that can be generated in a plasma, its main characteristics are the following: extended bandwidth of analysed frequencies, on both sides of the ion cyclotron frequency in a magnetic field up to 20 kGs; linear amplitude and frequency response; possibility of analysing a narrow band; high sensitivity; analysis repetition rate of 25 per second. The different parts of the analyzer are described after a discussion of the choice of the techniques used in their design. In addition to its present use, the device can be applied to perform all the functions of a commercial spectral analyzer. (author) [French] Cet appareil est destine a l'analyse en frequence et amplitude de signaux electriques ou electromagnetiques dans une gamme de frequences de 0 a 55 MHz. Couple a un oscillographe, il permet de faire apparaitre sur l'ecran, le spectre de frequences dans une gamme choisie. Etudie dans le but d'analyser les oscillations electromagnetiques pouvant apparaitre dans un plasma, ses principales caracteristiques sont les suivantes: une bande etendue de frequences analysees, de part et d'autre de la frequence cyclotronique des ions dans un champ magnetique pouvant atteindre 20 kGs (valeur maximum 55 MHz); une reponse lineaire en amplitude et en frequence; la possibilite d'analyser, une bande restreinte de frequences; une grande sensibilite La frequence d'analyse est de 25 periodes par seconde. Les diverses parties de l'analyseur sont decrites apres l'expose des motifs ayant guide le choix des solutions adoptees pour sa realisation. Les schemas electriques sont egalement presentes. En dehors du but precis qui a motive la realisation de cet appareil, son usage peut s'etendre a toutes les applications

KEY COMPARISON: CCEM.RF-K9: International comparison of thermal noise standards between 12.4 GHz and 18 GHz (GT-RF/99-1)

Science.gov (United States)

Allal, Djamel; Achkar, Joseph

2006-01-01

An international comparison of thermal noise-power measurements has been carried out among five national metrology institutes between 12.4 GHz and 18 GHz. Four transfer standards were measured. The following national institutes participated: BNM-LCIE (France), NPL (United Kingdom), PTB (Germany), NIST (United States of America) and VNIIFTRI (Russia). The Bureau National de Métrologie-Laboratoire Central des Industries Electriques (France) acted as the pilot laboratory for the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Controlled Operation of the Islanded Portion of the International Council on Large Electric Systems (CIGRE) Low Voltage Distribution Network

DEFF Research Database (Denmark)

Mustafa, Ghullam; Bak, Claus Leth; Ali, Ehsan

2017-01-01

In islanding, a portion of the power network, comprised of the loads and distributed generation (DG) units, is isolated from the rest of the power grid and forms a micro grid (MG). In this condition, it becomes essential for the islanded MG to operate in a stable and controlled manner by providing...... ancillary services. When the MG is cut off from the main grid, the islanding must be detected by the DG units. In this condition it is essential that one of the controllers should be switched to the voltage-frequency (VF) control mode. In islanding, the network loses it slack reference and this reference...

Promises of the electric-powered car; Promesses de la voiture electrique

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

This document analyses the energy needs of an automobile and makes a comparison between the characteristics of a thermal engine car and an electric-powered car with batteries in terms of cost and energy efficiency. The future of the electric-powered car depends mainly on the improvements that will be made in battery technologies in terms of weight, energy density, number of charge-discharge cycles and cost. (J.S.)

Energy report 2003; L'energie electrique en France en 2003

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

Provisional results of power flows on the French power system in 2003: net generation; national consumption; physical exchanges with foreign countries (total of instantaneous exchange balances measured by metering on each interconnection lines); adjusted consumption (values adjusted for climatic contingencies and leap years); electrical energy balance in France in 2003; noteworthy data for the year 2003 (these values reflect all of the flows on the RTE network, as well as generation auto-consumed by the industrial consumers connected to this network); electricity market: contractual exchanges with foreign countries, base load blocks exchanged between balance responsible entities; power facilities (situation on 2003/12/31); generating facilities connected to the RTE network during the year: connection to the RTE network of two cogeneration units in Haute Normandie region, and of three household waste incineration plants in Picardie, Haute Normandie and Languedoc-Roussillon regions representing a total capacity of 285.5 MW, increase in capacity of the two units of the Chooz B nuclear power plant in the Ardennes (total increase of 90 MW), to be noted that the total France includes in particular the connection of wind farms on distribution networks for a total capacity of 80 MW; main RTE facilities commissioned during the year: 22 new substations connected to the RTE network, 4 of them at 225 kV (Amfard, Bouscat, Braek, Volvon), 6 of them at 90 kV and 12 of them at 63 kV; at 400 kV, 130 km of new or replaced circuits (together with the removal of 30 km of network lines), of which: circuit 4 and 5 of Tavel-Tricastin line in order to increase the transit capacity between the Rhone-Alpes region and the Languedoc-Roussillon and Provence-Alpes-Cote d'Azur regions; Chevalet-Gavrelle line, after the modification of the previous line to a dual circuit, in order to cover quality and security of supply requirements for the Somme and Pas-de-Calais departments, at 225 kV, 200 km of new or replaced circuits, of which: Boutre-Coudon line after reconstruction thus doubling its capacity and securing the energy supply of south of the Var department; three lines as part of work to restructure the 225 kV network between Tavel and Tricastin in the Bollene area; Soleil-Volvon line in Loire to strengthen the energy supply to the area of St Etienne; the underground Bouscat-Bruges line to strengthen the energy supply to the area of Bordeaux. The total circuits evolution, that decreased by about 30 km compared to 2002, is the result of facilities removals and various modifications.

Power system reliability memento; Memento de la surete du systeme electrique

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-07-01

The reliability memento of the French power system (national power transmission grid) is an educational document which purpose is to point out the role of each one as regards power system operating reliability. This memento was first published in 1999. Extensive changes have taken place since then. The new 2002 edition shows that system operating reliability is as an important subject as ever: 1 - foreword; 2 - system reliability: the basics; 3 - equipment measures taken in order to guarantee the reliability of the system; 4 - organisational and human measures taken to guarantee the reliability of the system; appendix 1 - system operation: basic concepts; appendix 2 - guiding principles governing the reliability of the power system; appendix 3 - international associations of transmission system operators; appendix 4 - description of major incidents.

Les Brulures Electriques par Haut Voltage - A Propos de 10 Cas

Science.gov (United States)

Belmir, R.; Fejjal, N.; El Omari, M.; El Mazouz, S.; Gharib, N.; Abassi, A.; Belmahi, A.

2008-01-01

Summary Les accidents électriques par haute tension (AEHT) provoquent des brûlures profondes par effet Joule le long des axes vasculo-nerveux entre les points d'entrée et de sortie, qui sont le siège de lésions délabrantes. Les Auteurs rapportent une série de dix cas d'AEHT admis au service de chirurgie réparatrice et de brûlés de l'Hôpital Ibn Sina de Rabat à travers laquelle ils étudient les caractéristiques épidémiologiques, cliniques et thérapeutiques. Tous les patients étaient des adultes de sexe masculin dont l'âge moyen était de 31 ans. Dans 70% des cas, ces brûlures étaient secondaires à un contact avec les distributeurs d'électricité avec une surface brûlée inférieure à 20%. Le traitement des lésions électrothermiques a nécessité des interventions itératives avec amputation des segments de membres nécrosés dans 70% des cas, dont les suites étaient marquées par des séquelles fonctionnelles invalidantes. La prévention des AEHT, en particulier pour les accidents du travail au sein des professions exposées, reste fondamentale. PMID:21991124

Brulure par Plaque de Bistouri Electrique: a Propos de Quatre Cas

Science.gov (United States)

Khales, A.; Achbouk, A.; Belmir, R.; Cherkab, L.; Ennouhi, M.A.; Ababou, K.; Ihrai, H.

2010-01-01

Summary La brûlure par plaque de bistouri électrique est un accident rare mais grave par la profondeur de la lésion et par sa localisation, surtout quand qu’elle survient dans un contexte chirurgical dont le vécu reste difficile de la part du malade et du chirurgien. Cette brûlure bien que imprévisible reste grave par la profondeur et la localisation de la brûlure et par sa survenue dans un contexte opératoire, chez des patients malades. La prise en charge de la brûlure doit se faire en milieu spécialisé. La prévention reste le seul moyen d’éviter ce type d’accident. PMID:21991216

Resetting dynamic behaviour of pipework systems; Recalage du comportement dynamique des reseaux de tuyauteries

Energy Technology Data Exchange (ETDEWEB)

Gaudin, M [Electricite de France (EDF), Direction des Etudes et Recherches, 92 - Clamart (France)

1998-12-31

Resetting models is applied to electricity generating plant pipework systems. A frequency approach to the problem is made in an original way thanks to the use of precise dynamic rigidity matrices. The method assumes two kinds of unknown: the usually processed mechanical characteristics (Young`s Modulus, density etc.) and new resetting parameters acting on the dynamic behaviour of unknown connections. As the latter have a very wide range of possible variation, they benefit from a change of variable which allows the assumptions formulated to be complied with. The minimized cost function is based on a error in load. The frequencies required for building it are automatically selected thanks to different tests on measurements. Minimization uses a sensitivity technique linked with a method of least standard squares. The method has been programmed in Fortran 90 within the CIRCUS code and tried out on various examples which were simulated and sound effects cases as well as an actual case. (author). 128 refs.

Resetting dynamic behaviour of pipework systems; Recalage du comportement dynamique des reseaux de tuyauteries

Energy Technology Data Exchange (ETDEWEB)

Gaudin, M. [Electricite de France (EDF), Direction des Etudes et Recherches, 92 - Clamart (France)

1997-12-31

Resetting models is applied to electricity generating plant pipework systems. A frequency approach to the problem is made in an original way thanks to the use of precise dynamic rigidity matrices. The method assumes two kinds of unknown: the usually processed mechanical characteristics (Young`s Modulus, density etc.) and new resetting parameters acting on the dynamic behaviour of unknown connections. As the latter have a very wide range of possible variation, they benefit from a change of variable which allows the assumptions formulated to be complied with. The minimized cost function is based on a error in load. The frequencies required for building it are automatically selected thanks to different tests on measurements. Minimization uses a sensitivity technique linked with a method of least standard squares. The method has been programmed in Fortran 90 within the CIRCUS code and tried out on various examples which were simulated and sound effects cases as well as an actual case. (author). 128 refs.

Interconnection and power transportation networks: operation; Reseaux d'interconnexion et de transport: fonctionnement

Energy Technology Data Exchange (ETDEWEB)

Bornard, P. [Reseau de Transport d' Electricite (RTE), Div. Systeme Electrique, 92 - Paris la Defense (France); Pavard, M. [Electricite de France (EDF), 75 - Paris (France); Testud, G. [Reseau de Transport d' Electricite (RTE), Dept. Exploitation du Systeme Electrique, 92 - Paris la Defense (France)

2005-10-01

For economical or technical reasons, the power generation units are in general grouped together in the same geographical areas, while the consumption points are much more dispersed. The power transportation and interconnection networks ensure the link between the big generation areas and the big consumption areas, and also with other foreign networks. The network manager must keep the balance between the available offer and the potential demand and ensures the transit of energy between the production units and the end-users with respecting the contractual voltage and frequency ranges. Incidents must be mastered to limit the inconvenience to users and to avoid the complete collapse of the power transportation system. This article describes the operation of such systems: 1 - problems linked with networks operation; 2 - transits distribution: general problem, transmissible power in a power line, voltage drop, calculations of power distributions; 3 - voltage and frequency adjustments; 4 - operation in disturbed regime: mastery of common incidents, mechanisms of major incidents (operation of a power system in strongly disturbed regime), protection of the power system, recovery; 5 - conclusion. (J.S.)

Safety Training: places available in October 2014

CERN Multimedia

2014-01-01

There are places available in the forthcoming Safety courses. For updates and registrations, please refer to the Safety Training Catalogue. Safety Training, HSE Unit safety-training@cern.ch Title of the course EN Title of the course FR Date Hours Language Chemical Safety ATEX Habilitation - Level 2 Habilitation ATEX - Niveau 2 16-Oct-14 to 17-Oct-14 9:00 - 17:30 French Cryogenic Safety Cryogenic Safety - Fundamentals Sécurité Cryogénie - Fondamentaux 23-Oct-14 10:00 - 12:00 English Cryogenic Safety - Helium Transfer Sécurité Cryogénie - Transfert d'hélium 30-Oct-14 9:30 - 12:00 English Electrical Safety Habilitation Electrique - Electrician Low Voltage - Initial Habilitation électrique - Électricien basse tension - Initial 02-Oct-14 to 06-Oct-14 9:00 - 17:30 English 20-Oct-14 to 22-Oct-14 9:00 -...

Continuous analytical control of the streaming waters in a uranium treatment plant and of various chemical products using automatic discharge valves; Controle par analyse en continu des eaux de ruissellement d'une usine traitant de l'uranium et divers produits chimiques avec commande automatique des vannes de decharge

Energy Technology Data Exchange (ETDEWEB)

Archimbaud, M; Simeon, C [Commissariat a l' Energie Atomique, Pierrelatte (France)

1968-07-01

This report describes a method for controlling the streaming waters produced by the Pierrelatte Centre; it is based on continuous analysis, with simultaneous recording of the species liable to be found accidentally in the corresponding hydrological circuits (chlorides, fluorides, chromium VI, uranium). An alarm set off at pre-determined thresholds leads to an automatic cutting off of the discharge valves; the outward flow of the waters is thus interrupted. This study has shown the various applications which can be found for this water control method, and gives an idea of the cost price. (authors) [French] Ce rapport decrit un mode de controle des eaux de ruissellement provenant du Centre de Pierrelatte base sur une analyse en continu, avec enregistrement des corps susceptibles de se retrouver accidentellement dans les reseaux hydrologiques correspondants (chlorures, fluorures, chrome VI, uranium). Le declenchement d'une alarme a partir de seuils choisis permet de fermer automatiquement les vannes de decharge et d'arreter ainsi l'ecoulement vers l'exterieur. Cette etude montre quelles peuvent etre les diverses applications de cette methode de controle des eaux et elle indique un ordre de grandeur du prix de revient. (auteurs)

New methods and applications in emission spectroscopy (1960); Methodes et applications nouvelles en spectroscopie d'emission (1960)

Energy Technology Data Exchange (ETDEWEB)

Baudin, G [Commissariat a l' Energie Atomique, Grenoble (France).Centre d' Etudes Nucleaires

1960-07-01

Emission spectroscopy, are already well-established instrumental analytical technique, has in recent years known important developments. Two mains factors are responsible; firstly the demands of metallurgy for purer and purer materials or alloys which are increasingly complex and difficult to analyse by chemical means; secondly, progress in optics, especially in the production of gratings, and in electronics in the field of photomultiplier tubes. We will not here catalogue all the new applications and methods, but we will consider a few amongst the most representative outside the conventional field. (author) [French] La spectroscopie d'emission, technique analytique instrumentale deja ancienne, a pris, depuis quelques annees, une extension notable. Deux facteurs principaux ont contribue a ce succes: d'une part, l'exigence de la metallurgie en materiaux de plus en plus pur ou en alliages de plus en plus complexes, difficiles a analyser chimiquement, d'autre part, les progres realises en optique, principalement dans la fabrication des reseaux, et en electronique dans le domaine des tubes photomultiplicateurs. Nous ne ferons pas ici le recensement de toutes les applications ou methodes nouvelles, mais nous en choisirons quelques unes des plus representatives hors du domaine classique. (auteur)

Transport properties of silver telluride in the solid and liquid states; Etude des proprietes de transport dans le tellurure d'argent Ag{sub 2}Te aux hautes temperatures a l'etat solide et a l'etat liquide

Energy Technology Data Exchange (ETDEWEB)

Pham, N T [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1969-01-01

Measurements of the electrical resistivity, Hall coefficient and thermoelectric power have been carried out for silver telluride over a large temperature range including both solid and liquid states. The analysis of the experimental data shows that in the solid state the transport properties are governed by an ambipolar process with an electron mobility much higher than the hole mobility ({mu}{sub n} = 10*{mu}{sub p}). It is found that the temperature dependence of the electron mobility can be represented by a T{sup -3} law. Deviations from the stoichiometric composition Ag{sub 2}Te have been studied. For all specimens, melting is accompanied by discontinuous variations in the transport properties. Above the melting point, the magnitude of the measured parameters and their temperature dependence show that liquid silver telluride behaves as a semiconductor. The contribution of Ag{sup +} ions to transport phenomena is suggested to account for the behaviour of the electrical properties. Experimental data have been analysed in terms of conventional theories. (author) [French] Les mesures de la resistivite electrique, du coefficient de Hall et du pouvoir thermoelectrique ont ete effectuees sur le tellurure d'argent dans un large domaine de temperature couvrant l'etat solide et l'etat liquide. L'analyse des resultats experimentaux obtenus a l'etat solide montre que les proprietes de transport sont gouvernees par le processus ambipolaire avec une mobilite des electrons beaucoup plus grande que celle des trous ({mu}{sub n} 10*{mu}{sub p}). On trouve que la mobilite des electrons varie avec la temperature suivant la loi T{sup -3}. Les ecarts de la composition stoechiometrique Ag{sub 2}Te ont ete etudies. Pour tous les echantillons, la fusion est caracterisee par des variations discontinues des proprietes de transport. Au dessus du point de fusion, la grandeur des parametres mesures ainsi que leur variation avec la temperature montrent que le tellurure d'argent liquide se

Effets du vieillisement de la batterie Li-ion sur les performances d'un vehicule recreatif hybride branchable a trois roues

Science.gov (United States)

Nadeau, Jonathan

La prediction de l'evolution du vieillissement de la batterie lithium-ion est source d'un grand defi, dans les applications liees aux vehicules electriques et hybrides. Sa meconnaissance est un risque considerable compromettant la viabilite d'un tel systeme. Invoquant les couts substantiels de la densite d'energie, liee a la degradation considerable des performances de la batterie au cours de sa duree de vie, il devient important d'en tenir compte des le processus de conception. La dependance de la strategie de controle du vehicule aux parametres de la batterie justifie aussi la necessite d'une telle prediction. Il est connu que le vieillissement, sensible aux facteurs tels que le courant, la temperature et la profondeur de decharge, a un impact considerable sur la perte de capacite de la batterie ainsi que sur l'augmentation de la resistance interne. Le premier est directement lie a l'autonomie electrique du vehicule, alors que le second mene a une surchauffe de la batterie, a une augmentation des pertes en puissance qui se manifeste par une diminution de la tension de bus. A cet egard, implique dans la conception d'un vehicule recreatif hybride branchable a trois roues, le Centre de Technologies Avancees s'interesse a l'etude du vieillissement de la batterie Li-ion pour une telle application. Pour ce faire, au contraire de la plupart des estimations empiriques de la duree de vie, basees sur des profils de decharge a courant constant, un profil de courant plus approprie pour l'application donnee, base sur un cycle de vitesse representatif de la conduite d'une motocyclette, a ete utilise. Par le biais d'un simulateur complet du vehicule, le cycle de courant a ete extrait du cycle de vitesse. Ainsi, les travaux menes impliquent l'analyse experimentale de la decharge cyclique de quatre cellules LiFePO 4. Pendant plus de 1400 cycles, un banc d'essai complet a permis l'acquisition de la capacite, de la resistance interne, du courant, de la tension ainsi que de la

Contribution a l'auscultation des chaussees mixtes par methodes GPR et electrique

Science.gov (United States)

Kaouane, Carole

Quebec's infrastructures are ageing. A reliable, quick and economical assessment of the state of urban roads would help to plan civil engineering. This M.Sc. thesis aims to investigate and develop the potential of Ground Penetrating Radar (GPR) and electrical methods to assess pavement condition subject to wetting, freezing and drying cycles. The objectives are to display defects and estimate water content in the materials used for the mixed pavement construction; these consist in layers of asphalt (top), concrete (middle) and grade and sub-grade (bottom). Prior studies showed a valuable potential of joint application of GPR and electrical resistivity to assess mixed pavement condition. These studies were mainly based on numerical modeling and some site tests using both methods. It was concluded that a better evaluation of the potential of the coupled methods would come from the assessment of physical properties and validation from geotechnical evidences. At first, we characterized the context. Structural defects and water content implied modification of physical properties of road materials. After running numerical modeling, we carried out an experiment in one of the streets in Montreal (Canada) where pavement needed complete rehabilitation. GPR surveys were carried out before the pavement was destroyed and removed, and subsequently a resistivity imaging was carried out on the subgrade layer. We also sampled blocks of asphalt and concrete along the street from the demolition rubble in order to study their physical properties in the lab. Soil samples were taken from trenches to measure water content. The grade and sub-grade were mainly a mix of clayey-silt and gravel, as the embedding ground is grey clay. We measured the complex dielectric constants of asphalt and concrete in the range 50 MHz-900 MHz with a recently developed dielectric probe sampling a volume of 30 cm3. Resistivity measurements were also performed on large cores of asphalt and concrete using an inhouse system. Measurements were carried out on dry and wet samples, which provided a range of values encompassing the climatic conditions for the whole year. Finally the physical property and geotechnical data were used as input to numerical modeling and the modeled responses compared to the survey data. The predicted data fit nicely with the observed data. This work aims to provide further information for a better calibration of geophysical devices in pavement condition assessment. Moreover, it gives a wide range of information, which could become a base for further and more specific works.

Strategie de commande optimale de la production electrique dans un site isole

Science.gov (United States)

Barris, Nicolas

Hydro-Quebec manages more than 20 isolated power grids all over the province. The grids are located in small villages where the electricity demand is rather small. Those villages being far away from each other and from the main electricity production facilities, energy is produced locally using diesel generators. Electricity production costs at the isolated power grids are very important due to elevated diesel prices and transportation costs. However, the price of electricity is the same for the entire province, with no regards to the production costs of the electricity consumed. These two factors combined result in yearly exploitation losses for Hydro-Quebec. For any given village, several diesel generators are required to satisfy the demand. When the load increases, it becomes necessary to increase the capacity either by adding a generator to the production or by switching to a more powerful generator. The same thing happens when the load decreases. Every decision regarding changes in the production is included in the control strategy, which is based on predetermined parameters. These parameters were specified according to empirical studies and the knowledge base of the engineers managing the isolated power grids, but without any optimisation approach. The objective of the presented work is to minimize the diesel consumption by optimizing the parameters included in the control strategy. Its impact would be to limit the exploitation losses generated by the isolated power grids and the CO2 equivalent emissions without adding new equipment or completely changing the nature of the strategy. To satisfy this objective, the isolated power grid simulator OPERA is used along with the optimization library NOMAD and the data of three villages in northern Quebec. The preliminary optimization instance for the first village showed that some modifications to the existing control strategy must be done to better achieve the minimization objective. The main optimization processes consist of three different optimization approaches: the optimization of one set of parameters for all the villages, the optimization of one set of parameters per village, and the optimization of one set of parameters per diesel generator configuration per village. In the first scenario, the optimization of one set of parameters for all the villages leads to compromises for all three villages without allowing a full potential reduction for any village. Therefore, it is proven that applying one set of parameters to all the villages is not suitable for finding an optimal solution. In the second scenario, the optimization of one set of parameters per village allows an improvement over the previous results. At this point, it is shown that it is crucial to remove from the production the less efficient configurations when they are next to more efficient configurations. In the third scenario, the optimization of one set of parameters per configuration per village requires a very large number of function evaluations but does not result in any satisfying solution. In order to improve the performance of the optimization, it has been decided that the problem structure would be used. Two different approaches are considered: optimizing one set of parameters at a time and optimizing different rules included in the control strategy one at a time. In both cases, results are similar but calculation costs differ, the second method being much more cost efficient. The optimal values of the ultimate rules parameters can be directly linked to the efficient transition points that favor an efficient operation of the isolated power grids. Indeed, these transition points are defined in such a way that the high efficiency zone of every configuration is used. Therefore, it seems possible to directly identify on the graphs these optimal transition points and define the parameters in the control strategy without even having to run any optimization process. The diesel consumption reduction for all three villages is about 1.9%. Considering elevated diesel costs and the existence of about 20 other isolated power grids, the use of the developed methods together with a calibration of OPERA would allow a substantial reduction of Hydro-Quebec's annual deficit. Also, since one of the developed methods is very cost effective and produces equivalent results, it could be possible to use it during other processes; for example, when buying new equipment for the grid it could be possible to assess its full potential, under an optimized control strategy, and improve the net present value.

Modele electrique d'une pile a combustible « pem » pour utilisation ...

African Journals Online (AJOL)

... with a limited number of elements. The influence of current output and operating temperature on the elements of the model is illustrated with an experimental test bed equipped with a fuel cell proton exchange membrane 500 W. The proposed model is then validated at current levels and at the speed of a DC-DC elevator.

Reference costs for power generation; Couts de reference de la production electrique

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-12-01

The first part of the 2003 study of reference costs for power generation has been completed. It was carried out by the General Directorate for Energy and Raw Materials (DGEMP) of the French Ministry of the Economy, Finance and Industry, with the collaboration of power-plant operators, construction firms and many other experts. A Review Committee of experts including economists (Forecasting Department, French Planning Office), qualified public figures, representatives of power-plant construction firms and operators, and non-governmental organization (NGO) experts, was consulted in the final phase. The study examines the costs of power generated by different methods (i.e. nuclear and fossil-fuel [gas-, coal-, and oil-fired] power plants) in the context of an industrial operation beginning in the year 2015. - The second part of the study relating to decentralized production methods (wind, photovoltaic, combined heat and power) is still in progress and will be presented at the beginning of next year. - 1. Study approach: The study is undertaken mainly from an investor's perspective and uses an 8% discount rate to evaluate the expenses and receipts from different years. In addition, the investment costs are considered explicitly in terms of interest during construction. - 2. Plant operating on a full-time basis (year-round): The following graph illustrates the main conclusions of the study for an effective operating period of 8000 hours. It can be seen that nuclear is more competitive than the other production methods for a year-round operation with an 8% discount rate applied to expenses. This competitiveness is even better if the costs related to greenhouse-gas (CO{sub 2}) emission are taken into account in estimating the MWh cost price. Integrating the costs resulting from CO{sub 2} emissions by non-nuclear fuels (gas, coal), which will be compulsory as of 2004 with the transposition of European directives, increases the total cost per MWh of these power generation methods. Two hypotheses are considered in terms of CO{sub 2} costs over the life span of the oil- and coal-fired power plants: 4 euro/t CO{sub 2} and 20 euro/t CO{sub 2}. The hypothesis of 4 euro/t CO{sub 2} can be considered as very low - it will be significantly more expensive in 2015 and beyond (post-Kyoto period). The choice of a discount rate respectively lower or higher than the baseline hypothesis of 8% will increase, or decrease, the competitiveness of nuclear-based power production compared to fossil- fuel methods of power production because the investment load, which is higher for nuclear than for the other methods, decreases or, conversely, increases. The 8% discount rate adopted here was the rate used by the French Planning Office and is compatible with the profitability requirements currently noted in the electricity sector. The different variants do not bring into question the order of competitiveness of the production methods. 3. Plant operating on a half-time basis (less than 5000 hours/year): Considering the size of the initial investment, a nuclear power plant's competitiveness requires that it operate all year round. Should the nuclear power plant be operational for a shorter duration, then its competitiveness fades in favour of gas-fired power plants. More specifically, gas is more competitive than nuclear power (excluding externalities) for operating periods of less than 5000 hours. - 4. Plant operating on a minimum basis (less than 3000 hours/year): For short periods, the gas turbine is more competitive than the oil-fired turbine. The oil-fired turbine, however, is competitive for durations of less than 250 hours.

Reference costs for power generation; Couts de reference de la production electrique

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-12-01

The first part of the 2003 study of reference costs for power generation has been completed. It was carried out by the General Directorate for Energy and Raw Materials (DGEMP) of the French Ministry of the Economy, Finance and Industry, with the collaboration of power-plant operators, construction firms and many other experts. A Review Committee of experts including economists (Forecasting Department, French Planning Office), qualified public figures, representatives of power-plant construction firms and operators, and non-governmental organization (NGO) experts, was consulted in the final phase. The study examines the costs of power generated by different methods (i.e. nuclear and fossil-fuel [gas-, coal-, and oil-fired] power plants) in the context of an industrial operation beginning in the year 2015. - The second part of the study relating to decentralized production methods (wind, photovoltaic, combined heat and power) is still in progress and will be presented at the beginning of next year. - 1. Study approach: The study is undertaken mainly from an investor's perspective and uses an 8% discount rate to evaluate the expenses and receipts from different years. In addition, the investment costs are considered explicitly in terms of interest during construction. - 2. Plant operating on a full-time basis (year-round): The following graph illustrates the main conclusions of the study for an effective operating period of 8000 hours. It can be seen that nuclear is more competitive than the other production methods for a year-round operation with an 8% discount rate applied to expenses. This competitiveness is even better if the costs related to greenhouse-gas (CO{sub 2}) emission are taken into account in estimating the MWh cost price. Integrating the costs resulting from CO{sub 2} emissions by non-nuclear fuels (gas, coal), which will be compulsory as of 2004 with the transposition of European directives, increases the total cost per MWh of these power generation methods. Two hypotheses are considered in terms of CO{sub 2} costs over the life span of the oil- and coal-fired power plants: 4 euro/t CO{sub 2} and 20 euro/t CO{sub 2}. The hypothesis of 4 euro/t CO{sub 2} can be considered as very low - it will be significantly more expensive in 2015 and beyond (post-Kyoto period). The choice of a discount rate respectively lower or higher than the baseline hypothesis of 8% will increase, or decrease, the competitiveness of nuclear-based power production compared to fossil- fuel methods of power production because the investment load, which is higher for nuclear than for the other methods, decreases or, conversely, increases. The 8% discount rate adopted here was the rate used by the French Planning Office and is compatible with the profitability requirements currently noted in the electricity sector. The different variants do not bring into question the order of competitiveness of the production methods. 3. Plant operating on a half-time basis (less than 5000 hours/year): Considering the size of the initial investment, a nuclear power plant's competitiveness requires that it operate all year round. Should the nuclear power plant be operational for a shorter duration, then its competitiveness fades in favour of gas-fired power plants. More specifically, gas is more competitive than nuclear power (excluding externalities) for operating periods of less than 5000 hours. - 4. Plant operating on a minimum basis (less than 3000 hours/year): For short periods, the gas turbine is more competitive than the oil-fired turbine. The oil-fired turbine, however, is competitive for durations of less than 250 hours.

Linear electrical circuits. Definitions - General theorems; Circuits electriques lineaires. Definitions - Theoremes generaux

Energy Technology Data Exchange (ETDEWEB)

Escane, J.M. [Ecole Superieure d' Electricite, 91 - Gif-sur-Yvette (France)

2005-04-01

The first part of this article defines the different elements of an electrical network and the models to represent them. Each model involves the current and the voltage as a function of time. Models involving time functions are simple but their use is not always easy. The Laplace transformation leads to a more convenient form where the variable is no more directly the time. This transformation leads also to the notion of transfer function which is the object of the second part. The third part aims at defining the fundamental operation rules of linear networks, commonly named 'general theorems': linearity principle and superimposition theorem, duality principle, Thevenin theorem, Norton theorem, Millman theorem, triangle-star and star-triangle transformations. These theorems allow to study complex power networks and to simplify the calculations. They are based on hypotheses, the first one is that all networks considered in this article are linear. (J.S.)

Ion conducting interpenetrated lattices for lithium generators; Reseaux interpenetres conducteurs ioniques pour generateurs au lithium

Energy Technology Data Exchange (ETDEWEB)

Grosz, M.; Boileau, S. [College de France, 75 - Paris (France); Guegan, P.; Cheradame, H. [Centre National de la Recherche Scientifique (CNRS), 94 - Thiais (France). LPCB; Deshayes, A. [CNET, 92 - Issy-les-Moulineaux (France)

1996-12-31

Interpenetrated lattices (IPL) are combinations of reticulated polymers linked together by permanent crisscross. This structure is well-adapted to combined highly incompatible pairs of polymers. The in-situ sequential method has been applied successfully to the synthesis of ethylene poly-oxides / poly-siloxanes IPLs. The results concerning the preparation of such lattices and their behaviour as solid polymer electrolytes are presented in this paper. (J.S.) 24 refs.

Ion conducting interpenetrated lattices for lithium generators; Reseaux interpenetres conducteurs ioniques pour generateurs au lithium

Energy Technology Data Exchange (ETDEWEB)

Grosz, M; Boileau, S [College de France, 75 - Paris (France); Guegan, P; Cheradame, H [Centre National de la Recherche Scientifique (CNRS), 94 - Thiais (France). LPCB; Deshayes, A [CNET, 92 - Issy-les-Moulineaux (France)

1997-12-31

Interpenetrated lattices (IPL) are combinations of reticulated polymers linked together by permanent crisscross. This structure is well-adapted to combined highly incompatible pairs of polymers. The in-situ sequential method has been applied successfully to the synthesis of ethylene poly-oxides / poly-siloxanes IPLs. The results concerning the preparation of such lattices and their behaviour as solid polymer electrolytes are presented in this paper. (J.S.) 24 refs.

Telecommunications networks, home integrated systems and remote control applications; Reseaux de telecommunications, domotique et teleaction

Energy Technology Data Exchange (ETDEWEB)

Cregut, F.; Treheux, M.

1996-12-31

Energy savings in residential sector can be performed by home integrated control systems. Remote controlled interfaces allow electric appliances consumption matching effective needs. Nevertheless, the uses of those techniques are stagnating since several years. The first reason is an awkward human factors engineering, that is now improving. The second reason is an lack of definition of the needs, that lead to commercialization problems. (D.L.)

Fuel elements for pressurised-gas reactors; Elements combustibles des piles a gaz sous pression

Energy Technology Data Exchange (ETDEWEB)

Stohr, J A; Englander, M; Gauthron, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

The design and fabrication of fuel elements for the first CO{sub 2} pressurized reactors have induced to investigate: various cladding materials, natural uranium base fuels, canning processes. The main analogical tests used in connection with the fuel element study are described. These various tests have enabled, among others, the fabrication of the fuel element for the EL2 reactor. Lastly, future solutions for electrical power producing reactors are foreseen. (author)Fren. [French] L'etude et la realisation d'elements combustibles pour les premieres piles a CO{sub 2} sous pression ont conduit a examiner: les divers materiaux de gaine, les combustibles a base d'uranium naturel, les modes de gainage. Les principaux essais analogiques ayant servi au cours de l'etude de la cartouche sont decrits. Ces divers essais ont notamment permis la realisation de la cartouche de la pile EL2. Enfin sont envisagees les solutions futures pour les piles productrices d'energie electrique. (auteur)

Superconducting transition and low-field magnetoresistance of a niobium single crystal at 4.2 deg. K; Transition supraconductrice et magnetoresistance en champ faible d'un echantillon monocristallin de niobium a 4.2 deg. K

Energy Technology Data Exchange (ETDEWEB)

Perriot, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires. Service de physique du solide et de resonnance magnetique

1967-01-01

We report the study of the electrical resistance of a niobium single crystal, at 4.2 deg. K, from the beginning of the superconductive transition to 80 kilo oersteds. Critical fieldsH{sub c2} and H{sub c3} have been determined. Influences on superconductive transition of current density, field-current angle, crystal orientation and magnetoresistance have been studied. Variation laws of low-field transverse and longitudinal magneto-resistances have been determined. (author) [French] La variation de la resistance electrique d'un monocristal cylindrique de niobium a ete etudiee, a 4,2 deg. K, depuis le debut de la transition supraconductrice jusqu'a 80 kilooersteds. Les champs critiques H{sub c2} et H{sub c3} ont ete determines. On a etudie l'influence de la densite de courant, de l'angle champ-courant, de l'anisotropie cristalline et de la magnetoresistance sur la transition supraconductrice. Les lois de variation des magnetoresistances transversale et longitudinale ont ete determinees dans le domaine des champs faibles. (auteur)

Tl response of LiF: Mg, Cu, P+Ptfe at X rays of 24, 42 and 100 KeV; Respuesta TL de LiF: Mg, Cu, P+Ptfe a rayos X de 24, 42 y 100 KeV

Energy Technology Data Exchange (ETDEWEB)

Gonzalez M, P.R.; Tovar M, V.M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Azorin N, J. [UAM-I, 09340 Mexico D.F. (Mexico); Furetta, C. [Universita degli Studi di Roma ' La Sapienza' , Piazzale Aldo Moro 2, 00185 Roma (Italy); Quiroz C, M.C. [Facultad de Medicina, UAEM, 50180 Toluca, Estado de Mexico (Mexico)

2005-07-01

In this work the obtained results of the irradiation of thermoluminescent dosemeters (Tl) of LiF: Mg,Cu,P + Ptfe with X rays for the effective radiation energy of 24, 42 and 100 keV, in an interval of Kerma in air in the sinus of the air between 0.05 and 1.0 Gy are presented. The rate of Kerma in air was determined with an ionization chamber PTW-1152, gauged by the Laboratoire Central des Industries Electriques (LCIE). As reference commercial TLD-100 dosemeters was used. The results showed that the studied Tl dosemeters presented a lineal response in the interval of mentioned Kerma. On the other hand the estimated Kerma with the Tl dosemeter in the calibration curves for X rays, were similar to the one measured with the previously gauged ionization chamber. The Tl of LiF: Mg, Cu, P + Ptfe, developed in the ININ, are highly reliable for X-ray dosimetry. (Author)

Tl response of LiF: Mg, Cu, P+Ptfe at X rays of 24, 42 and 100 KeV

International Nuclear Information System (INIS)

Gonzalez M, P.R.; Tovar M, V.M.; Azorin N, J.; Furetta, C.; Quiroz C, M.C.

2005-01-01

In this work the obtained results of the irradiation of thermoluminescent dosemeters (Tl) of LiF: Mg,Cu,P + Ptfe with X rays for the effective radiation energy of 24, 42 and 100 keV, in an interval of Kerma in air in the sinus of the air between 0.05 and 1.0 Gy are presented. The rate of Kerma in air was determined with an ionization chamber PTW-1152, gauged by the Laboratoire Central des Industries Electriques (LCIE). As reference commercial TLD-100 dosemeters was used. The results showed that the studied Tl dosemeters presented a lineal response in the interval of mentioned Kerma. On the other hand the estimated Kerma with the Tl dosemeter in the calibration curves for X rays, were similar to the one measured with the previously gauged ionization chamber. The Tl of LiF: Mg, Cu, P + Ptfe, developed in the ININ, are highly reliable for X-ray dosimetry. (Author)

Isotopic Thermionic Generator; Generateur thermoionique isotopique

Energy Technology Data Exchange (ETDEWEB)

Clemot, M; Devin, B; Durand, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-07-01

This report describes the general design of a thermionic direct conversion space generator. The power source used is a radioisotope. Two radioisotopes are considered: Pu 238 and Cm 244. The system is made up of a heat pipe concentrating the thermal flux from the isotope to the emitter, and of a second heat pipe evacuating the waste heat from the collector to the outer wall used as radiating panel. Calculations are given in the particular case of a 100 electrical watts output power. (authors) [French] Ce rapport decrit la structure d'un generateur spatial d'electricite a conversion directe du type thermoionique. La source d'energie est un radioisotope. Deux isotopes sont envisages: le Pu 238 et le Cm 244. Le systeme comporte pour l'emetteur un caloduc concentreur de flux thermique et pour le collecteur, un caloduc evacuateur vers l'enveloppe du generateur utilise, en panneau rayonnant. Les calculs ont ete conduits dans le cas particulier d'une puissance convertie de 100 watts electriques. (auteurs)

Modeling of demand response in electricity markets : effects of price elasticity

International Nuclear Information System (INIS)

Banda, E.C.; Tuan, L.A.

2007-01-01

A design mechanism for the optimal participation of customer load in electricity markets was presented. In particular, this paper presented a modified market model for the optimal procurement of interruptible loads participating in day-ahead electricity markets. The proposed model considers the effect of price elasticity and demand-response functions. The objective was to determine the role that price elasticity plays in electricity markets. The simulation model can help the Independent System Operator (ISO) identify customers offering the lowest price of interruptible loads and load flow patterns that avoid problems associated with transmission congestion and transmission losses. Various issues associated with procurement of demand-response offerings such as advance notification, locational aspect of load, and power factor of the loads, were considered. It was shown that demand response can mitigate price volatility by allowing the ISO to maintain operating reserves during peak load periods. It was noted that the potential benefits of the demand response program would be reduced when price elasticity of demand is taken into account. This would most likely occur in actual developed open electricity markets, such as Nordpool. This study was based on the CIGRE 32-bus system, which represents the Swedish high voltage power system. It was modified for this study to include a broad range of customer characteristics. 18 refs., 2 tabs., 14 figs

History of the electric-powered car...-1959; Histoire de la voiture electrique...-1959

Energy Technology Data Exchange (ETDEWEB)

Boursin, P

2005-07-01

This document is an exhaustive and well-documented review of the history of electric-powered vehicles between 1847 and 1959. Each prototype/model is described according to the available information. (J.S.)

Electrical installations of the Channel tunnel; Installations electriques du Tunnel sous la Manche

Energy Technology Data Exchange (ETDEWEB)

Kersabiec, G. de [Eurotunnel, Folkestone (United Kingdom)

2002-08-01

Like an underground factory, the railway and auxiliary equipments of the Channel tunnel between France and UK, need a reliable and redundant power supply with a high quality maintenance. This article presents: the design criteria of the power distribution systems, the installation itself and the organisation of its exploitation: 1 - transportation system of the Channel tunnel (loads to supply, exploitation imperatives, fundamental criteria); 2 - external power sources (connection to the UK and French grids, values used by the national grids); 3 - exploitation criteria, tunnel design; 4 - description (main UK and French power stations, 25 kV traction network, 21 kV distribution network, tunnels, lighting in railway tunnels, supply of terminals, earthing network); 5 - exploitation; 6 - maintenance and quality. (J.S.)

Towards future organization of French electricity sector; Vers la future organisation electrique francaise

Energy Technology Data Exchange (ETDEWEB)

Strauss-Kahn, Dominique; Pierret, Christian [Ministere de l' Economie, des Finances et de l' Industrie, Paris (France)

2000-02-07

This document displays information and questions concerning the future organization of the French electric sector. The directive on the domestic electricity market was adopted in 1996 by the Council of the Ministers of European Union and Parliament. The member states were due to transpose the directive within their national legislation up to 19 February 1999. The directive establishes principles but provides large reaches of maneuver to the member states which can choose the organizational means according to their own expectations. These task is considered as feasible by the authors. It must reinforce the public service by giving added strength to the security of supply and ensuring everybody's access to a well marketed and high quality electric supply. By introduction of certain well controlled elements of competition this evolution should also contribute to cost lowering, boost of the national competitiveness and support of employment. The document contains seven chapters which expose the following items: 1. The objectives of reorganization; 2. The directive and its reach; 3. Strengthening the public service; 4. Revamping the electric service to promote the growth; 5. Preserving the grids for the general benefit; 6. Defining the place of EDF within the new organizational scheme; 7. Developing an efficient regulation. Finally, an appendix is given containing the Directive 96/92/CE of the European Parliament and Council of 19 October 1996, concerning the common rules for domestic electricity market.

Lambeaux autofermants pour le traitement des brulures electriques du scalp par haut voltage

Science.gov (United States)

Hafidi, J.; El Mazouz, S.; El Mejatti, H.; Fejjal, N.; Gharib, N.E.; Abbassi, A.; Belmahi, A.M.

2011-01-01

Summary Les brûlures électriques par haut voltage sont responsables de gros dégâts tissulaires en immédiat et dans les jours suivant l’accident du fait de la chaleur importante dégagée par effet joule et de la thrombose microvasculaire évolutive. Les pertes de substances du scalp secondaires à ces brûlures nécessitent une couverture par lambeaux vu la destruction du périoste et du calvarium en regard. De juin 1997 à juin 2008, 15 patients ont été traités pour des pertes de substance du scalp secondaires à des brûlures électriques par haut voltage de diamètre allant de 8 à 11 cm et siégeant dans la région tonsurale. Ces patients ont été opérés dans la première semaine suivant l’accident. Les pertes de substance du scalp de taille moyenne secondaires à ces brûlures peuvent être couvertes per primam de façon fiable par des lambeaux locaux axialisés et multiples. Nous relatons l’expérience du Service de Chirurgie Plastique du Centre Hospitalier Universitaire Ibn-Sina, Rabat, Maroc, dans la gestion et la prise en charge de ces brûlures. PMID:22262963

Distributed Generation Management in Distribution Networks; Gestion de la production decentralisee dans les reseaux de distribution

Energy Technology Data Exchange (ETDEWEB)

Caire, R.

2004-04-15

Deregulations of the energy market, followed by many privatizations, and vertical disintegrations brought a complete reorganization of the electric sector. The opening of the energy markets as well as the technological developments of the means of production of small and average power strongly encourage this evolution. A systematic methodology to study the transmission of impacts between the Low and Medium Voltage is initially proposed, after a quick state of the art of the various possible impacts. The voltage deviation is then identified as the most critical impact. This criticality is supported by quantitative studies on French typical networks, and is confirmed by the related literature. In order to solve this impact, a research of the means of action within tension of the distribution network and their modeling is carried out. As the manipulated variables of the means of adjustment available are discrete or continuous, specific tools are then developed to coordinate them. This coordination is pressed on optimization algorithms developed by holding account of inherent specificity with the manipulated variables. A methodology for the choice or optimal location of the adjustment means associated with a management of the voltage deviation is presented. Lastly, 'decentralized' strategies of coordination for the means of adjustment and a proposal for an experimental validation are presented, thanks to a real time simulator, making it possible to test the strategies of coordination and the necessary means of communication. (author)

Architecture, design and protection of power distribution networks; Architecture, conception et protection des reseaux de distribution

Energy Technology Data Exchange (ETDEWEB)

Sorrel, J.P. [Schneider Electric SA, 92 - Boulogne-Billancourt (France)

2000-10-01

The design of all-electric ships calls for high power levels in the propulsion systems. Merchant ships and especially naval vessels demand rugged, reliable propulsion systems with high availability, low maintenance and ease of operation. These constraints imply the choice of an optimized single winding system. The design of the network topology and protection system, and the choice of operating voltage and HT neutral configuration are the main steps in the design. (author)

Distributed Generation Management in Distribution Networks; Gestion de la production decentralisee dans les reseaux de distribution

Energy Technology Data Exchange (ETDEWEB)

Caire, R

2004-04-15

Deregulations of the energy market, followed by many privatizations, and vertical disintegrations brought a complete reorganization of the electric sector. The opening of the energy markets as well as the technological developments of the means of production of small and average power strongly encourage this evolution. A systematic methodology to study the transmission of impacts between the Low and Medium Voltage is initially proposed, after a quick state of the art of the various possible impacts. The voltage deviation is then identified as the most critical impact. This criticality is supported by quantitative studies on French typical networks, and is confirmed by the related literature. In order to solve this impact, a research of the means of action within tension of the distribution network and their modeling is carried out. As the manipulated variables of the means of adjustment available are discrete or continuous, specific tools are then developed to coordinate them. This coordination is pressed on optimization algorithms developed by holding account of inherent specificity with the manipulated variables. A methodology for the choice or optimal location of the adjustment means associated with a management of the voltage deviation is presented. Lastly, 'decentralized' strategies of coordination for the means of adjustment and a proposal for an experimental validation are presented, thanks to a real time simulator, making it possible to test the strategies of coordination and the necessary means of communication. (author)

Le systeme d’information des reseaux de sante: la reorganisation de la medecine en e-sante

Directory of Open Access Journals (Sweden)

Maryline Margueritte

2013-01-01

Full Text Available Les réseaux de santé ont développé depuis plusieurs années des dispositifs permettant une prise en charge coordonnée des patients en France, tant sur les plans médical que médico-psycho-social et humain. Certains ont développé des dossiers de santé partagés informatisés permettant la mise en commun d’informations utiles à la coordination et à la continuité des soins. Depuis 2009 avec la réforme de l’hôpital on veut installer des modes de fonctionnement coopératifs entre les professionnels et avec les usagers du système de santé. La mise en œuvre d’un système d’information de santé pour assurer d’une part, la transversalité du processus métier avec le patient et d’autre part pouvoir mesurer les résultats médicaux et économiques de cette évolution d’un système complexe d’information. Dans ce contexte, les possibilités offertes par les technologies de l’information et de la communication (TIC permettent la mise en place d’applications favorisant une augmentation de la participation « on line » des citoyens. Le « virage ambulatoire » exporte la santé hors des murs. C’est une médecine innovante qui permet au patient de rester dans son « chez soi ». En France, ce re-engeneering repose sur quatre domaines : un dossier médical informatisé, une prise en charge collective par les professions médicales et paramédicales, une autonomisation et une mise en réseau du secteur de santé.

Detecteur multibandes libs a base de reseaux holographiques epais: Conception optomecanique et gestion de l'innovation

Science.gov (United States)

Gagnon, Daniel

Detection of sulfur by optical emission spectroscopy generally presents difficulties because the strongest lines are in the vacuum ultraviolet and therefore are readily absorbed by oxygen molecules in air. A novel concept for a low cost and efficient system to detect sulfur using near infrared lines by Laser-Induced Breakdown Spectroscopy is proposed in this thesis. The concept proposes to use customized thick holographic gratings, also referred as Volume Bragg Grating, for spectral filtering of the plasma light, and built-in custom electronics that amplify and integrate photodiodes output signals. In this work, the optomechanical design, manufacturing and trials of a multiband sensor's prototype is reviewed. Preliminary results has been presented at NASLIBS 2011 and showed a limit of detection comparable to that of a conventional high-end system. An article describing the concept and results has been published in a special issue of the Applied Optics journal. To turn this newly patented concept into commercial success, the management of the innovation has been performed by proposing strategic and tactic alliances for commercialisation purposes applied to strategic business positioning structured along the 3 axis Technology -- Product -- Market. Open innovation is here acting as the paradigm to efficiently reach the market. Discussion relative to strategic and tactic alliance is actually taking place for deployment of the LIBS multiband sensor in the mining industry.

Neural networks applied to inverters control; Les reseaux de neurones appliques a la commande des convertisseurs

Energy Technology Data Exchange (ETDEWEB)

Jammes, B; Marpinard, J C

1996-12-31

Neural networks are scarcely applied to power electronics. This attempt includes two different topics: optimal control and computerized simulation. The learning has been performed through output error feedback. For implementation, a buck converter has been used as a voltage pulse generator. (D.L.) 7 refs.

Contribution to the asymptotic estimation of the global error of single step numerical integration methods. Application to the simulation of electric power networks; Contribution a l'estimation asymptotique de l'erreur globale des methodes d'integration numerique a un pas. Application a la simulation des reseaux electriques

Energy Technology Data Exchange (ETDEWEB)

Aid, R.

1998-01-07

This work comes from an industrial problem of validating numerical solutions of ordinary differential equations modeling power systems. This problem is solved using asymptotic estimators of the global error. Four techniques are studied: Richardson estimator (RS), Zadunaisky's techniques (ZD), integration of the variational equation (EV), and Solving for the correction (SC). We give some precisions on the relative order of SC w.r.t. the order of the numerical method. A new variant of ZD is proposed that uses the Modified Equation. In the case of variable step-size, it is shown that under suitable restriction, on the hypothesis of the step-size selection, ZD and SC are still valid. Moreover, some Runge-Kutta methods are shown to need less hypothesis on the step-sizes to exhibit a valid order of convergence for ZD and SC. Numerical tests conclude this analysis. Industrial cases are given. Finally, an algorithm to avoid the a priori specification of the integration path for complex time differential equations is proposed. (author)

A study of filtering problems of background noise in nuclear spectrometry, improvement of signal-to-noise ratio, and of pulse characteristics produced by the optimum predictor device; Etude de problemes de filtrage de bruit de fond en spectrometrie nucleaire, amelioration du rapport signal sur bruit et des caracteristiques de l'impulsion mise en forme par le dispositif du predicteur optimum

Energy Technology Data Exchange (ETDEWEB)

Benda, J [Commissariat a l' Energie Atomique, 91 - Saclay (France). Centre d' Etudes Nucleaires

1967-05-01

The purpose of nuclear spectrometry is the precise measurement of particles energy. The resolving power of a spectrometer design is an important factor. Two main phenomena are involved in the limitation of this resolving power: The statistical fluctuations of the detector itself, and the background noise. For a given noise, the theory of filters enables the calculation of networks specially designed for the improvement of signal to noise ratio. The proposed system should lead to an improvement of 10.5 per cent of this ratio. Experiments have confirmed this theoretical estimation. The predictor device also makes possible the obtaining of shortened pulses. (author) [French] Les mesures en spectrometrie nucleaire ont pour but la determination precise de l'energie des particules. Le pouvoir de resolution d'une chaine de spectrometrie est une caracteristique importante. Deux phenomenes principaux concourent a limiter ce pouvoir de resolution: les fluctuations statistiques du detecteur et le bruit de fond. Pour un bruit de fond donne, la theorie des filtres permet de calculer des reseaux susceptibles de modifier le rapport signal sur bruit. Le systeme propose permet d'ameliorer de 10.5 pour cent ce rapport lorsqu'on se place dans les conditions optimales. Les resultats experimentaux confirment les previsions. Le dispositif predicteur permet aussi un raccourcissement de l'impulsion dans le temps. (auteur)

Damage caused to houses and equipment by underground nuclear explosions; Degats dus aux explosions nucleaires souterraines sur les habitations et les equipements

Energy Technology Data Exchange (ETDEWEB)

Delort, F; Guerrini, C [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

1969-07-01

A description is given of the damaged caused to various structures, buildings, houses, mechanical equipment and electrical equipment by underground nuclear explosions in granite. For each type of equipment or building are given the limiting distances for a given degree of damage. These distances have been related to a parameter characterizing the movement of the medium; it is thus possible to generalize the results obtained in granite, for different media. The problem of estimating the damage caused at a greater distance from the explosion is considered. (authors) [French] Les degats sur diverses structures, constructions, habitations, equipements mecaniques et materiels electriques provoques par des explosions nucleaires souterraines dans le granite sont decrits. On a indique pour chaque type de materiel ou de construction, les distances limites correspondant a un degre de gravite de dommage observe. Ces distances ont ete reliees a un parametre caracterisant le mouvement du milieu, permettant ainsi de generaliser les resultats obtenus dans le granite, a differents milieux. Le probleme de la prevision des degats en zone lointaine a ete aborde. (auteurs)

The effects of spots (or grains) and the mean work function of a polycrystalline emitter; Les effets des taches (ou grains) et le travail de sortie moyen d'un emetteur polycristallin

Energy Technology Data Exchange (ETDEWEB)

Devin, B; Phuc Nguyen, Xuan [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

The direct conversion of thermal energy at high temperature to electrical energy using plasma diodes is studied in the Electronic Physics Service of the French Atomic Energy Commission. Research concerns the adaptation of these diodes to nuclear reactors with a view especially to providing power for operating the instruments of space vehicles. In parallel with the semi-industrial realizations and tests, an important part of the activity of the service is directed towards fundamental research into physical phenomena convected with thermionic emission with a view to improving present performances. (authors) [French] La conversion directe de l'energie thermique a haute temperature en energie electrique par diodes a plasma est etudiee au Service d'Electronique Physique du Commissariat a l'Energie Atomique. On etudie l'adaptation de ces diodes aux reacteurs nucleaires, notamment en vue de fournir l'energie de servitude dans les vehicules spatiaux. Parallelement aux realisations et essais semi-industriels, une part importante de l'activite du Service est orientee vers l'etude fondamentale des phenomenes physiques lies a la conversion thermoionique dans le but d'ameliorer les performances actuelles. (auteurs)

Isotope analysis of uranium by optical spectroscopy; Analyse isotopique de I'uranium par spectroscopie optique

Energy Technology Data Exchange (ETDEWEB)

Gerstenkorn, S [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

Isotope analysis of uranium is made by means of hollow cathode lamp and Fabry-Perot photoelectric spectrometer. When using the line U I 5027 A, this method allows to determine isotopic concentrations in {sup 235}U down to 0,1 per cent. The relative precision is about 2 per cent for amounts of {sup 235}U over 1 per cent. For weaker amounts this line would allow relative measurements of better precision when using standard mixtures. (author) [French] L'analyse isotopique de l'uranium est effectuee a l'aide d'une lampe a cathode creuse et du spectrometre Fabry-Perot photo-electrique. On utilise la raie U I 5027 A. Cette methode permet de doser des melanges isotopiques dont la teneur en {sup 235}U, peut descendre jusqu'a 0,1 pour cent. La precision relative est de l'ordre de 2 pour cent pour des teneurs en {sup 235}U superieures a 1 pour cent. Pour des teneurs plus faibles cette raie {lambda} = 5027 A permettrait des mesures relatives de meilleure precision, en utilisant des melanges prealablement doses. (auteur)

Monthly Electrical Energy Overview December 2016

International Nuclear Information System (INIS)

2017-01-01

This publication presents the electricity characteristics and noteworthy developments in France every month: consumption, generation, renewable energies, cross-border trades and transmission system developments, along with feedback on the highlights affecting this data. This issue presents the key figures for December 2016. Demand in December 2016 was higher by more than 13% compared to December 2015, due to the significantly lower temperatures. The balance of exchanges was in favour of imports for the first time since February 2012. The December overview is published in the same time as the 2016 annual electricity report (http://bilan-electrique-2016.rte-france.com/). You will find there the analysis of the whole year. Adjusted electricity demand remained unchanged. Fossil fuel thermal generation reached 7.4 TWh, its highest level since February 2012. Wind power production was low, with an average wind load factor of around 17%. The monthly balance of French exchanges was in favour of imports, which had not happened since February 2012. 25 new installations went into service in December 2016

Superconducting transition and low-field magnetoresistance of a niobium single crystal at 4.2 deg. K; Transition supraconductrice et magnetoresistance en champ faible d'un echantillon monocristallin de niobium a 4.2 deg. K

Energy Technology Data Exchange (ETDEWEB)

Perriot, G. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires. Service de physique du solide et de resonnance magnetique

1967-01-01

We report the study of the electrical resistance of a niobium single crystal, at 4.2 deg. K, from the beginning of the superconductive transition to 80 kilo oersteds. Critical fieldsH{sub c2} and H{sub c3} have been determined. Influences on superconductive transition of current density, field-current angle, crystal orientation and magnetoresistance have been studied. Variation laws of low-field transverse and longitudinal magneto-resistances have been determined. (author) [French] La variation de la resistance electrique d'un monocristal cylindrique de niobium a ete etudiee, a 4,2 deg. K, depuis le debut de la transition supraconductrice jusqu'a 80 kilooersteds. Les champs critiques H{sub c2} et H{sub c3} ont ete determines. On a etudie l'influence de la densite de courant, de l'angle champ-courant, de l'anisotropie cristalline et de la magnetoresistance sur la transition supraconductrice. Les lois de variation des magnetoresistances transversale et longitudinale ont ete determinees dans le domaine des champs faibles. (auteur)

Interconnection and transportation networks: adjustments and stability; Reseaux d'interconnexion et de transport: reglages et stabilite

Energy Technology Data Exchange (ETDEWEB)

Bornard, P. [Reseau de Transport d' Electricite (RTE), Div. Systeme Electrique, 92 - Paris la Defense (France); Pavard, M. [Electricite de France (EDF), 75 - Paris (France); Testud, G. [Reseau de Transport d' Electricite (RTE), Dept. Exploitation du Systeme Electrique, 92 - Paris la Defense (France)

2005-10-01

Keeping the mastery of the safety of a power transportation system and respecting the contractual commitments with respect to the network users implies the implementation of efficient frequency and voltage adjustment systems. This article presents a synthetic overview of the methods and means implemented to ensure the adjustment of the voltage and frequency and the stability of very-high voltage power transportation networks: 1 - recalls of the general problem; 2 - frequency and active power adjustment: adapting generation to consumption, adapting consumption to generation; 3 - voltage and reactive power adjustment: duality of the voltage-reactive compensation adjustment, compensation of the reactive power, voltage adjustment chain, voltage adjustment of very high voltage networks, collapse of the voltage plan; 4 - alternators stability: static stability, transient stability, numerical simulation methods, stability improvement; 5 - conclusion. (J.S.)

Modelling and control of an electric vehicle; Modelisation et controle d`un vehicule electrique

Energy Technology Data Exchange (ETDEWEB)

Kwartnik, J

1995-11-28

The work described in this report provides to engineers or researchers a tool for electric vehicle simulation. The different components included in the system are described with in particular the choppers, the pedal accelerator and the vehicle dynamic represented by the different constraints applied to the vehicle (efforts of drag, of lift, of rolling and slope resistance). This study has been realized by considering nonlinear phenomenons such as the armature magnetic reaction or the resistance change due to temperature increasing. The complexity of the system leads to use several of control. The theory of linear systems made possible the synthesis of PID controllers after few hypothesis. An on line adaptation technique completed this synthesis by considering nonlinear effects. For the cruise control we have used a control based on fuzzy set theory. We showed through two examples, the cruise control and the motor control using a strategy which minimize the Joule effect looses, the interest and the possibilities of the model evolution. (author) 21 refs.

Electric technology in the food service industry; Les technologies electriques dans les services alimentaires

Energy Technology Data Exchange (ETDEWEB)

Labonte, A. [Hydro-Quebec, Montreal, PQ (Canada)

1997-04-01

Many innovative technologies in the food service industry have been made through the use of electricity as a source of energy. Electricity made it possible to improve the productivity and profitability of the food industry. Some of these technologies include: (1) cooking by induction, which is based on the principle of magnetic fields, (2) combined convection ovens which accelerate thermal exchange, and (3) electric fryers. The advantages of each technology were described. The environmental advantage of using electricity as an energy source in the food service industry was also discussed.

Electric discharge in gases: Toepler's formula; Decharge electrique dans les gaz formule de Toepler

Energy Technology Data Exchange (ETDEWEB)

Ahier, G.

1957-07-01

In this technical note, the author recalls that when a potential difference at least equal to the disruptive voltage is applied between two electrodes which separate a gaseous medium, after some preliminary phenomena, the apparent electric resistance of the gaseous spacing quickly decreases until breakdown. He recalls the formula which has been experimentally established by Toepler for the resistance. Then, in order elaborate a theoretical justification of the Toepler formula which has a rather important role in issues related to plasma formation, two methods are proposed for this justification.

Reference costs of the electric power production; Couts de reference de la production electrique

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-06-01

This study periodically realized by the DGEMP aims to compare the competitiveness of the different channels of electric power production, for different utilization conditions. The first part ''reference costs of the 2003 electric power production'' examines the prices of the electric power produced by different channels in particular in the framework of the industrial implementing in 2015. The nuclear and thermal power plants are concerned. The second part is devoted to the decentralized production channels (wind energy, photovoltaic, cogeneration heat-electricity) is under construction and will be presented next year. (A.L.B.)

Imagerie par modulation acoustique de conductivite electrique destinee au diagnostic du cancer du sein

Science.gov (United States)

Gendron, Mathieu

This thesis describes a new medical imaging technique for determining the electrical conductivity distribution of tissues in a body region with a resolution comparable to that of current ultrasound techniques. The new technique, henceforth referred to as "Acousto-Electric Conductivity Modulation" (AECM) imaging, is based on the interaction of a sound wave with an electrical field. In its simplest form, four electrodes located near the region to be imaged apply a low-amplitude electrical current and measure the potential difference arising from current flow in the tissues. A focused ultrasound transducer directs a pressure wave to a voxel of the region of interest, modifying its conductivity distribution and, as a result, the amplitude of the potential measured by the electrodes. An image of the conductivity distribution can thus be constructed point-by-point by moving the electrodes and transducer to scan the object. In this context, the acoustic wave acts as the localization agent while the electrical potential provides a measure of the local conductivity change that occurs in the voxel. The first model presented in the thesis is based on the use of bipolar acoustic waves for excitation. This waveform is generally used with narrow band transducers. Acoustic waves generated by an ultrasound transducer driven with a burst of sine waves consists of alternating compression and rarefaction phases which tend to cancel each other in terms of the conductivity changes they produce. However when the thickness of the target object is small compared to the wavelength of the acoustic wave, this cancelling effect will not occur and the AECM signals will have sufficiently high amplitude to achieve image reconstruction using successive transducer positions to scan the region of interest. By extracting from the spectra of the AECM signals the amplitude of the peak at the excitation frequency, a map of the acousto-electric sensitivity of the system can be obtained. This map is then used to reconstruct the electrical conductivity distribution. The second model presented in the thesis uses a unipolar acoustic wave to generate AECM signals of relatively large amplitude. There are two aspects related to this type of wave. The first aspect is that the acoustic modulation is unidirectional if the applied pressure is unidirectional. As a result, a positive pressure only produces an increase in electrical conductivity and this will result in a large AECM signal even when the thickness of the object is large. The second aspect concerns the shape of the acoustic field. Since the unipolar acoustic wave is not focused, it modulates the conductivity over a large area, and thus the associated AECM signals needs to be processed through a reconstruction algorithm so as to recover local conductivity. In this model, the data required for image reconstruction are acquired by rotating the transducer around the target object. An experimental setup has been developed during our project to get values of certain parameter that are required to define the numerical models. The setup comprises a large tank which is filled with water and in which are immersed the ultrasound transducer, a hydrophone and a measurement cell. The acousto-electric interaction takes place within this cell. A computer controlled positioning system allows precise displacements of the transducer relative to the hydrophone and the measurement cell. This cell comprises a cavity in which the object to be analyzed is placed and that is then filled with an electrolytic solution. The cavity is closed on two sides by an acoustic window to allow propagation of the ultrasound wave and on another side by six Ag/AgCl electrodes that are used to apply current and to measure the resulting electrical potential. Mammography is presently the most widely used medical imaging procedure for breast cancer screening. The average sensitivity of this technique is 80 % but it is less for younger women. According to recent studies, MRI offers a higher sensitivity and the possibility of detecting very small tumors, thus allowing earlier treatment. The operating costs of MRI systems are at the moment too high to consider using the modality for breast cancer screening on a large scale. AECM imaging could eventually provide an interesting compromise between operating costs and the sensitivity required for screening patients of all ages. (Abstract shortened by UMI.).

The power consumption of mural central heating boilers; La consommation electrique des chaudieres murales

Energy Technology Data Exchange (ETDEWEB)

Anon.

1997-10-01

Two huge campaigns of measurements in the residential sector have revealed the unsuspected level of power consumption of heating and ventilation auxiliaries. It is important to know these levels in order to reduce them as they can significantly increase the energy bill of the lodging. This paper analyzes the case of mural central heating boilers with their auxiliaries: circulating pump of the heating loop and of the sanitary hot water production, ventilation systems, impact of the type of control system used (programmable clock, thermostat or none), annual and seasonal power consumption and the different solutions to reduce these over-consumptions. (J.S.)

Active component modeling for analog integrated circuit design. Model parametrization and implementation in the SPICE-PAC circuit simulator; Modelisation de composants actifs pour la CAO de circuits integres analogiques. Parametrage et implantation de modeles dans le simulateur SPICE-PAC

Energy Technology Data Exchange (ETDEWEB)

Marchal, Xavier

1992-06-19

. The first approach, physically based, is often time-consuming and results can be not accurate enough over all useful physical range. The second approach is achieved through the use of an optimizing program, FIT-PAC, which is closely associated to the modular circuit Simulator SPICE-PAC; a detailed description of it is given for a better overall understanding of the topic. FIT-PAC adjusts simultaneously ail parameters values, through use of 2 complementary optimizing methods: simulated annealing and SIMPLEX (or polytope) algorithms. We found this approach to be more efficient, systematic and easier to use than the Levenberg-Marquardt based fitting programs; this is due to the tact that neither simulated annealing nor simplex need the evaluation of the objective parametrization function gradient; this gradient can be very tedious to evaluate in many cases. We present results and discuss them in the case of static (DC) and dynamic (TRAN) MOS SPICE LEVEL 3 parameters determination. (author) [French] L'essor de l'industrie electronique est du principalement a l'integration accrue de dispositifs semi-conducteurs sur un meme support. Les programmes de conception assistee par ordinateur (CAO) sont les outils indispensables des concepteurs; ils permettent, avant fabrication, le test exhaustif de circuits complexes en evaluant leurs performances pour des conditions de fonctionnement normales ou extremes. Parmi tous ces logiciels, ceux de simulation electrique sont les plus largement utilises. Nous presentons les principaux en insistant sur le programme SPICE (Simulation Program with Integrated Circuit Emphasis) de Berkeley, reconnu comme la reference de la simulation de circuits. Cependant ce programme ne permet que des analyses standard; nous detaillons le programme SPICE-PAC qui possede toutes les fonctionnalites de SPICE, dont il est derive, mais permet, du fait de sa structure modulaire, des analyses nouvelles et variees. Cependant les programmes de simulation les plus

Behaviour of uranium under irradiation; Comportement de l'uranium sous irradiation

Energy Technology Data Exchange (ETDEWEB)

Adda, Y; Mustelier, J P; Quere, Y [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1964-07-01

phase alloys (U Nb, U Mo) the size and distribution of the bubbles are greatly influenced by the existence of a polygonization lattice, formed before irradiation, inside the grains. During high temperature annealings the bubbles situated on the polygonization lattice grow much faster than those which are distributed inside the crystal. In the case of uranium the bubbles are either distributed at random, or grouped in flat accumulations which can give rise to transgranular cracks, according to the state of the metal and the irradiation temperature. At high temperature an intergranular de-cohesion is also observed. (authors) [French] On expose les principaux resultats obtenus dans l'etude de la formation des defauts introduits dans l'uranium par la fission a basse temperature. Par irradiation a 20 K on a pu evaluer le nombre de paires de Frenkel produites par une fission. L'analyse des courbes de variation de resistivite electrique a permis de preciser l'etendue des pointes de deplacement (deplacement Spike) et le mecanisme de la creation des defauts dus a la fission. Des irradiations a 77 K ont apporte des precisions supplementaires et indiquent un comportement different de l'uranium recristallise et ecroui. On a etudie la diffusion des gaz rares a partir d'alliages metal-gaz rare obtenus par decharge electrique et d'echantillons d'uranium irradie. Le degagement des gaz rares sous vide n'est controle par un processus de diffusion simple que dans le cas ou la teneur en gaz rare est tres faible (U tres faiblement irradie). Par contre quand la teneur en gaz rare est plus forte (echantillons prepares par decharge electrique) le degagement du gaz se produit par formation, croissance et coalescence de bulles; le coefficient de diffusion apparent est alors tres different du coefficient vrai et ne peut etre utilise dans les calculs de gonflement. Dans le cas d'un processus de diffusion simple on a etudie les differents facteurs qui regissent le phenomene. On a montre en

Les fluctuations supraconductrices dans le compose praseodyme-cerium-oxyde de cuivre

Science.gov (United States)

Renaud, Jacques

Ce travail etudie les fluctuations supraconductrices dans le compose supraconducteur a haute temperature critique dope aux electrons Pr2-xCe xCuO4+delta. La technique utilisee pour sonder ces fluctuations est le transport electrique DC dans le plan ab. Il s'agit, a notre connaissance, de la premiere etude de ce type dans la classe generale des supraconducteurs a haute temperature critique dopes aux electrons et, plus particulierement, dans Pr2-xCe xCuO4+delta. De plus, l'etude est effectuee pour trois regimes de dopage, soit sous-dope x = 0.135, dopage optimal x = 0.15 et surdope x = 0.17. Les echantillons etudies sont des couches minces d'epaisseur plus grande que 100 nm crues par ablation laser. Les mesures electriques DC effectuees dans ce travail sont la resistance en reponse lineaire et les courbes IV en reponse non lineaire en fonction de la temperature. La mise en oeuvre experimentale de ces mesures a necessite une grande attention au filtrage et aux effets de chauffage a haut courant. Nous montrons que, sans cette attention, les donnees experimentales sont toujours erronees dans le regime pertinent pour nos echantillons. Les resultats pour le dopage optimal x = 0.15 sont expliques de facon tres convaincante dans le cadre de fluctuations purement 2D. D'abord, le regime des fluctuations gaussiennes est tres bien decrit par le modele d'Aslamazov-Larkin en deux dimensions. Ensuite, le regime de fluctuations critiques, se trouvant a plus basse temperature que le regime gaussien, est tres bien decrit par la physique 2D de Kosterlitz-Thouless. Dans cette analyse, les deux regimes ont des temperatures critiques coherentes entre elles, ce qui semble confirmer ce scenario 2D. Une analyse des donnees dans le cadre de fluctuations 3D est exploree mais donne des conclusions incoherentes. Les resultats pour les autres dopages sont qualitativement equivalents avec le dopage optimal et permettent donc une explication purement 2D. Par contre, contrairement au dopage optimal

Contribution to the study of U-Ti and U-Pu-Ti carbides; Contribution a l'etude des carbures U-C-Ti et (U, Pu) - C-Ti

Energy Technology Data Exchange (ETDEWEB)

Milet, C A [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1968-07-01

After having discussed the reasons to use (U,Pu) carbides as fast reactor fuel, we examine the influence of the addition of titanium to these carbides. A preliminary study has been done on the system of U-C-Ti and some properties have been measured such as: density, thermal expansion, electrical resistivity, atmospheric corrosion and compatibility with stainless steel. The systems U-Pu-C-Ti (Pu/U + Pu equal to 15 per cent) and U-C-Ti have been found to be very similar. There exists a two phases region (U,Pu)C + TiC, an eutectic between (U,Pu)C and TiC for approximately 15 at %. The solubilities of U + Pu in TiC and of Ti in (U,Pu)C is less than 1 % at. The addition of titanium does not markedly change thermal expansion coefficients of (U,Pu)C. However the resistance to atmospheric corrosion and compatibility with stainless steel is improved. Thermal conductivity, calculated from electrical resistivity, has increased. On the other side, the density of fissile material is lowered. The combination of (U,Pu)C + TiC seems to be the most promising alloy for application as nuclear fuel. (author) [French] Apres avoir rappele les problemes poses par un combustible pour les reacteurs a neutrons rapides et l'interet des carbures U-Pu-C comme combustible, on examine l'influence de l'addition de titane dans ces carbures. Une etude preliminaire sur le systeme U-C-Ti a ete effectuee et quelques proprietes sont indiquees: densite, coefficients de dilatation, resistivite electrique, tenue a la corrosion atmospherique, compatibilite avec l'acier inoxydable. Le systeme U-Pu-C-Ti (Pu/U + Pu egal a 15 pour cent) presente de grandes analogies avec le systeme U-C-Ti. Il existe un domaine biphase (U,Pu)C + TiC, un eutectique entre (U,Pu)C et TiC pour environ 15 at % Ti; les solubilites de U + Pu clans TiC et de Ti dans (U,Pu)C sont inferieures a 1 at %. Par rapport a la phase (U,Pu)C, l'addition de titane est sans effets importants sur les coefficients de dilatation. Par contre la tenue a

Gases e ruídos em edificações para suínos: aplicação das normas NR-15, CIGR e ACGIH

OpenAIRE

Sampaio,Carlos A. de P.; Nääs,Irenilza de A.; Nader,Alexandre

2005-01-01

A produção de suínos representa importante setor da economia brasileira, e a possibilidade de crescimento na produção é iminente, principalmente se considerar o baixo consumo de carne suína comparado ao de outras carnes e com outros países. As transformações e exigências de mercado que vêm ocorrendo no cenário mundial mostram que, num futuro muito próximo, as barreiras serão baseadas no bem-estar dos animais, na proteção ao meio ambiente e na legislação trabalhista. Pouco conhecimento está di...

Biological monochromator with a high flux in the visible spectrum; Un monochromateur biologique a haut flux dans le visible

Energy Technology Data Exchange (ETDEWEB)

Andre, M; Guerin de Montgareuil, P [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

1965-07-01

The object is to carry out research into photosynthesis using energetic illuminations similar to those employed with white light studies. The limitations are due mainly to the source. A comparison of various possible solutions has led to the choice of the sun used in conjunction with 4 large gratings. In an intermediate stage, a description is given of a medium-aperture monochromator with a 3 kW xenon arc and a single grating. With this set-up it is possible to obtain the following performance, given as an example; energy illumination, 1.3 mW/cm{sup 2} over a surface of 50 cm{sup 2} and for a bandwidth at half-height of 50 Angstroms. (authors) [French] L'objectif est de poursuivre en lumiere monochromatique des etudes de photosynthese avec des eclairements energetiques analogues a ceux qu'on utilise en lumiere blanche. Les limitations se situent principalement au niveau de la source. Une comparaison effectuee entre differentes solutions possibles conduit a preconiser l'emploi du soleil associe a 4 grands reseaux. En etape intermediaire on decrit un monochromateur de moyenne ouverture, avec un arc au xenon de 3 kW et un seul reseau, qui permet d'atteindre les performances suivantes donnees a titre d'exemple: eclairement energetique de 1,3 mW/cm{sup 2} sur une surface de 50 cm{sup 2} et pour une bande passante a mi-hauteur de 50 Angstroems. (auteurs)

Canadian conference on electrical and computer engineering proceedings. Congres canadien en genie electrique et informatique

Energy Technology Data Exchange (ETDEWEB)

Bhargava, V K [ed.

1993-01-01

A conference was held on the subject of electrical and computer engineering. Papers were presented on the subjects of artificial intelligence, video, signal processing, radar, power electronics, neural networks, control, computer systems, transportation electronics, software tools, error control coding, electrothermal phenomena, performance evaluation of computer systems, wireless communication, satellite communication, very large scale integration, parallel processing, pattern recognition, telephony, graphs and algorithms, multimedia, broadcast systems, remote sensing, computer networks, modulation and coding, robotics, computer architecture, spread spectrum, image processing, microwave circuits, biomedical engineering, specification and verification, image restoration, communications networks, computer-aided design, drives, energy systems, expert systems, and optics. Separate abstracts have been prepared for 56 papers from the conference.

Electrical circuits of an electromagnetic isotope separator; Circuits electriques d'un separateur d'isotopes electromagnetique

Energy Technology Data Exchange (ETDEWEB)

Neyron, A. [Commissariat a l' energie atomique et aux energies alternatives - CEA, Centre d' etudes nucleaires de Saclay (France)

1959-07-01

After an outline of the general principles governing the operation of an electromagnetic isotope separator, the electrical characteristics necessary to this operation are given. First the electrical characteristics of the ion source are briefly presented. The author then gives a detailed account of the construction of the H.T. acceleration supply of which the maxima characteristics are 80 kV and 150 mA with stabilisation of the order of 4.10{sup -4}. Reprint of a paper published in 'Industries Atomiques' - n. 3-4, 1959.

Electrical Energy Statistics for France 2002; Statistiques de l'energie electrique en France - 2002

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-11-01

Detailed statistics on electricity flows in France and on facilities. Regional data / Consumption per sector of activity / Records over last 10 years (definitive results). In 2002, national electrical consumption reached 449.9 TWh, an increase of 0.3% compared with 2001 (448.6 TWh). Adjusted for winter and summer climate contingencies, its growth rate was 0.9% compared with 2001. Consumption by customers connected at high or medium voltage levels came to 254.2 TWh, an increase of 0.8% compared with 2001 (252.3 TWh); consumption by customers connected at low voltage levels came to 165 TWh, a decrease of 0.8% compared with 2001 (166.4 TWh). Generation in France reached 534.3 TWh, an increase of 11.5 TWh or 2.2% compared with 2001 (522.8 TWh). This increase broke down between nuclear generation and conventional thermal generation. Net nuclear generation injected, as measured by RTE, came to 415.5 TWh in 2002, an increase of 4.0% compared with 2001 (399.6 TWh). Conventional thermal generation came to 51.1 TWh, an increase of 15.4 % compared with 2001 (44.3 TWh). Hydro-electric generation amounted to 65.5 TWh, a fall of 15.3% compared with 2001 (77.3 TWh). In terms of physical exchanges with foreign countries, France exported a net total of 77 TWh, an increase of 12.6% compared with 2001 (68.4 TWh). Contractual exchanges with foreign countries, recorded by RTE, fell by 9.9 % to reach a cumulative value for exports and imports of 107.8 TWh (compared with 120 TWh in 2001)

MECANISME DE DEGRADATION DE FILMS DE POLYPROPYLENE IMPREGNE SOUS CHAMP ELECTRIQUE EN PRESENCE D'OXYGENE

OpenAIRE

Said , Sylvère

1994-01-01

The concern of this body of work is the mechanism of dégradation of impregnated polypropylène film capacitors in an oxygen blanket. Tins study is carried out on plane électrode capacitor models with expérimental parameters (AC electrical field in the range 66 V/um-200 V/pm, oxygen blanket, température 80°C) which hâve enabled us to obtain results in good agreement with industrial capacitor behaviour.Capacitor ageing is mainly assessed by its mean life-time and the change in the physio-chemica...

The fuel cell and the electrical vehicle; La pile a combustible et la voiture electrique

Energy Technology Data Exchange (ETDEWEB)

Dubois, J C [Universite Pierre et Marie Curie, 75 - Paris (France)

1999-01-01

The fuel cell is an electrochemical generator able to transform directly the chemical energy of a gaseous fuel (hydrogen, natural gas, coke gas or methanol...) with a combustive (oxygen for example) in electricity, heat, water and carbon dioxide. This article briefly describes at first the history of the fuel cell and after its working principle with the main reasons of its present development. Indeed, the fuel cell could be an alternative to the batteries for the electrically powered vehicles but also for other applications demanding autonomous electrical supply. The different types of fuel cells are described with their own performances. The proton exchange membrane fuel cells (PEMFC) are more specially described. Examples of polymer membranes with their performances are given. The different programs in the EC and in the world are described as well as their applications in different domains such as the electrical powered car. (authors) 10 refs.

Investment and deregulation in the electricity generation industry; Investissement et dereglementation dans le secteur electrique

Energy Technology Data Exchange (ETDEWEB)

Peluchon, B

2007-12-15

This work addresses the issue of investment in the electricity generation industry. As the analysis of many crisis which have affected electricity markets shows, there is a systematic under-investment in peak capacity. Electricity prices are not high enough to cover fixed costs of such generators, a phenomenon that has been dubbed 'missing money' in some recent papers (Stoft). The investment decisions of a duo-poly facing random demand are then compared to those of a public monopoly. The results are that no prices may be high enough to solve the 'missing money' problem, since the duo-poly is able to exercise market power in order to maximize his profit. This results systematically in fewer peak capacity in the duo-poly case than in the public monopoly case. This remains true in the case of a n-oligopoly. The necessity of designing a mechanism remunerating capacity is thus demonstrated. Capacity markets are then analysed in the light of those results. What appears is that operating reserves are a public good and, as such, prevents capacity markets to solve the 'missing money' problem. This casts a shadow on the pursuit of deregulation in the electricity industry. (author)

Control of peripheral units by satellite computer

International Nuclear Information System (INIS)

Tran, K.T.

1974-01-01

A computer system was developed allowing the control of nuclear physics experiments, and use of the results by means of graphical and conversational assemblies. This system which is made of two computers, one IBM-370/135 and one Telemecanique Electrique T1600, controls the conventional IBM peripherals and also the special ones made in the laboratory, such as data acquisition display and graphics units. The visual display is implemented by a scanning-type television, equipped with a light-pen. These units in themselves are universal, but their specifications were established to meet the requirements of nuclear physics experiments. The input-output channels of the two computers have been connected together by an interface, designed and implemented in the Laboratory. This interface allows the exchange of control signals and data (the data are changed from bytes into word and vice-versa). The T1600 controls the peripherals mentionned above according to the commands of the IBM370. Hence the T1600 has here the part of a satellite computer which allows conversation with the main computer and also insures the control of its special peripheral units [fr

G2 - G3 inventive properties, the first french nuclear plants; Caracteristiques generales et aspects originaux des reacteurs G2 et G3

Energy Technology Data Exchange (ETDEWEB)

Pascal,; Horowitz,; Bussac,; Joatton,; de Meux, De Lagge; Martin, [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

This paper points out the inventive properties of the frenchctors G2 and G3. These are dual purpose reactors, i.e. designed for the production of both plutonium and energy (30 electrical MW); in this respect, they can be considered as the start point of the french electrical energy produced from nuclear fuel. The following points are specially discussed in this paper: the choice of the prestressed concrete pressure vessel, the horizontal arrangement of the channels, the interest of neutron flux flattening, the advantages of the charging and discharging device working during pile operation. (author)Fren. [French] Les caracteres originaux des reacteurs fran is G2 et G3 sont decrits dans ce rapport. Ce sont des reacteurs a double fin, plutonigenes et aussi producteurs d'energie (30 MW electriques); ils constituent a ce titre le point de depart de la production fran ise d'electricite d'origine nucleaire. Sont discutes, en particulier, dans ce rapport: le choix du caisson en beton precontraint pour tenir la pression, la disposition horizontale des canaux, l'interet de l'aplatissement du flux neutronique, les avantages de l'appareil permettant le chargement et le dechargement du combustible sans arreter la pile. (auteur)

Impact de la preparation des anodes crues et des conditions de cuisson sur la fissuration dans des anodes denses

Science.gov (United States)

Amrani, Salah

fabriquees industriellement. Cette technique a consiste a determiner le profil des differentes proprietes physiques. En effet, la methode basee sur la mesure de la distribution de la resistivite electrique sur la totalite de l'echantillon est la technique qui a ete utilisee pour localiser la fissuration et les macro-pores. La microscopie optique et l'analyse d'image ont, quant a elles, permis de caracteriser les zones fissurees tout en determinant la structure des echantillons analyses a l'echelle microscopique. D'autres tests ont ete menes, et ils ont consiste a etudier des echantillons cylindriques d'anodes de 50 mm de diametre et de 130 mm de longueur. Ces derniers ont ete cuits dans un four a UQAC a differents taux de chauffage dans le but de pouvoir determiner l'influence des parametres de cuisson sur la formation de la fissuration dans ce genre de carottes. La caracterisation des echantillons d'anodes cuites a ete faite a l'aide de la microscopie electronique a balayage et de l'ultrason. La derniere partie des travaux realises a l'UQAC contient une etude sur la caracterisation des anodes fabriquees au laboratoire sous differentes conditions d'operation. L'evolution de la qualite de ces anodes a ete faite par l'utilisation de plusieurs techniques. L'evolution de la temperature de refroidissement des anodes crues de laboratoire a ete mesuree; et un modele mathematique a ete developpe et valide avec les donnees experimentales. Cela a pour objectif d'estimer la vitesse de refroidissement ainsi que le stress thermique. Toutes les anodes fabriquees ont ete caracterisees avant la cuisson par la determination de certaines proprietes physiques (resistivite electrique, densite apparente, densite optique et pourcentage de defauts). La tomographie et la distribution de la resistivite electrique, qui sont des techniques non destructives, ont ete employees pour evaluer les defauts internes des anodes. Pendant la cuisson des anodes de laboratoire, l'evolution de la resistivite

Prospects for the Use of Plutonium in Reactors; Prospective d'Utilisation du Plutonium dans les Reacteurs

Energy Technology Data Exchange (ETDEWEB)

Fossoul, E.; Haubert, P. [BELGONUCLEAIRE (Belgium); Hirschberg, D.; Morlet, E. [International Business Machines of Belgium, Bruxelles (Belgium)

1967-09-15

The introduction, at an increasing rate, of power reactors using slightly enriched uranium will inevitably lead to the production of considerable quantities of plutonium over the next decade. Fast reactors will not be capable of absorbing this material before 1980. The question thus arises of whether one should store the plutonium far future use in fast reactors, recycle it in existing thermal reactors, or try to sell it. The problem has been studied for an electric power generating system that does not foresee selling the plutonium produced by its reactors and does not buy plutonium outside, which enables a good approximation to be made and eliminates the major unknown quantity represented by the future market price of plutonium. Assuming within this system a programme that provides for the construction of power reactors of a given type and capacity at specific dates, the utilization of the plutonium produced can be optimized by linear programming techniques so as to minimize the discounted total cost of the power generated over a given period. A later stage consists in optimizing, by various techniques, not only the utilization but also the production of plutonium by appropriate selection of the power reactor types to be constructed. (author) [French] L'implantation, a un rythme croissant, de centrales nucleaires a uranium legerement enrichi entrainera la production ineluctable d'une quantite importante de plutonium au cours de la prochaine decennie. Les reacteurs a neutrons rapides ne seront capables d'absorber cette production qu'apres 1980. La question se pose donc de savoir s'il est preferable de stocker le plutonium en vue de son utilisation ulterieure dans les reacteurs a neutrons rapides plutot que de le recycler dans les reacteurs actuels a neutrons thermiques ou d'essayer de le vendre. Ce probleme a ete etudie dans le cadre d'un systeme de production d'energie electrique qui ne prevoirait pas la vente du plutonium produit par ses reacteurs nucleaires ni

Pulsed Neutron Studies of BeO-Natural Uranium Lattices; Etudes de Reseaux Uranium Naturel-Glucine, par la Methode des Neutrons Pulses; Issledovanie reshetok BeO-prirodnyj uran s pomoshch'yu impul'snykh nejtronov; Estudio de Reticulados de Beo-Uranio Natural con Ayuda de Neutrones Pulsados

Energy Technology Data Exchange (ETDEWEB)

Joshi, B. V.; Nargundkar, V. R.; Subbarao, K. [Atomic Energy Establishment Trombay, Bombay (India)

1965-10-15

The use of the pulsed neutron method for determination of the diffusion parameters and multiplication constants of lattices is described. The diffusion parameters and multiplication constants of BeO-natural uranium lattices are obtained by this method. The uranium rods used were 2.92 cm diameter clad in aluminium 0.072 cm thick and were arranged vertically in channels of square cross-section 5 cm x 5 cm, in a square lattice of pitch 15 cm. The neutron bursts were produced from a cascade accelerator by pulsing the ion source and using the Be(d,n) reaction. The detectors were enriched boron trifluorfde proportional counters. The space and time harmonics were eliminated as described by the authors in another paper at this Symposium. The decay constant of the fundamental mode was determined for several bucklings, far from criticality. In these calculations the effect of diffusion cooling and anisotropy was taken into account. All the diffusion and multiplication constants were determined by the method of least squares fit by three different approaches. The prompt critical buckling was determined by solving the decay constant equation for {lambda} = 0. The final results are: Diffusion length L = 15.2 cm Absorption constant {lambda}{sub 0} = 762.5 s{sup -1}. Diffusion coefficient D = 1.761 x 10{sup 5} cm{sup 2}/s Diffusion cooling constant C = -8.766 x 10{sup 5} cm{sup 4}/s Age {tau} = 150.7 cm{sup -2} Infinite multiplication factor k{sub {infinity}} = 1.126 Prompt critical buckling B{sup 2} = 3.00 x 10{sup -4} cm{sup -2}. (author) [French] Les auteurs decrivent l'utilisation de la methode des neutrons puises pour la determination des parametres de diffusion et des constantes de multiplication des reseaux. Cette methode permet d'obtenir les parametres de diffusion et les constantes de multiplication du reseau uranium naturel-glucine. Les barres d'uranium utilisees avaient un diametre de 2,92 cm et un gainage'd'aluminium d'une epaisseur de 0,072 cm elles etaient disposees

Electronic methods for discriminating scintillation shapes; Methodes electroniques de discrimination des formes des impulsions issues de scintillateurs; Ehlektronnye metody diskriminatsii form stsintillyatsii; Metodos electronicos de discriminacion de forma de impulsos de centelleo

Energy Technology Data Exchange (ETDEWEB)

Forte, M; Konsta, A; Maranzana, C [European Atomic Energy Community, CCR, ISPRA (Italy)

1962-04-15

ne doit se faire qu'entre deux types d'impulsions seulement (neutrons et rayons gamma, par exemple), on a egalement envisage l'emploi de reseaux passifs qu'il serait possible d'ameliorer et de simplifier. Les auteurs ont fait l'essai de quelques reseaux; ils sont notamment parvenus, en presence d'un bruit de fond du a des rayons gamma, a realiser la discrimination dans des scintillateurs liquides de protons de recul ne delivrant que de faibles impulsions (quelques dizaines de photo-electrons) et celle de fragments de capture de neutrons dans des scintillateurs liquides contenant du bore. Certains de ces reseaux ont pu fonctionner avec des impulsions de meme polarite issues de deux des dernieres dynodes, et meme avec les impulsions de sortie delivrees par une seule electrode. Il y a la une possibilite interessante pour les cas ou il est indique d'utiliser l'anode separement, par exemple pour le cycle de synchronisation. (author) [Spanish] Como ya se ha senalado, la forma de los impulsos emitidos por un centelleador, que es caracteristica del tipo de particula excitante (electron, proton, particulas alfa, etc.), puede convertirse en una amplitud de impulso como parametro independiente. Ello permite determinar, utilizando un analizador multicanal, la composicion de un haz mixto de particulas que excite el centelleador. Este metodo se ha aplicado con exito empleando varios centelleadores de tipo organico e inorganico. Los autores describen con detalle las tecnicas electronicas utilizadas para convertir la forme de los impulsos. En el caso mas sencillo de discriminacion entre solo dos clases de impulsos (por ejemplo, discriminacion de neutrones y rayos gamma), se ha estudiado la conveniencia de utilizar redes pasivas, susceptibles de nuevos perfeccionamientos y simplificaciones. Se han ensayado varios tipos de redes y el principal resultado obtenido consiste en la discriminacion, en presencia de un fondo gamma, de los protones de retrocesco en centelleadores liquidos

Pulsed-Source Experiments with Multiplying and Non-Multiplying Heavy Water Systems; Experiences a l'Aide de Sources Pulsees sur des Systemes Multiplicateurs et Non Multiplicateurs a Eau Lourde; Ehksperimenty s pul'siruyushchim istochnikom na nerazmnozhayushchikh i razmnozhayushchikh ustrojstvakh s tyazheloj vodoj; Experimentos con Fuentes Pulsadas en Sistemas de Agua Pesada Multiplicadores y No Multiplicadores

Energy Technology Data Exchange (ETDEWEB)

Utzinger, E.; Heer, W.; Lutz, H. R. [Swiss Federal Institute for Reactor Research, Wuerenlingen (Switzerland)

1965-10-15

An extensive series of measurements with a pulsed source of the {sup 3}T(d, n)He{sup 4} type has been performed at the subcritical facility MINOR of the Swiss Federal Institute for Reactor Research, Wuerenlingen. Three types of experiments were carried out to measure: (a) Decay constants of prompt neutron modes in natural and slightly enriched lattices; (b) Subcritical reactivity by means of the prompt decay and delayed neutron tails in natural and slightly enriched lattices; (c) Anisotropy of the thermal diffusion constant in D{sub 2}O containing different numbers of parallel empty tubes of various size. The time-dependent thermal neutron flux was measured in each system at different axial positions to obtain decay constants of the prompt modes for different axial bucklings (Fourier analysis) without changing the actual height of the D{sub 2}O level. The experimental values were compared with theoretical two-group parameters. Limitations of the technique are discussed. In addition, reactivity in highly subcritical systems with p {>=} -40$ was measured directly by utilizing the delayed neutron tail of the pulses. Results are compared with static measurements and show rather good agreement. (author) [French] Une longue serie de mesures a l'aide d'une source puisee du type {sup 3}T(d,n){sup 4}He a ete faite avec l'assemblage sous-critique MINOR de l'Institut federal suisse de recherches nucleaires, a Wuerenlingen. Il s'agissait d'experiences de trois types visant a mesurer les caracteristiques suivantes: a) Les constantes de decroissance des modes de neutrons instantanes dans des reseaux a uranium naturel et des reseaux a uranium faiblement enrichi; b) La reactivite sous-critique au moyen de la decroissance des neutrons instantanes et de la queue des bouffees constituee par des neutrons retardes, dans des reseaux naturels et des resaux faiblement enrichis; c) L'anisotropie de la constante de diffusion des neutrons thermiques dans D{sub 2}O contenant des tubes vides

Prospective economical study of the nuclear power file; Etude economique prospective de la filiere electrique nucleaire

Energy Technology Data Exchange (ETDEWEB)

Charpin, J M [Commissariat General du Plan, 75 - Paris (France); Dessus, B [Ecodev-CNRS, 92 - Meudon (France); Pellat, R [CEA, 75 - Paris (France)

2000-07-01

On May 7, 1999 an economical study of the overall nuclear file, and in particular, of the back-end part of the fuel cycle and including the reprocessing, was requested by the French Prime Minister. This study includes the cost comparisons with the other means of power production and takes into consideration the environmental costs. The study is shared into five chapters dealing with: 1 - the legacy of the past: todays park of nuclear plants, economical and material status; 2 - the international evolution: the dynamics of nuclear policies worldwide (existing parks and R and D programs), the rise of environmental problems worldwide (CO{sub 2} and the climate convention, nuclear risks, attempts of including environment in the power costs), the choices made for the management of spent fuels in the main countries; 3 - the technological prospects for the power production and use: technologies for the mastery of power demand (residential, industrial and tertiary sectors, power transportation), technologies of power production (production from nuclear, fossil and renewable energies); 4 - prospective scenarios for France: two demand scenarios at the year 2050 vista (energy, electric power), power supply (supply structure with respect to scenarios, nuclear parks, power capacities), environmental aspects (CO{sub 2} emissions, plutonium and minor actinides production); 5 - the economical status of the different scenarios: data preparation, fossil fuel price scenarios, investment and operation costs of the different power production means (nuclear, fossil and renewable energies, natural gas and power distribution networks), comparison between fluxes and cumulated economic costs linked with the different scenarios (investments, exploitation, fuels, R and D, status for 2000 to 2050), time structure of expenditures with respect to the different scenarios (chronology, statuses, kWh costs, sensitivity with respect to the rate of discount, valorization of existing parks in 2050), cost overruns with respect to pollutant emissions. (J.S.)

Electric power in Europe: towards a competitive oligopoly?; L'Europe electrique: vers un oligopole concurrentiel?

Energy Technology Data Exchange (ETDEWEB)

Huby, J.; Noilhan, F.; Sauvage, Ph

2002-09-01

The Electricity Sector of the European Union has experienced very deep changes in the last decade, in the wake of the 1996 'Electricity Directive'. In most Member States, companies that once enjoyed the position of de facto or de jure monopolists have been facing an increasing competitive pressure, while development of cross-border trade combined with cross-border Mergers and Acquisitions indicates a deeper European integration. It seems that the 'internal market in Electricity', targeted by the 1996 Directive, is slowly but surely taking shape. The present study intends to draw a picture of the recent evolution in the European Electricity Sector and to identify the challenges and options the European public authorities are now facing. Our starting point is an in-depth analysis of the idiosyncrasies of the Electricity Sector in general and of the constraints they impose on the market design. We move then to the peculiarities of the 'Continental Europe', an area including France, Germany, the Benelux and the 'electric peninsulas' of Italy and Spain, but excluding the United Kingdom and the Scandinavian countries. The latter have indeed a longer and quite different experience of liberalization. We then describe the current regulatory and legislative state of the play and try to identify clear-cut tendencies for the future evolution. We conclude that the 'internal market in Electricity' is far from completion and that the strategy adopted by the European Union seems to be that of a slow and cautious deepening of reforms that are already 'on the way'. Thus one can anticipate that the present framework will not - and maybe should not - experience a radical upheaval. After having built up the setting, we focus on the industrial organisation of the sector. It seems to us that the consolidation that took place in 'Continental Europe' during the last five years is now settling down. Seven or eight major players are emerging, each of which is relying on a geographical 'stronghold' and is present both at the production and supply level. Several possible newcomers are described but we conclude that they are very unlikely to dramatically alter the possible outcome described above. Such a structure may raise competitive concerns, as the Electric Industry presents many features that could foster the formation and maintenance of a collective dominant position. This suggests that potential new concentrations should be subject to deep scrutiny by Competition authorities. However, we contend that strong economic efficiencies justify a moderate level of concentration. In the perspective of a real integration that would suppress the barriers still splitting the 'Continental Europe' area into different markets, we anticipate the present evolution will need of a 'competitive oligopoly'. Rather than authoritarian 'de-mergers', which are anyway very unlikely to take place, the setting up of a more coherent regulatory framework at European level and a strong political commitment to adapt the trans-european Energy networks to the needs of a liberalized internal market appear to us as key conditions of success. (authors)

Minautor: the 100% electric mining vehicle; Developpement d'un vehicule minier 100% electrique le Minautor

Energy Technology Data Exchange (ETDEWEB)

Adam, Francois

2011-04-15

PEDNO, in collaboration with Quebec's advanced transport institute (ITAQ) has developed a 4x4 fully electric vehicle suitable for use in mines. PEDNO undertook this project to replace diesel-powered vehicles which emit high levels of pollutants and push up ventilation costs. This vehicle, named Minautor, has certain features designed to meet the conditions of a subterranean environment: the body is made of aluminum to reduce weight and therefore the energy needed for mobility while Li-ion batteries, which are lighter and safer, have also been incorporated. After the vehicle was successfully tested, ITAQ transferred the technology to PEDNO so that they would be in a position to develop the next generation of the Minautor themselves.

Electrochemical generation and storage of electrical energy; Production et stockage electrochimiques de l'energie electrique

Energy Technology Data Exchange (ETDEWEB)

Fauvarque, J.F.

2005-07-01

Electrochemical systems have the remarkable property of being able to convert chemical energy into electrical energy and vice-versa, and this, in conditions close to the thermodynamical reversibility, without any pollutant and noise emissions, and without the need of heavy maintenance. These systems can find various applications in the different domains of the economical life, in particular in the transportation sector. Depending on the application in concern, the batteries, fuel cells and super-capacitors are more or less well-adapted and the choice of a given, or of a combination of technologies must be made with respect to the final objective of the application. This document presents the history, principle, electromotive force, capacity, power, and cyclability of closed electrochemical generators (batteries and capacitors). It presents also the principle and characteristics of open systems (fuel cells and redox systems). (J.S.)

L'Attitude Chirurgicale dans les Brulures Electriques Graves par Haut Voltage: À Propos de Deux Cas

Science.gov (United States)

Moussaoui, A.; Fejjal, N.; Achbouk, A.; Tourabi, K.; Ribag, Y.; Bakkali, H.; Ababou, K.; Ihrai, H.

2008-01-01

Summary Devant une brûlure électrique grave, deux attitudes chirurgicales se distinguent: 1. une attitude conservatrice; 2. une attitude d'amputation. A la lumière de deux observations, les Auteurs discutent les avantages et les difficultés de la mise en oeuvre de chaque attitude. PMID:21991118

CO{sub 2} contain of the electric heating; Contenu en CO{sub 2} du chauffage electrique

Energy Technology Data Exchange (ETDEWEB)

Bacher, P

2008-02-15

A recent announcement of the RTE and the ADEME on the CO{sub 2} contain of the electric kW, refuting a 2005 study of EDF and ADEME, perturbed the public opinion and was presented as the proof that the nuclear has no part in the fight against the climatic change. The author aims to set things straight. (A.L.B.)

Production of a magnetic field of 1 600 000 At/m in a non-magnetic region of volume 0.5 cubic decimeters by a coil cooled by liquid hydrogen (1963); Production d'un champ magnetique de l 600 000 At/m dans un milieu non magnetique dont le volume est 0,5 decimetre cube. Enroulement refroidi a l'hydrogene liquide (1963)

Energy Technology Data Exchange (ETDEWEB)

Garin, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

The eventual application of the technique of cryogenic coils for the production of magnetic fields for liquid hydrogen bubble chambers has led us to the study and construction of two copper coils (cooled in a bath of liquid hydrogen). Part one treats certain generalities concerning the resistivity of several pure metals at very low temperatures, the gain in power, thermal isolation and the choice of conductor and power supply. Part two describes the experimental arrangement. The last part is devoted to a description of the two coils which were constructed, and to the results obtained. (author) [French] L'application eventuelle de la technique des ''bobines cryogeniques'' aux chambres a bulles a hydrogene liquide pour la production du champ magnetique nous a conduits a l'etude et a la construction de deux bobines en cuivre (refroidies dans un bain d'hydrogene liquide). La premiere partie traite de generalites concernant la resistivite de quelques metaux purs, a tres basse temperature, le gain de puissance, l'isolement thermique et le choix du conducteur et de l'alimentation electrique. Dans la seconde partie on decrit l'installation d'essais. La derniere partie est consacree a la description des deux bobines realisees et aux resultats obtenus. (auteur)

Electrolytic dissociation of NH{sub 2}K in liquid ammonia; Dissociation electrolytique de NH{sub 2}K dans NH{sub 3} liquide

Energy Technology Data Exchange (ETDEWEB)

Botter, F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

By assuming the Debye and Huckel approximation giving the activity coefficient and the Onsager relationship linking the conductivity and infinite dilution conductivity of an electrolyte, it has been possible using the available literature data and the electrical conductivity measurements carried out for this purpose, to calculate certain typical parameters of the dissociation of potassium amide in liquid ammonia in the temperature range of -77 deg. C to -33.5 deg. C: degree of dissociation, mean activity coefficient of the ions NH{sub 2}{sup -} and K{sup +}, and the mean activity of these ions. (author) [French] En admettant l'approximation de Debye et Huckel donnant le coefficient d'activite et la relation d'Onsager reliant conductivite et conductivite a dilution infinie d'un electrolyte, on a, en se basant sur les donnees bibliographiques disponibles et des mesures de conductivite electrique effectuees a cette fin, determine par un calcul, certains parametres caracteristiques de la dissociation de l'amidure de potassium dans l'ammoniac liquide dans un domaine de temperature de -77 deg. C a -33,5 deg. C: degre de dissociation, coefficient d'activite moyen des ions NH{sub 2}{sup -} et K{sup +} et activite moyenne de ces ions. (auteur)

Application of the Moessbauer effect to the study of the structure of transition metal complexes; Applications de l'effet Mossbauer a l'etude de la structure des complexes des metaux de transition

Energy Technology Data Exchange (ETDEWEB)

Tsymbal, C [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1968-07-01

In this survey, the structural investigations of transition metal complexes by the hyperfine interactions in the Moessbauer effect are described. The isomer shift provides a unique tool for estimating s electrons covalency in high spin complexes and one of the best pieces of evidence for the importance of bacle donation in low spin complexes. The electric field gradient deriving from quadrupole coupling measurements is correlated with the energy levels distribution of d orbitals in high spin complexes, whereas in low spin complexes it originates from the unbalanced d electrons. (authors) [French] Dans cette etude, nous decrivons les applications des interactions hyperfines dans l' effet Mossbauer a l'etude de la structure des complexes des metaux de transition. Le deplacement isomerique donne des informations tres utiles sur la covalence des electrons s dans les complexes a spin eleve et met en evidence d'une maniere nette l'importance du phenomene de 'bacle donation' dans les complexes a spin faible. Le gradient de champ electrique qui provient des mesures d'interaction quadripolaire est lie a la distribution des niveaux d'energie des orbitales d dans les complexes a spin eleve alors que dans les complexes a spin faible, il est provoque par des electrons d non apparies. (auteurs)

SOA Challenges for Real-Time and Disadvantaged Grids (Defis de la SOA pour les reseaux defavorises et en temps reel)

Science.gov (United States)

2014-04-01

l’utilisation de normes ouvertes, la facilité de gestion et de configuration et la transparence pour l’utilisateur. L’infrastructure de messagerie doit...et w or k A cc es s Netw ork Configurat ion Applicat ions Transport API Control API Cr os s- La ye r Co or di na ti on Netw ork Information...di na ti on Transport Requirements Netw ork Environment Applicat ion Direct ives Applicat ion Information Figure C-2: Sub Interfaces of the

CARACTERISATION DE RESEAUX DE POLYMERES RETICULES ACRYLIQUES ETUDE DE L’INFLUENCE DES PARAMETRES DE PH DES SOLVANTS ET DE TEMPERATURE

OpenAIRE

HAMRI, Salah

2009-01-01

La préparation des solutions de PH différents, ainsi que la synthèse des réseaux de poly(acrylate de nbutyle)( PABu) et de poly(acrylate de 2-éthylhexyl)(PEHA), par photo polymérisation, constitue la première étape de notre travail, Le comportement de gonflement de réseaux réticulés acryliques l’ABu et l’EHA a été étudié en fonction de trois paramètres : le PH du milieu, le taux de réticulation et la température, Suivant les courbes que nous ayons obtenues, l’influence du PH reste...

The effect of an homogeneous magnetic field on the line profiles of hydrogen; Effet d'un champ magnetique uniforme sur les profils des raies de l'hydrogene

Energy Technology Data Exchange (ETDEWEB)

Nguyen, H; Herman, L [Universite de Paris Sorbonne, Lab. de Recherche Physique, 75 - Paris (France); Drawin, H W [Association Euratom-CEA, Centre d' Etudes Nucleaires de Fontenay-aux-Roses, 92 (France)

1966-07-01

The profiles of the hydrogen lines have been calculated taking into account the intermolecular electric field, the electronic collisions, and an external homogeneous magnetic field in which the plasma is imbedded. We considered electron densities N within the range 10{sup 15} {<=} N {<=} 10{sup 18} cm{sup -3} and magnetic field strengths < 1,2 10{sup 5} gauss. These values cover practically most of the experimental conditions in which one is interested in the present state of research. In the present paper we only present the numerical results for the lines Ly-{alpha}, Ly-{beta} and H-{alpha}. For very small magnetic fields our calculated line profiles coincide with the pure Stark profiles recently calculated by GRIEM, KOLB and SHEN (1960). With increasing magnetic fields, important deviations appear. The essential parameters for these deviations are, firstly: the direction of observation with regard to the direction of the magnetic field, and secondly: the ratio between the Zeeman splitting in a magnetic field only and the Stark splitting due to the mean intermolecular electric field. Experimental line profiles have been obtained using a linear discharge tube surrounded by an induction coil, the comparison of tie theoretical profiles with the experimental ones shows a satisfying agreement. The results for the lines originating from higher principal quantum numbers are actually exploited and will be communicated soon. (author) [French] Les profils des raies de l'hydrogene ont ete calcules en tenant compte des collisions electroniques, du champ electrique intermoleculaire et d'un champ magnetique uniforme exterieur. Nous avons considere des concentrations electroniques comprises entre 10{sup 15} cm{sup -3} et 10{sup 18} cm{sup -3} et des champs magnetiques inferieurs ou egaux a 1,2 10{sup 5} gauss. Ces valeurs couvrent pratiquement toutes les conditions experimentales qui ont un interet a l'heure actuelle. Dans le present travail, nous ne donnons que des resultats

Notes on the Start-Up of the Latina Power Station; Notes concernant le demarrage de la centrale nucleaire de Latina; Zapusk ehlektrostantsii Latina; Notas sobre la puesta en marcha de la central electrica de Latina

Energy Technology Data Exchange (ETDEWEB)

Calabria, G.; Gualtieri, G. [AGIP Nucleare, Milano (Italy)

1963-10-15

Information is given on the start-up of the first Italian nuclear power plant, the Latin Power Station, designed for an electrical output of 200 MW, incorporating a natural uranium-gas-graphite reactor. After a brief description of the main characteristics of the station, details are given on die performance of the final tests of the plant, on the fuel loading and on the sequence of commissioning operations, measurements and controls subsequent to the criticality attained. The operations for the start-up and connection of the station to the electrical network are treated. The organization problems relevant to the station operation including personnel preparation and qualification, safety measures, are also illustrated. (author) [French] Le memoire donne des renseignements sur le demarrage de la premiere centrale nucleaire italienne, la centrale de Latina, dont la puissance electrique est de 200 MW et qui fonctionne avec un reacteur du type uranium naturel-gaz-graphite. Apres une breve description des caracteristiques essentielles de la centrale, des explications detaillees sont donnees sur les resultats des derniers essais auxquels elle a ete soumise, sur le chargement du combustible et sur la serie des operations de mise en service, des mesures et des verifications auxquelles il a ete procede lorsque l'etat critique a ete atteint. Les operations de demarrage et de raccordement de la centrale au reseau electrique sont etudiees dans le memoire, ainsi que les problemes d'organisation que pose l 'exploitation de la centrale, notamment en ce qui concerne la formation du personnel et les mesures de securite. (author) [Spanish] Se comunican datos sobre la puesta en marcha de la primera central nucleoelectrica italiana, en Latina, proyectada para desarrollar una potencia de 200 MW (e), que se basa en un reactor de uranio natural moderado por grafito u refrigerado por gas. Despues de describir brevemente las caracteristicas de la central, se dan detalles sobre el

An electric-powered vehicle with contactless battery loading from the grid; Un vehicule electrique alimente sans contact

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-07-01

In this short article the prototype of a 3.5 t pick-up vehicle with an electric drive by Numexia is described. Its unique feature is the contactless battery loading from the grid, by means of an electromagnetic coil located in the ground under the vehicle at the loading station. This technology has been developed at the Swiss Federal Institute of Technology EPFL, Lausanne, Switzerland in the framework of an abandoned project named Swissmetro. (The aim of this project was to connect the main Swiss cities of Geneva, Lausanne, Berne, Lucerne, Zurich and St-Gallen by an underground fast train that would have needed about 12 minutes from one city to the next, i.e. for a distance of 60 to 100 km. Several innovative technologies were developed in the preliminary phase of the project.) The pick-up vehicle, a modified Renault Maxity, reaches 100 km/h. The electric motor power is 100 kW. LiFePO{sub 4} batteries are used to store energy. Reloading takes 30 minutes under optimum conditions. An energy management unit and a 33 kW auxiliary diesel-engine-powered generator are integrated. The pick-up is able to carry a useful load up to 1557 kg and to cover a distance of 100 km with one battery load, without using the auxiliary generator. This new propulsion system is thought to become a frequently used device in vehicles for urban transportation. Numexia intends to cooperate with big car manufacturers to build in its new drive into their vehicles.

The electric-powered vehicle reaches the town center; Le vehicule electrique gagne le coeur de la ville

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

The second edition of this book on electric-powered vehicles has been actualized and completed with the presentation of clean public transportation systems and hybrid electric-powered vehicles. It shows the practical aspects of some recent and innovative projects. All pictures, tables and data have been updated. (J.S.)

Technical results of the French electricity supply industry 2002; Resultats techniques du secteur electrique en France 2002

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-07-01

Provisional detailed results of power flows in France in 2002, with the operating context and international comparisons. This booklet presents provisional results, expressed in rounded values because of some estimated values. Data come from measures made by RTE, completed by various actors of the power system and by estimations made by RTE: general results France; operation outlook; energy flows; exchanges with foreign countries; French consumption; French generation; network operation; access to the transmission network; development over the past 15 years; international comparisons; terminology.

Modelisation temporelle de la consommation electrique en analyse du cycle de vie appliquee au contexte des TIC

Science.gov (United States)

Maurice, Elsa

Fossil fuels are a scarce energy resource. Since the industrial revolution, mankind uses and abuses of non-renewable energies. They are responsible for many environmental damages. The production of energy is one of the main challenges for a global sustainable development. In our society, we can witness an exponential increase of the usage of the systems of Information and Communication Technologies (ICT) such as Internet, phone calls, etc. The ICT development allows the creation and optimization of many smart systems, the pooling of services, and it also helps damping the climate change. However, because of their electric consumption, the ICT are also responsible for some green house gases (GHG) emissions: 3% in total. This fact gives them the willingness to change in order to limit their GHG emissions. In order to properly evaluate and optimize the ICT services, it is necessary to use some methods of evaluation that comply with the specificity of these systems. Currently, the methods used to evaluate the GHG emissions are not adapted to dynamic systems, which include the ICT systems. The variations of the production of electricity in a day or even a month are not yet taken into account. This problem is far from being restricted to the modelling of GHG emissions, it widens to the global variation in production and consumption of electricity. The Life Cycle Assessment (LCA) method grants useful and complete tools to analyse their environmental impacts, but, as with the GHG computation methods, it should be dynamically adapted. In the ICT framework, the first step to solve this LCA problem is to be able to model the variations in time of the electricity production. This master thesis introduces a new way to include the variation in time of the consumption and production of electricity in LCA methods. First, it generates an historical hourly database of the electricity production and import-export of three Canadian states: Alberta, Ontario and Quebec. Then it develops a model in function of time to predict their electricity consumption. This study is done for a project implementing a " cloud computing " service in between these states. The consumption model then provides information to optimize the best place and time to make use of ICT services such as Internet messaging or server maintenance. This first-ever implementation of time parameter allows more precision and vision in LCA data. The disintegration of electrical inventory flows in LCA refines the effects of the electricity production both historically and in real time. Some short-term predictions for the state of Quebec electrical exportations and importations were also computed in this thesis. The goal is to foresee and optimize in real time the ICT services use. The origin of a kilowatt-hour consumed in Quebec depends on the import-export variable with its surrounding states. This parameter relies mainly on the price of the electricity, the weather and the need for the state of Quebec in energy. This allows to plot a time-varying estimate of the environmental consequences for the consumption of a kilowatt-hour in Quebec. This can then be used to limit the GHG emission of ICT services like " cloud-computing " or " smart-grids ". A smart trade-off between electricity consumption and environmental issues will lead to a more efficient sustainable development.

Technical results of the power sector in France 2001; Resultats techniques du secteur electrique en France 2001

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

Provisional detailed results of power flows in France in 2002, with the operating context and international comparisons. This booklet presents provisional results, expressed in rounded values because of some estimated values. Data come from measures made by RTE, completed by various actors of the power system and by estimations made by RTE: general results France; operation outlook; energy flows; exchanges with foreign countries; French consumption; French generation; network operation; access to the transmission network; development over the past 15 years; international comparisons; terminology.

The electric charge of the aerosols under gamma radiation; La charge electrique des aerosols sous irradiation gamma

Energy Technology Data Exchange (ETDEWEB)

Gensdarmes, F.; Cetier, P.; Boulaud, D. [CEA/Saclay, Inst. de Protection et de Surete Nucleaire, IPSN/DPEA/SERAC, 91 - Gif-sur-Yvette (France); Renoux, A. [Paris-12 Univ., Lab. de Physique des Aerosols et de Transfert des Contaminations, 94 - Creteil (France)

2000-07-01

During a PWR type reactor accident, the gamma radiation may create a high ionized atmosphere. In such a situation the aerosols properties knowledge is useful to simulate the particles transport and deposit in the enclosed. The aim of this study is to determine the aerosol charges distribution in a high ionized medium, in function of the ionic properties of the medium. (A.L.B.)

2002 reliability report on the French power system; Bilan 2002 de la surete du systeme electrique francais

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

Ensuring the reliability of the power system is one of the main responsibilities entrusted to RTE, the French transmission system operator, by the Act of February 10, 2000. Reliability must be maintained, both now and in the future. This means that RTE is required to: ensure the normal operation of the power system, limit the number of incidents and avoid major incidents, limit the consequences of major incidents when they do occur. By publishing a yearly reliability report on the French power system, RTE is clearly showing its ambition to encourage long-term supervision of all aspects of system reliability development. By this approach, RTE's intention is to help develop a reliability culture, by all the actors concerned (both RTE and network users) more aware of their role in establishing reliability, and by promoting reliability issues and comparisons with international transmission system operator associations (UCTE , ETSO ). The annual reliability report is drawn up around the following themes: a broad overview of changes in the internal and external environment that have implications for reliability, developments in the various elements that make up the reliability referential during the course of the year, developments on measures aimed at promoting reliability, in terms of equipment, organisation and human resources, lessons learned from events that took place over the year, the presentation of reliability-related indicators, RTE's control loop, and the developments under way at present.

Electrical transport through a metal-molecule-metal junction; Transport electrique a travers une jonction metal-molecule-metal

Energy Technology Data Exchange (ETDEWEB)

Kergueris, Ch

1998-12-17

We investigate the electrical transport through a very few molecules connected to metallic electrodes at room temperature. First, the state of the art in molecular electronics is outlined. We present the most convincing molecular devices reported so far in the literature and the theoretical tools available to analyze the electron transport mechanism through a molecular junction. Second, we describe the use of mechanically controllable break junctions to investigate the electron transport properties through a metal-molecule-metal junction. Two kindsof molecules were adsorbed on the two facing gold electrodes, dodecane-thiol (DT) and bis-thiol-ter-thiophene ({alpha},{omega} T3), that are basically expected to behave as an insulator and as a molecular wire, respectively. In the latter case, we study the chemical reactivity of the molecule and show that {alpha},{omega} T3 is chemically adsorbed on gold electrodes. Current-voltage characteristics of the junction were observed at room temperature. The Gold-DT-Gold junction behaves as a simple metal-insulator-metal junction. On the other hand, the electron transport through a Gold-{alpha},{omega} T3-Gold junction explicitly involves the electronic structure of the molecule which gives rise to step-like features in the current-voltage characteristics. The measured zero bias conductance is interpreted using the scattering theory. At high bias, we discuss two different models: a coherent model where the electron has no time to be completely re-localized in the molecule and a sequential model where the electron is localized in the molecule during the transfer. Finally, we show that the mechanical action of decreasing the inter-electrodes spacing can be used to induce a strong modification of the current-voltage characteristics. (author)

50-60 Hz frequency electric and magnetic fields; Champs electriques et magnetiques de frequence 50-60 Hz

Energy Technology Data Exchange (ETDEWEB)

Lambrozo, J. [Electricite de France (EDF), 75 - Paris (France). Service Etudes Medicales

1999-07-01

After more than twenty years of research, if biological effects exist for electromagnetic fields intensity over 1000 times the public usual exposure levels, the demonstration of a risk for health has not been brought. The actual data do not demonstrate that these fields can be dangerous for Health, more particularly, no solid nor conclusive proof shows that the residential exposure to electromagnetic fields can be responsible of cancer, undesirable neurological effects, or effects about the reproduction or development ( report extract of the Academy of Sciences in Usa, october 1996). (N.C.)

Long-term congestion management by investment in gas-turbine generators : a cost-benefit analysis

International Nuclear Information System (INIS)

Tuan, L.A.; Bhattacharya, K.

2007-01-01

Load management is one of the most important tasks in the operation of an electric power system. Transmission congestion occurs whenever the grid has one or more violations of the physical, operation, or policy constraints under which it normally operates. In a deregulated electricity market, the independent system operator (ISO) must ensure that contracted power transactions are carried out reliably. Several schemes of congestion management run the risk of increasing electricity prices due to the market power of local generators in congested areas. An alternative is to manage congestion through the installation of reserve gas turbine generators which can be brought online to the system within a short time. The use of gas turbines at different buses in the system can enhance the system in ways of transmission relief during emergency events. This paper proposed a framework for the evaluation of long-term investment by the ISO on gas-turbine generators as a tool for providing transmission congestion relief in the dispatch stage based on cost-benefit analysis. The objective of the framework is to optimally decide the locations and sizes of the generators at different buses in the network in order to minimize the total cost of investment of gas turbines and to minimize total system congestion. A bus-wise cost-benefit analysis was carried out by solving the DC optimal power flow (dc-OPF) model. The CIGRE 32-Bus system was used for the case study. It was shown that network overloading can be significantly reduced with the support of gas turbines at selected buses. The long-term decision of the investment on gas-turbine would depend on the opportunity cost of the gas-turbine with respect to the congestion problem. The gas turbines could also reduce the amount of unserved energy during peak load conditions. 11 refs., 4 tabs., 3 figs

Multi-purpose reactor

International Nuclear Information System (INIS)

1991-05-01

The Multi-Purpose-Reactor (MPR), is a pool-type reactor with an open water surface and variable core arrangement. Its main feature is plant safety and reliability. Its power is 22MW t h, cooled by light water and moderated by beryllium. It has platetype fuel elements (MTR type, approx. 20%. enriched uranium) clad in aluminium. Its cobalt (Co 60 ) production capacity is 50000 Ci/yr, 200 Ci/gr. The distribution of the reactor core and associated control and safety systems is essentially based on the following design criteria: - upwards cooling flow, to waive the need for cooling flow inversion in case the reactor is cooled by natural convection if confronted with a loss of pumping power, and in order to establish a superior heat transfer potential (a higher coolant saturation temperature); - easy access to the reactor core from top of pool level with the reactor operating at full power, in order to facilitate actual implementation of experiments. Consequently, mechanisms associated to control and safety rods s,re located underneath the reactor tank; - free access of reactor personnel to top of pool level with the reactor operating at full power. This aids in the training of personnel and the actual carrying out of experiments, hence: - a vast water column was placed over the core to act as radiation shielding; - the core's external area is cooled by a downwards flow which leads to a decay tank beyond the pool (for N 16 to decay); - a small downwards flow was directed to stream downwards from above the reactor core in order to drag along any possibly active element; and - a stagnant hot layer system was placed at top of pool level so as to minimize the upwards coolant flow rising towards pool level

Magnetic properties of Kramers rare earth ions in aluminium and gallium garnets; Proprietes magnetiques des ions de kramers des terres rares dans les grenats de terres rares et d'aluminium et les grenats de terres rares et de gallium

Energy Technology Data Exchange (ETDEWEB)

Capel, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

The magnetic properties of Kramers rare earth ions in aluminium and gallium garnets (MAlG and MGaG) are discussed by means of a molecular field treatment. The symmetry properties of the space group permit to establish a parametrization for the magnetic dipolar and exchange couplings. The magnetic properties of the system can be expressed in terms of these parameters and the g factors of the rare earth ions. We have calculated the transition temperatures, the sub-lattice magnetizations, the susceptibility in the paramagnetic region and the antiferromagnetic susceptibility for a special type of magnetic ordering. The influence of the excited Kramers doublets is described by means of a generalization of the usual g tensor. (authors) [French] Les proprietes magnetiques des ions de Kramers des terres rares dans les grenats de terre rare et d'aluminium et les grenats de terre rare et de gallium sont discutees a l'aide d'un traitement du champ moleculaire. Les proprietes de symmetrie du groupe d'espace permettent d'exprimer les couplages dipolaires et les interactions d'echange en fonction de quelques parametres. Les proprietes magnetiques peuvent etre exprimees en fonction de ces parametres et les facteurs g des ions de terre rare. Nous avons calcule les temperatures de transition, les aimantations des sous-reseaux pour 0

Formação de professores: licenciaturas, currículos e políticas

Directory of Open Access Journals (Sweden)

Bernardete Gatti

2015-08-01

Full Text Available O artigo associa questões humanas emergentes na contemporaneidade com aimportância dos processos educacionais. Nos anos vindouros, cada vez mais oacesso e o domínio de conhecimentos relevantes socialmente associam-se adomínio de linguagens, ciências, tecnologias, e à construção moral e ética. Aimportância da escola e dos professores nesse processo é ressaltada. Um olharcrítico sobre a realidade educacional brasileira, através de seus dados e realizações,conduz à discussão da demanda de professores nas redes de ensino e dasdemandas que lhes são postas, no confronto com a formação que lhes é propiciadanos cursos de licenciatura. Palavras-chave: Formação de professores; Políticas educacionais; Currículos;Licenciatura. L’article associe les conditions qui émergent dans la situation humainecontemporaine avec l’importance des processus educationelles. Dans les années àvenir, chaque foi plus, le domaine de connaissances importants pour la viequotidienne et des citoyens seront associés à la compréhension des langages, dessciences, des technologies, et à la formation morale et éthique. Alors, l’importancede l’école et des maîtres dans ce processus est decelé. Um coup d’oeil critique estlancé sur la réalité de l’éducation scolaire au Brésil conduisant à la discussion sur lademande de maîtres dans les reseaux d’enseignement e sur sa formation dans descours universitaires. Mots-clés: Formation de maîtres; Politiques éducacionelles; Curriculum scolaire;Licence.

Parallelization of applications for networks with homogeneous and heterogeneous processors; Parallelisation d`applications pour des reseaux de processeurs homogenes ou heterogenes

Energy Technology Data Exchange (ETDEWEB)

Colombet, L

1994-10-07

The aim of this thesis is to study and develop efficient methods for parallelization of scientific applications on parallel computers with distributed memory. The first part presents two libraries of PVM (Parallel Virtual Machine) and MPI (Message Passing Interface) communication tools. They allow implementation of programs on most parallel machines, but also on heterogeneous computer networks. This chapter illustrates the problems faced when trying to evaluate performances of networks with heterogeneous processors. To evaluate such performances, the concepts of speed-up and efficiency have been modified and adapted to account for heterogeneity. The second part deals with a study of parallel application libraries such as ScaLAPACK and with the development of communication masking techniques. The general concept is based on communication anticipation, in particular by pipelining message sending operations. Experimental results on Cray T3D and IBM SP1 machines validates the theoretical studies performed on basic algorithms of the libraries discussed above. Two examples of scientific applications are given: the first is a model of young stars for astrophysics and the other is a model of photon trajectories in the Compton effect. (J.S.). 83 refs., 65 figs., 24 tabs.

Determination of local boiling in light water reactors by correlation of the neutron noise; Determination de l'ebullition locale dans les reacteurs a eau legere par correlation du bruit neutronique

Energy Technology Data Exchange (ETDEWEB)

Zwingelstein, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1968-07-01

The power limit of swimming-pool type reactors depends on the phenomenon of the appearance of burn-out. In order to determine this limit we have attempted to detect the local boiling which usually occurs before the burn out. Local boiling has been simulated by an electrically heated plate placed in the core of the reactor Siloette. The study of local boiling, which is based on the properties of the correlation functions for the neutron noise of detectors placed in the core, shows that a privileged frequency occurs in the power spectrum of the noise. It is intended in the future to determine the influence of various parameters on this characteristic frequency. (author) [French] La limitation de la puissance des reacteurs nucleaires de type piscine est due au phenomene d'apparition de 'burn out'. Pour determiner cette limitation, nous nous sommes proposes dans ce rapport de detecter l'ebullition locale qui apparait generalement avant le 'burn out'. L'ebullition locale a ete simulee par une plaque chauffee electriquement et placee dans le coeur du reacteur SILOETTE. L'etude de l'ebullition locale, qui est basee sur les proprietes des fonctions de correlation du bruit neutronique de detecteurs places clans le coeur, fait apparaitre une frequence privilegiee dans le spectre de puissance du bruit. On envisage dans l'avenir, de determiner l'influence des divers parametres sur cette frequence caracteristique. (auteur)

Integration of the nuclear energy among the production facilities of energy in France; Integration de l'energie nucleaire parmi les moyens de production de l'energie en france

Energy Technology Data Exchange (ETDEWEB)

Ailleret, P [Electricite de France (EDF), 75 - Paris (France). Direction des Etudes et Recherches; Taranger, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1955-07-01

The present report gives an overview of the present facilities of energy productions in France and their perspectives. the electric production comes for half about power stations hydraulics and for half of thermal power stations. However due to the increase of the energy consumption, France is particularly interested by the atomic energy that appears to bring a supply in due time to the hydraulics and to limit a development of the thermal power stations to which the natural resources of France in classic fuel would not permit to cope presumably. The integration of the nuclear plants to the other production facilities will make itself gradually according to the evolution of the energy needs. (M.B.) [French] Le present rapport donne un apercu des moyens actuels de productions energetiques en France et de ses perspectives. la production electrique provient pour moitie environ de centrales hydraulique et pour moitie de centrales thermiques. Cependant face a l'augmentation de la consommation energetique, la France est tres particulierement interessee par l'energie atomique qui parait devoir apporter en temps utile la releve a l'hydraulique et limiter un developpement des centrales thermiques auxquels les ressources naturelles de la France en combustible classique ne permettraient vraisemblablement pas de faire face. L'integration des centrales nucleaires aux autres moyens de production se fera graduellment en fonction de l'evolution des besoins energetiques. (M.B.)

Contribution to the study of the electrostatic precipitation of aerosols; Contribution a l'etude de la precipitation electrostatique des aerosols

Energy Technology Data Exchange (ETDEWEB)

Madelaine, G [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires; Roure, L [Societe Bertin et Cie, 89 - Druyes Les Belles Fontaine (France)

1966-07-01

The first part is devoted to the theory of the electrostatic precipitation of ions in a cylindrical apparatus. Some aerodynamic factors influencing the quality of the flow are deduced. The second part of the report deals with the experimental verification of the hypotheses concerning the laminarity of the gas flow. The presence of a guard tube which ensures a steady state of velocity and which reduces electrical field end-effects should make it possible to obtain a better knowledge of the distribution function of the captured particles. The third part deals with the treatment of the results and with the processing method making it possible to obtain the spectral distribution of the particles captured on the electrode. (authors) [French] La premiere partie est consacree a la theorie de la precipitation electrostatique des ions dans un capteur cylindrique. Des imperatifs d'ordre aerodynamique caracterisant la qualite de l'ecoulement sont degages. La seconde partie traite de la verification experimentale des hypotheses de laminarite du courant gazeux. La presence d'un tube de garde assurant un profil stationnaire de vitesse et attenuant les effets de bouts du champ electrique, doit permettre de mieux connaitre la fonction de repartition des particules captees. La troisieme partie traite de l'exploitation des resultats et de la methode de depouillement permettant l'obtention de la repartition spectrale des particules captees sur l'electrode. (auteurs)

R. F. plasmoids and resonant discharges; Plasmoides a haute frequence et decharges resonnantes

Energy Technology Data Exchange (ETDEWEB)

Taillet, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-06-15

In R.F. discharges at reduced pressure a resonance can increase by an order of magnitude the intensity of the plasma R.F. electric field. The electron density of the plasma adjusts itself to keep the resonant frequency equal to the excitation frequency. This behaviour has been observed by an electron beam technique. When such a discharge is excited in electronegative gases, the negative ion density may be higher than the electron density. Therefore, the D.C. potential distribution in plasma and sheath is modified. The plasma appears as a luminous body isolated from the walls by a large sheath (R.F. plasmoid). (author) [French] Dans les decharges H.F. a faible pression une resonance peut elever d'un ordre de grandeur l'intensite du champ electrique interne du plasma. La densite electronique s'ajuste elle-meme de facon a rendre egales la frequence d'excitation et la frequence de la resonance. Ce mecanisme a ete observe a l'aide de faisceaux electroniques. Lorsqu'une telle decharge est excitee dans un gaz electronegatif, la densite des ions negatifs peut etre plus elevee, que la densite electronique, ce qui modifie la distribution du potentiel continu dans le plasma et la gaine. Le plasma apparait comme un corps lumineux isole des parois par une large gaine (plasmoide a haute frequence). (auteur)

Mixed helium-3 - helium-4 calorimeter. Very low temperature calorimetry; Calorimetre mixte a helium-3 et helium-4. Calorimetrie a tres basse temperature

Energy Technology Data Exchange (ETDEWEB)

Testard, O [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1966-06-01

A description is given of a double-racket calorimeter using helium-4 and helium-3 as the cryogenic fluids and making it possible to vary the temperature continuously from 0.35 K to 4.2 K. By using an electric thermal regulator together with liquid hydrogen it is possible to extend this range up to about 30 K. In the second part, a review is made of the various, methods available for measuring specific heats. The method actually used in the apparatus previously described is described in detail. The difficulties arising from the use of an exchange gas for the thermal contact have been solved by the use of adsorption pumps. (author) [French] On decrit un calorimetre a double enceinte utilisant comme fluide cryogenique l'helium-4 et l'helium-3 et permettant de varier continuement la temperature de 0,35 K a 4,2 K. L'utilisation d'un regulateur thermique electrique ainsi que celle d'hydrogene, liquide permettent d'etendre cette gamme jusqu'a 30 K environ. Dans une deuxieme partie, on passe en revue les diverses methodes de mesure des chaleurs specifiques. La methode concrete utilisee dans l'appareil precedemment decrit est exposee en detail. Les difficultes inherentes a l'utilisation de gaz d'echange comme agent de contact thermique ont ete levees par la mise en oeuvre de pompes a adsorbant. (auteur)

R. F. plasmoids and resonant discharges; Plasmoides a haute frequence et decharges resonnantes

Energy Technology Data Exchange (ETDEWEB)

Taillet, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-06-15

In R.F. discharges at reduced pressure a resonance can increase by an order of magnitude the intensity of the plasma R.F. electric field. The electron density of the plasma adjusts itself to keep the resonant frequency equal to the excitation frequency. This behaviour has been observed by an electron beam technique. When such a discharge is excited in electronegative gases, the negative ion density may be higher than the electron density. Therefore, the D.C. potential distribution in plasma and sheath is modified. The plasma appears as a luminous body isolated from the walls by a large sheath (R.F. plasmoid). (author) [French] Dans les decharges H.F. a faible pression une resonance peut elever d'un ordre de grandeur l'intensite du champ electrique interne du plasma. La densite electronique s'ajuste elle-meme de facon a rendre egales la frequence d'excitation et la frequence de la resonance. Ce mecanisme a ete observe a l'aide de faisceaux electroniques. Lorsqu'une telle decharge est excitee dans un gaz electronegatif, la densite des ions negatifs peut etre plus elevee, que la densite electronique, ce qui modifie la distribution du potentiel continu dans le plasma et la gaine. Le plasma apparait comme un corps lumineux isole des parois par une large gaine (plasmoide a haute frequence). (auteur)

Production and study of mixed Al-Al{sub 2}O{sub 3} thin films for passive electronic circuits; Realisation et etude des couches minces mixtes Al-Al{sub 2}O{sub 3} pour circuits electroniques passifs

Energy Technology Data Exchange (ETDEWEB)

Pruniaux, B [Commissariat a l' Energie Atomique, 38 - Grenoble (France). Centre d' Etudes Nucleaires

1967-07-01

A new vacuum deposition process, named reactive evaporation, is used to realize passive thin film circuits. Using aluminium, oxidized at various steps in its vapor phase, we obtain: - Al-Al{sub 2}O{sub 3} cermet resistors (R{sub {open_square}} = 10000 {omega}{sub {open_square}}, CTR <{+-} 150 ppm/deg. C) which show oscillations of the resistivity versus the thickness of the layer, in distinction to classical theory. - Al{sub 2}O{sub 3} capacitors (C{sub {open_square}} = 60000 pf/cm{sup 2}, tg {delta} < 0.5 per cent). These thin film components present good electrical behaviour and should find interesting applications in integrated circuits. (author) [French] Une nouvelle technique de depot sous vide, l'evaporation reactive est utilisee pour realiser des circuits passifs en couches minces. En oxydant, en phase vapeur, de l'aluminium a differents degres, on obtient: - des resistances en cermet Al-Al{sub 2}O{sub 3} (R{sub {open_square}} = 10000 {omega}{sub {open_square}}, CTR <{+-} 150 ppm) dont Ia resistivite oscille en fonction de l'epaisseur, contrairement aux previsions de la theorie classique. - Des capacites en Al{sub 2}O{sub 3} (C{sub {open_square}} = 60000 pf/cm{sup 2}, tg {delta} < 0.5 pour cent). Ces elements presentent de bonnes caracteristiques electriques et seraient avantageusement utilises en circuits integres. (auteur)

Modelisation agregee de chauffe-eau electriques commandes par champ moyen pour la gestion des charges dans un reseau

Science.gov (United States)

Losseau, Romain

The ongoing energy transition is about to entail important changes in the way we use and manage energy. In this view, smart grids are expected to play a significant part through the use of intelligent storage techniques. Initiated in 2014, the SmartDesc project follows this trend to create an innovative load management program by exploiting the thermal storage associated with electric water heaters existing in residential households. The device control algorithms rely on the recent theory of mean field games to achieve a decentralized control of the water heaters temperatures producing an aggregate optimal trajectory, designed to smooth the electric demand of a neighborhood. Currently, this theory does not include power and temperature constraints due to the tank heating system or necessary for the user's safety and comfort. Therefore, a trajectory violating these constraints would not be feasible and would not induce the forecast load smoothing. This master's thesis presents a method to detect the non-feasability, of a target trajectory based on the Kolmogorov equations associated with the controlled electric water heaters and suggests a way to correct it so as to make it achievable under constraints. First, a partial differential equations based model of the water heaters under temperature constraints is presented. Subsequently, a numerical scheme is developed to simulate it, and applied to the mean field control. The results of the mean field control with and without constraints are compared, and non-feasabilities of the target trajectory are highlighted upon violations. The last part of the thesis is dedicated to developing an accelerated version of the mean field and a method of correcting the target trajectory so as to enlarge as much as possible the set of achievable profiles.

Influence of meteorological conditions on electricity consumption in France. Influence des conditions meteorologiques sur la consommation electrique francaise

Energy Technology Data Exchange (ETDEWEB)

Chauvin, F; Javelle, J P; Calvayrac, A M

1992-04-01

Electric consumption is modeled by Electricite de France, in taking into account temperature and cloud cover in 6 selected sites. The aim of the study is to improve this model by a better climate representation and introduction of new parameters. The model is improved by taking into account climatic characteristics of each region and a simplification of the cloudiness factor facilitates the forecast. Furthermore no new parameter is required.

Electrical engineering design using characterized elements; Conception en genie electrique a l'aide d'elements caracterises

Energy Technology Data Exchange (ETDEWEB)

Demni, H.E.

2004-10-15

This work treats systematic design of energy transformation structures used in Electrical Engineering. We propose an approach dedicated to design by association of characterized elements. Starting from a set of specifications, the designer has to define a coherent structure by assembling predefined elements. Within this framework, we adopt a characterization approach that takes into account various criteria necessary for design. Then, this approach allowed us to develop methodologies for designing electric energy transformation structures. These methodologies were used to implement a software application based on three tools: a data base as an elements library, a graphic tool allowing the construction of energy transformation structures, an expert module which helps the designer in his work. (author)

Measures of protection against power network collapses; Les dispositions de defense contre les ecroulements du reseau electrique francais

Energy Technology Data Exchange (ETDEWEB)

Tesseron, J.M.; Testud, G.; Harmand, Y. [Reseau de transport de l' Electricite Francais, 75 Paris (France); Hoffmann, D. [Reseau de transport de l' Electricite Francais, Dir. du Groupe Exploitation Transport Sologne, 75 Paris (France)

2002-10-01

History shows that even the main industrialized countries may happen to face complex and rare disturbances liable to lead to a power system collapse. In order to avoid such situations, France has defined a policy to preserve power system reliability, which includes ensuring normal system operation, reducing the occurrence of incidents and avoiding system collapses, and mastering the consequences of a main incident. This article presents the basic principles of power system reliability, then the main current measures which are taken in the material, human and organisational fields. These measures are organized in defence lines, according to a 'in-depth defence' concept. (authors)

High energy discharge through deuterium in a metal-lined torus; Decharges a forte intensite dans le deuterium dans un tore a parois metalliques

Energy Technology Data Exchange (ETDEWEB)

Andreoletti, J; Breton, C; Charon, J; Hubert, P; Jourdan, P; Vendryes, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

The discharge chamber is an aluminium torus, measuring 80 cm (about 2'8'') large medium diameter and 8 cm (about 3'5'') small diameter. The torus contains a double disruption, formed by two isolating mantles, to prevent short-circuiting of the discharge by the metallic partitions. Openings have been provided for the purpose of studying the characteristics of the discharge by means of electro or magnetic sounding apparatus (double sounding type). A constant longitudinal field (maximum value of the order of 5000 gauss) can be established. One can also realize pre-ionization from the chamber gas by means of an H.F. generator (27 MHz). The energy for the generating of the discharge is drawn from a 31 condenser battery, forming a total of 62 {mu}F, 50 kV. The studies already accomplished, and those we anticipate chiefly bear upon the following points: 1) the starting off and intensity of current in the discharge as regards the following parameters: a) intensity and electric field, b) initial pressure of filling, c) intensity of the longitudinal magnetic field, d) pre-ionization, e) length of the isolating disruptions; 2) cinematographic study of the section of discharge in the course of time; 3) spectrographic study of the discharge; 4) research of electrons accelerated during the discharge; 5) research of electronic density, electronic temperature, and of longitudinal and azimuthal magnetic fields in the discharge as regards distance, at the center of column of the discharge and as regards time; 6) the use of micro-waves for the study of the characteristics of the discharge. (author)Fren. [French] La chambre a decharge est un tore en aluminium de 80 cm de grand diametre moyen et de 8 cm de petit diametre. Le tore comporte deux coupures formees par deux manchons isolants afin d'eviter un court-circuit de la decharge par les parois metalliques. Des orifices sont prevus pour etudier les caracteristiques de la decharge au moyen de sondes electriques (type double

Comparison between electrostatic generators of Van de Graaff and Pauthenier; Essai de comparaison des generateurs electrostatiques de Van de Graaff et de Pauthenier

Energy Technology Data Exchange (ETDEWEB)

Prevot, F [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

1953-07-01

montre que la vitesse des charges en sens inverse du courant gazeux, sous l'action du champ electrique longitudinal, peut etre faible devant la vitesse de ce courant gazeux. Afin d'eviter le depot des particules electrisees sur les parois du tube, sous l'action du champ electrique radial, on est conduit a une limite superieure de 10{sup -3} cm pour leur rayon. Pour des particules chargees au maximum, la vitesse radiale augmente tres rapidement avec la pression. Ceci conduit a ne pas pouvoir faire fonctionner d'une facon avantageuse un appareil de Pauthenier sous une pression superieure a 5 atmospheres. De plus, le courant maximum que l'on peut transporter est une fonction decroissante du potentiel atteint. Le transport direct des ions par un gaz en mouvement est condamne par la trop grande mobilite des ions. Cette mobilite diminue si on augmente la pression, mais cela conduit a des pression de l'ordre de 100 atmospheres, qui sont inacceptables. (auteur)

Electrodeposition of ZnO nano-wires lattices with a controlled morphology; Electrodepot de reseaux de nanofils de ZnO a morphologie controlee

Energy Technology Data Exchange (ETDEWEB)

Elias, J.; Tena-Zaera, R.; Katty, A.; Levy-Clement, C. [Centre National de la Recherche Scientifique (CNRS), Lab. de Chimie Metallurgique des Terres Rares, UPR 209, 94 - Thiais (France)

2006-07-01

In this work, it is shown that the electrodeposition is a changeable low cost method which allows, according to the synthesis conditions, to obtain not only plane thin layers of ZnO but different nano-structures too. In a first part, are presented the formation conditions of a compact thin layer of nanocrystalline ZnO electrodeposited on a conducing glass substrate. This layer plays a buffer layer role for the deposition of a lattice of ZnO nano-wires. The step of nano-wires nucleation is not only determined by the electrochemical parameters but by the properties of the buffer layer too as the grain sizes and its thickness. In this context, the use of an electrodeposition method in two steps allows to control the nano-wires length and diameter and their density. The morphology and the structural and optical properties of these nano-structures have been analyzed by different techniques as the scanning and transmission electron microscopy, the X-ray diffraction and the optical spectroscopy. These studies show that ZnO nano-structures are formed of monocrystalline ZnO nano-wires, presenting a great developed surface and a great optical transparency in the visible. These properties make ZnO a good material for the development of nano-structured photovoltaic cells as the extremely thin absorber cells (PV ETA) or those with dye (DSSC) which are generally prepared with porous polycrystalline TiO{sub 2}. Its replacement by a lattice of monocrystalline ZnO nano-wires allows to reduce considerably the number of grain boundaries and in consequence to improve the transport of the electrons. The results are then promising for the PV ETA cells with ZnO nano-wires. (O.M.)

Safety of the French power grid: audit and annual reporting; Surete du systeme electrique francais: audit et reporting annuel

Energy Technology Data Exchange (ETDEWEB)

Tesseron, J.M. [Reseau de Transport d' Electricite (RTE), 92 - Paris la Defense (France)

2006-09-15

Power system reliability is at the core of the responsibilities entrusted to RTE, the French transmission system operator. Considering the particularly important issue of reliability, RTE's management has set up an entity which reports to it directly on this subject. The two main activities of this entity involve drawing up the annual system reliability report and carrying out audits devoted to reliability. After going over the principles governing the control of system reliability in France, the document presents the experience acquired since 2000. The principles underlying the drafting of the annual reliability report and the method for scheduling and performing the reliability audits are first set out. The author then goes on to present how these principles are applied to two reliability audits, one carried out on voltage control and the other on the control of the clearance time of short-circuits affecting the 400 kV grid. (author)

A compilation of correlation parameters for predicting the enthalpy and thermal conductivity of solid foods within the temperature range of -40 C to +40 C

Energy Technology Data Exchange (ETDEWEB)

Amos, N.D. [Comvita New Zealand Limited, Private Bag 1, Te Puke 3153 (New Zealand); Willix, J.; North, M.F. [AgResearch Limited, MIRINZ Centre, Ruakura Campus, East Street, Private Bag 3123, Hamilton (New Zealand); Chadderton, T. [Crop and Food Research Ltd, PO Box 5114, Nelson (New Zealand)

2008-11-15

This paper presents thermal conductivity data for 40 foods, enthalpy data for 58 foods and density data for nine foods, along with the compositions of the foods. Measurements cover a range of solid food types (including meats, fats, offal, fish, dairy products and horticultural products). Some measurements reported are for foods that have never before been studied, others have been published elsewhere, but are included here for convenience. Thermal conductivity was measured using a guarded hot-plate apparatus, enthalpy using an adiabatic calorimeter and density using a water displacement meter. Thermal conductivity and enthalpy values were measured within the temperature range of -40 C to +40 C. (author) [French] Cette publication presente des donnes sur la conductivite thermique, l'enthalpie et la densite respectivement de 40, 58 et 9 produits alimentaires, ainsi que leurs compositions. Les mesures couvrent une variete de types de produits alimentaires (viande, matieres grasses, abats, poisson, produits laitiers, produits horticoles). Certaines sont rapportees pour des produits qui n 'ant jamais ete etudie auparavant, d'autres ant ete publie ailleurs mais sont aussi inclues pour plus de commodite. La conductivite thermique a ete mesure avec un appareil a plaque electrique protegee, l'enthalpie avec un calorimetre adiabatique et la densite avec un appareil mesurant Ie deplacement d'eau. La conductivite thermique et l'enthalpie ont ete toutes les mesures pour une fourchette de temperatures allant de -40 C a 40 C. (orig.)

Some aspects of nuclear graphite production in France; Etude generale sur les graphites nucleaires produits en France

Energy Technology Data Exchange (ETDEWEB)

Gueron, J; Hering, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Legendre, A [Pechiney, 75 - Paris (France)

1958-07-01

1) Manufacturing: A summary and results on the CEA-Pechiney purification process are given. Variations in the preparation of green pastes and their effects on graphitized material are described. 2) Physical and mechanical properties: Results are given on: - Statistics of dimensional variatior products having square cross-section. - Statistical variation of thermal expansion coefficients and of electrical conductivity. - Density of normals to carbon layer planes and their connexion with thermal expansion. - Stress-strain cycles and conclusions drawn therefrom. - Mechanical resistance and gas permeability of items for supporting fuel elements. 3) Behaviour under radiation: Alteration under radiation of French graphites irradiated either in G1 pile or in experimental piles, and thermal annealing of those alterations, are given. (author)Fren. [French] 1) Fabrication: On resume le procede d'epuration CEA-PECHINEY, ainsi que diverses modalites de preparation des pates et on expose les resultats obtenus. 2) Proprietes physiques et mecaniques: On indique le resultat d'etudes sur: - la statistique des dimensions de produits a section carree. - celle des variations des coefficients de dilatation thermique et de la conductibilite electrique. - la densite des normales aux plans graphitiques et leur connexion avec la dilatation thermique. - la compression mecanique du graphite. - la solidite mecanique et la permeabilite aux gaz de pieces destinees a supporter des cartouches de combustible. 3) Tenue sous rayonnement: Modification sous rayonnement des graphites fran is irradies soit dans la pile G1, soit dans des piles experimentales, et guerison thermique de ces modifications. (auteur)

Formation and evolution of aerosols in filtered air and in natural air. Effect of radioactivity; Formation et evolution des aerosols dans l'air filtre et dans l'air naturel action de la radioactivite

Energy Technology Data Exchange (ETDEWEB)

Madelaine, G J [Commissariat a l' Energie Atomique, 92 - Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1968-06-01

Results are presented concerning the formation, the evolution, the coagulation and the electrical charge of aerosols which form in natural filtered air containing only gaseous impurities, under the influence of solar light (photolysis) and of radioactive disintegrations (radiolysis). The modifications brought about in the aerosol by an increase in the sulphur dioxide content and in the natural radioactive gas content are studied. The work is then repeated with non-filtered natural atmospheric air. A comparison is also made of the behaviour of non-radioactive and radioactive particles (active thoron deposit). In conclusion, the possible consequences of these phenomena on the origin and the size distribution of particles occurring in the atmosphere is considered. (author) [French] On expose les resultats obtenus sur la formation, l'evolution, la coagulation et la charge electrique des aerosols qui se forment dans l'air naturel filtre, ne contenant que des impuretes gazeuses, sous l'influence de la lumiere solaire (photolyse) et des desintegrations radioactives (radiolyse). On examine les modifications apportees a l'aerosol forme par l'augmentation de la teneur de l'air en anhydride sulfureux et en gaz radioactif naturel. Cette etude est ensuite reprise mais avec de l'air naturel atmospherique non filtre. On compare egalement le comportement des particules non radioactives et radioactives (depot actif du thoron). En conclusion, on examine les consequences que peuvent avoir ces phenomenes sur l'origine et la granulometrie des particules contenues dans l'atmosphere. (auteur)

Production of C{sup 14}-labelled compounds from C{sup 14}O{sub 2} accelerated in an electric field - Physico-chemical analysis of some radioactive compounds obtained; Production de composes marques au {sup 14}C a partir de {sup 14}CO{sub 2} accelere dans un champ electrique - Analyse physico-chimique de quelques composes radioactifs obtenus; Proizvodstvo mechennykh uglerodom-14 soedinenij iz C{sup 14}O{sub 2}, uskorennogo v ehlektricheskom pole - Fiziko-khimicheskij analiz neskol'kikh poluchennykh radioaktivnykh soedinenij; Obtencion de compuestos marcados con {sup 14}C a partir de {sup 14}CO{sub 2} acelerado en un campo electrico - Analisis fisicoquimico de algunos de los compuestos radiactivos obtenidos

Energy Technology Data Exchange (ETDEWEB)

Guillaume, M [Universite de Liege, Belgique (Belgium)

1962-03-15

This paper describes a method of labelling which is based on the acceleration by an electric field of C{sup 14}O{sub 2}, which can then react with an organic target in its path. The discharge cell described operates at 500 Y, 150 {mu}A, and the organic products to be labelled are exposed to this field for about three hours with CO{sub 2} having a specific activity of 24mc/mmole. The maximum yield remains low (about 6%), and 60% of the C{sup 14}O{sub 2} is destroyed. This maximum activity is obtained only for aliphatic chains (50 {mu}c/g for glutaric acid) or for aromatic substances with an aliphatic chain (acetyl-salicylic acid). (author) [French] Le present memoire expose une methode de marquage basee sur l'acceleration par un champ electrique de {sup 14}CO{sub 2}, qui est alors susceptible d'entrer en reaction avec une cible organique se trouvant dans sa trajectoire. La cellule a decharge decrite fonctionne sous 500 V, 150 {mu}A, et les produits organiques a marquer sont soumis a ce champ pendant environ trois heures, avec du CO{sub 2} d'activite specifique 24 mc/mmole. Le rendement maximum obtenu reste faible (6% environ), et 60% du {sup 14}CO{sub 2} est detruit. Ce rendement maximum n'est obtenu que pour les chaines aliphatiques (50 {mu}c/g pour l'acide glutarique) ou pour des substances aromatiques presentant une chaine aliphatique (acide acetylsalicylique). (author) [Spanish] La memoria describe un metodo de marcacion que consiste en acelerar {sup 14}CO{sub 2} en un campo electrico para que pueda reaccionar con blancos constituidos por sustancias organicas colocadas en su trayectoria. La celda de descarga que describe la memoria funciona a 500 V y 150 {mu}A, y los productos organicos que se desean marcar se exponen al campo asi creado durante unas tres horas a CO{sub 2} de una actividad especifica de 24 mc/mmol. El rendimiento maximo obtenido es bajo (aproximadamente 6%) y el 60% del {sup 14}CO{sub 2} queda destruido. Este rendimiento maximo solo se alcanza

L'effet Hall Quantique

Science.gov (United States)

Samson, Thomas

Nous proposons une methode permettant d'obtenir une expression pour la conductivite de Hall de structures electroniques bidimensionnelles et nous examinons celle -ci a la limite d'une temperature nulle dans le but de verifier l'effet Hall quantique. Nous allons nous interesser essentiellement a l'effet Hall quantique entier et aux effets fractionnaires inferieurs a un. Le systeme considere est forme d'un gaz d'electrons en interaction faible avec les impuretes de l'echantillon. Le modele du gaz d'electrons consiste en un gaz bidimensionnel d'electrons sans spin expose perpendiculairement a un champ magnetique uniforme. Ce dernier est decrit par le potentiel vecteur vec{rm A} defini dans la jauge de Dingle ou jauge symetrique. Conformement au formalisme de la seconde quantification, l'hamiltonien de ce gaz est represente dans la base des etats a un-corps de Dingle |n,m> et exprime ainsi en terme des operateurs de creation et d'annihilation correspondants a_sp{ rm n m}{dag} et a _{rm n m}. Nous supposons de plus que les electrons du niveau fondamental de Dingle interagissent entre eux via le potentiel coulombien. La methode utilisee fait appel a une equation mai tresse a N-corps, de nature quantique et statistique, et verifiant le second principe de la thermodynamique. A partir de celle-ci, nous obtenons un systeme d'equations differentielles appele hierarchie d'equations quantique dont la resolution nous permet de determiner une equation a un-corps, dite de Boltzmann quantique, et dictant l'evolution de la moyenne statistique de l'operateur non-diagonal a _sp{rm n m}{dag } a_{rm n}, _{rm m}, sous l'action du champ electrique applique vec{rm E}(t). C'est sa solution Tr(p(t) a _sp{rm n m}{dag} a_{rm n},_ {rm m}), qui definit la relation de convolution entre la densite courant de Hall vec{rm J}_{rm H }(t) et le champ electrique vec {rm E}(t) dont la transformee de Laplace-Fourier du noyau nous fournit l'expression de la conductivite de Hall desiree. Pour une valeur de

Resistivity measurements using a direct current induction method (1963); Mesure de resistivite par la methode d'induction en courant continu (1963)

Energy Technology Data Exchange (ETDEWEB)

Delaplace, J; Hillairet, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

The conventional methods for measuring electrical resistivities necessitate the fixing of electrical contacts on the sample either mechanically or by soldering. Furthermore it is also necessary to carry,out the measurements on low cross-section samples which are not always easy to obtain. Our direct-current induction method on the other hand requires no contacts and can easily be applied to samples of large cross-section. The sample is placed in a uniform magnetic field; at the moment when the current is cut, eddy currents appear in the sample which tend to oppose the disappearance of the field. The way in which the magnetic flux decreases in the sample makes it possible to determine the resistivity of the material. This method has been applied to samples having diameters of between 1 and 30 mm in the case of metals which are good conductors. It gives a value for the local resistivity and makes it possible to detect any variation along a sample. The measurements can be carried out at all temperature from a few degrees absolute to 500 deg. C. We have used the induction method to follow the purification of beryllium by zone-melting; it is in effect possible to estimate the purity of a material by resistivity measurements. We have measured the resistivity along each bar treated by the zone-melting technique and have thus, localised the purest section. High temperature measurements have been carried out on uranium carbide and on iron-aluminium alloys. This method constitutes an interesting means of investigation the resistivity of solid materials. Its accuracy and rapidity make it particularly adapted both to fundamental research and to production control. (authors) [French] Les methodes classiques de mesure de resistivite electrique imposent la realisation sur l'echantillon de contacts electriques obtenus soit mecaniquement, soit par soudure. En outre, elles demandent, le plus souvent, d'effectuer les mesures sur des echantillons de faible section qu'il n'est pas

Ixtetreco: recent extensions for the supervision of a power network; Ixtetreco: extensions recentes pour la supervision d`un reseau electrique

Energy Technology Data Exchange (ETDEWEB)

Despouys, O.

1998-04-01

A chronicle model describes a class of evolutions or possible behaviours for a given dynamical system. Ixtetreco uses a reified logics and time constraints to describe these chronicles and algorithms which allow to recognize all instances of these chronicles in a given stream of observations in entry. Ixtetreco is used in several applications for the supervision of complex processes. This paper presents the recent extensions of Ixtetreco which allow to use it in the supervision of power networks. (J.S.) 14 refs.

The electromagnetic compatibility of the PLC technology; La compatibilite electromagnetique de la technologie CPL. Des donnees sur les lignes electriques

Energy Technology Data Exchange (ETDEWEB)

Bermudez, J.-L.; Marthe, E.; Rachidi, F.; Rubinstein, M.; Vukicevic, A.

2006-07-01

PLC (Power Line Communications) in Europe or BPL (Broadband over Power Lines) in the US are techniques that allows the utilization of low and middle voltage power lines for the transmission of high frequencies by coupling electrical signals to them. In this way, unshielded power lines may be used for the transmission of numerical information similar to the well known xDSL-techniques using telephone lines. Typically, the frequency range used by PLC is between 9 kHz and 30 MHz. The authors describe the general principles and investigate possible electromagnetic interference with existing radio frequency equipment like xDSL, CATV (Cable Television) and Wireless (GSM, Bluetooth, WiFi). Finally, they present theoretical and experimental results of techniques allowing the reduction of such interference by reducing the emission of electromagnetic signals from PLC systems. The preferred method is based on an active control by injecting an auxiliary signal into the third conductor (ground)

Power plants of the future. What possibilities for waste heat ?; Centrales electriques du futur. Quelles possibilites pour les rejets thermiques?

Energy Technology Data Exchange (ETDEWEB)

Cherix, G.; Storelli, S. [Centre de Recherches Energetiques et Municipales (CREM), Martigny (Switzerland); Weissbrodt, D. [Swiss Federal Institute of Technology (EPFL), Lausanne (Switzerland); Papina, A. [CTVA SA, Lausanne (Switzerland); Ohana, G. [Services Industriels de Lausanne, Lausanne (Switzerland)

2008-07-01

This article discusses how the production of electricity in thermal power stations can be combined with district heating. An analysis of the density of thermal consumption in the french part of Switzerland was done and it shows the region with interest for district heating installations. Different existing installations are commented. The example of district heating in Copenhagen (Denmark) gives practical information and shows that heat can be transported over long distances. A project of district heating for the Lausanne's agglomeration is presented and its influence on reduction of carbon dioxide production is shown. Economical, political and practical aspects are discussed. Figures of heating costs are given.

The electric heating: solutions and advices for any situation; Le chauffage electrique: des solutions et des conseils pour chaque situation

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NONE

2001-07-01

Since four years, EDF proposes the customers advices to help them in the choice of an electric heating of their house. More specially for those who want to upgrade or change their heating installation, EDF proposes a personalized advice and for those who have a project of building, the Vivrelec solutions. This document presents the EDF policy in the domain of the houses electric heating and the technical solutions proposed. Examples of installations and costs are provided. (A.L.B.)

A statistical analysis of electrical cerebral activity; Contribution a l'etude de l'analyse statistique de l'activite electrique cerebrale

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Bassant, Marie-Helene

1971-01-15

The aim of this work was to study the statistical properties of the amplitude of the electroencephalographic signal. The experimental method is described (implantation of electrodes, acquisition and treatment of data). The program of the mathematical analysis is given (calculation of probability density functions, study of stationarity) and the validity of the tests discussed. The results concerned ten rabbits. Trips of EEG were sampled during 40 s. with very short intervals (500 μs). The probability density functions established for different brain structures (especially the dorsal hippocampus) and areas, were compared during sleep, arousal and visual stimulus. Using a Χ{sup 2} test, it was found that the Gaussian distribution assumption was rejected in 96.7 per cent of the cases. For a given physiological state, there was no mathematical reason to reject the assumption of stationarity (in 96 per cent of the cases). (author) [French] Le but de ce travail est d'etudier les proprietes statistiques des amplitudes du signal electroencephalographique. La methode experimentale est decrite (implantation d'electrodes, acquisition et traitement des donnees). Le programme d'analyse mathematique est precise (calcul des courbes de repartition statistique, etude de la stationnarite du signal) et la validite des tests, discutee. Les resultats de l'etude portent sur 10 lapins. Des sequences de 40 s d'EEG sont echantillonnees. La valeur de la tension est prelevee a un pas d'echantillonnage de 500 μs. Les courbes de repartition statistiques sont comparees d'une region de l'encephale a l'autre (l'hippocampe dorsal a ete specialement analyse) ceci pendant le sommeil, l'eveil et des stimulations visuelles. Le test du Χ{sup 2} rejette l'hypothese de distribution normale dans 97 pour cent des cas. Pour un etat physiologique donne, il n'existe pas de raison mathematique a ce que soit repoussee l'hypothese de stationnarite, ceci dans 96.7 pour cent des cas. (auteur)

Pluri-annual planning of power generation investments. 2005-2015 era; Programmation pluriannuelle des investissements de production electrique. Periode 2005-2015

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NONE

2006-07-01

The pluri-annual planning of power generation investments (PPI) is provided by article 6 of the law from February 10, 2000 relative to the modernization and development of the electric utility. The PPI is the concrete translation of the energy policy and aims to identify the necessary investments with respect to the security of power supplies and beyond the already known commitments. In the framework of market deregulation and respect of competition, the PPI is limited to the identification of such investments but not to their realization. This document, which corresponds to the 2005 exercise, is the second report to the Parliament. It stresses on the following points: the mastery of power demand and the demand scenarios, the level of accepted risk, the carrying out of the development of renewable energy sources (5 GW by 2010 and 12.5 GW by 2016 for wind power, and 6 TWh more for biomass by 2016), the start-up of an EPR reactor in 2012, the investment needs for classical thermal power plants (+2.6 GW of diesel fuel power plants and +500 MW of combustion turbines as decided by EdF), the development of production means in 2 regions with specific needs: Provence-Alpes-Cote d'Azur and Bretagne (Brittany), and also in insular areas (Corsica and overseas territories), and the reflexions to carry on in continuation of the PPI. (J.S.)

Information letter on industrial and commercial applications of electrical equipment; La lettre des applications industrielles et tertiaires du materiel electrique

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NONE

1995-12-31

This issue of Electricite de France research department newsletter, is composed of three articles, which titles and themes are: series reactance, a solution for the optimization of alternating current arc furnace performances; from industrial field buses to smart building field buses, owing to EDF testing; new methods for the voltage drop desensitization of frequency converters for asynchronous machines

Study of the behaviour of some heavy elements in solvents containing hydrogen fluoride; Etude du comportement de quelques elements lourds dans des solvants a base d'acide fluorhydrique

Energy Technology Data Exchange (ETDEWEB)

Tarnero, M [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1967-01-01

The anhydrous liquid mixtures: dinitrogen tetroxide-hydrogen fluoride and antimony pentafluoride-hydrogen fluoride were studied as solvents for heavy elements interesting nuclear energy: uranium, thorium, zirconium and for some of their compounds. For N{sub 2}O{sub 4}-HF mixtures, electric conductivity measurements and liquid phase infrared spectra were also obtained. Uranium and zirconium tetrafluoride are much more soluble in N{sub 2}O{sub 4}-HF mixtures than in pure hydrogen fluoride. Uranium dissolved in these mixtures is pentavalent. In SbF{sub 5}-HF mixtures, uranium dissolves with hydrogen evolution and becomes trivalent. The solid compound resulting from the dissolution is a fluoro-antimonate: U(SbF{sub 6}){sub 3}. (author) [French] On a etudie les melanges liquides anhydres: peroxyde d'azote-acide fluorhydrique et pentafluorure d'antimoine-acide fluorhydrique comme solvants d'elements lourds interessant l'energie nucleaire: uranium, thorium, zirconium et de quelques uns de leurs composes. Pour les melanges N{sub 2}O{sub 4}-HF on a egalement effectue des mesures de conductivite electrique, ainsi que des spectres d'absorption infrarouge en phase liquide. Le tetrafluorure d'uranium et le tetrafluorure de zirconium sont beaucoup plus solubles dans les melanges N{sub 2}O{sub 4}-HF que dans l'acide fluorhydrique. L'uranium dissous dans ces melanges est a l'etat pentavalent. Dans les melanges SbF{sub 5}-HF l'uranium se dissout avec degagement d'hydrogene et passe a l'etat trivalent. Le compose solide resultant de la dissolution est un fluoantimoniate: U(SbF{sub 6}){sub 3}. (auteur)

Contribution to the study of the molecular scattering of light. Use of a laser as light source (1963); Contribution a l'etude de la diffusion moleculaire de la lumiere. Utilisation d'un laser comme source lumineuse (1963)

Energy Technology Data Exchange (ETDEWEB)

Slama, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

The experiments of the molecular scattering of light have been repeated using a ruby laser as a light source. The angular distribution of the scattered light intensity has been measured when the electric vector of the incident beam is either in the plane of observation or perpendicular to that plane. In the first case a good agreement with the Rayleigh theory has been found but this is not true in the second case. The differential cross sections for scattering have been measured for various gases. The values found are two or three times larger than the ones deduced from the classical theory. The possible effect of a variation of the beam intensity upon the linearity of the scattering process has been looked for. (author) [French] Les experiences sur la diffusion moleculaire de la lumiere ont ete reprises en utilisant un laser a rubis comme source lumineuse. La distribution angulaire de l'intensite diffusee a ete mesuree dans le cas ou le vecteur electrique de l'onde lumineuse incidente est soit dans le plan, soit perpendiculaire a ce plan. Dans le premier cas un bon accord est observe avec la theorie de Rayleigh, ce qui n'est plus vrai dans le second cas. Des sections efficaces differentielles de diffusion ont ete mesurees pour differents gaz. Les valeurs trouvees sont 2 a 3 fois plus grandes que celles prevues par la theorie classique. On a recherche enfin l'effet d'une variation d'intensite du faisceau du laser sur la linearite du phenomene de diffusion. (auteur)

A study of point defects created by electron irradiation of dilute iron-carbon alloys; Etude des defauts crees par irradiation electronique dans les alliages de fer carbone dilues

Energy Technology Data Exchange (ETDEWEB)

Leveque, J L [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1969-10-01

Resistivity and magnetic after effect (m.a.e.) measurements are used to study the influence of carbon atoms on the annealing process of point defects created by electron irradiation (3 MeV) at low temperature (20 deg. K). The presence of the carbon atoms has a strong influence on the recovery sub-stage I{sub E} and stage III. For the former, the carbon impurity traps the freely migrating iron interstitial. For the latter the effect is interpreted as being due to formation during annealing, of a carbon vacancy pair. A pronounced m.a.e. band is attributed to the reorientation of this carbon vacancy complex. All these results are coherent with the interpretation of a low temperature migrating free interstitial. (author) [French] L'influence des atomes de carbone sur le recuit des defauts ponctuels crees par irradiation electronique (3 MeV) a basse temperature (20 deg. K) dans le fer est mise en evidence par des mesures de resistivite electrique, et de trainage magnetique. Cette influence se manifeste principalement au cours du sous stade I{sub E} et du stade III de resistivite. Au sous stade I{sub E} les atomes de carbone piegeraient les interstitiels libres de fer au cours de leur migration. Le stade III est interprete comme etant du a la recombinaison du carbone dans les lacunes. Une importante bande de tramage magnetique etant attribuee a la reorientation de ce complexe. Ces resultats sont coherents avec l'interpretation faisant migrer a basse temperature l'interstitiel libre. (auteur)

Contribution to the study of magnetic fields in a configuration having radial symmetry; Contribution a l'etude des champs magnetiques dans une configuration a symetrie axiale

Energy Technology Data Exchange (ETDEWEB)

Bliaux, T; Durand, J P; Giraud-Carrier, C; Merard, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

First, the method for tracing on 'Teledeltos' paper magnetic induction lines (by analogy with electrical equipotential lines) in order to obtain rapid and qualitative results, is recalled. Then the authors present, computed from the law of Biot and Savart, the values of radial and tangential components of the magnetic induction. These results are presented under the form of abaci for a configuration of parallel conductors in a rotational symmetry. Each configuration is defined by the number of conductors 1 {<=} N {<=} 12 and by the the radius R of the circle. The domain of computation of the value of the magnetic induction at point M (r, {theta}) is limited by symmetry in a sector defined by 0 {<=} r {<=} 2,5*R and 0 {<=} {theta} {<=} {theta}{sub max}. (authors) [French] Apres un rappel du trace sur papier semi-conducteur 'Teledeltos' des lignes d'induction magnetique (par analogie avec des lignes equipotentielles electriques), methode rapide qui donne des resultats qualitatifs, les auteurs presentent sous forme d'abaques les valeurs des composantes radiale et tangentielle de l'induction magnetique calculees par la loi de Biot et Savart, pour une configuration de conducteurs paralleles dans une symetrie axiale de revolution. La configuration est definie par le nombre N de conducteurs [1 {<=} N {<=} 12] et par le rayon R du cercle de repartition des conducteurs. Le point courant M (r, {theta}) est limite, pour des raisons de symetrie, dans un secteur defini par [0 {<=} r {<=} 2,5*R] et 0 {<=} {theta} {<=} {theta}{sub max}. (auteurs)

Existence and structure of rare-earth mono-carbides: study of their low-temperature magnetic properties; Existence et structure des monocarbures de terres rares. Etude de leurs proprietes magnetiques a basses temperatures

Energy Technology Data Exchange (ETDEWEB)

Lallement, R [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Fontenay-aux-Roses, 92 (France)

1966-07-01

There are two types of rare earth carbides, the first one is face-centered cubic, stable at high temperature, and very hypo-stoichiometric (formula MC{sub x} with 0.35 < x < 0.65); the other is rhombohedric, stable at lower temperature, with a formula M{sub 2}C. These two carbides are magnetically ordered at low temperatures (ferro or ferri-magnetism). They are highly anisotropic. A great part of the electric and magnetic properties can be explained from the following ideas: the M{sup 3+} ions are coupled via the conduction electrons, there are more conduction electrons in the carbides than in the metals, and there is some local order around the transition temperatures. (author) [French] Nous avons mis en evidence l'existence de deux carbures de terres rares, l'un de formule MC{sub x} (0,35 < x < 0,65) de structure cubique a faces centrees, stable a haute temperature, l'autre de formule M{sub 2}C, de structure rhomhoedrique, stable a temperature moyenne. Ces deux types de carbures presentent des phenomenes d'ordre magnetique a basses temperatures (ferro ou ferrimagnetisme). Ils sont caracterises par une forte anisotropie magnetique. Une grande partie des proprietes electriques et magnetiques s'explique a partir des hypotheses suivantes: a) Les ions M{sup 3+} sont couples entre eux par l'intermediaire des electrons de conduction; b) Le nombre d'electrons de conduction dans les carbures est plus grand que dans les metaux; c) Autour des temperatures de transition se manifestent des phenomenes d'ordre local. (auteur)

Motion of a particle in a radial space-charge field and in an axial magnetic field; Le mouvement d'une particule dans un champ de charge d'espace radial et un champ magnetique axial

Energy Technology Data Exchange (ETDEWEB)

Canobbio, E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires. Services de Physique Appliquee, Service d' Ionique Generale, Section d' Etudes des Interactions Ondes Plasmas; Finzi, U [Institut de Physique Theorique de Milan (Italy)

1966-07-01

The motion of a charged particle in an axial uniform steady magnetic field, under the action of a radial space charge is calculated. A cylindrical symmetric charge distribution similar to the one which is observed in HF plasma accelerators is assumed. The particle motion is discussed with the method of effective potentials. A radial acceleration of ions is shown to be possible if the space charge density is sufficiently high. The displacement of the turning points of the trajectories due to the electrostatic field is calculated in the low plasma density approximation. Finally a HF circularly polarized electric field is introduced, the shift in cyclotron resonance is calculated and a low frequency resonance is found to be possible. (authors) [French] On etudie le mouvement d'une particule dans un champ magnetique axial uniforme et constant en presence d'un champ de charge d'espace radial. On considere une distribution de charge a symetrie cylindrique, semblable a celle qu'on observe dans les accelerateurs de plasma a H.F. On se sert des potentiels effectifs pour discuter les caracteristiques du mouvement. Une acceleration radiale des ions est possible lorsque la densite de charge est assez elevee. On calcule aussi les deplacements des points de rebroussement des trajectoires produits par un champ electrostatique faible. On introduit enfin un champ electrique HF polarise circulairement et on calcule le deplacement de la resonance de cyclotron du au champ de charge d'espace. En meme temps on voit apparaitre dans l'energie cinetique de la particule une resonance a basse frequence. (auteurs)

Anisotropic Migration in Slab Lattices; Migration Anisotrope dans les Reseaux a Plaques; Anizotropicheskaya migratsiya v reshetkakh iz plastin; Migracion Anisotropica en Reticulados de Placas

Energy Technology Data Exchange (ETDEWEB)

Honeck, H. C.; Quiquemelle, B. C. [Brookhaven National Laboratory, Upton, NY (United States)

1965-08-15

One of the newest applications of pulsed neutron experiments is the measurement of the thermal neutron diffusion coefficient in different directions in a heterogeneous medium. This paper describes a theoretical method developed to predict these diffusion coefficients and presents some results for experiments in progress at Brookhaven National Laboratory. The interpretation of these experiments is considerably simplified if the experimental assembly is large. Diffusion cooling can then be ignored, the spectra taken to be Maxwellian, and a single energy group considered. With this simplification, it is possible to solve the transport equation numerically for the case of slab geometry. We insert a solution of the form Empty-Set (x, y, z, {Omega}, t) = exp (iB{sub 1}X + iB{sub 2}y - {lambda}t) Empty-Set (x, {Omega}) into the transport equation and solve for Empty-Set (x, {Omega}) by a combination of DSN and integral transport theory methods. The principal advantages of this method over existing methods is that absorption and anisotropic scattering are easily included, and the cell may be composed of many sub-regions. While we might attempt to find the eigenvalue {lambda}, given B{sub 1} and B{sub 2}, it is more convenient to replace iB{sub 1} by K{sub 1}, iB{sub 2} by K{sub 2}, and determine K{sub 1}, given K{sub 2} and {lambda}. The {lambda} can then be expressed as a power series in K{sup 2}{sub 1} and K{sup 2}{sub 2} (or equivalently B{sup 2}{sub 1} and B{sup 2}{sub 2}). The diffusion coefficients are then given by D{sub n} = -d{lambda}/K{sup 2}{sub n} Experiments are in progress at Brookhaven National Laboratory on alternating slabs of aluminium and polyethylene. We have selected the following one-group cross-sections: aluminium, {Sigma}{sub a} = 0.01228 cm{sup -1}, {Sigma}{sub S} = 0.08428 cm{sup -1}, {mu} = 0; polyethylene, {Sigma}{sub a} = 0.01947 cm{sup -1}, {Sigma}{sub S} = 2.593 cm{sup -1}, {mu} = 0.25. (author) [French] Une des dernieres applications des experiences au moyen des neutrons puises est la mesure des coefficients de diffusion anisotrope des neutrons thermiques dans un milieu heterogene. Les auteurs exposent une methode theorique elaboree pour prevoir ces coefficients de diffusion et ils indiquent quelques resultats obtenus au cours des experiences qui sont actuellement faites au Laboratoire national de Brookhaven. L'interpretation de ces experiences se trouve grandement simplifiee si l'assemblage experimental est de grande dimension. On peut alors negliger le refroidissement par diffusion, admettre que les spectres sont maxwelliens et ne considerer qu'un seul groupe d'energies. Grace a cette simplification, il est possible de resoudre numeriquement l'equation de transport pour le cas d'une geometrie a plaques. Dans l'equation de transport, les auteurs introduisent une solution ayant la forme Empty-Set (x, y, z, {Omega}, t) = exp (iB{sub 1}X + iB{sub 2}y - {lambda}t) Empty-Set (x, {Omega}) et ils la resolvent par rapport a Empty-Set (x, {Omega}) a) en combinant la methode DSN et des methodes fondees sur la theorie du transport. Les principaux avantages de ce procede par rapport aux methodes existantes sont les suivants: il permet d'inclure facilement l'absorption et la diffusion anisotrope et la cellule peut etre composee de nombreuses subdivisions. Les auteurs auraient pu essayer de determiner la valeur propre{lambda}pour Bx et B2 donnes, mais il est plus commode de remplacer iB{sub 1} par et iB{sub 2} par K{sub 2}, puis de determiner pour et {lambda} donnes. La valeur de {lambda} peut alors etre exprimee sous la forme d'une serie de puissances en K{sup 2}{sub 1} et K{sup 2}{sub 2} (ou de maniere equivalente en B{sup 2}{sub 1} et B{sup 2}{sub 2}). Dans ce cas les coefficients de diffusion sont donnes par la formule D{sub n} = -d{lambda}/K{sup 2}{sub n}. Au Laboratoire national de Brookhaven des experiences sont actuellement en cours sut des plaques alternees d'aluminium et de polyethylene. Les auteurs ont choisi les sections efficaces 3 un groupe ci-apres: aluminium, {Sigma}{sub a} = 0.01228 cm{sup -1}, {Sigma}{sub S} = 0.08428 cm{sup -1}, {mu} = 0; polyethylene, {Sigma}{sub a} = 0.01947 cm{sup -1}, {Sigma}{sub S} = 2.593 cm{sup -1}, {mu} = 0.25. (author) [Spanish] Una de las aplicaciones mas modernas de los experimentos con neutrones pulsados es la medicion en diferentes direcciones de los coeficientes de difusion anisotropica de neutrones termicos en un medio heterogeneo. La memoria describe un metodo teorico que se ha establecido para predecir estos coeficientes de difusion, y presenta algunos de los resultados obtenidos en los experimentos que se realizan en el Brookhaven National Laboratory. La interpretacion de los resultados se simplifica considerablemente si el conjunto experimental es de grandes dimensiones. En este caso cabe prescindir del enfriamiento por difusion, suponeT que los espectros son maxwellianos y considerar un solo grupo energetico. Gracias a esta simplficacion se consigue resolver numericamente la ecuacion de transporte cuando se trata de una geometria de placas. Los autores introducen en esta ecuacion una solucion de la forma Empty-Set (x, y, z, {Omega}, t) = exp (iB{sub 1}X + iB{sub 2}y - {lambda}t) Empty-Set (x, {Omega}) y despejan Empty-Set (x, {Omega}) por una combinacion de metodos DSN y de teorfa integral del transporte. Las principales ventajas de este procedimiento son que permite facilmente incluir la absorcion y la dispersion anisotropica, y que la celda se puede componer de muchas subregiones. Es posible tratar de encontrar el valor propio {lambda} cuando se conocen B{sub 1} y B{sub 2}, pero conviene mas sustituir iB{sub 1} por K{sub 1}, iB{sub 2} por K{sub 2}, y determinar K{sub 1}, una vez conocidos K{sub 2} y {lambda}. En este caso, {lambda} se puede expresar como serie exponencial de K{sup 2}{sub 1} y K{sup 2}{sub 2} (o lo que es equivalente, de B{sup 2}{sub 1} y de B{sup 2}{sub 2}). Entonces, la ecuacion D{sub n} = -d{lambda}/K{sup 2}{sub n} dara los coeficientes de difusion. En el Brookhaven National Laboratory se estan haciendo experimentos con placas alternadas de aluminio y polietileno. Los autores han seleccionado las siguientes secciones eficaces en un solo grupo: aluminio, {Sigma}a = 0, 01228 cm{sup -1}, {Sigma}s = 0, 08428 cm{sup -1}, {mu} = 0; polietileno, {Sigma}a - 0, 01947 cm-1, {Sigma}s = 2,593 cm{sup -1}, {mu} = 0,25. (author) [Russian] Odnoj iz samyh novyh oblastej primenenija jeksperimentov s impul'snymi nejtronami javljaetsja izmerenie kojefficienta diffuzii teplovyh nejtronov v razlichnyh napravlenijah v geterogennoj srede. Opisyvaetsja teoreticheskij metod, razrabotannyj s celyo predskazanija takih kojefficientov diffuzii, i predstavljajutsja nekotorye rezul'taty jeksperimentov, provodimyh v nastojashhee vremja v Brukhejvene. Interpretacija jetih jeksperimentov v znachitel'noj stepeni uproshhaetsja, esli jeksperimental'naja sborka javljaetsja bol'shoj. V jetom sluchae mozhno prenebregat' diffuzionnym ohlazhdeniem, spektry schitat' maksvellovskimi i rassmatrivat' edinstvennuju gruppu energii. Pri takom uproshhenii mozhno chislenno reshit' uravnenie perekosa dlja sluchaja plastinchatoj geometrii. My podstavljaem reshenie modeli Empty-Set (x, y, z, {Omega}, t) = exp (iB{sub 1}X + iB{sub 2}y - {lambda}t) Empty-Set (x, {Omega}) v uravnenie perenosa i reshaem Empty-Set (x, {Omega}) putem sochetanija metodov fil'trov dlja vyravnivanija dannyh i integral'noj teorii perenosa. Osnovnye preimushhestva jetogo metoda po sravneniju s sushhestvujushhimi sostojat v tom, chto legko vkljuchajutsja pogloshhenie i anijeotropiches- koe rassejanie i jachejka mozhet sostojat' iz mnogih podoblastej. Hotja sdelana popytka najti B{sub 1} i B{sub 2} s dannym sobstvennym znacheniem {lambda}, udobnee vmesto iB{sub l} postavit' kj i vmesto i V{sub 2} - k{sub 2} i opredelit' k{sub 2} s dannym k{sub 1} i {lambda} takom sluchae {lambda} mozhno vyrazit' v vide stelennogo rjada K{sup 2}{sub 1} i K{sup 2}{sub 2} (ili sootvetstvenno a B{sup 2}{sub 1} i B{sup 2}{sub 2}). Kojefficienty diffuzii zatem vyvodjatsja iz uravnenija D{sub n} = -d{lambda}/K{sup 2}{sub n}. V nastojashhee vremja v BNL provodjatsja jeksperimenty s peremennymi plastinami iz aljuminija i polijetilena. Otobrany sledujushhie poperechnye sechenija odnoj gruppy: aljuminij {Sigma}a - 0,01228sm{sup -1}, {Sigma}s = 0,08428 sm{sup -1}, {mu} = 0; polijetilen {Sigma}a = 0,01947 sm{sup -1}, {Sigma}s = 2,593 sm{sup -1} , {mu} = 0,25. (author)

On the integration of wind generators on weak grids and island grids; Sur l'integration des generateurs eoliens dans les reseaux faibles ou insulaires

Energy Technology Data Exchange (ETDEWEB)

Laverdure, N

2005-12-15

Wind energy is now an energy that can not be ignored. Because of intrinsic characteristics (scattered primary energy, generators with different technologies, use of power electronics interface), wind energy system integration in distribution grids leads to real problems in terms of impacts. With recent standard changes, it is necessary to study the possibilities of each technology of wind turbines to answer or not to these new constraints. This PhD thesis focuses on a comparison of the main present wind turbines concerning three points of discussion: energy quality, fault ride through, ancillary services (voltage and frequency). It insists on the possibilities in terms of control laws for variable speed wind turbines. (author)

Fuzzy logic and modeling of ventilation networks in the nuclear industry; Logique floue et modelisation des reseaux de ventilation dans l'industrie nucleaire

Energy Technology Data Exchange (ETDEWEB)

Floquet, P.; Lhoste, J.C.; Domenech, S.; Pibouleau, L. [Ecole Nationale Superieure des Arts Chimiques et Technologiques, Lab. de Genie Chimique, LGC, UMR CNRS/INP/UPS 5503, 31 - Toulouse (France); Laborde, J.C. [CEA Saclay, Institut de la Protection et de la Surete Nucleaire, IPSN, DPEA/SERAC, 91 - Gif-sur-Yvette (France)

2001-07-01

This article presents the implementation of fuzzy logic in the modeling of ducts, filters and pressures of the ventilation networks of the nuclear industry, taking into account the uncertainties of the aeraulic parameters. (J.S.)

First Modelling Results of the EM Response of a CO2 Storage in the Paris Basin Premières modélisations de la réponse EM d’un stockage de CO2 dans le bassin Parisien

Directory of Open Access Journals (Sweden)

Bourgeois B.

2010-07-01

electriques/EM pour surveiller l’injection de CO2 supercritique a 1700 m de profondeur dans un aquifere salin du Bassin Parisien (Carbonates du Dogger. Nous demontrons d’abord l’interet theorique des methodes de resistivite pour une telle surveillance a l’aide des lois fondamentales de la petrophysique dans les roches sedimentaires poreuses, en supposant que le CO2 supercritique est un isolant parfait. Diverses combinaisons de sources et de capteurs sont discutees et il est conclu que le dispositif le plus performant consiste en une source de type galvanique (injection de courant dans le sol a l’aide d’unepaire d’electrodes A et B et d’une grille de capteurs electriques (et peut-etre magnetiques a la surface du sol. Compte tenu de la profondeur et de la finesse des couches reservoir, l’injection du courant en profondeur est envisagee dans le but d’augmenter la densite de courant circulant dans la couche reservoir. L’injection ponctuelle a la profondeur du reservoir, dans une configuration de type « Mise A la Masse » (MAM, etant generalement impossible a cause de la presence de tubages metalliques dans les forages, nous avons etudie la possibilite d’utiliser ces memes tubages comme des longues electrodes distribuant le courant tout le long du forage. Ce type de source est denomme « LEMAM » (Long Electrode Mise A la Masse, pour le distinguer du MAM conventionnel. Des simulations numeriques sont presentees a la fois pour le dispositif LEMAM et pour le dispositif « rectangle » (RECT, lequel emploie une injection de courant ponctuelle a la surface du sol. Le modele geoelectrique utilise est base sur une zone proche du champ petrolier de Saint-Martin-de-Bossenay (SMB, au sud-est du Bassin Parisien. La couche reservoir consideree dans cette etude est la formation de l’“ Oolithe Blanche ” (Dogger qui a une epaisseur de 75 m et se situe a une profondeur de 1700 m sous la surface du sol. Dans les modeles presentes, le panache de CO2 est simplifie en

Critical experiments in AQUILON with fuels slightly enriched in uranium 235 or in plutonium; Experiences critiques dans aquilon portant sur des combustibles legerement enrichis en uranium 235 et en plutonium

Energy Technology Data Exchange (ETDEWEB)

Chabrillac, M; Ledanois, G; Lourme, P; Naudet, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

Reactivity comparisons have been, made in Aquilon II between geometrically identical lattices differing only by the composition of the fuel. The fuel elements consist in metallic uranium single rods with either slight differences of the isotopic composition (0.69 - 0.71 - 0.83 - 0.86 per cent of uranium 235) or slight additions of plutonium (0.043 per cent). Five lattices pitches have bean used, in order to produce a large variation of spectrum. Two additional sets of plutonium fuels are prepared to be used in the same conditions. The double comparisons: natural enriched 235 versus natural-enriched plutonium are made in such a way that a very precise interpretation is permitted. The results are perfectly consistent which seems to prove that the calculation methods are convenient. Further it can been inferred that the usual data, namely for the ratio of the {eta} of {sup 235}U and {sup 239}Pu seem reliable. (authors) [French] On a compare neutroniquement dans Aquilon II des reseaux geometriquement identiques mais comportant de petites differences de composition du combustible. EL s'agit de barres d'uranium metallique, les unes avec des teneurs differentes en isotopes 235 (0,69 - 0,71 - 0,83 - 0,86 pour cent) les autres comportant une legere addition de plutonium (0,043 pour cent). Les comparaisons ont ete faites a cinq pas differents, de maniere a mettre en jeu une assez large variation de spectre. Deux autres jeux de combustible au plutonium seront utilises ulterieurement dans les memes conditions. Les resultats des mesures se presentent sous forme de doubles comparaisons: naturel-enrichi 235/naturel-enrichi plutonium. On s'est place dans des conditions qui permettent des interpretations tres precises. Les resultats sont remarquablement coherents, ce qui semble montrer que les methodes de calcul sont bien adaptees, Ils tendent d'autre part a prouver que les valeurs numeriques admises dans la litterature, notamment pour le rapport des {eta} de l'U 235 et de Pu 239

The structure of magnetic materials; La structure des substances magnetiques

Energy Technology Data Exchange (ETDEWEB)

Villain, J. [Commissariat a l' energie atomique et aux energies alternatives - CEA, C.E.N. Saclay (France)

1960-07-01

The paper deals with the prediction of the structure of magnetic materials below the critical point. The molecular field approximation is used: exchange interactions with unlimited range are assumed; the magnetic ions are supposed to form a Bravais lattice. The critical temperature T{sub c} is first calculated (section 1) without assuming any decomposition of the crystal into sublattices, and the magnetic structure at T{sub c} is given. It is next shown (section 2) that the essential features of this structure persist below T{sub c}, and the various possible cases are considered. It is possible that no decomposition into sublattices takes place, i.e. the magnetic structure and the nuclear structure have incommensurable periods. A detailed treatment is then given for the body-centered quadratic lattice (section 3) with interaction between first, second and third neighbours. Reprint of a paper published in Journal of Physical Chemistry, vol. 11, no. 3/4, p. 303-309, 1959 [French] Ce travail a pour objet la prevision systematique de la structure des substances magnetiques au-dessous du point de transition et l'etude des differents cas qui peuvent se presenter lorsque les ions magnetiques forment un reseau de Bravais. On se place dans une approximation de champ moleculaire, mais on ne fait aucune restriction concernant la portee des interactions d'echange. Apres avoir determine (Section 1) la temperature critique et la structure magnetique a cette temperature sans supposer a priori l'existence d'une decomposition en sous-reseaux, on montre (Section 2) que cette structure reste stable en dessous de la temperature critique, et on etudie les divers cas possibles. Il peut arriver en particulier que la structure magnetique ait une periode incommensurable avec celle du reseau cristallin. L'example du reseau quadratique centre avec couplage entre premiers, seconds et troisiemes voisins (Section 3) fournit une bonne illustration de cette etude. Reproduction d'un article publie

Use of an oscillation technique to measure effective cross-sections of fissionable samples in critical assemblies; Mesure des sections efficaces effectives d'echantillons fissiles par une methode d'oscillation dans les-assemblages critiques

Energy Technology Data Exchange (ETDEWEB)

Tretiakoff, O; Vidal, R; Carre, J C; Robin, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

The authors describe the technique used to measure the effective absorption and neutron-yield cross-sections of a fissionable sample. These two values are determined by analysing the signals due to the variation in reactivity (over-all signal) and the local perturbation in the flux (local signal) produced by the oscillating sample. These signals are standardized by means of a set of samples containing quantities of fissionable material ({sup 235}U) and an absorber, boron, which are well known. The measurements are made for different neutron spectra characterized by lattice parameters which constitute the central zone within which the sample moves. This technique is used to study the effective cross-sections of uranium-plutonium alloys for different heavy-water and graphite lattices in the MINERVE and MARIUS critical assemblies. The same experiments are carried out on fuel samples of different irradiations in order to determine the evolution of effective cross-sections as a function of the spectrum and the irradiations. (authors) [French] On decrit la methode utilisee pour mesurer les sections efficaces effectives d'absorption et de production de neutrons d'un echantillon fissile. Ces deux grandeurs sont determinees en analysant les signaux dus a la variation de reactivite (signal global) et a la perturbation locale de flux (signal local) produits par l'echantillon oscillant. Ces signaux sont etalonnes a l'aide d'un jeu d'echantillons dont les teneurs en materiau fissile ({sup 235}U) et en absorbeur (bore) sont bien connues. Les mesures sont realisees pour differents spectres de neutrons caracterises par les parametres du reseau constituant la zone centrale a l'interieur de laquelle se deplace l'echantillon. A l'aide de cette methode on etudie les sections efficaces effectives d'alliage uranium-plutonium pour differents reseaux a eau lourde et a graphite dans les assemblages crtiques MINERVE et MARIUS. Les memes experiences sont effectuees sur des echantillons de

Against the electric heating. Little calculations and big manipulations; L'offensive contre le chauffage electrique. Petits calculs et grandes magouilles

Energy Technology Data Exchange (ETDEWEB)

Nifenecker, H

2008-02-15

The author aims to denounce a report presented by the ADEME and the RTE, concerning the electric heating which could lead to the implementing of an electric production by coal and gas power plants. The authors aims to show why this affirmation is wrong. He explains also that this calculation has no sense in the context of the CO{sub 2} emissions, in the framework of the methods used by the European Union to evaluate these emissions. (A.L.B.)

Power frequency electric and magnetic fields: Questions and answers; Champs electriques et magnetiques produits par le courant industriel: Questions et reponses

Energy Technology Data Exchange (ETDEWEB)

NONE

1990-10-01

Power frequency fields are electric and magnetic fields produced by electric power. The first evidence to show that power frequency fields may have an effect on human health was noted in 1972 when it was reported that workers in high voltage switchyards suffered from a number of ailments. Fundamentals of electric and magnetic fields, and methods of their measurement, are explained. Some sources of power frequency fields are reviewed, and measured occupational exposures to these fields by electric utility workers are listed. Possible biological and health effects from power frequency fields are summarized from epidemiological, whole-animal, cellular, and observational studies reported in the literature. These include increased risk of cancer, decrease in melatonin, reproductive and developmental abnormalities, decreased heart rates, changes in calcium flow across cell membranes, and changes in neurotransmitters and corticosterone. Exposure standards for power frequency fields are given and methods for controlling exposure to those fields are noted. 53 refs., 1 fig., 2 tabs.

Report to the parliament. Pluri-annual planning of power production investments; Rapport au parlement. Programmation pluriannuelle des investissements de production electrique

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-01-01

The article 6 of the law from February 10, 2000, relative to the modernization and development of the electric utility, schedules a pluri-annual planning of the production investments (PPI) which represents a concrete translation of the energy policy in the domain of electricity. The PPI will allow to reach the energy policy goals using a balanced development of the national production means in terms of primary energy sources, techniques of production and geographical distribution of investments. This document is the first PPI report to the parliament. It is based on the scheme of energy collective services and on a provisional status made by the manager of the transportation network (RTE). In 2010, renewable energies should cover 21% of the French electricity needs. This ratio will be reached mainly thanks to the development of wind power (7000 to 14000 MW of installed power, which represents 20 to 35 TWh of additional production). Hydro-power should be increased of 8 TWh max, depending on the public policies implemented, and biomass will have a significant contribution too. On the other hand, actions of mastery of the electricity demand will have to be implemented. From 2008 onward, the decommissioning of several power plants will impose to find new solutions to satisfy the peak power needs. The covering of consumption peaks requires a correlation study of the power peaks at the European scale. Finally, the situation of non-interconnected areas and of areas with fragile supply has been carefully considered. The creation of new power production means must be envisaged in most of these areas. (J.S.)

Etude par resistivite electrique du comportement d'un alliage amorphe Fe 40Ni 38Mo 4B 18 deforme par traction

Science.gov (United States)

Hoang, Long Phan; Sacovy, Paulette; Delaplace, Jean

1983-02-01

Des rubans d'alliages amorphes Metglas du type Fe 40Ni 38Mo 4B 18 à l'état brut de trempe ont été déformés par traction à la température ambiante et l'on a suivi les variations de la résistance électrique des échantillons au cours de la déformation. Il ressort de ces essais que la déformation plastique qui est de l'ordre de 0.5% avant rupture ne se produit pas de faĉon homogène dans l'échantillon. Les mesures électriques effectuées au cours de la déformation mettent en évidence dans le domaine élastique un effet d'élastorésistance, relativement important ( K ≠ 1); elles montrent que dans le domaine plastique la déformation permanente des échantillons s'accompagne d'une diminution de la résistivité électrique du matériau. Deux hypothèses sont discutées pour expliquer cet effet inattendu, l'un qui fait appel à l'existence de volumes libres, l'autre qui suppose une cristallisation localisée du matériau sous l'effet de la contrainte.

On the integration of wind generators on weak grids and island grids; Sur l'integration des generateurs eoliens dans les reseaux faibles ou insulaires

Energy Technology Data Exchange (ETDEWEB)

Laverdure, N

2005-12-15

Wind energy is now an energy that can not be ignored. Because of intrinsic characteristics (scattered primary energy, generators with different technologies, use of power electronics interface), wind energy system integration in distribution grids leads to real problems in terms of impacts. With recent standard changes, it is necessary to study the possibilities of each technology of wind turbines to answer or not to these new constraints. This PhD thesis focuses on a comparison of the main present wind turbines concerning three points of discussion: energy quality, fault ride through, ancillary services (voltage and frequency). It insists on the possibilities in terms of control laws for variable speed wind turbines. (author)

Solution of the transfer functions and the linear networks by an analog computer; Resolution des fonctions de transfert et des reseaux lineaires sur calculateur analogique

Energy Technology Data Exchange (ETDEWEB)

Bras, D

1967-09-27

This study presents five methods used to realize a transfer function on analog computer - method of operational amplifiers - method of successive integrations - method of the auxiliary variable - method of the Horner decomposition - method of the direct analog transposition. The method that seems to us the most interesting, this one of Horner, is exposed with some complements. The last method presents the study of a linear network (mechanical, electronic) by direct analog transposition, without having to calculate its transfer function. Several aspects are studied the economy or the material type, the simpleness of implementing the adaptation of coefficients to the computer, the introduction of initial conditions of input and output functions. Every method presented is discussed in function of these problems. The precision of the result is not studied here, but we can indicate that the methods treated here, do not include approximations other than these ones of the computer elements. [French] Cette etude presente cinq methodes utilisees pour realiser une fonction de transfert quelconque sur calculateur analogique - methode des Amplificateurs operationnels - methode des integrations successives - methode de la variable auxiliaire - methode de la decomposition de Horner - methode de la transposition analogique directe. La methode qui nous semble la plus interessante, celle de Horner, est exposee avec quelques complements. La derniere methode presente l'etude d'un reseau lineaire (mecanique, electronique...) par transposition analogique directe, sans avoir a calculer sa fonction de transfert. Plusieurs aspects sont etudies l'economie ou le type de materiel, la simplicite de mise en oeuvre l'adaptation des coefficients au calculateur, l'introduction des conditions initiales des fonctions d'entree et de sortie. Chaque methode presentee est discutee en fonction de ces problemes. La precision du resultat n'est pas etudiee ici, mais on peut indiquer toutefois que les methodes traitees ne comportent pas d'approximations autres que celles des elements du calculateur. (auteur)

Multi-criteria optimization of dryers: use of neural networks and genetical algorithms; Optimisation multi-criteres de sechoirs: utilisation des reseaux de neurones et algorithmes genetiques

Energy Technology Data Exchange (ETDEWEB)

Hugget, A.; Nadeau, J.P.; Sabastian, P. [Ecole Nationale Superieure des Arts et Metiers, 33 - Talence (France)

1997-12-31

Drying remains a complex process to model and thus to optimize. In this paper a new approach is proposed which allows to perform a compression in the drying model in order to integrate it using neural networks. The simulation times become very small and allow to test a great number of configurations. This decisive advantage allows to perform a multi-criteria optimization using hybrid genetical algorithms based on technical-economical criteria like drying cost, production or final product quality. (J.S.) 10 refs.

The Role of Diffusion Measurements in the Study of Crystal Lattice Defects; Role des Mesures de la Diffusion dans l'Etude des Defauts des Reseaux Cristallins; Rol' diffuzionnykh izmerenij v izuchenii defektov kristallicheskikh reshetok.rol' diffuzionnykh izmerenij v izuchenii defektov kristallicheskikh reshetok; Las Mediciones de la Difusion en el Estudio de Defectos de los Reticulados Cristalinos

Energy Technology Data Exchange (ETDEWEB)

Kidson, G. V. [Chalk River Nuclear Laboratories, ON (Canada)

1966-02-15

transport atomique dans les solides presentent souvent un interet direct pour les ingenieurs specialises dans l'etude, la mise au point et l'utilisation de materiaux. Actuellement on s'efforce de plus en plus d'aboutir a la comprehension de ces proprietes en fonction de l'apparition et la nature de defauts ponctuels et lineaires dans les cristaux. Le memoire fait le point de certaines etudes de diffusion effectuees recemment a Chalk River; ces travaux non seulement fournissent des resultats importants pour la technologie nucleaire, mais permettent egalement de mieux comprendre la nature des defauts de reseaux que l'on rencontre dans les materiaux. Les questions etudiees sont: a) l'autodiffusion dans la phase de zirconium pur a haute temperature; b) la diffusion d'un solute dans le plomb; c) l'interdiffusion de l'aluminium et du zirconium. L'auteur discute brievement les resultats assez surprenants et encore imparfaitement compris qui sont decrits sous a). Certaines indications donnent a penser que la diffusion se produit soit par un reseau serre de dislocation resultant d'une transformation de la phase martensitique, soit par un excedent de lacunes provoquees dans le cristal par des impuretes. Sous b), l'auteur discute la diffusion extraordinairement rapide des solutes de metaux nobles dans des monocristaux de plomb de grande purete selon l'etat de solution des atomes du solute. Il montre que Ton peut comprendre leur comportement de diffusion si l'on admet qu'une fraction f Inverted-Question-Mark des atomes dissous du solute occupe des sites interstitiels. Le coefficient de diffusion mesure D{sub m} et le coefficient de diffusion interstitielle sont lies par la relation D{sub m} = f{sub i}D{sub i}. Sous c), l'auteur decrit la formation et la croissance rapide d'un compose intermetallique unique ZrAl{sub 3} dans la zone de diffusion formee entre le zirconium et l'aluminium purs et il interprete le mecanisme de diffusion en fonction de la structure du reseau compose. Il

The circular thermo-phoretic spectrometer (CTSM), a new device for the study of the thermophoresis, Application on the fractals soot particles

International Nuclear Information System (INIS)

Brugiere, E.

2012-01-01

This work aims to improve the understanding of soot particle deposition by thermophoresis. In order to show the influence of the morphology of a fractal aggregate on its thermo-phoretic behavior, a new experimental device has been developed; the SpectroMetre Thermophoretique Circulaire (SMTC). This instrument is used to measure the mean thermo-phoretic velocity of particles selected between a hot plate and a cold plate thanks to a transfer function based on the geometry of the radial flow differential mobility analyser RF-DMA or SMEC (Spectrometre de Mobilite Electrique Circulaire). For the experimental validation, effective thermo-phoretic velocities of monodispersed spherical latex particles for diameters ranging from 64 nm to 500 nm and a temperature gradient equal to 50 750 K/m are measured and compared with theoretical values. The good agreement between the experimental results and theoretical values of Beresnev and Chernyak (1995) helps us to validate the operation of the instrument. Then we compare experimental thermo-phoretic velocity obtained with the SMTC for spherical particles and aggregates produced by a combustion aerosol generator. Contrary to the results obtained with the PSL particles, we observe that the thermo-phoretic velocity of aggregates increases with the electrical mobility diameter. Thanks to a morphological study of the aggregates, we showed that the thermo-phoretic velocity depends on the number of primary particles of the aggregate. These experimental results confirm, for the first time, the theoretical data of Mackowski (2006) obtained by a Monte Carlo simulation. Moreover, a comparison with the experimental results of Messerer et al. (2003) shows that the thermo-phoretic velocity of aggregates seems independent of the primary particle size. (author)

Contribution to the study of detonation initiation by shock in solid explosives (1961); Contribution a l'etude de l'initiation de la detonation par choc dans les explosifs solides (1961)

Energy Technology Data Exchange (ETDEWEB)

Fauquignon, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-05-15

When a shock wave is induced in an explosive, it can initiate chemical reactions which lead more or less rapidly to a stable detonation state. In this study more particular attention was paid to the transition phase, in which has been evaluated the increases in the wave velocity, the pressure, and the electrical conductivity. The influence of the nature of the medium in front of the wave and in contact with the explosive has also been the subject of an experimental study designed to determine the extent to which its nature can be ignored and, subsequently, to characterise the initiation conditions using only the shock intensity induced in the explosive. Finally, the results were generalized for various explosive compositions and led to the development of a possible mechanism for shock initiation. (author) [French] Lorsqu'une onde de choc est induite dans un explosif, elle peut y amorcer des reactions chimiques qui conduisent plus ou moins rapidement a un regime de detonation stable. Dans cette etude, on s'est interesse plus particulierement a la phase transitoire dans laquelle on a evalue l'accroissement de la vitesse d'onde, de la pression et de la conductibilite electrique. L'influence du milieu amont, au contact de l'explosif, a egalement fait l'objet de recherches experimentales de facon a determiner dans quelle mesure on pouvait s'affranchir de sa nature et, par suite, caracteriser les conditions d'initiation par la seule intensite du choc induit dans l'explosif. Enfin, les resultats ont ete generalises a diverses compositions explosives et ont conduit a l'elaboration d'un schema possible du mecanisme de l'initiation par choc. (auteur)

Transistorized pulse amplifiers (A.I.T.); Amplificateurs d'impulsions a transistors (A.I.T.)

Energy Technology Data Exchange (ETDEWEB)

Feyt, J; Couly, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1962-07-01

The two amplifiers whose design and operation are described in this report have been studied for neutron detection units used in piles. They are designed to allow an important reduction of the volume and of the weight of the detector and its amplifier, and to simplify the operation of the detection assembly. To these characteristics can be added the mechanical and electrical robustness and the very reduced micro-phony. The first transistorized amplifier (AIT.1) is simple, very robust, and can be used for radioprotection installations. The second (AIT.4) has a better performance and makes it possible to replace the APT.2 in most of its applications (it has even been used satisfactorily in an apparatus where the micro-phony and the sensitivity to interference of the APT.2 made this latter unusable). (author) [French] Les deux amplificateurs dont ce rapport decrit la conception et le fonctionnement ont ete etudies pour les ensembles de detection des neutrons aupres des piles. Ils ont ete concus pour permettre une reduction importante du volume et du poids du detecteur et de son amplificateur, et pour simplifier le fonctionnement de l'ensemble de detection. A ces caracteristiques s'ajoutent une grande robustesse mecanique et electrique et une microphonie quasi nulle. Le premier amplificateur a transistors (AIT.1) simple, tres robuste, convient pour les installations de radioprotection. Le deuxieme (AIT.4) de performances plus elevees permet de remplacer l'APT.2 dans la plupart de ses applications (il a meme ete utilise avec satisfaction dans un montage ou la microphonie et la sensibilite aux parasites de l'APT.2 rendaient celui-ci inutilisable). (auteur)

Modelling of a Spark Ignition Engine for Power-Heat Production Optimization Modèle de moteur à allumage commandé en vue de l’optimisation de la production chaleur-force

Directory of Open Access Journals (Sweden)

Descieux D.

2011-09-01

Full Text Available Spark ignition gas engine is more and more used in order to produce electricity and heat simultaneously. The engine crankshaft drives a synchronous electric generator. The thermal power output is recovered from the engine coolant system and exhaust gas, and is used to produce generally hot water for heating system. In order to have a better adequacy between supply (production of the engine and user demand, good knowledge of the engine and implemented phenomena are necessary. A generic methodology is proposed to simulate the stationary state response of a SI engine. The engine simulation is based on a one zone thermodynamic model, which characterizes each phase of the engine cycle to predict energy performances: exergy efficiency as high as 0.70 is attainable. Le moteur a allumage commande alimente en gaz est un moteur de plus en plus utilise pour la production simultanee d’electricite et de chaleur. Classiquement le moteur entraine sur l’arbre une generatrice electrique. Le flux thermique est recupere principalement sur le systeme de refroidissement du moteur ainsi que sur les fumees chaudes et il est generalement utilise pour produire de la chaleur pour les systemes de chauffage. Pour avoir une meilleure adaptation entre la production du moteur et la demande de l’usager, une bonne connaissance des evolutions dans le moteur et des phenomenes correspondants est necessaire. Une methode thermodynamique generale est proposee pour simulation du fonctionnement dynamique stationnaire d’un MACI. Le modele utilise une analyse monozone et les caracteristiques de chaque transformation du cycle pour etudier les performances energetiques : rendement exergetique de l’ordre de 0,70.

Les vehicules spatiaux a source d'energie solaire Le Projet Phaetan

Directory of Open Access Journals (Sweden)

M. VERNET-LOZET

1964-06-01

Full Text Available II est permis, a priori au moins, d'envisager un assez
grand nombre de mdtliodes pour transformer l'6nergie solaire en energie
utilisable pour la propulsion d'un vehicule spatial. Toutefois dans la mesure
ou 1'on s'impose un certain nombre de conditions, entre autres celle de
produire une poussee qui ne soit pas parfaitement negligeable devant le
poids du vehicule, on constate que dans l'etat actuel de nos connaissances
et de nos possibilitcs technologiques, il n'est guere raisonnable de penser
utiliser une autre methode que celle, bien classique et sans doute demodee
aux yeux de certains qui eonsiste a passer par l'intermediaire d'une machine
thermique.
II apparait clairement d'ailleurs que l'originalite d'un tel mode de
propulsion ne reside pas dans le systeme de propulsion lui-meme qui pourra
etre n'importe quel type de propulseur electrique, le clioix pouvant etre
fait en fonction de la mission que l'on se propose d'effectuer et de la charge
utile que l'on desire transporter, mais au contraire dans la conception de
l'ensemble constitue par le miroir, la machine thermique et le condenseur.
Nous nous proposons sur la base du projet « Phaeton » actuelleinent en
cours d'etude a la Societe d'Etude de la Propulsion par Reaction, d'examiner
un peu plus en detail qu'il ne l'a ete fait jusqu'ici, quels iinperatifs regissent
le dimensionnement d'une telle machine.

Experimental study of an ion cyclotron instability in a magnetic well confined plasma; Etude experimentale d'une instabilite cyclotronique ionique dans un plasma confine dans un puits magnetique

Energy Technology Data Exchange (ETDEWEB)

Brossier, P [Commissariat a l' Energie Atomique, Fontenay-Aux-Roses (France). Centre d' Etudes Nucleaires

1969-07-01

This report is a contribution to the study of microinstabilities in macroscopically stable plasmas, in the low-{beta} limit. Ion cyclotron instabilities, with k{sub ||} = 0, have been numerically studied in detail; the computation of the density thresholds and growth rates of the different harmonics showed the relative role played by the following energy sources: density gradient, perpendicular distribution function and cold plasma component. This theoretical model has been compared with the results of a detailed study (density thresholds, wave structure, frequency spectrum, wavelengths, growth rate, amplitude of the electric field) of the instability observed in the DECA II device. This comparison gave a good agreement which shows the destabilising role played by the cold plasma component on a hot plasma with a loss cone distribution function. (author) [French] Ce rapport est une contribution a l'etude des microinstabilites dans les plasmas macroscopiquement stables, dans la limite des {beta} << 1. Les instabilites cyclotroniques ioniques, a k{sub ||} = 0, ont ete etudiees numeriquement en detail; le calcul des seuils de densite et taux de croissance des differents harmoniques a permis de preciser l'importance relative des facteurs destabilisants suivants: gradient de densite, fonction de distribution perpendiculaire, presence de plasma froid. Ce modele theorique a ete confronte avec les resultats d'une etude detaillee (seuils de densite, structure de l'onde, spectres de frequence, longueurs d'onde, taux de croissance, amplitude du champ electrique) de l'instabilite observee dans l'experience DECA II, Cette confrontation aboutit a un accord satisfaisant qui montre le role destabilisant joue par le plasma froid sur un plasma chaud presentant une distribution de cone de pertes. (auteur)

Conditions for the Use of Ducts of Disc Geometry in MHD Conversion; Conditions d'Emploi des Tuyeres Disques en Conversion MHD

Energy Technology Data Exchange (ETDEWEB)

Azalbert, J. P.; Zettwoog, P. [Centre d' Etudes Nucleaires de Saclay, Gif-Sur-Yvette (France)

1966-11-15

Laplace forces acting on the radial component of the current, fluid rotation was found to occur. It is shown that there is an initial velocity of rotation which optimizes the inlet conditions. . The above calculations presuppose that the electron density at the inlet corresponds to a regime in which the electric field is that of the inlet. This means assuming either that the ionization time is very short vis-a-vis the transit time, or that there is a suitably adapted pre-ionization device. Since the stability of MHD flows cannot be guaranteed beyond a certain critical value of the Hall parameter, the values of this parameter are given for each duct. (author) [French] Le memoire examine les conditions d'emploi des tuyeres disques pour la conversion par voie MHD de l'energie thermique contenue dans un gaz rare ensemence en cesium. On envisage des temperatures de sources.chaudes comprises entre 1600 Degree-Sign K et 2000 Degree-Sign K et des pressions d'helium ou d'argon allant de 1 a 50 bars. La temperature totale du gaz a la sortie de la MHD est fixee a 1250 Degree-Sign K, temperatures partir de laquelle le gaz peut etre pris en charge par des ensembles plus classiques. Pour chaque niveau de pression, on determine la puissance thermique a partir de laquelle les pertes entropiques visqueuses par unite de longueur de parois sont negligeables devant les pertes joules volumiques correspondant a la marche normale de la tuyere. Les champs magnetiques sont obtenus a partir de bonines supraconductrices; on traite les cas 5 et 6 teslas. Pour la gamme des temperatures considerees, seule l'ionisation hors d'equilibre permet une conversion efficace. On suppose donc que l'ionisation est hors d'equilibre sous l'action du champ electrique induit, et on calcule la conductivite a partir d'un modele du plasma a 2 fluides qui donne o connaissant la densite de courant. En tuyere de Hall, les conditions d'echauffement electronique en une section donnee dependent de ce qui se passe dans l

Fuel and Electrical Systems Mechanic. Apprenticeship Training Standards = Mecanicien de systemes d'alimentation en carburant et electriques. Normes de formation en apprentissage.

Science.gov (United States)

Ontario Ministry of Skills Development, Toronto.

These training standards for fuel and electrical systems mechanics are intended to be used by apprentice/trainees, instructors, and companies in Ontario, Canada, as a blueprint for training or as a prerequisite for prerequisite for accreditation/certification. The training standards identify skills required for this occupation and its related…

Fostering future organization of French Electric Power. A report to Prime Minister; Reussir la future organisation electrique francaise. Rapport au Premier Ministre

Energy Technology Data Exchange (ETDEWEB)

Dumont, Jean Louis [Assemblee Nationale, Paris (France)

1998-07-02

This report addressed to the prime minister deals with the main four issues relating to the problem of revamping the French electricity sector. These are featured as: 1. The public electricity supply; 2. The future development of 'Electricite de France'; 3. The social renovation of the electricity sector; 4. Management and the role of policy. In turn these four chapters are detailed. Thus the first one addresses the problems: 1. Customizing the general interest supply; 2. Electricity general supply and the state policy; 3. Sustaining innovation, environmental protection and energy management; 4. The transport and distribution grid, the resistance structure of the public supply. Also, this chapter describes the role of the operators in the public electricity supply and tackles the problem of financing the commitments of the public supply. The second chapter sketches the tasks and management of EDF, considers establishing an agency to ensure accounting transparency, discusses the major significance of local collectivities and personnel. The third chapter addresses the following issues: 1. The range of application of the statute of electric and gas industries; 2. Adaptation of the statute; 3. Development of the statute; 4. Pensioners. The forth chapter deals with the definition of regulation, i.e. the management of the network authority and makes proposals for constituting relating commissions. In conclusion, the author pleads for maintaining and developing a major national operator ensuring public supply requirements as well as promotion of French electricity industry. The proposals made by the report's author concerning the operational ways of renewing the nuclear sector, the management of grid of electric transport, the role of local collectivities, creation of a professional trade, the founding regulation commissions and others are thought to prepare France to cope efficiently to the international competition in the years to come. The report is completed by two appendices containing the proposals of the author and a list of the persons interviewed during the mission.

Modeling of an electric arc transferred on a melted glass bath; Modelisation d`un arc electrique transfere sur un bain de verre

Energy Technology Data Exchange (ETDEWEB)

Mehlman, G.; Langlois, A. [SGN, 78 - Saint Quentin en Yvelines (France)

1997-12-31

The aim of this study is to propose a methodology allowing the simulation of melting processes involving electromagnetic phenomena. This methodology is based on the use of scientific calculation tools currently used elsewhere. The case considered in this study has been defined in collaboration with Electricite de France (EdF) and concerns more particularly an electric arc vitrification process for wastes. Basic data have been determined in order to obtain results representative of the tests performed by EdF with pilot installations. (J.S.)

Global Methodology to Integrate Innovative Models for Electric Motors in Complete Vehicle Simulators Méthodologie générale d’intégration de modèles innovants de moteurs électriques dans des simulateurs véhicules complets

Directory of Open Access Journals (Sweden)

Abdelli A.

2011-11-01

. Comment reduire les emissions moyennes de CO2 des vehicules particuliers a 120 g/km en 2012 et 95 g/km en 2020 comme le prevoit l’accord conclu entre la Commission Europeenne et les constructeurs europeens ? Cette question a reponses multiples preoccupe a l’heure actuelle l’ensemble du monde automobile. L’electrification des vehicules semble etre une des solutions les plus pertinentes, ce qui pousse les constructeurs a envisager des vehicules hybrides de plus en plus innovants. Cette solution, theoriquement tres interessante, complexifie encore un peu plus les groupes moto-propulseurs des vehicules, ce qui necessite l’utilisation d’outils de simulation adequats pour reduire les couts et les durees de developpement. La simulation systeme, outil deja primordial dans le processus de developpement des moteurs a combustion interne, devient alors incontournable. Pour etudier ce type d’architectures hybrides complexes, et a l’instar des modeles physiques developpes pour le moteur a combustion interne, la simulation systeme doit se doter de modeles predictifs comparables pour les machines electriques. Des leurs specifications, ces modeles doivent integrer certaines contraintes tres exigeantes sur les temps de simulation, contrainte garantissant par la suite une plus large utilisation des simulateurs, notamment pour le developpement et la validation de strategies de controle. L’objectif de ce papier est donc de presenter une methodologie generale de developpement de modeles de machines electriques, modeles ayant pour objectif final d’etre integres dans un simulateur vehicule complet. Cette methodologie met en scene differents types de modelisations (modeles elements finis, modeles de caracterisation, modele de simulation permettant un compromis temps de calcul – precision adequat. Cette methodologie a ete deployee avec succes pour la modelisation d’un moteur synchrone a aimants permanents. A l’issue du processus de modelisation, ce dernier a ete integre

Protection des ions organiques contre les dommages induits a l'ADN par les electrons de basse energie

Science.gov (United States)

Dumont, Ariane

'ADN de differentes epaisseurs, possedant entre 0 et 32 ions organiques/ nucleotide, ont ete irradies avec des electrons de 10eV. Les dommages induits par les electrons, sous forme de cassures, ont ete detectes par electrophorese. Nous avons demontre que le rendement de cassure simple brin diminuait de facon dramatique en fonction du nombre d'ions organiques/ nucleotide. Aussi peu que 2 ions organiques/ nucleotide sont suffisant pour decroitre le rendement de SSB de 70%. Cet effet radioprotecteur est en partie explique par l'augmentation de l'epaisseur des films, mais surtout par la modification du champ electrique a proximite de l'ADN, due a l'ajout de molecules chargees positivement. La modification du champ electrique pres de l'ADN altere les parametres de resonance comme le temps de vie de l'anion transitoire et la limite de dissociation, qui influent directement sur la section efficace d'attachement dissociatif. L'effet protecteur peut egalement etre explique par la restauration des bases anioniques deshydrogenees induites par l'attachement dissociatif de l'electron sur une base (G(-H)-). Ce sont les molecules Tris qui, en transferant un atome d'hydrogene ou un proton, restaurent les bases deshydrogenees et inhibent par le fait meme la formation de cassures simple brin. Ces resultats indiquent que les histones peuvent egalement participer a la reparation de dommages precoces induits a l'ADN avant qu'elles ne menent a des dommages encore plus nocifs et difficiles a reparer, comme les cassures simples brins. Mots cles : Electrons de basse energie, dommage a l'ADN, ions organiques, attachement dissociatif de l'electron.

Burn up physics; Physique des combustibles irradies

Energy Technology Data Exchange (ETDEWEB)

Tretiakoff, O [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

. Une deuxieme serie d'experiences, plus recente, porte sur l'etude de reseaux utilisant des combustibles reconstitues (alliages Uranium - Plutonium), compares a de l'Uranium legerement appauvri ou enrichi. On decrit les experiences prevues (eau lourde, graphite a froid puis jusqu'a 500 C) et on expose les resultats deja obtenus. Ces experiences, necessitant pres d'une tonne de combustible de chaque espece, ne peuvent se preter a des etudes systematiques. C'est pourquoi on a poursuivi depuis quelques annees la mise au point d'une methode de mesure differentielle par oscillation, ne necessitant que des echantillons de l'ordre de quelques kilogrammes. On discute les relations entre ces mesures et les etudes de reseaux et on montre comment est effectuee l'etude systematique de compositions de combustible variees. La methode a pu etre appliquee avec succes a l'etude systematique de combustibles irradies (soumis par ailleurs aux analyses citees dans la premiere partie) donnant ainsi la possibilite de mesurer in situ l'absorption des produits de fission. (auteur)

Drainage water use from the railway Mont d'Or tunnel in Vallorbe, Switzerland; Centrale du Bief-Rouge. Recuperation des eaux du tunnel du Mont d'Or a Vallorbe - Rapport 2009

Energy Technology Data Exchange (ETDEWEB)

Gerodetti, M.

2009-02-15

The 6'097 m long Railway Tunnel under the Mont d'Or (western Switzerland, under the Jura mountains) was constructed at the beginning of the 20{sup th} century and inaugurated on 16 May 1915. During the construction there was an important break-in of water in the tunnel that flooded the whole construction area. Since the completion of the tunnel, the water incursion is drained and conveyed to the Swiss entrance. The flow rate coming from the tunnel is constant at about 120 l/s and didn't show any variation during all the past decades. The idea of using the tunnel water energy in a turbine is thought of since a long time. Considering the present situation on the energy sector, the 'Societe electrique du Chatelard' (the local electricity utility) with the support of the municipal authority, decided now to realize this concept and to turbine the water from the tunnel, also known as 'Bief Rouge', for power generation. The 'Bief Rouge' project consists in catching the flow at the Vallorbe entrance of the tunnel and conducting it into a new penstock down to the river Orbe situated some 65 m downhill where electricity will be produced in a new small-scale power plant. The planned scheme will have an electrical power of 54.5 kW and be located in a new building near the existing sewage pumping station of Vallorbe. The total investment cost is 1.3 million CHF and includes the construction of a new headwater basin, a penstock, a power plant and a tailrace channel as well as the electro-mechanical equipment for power production. Based on a mean annual power production of some 465,000 kWh, the retail price of the kWh has been evaluated to 21 Swiss cents/kWh. (author)

Problems of pricing fresh water obtained from a sea water desalination plant; Problemes de tarification de l'eau douce obtenue a partir d'une installation de dessalement d'eau de mer

Energy Technology Data Exchange (ETDEWEB)

Gaussens, J [Commissariat a l' Energie Atomique, (France). Centre d' Etudes Nucleaires

1967-07-01

Integrating a double-purpose desalination and electricity generating plant into a water supply system alters the conditions in which the other water and electricity sources are used, as the peak and the base load water and electricity demands have to be met at the least cost. This paper attempts to show how the problem of determining optimal water supply structures can be approached, in definite cases, but against a global economic back-ground. It becomes necessary to define the competition between classical resources and desalination plants, as these plants introduce into optimum studies new factors due to the peculiar shape of their production functions. These new factors (fixed and proportional costs structures, flow availabilities) are studied in relation to the production functions in various management cases (private monopoly, public monopoly). (author) [French] L'intervention d'une installation egalement productrice d'energie electrique dans l'alimentation en eau d'une zone modifie les conditions d'utilisation des autres ressources en eau et en electricite, compte tenu de la necessite d'assurer les pointes et la base des diagrammes de demande d'eau et d'electricite au moindre cout. Cet expose se propose de montrer comment on peut approcher le probleme de la determination des structures optimales d'approvisionnement en eau pour des cas precis, mais dans un cadre economique global, II devient en effet necessaire de situer la competition: ressources classiques/installation de dessalement; ces dernieres introduisent, dans les etudes d'optimum, des elements nouveaux dus a la forme particuliere de leurs fonctions de production. On etudie ces elements nouveaux (structures des couts fixes et des couts proportionnels, disponibilite des debits) en liaison avec les fonctions de production dans divers cas de gestion (monopole prive, monopole public). (auteur)

The beam-kicker system of the synchrotron Saturne. Magnetic field and particle orbit computations. Experimental results (1963); Le percuteur de faisceau de Saturne. Calcul du champ magnetique et des trajectoires. Verifications experimentales (1963)

Energy Technology Data Exchange (ETDEWEB)

Gouttefangeas, M; Katz, A; Rastoix, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

In this report is briefly described the beam-kicker system of the synchrotron Saturne. An analysis of its operation based on the sampling method is given, as well as two methods for computing toe magnetic field produced by a set of endless conductors in the neighbourhood of a conducting shield where eddy currents are circulating. The first method leads to the resolution of a bi-dimensional Laplace equation with first kind boundary conditions (Dirichlet problem); the second one translates to electromagnetism the electrical images method currently used in electrostatics and yields the magnetic field as the sum of a triple series expansion in the general case of a set of conductors located in a parallelepipedal box. Finally are given the results obtained in computing on IBM 7090 the perturbation of the particle motion due to the beam-kicker. These results are compared with the experimental data. (authors) [French] Ce rapport decrit brievement le dispositif percuteur de faisceau mis en place sur le synchrotron Saturne. On y trouvera une analyse de se fonctionnement a partir de la theorie des echantillonnages. On indique egalment deux methodes de calcul du champ magnetique produit par un system de conducteurs indefinis en presence d'un blindage conducteur parcouru par des courants de Foucault: la premiere se ramene a la resolution d'une equation de Laplace a deux dimensions avec des conditions aux limites de premiere espece (probleme de Dirichlet), la seconde transpose en electromagnetisme la methode des images electriques classique en electrostatique et permet d'exprimer le champ magnetique sous la forme de la somme d'une serie triple dans le cas general d'un systeme de conducteurs contenus dans un blindage parallelepipedique. Pour terminer, on mentionne les resultats du calcul numerique de la perturbation de la trajectoire des particules sous l'effet du percuteur et on compare ces resultats aux resultats experimentaux. (auteurs)

Research experiments on striction; Etudes experimentales sur le phenomene de striction

Energy Technology Data Exchange (ETDEWEB)

Aymar, R; Etievant, C; Hubert, P; Samain, A; Taquet, B; Torossian, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

Research work presented herewith concerns the behaviour of high intensity discharges in low pressure gases and examines the means of using the associated electromagnetic forces to heat the ionized gas and to avoid at the same time the cooling of the gas through contact with the walls of the chamber. We tried to stabilize the discharges by means of the combined action of a longitudinal magnetic field and of eddy currents induced in a conducting sheath. Devices for straight line and toroidal discharges have been tested. Research has been conducted with the aid of measurements of electric magnitudes, of penetrating radiations (x-rays, neutrons), and optical properties. The deformations of the luminous column have been followed by ultra rapid cinematography, whereas the evolution of the optical spectrum with time provided a monitor of the physical state of the plasma at any time. (author)Fren. [French] Les travaux presentes au cours de cette communication ont pour but d'etudier le comportement des decharges a forte intensite dans les gaz sous basse pression et de rechercher le moyen d'utiliser les forces electromagnetiques dont elles sont le siege pour chauffer un gaz ionise tout en lui evitant de se refroidir au contact de parois materielles. La stabilisation des decharges a ete recherchee par l'action conjuguee d'un champ magnetique longitudinal et des courants de Foucault induits dans une enveloppe conductrice. Des dispositifs de decharges rectilignes et toroidales ont ete essayes. Les moyens d'investigation ont comporte des mesures de grandeurs electriques, des mesures de rayonnements penetrants (rayons X-neutrons) et des mesures optiques. Les deformations de la colonne lumineuses ont ete suivies par cinematographie ultra-rapide tandis que l'evolution du spectre optique au cours du temps a permis de controler, a chaque instant, l'etat physique du plasma. (auteur)

Measurement of the purity of graphite and heavy water; Controle de purete du graphite et de l'eau lourde

Energy Technology Data Exchange (ETDEWEB)

Hering, H

1959-02-01

The analytical methods used by the C.E.A. are described, I -- Graphite. The determination of the change in the neutron capture cross section from sample to sample is determined by, an oscillation method in the Zoe reactor, or by measuring the attenuation of a neutron flux in the subcritical system Mireille. Methods of analysing total ash, B, H, Cl, Na, Ca. Fe, Mo, Ti, V, Sm, Eu, Dy, S, Co and Cd are described and mean results are given. The methods for sampling are indicated. II -- Heavy crater. The isotopic analysis of heavy water is carried out by infra-red absorption measurements. Chemical purity is evaluated by electrical conductivity measurements, B, Na, Mg, K, Cr, Mn, Ni, Cu, Cd, are determined by spectrographic methods, and Cl{sup -}, NO{sub 3}{sup -}, SO{sub 4}{sup --}, NH{sub 4}{sup +} by chemical methods; finally, sensitive pH measurements are described. [French] On decrit les methodes d'examen en usage au Commissariat a l'Energie Atomique. I -- Graphite. L'evaluation de la capture neutronique se fait par oscillation dans la pile Zoe, ou par mesure de l'attenuation d'un flux neutronique dans l'empilement sous critique Mireille. On indique les methodes de dosages et des resultats de: cendres, B, H, Cl, Na, Ca, Fe, Mo, Ti, V, Sm, Eu, Dy, et de S, Co, Cd, ainsi que les modalites d'echantillonnage. II.- Eau lourde. Le dosage isotopique dans les eaux lourdes se fait par absorptiometrie infrarouge. Leur purete chimique est evaluee par mesure de leur conductibilite electrique; les dosages d'impuretes se font par spectrographie d'emission (B, Na, Mg, K, Mn, Ni, Cu, Cd) et par des methodes chimiques (Cl{sup -}, NO{sub 3}{sup -}, SO{sub 4}{sup --}, NH{sub 4}{sup +}). On decrit la delicate mesure de pH. (auteur)

Kinetic equations for an unstable plasma; Equations cinetiques d'un plasma instable

Energy Technology Data Exchange (ETDEWEB)

Laval, G; Pellat, R [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1968-07-01

In this work, we establish the plasma kinetic equations starting from the Bogoliubov-Born-Green-Kirkwood-Yvon hierarchy of equations. We demonstrate that relations existing between correlation functions may help to justify the truncation of the hierarchy. Then we obtain the kinetic equations of a stable or unstable plasma. They do not reduce to an equation for the one-body distribution function, but generally involve two coupled equations for the one-body distribution function and the spectral density of the fluctuating electric field. We study limiting cases where the Balescu-Lenard equation, the quasi-linear theory, the Pines-Schrieffer equations and the equations of weak turbulence in the random phase approximation are recovered. At last we generalise the H-theorem for the system of equations and we define conditions for irreversible behaviour. (authors) [French] Dans ce travail nous etablissons les equations cinetiques d'un plasma a partir des equations de la recurrence de Bogoliubov, Born, Green, Kirkwood et Yvon. Nous demontrons qu'entre les fonctions de correlation d'un plasma existent des relations qui permettent de justifier la troncature de la recurrence. Nous obtenons alors les equations cinetiques d'un plasma stable ou instable. En general elles ne se reduisent pas a une equation d'evolution pour la densite simple, mais se composent de deux equations couplees portant sur la densite simple et la densite spectrale du champ electrique fluctuant. Nous etudions le cas limites ou l'on retrouve l'equation de Balescu-Lenard, les equations de la theorie quasi-lineaire, les equations de Pines et Schrieffer et les equations de la turbulence faible dans l'approximation des phases aleatoires. Enfin, nous generalisons le theoreme H pour ce systeme d'equations et nous precisons les conditions d'evolution irreversible. (auteurs)

Conception and fabrication of a real time automatic correlator (multi-correlator); Etude et realisation d'un correlateur automatique (multicorrelateur) fonctionnant en temps reel

Energy Technology Data Exchange (ETDEWEB)

Berthier, D [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1967-10-01

The purpose of this work is to elaborate a specific computer able to display the real.time correlation function of two variables represented by two electrical signals. The various functions to be done are dealt with the best suited technology: delays from numerical method, hybrid multiplication, analog integration. This method proved very versatile so that it has been possible to modify the circuits with more performing components without changing the general conception of the whole system. In particular, the bandwidth, which was originally 125 kHz (1966) is now 1 MHz and will be 5 MHz, January 1968. Many results are obtained from the correlator such as: - determination of pulse responses of linear systems (1. and 2. order filters, oscillating circuits); - extraction of signals from noise; - measurement of time and space correlation in a turbulent plasma; - treatment of electro-biological signals. (author) [French] Nous nous sommes proposes de concevoir un calculateur specialise pour l'estimation en temps reel de la fonction de correlation de deux phenomenes representes par deux tensions electriques. Il a ete retenu les procedes de calcul s'adaptant le mieux aux diverses fonctions a realiser: retard par une technique numerique, multiplication hybride, integration analogique. Cette methode s'est revelee tres souple d'emploi: en effet les circuits ont pu etre modifies, sans changer la conception de l'appareil, au fur et a mesure de l'evolution des performances des composants electroniques. Ainsi la bande passante de l'appareil qui initialement etait de 125 KHz (1966) est actuellement de 1 MHz et sera 5 MHz en janvier 1968. De nombreux resultats ont ete obtenus avec l'appareil: - determination de reponses impulsionnelles de systemes lineaires (filtres 1er ordre, 2eme ordre, circuit oscillant, etc... ); - detection de signaux dans le bruit; - mesure de correlation spatiale et temporelle dans le plasma - traitement de signaux electrobiologiques. (auteur)

Contribution to the study of detonation initiation by shock in solid explosives (1961); Contribution a l'etude de l'initiation de la detonation par choc dans les explosifs solides (1961)

Energy Technology Data Exchange (ETDEWEB)

Fauquignon, C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-05-15

When a shock wave is induced in an explosive, it can initiate chemical reactions which lead more or less rapidly to a stable detonation state. In this study more particular attention was paid to the transition phase, in which has been evaluated the increases in the wave velocity, the pressure, and the electrical conductivity. The influence of the nature of the medium in front of the wave and in contact with the explosive has also been the subject of an experimental study designed to determine the extent to which its nature can be ignored and, subsequently, to characterise the initiation conditions using only the shock intensity induced in the explosive. Finally, the results were generalized for various explosive compositions and led to the development of a possible mechanism for shock initiation. (author) [French] Lorsqu'une onde de choc est induite dans un explosif, elle peut y amorcer des reactions chimiques qui conduisent plus ou moins rapidement a un regime de detonation stable. Dans cette etude, on s'est interesse plus particulierement a la phase transitoire dans laquelle on a evalue l'accroissement de la vitesse d'onde, de la pression et de la conductibilite electrique. L'influence du milieu amont, au contact de l'explosif, a egalement fait l'objet de recherches experimentales de facon a determiner dans quelle mesure on pouvait s'affranchir de sa nature et, par suite, caracteriser les conditions d'initiation par la seule intensite du choc induit dans l'explosif. Enfin, les resultats ont ete generalises a diverses compositions explosives et ont conduit a l'elaboration d'un schema possible du mecanisme de l'initiation par choc. (auteur)

Structures and properties of (U,Pu)O{sub 2} containing non-active fission products. A simulation of irradiated nuclear fuel; Structure et proprietes de (U, Pu)O{sub 2} contenant des produits de fission sous forme inactive. Une simulation de combustible nucleaire irradie

Energy Technology Data Exchange (ETDEWEB)

Schmitz, F [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1969-07-01

We have made oxides with the same uranium and plutonium content, the same stoichiometry and the same fission product content as an oxide fuel (U{sub 0,8}PuO{sub 2})O{sub 1,96} after 2 per cent burn up. We have calculated the stoichiometry changes due to irradiation and checked the calculation by X rays parameters measurements. We have calculated and measured the contraction of the oxide lattice due to fission products in solid solution. Microprobe analysis of precipitates have been made and have lead to the identification of non metallic barium containing compounds and have shown the particular behaviour of molybdenum. Some physical properties have been measured especially the electrical resistivity, the thermal diffusivity and the vapour pressure of zirconium in solid solution. (author) [French] Nous avons fabrique des oxydes dont la composition en uranium et plutonium, la stoechiometrie et la teneur en produit de fission, sont identiques a celles d'un oxyde (U{sub 0,8}PuO{sub 2})O{sub 1,96} ayant subi 2 pour cent de combustion. Nous avons calcule les changements de stoechiometrie entraines par l'irradiation et controle ces calculs par des mesures de parametre. Nous avons calcule et mesure la contraction du reseau due aux produits de fissions solubles dans la matrice. Des analyses a la microsonde des precipites de produits de fission insolubles ont ete faites et ont conduit a l'identification de composes non metalliques contenant du baryum et a la mise en evidence du role particulier du molybdene. Certaines proprietes physiques ont ete mesurees sur ces composes, en particulier la resistivite electrique, la diffusivite thermique et la tension de vapeur du zirconium dissout dans la matrice. (auteur)

Contribution to the study of vacancies in silver and uranium (1962); Contribution a l'etude des lacunes dans l'argent et l'uranium (1962)

Energy Technology Data Exchange (ETDEWEB)

Quere, Y [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-12-15

In metals, high temperature vacancies can be retained by quenching. Results are given for the quenching of uranium (in liquid helium) and of silver (in liquid nitrogen). In this last case the energy of formation (1.06 eV) and the energy of mobility (0.86 eV) of the vacancies have been measured as well as the energy of mobility of the divacancies (0.58 eV). If the quenching is slow, it is shown that it is possible to trap the vacancies on the impurities of the metal. This leads to increases in the electrical resistivity observed by annealing after quenching, the vacancies being released before disappearing into sinks. The vacancy-impurity binding energy (the impurity being probably oxygen which is present in the silver used at a concentration of 20 ppm. atom.) can thus be estimated to be 0.4 eV. (author) [French] Dans un metal, les lacunes de haute temperature peuvent etre retenues par trempe. On presente des experiences de trempe d'uranium (dans l'helium liquide) et d'argent (dans l'azote liquide). Dans ce dernier cas, on mesure l'energie de formation (1,06 eV) et l'energie de mobilite (0,86 eV) des lacunes ainsi que l'energie de mobilite des bilacunes (0,58 eV). Si la trempe est lente, on montre que l'on peut pieger des lacunes sur les impuretes du metal. On interprete de cette facon des augmentations de resistivite electrique observees par recuit apres trempe, les lacunes se depiegeant avant de disparaitre dans des puits. L'energie de liaison lacune-impurete (l'impurete etant probablement l'oxygene dont l'argent utilise contient 20 ppm. atom.) peut alors etre evalue 0,4 eV. (auteur)

Commercialization of an electric propulsion unit for ecological ice resurfacers

Energy Technology Data Exchange (ETDEWEB)

Giroux, M. [MG Service, L' Assomption, PQ (Canada); Sylvestre, P. [Environment Canada, Montreal, PQ (Canada)

2000-03-01

Community health departments (CHD) and the general public are greatly concerned about the air quality at indoor skating rinks. A solution now exists whereby municipalities can convert their internal combustion resurfacers to electricity, using a system proposed by MG Service. This electric propulsion unit was developed and designed by MG Service, in conjunction with the Centre d'experimentation des vehicules electriques du Quebec (CEVEQ) and TPR Inc., an engineering firm. The main advantage of this technology is the ease of integration into the chassis of conventional resurfacers currently in use throughout the various municipalities. The propulsion unit is battery-powered and designed to replace the internal combustion engine. As a result, it eliminates carbon monoxide and nitrogen dioxide emissions, and more than meets the requirements set by health boards with regard to air quality at indoor skating rinks. Recyclable, maintenance-free and manufactured according to the standards set by the Underwriters Laboratories of Canada (ULC), the gel-sealed batteries display great advantages. The cost effectiveness of the electric propulsion unit is more impressive when considering that electricity is clean and costs five times less than conventional fuels currently in use. Regular verifications and calibrations are not required and the maintenance is minimal. The ventilation requirements are also reduced, leading to savings in energy costs required for the aeration of the indoor skating rink. Finally, the elimination of tank rental and fuel costs represent an added benefit. A detailed description of the components is provided. Following a series of trials, the operators were impressed by the surface gripability, traction and manoeuvrability. The resurfacers also gave an impression of greater raw power and were very quiet and easy to use, resulting in better overall operation when compared to conventional resurfacers. 1 fig.

Theory of a metrology for the earths magnetic field based on the resonance of polarised atomic nuclei (1962); Theorie d'une metrologie du champ magnetique terrestre basee sur la resonance de noyaux atomiques polarises (1962)

Energy Technology Data Exchange (ETDEWEB)

Bonnet, G [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1961-06-15

The problems presented by the metrology of the earths field are studied from two points of view. a. The first, purely physical, concerns the study of NMR transducers in their role for the transformation of the magnetic field into a frequency. The possibilities and limitations are outlined. The use of an equivalent model is introduced systematically in the considerations of NMR phenomena, this makes it possible to treat all problems of interaction between a spin system and an electric detection system in a unified form. b. The other point of view concerns the restitution of the nuclear signal frequency in the form of a directly perceptible observable. The treatment of information is considered from a statistical angle, which leads to the study of an optimisation process concerning the linearization of the measurement as well as the minimisation of noise effects. (author) [French] Les problemes que pose la metrologie du champ terrestre sont etudies sous un double aspect: a. L'un, purement physique, concerne l'etude des traducteurs a RMN dans leur role de transformation du champ magnetique en une frequence. On en degage les possibilites et les limitations. L'emploi d'un modele equivalent est introduit de maniere systematique pour rendre compte des phenomenes de RMN, ce qui permet de traiter sous forme unifiee tous les problemes d'interaction entre un systeme de spins et un systeme electrique de detection. b. L'autre aspect concerne la restitution de la frequence du signal nucleaire sous la forme d'une observable directement perceptible. On considere le traitement de l'information sous l'aspect statistique, ce qui amene a etudier un processus d'optimisation concernant la linearisation de la mesure aussi bien que la minimisation des effets des bruits. (auteur)

Continuous measurement of neutron flux with the help of a converter; Mesure continue des flux de neutrons a l'aide d'un dispositif convertisseur

Energy Technology Data Exchange (ETDEWEB)

Mas, P; Sciers, P [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1964-07-01

The device described in this report is working from this following principle: an element, the thermal neutron activate of which has a short period and is emitter of a {beta} particle, is surrounded with a dielectric which is itself surrounded by a conducting metal. {beta} particles are stopped in the conducting metal. Thus an electric current rises between the emitter element and the collector metal. The experimental study has been-done with rhodium as emitter. The linearity as function of thermal flux of the power of the pile, the accuracy, the efficiency of the device have been measured and are satisfactory. Just the stability of the measure equipment is not very good. This method gives, us at moment the instantaneous flux and the integrated flux, is well adapted for the measurements in pile to execute on loops. It is possible to continue to perfect the process. (authors) [French] Le dispositif decrit dans ce rapport fonctionne d'apres le principe suivant: un corps, dont le produit d'activation en neutrons thermiques a une courte periode et est emetteur d'une particule {beta}, est entoure d'un dielectrique lui-meme entoure d'un metal conducteur. Les particules {beta} sont arretees dans le metal conducteur. Il y a ainsi naissance d'un courant electrique entre le corps emetteur et le metal collecteur. L'etude experimentale a ete menee avec le rhodium comme emetteur. La linearite en fonction du flux thermique, de la puissance de la pile, la precision, le rendement du dispositif ont ete mesures et sont satisfaisants. Seule la stabilite de l'appareillage de mesure n'est pas tres bonne. Cette methode, qui peut nous donner a tout instant le flux instantane et le flux integre, est tout a fait adaptee aux mesures en pile a effectuer. sur des boucles. On peut poursuivre la mise au point du procede. (auteurs)

Density and electrical conductivity of molten salts. Comparative study of binary mixtures of alkali nitrates with silver nitrate and with thallium nitrate; Densite et conductibilite de sels fondus. Etude comparative des melanges binaires nitrates alcalins-nitrate d'argent et nitrates alcalins-nitrate de thallium

Energy Technology Data Exchange (ETDEWEB)

Brillant, S [Commissariat a l' Energie Atomique Saclay (France). Centre d' Etudes Nucleaires

1967-10-01

The choice of methods and the number of measurements made enable us to give results on the density and electrical conductivity of molten binary mixtures, alkali nitrate and silver nitrate, and alkali nitrate and thallium nitrate, in the form of equations. The deviations from linearity of the volume and the molar conductivity are determined by calculating the corresponding excess values whose variations are analyzed as a function of the Tobolsky parameter. The absence of any relationship in the sign of the entropy and the excess volume is justified. It is shown that the silver and thallium nitrates, in contrast to the thermodynamic properties, behave as the alkali nitrates in so far as the excess conductivity is concerned. This result is confirmed by the study of changes in the activation enthalpy for the partial molar conductivity; this study also shows the particular behaviour of lithium nitrate. (author) [French] Le choix des methodes et le nombre de mesures effectuees nous permettent de donner les resultats de densite et de conductibilite electrique des melanges fondus binaires nitrate alcalin-nitrate d'argent et nitrate alcalin-nitrate de thallium sous forme d'equations. Les ecarts a la linearite des isothermes de volume et de conductibilite molaire sont precises en calculant les grandeurs d'exces correspondantes dont les variations sont analysees en fonction du parametre de Tobolsky. Nous justifions l'absence de relation de signe entre l'entropie et le volume d'exces. Nous montrons que les nitrates d'argent et de thallium, vis-a-vis de la conductibilite d'exces, contrairement aux proprietes thermodynamiques, se conduisent comme les nitrates alcalins. Ce resultat est confirme par l'etude des variations des enthalpies d'activation de conductibilite partielle molaire qui met d'autre part en evidence le comportement particulier du nitrate de lithium. (auteur)

Modeling of a tram power network: from the component to the system; Modelisation d'un reseau electrique de tramway: du composant au systeme

Energy Technology Data Exchange (ETDEWEB)

Morin, E

2005-01-15

The study and the modeling of tram power networks require a system analysis. The use of several power-electronic converters in these networks significantly modifies both their topology and their function. Therefore, modeling methods developed in this thesis differ from traditional approaches, since a global analysis of a system should be linked with the study of its components.To satisfy the demands of the tram domain, this thesis develops modeling methods for transmission lines and transformers. Two levels of analysis are considered. Firstly, the tram power network is evaluated in relation to time. Secondly, an Iterative Harmonic Analysis (IHA) program is developed to compute the spectra of the system accurately. (author)

An experimental study of electrical and dielectric properties of consolidated clayey materials; Etude experimentale des proprietes electriques et dielectriques des materiaux argileux consolides

Energy Technology Data Exchange (ETDEWEB)

Comparon, L

2005-06-15

This study is devoted to the electrical and dielectric properties of consolidated clays. A better understanding of the conduction and polarization phenomena in clays is necessary to better interpret in situ measurements in terms of water saturation and texture. An experimental study was carried out on synthetic clay samples (kaolinite and smectite) compacted with various water contents, porosities and mineralogical compositions, on a large frequency range, using three laboratory setups. The electrical properties of natural argillites (from ANDRA) were then investigated. We found that the response of the synthetic samples is mainly controlled by water content on the whole frequency range; two polarization phenomena were observed, which were related to the Maxwell-Wagner polarization and the electrical double layer polarization around the clay particles. The electrical response of argillites is more complex; it is controlled by water content but also by the microstructure of the rock. In these rocks, the electrical and dielectric anisotropies are high; anisotropy was also measured for the synthetic clays. The existing models explain the high frequency limit of the dielectric permittivity of the clayey materials, but the low frequency part of the spectra ({<=}1 MHz) needs theoretical developments. (author)

Study of the crystallographic and magnetic properties of cubic manganite spinels NiMn{sub 2}O{sub 4}; Etude des proprietes cristallographiques et magnetiques des manganites spinelles cubiques NiMn{sub 2}O{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Boucher, B [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1969-07-01

We study the variation of the crystallographic properties (inversion degree, position parameters and short range order) of the cubic spinel Mn{sub {nu}}Ni{sub 1-{nu}}[Mn{sub 2{nu}}Ni{sub {nu}}]O{sub 4}, as a function of the thermal treatment applied to the sample. {nu} lies between 0. 74 and 0. 93; the slower the sample is cooled the more inverse it is. We show, in a molecular field theory, that a system of three magnetic sublattices can afford a 'star' configuration. We establish the conditions of stability of such a structure and its evolution as a function of temperature is foreseen. Neutron diffraction measurements show that the magnetic structure of NiMn{sub 2}O{sub 4} at 4.2 K is a 'star' configuration and that with increasing temperature it becomes a collinear structure in agreement with the theory. Furthermore, we find an anomaly in the value of specific heat at the transition temperature between 'star' and collinear structures. (author) [French] On etudie la variation des proprietes cristallographiques (inversion, parametre de position, ordre a courte distance) du spinelle cubique Mn{sub {nu}}Ni{sub 1-{nu}}[Mn{sub 2{nu}}Ni{sub {nu}}]O{sub 4}, en fonction du traitement thermique que subit l'echantillon, {nu} est compris entre 0,74 et 0,93; plus le corps est refroidi lentement, plus il est inverse. On montre, dans le cadre d'une theorie de champ moleculaire, qu'un systeme a trois sous-reseaux magnetiques peut presenter une configuration en ''etoile''. On etablit les conditions de stabilite d'une telle structure et on prevoit son evolution en fonction de la temperature. Les mesures de diffraction de neutrons montrent que la structure magnetique de NiMn{sub 2}O{sub 4} a 4,2 K est du type ''en etoile'' et qu'elle evolue en fonction de la temperature vers une structure colineaire comme le prevoit la theorie. De plus on observe une anomalie de chaleur specifique a la temperature de la transition entre la structure ''en etoile'' et la structure colineaire. (auteur)

Application of the pulsed neutron technique on the reactors ALIZE - AQUILON (1963); Application de la methode des neutrons pulses sur les piles ALIZE et AQUILON (1963)

Energy Technology Data Exchange (ETDEWEB)

Jacquemart, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

sensibilite spectrale des absorbants. Une methode modifiee utilisant la technique des neutrons pulses a ete experimentee. Les experiences sous-critiques ont permis de definir avec une bonne precision des tailles critiques de reseaux uranium-eau lourde. (auteur)

Application of the pulsed neutron technique on the reactors ALIZE - AQUILON (1963); Application de la methode des neutrons pulses sur les piles ALIZE et AQUILON (1963)

Energy Technology Data Exchange (ETDEWEB)

Jacquemart, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

affectes par la sensibilite spectrale des absorbants. Une methode modifiee utilisant la technique des neutrons pulses a ete experimentee. Les experiences sous-critiques ont permis de definir avec une bonne precision des tailles critiques de reseaux uranium-eau lourde. (auteur)

Synthesis of amphiphilic macrocyclic molecules from family of aza-porphyrins and study in Langmuir-Blodgett films; Synthese de molecules macrocycliques amphiphiles de la famille des azaporphyrines et etude en films de Langmuir-Blodgett

Energy Technology Data Exchange (ETDEWEB)

Palacin, Serge

1988-03-04

The cellular automata, also called formal neurons, directly inspired by the knowledge concerning the nervous system, are able to mimic some basic processes of brain, as shape recognition, connecting memory, information sorting... This work aims to build a molecular structure able to fit the working rules of a bidimensional cellular automata. So, amphiphilic molecules belonging to the aza-porphyrin family are synthesized and organized into a planar paving by the Langmuir-Blodgett technique. The regular structure of the outcoming ultra-thin films is studied by linear dichroism and anisotropic electron spin resonance. The physico-chemical behaviour of the amphiphilic molecules is studied and brings about an explanation of the redox phenomena which are observed on the monomolecular film on the water surface. So are we able to outline the future chemical addressing ways of the bidimensional cellular automata. In the end of this dissertation, different ways likely to insure covalent bindings between the active sites and allow the transfer of information within the cellular network are discussed. (author) [French] Les reseaux d'automates, aussi appeles neurones formels, directement inspires par les connaissances nouvelles concernant le fonctionnement du systeme nerveux, sont a l'heure actuelle capables de reproduire certaines operations fondamentales du cerveau, telles que la reconnaissance de forme, la memoire associative, le tri d'information... Le travail a pour but de realiser une structure moleculaire susceptible d'obeir aux regles de fonctionnement d'un automate cellulaire bi-dimensionnel. Dans ce but, des molecules amphiphiles de la famille des azaporphyrines sont synthetisees et organisees en un pavage plan par la methode de Langmuir-Blodgett. La structure reguliere des films ultraminces obtenus est determinee par dichroisme lineaire et resonance paramagnetique electronique anisotrope. Les caracteristiques physico-chimiques des molecules amphiphiles sont etudiees

Diferenciación étnica y redes de larga distancia entre migrantes andinos: el caso de Sanka y Colcha

Directory of Open Access Journals (Sweden)

1991-01-01

Full Text Available DIFFERENTIATION ETHNIQUE ET RESEAUX DE LONGUE DISTANCE CHEZ LES MIGRANTS ANDINS : LE CAS DE “SANKA” ET “COLCHA”. Les migrants andins ne limitent pas leurs réseaux sociaux d’interaction au milieu urbain. La réorientation spatiale des migrants devient notable au moment de l’aggravation de la crise nationale au Pérou qui affecte avec une particulière dureté la population liménienne. La formation de nouveaux réseaux de longue distance entre migrants est déterminée historiquement par l’espace géographique que couvre l’histoire de leur migration. De tels réseaux d’interaction impliquent un mécanisme spécifique de reproduction sociale des migrants andins et constituent un facteur important de changement social. Los migrantes andinos en Lima no limitan sus redes sociales de interacción al centro urbano. Sobre todo con la agudización de la crisis nacional en el Perú, que afecta con particular dureza a la población limeña, comienza una notable reorientación espacial de los migrantes. La formación de nuevas redes de larga distancia entre migrantes es históricamente determinada por el espacio geográfico que cubre su historia migracional. Tales redes de interacción significan un mecanismo específico de reproducción social de migrantes andinos y son factor importante del cambio social. ETHNIC DIFFERENTIATION AND LONG-DISTANCE-NETWORKS BETWEEN ANDEAN MIGRANTS: THE CASE OF “SANKA” AND “COLCHA”. The andean migrants in Lima do not limit their social networks of interaction on the urban center. Together with the aggravation of the national crisis in Peru, which affects the urban population of Lima particularly hard, is emerging a remarkable spatial reorientation of those migrants. The formation of long-distance-networks between migrants is historically determined by the geographical space, which covers their migration history. Such networks of interaction suggest a specific form of social reproduction of the andean migrants

Economic assessment group on power transmission and distribution networks tariffs; Groupe d'expertise economique sur la tarification des reseaux de transport et de distribution de l'electricite

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-06-01

Facing the new law on the electric power market liberalization, the french government created an experts group to analyze solutions and assessment methods of the electrical networks costs and tariffs and to control their efficiency. This report presents the analysis and the conclusions of the group. It concerns the three main subjects: the regulation context, the tariffing of the electric power transmission and distribution (the cost and efficiency of the various options) and the tariffing of the electric power supply to the eligible consumers. The authors provide a guideline for a tariffing policy. (A.L.B.)

History matching of large scale fractures to production data; Calage de la geometrie des reseaux de fractures aux donnees hydrodynamiques de production d'un champ petrolier

Energy Technology Data Exchange (ETDEWEB)

Jenni, S.

2005-01-01

Object based models are very helpful to represent complex geological media such as fractured reservoirs. For building realistic fracture networks, these models have to be constrained to both static (seismic, geomechanics, geology) and dynamic data (well tests and production history). In this report we present a procedure for the calibration of large-scale fracture networks to production history. The history matching procedure includes a realistic geological modeling, a parameterization method coherent with the geological model and allowing an efficient optimization. Fluid flow modeling is based on a double medium approach. The calibration procedure was applied to a semi-synthetic case based on a real fractured reservoir. The calibration to water-cut data was performed. (author)

Parallelization of learning problems by artificial neural networks. Application in external radiotherapy; Parallelisation de problemes d'apprentissage par des reseaux neuronaux artificiels. Application en radiotherapie externe

Energy Technology Data Exchange (ETDEWEB)

Sauget, M

2007-12-15

This research is about the application of neural networks used in the external radiotherapy domain. The goal is to elaborate a new evaluating system for the radiation dose distributions in heterogeneous environments. The al objective of this work is to build a complete tool kit to evaluate the optimal treatment planning. My st research point is about the conception of an incremental learning algorithm. The interest of my work is to combine different optimizations specialized in the function interpolation and to propose a new algorithm allowing to change the neural network architecture during the learning phase. This algorithm allows to minimise the al size of the neural network while keeping a good accuracy. The second part of my research is to parallelize the previous incremental learning algorithm. The goal of that work is to increase the speed of the learning step as well as the size of the learned dataset needed in a clinical case. For that, our incremental learning algorithm presents an original data decomposition with overlapping, together with a fault tolerance mechanism. My last research point is about a fast and accurate algorithm computing the radiation dose deposit in any heterogeneous environment. At the present time, the existing solutions used are not optimal. The fast solution are not accurate and do not give an optimal treatment planning. On the other hand, the accurate solutions are far too slow to be used in a clinical context. Our algorithm answers to this problem by bringing rapidity and accuracy. The concept is to use a neural network adequately learned together with a mechanism taking into account the environment changes. The advantages of this algorithm is to avoid the use of a complex physical code while keeping a good accuracy and reasonable computation times. (author)

On the calculation of the temperature difference in the wall of an electrically heated circular canal, when the electrical and thermal conductivities vary with temperature; Sur le calcul de l'ecart de temperature dans la paroi d'un canal circulaire, chauffe electriquement, lorsque les conductivites electrique et thermique varient avec la temperature

Energy Technology Data Exchange (ETDEWEB)

Gerber, R [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

The wall correction is given as a function of the temperature of the insulated face, in the form of a series in which the first terms are presented. The convergence is studied and a maximum estimate is made of the error committed when only the first terms of the developpement are retained. (author) [French] La correction de paroi des donnees, en fonction de la temperature de la face isolee, sous forme d'une serie dont on explicite les premiers termes. La convergence est etudiee et l'on majore l'erreur que l'on commet en ne conservant que les premiers termes du developpement. (auteur)

Power system security enhancement through direct non-disruptive load control

Science.gov (United States)

Ramanathan, Badri Narayanan

The transition to a competitive market structure raises significant concerns regarding reliability of the power grid. A need to build tools for security assessment that produce operating limit boundaries for both static and dynamic contingencies is recognized. Besides, an increase in overall uncertainty in operating conditions makes corrective actions at times ineffective leaving the system vulnerable to instability. The tools that are in place for stability enhancement are mostly corrective and suffer from lack of robustness to operating condition changes. They often pose serious coordination challenges. With deregulation, there have also been ownership and responsibility issues associated with stability controls. However, the changing utility business model and the developments in enabling technologies such as two-way communication, metering, and control open up several new possibilities for power system security enhancement. This research proposes preventive modulation of selected loads through direct control for power system security enhancement. Two main contributions of this research are the following: development of an analysis framework and two conceptually different analysis approaches for load modulation to enhance oscillatory stability, and the development and study of algorithms for real-time modulation of thermostatic loads. The underlying analysis framework is based on the Structured Singular Value (SSV or mu) theory. Based on the above framework, two fundamentally different approaches towards analysis of the amount of load modulation for desired stability performance have been developed. Both the approaches have been tested on two different test systems: CIGRE Nordic test system and an equivalent of the Western Electric Coordinating Council test system. This research also develops algorithms for real-time modulation of thermostatic loads that use the results of the analysis. In line with some recent load management programs executed by utilities, two

Report for the Prime Minister. Making the future French electric power organization a success; Rapport au Premier Ministre. Reussir la future organisation electrique francaise

Energy Technology Data Exchange (ETDEWEB)

Dumont, J L

1999-12-31

This report from the French Deputy of the Meuse region aims at taking stock of four main questions raised by the future organization of the French electric power industry in the context of the opening of the European power market: the public utility of electric power, the future missions of Electricite de france (EdF) company, the questions in relation with the personnel status in the electric power industry, and the status of the regulating authority. In order to give some elements of answer to these questions, the report has been divided into 2 parts: part 1 presents the power production, transport and distribution in the future electric power regulation (the renewal of nuclear facilities, the building of non-nuclear units, the exploitation of the power distribution network, the accounting dissociation and the transparency of accountancy, the organization of network access, the eligible clients, the direct power lines, the obligations of purchase, the distribution and the role of local authorities). Part 2 presents the four main stakes of the modernization of the French electric power sector: the electric power public utility (public concern and rights, government policy, sustain of innovation, environment protection and energy mastery, the transportation and distribution networks, the role of operators and the financing), the future evolution of EdF (missions and organization, future of the public company), the social modernization of the electric power sector (present day status, adaptation, evolution, pensions), the organization and role of the future regulation authority. The propositions of the author are reported in the appendix. (J.S.)

Reforms in the electrical sector: the case of the Ivory Coast; Les reformes du secteur electrique: le cas de la Cote d'Ivoire

Energy Technology Data Exchange (ETDEWEB)

Vei, G. [Compagnie Ivorienne d' Electricite (Cote d' Ivoire)

1999-09-30

The electrical industry plays an important role in the economic development of the country by ensuring that the energy needs of the industrial sector are met and by responding to the betterment of the life of the population. After the country achieved its independence in 1960, successive governments organized this important instrument of the economy as a vertically integrated, monopolistic public utility. With the economic crisis of the 1980s, the public enterprise model was quickly reaching its limit of usefulness. This was the result of a slowdown in the growth of demand, difficulties in supporting the existing rates, financing investment through international loans, and servicing the accumulated debt. As a result of the extreme difficulties affecting the industry at the beginning of the 1990s, the government decided to reform the electrical sector by separating generation and transmission from regulation, i. e., it relinquished daily operation of the generation and the transmission system to a private company (la Compagnie Ivoirienne d'Electricite (CIE)) and confined its activities to regulation, strategic policy formulation and rate setting. A second reform was undertaken in 1998 aimed at introducing competition in the production of electricity and separating the generation, transmission and distribution functions. The deregulation is now complete, nevertheless, anxiety remains with regard to the real efficiencies that the introduction of competition in generation and distribution will produce.

Optimal unit sizing of a hybrid renewable energy system for isolated applications; Optimalite des elements d'un systeme decentralise de production d'energie electrique

Energy Technology Data Exchange (ETDEWEB)

Morales, D

2006-07-15

In general, the methods used to conceive a renewable energy production system overestimate the size of the generating units. These methods increase the investment cost and the production cost of energy. The work presented in this thesis proposes a methodology to optimally size a renewable energy system.- This study shows that the classic approach based only on a long term analysis of system's behaviour is not sufficient and a complementary methodology based on a short term analysis is proposed. A numerical simulation was developed in which the mathematical models of the solar panel, the wind turbines and battery are integrated. The daily average solar energy per m2 is decomposed into a series of hourly I energy values using the Collares-Pereira equations. The time series analysis of the wind speed is made using the Monte Carlo Simulation Method. The second part of this thesis makes a detailed analysis of an isolated wind energy production system. The average energy produced by the system depends on the generator's rated power, the total swept area of the wind turbine, the gearbox's transformation ratio, the battery voltage and the wind speed probability function. The study proposes a methodology to determine the optimal matching between the rated power of the permanent magnet synchronous machine and the wind turbine's rotor size. This is made taking into account the average electrical energy produced over a period of time. (author)

The independent power production and the reorganization of the electric power sector; La production independante d'electricite et la reconfiguration du secteur electrique

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-12-01

The transformation of the electric power production and distribution sector is in progress thanks to the progressive opening of markets and to the emergence of a new kind of actor: the independent producer. After the USA, the UK, and most of the emerging countries, the continental Europe is actively preparing its mutation. The historical actors try to protect their positions on their own national markets and at the same time to develop their international position. The newcomers (oil companies, independent power producers, collective service companies) have adopted a radically offensive strategy based on an international development and a skimming of the market. This study takes stock of the degree of liberalization of the different markets and analyzes their structuring elements and dynamism. An analytical presentation of the main actors of the electric power market is performed in order to evaluate their forces and feeblenesses in front of this mutation. Finally, ittries to answer the following questions: which are the most promising zones for the newcomers, and which companies will win this new deal? (J.S.)

Performances of a lithium-carbon ``lithium ion``battery for electric powered vehicle; Performances d`un accumulateur au lithium-carbone ``Lithium Ion`` pour vehicule electrique

Energy Technology Data Exchange (ETDEWEB)

Broussely, M.; Planchat, J.P.; Rigobert, G.; Virey, D.; Sarre, G. [SAFT, Advanced and Industrial Battery Group, 86 - Poitiers (France)

1996-12-31

The lithium battery, also called `lithium-carbon` or `lithium ion`, is today the most promising candidate that can reach the expected minimum traction performances of electric powered vehicles. Thanks to a more than 20 years experience on lithium generators and to a specific research program on lithium batteries, the SAFT company has developed a 100 Ah electrochemical system, and full-scale prototypes have been manufactured for this application. These prototypes use the Li{sub x}NiO{sub 2} lithiated graphite electrochemical pair and were tested in terms of their electrical performances. Energy characteristics of 125 Wh/kg and 265 Wh/dm{sup 3} could be obtained. The possibility of supplying a power greater than 200 W/kg, even at low temperature (-10 deg. C) has been demonstrated with these elements. A full battery set of about 20 kWh was built and its evaluation is in progress. It comprises the electronic control systems for the optimum power management during charge and output. (J.S.) 9 refs.

Performances of a lithium-carbon ``lithium ion``battery for electric powered vehicle; Performances d`un accumulateur au lithium-carbone ``Lithium Ion`` pour vehicule electrique

Energy Technology Data Exchange (ETDEWEB)

Broussely, M; Planchat, J P; Rigobert, G; Virey, D; Sarre, G [SAFT, Advanced and Industrial Battery Group, 86 - Poitiers (France)

1997-12-31

The lithium battery, also called `lithium-carbon` or `lithium ion`, is today the most promising candidate that can reach the expected minimum traction performances of electric powered vehicles. Thanks to a more than 20 years experience on lithium generators and to a specific research program on lithium batteries, the SAFT company has developed a 100 Ah electrochemical system, and full-scale prototypes have been manufactured for this application. These prototypes use the Li{sub x}NiO{sub 2} lithiated graphite electrochemical pair and were tested in terms of their electrical performances. Energy characteristics of 125 Wh/kg and 265 Wh/dm{sup 3} could be obtained. The possibility of supplying a power greater than 200 W/kg, even at low temperature (-10 deg. C) has been demonstrated with these elements. A full battery set of about 20 kWh was built and its evaluation is in progress. It comprises the electronic control systems for the optimum power management during charge and output. (J.S.) 9 refs.

Modeling of a tram power network: from the component to the system; Modelisation d'un reseau electrique de tramway: du composant au systeme

Energy Technology Data Exchange (ETDEWEB)

Morin, E.

2005-01-15

The study and the modeling of tram power networks require a system analysis. The use of several power-electronic converters in these networks significantly modifies both their topology and their function. Therefore, modeling methods developed in this thesis differ from traditional approaches, since a global analysis of a system should be linked with the study of its components.To satisfy the demands of the tram domain, this thesis develops modeling methods for transmission lines and transformers. Two levels of analysis are considered. Firstly, the tram power network is evaluated in relation to time. Secondly, an Iterative Harmonic Analysis (IHA) program is developed to compute the spectra of the system accurately. (author)

Report of study group 5.4 remote operation of distribution networks; Rapport du comite de travail 5.4 distribution du gaz: exploitation a distance des reseaux de distribution

Energy Technology Data Exchange (ETDEWEB)

Spohn, D.; Osiadacz, A.

2000-07-01

This study by the IGU WOC 5.4 reviews, at a management level, the application of remote monitoring and control systems for distribution networks. Gas distribution companies have to carefully balance the safety, quality, economic and financial aspects of managing geographically distributed assets to meet customer needs. Remote systems are a key tool in meeting these objectives. A questionnaire was developed to identify the key drives for the selection of remote monitoring and control systems, high level company parameters and current technologies in use. The field in questionnaires received by the WOC 5.4 show that monitoring equipment and remote control systems for gas distribution in various configurations are commonly utilized by the firms operating in this field. The reason why the firms themselves did adopt a remote control system mainly depends on safety as well as on a reduction of operating costs due to reduction in the personnel and related overheads associated with the management of the system. (authors)

The tariffs of use of liquefied natural gas transportation networks and facilities; Les tarifs d'utilisation des reseaux de transport et des installations de gaz naturel liquefie

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

The new tariff proposals for the use of natural gas transportation networks were transmitted to the French Ministry of economy, finances and industry on October 27, 2004 by the commission of energy regulation. These proposals have been adopted and are the object of three legislative texts: the decree no. 2005-607 from May 27 2005 relative to the tariffing rules, the by-law from May 27, 2005 relative to the definition of balancing areas, and the advice from May 27, 2005 relative to the tariffs of use of natural gas transportation networks. In application of article 7 of the law from January 3, 2003, the implementation of the first tariffs of use of natural gas transportation networks and of liquefied natural gas (LNG) facilities is defined in the decree no. 2004-994 from September 21, 2004. On the main transportation network, the tariffing is of 'input-output' type and does not depend on the distance, while at the regional network scale, the tariffing is linked with the distance. The tariff of use of LNG facilities is the sum of 4 terms: a fixed term applied to each batch unloaded at the methane terminal, a term proportional to the unloaded LNG quantities, a term depending on the duration of use of LNG storage facilities and a term covering the gas consumptions of LNG facilities. This document gathers these different legislative texts with their appendixes. (J.S.)

Plasma Equilibrium in a Torus with High-Frequency Fields and Plasma Heating Resulting from the Development of a Powerful Beam of ''Escaping Electrons''; Plasma Torique: Stabilisation au Moyen de Champs de Haute Frequence et Chauffage par Formation d'un Flux Intense d'Electrons 'Emballes'; Ehksperimental'noe issledovanie ravnovesiya plazmy v tore pri nalichii vysokochastotnykh polej i nagreva plazmy za schet razvitiya moshchnogo puchka ''ubegayushchikh ehlektronov''; Equilibrio del Plasma en un Toro, en Presencia de Campos de Alta Frecuencia, y Calentamiento del Plasma por el Desarrollo de un Haz Potente de 'Electrones Desbocados '

Energy Technology Data Exchange (ETDEWEB)

Demirkhanov, R. A.; Kirov, A. G.; Stotland, M. A.; Malykh, N. I.; Horasanov, G. L.; Vishnevskij, N. K.; Gutkin, T. I.; Jampol' skij, I. R. [Fiziko-Tehnicheskij Institut Gosudarstvennogo Komiteta po Ispol' zovaniju Atomnoj Ehnergii SSSR, Sukhumi, SSSR (Russian Federation)

1966-04-15

electron temperature of the order of a few eV. When a rotating quadrupole high-frequency field is applied, the plasma is forced away from the walls and is localized in the centre with an increase in temperature. Attention was also paid to heating by a strong electric field in the absence of a rotating high-frequency quadrupole field. In this case, when the electric field is E{sub z} = 100 to 200 V cm{sup -}{sub 1}, a current Jp=3 to 5 kA is developed in the plasma; on being strongly damped, this current becomes essentially ohmic in character. At the same time the voltage in the bypass is very strongly damped in comparison with the inactive condition, which indicates effective absorption of the loop energy by the plasma. The energy absorbed by the plasma during the first half-cycle of the current, that is during about 1{mu}s, represents about 20 J, and the conductivity of the plasma is anomalously low. When heating is performed by a strong electric field, an intensive burst of X-radiation with an energy of the order of 100 keV is observed, together with the emission of.micro-wave noises at frequencies close to that of the plasma. (author) [French] Le memoire decrit les experiences qui ont ete effectuees dans l'installation RT-0. Cette installation est constituee par un tore ayant un grand diametre de 100 cm et un petit diametre de 10 cm. Le long de la chambre, il se forme un champ magnetique torique d'environ 6 kOe. L'ignition du plasma se fait sous une pression superieure ou egale a 5 x 10{sup -4} Torr au moyen d'un champ electrique longitudinal tournant (8,3 MHz). Au voisinage de la paroi de la chambre se trouve un champ quadripolaire de haute frequence (540 kHz), qui tourne autour du plus petit diametre, avec H{phi} = 200 Oe. Lorsque le banc de condensateurs a faible induction envoie une decharge dans les spires disposees le long du tore, il peut se creer a l'interieur de la chambre un champ electrique turbulent du type decroissant, ayant une intensite maximum E{sub z

Europe-United States: two diverging evolutions of electricity restructuring? a prospective study on the functioning and the regulation of electrical markets on both sides of the Atlantic; Europe - Etats-Unis: des divergences electriques assumees? une perspective sur le fonctionnement et la regulation des marches electriques de part et d'autre de l'Atlantique

Energy Technology Data Exchange (ETDEWEB)

Derdevet, M.; Veyrenc, Th. [Institut d' Etudes Politiques de Paris, 75 (France)

2008-01-15

On both sides of the Atlantic, the same broad purpose was at the heart of electricity restructuring policies: substituting competition to the monopolistic organisation as a means of increased efficiency, and transforming sets of local markets into large continental-wide integrated markets. The current diversity between European and American systems is thus intriguing. The relative homogeneity of electrical systems in the old continent, which is being reinforced by the gradual though delicate elaboration of shared principles on the general organisation of the electricity industry at the European level, compares to a genuine diversity on the American side, where each State remains responsible for conducting its own restructuring policy, even if similar rules on wholesale markets are acknowledged and implemented at a federal level. Yet Europe and the United States face the same kind of issues regarding the future of the energy industry: which status for grid operators, how to respond to growing concerns on security of supply, what to do to mitigate the sharp increase in energy prices? Evidence thereof are the similar attempts by some States to retain direct price control methods, rather than to bank on the virtues of competition to prompt investments in generation and lead prices to drop. It currently appears that the answers to these shared challenges are not converging. On behalf of a comparatively strong freedom of action relatively to the initial competitive paradigm, the array of polio/ responses available in the United States seems broader than in Europe, where the approach recommended by the European Commission consists of further deepening the initial model without altering it. The future will show whether that trend is lasting, or if two structurally different models can emerge from such differences. (authors)

Measurement of {beta} Emitters by the Radiated Charge; Mesure des Emetteurs {beta} par la Charge Rayonnee. Mesure de l'activite des emetteurs {beta} a partir de la charge rayonnee; Izmerenie aktivnosti izluchatelya {beta}-chaetits na osnove izluchaemogo zaryada; Medicion de la actividad de los emisores {beta} a partir de la carga irradiada

Energy Technology Data Exchange (ETDEWEB)

Engelmann, J J [Centre d' Etudes Nucleaires de Saclay (France)

1960-06-15

The method is based on the principle recently described by Failla and his associates: Two plane electrodes of the same material are mounted parallel to, and close beside, each other in a vacuum container and the source which is to be measured is laid on one of them. The back-scattering on this electrode is offset by the reflections on the other electrode. A magnetic or electrical field makes it possible to eliminate the effect of low-energy secondary electrons. In the case of magnetic deflection, the apparatus includes an extrapolation chamber and, in the case of electrical deflection, a chamber with a very fine grille. In the case of Sr{sup 90}-Y{sup 90} and P{sup 32} the results obtained tally very well with the measurements made with the 4 {pi} counter (better than {+-} 2%) In the case of S{sup 35} the results are seen to be affected by the atomic number of the substance of which the electrode whereon the source is placed consists; this must therefore be chosen with care. The theories on back-scattering provide an explanation of these results. (author) [French] Le principe de la methode est celui decrit recemment par Failla et ses collaborateurs: Deux electrodes planes paralleles, de meme substance et tres voisines, sont disposees dans une enceinte videe. Sur une des electrodes est deposee la source a mesurer. La retrodiffusion sur l'electrode porte-source est compensee par les reflexions sur l'autre electrode. Un champ magnetique ou electrique permet d'eliminer l'effet des electrons secondaires de faible energie. Le dispositif experimental comporte, dans le cas de la deflexion magnetique, une chambre a extrapolation et dans le cas de la deflexion electrique, une chambre a grille tres fine. L'accord avec des mesures effectuees au compteur 4 {pi} est excellent dans le cas du Sr{sup 90}-Y{sup 90} et du P{sup 32} (mieux que {+-}2%). Dans le cas du S{sup 35}, les experiences mettent en evidence l'influence du nombre atomique du support de source et en imposent le

Dams. Bulletin of the Technical Service of Electric Power and Big Dams; Barrages. Bulletin du Service Technique de l`Energie Electrique et des Grands Barrages

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-31

Three papers were selected in this issue of the bulletin of the Technical Service of Electric Power and Big Dams. The first one concerns the experience feedback gained from the accident of the Drac river near Grenoble (France) due to a spillover at the Notre-Dame-de-Commiers` dam and which led to the death of 6 children and their teacher. The second one is a report of the conclusions of decennial and annual safety inspections of French dams, while the third one is a report of the Control Services activities for the third quarter of the year 1996 concerning the French dams in operation. (J.S.)

Dams. Bulletin of the technical service of electric power and big dams; Barrages. Bulletin du service technique de l`energie electrique et des grands barrages

Energy Technology Data Exchange (ETDEWEB)

Davard, J.

1997-12-31

The Dams bulletin reports on technical news concerning big French dams in operation. This issue comprises 5 papers. Two of them are examples of granting problems which led to the dismantling of the dams of Kernansquillec (Cotes d`Armor, France) and Maisons-Rouges (Indre-et-Loire, France) for economical and environmental reasons. The 3 other papers concern the life of French dams (technical control reports of the French dams in operation), the activities of the control service (annual inspections, preparation of draining operations, renewing of granting), and some general information (organisation of competent authorities, colloquium reports, hydro-power production during the first quarter of 1997). (J.S.)

Dams. Bulletin of the Technical Service of Electric Power and Big Dams; Barrages. Bulletin du Service Technique de l`Energie Electrique et des Grands Barrages

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-31

Four papers were selected in this issue of the bulletin of the Technical Service of Electric Power and Big Dams. The first one concerns the `Catastrophe Medicine` congress which took place in Amiens (France) in December 5 to 7 1996 and during which the analysis of experience feedbacks and lessons gained after dam accidents and organisation of emergency plans was discussed. The second one is a report of the conclusions of the decennial and annual inspections of French dams. The third paper describes the reinforcement of the Lavaud-Gelade dam embankment and the last paper reports on the Control Services activities concerning the French dams in operation for the forth quarter of the year 1996. (J.S.)

Reconstruction de la surface de Fermi dans l'etat normal d'un supraconducteur a haute Tc: Une etude du transport electrique en champ magnetique intense

Science.gov (United States)

Le Boeuf, David

Des mesures de resistance longitudinale et de resistance de Hall en champ magnetique intense transverse (perpendiculaire aux plans CuO2) ont ete effectuees au sein de monocristaux de YBa2Cu3Oy (YBCO) demacles, ordonnes et de grande purete, afin d'etudier l'etat fondamental des supraconducteurs a haute Tc dans le regime sous-dope. Cette etude a ete realisee en fonction du dopage et de l'orientation du courant d'excitation J par rapport a l'axe orthorhombique b de la structure cristalline. Les mesures en champ magnetique intense revelent par suppression de la supraconductivite des oscillations magnetiques des resistances longitudinale et de Hall dans YBa2Cu 3O6.51 et YBa2Cu4O8. La conformite du comportement de ces oscillations quantiques au formalisme de Lifshitz-Kosevich, apporte la preuve de l'existence d'une surface de Fermi fermee a caractere quasi-2D, abritant des quasiparticules coherentes respectant la statistique de Fermi-Dirac, dans la phase pseudogap d'YBCO. La faible frequence des oscillations quantiques, combinee avec l'etude de la partie monotone de la resistance de Hall en fonction de la temperature indique que la surface de Fermi d'YBCO sous-dope comprend une petite poche de Fermi occupee par des porteurs de charge negative. Cette particularite de la surface de Fermi dans le regime sous-dope incompatible avec les calculs de structure de bande est en fort contraste avec la structure electronique presente dans le regime surdope. Cette observation implique ainsi l'existence d'un point critique quantique dans le diagramme de phase d'YBCO, au voisinage duquel la surface de Fermi doit subir une reconstruction induite par l'etablissement d'une brisure de la symetrie de translation du reseau cristallin sous-jacent. Enfin, l'etude en fonction du dopage de la resistance de Hall et de la resistance longitudinale en champ magnetique intense suggere qu'un ordre du type onde de densite (DW) est responsable de la reconstruction de la surface de Fermi. L'analogie de la phenomenologie entourant le comportement des resistances longitudinale et de Hall dans YBa2Cu3Oy, avec des systemes dans lesquels l'existence d'un ordre du type DW est etablie, notamment des cuprates a structure tetragonale a basse temperature ("Low Temperature Tetragonal", LTT), indique que l'ordre causant la reconstruction de la surface de Fermi est stabilise au voisinage du dopage p = 1/8, et est en competition directe avec la supraconductivite.

Electrical infrared in the baking of paints and the drying of coatings; L`infrarouge electrique dans la cuisson des peintures et le sechage des revetements

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-12-31

This conference day was organized by the `industrial electro-thermal engineering` section of the French association of thermal engineers. This book of proceedings contains 11 papers entitled: `recalls about infrared emitters and furnaces technology`; `experimental study of transfer phenomena and of the thermophysical properties of paints during baking under infrared radiation`; `synthetic report of a theoretical and experimental study about drying and reticulation under infrared radiation of a aqueous-based epoxy-amine-type paint on metal support`; `short IR baking as viewed by the paint manufacturer`; `influence of texture and impurities on the radiative properties of materials`; `contribution of modeling to the dimensioning of IR furnaces`; `IR baking of paints`; `experimental studies and testing means of EdF`; `presentation of ABB Capponi Alesina company`; `presentation report of the Infrarouge System company`; `the choice of heat transfer technologies`. (J.S.)

Concession renewal of Kembs' hydroelectric head on the Rhine river; Renouvellement de la concession de la chute hydro-electrique de Kembs sur le Rhin

Energy Technology Data Exchange (ETDEWEB)

Baron, P.; Defoug, H.; Petit, D

2000-07-15

In order to evaluate the different impacts of the concession renewal of Kembs' water head on the Rhine river, all aspects have been considered and are reported in this document: international aspects, influence of the dam on navigation and floods, hydrology of Alsace plain, ecological, energetic and economical aspects, leisure and safety aspects. Several questions have to be put forward which concern the transfrontier relations, the water rights, the problem of derivations, of Rhine river maintenance, the turbine and water depth warranty problems, the flow rate and the restoration of the Rhine island. All these questions must be tackled by the impact study. The implementation of a local procedure follow up made of a permanent technical working group and of a management committee is recommended. (J.S.)

The narrow-gap TIG welding concerns the electric power plants manufacturers; Le soudage en joint etroit suscite l'interet des constructeurs de centrales electriques

Energy Technology Data Exchange (ETDEWEB)

Anon

2009-05-15

Polysoude, France, played host to an expert forum on narrow gap welding from 5-7 November 2008. The successful event welcomed around one hundred experts.The power plant construction sector is currently booming worldwide. For plant construction this means using more pressure-resistant, thick-walled pipes made from high temperature steels. The key quality features of this new steel grade are the values for high creep rupture strength that also apply without restriction as the benchmark for every weld seam on these pipes. In particular, the forum on narrow gap welding addressed this area of automated welding technology. During the forum, Mr Hans-Peter Mariner (Polysoude's CEO), has offered an in-depth insight into the latest developments in narrow gap welding. This presentation highlighted that with wall thicknesses of over 60 mm, welding time is shortened by a factor of five to ten in comparison to conventional TIG processes with a traditional V seam. The welding characteristics of the parent material are the decisive factor in the application of the narrow gap process. Technical advances in equipment technology such as automatic centring, HF-free ignition, seam preparation and optimised gas protection further increase the application limits. The geometry and gap width of the weld groove are based on the mechanical properties of the materials being joined, with the shrinkage characteristics of the seam being particularly important. Another key part of the programme was a presentation on the three different narrow gap-welding techniques. The first involves a single pass weld per layer and torch or work-piece revolution. The second is dual pass welding next to one another, when the seam preparation or positioning exceed the required narrow tolerances of a few tenths of a millimetre for one stringer bead per layer. TIG narrow gap welding with a shuttle-motion electrode is ideal with very large wall thicknesses of 150-200 mm. This is particularly the case if the necessary boundary conditions such as accuracy of the seam preparation, handling of the shrinkage process and torch design cannot easily be ensured for joining using one stringer bead per layer. (O.M.)

Turbulence in tokamak plasmas. Effect of a radial electric field shear; Turbulence dans les plasmas de tokamaks. Effet d`un cisaillement de champ electrique radial

Energy Technology Data Exchange (ETDEWEB)

Payan, J

1994-05-01

After a review of turbulence and transport phenomena in tokamak plasmas and the radial electric field shear effect in various tokamaks, experimental measurements obtained at Tore Supra by the means of the ALTAIR plasma diagnostic technique, are presented. Electronic drift waves destabilization mechanisms, which are the main features that could describe the experimentally observed microturbulence, are then examined. The effect of a radial electric field shear on electronic drift waves is then introduced, and results with ohmic heating are studied together with relations between turbulence and transport. The possible existence of ionic waves is rejected, and a spectral frequency modelization is presented, based on the existence of an electric field sheared radial profile. The position of the inversion point of this field is calculated for different values of the mean density and the plasma current, and the modelization is applied to the TEXT tokamak. The radial electric field at Tore Supra is then estimated. The effect of the ergodic divertor on turbulence and abnormal transport is then described and the density fluctuation radial profile in presence of the ergodic divertor is modelled. 80 figs., 120 refs.

Atom interferometry experiments with lithium. Accurate measurement of the electric polarizability; Experiences d'interferometrie atomique avec le lithium. Mesure de precision de la polarisabilite electrique

Energy Technology Data Exchange (ETDEWEB)

Miffre, A

2005-06-15

Atom interferometers are very sensitive tools to make precise measurements of physical quantities. This study presents a measurement of the static electric polarizability of lithium by atom interferometry. Our result, {alpha} = (24.33 {+-} 0.16)*10{sup -30} m{sup 3}, improves by a factor 3 the most accurate measurements of this quantity. This work describes the tuning and the operation of a Mach-Zehnder atom interferometer in detail. The two interfering arms are separated by the elastic diffraction of the atomic wave by a laser standing wave, almost resonant with the first resonance transition of lithium atom. A set of experimental techniques, often complicated to implement, is necessary to build the experimental set-up. After a detailed study of the atom source (a supersonic beam of lithium seeded in argon), we present our experimental atom signals which exhibit a very high fringe visibility, up to 84.5 % for first order diffraction. A wide variety of signals has been observed by diffraction of the bosonic isotope at higher diffraction orders and by diffraction of the fermionic less abundant isotope. The quality of these signals is then used to do very accurate phase measurements. A first experiment investigates how the atom interferometer signals are modified by a magnetic field gradient. An absolute measurement of lithium atom electric polarizability is then achieved by applying a static electric field on one of the two interfering arms, separated by only 90 micrometers. The construction of such a capacitor, its alignment in the experimental set-up and its operation are fully detailed.We obtain a very accurate phase measurement of the induced Lo Surdo - Stark phase shift (0.07 % precision). For this first measurement, the final uncertainty on the electric polarizability of lithium is only 0.66 %, and is dominated by the uncertainty on the atom beam mean velocity, so that a further reduction of the uncertainty can be expected. (author)

Icogne irrigation-network hydro-power installation; Petite centrale hydro-electrique sur le reseau d'irrigation de la commune d'Icogne. Etude de faisabilite

Energy Technology Data Exchange (ETDEWEB)

Cordonier, N.; Rey, G. [Nicolas Cordonier et Gilles Rey SA, Sierre (Switzerland)

2007-01-15

This final report for the Swiss Federal Office of Energy (SFOE) presents the feasibility study for a hydro-power installation that uses an existing municipal irrigation scheme in the alpine region of Icogne, Switzerland. The report takes a look at the present situation which features, apart from the irrigation scheme itself, mountain torrents and artificial compensation lakes. The concept for the use of the available water pressure due to height-difference between these two lakes to drive a turbine and so generate electricity is described. Variants considered are reviewed. Investment and operating costs are examined as are the electricity production and the cost of the power generated. Finally, investments and other financial aspects are looked at and the further course of action is discussed.

Policies and means to assess and improve service quality in electricity supply systems; Methods et moyens pour ameliorer la qualite` du service des reseaux publics de distribution d`electricite`

Energy Technology Data Exchange (ETDEWEB)

Lagostena, L.; Mirra, C.; Noferi, P.L.; Sani, G.

1992-03-01

Quality of electricity supply to users consists of a series of characteristics of the voltage at the points of delivery. This report shows how service quality, in the past basically related to the tolerance of voltage and frequency with respect to the nominal value, as well as, to the continuity of supply, is nowadays assessed also in relation to other aspects, generally referred to as disturbances. Short interruptions, voltage dips, transient overvoltages, harmonics and flicker are mainly taken into consideration. A description is given of the approach adopted by ENEL (the Italian Electricity Board) in order to evaluate and, if required, improve the quality of service, based upon the acquisition of data related to faults, interruptions and disturbances. These data are processed in order to obtain significant indices on the state of the network and on the effectiveness of the actions which can be implemented. Finally, the measures which may lead to an improvement in the quality of service are identified, and potential advantages, in terms of the reduction of non-supplied energy and number of faults, of adopting appropriate automatic devices and optimizing maintenance work on some distribution networks are illustrated.

Application of neural networks to measurement methods based on radiation interactions with matter; Application des reseaux de neurones aux methodes de mesure basees sur l'interaction rayonnement matiere

Energy Technology Data Exchange (ETDEWEB)

Pilato, V

1999-07-01

The possibility of improving by neuronal techniques the preparation and interpretation of nuclear measurements was investigated. A general methodology was developed and applied to various problems in this field. Whatever the problem to be treated, to solve it comes to determine the relation which binds the inputs to the outputs. Neural networks based on supervised training, like the multilayer Perceptron, have the capability to calculate any relation between a set of input and output data. On the other hand, the training phase is often a long and delicate operation whose difficulties grow with the size of the network:it is thus interesting to reduce it by introducing knowledge a priori and/or by reducing the number of inputs in order to extract the relevant information. If the correlations between the inputs are linear, the Principal Components Analysis (PCA) and its neuronal equivalents make it possible to obtain by orthogonal projection a reduced number of input components while preserving the maximum of initial information. If the correlations are nonlinear, the Curvilinear Components Analysis (CCA) allows, by a unsupervised training, to carry out a nonlinear projection of the inputs in a space of reduced size. Besides, it is noticed that when the dimension of the input space is equal to the intrinsic dimension of the problem, this last is practically solved by CCA. We propose a general method which consists in characterizing as well as possible the problem by its inputs and then to extract and classify the information contained in those by projection in a space of reduced size. Association between the projected data and the problem outputs is then carried out by a supervised training network. Certain results having to be provided with their associated uncertainty, a statistical method based on the bootstrap algorithm is proposed. Potential applications other that those treated are considered. (author)

Economic assessment group on power transmission and distribution networks tariffs; Groupe d'expertise economique sur la tarification des reseaux de transport et de distribution de l'electricite

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-06-01

Facing the new law on the electric power market liberalization, the french government created an experts group to analyze solutions and assessment methods of the electrical networks costs and tariffs and to control their efficiency. This report presents the analysis and the conclusions of the group. It concerns the three main subjects: the regulation context, the tariffing of the electric power transmission and distribution (the cost and efficiency of the various options) and the tariffing of the electric power supply to the eligible consumers. The authors provide a guideline for a tariffing policy. (A.L.B.)

Le changement comme tradition dans la recherche et la formation a la recherche en biotechnologie et en peripherie Etude de cas en sciences de la sante, sciences naturelles et genie

Science.gov (United States)

Bourque, Claude Julie

luttes universitaires que scientifiques, concentrees sur la negociation du capital scientifique, symbolique et economique en jeu dans la formation doctorale, dans les carrieres auxquelles elle mene, et dans les qualites du titre de Ph.D. Au final, la confusion entre des logiques opposees peut etre reduite en reinterpretant le changement comme tradition du champ scientifique. Mots-cles Sociologie, education, enseignement superieur, science et technologie, biotechnologie, formation doctorale, champ scientifique, reseaux sociaux

Contribution to the study of the role of diffusion in the growth of crystals from solution; Contribution a l'etude du role de la diffusion dans la croissance des cristaux a partir de solution

Energy Technology Data Exchange (ETDEWEB)

Quivy, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-12-01

In the case of the two-dimensional growth of crystals from solution, the concentration distribution could be explained on the basis of Fick diffusion equation. The limiting conditions are defined in a satisfactory way, and the curves of equal concentration in the solution surrounding the crystal are calculated using a resistance network device. These curves are similar to the observed interference fringes. The limiting conditions are different according as to whether the type of crystal growth is regular or dendritic. In this work the growth rate of the crystal faces in solution has been measured for various substances. These direct measurements were carried out using a micrometric eye-piece and chrono-photographs. The interferential method using polarized light has been used for determining the concentration distribution in the neighbourhood of the crystal; it was thereby possible, knowing the diffusion coefficient, to calculate the growth rate and to observe the existence of a disagreement, of the order of two, with the direct measurements. This discrepancy can even attain a value of ten in the case of very soluble substances; these latter have been studied by R. ITTI. (author) [French] Dans le cas de la croissance a deux dimensions de cristaux a partir de solution, la distribution des concentrations pouvait etre expliquee a partir de l'equation de diffusion de FICK. En fixant les conditions aux limites de facon convenable, on calcule, au moyen d'un dispositif a reseaux resistifs, les courbes d'egale concentration de la solution entourant le cristal. On constate que ces courbes sont semblables aux franges d'interferences observees. Les conditions aux limites sont differentes suivant que le type de croissance du cristal est regulier ou dendritique. Dans ce travail, on a egalement mesure les vitesses de croissance des faces cristallines a partir de solutions, en employant differentes substances. Ces mesures directes ont ete effectuees au moyen d'un oculaire

ATES Contribution to the Housing Energy Balance: a Simple Assessment Methodology Contribution du stockage d’énergie thermique en aquifère au bilan énergétique lié à l’habitat : méthodologie d’évaluation rapide

Directory of Open Access Journals (Sweden)

Bourbiaux B.

2011-02-01

Full Text Available The reduction of Green-House Gas Emissions (GHGE goes through a sum of solutions that need to be tuned to the local context in terms of energy needs and resources, and also to the demand and offer variations with time. The housing heat consumption is particularly concerned as it is seasonal and rarely in phase with the deliverability of alternative or renewable energy sources. This paper studies heat storage in saline untapped aquifers as a solution to overcome the time lag between production and consumption. This process applies to heat networks that supply dense housing complexes. Firstly, a methodology is described to size an Aquifer Thermal Energy Storage (ATES project as a function of the heat production and consumption characteristics on the one hand, and of the recovery factor of the stored heat on the other hand. The major role played by this recovery factor leads to a review of thermal losses of various origins and to a sensitivity study of influent reservoir parameters such as the aquifer thickness, productivity and heterogeneity, for the purpose of aquifer selection and storage project management. La reduction des Gaz a Effet de Serre (GES passe par un ensemble de solutions qui doivent etre adaptees au contexte local des besoins et ressources en energie, ainsi qu’aux variations de l’offre et la demande au cours du temps. Ce constat concerne en particulier la consommation d’energie calorifique destinee a l’habitat. En effet, cette consommation de chaleur est saisonniere et rarement en phase avec la disponibilite des sources d’energie alternatives ou renouvelables. Cet article etudie le stockage de chaleur dans des aquiferes salins inexploites en tant que solution pour pallier ce dephasage entre production et consommation. Ce procede concerne les reseaux de chaleur desservant un habitat concentre. En premier lieu, une methodologie quantitative est decrite pour dimensionner le projet de stockage d’energie thermique en

Awareness of households to the development of wind energy sites - Reporting on a survey; Receptivite des menages au developpement des sites eoliens. Rapport d'enquete

Energy Technology Data Exchange (ETDEWEB)

Voisard, M

2000-07-01

This report for the Swiss Federal Office of Energy presents in tables and diagrams the results of a survey involving 421 households in Switzerland, about their awareness to energy issues and, in particular, to all what regards wind energy and wind power plants. Globally, 80% of the persons asked for their opinion believe that electric power demand will continue to increase. 66% of them are in favour of increased use of renewable energy sources and would consequently agree with a 10% more expensive end-user energy price. 89% of the persons taking part to the survey approve the installation of wind energy farms in Switzerland. Moreover, statistics indicates that the households living in regions already equipped with wind farms are significantly more favorable to the creation of new wind energy sites than those not living in these regions. By the end of the day, it turns out that the main reasons for accepting wind energy are environmental concerns as well as the fear of being obliged to use nuclear power. [French] Ce rapport presente par des graphiques et des tableaux le resultat d'un sondage d'opinion aupres de 421 menages en Suisse, sur la sensibilite du public aux problemes de l'energie et plus particulierement sur sa perception de tout ce qui concerne l'energie du vent et son exploitation par l'implantation d'eoliennes. Globalement, 80% des menages pensent que la demande d'energie electrique va poursuivre sa croissance. 66% d'entre eux sont favorables au developpement des energies renouvelables et prets a accepter en consequence une augmentation du prix de l'energie allant jusqu'a 10%. 89% des personnes interrogees sont favorables au developpement des eoliennes en Suisse. De plus, la statistique montre de maniere significative que les menages des regions dans lesquelles sont deja implantes des sites eoliens sont plus favorables au developpement des eoliennes que les autres. Finalement, le respect de l'environnement et la crainte d'avoir a recourir a l

Batteryless {gamma}-Ray Dosimeter; Dosimetre de rayons {gamma}, sans batteries; {gamma}-dozimetr bez batarei; Dosimetro a rayos {gamma} sin bateria

Energy Technology Data Exchange (ETDEWEB)

Gross, Bernhard [National Institute of Technology, Rio de Janeiro (Brazil)

1960-06-15

The Compton current produced by X-rays and {gamma}-rays in the 0.3 to 3 MeV range is proportional to the radiant energy flux. Therefore the intensity of the current can be used as a measure of radiation dose. The present paper describes a radiation receiver and electrical measuring system suitable for Compton current measurements and results obtained with this device under irradiation from a 2000 curie Co{sup 60} source. (author) [French] Le courant de Compton produit par des rayons X et {gamma} dans le domaine d'energies compris entre 0,3 et 3 MeV est proportionnel au flux d'energie rayonnante. C'est pourquoi l'intensite du courant peut servir de mesure de la dose de rayonnements. Le memoire decrit un ensemble, appareil recepteur de rayonnements et appareil de mesure electrique, permettant de mesurer le courant de Compton et il expose les resultats obtenus, au moyen de ce dispositif, sous irradiation par une source de Co{sup 60} de 2000 curies. (author) [Spanish] La corriente de Compton producida por rayos X y rayos {gamma} de energia comprendida entre 0,3 y 3 MeV es proporcional al flujo de energia radiante. Por consiguiente, la intensidad de la corriente puede servir para medir la dosis de radiacion. En este trabajo se describen un receptor de radiaciones y un sistema de medicion electrica apropiados para determinar la intensidad de la corriente de Compton, asi como los resultados obtenidos mediante este dis- positivo cuando se irradia con una fuente de Co{sup 60} de 2000 curies. (author) [Russian] Komptonovskij potok, obrazuemyj rentgenovskim i luchami i {gamma}-luchami v predelakh ot 0,3 do 3 mehv, proportsionale n potoku luchistoj ehnergii. Poehtomu intensivnost' potoka mozhet byt' ispol'zovana dlya izmereniya dozy radiatsii. V nastoyashchem dokumente opisyvayutsya radiatsionny j priemnik i ehlektricheskaya izmeritel'naya sistema, prigodnye dlya izmerenij s pomoshch'yu komptonovskog o potoka, i rezul'taty, poluchennye s pomoshch'yu ehtogo ustrojstva v khode

Model of a plasma without collisions in a cylindrical geometry by the study of the motions of the particles (1960); Modele d'un plasma sans collisions dans une geometrie cylindrique par l'etude des mouvements de particules (1960)

Energy Technology Data Exchange (ETDEWEB)

Rebut, P H [Association Euratom-CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee

1960-07-01

The Boltzmann equation for a group of particles in the absence of collisions may be written df/dt = 0, where f is the distribution function in the phase space. This equation means that f is an individual motion constant. This leads to a study, of the paths and to a research of the first integrals of the differential system related to them. This study leads also to a confinement condition on the velocities of a particle. The following step is related to the theoretical study of some distribution functions and of the resulting consequences. A differential system is obtained, giving density and magnetic and electric fields. This system has been in a number of cases solved by a digital computer. This solution allows an experimental comparison to be made. The first integrals obtained are still valid when magnetic 'screw-type' fields are concerned, which results in the obtention of a type of helicoidal deformation and of a stability criteria with respect to these deformations. (author) [French] L'equation de Boltzmann pour un groupe de particules en l'absence de collision peut s'ecrire df/dt = 0, ou f est la fonction de distribution dans l'espace des phases. Cette equation signifie que f est une constante du mouvement individuel. On est donc amene a etudier les trajectoires et a rechercher des integrales premieres du systeme differentiel qui leur est lie; cette etude conduit aussi a une condition de confinement portant sur les vitesses d'une particule. L'etape suivante se rapporte a l'etude theorique de certaines fonctions de distribution et des consequences qui en decoulent. On arrive a un systeme differentiel donnant densite, champs magnetiques et electriques, systeme qui a ete resolu dans un certain nombre de cas par une machine a calculer digitale. Cette resolution permet une confrontation experimentale. Les integrales premieres obtenues restent encore valables lors de champs magnetiques en 'vis'; il en resulte l'obtention d'un type de deformation helicoidale et d

PH measurement under pressure and at high temperatures; Mesure du pH sous pression et a temperature elevee

Energy Technology Data Exchange (ETDEWEB)

Fournie, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Le Peintre, M; Mahieu, C [Centre National de la Recherche Scientifique (CNRS), 91 - Gif-sur-Yvette (France)

1961-07-01

In the first part the development and operation of a glass electrode under pressure at room temperature is described. The pressure equilibrium between the inside and outside of the glass membrane several centimetres thick is obtained instantaneously by means of a siphon. The use of a silicone oil as electrical insulator makes possible the working of the glass electrode with the siphon at high pressures (100 kg/cm{sup 2}). In the second part, we determined the pH of various buffer solutions up to 250 deg. C using a cell of our design having two hydrogen electrodes. The values thus obtained for the buffer solutions make it possible to verify and calibrate the pH electrodes independently of the oxido-reduction potential of the medium. In the third part we give the results obtained up to 200 deg. C with the glass electrodes developed in conjunction with the Societe St Gobain. (author) [French] Dans une premiere partie, nous exposons la mise au point et le fonctionnement d'une electrode en verre sous pression a la temperature ordinaire. L'equilibrage instantane de la pression a l'interieur et a l'exterieur de la membrane en verre de quelques diziemes de millimetres d'epaisseur s'effectue par l'intermediaire d'un siphon. L'emploi d'une huile de silicone comme isolant electrique a permis le fonctionnement de l'electrode en verre a siphon sous haute pression (1000 kg/cm{sup 2}). Dans une deuxieme partie, nous avons determine jusqu'a 250 deg. C les valeurs du pH des diverses solutions tampons avec une cellule de notre conception a deux electrodes d'hydrogene. Les valeurs des solutions tampons ainsi obtenues permettent de verifier et d'etalonner les electrodes a pH independantes du potentiel d'oxydo-reduction du milieu. Dans une troisieme partie, nous relatons les resultats obtenus jusqu'a 200 deg. C avec les electrodes en verre mis au point en collaboration avec la Societe Saint-Gobain. (auteur)

Manipulation coherente de qubits de spin dans une boite quantique triple

Science.gov (United States)

Gaudreau, Louis

Nous presentons dans cette these une etude detaillee du moment magnetique intrinseque de l'electron, i.e. le spin electronique, incluant la manipulation quantique coherente des etats de spin de trois electrons couples. A cette fin, nous utilisons des boites quantiques laterales pour confiner les electrons. Ces nano-structures, d'une grandeur autour de 1 pm, permettent de confiner un nombre precis d'electrons de facon controlee, allant jusqu'a zero electrons. Les developpements technologiques et d'ingeniosite durant la derniere decennie ont permis de coupler trois boites quantiques, ainsi l'interaction entre plusieurs electrons confines peut etre controlee comme par exemple le couplage quantique tunnel et l'interaction d'echange entre les spins de chacun d'entre eux. A l'aide de boites quantiques couplees, il est possible de realiser des experiences dans plusieurs domaines de la physique moderne : les etats up et down du spin des electrons confines peuvent etre utilisees comme etats quantiques binaires (qubits) dans le domaine de l'informatique quantique, la non-localite quantique peut etre testee en separant spatialement deux electrons enchevetres, il est possible de creer des 'courants de spin enchevetres' utiles en spintronique, et bien d'autres. La manipulation coherente des etats de spin du systeme a trois electrons se fait de facon purement electrique grace a des pulses a haute frequence qui permettent d'augmenter le couplage entre les electrons et de faire la mesure de l'etat resultant apres la manipulation. Nous utilisons l'interaction hyperfine entre les spins des electrons et ceux des noyaux du cristal dans lequel ils resident pour creer les rotations quantiques entre les etats, notamment les etats |Q +3/2> et (D+1/2>. Les resultats obtenus indiquent un temps de coherence de l'ordre de 10 ns. Ces experiences demontrent un niveau de controle sans precedant de boites quantiques triples et pavent la voie vers des nano-structures plus sophistiquees dans

Development of an apparatus for measuring the thermal conductivity of irradiated or non-irradiated graphite; Realisation d'un appareil de mesure de la conductibilite thermique du graphite irradie ou non irradie

Energy Technology Data Exchange (ETDEWEB)

Bocquet, M; Micaud, G

1962-07-01

An apparatus was developed for measuring the thermal conductivity coefficient K of irradiated or non-irradiated graphite. The measurement of K at around room temperature with an accuracy of about 6% is possible. The study specimen is placed in a vacuum between a hot and a cold source which create a temperature gradient {delta}{theta}/ {delta}x in the steady state. The amount of heat transferred, Q, is deduced from the electrical power dissipated at the hot source, after allowing for heat losses. The thermal conductivity coefficient is defined as: K = Q/S. {delta}x/{delta}{theta}, S being the cross section of the sample. Systematic studies have made it possible to determine the mean values of the thermal conductivity. (authors) [French] Un appareil de mesure du coefficient de conductibilite thermique K du graphite irradie ou non irradie a ete realise. Utilisant le principe du transfert de chaleur, il permet de mesurer K au voisinage de la temperature ambiante avec une precision de 6 pour cent environ. L'echantillon de graphite etudie est place sous vide entre une source chaude et une source froide qui creent en regime permanent un gradient de temperature {delta}{theta}/{delta}x La quantite de chaleur transferee Q est deduite de la puissance electrique dissipee dans la source chaude en deduisant les pertes thermiques. Le coefficient de conductibilite thermique est defini par: K = Q/S. {delta}x/{delta}{theta} S designant la section de l'echantillon. Des etudes systematiques ont permis de determiner pour differents graphites non irradies les valeurs moyennes des coefficients de conductibilite thermique. Ces etudes ont mis en evidence pour un type de graphite donne, l'influence de la densite apparente sur le coefficient de conductibilite thermique. A partir de mesures effectuees sur des echantillons de graphite irradies preleves par carottage dans les empilements des reacteurs a moderateur de graphite les variations du rapport K0/Ki en fonction de la dose et de la

Shocks in magneto-reactive-gas dynamics with application to the piston problem; Sur les chocs dans un milieu magnetodynamique reactif avec application au probleme du piston

Energy Technology Data Exchange (ETDEWEB)

Soubbaramayer, [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-03-01

electrique et thermique). Enfin on discute de toutes les solutions possibles du probleme du piston dans un cas simple. Les methodes developpees ici peuvent etre etendues au choc ionisant. (auteur)

Theoretical profiles of the spectral lines of the hydrogen atom; Profils theoriques des raies spectrales de l'atome d'hydrogene

Energy Technology Data Exchange (ETDEWEB)

Nguyen, H; Herman, L [Universite de la Sorbonne, Lab. de Recherche Physique, 75 - Paris (France); Drawin, H W [Commissariat a l' Energie Atomique, Fontenay-aux-Roses, Association Euratom-CEA, Groupe de Recherches sur la Fusion Controlee (France). Centre d' Etudes Nucleaires

1965-07-01

The line-broadening problem of the hydrogen lines has been formulated in the quasistatic approximation as far as the ions are concerned, and in the classical path approximation as far as the broadening due to collisions with electrons is concerned. These electrons interfere in different numerical results only by the self-correlation function of the fluctuating electrical field strength created at each point in the plasma. The Lewis correction has been applied, but using the whole velocity distribution function of the electrons. The formula which represents the usual impact profile, valid only for frequencies much smaller than the plasma frequency, has been extended using another formula which will be valid up to the neighbourhood of that spectral region where the quasi-static approximation begins to be valid also for the electrons. As an example, the line profile of Ly {alpha} is given by some graphs for T = 10{sup 4} deg. K and electron densities N = 10{sup 17} cm{sup -3} and N = 10{sup 18}cm{sup -3}. (authors) [French] Le probleme d'elargissement des raies de l'atome H est formule dans l'approximation quasi-statique en ce qui concerne les ions et dans l'approximation du chemin classique en ce qui concerne les electrons. Ceux-ci interviennent dans differents resultats uniquement par la fonction auto-correlation du champ electrique fluctuant qu'ils creent en chaque point du plasma. La correction de Lewis a ete appliquee mais en tenant compte de la distribution des vitesses electroniques. La formule donnant les profils d'impact habituels, valable seulement pour des frequences tres inferieures a la frequence du plasma, est ainsi prolongee de maniere continue par une autre formule, valable jusqu'au voisinage de la region spectrale ou l'approximation quasistatique commence a etre egalement justifiee pour les electrons. A titre d'illustration on represente graphiquement le profil de la raie Ly {alpha} pour T = 10{sup 4} deg. K et des densites electroniques de N = 10{sup

Perceptions of the Quebec population regarding the development of the electric power industry in Quebec

International Nuclear Information System (INIS)

Lefebvre, M.; Deland, I.

2000-04-01

In March 2000 the Association de l'industrie electrique du Quebec hired the strategic marketing firm of Leger and Leger to conduct a survey of the Quebec population with the following three objectives in mind: (1) to evaluate the general opinion of the Quebec population regarding the development of new hydroelectric projects, (2) to determine the public opinion regarding the exportation of electricity, and (3) to evaluate the public opinion regarding certain hydroelectric projects that were already underway. 1000 adults were polled. It was determined that a large majority (84.2 per cent) of Quebecers are in favour of new hydroelectric development in the province as long as certain conditions are respected, such as maintaining jobs and not incurring an increase in the price of electricity. It was also determined that Quebecers are under the impression that the province exports much more electricity than it actually does. 66 per cent of the population believe that the province is exporting more than 20 per cent of its electric power production outside of the province. In reality, the province exports on average 10 per cent of its production. 71.5 per cent of Quebecers agree to new projects of exportation as long as the projects do not decrease the capacity for the province to fulfill its own power needs. In terms of environmental perceptions, hydroelectric power is considered to be the second least polluting source of energy both from an air pollution and visual pollution point of view. 72.6 per cent of the people said that hydro produces less greenhouse gases than electricity produced by natural gas or coal. Also 83.4 per cent recognized that hydro is a renewable resource. In general, the people surveyed were also in agreement with the development of new transmission lines. 86.8 per cent agreed with the construction of a transmission line between the Laurentians and the Outaouais. The polls are accurate to 3.1 per cent precision 19 times out of 20. tabs., figs

Conception and fabrication of a real time automatic correlator (multi-correlator); Etude et realisation d'un correlateur automatique (multicorrelateur) fonctionnant en temps reel

Energy Technology Data Exchange (ETDEWEB)

Berthier, D. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1967-10-01

The purpose of this work is to elaborate a specific computer able to display the real.time correlation function of two variables represented by two electrical signals. The various functions to be done are dealt with the best suited technology: delays from numerical method, hybrid multiplication, analog integration. This method proved very versatile so that it has been possible to modify the circuits with more performing components without changing the general conception of the whole system. In particular, the bandwidth, which was originally 125 kHz (1966) is now 1 MHz and will be 5 MHz, January 1968. Many results are obtained from the correlator such as: - determination of pulse responses of linear systems (1. and 2. order filters, oscillating circuits); - extraction of signals from noise; - measurement of time and space correlation in a turbulent plasma; - treatment of electro-biological signals. (author) [French] Nous nous sommes proposes de concevoir un calculateur specialise pour l'estimation en temps reel de la fonction de correlation de deux phenomenes representes par deux tensions electriques. Il a ete retenu les procedes de calcul s'adaptant le mieux aux diverses fonctions a realiser: retard par une technique numerique, multiplication hybride, integration analogique. Cette methode s'est revelee tres souple d'emploi: en effet les circuits ont pu etre modifies, sans changer la conception de l'appareil, au fur et a mesure de l'evolution des performances des composants electroniques. Ainsi la bande passante de l'appareil qui initialement etait de 125 KHz (1966) est actuellement de 1 MHz et sera 5 MHz en janvier 1968. De nombreux resultats ont ete obtenus avec l'appareil: - determination de reponses impulsionnelles de systemes lineaires (filtres 1er ordre, 2eme ordre, circuit oscillant, etc... ); - detection de signaux dans le bruit; - mesure de correlation spatiale et temporelle dans le plasma - traitement de signaux

Comparison Of The Worth Of Critical And Exponential Measurements For Heavy-Water-Moderated Reactors; Valeur Relative des Mesures Critiques et Exponentielles pour l'Etude des Reacteurs Ralentis a l'Eau Lourde; Sravnenie tsennosti kriticheskikh i ehksponentsial'nykh izmerenij dlya reaktorov s tyazhelovodnym zamedlitelem; Valor Relativo de las Mediciones Criticas y Exponenciales para los Reactores Moderados por Agua Pesada

Energy Technology Data Exchange (ETDEWEB)

Graves, W. E.; Hennelly, E. J. [Savannah River Laboratory, E.I. Du Pont De Nemours and Co., Aiken, SC (United States)

1964-02-15

direct effects in mock-ups and as a test for heterogeneous and two-dimensional diffusion calculations. (6) Criticality studies of heavy-water lattice fuel in light water The SRL exponentials have proved particularly valuable for criticality studies to determine safe methods of handling enriched fuel in light water. High accuracy is not required in this case, and the generalized exponential buckling studies are definitely preferable to the more particularized critical studies. (author) [French] En regle generale, les experiences critiques et exponentielles sur des reseaux de reacteurs fournissent des renseignements qui font double emploi. Durant les dix dernieres annees, le Savannah River Laboratory (SRL) a fait fonctionner simultanement un ensemble critique a eau lourde (PDP) et un ensemble exponentiel (SE). Les auteurs exposent brievement l'experience acquise au SRL, indiquent les resultats obtenus et font des recommandations au sujet de la possibilite d'appliquer ces deux genres d'installations dans differentes experiences. Les auteurs examinent les six types d'experiences ci-apres: 1. Mesures du laplacien dans les reseaux isotropiques uniformes Le SRL a procede a de nombreuses comparaisons entre les mesures faites a l'aide d'ensembles critiques a une seule region, d'ensembles exponentiels, d'ensembles critiques a substitution et du reacteur d'essai des constantes physiques (PCTR). El semble que les seules difficultes que presentent les experiences exponentielles, resident dans les determinations du laplacien dans le sens radial. Si l'on reussit a faire ces determinations, les experiences exponentielles peuvent etre comparees favorablement aux experiences critiques. Les ensembles critiques a une seule region necessitent le plus de matieres; viennent ensuite les ensembles critiques a substitution et les ensembles exponentiels dont les besoins sont en gros comparables; enfin le PCTR ou les mesures en exigent le moins. 2. Effets anisotropiques et effets cavitaires Des

Market-opening rules and potentialities of destabilization of hierarchical power industries in an open economy: institutional scenarios on the French power industry; Cahier de recherche no.17. Regles d'ouverture de marche et potentialites de destabilisation d'une industrie electrique integree en economie ouverte. Scenarios institutionnels d'evolution de l'industrie electrique francaise

Energy Technology Data Exchange (ETDEWEB)

Finon, D

1999-08-01

The purpose of the paper is to analyse the reform of the French power industry, the extreme integration of the industrial organisation of which is deeply rooted in the French institutional particularisms. After the presentation of the main features of the 1999 reform, different elements of instability of the new structure are pointed out: the over-dominant position of the incumbent company which dissuades entries, institutional isomorphism between economies integrated to a regional space (heterogeneity of structures between European Community countries generates problems of reciprocity and fairness), and the end of the traditional capture of the regulator by the incumbent company because of the autonomy of the function of regulation. Two institutional scenarios are defined, which give a different weight to two competition paradigms in conflicts: the traditional ''industrial economics'' which inclines to preserve hierarchy in the national area to gain competitive advantages in the European field, and the neo-classical paradigm. In the first one, in the name of strategic efficiency, the integration of the industrial organisation could be preserved in spite of the asymmetry of structures between countries, and the playing field is the continental Europe on which national champions compete. In the second one the French industrial organisation has to conform to the competitive model, with vertical and horizontal disintegration and creation of a power exchange market. This scenario necessitates to test the force of the institutional determinism of the nuclear legacy. (author)

New Methods and Facilities for the Measurement of Physical Properties of Reactor Components and Irradiated Materials; Nouveaux Procedes et Instruments de Mesure des Proprietes Physiques des Elements de Reacteur et des Matieres Irradiees; Novye metody i sredstva izmereniya fizicheskikh s vojstv komponentov reaktora i obluchennykh materialov; Nuevos Metodos y Equipos para Medir Propiedades Fisicas de Componentes de Reactor y de Materiales Irradiados

Energy Technology Data Exchange (ETDEWEB)

Foerster, F.; Mueller, P. [Institut Dr. Foerster, Reutlingen, Federal Republic of Germany (Germany)

1965-09-15

direct reading of the permeability and stainless- steel components. The correlation between permeability and {Delta} ferrite content is explained. Measurements of the {Delta} ferrite percentage across welds in stainless-steel tubes and measurements of the {Delta} ferrite precipitations as a function of the plastic strain are discussed (hammer-forging of reactor fuel-elements). (author) [French] Les auteurs decrivent un instrument permettant de mesurer et d'enregistrer automatiquement le module de Young, le module de cisaillement et la capacite d'amortissement en fonction de la temperature et du temps. On mesure le module de Young en excitant des specimens de diverses dimensions a leur frequence propre. On mesure la capacite d'amortissement d'apres la libre decroissance de la vibration ou la largeur a mi-hauteur de la courbe de resonance. Le memoire donne des exemples de mesures de la guerison apres irradiation et apres deformation inelastique, ainsi que des exemples du degre de graphitisation. Les auteurs demontrent que l'on peut detecter des defauts et des variations de densite dans les banes de graphite. Ils expliquent, en outre, une methode d'etude de la fixation de pastilles d' UO{sub 2} sur des tubes en acier austenitique a parois minces. Us decrivent un four special pour l'etude du comportement elastique ou inelastique de specimens 'chauds ' a des temperatures variant entre 20 et 1000 Degree-Sign C. Les auteurs discutent le controle de la qualite de metaux non ferreux par mesure de ia conductivite electrique au moyen de courants de Foucault et decrivent un instrument permettant de mesurer sans aucun contact la conductivite electrique de metaux non ferreux. Ils expliquent la correlation entre la conductivite electrique et l'allongement sous l'effet des contraintes dans le cas de metaux et d'alliages non ferreux. Ils s'attachent particulierement a la mesure d'echantillons de petites dimensions. Ils decrivent un dispositif pour la mesure directe a distance dans la

Modeling by artificial neural networks. Application to the management of fuel in a nuclear power plant; Modelisation par reseaux de neurones. Application a la gestion du combustible dans un reacteur

Energy Technology Data Exchange (ETDEWEB)

Gaudier, F

1999-07-01

The determination of the family of optimum core loading patterns for Pressurized Water Reactors (PWRs) involves the assessment of the core attributes, such as the power peaking factor for thousands of candidate loading patterns. Despite the rapid advances in computer architecture, the direct calculation of these attributes by a neutronic code needs a lot of of time and memory. With the goal of reducing the calculation time and optimizing the loading pattern, we propose in this thesis a method based on ideas of neural and statistical learning to provide a feed forward neural network capable of calculating the power peaking corresponding to an eighth core PWR. We use statistical methods to deduct judicious inputs (reduction of the input space dimension) and neural methods to train the model (learning capabilities). Indeed, on one hand, a principal component analysis allows us to characterize more efficiently the fuel assemblies (neural model inputs) and the other hand, the introduction of the a priori knowledge allows us to reducing the number of freedom parameters in the neural network. The model was built using a multi layered perceptron trained with the standard back propagation algorithm. We introduced our neural network in the automatic optimization code FORMOSA, and on EDF real problems we showed an important saving in time. Finally, we propose an hybrid method which combining the best characteristics of the linear local approximator GPT (Generalized Perturbation Theory) and the artificial neural network. (author)

Quality of electricity service: Evaluation of nuisance index (IGI) of industrial customers; Qualite du service electrique:evaluation de l`indice de gene individuel des clients industriels

Energy Technology Data Exchange (ETDEWEB)

Naggar, R. [Hydro-Quebec, Montreal, PQ (Canada)

1996-08-01

The effects of power interruption on individual industrial customers by computing an individual nuisance index (IGI) is one of the tools planned by Hydro-Quebec to measure quality of service to its customers. When fully functioning, IGI will represent a combined value of loss of sales, overtime, lost materials and other direct costs, each IGI tailor-made for a particular company. Data for computing the index will be obtained from Hydro-Quebec`s own customer classification database, plus a commercial technical database (DTC) containing data required for the assessment of the nuisance, and a survey carried out by Hydro-Quebec involving some 1600 industrial customers. As of this date, the DTC is not yet available. A statistical analysis of survey responses was substituted to provide default values based on available parameters. Hydro-Quebec is confident that this new approach to evaluating service quality will open new horizons in quality assurance. 3 refs., 5 tabs.

Dams. Bulletin of the technical service of electric power and big dams; Barrages. Bulletin du service technique de l`energie electrique et des grands barrages (STEEGB)

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-31

Four papers were selected in this issue of `Barrages` bulletin. The first one concerns the surveillance of medium size dams, the second one deals with the life of French dams in operation (safety decennial and annual inspections). The third paper describes the behaviour of free flow spillways installed on loam dams while the last paper reports on the activities of the control service of the STEEGB for the second quarter of 1997 (decennial and annual inspections, important facts, administrative instructions, draining, floods, granting etc..). (J.S.)

Optimal unit sizing of a hybrid renewable energy system for isolated applications; Optimalite des elements d'un systeme decentralise de production d'energie electrique

Energy Technology Data Exchange (ETDEWEB)

Morales, D

2006-07-15

In general, the methods used to conceive a renewable energy production system overestimate the size of the generating units. These methods increase the investment cost and the production cost of energy. The work presented in this thesis proposes a methodology to optimally size a renewable energy system.- This study shows that the classic approach based only on a long term analysis of system's behaviour is not sufficient and a complementary methodology based on a short term analysis is proposed. A numerical simulation was developed in which the mathematical models of the solar panel, the wind turbines and battery are integrated. The daily average solar energy per m2 is decomposed into a series of hourly I energy values using the Collares-Pereira equations. The time series analysis of the wind speed is made using the Monte Carlo Simulation Method. The second part of this thesis makes a detailed analysis of an isolated wind energy production system. The average energy produced by the system depends on the generator's rated power, the total swept area of the wind turbine, the gearbox's transformation ratio, the battery voltage and the wind speed probability function. The study proposes a methodology to determine the optimal matching between the rated power of the permanent magnet synchronous machine and the wind turbine's rotor size. This is made taking into account the average electrical energy produced over a period of time. (author)

Modalities of vegetation management beneath and in the vicinity of overhead power lines; Modalites de gestion de la vegetation sous et aux abords des lignes electriques

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

This guidebook was elaborated in coordination with the French professional national center of forestry property (CNPPF), Electricite de France (EDF), the national federation of contractors of rural agricultural and forestry works (FNETARF), the national federation of the syndicates of sylviculture forestry owners (FNSPFS), the institute for forest development (IDF), the national forest office (ONF), the French manager of the power grid (RTE) and some local agriculture organizations. Its goal is to supply concrete answers to the questions concerning the management of vegetation in the direct vicinity of overhead power lines, and in particular the rights and obligations of land owners with respect to the maintenance of vegetation. This guidebook represents a first step towards the improvement of today's practices in this domain: legal and technical questions and answers, glossary, regulatory texts, useful addresses and bibliography. (J.S.)

Atom interferometry experiments with lithium. Accurate measurement of the electric polarizability; Experiences d'interferometrie atomique avec le lithium. Mesure de precision de la polarisabilite electrique

Energy Technology Data Exchange (ETDEWEB)

Miffre, A

2005-06-15

Atom interferometers are very sensitive tools to make precise measurements of physical quantities. This study presents a measurement of the static electric polarizability of lithium by atom interferometry. Our result, {alpha} = (24.33 {+-} 0.16)*10{sup -30} m{sup 3}, improves by a factor 3 the most accurate measurements of this quantity. This work describes the tuning and the operation of a Mach-Zehnder atom interferometer in detail. The two interfering arms are separated by the elastic diffraction of the atomic wave by a laser standing wave, almost resonant with the first resonance transition of lithium atom. A set of experimental techniques, often complicated to implement, is necessary to build the experimental set-up. After a detailed study of the atom source (a supersonic beam of lithium seeded in argon), we present our experimental atom signals which exhibit a very high fringe visibility, up to 84.5 % for first order diffraction. A wide variety of signals has been observed by diffraction of the bosonic isotope at higher diffraction orders and by diffraction of the fermionic less abundant isotope. The quality of these signals is then used to do very accurate phase measurements. A first experiment investigates how the atom interferometer signals are modified by a magnetic field gradient. An absolute measurement of lithium atom electric polarizability is then achieved by applying a static electric field on one of the two interfering arms, separated by only 90 micrometers. The construction of such a capacitor, its alignment in the experimental set-up and its operation are fully detailed.We obtain a very accurate phase measurement of the induced Lo Surdo - Stark phase shift (0.07 % precision). For this first measurement, the final uncertainty on the electric polarizability of lithium is only 0.66 %, and is dominated by the uncertainty on the atom beam mean velocity, so that a further reduction of the uncertainty can be expected. (author)

Public synthesis of the reference costs study of the electric power production; Synthese publique de l'etude des couts de reference de la production electrique

Energy Technology Data Exchange (ETDEWEB)

NONE

2008-07-01

Every 3 or 5 years, the DGEC published the reference costs study of the electric power production which evaluates, in a theoretical framework, the total cost of an electrical MWh, from different production ways. These studies bring information for the definition of the energy policy and the elaboration of the investments program. because of the great competition of the market, it was decided not to publish the absolute value of the hypothesis and the results but under indexed form. (A.L.B.)

Use of powered electric vehicles in automobile fleets. Help elements for decision; Utilisation de vehicules electriques dans les flottes automobiles. Elements d`aide a la decision

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-11-01

One of the primary causes of degradation in the quality of urban life is automobile transportation. The introduction of electric vehicles within automobile fleets can help mitigate some of the associated impacts. This guide has assembled a set of technical tools vital to all fleet managers, whether they be with public-sector agencies or companies, who are involved in vehicle-purchasing decisions. It deals with the specific issues related to the use, maintenance and acquisition of electric vehicles. Besides those elements intended to convince both decision-makers and users alike, the automobile fleet manager will find herein, as a conclusion, some examples of comparative economic assessments. These serve to highlight the opportunities available for using electric vehicles in a wide variety of situations. (authors) 18 refs.

Study of point defects in pure iron by means of electrical resistivity; Etude au moyen de la resistivite electrique des defauts ponctuels dans le fer pur

Energy Technology Data Exchange (ETDEWEB)

Minier-Cassayre, C [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1965-04-01

In the first part of this work, after having reviewed the production, observation and the annealing of point defects In metals, we resume the present state of research. In the second part, we explain the techniques we have employed to produce point defects at low temperatures: irradiation, quenching and cold-work; and go on to the study of their migration and annealing. The experimental results obtained for pure iron and for iron containing certain impurities are presented in the third part. In the fourth part we suggest a model which explains the different stages of annealing observed, and their properties. We then compare the energies of interaction between point defects with the values deduced from the theory of elasticity. (author) [French] Dans la premiere partie de cette etude, apres avoir passe en revue la production, l'observation et les modes de guerison des defauts ponctuels dans les metaux, nous exposons l'etat actuel des recherches. La seconde partie est consacree aux techniques que nous avons employees pour produire des defauts ponctuels a basse temperature: irradiations, trempe et ecrouissage puis a l'etude de leur migration et de leur guerison. Les resultats experimentaux obtenus dans le fer pur et le fer contenant certaines impuretes sont presentes dans le troisieme chapitre. Nous proposons ensuite un modele qui explique les differents stades de guerison observes et leurs nombreuses proprietes: nous comparons les energies d'interaction entre defauts ponctuels aux valeurs que l'on pourrait deduire d'un modele elastique. (auteur)

With the 42 V voltage, the automotive industry enters the all-electrical revolution; Avec le 42V, l'automobile aborde la revolution du tout-electrique

Energy Technology Data Exchange (ETDEWEB)

Landragin, J.P.

2003-06-01

The imminent change of the power voltage from 12 to 42 V will revolutionize the automotive industry world. Initially motivated by comfort reasons (space heating and air conditioning accessories), this evolution will have major impacts on the overall architecture of the vehicle, from the engine to the control parts (electric power steering, water and oil pumps, electromagnetic breaking, electrical suspension control, electromagnetic valve operation, air-conditioning compressor, heating of the passenger space, windscreen deicing, preheating of the catalytic converter etc..). The conversion to 42 V will require efficient and reliable power electronic systems (high frequency switching circuits, MOSFET, IGBT) which represent a real challenge for car makers with certainly a transition period during which vehicles will have two batteries: a 12 V one and a 36 V one. Moreover, the proliferation of electronic equipments with different powers and frequencies will lead to complex electromagnetic environments. The entirely powered-controlled vehicle concept ('X-by-wire' technology) is progressively making its way. It will require a perfectly safe and fault tolerant communication system (time-triggered protocol) for the automatic control of the different actuators. (J.S.)

Abstracts of the 10th Conference of the Italian Society of Agricultural Engineering

Directory of Open Access Journals (Sweden)

Danilo Monarca

2013-09-01

sustainable development. I wish all the participants a pleasant stay in Viterbo and Italy. In closing this brief greeting I want to thank: - CEFAS, Special Agency of the Chamber of Commerce, for the logistic support to the Conference, - the Tuscia University, which offered the beautiful and historic seat of the Conference - the Ministry of Agriculture, the Lazio Region, the Provincial Administration and the Municipality of Viterbo, UNACOMA and CRA-Ing, for their support, - CIGR and EURAGENG, for their sponsorship, - FACMA and Enama, sponsors of the Conference. A special thanks to the Carivit Foundation of Viterbo, whose contribution has enabled the printing of the Conference Proceedings.

Heavy nucleus resonant absorption in heterogeneous lattices. I- Apollo 2 self-shielding formalism; Absorption resonnante des noyaux lourds dans les reseaux heterogenes. I -Formalisme du module d`autoprotection d`Apollo 2

Energy Technology Data Exchange (ETDEWEB)

Coste, M.

1994-01-01

This note gives in detailed way the self-shielding formalism which is used in the multigroup transport code APOLLO2. The self-shielded cross-sections are performed with the same scheme as in APOLLO1. We use two equivalencies, first an heterogeneous/homogeneous equivalence which gives the reaction rates and then a multigroup equivalence in order to obtain the cross-sections which preserve these reaction rates. However, numerous improvements were implemented, specially in the homogenization step. Homogenization can be performed group per group with different modelizations of the heavy slowing-down operator (statistical, intermediary and ``wide resonance`` models), which allows us to fit correctly the resonance shapes. Moreover, we can take exactly into account the spatial interferences between resonant isotopes with the background matrix model. Consequently, we are now able to perform, for instance, the radial distribution of the resonant absorption inside a fuel pin. (author). 7 refs., 3 figs.

Eurelectric annual conference (electric power industry union) on the energy liberalization; Conference annuelle Eurelectric (Union de l'industrie electrique) sur la liberalisation de l'energie

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-06-01

This document is a reprint of the talk given by P. Devedjian, French minister of industry, at the Eurelectric 2004 conference. After a brief recall of the energy situation of the European Union, P. Devedjian treats of the following points: the evolution of electricity prices, the increase of CO{sub 2} emissions despite a courageous environmental policy, the three main goals of the energy policy: European economic competitiveness, European solidarity, fight against greenhouse effect, implementation of a common energy policy based on 4 guidelines: common rules, better convergence of energy policies, reinforcement of research, definition of a common energy diplomacy. (J.S.)

Amelioration de la qualite d'energie d'un systeme de conversion d'energie eolienne a base de machine asynchrone a double alimentation et connecte au reseau electrique =

Science.gov (United States)

Abderrahim, Iheb

Wind power generation has grown strongly in the last decade. This results in the development of Wind Energy Conversion System WECS at the levels of modeling and electrical control. Modern WECS operate at varying wind speeds and are equipped with synchronous and asynchronous generators. Among these generators, the Doubly-Fed Induction Generator (DFIG) offers several advantages and capabilities of active and reactive power in four quadrants. WECS based DFIG also causes less conversion costs and minimum energy losses compared with a WECS based on a synchronous generator powered entirely by full scale of power converters. The connection of such a system to the electrical distribution network involves bidirectional operation of networks. This is clearly established in sub and super synchronous operating modes of DFIG. The grid provides the active power to the rotor of DFIG in sub synchronous operating mode and receives the active power of the rotor in super synchronous operating mode of DFIG. Energy quality is thus of major importance during the integration of wind power to the grid. Poor wave quality can affect network stability and could even cause major problems and consequences. This is even more critical where non-linear loads such as the switching power supplies and variable speed drives, are connected to the grid. The idea of this research work is how to mitigate the problems associated with the wave quality while ensuring better implementation of DFIG so that the whole of WECS remains insensitive to external disturbances and parametric variations. The Grid Side Converter (GSC) must be able to compensate harmonics, current unbalance and reactive power injected by a nonlinear three-phase unbalanced load connected to the grid. In addition to these innovative features to improve the conditions of operation of the grid, it provides also the power flow during different modes of operation of the DFIG. It is considered a simple, efficient and cost competitive solution by saving the use of other power equipment. At the same time, the energy efficiency of wind power conversion chain should be improved by extracting the MPPT. Searching allows us to select vector control and control in synchronous reference to achieve these objectives. WECS based DFIG is simulated in MATLAB SIMULINK in the presence of a non-linear balanced and unbalanced three-phase load.

The electric comfort in social housing. EDF is going on. Agreements with concrete results; Le confort electrique en logement social. EDF avance. Des engagements aux resultats concrets

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-11-01

This document deals the wrap-up of the agreement signed between EDF and the HLM Union, in 1997, concerning the quality of the electric heating and warm water in social housing. The convention is described and technical solutions are discussed. The relations with the tenants and the mission of advice are also presented. (A.L.B.)

Systemic design of synchronous traction drives for large speed-range electric vehicle; Conception systemique de chaines de traction synchrones pour vehicule electrique a large gamme de vitesse

Energy Technology Data Exchange (ETDEWEB)

Randi, S.A.

2003-04-15

The presented study deals with a systemic approach based design of permanent magnet brush-less actuators. The considered system is the electric vehicle motorized with this actuator on a large speed range. First, the review of vehicles architectures and general specifications put emphasis on the design problem complexity and the interest of a simultaneous design taking account of the whole traction chain driving cycle. Then the IPM plane and lumped parameter models are used to bring out the variables which characterizes the work beyond the base speed and the ability in flux weakening operation. The properties of machines with two rotor parts in such operation are studied. The new degrees of freedom available with these structures bring new solutions for drives with larger speed range. Then a model taking account each subsystem is presented and implemented in a global SABER simulator, involving sizing models of components. This tool enables to study the work of the traction chain over significant driving cycles and the performances evaluation. A last, this simulator is brought into work so as to perform a simultaneous design of the traction chain components as battery, inverter, machine, gear, thanks to an optimisation procedure based on genetic algorithm able to process continuous sizes variations and structure modifications, considering performance criteria on losses and cost. (author)

Contribution to the improvement of VRLA batteries for cycling applications; Contribution a l'amelioration des batteries au plomb fermees pour l'application au vehicule electrique

Energy Technology Data Exchange (ETDEWEB)

Perrin, M.

2001-07-01

Life time and performance of lead batteries for electric-powered vehicles have been optimized by the application of a mechanical pressure on electrodes blocks with a new separator AJS. On the positive grid, the corrosion decreases as the associated effects because AJS stabilizes mechanically the block. The use of phosphoric acid increases the high discharge currant cells performance if they are loaded by an adequate regime. This effect disappears during the cycle. (A.L.B.)

RTE takes over Houilleres du Bassin de Lorraine's high voltage electricity network; RTE reprend le reseau electrique haute tension des Houilleres du Bassin de Lorraine

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-12-01

Houilleres du Bassin de Lorraine (HBL) decided to sell their high voltage electricity network to RTE. This takeover by RTE, the French transmission system operator, corresponds to the public service mission entrusted to it by the law of February 10, 2000, concerning the rational distribution of an electricity service in France and the local servicing of customers through the public transmission system.

The reversible air-conditioning: economical and ecological asset recognized by the public authorities; La climatisation reversible electrique: des atouts economiques et ecologiques reconnus par les pouvoirs publics

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-05-01

The reversible air-conditioning allows at once the heating and the cooling of the building. This system is very powerful from an energetic and an environmental point of view. Moreover the government proposes financial assistance to the system implementation with a fiscal amortization. (A.L.B.)

Purification by high vacuum fusion and progressive solidification of uranium from electrolytic origin; Purification par fusion sous vide eleve et solidification progressive d'uranium d'origine electrolytique

Energy Technology Data Exchange (ETDEWEB)

Poeydomenge, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-01-15

grain observed, so-called secondary recrystallisation. in appendix, the method for measuring the electrical resistance by induction (with direct current)is studied from the fundamental and experimental point of view. The author applied it to the particular case of uranium for measuring the low-temperature resistance of the bars from the same which solidified first to the least pure ended the ingot. (author) [French] Dans le cadre de recherches generales sur la purification de l'uranium par fusion de zone, on a entrepris de determiner le degre de purification que l'on pourrait atteindre par une simple solidification progressive a vitesse et direction soigneusement controlees d'un uranium de purete nucleaire courante. Cet uranium de purete intermediaire fournirait un materiau de depart approprie au mode de purification ultime qu'est la fusion a zone verticale, dite ''flottante''. Dans ce but, des lingots d'uranium d'origine electrolytique ont ete refondus sous vide (2 a 5 x 10{sup -6} mm) dans une longue nacelle en UO{sub 2} apres une monte lente en temperature pour eliminer le maximum de gaz et d'impuretes volatiles. Ce degazage et cette volatilisation d'impuretes sont completes par maintien prolonge a haute temperature du bais liquide. Celui-ci est ensuite solidifie d'une extremite a l'autre de la nacelle par deplacement a vitesse lente et constante du front de solidification de facon a obtenir une repartition des impuretes selon les lois etablies par PFANN. Differentes methodes experimentales ont permis de montrer que le metal solidifie en premier lieu est nettement plus pur que celui de la partie solidifie a l'extremite opposee du lingot. Le degre de purification du metal en tete du lingot a ete apprecie, soit quantitativement par mesure du rapport des resistivites electriques a la temperature ambiante et a celle de l'azote liquide, soit qualitativement par l'examen de la structure micrographique et par l'etude de la recristallisation du metal. D'une part, le metal

Thermal Neutron Spectral and Spatial Distributions in Light-Water-Moderated Uranium Lattices; Distributions Spectrale et Spatiale des Neutrons Thermiques dans des Reseaux a Uranium et a Eau Leger; Spektral'noe i prostranstvennoe raspredelenie teplovykh nejtronov v uranovykh reshetkakh s vodnym zamedlitelem; Distribuciones Espectral y Espacial de los Neutrones Termicos en los Reticulados de Uranio Moderados por Agua Ligera

Energy Technology Data Exchange (ETDEWEB)

Hardy, J.; Volpe, J. J.; Klein, D.; Schmidt, E.; Gelbard, E. [Bettis Atomic Power Laboratory, Pittsburgh, PA (United States)

1964-02-15

distorted by cadmium poison. Calculations with each kernel were done, for this experiment, in a 12-energy group, P{sub 3} approximation. The slowing-down source shape was obtained by means of an eigenvalue calculation of the spatial modal shapes, decaying exponentially in lethargy, which are sustained by the system, supplemented by measured epicadmium activation shapes. Between the poisoned and unpoisoned cases, calculated relative activation rates predicted by the two kernels differed by as much as 10%. Comparisons of the experimental results with calculations using the Radkowsky kernel and the Nelkin kernel were made. Results strongly favour the harder spectrum predicted by the Nelkin kernel. (author) [French] Les auteurs passent en revue certaines experiences sur le comportement des neutrons thermiques dans les reseaux a uranium et a eau legere. Les experiences sont de deux types principaux: mesures de l'utilisation thermique et mesures par activation de la distribution spatiale des neutrons thermiques dans un milieu aqueux uniformement empoisonne. Ces experiences ont ete concues pour verifier la validite des modeles theoriques actuels en separant les effets spectraux des effets spatiaux a l'interieur d'un reacteur. On a procede a des comparaisons avec des modeles theoriques impliquant differentes approximations touchant la theorie du transport et le noyau de diffusion des neutrons thermiques. La premiere serie d'experiences a consiste en mesures par activation des facteurs de desavantage pour le flux thermique dans differentes cellules du reseau de l'assemblage TRX, qui est un reacteur a uranium faiblement enrichi et a eau legere et dont les barreaux de combustible cylindriques sont disposes en un faisceau hexagonal. Les auteurs ont compare les mesures de l'utilisation thermique avec les resultats de calculs faits par une methode de Monte-Carlo. Ils ont fait usage du noyau de Radkowsky et du noyau de Nelkin. Le noyau de Radkowsky est une approximation de premier ordre

National debate on the energies: Report of the Senior citizens Committee, report of M. Jean Besson. Our electric system proof against the heat wave. The italian electric network failure; Debat national sur les energies: les suites rapport du comite des Sages, rapport de M. Jean Besson. Notre systeme electrique a l'epreuve de la canicule. La panne du reseau electrique italien

Energy Technology Data Exchange (ETDEWEB)

Castillon, P.; Lesggy, M.; Morin, E.; Besson, J.; Mattatia, St.; Barthe, F.; Bouley, N.; Kahan, J.M. [Direction de la Demande et des Marches Energetiques (DIDEME), 75 - Paris (France)

2003-07-01

To preserve the impartiality and the serenity of the discussions, the National Debate on the Energies based on three channels: a Senior Citizens, a consultative Committee and the Parliamentarian Jean Besson. This document published extracts of the reports of the Senior Citizens Committee and Jean Besson. It also provides an analysis of the consequences on the electric power supply during the 2003 summer heat wave in France and the great failure of the italian electric power network during the 28 september 2003. (A.L.B.)

Policies and means to assess and improve service quality in public electricity supply systems; Methodes et moyens pour evaluer et ameliorer la qualite du service des reseaux publics de distribution d`electricite

Energy Technology Data Exchange (ETDEWEB)

Lagostena, L.; Mirra, C.; Noferi, P.L.; Sani, G. [ENEL, (Italy)

1992-12-31

Quality in service from electric utilities does not only imply voltage characteristics and points of delivery. Continuity of supply is also an important factor which needs to be assessed in relation to the disturbances and outages. Short interruptions, voltage dips, transient overvoltages, harmonics and flicker are the main occurrences taken into consideration. Measures which may lead to an improvement in the quality of service were identified. The potential advantages of adopting automatic devices and optimizing maintenance work on distribution networks was discussed. 2 refs., 2 tabs., 3 figs.

Experimental study of the heat of combustion of electrical cables: Pitcairn/calorimetre test bench; Etude experimentale sur la combustion de cables electriques: le banc d`essais Pitcairn/calorimetre

Energy Technology Data Exchange (ETDEWEB)

Gautier, B.; Bosseboeuf, G.

1995-11-01

The R and D has been developing for about ten years, through the MAGIC software, a modeling program on the propagation of fire in power plants. The potential fuels in a power plant are mainly limited to the oils existing in engines and control systems, and electric cables. Those cables present a complex combustion due to their fire-resistant design. In order to study that combustion, two test benches, the PITCAIRN oven and the CALORIMETRE EDF/CNRS have been linked. This report presents briefly the experimental installation, then it comments on the first experimental data obtained with two types of samples, a PVC and an EPR-Hypalon cable. The tested cables are selected from those commonly used in French Nuclear Power Plants. They present complex components (fire-retarding chemical agents, mechanical reinforcement). The data show that the behavior of those cables cannot be reduced to a mass loss rate associated to a constant Heat of Combustion. The Heat of Combustion of the PVC cable tested varies little at the beginning of the pyrolysis from 5 kJ.g{sup -1} to 10 kJ.g{sup -1}, then increases quickly up to 30 kJ.g{sup -1}. In the same way, the EPR-Hypalon cable shows a continuous and slow increase of the Heat of Combustion from 1 kJ.g{sup -1} to 20 kJ.g{sup -1} during the pyrolysis, then rises quickly up to 40 kJ.g{sup -1} at the end. Those data corroborate the thesis of the dilution of flammable species by fire-retarding agents, which lower the Heat of combustion but seems to disappear at the end of the pyrolysis. (authors). 7 refs., 6 figs.

Expert system for the real-time management of alarms in an electric grid. Un systeme expert pour la gestion en temps reel des alarmes dans un reseau electrique

Energy Technology Data Exchange (ETDEWEB)

Girouard, P.

1987-01-01

A model-base expert system is presented for the processing of alarm messages in power networks' control centers. This alarm processor, called GESTAL, generates concise diagnoses identifying the causes(s) of network disturbances and describing the operation of the protection and alarm systems which operate to isolate faulty components. Essentially, the alarm processor is an agenda driven expert system which is composed of a model of the power network's alarm and protection systems as well as several sets of rules. Based on the nextwork model, graph structures are constructed which represent relationships between alarms as they are received. These graph structures are then analysed in order to diagnose the disturbances(s). The alarm processor has been developed using the ART 3.0 programming language in a Symbolics Lisp-machine environment. Background material on expert systems, electric power networks, and alarm processing software is included, as well as a description of GESTAL'S functional characteristics and design. 51 refs., 28 figs.

Feasibility study for the construction of a methane production plant on the basis of 'green waste' collected in the canton of Ticino; Machbarkeitsstudie Biogasanlage im Tessin -- Studio di fattibilita di un impianto di biometanizzazione per i rifiuti verdi

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

This report for the Swiss Federal Office of Energy presents a feasibility study for the construction of a methane production plant on the basis of 'green waste' collected in the canton of Ticino, in Southern Switzerland. The objective is power generation from compostable organic waste (about 10'000 t/year) and marketing of this electrical energy under a 'clean energy' label. The biogas process together with the technologies used are described. A review of the methane production plants available today on the European market is given, together with a presentation of some manufacturers. The local situation in Ticino, including available volume and composition of green waste as well as the possible usages for the residues from the methane production plants, is discussed. Potential sites for the future production plant are listed. Economic aspects are summarised in the form of diagrams. In annexes, more details on the plant operation cost are given and pictures of the different fermentation installation candidates are presented. [French] Ce rapport est le resultat de l'etude de la faisabilite de l'implantation d'une usine de methanisation des dechets verts pour le canton du Tessin en Suisse. L'objectif est de valoriser l'energie des dechets compostables (typiquement 10'000 t/an) et d'en produire de l'energie electrique qui sera vendue sous un label d'energie propre. Le processus de biomethanisation est presente, de meme que les techniques utilisees. Suit une presentation des diverses installations de methanisation actuellement disponibles sur le marche europeen et des entreprises qui les proposent. La situation propre au Tessin comme la quantite et la composition des dechets verts et les possibilites d'utilisation des masses residuelles est analysee. Le lieu d'implantation de l'usine est aussi discute. Finalement, un bilan economique est presente sous forme graphique. Le document est

Preparation of high critical temperature YBa{sub 2}Cu{sub 3}O{sub 7} superconducting coatings by thermal spray; Elaboration par projection a chaud de revetements supraconducteurs a haute temperature critique de type YBa{sub 2}Cu{sub 3}O{sub 7}

Energy Technology Data Exchange (ETDEWEB)

Lacombe, Jacques

1991-09-20

The objective of this research thesis is the elaboration of YBa{sub 2}Cu{sub 3}O{sub 7} superconducting coatings by thermal spray. These coatings must have a high adherence, a high cohesion, and the best possible electrical characteristics. The author first briefly presents physical-chemical characteristics of this ceramic, and proposes a bibliographical synthesis on thick coatings prepared by thermal spray. In the next parts, he studies and describes conditions of elaboration of poly-granular coatings of YBa{sub 2}Cu{sub 3}O{sub 7}, and their structural and electric characteristics [French] Des revetements epais de YBa{sub 2}Cu{sub 3}O{sub 7} ont ete elabores par projection a chaud sur des substrats d'acier inoxydable revetus d'une sous-couche de Ni-Cr-Al-Y. Les principales etapes du processus de fabrication sont les suivantes: - preparation de la poudre par voie humide selon un procede mis au point au C.E.R.E.M., - realisation des revetements epais par projection a chaud de cette poudre selon trois differentes techniques: projection plasma atmospherique, projection plasma sous pression reduite, projection flamme oxyacetylenique. - traitement thermique en deux etapes des revetements pour recristalliser la phase YBa{sub 2}Cu{sub 3}O{sub 7} et la reoxygener (traitement thermique dans un four sous oxygene). Les depots elabores selon cette voie sont adherents et homogenes a la fois en composition et en morphologie. La phase supraconductrice YBa{sub 2}Cu{sub 3}O{sub 7} determinee par diffraction de rayons X est bien cristallisee; elle se presente sous forme de plaquettes d'environ 10 μm de long et 1 μm d'epaisseur sans orientation preferentielle. Les revetements realises par projection plasma atmospherique presentent les meilleures caracteristiques electriques: Tc(R=0) = 90.5K; ΔTc = 1K; ρ (300 K) = 0.7 - 0.8 mΩ.cm; Jc(77 K,0 T) = 1000 A/cm{sup 2}. Les proprietes d'ecrantage magnetique ont ete comparees a celles de materiaux utilises pour le blindage magnetique

Study of the synthesized plasma resulting from forced neutralization of a mercury ions beam; Etude du plasma de synthese resultant de la neutralisation forcee d'un faisceau d'ions Hg{sup +}

Energy Technology Data Exchange (ETDEWEB)

Spiess, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1969-07-01

, en l'absence de champ electromagnetique externe. La presence d'un champ electrique longitudinal, cree par une grille polarisee et plongee dans le faisceau, modifie les conditions de stabilite du plasma de synthese. (auteur)

Study of thick, nuclear-compensated silicon detectors; Etude des detecteurs epais au silicium compense nucleairement

Energy Technology Data Exchange (ETDEWEB)

Le Coroller, Y. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-09-01

A study is made here, from the point of view of the realization and the performance, of thick nuclear-compensated silicon detectors. After recalling the need for compensation and reviewing the existing methods, the author describes in detail the controlled realization of thick detectors by nuclear compensation from the theoretical and experimental points of view. The practical precautions which should be observed are given: control of the homogeneity of the starting material, control of the evolution of the compensation, elimination of parasitic processes. The performances of the detectors obtained are then studied: electrical characteristics (current, life-time) on the one hand, detection and spectrometry of penetrating radiations on the other hand. The results show, that the compensated diodes having an effective thickness of two millimeters operate satisfactorily as detectors for applied voltages of about 500 volts. The resolutions observed are then about 2 per cent for mono-energetic electrons and about 4 per cent for the gamma; they can be improved by the use of a pre-amplifier of very low background noise. (author) [French] Les detecteurs epais au silicium compense nucleairement sont etudies ici du double point de vue realisation et performances. Apres un rappel sur la necessite de la compensation et les procedes existants, la realisation controlee des detecteurs epais par compensation nucleaire est decrite en detail sous l'aspect theorique et l'aspect experimental. On met en evidence les precautions a prendre dans la pratique: controle de l'homogeneite du materiau de base, controle de l'evolution de la compensation, elimination des processus parasites. On etudie ensuite les performances de detecteurs obtenus : caracteristiques electriques (courant, duree de vie) d'une part, d'autre part detection et spectrometrie des rayonnements penetrants. Les resultats montrent que les diodes compensees ayant une epaisseur utile de deux

Study of thick, nuclear-compensated silicon detectors; Etude des detecteurs epais au silicium compense nucleairement

Energy Technology Data Exchange (ETDEWEB)

Le Coroller, Y [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-09-01

A study is made here, from the point of view of the realization and the performance, of thick nuclear-compensated silicon detectors. After recalling the need for compensation and reviewing the existing methods, the author describes in detail the controlled realization of thick detectors by nuclear compensation from the theoretical and experimental points of view. The practical precautions which should be observed are given: control of the homogeneity of the starting material, control of the evolution of the compensation, elimination of parasitic processes. The performances of the detectors obtained are then studied: electrical characteristics (current, life-time) on the one hand, detection and spectrometry of penetrating radiations on the other hand. The results show, that the compensated diodes having an effective thickness of two millimeters operate satisfactorily as detectors for applied voltages of about 500 volts. The resolutions observed are then about 2 per cent for mono-energetic electrons and about 4 per cent for the gamma; they can be improved by the use of a pre-amplifier of very low background noise. (author) [French] Les detecteurs epais au silicium compense nucleairement sont etudies ici du double point de vue realisation et performances. Apres un rappel sur la necessite de la compensation et les procedes existants, la realisation controlee des detecteurs epais par compensation nucleaire est decrite en detail sous l'aspect theorique et l'aspect experimental. On met en evidence les precautions a prendre dans la pratique: controle de l'homogeneite du materiau de base, controle de l'evolution de la compensation, elimination des processus parasites. On etudie ensuite les performances de detecteurs obtenus : caracteristiques electriques (courant, duree de vie) d'une part, d'autre part detection et spectrometrie des rayonnements penetrants. Les resultats montrent que les diodes compensees ayant une epaisseur utile de deux millimetres fonctionnent

Installation of a bitumen coating plant for high-activity concentrates; Installation pilote d'enrobage par le bitume de concentrats de haute activite

Energy Technology Data Exchange (ETDEWEB)

Rodier, J; Lefillatre, G; Seyfried, P [Commissariat a l' Energie Atomique, Chusclan (France). Centre de Production de Plutonium de Marcoule

1969-07-01

permettra des etudes de laboratoire sur les enrobes (mesures d'auto-echauffement, des charges electriques, des gaz de radiolyse, essais de lixiviation). Dans l'etat actuel des choses, les donnees que nous avons nous permettent de penser que l'on peut enrober des concentrats d'une activite de 20 Ci/l au prix de 1840 F le metre cube. (auteurs)

Can-rupture detection in gas-cooled nuclear reactors; La detection des ruptures de gaine dans les piles nucleaires refroidies par gaz

Energy Technology Data Exchange (ETDEWEB)

Roguin, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-07-01

Can-rupture detection (DRG) is one important aspect of pile safety, more particularly so in the case of gas-cooled reactors. A rapid and sure detection constitutes also an improvement as far as the efficiency of electricity-producing nuclear power stations are concerned. Among the numerous can-rupture detection methods, that based on the measurement of the concentration of short-lived fission gases in the heat-carrying fluid has proved to be the most sensitive and the most rapid. A systematic study of detectors based on the electrostatic collection of the daughter products of fission gases has been undertaken with a view to equip the reactors EL 2, G 3, EDF 1, EDF 2 and EDF 3, the gas loops of PEGASE and EL 4. The different parameters are studied in detail in order to obtain a maximum sensitivity and to make it possible to construct detection devices having the maximum operational reliability and requiring the minimum maintenance. The primary applications of these devices are examined in the case of the above-mentioned reactors. (author) [French] La Detection des Ruptures de Gaines (D. R. G.) est un aspect important de la securite des piles et plus particulierement des piles refroidies par un gaz. Une detection rapide et sure constitue aussi un element d'amelioration du rendement des centrales nucleaires productrices d'energie electrique. Parmi les nombreuses methodes de detection des ruptures de gaines, la mesure de la concentration dans le fluide caloporteur des gaz de fission a vie courte s'est revelee comme la plus sensible et la plus rapide. Une etude systematique des detecteurs a collection electrostatique des descendants des gaz de fission a ete entreprise en vue d'equiper les piles EL 2, G 3, EDF 1, EDF 2 et EDF 3, les boucles a gaz de la pile Pegase et la pile EL 4. Les divers parametres sont etudies en detail pour obtenir une sensibilite maximum et permettre la realisation de dispositifs de detection ayant le maximum de securite de fonctionnement et le

Awareness of households to the development of wind energy sites - Reporting on a survey; Receptivite des menages au developpement des sites eoliens. Rapport d'enquete

Energy Technology Data Exchange (ETDEWEB)

Voisard, M.

2000-07-01

This report for the Swiss Federal Office of Energy presents in tables and diagrams the results of a survey involving 421 households in Switzerland, about their awareness to energy issues and, in particular, to all what regards wind energy and wind power plants. Globally, 80% of the persons asked for their opinion believe that electric power demand will continue to increase. 66% of them are in favour of increased use of renewable energy sources and would consequently agree with a 10% more expensive end-user energy price. 89% of the persons taking part to the survey approve the installation of wind energy farms in Switzerland. Moreover, statistics indicates that the households living in regions already equipped with wind farms are significantly more favorable to the creation of new wind energy sites than those not living in these regions. By the end of the day, it turns out that the main reasons for accepting wind energy are environmental concerns as well as the fear of being obliged to use nuclear power. [French] Ce rapport presente par des graphiques et des tableaux le resultat d'un sondage d'opinion aupres de 421 menages en Suisse, sur la sensibilite du public aux problemes de l'energie et plus particulierement sur sa perception de tout ce qui concerne l'energie du vent et son exploitation par l'implantation d'eoliennes. Globalement, 80% des menages pensent que la demande d'energie electrique va poursuivre sa croissance. 66% d'entre eux sont favorables au developpement des energies renouvelables et prets a accepter en consequence une augmentation du prix de l'energie allant jusqu'a 10%. 89% des personnes interrogees sont favorables au developpement des eoliennes en Suisse. De plus, la statistique montre de maniere significative que les menages des regions dans lesquelles sont deja implantes des sites eoliens sont plus favorables au developpement des eoliennes que les autres. Finalement, le respect de l

Determination of the sanguine iodine content by activation analysis (1962); Determination de l'iode sanguin par analyse d'activation (1962)

Energy Technology Data Exchange (ETDEWEB)

Kellershohn, C; Comar, D; Le Poec, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1962-07-01

Two methods of measuring the iodine content of the blood by activation analysis after 30 min irradiation in a flux of 6.10{sup 12} n/cm{sup 2}.s are described. One method includes a chemical separation of iodine before irradiation. The radioactivity of this specimen is determined on the basis of the amplitude of the iodine 128 photoelectric peak measured by {gamma}-spectrometry. The sensitivity of this method is about 10{sup -8} g. The other includes chemical separation after irradiation, and radioactivity is subsequently measured with a Geiger-Muller counter. The sensitivity of this second method is about 10{sup -10} g, sufficient for determination of the plasmatic mineral content. The advantages of activation analysis over the conventional method based on colorimetric measurement of the catalytic action of iodine in the oxidation of arsenious anhydride with ceric sulphate are discussed. Initial results obtained with this new form of analysis are detailed as are also the possibilities of measuring plasmatic proteic iodine by scintillation spectrometry without prior chemical separation. (authors) [French] Deux methodes de dosage de l'iode sanguin par analyse d'activation apres irradiation de 30 minutes a 6.10{sup 12} n/cm{sup 2} s sont decrites. L'une comprend une separation chimique de l'iode avant l'irradiation et la mesure de la radioactivite est effectuee a partir de l'amplitude du pic photo-electrique de l'iode 128 obtenu par spectrometrie-{gamma}. Sa sensibilite est de l'ordre de 10{sup -8} g. L'autre comprend une separation chimique de l'iode apres l'irradiation et la radioactivite de l'iode-128 est mesuree par comptage-{beta} avec un compteur Geiger. Sa sensibilite est de l'ordre de 10{sup -10} g, permettant d'envisager le dosage de l'iode mineral plasmatique. Les avantages de l'analyse d'activation sur la methode classique, basee sur la mesure colorimetrique de l'action catalytique de l'iode dans l'oxydation de l'anhydride arsenieux par le sulfate cerique

Can-rupture detection in gas-cooled nuclear reactors; La detection des ruptures de gaine dans les piles nucleaires refroidies par gaz

Energy Technology Data Exchange (ETDEWEB)

Roguin, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-07-01

Can-rupture detection (DRG) is one important aspect of pile safety, more particularly so in the case of gas-cooled reactors. A rapid and sure detection constitutes also an improvement as far as the efficiency of electricity-producing nuclear power stations are concerned. Among the numerous can-rupture detection methods, that based on the measurement of the concentration of short-lived fission gases in the heat-carrying fluid has proved to be the most sensitive and the most rapid. A systematic study of detectors based on the electrostatic collection of the daughter products of fission gases has been undertaken with a view to equip the reactors EL 2, G 3, EDF 1, EDF 2 and EDF 3, the gas loops of PEGASE and EL 4. The different parameters are studied in detail in order to obtain a maximum sensitivity and to make it possible to construct detection devices having the maximum operational reliability and requiring the minimum maintenance. The primary applications of these devices are examined in the case of the above-mentioned reactors. (author) [French] La Detection des Ruptures de Gaines (D. R. G.) est un aspect important de la securite des piles et plus particulierement des piles refroidies par un gaz. Une detection rapide et sure constitue aussi un element d'amelioration du rendement des centrales nucleaires productrices d'energie electrique. Parmi les nombreuses methodes de detection des ruptures de gaines, la mesure de la concentration dans le fluide caloporteur des gaz de fission a vie courte s'est revelee comme la plus sensible et la plus rapide. Une etude systematique des detecteurs a collection electrostatique des descendants des gaz de fission a ete entreprise en vue d'equiper les piles EL 2, G 3, EDF 1, EDF 2 et EDF 3, les boucles a gaz de la pile Pegase et la pile EL 4. Les divers parametres sont etudies en detail pour obtenir une sensibilite maximum et permettre la realisation de dispositifs de detection ayant le maximum de securite de

A spectrometer using semi-conductor detectors; study and applications (1963); Spectrometre utilisant les detecteurs a semi-conducteur: etudes et applications (1963)

Energy Technology Data Exchange (ETDEWEB)

Roux, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

The low average energy, 2.5 to 3.5 eV, required to produce one hole-electron pair in a semiconductor allows an accurate measurement of the energy of the ionizing particles. A high resolution spectrometer has been built using semiconductor detectors. The limit of resolution, due to electronics associated to the detector, to the detector itself and to the source of particles is studied here. The present practical limit of resolution of the spectrometer is 1700 elementary electric charges (full width at half maximum of a ray of a spectrum) or 6 keV in terms of energy lost by a particle in a silicon detector. The physical resolution usually obtained is 20 keV (0.33 per cent) with {alpha} particles of the {sup 212}Bi (6.087 MeV). It depends a lot of the kind of detector used. Some results, concerning the background of the detectors and limit of measurements for low energies are given. Various applications are presented: spectrometry {beta}, spectrometry {gamma} and X, spectrometry of mixtures of {alpha} radioactive elements, collection of {alpha} spectra. (author) [French] La faible energie moyenne, 2,5 a 3,5 eV, necessaire pour produire une paire electron-trou dans un semi-conducteur, permet une mesure precise de l'energie des particules ionisantes. Un spectrometre a haute resolution a ete construit utilisant des detecteurs a semi-conducteur. La limitation en resolution due a l'electronique associee au detecteur, au detecteur lui-meme et a la source de particules, est etudiee. La resolution pratique limite actuelle du spectrometre est 1700 charges electriques elementaires (largeur a mi-hauteur d'une raie de spectre) ou 6 keV exprimee en energie perdue par une particule dans un detecteur au silicium. La resolution physique couramment obtenue est de 20 keV (0,33 pour cent) pour les particules {alpha} du bismuth 212 (6,087 MeV). Elle depend beaucoup du detecteur utilise. Quelques resultats sont donnes concernant le mouvement propre des detecteurs et la limitation des

Stability of a Magnetically Confined 20-KeV Steady-State Plasma; Stabilite d'un Plasma Stationnaire de 20 KeV Confine par un Champ Magnetique; Ustojchivost' 20 KehV-statsionarnoj plazmy, uderzhivaemoj magnitnym polem; Estabilidad en Regimen Estacionario de un Plasma de 20 KeV Confinado Magneticamente

Energy Technology Data Exchange (ETDEWEB)

Futch, Jr., A. H.; Damm, C. C.; Foote, J. H.; Freis, R.; Gordon, F. J.; Hunt, A. L.; Killeen, J.; Moses, K. G.; Post, R. F.; Steinhaus, J. F. [Lawrence Radiation Laboratory, Livermore, CA (United States)

1966-04-15

oscillations at the ion gyrofrequency and with pulsed emission of electrons through the mirror region accompanied by increases in the plasma potential suggests the presence of an electrostatic resonance instability. Differences in gyrofrequency activity among simple mirror, dodecapole and octopole cases are described but specific mode identification is not yet possible. (author) [French] Les auteurs ont etudie la stabilite d'un plasma d'hydrogene stationnaire de 20 keV dans l'appareil a injection d'atomes neutres 'Alice ' de Livermore, dans differents champs magnetiques de confinement. Dans un champ simple a miroirs, l'observation d'oscillations a basse frequence et d'une limite de la densite des ions pieges fait l'objet d'une interpretation en fonction de l'instabilite de derive a basse frequence. Les auteurs ont effectue un traitement theorique de cette instabilite qui porte sur les effets de la dimension finie des orbites des ions, les effets d'un champ electrique d'ordre zero et les effets de la difference entre la densite des ions et celle des electrons. Le champ electrique et le champ magnetique peuvent etre des fonctions arbitraires de la coordonnee spatiale r. Comme il n'est pas possible en general de resoudre analytiquement les equations differentielles ainsi calculees, les auteurs ont resolu numeriquement les equations fondamentales par la methode des differences finies. Ces resultats, qui concordent avec les solutions analytiques obtenues dans le cas limite d'un champ electrique qui n'est pas d'ordre zero, permettent d'expliquer les variations de la densite et de la frequence de la derive observees experimentalement en presence d'un champ electrique fini d'ordre zero. Comme ce traitement theorique part de l'hypothese que le champ magnetique est une fonction arbitraire de r, il est possible d'obtenir des resultats pour des champs ayant un gradient d'abord negatif qui devient ensuite positif lorsque r augmente. Les auteurs comparent les resultats de ces calculs aux

Information manual for the experimentation of the deployment of optical fibers on public power distribution networks; Notice d'information pour l'experimentation du deploiement de fibres optiques sur les reseaux publics d'electricite

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

During the French inter-ministry committee for the national development (CIADT) of July 9, 2001, the government decided to launch a feasibility study about the deployment of telecommunication optical fibers over the whole territory using the electricity transportation grid. The aim is to give access to high-speed Internet to everyone and at a reasonable cost. This manual summarizes the technical, legal and economical results of the study carried out by the working group: 1 - the actors in concern (managers of power transportation and distribution networks, country authorities, managers and users of telecommunication infrastructures, regulatory agencies, financial organizations); 2 - the telecommunication networks on power lines; 3 - the feasibility of the experimentation (relations between the different partners, conditions); 4 - the implementation of the experimentation (useful contacts, contracts); 5 - the experimentation areas. Appendixes. (J.S.)

Transverse Injection Experiment; Injection Transversale; Poslednie dostizheniya v oblasti inzhektirovaniya plazmy poperek magnitnogo polya; Inyeccion Transversal

Energy Technology Data Exchange (ETDEWEB)

Hammel, J. E.; Baker, D. A. [Los Alamos Scientific Laboratory, Los Alamos, NM (United States)

1966-04-15

magnetique a fait l'objet de diverses etudes. Au cours des premieres experiences d'injection d'un plasma rapide (50-70 cm/{mu}s) et dense (10{sup 14} ion/cm{sup 3}) transversalement a un champ magnetique, les auteurs ont observe un champ electrique d'autopolarisation et le plasma traversait le champ magnetique avec une derive du type E x B. Le champ magnetique n'etait que faiblement perturbe par le faisceau (| {Delta}B/B | <0.1), tandis que la vitesse de la derive, a travers des champs magnetiques pouvant atteindre 5 kG, etait approximativement egale a celle du plasma injecte. Le plasma derivant dans des regions a champ magnetique eleve, son epaisseur dans la direction de V x B diminue. Simultanement, des mesures de la densite des electrons par des methodes interferometriques avec le laser He-Ne montrent que le champ transversal pouvant atteindre 7 kG ne provoque pas d'etalement notable du plasma dans la direction de B. Il est interessant d'observer le comportement du plasma lorsqu'il traverse une region oh les lignes de champ magnetique changent de sens de part et d'autre d'une ligne d'intensite nulle. Lorsque le plasma traverse la separatrice entre les deux directions, il faut que le champ electrique change de sens pour que la derive du plasma puisse se prolonger. Le plasma s'arrete au voisinage de la separatrice et on mesure des courants importants le long des lignes de champ magnetique reliant la partie frontale du plasma aux parties suivantes. Des isolateurs, placesde maniere a interrompre le courant, permettent au plasma de passer dans la region de champ inverse. En utilisant l'inductance liee au courant de depolarisation lorsque les lignes de champ magnetique sont fixees a une certaine distance de la lisiere du plasma, il a ete possible de Separer les composantes lente et rapide du plasma. Les auteurs ont observe, par des methodes interferometriques, la coupure de la composante lente du plasma, a l'aide d'un laser He-Ne. Des mesures du champ electrique en plusieurs

The economic analysis of power market architectures: application to real-time market design; L' analyse economique des architectures de marche electrique: application au market design du temps reel

Energy Technology Data Exchange (ETDEWEB)

Saguan, M

2007-04-15

This work contributes to the economic analysis of power market architectures. A modular framework is used to separate problems of market design in different modules. The work's goal is to study real-time market design. A two-stage market equilibrium model is used to analyse the two main real-time designs: the 'market' and the 'mechanism' (with penalty). Numerical simulations show that design applied in real-time is not neutral vis-a-vis of energy markets sequence and the competition dynamic. Designs using penalty (mechanisms) cause distortions, inefficiencies and can create barriers to entry. The size of distortions is given by the temporal position of the gate that closure the forward markets. This model has also allowed us to show the key role of real-time integration between zones and the importance of good harmonization between real-time designs of each zone. (author)

A 20 MW podded ship underwater electromagnetic signature - the alternative electric field; Signature electromagnetique sous-marine d'un paquebot de 20 MW a pods - le champ electrique alternatif

Energy Technology Data Exchange (ETDEWEB)

Lucas, B.; Henocq, H.; Rannou, C. [Delegation Generale pour l' Armement, DET/GESMA, 75 - Paris (France); Albert, Th.; Harpin, D. [ALSTOM Marine (France); Bourguet, S.; Guerin, P. [Institut de Recherche en Electrotechnique et Electronique de Nantes Atlantique, 44 (France)

2006-03-15

Today, electric podded propulsion is used for many ships, cruise liners and Navy vessels.This propulsion uses high currents in extremely low frequencies (ELFE); currents flow through electrical network, equipment and pods. These alternative currents could generate important underwater electromagnetic field. GESMA has to quantify the level of this field and its impact on the signature of this kind of ship. Then, GESMA carried out electromagnetic measurements using a multi-sensors underwater and autonomous facility named AMI. It was placed on the route of a 20 MW podded ship, at one hundred meters depth from the surface. Especially, AMI observed an alternative radiated electric field... (authors)

Feasibility study for the installation of a small hydro electric power plant; Etude de faisabilite. Petite centrale hydro-electrique au lieu dit 'Sous les Roches' a Sonceboz

Energy Technology Data Exchange (ETDEWEB)

Tissot, N. [MHyLab, Mini-Hydraulics Laboratory, Montcherand (Switzerland); Hausmann, H. [Hans Hausmann, Bevilard (Switzerland)

2003-07-01

This report for the Swiss Federal Office of Energy presents a technical, economical and ecological analysis of the feasibility of a small hydroelectric power plant at Sonceboz, in the Swiss Jura mountains. The power of the planed plant would typically be 500 kW for a water head of about 10 m. The study shows that, compared to one single turbine, a pair of Kaplan type turbines would be operational over a larger range of the river's water flow rate. This solution would be a little bit more costly but offer more flexibility for maintenance. Two maximum water flow rates are considered, 4.5 and 6 m{sup 3}/s respectively. According to the economical study, done with current electric kWh prices, both configurations are viable while the largest flow rate leads to a larger profit. The report is rounded up by a sensitivity analysis considering variations in annual power generation, electro-mechanical and construction cost as well as turbine efficiency. It indicates that this last factor could be crucial for the overall profitability. [French] Ce rapport est le resultat detaille de l'analyse technico-economique et ecologique de faisabilite de la realisation d'une petite centrale hydroelectrique basse chute qui pourrait exploiter une denivellation d'environ 10 m pour une puissance de l'ordre de 500 kW pres de Sonceboz dans le Jura suisse. L'etude montre que le couplage de deux turbines Kaplan offrirait une possibilite de fonctionnement sur une plus grande plage de flux ainsi qu'une plus grande flexibilite de maintenance, ceci pour un cout legerement superieur a l'option a une seule turbine. Les debits de 4.5 et 6 m{sup 3}/s sont consideres. L'etude economique montre que le debit de 6 m{sup 3}/s est plus rentable au prix de vente actuel du kWh. L'article se termine par une analyse de sensibilite sur les incertitudes concernant la production annuelle, les prix de l'electromecanique et du genie civil et le rendement des turbines.

Conference Proceedings of International High Speed Networks for Scientific and Technical Information, Held at Ottawa, Canada on 6-7 October 1993 (Les Reseaux Internationaux Rapides D’Echange D’Information Scientifique et Technique)

Science.gov (United States)

1994-02-01

reseau systtme pour que toutes les commandes soient girkes local Ethernet. dlectroniquement. Trois micro -ordinateurs permettent Ia transmission des...May 1993, ISBN 0.88736-936-7. Networking and the future of the Libraries, April 2-5, 1992. Paper 17. [71 Goodman, D., "El servicio de Directorio de

Research with a Natural-Uranium Light-Water Subcritical Assembly; Recherches au Moyen d'un Ensemble Sous-Critique a Uranium Naturel et a Eau Ordinaire; Issledovaniya na podkriticheskoj sborke,rabotayushchej na prirodnom urane i obychnoj vode; Investigaciones con un Conjunto Subcritico de Uranio Natural y Agua Ligera

Energy Technology Data Exchange (ETDEWEB)

Koskinen, H. [Institute of Technical Physics, Otaniemi (Finland)

1964-02-15

systematic study of non-uniform lattices. In the future, enriched elements will be included in the assembly. Then systematic study of mixed lattices becomes possible, and also research with other non-uniformities will be easier because of the higher flux. Some discussion of this future programme is included in this paper. (author) [French] L'auteur relate les recherches effectuees avec un ensemble uranium naturel-eau ordinaire et enumere certains des sujets qui feront l'objet d'un prochain programme. La plus grande partie de la documentation est nouvelle. Certaines donnees ont encore un caractere provisoire, car les experiences et l'analyse des resultats se poursuivent. . Les travaux sont axes sur deux objectifs principaux: 1. Etude experimentale de la validite des methodes de calcul que l'on se propose d'utiliser, notamment en cas de geometries speciales (repartitions non uniformes du combustible, configurations de s'ous- ensembles, limites de forme particuliere, etc.). Les etudes theoriques conduisent souvent ici a certaines difficultes de convergence. Il faut donc les comparer avec les repartitions du flux mesurees. 2. Etude des proprietes particulieres des reseaux uranium naturel-eau ordinaire et notamment de la validite des modeles de ralentissement a plusieurs groupes pour des structures de coeur uniformes et non uniformes. On pense qu'un ensemble comportant une seule source de fission spontanee convient particulierement pour les recherches de ce genre, bien que la statistique ne porte que sur un petit nombre d'observations. Cela est du a deux faits: 1. On peut considerer que le spectre de la source primaire est identique a celui de la fission induite, si bien qu'il n'y a pas d'oscillations transitoires d'energie, comme dans le cas d'une source ponctuelle de neutrons rapides. 2. L'intensite de la source primaire en chaque point de l'espace est proportionnelle a la section efficace de fission du combustible lorsqu'on considere egalement cette derniere comme une fonction

Proceedings of the Prop'Elec 2000 colloquium. Advances of electric drive in urban transportation systems; Actes du colloque Prop'Elec 2000. Progres de la traction electrique dans les transports urbains

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

This document is the proceedings of Prop'Elec 2000 colloquium on the advances in electric power drive in urban transportation systems. The colloquium comprises 5 sessions dealing with: 1 - public collective electric-powered transportation system: synthesis of urban guided systems (C. Soulas, INRETS), the fast travelator (A. Cote, RATP), the power supply system of METEOR automatic underground railway (P. Lagrange, W. Seiler, RATP); 2 - electrical drive in urban transportation systems: start-up of a thermal engine with super-capacitors (D. Bouquain (CREEBEL), H. Gualous, A. Djerdir, A. Berthon, J.M. Kauffmann (L2ES, IGE)), The LEV (light weight electric vehicle) project in Mendrisio (U. Schwegler, LEV/Suisse), prototype of electrical bike that use a wheel-engine (C. Espanet, F. Gustin, J.M. Kauffmann (IGE), S. Robert, M. Karmous (EICN)), TWIL: a new generation of small electrical bikes (E. Escallot, T. Bontems (EPMI)), thermal and magnetic analysis of a rectilinear movement actuator (J.C. Vannier, M. Kadiri (SUPELEC)), torque undulation and vibrations in automobile electrical drives (A.L. Bui-Van (Renault), A. Fonseca (LEG)); 3 - collective electric-powered transportation systems: STARS: autonomous transportation system with flywheel charging at the station (P. Gibard (Alstom Transport), K. Abuda, J.M. Vinassa (IXL Bordeaux)), Translhor tramway: presentation of the drive system (L. Verdier, LHOR); 4 - electric-powered and hybrid vehicles: batteries for electric-powered vehicles (J.F. Fauvarque, CNAM), Li-ion batteries and their application in automotive industry (T. Faugeras, SAFT), optimized drive systems for electric-powered vehicles (J. Saint-Michel, Leroy Somer), the Citroen Xsara Dynactive (S. Derou, PSA), 5 - electric-powered and hybrid vehicles: the electrical car in tomorrows' city (M. Parent, INRIA), the market of electric-powered vehicles in France and Europe (M. Valet, PSA). (J.S.)

The application of the ISO 14001 environmental management system to small hydropower plants; L'application de l'ISO 14001 systeme environnemental de gestion aux petites centrales hydro-electriques

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-07-01

The ISO 14000 environmental management standards exist to help organisations minimise how their operations negatively affect the environment and to comply with applicable laws and regulations. More specifically, ISO 14001 is the international specification for an environmental management system (EMS). It specifies requirements for establishing an environmental policy, determining environmental aspects and impacts of products/activities/services, planning environmental objectives and measurable targets, implementation and operation of programs to meet objectives and targets, checking and corrective action, and management review. The overall idea is to establish an organized approach to systematically reduce the impact of the environmental aspects that an organization can control. Tools are available for the analysis of environmental aspects and for the generation of options for improvement. As with ISO 9000 (quality management), certification is performed by third-party organizations. Hydroelectricity enables to generate clean energy with no direct emissions of greenhouse gases and without consuming fossil fuels. However, this activity is implemented within a sensitive natural environment: the watercourses are shared with several users such as the fishermen, the kayakers, farmers and industry. Generating hydroelectricity induces very little discharges into the environment. Conversely, its implementation on the watercourses can alter the flow rates and the ecosystem: leading to disruption in the free passage of fish, change in the hydrodynamics of a watercourse, emission of noise, production of waste, pollution through oil leak, damage inflicted on the landscape, etc. These environmental impacts form the subject of several monitoring and control operations that are designed to limit and preserve the natural environment. Additionally, relations with the water users and the administrations are sometimes difficult and this would require a dialogue to be established to advance appropriate environmental actions. The process includes six stages: (1) Initial environmental review, (2) Environmental policy, (3) Planning, (4) Implementation and Operation, (5) Checking and Correcting action and (6) Management review. Certification process in practice is also divided in four steps: (1) Analysis of the environment, (2) List of the regulatory requirements and Checking of conformity with the environmental laws, (3) Defining the environmental policy and building the environmental management system and finally (4) Test audit. The output of this process is Certification audit. Experience feedbacks and testimonies of ISO 14001 certification of small hydroelectric power stations are presented in the second part of this document: - The hydroelectric power stations of Mas Naffre (Tarn - 81, France), of Nevache (Hautes Alpes - 05, France), of Couscouillets (Villelongue, Hautes- Pyrenees, France) and other examples in the EU (Switzerland and Sweden). Existing alternative environmental standards, like 'Eugene' and 'Greenhydro' Standards are presented as well

Trading in the rain. Rainfall and European power sector emissions. Research note no. 9; Trading in the rain. Precipitations et emissions du secteur electrique europeen. Note d'etude n.9

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-07-01

Analysts often say that temperature and rainfall have an impact on the price of CO{sub 2}, as they influence the conditions of electric power supply and demand. Rainfall mainly affects the capacity of hydropower production, the third largest source of electricity in Europe and by far the leading source of renewable energy. The variability of hydroelectric volumes is indeed usually offset by other, higher-emitting sources of electricity, which has repercussions on the European allowances trading market. In 2005, rainfall was unusually low in several European countries: in the Iberian peninsula and in France, drought is believed to have brought about a rise of approximately 15 Mt CO{sub 2} in power sector emissions. In contrast, hydrological conditions were particularly good in the Nordic countries, allowing them to reduce CO{sub 2} emissions in the region as a whole through hydropower-based exports. The additional allowances demand would therefore have been 'only' about 9 Mt CO{sub 2}. To make the interaction with the CO{sub 2} market easier to understand, an indicator of rainfall in Europe must include this compensating phenomenon resulting from the heterogeneity of the climatic conditions and volumes produced in Europe.

Crystal Dynamics from Neutron Spectrometry; Etude de la dynamique des cristaux par la spectrometrie neutronique; Izuchenie voprosov dinamiki kristallov metodami nejtronnoj spektrometrii; Estudio de la dinamica de redes cristalinas por espectrometria neutronica

Energy Technology Data Exchange (ETDEWEB)

Woods, A. D.B. [Atomic Energy of Canada Ltd., Chalk River, ON (Canada)

1963-01-15

This paper reviews investigations carried out at Chalk River on the lattice dynamics of various crystals including lead, sodium, alkali halides, semi-conductors, and other more complex compounds. Analysis of the low temperature results (-{approx}100{sup o}K) gives considerable insight into the nature of the interatomic forces. In sodium, a simple metal, the interatomic forces are very nearly derivable from a potential. Lead, a more complicated metal, has extremely long range forces accompanied by strong electronic effects. At higher temperatures anharmonic effects are very pronounced in both metals, especially in lead. The alkali halide results can be interpreted on a ''shell'' model, with polarizable ions. Even at low temperature neutron groups corresponding to the longitudinal optical modes. (author) [French] Dans ce memoire, l'auteur decrit les recherches faites a Chalk River sur la dynamique des reseaux de certains cristaux, y compris le plomb, le sodium, les halogenures alcalins, les semi-conducteurs et d'autres composes complexes. L'analyse des resultats obtenus a basse temperature (environ 100{sup o}K) fournit de nombreux renseignements sur la nature des forces interatomiques. Dans le sodium (metal simple), les forces interatomiques peuvent presque etre derivees d'un potentiel. Dans un metal plus complique, tel que le plomb, on trouve des forces ayant une portee extremement grande et comportant des effets electroniques marques. A des temperatures plus elevees, il se produit des effets anharmoniques tres prononces dans les deux metaux et particulierement dans le plomb. On peut interpreter les resultats obtenus pour les halogenures alcalins en se fondant sur le modele en couche comportant des ions polarisables. Meme aux basses temperatures, les groupes de neutrons correspondant aux modes optiques longitudinaux possedent des largeurs dependant de la temperature, que l'on ne comprend pas encore parfaitement. (author) [Spanish] Los autores pasan revista a las

Local-regional networks of persons with abilities in radioprotection and other actors in radioprotection. Audit report; Les reseaux loco-regionaux de personnes competentes en radioprotection et autres acteurs de la radioprotection. Rapport d'audit

Energy Technology Data Exchange (ETDEWEB)

Lefaure, Ch.

2009-03-15

As the regulation requires the existence of persons with abilities in radioprotection (PCR, personnes competentes en radioprotection) in many industrial, medical or research activities where ionizing radiations are present, in order to improve worker protection, these professionals who are much less acknowledged in these sectors than in the nuclear sector, felt the need to gather in regional and sector-based networks. This report proposes a presentation of three existing networks (the APCRAP, the Grand-Ouest network, and the Aquitaine-Sud-Ouest network). For each of them, the report addresses the following aspects: creation, objectives, statutes, members, activities, human, technical and financial resources, role. Then answers to a survey and to interviews are analyzed with respect to the professional sector and to the region, in terms of expectations towards the networks, and in terms of network operation and services. Interviews of institutional actors and union and management representatives are also analysed

The study by means of a photomultiplier of the scintillations produced by {alpha} particles striking a zinc sulphide screen; Etude, au photomultiplicateur, des scintillations produites par les particules {alpha} dans un ecran de sulfure de zinc. Application a la numeration precise des particules {alpha}

Energy Technology Data Exchange (ETDEWEB)

Anthony, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1955-06-15

The object of the study is the accurate counting of {alpha} particles by p-m. detection of their scintillations upon impact with a zinc sulphide screen. The main advantage of the method is the extreme simplicity of the electronics used: the possibility of obtaining a utilizable pulse from the p-m. (EMI5311) without any amplification, and in linear response, is demonstrated. The scintillation produced by an impact on Zn-S has also been studied experimentally. The decrease of light intensity in relation to time may be interpreted by the exponential relation: I = I{sub 0} exp (-t / {tau}) whereby {tau} = (39 {+-} 0,1) 10{sup -6} s. The relation between scintillation intensity and remaining trajectory after travel through a given air-space has also been determined. Possible suitable applications of this method of {alpha} counting are those where good stability and low background are necessary. Results stated bear on air contamination studies, isotopic composition variation measurement of uranium, bismuth content measurement in alloys by irradiation of specimens in a thermal neutron flux and {alpha} count on the Po formed. (author) [French] Ce travail est consacre a l'etude de la numeration precise des particules {alpha} par detection au photomultiplicateur des scintillations produites par ces particules dans un ecran de sulfure de zinc. Le principal avantage de cette methode reside dans l'extreme simplicite de l'appareillage electronique; il est en effet montre qu'il est possible, tout en convoyant une reponse lineaire, d'obtenir du photomultiplicateur (EMI5311) un signal electrique utilisable sans aucune amplification. La scintillation produite par l'impact des particules {alpha} sur un ecran de Zn-S est etudiee experimentalement. La decroissance de l'intensite lumineuse en fonction du temps est interpretable par la relation exponentielle I = I{sub 0} exp (-t / {tau}) avec {tau} = (39 {+-} 0,1) 10{sup -6} s. La relation entre l'intensite de la scintillation et le

The Radiation Induced Graft Copolymerization of Methacrylic Acid to Nylon; Copolymerisation par greffe de l'acide methacrylique sur le nylon, provoquee par irradiation; Obluchenie vyzyvaet graft-kopolimerizats yu metakrilovoj kisloty v nejlone; Injerto del acido metacrilico en el nylon por copolimerizacion radioinducida

Energy Technology Data Exchange (ETDEWEB)

Roberts, R; Thomas, J K

1960-07-15

The grafting of methacrylic acid to nylon by the preirradiation technique has been studied. The rate of grafting is appreciably larger than that of homopolymerization. No simple relation exists between reaction rate and total dose. The temperature dependence of the rate of grafting to the fibre, preirradiated in air, indicates that initiation of grafting is likely to take place by decomposition of peroxide groups formed on irradiation. Electrical resistance measurements on the irradiated fibre indicate that this has been reduced by a factor of 10. (author) [French] On a etudie le greffage de l'acide methacrylique sur du nylon par la technique de preirradiation. La vitesse du greffage est sensiblement plus grande que celle de l'homopolymerisation. Il n'existe pas de rapport simple entre la vitesse de reaction et la dose totale. Le fait que la vitesse du greffage sur la fibre, pre-irradiee a l'air, depend de la temperature, indique que l'amorcage de la greffe est susceptible d'etre provoque par la decomposition des groupements de peroxyde formes lors de l'irradiation. Les mesures de resistance electrique effectuees sur la fibre irradiee indiquent que cette resistance a ete reduite au dixieme de la valeur originale. (author) [Spanish] Al estudiar la copolimerizacio n de injerto del acido metacrilico en el nylon por el procedimiento de preirradiacion, los autores comprobaron que la velocidad de injerto es sensiblemente mas elevada que la de homopolimerizacion. No existe una relacion sencilla entre la velocidad de reaccion y la dosis total. La influencia de la temperatura sobre la velocidad de injerto en la fibra previamente irradiada en aire indica que el proceso se inicia por descomposicion de los grupos peroxido formados durante la irradiacion. Las mediciones efectuadas demuestran que la resistencia electrica de la fibra irradiada solo alcanza la decima parte de la correspondiente a la fibra no tratada. (author) [Russian] Bylo provedeno izuchenie prosachivaniya

Contribution to the analysis of light elements using x fluorescence excited by radio-elements; Contribution a l'analyse des elements legers par fluorescence x excitee au moyen de radioelements

Energy Technology Data Exchange (ETDEWEB)

Robert, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

In order to study the possibilities of using radioactive sources for the X-fluorescence analysis of light elements, the principle is given, after a brief description of X-fluorescence, of the excitation of this phenomenon by X, {beta} and {alpha} emission from radio-elements. The operation and use of the proportional gas counter for X-ray detection is described. A device has been studied for analysing the elements of the 2. and 3. periods of the Mendeleev table. It makes it possible to excite the fluorescence with a radioactive source emitting X-rays or a particles; the X-ray fluorescence penetrates into a window-less proportional counter, this being made possible by the use of an auxiliary electric field in the neighbourhood of the sample. The gas detection pressure leading to the maximum detection yield is given. The spectra are given for the K{sub {alpha}} lines of 3. period elements excited by {sup 55}Fe, {sup 3}H/Zr and {sup 210}Po sources; for the 2. period the K{sub {alpha}} spectra of carbon and of fluorine excited by the {alpha} particles of {sup 210}Po. (author) [French] Afin d'etudier les possibilites d'emploi de sources radioactives a l'analyse par fluorescence X des elements legers, on presente apres rappel de notions generales sur la fluorescence X, le principe de l'excitation de ce phenomene par emission X, {beta}, {alpha} de radioelements. Le fonctionnement et l'utilisation du compteur proportionnel a gaz a la detection du rayonnement X est developpe. Un dispositif permettant l'analyse des elements des 2eme et 3eme periodes de la classification de Mendeleev est etudie. Il permet l'excitation de la fluorescence par source radioactive emettrice de rayons X ou de particules {alpha}; le rayonnement X de fluorescence penetre dans un compteur proportionnel depourvu de fenetre, ceci est rendu possible en creant un champ electrique auxiliaire au voisinage de l'echantillon. On definit une pression du gaz de detection pour un rendement de detection maximal

Economic aspects of electricity and industrial heat generating reactors; Aspect economique des reacteurs produisant de l'electricite et de la chaleur industrielle

Energy Technology Data Exchange (ETDEWEB)

Gaussens, J; Moulle, N; Dutheil, F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Aldebert, J [Institut National des Sciences et Techniques Nucleaires (INSTN), CEA Saclay, 91 - Gif sur Yvette (France)

1964-07-01

The economic advantage of electricity-generating nuclear stations decreases when their size decreases. However, when a counter-pressure turbine is joined on to a reactor and the residual heat can be properly used, it can be shown that fairly low capacity nuclear equipment may compete with conventional equipment under certain realistic enough conditions. The aim of this paper is to define these special conditions under which nuclear energy can be profitable. They are connected with the location and the general economic environment of the station, the pattern of the electricity and heat demands it must meet, the level of fuel and specific capital costs, nuclear and conventional. These conditions entail certain technical and economic specifications for the reactors used in this way otherwise they are unlikely to be competitive. In addition, these results are referred to the potential steam and electricity market, which leads us to examine certain uses for the heat generated by double purpose power stations; for example, to supply combined industrial plants, various types of town heating and for removal of salt from sea water. (authors) [French] L'interet economique de centrales nucleaires productrices d'electricite decroit lorsque la puissance decroit. Cependant, lorsqu'on associe une turbine a contrepression a un reacteur et qu'il est possible d'utiliser dans de bonnes conditions la chaleur residuelle, on peut montrer que dans certaines conditions assez realistes, des equipements nucleaires d'une puissance unitaire peu elevee peuvent etre competitifs avec des equipements conventionnels. Cette communication a donc pour but de mettre en evidence quelles sont ces conditions particulieres de rentabilite de l'energie nucleaire. Elles sont liees a la localisation de la centrale et a son contexte economique general, a la structure de la demande d'energie electrique et thermique a laquelle elle doit satisfaire, au niveau des couts des combustibles et des investissements

Contribution to the analysis of light elements using x fluorescence excited by radio-elements; Contribution a l'analyse des elements legers par fluorescence x excitee au moyen de radioelements

Energy Technology Data Exchange (ETDEWEB)

Robert, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

In order to study the possibilities of using radioactive sources for the X-fluorescence analysis of light elements, the principle is given, after a brief description of X-fluorescence, of the excitation of this phenomenon by X, {beta} and {alpha} emission from radio-elements. The operation and use of the proportional gas counter for X-ray detection is described. A device has been studied for analysing the elements of the 2. and 3. periods of the Mendeleev table. It makes it possible to excite the fluorescence with a radioactive source emitting X-rays or a particles; the X-ray fluorescence penetrates into a window-less proportional counter, this being made possible by the use of an auxiliary electric field in the neighbourhood of the sample. The gas detection pressure leading to the maximum detection yield is given. The spectra are given for the K{sub {alpha}} lines of 3. period elements excited by {sup 55}Fe, {sup 3}H/Zr and {sup 210}Po sources; for the 2. period the K{sub {alpha}} spectra of carbon and of fluorine excited by the {alpha} particles of {sup 210}Po. (author) [French] Afin d'etudier les possibilites d'emploi de sources radioactives a l'analyse par fluorescence X des elements legers, on presente apres rappel de notions generales sur la fluorescence X, le principe de l'excitation de ce phenomene par emission X, {beta}, {alpha} de radioelements. Le fonctionnement et l'utilisation du compteur proportionnel a gaz a la detection du rayonnement X est developpe. Un dispositif permettant l'analyse des elements des 2eme et 3eme periodes de la classification de Mendeleev est etudie. Il permet l'excitation de la fluorescence par source radioactive emettrice de rayons X ou de particules {alpha}; le rayonnement X de fluorescence penetre dans un compteur proportionnel depourvu de fenetre, ceci est rendu possible en creant un champ electrique auxiliaire au voisinage de l'echantillon. On definit une pression du gaz de detection

Economic aspects of electricity and industrial heat generating reactors; Aspect economique des reacteurs produisant de l'electricite et de la chaleur industrielle

Energy Technology Data Exchange (ETDEWEB)

Gaussens, J.; Moulle, N.; Dutheil, F. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Aldebert, J. [Institut National des Sciences et Techniques Nucleaires (INSTN), CEA Saclay, 91 - Gif sur Yvette (France)

1964-07-01

The economic advantage of electricity-generating nuclear stations decreases when their size decreases. However, when a counter-pressure turbine is joined on to a reactor and the residual heat can be properly used, it can be shown that fairly low capacity nuclear equipment may compete with conventional equipment under certain realistic enough conditions. The aim of this paper is to define these special conditions under which nuclear energy can be profitable. They are connected with the location and the general economic environment of the station, the pattern of the electricity and heat demands it must meet, the level of fuel and specific capital costs, nuclear and conventional. These conditions entail certain technical and economic specifications for the reactors used in this way otherwise they are unlikely to be competitive. In addition, these results are referred to the potential steam and electricity market, which leads us to examine certain uses for the heat generated by double purpose power stations; for example, to supply combined industrial plants, various types of town heating and for removal of salt from sea water. (authors) [French] L'interet economique de centrales nucleaires productrices d'electricite decroit lorsque la puissance decroit. Cependant, lorsqu'on associe une turbine a contrepression a un reacteur et qu'il est possible d'utiliser dans de bonnes conditions la chaleur residuelle, on peut montrer que dans certaines conditions assez realistes, des equipements nucleaires d'une puissance unitaire peu elevee peuvent etre competitifs avec des equipements conventionnels. Cette communication a donc pour but de mettre en evidence quelles sont ces conditions particulieres de rentabilite de l'energie nucleaire. Elles sont liees a la localisation de la centrale et a son contexte economique general, a la structure de la demande d'energie electrique et thermique a laquelle elle doit satisfaire, au niveau des couts des

Bilateral comparison of 1 V and 10 V standards between the DEFNAT (Tunisia) and the BIPM February to March 2016 (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)

Science.gov (United States)

Solve, S.; Chayramy, R.; Ben Salah, B.; Mallat, A.; Abene, L.; Stock, M.

2016-01-01

As part of the ongoing BIPM key comparison BIPM.EM-K11.a and b, a comparison of the 1 V and 10 V voltage reference standards of the BIPM and the Laboratoire de Métrologie Electrique, DEFNAT (Tunisia), was carried out from February to March 2016. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPMC (ZC) and BIPM6 (Z6), were transported by freight to DEFNAT and back to BIPM. In order to keep the Zeners powered during their transportation phase, a BIPM in-house voltage stabiliser was connected in parallel to the internal battery. The voltage stabiliser consists of a set of two batteries, electrically protected from surcharge-discharge, easy to recharge and is designed to power two transfer standards for 10 consecutive days. At DEFNAT, the reference standard for DC voltage is a Josephson Voltage Standard. The output EMF (Electromotive Force) of each travelling standard was measured by direct comparison with the primary standard. At the BIPM, the travelling standards were calibrated, before and after the measurements at DEFNAT, with the Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages of the Zener standards on internal temperature and ambient atmospheric pressure. The final result of the comparison is presented as the difference between the values assigned to DC voltage standards by DEFNAT, at the level of 1.018 V and 10 V, at DEFNAT, UDEFNAT, and those assigned by the BIPM, at the BIPM, UBIPM, at the reference date of the 26th of February 2016. UDEFNAT - UBIPM = + 0.07 μV uc = 0.04 μV, at 1.018 V UDEFNAT - UBIPM = + 0.38 μV uc = 0.10 μV, at 10 V where uc is the combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at NSAI-NML, based on KJ-90, and the uncertainty related to the comparison. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which

Forced convection of ammonia. 2. part.: gaseous ammonia - very high wall temperatures (1000 to 3000 K); Convection forcee de l'ammoniac. 2. partie: ammoniac gazeux - cas de tres hautes temperatures de paroi (1000 a 3000{sup 0} K)

Energy Technology Data Exchange (ETDEWEB)

Perroud, P; Rebiere, J; Strittmatter, R [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1969-07-01

Heat transfer coefficients and pressure drop of gaseous ammonia in forced convection are experimentally determined. The fluid flows (mass flow rate 0.6 to 2.4 g/s) in a long tungsten tube (d{sub i} = 2.8 mm, d{sub e} = 5.1 mm, L = 700 mm) electrically heated. The temperature of the wall reaches 3000 deg. K and the fluid 2500 deg. K; maximum heat flux 530 w/cm{sup 2}. Ammonia is completely dissociated and the power necessary for dissociation reaches 30 per cent of the total power exchanged. Inlet pressure varies between 6 and 16 bars and the maximum pressure drop in the tube reaches 15 bars. Two regimes of dissociation have been shown: catalytic and homogeneous and the variation of dissociation along the length of the tube is studied. The measured heat transfer coefficients may be about 10 times these calculated by the means of classical formulae. A correlation of experimental results using enthalpy as a driving force for heat transmission is presented. Pressure drops may be calculated by the means of a classical friction factor. (authors) [French] On determine experimentalement les coefficients d'echange thermique et les pertes de charge de l'ammoniac gazeux en convection forcee. Le fluide circule avec un debit en masse compris entre 0.6 et 2.4 g/s (G = 10 a 40 g/cm{sup 2}.s) dans un tube long en tungstene (d{sub i} = 2.8 mm, d{sub e} = 5.1 mm, L = 700 mm), chauffe electriquement. La temperature de paroi atteint 3000 deg. K, celle du fluide 2500 deg. K et le flux de chaleur maximal est de 530 W/cm{sup 2}. L'ammoniac se dissocie completement, la puissance correspondant a la dissociation atteint 30 pour cent de la puissance totale echangee. La pression d'entree varie entre 6 et 16 bars et la chute de pression maximale dans le canal est de 15 bars. On distingue deux regimes de dissociation, catalytique et homogene, et on etudie la variation du taux de dissociation en fonction de la longueur du tube. Les coefficients d'echange thermique mesures peuvent etre environ 10

Massive deployment of electrical vehicles on the horizon 2020: an evaluation of the charging facilities; Deploiement massif des vehicules electriques a l'horizon 2020. Evaluation des infrastructures de recharge necessaires

Energy Technology Data Exchange (ETDEWEB)

Mean, P.; Gerbex, S. [Alpiq, Lausanne (Switzerland); Studer, Ch. [Alpiq Netz AG, Niedergoesgen (Switzerland)

2010-07-01

If 15% of the Swiss cars (i.e. 720,000 units) would be replaced by electrical vehicles, yearly CO{sub 2} emissions would decrease by about 1.2 million tons. This figure must be compared with the international commitment of Switzerland concerning its reduction of the global greenhouse gas emissions by 20%, i.e. 10.5 million tons of CO{sub 2} equivalent a year. These 720,000 electrical vehicles would increase the electric demand by 1.2 to 1.7 TWh a year, i.e. only 1.8 to 2.6 % of the Swiss power generation (66 TWh a year). Simultaneously charging 50% of these electric vehicles would also demand an output power of about 1.3 GW. In a Vision 2020 study entitled 'Electric vehicle market penetration in Switzerland by 2020 (Lausanne and Olten, July 2009)' the Swiss electric utility Alpiq evaluated the impact of such a measure on production and distribution of electric power. Following assumptions were made: 4/5 of the electrical cars would be Plug-in Hybrid Vehicles and 1/5 Battery Electric Vehicles; each car would run 37 km a day on average, or 13,500 km a year; and the mean electric consumption would be 20 kWh for a guaranteed range of 120 km, with one charging at least each third day, mainly slowly in the night ('Sleep and Charge' with a domestic low input power of 3.5 kW for 8 hours), but also quickly ('Coffee and Charge' with a particularly high input power of 55 kW), and with possible intermediate accelerated charging modes ('Work/Shop and Charge' with a mean input power of 7 to 12 kW). Eventually, the number, type and location of the charging facilities needed were estimated on the basis of a characterization of electrical vehicles owners. On the basis of an electric fleet of 720,000 cars, it is concluded that about 650,000 domestic slow charging points, 80,000 private accelerated charging points at working places, 23,000 public accelerated charging points in cities, and 150 quick charging points with each 6 sockets located in ordinary petrol (gas) service stations would be needed

Vaye-Planaz drinking-water hydro-power installation; Petite centrale hydro-electrique de Vaye-Planaz sur le reseau d'eau potable de la commune de Grone. Etude de faisabilite. Rapport final

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-02-15

This final report for the Swiss Federal Office of Energy (SFOE) presents the concept for a hydro-power installation that uses an existing drinking-water supply system. The report takes a look at the present situation which features ground-water sources, a transport pipeline and two reservoirs. The concept for the use of the available water pressure due to height-difference to drive a turbine and so generate electricity is described. Variants considered are reviewed. Investment and operating costs are examined as are the electricity production and the cost of the power generated. Finally, investments and other financial aspects are looked at and the further course of action is discussed.

Trading in the rain. Rainfall and European power sector emissions. Research note no. 9; Trading in the rain. Precipitations et emissions du secteur electrique europeen. Note d'etude n.9

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-07-01

Analysts often say that temperature and rainfall have an impact on the price of CO{sub 2}, as they influence the conditions of electric power supply and demand. Rainfall mainly affects the capacity of hydropower production, the third largest source of electricity in Europe and by far the leading source of renewable energy. The variability of hydroelectric volumes is indeed usually offset by other, higher-emitting sources of electricity, which has repercussions on the European allowances trading market. In 2005, rainfall was unusually low in several European countries: in the Iberian peninsula and in France, drought is believed to have brought about a rise of approximately 15 Mt CO{sub 2} in power sector emissions. In contrast, hydrological conditions were particularly good in the Nordic countries, allowing them to reduce CO{sub 2} emissions in the region as a whole through hydropower-based exports. The additional allowances demand would therefore have been 'only' about 9 Mt CO{sub 2}. To make the interaction with the CO{sub 2} market easier to understand, an indicator of rainfall in Europe must include this compensating phenomenon resulting from the heterogeneity of the climatic conditions and volumes produced in Europe.

Transportation network development in a liberalized power system, a coordination problem with production; Le developpement du reseau de transport dans un systeme electrique liberalise, un probleme de coordination avec la production

Energy Technology Data Exchange (ETDEWEB)

Rious, V

2007-10-15

This thesis analyses how the long term coordination between generation and transmission is organised in a liberalized power system. It relies on a modular analysis framework that allows us to separate the coordination mechanisms into distinct modules. The governance structure of the power network completes this analysis framework. In a rationale of institutional complementarity, this governance structure impacts the way the TSOs effectively implement the power flow management. The proactive behaviour of the TSO for the coordination of generation and transmission can be explained in two ways. Firstly, the network investment can be the only effective process of long term coordination between generation and transmission. Secondly, when forecasting network investment, the TSO can prepare the accommodation of the fast-built generation units and detect the potential failures of locational incentive signals. (author)

Feasibility study for the retrofitting a small hydroelectric power station at the mill of Noiraigue, Switzerland; Projet de rehabilitation d'une centrale hydro-electrique au moulin de Noiraigue. Etude de faisabilite

Energy Technology Data Exchange (ETDEWEB)

Choulot, A; Chenal, R; Denis, V [MHyLab, Montcherand (Switzerland); Chuat, O [RWB SA, Cernier (Switzerland)

2006-07-01

For the time being, the old mill on the left bank of the river Noiraigue, Switzerland is equipped with a small turbine of only a few kW. The present study investigates the technical and economical possibilities for maximizing the electric power production at the site. Two variants were studied: variant A retains the existing construction at the site and comprises a single turbine with a maximum electric power output of 70 kW. The annual energy production would be 348'300 kWh and the production cost 0.13 CHF/kWh. Variant B includes important modifications in the construction - especially the dam and the channels. Two turbines with a total maximum power output of 118 kW are foreseen. The annual energy production would be 448'500 kWh and the production cost 0.15 CHF/kWh. Due to these findings, variant A is preferred and proposed for realization.

Control of the electrical operating point of an electric discharge by mean of its power supply; Controle du point de fonctionnement des decharges electriques par l'intermediaire de leur alimentation

Energy Technology Data Exchange (ETDEWEB)

Salanne, J.Ph.

2005-11-15

The operating points obtained by the coupling of the power supply with the electric discharge system can be unstable because of the dynamical behaviour of the discharge or because of a change in its length. In this work, the different possible couplings existing between the discharge and the characteristics of its power supply are analyzed in order to optimize the design and control of the power supply and to control the operating point. Analytical and numerical modeling of the system are proposed which allow to simulate the couplings between the power supply and the discharge. This approach is completed by experimental investigations allowing to consider the cases of peak/peak discharges, dielectric barrier discharges (DBD), and gliding arcs. (J.S.)

Study of hydrogenated amorphous silicon devices under intense electric field: application to nuclear detection; Etude de dispositifs electroniques en silicium amorphe hydrogene sous fort champ electrique: application a la detection nucleaire

Energy Technology Data Exchange (ETDEWEB)

Ilie, A. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Direction des Technologies Avancees]|[Paris-11 Univ., 91 - Orsay (France)

1996-12-31

The goal of this work was the study, development and optimization of hydrogenated amorphous silicon (a-Si:H) devices for use in detection of ionizing radiation. Thick p-i-n devices, capable of withstanding large electric fields (up to 10{sup 6} V/cm) with small currents (nA/cm{sup 2}), were developed. To decrease fabrication time, films were made using the `He diluted` PECVD process and compared to standard a-Si:H films. Aspects connected to specific detector applications as well as to the fundamental physics of a-Si:H were considered: the internal electric field technique, in which the depletion charge was measured as a function of the applied bias voltage; study of the leakage current of p-i-n devices permitted us to demonstrate different regimes: depletion, field-enhanced thermal generation and electronic injection across the p layer. The effect of the electric field on the thermal generation of the carriers was studied considering the Poole-Frenkel and tunneling mechanisms. A model was developed taking under consideration the statistics of the correlated states and electron-phonon coupling. The results suggest that mechanisms not included in the `standard model` of a Si:h need to be considered, such as defect relaxation, a filed-dependent mobility edge etc...; a new metastable phenomenon, induced by prolonged exposure to a strong electric field, was observed and studied. It is characterized by marked decrease of the leakage current and the detector noise, and increase in the breakdown voltage, as well as an improvement of carrier collection efficiency. This forming process appears to be principally due to an activation of the dopants in the p layer; finally, the capacity of thick p-i-n a Si:H devices to detect ionizing radiation has been evaluated. We show that it is possible, with 20-50 micron thick p-i-n devices, to detect the full spectrum of alpha and beta particles. With an appropriate converter, neutron detection then becomes possible. (author). 137 refs.

Control strategy minimizing the converter-alternating current motor losses: application to electric traction; Strategies de commande minimisant les pertes d'un ensemble convertisseur - machine alternative: application a la traction electrique

Energy Technology Data Exchange (ETDEWEB)

Bastiani, Ph.

2001-02-01

Improving the efficiency of the converter-alternating current motor system is a major task in electric traction. Global energy optimisation implies a specific approach at system scale. To reach this goal, we have chosen an algebraic method using sub-system models. To start with, a synchronous machine Park model is developed to take account magnetic saturation and iron losses. Then, an averaged model of the voltage inverter is used in order to obtain a simplified model of the losses to be implemented in our optimisation method. This is how the global model is built including losses in the synchronous machine along with the losses of the power converter. Experimental results are there to validate our approach. This study proposes a method based on algebraic formulation of the general laws to control torque. Algorithms take into account magnetic circuits saturation and power losses in both the machine and its converter. Here again, experimental results validate the algorithm on several test benches. Achieved efficiency improvement is important compared to existing usual control strategies. The proposed method can be generalised to other machine-converter systems. As a matter of fact we have extended our study to the induction machine. As a complement ti this study we have looked at the effects natural limitations of voltages and currents in the torque-speed plane. Therefore algebraic formulation of the torque-speed plane and optimisation strategies are proposed including those constraints. (author)

On tariffs of the transport and electricity distribution network. Stage report of the economic analysis group; Groupe d'expertise economique sur la tarification des reseaux de transport et de distribution de l'electricite. Rapport d'etape

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-08-17

This report contains an Introduction, seven Sections, Conclusions and Summary of Recommendations, a Glossary and three Appendices. In the Introduction the work of the group is presented, the question of the access to the network is outlined and the approach adopted by the group is explained. The Section 1 is titled 'The electricity market and the questions raised by the access to network. The following issues are exposed: - Institutional and regulation context; - Transposition of the directive 96/92/CE within member states; - The effects of offer expected by France; - Expected effects for electricity consumers; - Abroad experience in organizing the access; - The role of the Electricity Regulation Commission and the objectives of tariffing and rules of access to transport network. The second section presents the characteristics of the Management of Distribution Network (GRT) and identification of the costs. The following items are treated: - Definition and description of the transport network; - Network development; - European interconnections; - Technical constraint; - Organization of GRT; - Calculation of transport; - Remuneration of capital; - Distribution, the transport's end-of-the-road; - Costs to recover: definition, problems of measurement and verification; - Transitory tariffs. The third section is titled 'Introduction to an economic approach' and it presents the nodal tariffing and an outlook of practical solutions. The forth section tackles with the main options in tariffing. Six issues are exposed: - The main choices to do; - Choosing between postal stamp and distant tariffing; - Sharing between producer and consumers; - Economic relevance of the postal stamp type formulas; - Sharing between energy and power; - A proposal of tariff structure. The Section 5 is devoted to tariffs for international transports. The following issues are exposed: - Specific questions posed by transfrontier contracts; - European Union frame; - Connection with the tariffs of domestic contracts; - Proposals for tariffing the international transports. The sixth section presents the efficiency of the short and medium term access. The following issues are tackled: - Regulation of access and transmission; - Short term treating of the bottlenecks; - De-congestion investments; - Tariffs for lead-in and reinforcement operations; - the case of proximity production, direct lines and self-production. Finally, the last section titled 'Inciting the GRT internal efficiency and tariffing evolution, displays the subject matters: - The GRT behaviour guide; - Evolution of tariffing; - Benchmarking possibilities. In the concluding section the basic ideas of the report i.e., improving the market functioning, developing the network management and inciting the grow in the internal efficiency of GRT are elaborated and entailing recommendations are set down.

Information manual for the experimentation of the deployment of optical fibers on public power distribution networks; Notice d'information pour l'experimentation du deploiement de fibres optiques sur les reseaux publics d'electricite

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

During the French inter-ministry committee for the national development (CIADT) of July 9, 2001, the government decided to launch a feasibility study about the deployment of telecommunication optical fibers over the whole territory using the electricity transportation grid. The aim is to give access to high-speed Internet to everyone and at a reasonable cost. This manual summarizes the technical, legal and economical results of the study carried out by the working group: 1 - the actors in concern (managers of power transportation and distribution networks, country authorities, managers and users of telecommunication infrastructures, regulatory agencies, financial organizations); 2 - the telecommunication networks on power lines; 3 - the feasibility of the experimentation (relations between the different partners, conditions); 4 - the implementation of the experimentation (useful contacts, contracts); 5 - the experimentation areas. Appendixes. (J.S.)

Proceedings of the Prop'Elec 2000 colloquium. Advances of electric drive in urban transportation systems; Actes du colloque Prop'Elec 2000. Progres de la traction electrique dans les transports urbains

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

This document is the proceedings of Prop'Elec 2000 colloquium on the advances in electric power drive in urban transportation systems. The colloquium comprises 5 sessions dealing with: 1 - public collective electric-powered transportation system: synthesis of urban guided systems (C. Soulas, INRETS), the fast travelator (A. Cote, RATP), the power supply system of METEOR automatic underground railway (P. Lagrange, W. Seiler, RATP); 2 - electrical drive in urban transportation systems: start-up of a thermal engine with super-capacitors (D. Bouquain (CREEBEL), H. Gualous, A. Djerdir, A. Berthon, J.M. Kauffmann (L2ES, IGE)), The LEV (light weight electric vehicle) project in Mendrisio (U. Schwegler, LEV/Suisse), prototype of electrical bike that use a wheel-engine (C. Espanet, F. Gustin, J.M. Kauffmann (IGE), S. Robert, M. Karmous (EICN)), TWIL: a new generation of small electrical bikes (E. Escallot, T. Bontems (EPMI)), thermal and magnetic analysis of a rectilinear movement actuator (J.C. Vannier, M. Kadiri (SUPELEC)), torque undulation and vibrations in automobile electrical drives (A.L. Bui-Van (Renault), A. Fonseca (LEG)); 3 - collective electric-powered transportation systems: STARS: autonomous transportation system with flywheel charging at the station (P. Gibard (Alstom Transport), K. Abuda, J.M. Vinassa (IXL Bordeaux)), Translhor tramway: presentation of the drive system (L. Verdier, LHOR); 4 - electric-powered and hybrid vehicles: batteries for electric-powered vehicles (J.F. Fauvarque, CNAM), Li-ion batteries and their application in automotive industry (T. Faugeras, SAFT), optimized drive systems for electric-powered vehicles (J. Saint-Michel, Leroy Somer), the Citroen Xsara Dynactive (S. Derou, PSA), 5 - electric-powered and hybrid vehicles: the electrical car in tomorrows' city (M. Parent, INRIA), the market of electric-powered vehicles in France and Europe (M. Valet, PSA). (J.S.)

RHP{sup 2} project : development and implementation of a heat management system for electric vehicles; Projet RHP{sup 2} : developpement et implantation d'un systeme de gestion thermique pour vehicule electrique

Energy Technology Data Exchange (ETDEWEB)

Bilodeau, S. [Groupe Enerstat, Sherbrooke, PQ (Canada)

2002-02-01

A project for the development and the implementation of a climate control system for electric vehicles, called the RHP{sup 2} adapted to cold climates was undertaken by the Groupe Enerstat. It offers an emission-free solution which combines the utilization of a heat pump with heat storage as the central component. Integrating various innovative technologies such as the compact air exchanger, phase transformation heat storage and a passive regenerator allows for the heat management of the electric vehicle as a whole. The project progressed from laboratory tests to the implementation of the system in a postal delivery vehicle to pilot vehicle tests in a climatic chamber. It was revealed that the performance of the system is less dependent on climatic conditions. The RHP{sup 2} system can perform under temperatures reaching minus 25 Celsius without any significant performance decrease, contrary to conventional air-to-air heat pumps. The whole heating and cooling load requirements of the vehicle were met. Continuous air renewal is allowed through energy regeneration, ensuring maximum air quality and efficient defrosting capabilities of the windows without resulting in a significant energy loss. The performance coefficient exceeded 3.0 at temperatures of minus 20 Celsius, as revealed by the results obtained. Comfort level, air renewal and minimum defrosting can be maintained without having to use fossil energy. The optimization of some components still requires some work, such as start-up power and the weight of the system. Some possible solutions are being investigated to meet these objectives. 25 refs., 4 tabs., 20 figs.

Feasibility study for the retrofitting a small hydroelectric power station at the mill of Noiraigue, Switzerland; Projet de rehabilitation d'une centrale hydro-electrique au moulin de Noiraigue. Etude de faisabilite

Energy Technology Data Exchange (ETDEWEB)

Choulot, A.; Chenal, R.; Denis, V. [MHyLab, Montcherand (Switzerland); Chuat, O. [RWB SA, Cernier (Switzerland)

2006-07-01

For the time being, the old mill on the left bank of the river Noiraigue, Switzerland is equipped with a small turbine of only a few kW. The present study investigates the technical and economical possibilities for maximizing the electric power production at the site. Two variants were studied: variant A retains the existing construction at the site and comprises a single turbine with a maximum electric power output of 70 kW. The annual energy production would be 348'300 kWh and the production cost 0.13 CHF/kWh. Variant B includes important modifications in the construction - especially the dam and the channels. Two turbines with a total maximum power output of 118 kW are foreseen. The annual energy production would be 448'500 kWh and the production cost 0.15 CHF/kWh. Due to these findings, variant A is preferred and proposed for realization.

Ozone production by pulsed dielectric barrier discharges in air at atmospheric pressure; Efficacite de production d'ozone par decharge electrique pulsee sur barriere isolante dans l'air a pression atmospherique

Energy Technology Data Exchange (ETDEWEB)

Odic, E.; Karimi, Ch. [Supelec, Service Electrotechnique et Electronique Industrielle, 91 - Gif-sur-Yvette (France); Dhainaut, M.; Goldman, A.; Goldman, M. [Supelec, Laboratoire de Physique des Gaz et des Plasmas (Univ. Paris-Sud/CNRS), Equipe Decharges Electriques et Environnement, 91 - Gif sur Yvette (France)

2005-02-01

Non-thermal plasmas have been extensively studied these past 20 years from a theoretical point of view, but also for practical applications. Atmospheric pressure electrical discharges appear as promising technologies for gas phase and aqueous phase pollution control applications. In such arrangements, arcing i.e. transition to thermal plasma, is classically prevented either by application of short high voltage pulses or by insulating one or both electrodes with a dielectric material. The aim of this paper is to report recent results on ozone formation indicating a significant increase of the energy yields by coupling these two techniques. The chemical behaviour of the discharge is correlated to its electrical characteristics. The physical role plaid by the dielectric surface is highlighted and an interpretation is proposed. (authors)

National measures fostering alternative vehicles: electric, natural gas, liquefied oil gas vehicles; Dispositions nationales en faveur des vehicules alternatifs: vehicules electriques, au gaz naturel (GNv) et au gaz de petrole liquefie (GPLc)

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-02-07

This document, issued by the French Ministry of Economy, Finances and Industry, presents national measures fostering alternative vehicles, i.e., electric, natural gas and liquefied oil gas vehicles. Financial supports for studies aiming at optimizing the fleet and choosing the alternative vehicles as well as for purchasing vehicles both by counter procedure and for demonstration programmes are provided. Amount of subsidies, conditions of obtaining and categories of addressees are indicated. The document contains also two relating studies. The first one is titled 'the policy of developing alternative vehicles'. The following four items are addressed: - the present frame favouring the alternative vehicles; - the electric vehicles; - natural gas fuelled vehicles (GNV); - liquefied oil gas fuelled vehicles (GPLc). Although non-polluting the electric vehicles are not tempting because of their rather limited range (80 Km at a battery charging). So far only around 3,000 vehicles were sold. Fifty GNV buses were ordered by RATP and the figure raised at 70 in 1998 and 1999. The GPLc fleet amounts up to 70,000 vehicles and by the end of 2000 it is foreseen to reach the level of 300,000 vehicles. The second study addresses to the issue of natural gas for vehicles. It presents: - its advantages; - its peculiarities; - the action of public authorities; -the current state and trends of GNV vehicles. In a joint effort public authorities and partners of this option are aiming at a fleet of 2500 light service vehicles and 300 bus for urban transport by the end of 1999.

Report of the experts group on the taxation of the access to gas transport and distribution network; Rapport du groupe d'experts sur la tarification de l'acces aux reseaux de transport et de distribution de gaz

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-04-01

In the framework of a new french gas industry organization (directive of the 22 june 1998), a concerting mission has been realized on prices taxation for the transport and distribution facilities. The following topics have been debated: the integration and competition of the european gas market, the gas market liberalization consistency and the taxation of transport and distribution network access. (A.L.B.)

Intelligent networks: evolution or revolution? Source of energy efficiency or economical optimisation? For who's benefit?; Reseaux intelligents: evolution ou revolution? Source d'efficacite energetique et/ou d'optimisation economique? Au benefice de qui?

Energy Technology Data Exchange (ETDEWEB)

Fontaine, Christian

2010-09-15

The electricity sector has experienced a slow evolution. Renewable production developments and telecommunications and computers usage will bring major changes with hard to predict effects. Computerized management of production and local storage combined to a certain mastering of the allowed consumption by home automation could improve reliability and the final price for consumers. This change offers great opportunities but also risks of failures, both financial and technical. The regulators have a major role to play in order to understand the concrete gains of the technological propositions and to regulate the investment costs involved. [French] Le secteur de l'electricite a connu une evolution lente. Le developpements des productions renouvelables, l'utilisation des telecommunications et de l'informatique provoquera un bouleversement majeur dont il est difficile de prevoir l'ampleur. La gestion automatisee des productions et stockages locaux combinee a une certaine maitrise de la consommation permise par la domotique pourrait ameliorer la fiabilite et le prix final pour les consommateurs. Ce changement presente de grandes opportunites mais aussi des risques d'echecs, tant financiers que techniques. Les regulateurs ont un role majeur a jouer pour comprendre les gains concrets des propositions technologiques et reguler les couts d'investissement qu'elles impliquent.

Assessment of the bioavailability and the transfer of organic and metallic pollutants in 'soil - plant - invertebrate' food webs; Evaluation de la biodisponibilite et des transferts de polluants metalliques et organiques dans les reseaux trophiques ''sols-plantes-invertebres''

Energy Technology Data Exchange (ETDEWEB)

Scheifler, R

2002-06-15

Pollution of ecosystems by metallic trace elements (MTEs) and organic compounds may lead to pollutant transfer in food webs. The aim of this work was to improve the assessment of bioavailability, transfer and effects of various MTEs (mainly cadmium (Cd) but also copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn)) and an organic pollutant, the herbicide Isoproturon. The food webs studied in this work were made up of 2 or 3 compartments among the following: soil - primary producer (lettuce Lactuca sativa, colza Brassica napus and maize Zea mays) - primary consumer (snail Helix aspersa) - secondary consumer (carabid beetle Chrysocarabus splendens). Three complementary approaches using food webs of increasing complexity were exploited. The first approach allowed studying pollutant bioavailability and transfers between 2 links of a food chain under controlled conditions. The isotopic dilution technique, until now only used to characterise the phyto-availability of major elements and MTEs in soils, was adjusted for the first time to an animal organism, the snail H. aspersa (assessment of zoo-availability) This work showed that snails, contrarily to plants, accessed the non-isotopically exchangeable Cd pool in soils, considered as non-bio-available by current risk assessment procedures. The study of Cd transfer from plants (B. napus contaminated by surface deposition) to the snail H. aspersa showed a high bioaccumulation of Cd in snail tissues and effects on snail growth and consumption at high concentrations. The bioaccumulation factor (BAF, herein defined as the ratio of the concentration of a pollutant in the tissues of an organism divided by the concentration of this pollutant in its food) was higher than 2. These results suggest that snails inhabiting polluted environments could represent a risk for their predators. To test this hypothesis, the transfer of Cd from contaminated snails to one of their predators, the carabid beetle C. splendens, was studied. Exposure of beetles to the most highly contaminated preys led to a significant increase in mortality (during metamorphosis). Cd concentrations in beetles were very low and much lower than those measured in snail tissues. These results confirmed previous studies, which showed that bio-magnification (increase of a pollutant concentration from one level in a food chain to the upper link) is not a general rule for pollutant transfers in contaminated ecosystems. In a second approach, microcosms were developed to study the transfers in at least three links of a food web. In a first experiment, the transfer of 5 ETMs was studied in the system 'soil (2 agricultural soils: one contaminated and one non-polluted) - plant (lettuce L. sativa) - invertebrate (snail H. aspersa)'. After 4 weeks of exposure, Cd, Zn and Pb concentrations were much higher in the tissues of snails exposed to the polluted soil. Cu concentrations were not different between snails exposed to the polluted soil and those exposed to the non-contaminated one, suggesting MTE regulation by snails. Ni concentrations were higher in snails exposed to the non-polluted soil. The transfer kinetic, which was studied for 2 months in the snails exposed to the polluted soil, showed a regular increase of Cd and Zn concentrations, a rapid increase then a stabilization of Pb concentrations and a regulation of Cu and Ni concentrations. In a second experiment, microcosms were used to study the transfers 'soil - snails', 'maize (Z. mays) - snails' and 'soil - maize - snails' of a {sup 14}C-labelled herbicide, the Isoproturon. The transfer 'soil - snails' was much higher than the transfer 'maize - snails'. Metabolites of Isoproturon were determined in snail tissues. Very small quantities of native Isoproturon were found in snail tissues and the metabolites were mainly unknown residues (i.e. different from those obtained during Isoproturon degradation in soils, plants and microorganisms). The herbicide did not exert toxic effects on snail growth. Finally, a third approach using the microcosms (previously described), allowed the in situ study of the transfer of 5 ETMs from soils amended by sewage sludge to the snail H. aspersa. Amendments did not exert either lethal or sublethal effects on snails. In contrast, a rapid (5 and 7 weeks of exposure) and significant increase of Zn concentrations in snail tissues was showed. In conclusion, the successful adaptation of the isotopic dilution technique to H. aspersa snails should improve the assessment of ETM bioavailability to soil invertebrates (zoo-availability). The transfer experiments made in this work contribute to a better knowledge of pollutant transfer routes in a 'soil - plant - primary consumer - predator' food web. In addition, the microcosms developed in this work constitute a new tool for evaluating the risk of pollutant transfer in food webs. (author)

The Verrès Castle Access Project

Directory of Open Access Journals (Sweden)

Tito Berti Nulli

2010-10-01

Full Text Available The article describes the access project of the Verrès castle, located in Aosta Valley in Italy, underlining some urban and transport planning and design elements. This project constitute in fact an interesting example of integration between transport infrastructure planning and design with urban planning strategy for tourism development. The transport infrastructure (in this case a vertical lift for tourism use has furthermore a deep attention to the landscape and social contest and a good architectural design. The Verrès castle access project represents and interesting example of sustainable mobility and of touristic area accessibility which is strong integrated with urban renewal and territorial development. The feasibility study, financed by the Verrès municipality, is part of a the INTERREG IIIA ACOLTRA Project financed by Italy and France with the aim of creating a network of transnational tourist itineraries. Through this initiative Aosta Valley and Haute-Savoy are developing a common tourism strategy that intends to promote cultural heritage and tourism mobility through the RITT (Reseaux d’Itineraires Touristiques Transfrontalieres. In this contest of intervention the study for the accessibility of the Verrès castle is inserted, with the aim of designing a mobility infrastructure for the main attraction of the valley and at the same of strengthening the appeal of tourist attraction of the whole area. The project is located in the small city of Verrés, that lies at 390m, on the banks of the river Evançon. As many of the Valdostani municipalities is characterized by several small urban centers, which are located in a around 8kmq, in a territory where live 2.700 inhabitants. The feasibility study examines three different alternative for a lift that should connect the Verrès centre with the castle. In particular different transport technology (inclined and vertical lift and several path alternatives have been evaluated. The final

Risk analysis of industrial plants operation; Integration des evenements accidentels dans les bilans sur les nuisances industrielles

Energy Technology Data Exchange (ETDEWEB)

Hubert, Philippe

1989-12-01

This study examines the possibilities of systematic technology risk analysis in view of territorial management (city, urban community, region), including chronic and accidental risks. The objective was to relate this evaluation with those done for permanent water and air pollution. Risk management for pollution are done for a long time. A number of studies were done in urban communities and regions both for air and water pollution. The second objective is related to management of industrial risks: nuclear, petrochemical, transport of hazardous material, pipelines, etc. At the beginning, three possibilities of effects are taken into account: human health, economic aspect and water, and possibilities of evaluation are identified. Elements of risk identification are presented for quantification of results. [French] Cette etude examine les possibilites d'une analyse systematique du risque accidentel technologique dans une optique d'evaluation et de gestion territoriale (ville, communaute urbaine, region), qui integre: tous les types de risque chroniques et accidentels. Un des objectifs est donc d'articuler de telles evaluations avec celles qui sont faites pour les pollutions chroniques de l'eau et de l'air. La gestion du risque dans ces domaines se fait en effet selon une approche spatiale depuis longtemps: les deux exemples les plus nets sont les agences de bassin et les reseaux de surveillance et d'alerte pour la pollution de l'air. Parallelement a ces systemes de gestion, et souvent pour les besoins de leur fonctionnement, de nombreuses etudes ont ete effectuees sur des communautes urbaines et des regions, tant pour l'air que pour l'eau. L'autre objectif est de tirer parti des analyses faites sur les objets industriels, qui sont, a l'image de la gestion de leurs risques, sectorielles: industrie nucleaire, industrie petrochimique, transport de matieres dangereuses, pipeline etc.. Dans un premier temps, les trois angles d'attaque possibles du risque accidentel sont

Contribution to the theoretical and experimental study of the electron-volt effect in N-P junctions; Contribution a l'etude theorique et experimentale de l'effet electronvoltaique dans les jonctions N-P

Energy Technology Data Exchange (ETDEWEB)

Nguyen Van, Dong [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1959-07-15

, taking into account other phenomena which occur at low temperature. In the fourth part, results concerning the healing of the defects and protection measures against too energetic {beta} rays are described. A healing difference was observed between the lifetime and the conductivity. Finally, interesting results were obtained from experiments using a cadmium sulphide film to transform the {beta} particles of {sup 90}Sr-{sup 90}Y into photons. (author) [French] Le but propose dons le cadre de ce travail est d'etudier le comportement d'une jonction semi-conductrice sous l'action des rayons {beta}. L'etude a porte d'une part sur la conversion directe de l'energie rayonnee par une source radioactive en energie electrique utilisable a l'aide des jonctions N-P, et d'autre part sur la cinetique des defauts produits dans les cristaux de semi-conducteur par les rayons {beta} de grande energie. Dans la premiere partie du travail, on a essaye de completer les theories anterieures de l'effet electron-voltaique dans les jonctions en faisant une analyse mathematique de l'effet. Ceci a permis d'atteindre une equation unique dans laquelle figurent les parametres electriques et geometriques du semi-conducteur, de la jonction et les proprietes du rayonnement incident. D'autre part, on a etudie d'une maniere plus approfondie le courant de diffusion des porteurs de charge crees par le bombardement en tenant compte de tous les facteurs intervenant dans l'expression de l'efficacite de collection de charge d'une jonction. Dans la deuxieme partie, ou des experiences d'irradiation des jonctions N-P ont ete effectuees avec une source de {sup 90}Sr- {sup 90}Y, on a signale l'interet particulier d'une jonction d'arseniure de gallium susceptible de travailler a des temperatures relativement elevees (voisines de 100 deg. C). La troisieme partie presente l'etude des defauts crees dans un cristal de semi-conducteur par les rayons {beta} de grande energie, selon la methode de l'effet electron

Contribution to the theoretical and experimental study of the electron-volt effect in N-P junctions; Contribution a l'etude theorique et experimentale de l'effet electronvoltaique dans les jonctions N-P

Energy Technology Data Exchange (ETDEWEB)

Nguyen Van, Dong [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1959-07-15

, taking into account other phenomena which occur at low temperature. In the fourth part, results concerning the healing of the defects and protection measures against too energetic {beta} rays are described. A healing difference was observed between the lifetime and the conductivity. Finally, interesting results were obtained from experiments using a cadmium sulphide film to transform the {beta} particles of {sup 90}Sr-{sup 90}Y into photons. (author) [French] Le but propose dons le cadre de ce travail est d'etudier le comportement d'une jonction semi-conductrice sous l'action des rayons {beta}. L'etude a porte d'une part sur la conversion directe de l'energie rayonnee par une source radioactive en energie electrique utilisable a l'aide des jonctions N-P, et d'autre part sur la cinetique des defauts produits dans les cristaux de semi-conducteur par les rayons {beta} de grande energie. Dans la premiere partie du travail, on a essaye de completer les theories anterieures de l'effet electron-voltaique dans les jonctions en faisant une analyse mathematique de l'effet. Ceci a permis d'atteindre une equation unique dans laquelle figurent les parametres electriques et geometriques du semi-conducteur, de la jonction et les proprietes du rayonnement incident. D'autre part, on a etudie d'une maniere plus approfondie le courant de diffusion des porteurs de charge crees par le bombardement en tenant compte de tous les facteurs intervenant dans l'expression de l'efficacite de collection de charge d'une jonction. Dans la deuxieme partie, ou des experiences d'irradiation des jonctions N-P ont ete effectuees avec une source de {sup 90}Sr- {sup 90}Y, on a signale l'interet particulier d'une jonction d'arseniure de gallium susceptible de travailler a des temperatures relativement elevees (voisines de 100 deg. C). La troisieme partie presente l'etude des defauts crees dans un cristal de

Approches pour la reduction de l'impact de defaut dans le transport d'energie du parc eolien offshore via VSC-HVDC =

Science.gov (United States)

Benadja, Mounir

Dans ce travail est presente un systeme de generation d'energie d'un parc eolien offshore et un systeme de transport utilisant les stations VSC-HVDC connectees au reseau principal AC onshore. Trois configurations ont ete etudiees, modelisees et validees par simulation. Dans chacune des configurations, des contributions ameliorant les cotes techniques et economiques sont decrites ci-dessous : La premiere contribution concerne un nouvel algorithme MPPT (Maximum Power Point Tracking) utilise pour l'extraction de la puissance maximale disponible dans les eoliennes des parcs offshores. Cette technique d'extraction du MPPT ameliore le rendement energetique de la chaine de conversion des energies renouvelables notamment l'energie eolienne a petite et a grande echelles (parc eolien offshore) qui constitue un probleme pour les constructeurs qui se trouvent confrontes a developper des dispositifs MPPT simples, moins couteux, robustes, fiables et capable d'obtenir un rendement energetique maximal. La deuxieme contribution concerne la reduction de la taille, du cout et de l'impact des defauts electriques (AC et DC) dans le systeme construit pour transporter l'energie d'un parc eolien offshore (OWF) vers le reseau principal AC onshore via deux stations 3L-NPC VSCHVDC. La solution developpee utilise des observateurs non-lineaires bases sur le filtre de Kalman etendu (EKF). Ce filtre permet d'estimer la vitesse de rotation et la position du rotor de chacune des generatrices du parc eolien offshore et de la tension du bus DC de l'onduleur DC-AC offshore et des deux stations 3L-NPC-VSC-HVDC (offshore et onshore). De plus, ce developpement du filtre de Kalman etendu a permis de reduire l'impact des defauts AC et DC. Deux commandes ont ete utilisees, l'une (commande indirect dans le plan abc) avec EKF integre destinee pour controler le convertisseur DC-AC offshore et l'autre (commande d-q) avec EKF integre pour controler les convertisseurs des deux stations AC-DC et DC-AC tout en

Dynamics of competitive strategies in de-regulated industries: the case of the electricity industry in France; Dynamique des strategies concurrentielles dans un contexte de liberalisation: le cas de l'industrie electrique en France

Energy Technology Data Exchange (ETDEWEB)

Cateura, O

2007-11-15

This research work is focused on the competitive dynamics approach and rivalry studies between competitors. It develops theses recent perspectives and particularly multi-market competition (also called multipoint competition) in de-regulated industries (network utilities). Indeed, competitive behaviours in liberalized industries are still badly-known. To conduct this research, we decided to analyze a selection of companies (EDF, Electrabel, Endesa, Enel, Gaz de France, Poweo, Direct Energie..) settled on the French electricity market presently in the course of liberalization (1996 - 2006). This qualitative research, through longitudinal case studies, has been developed thanks to a CIFRE agreement (between the French Ministry of Research and the firm Electrabel France) including action research and participant observation. Using multidimensional strategic sequences, we identified two periods, the first one characterized by a confrontation movement and a second one by mutual forbearance. We argue that after learning the rules of a newly liberalized market (confrontation, diversification, internationalization), competitors rapidly and collectively shift there positions towards a focused European strategy based on the gas-electricity convergence. The development of multi-market competition has conducted to mutual forbearance, which was particularly profitable to the major participants. Integrated strategy (market and non-market) appears as an important driver for legitimizing theses behaviours. (author)

Deregulation of the electric power industry in Europe and in the USA: a decomposition-recombining process; La deregulation de l'industrie electrique en Europe et aux Etats-Unis: un processus de decomposition-recomposition

Energy Technology Data Exchange (ETDEWEB)

Percebois, J

1997-07-01

The deregulation of electric industry in Europe and in the U.S.A. assumes various aspects according to each country. Several institutional, economic and political reasons explain this evolution. Electric firms take this opportunity to merge and to implement offensive strategies on global markets. A lot of questions remains unsolved, in particular the problem of TPA pricing and the problem of planning of network infrastructures over the long run. (authors)

Drinking-water hydropower station 'Loye' in Grone, Switzerland - Feasibility study; Petite centrale hydro-electrique de Loye sur le reseau d'eau potable de la commune de Grone. Etude de faisabilite

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-11-15

This final report for the Swiss Federal Office of Energy (SFOE) describes a small hydropower project to be realised in Grone, southern Switzerland. The system planed is described. This provides the necessary pressure reduction in the drinking-water supply system between the springs in the mountains and the reservoir in the valley whilst generating electrical power at the same time. A one-injector Pelton turbine that meets all drinking-water quality requirements is used to generate 48 kW of electrical power using the pressure obtained from the height-difference of around 164 metres. The forecast electricity production amounts to 283,000 kWh/y, of which 88,000 kWh in the wintertime. The expected production cost is 0.219 CHF/kWh. A 550 m long pipeline has to be replaced.

Animal experimentation contribution to the study of electric and magnetic fields (50/60 Hz) effects; Contribution de l`experimentation animale a l`etude des effets des champs electriques et magnetiques (50/60 Hz)

Energy Technology Data Exchange (ETDEWEB)

Lambrozo, J. [Electricite de France (EDF), 75 - Paris (France); Brugere, H. [Ecole Nationale Veterinaire d`Alfort, 94 - Maison-Alfort (France)

1996-10-01

Since 20 years, studies have been made on the biological effects of 50 / 60 Hz electric and magnetic fields, due to environmental exposure. Two topic have been studied, thanks to rat experimentation. For the first topic: mutagen and reproduction impacts, no obvious effect appeared. For the second one, concerning carcinogen effects for the different organs, a slight tumor promoting effect appeared with magnetic fields for cerebral cortex, and a slightly more significant one for mammary glands. (D.L.)

Numerical simulations of flows through fixed networks of monodispersed and bi-dispersed spheres, for moderate Reynolds numbers; Simulations numeriques d'ecoulements a travers des reseaux fixes de spheres monodisperses et bidisperses, pour des nombres de Reynolds moderes

Energy Technology Data Exchange (ETDEWEB)

Massol, A.

2004-02-15

The application of statistically averaged two-fluid models for the simulation of complex indus- trial two-phase flows requires the development of adequate models for the drag force exerted on the inclusions and the interfacial heat exchange. This task becomes problematic at high volume fractions of the dispersed phase. The quality of the simulation strongly depends upon the inter- facial exchange terms, starting with the steady drag force. For example, an accurate modelling of the drag force is therefore a crucial point to simulate the expansion of dense fluidized beds. Most models used to study the exchange terms between particles and fluids are based on the interaction between an isolated particle and a surrounding gas. Those models are clearly not adequate in cases where the volume fraction of particles increases and particle-particle interactions become important. Studying such cases is a complex task because of the multiple possible configurations. While the interaction between an isolated sphere and a gas depends only on the particle size and the slip velocity between gas and particles, the interaction between a cloud of particles and a gas depends on many more parameters: size and velocity distribution of particles, relative position of particles. Even if the particles keep relative fixed positions, there is an infinite number of combinations to construct such an array. The objective of the present work is to perform steady and unsteady simulations of the flow in regular arrays of fixed particles in order to analyze the influence of the size and distributions of spheres on drag force and heat transfer (the array of spheres can be either monodispersed, either bi-dispersed). Several authors have studied the drag exerted on the spheres, but only for low Reynolds numbers and/or solid volume fractions close to the packed limit. Moreover some discrepancies are observed between the different studies. On top of that, all existing studies are limited to steady flows, and do not deal with heat transfer and poly-dispersion. First of all, the steady viscous drag exerted on the spheres of face-centered cubic, simple cubic and tetragonal arrays is evaluated. This allows to analyze the influence of the spheres distribution and solid volume fraction on drag coefficient. Next, the influence of Reynolds number and solid volume fraction on heat transfer from spheres to the surrounding fluid in face-centered cubic arrays is studied. Finally, the history effects on the total force exerted on the inclusions and on the heat transfer between the inclusions and the surrounding fluid are studied. (author)

Is the cooling of coils of pulsed accelerators profitable?; Le refroidissement des bobines des accelerateurs pulses est-il avantageux?

Energy Technology Data Exchange (ETDEWEB)

Neyret, G.; Parain, J.; Schnuriger, J. C.

1960-05-15

In this report, the authors recall how metal resistivity decreases at low temperatures, and give some indications about the power and price of cryogenic installations. They report the study of the cooling of coils in accelerators displaying an alternate gradient with a 15 GeV energy, with or without a magnetic circuit in iron. They establish that cooling does not result in a decrease in the cost price for an hour of operation. They also state that it is not even sure that this cooling would result in a dimension reduction while increasing the maximum achievable induction [French] On rappelle comment la resistivite des metaux diminue aux basses temperatures, et on donne des indications sur la puissance et le prix des installations cryogeniques. On etudie le refroidissement des bobines d'accelerateurs a gradient alterne d'une energie de 15 GeV, avec ou sans circuit magnetique en fer; on trouve que le refroidissement ne permet pas de diminuer le prix de revient de l'heure de fonctionnement; il n'est meme pas sur qu'il puisse permettre de reduire les dimensions en elevant l'induction maximum realisable. L'idee de refroidir les bobines sans fer jusqu'a la temperature de l'air liquide est ancienne: Jean Perrin des 1907, puis Charly Fabry en 1910 l'avaient deja proposee. Recemment, cette idee est revenue a l'actualite: en 1958, R.F. Post a suggere de l'appliquer a la production de champs intenses en vue du confinement des plasmas thermonucleaires; en 1959, N.C. Christofilos a publie un projet d'accelerateur refroidi a 80 deg. K. Nous voulons examiner l'interet de refroidir les bobines d'un accelerateur, d'une part pour augmenter l'induction maximum (dans le cas de machines sans fer) et d'autre part pour diminuer l'importance de l'alimentation electrique. Cet examen est precede de generalites sur le refroidissement des bobines, generalites qui s'appliquent d'ailleurs a tous les champs magnetiques. Les trois metaux etudies sont ceux retenus comme les meilleurs par Post: le

Effets thermoelectrique et thermomagnetique du yttrium barium copper oxide monocristallin

Science.gov (United States)

Ghamlouche, Hassan

1998-09-01

Des la decouverte des supraconducteurs a haute temperature critique, les recherches se sont intensifiees afin de comprendre les mecanismes qui sont a l'origine des proprietes de ces materiaux L'etat mixte, tout comme l'etat supraconducteur pur et l'etat normal, a fait l'objet de nombreux travaux de recherche. En particulier, la structure des vortex a l'etat mixte, et leur mouvement sous l'effet d'une force quelconque, etaient et restent le centre de preoccupation. Les effets thermoelectrique (Seebeck) et thermomagnetique (Nernst) sont parmi les differentes mesures qui peuvent donner de l'information sur les etats des vortex a l'etat mixte. L'avantage essentiel de ces deux effets est l'absence d'un courant electrique applique. Ce dernier peut donner des perturbations indesirables durant les mesures. D'autre pari, nous avons utilise la methode CA (Courant Alternatif) pour effectuer nos mesures. Cette methode est caracterisee par une meilleure resolution par rapport a la methode CC (Courant Continu) conventionnelle. Nous avons etudie autant des echantillons macles que des echantillons sans macles. D'abord nous avons teste notre montage a champ magnetique nul. Nous avons alors montre que le pic rapporte par certains dans l'effet Seebeck a la transition supraconductrice ne correspond pas a une realite physique mais a un artefact experimental. On avait associe ce pic aux fluctuations. Par la suite, nous avons mis en evidence et etudie pour la premiere fois avec les effets Seebeck et Nernst le phenomene de la fusion du reseau de vortex grace a des mesures sur les echantillons sans macles. Cette etude s'est faite pour deux concentrations d'oxygene differentes et pour un gradient de temperature parallele, consecutivement, aux deux axes cristallographiques dans le plan ab. Finalement, nous avons etudie l'effet des plans de maclage sur le mouvement des vortex. Ceci a ete realise en appliquant le gradient de temperature selon trois directions differentes (0, 45 et 90°) avec

Corrosion of metallic materials by uranium hexafluoride at high temperatures (1963); Corrosion de materiaux metalliques par l'hexafluorure d'uranium a haute temperature (1963)

Energy Technology Data Exchange (ETDEWEB)

Langlois, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

The corrosion of the following metals or alloys by UF{sub 6}: nickel, monel, Inconel, gold, platinum, stainless steel, is studied in the temperature range from 300 to 1000 deg. C. The test method, designed to avoid heating the apparatus containing the corrosive fluid to a high temperature, consists in using threadlike samples heated by the Joule effect, the rest of the apparatus being maintained close to room temperature. This technique makes it possible also to determine continuously the penetration of the corrosion by measuring the electrical resistance of the sample with a double Thomson bridge. A series of rapid comparison tests shows that stainless steel, precious metals and Inconel are attacked far too rapidly to be used above 500 deg. C; only monel and especially nickel appear capable of resisting at high temperatures. The detailed examination of the behaviour of nickel shows that the metallic fluoride is volatilized and that this influences the corrosion rate. It shows also the existence of a temperature zone situated between 550 and 700 deg. C in which occurs A strong intergranular corrosion the cause of which appears to be the presence of impurities in the metal. (author) [French] La corrosion par l'UF{sub 6} des metaux ou alliages suivants: lickel, monel, inconel, or, platine, acier inoxydable, est etudiee dans le un domaine de temperature compris entre 300 et 1000 deg. C. La methode d'essai, destinee a eviter le chauffage de l'enceinte contenant le fluide corrosif a temperature elevee, consiste a utiliser des eprouvettes filiformes, echauffees par effet Joule, le reste de l'appareillage etant maintenu a une temperature proche de l'ambiance. Cette technique permet en outre de determiner en continu la penetration de la corrosion, par mesure de la resistance electrique de l'eprouvette, au moyen d'un pont double de Thomson. Une serie d'essais comparatifs, assez sommaires, montre que l'acier inoxydable, les metaux precieux et l'inconel sont attaques beaucoup

The use of tracers in the study of the ionic permeability of the nerve; Utilisation des indicateurs nucleaires dans l'etude de la permeabilite ionique du nerf

Energy Technology Data Exchange (ETDEWEB)

Guinnebault, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

The use of the radioactive tracers {sup 24}Na and {sup 42}K, and the electrophysiological fine study carried out on the plant Cephalopods nervous cells have made it possible, during ten years, to study the relationships between the electrical phenomena observed during the propagation of the nervous impulse and the ionic movements which occur at the cell membrane between the intra- and extra-cellular media. In the state of rest, the nerve fibres present a certain permeability towards sodium and potassium, a permeability which allows the renewal, from the extra-cellular medium, of the cations contained in the cytoplasm. At the moment of the passage of the nervous impulse, it is possible to demonstrate a temporary increase in the permeability towards the sodium which causes the entry of Na{sup +} ions into the nerve fibre, whilst, a few milliseconds later, the increase in the potassium permeability causes the departure of an equivalent quantity of K{sup +} ions. A recovery phase follows the passage of the nervous impulse, during which the original ionic conditions are re-established. If the potassium movements can be considered as passive, the expulsion of Na{sup +} requires, on the part of the cell, the use of a part of the metabolic energy. (author) [French] L'utilisation des indicateurs radioactifs {sup 24}Na et {sup 42}K, et l'etude electrophysiologique fine realisee sur des cellules nerveuses geantes de Cephalopodes a permis, depuis une dizaine d'annees, d'etudier les rapports entre les phenomenes electriques observes lors de la propagation de l'influx nerveux et les mouvements ioniques qui s'effectuent au niveau de la membrane cellulaire entre milieux intracellulaire et extracellulaire. A l'etat de repos, les fibres nerveuses possedent pour le sodium et le potassium, une permeabilite qui permet le renouvellement, a partir du milieu extracellulaire des cations contenus dans le cytoplasme. Au moment du passage de l'influx nerveux, on peut mettre en evidence une

Forced convection of ammonia. 2. part.: gaseous ammonia - very high wall temperatures (1000 to 3000 K); Convection forcee de l'ammoniac. 2. partie: ammoniac gazeux - cas de tres hautes temperatures de paroi (1000 a 3000{sup 0} K)

Energy Technology Data Exchange (ETDEWEB)

Perroud, P.; Rebiere, J.; Strittmatter, R. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1969-07-01

Heat transfer coefficients and pressure drop of gaseous ammonia in forced convection are experimentally determined. The fluid flows (mass flow rate 0.6 to 2.4 g/s) in a long tungsten tube (d{sub i} = 2.8 mm, d{sub e} = 5.1 mm, L = 700 mm) electrically heated. The temperature of the wall reaches 3000 deg. K and the fluid 2500 deg. K; maximum heat flux 530 w/cm{sup 2}. Ammonia is completely dissociated and the power necessary for dissociation reaches 30 per cent of the total power exchanged. Inlet pressure varies between 6 and 16 bars and the maximum pressure drop in the tube reaches 15 bars. Two regimes of dissociation have been shown: catalytic and homogeneous and the variation of dissociation along the length of the tube is studied. The measured heat transfer coefficients may be about 10 times these calculated by the means of classical formulae. A correlation of experimental results using enthalpy as a driving force for heat transmission is presented. Pressure drops may be calculated by the means of a classical friction factor. (authors) [French] On determine experimentalement les coefficients d'echange thermique et les pertes de charge de l'ammoniac gazeux en convection forcee. Le fluide circule avec un debit en masse compris entre 0.6 et 2.4 g/s (G = 10 a 40 g/cm{sup 2}.s) dans un tube long en tungstene (d{sub i} = 2.8 mm, d{sub e} = 5.1 mm, L = 700 mm), chauffe electriquement. La temperature de paroi atteint 3000 deg. K, celle du fluide 2500 deg. K et le flux de chaleur maximal est de 530 W/cm{sup 2}. L'ammoniac se dissocie completement, la puissance correspondant a la dissociation atteint 30 pour cent de la puissance totale echangee. La pression d'entree varie entre 6 et 16 bars et la chute de pression maximale dans le canal est de 15 bars. On distingue deux regimes de dissociation, catalytique et homogene, et on etudie la variation du taux de dissociation en fonction de la longueur du tube. Les coefficients d'echange thermique mesures

Perturbation analysis of cyclotron resonance in the electromagnetic field of a TE{sub 011} mode; Analyse par perturbation de la resonance cyclotronique dans le champ electromagnetique en mode TE{sub 011} mode

Energy Technology Data Exchange (ETDEWEB)

Dreicer, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1968-07-01

The motion of an electron orbiting under the combined action of a static magnetic field and the AC azimuthal electric field of a cylindrical TE{sub 011} mode is analyzed with help of a perturbation technique. The first and second order perturbation results indicate that at cyclotron resonance the electron's center of gyration oscillates slowly at right angles to the magnetic field between two turning points. We find that superimposed upon this nearly static Exb drift the electron cyclically undergoes the process of cyclotron absorption and induced emission. Our results indicate that it is possible to insure maser action (i.e. induced emission rather than absorption) without special preparation of the electron's velocity provided that the electron is introduced into the field in certain special regions of space pervaded by the TE mode. This is a case where over-population of the upper state is accomplished through 'pumping' in real space. The relation between an electron cyclotron resonance maser based upon this principle and one based upon the principle of velocity space pumping, due to Twiss, is examined. This treatment provides physical interpretations and verifies the numerical results found earlier by Le Gardeur. (author) [French] Le mouvement d'un electron soumis a l'action combinee d'un champ magnetique statique et d'un champ electrique haute frequence azimutal engendre dans une cavite cylindrique en mode TE{sub 011} est analyse a partir d'une methode de perturbation. Les resultats des perturbations au premier et deuxieme ordre indiquent qu'a la resonance cyclotronique, le centre de giration de l'electron oscille lentement dans le plan perpendiculaire au champ magnetique entre deux points de rebroussement. En plus de la derivee quasi-statique ExB, l'electron passe par des etats d'absorption et emission cyclotronique. Les resultats du calcul confirment la possibilite d'avoir une action maser (c'est-a-dire: emission au lieu d'absorption) sans que la vitesse des

Preparation and study of the properties of lead telluride and cadmium telluride diodes for use in nuclear spectrometry; Preparation et etude des proprietes de diodes au tellurure de plomb et au tellurure de cadmium en vue d'une utilisation en spectrometrie nucleaire

Energy Technology Data Exchange (ETDEWEB)

Lancon, R [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1969-07-01

This work studies the possibility of using high atomic number compound semiconductors, like lead telluride and cadmium telluride as to realize nuclear radiation detectors, specially in gamma ray spectrometry because of their high absorption coefficient. The problems related to the preparation of binary compounds are exposed. Experiments on PbTe show the influence of the conditions of preparation on the electrical properties of the semiconductor which are greatly dependent on the stoichiometry of the compound. PbTe surface-barrier diodes were realized and have been used to study the surface properties of this semiconductor. These diodes cannot detect nuclear radiations because of the too weak resistivity of our material. Different types of devices made of Cd Te have been studied. One of these diodes has been used as an alpha particle detector. We explain the relative poor performances of that detector by the presence of lattice defects in Cd Te where charge carriers may recombine themselves. By analysing the properties of gold diffused Cd Te diodes we identified this defect, the cadmium vacancy, the presence of which is due to the deviation from stoichiometry during the preparation of the material. (author) [French] Ce travail etudie la possibilite d'utiliser des semiconducteurs composes d'elements a numero atomique eleve, tels que le tellurure de plomb et le tellurure de cadmium pour la realisation de detecteurs de rayonnements nucleaires, grace notamment a la section efficace de capture elevee qu'ils presentent vis-a-vis des rayons gamma. On souligne les problemes relatifs a la preparation des composes binaires. Les experiences realisees sur PbTe mettent en evidence l'influence des conditions de preparation sur les proprietes electriques du semiconducteur qui dependent fortement de la stoechiometrie du compose. Nous avons realise des diodes au PbTe a barriere de surface qui ont permis de preciser les proprietes de surface de ce semiconducteur. La trop faible

Setting-Up of a Neutron Dosimeter Using Ionographic Tracks in an Insulating Solid; Realisation d'un Dosimetre a Neutrons Utilisant les Traces Ionographiques dans un Solide Isolant

Energy Technology Data Exchange (ETDEWEB)

Carfi, N.; Dugnani Lonati, R.; Mangialajo, M. [Centro Informazioni Studi Esperienze, Segrate, Milan (Italy)

1971-06-15

The use of dielectrics such as mica, glasses and plastic materials for charged particle track recording has been developed in the past years; track recording of fission fragments produced in fissile materials under neutron irradiation is particularly interesting. The method has not as yet been applied to neutron dosimetry owing to the difficulties of track observation and counting using optical microscopes. A method has recently been proposed which results in markedly reduced counting times, electronic counting of the electric discharges between two electrodes through the dielectric which was perforated by the fission fragments. The reasons for adopting this new technique to set-up a neutron dosimeter are: (a) economic advantages, since a rather simple electronic instrumentation will give a reading of the dosimeter, preparation of which can be carried out immediately and at a modest cost; (b) fast reading, since the response can be obtained in less than two hours from irradiation; (c) dosimetric advantages owing to the lack of fading and insensitivity to {beta} or {gamma} radiations. The present work describes the method adopted and the equipment used to set up the dosimeter. Results are reported and briefly discussed. (author) [French] Au cours des dernieres annees on a assiste a un developpement remarquable de l' utilisation d' isolants tels que le mica, les verres et les materiaux plastiques pour l' enregistrement des traces de particules chargees; l' enregistrement des traces de fragments de fission produits dans les materiaux fissiles sous irradiation neutronique est particulierement interessant. Cette methode n'a pas, jusqu a present, ete appliquee a la dosimetrie des neutrons a cause des difficultes que presentent l' observation et le comptage des traces au microscope optique. On a propose recemment une methode qui permet de reduire considerablement la duree de l' operation en comptant electroniquement les decharges electriques qui se produisent entre deux

SAETTA: high resolution 3D mapping of the lightning activity around Corsica Island

Science.gov (United States)

Coquillat, Sylvain; Defer, Eric; Lambert, Dominique; Pinty, Jean-Pierre; Pont, Véronique; Prieur, Serge

2017-04-01

In the frame of the French atmospheric observatory CORSiCA (http://www.obs-mip.fr/corsica), a total lightning activity detection system called SAETTA (Suivi de l'Activité Electrique Tridimensionnelle Totale de l'Atmosphère) has been deployed in Corsica Island in order to strengthen the potential of observation of convective events causing heavy rainfall and flash floods in the West Mediterranean basin. SAETTA is a network of 12 LMA stations (Lightning Mapping Array) developed by New Mexico Tech (USA). The instrument allows observing lightning flashes in 3D and real time, at high temporal (80 µs) and spatial resolutions. It detects the radiations emitted by cloud discharges in the 60-66 MHz band, in a radius of about 350 km from the centre of the network, in passive mode and standalone (solar panel and batteries). Initially deployed in May 2014, SAETTA operated from July 13 to October 20 in 2014 and from April 19 to December 1st in 2015. It is now in permanent operation since 16 April 2016. Many high quality observations have been performed so far that provide an accurate location in space and time of the convective events. They also bring interesting dynamical and microphysical features of those events. For example the intensity of the convective surges, the transport of charged ice particles in the stratiform area of the thunderclouds can be deduced from SAETTA observations. Specific events have also been detected as well: bolts-from-the-blue, inter cloud discharges, high level discharges in convective but also in stratiform areas, inverted dipoles. The specific lightning patterns of 2015 illustrate the complex influence of the relief, probably via slope and valley winds over Corsica and via induced lee-side convergences over the sea. SAETTA is expected to operate for at least a decade over Corsica so it will participate to the calibration/validation of upcoming lightning detectors from space such as MTG-LI. It will also be a key instrument during the field

Corrosion of metallic materials by uranium hexafluoride at high temperatures (1963); Corrosion de materiaux metalliques par l'hexafluorure d'uranium a haute temperature (1963)

Energy Technology Data Exchange (ETDEWEB)

Langlois, G. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

The corrosion of the following metals or alloys by UF{sub 6}: nickel, monel, Inconel, gold, platinum, stainless steel, is studied in the temperature range from 300 to 1000 deg. C. The test method, designed to avoid heating the apparatus containing the corrosive fluid to a high temperature, consists in using threadlike samples heated by the Joule effect, the rest of the apparatus being maintained close to room temperature. This technique makes it possible also to determine continuously the penetration of the corrosion by measuring the electrical resistance of the sample with a double Thomson bridge. A series of rapid comparison tests shows that stainless steel, precious metals and Inconel are attacked far too rapidly to be used above 500 deg. C; only monel and especially nickel appear capable of resisting at high temperatures. The detailed examination of the behaviour of nickel shows that the metallic fluoride is volatilized and that this influences the corrosion rate. It shows also the existence of a temperature zone situated between 550 and 700 deg. C in which occurs A strong intergranular corrosion the cause of which appears to be the presence of impurities in the metal. (author) [French] La corrosion par l'UF{sub 6} des metaux ou alliages suivants: lickel, monel, inconel, or, platine, acier inoxydable, est etudiee dans le un domaine de temperature compris entre 300 et 1000 deg. C. La methode d'essai, destinee a eviter le chauffage de l'enceinte contenant le fluide corrosif a temperature elevee, consiste a utiliser des eprouvettes filiformes, echauffees par effet Joule, le reste de l'appareillage etant maintenu a une temperature proche de l'ambiance. Cette technique permet en outre de determiner en continu la penetration de la corrosion, par mesure de la resistance electrique de l'eprouvette, au moyen d'un pont double de Thomson. Une serie d'essais comparatifs, assez sommaires, montre que l'acier inoxydable, les metaux

Deregulation of the electric power industry in Europe and in the USA: a decomposition-recombining process; La deregulation de l'industrie electrique en Europe et aux Etats-Unis: un processus de decomposition-recomposition

Energy Technology Data Exchange (ETDEWEB)

Percebois, J

1997-07-01

The deregulation of electric industry in Europe and in the U.S.A. assumes various aspects according to each country. Several institutional, economic and political reasons explain this evolution. Electric firms take this opportunity to merge and to implement offensive strategies on global markets. A lot of questions remains unsolved, in particular the problem of TPA pricing and the problem of planning of network infrastructures over the long run. (authors)

Simulation of the thermal behaviour of electric industrial resistance furnaces using the I-DEAS/TMG code; Simulation du comportement thermique des fours electriques industriels a resistances a l`aide du code I-DEAS/TMG

Energy Technology Data Exchange (ETDEWEB)

Plard, Ch; Branchu, K; Le Cloirec, B [Electricite de France, 77 - Moret sur Loing (France). Direction des Etudes et Recherches

1997-12-31

In order to answer the modeling needs of manufacturers and users of electrical resistance furnaces, Electricite de France (EdF) has been appealed to search for a numerical simulation tool for the modeling of thermal phenomena and to carry out its qualification. The TNG software has been retained according to its modeling characteristics of radiant heat transfers and to the coupling with thermal conduction. After a description of the main characteristics of this code, two examples of application to electrical furnaces are presented. The first example illustrates how it can be possible to accurately reproduce the behaviour of a big industrial furnace. The second example is an illustration of numerical simulation possibilities for the optimization of processes performed with an electric furnace. (J.S.)

Application of a radiant heat transfer model to complex industrial reactive flows: combustion chambers, electric arcs; Application d`un modele de transfert radiatif a des ecoulements reactifs industriels complexes: chambres de combustion, arcs electriques

Energy Technology Data Exchange (ETDEWEB)

Mechitoua, N; Dalsecco, S; Delalondre, C; Simonin, O [Electricite de France (EDF), 78 - Chatou (France). Lab. National d` Hydraulique

1997-12-31

The direction of studies and researches (DER) of Electricite de France (EdF) has been involved for several years in a research program on turbulent reactive flows. The objectives of this program concern: the reduction of pollutant emissions from existing fossil-fueled power plants, the study of new production means (fluidized beds), and the promotion of electric power applications in the industry. An important part of this program is devoted to the development and validation of 3-D softwares and to the modeling of physical phenomena. This paper presents some industrial applications (furnaces, boilers, electric arcs) for which radiant heat transfers play an important role and the radiation models used. (J.S.) 8 refs.

Dynamics of competitive strategies in de-regulated industries: the case of the electricity industry in France; Dynamique des strategies concurrentielles dans un contexte de liberalisation: le cas de l'industrie electrique en France

Energy Technology Data Exchange (ETDEWEB)

Cateura, O

2007-11-15

This research work is focused on the competitive dynamics approach and rivalry studies between competitors. It develops theses recent perspectives and particularly multi-market competition (also called multipoint competition) in de-regulated industries (network utilities). Indeed, competitive behaviours in liberalized industries are still badly-known. To conduct this research, we decided to analyze a selection of companies (EDF, Electrabel, Endesa, Enel, Gaz de France, Poweo, Direct Energie..) settled on the French electricity market presently in the course of liberalization (1996 - 2006). This qualitative research, through longitudinal case studies, has been developed thanks to a CIFRE agreement (between the French Ministry of Research and the firm Electrabel France) including action research and participant observation. Using multidimensional strategic sequences, we identified two periods, the first one characterized by a confrontation movement and a second one by mutual forbearance. We argue that after learning the rules of a newly liberalized market (confrontation, diversification, internationalization), competitors rapidly and collectively shift there positions towards a focused European strategy based on the gas-electricity convergence. The development of multi-market competition has conducted to mutual forbearance, which was particularly profitable to the major participants. Integrated strategy (market and non-market) appears as an important driver for legitimizing theses behaviours. (author)

Simulation of the thermal behaviour of electric industrial resistance furnaces using the I-DEAS/TMG code; Simulation du comportement thermique des fours electriques industriels a resistances a l`aide du code I-DEAS/TMG

Energy Technology Data Exchange (ETDEWEB)

Plard, Ch.; Branchu, K.; Le Cloirec, B. [Electricite de France, 77 - Moret sur Loing (France). Direction des Etudes et Recherches

1996-12-31

In order to answer the modeling needs of manufacturers and users of electrical resistance furnaces, Electricite de France (EdF) has been appealed to search for a numerical simulation tool for the modeling of thermal phenomena and to carry out its qualification. The TNG software has been retained according to its modeling characteristics of radiant heat transfers and to the coupling with thermal conduction. After a description of the main characteristics of this code, two examples of application to electrical furnaces are presented. The first example illustrates how it can be possible to accurately reproduce the behaviour of a big industrial furnace. The second example is an illustration of numerical simulation possibilities for the optimization of processes performed with an electric furnace. (J.S.)

Application of a radiant heat transfer model to complex industrial reactive flows: combustion chambers, electric arcs; Application d`un modele de transfert radiatif a des ecoulements reactifs industriels complexes: chambres de combustion, arcs electriques

Energy Technology Data Exchange (ETDEWEB)

Mechitoua, N.; Dalsecco, S.; Delalondre, C.; Simonin, O. [Electricite de France (EDF), 78 - Chatou (France). Lab. National d`Hydraulique

1996-12-31

The direction of studies and researches (DER) of Electricite de France (EdF) has been involved for several years in a research program on turbulent reactive flows. The objectives of this program concern: the reduction of pollutant emissions from existing fossil-fueled power plants, the study of new production means (fluidized beds), and the promotion of electric power applications in the industry. An important part of this program is devoted to the development and validation of 3-D softwares and to the modeling of physical phenomena. This paper presents some industrial applications (furnaces, boilers, electric arcs) for which radiant heat transfers play an important role and the radiation models used. (J.S.) 8 refs.