WorldWideScience

Sample records for du combustible nucleaire

  1. A mathematical model for cost of maritime transport. Application to competitiveness of nuclear vessels; Modele mathematique du cout de transport maritime application a la competitivite du navire nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Dorval, C. [Commissariat a l' Energie Atomique, 75 - Paris (France)

    1966-05-01

    recherche de la competitivite, nous considerons deux cas: 1) le tonnage a transporter annuellement est limite; 2) le tonnage a transporter annuellement n'est pas limite. Dans les deux cas, nous recherchons les optima du navire classique et du navire nucleaire, et nous les comparons. Nous construisons les courbes de competitivite en fonction des rapports des couts de combustible nucleaire et classique, et des couts marginaux de la puissance nucleaire et classique. Ces courbes traduisent les valeurs limites des deux rapports ci-dessus pour lesquelles les couts de transport du navire nucleaire et du navire classique sont egaux. Suivant les hypotheses adoptees pour le marche du fret et pour la limite du tonnage transporte annuellement, nous avons des courbes de competitivite tres differentes. De toute facon, c'est l'augmentation de puissance qui favorise le nucleaire. On peut obtenir cette augmentation en accroissant le deplacement ce qui est toujours interessant dans la mesure ou le fret le justifie, et en accroissant la vitesse, mais dans ce cas le modele met en evidence l'existence d'une limite. Le sous-marin peut presenter certains avantages (moindre resistance hydrodynamique de l'eau, possibilite de vitesse plus reguliere, et eventuellement reduction de trajet) qui rendent la competitivite du nucleaire plus aisee. (auteur)

  2. Continuous dissolution of irradiated nuclear fuels; Dissolution continue des combustibles nucleaires irradies

    Energy Technology Data Exchange (ETDEWEB)

    Michel, P.; Talmont, X.; Tarnerq, M. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1967-07-01

    In the case of the continuous dissolution of nuclear fuels, the equations for the calculation of the fuel concentration of the solution flowing out of a pot dissolver have been written. Nitric acid feed flow rates have been calculated in order to obtain an adjusted solution when starting or stopping a dissolution, or when changing the number of rods introduced per hour. Then some transient states brought on by perturbations, have been studied: a) sudden change in nitric acid flow rate; b) continuous drift of the latter; c) sudden change in nitric acid feed concentration; d) transition from a fuel concentration to another by changing the flow rate of nitric acid feed. It has been shown that some transient states cannot be solved with general equations. Computer calculation programs would be probably more useful. (authors) [French] L'etude se rapporte a la dissolution dans l'acide nitrique des combustibles nucleaires irradies, en vue de la recuperation de la matiere fissile qu'ils contiennent. On a etabli, dans le cas de la dissolution continue, les differentes equations permettant le calcul de la concentration en combustible a la sortie d'un dissolveur du type 'marmite'. On a etudie les regimes du debit d'alimentation en acide nitrique a imposer lors du demarrage, de l'arret d'une dissolution, ou lors d'un changement de cadence d'introduction des barreaux, de facon a obtenir une solution ajustee. On a etudie ensuite differents regimes transitoires consecutifs a des perturbations: changement brusque du debit d'acide d'alimentation, derive continue de ce debit, changement brusque de la concentration de l'acide d'alimentation, passage d'une concentration en combustible a une autre par changement du debit d'acide d'alimentation. On a pu montrer que certains regimes transitoires ne peuvent se traiter par des equations generales, et necessiteraient plustot l'etablissement d

  3. The nuclear power stations of the French atomic energy programme (1960); Les centrales nucleaires de puissance du programme francais (1960)

    Energy Technology Data Exchange (ETDEWEB)

    Leduc, C. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Roux, J.P. [Electricite de France (EDF), 75 - Paris (France)

    1960-07-01

    After recalling the entry of nuclear energy into energy production in France, the paper emphasizes the evolution of techniques applied in the designing of French nuclear power plants and describes the means employed for reducing costs per kWh of EDF2 and EDF3 compared with EDF1: the electric power per ton of uranium varies from 493 kW/t for EDF1 to 970 kW/t for EDF3. For this purpose the thermal power and electric power of units are changed respectively from 290 MWt for EDF1 to 1200 or 1600 MWt for EDF3 and from 28 to 250 MW. The results are obtained by an improvement in neutronic characteristics, developments in nuclear fuel technology, and simplification of the system of charging the reactor, whose means of maintenance are increased; the EDF2 heat-exchangers have been so designed as to increase the unit power of the elements, which will attain 9 MWt, as against 3 for EDF1. For EDF3 an advance project forecasts a thermodynamic layout with only one pressure stage. The paper ends with a description of the burst-slug detection systems, and an appendix gives a detailed comparative table of EDF1, EDF2 and EDF3 plant characteristics. (author) [French] Apres avoir rappele l'integration de l'energie nucleaire parmi les moyens de production de l'energie en France, les auteurs se penchent surtout sur l'evolution des techniques appliquees dans l'equipement des centrales nucleaires francaises et decrivent les moyens mis en oeuvre pour reduire les prix de revient du kWh d'EDF2 et d'EDF3 par rapport a EDF1: la puissance electrique par tonne d'uranium varie de 493 kW/t pour EDF1 a 970 kW/t pour EDF3. C'est dans ce but que les puissances thermiques et la puissance unitaire des groupes turbo-alternateurs passent respectivement de 290 MWt pour EDF1 a 1200 ou 1600 MWt pour EDF3 et de 82 a 250 MW. Les resultats sont obtenus par une amelioration des caracteristiques neutroniques, des progres realises sur la technologie des elements

  4. The nuclear fuel cycle; Le cycle du combustible nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

    After a short introduction about nuclear power in the world, fission physics and the French nuclear power plants, this brochure describes in a digest way the different steps of the nuclear fuel cycle: uranium prospecting, mining activity, processing of uranium ores and production of uranium concentrates (yellow cake), uranium chemistry (conversion of the yellow cake into uranium hexafluoride), fabrication of nuclear fuels, use of fuels, reprocessing of spent fuels (uranium, plutonium and fission products), recycling of energetic materials, and storage of radioactive wastes. (J.S.)

  5. Some aspects of the nuclear fission process; Quelques aspects du processus de fission nucleaire

    Energy Technology Data Exchange (ETDEWEB)

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

    1961-07-01

    In the following report one can find first a short general view on the present situation of our knowledge concerning the nuclear fission process, namely on the nucleus going through the saddle-point. Then there are some aspects connected with the excitation energy of the fissioning nucleus. The measurements made at Saclay on the fast neutron fission cross-section of U{sup 233}, U{sup 235}, Pu{sup 239}, U{sup 238} are described at the beginning of this work. It appears that for U{sup 233} there is some characteristic shape modulation of the cross-section curve, in relation with the collective excited state of the deformed nucleus at the saddle-point. Good evidence of this is also given by the study of the relative fission rate with emission of long-range particles; it appears also that this ternary fission rate does not change substantially for neutron between thermal energy and 2 MeV, but that is very lower for the compound nucleus U{sup 239} than for even-even compound nuclei. At the end there are some experiments on the strong 4,5 MeV gamma-ray originated by slow neutron absorption in U{sup 235}. Time-of-flight device is used to establish that this 4,5 MeV gamma-ray seems mostly connected with radiative capture. (author) [French] Le present travail debute par un apercu de l'etat actuel de nos connaissances sur le processus de fission nucleaire, notamment sur le passage par le point-seuil. Puis sont evoques des aspects lies au niveau d'energie d'excitation auquel est porte le noyau qui subit la fission. Les mesures de sections efficaces de fission induite dans {sup 233}U, {sup 235}U, {sup 239}Pu et {sup 238}U par des neutrons rapides effectuees a Saclay sont decrites en premier lieu; elles font apparaitre pour {sup 233}U une ondulation caracteristique du role des etats collectifs d'excitation du noyau deforme au point-seuil. Des experiences sur la fission avec emission de particules de long parcours confirment cet aspect tout en demontrant que

  6. Back end of the nuclear fuel cycle; Aval du cycle du combustible nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Dognon, J.P.; Rabbe, C.; Beudaert, Ph.; Lamare, V.; Wipff, G.; Moisy, Ph.; Charrin, N.; Blanc, P.; Den Auwer, Ch.; Revel, R.; Charbonnel, M.C.; Presson, M.T.; Cau Dit Coumes, C.; Chopin-Dumas, J.; Devisme, F.; Rat, B.; Hill, C.; Guillaneux, D.; Madic, C.; Carrera, A.; Dozol, J.F.; Rouquette, H.; Allain, F.; Virelizier, H.; Moulin, Ch.; Lemort, F.; Orlhac, X.; Fillet, C.; Carpena, J.; Advocat, T.; Leturcq, G.; Lacombe, J.; Bonnetier, A.; Ribet, I.; Poitou, S.; Richaud, D.; Fiquet, O.; Gramondi, P.; Massit, H.; Meyer, D.; Conocar, O.; Pettier, J.L.; Raphael, T.; Bouniol, P.; Sercombe, J.; Badouix, P.; Adenot, F.; Le Bescop, P.; Mazoin, C.; Motellier, S.; Charles, Y.; Richet, C.; Ayache, R.; Pitsch, H.; Ly, J.; Beaucaire, C.; Devol-Brown, I.; Libert, M.F.; Besnainou, B

    1999-07-01

    In this chapter of the DCC 1999 scientific report, the following theoretical studies are detailed: electronic structure of lanthanides or actinides complexes, forecasting of the stoichiometry of europium nitrate complexes, actinides aqueous solutions analytical and thermodynamical chemistry, actinides complexes structural determination. It also provides experimental studies: actinides and lanthanides separation, radioactive wastes processing and conditioning, plasma torch vitrification process, simulation of the wastes packages characterization, wastes storage with concrete behaviour and biodegradation. (A.L.B.)

  7. 1. round table - Spent fuels composition. Back-end of the fuel cycle and reprocessing, plutonium and other nuclear materials management. 2. round table - Separation-transmutation. 3. round table - Scenarios for a long term inventory of nuclear materials and wastes; 1. table ronde - La composition des combustibles uses. L'aval du combustible et le retraitement, la gestion du plutonium et des autres matieres nucleaires. 2. table ronde - Separation-transmutation. 3. table ronde - Scenarii pour un inventaire des matieres et des dechets nucleaires a LT

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The law from December 30, 1991, precisely defines 3 axes of researches for the management of high level and long-lived radioactive wastes: separation/transmutation, surface storage and underground disposal. A global evaluation report about these researches is to be supplied in 2006 by the French government to the Parliament. A first synthesis of the knowledge gained after 14 years of research has led the national commission of the public debate (CNDP) to organize a national debate about the general options of management of high-level and long-lived radioactive wastes before the 2006 date line. The debate comprises 4 public hearings (September 2005: Bar-le-Duc, Saint-Dizier, Pont-du-Gard, Cherbourg), 12 round-tables (October and November 2005: Paris, Joinville, Caen, Nancy, Marseille), a synthesis meeting (December 2005, Dunkerque) and a closing meeting (January 2006, Lyon). This document is the synthesis of the round table debates which took place at Paris on the reprocessing of spent fuels. Three aspects are discussed: the risks linked with the recovery of valorizable materials, the economical viability of the separation/transmutation option, and the future of the nuclear option in the French energy policy. Six presentations (transparencies) are attached with these proceedings which treat of: the reprocessing/recycling to the test, perspectives of future wastes, present day wastes/valorizable materials and future scenarios, critical analysis scenarios, why reprocessing spent fuels?, processing of spent fuels and recycling, separation and transmutation of long-lived radioactive wastes, thorium-uranium cycle. (J.S.)

  8. Relationship between the nuclear resonance of cobalt metal and its ferromagnetic properties; Relations entre la resonance nucleaire du cobalt metallique et ses proprietes ferromagnetiques

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-05-15

    resulte du couplage intense existant entre les noyaux et les electrons porteurs du magnetisme. Ces derniers excitent les noyaux et, dans les parois de Bloch, les soumettent a un champ radio-frequence bien plus intense que le champ RF applique. Les parametres de la resonance se determinent alors a partir du mouvement des parois, et dependent donc des constantes ferromagnetiques. La theorie permet de prevoir quantitativement certains effets particuliers, notamment par action d'un champ magnetique continu ou de la temperature. L'etude expeimentale a porte sur des poudres de cobalt et est en bon accord avec la theorie. Toutefois il faut tenir compte de l'effet de peau et reviser la theorie en consequence. Ceci permet d'expliquer certaines divergences observees, ainsi que l'influence de la taille des grains et celle du champ magnetique sur la forme de raie. Des renseignements originaux ont ete obtenus sur certaines proprietes purement ferromagnetiques du cobalt, en etudiant l'effet d'un champ magnetique et cette methode a pu etre appliquee a d'autres corps ferromagnetiques. En raison du caractere particulier de cette resonance nucleaire, qui se produit en l'absence de champ directeur et possede une importante largeur de raie, des spectrographes de type nouveau ont ete realises qui ont rendu possible des mesures precises de la forme de raie. La faible intensite des signaux obtenus dans certains cas a conduit a la mise au point d'une methode originale d'extraction dont la theorie et les applications pratiques sont donnees ici. L'ensemble de ces experiences fait apparaitre la resonance nucleaire comme un puissant moyen d'etude du ferromagnetique permettant de deceler des phenomenes microscopiques difficilement accessibles par les methodes classiques. (auteur)

  9. Valorisation du biogaz de fermentation : combustion catalytique

    OpenAIRE

    Dupont, Nicolas

    2010-01-01

    The objective of this work concerns the study of two classes of catalysts, mixed oxides (CuO/Al2O3, CuO-CuAl2O4, CuO-CuCr2O4, CuO-ZnO-Al2O3 undoped or doped with Ag and Mn) and nobles supported metals (Pd/Al2O3 and Pt/ Al2O3, Pd-Pt /Al2O3 undoped or doped with B) used in two different reactions: low temperature gas phase ammonia oxidation into nitrogen and high temperature methane catalytic combustion for energy production. Biogas, a renewable energy, is mainly constituted of methane and carb...

  10. Improvement of Sodium Neutronic Nuclear Data for the Computation of Generation IV Reactors; Contribution a l'amelioration des donnees nucleaires neutroniques du sodium pour le calcul des reacteurs de generation IV

    Energy Technology Data Exchange (ETDEWEB)

    Archier, P.

    2011-09-14

    de ces incertitudes provient des donnees nucleaires et, dans le cas des RNR-Na, des donnees nucleaires du sodium, qui presentent des differences significatives entre les bibliotheques internationales (JEFF-3.1.1, ENDF/B-VII.0, JENDL-4.0). L'objectif de cette these est d'ameliorer la connaissance sur les donnees nucleaires du sodium afin de mieux calculer les parametres neutroniques des RNR-Na et fournir des incertitudes fiables. Apres un etat des lieux des presentes donnees du {sup 23}Na, l'impact des differences est quantifie notamment sur les effets en reactivite de vidange du sodium, calcules avec des outils neutroniques deterministe et stochastique. Les resultats montrent qu'il est necessaire de reevaluer entierement les donnees nucleaires du sodium. Plusieurs developpements ont ete effectues dans le code d'evaluation Conrad, pour integrer de nouveaux modeles de reactions nucleaires et leurs parametres ainsi que pour permettre de proceder a des ajustements avec des mesures integrales. Suite a ces developpements, l'analyse des donnees differentielles et la propagation des incertitudes experimentales avec Conrad ont ete realisees. Le domaine des resonances resolues a ete etendu a 2 MeV et le domaine du continuum debute directement au-dela de cette energie. Une nouvelle evaluation du {sup 23}Na et les matrices de covariances multigroupes associees ont ete generees pour de futurs calculs d'incertitudes. La derniere partie de la these se focalise sur le retour des experiences integrales de vidange du sodium, par des methodes d'assimilation de donnees integrales, afin de reduire les incertitudes sur les sections efficaces du sodium. Ce document se clot sur des calculs d'incertitudes pour des RNR-Na de type industriel, qui montrent une meilleure prediction de leurs parametres neutroniques avec la nouvelle evaluation

  11. Is it possible to recycle nuclear wastes? Costs, risks and stakes of the plutonium industry; Peut-on recycler les dechets nucleaires? Couts, risques et enjeux de l'industrie du plutonium

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    This document, published by the French association 'Sortir du nucleaire' (Get out of nuclear), gives some information on the chain reaction from uranium to plutonium, the difference between reprocessing (which does not reduce waste volumes but multiply waste types) and recycling, the high risks associated with plutonium transport, La Hague as the most dangerous nuclear site in France, reprocessing as the alibi for the French nuclear industry, Areva as an expert in propaganda, reprocessing as an absurd world strategy, plutonium as a fuel for proliferation, the myth of unlimited energy with the breeder reactors, and so on

  12. Differential measurement of the earth's magnetic field by nuclear magnetic resonance; Mesure differentielle du champ magnetique terrestre par resonance magnetique nucleaire

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-07-01

    MNR transducers using proton dynamic polarisation allows to convert into a phase measurement any variation of the earth magnetic field. There exist several versions of the instrument corresponding to various models of MNR transducers, which the author analyses in detail, devoting an important place to influence of their alignment with respect to the earth's magnetic field. The sensibility obtained is of one hundredth of a gamma over a bandwidth of (0-0,1 Hz). - This instrument is designed for measuring field gradients in airborne magnetic surveying, for detecting nearly magnetic anomalies, and for distinguishing between nearly and distant magnetic phenomena. (author) [French] L'emploi de capteurs, bases sur la resonance magnetique nucleaire des protons en presence de polarisation dynamique, permet de traduire une difference de champ magnetique terrestre en une mesure de phase. L'appareil existe sous plusieurs versions avec des capteurs de modeles differents dont l'auteur fait une analyse detaillee en accordant une part importante a l'influence de l'orientation des capteurs par rapport au champ magnetique terrestre. La sensibilite est de 1/100 {gamma} pour une bande passante de (0 - 0,1 Hz). Cet appareil s'applique a la mesure du gradient en prospection magnetique aeroportee, a la detection d'anomalies magnetiques proches, a la differentiation d'effets magnetiques proches et lointains. (auteur)

  13. Factors and uncertainties in the profitability of using nuclear energy in desalination of water; Facteurs et incertitudes de la rentabilite du recours a l'energie nucleaire dans le dessalement des eaux

    Energy Technology Data Exchange (ETDEWEB)

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

    1969-07-01

    coefficients de transmission, les durees de vie des materiels, selon le choix des materiaux, l'evolution des prix, la forme des fonctions de prix et les taux d'interet) et aux contraintes. Dans une deuxieme partie, on etudie et on discute les incertitudes liees, a la methode d'optimisation utilisee et au critere de choix retenu. On montre ainsi qu'il est extremement difficile dans la plupart des cas de conclure sans nuances a la competitivite ou, a l'inverse, a la non competitivite du recours a l'energie nucleaire dans le dessalement des eaux et qu'un grand nombre d'aspects doivent etre soigneusement examines. (auteur)

  14. The origin of cholesterol in chyle demonstrated by nuclear indicator methods; Origines du cholesterol du chyle mises en evidence par la methode des indicateurs nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Vyas, M

    1962-07-01

    In order to obtain information about the mechanism of the intestinal absorption of cholesterol, rats having a lymphatic abdominal fistula are used. The animals receive either 4-{sup 14}C- cholesterol subcutaneously or orally, or the 1-{sup 14}C acetate. The study of the specific radio-activities of the cholesterol in chyle, in serum, in the lining, and in the intestinal contents makes it possible to define the roles played by the transfer cholesterol from the serum, by the cholesterol synthesised intestinally, and by the absorption cholesterol, in the formations of the lymph and of the chylomicrons. A new theory is proposed for the mechanism of cholesterol absorption. (author) [French] Pour obtenir des renseignements concernant le mecanisme de l'absorption intestinale du cholesterol, on utilise des rats porteurs d'une fistule lymphatique abdominale. Les animaux recoivent soit du cholesterol 4-{sup 14}C par voie sous-cutanee ou par voie orale, soit de l'acetate 1-{sup 14}C. L'etude des radioactivites specifiques du cholesterol du chyle, du serum, de la paroi et du contenu intestinal permet de preciser les roles joues par le cholesterol de transfert d'origine serique, par le cholesterol de synthese intestinale et par le cholesterol d'absorption, dans la formation de la lymphe et des chylomicrons. Une theorie nouvelle concernant le mecanisme de l'absorption du cholesterol est proposee. (auteur)

  15. Prediction du transfert thermique parietal pour la chambre de combustion d'une turbine a gaz

    Science.gov (United States)

    Gosselin, Pierre

    Des travaux ont demontre que la temperature de paroi pouvait etre predite avec precision (+/-6 a 10%) pour une chambre de combustion a pleine-echelle. Pour les resultats obtenus d'une autre chambre, aussi identique mais de plus petit diametre, la prediction de temperature de paroi n'offrait pas la meme precision de calcul. Cette etude est limitee aux turbines aeronautiques. L'objectif a ete de reevaluer globalement la prediction de la temperature de paroi d'une chambre de combustion de type GHOST a la lumiere des resultats obtenus des programmes experimentaux, tout en prenant en consideration l'influence des differents types de carburants. Par l'analyse du grand nombre de donnees experimentales, des modifications furent apportees a la methode de prediction utilisee pour les chambres a pleine echelle afin de reduire l'erreur de prediction pour les echelles a 1:2 (basse pression), 1:3 (basse pression) et 1:3 (haute pression). Une modelisation de la chambre de combustion a ete effectuee. L'analyse numerique nous a demontree que le code FLUENT/UNS predisait tres bien l'ecoulement a froid a l'interieur de la chambre de combustion GHOST echelle 1:1. La prediction etait acceptable au niveau des profils de temperature a l'interieur de la chambre. Cependant, une lacune a ete observee au niveau du modele d'evaporation du code.

  16. {alpha} grain refining and metallurgical study of alloyed uranium, Sicral F1, used for fuel elements; Affinage du grain {alpha} et etude metallurgique de l'alliage d'uranium sicral F1 pour elements combustibles

    Energy Technology Data Exchange (ETDEWEB)

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

    1969-07-01

    This study was made to know more about grain refining in low alloyed uranium of composition not very different from SICRAL F 1. Alpha grain refining of fuel elements made of these alloys was studied after casting and quenching by the methods used for mass production. The author describes the effect: - of the metallurgical history before quenching: - casting - purity - rate of solidification - of quenching parameters: - annealing temperature before quenching - annealing time - quenching rate - of the composition of the alloy. For the graphite gas fuel elements of various dimensions, he suggests some modifications to give a better adaptation of fabrication to size. He describes the grain refining made during quenching and the {beta} -> {alpha} and {gamma} -> {alpha} transformation types. He proposes the use of a U-Fe-Si especially useful from the point of view of grain refining. (author) [French] Le but de l'etude est de determiner les facteurs metallurgiques favorables a l'affinage du grain {alpha} des alliages d'uranium a tres faibles teneurs en elements d'addition voisins du SICRAL F 1 au cours du cycle de fabrication et de trempe industrielle des elements combustibles nucleaires prepares avec ces alliages. L'auteur met en evidence l'influence: - de l'histoire metallurgique avant trempe: - coulee - teneur en impuretes - vitesse de solidification - des parametres de la trempe: - temperature de trempe - temps et maintien a cette temperature - vitesse de trempe - des variations de composition de l'alliage. Il envisage les modifications a apporter au cycle de fabrication du SICRAL F 1 de facon a l'adapter aux differentes geometries des elements combustibles des reacteurs de la filiere graphite-gaz. L'auteur presente a cette occasion les mecanismes de l'affinage du grain {alpha} par trempe dans les alliages d'uranium et les modes de transformation {beta} -> {alpha} et {gamma} -> {alpha} au cours de la trempe

  17. Fessenheim: 30 years of nuclear fuel operation; Fessenheim: 30 ans d'exploitation du combustible nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Abgrall, G. [Centrale de Fessenheim, EDF, 68 - Dessenheim (France)

    2008-03-15

    Fessenheim units 1 and 2 are the first two 900 MW PWR put into operation in France (1977). This article reviews 30 years of change, optimization and feedback experience from Fessenheim, concerning: -) fuel assemblies (particularly the design of some components like grids, ends and guide tubes), -) the reload fuel management (to get a higher unloading burn-up), -) the refueling machine and tools (heavy modifications to reduce the human factor), and -) work organization (work shifts and staff training). (A.C.)

  18. Conformity of nuclear construction codes with the requirements of the French order dated December 12, 2005 related to nuclear pressure equipment; Conformite des codes de construction nucleaires avec les exigences de l'arrete du 12 decembre 2005 relatif aux equipements sous pression nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Grandemange, J.M.; Renaut, P. [Areva-NP, Tour AREVA, 92084 - Paris La Defense cedex, (France); Paris, D. [EDF-Ceidre 2 rue Ampere - 93206 SAINT-DENIS Cedex (France); Faidy, C. [EDF-Septen 12/14, Avenue Dutrievoz 69628 Villeurbanne Cedex (France)

    2007-07-01

    The French Decree dated December 13, 1999 transposing the Pressure Equipment Directive (PED) has replaced the fundamental texts on which up to now the regulation for pressure equipment important for the safety of nuclear reactors was also founded. By a Ministerial Order - called 'ESPN Order' - dated December 12, 2005, a new regulation has been issued for nuclear pressure equipment. This text makes reference to the Decree transposing the PED while completing these provisions by supplementary requirements having the objective to provide a very high level of integrity guarantee for equipments which are the most important for safety, and to cover the prevention of radioactive release risks. These regulatory evolutions are presented in the Plenary Session of the ESOPE conference. Referencing the Decree and thus the PED, and including specific provisions, the Ministerial Order implies that the Manufacturers update their documents and, if necessary, their prescriptions in the following two domains: - that of the conformity of Codes and Standards used, generally inspired from the ASME Code Section III, with the essential safety requirements of the PED, - that of the respect of the complementary provisions brought by the ESPN Order. This paper presents the more significant conclusions of this work and the resulting amendments of the RCC-M Code, introduced by the 2007 addendum to that Code. The analysis will lead to specify the same type of complementary requirements to Code when a manufacturer wishes to use the German KTA Rules or the ASME Code Section III. (authors) [French] Le decret du 13 decembre 1999 transposant la directive europeenne (DESP) relative aux equipements sous pression a remplace les textes fondamentaux sur lesquels se fondait egalement jusque la la reglementation des appareils a pression importants pour la surete des reacteurs nucleaires. Par arrete - dit 'arrete ESPN' - du 12 decembre 2005, une nouvelle reglementation a ete dictee. Ce

  19. Processing Th C{sub 2} - UC{sub 2} fuel extracted from high temperature reactors HTGCR; Etude du traitement des combustibles Th C{sub 2} - UC{sub 2} issus de reacteurs a haute temperature

    Energy Technology Data Exchange (ETDEWEB)

    Derrien, C.; Lessart, P.; Pianezza, E.; Verry, C.; Villain, G. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    The object of this investigation is solubilisation head-end (from crushing and grinding phase to non included first purification phase) of pulverulent ({sup 233}U/{sup 232}Th)C{sub 2} (200 - 500 microns diameter) contained in a graphite matrix extracted from a 4.10{sup 13} n.cm{sup -2}.s{sup -1} thermalized neutrons average flux with an irradiation of 80000 MWjT{sup -1} HTGCR reactor. After having succinctly described different bibliographic processes we have chosen the burn - leach of reactor fuel and graphite matrix containing it. The technology of burner is original in nuclear field and still more by utilizing ultra-sounds to intensify burning reaction and to minimize the weight of unburnables. The mixture of ThO{sub 2}, U{sub 3}O{sub 8}, and fission products oxides is solubilized by boiling HNO{sub 3} 13 M + HF 0.05 M. This process is profit-learning in a thorium recuperation and reprocessing point of view. In the contrary-case it would be interesting to consider a dry-process which would permit to separate solid ThF{sub 4} from gaseous UF{sub 6}. (authors) [French] Cette etude a pour objet le traitement initial de mise en solution ou 'head-end' (allant de la phase broyag-concassage a la phase de premiere purification exclue) d'un combustible ({sup 233}U/{sup 232}Th)C{sub 2} pulverulent (de 200 a 500 {mu} de diametre) contenu dans une matrice de graphite issu d'un reacteur HTGCR surgenerateur a neutrons thermiques de flux moyen 4. l0{sup 13} n.cm{sup -2}.s{sup -1} et taux d'irradiation 80000 MWjT{sup -1}. Apres exposition succincte des differents procedes bibliographiques decrits, nous avons finalement choisi le traitement par combustion-attaque ('Burn-Leach') du combustible et de la matrice etanche graphite qui le contient. La technologie du bruleur est originale dans le domaine nucleaire d'autant qu'elle utilise les ultra-sons pour ameliorer le rendement de la reaction de combustion et reduire au minimum le poids

  20. Atomic scale modelling of materials of the nuclear fuel cycle; Modelisation a l'echelle atomique de materiaux nucleaires du cycle du combustible

    Energy Technology Data Exchange (ETDEWEB)

    Bertolus, M.

    2011-10-15

    This document written to obtain the French accreditation to supervise research presents the research I conducted at CEA Cadarache since 1999 on the atomic scale modelling of non-metallic materials involved in the nuclear fuel cycle: host materials for radionuclides from nuclear waste (apatites), fuel (in particular uranium dioxide) and ceramic cladding materials (silicon carbide). These are complex materials at the frontier of modelling capabilities since they contain heavy elements (rare earths or actinides), exhibit complex structures or chemical compositions and/or are subjected to irradiation effects: creation of point defects and fission products, amorphization. The objective of my studies is to bring further insight into the physics and chemistry of the elementary processes involved using atomic scale modelling and its coupling with higher scale models and experimental studies. This work is organised in two parts: on the one hand the development, adaptation and implementation of atomic scale modelling methods and validation of the approximations used; on the other hand the application of these methods to the investigation of nuclear materials under irradiation. This document contains a synthesis of the studies performed, orientations for future research, a detailed resume and a list of publications and communications. (author)

  1. Aspects chimiques de la combustion du charbon pulvérisé. Première partie Chemical Aspects of the Combustion of Pulverized Coal. Part One

    Directory of Open Access Journals (Sweden)

    De Soete G. G.

    2006-11-01

    Full Text Available II n'est pas facile de parvenir à une vue complète des multiples phénomènes chimiques dont la flamme de charbon pulvérisé est le siège. La présente étude bibliographique s'efforce de donner plus qu'une juxtaposition des données de la littérature récente, en risquant une tentative de présentation cohérente des mécanismes chimiques clés qui s'affrontent dans cette combustion. Ces mécanismes font intervenir des réactions en phase gazeuse relativement rapides (combustion des produits gazeux de pyrolyse, formation d'oxydes d'azote à partir de l'azote organique ainsi qu'un certain nombre de réactions hétérogènes très importantes (dévolatilisation pyrolysante rapide, oxydation du coke, réduction hétérogène d'oxydes d'azote qui peuvent se dérouler de façon beaucoup plus lente. En ce qui concerne ces dernières, le régime non isotherme, auquel les soumet l'existence de gradients de température dans la flamme industrielle, entraîne souvent des conséquences non négligeables pour le déroulement de ces mécanismes cinétiques complexes : ainsi la quantité et la composition des produits de pyrolyse est fortement tributaire de ces conditions non isothermes. Carrefour de plusieurs mécanismes chimiques complexes, la flamme de charbon est caractérisée chimiquement par un grand nombre de cas de compétition : a compétition entre différentes voies réactionnelles à l'intérieur d'un mécanisme donné ; à titre d'exemple typique : la pyrolyse du charbon ; b compétition entre phénomènes chimiques et physiques, également à l'intérieur d'un même mécanisme, entraînant la transition éventuellement réversible d'un régime cinétique vers un régime diffusionnel, comme c'est le cas dans l'oxydation du coke, avec des conséquences sensibles pour la vitesse réactionnelle globale et sa dépendance par rapport à la température, pouvant même aller jusqu'à l'extinction de la combustion du coke ; c compétition entre

  2. Nuclear energy; Le dossier du nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Pierret, Ch. [Ministere de l' Industrie et de l' Amenagement du Territoire, 75 - Paris (France); Bacher, P.; Tanguy, P. [and others

    2001-11-01

    11 contributions written by experts are gathered in this document dedicated to nuclear energy (N.E): 1) could we live without N.E?, 2) do we have to fear N.E?, 3) a critical point of view on N.E, 4) the sanitary consequences of Chernobyl accident, 5) the impact of low radiation doses, 6) the management of a nuclear power plant, 7) the optimisation of wastes at The Hague facility, 8) the management of radioactive wastes in France, 9) the next generation of nuclear reactors, 10) N.E and public acceptance, and 11) is N.E the energy for the future? (A.C.)

  3. The nuclear refugees; Les refugies du nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Linton, M.

    2011-06-15

    The authors propose a report on the various situations of people who had to be evacuated after the Fukushima accident. Along with examples of people who left their homes with taking with them a single object, the authors describe and comment how this evacuation occurred, the problems faced by the authorities for refugee reception and accommodation. This evacuation has been either organised or spontaneous. Hospitals had to be evacuated as well. Then, local authorities faced food shortage. Some animals have been saved, other starved to death. Dead animals are covered with lime. Dead bodies are decontaminated before being given back to families. Tests are regularly performed to assess people contamination. A second article discussed the bad news concerning the different Fukushima reactors with their melted cores. The geophysical aspects of the earthquake are evoked in a last article

  4. Contribution to the study of nuclear resonance in magnetic media (1963); Contribution a l'etude de la resonance nucleaire dans les milieux magnetique (1963)

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-06-15

    An attempt is made to interpret the results of nuclear magnetic resonance experiments made by various workers on ferro and ferrimagnetic compounds of the iron group. The problems encountered are the following: effects of the dipolar fields and the hyperfine structure anisotropy; signal intensity; frequency pulling due to the Suhl-Nakamura interaction between nuclear spins ; nuclear relaxation and ferrimagnetic resonance in single domain samples of impure YIG; nuclear relaxation in the Bloch walls of insulators. The results of our calculations are generally in good agreement with experiment. (author) [French] On se propose d'interpreter les resultats d'experiences de resonance magnetique nucleaire fates par divers auteurs sur des composes ferro et ferrimagnetiques du groupe du fer. Les problemes abordes sont les suivants: effets des champs dipolaires et de l'anisotropie de structure hyperfine; intensite des signaux; deplacement de frequence du a l'interaction de Suhl-Nakamura entre spins nucleaires; relaxation nucleaire et resonance ferrimagnetique dans les echantillons monodomaines de grenat de fer et d'yttrium impur; relaxation nucleaire dans les parois de Bloch des isolants. Les resultats des calculs sont generalement en bon accord avec l'experience. (auteur)

  5. Combustion

    CERN Document Server

    Glassman, Irvin

    1987-01-01

    Combustion, Second Edition focuses on the underlying principles of combustion and covers topics ranging from chemical thermodynamics and flame temperatures to chemical kinetics, detonation, ignition, and oxidation characteristics of fuels. Diffusion flames, flame phenomena in premixed combustible gases, and combustion of nonvolatile fuels are also discussed. This book consists of nine chapters and begins by introducing the reader to heats of reaction and formation, free energy and the equilibrium constants, and flame temperature calculations. The next chapter explores the rates of reactio

  6. The cycle of the nuclear fuel used in EDF power plants; Le cycle du combustible nucleaire utilise dans les centrales EDF

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-11-15

    This document briefly indicates the different stages of the nuclear fuel cycle, from the purchase of natural uranium to waste storage. It also indicates the main responsibilities of EDF regarding this fuel cycle (to secure supplies, to organise material transportation, to process and store used fuels and associated wastes). It presents the different associated processes: uranium extraction, purification and concentration, conversion or fluoridation, enrichment. It briefly describes the fuel assembly fabrication, and indicates the main uranium producers in the world. Other addressed steps are: the transportation of fuel assembly, fuel loading, and spent fuel management, the processing of spent fuel and radioactive wastes

  7. Production and validation of nuclear data for reactor and fuel cycle applications; Production et validation des donnees nucleaires pour les applications reacteurs et cycle du combustible

    Energy Technology Data Exchange (ETDEWEB)

    Trakas, C. [Framatome ANP GmbH NBTT, Erlangen (Germany); Verwaerde, D. [Electricite de France EDF, 75 - Paris (France); Toubon, H. [Cogema, 78 - Velizy Villacoublay (France)] [and others

    2002-07-01

    The aim of this technical meeting is the improvement of the existing nuclear data and the production of new data of interest for the upstream and downstream of the fuel cycle (enrichment, fabrication, management, storage, transport, reprocessing), for the industrial reactors, the research reactors and the new reactor concepts (criticality, dimensioning, exploitation), for the instrumentation systems (external and internal sensors), the radioprotection, the residual power, the structures (neutron bombardment effect on vessels, rods etc..), and for the activation of steel structures (Fr, Ni, Co). The expected result is the collection of more reliable and accurate data in a wider spectrum of energies and temperatures thanks to more precise computer codes and measurement techniques. This document brings together the communications presented at this meeting and dealing with: the process of production and validation of nuclear data; the measurement facilities and the big international programs; the users needs and the industrial priorities; the basic nuclear data (BND) needs at Cogema; the expression and evaluation of BND; the evaluation work: the efficient cross-sections; the processing of data and the creation of activation libraries; from the integral measurement to the qualification and the feedback on nuclear data. (J.S.)

  8. Safe management of actinides in the nuclear fuel cycle: Role of mineralogy; La gestion des actinides dans le cycle du combustible nucleaire: le role de la mineralogie

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, R.C. [Department of Nuclear Engineering and Radiological Sciences, Department of Geological Sciences, Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-1005 (United States)

    2011-02-15

    During the past 60 years, more than 1800 metric tonnes of Pu, and substantial quantities of the 'minor' actinides, such as Np, Am and Cm, have been generated in nuclear reactors. Some of these transuranium elements can be a source of energy in fission reactions (e.g., {sup 239}Pu), a source of fissile material for nuclear weapons (e.g., {sup 239}Pu and {sup 237}Np), and of environmental concern because of their long-half lives and radiotoxicity (e.g., {sup 239}Pu and {sup 237}Np). There are two basic strategies for the disposition of these heavy elements: (1) to 'burn' or transmute the actinides using nuclear reactors or accelerators; (2) to 'sequester' the actinides in chemically durable, radiation-resistant materials that are suitable for geologic disposal. There has been substantial interest in the use of actinide-bearing minerals, especially isometric pyrochlore, A{sub 2}B{sub 2}O{sub 7} (A rare earths; B = Ti, Zr, Sn, Hf), for the immobilization of actinides, particularly plutonium, both as inert matrix fuels and nuclear waste forms. Systematic studies of rare-earth pyrochlores have led to the discovery that certain compositions (B = Zr, Hf) are stable to very high doses of alpha-decay event damage. Recent developments in our understanding of the properties of heavy element solids have opened up new possibilities for the design of advanced nuclear fuels and waste forms. (author)

  9. Assessment of the feasibility of indefinite containment of canadian nuclear fuel wastes; Evaluation de la faisabilite du confinement illimite des dechets de combustible nucleaire canadiens

    Energy Technology Data Exchange (ETDEWEB)

    Shoesmith, D.W.; King, F.; Ikeda, B.M.

    1995-05-01

    This report presents an analysis of the expected corrosion behavior of nuclear fuel waste containers in a conceptual Canadian disposal vault. The container materials considered are dilute Ti alloys (Grades-2, -12 and -16) and oxygen-free copper.

  10. AREVA Technical Days (ATD) session 2: operations of the back-end of the nuclear fuel cycle; AREVA Technical Days (ATD) session 2: les activites du pole Aval du cycle du combustible nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    These technical days organized by the Areva Group aims to explain the group activities in a technological and economic point of view, to provide an outlook of worldwide energy trends and challenges and to present each of their businesses in a synthetic manner. This second session deals with the reprocessing business, back-end financing mechanisms, technology transfer, environmental management, risk management programs, research and development contribution to waste volume reductions, issues and outlook of nuclear wastes, comparison of the open and closed cycles. (A.L.B.)

  11. Decision no. 2011-DC-0220 of the French nuclear safety authority from May 5, 2011, ordering the FBFC company to proceed to a complementary safety evaluation of some of its basic nuclear facilities in the eyes of the Fukushima Daiichi nuclear power plant accident; Decision no. 2011-DC-0220 de l'Autorite de surete nucleaire du 5 mai 2011 prescrivant a FBFC de proceder a une evaluation complementaire de la surete de certaines de ses installations nucleaires de base au regard de l'accident survenu a la centrale nucleaire de Fukushima Daiichi

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    As a consequence of the accident of the Fukushima Daiichi nuclear power plant (Japan), the French Prime Minister entrusted the French nuclear safety authority (ASN) with the mission to carry out a safety analysis re-evaluation of the French nuclear facilities, and in particular the nuclear power plants. A decision has been addressed by the ASN to each nuclear operator with the specifications of this safety re-evaluation analysis and the list of facilities in concern. This document is the decision addressed to the FBFC (Franco-Belge de Fabrication du Combustible), a daughter fuel fabrication company of Areva NC (France). (J.S.)

  12. Essais préliminaires de combustion d'asphaltes par la technique du charbon pulvérisé Preliminary Tests of Asphalt Combustion by the Pulverized Coal Technique

    Directory of Open Access Journals (Sweden)

    Flament G.

    2006-11-01

    Full Text Available Les possibilités offertes par le procédé de désasphaltage étudié à L'Institut Français du Pétrole (IFP sont rapidement exposées. On montre en particulier que les asphaltes recueillis grâce à ce procédé ont des propriétés physiques telles, qu'il est possible de s'en servir comme combustible et donc de les valoriser sur le plan énergétique. The possibilities offered by the deasphalting process researched by Institut Français du Pétrole (IFP are briefly described. It is shown in particular that the types of asphalts gathered by means of this process have physical properties enabling them to be used as a fuel so that they can be upgraded from the energy standpoint.

  13. Essais préliminaires de combustion d'asphaltes par la technique du charbon pulvérisé Preliminary Tests of Asphalt Combustion by the Pulverized Coal Technique

    OpenAIRE

    Flament G.; Mauss F.

    2006-01-01

    Les possibilités offertes par le procédé de désasphaltage étudié à L'Institut Français du Pétrole (IFP) sont rapidement exposées. On montre en particulier que les asphaltes recueillis grâce à ce procédé ont des propriétés physiques telles, qu'il est possible de s'en servir comme combustible et donc de les valoriser sur le plan énergétique. The possibilities offered by the deasphalting process researched by Institut Français du Pétrole (IFP) are briefly described. It is shown in particular ...

  14. Research on nuclear energy in the fields of fuel cycle, PWR reactors and LMFBR reactors; Recherche sur l`energie nucleaire dans les domaines du cycle du combustible des reacteurs a eau legere et des reacteurs a neutrons rapides

    Energy Technology Data Exchange (ETDEWEB)

    Barre, B.; Camarcat, N.

    1995-12-31

    In this article we present the CEA research programs to improve the safety of the next generation of reactors, to manage the Plutonium and the wastes of the fuel cycle end and to ameliorate the competitiveness. 6 refs.

  15. Microbial issues pertaining to the canadian concept for the disposal of nuclear fuel waste. Questions a examiner quant aux microbes lors du developpement du concept canadien de stockage permanent des dechets de combustible nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Stroes-Gascoyne, S.; West, J.M.

    1994-01-01

    This report formulates a number of views and positions on microbiological factors that could influence the performance of a disposal vault in plutonic rock. Microbiological factors discussed include the presence and survival of microbes, biofilms, corrosion, biodegradation (of emplaced materials), gas production, geochemical changes, radionuclide migration, colloid formation, mutation, pathogens and methylation. Not all issues can be fully resolved with the current state of knowledge. Studies being performed to underscore and strengthen current knowledge are briefly discussed.

  16. Research on the chemistry of actinides and fission products for the development of nuclear fuel cycle; Developpement du cycle du combustible nucleaire. Recherche sur la chimie des actinides et des produits de fission

    Energy Technology Data Exchange (ETDEWEB)

    Peretroukhine, V.F. [Institute of Physical Chemistry Russian Academy of Sciences (IPC-Moscow) (Russian Federation); Lecomte, M. [CEA Valrho, Dept. Radiochimie et Procedes, 30 - Marcoule (France); David, F. [Institut de Physique Nucleaire, (IN2P3/CNRS) 91 - Orsay (France)

    2004-07-01

    The present document is prepared for CEA, IPNO and Russian Academy of Sciences administrations in compliance with the decision, accepted by the Director Committee of the three-parties-Convention on its seventh meeting in Moscow 21 May 2002. Being the general frame, determining the strategy of three-party cooperation, the Convention 1993-2003 consists of the number of contracts between organisation-participants. The present document is compiled, using annual proceedings of Director Committee and Technical Committee meetings and using published French-Russian papers and technical reports, produced in the frame of all contracts of the convention. Lists of published papers and personal summary reports of Russian participants of the contracts are presented in Appendix 1. (authors)

  17. Dynamic method for the measurement of Young'S modulus. Application to nuclear graphites; Methode de mesure dynamique du module d'Young. Application aux graphites nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Pattou, F.; Trutt, J.C

    1963-07-01

    A dynamic method has been developed for measuring Young's modulus and the rigidity modulus using the 'Forster Elastomat'. The principle consists in the determination of the resonance frequencies of graphite samples submitted to transverse, longitudinal, and torsional vibrations. The first two modes of vibration make it possible to calculate the elasticity modulus or the Young's modulus E, the third mode makes possible the calculation of the rigidity modulus G. The relationships from which the moduli E and G are measured are given. A systematic study has been made of graphite samples produced by extrusion or compression and submitted afterwards to one or several impregnations with pitch. For graphites made from the same coke by the same method, a linear relationship has been found for Young's modulus as a function of the apparent density. For the same apparent density, graphites made from different starting materials have generally different Young's moduli that bear a relationship to the crystalline characteristics of the material. The measurements of the rigidity modulus C made on different graphites also show the influence of crystallite orientation. (authors) [French] Une methode de mesure dynamique du module d'Young et du module de rigidite du graphite utilisant 'l'Elastomat Forster' a ete mise au point. Le principe consiste a determiner les frequences de resonance d'echantillons de graphite soumis a des vibrations transversales, longitudinales et de torsion. Les deux premiers modes de vibration permettent de calculer le module d'elasticite ou module d'Young E, le troisieme mode de vibration permet de calculer le module de rigidite G. Apres avoir decrit la methode de mesure, on rappelle les relations qui permettent de calculer les modules E et G. L'etude systematique d'echantillons de graphite, fabriques par filage ou pressage et ayant subi eventuellement une ou plusieurs impregnations au

  18. Activities report of the Nuclear Physics Department (CEN Saclay). 1 Oct 1966 - 30 Sep 1967; Compte rendu d'activite du Departement de Physique Nucleaire (CEN Saclay). 1 Oct 1966 - 30 Sep 1967

    Energy Technology Data Exchange (ETDEWEB)

    Cotton, E. [and others

    1967-07-01

    Three parts of the report treat the questions related to the tandem, the cyclotrons and the electrons linear accelerators, then two annexes give the role of publications in this year, and the list of scientific and technical personnel. In the area of Van de Graaff and cyclotrons, progress has been made in the realisation of particles identification systems and in the methods of data processing. The starting up of the trochoidal injection has allowed an improvement of the protons polarisation rate and the intensity increase by a factor 1000. [French] Trois parties traitent des questions concernant le tandem, les cyclotrons et les accelerateurs lineaires a electrons, puis deux annexes donnent la liste des publications de l'annee et la liste du personnel scientifique et technique. Dans le domaine des Van de Graaf et cyclotrons, il faut signaler les progres dans la realisation de systemes d identification de particules et dans les methodes de traitement de donnees. La mise en service de l injection trochoidale a permis une amelioration du taux de polarisation des protons et l'accroissement de l'intensite d un facteur 1000. (auteurs)

  19. Nuclear study of Melusine; Etude nucleaire de Melusine

    Energy Technology Data Exchange (ETDEWEB)

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

    1959-07-01

    In this report are reviewed - with respect to starting of experiments - the main nuclear characteristics of a 20 per cent enriched uranium lattice, with light water as moderator and reflector. The reactor is to operate at 1 MW. 1) Study of various critical masses. 2) Control. Effectiveness of cadmium. Control rods and of a stainless steel regulating rod. 3) Study of the effect on reactivity of disturbances in the core center. 4) Study of xenon and samarium poisoning. 5) Temperature factor. 6) Heat exchanges in a fuel element. (author) [French] On etudie, dans ce rapport, les principales proprietes nucleaires d'un reseau a uranium enrichi (20 pour cent), dont le moderateur et le reflecteur sont l'eau legere en vue des experiences de demarrage. Ce reacteur devra fonctionner a 1 MW. 1) Etude de diverses masses critiques. 2) Controle. Efficacite des barres de controle en cadmium et d'une barre de reglage en acier inoxydable. 3) Etude de l'effet sur la reactivite de perturbation au centre du coeur. 4) Etude de l'empoisonnement xenon et samarium. 5) Coefficient de temperature. 6) Echanges thermiques dans un element. (auteur)

  20. Analytic index for nuclear physicians uses; Repertoire analytique a l'usage des physiciens nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Ballini, R.; Barloutaud, R.; Bernas, R.; Bretonneau, P.; Chaminade, R.; Cohen, R.; Conjeaud, M.; Cotton, E.; Faraggi, H.; Grjebine, T.; Joffre, H.; Laboulaye, H. de; Lesueur, C.; Leveque, A.; Moreau, J.; Naggiar, V.; Papineau, L.; Prugne, P.; Schuhl, C.; Studinowski, FJ.; Netter, F.; Raievski, V.; Valladas, G. [Commissariat a l' Energie Atomique, Lab. du Fort de Chatillon, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires; Marty, N.; Renard, G. [College de France, Lab. de Chimie Nucleaire (France)

    The problem of the documentation in nuclear physics becomes constantly more complex. Every week brings its share of new publications, always more numerous and more varied. To remedy to this facts that we tried, in the service of Nuclear Physics of the CEA, to give to the documentation a character of a collective and systematized work. The present report covers the literature appeared between first January 1950 and first July 1951. (Volume 1: CEA report number 120; Volume 2: CEA report number 184). (M.B.) [French] Le probleme de la documentation en physique nucleaire devient sans cesse plus complexe. Chaque semaine apporte son lot de publications, toujours plus nombreuses et plus diversifiees. C'est pour essayer de porter remede a cet etat de choses que nous avons essaye, au service de Physique Nucleaire du C.E.A., de donner a la documentation le caractere d'un travail collectif systematise. Le present rapport couvre la litterature parue entre le premier Janvier 1950 et le premier Juillet 1951. (Tome 1: Rapport CEA numero 120; Tome 2: Rapport CEA numero 184). (M.B.)

  1. La pulvérisation du fuel oïl lourd par des combustibles gazeux Using Gaseous Fuels to Spray Heavy Fuel Oil

    Directory of Open Access Journals (Sweden)

    Ladurelli A.

    2006-11-01

    Full Text Available Pour faciliter l'inflammation du fuel lourd on procède à sa pulvérisation au droit du brûleur. Deux méthodes sont généralement employées à cet effet : - La pulvérisation mécanique qui consiste à faire passer le liquide sous forte pression au travers d'orifices calibrés de petit diamètre. - La pulvérisation pneumatique qui consiste à utiliser la détente d'un fluide auxiliaire préalablement comprimé. Les fluides couramment utilisés pour cela sont l'air comprimé et la vapeur d'eau ; toutefois tous les combustibles gazeux, notamment le gaz naturel et les gaz de raffinerie, peuvent également servir de fluide de pulvérisation quand ils sont disponibles sous pression. The igniting of heavy fuel oil is facilitated by spraying it at the burner. Two methods are used as a rule: - Pressure atomization, consisting in causing the liquid to pass at high pressure through calibrated small-diameter orifices. - Twin-fluid atomization, which consists in using the expansion of a previously compressed auxiliary fluid. The fluids commonly used for the purpose are compressed air and steam. However, any gaseous fuel, particularly natural gas and the refinery gases, can be used as the spraying fluid provided it is available under pressure.

  2. 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

  3. Contribution to the study of several chemical hazards in the Centre d'Etudes Nucleaires of Fontenay-aux-Roses; Contribution a l'etude de quelques nuisances chimiques au centre d'etudes nucleaires de Fontenay-aux-Roses

    Energy Technology Data Exchange (ETDEWEB)

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

    1968-10-01

    From the checking of 2750 index cards of hazards, the study relates the distribution of the chemical hazards in the Centre d'Etudes Nucleaires of Fontenay-aux-Roses. Those concerning the greatest number of agents in the Centre are classified according to the categories corresponding to the different conditions of working. Thus, the most important are put forward. Then, the authors rapidly make a review of hazards which may have some special interest because they appear more specific of the nuclear energy or because they are the most frequently noted on the index cards of hazards. The case of the tributylphosphate is studied more precisely. (authors) [French] A partir de l'examen de 2750 fiches de nuisances, l'etude porte sur la repartition des nuisances chimiques au Centre d'Etudes Nucleaires de Fontenay-aux-Roses. Celles qui concernent le plus grand nombre d'agents du Centre sont classees selon les categories correspondant aux differentes conditions de travail. Les plus importantes d'entre elles sont ainsi mises en evidence. | Les auteurs passent ensuite en revue, rapidement, les nuisances qui peuvent presenter un interet particulier soit parce qu'elles semblent plus specifiques de l'Energie Nucleaire, soit parce qu'on les rencontre le plus frequemment sur les fiches de nuisances. Le cas du tributylphosphate est envisage de facon plus detaillee. (auteurs)

  4. Natural gas combustion and indoor air quality in domestic premises; Combustion du gaz naturel et qualite de l'air a l'interieur des habitations

    Energy Technology Data Exchange (ETDEWEB)

    Occhio, L.; Riva, A. [Snam, (Italy); Canci, F.; Scevarolli, V. [Italgas, Torino (Italy)

    2000-07-01

    Indoor air quality depends on many factors; combustion appliances are one of the sources of emissions inside dwellings. Their installation is regulated by UNI-CIG standards which also establish the ventilation and aeration requirements needed to guarantee the safety and healthiness of the environment. In order to critically evaluate the effect on indoor air quality of using gas appliances under different operational regimes and in different types of building, Snam and Italgas have developed a research project in co-operation with Enitecnologie and Turin Polytechnic, even to provide theoretical and experimental support for standardisation activities. The results of the presented research include experimental measurements made in real buildings, mathematical modelling and analysis of Italian and international literature. The results show that use of combustion appliances has little influence on indoor air quality and does not affect people's health. (authors)

  5. Aspects chimiques de la combustion du charbon pulvérisé. Première partie Chemical Aspects of the Combustion of Pulverized Coal. Part One

    OpenAIRE

    De Soete G. G.

    2006-01-01

    II n'est pas facile de parvenir à une vue complète des multiples phénomènes chimiques dont la flamme de charbon pulvérisé est le siège. La présente étude bibliographique s'efforce de donner plus qu'une juxtaposition des données de la littérature récente, en risquant une tentative de présentation cohérente des mécanismes chimiques clés qui s'affrontent dans cette combustion. Ces mécanismes font intervenir des réactions en phase gazeuse relativement rapides (combustion des produits gazeux de py...

  6. Experimental and numerical study of the active control of jets inside combustion chambers; Etude experimentale et numerique du controle actif de jets dans des chambres de combustion

    Energy Technology Data Exchange (ETDEWEB)

    Faivre, V.

    2003-12-15

    Combustion instabilities occur when the flame heat release couples with the acoustic waves propagating in the combustion chamber. This phenomenon can lead to strong vibrations and noise but also, sometimes, to the complete combustion device failure. That is the reason why so many studies focus on the control of those instabilities. The method chosen in this study consists in an active control device (or set of actuators) having a strong effect on the mixing of the burner exhaust flow with the ambient fluid. The model configuration studied consists in a non reactive jet of air controlled by four small tangential secondary jets. Experiments have been carried out to optimize the control device geometry. The configuration identified as the most efficient, in terms of mixing enhancement, has been simulated through Large Eddy Simulations (LES). The objective of the numerical part of the present work is double. First, the numerical simulations provide a better understanding of the phenomena occurring when the control is on. Then, it is shown that LES can be considered as a tool to predict the effects of a control device on a flow. (author)

  7. Statistical pulses generator. Application to nuclear instrumentation (1962); Generateur d'impulsions aleatoires. Application a l'instrumentation nucleaire (1962)

    Energy Technology Data Exchange (ETDEWEB)

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

    1962-07-01

    This report describes a random pulses generator adapted to nuclear instrumentation. After a short survey on the statistical nature of electronic signals, the different ways for generating pulses with a Poisson's time-distribution are studied. The final generator built from a gaseous thyratron in a magnetic field is then described. Several tests are indicated : counting-rate stability, Pearson's criterion, distribution of time-intervals. Applications of the generator in 'whole testing' of nuclear instrumentation are then indicated for sealers, dead time measurements, time analyzers. In this application, pulse-height spectrums have been made by Poissonian sampling of a recurrent or random low-frequency signal. (author) [French] Cette etude decrit un generateur d'impulsions aleatoires et ses applications a l'instrumentation nucleaire. Apres un bref rappel sur la nature statistique des signaux en electronique nucleaire, sont passes en revue les principaux moyens d'obtenir des impulsions distribuees en temps suivant une loi de Poisson. Le generateur utilisant un thyratron a gaz dans un champ magnetique est ensuite decrit; diverses methodes de test sont appliquees (stabilite du taux de comptage, criterium de Pearson, spectre des intervalles ds temps). Les applications du generateur a l'electronique nucleaire dans le domaine des 'essais globaux' sont indiques: test des echelles de comptage et mesure des temps morts, test des analyseurs en temps apres division du taux de comptage par une puissance de deux, test des analyseurs multicanaux en amplitude. Pour cette derniere application, on a realise des spectres d'amplitudes suivant une loi connue, par echantillonnage poissonien d'un signal basse frequence recurrent ou aleatoire. (auteur)

  8. Nuclear situation in Japan; La situation du nucleaire au Japon

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This analysis takes stock on the nuclear situation in Japan. It discusses the ambitious equipment program in collaboration with the France, the destabilization of the japanese nuclear industry following the accidents and the energy policy evolutions. It presents the projects of the japanese nuclear industry: the Monju reactor restart, the Pluthermal project, the reprocessing power plant of Rokkasho Mura, the new reactors, the russian weapons dismantling, the ITER site selection and the buy out of Westinghouse by Toshiba. (A.L.B.)

  9. The control of nuclear sector; Le controle du nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    The Asn is loaded with the control of the nuclear safety and the radiation protection in France: it provides this control, in the name of the state, to protect the workers, the patients, the public and the environment of the risks in relation with nuclear activities. The control is the core business of Asn. Asn so checks the nuclear basic installations (I.N.B.), since their conception until their dismantling, the pressure equipment specially conceived for these installations, the management of the radioactive waste as well as the transport of radioactive substances. Asn also checks all the industrial and research installations as well as the hospitals where are used ionizing radiations. It is a more recent profession there, because dating the reform of the control of the nuclear power of 2002, which constitutes that of the radiation protection. The first responsibility of the activities at risks falls to the one who begins them. This principle applies to all the sectors checked by Asn: an industrialist is responsible for the safety of the nuclear installations which he exploits, a doctor is responsible for the use of the ionizing radiations which he uses. (N.C.)

  10. Exit this way; Par ici la sortie du nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This paper aims to inform the public on the nuclear power phaseout necessity. The fist part presents the hazards bound the nuclear activities, from the uranium mines to the radioactive wastes disposal and the reasons of a necessary phaseout. The second part recalls the historical aspects of the nuclear power implementation in the french energy policy and the today government attitude to value its choice. The last part presents the advantages of other energies sources and scenario of nuclear power phaseout. (A.L.B.)

  11. Analytic catalog for the use of the nuclear physicists; Repertoire analytique a l'usage des physiciens nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Ballini, R.; Barloutaud, R.; Bernas, R.; Chaminade, R.; Cohen, R.; Conjeaud, M.; Cotton, E.; Faraggi, H.; Grjebine, T.; Laboulaye, H. de; Lehmann, P.; Leveque, A.; Levi, C.; Moreau, J.; Naggiar, V.; Olkowsky, J.; Papineau, L.; Papineau, L.; Prugne, P.; Schuhl, C.; Szteinsznaider, D.; Tzara, C.; Valladas, G. [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires; Marty, N.; Renard, G. [College de France, Lab. de Chimie Nucleaire (France)

    1952-07-01

    The problem of the documentation in nuclear physics becomes constantly more complex. Every week brings its share of publications, always more numerous and more varied. To remedy to this problem, we tried, at the Nuclear Physics Services of the CEA, to give to the documentation the character of a collective and systematized work. The present report covers the literature appeared between January 1, 1950 and July 1, 1951. (Volume 1: CEA report number 120; Volume 2: CEA report number 184). (M.B.) [French] Le probleme de la documentation en physique nucleaire devient sans cesse plus complexe. Chaque semaine apporte son lot de publications, toujours plus nombreuses et plus diversifiees. C'est pour essayer de porter remede a cet etat de choses que nous avons essaye, au service de Physique Nucleaire du C.E.A., de donner a la documentation le caractere d'un travail collectif systematise. Le present rapport couvre la litterature parue entre le 1 Janvier 1950 et le 1 Juillet 1951. (Tome 1: Rapport CEA numero 120; Tome 2: Rapport CEA numero 184). (M.B.)

  12. The molten salt reactors (MSR) pyro chemistry and fuel cycle for innovative nuclear systems; Congres sur les reacteurs a sels fondus (RSF) pyrochimie et cycles des combustibles nucleaires du futur

    Energy Technology Data Exchange (ETDEWEB)

    Brossard, Ph. [GEDEON, Groupement de Recherche CEA CNRS EDF FRAMATOME (France); Garzenne, C.; Mouney, H. [and others

    2002-07-01

    In the frame of the studies on next generation nuclear systems, and especially for the molten salt reactors and for the integrated fuel cycle (as IFR), the fuel cycle constraints must be taken into account in the preliminary studies of the system to improve the cycle and reactor optimisation. Among the purposes for next generation nuclear systems, sustainability and waste (radio-toxicity and mass) management are important goals. These goals imply reprocessing and recycling strategies. The objectives of this workshop are to present and to share the different strategies and scenarios, the needs based on these scenarios, the experimental facilities available today or in the future and their capabilities, the needs for demonstration. It aims at: identifying the needs for fuel cycle based on solid fuel or liquid fuel, and especially, the on-line reprocessing or clean up for the molten salt reactors; assessing the state-of-the-art on the pyro-chemistry applied to solid fuel and to present the research activities; assessing the state-of-the-art on liquid fuels (or others), and to present the research activities; expressing the R and D programs for pyro-chemistry, molten salt, and also to propose innovative processes; and proposing some joint activities in the frame of GEDEON and PRACTIS programs. This document brings together the transparencies of 18 contributions dealing with: scenario studies with AMSTER concept (Scenarios, MSR, breeders (Th) and burners); fuel cycle for innovative systems; current reprocessing of spent nuclear fuel (SNF) in molten salts (review of pyro-chemistry processes (non nuclear and nuclear)); high temperature NMR spectroscopies in molten salts; reductive extraction of An from molten fluorides (salt - liquid metal extraction); electrochemistry characterisation; characterisation with physical methods - extraction coefficient and kinetics; electrolytic extraction; dissolution-precipitation of plutonium in the eutectic LiCl-KCl (dissolution and precipitation processes); cold salt: potentiality and preliminary results; TOPIC: redox control of MSR fuel (MSR: nominal operating conditions for the reprocessing process and redox control); technical aspects of R and D of some advanced non-aqueous reprocessing technologies for MSR systems (promising innovative separation and partitioning processes for the MSR fuel cycle); nominal operating conditions for MSR reprocessing process - data base needed and experiments for reprocessing validation; corrosion and materials for MSR and for pyro-chemistry processes; MSR reactor physics - dynamic behaviour; what safety principles for MSR? (MSR and integrated cycle (IFR) safety approach); experimental programmes in the frame of the SPHINX project of MS transmuter (programme of irradiated probes BLANKA, experimental facilities (MSR)); ISTC 1606 status - experimental study of molten salt technology for safe, low-waste and proliferation resistant treatment of radioactive waste and plutonium in accelerator-driven and critical systems. (J.S.)

  13. Oxidation of nuclear fuel below 400 deg. Consequence on long-term dry storage; L'oxydation du combustible nucleaire au-dessous de 400 deg. Consequences sur l'entreposage a sec de longue duree

    Energy Technology Data Exchange (ETDEWEB)

    Dehaudt, Ph

    2000-07-01

    This document reviews the status of the knowledge on the oxidation of fuels below 400 deg C, in all its forms, including fuel rods, by examining the consequences of this reaction on the strength or ruin of the fuel rods during dry storage in air for a hundred years. The data available in the scientific literature, and the data acquired by CEA, are abundant on irradiated powders and pellets, but sparser for irradiated fuel fragments and for rods or sections of fuel rods. A bibliographic review is made to identify the morphological and structural changes, as well as the kinetic laws. An analysis and a summary is made with a concern to evaluate the risks of rod ruin by oxidation. The final section, in a few pages, addresses the essential lessons from this study. It presents: first, a summary of the main results of this review and its analysis, recommendations and remedies for storage; proposed research guidelines as well as precise topics, in order to fill out our knowledge and, even better, to identify the acceptable limits for storage. (author)

  14. Studies of neo-formed phases occurring during spent nuclear fuel dissolution in geological repository: influence of silicate ions; Etude des phases neoformees lors de la dissolution du combustible nucleaire en condition de stockage geologique: influence des ions silicate

    Energy Technology Data Exchange (ETDEWEB)

    Robit-Pointeau, V

    2005-12-15

    Spent nuclear fuel alteration in deep storage conditions may proceed by local oxidising conditions at the fuel / water interface under influence of alpha irradiation. However, due to the strong redox buffer capacity of the near-field materials (especially the canister and the geological media), most of the near-field environment will remain reducing. Due to the relative high concentration in silica in such system, coffinite USiO{sub 4}.n(H{sub 2}O) may be a relevant phase to consider as it has been suggested from the natural analogues observations (Oklo). The aim of this work was to assess the relevance of coffinitisation of the spent fuel phenomena. The results of the experimental work contest the thermodynamic predictions. Instead of coffinite, a new U(IV)-Si phase has been observed in water simulating storage conditions. The thermodynamic data on coffinite validated by OECD are based on the average concentration of dissolved silica present in natural system containing uraninite and quartz. As the silica concentration in natural groundwaters is more probably controlled by minerals like chalcedony or silica gel, the coffinite present with uraninite in such systems, is probably not in equilibrium even in 2-billion years- old geological sites. Based on the results of this study, coffinitisation of the spent nuclear fuel in deep geological disposal is not anticipated to be a dominant short term process. (author)

  15. French research in the field of nuclear agronomy; Les recherches francaises en agronomie nucleaire

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-07-01

    , industrial firms, university laboratories scientific institutes. The role of the Commissariat a l'Energie Atomique is defined: on the one hand it supplies information and support, and on the other hand it takes charge of specifically nuclear aspects of the work. Its part in the field has recently found expression in the creation, within the Biology Department, of a Radio-agronomy Section; its objective are described,, as well as the, means placed att its disposal at the Centre d'etudes Nucleaires, Cadarache. (author) [French] On propose un bilan des travaux les plus significatifs effectues en France depuis la deuxieme conference internationale en matiere d'agronomie nucleaire et qui vont d'une recherche apparemment desinteressee a l'application la plus directe. Une telle differenciation recouvre de moins en moins, au fur et a mesure de l'evolution des programmes, la distinction qui est faite dans l'expose entre l'action biologique des rayonnements et les autres emplois des techniques nucleaires. C'est ainsi que les recherches do radiogenetique agricole sont poursuivies dans deux directions: d'un point de vue theorique et methodologique avec l'etude comparative de l'action des divers types de rayonnements, l'influence du debit de dose et de la temperature, l'action des agents mutagenes chimiques, la production de chimeres sous irradiation gamma; et d'autre part, sous un aspect pratique aboutissant a la creation de varietes nouvelles plus resistantes ou plus precoces (riz, mil, arachide). Les problemes de destruction des insectes (eradication) et de conservation des denrees sous irradiation se trouvent egalement abordes par des voies et avec des objectifs tres divers. A la demarche globale representee par une irradiation pure et simple (grains humides, pommes de terre...) sont parfois associees des etudes souvent originales, d'ordre biochimique ou microbiologique (par exemple: alteration de l

  16. 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.)

  17. Chemical Looping with Copper Oxide as Carrier and Coal as Fuel Boucle chimique pour la combustion du charbon avec un transporteur d’oxygène à base d’oxyde de cuivre

    Directory of Open Access Journals (Sweden)

    Eyring E.M.

    2011-04-01

    Full Text Available A preliminary analysis has been conducted of the performance of a Chemical Looping system with Oxygen Uncoupling (CLOU with copper oxide as the oxygen carrier and coal approximated by carbon as the fuel. The advantages of oxygen uncoupling are demonstrated by providing the energy balances, the circulation rate of oxygen carrier, the oxygen carrier mass loadings, the carbon burnout and oxygen partial pressure in the fuel reactor. Experimental data on the cycling of cuprous oxide to cupric oxide and kinetics for the oxidation and decomposition reactions of the oxides were obtained for use in the analysis. For this preliminary study unsupported oxides were utilized. The decomposition temperatures were rapid at the high temperature of 950°C selected for the fuel reactor. The oxidation kinetics peaked at about 800°C with the decrease in rate at higher temperatures, a decrease which is attributed in the literature to the temperature dependence of the diffusional resistance of the CuO layer surrounding the Cu2O; the diffusion occurs through grain boundaries in the CuO layers and the rate of diffusion decreases as a consequence of growth of CuO grains with increasing temperature. The analysis shows the advantages of CLOU in providing rapid combustion of the carbon with carbon burnout times lower than the decomposition times of the oxygen carrier. For the full potential of CLOU to be established additional data are needed on the kinetics of supported oxides at the high temperatures (>850°C at which oxygen is released by the CuO in the fuel reactor. Une analyse préliminaire a été conduite pour estimer les performances d’un procédé en boucle chimique découplé (CLOU, chemical looping uncoupling pour la combustion du charbon avec un transporteur d’oxygène à base d’oxyde de cuivre. Les avantages de ce système sont démontrés en établissant le bilan énergétique, l’inventaire et le débit de circulation du matériau transportant l

  18. Development and validation of calculation schemes dedicated to the interpretation of small reactivity effects for nuclear data improvement; Developpement et validation de schemas de calcul dedies a l'interpretation des mesures par oscillation pour l'amelioration des donnees nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Gruel, A.

    2011-10-24

    afin d'obtenir des informations pertinentes sur les donnees nucleaires de base. L'enjeu de cette these est le developpement d'un schema de calcul de reference, dont les incertitudes sont clairement identifiees et quantifiees, permettant l'interpretation des mesures par oscillation. Dans ce document plusieurs methodes de calcul de ces faibles effets en reactivite sont presentees, basees sur des codes de calculs neutroniques deterministes et/ou stochastiques. Ces methodes sont comparees sur un benchmark numerique, permettant leur validation par rapport a un calcul de reference. Trois applications sont ici presentees dans le detail: une methode purement deterministe utilisant la theorie des perturbations exacte pour la qualification des sections efficaces des principaux produits de fission en REP, dans le cadre d'etudes sur l'estimation de la perte du reactivite du combustible au cours du cycle; une methode hybride, basee sur un calcul stochastique et la theorie des perturbations exacte, permet d'obtenir un retour precis sur les donnees nucleaires de bases d'isotopes, dans notre cas l'{sup 241}Am; et enfin, une troisieme methode, reposant sur un calcul perturbatif Monte Carlo, est utilisee pour une etude de conception

  19. 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

  20. Siloette, Siloe mock-up; Siloette, modele nucleaire de siloe

    Energy Technology Data Exchange (ETDEWEB)

    Delcroix, V.; Jeanne, G.; Mitault, G.; Schulhof, P. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1964-07-01

    Siloette is the Siloe mock-up. The main installations are described: various tanks, building, auxiliaries, control systems... Precis ions are given about precautions taken for using spent fuel elements. (authors) [French] Siloette est le modele nucleaire de SILOE. On decrit ses diverses installations: bassins, batiments, auxiliaires, controle... Des precisions sont donnees sur les precautions prises pour y utiliser des elements uses. (auteurs)

  1. A Study on the Role of Reaction Modeling in Multi-phase CFD-based Simulations of Chemical Looping Combustion Impact du modèle de réaction sur les simulations CFD de la combustion en boucle chimique

    Directory of Open Access Journals (Sweden)

    Kruggel-Emden H.

    2011-03-01

    Full Text Available Chemical Looping Combustion is an energy efficient combustion technology for the inherent separation of carbon dioxide for both gaseous and solid fuels. For scale up and further development of this process multi-phase CFD-based simulations have a strong potential which rely on kinetic models for the solid/gaseous reactions. Reaction models are usually simple in structure in order to keep the computational cost low. They are commonly derived from thermogravimetric experiments. With only few CFD-based simulations performed on chemical looping combustion, there is a lack in understanding of the role and of the sensitivity of the applied chemical reaction model on the outcome of a simulation. The aim of this investigation is therefore the study of three different carrier materials CaSO4, Mn3O4 and NiO with the gaseous fuels H2 and CH4 in a batch type reaction vessel. Four reaction models namely the linear shrinking core, the spherical shrinking core, the Avrami-Erofeev and a recently proposed multi parameter model are applied and compared on a case by case basis. La combustion en boucle chimique (Chemical Looping Combustion est une technologie de combustion efficace permettant le captage in situ du CO2 pour des charges gazeuses ou solides. Dans l’optique du développement et de l’extrapolation du procédé, la CFD est un outil de simulation à fort potentiel qui s’appuie notamment sur des modèles cinétiques pour décrire les réactions gaz-solide. Ces modèles décrivant les réactions sont généralement assez simples pour limiter les temps de simulation et sont obtenus à partir d’expérimentations en thermobalance. Il y a encore peu de travaux de modélisation CFD du procédé CLC et il est difficile d’estimer l’importance du modèle décrivant les réactions chimiques sur les résultats des simulations. Le but de ce travail est donc d’étudier la combustion de charges gazeuses H2 et CH4 dans des réacteurs en batch en consid

  2. 1: the atom. 2: radioactivity. 3: man and radiations. 4: the energy. 5: nuclear energy: fusion and fission. 6: the operation of a nuclear reactor. 7: the nuclear fuel cycle; 1: l'atome. 2: la radioactivite. 3: l'homme et les rayonnements. 4: l'energie. 5: l'energie nucleaire: fusion et fission. 6: le fonctionnement d'un reacteur nucleaire. 7: le cycle du combustible nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    This series of 7 digest booklets present the bases of the nuclear physics and of the nuclear energy: 1 - the atom (structure of matter, chemical elements and isotopes, the four fundamental interactions, nuclear physics); 2 - radioactivity (definition, origins of radioelements, applications of radioactivity); 3 - man and radiations (radiations diversity, biological effects, radioprotection, examples of radiation applications); 4 - energy (energy states, different forms of energy, characteristics); 5 - nuclear energy: fusion and fission (nuclear energy release, thermonuclear fusion, nuclear fission and chain reaction); 6 - operation of a nuclear reactor (nuclear fission, reactor components, reactor types); 7 - nuclear fuel cycle (nuclear fuel preparation, fuel consumption, reprocessing, wastes management). (J.S.)

  3. General phenomenology of underground nuclear explosions; Phenomenologie generale des explosions nucleaires souterraines

    Energy Technology Data Exchange (ETDEWEB)

    Derlich, S.; Supiot, F. [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

    1969-07-01

    An essentially qualitatively description is given of the phenomena related to underground nuclear explosions (explosion of a single unit, of several units in line, and simultaneous explosions). In the first chapter are described the phenomena which are common to contained explosions and to explosions forming craters (formation and propagation of a shock-wave causing the vaporization, the fusion and the fracturing of the medium). The second chapter describes the phenomena related to contained explosions (formation of a cavity with a chimney). The third chapter is devoted to the phenomenology of test explosions which form a crater; it describes in particular the mechanism of formation and the different types of craters as a function of the depth of the explosion and of the nature of the ground. The aerial phenomena connected with explosions which form a crater: shock wave in the air and focussing at a large distance, and dust clouds, are also dealt with. (authors) [French] On donne une description essentiellement qualitative des phenomenes lies aux explosions nucleaires souterraines (explosion d'un seul engin, d'engins en ligne et explosions simultanees). Dans un premier chapitre sont decrits les phenomenes communs aux explosions contenues et aux explosions formant un cratere (formation et propagation d'une onde de choc provoquant la vaporisation, la fusion et la fracturation du milieu). Le deuxieme chapitre decrit les phenomenes lies aux tirs contenus (formation d'une cavite et d'une cheminee). Le troisieme chapitre est consacre a la phenomenologie des tirs formant un cratere et decrit notamment le mecanisme de formation et les differents types de crateres en fonction de la profondeur d'explosion et de la nature du terrain. Les phenomenes aeriens lies aux explosions formant un cratere: onde de pression aerienne et focalisation a grande distance, nuages de poussieres, sont egalement abordes. (auteurs)

  4. French research in the field of nuclear agronomy; Les recherches francaises en agronomie nucleaire

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-07-01

    , industrial firms, university laboratories scientific institutes. The role of the Commissariat a l'Energie Atomique is defined: on the one hand it supplies information and support, and on the other hand it takes charge of specifically nuclear aspects of the work. Its part in the field has recently found expression in the creation, within the Biology Department, of a Radio-agronomy Section; its objective are described,, as well as the, means placed att its disposal at the Centre d'etudes Nucleaires, Cadarache. (author) [French] On propose un bilan des travaux les plus significatifs effectues en France depuis la deuxieme conference internationale en matiere d'agronomie nucleaire et qui vont d'une recherche apparemment desinteressee a l'application la plus directe. Une telle differenciation recouvre de moins en moins, au fur et a mesure de l'evolution des programmes, la distinction qui est faite dans l'expose entre l'action biologique des rayonnements et les autres emplois des techniques nucleaires. C'est ainsi que les recherches do radiogenetique agricole sont poursuivies dans deux directions: d'un point de vue theorique et methodologique avec l'etude comparative de l'action des divers types de rayonnements, l'influence du debit de dose et de la temperature, l'action des agents mutagenes chimiques, la production de chimeres sous irradiation gamma; et d'autre part, sous un aspect pratique aboutissant a la creation de varietes nouvelles plus resistantes ou plus precoces (riz, mil, arachide). Les problemes de destruction des insectes (eradication) et de conservation des denrees sous irradiation se trouvent egalement abordes par des voies et avec des objectifs tres divers. A la demarche globale representee par une irradiation pure et simple (grains humides, pommes de terre...) sont parfois associees des etudes souvent originales, d'ordre biochimique ou microbiologique (par exemple: alteration de l

  5. Iranian nuclear power and international law; La question du nucleaire iranien au regard du droit international

    Energy Technology Data Exchange (ETDEWEB)

    Aivo, G. [Centre de droit international, 75 - Paris (France)

    2006-07-15

    Does the Iranian programme violate the Non-Proliferation Treaty (NPT)? Iran is a signatory to the NPT and whilst certainly within its rights in developing civil nuclear energy, this is not so for the development of nuclear weapons in order to become a regional power which Iran is already not far from becoming. In the face of diverging opinions among the major interested parties (including the UN, United States, EU, Russia and China), how might this crisis be resolved? (author)

  6. Nouveaux critères pour juger de l'efficacité d'un fourneau à la combustion du charbon de bois

    Directory of Open Access Journals (Sweden)

    Ndaysenga, M.

    1994-01-01

    Full Text Available New Criteria to Judge Stove Efficiency in the Charcoal Combustion. The water boil test efficiency for choosing the most economic stove in combustion is estimated on the basis of four stoves. In addition to the heating and boiling energy usually considered as selection criterion, other criteria such as the boiling time and the combustion rate have been taken to indicate efficiency. Strangely, it appeared that the stove which maintains water at its boiling point for a long time and has the lowest combustion rate doesn 't valorize fuel energy efficiently if you only keep to the heating and boiling energy. The cooking test made it possible to explain that apparent contradiction : the fuel energy fraction which doesn't enter in the calculation of the heating and boiling energy isn't really lost. A low combustion rate associated with a long boiling time proved to be the best criteria of choosing the most economic stove in fuel. Therefore, the only water boil test doesn't make it possible to identify the most economically efficient stove. Resorting to the cooking test is compelling.

  7. Effect of Ash on Oxygen Carriers for the Application of Chemical Looping Combustion to a High Carbon Char Effet des cendres sur l’activité des porteurs d’oxygène dans la combustion du charbon en boucle chimique

    Directory of Open Access Journals (Sweden)

    Rubel A.

    2011-02-01

    activity of the OCs and both OCs performed well. The results were promising for the application of CLC directly to solid fuels. L’application de la combustion en boucle chimique (CLC aux combustibles solides est actuellement étudiée à l’Université du Kentucky, au Centre de Recherche de l’Energie Appliquée (CAER dans le but de développer un procédé de gazéification/combustion en boucle chimique pressurisé (PCLC/G afin de générer de l’électricité à partir de charbon. Un des principaux aspects de la combustion en boucle chimique de combustibles solides est la compréhension de l’effet des cendres sur la réactivité des porteurs d’oxygène (OCs. L’effet des cendres sur la capacité de transfert d’oxygène et sur l’aptitude à oxyder le charbon est étudié avec deux porteurs d’oxygène à base d’oxydes de fer. Les cendres utilisées sont des cendres volantes provenant d’une centrale thermique au charbon. Les expériences sont réalisées dans un système composé d’une thermo-balance couplée à un spectrographe de masse (TGMS dans lequel on utilise d’abord 500 mg d’un mélange de cendres/porteurs d’oxygène à différentes concentrations de cendres allant jusqu’à 75 %. Le gaz réducteur est composé de 10 % de H2, 15 % de CO, 20 % de CO2 et de 55 % de Ar; et le gaz oxydant est composé de 20 % de O2 dans Ar. Les réactions d’oxydation/réduction sont quasi totales. D’après ces expériences, les cendres ont une activité propre de porteur d’oxygène, liée à la présence de fer dans les cendres, confirmée par les analyses DRX. Cela génère une augmentation du gain ou de la perte de masse du mélange pendant l’oxydation/réduction. Les vitesses d’oxydation/réduction augmentent avec la concentration des cendres à cause de l’augmentation de la porosité du mélange de porteurs d’oxygène avec les cendres, ce qui permet un meilleur accès des gaz réactifs sur les sites actifs des porteurs d’oxygène. Dans un

  8. Experimental study of a separated jets burner: application to the natural gas-pure oxygen combustion; Etude experimentale du comportement de bruleurs a jets separes: application a la combustion gaz naturel-oxygene pur

    Energy Technology Data Exchange (ETDEWEB)

    Salentey, L.

    2002-04-15

    The evolution of pollution standards and the optimisation of furnaces performances require a development of new burner generation and also the improvement of combustion techniques. Actually, the use of oxy-combustion in separated jets burners offers interesting prospects for NO{sub x} emission reduction and on the modularity of flames properties (lift off, flame front topology, flame length). The complex geometry of those burners leads to several problems like the three-dimensional character of the flow, which may sometimes disturb the flame stability as flames are lifted above the burner. This experimental study deals with a simplified version of that kind of burner constituted with a central natural gas jet surrounded by two oxygen jets. Primary, the study of non-reactive jet was planned in order to understand dynamic and mixture phenomena involved between jets and to provide a database useful for the computer code validation. The reactive flow developed in a furnace, which simulates the real conditions, had been characterised. The studies of the dynamic field using Laser Doppler Velocimetry (LDV) and of the turbulent mixture by conditional Laser tomography were supplemented in combustion by the visualisation of the spontaneous emission of radical OH, in the initial and final zone of the oxy-flames, like by the measurement of pollutants like NO{sub x} and soot. The measurements carried out while varying speeds of injection as well as the gap between the jets made possible the highlight of the influence of these parameters upon the stabilisation of the oxy-flames as well as the modification of the topology and the characteristics of the flows. The comparison of the measurements made in non-reactive and reactive flow shows the influence of oxy-combustion on the dynamic and scalar development of the flow for this type of burners. (author)

  9. Study of the uniform corrosion of an aluminium alloy used for the fuel cladding of the Jules Horowitz experimental reactor; Etude de la corrosion uniforme d'un alliage d'aluminium utilise comme gainage du combustible nucleaire du reacteur experimental Jules Horowitz

    Energy Technology Data Exchange (ETDEWEB)

    Wintergerst, M. [CEA Saclay, Dept. des Materiaux pour le Nucleaire (DEN/DANS/DMN/SEMI), 91 - Gif-sur-Yvette (France)

    2008-07-01

    For the Jules Horowitz new material testing reactor, an aluminium base alloy, AlFeNi, will be used for the cladding of the fuel plates. Taking into account the thermal properties of the alloy and of its oxide, the corrosion of the fuel cans presents many problems. The aim of this thesis is to provide a growing kinetic of the oxide layer at the surface of the AlFeNi fuel can in order to predict the life time of fuel element. Thus the mechanism of degradation of the cladding will be describe in order to integrate the different parameters of the operating reactor. (A.L.B.)

  10. Study of molybdenum (VI) complexation and precipitation by zirconium (IV) in strongly acid medium. Application to nuclear spent fuel dissolution; Etude de la complexation et de la precipitation du molybdene (VI) par le zirconium (IV) en milieu tres acide. Application a la dissolution du combustible nucleaire irradie

    Energy Technology Data Exchange (ETDEWEB)

    Esbelin, E

    1999-07-01

    These last years the formation of solid deposits has been observed in the dissolution workshops of the La Hague plant. A sample of the solid was withdrawn for expertise: molybdenum and zirconium are the two major components of the solid, identified as zirconium molybdate. This thesis consisted in the approach of the mechanisms in solution liable to induce precipitate formation. After a bibliographical overview on the chemistry of Mo(VI) in highly acidic solution, this system was studied by absorption spectrophotometry in perchloric medium. The implication of two major forms of Mo(VI) in a dimerization equilibrium was confirmed by this way and by {sup 95}Mo NMR. The principal parameters governing this equilibrium were identified. It is thus shown that the molybdenum dimerization reaction is exothermic. Disturbance of the Mo(VI) system in highly acidic solution by Zr(IV) was also studied. In a restricted experimental field, for which 'conventional' exploitation methodologies had to be adapted to the system, a main complex of stoichiometry 1:1 between Mo(VI) and Zr(IV) was found. The precipitation study of Mo(VI) by Zr(IV) under conditions close to those of the dissolution medium of nuclear spent fuel was undertaken. The main parameters which control precipitation kinetics were identified. The results obtained reveal that precipitation is controlled by a single macroscopic process and therefore can be described by a single equation. The solid obtained is composed of only one phase presenting a Mo:Zr non-stoichiometry when compared to the theoretical formula ZrMo{sub 2}O{sub 7}(OH){sub 2},2H{sub 2}O. At last, on the basis of the research results, a descriptive mechanism of the system is proposed in which intervenes a 1:1 intermediate complex, much more soluble than a probable 2:1 precipitation precursor. (author)

  11. Application of steric exclusion chromatography for the separation of degradation products of the solvent used for the reprocessing of the nuclear fuels; Application de la chromatographie d`exclusion sterique a la separation de produits de degradation du solvant du retraitement des combustibles nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Pozo, C.

    1993-08-01

    The solvent, used in France in Purex reprocessing plants at La Hague is tributylphosphate (TBP) diluted to 30% with a mixture of branched alkanes, for which the main component is branched dodecane (70%). In order to minimize volumes of organic wastes, we have to maintain Purex solvent qualities and to get rid of degradation products. The subject of this memoir concerns among all the degradation products the heaviest molecules. The separation and the identification of these products have been carried out by preparative steric exclusion chromatography, followed by the analysis of the samples by various analytical methods. An inactive residue containing heavy degradation products was prepared according to the process used in the UP3 La Hague plant. The Analysis of this residue using steric exclusion chromatography and GPC/MS methods, shows the presence of three families of compounds heavier than TBP: the ``dimers of TBP`` (provided from the addition of two molecules of TBP), the ``TBP-alkanes`` (the main molecule is the result of the addition of dodecane with TBP), and ``the functionalized TBP`` (hydroxyled TBP, nitrous TBP, nitrated TBP). Plutonium (IV) retention tests were made on the various fractions generated by steric chromatography. They showed that ``the dimers of TBP`` and ``the functionalized TBP`` families are responsible for that retention. These results confirm the good efficiency of the solvent distillation system operated in UP3 plant which allow the elimination of heavy degradation products of the solvent with the residue and then restore excellent extracting properties for the recycled solvent. (author). 35 figs., 69 refs., 15 tabs.

  12. Formation and destruction mechanisms of nitrogen oxides during coal combustion in circulating fluidized beds; Mecanismes de formation et de destruction des oxydes d`azote lors de la combustion du charbon en lit fluidise circulant

    Energy Technology Data Exchange (ETDEWEB)

    Borrel, G.; Lecuyer, I. [Universite du Haut-Rhin, 68 - Mulhouse (France)

    1997-01-01

    Formation and reduction of nitrogen oxides (NO and N{sub 2}O) during coal combustion in a circulating fluidized bed (CFBC) are very complicated and yet badly known. The aim of the present study was to better characterize these phenomena on a small-sized experimental unit (reactor diameter: 5 cm), with the possibility to re-inject the solids in the bottom of the furnace, as in a real industrial unit. This should allow then to develop a numerical set of chemical reactions involving the nitrogen oxides. The experimental results showed that coal ash plays a great role in reducing nitrogen oxides, the determining parameter being the quantity of unburnt carbon remaining in the ash. The study then detailed the interaction between nitrogen oxides and de-volatilized (char) according to the temperature, NO{sub x} concentration and the mass of solid. In the absence of oxygen small quantities of char can very significantly reduce NO as well as N{sub 2}O. It was possible to establish destruction kinetics on these particles, and orders of reaction could be determined versus the NO{sub x} concentration and the char particle mass (heterogeneous phase chemical reactions). Then, the coal pyrolysis study enabled to identify the products released during coal devolatilization and thermogravimetric analyses displayed several successive weight losses due CO, CO{sub 2} and CH{sub 4} releases, during a linear temperature increase. Lastly coal combustion was studied in the small pilot with variable experimental conditions. Using the previous experimental was studied in the small pilot with variable experimental conditions. Using the previous experimental results, a model was developed to calculate NO{sub x} concentrations during the coal combustion and validated. The NO and N{sub 2}O contents calculated are thoroughly correlated with the experimental data whatever the injection carbon/oxygen ratio is. (author) 96 refs.

  13. Public debate about the EPR nuclear power plant at Flamanville; Debat public sur la centrale nucleaire EPR a Flamanville

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The project of building of he EPR reactor at Flamanville (Manche, France) has been submitted to the public debate. This document includes a presentation of the project and of the rules of the public debate, a synthesis of the file made by the prime contractor (EDF), a synthesis of the collective book of national actors concerned by the project (a group of associations for environment protection, Areva company, the ministries of economy and ecology, Global Chance, association of pro-nuclear ecologists (AEPN), 'Sortir du Nucleaire' (out-of nuclear) network, group of scientists for the information about nuclear (GSIEN), association for the promotion of the Flamanville site (Proflam), French nuclear energy society (SFEN) in association with 'Sauvons le Climat' (let's save climate), regional collective association 'EPR non merci, ni ailleurs, ni ici' (EPR, no thanks, neither elsewhere, nor here), NegaWatt), and 5 detailed books of actors: ACRO (association for the control of radioactivity in Western France), CFDT and CGT syndicates, the economic and social council of Basse Normandie region, and Proflam. (J.S.)

  14. Periodical control of combustion facilities in agreement with the decree no. 98-833 from September 16, 1998. Specialist's guidebook; Controle periodique des installations de combustion au titre du decret no. 98-833 du 16 septembre 1998. Guide de l'expert

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This guidebook aims at specifying some of the conditions of application of the French decree no. 98-833 from September 16, 1998 relative to the periodical control of combustion facilities: 1 - introduction (goal, definitions, reference documents); 2 - objective of the periodical control; 3 - calculation of the characteristic efficiency of a boiler (type of boiler, losses with smokes, losses with unburnt solid residues, radiant and convection losses); 4 - measurement and control instrumentation; 5 - facilities devoted to thermal energy distribution; 6 - combustion quality and good operation of boilers; 7 - filling up of the maintenance book; 8 - operation and maintenance; 9 - report. (J.S.)

  15. Nuclear developments at the international inter govern mental level (1961); Developpements nucleaires sur le plan international intergouvernemental (1961)

    Energy Technology Data Exchange (ETDEWEB)

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

    1961-07-01

    The United Nations organisation and nuclear energy rose simultaneously, in 1945, to occupy an important place in the public eye. The spiritual succession of the League of Nations which had foundered during the war was taken up by the new organisation which sought to implant its political ideal in a more tangible reality, so that it might thereby be inspired by concrete and substantial objectives. This is one of the reasons for the existence of the dozen specialized agencies created by the family of the United Nations and dealing with Health, Culture, Agriculture, Finance, etc. Nuclear energy is one of these techniques. Becoming suddenly an important power factor and exploiting for itself the prestige of Science, it became the favorite domain for the growth of this new spirit, as much in its universal form in 1945 as in its more regional form which it was later to adopt. The achievements are numerous and of varying importance; they deserve te be studied carefully. (author) [French] L'organisation des Nations Unies et le nucleaire ont ete places simultanement, en 1945, au premier plan de la scene mondiale. La Societe des Nations ayant sombre pendant la guerre, son heritage spirituel fut recueilli par la nouvelle organisation qui chercha a enraciner son ideal politique dans une realite plus materielle, de facon a y puiser une nourriture concrete et substantielle. C'est une des raisons d'existence de la douzaine d'institutions specialisees gravitant dans la famille des Nations Unies et s'occupant de Sante, de Culture, d'Agriculture, de Finances, etc. Le nucleaire est l'une de ces techniques. Devenu soudainement un facteur primordial de puissance, Cristallisant a son benefice le prestige de la Science, c'etait un terrain de predilection pour le developpement du nouvel esprit, aussi bien sous la forme universelle de 1945, que sous les formes regionales qui ont vu le jour ensuite. Les travaux realises que nombreux, d

  16. Visualisation of Gasoline and Exhaust Gases Distribution in a 4-Valve Si Engine; Effects of Stratification on Combustion and Pollutants Visualisation de la répartition du carburant et des gaz brûlés dans un moteur à 4 soupapes à allumage commandé ; effet de la stratification sur la combustion et les polluants

    Directory of Open Access Journals (Sweden)

    Deschamps B.

    2006-12-01

    des dégagements d'énergie et des émissions de polluants très distincts. Le niveau de tumbleet l'emplacement de l'étincelle sont aussi modifiés. L'observation de la stratification telle qu'elle est réellement dans le moteur constitue un moyen pertinent pour expliquer ses performances. Les paramètres permettant d'optimiser les niveaux de NOx et d'HC peuvent en être déduits, de même que l'efficacité des stratégies de recirculation et d'injection du carburant. Les résultats des visualisations ont été confirmés par des mesures obtenues dans un moteur monocylindre muni d'une culasse conventionnelle avec la même géométrie de chambre de combustion.

  17. Contribution to the study of {beta} disintegration and of nuclear structure using experiments on certain {beta}-{gamma} cascades: 198{sub Au}, 86{sub Rb}, 170{sub Tm}; Contribution a l'etude de la desintegration beta et a l'etude de la structure nucleaire a l'aide d'experiences sur certaines cascades beta-gamma: 198{sub Au}, 86{sub Rb}, 170{sub Tm}

    Energy Technology Data Exchange (ETDEWEB)

    Lachkar, J. [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes; Paris-11 Univ., fabulte des Sciences 91 - Orsay (France)

    1969-07-01

    {beta}{gamma} directional angular correlations and shapes of inner beta spectra leading to the first excited level of the final nucleus enable one to determine the nuclear matrix elements typical of the {beta} transition. In the three observed first forbidden cases: {sup 170}Tm, {sup 86}Rb, {sup 198}Au, these matrix elements do not confirm the independent shell model theory. Other hypotheses are then suggested and discussed. (author) [French] Les experiences de correlation angulaire {beta}{gamma} et l'etude du spectre {beta} conduisant au premier niveau excite du noyau final permettent de determiner les elements de matrices nucleaires caracteristiques de cette transition. Dans les trois cas etudies (transitions une fois interdites): {sup 170}Tm, {sup 86}Rb, {sup 198}Au, ces elements de matrices ne peuvent etre retrouves a l'aide du modele en couches et a particules independantes. D'autres hypotheses sont alors emises et discutees. (auteur)

  18. Study of physico-chemical release of uranium and plutonium oxides during the combustion of polycarbonate and of ruthenium during the combustion of solvents used in the reprocessing of nuclear fuel; Etude de la mise en suspension physico-chimique des oxydes de plutonium et d'uranium lors de la combustion de polycarbonate et de ruthenium lors de la combustion des solvants de retraitement du combustible irradie

    Energy Technology Data Exchange (ETDEWEB)

    Bouilloux, L

    1998-07-01

    The level of consequences concerning a fire in a nuclear facility is in part estimated by the quantities and the physico-chemical forms of radioactive compounds that may be emitted out of the facility. It is therefore necessary to study the contaminant release from the fire. Because of the multiplicity of the scenarios, two research subjects were retained. The first one concerns the study of the uranium or plutonium oxides chemical release during the combustion of the polycarbonate glove box sides. The second one is about the physico chemical characterisation of the ruthenium release during the combustion of an organic solvent mixture (tributyl phosphate-dodecane) used for the nuclear fuel reprocessing. Concerning the two research subjects, the chemical release, i.e. means the generation of contaminant compounds gaseous in the fire, was modelled using thermodynamical simulations. Experiments were done in order to determine the ruthenium release factor during solvent combustion. A cone calorimeter was used for small scale experiments. These results were then validated by large scale tests under conditions close to the industrial process. Thermodynamical simulations, for the two scenarios studied. Furthermore, the experiments on solvent combustion allowed the determination of a suitable ruthenium release factor. Finally, the mechanism responsible of the ruthenium release has been found. (author)

  19. Nuclear reactor (1960); Reacteurs nucleaires (1960)

    Energy Technology Data Exchange (ETDEWEB)

    Maillard, M.L. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Leo, M.B. [Electricite de France (EDF), 75 - Paris (France)

    1960-07-01

    The first French plutonium-making reactors G1, G2 and G3 built at Marcoule research center are linked to a power plant. The G1 electrical output does not offset the energy needed for operating this reactor. On the contrary, reactors G2 and G3 will each generate a net power of 25 to 30 MW, which will go into the EDF grid. This power is relatively small, but the information obtained from operation is great and will be helpful for starting up the power reactor EDF1, EDF2 and EDF3. The paper describes how, previous to any starting-up operation, the tests performed, especially those concerned with the power plant and the pressure vessel, have helped to bring the commissioning date closer. (author) [French] Les premiers reacteurs industriels plutonigenes francais G1 - G2 - G3 du Centre de Marcoule comportent une installation de recuperation d'energie. La production d'electricite de G1 ne compense pas l'energie depensee par ailleurs pour le fonctionnement de l'ensemble, par contre, G2 et G3 doivent fournir chacun une puissance de 25 a 30 MW au reseau national d'Electricite de France. Cette puissance est modeste, mais l'experience acquise grace a ces reacteurs est tres grande et c'est grace a elle qu'il nous sera possible de mettre en exploitation les reacteurs energetiques EDF1 - EDF2 - EDF3. Le memoire decrit comment, avant tout demarrage du reacteur, les essais effectues, en particulier ceux concernant l'installation de recuperation d'energie et le caisson, ont permis d'abreger la phase de montee en puissance. (auteur)

  20. Micro manometer and pitot tube for measuring the velocity distribution in a natural convection water stream between two vertical parallel plates (1961); Micromano metre et tube de pitot destines a l'exploration du profil de vitesse dans un ecoulement d'eau de convection naturelle entre deux plaques verticales paralleles (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Santon, L.; Vernier, Ph. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1961-07-01

    For heat transfer studies in certain cases of cooling in swimming-pool type nuclear reactors, a knowledge of the distribution of the velocities between two heating elements is of prime importance. A Pitot tube and a micro-manometer have been developed for making these measurements on an experimental model. (authors) [French] Pour l'etude du transfert de chaleur dans certains cas de refroidissement des reacteurs nucleaires du type piscine, la connaissance de la repartition des vitesses entre deux elements chauffants est primordiale. On a mis au point un tube de Pitot et un micromanometre pour effectuer ces mesures sur une maquette experimentale. (auteurs)

  1. Instruments used to measure or check {alpha}, {beta}, {gamma} activity and neutron emission in the course of processing ore or irradiated fuel; Appareils de mesure ou de controle {alpha}, {beta}, {gamma}, n, des circuits des usines de traitement du minerai ou du combustible irradie

    Energy Technology Data Exchange (ETDEWEB)

    Blanc, A.; Brunet, M.; Kermagoret, M.; Labeyrie, J.; Roux, G.; Vasseur, J.; Weil, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-07-01

    One of the methods checking ores in the course of treatment is the rapid quantitative determination of thorium. This measurement is carried out by means of a scintillation instrument which shows the {beta} and {alpha} coincidences of ThC and ThC'. The treatment of irradiated fuel is accompanied by a large number of radioactive checks relative to the performance of the fixation and elution operations of uranium in the ion exchangers, to the concentration of radioactivity of effluent sent from the plant into watercourses. The operations of fixation and elution of the uranium are checked automatically by an instrument which takes a sample of 5 cm{sup 3} of solution, evaporates it and measures its activity every 10 or 20 minutes. Plutonium concentrations are measured: - in the presence of strong {beta} {gamma} activities, by means of rotating cylinder detectors; - in the presence of weak {beta} {gamma} activities, by means of {alpha} detectors scanning a constant level liquid surface; - by means of fission chambers relatively insensitive to {gamma}. Fission product concentrations are measured by chambers, counters or scintillators, according to the amount of {gamma} activity present. Finally, the activity of effluent to be emptied into watercourses is checked by means of a scintillation instrument, which measures the {alpha} activity on the one hand, and on the other hand the {beta} {gamma} activity of residue from a 100 cm{sup 3} sample taken and evaporated in 20 minutes. (author) [French] Parmi les controles relatifs au minerai en cours de traitement, figure le dosage rapide de thorium. Cette mesure est realisee au moyen d'un appareillage a scintillation qui met en evidence la coincidence des emissions {beta} et {alpha} du ThC et du ThC'. Le traitement des combustibles irradies s'accompagne d'un grand nombre de controles radioactifs portant sur le fonctionnement des operations de fixation et d'elution de l'uranium dans les

  2. Récupération du platine contenu dans les piles à combustible basse température par voie hydrométallurgique Platinum Recovery from used PEMFC by hydrometallurgy

    Directory of Open Access Journals (Sweden)

    Vincent Denis

    2013-11-01

    Full Text Available La récupération du platine contenu dans la couche catalytique des piles à combustible est nécessaire pour viabiliser cette technologie vers le secteur industriel. Dans cette étude la voie purement hydrométallurgique a été privilégiée au procédé de récupération pyrométallurgique, évitant la destruction des autres constituants de la pile (membrane, … et limitant la formation de gaz toxique. Le procédé mise en œuvre est constitué d'une étape de lixiviation à partir d'un mélange HCl/HNO3, suivie par la précipitation d'un sel de platine (NH42PtCl6 pouvant soit servir à la synthèse d'un nouveau catalyseur soit à l'obtention de platine métallique. Sur l'ensemble de la chaîne un rendement de récupération de plus de 80 % a pu être obtenu mettant en avant le potentiel de cette stratégie. The recovery of platinum in the catalyst layers of PEMFCs (proton exchange membrane fuel cells is required to allow a transfer in industry. In this study, hydrometallurgical route was preferred to pyrometallurgical process, reducing both the destruction of the other components of the cell (membrane, … and the formation of hazardous gas. In this work, the process includes a leaching step from a diluted aqua regia solution, followed by a precipitation step of platinum under the (NH42PtCl6 form. This salt can be used either for the synthesis of a new catalyst or to obtain a metallic platinum. Considering these steps the recovery efficiency has been found to be over 80 %, which bring out the potential of this strategy.

  3. Combustion of Solid Propellants (La Combustion des Propergols Solides)

    Science.gov (United States)

    1991-07-01

    on peut s’interroger sur l’adquation des moyens engages ausceptiblea do se manifester naturellement au cours du A Ia complexit6 du probl~me... capteur d’Helmoltz; de pression lorsque Ia fr~quence vanet. Calcul num~rique et mithode expdrimentale donnent des irdsultats en bon accord, c’cst-i... naturellement , avec des niveaux stabilis~s moddr~s. mod~le de combustion (r~f. 30) et des limites de L’opinion est r~pandue que la segmentation peut l’approche

  4. Du fratinoj

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    Vivis iam du fratinoj-Aje kaj Fatme.Iliapatrino estis duon-patrino por Fatme kaj in neamis.Foje i diris al sia edzo:-Faru kion ajn,sed mi ne plu volas vidiFatme.La sekvan tagon la patro forkondukis la

  5. The use and evolution of the CEA research reactors; Utilisation et evolution des reacteurs de recherche du C.E.A

    Energy Technology Data Exchange (ETDEWEB)

    Rossillon, F.; Chauvez, C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    retracent brievement l'histoire de ces reacteurs en montrant ce qu'a ete jusqu'a present leur utilisation, et comment certaines modifications ont permis de les adapter a l'evolution des programmes. Ils precisent egalement les raisons qui ont conduit a l'elaboration du projet de la nouvelle pile OSIRIS, La pile ZOE, la plus ancienne du CEA, est en service au Centre de Fontenay-aux-Roses depuis 1948. Elle est principalement utilisee pour les mesures de section efficace d'absorption du graphite, et pour diverses irradiations de courte duree ne necessitant que des flux peu eleves. La Pile EL2, en service depuis 1952, a permis les premieres etudes liees au refroidissement par gaz. Elle a ete tres utilisee pour la production des radioisotopes et pour de nombreuses experiences de physique, de metallurgie et de physico-chimie - le vieillissement de certaines parties du reacteur a conduit a decider l'arret prochain de cette installation. La Pile EL. 3 a ete tres utilisee pour les experiences de physique et pour l'etude des combustibles. L'adoption d'une nouvelle structure pour le coeur (solution 'Cristal de neige') va permettre d'accroitre considerablement les possibilites de la pile pour les irradiations en neutrons rapides. La pile TRITON-I, piscine de 2 MW, est surtout utilisee pour les irradiations en neutrons rapides et en gamma. Certaines modifications, actuellement en cours, permettront d'accroitre la puissance du reacteur jusqu'a 4 ou 5 MW. Dans un compartiment voisin de TRITON-I est implantee la Pile TRITON-II, de meme structure generale, mais dont la puissance maximum est de 100 kW. TRITON-II est utilisee exclusivement pour les etudes de protections. MELUSINE, pile piscine de 2 MW est en fonctionnement au Centre d'Etudes Nucleaires de Grenoble depuis 1959. Elle a permis l'execution d'un programme important concernant surtout la physique du solide, l'etude fondamentale de

  6. Contribution to the study of the evolution of radiation induced He in Be O; Etudes sur l'evolution de l'helium produit par reactions nucleaires dans l'oxyde de beryllium

    Energy Technology Data Exchange (ETDEWEB)

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

    1966-11-15

    The purpose of this work in-pile investigation of He formed by (n, 2n) and (n, {alpha}) nuclear reactions, released from irradiated BeO, in the temperature range 1000 - 1350 deg. C. The experimental results show that, for an instantaneous neutron fast flux of 10{sup 13} n cm{sup -2} sec{sup -1}, an equilibrium is attempted, after several days, for a part lower than 20 per cent of the quantity of He formed, theoretically calculated from the neutron cross sections of nuclear reactions, and from the analytical form of the neutron fast flux, releases from the solid. The validity of the values of calculated helium and the gas chromatographic analytical method are also verified by dissolution of the BeO pellets in cryolite. A new fast neutron flux measuring method may be so defined. The discussion of the experimental results enables to establish that the processus of He release is characterized by two phenomena: the first one which controls the release of He atoms out of the solid and the second which reveals a capture processus, connected to the irradiation and probably due to the vacancies induced in the lattice. (author) [French] On etudie en pile le degagement de l'helium forme par reactions nucleaires (n, 2 n) et (n, {alpha}) dans l'oxyde de beryllium irradie entre 1000 et 1350 deg. C. Les resultats experimentaux montrant que, pour un flux rapide instantane de 10{sup 13} n{sub r} cm{sup -2} s{sup -1}, on aboutit, au bout de quelques jours, a un etat d'equilibre pour lequel une partie, inferieure a 20 pour cent de la quantite d'helium forme, calculee theoriquement a partir des sections efficaces des reactions nucleaires et de la forme analytique du flux rapide, s'echappe du solide. On verifie egalement par dissolution des echantillons de BeO dans la cryolithe la validite du calcul de l'helium et de la methode de dosage par chromatographie en phase gazeuse. On peut ainsi definir une methode nouvelle de mesure des flux rapides. La

  7. Study, with the help of nuclear indicators (HTO, Urea {sup 14}C and {sup 24}Na), of the renewal of water, urea and sodium in different parts of the rat kidney in aqueous diuresis and of the gerbil kidney in osmotic diuresis or in oliguria; Etude, a l'aide d'indicateurs nucleaires (HTO, UREE {sup 14}C et {sup 24}Na), du renouvellement de l'eau, de l'uree et du sodium dans les differentes regions du rein de rat en diurese aqueuse et de merion en diurese osmotique ou en oligurie

    Energy Technology Data Exchange (ETDEWEB)

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

    1965-06-01

    In the kidney of the gerbil in oliguria there exists a cortico-papillary gradient in the concentration of the sodium and of the urea; this gradient disappears in the gerbil kidney in osmotic diuresis or in the rat kidney in aqueous diuresis; in these three states of diuresis there is no significant difference in the potassium concentration between the surface and interior regions of the kidneys. Kinetic studies using tritiated water, urea {sup 14}C and {sup 24}Na show that water and urea in the interior regions of the kidney are only renewed very slowly (1 h) whereas the sodium is rapidly changed (1 mn). These results can be explained using WIRZ's theory concerning the mechanism of the counter-current concentration of urine. Furthermore, the evolution of the specific radioactivity of urea {sup 14}C is favorable for a cortical synthesis of urea. (author) [French] II existe dans le rein de Merions en oligurie un gradient cortico papillaire de la concentration du sodium et de l'uree; ce gradient est aboli dans le rein de Merions en diurese osmotique ou de rats en diurese aqueuse; dans ces 3 etats de diurese il n'y a pas de difference significative de la concentration du potassium entre les regions superficielles et profondes des reins. Des etudes cinetiques a l'aide d'eau tritiee, d'uree {sup 14}C et de {sup 24}Na montrent que l'eau et l'uree des regions profondes des reins ne sont renouveles que tres lentement (1 h), alors que le sodium est tres vite renouvele (1 mn). Ces resultats s'expliquent par la theorie de WIRZ sur le mecanisme de la concentration de l'urine par contre-courant. En outre, l'evolution renale de la radioactivite specifique de l'uree {sup 14}C est en faveur d'une synthese corticale de l'uree. (auteur)

  8. Second inter-association evaluation of the PNLCC implementation. PNLCC 2000-2003: The Government economizes its energy; Deuxieme evaluation interassociative de la mise en oeuvre du PNLCC. PNLCC 2000-2003: Le gouvernement economise son energie

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-11-01

    A group of associations (RAC-F, FNE, WWF, ''les amis de la terre'', CLER, Greenpeace, Helio international, Hespul, ''energies et territoires'', Detente, ''sortir du nucleaire'') realized its own 2002 evaluation of the PNLCC implementation. For each chapters of the Plan (industry, transports, buildings, agriculture and forests, wastes, energy production and conservation and cooling gases, the document takes stock on the actions decided and realized and shows the deficiencies of the government management. (A.L.B.)

  9. modelisation du comportement hydrologique du bassin versant du ...

    African Journals Online (AJOL)

    LGE

    caractéristiques physiographiques du bassin dans le modèle permet la mise en évidence de son ... espèces les plus hygrophiles du secteur ombrophile. ...... [13] - F. HENDRICKX, Impact hydrologique d‟un changement climatique sur le bassin du ... LOPES, On the effect of uncertainty in spatial distribution of rainfall on ...

  10. 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)

  11. Health survey on cancers about the Tricastin nuclear site; Etude sanitaire sur les cancers autour du site nucleaire du Tricastin

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    This survey aims at describing the health status of the population around the Tricastin site, and more particularly at determining whether there is a difference between death or cancer occurrence frequencies observed around this site with respect to reference frequencies. It does not aim at assessing the health impact of the site industrial installations. Cancer mortality data, cancer diagnosis data, demographic data, child cancer data, data related to hospital stays in relationship with cancer, long duration hospital stay data, and mortality data are used. Several indicators are defined and used: standardised mortality ratio, standardised hospitalisation ratio. Data are also analysed in terms of location, and socio-demographic categories. It appears that there is no specific health situation for the considered area, except for pancreas cancer for women

  12. Situation of nuclear industry in Japan; La situation du nucleaire au Japon

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-03-01

    This document presents the situation of nuclear industry in Japan: cooperation with France in the domain of the fuel cycle (in particular the back-end) and of for the industrial R and D about fast reactors and nuclear safety; present day situation characterized by a series of incidents in the domain of nuclear safety and by an administrative reorganization of the research and safety organizations; power of local representatives, results of April 2003 elections, liberalization of the electric power sector, impact of the TEPCO affair (falsification of safety reports) on the nuclear credibility, re-start up of the Monju reactor delayed by judicial procedures, stopping of the program of MOX fuel loading in Tepco's reactors, discovery of weld defects in the newly built Rokkasho-mura reprocessing plant, an ambitious program of reactors construction, the opportunity of Russian weapons dismantling for the re-launching of sodium-cooled fast reactors; the competition between France and Japan for the setting up of ITER reactor and its impact of the French/Japanese partnership. (J.S.)

  13. The nuclear future in France; Le futur du nucleaire en France

    Energy Technology Data Exchange (ETDEWEB)

    Lemperiere, F.

    2011-12-15

    After having outlined some important facts in the world concerning energy production (phasing out nuclear by many countries, share of nuclear energy, development of wind and solar energy, possibility of meeting electricity demand with 80% of renewable energies) and in France (nuclear plants, debate about nuclear, slow development of renewable energies), the author briefly assesses the cost of two scenarios: a reduction of nuclear energy from 450 to 300 TWh/year by 2025, and a reduction of nuclear energy from 300 to 0 TWh/year between 2025 and 2040

  14. The diverse applications of the nuclear power; Les diverses applications du nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    The three great categories of application in industry and environment of ionizing radiations are the use of ionizing radiation to transport energy in matter it is industrial irradiation, the use of radioactive sources of low activity to analyze and measure, it is the nucleonic instrumentation, the use of radioactive tracers to follow and study the matter transfer. Are explained the treatments to improve the plastic materials and the ionisation of food. (N.C.)

  15. Phasing out nuclear, a credible scenario; Sortir du nucleaire, un scenario credible

    Energy Technology Data Exchange (ETDEWEB)

    Chatelain, C.; Mulot, R.; Chauveau, L.; Hait, J.F.

    2011-08-15

    Based on data from different companies, institutions and associations involved in nuclear energy (either in its production or in its critic), this article comments the possible energy savings (50 to 64%) that may be reached in the different sectors, and more particularly in the building sector and in electrical equipment. It discusses the potential production from solar, wind and biogas energy. It notices that phasing out nuclear is possible by 2030-2050, but would entail an increase of electricity prices. The German approach is presented. An article comments the anger of Fukushima Japanese farmers and evokes the slow building up of a solidarity network between France and Japan. A last article comments the authorization given to a further exploitation of the Fessenheim nuclear power plant (ten more years)

  16. Critical aspects of the nuclear multifragmentation; Etude du caractere critique de la multifragmentation nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Marie, J

    2004-06-01

    From statistical mechanics, this thesis looks for a phase transition signal in nuclei. We try to describe critical aspects of the nuclear multifragmentation. Thermodynamical observables as fragment mass/charge distributions are used in those finite systems. The percolation theory is first applied to strictly statistical events from the lattice gas model framework at the thermodynamical critical point. The scaling functions obtained are quantitatively comparable for every sample. Critical exponents are almost the same as the liquid/gas universality class ones. The second part is devoted to Fisher's model framework taking into account for the chemical potential and the surface energy coefficient. The extracted critical temperature is compatible with the percolation one. Experimental samples are then studied from peripheral (Au+Au) and central (Xe+Sn) heavy ion collisions. Entrance channel memory effects are evidenced in peripheral events. The presence of collective flow make the central ones far away from the conditions required by Fisher's model. Nevertheless, the critical energy found is independent of the data characteristics. This curious stability has to be studied. (authors)

  17. Nuclear Power's Big Comeback?; Le grand retour du nucleaire?

    Energy Technology Data Exchange (ETDEWEB)

    Bonnaure, P.

    2011-01-15

    The autumn of 2010 has, in its turn, brought a trial of strength between anti-nuclear protestors and the authorities - in this case, over the train transporting 123 tons of nuclear waste between La Hague in France and Dannenberg in Germany. However, this episode, despite its spectacular nature and media impact, does not provide a true reflection of public opinion - and European opinion, in particular - with regard to nuclear power. As Pierre Bonnaure shows here, in the context of a progressive exhaustion of fossil fuels and the battle against climate change - which involves a reduction in greenhouse gas emissions - nuclear power may well recover its credibility. Public opinion seems less averse to it; states are developing new projects and ambitious nuclear programmes; and prospects in terms of resources (particularly, uranium) and technological developments seem set fair. After surveying the field and examining these various aspects, Pierre Bonnaure also reminds us of the remaining stumbling blocks: the question of radioactive waste, the lack of qualified labour in this sector and the funding difficulties. However, in these areas, it only needs states to make a substantial investment to consolidate an energy sector that has a bright future, provided it is assured of a technological research potential and safety conditions commensurate with the risks inherent in nuclear power. (author)

  18. Abandoning nuclear energy, a total industrial absurdity; Sortir du nucleaire, un non-sens industriel

    Energy Technology Data Exchange (ETDEWEB)

    Sorin, F.

    2011-09-15

    The abandoning of nuclear energy can not be considered without economic and social damages, it would amplify the des-industrialization process of France and would spoil its energy independence and would mean a step backwards in terms of world strategy. In France the nuclear sector gives work to a total of 410.000 people and generates a total added value of 33 billions euros each year. It would make no sense to stop an activity whose perspective is promising: a lot of reactors in the world will need soon maintenance, upgrading or replacement. (A.C.)

  19. The power of the will and the French nuclear programme; Volontarisme du programme nucleaire francais

    Energy Technology Data Exchange (ETDEWEB)

    Boureille, P. [Ministre de la Defense, Dept. Marine, Service Historique de la Defense, 75 - Paris (France)

    2010-03-15

    Using certain key episodes in the development of the French nuclear deterrent as examples, the author illustrates the extent to which boldness of decision-making, combined with far-thinking and resolute vision, is the foundation of any international defence policy built for the long term. (author)

  20. Situation of nuclear industry in Japan; La situation du nucleaire au Japon

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-08-01

    This document is a reprint of a note published by the nuclear service of the French embassy in Japan. It evokes the present day situation of nuclear facilities in Japan, the public acceptance and its attitude in front of accidents, the national energy program, the deregulation and competitiveness of nuclear power, the carrying out of the nuclear program, the future reactors, the fast neutron reactors, the dismantling activities, the fuel enrichment and reprocessing of spent fuels, the use of MOX fuel, the off-site storage, the vitrified and radiological wastes, the geological disposal of wastes, the prospects of the nuclear program, the companies involved in the Japan nuclear industry, the French-Japanese bilateral cooperation, and the ITER project in the domain of nuclear fusion. (J.S.)

  1. Application des modèles mécanistiques de cinétique chimique aux combustions industrielles. Illustration par la fabrication du gaz de synthèse Application of Mechanistic Models of Chemical Kinetics to Industrial Combustion. Illustration by Synthetic Gas Manufacturing

    Directory of Open Access Journals (Sweden)

    Gateau P.

    2006-11-01

    Full Text Available En combustion, la formation d'espèces mineures clés, comme les polluants, peut être interprétée par des modèles mécanistiques de cinétique chimique. Les informations que fournissent ces modèles, même s'il ne s'agit que de tendances, sont suffisamment fiables pour définir des choix technologiques. Toutefois, compte-tenu de la complexité des phénomènes traités, leur emploi fait appel à une méthode indirecte décrite dans cet article et illustrée par la conception d'un réacteur autotherme destiné à la préparation d'un syngaz (gaz de synthèse. Dans l'exemple proposé comme application, l'objectif est de faire fonctionner à l'air un réacteur opérant actuellement à l'oxygène pur. Le modèle mécanistique choisi établit très clairement les contraintes imposées par ce choix. During the development of a partial combustion reactor for natural gas [1], Institut Français du Pétrole (IFP has made use of a mechanistic model to determine the impact of operational parameters on the formation of soot. The model we chose deals with the oxidation and pyrolysis of light hydrocarbons by several hundred elementary reactions, some of which are shown in Table 1. All the species taken into consideration as well as their linking are shown in the flowchart in Fig. 3. Our data mainly came from References [2] and [8], from which we took all the reactions of species having three carbon atoms or less as well as the pyrolysis reactions of hydrocarbons with four carbon atoms. In this database, the kinetic coefficients of reactions between CH4 and the C2H5, C2H3 and C2H radicals were replaced by the values published in Reference [9]. This set of reactions is not sufficient to analyze the formation of soot, and so we added on the pyrolysis reactions of acetylene from Reference [10]. The model assimilated the total mass of carbon contained in C5 and C6 hydrocarbons with a soot number assumed to be proportional to the mass of soot formed by the

  2. Nuclear fuel cycle and marine environment. Behavior of the Rhone river effluents in the mediterranean sea and of wastes dumped in the northeast atlantic; Cycle du combustible nucleaire et milieu marin. Devenir des effluents rhodaniens en mediterranee et des dechets immerges en atlantique nord-est

    Energy Technology Data Exchange (ETDEWEB)

    Charmasson, S

    1998-07-01

    Man-made radionuclides released into the marine environment by the installations from the nuclear fuel cycle are used as tracers of various bio-geochemical processes. Several installations belonging to the whole nuclear fuel cycle, except the uranium mining, are set up on the Rhone River Banks. The sea disposal of low and intermediate level radioactive waste has never been authorized in the Mediterranean sea but several sites have been used in the North-East especially in abyssal waters. Radionuclides released by the Rhone river installations are used in order to study the dynamics of the Rhone inputs into the Mediterranean Sea. In the river, freshwater samples reflect quite accurately the discharge composition with a predominance of {sup 106}Ru, a radionuclide mostly released by the spent nuclear fuel reprocessing plant in Marcoule. Conversely, at the Rhone mouth, in the sediment compartment {sup 106}Ru yields to caesium isotopes ({sup 134}Cs and {sup 137}Cs) in importance. As these two isotopes demonstrate very different half-lives (30,2 and 2,1 years respectively), the temporal evolution of their ratio acts as a chronometer enabled to date sediment accumulation near the river mouth. Mean accumulation rates greater than 35 cm y{sup -1} have been determined in the pro-deltaic zone near the Roustan buoys over the period 1983-1991. Accumulation rates decrease rapidly with distance from the mouth and therefore most of the {sup 137}Cs inventory in this part of the Gulf of Lions is limited to the pro-deltaic area. A first study about the part the different {sup 137}Cs sources in the Mediterranean Sea play in this inventory has been carried out. Direct (atmospheric) and indirect (fluviatile) inputs due to fallout from both past nuclear tests and the Chernobyl accident could contribute to this inventory at the highest to 40 % while the industrial releases could contribute at the lowest to 60 %. The last site used for the dumping of low and intermediate level radioactive waste in the North-East Atlantic has been the subject of studies especially as regards the biological compartment. Indeed, the occurrence in abyssal waters of a very motile fauna, i.e. fish (Coryphaenoides armatus) and amphipods (Eurythenes gryllus), able to undertake important vertical migrations into the water column, represents a possible pathway towards the surface for the dumped radionuclides. The ignorance as regards populations inhabiting this site has led to a study of the population structure for the amphipod Eurythenes gryllus. This species is cosmopolite since it is found at all the latitudes in the world ocean both in bathyal and abyssal waters. Well known for its necrophagy and ability to consume baits, it is supposed to feed on carcasses. However, study of a natural radionuclide, i.e. {sup 210}Po, in this species has shown that it is possible that it feeds also on particle fluxes. In order to verify the validity of the data used for the modelling of the radiological assessment of these operations, in situ labelling experiments have been realized on these amphipods as well as on polychaetes from food labelled with radionuclides characterizing the dumped wastes. Though these results are still too few to acknowledge this validity, as expected from studies on coastal species the transfer factors food-organisms are quite low. Analyses carried out for surveillance purposes both on the fish Coryphaenoides armatus and the amphipod Eurythenes gryllus show that in these deep waters the main source of man-made radioactivity is the global fallout due to the atmospheric nuclear testing carried out mainly in the sixties. A transfer via the particle fluxes is necessary to explain the concentrations found for {sup 3}H, {sup 137}Cs, {sup 238}Pu and {sup 239+240}Pu. However, {sup 238}Pu/{sup 239+240}Pu isotopic ratios in some fish samples suggest and influence from the dumped wastes and underline the possible part taken by these necrophagous organisms in the dispersion of radionuclides released form the low and intermediate level radioactive waste dumped in the North-East Atlantic. (author)

  3. Nuclear fuel cycle and marine environment. Behavior of the Rhone river effluents in the mediterranean sea and of wastes dumped in the northeast atlantic; Cycle du combustible nucleaire et milieu marin. Devenir des effluents rhodaniens en mediterranee et des dechets immerges en atlantique nord-est

    Energy Technology Data Exchange (ETDEWEB)

    Charmasson, S

    1998-07-01

    Man-made radionuclides released into the marine environment by the installations from the nuclear fuel cycle are used as tracers of various bio-geochemical processes. Several installations belonging to the whole nuclear fuel cycle, except the uranium mining, are set up on the Rhone River Banks. The sea disposal of low and intermediate level radioactive waste has never been authorized in the Mediterranean sea but several sites have been used in the North-East especially in abyssal waters. Radionuclides released by the Rhone river installations are used in order to study the dynamics of the Rhone inputs into the Mediterranean Sea. In the river, freshwater samples reflect quite accurately the discharge composition with a predominance of {sup 106}Ru, a radionuclide mostly released by the spent nuclear fuel reprocessing plant in Marcoule. Conversely, at the Rhone mouth, in the sediment compartment {sup 106}Ru yields to caesium isotopes ({sup 134}Cs and {sup 137}Cs) in importance. As these two isotopes demonstrate very different half-lives (30,2 and 2,1 years respectively), the temporal evolution of their ratio acts as a chronometer enabled to date sediment accumulation near the river mouth. Mean accumulation rates greater than 35 cm y{sup -1} have been determined in the pro-deltaic zone near the Roustan buoys over the period 1983-1991. Accumulation rates decrease rapidly with distance from the mouth and therefore most of the {sup 137}Cs inventory in this part of the Gulf of Lions is limited to the pro-deltaic area. A first study about the part the different {sup 137}Cs sources in the Mediterranean Sea play in this inventory has been carried out. Direct (atmospheric) and indirect (fluviatile) inputs due to fallout from both past nuclear tests and the Chernobyl accident could contribute to this inventory at the highest to 40 % while the industrial releases could contribute at the lowest to 60 %. The last site used for the dumping of low and intermediate level radioactive waste in the North-East Atlantic has been the subject of studies especially as regards the biological compartment. Indeed, the occurrence in abyssal waters of a very motile fauna, i.e. fish (Coryphaenoides armatus) and amphipods (Eurythenes gryllus), able to undertake important vertical migrations into the water column, represents a possible pathway towards the surface for the dumped radionuclides. The ignorance as regards populations inhabiting this site has led to a study of the population structure for the amphipod Eurythenes gryllus. This species is cosmopolite since it is found at all the latitudes in the world ocean both in bathyal and abyssal waters. Well known for its necrophagy and ability to consume baits, it is supposed to feed on carcasses. However, study of a natural radionuclide, i.e. {sup 210}Po, in this species has shown that it is possible that it feeds also on particle fluxes. In order to verify the validity of the data used for the modelling of the radiological assessment of these operations, in situ labelling experiments have been realized on these amphipods as well as on polychaetes from food labelled with radionuclides characterizing the dumped wastes. Though these results are still too few to acknowledge this validity, as expected from studies on coastal species the transfer factors food-organisms are quite low. Analyses carried out for surveillance purposes both on the fish Coryphaenoides armatus and the amphipod Eurythenes gryllus show that in these deep waters the main source of man-made radioactivity is the global fallout due to the atmospheric nuclear testing carried out mainly in the sixties. A transfer via the particle fluxes is necessary to explain the concentrations found for {sup 3}H, {sup 137}Cs, {sup 238}Pu and {sup 239+240}Pu. However, {sup 238}Pu/{sup 239+240}Pu isotopic ratios in some fish samples suggest and influence from the dumped wastes and underline the possible part taken by these necrophagous organisms in the dispersion of radionuclides released form the low and intermediate level radioactive waste dumped in the Nor

  4. Proportioning of {sup 79}Se and {sup 126}Sn long life radionuclides in the fission products solutions coming from spent fuels processing; Dosage des radionucleides a vie longue {sup 79}Se et {sup 126}Sn dans les solutions de produits de fission issues du traitement des combustibles nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Comte, J

    2001-11-01

    The determination of radionuclides present in waste resulting from the nuclear fuel reprocessing is a request from the regulatory authorities to ensure an optimal management of the storage sites. Long-lived radionuclides (T{sub 1/2} > 30 years) are particularly concerned owing to the fact that their impact must be considered for the long term. Safety studies have established a list of long-lived radionuclides (LLRN) whose quantification is essential for the management of the disposal site. Among these, several are pure {beta} emitters, present at low concentration levels in complex matrices. Their determination, by radiochemical method or mass spectrometry, involves selective chemical separations from the others {beta}/{gamma} emitters and from the measurement interfering elements. The work undertaken in this thesis relates to the development of analytical methods for the determination of two long-lived radionuclides: selenium 79 and tin 126, in acid solutions of fission products present in nuclear fuel reprocessing plant. For selenium 79, a {beta} emitter with a half live estimated to be 10{sup 6} years, the bibliography describes different chemical separation methods including precipitation, liquid-liquid extraction and chromatography on ionic resins. After optimisation on a synthetic solution, two of these techniques, precipitation by potassium iodine and separation with ion exchange resins were applied to a genuine solution of fission products at Cogema La Hague. The results showed that only the ion exchange method allows us to obtain a solution sufficiently decontaminated (FD{beta}{gamma} = 250) with a significant selenium recovery yield (85%). This separation allows the measurement of the {sup 79}Se by electrothermal vaporization coupled with inductively coupled plasma mass spectrometry (ETV-ICP/MS), after transfer of the samples to CEA/Cadarache. The concentration of {sup 79}Se measured is 0,42 mg/L in the solution of fission products with an isotopic ratio {sup 79}Se/{sup 82}Se equal to that recommended by the modelling codes for this fuel. Further analyses were carried out by liquid scintillation counting after two additional chemical treatment steps for purification. For tin 126, a {beta} emitter with a half-live estimated to 10{sup 5} years, the studies of separation methods described in the literature made it possible to define a liquid-liquid protocol of extraction with N-benzyl-phenylhydroxylamine (BPHA). Its application on genuine solution of fission products was performed with high chemical recovery yield (90%) and decontamination factors (FD{sub {beta}}{sub {gamma}} = 10{sup 5}). The measurements carried out by ICP/MS made it possible to quantify {sup 126}Sn (2,3 mg/L) and to determine the isotopic composition of tin in the fission product solution. The isotopic composition of tin obtained was in good agreement with the data recommended by modelling codes. Complementary measurement on {sup 126}Sn, and its decay products, were carried out by gamma spectrometry. Therefore, it was possible to deduce a value of the half-life of {sup 126}Sn found equal to 2,63.10{sup 5} years. (author)

  5. La maquette digitale du tunnel du LEP

    CERN Document Server

    Brouns, G

    2000-01-01

    Pour l'installation du LHC et son équipement périphérique (ligne cryogénique, câbles, tuyauterie, etc.) dans le tunnel du LEP, une maquette digitale CAO doit être faite. Après un rappel de la définition théorique du tunnel du LEP, cette LHC project Note décrit comment sont utilisées et intégrées d'anciennes et de nouvelles mesures du tunnel pour arriver à un ensemble de données qui permettent de construire la maquette digitale (CAO) du tunnel du LHC. Ensuite, les résultats sont comparés à leur valeur théorique d'une part, et aux anciennes valeurs disponibles d'autre part.

  6. Computational Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Westbrook, C K; Mizobuchi, Y; Poinsot, T J; Smith, P J; Warnatz, J

    2004-08-26

    Progress in the field of computational combustion over the past 50 years is reviewed. Particular attention is given to those classes of models that are common to most system modeling efforts, including fluid dynamics, chemical kinetics, liquid sprays, and turbulent flame models. The developments in combustion modeling are placed into the time-dependent context of the accompanying exponential growth in computer capabilities and Moore's Law. Superimposed on this steady growth, the occasional sudden advances in modeling capabilities are identified and their impacts are discussed. Integration of submodels into system models for spark ignition, diesel and homogeneous charge, compression ignition engines, surface and catalytic combustion, pulse combustion, and detonations are described. Finally, the current state of combustion modeling is illustrated by descriptions of a very large jet lifted 3D turbulent hydrogen flame with direct numerical simulation and 3D large eddy simulations of practical gas burner combustion devices.

  7. Nuclear program of Iran. Towards de-escalation of a nuclear crisis. Advisory letter; Nucleair programma van Iran. Naar de-escalatie van een nucleaire crisis. Briefadvies

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-04-15

    The Dutch government, partly at the request of the House of Representatives (Second Chamber), the AIV asked to give an opinion about the position of Iran in the region and the role of the nuclear program of Iran in the geopolitical relations, in view of the most recent developments [Dutch] De Nederlandse regering heeft, mede op verzoek van de Tweede Kamer der Staten-Generaal, de AIV gevraagd advies uit te brengen over de positie van Iran in de regio en de rol van het nucleaire programma van Iran in de geopolitieke verhoudingen hierin, mede gelet op de meest recente ontwikkelingen.

  8. Narrow gap mechanised arc welding in nuclear components manufactured by AREVA NP; Le soudage mecanise a l'arc en chanfrein etroit dans les constructions nucleaires realisees par AREVA NP

    Energy Technology Data Exchange (ETDEWEB)

    Peigney, A. [Departement Soudage AREVA Centre Technique - 71380 Saint-Marcel (France)

    2007-07-01

    soude avec un ou deux fils en deux passes par couche. En TIG, on rencontre de multiples applications car ce procede presente l'avantage de permettre le soudage en toutes positions. On soude selon les cas en une ou deux passes par couche. Le procede est utilise en usine et sur les sites nucleaires pour des operations de montage neuf mais aussi pour des remplacements de composants et en reparation. Actuellement, on cherche a augmenter la productivite de ce procede en utilisant un fil chaud et/ou deux fils. Concernant le MIG/MAG, on developpe son utilisation dans les constructions nucleaires, y compris en chanfrein etroit. Ce procede, limite dans ses applications dans le passe a cause des defauts qu'il generait, beneficie actuellement des progres des generateurs de soudage. On peut alors utiliser ce procede performant pour des constructions de haute securite telles que celles du nucleaire. A noter que le procede est applicable dans diverses positions de soudage comme c'est le cas pour le TIG, tout en etant plus performant que ce dernier. La communication presente l'etat de l'art de l'utilisation des procedes de soudage mecanises a l'arc en chanfrein etroit par les unites d'AREVA NP. (auteur)

  9. Health physics problems in the context of the development of industrial uses of nuclear energy; Les problemes de radioprotection devant le developpement de l'utilisation industrielle de l'energie nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Duhamel, F.; Menoux, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    fate of radioactive ions in the hydrosphere may be determined. - experiments and studies linked with the possibilities for disposal a underground storage of wastes. All these studies cover a complementary field, that of radioprotection, which forms the necessary link between nuclear safety proper, which concerns the actual operation of nuclear installations and medical supervision which directly concerns the health of the individual and the population. At the same time each one of the Health Physics disciplines possesses an independence which increases their efficiency on the safety level. (authors) [French] Le developpement de l'utilisation industrielle de l'energie nucleaire a mis l'accent sur la necessite de promouvoir une doctrine rationnelle et coherente en matiere de securite des installations atomiques et plus particulierement en matiere de securite des sites nucleaires. Le but principal de la securite est de diminuer, voire d'annuler les risques d'irradiation ou de contamination des travailleurs et de la population, consecutifs au fonctionnement normal ou accidentel des installations. La securite est obtenue par la mise en oeuvre d'un ensemble complexe de moyens. Parmi ces moyens les auteurs considerent essentiellement ceux qui presentent une certaine independance a l'egard du type d'installation: moyens d'alerte et de mesure et leur mise en oeuvre - preparation psychologique et technique des individus - evaluation de la capacite d'un site a absorber les rejets radioactifs sans dommage pour la population. Il est clair en effet que les consequences d'un accident sont diminuees par l'augmentation de la valeur des moyens de surveillance, de mesure et d'alerte, l'elevation du niveau technique et l'entrainement du personnel, l'education de la population. Ceci est particulierement vrai aupres d'une installation nucleaire ou l'etude des dangers presente un caractere abstrait et

  10. Protection of zirconium and its alloys by metallic coatings; Protection du zirconium et de ses alliages par des revetements metalliques

    Energy Technology Data Exchange (ETDEWEB)

    Loriers, H.; Lafon, A.; Darras, R.; Baque, P. [Commissariat a l' Energie Atomique, 91 - Saclay (France). Centre d' Etudes Nucleaires

    1968-07-01

    At 600 deg. C in an atmosphere of carbon dioxide, zirconium and its alloys undergo corrosion which presents two aspects simultaneously: - formation of a surface layer of zirconia, - dissolution of oxygen in the alloy sub-layer leading to brittleness. The two phenomena greatly restrict the possibilities of using zirconium alloys as a canning material for fuel elements in CO{sub 2} cooled nuclear reactors. An attempt has thus been made to limit, and perhaps to suppress, the corrosion effects in zirconium under these conditions by protecting it with metallic coatings. A first attempt to obtain a protection using copper-based coatings did not produce the result hoped for. Aluminium coatings produced by vacuum evaporation, followed by a consolidating thermal treatment make it possible to prevent the formation of the zirconia layer, but they do not eliminate the hardening effect produced by oxygen diffusion. On the other hand, electrolytically produced chromium deposits whose adherence is improved by a thermal vacuum treatment, counteract both these phenomena simultaneously. A similar result has been obtained with coatings of molybdenum produced by the technique of high-frequency inductive plasma sputtering. The particular effectiveness of the last two types of coatings is due to their structures characterized by the existence of an adherent film of chromium or molybdenum in the free state. (authors) [French] Le zirconium et ses alliages subissent, en atmosphere de gaz carbonique vers 600 deg. C, une corrosion qui prend deux aspects simultanes: - formation d'une couche de zircone superficielle, - dissolution fragilisante de l'oxygene dans l'alliage sous-jacent. Ces deux phenomenes restreignent fortement les possibilites d'utilisation des alliages de zirconium comme materiaux de gaine d'elements combustibles pour reacteurs nucleaires refroidis par le gaz carbonique. Il a donc ete cherche a limiter, voire supprimer, les effets de la corrosion du

  11. The use of slightly alloyed uranium as fuel: its influence on the dissolution and other stages of treatment; Emploi de l'uranium faiblement allie comme combustible: son incidence sur la dissolution et les autres phases du retraitement

    Energy Technology Data Exchange (ETDEWEB)

    Faugeras, P.; Leroy, P.; Lheureux, C. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    This report deals chiefly with the treatment of binary alloys (UAI, UMo, UZr, UCr, USi) with a low concentration of the additional element ({<=}2 per cent). The investigation was pursued with a view to the continued utilisation, with a minimum of modification, of the existing plants for treatment of non-alloyed irradiated uranium. In the first part, the usual process for the treatment of irradiated uranium by solvent extraction is briefly recalled. The second part is devoted to a study of the selective dissolution of the canning around certain of these alloys. The third part gives the behaviour of these different alloys at various phases of the usual treatment: a) dissolution; b) extractions; c) final treatment of fission products; d) final purification of plutonium. To conclude, possible alloys are classed as a function of their repercussions on the normal treatment. (author) [French] Il s'agit surtout du traitement d'alliages binaires (UAI, UMo, UZr, UCr, USi) a faible teneur en element etranger ({<=}2 pour cent). L'etude a ete conduite en vue d'utiliser un minimum de modifications les usines de traitement d'uranium irradie non allie. Dans une premiere partie, nous rappelons brievement le procede habituel de traitement de l'uranium irradie par extraction au solvant. La deuxieme partie est consacree a l'etude de la dissolution selective de la gaine entourant certains de ces alliages. La troisieme partie donne le comportement de ces differents alliages au cours des phases du traitement habituel: a) dissolution; b) extractions; c) traitement final des produits de fission; d) purification finale du plutonium. Enfin, en conclusion, nous etablirons un classement des alliages possibles en fonction des repercussions sur le traitement normal. (auteur)

  12. Study of the combustion of aluminium and magnesium particulates: influence of the composition of the gaseous mixture and of pressure; Etude de la combustion de particules d'aluminium et de magnesium: influence de la composition du melange gazeux et de la pression

    Energy Technology Data Exchange (ETDEWEB)

    Legrand, B.

    2000-07-01

    The combustion of metal particulates has a major interest in the domain of space propulsion. Aluminium is today used as doping material in the solid propellant of Ariane 5 rocket engines. Magnesium represents a possible fuel for propellers allowing a come back from Mars. An electrostatic levitation device has been used to study the combustion in controlled environment of particulates having a size representative of those encountered in propellers. The particulates are ignited with a laser and observed by fast cinematography. The inhibitive property of hydrogen chloride, an important constituent of the propellant atmosphere, on the combustion of aluminium particulates has been evidenced. These results have been compared with those obtained with a kinetic model in gaseous phase. The combustion of magnesium particulates in carbon dioxide has been studied for 53-63 {mu}m and 1-2 mm particulates. It is shown that the ignition of small particulates is controlled by the chemical kinetics and that the limit ignition pressure is reversely proportional to the particulates size. A study on big samples, performed in normal gravity but also in reduced gravity to get rid of the natural convection phenomena, has permitted to show a pulsed combustion regime linked with the presence of heterogenous reactions. The measurement of the combustion durations for the different sizes of particulates has permitted to propose a correlation between these two parameters for the particulate diameters comprised between 50 {mu}m and 2 mm. (J.S.)

  13. Optimization of fuel cycles: marginal loss values; Optimisation des cycles de combustibles: valeurs marginales des pertes

    Energy Technology Data Exchange (ETDEWEB)

    Gaussens, J. [Commissariat a l' Energie Atomique, 75 - Paris (France); Lasteyrie, B. de; Doumerc, J. [Compagnie pour l' Etude et la Realisation de Combustibles Atomiques, 75 - Paris (France)

    1965-07-01

    'uranium doit etre consideree comme definitivement perdue, alors que le reste pourrait etre recupere et recycle. Le cout eleve des pertes, recyclees ou non, d'autant plus eleve que l'uranium est plus enrichi, exige qu'il en soit tenu compte dans l'optimisation generale des cycles de combustible. Il importe donc de determiner leur niveau le plus souhaitable economiquement, aux diverses etapes d'elaboration du combustible nucleaire. Mais en France et dans d'autres pays, la production de matieres fissiles est geree par l'Etat, tandis que la fabrication de l'element combustible est effectuee par l'industrie privee. Les criteres d'optimisation et l'interet economique accorde aux pertes sont donc differents pour les deux parties de la chaine de fabrication. Pour tenter neanmoins d'atteindre un optimum conforme a l'interet collectif sans intervenir dans la politique de prix de l'entreprise, on peut utiliser la propriete des couts marginaux d'etre egaux entre eux a l'optimum, pour un volume de production donne. On peut donc ajuster le niveau des pertes pour realiser cette egalite des couts marginaux dont le calcul est plus facile a obtenir de la firme que la justification des prix eux-memes. On s'apercoit d'ailleurs que, bien qu'axee essentiellement sur les pertes, cette analyse globale peut conduire a une meilleure utilisation d'autres facteurs de production. On donne un expose theorique et des exemples pratiques de cette methode d'optimisation economique dans le cadre de la fabrication d'elements combustibles destines a des reacteurs du type: uranium naturel, moderes au graphite et refroidis par le gaz carbonique. (auteurs)

  14. Combustion physics

    Science.gov (United States)

    Jones, A. R.

    1985-11-01

    Over 90% of our energy comes from combustion. By the year 2000 the figure will still be 80%, even allowing for nuclear and alternative energy sources. There are many familiar examples of combustion use, both domestic and industrial. These range from the Bunsen burner to large flares, from small combustion chambers, such as those in car engines, to industrial furnaces for steel manufacture or the generation of megawatts of electricity. There are also fires and explosions. The bountiful energy release from combustion, however, brings its problems, prominent among which are diminishing fuel resources and pollution. Combustion science is directed towards finding ways of improving efficiency and reducing pollution. One may ask, since combustion is a chemical reaction, why physics is involved: the answer is in three parts. First, chemicals cannot react unless they come together. In most flames the fuel and air are initially separate. The chemical reaction in the gas phase is very fast compared with the rate of mixing. Thus, once the fuel and air are mixed the reaction can be considered to occur instantaneously and fluid mechanics limits the rate of burning. Secondly, thermodynamics and heat transfer determine the thermal properties of the combustion products. Heat transfer also plays a role by preheating the reactants and is essential to extracting useful work. Fluid mechanics is relevant if work is to be performed directly, as in a turbine. Finally, physical methods, including electric probes, acoustics, optics, spectroscopy and pyrometry, are used to examine flames. The article is concerned mainly with how physics is used to improve the efficiency of combustion.

  15. Applied combustion

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    From the title, the reader is led to expect a broad practical treatise on combustion and combustion devices. Remarkably, for a book of modest dimension, the author is able to deliver. The text is organized into 12 Chapters, broadly treating three major areas: combustion fundamentals -- introduction (Ch. 1), thermodynamics (Ch. 2), fluid mechanics (Ch. 7), and kinetics (Ch. 8); fuels -- coal, municipal solid waste, and other solid fuels (Ch. 4), liquid (Ch. 5) and gaseous (Ch. 6) fuels; and combustion devices -- fuel cells (Ch. 3), boilers (Ch. 4), Otto (Ch. 10), diesel (Ch. 11), and Wankel (Ch. 10) engines and gas turbines (Ch. 12). Although each topic could warrant a complete text on its own, the author addresses each of these major themes with reasonable thoroughness. Also, the book is well documented with a bibliography, references, a good index, and many helpful tables and appendices. In short, Applied Combustion does admirably fulfill the author`s goal for a wide engineering science introduction to the general subject of combustion.

  16. Contribution to the study of molecular movements in cyclohexane by electron spin resonance and electron-nuclear double resonance using a radical probe; Contribution a l'etude des mouvements moleculaires dans le cyclohexane par resonance paramagnetique electronique et double resonance electronique-nucleaire a l'aide d'une sonde radicalaire

    Energy Technology Data Exchange (ETDEWEB)

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

    1969-07-01

    Solutions of stable free radicals of the nitroxide type have been studied as a function of temperature. In the plastic or globular state, the cyclohexane molecules have rapid rotational and diffusional movements. They transmit this movement to dissolved free radicals. Conversely, measurements by electron spin resonance of the absolute movement of the radicals, and by electron nuclear double resonance of their movement relative to the cyclohexane molecules give very precise methods for local analyses of the movement present in the cyclohexane matrix. The principle of these techniques makes up the 'radical probe method'. (author) [French] Des solutions de radicaux libres stables, du type nitroxyde dans le cyclohexane ont ete etudiees, en fonction de la temperature. Les molecules de cyclohexane, dans l'etat plastique ou globulaire, sont animees de mouvements rapides de rotation sur elles-memes et de diffusion. Elles transmettent leur mobilite aux radicaux libres dissous. Reciproquement, la mesure du mouvement absolu des radicaux, a l'aide de la resonance paramagnetique electronique, et celle du mouvement relatif des radicaux et des molecules de cyclohexane par double resonance electronique-nucleaire, constituent des methodes tres precises pour analyser localement les mouvements presents dans la matrice de cyclohexane. Ce principe et ces techniques constituent la 'methode de la sonde radicalaire'. (auteur)

  17. Some fundamental aspects of boiling in nuclear reactors; Quelques aspects fondamentaux de l'ebullition dans les reacteurs nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Mondin, H.; Lavigne, P.; Semeria, R. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1964-07-01

    oscillation, the conditions of burnout are compared with those obtained under steady conditions. The burn-out flux following uniform 'stopped' heating has been studied in a channel containing still water. The flux shows a maximum as a function of unsaturation. The influence of the geometry and the nature of the metal was investigated. 4 - Output Oscillations: Using a low pressure (8 atm) loop, the influence of various parameters on the periods of output oscillations in a boiling channel on the thresholds at which they appear, was studied. Some new aspects of this complex phenomena were observed and are reported. (authors) [French] On indique les principaux resultats obtenus a Grenoble depuis quatre ans dans le domaine des mecanismes de l'ebullition et des phenomenes connexes dans les reacteurs nucleaires. 1 - OBSERVATION DE L'EBULLITION: Par photographie et cinematographie ultrarapide (8000 images par seconde maximum) on a observe l'ebullition en vase ou en canal jusqu'a 140 kg/cm{sup 2}. On a denombre les populations de germes (sites) generateurs de bulles et obtenu une correlation donnant leur nombre par unite de surface en fonction du flux thermique et de la pression. Le diametre des bulles se detachant de la paroi a ete etudie jusqu'a 140 kg/cm{sup 2}. On a mis en evidence trois types de bulles: - Les bulles en equilibre dont le diametre suit la formule de Fritz et Ende, - Les bulles d'ebullition dont le diametre diminue rapidement avec la pression (1/100 mm a 140 kg/cm{sup 2}), - Les coalescences apparaissant en liquide sature au-dessus de 15 W/cm{sup 2} et dont la proportion est independante de la pression. Par visualisation en strioscopie on observe les mouvements du film thermique associes a l'amorcage des germes, au depart et a la condensation des bulles; les mecanismes responsables de l'excellent transfert de chaleur ont pu ainsi etre precises. 2 - PERTES DE PRESSION EN ECOULEMENT DIPHASE: On a etabli un modele de

  18. Biofuels combustion.

    Science.gov (United States)

    Westbrook, Charles K

    2013-01-01

    This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acids and used primarily to replace or supplement conventional diesel fuels. Research efforts on so-called second- and third-generation biofuels are discussed briefly.

  19. Turbulent combustion

    Energy Technology Data Exchange (ETDEWEB)

    Talbot, L.; Cheng, R.K. [Lawrence Berkeley Laboratory, CA (United States)

    1993-12-01

    Turbulent combustion is the dominant process in heat and power generating systems. Its most significant aspect is to enhance the burning rate and volumetric power density. Turbulent mixing, however, also influences the chemical rates and has a direct effect on the formation of pollutants, flame ignition and extinction. Therefore, research and development of modern combustion systems for power generation, waste incineration and material synthesis must rely on a fundamental understanding of the physical effect of turbulence on combustion to develop theoretical models that can be used as design tools. The overall objective of this program is to investigate, primarily experimentally, the interaction and coupling between turbulence and combustion. These processes are complex and are characterized by scalar and velocity fluctuations with time and length scales spanning several orders of magnitude. They are also influenced by the so-called {open_quotes}field{close_quotes} effects associated with the characteristics of the flow and burner geometries. The authors` approach is to gain a fundamental understanding by investigating idealized laboratory flames. Laboratory flames are amenable to detailed interrogation by laser diagnostics and their flow geometries are chosen to simplify numerical modeling and simulations and to facilitate comparison between experiments and theory.

  20. Associative memories in nuclear physics; Les memoires associatives en physique nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Blanca, E.; Carriere, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    Experiments in nuclear physics involve the use of large size 'memories'. After showing the difficulties arising from the use of such memories, the authors give the principles of the various programming methods which make it possible to operate the memories associatively thus benefiting from a reduction in size and better operational conditions. They attempt to estimate the shape and dimensions of an associative memory with cable connections which could be designed specially for nuclear research, contrary to those actually in service. (authors) [French] Les experiences de physique nucleaire necessitent l'emploi de 'memoires' de grandes dimensions. Apres avoir montre les inconvenients que presente l'utilisation de telles memoires, les auteurs exposent les principes des diverses methodes de programmation qui permettent d'assurer un fonctionnement des memoires sur le mode associatif donc une reduction de leurs dimensions et un meilleur usage. Ils tentent d'evaluer le format d'une memoire associative cablee qui, contrairement a celles qui existent actuellement, serait prevue specialement pour l'experimentation nucleaire. (auteurs)

  1. Nuclear biological studies in France; Les etudes de biologie nucleaires en France

    Energy Technology Data Exchange (ETDEWEB)

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

    1961-07-01

    On the occasion of a colloquium on radiobiological research programmes, a number of documents dealing with French accomplishments and projects in this field were collected together. We felt that it would be useful to assemble these papers in one report; although they are brief and leave gaps to be filled in, they provide certain data, give an overall view of the situation, and can also suggest a rough plan for the general policy to adopt in the field of 'nuclear' biological research; i.e. research based on the nuclear tracer method or devoted to the action of ionising radiations. (author) [French] Un colloque sur les programmes de recherche en radiobiologie nous a donne l'occasion de reunir des documents sur les realisations et les projets francais dans ce domaine. Il nous a semble utile de reunir en un rapport l'ensemble de ces documents, qui, malgre leur brievete et malgre les lacunes qu'ils comportent, donnent un certain nombre d'informations, permettent une vue d'ensemble et peuvent dessiner aussi l'ebauche d'une politique coherente en matiere de recherches biologiques 'nucleaires', c'est-a-dire de recherches basees sur la methode des indicateurs nucleaires ou consacrees a l'action des rayonnements ionisants. (auteur)

  2. Combustion en lit fluidisé Fluidized-Bed Combustion

    Directory of Open Access Journals (Sweden)

    Chrysostome G.

    2006-11-01

    Full Text Available Après quelques rappels généraux sur la fluidisation où seront présentés en par-ticulier les avantages qu'elle offre en combustion, on exposera l'état actuel du développement des générateurs à lit fluidisé opérant avec les combustibles suivants : charbon, combustibles pétroliers, résidus divers ; il sera fait mention de la contribution de l'Institut Français du Pétrole (IFP dans les deux derniers domaines.On présentera ensuite les installations les plus récentes en traitement de minerais (grillage des sulfures, calcination de calcaires. En raison de son importance on examinera encore les possibilités de désulfuration au sein de lits fluidisés, de même que seront commentés les travaux de régénération des absorbants.On terminera enfin en mentionnant les développements des lits circulants ou rapides, considérés comme les réacteurs de la seconde génération. After a general review of fluidization including in particular the advantages it offers for combustion, this article describes the present state of the development of fluidized-bed gcnerators operating with the following fuels : cool, petroleum fuels, different residues. Mention is made of Institut Français du Pétrole (IFP contribution in the last two fields. Then the most recent ore-treating installations are described (roasting of sulfides, calcination of limestones. Because of its importance, the possibilities of desulfurizoticn inside fluidized beds is examined, and research on the regeneration of absorbants is commented on. The article ends by mentioning the development of circulating or fast beds which are considered as second generation reactors.

  3. Learning about Cri du Chat Syndrome

    Science.gov (United States)

    ... Learning About Prostate Cancer Learning About Cri du Chat Syndrome What is cri du chat syndrome? What ... cri du chat syndrome What is cri du chat syndrome? Cri du chat syndrome - also known as ...

  4. Advanced Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, Gordon R. [NETL

    2013-03-11

    The activity reported in this presentation is to provide the mechanical and physical property information needed to allow rational design, development and/or choice of alloys, manufacturing approaches, and environmental exposure and component life models to enable oxy-fuel combustion boilers to operate at Ultra-Supercritical (up to 650{degrees}C & between 22-30 MPa) and/or Advanced Ultra-Supercritical conditions (760{degrees}C & 35 MPa).

  5. "Cirque du Freak."

    Science.gov (United States)

    Rivett, Miriam

    2002-01-01

    Considers the marketing strategies that underpin the success of the "Cirque du Freak" series. Describes how "Cirque du Freak" is an account of events in the life of schoolboy Darren Shan. Notes that it is another reworking of the vampire narrative, a sub-genre of horror writing that has proved highly popular with both adult and…

  6. "Cirque du Freak."

    Science.gov (United States)

    Rivett, Miriam

    2002-01-01

    Considers the marketing strategies that underpin the success of the "Cirque du Freak" series. Describes how "Cirque du Freak" is an account of events in the life of schoolboy Darren Shan. Notes that it is another reworking of the vampire narrative, a sub-genre of horror writing that has proved highly popular with both adult and…

  7. Restaurant du Rivage, Vevey

    OpenAIRE

    Basini, Sari Bianca; Glocki, Ryszard Nikodem

    2015-01-01

    Après cinquante ans de mutilations, d'abandon et de spéculations économiques, le complexe du château de l'Aile et de la salle du Castillo à Vevey doit redéfinir son rôle public par rapport à la place du Marché et au Jardin du Rivage. S'appuyant sur la mémoire historique en ajoutant une unité à l'ensemble, nous créons un îlot regroupant des fonctions publiques. Il dessert ainsi l'espace ouvert environnant en articulant la relation entre le jardin et la place. L'élargissement de la promenade du...

  8. Atlas du Liban

    Directory of Open Access Journals (Sweden)

    Ramez Philippe Maalouf

    2008-11-01

    Full Text Available Compte-rendu de l’ouvrage Atlas du Liban: territoires et société, sous la direction d’Éric Verdeil, Ghaleb Faour et Sébastien Velut, édition franco-libanaise de l’IFPO (Institut Français du Proche-Orient et du CNRS Liban (Conseil National de la Recherche Scientifique – Liban, Beyrouth 2007.Resenha do livro Atlas du Liban: territoires et société, sob a direção de Éric Verdeil, Ghaleb Faour e Sébastien Velut, editado por iniciativa franco-libanesa do IFPO (Institut Français du Proche-Orient e pelo CNRS Liban (Conseil National de la Recherche Scientifique – Liban, Beirute, 2007.Review of Atlas du Liban: territoires et société, edited by Éric Verdeil, Ghaleb Faour and Sébastien Velut, french-lebanese edition by IFPO (Institut Français du Proche-Orient and CNRS Liban (Conseil National de la Recherche Scientifique – Liban Beirut, 2007.

  9. Ecologie du phytoplancton du lac Kivu

    Directory of Open Access Journals (Sweden)

    Sarmento, H.

    2008-01-01

    Full Text Available Speciation within the African Coffee Pathogen. Cet article analyse s'il est avantageux d'utiliser le compost au lieu de l'engrais minéral pour produire la laitue dans la zone urbaine et péri-urbaine de Yaoundé. Les résultats de terrain montrent l'obtention de rendements et profits plus élevés lorsqu'on utilise le compost. Les résultats de la fonction de production Cobb-Douglas prouvent que l'utilisation du compost est statistiquement significative pour expliquer la variation de rendement de la laitue et que le compost est l'intrant le plus productif. D'autres résultats montrent que le compost fournit la matière organique utile au sol et que les besoins d'irrigation en eau de la culture sont réduits grâce à l'utilisation du compost. Par conséquent, malgré le fait que l'application du compost demande une main-d'oeuvre beaucoup plus élevée, son utilisation est généralement bénéfique pour les agriculteurs vivant aux alentours de Yaoundé. Les programmes de vulgarisation de cet intrant pour encourager son adoption devraient donc figurer parmi les points prioritaires dans la politique agricole du gouvernement camerounais.

  10. Biomass Conversion to Hydrocarbon Fuels Using the MixAlcoTM Process Conversion de la biomasse en combustibles hydrocarbonés au moyen du procédé MixAlcoTM

    Directory of Open Access Journals (Sweden)

    Taco-Vasquez S.

    2013-04-01

    Full Text Available The MixAlcoTM process converts biomass to hydrocarbons (e.g., gasoline using the following generic steps: pretreatment, fermentation, descumming, dewatering, thermal ketonization, distillation, hydrogenation, oligomerization and saturation. This study describes the production of bio-gasoline from chicken manure and shredded office paper, both desirable feedstocks that do not require pretreatment. Using a mixed culture of microorganisms derived from marine soil, the biomass was fermented to produce a dilute aqueous solution of carboxylate salts, which were subsequently descummed and dried. The dry salts were thermally converted to raw ketones, which were distilled to remove impurities. Using Raney nickel catalyst, the distilled ketones were hydrogenated to mixed secondary alcohols ranging from C3 to C12. Using zeolite HZSM-5 catalyst, these alcohols were oligomerized to hydrocarbons in a plug -flow reactor. Finally, these unsaturated hydrocarbons were hydrogenated to produce a mixture of hydrocarbons that can be blended into commercial gasoline. Le procédé MixAlcoTM convertit la biomasse en hydrocarbures (par exemple, en essence selon les étapes génériques suivantes : prétraitement, fermentation, écumage, déshydratation, cétonisation thermique, distillation, hydrogénation, oligomérisation et saturation. Cette étude décrit la production de bioessence à partir de fumier de poulet et de papier en lambeaux, ces deux sources étant des matières premières convoitées ne nécessitant pas de prétraitement. À l’aide d’une culture mixte de microorganismes dérivés de sols marins, la biomasse a été soumise à une fermentation de manière à produire une solution aqueuse diluée de sels de carboxylates, ultérieurement écumés et séchés. Les sels séchés ont été thermiquement convertis en cétones brutes, ensuite distillées afin d’éliminer les impuretés. À l’aide du catalyseur à base de nickel de Raney, les c

  11. MODELES EPIDEMIOLOGIQUES DU SIDA

    OpenAIRE

    M MERAIHI; F. L RAHMANI

    2009-01-01

    L’objectif de cet article est de présenter la modélisation mathématique de la propagation de l’infection dans le contexte de la transmission du virus de l’immunodéficience humaine (VIH) et du syndrome d’immunodéficience acquise (SIDA). Ces modèles sont basés en partie sur les modèles proposés dans le domaine de la modélisation mathématique du SIDA.

  12. The French civilian nuclear: connections and stakes; Le nucleaire civil francais: filieres et enjeux

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    This document (18 power point slides) gives an overview of the French civilian nuclear industry and research and development: importance of the nuclear power generation in France, excellence of the education in nuclear sciences, organization of the nuclear connection (CEA, Areva, EDF, IRSN), the role of the French International Nuclear Agency (AFNI), the requirements for a renewal of human resources (French and foreign engineers) in the field of nuclear energy, the degree course for a diploma, examples of engineer and university diplomas, the educational networks in various regions of France, presentation of the Institut National des Sciences et Techniques Nucleaires (Nuclear Sciences and Techniques National Institute) and its master degrees, organization of the French education system in nuclear sciences with strong relations with the research and development programs

  13. The nuclear law: safety. 2006-2010; Le droit nucleaire: la surete 2006-2010

    Energy Technology Data Exchange (ETDEWEB)

    Bringuier, P. [Montpellier-1 Univ., UMR 5815, 34 (France)

    2010-11-15

    The author discusses the legal evolutions related to nuclear safety between 2006 and 2010. He identifies three main topics of unequal importance. Firstly, he comments the implementation of an international reference framework which has been completed at the European level and which aims at the harmonization of safety and security rules. Secondly, he comments the creation of the French Nuclear Safety Authority (ASN, Autorite de Surete Nucleaire). Thirdly, he comments the recast of the standard framework in order to update the French law with respect to the international reference framework. This leaded to a new distribution of power and authority, to more complete and constraining procedures, and to the definition of procedures for each step of an installation life cycle

  14. Combustion Research Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Combustion Research Laboratory facilitates the development of new combustion systems or improves the operation of existing systems to meet the Army's mission for...

  15. High Combustion Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — At NETL's High-Pressure Combustion Research Facility in Morgantown, WV, researchers can investigate new high-pressure, high-temperature hydrogen turbine combustion...

  16. The Pegase reactor loops; Les boucles du reacteur Pegase

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1968-07-01

    After 4 years operation, experimentation and maintenance of the gas loops built especially for the nuclear fuel testing reactor Pegase, it appears desirable not only to gather together in a single document the essential characteristics and particularities of these devices and of their associated equipment, but also to give the reasons for the technical modifications and the way in which they were carried out; this is done here by the persons themselves who were responsible, day after day, for operating these loops. This essentially practically experience thus complements the careful research and preliminary testing carried out on these loops or on their prototypes. It should be of interest to those who deal with problems concerned with the design or operation of irradiation loops in experimental reactors or of similar equipment. (authors) [French] Apres 4 annees de fonctionnement, d'experimentation et d'entretien sur les boucles a gaz, construites specialement pour le reacteur d'essai des combustibles nucleaires Pegase, il a paru souhaitable non seulement de rassembler dans un meme document les caracteristiques et les particularites essentielles de ces dispositifs et des appareillages qui leur sont associes, mais aussi d'y preciser les raisons et les modalites des mises au point techniques, apportees par ceux qui, jour apres jour pendant cette periode, ont eu la charge de mettre en oeuvre ces boucles. Cette experience essentiellement pratique complete donc les etudes minutieuses et les essais preliminaires de ces boucles ou de leurs prototypes. Elle doit etre de quelque interet pour ceux qui sont confrontes aux problemes de conception ou d'exploitation de boucles d'irradiation dans des reacteurs experimentaux ou des dispositifs analogues. (auteurs)

  17. Nuclear systems of the future - generation 4. Proposals of strategic orientations for the nuclear systems of the future; Les systemes nucleaires du futur - generation 4. Propositions d'orientations strategiques pour les systemes nucleaires du futur

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    Several points, specific to France, must be taken into consideration for the long term strategic choice of future nuclear systems, in particular: taking the best profit of the progress potentialities of water reactors, optimizing the opportunities offered by the renewal of power plants in operation, integrating the consequences and the implementation of a strategy of optimized management of radioactive wastes, and looking for improvements that would make nuclear energy an active contributor to sustainable development. The prospective researches carried out by the CEA and its industrial partners have led to propose a R and D strategy with 3 complementary goals: search for innovations for water reactors, development of fast neutron reactors with closed fuel cycle (sodium fast reactor (SFR), gas fast reactor (GFR)), and development of key-technologies for nuclear hydrogen production (very high temperature reactor (VHTR)). The R and D effort concerns also the subcritical systems devoted to transmutation, the new cycle processes for a global management of actinides, and some other nuclear systems like the molten salt reactors (MSR) and the supercritical water reactors (SCWR). This paper presents the R and D strategy for each technology with its priorities, steps, financial means and collaborations. (J.S.)

  18. Types du Caucase

    OpenAIRE

    Makhacheva, Taus

    2015-01-01

    Tiré du site Internet de Onestar Press: "Types du Caucase - antique postcard collection/ 2013 to the present time. Coming from the personal archive of the artist, these postcards date back to the 19th century and can be considered representative for the "popularized ethnography" of the Russian Empire. Their primitive typology follows the classical rules of exotization : they depict "pittoresque" groups from various tribes, families or nationalities, or representatives of diverse professions. ...

  19. Les outils du CERN

    CERN Multimedia

    1999-01-01

    C'est le plus grand centre mondial de recherche en physique des particules. Les outils du Laboratoire, accélérateurs et détecteurs de particules, figurent parmi les instruments scientifiques les plus complexes au monde. Des prix Nobels ont d'ailleurs été attribués aux physiciens du CERN pour leurs développements.

  20. Combustion chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Brown, N.J. [Lawrence Berkeley Laboratory, CA (United States)

    1993-12-01

    This research is concerned with the development and use of sensitivity analysis tools to probe the response of dependent variables to model input variables. Sensitivity analysis is important at all levels of combustion modeling. This group`s research continues to be focused on elucidating the interrelationship between features in the underlying potential energy surface (obtained from ab initio quantum chemistry calculations) and their responses in the quantum dynamics, e.g., reactive transition probabilities, cross sections, and thermal rate coefficients. The goals of this research are: (i) to provide feedback information to quantum chemists in their potential surface refinement efforts, and (ii) to gain a better understanding of how various regions in the potential influence the dynamics. These investigations are carried out with the methodology of quantum functional sensitivity analysis (QFSA).

  1. 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

  2. Les méthodes thermiques de production des hydrocarbures. Chapitre 5 : Combustion "in situ". Pricipes et études de laboratoire Thermal Methods of Hydrocarbon Production. Chapter 5 : "In Situ" Combustion. Principles and Laboratory Research

    Directory of Open Access Journals (Sweden)

    Burger J.

    2006-11-01

    Full Text Available II existe plusieurs variantes de la combustion in situ, suivant le sens de déplacement du front de combustion, à co-courant ou à contre-courant, et suivant la nature des fluides injectés, air seul ou injection combinée d'air et d'eau. Les réactions de pyrolyse, d'oxydation et de combustion mises en jeu par ces techniques sont discutées, en particulier la cinétique des principaux mécanismes réactionnels, l'importance du dépôt de coke et l'exothermicité des réactions d'oxydation et de combustion. Les résultats d'essais de déplacement unidirectionnel du front de combustion dans des cellules de laboratoire sont présentés et discutés. Enfin on indique les conditions pratiques d'application des méthodes de combustion in situ sur champ. Possible variations of in situ combustion technique ore as follows : forward or reverse combustion depending on the relative directions of the air flow and the combustion front, dry combustion if air is the only fluid injected into the oil-bearing formation, or fixe/woter flooding if water is injected along with air. The chemical reactions of pyrolysis, oxidation and combustion involved in these processes are described. The kinetics of these reactions is discussed as well as fuel availability in forward combustion and the exothermicity of the oxidation and combustion reactions. The results obtained in the laboratory when a combustion front propagates in unidirectional adiabatic tells are described and discussed. This type of experimentation provides extensive information on the characteristics of the processes. Screening criteria for the practical application of in situ combustion techniques are presented.

  3. Civil liability and nuclear coverage: synthesis report; Responsabilite civile et coverture nucleaires. Rapport du Groupe de Travail

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The report has been written considering the advanced work which has been done by the Expert Committee, sponsored by the International Atomic Energy Agency (IAEA), Vienna, having the purpose to examine the modifications issued in course of Vienna Convention as well as the Paris convention and the complementary Brussels Convention, in view to adapt the legislation to the actual context and to answer the populations expectations. The work has been organized in three majors chapters: the first one in concerned to the damage definition, proposition to the to reach the environment, the prevention and charges. the research and military installations are also considered. The second chapter has been dedicated to the civil responsibility, its limits, financing modes, the national and international legal competence besides the litigation charges due to the nuclear accidents born on the occasion. In the third chapter the insurance considering the damage nature, the capacity to assure liability coverage and the damage management are harmonized.

  4. Nuclear power plant of Fessenheim: evaluation of the seismic risk; Centrale Nucleaire de Fessenheim: appreciation du risque sismique

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    The seismic risk taken into account during the sizing of the nuclear power plant of Fessenheim seems to have been under evaluated at this time. The revaluation of the seismic risk, as proposed, until this day by EDF in order to the third ten-year visit of the power plant, planned for 2009, leads to a significant under evaluation of the risk and then is not acceptable. The present expertise details point by point the weaknesses of these revaluation. The power plant has been sized in an elastic manner that is generally strongly for the safety side. It is imperative to proceed the most quickly as possible to a deep control of the seismic resistance of the power plant of Fessenheim and then after having proceeded to a revision of the seismic risk in taking into account the actual knowledge in this field. (N.C.)

  5. Propagation of neutrinos in nuclear matter; Effets du milieu sur la propagation des neutrinos dans la matiere nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Margueron, J

    2001-07-01

    We study the elementary interactions between neutrinos and dense matter in a proto-neutron star. Equations of state obtained with different nuclear effective interactions (Skyrme, Gogny, Relativistic Lagrangians) are first discussed. Then, we characterize their stability in spin and isospin. We derive magnetic susceptibilities for all isospin asymmetry values as a function of Landau parameters G{sup {pi}}{sup {pi}}{sup '}{sub 0} (where {pi}, {pi}' = proton or neutron). From this work, we select a parametrization for each of the 3 effective forces: Sly230b,D1P,NL3. We calculate the pure neutron matter and asymmetric nuclear matter response functions with and without charge exchange, describing nuclear correlations in both approaches: non-relativistic (Hartree-Fock with Skyrme forces, then complete RPA) and relativistic (in the Hartree approximation). At the end, we calculate neutrino mean free paths neutral current and charged current reactions. Comparisons between relativistic and non-relativistic approaches allow us to identify relativistic effects in nuclear matter at densities as low as twice the saturation density. RPA correlations make the medium more transparent to neutrinos compared to free Fermi gas. The importance of the effective mass in mean free path calculations is also shown. (author)

  6. IAEA and the international nuclear law development; L`A.I.E.A. et le developpement du droit nucleaire international

    Energy Technology Data Exchange (ETDEWEB)

    Jankowitsh, O. [International Atomic Energy Agency, Vienna (Austria)

    1996-10-01

    This paper summarizes the different objectives of the IAEA (International Atomic Energy Agency) as far as nuclear energy use is concerned. It presents the status of the organization, its action int the non-proliferation treaty, and its work on the safeguard regulations. These measures have been taken during the Convention on nuclear safety in 1994. This convention concerns nuclear power plants as well as storage of radioactive wastes. (TEC).

  7. The radioactive wastes management of the little nuclear industry; La gestion des dechets radioactifs du nucleaire diffus

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    Among the ANDRA customers, more than one million are little producers: hospital, research centers and industries. They are called little producers because of the low volume of produced wastes. Meanwhile these wastes management need an appropriate technology which is presented in this document. (A.L.B.)

  8. The nuclear industry: a new weapon for the Kremlin?; L'industrie nucleaire: nouvelle arme du Kremlin?

    Energy Technology Data Exchange (ETDEWEB)

    Du Castel, V.

    2010-07-01

    After having noticed the recent evolution of the Russian policy which tends to concentrate the economical and political power with a limited democratic pluralism, the author describes the re-structuring policy adopted for the energy sector, and notably the nuclear sector, in order to become a major international actor. First, she analyses the evolution of the hydrocarbon sector with a better management of tax incomes, and a stronger control of the industries of this sector based on a State capitalism development. She outlines that Russia now uses energy as a diplomatic arm, particularly in its relationship with the European Union. She states that Russia may want to follow the same kind of policy for nuclear energy as for the hydrocarbon sector by developing partnership with other countries, by regrouping the concerned activities within a single holding company (Atomenergoprom) and a federal agency (Rosatom). Russia increased its uranium production and became a powerful actor who challenges other international companies (Areva, Westinghouse, Toshiba). The author discusses the strategy defined by the Kremlin to reach supremacy in the nuclear sector

  9. Facing the climatic threat, the nuclear illusion; Face a la menace climatique, l'illusion du nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    In the framework of the energy problem, the network Action Climate brings many propositions to explain that the nuclear is not a solution to the global warming. A boost to the nuclear will be done to the detriment of cheaper, safer and more adapted policies, as the energy conservation and efficiency, the energy production decentralization and the renewable energies development. The three parts shows how the nuclear cannot answer to the climatic problem, the nuclear refutes the Rio declaration on the environment and the sustainable development, the nuclear is a french specificity which damages the national policy against the climatic change. (A.L.B.)

  10. Japan abandons its all-nuclear policy; Le Japon s'eloigne du tout-nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Triendl, R. [Asian Technology Information Program, Tokyo (Japan)

    2000-06-01

    Japanese courts appear to be very lenient concerning accidents in nuclear facilities, and as a consequence they do not play an active role in reinforcing safety measures or questioning security procedures that have failed. Because of a series of accidents in nuclear facilities, the Japanese society becomes more aware of the weaknesses of the nuclear industry concerning safety. The MITI might relinquish its only-nuclear-energy policy and promote natural gas. (A.C.)

  11. Oxygen-enhanced combustion

    CERN Document Server

    Baukal, Charles E

    2013-01-01

    Combustion technology has traditionally been dominated by air/fuel combustion. However, two developments have increased the significance of oxygen-enhanced combustion-new technologies that produce oxygen less expensively and the increased importance of environmental regulations. Advantages of oxygen-enhanced combustion include less pollutant emissions as well as increased energy efficiency and productivity. Oxygen-Enhanced Combustion, Second Edition compiles information about using oxygen to enhance industrial heating and melting processes. It integrates fundamental principles, applications, a

  12. The evaluation of the nuclear facilities safety at the CEA from 1999 to 2001; Le bilan de la surete des installations nucleaires du CEA du 1999 a 2001

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-11-01

    The aim of this document is the presentation of an evaluation of the problems and the safety methods in the concerned period. The first chapter presents the nuclear safety in the CEA. The second chapter is devoted to the organization and the quality for the safety: liabilities, audits, relations with the safety authorities and with the public. The chapters three and four deal respectively with the methodological and technical abilities supporting the exploitation teams and with the nuclear safety projects. The last chapter presents the experiments and events from 1999 to 2001. (A.L.B.)

  13. Phasing out nuclear: shock statements by the EDF's CEO; Sortie du nucleaire: les declarations chocs du PDG d'EDF

    Energy Technology Data Exchange (ETDEWEB)

    Benezet, E.; Mouchon, F.; Lomazzi, M.; Jeanne, M.

    2011-11-09

    While costs associated with phasing out nuclear or cancelling of nuclear programs are briefly evoked for different European countries (Belgium, Germany, Italy), the EDF Chairman, Mr Proglio, comments the decisions of these countries, outlines the various risks associated with such a decision in France (job losses, greenhouse gas emissions), also outlines EDF involvement in nuclear safety and evokes the issues of Fessenheim and of the EPR. Some French political aspects on that matter are also evoked

  14. Le rythme du silence

    OpenAIRE

    Meschonnic, Henri

    2017-01-01

    1. Pour rompre le silence Dire « rythme du silence », c’est non seulement penser le silence comme langage, et parfois la réalisation maximale du langage, mais aussi parcourir les acceptions de la notion de silence. De ce qui n’est pas dit, ou qu’on est incapable de dire à ce que les mots ne peuvent pas dire, le fameux indicible, mais aussi l’innommable, et la censure, faire silence sur, jusqu’au problème poétique. Il y a aussi une langue de bois du silence. Et aussi le silence de ce qu’on ent...

  15. La profanation du montage

    OpenAIRE

    Hildebrandt, Toni

    2017-01-01

    Cet article examine les liens entre, pour l’aspect technique, le plan séquence et le montage, et, pour l’aspect philosophico-historique, la vie quotidienne et la politique mondiale, du point de vue d’une profanation capable de désamorcer la puissance et avec une attention particulière portée à l’unique film expérimental de Pasolini : La sequenza del fiore di (1968). Ce court métrage n’a pas seulement un statut spécial dans la filmographie de Pasolini, il marque aussi un tournant du tragique v...

  16. Combustion 2000

    Energy Technology Data Exchange (ETDEWEB)

    A. Levasseur; S. Goodstine; J. Ruby; M. Nawaz; C. Senior; F. Robson; S. Lehman; W. Blecher; W. Fugard; A. Rao; A. Sarofim; P. Smith; D. Pershing; E. Eddings; M. Cremer; J. Hurley; G. Weber; M. Jones; M. Collings; D. Hajicek; A. Henderson; P. Klevan; D. Seery; B. Knight; R. Lessard; J. Sangiovanni; A. Dennis; C. Bird; W. Sutton; N. Bornstein; F. Cogswell; C. Randino; S. Gale; Mike Heap

    2001-06-30

    . To achieve these objectives requires a change from complete reliance of coal-fired systems on steam turbines (Rankine cycles) and moving forward to a combined cycle utilizing gas turbines (Brayton cycles) which offer the possibility of significantly greater efficiency. This is because gas turbine cycles operate at temperatures well beyond current steam cycles, allowing the working fluid (air) temperature to more closely approach that of the major energy source, the combustion of coal. In fact, a good figure of merit for a HIPPS design is just how much of the enthalpy from coal combustion is used by the gas turbine. The efficiency of a power cycle varies directly with the temperature of the working fluid and for contemporary gas turbines the optimal turbine inlet temperature is in the range of 2300-2500 F (1260-1371 C). These temperatures are beyond the working range of currently available alloys and are also in the range of the ash fusion temperature of most coals. These two sets of physical properties combine to produce the major engineering challenges for a HIPPS design. The UTRC team developed a design hierarchy to impose more rigor in our approach. Once the size of the plant had been determined by the choice of gas turbine and the matching steam turbine, the design process of the High Temperature Advanced Furnace (HITAF) moved ineluctably to a down-fired, slagging configuration. This design was based on two air heaters: one a high temperature slagging Radiative Air Heater (RAH) and a lower temperature, dry ash Convective Air Heater (CAH). The specific details of the air heaters are arrived at by an iterative sequence in the following order:-Starting from the overall Cycle requirements which set the limits for the combustion and heat transfer analysis-The available enthalpy determined the range of materials, ceramics or alloys, which could tolerate the temperatures-Structural Analysis of the designs proved to be the major limitation-Finally the commercialization

  17. Combustion 2000

    Energy Technology Data Exchange (ETDEWEB)

    A. Levasseur; S. Goodstine; J. Ruby; M. Nawaz; C. Senior; F. Robson; S. Lehman; W. Blecher; W. Fugard; A. Rao; A. Sarofim; P. Smith; D. Pershing; E. Eddings; M. Cremer; J. Hurley; G. Weber; M. Jones; M. Collings; D. Hajicek; A. Henderson; P. Klevan; D. Seery; B. Knight; R. Lessard; J. Sangiovanni; A. Dennis; C. Bird; W. Sutton; N. Bornstein; F. Cogswell; C. Randino; S. Gale; Mike Heap

    2001-06-30

    . To achieve these objectives requires a change from complete reliance of coal-fired systems on steam turbines (Rankine cycles) and moving forward to a combined cycle utilizing gas turbines (Brayton cycles) which offer the possibility of significantly greater efficiency. This is because gas turbine cycles operate at temperatures well beyond current steam cycles, allowing the working fluid (air) temperature to more closely approach that of the major energy source, the combustion of coal. In fact, a good figure of merit for a HIPPS design is just how much of the enthalpy from coal combustion is used by the gas turbine. The efficiency of a power cycle varies directly with the temperature of the working fluid and for contemporary gas turbines the optimal turbine inlet temperature is in the range of 2300-2500 F (1260-1371 C). These temperatures are beyond the working range of currently available alloys and are also in the range of the ash fusion temperature of most coals. These two sets of physical properties combine to produce the major engineering challenges for a HIPPS design. The UTRC team developed a design hierarchy to impose more rigor in our approach. Once the size of the plant had been determined by the choice of gas turbine and the matching steam turbine, the design process of the High Temperature Advanced Furnace (HITAF) moved ineluctably to a down-fired, slagging configuration. This design was based on two air heaters: one a high temperature slagging Radiative Air Heater (RAH) and a lower temperature, dry ash Convective Air Heater (CAH). The specific details of the air heaters are arrived at by an iterative sequence in the following order:-Starting from the overall Cycle requirements which set the limits for the combustion and heat transfer analysis-The available enthalpy determined the range of materials, ceramics or alloys, which could tolerate the temperatures-Structural Analysis of the designs proved to be the major limitation-Finally the commercialization

  18. Utilisation de l'essai comete et du biomarqueur gamma-H2AX pour detecter les dommages induits a l'ADN cellulaire par le 5-bromodeoxyuridine post-irradiation

    Science.gov (United States)

    La Madeleine, Carole

    Ce memoire est presente a la Faculte de medecine et des sciences de la sante de l'Universite de Sherbrooke en vue de l'obtention du grade de maitre es sciences (M.Sc.) en radiobiologie (2009). Un jury a revise les informations contenues dans ce memoire. Il etait compose de professeurs de la Faculte de medecine et des sciences de la sante soit : Darel Hunting PhD, directeur de recherche (departement de medecine nucleaire et radiobiologie), Leon Sanche PhD, directeur de recherche (departement de medecine nucleaire et radiobiologie), Richard Wagner PhD, membre du programme (departement de medecine nucleaire et radiobiologie) et Guylain Boissonneault PhD, membre exterieur au programme (departement de biochimie). Le 5-bromodeoxyuridine (BrdU), un analogue halogene de la thymidine reconnu depuis les annees 60 comme etant un excellent radiosensibilisateur. L'hypothese la plus repandue au sujet de l'effet radio sensibilisant du BrdU est qu'il augmente le nombre de cassures simple et double brin lorsqu'il est incorpore dans l'ADN de la cellule et expose aux radiations ionisantes. Toutefois, de nouvelles recherches semblent remettre en question les observations precedentes. Ces dernieres etudes ont confirme que le BrdU est un bon radiosensibilisateur, car il augmente les dommages radio-induits dans l'ADN. Mais, c'est en etant incorpore dans une region simple brin que le BrdU radiosensibilise l'ADN. Ces recherches ont egalement revele pour la premiere fois un nouveau type de dommages produits lors de l'irradiation de l'ADN contenant du BrdU : les dimeres interbrins. Le but de ces travaux de recherche est de determiner si la presence de bromodeoxyuridine dans l'ADN augmente l'induction de bris simple et / ou double brin chez les cellules irradiees en utilisant de nouvelles techniques plus sensibles et specifiques que celles utilisees auparavant. Pour ce faire, les essais cometes et la detection des foci H2AX phosphorylee pourraient permettre d'etablir les effets engendres par

  19. Historique du Web

    CERN Multimedia

    TV8 Mont-Blanc

    1995-01-01

    Documentaire court qui retrace l'implication de différentes personalités à la création du Web. Entrevues avec Robert Cailliau, Chris Llewellyn-Smith, David Williams, Tim Berners-Lee, Mike Sendall, Brian Carpenter.

  20. La foret du Banco

    NARCIS (Netherlands)

    Koning, de J.

    1983-01-01

    Deze publicatie over het Nationaal Park 'La Forêt du Banco' nabij Abidjan, Ivoorkust, verschijnt als resultaat van vier jaar veldwerk (1972-1976) in dat land.Het Centre Néerlandais, onderzoeks- en stageverblijf van de Landbouwhogeschool, was basis en de faciliteiten verleend door het Franse ORSTOM-i

  1. Origine du vieux slave

    Directory of Open Access Journals (Sweden)

    Witold Mańczak

    2005-12-01

    Full Text Available Comme, pour prouver l'identité du vieux slave et du vieux bulgare, on invoque uniquement des critères phonétiques, rappelons que l'orientaliste allemand du XVIIe siècle Ludolf affirmait déjà que "die Sprachverwandtschaft offenbart sich nicht im Wörterbuch, sondern in der Grammatik"3. Pendant les 300 dernières années, tellement d'autorites ant approuvé !l’opinion de Ludolf qu'elle est devenue un dogme de la linguistique. Pourtant il nous est venu à l'esprit de le confronter avec des faits et ainsi nous sommes arrivé à la conclusion qu'en réalité, c'est le vocabulaire (et non la phonétique et la flexion qui décide du degre de la parenté des langues4. Voici des arguments à l'appui de cette thèse.

  2. 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)

  3. On supersonic combustion

    Institute of Scientific and Technical Information of China (English)

    袁生学

    1999-01-01

    Some basic concepts and features of supersonic combustion are explained from the view point of macroscopic aerodynamics. Two kinds of interpretations of supersonic combustion are proposed. The difference between supersonic combustion and subsonic combustion is discussed, and the mechanism of supersonic combustion propagation and the limitation of heat addition in supersonic flow are pointed out. The results of the calculation of deflagration in supersonic flow show that the entropy increment and the total pressure loss of the combustion products may decrease with the increase of combustion velocity. It is also demonstrated that the oblique detonation wave angle may not be controlled by the wedge angle under weak underdriven solution conditions and be determined only by combustion velocity. Therefore, the weak underdriven solution may become self-sustaining oblique detonation waves with a constant wave angle.

  4. Combustion Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — For more than 30 years The Combustion Research Facility (CRF) has served as a national and international leader in combustion science and technology. The need for a...

  5. Nuclear fuel: from the mine to the reactor. Part. 1; Les combustibles nucleaire: de la mine au reacteur (1. partie)

    Energy Technology Data Exchange (ETDEWEB)

    Maillard, D. [Direction Generale de l' Energie et des Matieres Premieres, Direction du Gaz, de l' Electricite et du Charbon, (STEEGB), 75 - Paris (France); Dujardin, Th. [OCDE, 92 - Issy les Moulineaux (France); Capus, G.; Durante, P.; Devos, L.; Canat, J.N. [AREVA NC, 13 --Saint-Paul-lez-Durance (France); Durret, L.F. [AREVA, Unit Enrichissement (United States); Delevallee, C. [AREVA, FBFC, 26 - Romans (France); Aullo, M.; Alonsa, J. [ENUSA, Industrias Avanzadas (Spain); Chapin, D.; Bellanger, Ph.; Buechel, R. [Westinghouse Electric Company (United States); Blanc, M. [Westinghouse Electric Company (Sweden)

    2006-07-15

    This issue contains a selection of articles from the S.F.E.N. convention 2006, held in Paris, June 13 and 14, 2006, which was dedicated to nuclear fuel. the second part will be published in R.G.N. 5 2006. (author)

  6. Experimental Investigations on a Novel Chemical Looping Combustion Configuration Étude expérimentale d’une nouvelle configuration de combustion en boucle chimique

    Directory of Open Access Journals (Sweden)

    Yazdanpanah M.M.

    2011-04-01

    Full Text Available Chemical Looping Combustion (CLC is a promising novel combustion technology involving inherent separation of carbon dioxide with minimum energy penalty. An oxygen carrier is employed to continuously transfer oxygen from the air reactor to the fuel reactor where the oxygen is delivered to the fuel. Consequently, direct contact between the air and fuel is prevented. The resulting flue gas is CO2-rich, without N2 dilution. The reduced oxygen carrier is then transported back to the air reactor for re-oxidation purposes, hence forming a chemical loop. Various CLC configurations have already been developed and tested on laboratory scales. However, more investigations are required to achieve feasible CLC processes. Among the different points to address, control of the solid circulation rate between the two reactors is of the highest importance regarding its effect on achievement of an appropriate oxygen transfer rate and solid oxidation degrees. Moreover, minimization of gas leakage between the fuel and air reactors is another important issue to be considered. A novel CLC configuration is proposed where reactions are carried out in two interconnected bubbling fluidized beds. Solid circulation rate control is achieved independently of gas flow rate in the reactors through use of pneumatic non-mechanical valves (L-valves. Moreover, loopseals are employed to minimize gas leakage while transferring solids. Experimental results from operation of a 10 kWth equivalent cold prototype are presented in this paper. The effect of operating variables on the solid circulation rate, gas leakage between the two beds and the pressure balance on all of the process elements is studied. The results demonstrate stable solid circulation with efficient control of the solid flow rate and effective gas tightness of the system. La combustion en boucle chimique (CLC est une nouvelle technologie prometteuse qui implique la separation inherente du dioxyde de carbone avec une perte

  7. Aux origines du monde

    CERN Multimedia

    2004-01-01

    "C'est l'histoire d'une aventure humaine, scientifique, international qui a vu le jour il y a cinquante ans, aux confins de la Suisse et du département de l'Ain. Le plus grand laboratoire de physique des particules du monde, le Cern, a été fondé en 1954. Les festivités organisées à l occasion de cet anniversaire connaîtront leur point d'orgue le 16 octobre prochain, avec portes-ouvertes, accueil de personallités et inauguration d'un monumnet spécifique, le Globe de l'innovation" (2 pages)

  8. Images du Valais

    Directory of Open Access Journals (Sweden)

    Micheline COSINSCHI

    1995-06-01

    Full Text Available Une étude des revenus fiscaux ventilés par branches économiques permet de clore un ouvrage portant sur ce canton alpin suisse par excellence qu’est le Valais. Pris comme traceurs de l’activité régionale, l’analyse de leurs configurations spatiales permet une évaluation pouvant être considérée comme une mesure de l’efficacité différentielle du système socio-spatial valaisan. L’article décrit certains processus qui ont permis la réalisation du dernier chapitre d’un atlas portant sur le Valais.

  9. CHOEUR DU CERN

    CERN Multimedia

    CHOEUR DU CERN

    2010-01-01

    Les répétitions du chœur du CERN reprendront le mercredi 15 septembre à 20.00 heures à l’amphithéâtre principal – bâtiment 500. Au programme la préparation de notre concert de Noël avec la Missa Brevis, KV115, de Léopold Mozart et de la musique de Noël d’Europe. Les personnes qui aiment chanter, notamment des sopranes et des ténors, sont les bienvenues. Pour tout contact s’adresser à : Baudouin Bleus - (tél.CERN 767 82 44) -(baudouin.bleus@cern.ch) ou Martin Gatehouse ( martin.gatehouse@wanadoo.fr) ou Jean-Paul Diss (jean-pauldiss@wanadoo.fr).  

  10. Les Cahiers du CREAD

    African Journals Online (AJOL)

    Admin

    les littératures économique et gestionnaire, mais souvent dans ces travaux, l'effet de ... chiffre d'affaires du nouvel ensemble résultant de la vente des produits mieux .... syndicalisme, droit de grève), fiscales (différents taux d'imposition, etc.) .... nouvel ensemble et aussi, les différentes relations avec les alliances verticales ...

  11. La mesure du danger

    CERN Document Server

    Manceron, Vanessa; Revet, Sandrine

    2014-01-01

    La mesure du danger permet d’explorer des dangers de nature aussi diverse que la délinquance, la pollution, l’écueil maritime, la maladie ou l’attaque sorcellaire, l’extinction d’espèces animales ou végétales, voire de la Planète tout entière. Au croisement de la sociologie, de l’anthropologie et de l’histoire, les différents articles analysent les pratiques concrètes de mesure pour tenter de comprendre ce qui se produit au cours de l’opération d’évaluation du danger sans préjuger de la nature de celui-ci. L’anthropologie a contribué à la réflexion sur l’infortune en s’intéressant aux temporalités de l’après : maladies, catastrophes, pandémies, etc. et en cherchant à rendre compte de l’expérience des victimes, de leur vie ordinaire bouleversée, de la recomposition du quotidien. Elle s’intéresse aussi aux autres types de mesures, les savoirs incorporés, qui reposent sur l’odorat, la vue ou le toucher et ceux qui ressortent d’une épistémologie « non ...

  12. Har du sikret din alderdom?

    DEFF Research Database (Denmark)

    Kiens, Bente; Aagaard, Peter Gjerndrup

    2006-01-01

    Daglig fysisk aktivitet kan betragtes som indbetaling op din personlige helbredspension. Jo mere du sætter ind på kontoen, og jo oftere du gør det, jo større er sandsynligheden for, at du lever længere og får et sundere helbred. Og det er aldrig for sent at starte med indbetalingerne....

  13. Decree no. 2001-1199 of the 10 december 2001 publishing the resolution MSC. 88 (71) notifying adoption of the international compilation of safety rules for the spent nuclear fuels, plutonium and high level radioactive wastes transport in casks on ships (compilation INF) (annexes), adopted at London the 27 may 1999; Decret no. 2001-1199 du 10 decembre 2001 portant publication de la resolution MSC.88 (71) portant adoption du recueil international de regles de securite pour le transport de combustible nucleaire irradie, de plutonium et de dechets hautement radioactifs en colis a bord de navires (recueil INF) (ensemble une annexe), adoptee a Londres le 27 mai 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    This legislative text concerns the safety rules of spent nuclear fuels, plutonium and high level radioactive wastes transport, in casks on ships. Rules, fire prevention, temperature control of casks, electric supply, radioprotection, management and emergency plans are detailed. (A.L.B.)

  14. Developpement d'une methode hybride pour le suivi du coeur et la gestion du combustible

    Science.gov (United States)

    Frenette, Eric

    The nuclear industry of CANDU reactors uses neutron physics methodologies (core follow-up, fuel management) that are considered out of date and do not reflect the latest developments in the field of neutronics. For instance, the software used by the reactor physics team in Gentilly-2, HQSIMEX 3, uses macroscopic cross sections ("grid-based" approach) calculated by two methods: (1) The "four factors" formula, an obsolete technique used in 1950; (2) The WIMS software, based on a microscopic cross section library. Among other method, the history-based approach is considered more precise but requires greater computing time. Processing a whole CANDU core follow-up through the history-based approach is not possible as of today with the actual computers, due to computing cost issues. The main goal of this research is to come up with a new strategy that will combine the interpolation technique of the "grid-based approach" with the isotopic depletion follow-up of the "history-based" approach.

  15. Boiler using combustible fluid

    Science.gov (United States)

    Baumgartner, H.; Meier, J.G.

    1974-07-03

    A fluid fuel boiler is described comprising a combustion chamber, a cover on the combustion chamber having an opening for introducing a combustion-supporting gaseous fluid through said openings, means to impart rotation to the gaseous fluid about an axis of the combustion chamber, a burner for introducing a fluid fuel into the chamber mixed with the gaseous fluid for combustion thereof, the cover having a generally frustro-conical configuration diverging from the opening toward the interior of the chamber at an angle of between 15/sup 0/ and 55/sup 0/; means defining said combustion chamber having means defining a plurality of axial hot gas flow paths from a downstream portion of the combustion chamber to flow hot gases into an upstream portion of the combustion chamber, and means for diverting some of the hot gas flow along paths in a direction circumferentially of the combustion chamber, with the latter paths being immersed in the water flow path thereby to improve heat transfer and terminating in a gas outlet, the combustion chamber comprising at least one modular element, joined axially to the frustro-conical cover and coaxial therewith. The modular element comprises an inner ring and means of defining the circumferential, radial, and spiral flow paths of the hot gases.

  16. Les pirogues du Maroni

    Directory of Open Access Journals (Sweden)

    Sophie François

    2012-04-01

    Full Text Available Sur le Maroni, fleuve frontière entre la Guyane française et le Surinam, les pirogues amarrées le long des berges se comptent par centaines. Elles représentent le seul moyen de transport pour les milliers de personnes vivant sur les rives du Maroni. Les différentes formes de pirogues sont révélatrices de la diversité géographique du Maroni et de la diversité culturelle des populations. Les Amérindiens du littoral naviguent uniquement dans l’estuaire du fleuve. Ils construisent des pirogues larges, hautes et terminées à la poupe par une haute étrave qui fend les vagues. Ces pirogues sont construites à partir d’une coque monoxyle expansée et rehaussée d’un ou de deux bordages. En chauffant la grume évidée, le bois acquiert une certaine plasticité qui permet d’écarter les flancs et d’obtenir une coque très large à partir d’un arbre de faible diamètre. Les Bushinenge, populations d’origine africaine qui ont déserté les grandes plantations de la Guyane hollandaise dès le début du XVIIe siècle et se sont installées sur les deux rives du Maroni, ont développé des formes de pirogues adaptées au passage des sauts. Leurs pirogues, construites également en expansant la coque au feu, sont étroites et longues et possèdent des extrémités curvilignes qui dépassent largement au–dessus du bordage. Les longues pirogues à moteur comme les canots–pagaies sont ornés de motifs d’entrelacs appelés tembé ; et de décors d’inspiration contemporaine. L’inventaire des pirogues du Maroni a mis en évidence la richesse et la vitalité du patrimoine nautique de cette région au début du XXIe siècle, tant au niveau des formes des embarcations que des décors et des pratiques de navigation.On the Maroni river, natural border between French Guyana and the Surinam, canoes tied to the river banks can be counted by the hundreds. They are the only mean of transportation for thousands of people living along the

  17. Analysis and separation of boron isotopes; Analyse et separation des isotopes du bore

    Energy Technology Data Exchange (ETDEWEB)

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

    1966-11-01

    The nuclear applications of boron-10 justify the study of a method of measurement of its isotopic abundance as well as of very small traces of boron in different materials. A systematic study of thermionic emission of BO{sub 2}Na{sub 2}{sup +} has been carried out. In the presence of a slight excess of alkalis, the thermionic emission is considerably reduced. On the other hand, the addition of a mixture of sodium hydroxide-glycerol (or mannitol) to borax permits to obtain an intense and stable beam. These results have permitted to establish an operative method for the analysis of traces of boron by isotopic dilution. In other respects, the needs of boron-10 in nuclear industry Justify the study of procedures of separation of isotopes of boron. A considerable isotopic effect has been exhibited in the chemical exchange reaction between methyl borate and borate salt in solution. In the case of exchange between methyl borate and sodium borate, the elementary separation factor {alpha} is: {alpha}=(({sup 11}B/{sup 10}B)vap.)/(({sup 11}B/{sup 10}B)liq.)=1.03{sub 3}. The high value of this elementary effect has been multiplied in a distillation column in which the problem of regeneration of the reactive has been resolved. An alternative procedure replacing the alkali borate by a borate of volatile base, for example diethylamine, has also been studied ({alpha}=1,02{sub 5} in medium hydro-methanolic with 2,2 per cent water). (author) [French] Les applications nucleaires du bore 10 justifient l'etude d'une methode de mesure de son abondance isotopique dans divers materiaux ainsi que le dosage de tres faibles traces de bore. Une etude systematique de l'emission thermoionique de BO{sub 2} Na{sub 2}{sup +} a ete effectuee. En presence d'un leger exces d'alcalins, l'emission thermoionique est considerablement reduite. Par contre l'addition au borax d'un melange soude-glycerol (ou mannitol) permet d'obtenir un faisceau stable et intense

  18. Coal combustion products

    Science.gov (United States)

    Kalyoncu, R.S.; Olson, D.W.

    2001-01-01

    Coal-burning powerplants, which supply more than half of U.S. electricity, also generate coal combustion products, which can be both a resource and a disposal problem. The U.S. Geological Survey collaborates with the American Coal Ash Association in preparing its annual report on coal combustion products. This Fact Sheet answers questions about present and potential uses of coal combustion products.

  19. Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management. Fourth National Report on Compliance with the Joint Convention Obligations. France; Convention commune sur la surete de la gestion du combustible use et sur la surete de la gestion des dechets radioactifs. Quatrieme rapport national sur la mise en oeuvre des obligations de la Convention commune. France

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-09-15

    The Joint Convention on the Safety of Spent Fuel Management and the Safety of Radioactive Waste Management, hereinafter referred to as the 'Joint Convention', is the result of international discussions that followed the adoption of the Convention on Nuclear Safety, in 1994. France signed the Joint Convention at the General Conference of the International Atomic Energy Agency (IAEA) held on 29 September 1997, the very first day the Joint Convention was opened for signature. She approved it on 22 February 2000 and filed the corresponding instruments with the IAEA on 27 April 2000. The Joint Convention entered into force on 18 June 2001. For many years, France has been taking an active part in the pursuit of international actions to reinforce nuclear safety and considers the Joint Convention to be a key step in that direction. The fields covered by the Joint Convention have long been part of the French approach to nuclear safety. This report is the fourth of its kind. It is published in accordance with Article 32 of the Joint Convention and presents the measures taken by France to meet each of her obligations set out in the Convention. The facilities and radioactive materials covered by the Joint Convention are much diversified in nature and are controlled in France by different regulatory authorities (see Section E). Over and above a specific threshold of radioactive content, a facility is referred to as a 'basic nuclear facility' (installation nucleaire de base - INB) and placed under the control of the French Nuclear Safety Authority (Autorite de surete nucleaire - ASN). Below that threshold and provided that the facility involved falls under a category of the nomenclature of classified facilities for other purposes than their radioactive materials, any facility may be considered as a 'classified facility on environmental-protection grounds' (installation classee pour la protection de l'environnement - ICPE) and placed under the

  20. L'Origine du Monde

    CERN Multimedia

    CNET & Ecole Polytechnique Paris; Vincent Ferreira

    1996-01-01

    Création, théologie, science, découverte, recherche, religion, condition humaine.Avec Maurice Jacob physicien, Hubert Curien Président du Conseil du CERN, Michael Doser physicien, Frère Emile Communauté de Taizé.

  1. Research Combustion Laboratory (RCL)

    Data.gov (United States)

    Federal Laboratory Consortium — The Research Combustion Laboratory (RCL) develops aerospace propulsion technology by performing tests on propulsion components and materials. Altitudes up to 137,000...

  2. Combustion Byproducts Recycling Consortium

    Energy Technology Data Exchange (ETDEWEB)

    Paul Ziemkiewicz; Tamara Vandivort; Debra Pflughoeft-Hassett; Y. Paul Chugh; James Hower

    2008-08-31

    Ashlines: To promote and support the commercially viable and environmentally sound recycling of coal combustion byproducts for productive uses through scientific research, development, and field testing.

  3. Research Combustion Laboratory (RCL)

    Data.gov (United States)

    Federal Laboratory Consortium — The Research Combustion Laboratory (RCL) develops aerospace propulsion technology by performing tests on propulsion components and materials. Altitudes up to 137,000...

  4. discours du Directeur General

    CERN Document Server

    CERN. Geneva

    2007-01-01

    L'année 2007 est une année très spéciale pour le CERN. Je vous propose de nous retrouver pour faire le point sur les activités en cours. Rendez-vous le mercredi 27 juin à 15h00 dans l'amphithéâtre principal. La transmission simultanée sera assurée dans les amphithéâtres IT, AT, AB Prevessin et dans la Salle du Conseil. Robert Aymar

  5. Les risques du travail

    CERN Document Server

    Thébaud-Mony, Annie

    2015-01-01

    Depuis les années 1990, les conditions de travail se sont peu à peu imposées dans le débat social. Néanmoins, la situation reste critique. Les risques traditionnels n'ont pas disparu : les manutentions lourdes, l'exposition professionnelle aux cancérogènes, au bruit ou aux vibrations demeurent répandues... De plus, certaines " améliorations " n'ont fait que déplacer et dissimuler les problèmes, telle l'externalisation des risques grâce à la sous-traitance. Dans le même temps, les transformations du travail et des modalités de gestion de la main-d'œuvre ont fragilisé les collectifs et accru l'isolement des salariés, conduisant à une montée visible de la souffrance psychique. Face à ces évolutions, il est plus que jamais nécessaire que tous les acteurs concernés, en particulier les salariés eux-mêmes et leurs représentants, s'approprient les connaissances indispensables pour améliorer la protection de la santé sur les lieux du travail. Tel est le but de ce livre, qui renouvelle int�...

  6. Les formes du fond

    Directory of Open Access Journals (Sweden)

    Michel Maffesoli

    2004-12-01

    Full Text Available Il n'est pas vrai que la nature a horreur du vide. Peut-être même s'y complait-elle. Le creux est aussi une modalité de l'être. Il est possible de s'y nicher, de s'y lover paresseusement et, ainsi, de se protéger contre l'angoisse du temps qui passe. Le creux des apparences est, à certains moments, une des formes d'expression de la vie sociale. Encore faut-il savoir le reconnaître. Certes, nous avons tous une existence personnelle, mais nous sommes, également, les représentants, parfois même les victimes, d'un "esprit commun", peut-être même d'un "inconscient collectif" qui s'est constitué de siècle en siècle. Et, très souvent, là où nous croyons exprimer nos propres idées, nous ne sommes que les porte-voix, les figurants d'un vaste "theatrum mundi" aux dimensions infinies.

  7. Choeur du CERN : Concert

    CERN Document Server

    CERN Choir

    2017-01-01

    Une œuvre à découvrir! La grande Missa pro defunctis de François-Joseph Gossec (1734-1829) est le chef-d’œuvre tôt venu (à vingt-cinq ans) d’un compositeur qui vivra encore 70 ans après sa création. Elle a connu la gloire, puis s’est fait un peu oublier. Pas du tout le monde cependant : des musicologues ont montré ce que le Requiem de Mozart lui devait ; et il suffit de l’avoir entendue pour comprendre pourquoi Berlioz (qui avait vingt-six ans à la mort de Gossec) en a été impressionné : les nombreux cuivres et bois répartis dans des endroits plus ou moins cachés de la salle de concert pour exprimer les frayeurs du Jugement dernier annoncent son Requiem – et celui de Verdi. Mais « plus encore que par...

  8. Avis d'expert sur la détermination des caractéristiques d'inflammabilité du chanvre

    OpenAIRE

    Evanno, Sébastien; Dupont, Laurent

    2010-01-01

    International audience; Des dépôts de chanvre de faible épaisseur (de l'ordre de quelques mm) sont sensibles au phénomène d'auto-échauffement avec amorçage d'une combustion retardée dans l'ensemble du dépôt. Le contact de points chauds peut amorcer localement un phénomène identique de combustion lente qui, à terme, va s'étendre à la totalité du dépôt. Sur la base du retour d'expérience mettant en oeuvre des travaux de meulage et de tronçonnage en présence de solide combustible pulvérulent, ai...

  9. Strobes: An oscillatory combustion

    NARCIS (Netherlands)

    Corbel, J.M.L.; Lingen, J.N.J. van; Zevenbergen, J.F.; Gijzeman, O.L.J.; Meijerink, A.

    2012-01-01

    Strobe compositions belong to the class of solid combustions. They are mixtures of powdered ingredients. When ignited, the combustion front evolves in an oscillatory fashion, and flashes of light are produced by intermittence. They have fascinated many scientists since their discovery at the beginni

  10. Strobes: An Oscillatory Combustion

    NARCIS (Netherlands)

    Corbel, J.M.L.; van Lingen, J.N.J.; Zevenbergen, J.F.; Gijzeman, O.L.J.; Meijerink, A.

    2012-01-01

    Strobe compositions belong to the class of solid combustions. They are mixtures of powdered ingredients. When ignited, the combustion front evolves in an oscillatory fashion, and flashes of light are produced by intermittence. They have fascinated many scientists since their discovery at the beginni

  11. Lectures on combustion theory

    Energy Technology Data Exchange (ETDEWEB)

    Burstein, S.Z.; Lax, P.D.; Sod, G.A. (eds.)

    1978-09-01

    Eleven lectures are presented on mathematical aspects of combustion: fluid dynamics, deflagrations and detonations, chemical kinetics, gas flows, combustion instability, flame spread above solids, spark ignition engines, burning rate of coal particles and hydrocarbon oxidation. Separate abstracts were prepared for three of the lectures. (DLC)

  12. Fifteenth combustion research conference

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-06-01

    The BES research efforts cover chemical reaction theory, experimental dynamics and spectroscopy, thermodynamics of combustion intermediates, chemical kinetics, reaction mechanisms, combustion diagnostics, and fluid dynamics and chemically reacting flows. 98 papers and abstracts are included. Separate abstracts were prepared for the papers.

  13. Coal Combustion Science

    Energy Technology Data Exchange (ETDEWEB)

    Hardesty, D.R. (ed.); Fletcher, T.H.; Hurt, R.H.; Baxter, L.L. (Sandia National Labs., Livermore, CA (United States))

    1991-08-01

    The objective of this activity is to support the Office of Fossil Energy in executing research on coal combustion science. This activity consists of basic research on coal combustion that supports both the Pittsburgh Energy Technology Center Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency Coal Combustion Science Project. Specific tasks for this activity include: (1) coal devolatilization - the objective of this risk is to characterize the physical and chemical processes that constitute the early devolatilization phase of coal combustion as a function of coal type, heating rate, particle size and temperature, and gas phase temperature and oxidizer concentration; (2) coal char combustion -the objective of this task is to characterize the physical and chemical processes involved during coal char combustion as a function of coal type, particle size and temperature, and gas phase temperature and oxygen concentration; (3) fate of mineral matter during coal combustion - the objective of this task is to establish a quantitative understanding of the mechanisms and rates of transformation, fragmentation, and deposition of mineral matter in coal combustion environments as a function of coal type, particle size and temperature, the initial forms and distribution of mineral species in the unreacted coal, and the local gas temperature and composition.

  14. Combustion of coffee husks

    Energy Technology Data Exchange (ETDEWEB)

    Saenger, M.; Hartge, E.-U.; Werther, J. [Technical Univ. Hamburg-Harburg, Chemical Engineering 1, Hamburg (Germany); Ogada, T.; Siagi, Z. [Moi Univ., Dept. of Production Engineering, Eldoret (Kenya)

    2001-05-01

    Combustion mechanisms of two types of coffee husks have been studied using single particle combustion techniques as well as combustion in a pilot-scale fluidized bed facility (FBC), 150 mm in diameter and 9 m high. Through measurements of weight-loss and particle temperatures, the processes of drying, devolatilization and combustion of coffee husks were studied. Axial temperature profiles in the FBC were also measured during stationary combustion conditions to analyse the location of volatile release and combustion as a function of fuel feeding mode. Finally the problems of ash sintering were analysed. The results showed that devolatilization of coffee husks (65-72% volatile matter, raw mass) starts at a low temperature range of 170-200degC and takes place rapidly. During fuel feeding using a non water-cooled system, pyrolysis of the husks took place in the feeder tube leading to blockage and non-uniform fuel flow. Measurements of axial temperature profiles showed that during under-bed feeding, the bed and freeboard temperatures were more or less the same, whereas for over-bed feeding, freeboard temperatures were much higher, indicating significant combustion of the volatiles in the freeboard. A major problem observed during the combustion of coffee husks was ash sintering and bed agglomeration. This is due to the low melting temperature of the ash, which is attributed to the high contents of K{sub 2}O (36-38%) of the coffee husks. (Author)

  15. Internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Helmich, M.J.; Hoagland, M.C.; Hubbard, R.L.; Schaub, F.S.

    1981-12-22

    A method of combusting natural gas fuel in a two cycle, turbocharged internal combustion engine substantially reduces the production of nitrogen-oxygen emissions. An improved turbocharger design provides increased air charging pressure, produces a controlled lean air/fuel mixture and lowers peak combustion temperatures. A jet cell ignition device ensures uniform, reliable ignition of the lean air/fuel mixture under all operating conditions and the lean air/fuel mixture in turn encourages complete fuel combustion and provides excellent combustion characteristics with methane, ethane and heavier paraffinic hydrocarbon fuels. These structural modifications and adjustment of other operating parameters combine to reduce nitric oxide (NO) and nitrogen dioxide (NO/sub 2/) emissions by as much as 75% while effecting only a negligible increase in fuel consumption.

  16. Fuels and Combustion

    KAUST Repository

    Johansson, Bengt

    2016-08-17

    This chapter discusses the combustion processes and the link to the fuel properties that are suitable for them. It describes the basic three concepts, including spark ignition (SI) and compression ignition (CI), and homogeneous charge compression ignition (HCCI). The fuel used in a CI engine is vastly different from that in an SI engine. In an SI engine, the fuel should sustain high pressure and temperature without autoignition. Apart from the dominating SI and CI engines, it is also possible to operate with a type of combustion: autoignition. With HCCI, the fuel and air are fully premixed before combustion as in the SI engine, but combustion is started by the increased pressure and temperature during the compression stroke. Apart from the three combustion processes, there are also a few combined or intermediate concepts, such as Spark-Assisted Compression Ignition (SACI). Those concepts are discussed in terms of the requirements of fuel properties.

  17. Development of the control assembly pattern and dynamic analysis of the generation IV large gas-cooled fast reactor (GFR); Developpement du design d'un assemblage de controle et analyse dynamique des reacteurs a neutrons rapides de quatrieme generation refroidis au gaz

    Energy Technology Data Exchange (ETDEWEB)

    Girardin, G.

    2009-07-09

    was paid to have each individual fuel sub-assembly and CA represented, in order to allow the analysis of local deformations of the 3D distributions of power and safety related parameters, such as the coolant, cladding and fuel temperatures. The validation of the coupled full core models was performed against reference ERANOS-VARIANT calculations. (author) [French] Le travail de recherche a ete mene dans le contexte du RNR-G de reference a 2400 MWth. Le but principal a ete de developper et de qualifier le design de l'assemblage de controle et le schema d'implantation correspondant a ce systeme. Le travail a ete realise en trois phases successives et complementaires: (1) la validation des outils neutroniques, (2) le developpement du design de l'assemblage de controle et les etudes statiques correspondantes, (3) les etudes du comportement dynamique du coeur durant des transitoires hypothetiques lies aux assemblages de controle. Pendant la premiere phase de la these, le reseau test de reference de PROTEUS utilise dans ces experiences, a ete reinterprete avec ERANOS et la bibliotheque nucleaire ajustee ERALIB1. De maniere complementaire, des calculs de references ont ete realises avec le code de Monte Carlo MCNPX, visant a verifier les resultats deterministes, et a analyser la sensibilite des resultats aux differentes modernes librairies. Pour les taux de reactions principaux, la nouvelle analyse du reseau de reference GCFR-PROTEUS donne generalement des resultats en bon accord - dans l'incertitude experimentale 1{sigma} - avec les resultats experimentaux, ainsi qu'avec les simulations de Monte Carlo. L'utilisation d'ERANOS-2.0/ERALIB1 comme outil neutronique de reference a ainsi pu etre demontree pour l'analyse du RNR-G. Dans une seconde phase de cette recherche, le design de l'assemblage de controle (AC) du GFR a ete developpe, base sur des calculs a caractere iteratif, neutroniques et thermo-hydrauliques. En premier, des

  18. Jouer du piano

    Directory of Open Access Journals (Sweden)

    Fériel Kaddour

    2011-04-01

    Full Text Available La réflexion s’appuie dans un premier temps sur une opposition entre deux attitudes de pianistes  à l’égard du travail à l’instrument : Gould, qui revendique une séparation d’avec le clavier pour ne privilégier que la lecture; Arrau, dont la technique au contraire vise à « faire corps » avec son piano. L’étude de ces deux démarches d’interprètes conduit à une conclusion croisée : l’abstraction gouldienne n’est rien d’autre qu’un déplacement du jeu vers d’autres instruments (ceux qui servent à la prise de son et au montage de ses enregistrements ; le « faire-corps » hérité de la culture pianistique romantique est plus dialectique que fusionnel, et en cela implique une capacité de mise à distance. A partir de cette double conclusion, on tâche enfin de repenser la place du jeu à l’instrument dans la mise en œuvre d’une interprétation, en interrogeant le dialogue qui s’instaure entre la partition telle qu’elle s’écrit et le geste tel qu’il se joue.Our study leans on an opposition between two pianists' attitudes about their work with the instrument. Gould claims a necessary separation from the keyboard in order to prioritize reading. Arrau, on the contrary, relies on a technique which consists in “being one” with his piano. The analysis of these two interprets’ behaviours leads to a crossed conclusion: the gouldian abstraction is nothing else than a displacement of the playing towards another kind of instruments, the ones he uses in sound recording and cut up; Arrau’s “being one” is more dialectic than at first sight, and it therefore implies a real distancing from the piano. This constatation leads to rethink the place of the piano playing in the setting of an interpretation, and to highlight the real dialogue which develops itself between the score as it has been written and the gesture as it is played.

  19. Le sacre du printemps

    Directory of Open Access Journals (Sweden)

    Denise Pumain

    2002-03-01

    Full Text Available Cybergeo aura six ans en avril : dans la réalité du virtuel, dans l'univers récent et fluctuant de la publication en ligne, cela fait de nous, tout à la fois, des pionniers et des vétérans. De façon plus surprenante, il se trouve que nous sommes aussi uniques : parmi toutes les revues électroniques de sciences sociales, aucune ne combine comme Cybergeo ancienneté, publication exclusivement électronique, liberté d'accès au texte intégral, édition et gestion par des chercheurs, et comité de lec...

  20. Le Brahmane du Komintern

    Directory of Open Access Journals (Sweden)

    Elizabeth Burgos

    2008-01-01

    Full Text Available Le Brahmane du Komintern, largometraje documental del realizador francés Vladimir León, constituye un ejercicio ejemplar de investigación histórica y  de lograda factura de realización. Y, pese a no haber contado con la ayuda de ninguno organismo público, se trata de un ambicioso proyecto que cubre una amplia extensión geográfica que abarca: Estados Unidos, México, Moscú, Berlín, y la India. Gira en torno a una figura que tuvo en su tiempo su hora de gloria. Un bengalí, hijo de braman, la c...

  1. Cultures du travail

    OpenAIRE

    de Bonnault-Cornu, Phanette; Charrasse, David; Herberich-Marx, Geneviève; Lamy, Yvon; Lazier, Isabelle; Mairot, Philippe; Morel, Alain; Périssère, Michèle; Raphaël, Freddy; Ribeill, Georges; Salmeron, Pierre; Vant, André

    2015-01-01

    Qu’est-ce qu’une culture du travail ? Comment la définir autrement qu’en opposition à la culture savante ? Quelles relations une société entretient-elle avec son ou ses industries ? Comment définir et appréhender ce qu’on appelle la culture d’entreprise ? A ces questions ethnologues, sociologues, géographes et historiens apportent ici des réponses.Ce livre est aussi consacré à l’intérêt que ces sociétés, villes, petites régions, entreprises, portent à ce qui constitue leur patrimoine industri...

  2. OPERATION DU FOISONNEMENT

    Directory of Open Access Journals (Sweden)

    Gholamreza Djelveh

    2010-04-01

    Full Text Available Mousses alimentaires sont un sous-ensemble des aliments connus sous le nom de produits fouettés ou des produits aérés. Ils sont des produits formulés avec des qualités telles que la légèreté et la souplesse et sont principalement consommés à l'apéritif ou au dessert. Les produits en mousse obtenue par dispersion d'un gaz dans une matrice alimentaire (la phase continue ont connu un développement croissant au cours des années 80 et 90. Le processus d'aération liés à leurs activités de production est appelée l'expansion ou à fouetter. Le document présente les principaux-paramètres du procédé du point permanent de la formulation, la mise en œuvre processus dans les installations pilotes et à l'échelle industrielle, la caractérisation des produits finis, la base énergétique de l'échelle de processus en place, et le lien entre la formulation, émulsion préparation de l'expansion. Cette vue d'ensemble de l'opération d'expansion continue, nous a permis de mettre en évidence le fait qu'il ya des opérations de l'unité encore mal décrite par le génie des procédés et pour lesquels les méthodes et outils pour l'extrapolation et la prédiction sont encore à leurs balbutiements.

  3. Sur quelques Ichthyurus du Tonkin

    NARCIS (Netherlands)

    Gestro, R.

    1906-01-01

    Les espèces d Ichthyurus du Tonkin connues jusqu’ici étaient seulement trois: denticornis Gestro, décrite d’abord du Tenasserim (récoltes de feu Mr. L. Fea) et retrouvée ensuite dans le Haut Tonkin par S. A. R. le Prince Henri d’Orléans; Henrici Gestro, découverte par ce même explorateur, et dont le

  4. Ageing of palladium tritide: mechanical characterization, helium state and modelling; Vieillissement du tritiure de palladium: caracterisation mecanique, etat de l'helium et modelisation

    Energy Technology Data Exchange (ETDEWEB)

    Segard, M.

    2010-11-29

    deux modeles traitant, d'une part, de la germination des bulles d'helium-3 (utilisation d'un automate cellulaire) et, d'autre part, de la croissance des bulles (mecanique des milieux continus). Ces modeles etaient fonctionnels, mais leur utilisation etait limitee par le manque de donnees experimentales d'entree et de recalage. Ce travail de these a donc consiste a acquerir les donnees experimentales les plus pertinentes pour ameliorer la modelisation du vieillissement du tritiure de palladium. La premiere partie de ce travail a consiste a estimer les proprietes mecaniques du tritiure de palladium (limite d'elasticite, contrainte maximale, loi de comportementale), deduites de celles de l'hydrure et du deuterure de palladium, mesurees a l'aide d'essais de traction in situ. En seconde partie, la caracterisation du vieillissement a ete entreprise, focalisee sur des observations de bulles dans le tritiure de palladium par microscopie electronique en transmission, des mesures de pression a l'intErieur des bulles par resonance magnetique nucleaire et des mesures de gonflement macroscopique du materiau par pycnometrie. Ces travaux ont conduit a des avancees significatives quant a la comprehension du vieillissement et ont permis d'ameliorer considerablement sa modelisation

  5. The nuclear and the energy supply of tomorrow. Stop the useless quarrels about the nuclear; Le nucleaire et l'approvisionnement energetique de demain. Cesser les querelles inutiles a propos du nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    Following the paper of Hubert Reeves which developed the reasons of the the nuclear stopping, the author presents arguments to ease this opinion ( economic growth of the developing countries, greenhouse gases reduction, fossil fuels conservation, transportation sector) and proposes a cooperation between the nuclear and the renewable energies to satisfy a sustainable development. (A.L.B.)

  6. Sandia Combustion Research: Technical review

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    This report contains reports from research programs conducted at the Sandia Combustion Research Facility. Research is presented under the following topics: laser based diagnostics; combustion chemistry; reacting flow; combustion in engines and commercial burners; coal combustion; and industrial processing. Individual projects were processed separately for entry onto the DOE databases.

  7. Analytic determination of plutonium in the environment; Determination analytique du plutonium dans l'environnement

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-07-01

    The work described in this report was undertaken with a view to determining the plutonium content in the fall-out from nuclear explosions. In the first part are described in turn the importance of the problems due to the plutonium, the physico-chemical properties of the radioelement and the biological dangers which it presents. A detailed and critical analysis is made of the radio-toxicological determination of the plutonium as reported in the literature prior to this report. The second part consists in the presentation of a judicious choice of techniques making it possible to determine plutonium in air, rain-water, soils and ash. After a detailed description of the measurement equipment and the operational techniques which have been developed, a justification of these techniques is given with particular reference to their sensitivity and specificity. After a brief conclusion concerning the preceding chapters, the results are presented. These are then discussed in the ease of each element in which the plutonium has been determined. This discussion is concluded by a consideration of the importance of the occurrence of fall-out plutonium on problems relating to public health. From a consideration of 200 analyses carried out, it is concluded that the contribution of plutonium to the exposure of populations is still very small compared to that of natural radiation and that due to such fission products as strontium 90. The report includes 63 literature references, 26 figures and 11 tables. (author) [French] Les travaux decrits dans ce memoire ont ete entrepris et eflectues dans le but de mettre en evidence le plutonium des retombees radioactives consecutives aux explosions nucleaires. Dans la premiere partie nous etudions successivement l'importance des problemes poses par le plutonium puis les proprietes physicochimiques du radioelement et les dangers qu'il presente du point de vue biologique. Nous effectuons une analyse detaillee et critique des techniques

  8. Improving combustion efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Bulsari, A.; Wemberg, A.; Multas, A. [Nonlinear Solutions Oy (Finland)

    2009-06-15

    The paper describes how nonlinear models are used to improve the efficiency of coal combustion while keeping NOx and other emissions under desired limits in the Naantali 2 boiler of Fortum Power and Heat Oy. 16 refs., 6 figs.

  9. Fluidized coal combustion

    Science.gov (United States)

    Moynihan, P. I.; Young, D. L.

    1979-01-01

    Fluidized-bed coal combustion process, in which pulverized coal and limestone are burned in presence of forced air, may lead to efficient, reliable boilers with low sulfur dioxide and nitrogen dioxide emissions.

  10. Modelling diesel combustion

    CERN Document Server

    Lakshminarayanan, P A; Shi, Yu; Reitz, Rolf D

    2010-01-01

    The underlying principles of combustion phenomena are presented here, providing the basis for quantitative evaluation. These phenomena - ignition delay, fuel air mixing, rate of release, etc. - are then modelled for greater understanding and applicability.

  11. TENORM: Coal Combustion Residuals

    Science.gov (United States)

    Burning coal in boilers to create steam for power generation and industrial applications produces a number of combustion residuals. Naturally radioactive materials that were in the coal mostly end up in fly ash, bottom ash and boiler slag.

  12. Scramjet Combustion Processes

    Science.gov (United States)

    2010-09-01

    plan for these flights is as follows: Scramjet Combustion Processes RTO-EN-AVT-185 11 - 21 HyShot 5 – A Free-Flying Hypersonic Glider HyShot...5 will be a hypersonic glider designed to fly at Mach 8. It will separate from its rocket booster in space and perform controlled manoeuvres as it...RTO-EN-AVT-185 11 - 1 Scramjet Combustion Processes Michael Smart and Ray Stalker Centre for Hypersonics The University of Queensland

  13. Sandia Combustion Research Program

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, S.C.; Palmer, R.E.; Montana, C.A. (eds.)

    1988-01-01

    During the late 1970s, in response to a national energy crisis, Sandia proposed to the US Department of Energy (DOE) a new, ambitious program in combustion research. Shortly thereafter, the Combustion Research Facility (CRF) was established at Sandia's Livermore location. Designated a ''user facility,'' the charter of the CRF was to develop and maintain special-purpose resources to support a nationwide initiative-involving US inventories, industry, and national laboratories--to improve our understanding and control of combustion. This report includes descriptions several research projects which have been simulated by working groups and involve the on-site participation of industry scientists. DOE's Industry Technology Fellowship program, supported through the Office of Energy Research, has been instrumental in the success of some of these joint efforts. The remainder of this report presents results of calendar year 1988, separated thematically into eleven categories. Referred journal articles appearing in print during 1988 and selected other publications are included at the end of Section 11. Our traditional'' research activities--combustion chemistry, reacting flows, diagnostics, engine and coal combustion--have been supplemented by a new effort aimed at understanding combustion-related issues in the management of toxic and hazardous materials.

  14. METC Combustion Research Facility

    Energy Technology Data Exchange (ETDEWEB)

    Halow, J.S.; Maloney, D.J.; Richards, G.A.

    1993-11-01

    The objective of the Morgantown Energy Technology Center (METC) high pressure combustion facility is to provide a mid-scale facility for combustion and cleanup research to support DOE`s advanced gas turbine, pressurized, fluidized-bed combustion, and hot gas cleanup programs. The facility is intended to fill a gap between lab scale facilities typical of universities and large scale combustion/turbine test facilities typical of turbine manufacturers. The facility is now available to industry and university partners through cooperative programs with METC. High pressure combustion research is also important to other DOE programs. Integrated gasification combined cycle (IGCC) systems and second-generation, pressurized, fluidized-bed combustion (PFBC) systems use gas turbines/electric generators as primary power generators. The turbine combustors play an important role in achieving high efficiency and low emissions in these novel systems. These systems use a coal-derived fuel gas as fuel for the turbine combustor. The METC facility is designed to support coal fuel gas-fired combustors as well as the natural gas fired combustor used in the advanced turbine program.

  15. Effect of CO Combustion Promoters on Combustion Air Partition in FCC under Nearly Complete Combustion

    Institute of Scientific and Technical Information of China (English)

    王锐; 罗雄麟; 许锋

    2014-01-01

    With CO combustion promoters, the role of combustion air flow rate for concerns of economics and control is important. The combustion air is conceptually divided to three parts:the air consumed by coke burning, the air consumed by CO combustion and the air unreacted. A mathematical model of a fluid catalytic cracking (FCC) unit, which includes a quantitative correlation of CO heterogeneous combustion and the amount of CO combustion promoters, is introduced to investigate the effects of promoters on the three parts of combustion air. The results show that the air consumed by coke burning is almost linear to combustion air flow rate, while the air consumed by CO combustion promoters tends to saturate as combustion air flow rate increases, indicating that higher air flow rate can only be used as a manipulated variable to control the oxygen content for an economic concern.

  16. Le bal du loup

    CERN Multimedia

    Happy Children's Home

    2013-01-01

    The Bord'eau amateur theatre group will graciously perform a play of their creation Le bal du loup Saturday 19 October 2013 at 20:00 Sunday 20 October at 17:00 in the Théâtre des Grottes Rue Louis Favre 43, 1201 Genève Children from age 12 upwards. Summary: The new-elected mayoress of a small village would like to clean up the town by prohibiting alcohol and getting rid of its prostitutes. Then along comes « Massimo Lupo » the pimp... The performances will be given to support the Happy Children's Home charity, which runs a foster-home in Pokhara for Nepali children:  http://www.happychildrenshome.org/ Admission : minimum charge of 10 CHF per person requested, to cover the cost of technical assistance and theatre rental. Any profit will be used solely for the foster-home. At the end of each performance members of the HCH charity will be happy to answer any questions you may have. The theatre has 86 seats, thank you for reserv...

  17. Le collisionneur du futur?

    CERN Multimedia

    CERN Audiovisual Service

    2009-01-01

    Pourquoi deux études parallèles pour un même collisionneur linéaire ? Loin d’être un double effort et un gaspillage de ressources, ces deux études s’inscrivent dans une stratégie de complémentarité afin de fournir la meilleure technologie requise par la physique du futur. Vendredi 12 juin a eu lieu au CERN la première réunion conjointe CLIC et ILC. Elle n’a pas été avare de bons résultats et d’importantes décisions. Le Collisionneur Linéaire International (ILC) et le Collisionneur Linéaire Compact (CLIC) sont deux études qui font, tous deux, appel à des technologies de pointe. A première vue en compétition, les deux études sont en réalité complémentaires et elles ont un objectif commun : proposer dans les plus brefs délais et au moindre coût, l‘accélérateur linéaire le mieux adapté pour prendre le relais de la physique des très hautes énergies après le LHC.

  18. Simulation numérique du transfert de chaleur dans un moteur-fusée à propergol liquide

    Directory of Open Access Journals (Sweden)

    B. KHELIDJ

    2015-03-01

    Full Text Available Ce travail est une contribution à l'étude du refroidissement d'un moteur-fusée à propergol liquide. En effet pour protéger la paroi de la chambre propulsive, un système de refroidissement est nécessaire, car la température des gaz de combustion du propergol liquide dans la chambre de combustion, est très élevée. C'est pour montrer l'intérêt du refroidissement de la paroi de la chambre propulsive qu'une étude de simulation numérique, des phénomènes de combustion et de refroidissement dans la chambre propulsive, a été réalisée en régime permanent à l'aide du code de calcul Fluent. Les résultats de simulation, notamment ceux relatifs aux températures des parois le long de la chambre propulsive ont été confrontés à ceux trouvés dans la littérature.

  19. Effets du fluor et du phosphogypse chez les organismes marins

    OpenAIRE

    Martin, J.L.; Le Guellec, Anne-marie; Cosson, R.

    1982-01-01

    Dans le cadre général des recherches visant à déterminer l'action des effluents industriels et plus précisément du fluor dans le cas de cette étude, le programme dont les résultats sont présentés avait pour but de déterminer les effets de cet élément sur les organismes marins. Trois aspects essentiels ont été envisagés : - Effets létaux du fluor ; - effets du fluor sur certaines fonctions éthologiques ; - bio-accumulation de l'élément par les organismes marins.

  20. Internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Williams, G.J.

    1986-06-03

    A variable power internal combustion engine is described which consists of: a separate air compressor for receiving and compressing a flow of air to a given pressure, the compressor having an inlet valve introducing a flow of air into the compressor and an outlet valve for exhausting compressed air out of the compressor into a compressed air storage means, at least one expander having a cylinder, a cylinder head closing an end of the cylinder, a piston reciprocally mounted in the cylinder for movement away from the cylinder head in a power stroke from an initial position defining a combustion chamber within the cylinder between the cylinder head and the piston, the compressed air storage means receiving the pressurized flow of air from the compressor and being of a volume adequate to provide compressed air in the combustion chamber essentially at the given pressure essentially over the power output of the engine, means for introducing an amount of combustible fuel in the compressed charge to be present with compressed air in the combustion chamber and providing combustion of the amount of fuel in the cylinder with the inlet and exhaust valves closed, cam shaft means in contact with the piston for absorbing and storing the energy of the power stroke of the piston and controlling movement of the piston within the cylinder during the exhaust stroke; the means for varying the volume of the combustion chamber being controlled in accordance with power requirements to provide variable power output and improved efficiency of the engine at power outputs reduced relative to a given design power output of the engine by providing a variable expansion ratio of a minimum of at least about 30 to 1 at the given design power output and higher with reduced power output.

  1. Main: 1DU5 [RPSD[Archive

    Lifescience Database Archive (English)

    Full Text Available 1DU5 トウモロコシ Corn Zea mays L. Zeamatin Precursor. Name=Zlp; Zea Mays Molecule: Zeama...NNACPVFKKDEYCCVGSAANDCHPTNYSRYFKGQCPDAYSYPKDDATSTFTCPAGTNYKVVFCP corn_1DU5.jpg ...

  2. Optimisation énergétique des chambres de combustion à haut taux de compression Energy Optimization of High-Compression-Ratio Combustion Chambers

    Directory of Open Access Journals (Sweden)

    Douaud A.

    2006-11-01

    Full Text Available Une synthèse des études entreprises à l'institut Français du Pétrole pour la compréhension des phénomènes de combustion, de transferts thermiques, de cliquetis et leur maîtrise pour l'optimisation du rendement de chambre à haut taux de compression conduit à proposer deux thèmes de réalisation : - chambre calme à double allumage; - chambre turbulente à effet de chasse. Les avantages de principe et les contraintes associés à la mise en oeuvre de chaque type de chambre sont examinés. A synthesis of research undertaken at the Institut Français du Pétrole on understanding combustion, heat-transfer and knock phenomena and on mastering them to optimize the efficiency of high-compression-ratio combustion chambers has led to the proposing of two topics of implementation:(a calm chamber with dual ignition;(b turbulent chamber with squish effect. The advantages of the principle and the constraints connected to the implementation of each type of chamber are examined.

  3. Gestion durable du paysage

    Directory of Open Access Journals (Sweden)

    Jean-David Gerber

    2009-03-01

    Full Text Available Le paysage est de plus en plus perçu comme une ressource. À ce titre, il est nécessaire de trouver des instruments juridiques, politiques ou économiques susceptibles de gérer cette « ressource-paysage » sur le long terme. Le gouvernement suisse a introduit récemment l’instrument des parcs naturels régionaux, organisés selon le modèle français, dans sa législation de protection de la nature et du paysage. Une mise en regard des nouveaux parcs avec des structures de gestion beaucoup plus anciennes, les bourgeoisies et les corporations, permet de mettre en évidence les forces et les faiblesses de chacun de ces instruments dans leur contribution à résoudre les rivalités d’usage entre acteurs utilisant ou influençant la ressource paysage. Cette comparaison permet de formuler des recommandations pratiques concernant la gestion de cette ressource.The landscape is increasingly perceived as a resource. For this reason, it is necessary to find legal, political and economic instruments that will succeed in managing this “resource landscape” in the long term. The Swiss government recently introduced the instrument of regional nature parks into the legislation governing nature and landscape preservation; the proposed parks are organized on the basis of the French model. The examination of the new parks from the perspective of much older management structures, i.e. the civic municipalities (bourgeoisies and corporations, makes it possible to demonstrate the strengths and weaknesses of each of these instruments in their contribution to the resolution of use rivalries between actors who use or influence the resource landscape. This comparison also enables the formulation of practical recommendations regarding the management of this resource.

  4. Cri du Chat syndrome

    Directory of Open Access Journals (Sweden)

    Cerruti Mainardi Paola

    2006-09-01

    Full Text Available Abstract The Cri du Chat syndrome (CdCS is a genetic disease resulting from a deletion of variable size occurring on the short arm of chromosome 5 (5p-. The incidence ranges from 1:15,000 to 1:50,000 live-born infants. The main clinical features are a high-pitched monochromatic cry, microcephaly, broad nasal bridge, epicanthal folds, micrognathia, abnormal dermatoglyphics, and severe psychomotor and mental retardation. Malformations, although not very frequent, may be present: cardiac, neurological and renal abnormalities, preauricular tags, syndactyly, hypospadias, and cryptorchidism. Molecular cytogenetic analysis has allowed a cytogenetic and phenotypic map of 5p to be defined, even if results from the studies reported up to now are not completely in agreement. Genotype-phenotype correlation studies showed a clinical and cytogenetic variability. The identification of phenotypic subsets associated with a specific size and type of deletion is of diagnostic and prognostic relevance. Specific growth and psychomotor development charts have been established. Two genes, Semaphorin F (SEMAF and δ-catenin (CTNND2, which have been mapped to the "critical regions", are potentially involved in cerebral development and their deletion may be associated with mental retardation in CdCS patients. Deletion of the telomerase reverse transcriptase (hTERT gene, localised to 5p15.33, could contribute to the phenotypic changes in CdCS. The critical regions were recently refined by using array comparative genomic hybridisation. The cat-like cry critical region was further narrowed using quantitative polymerase chain reaction (PCR and three candidate genes were characterised in this region. The diagnosis is based on typical clinical manifestations. Karyotype analysis and, in doubtful cases, FISH analysis will confirm the diagnosis. There is no specific therapy for CdCS but early rehabilitative and educational interventions improve the prognosis and considerable

  5. Combustible structural composites and methods of forming combustible structural composites

    Science.gov (United States)

    Daniels, Michael A.; Heaps, Ronald J.; Steffler, Eric D; Swank, William D.

    2011-08-30

    Combustible structural composites and methods of forming same are disclosed. In an embodiment, a combustible structural composite includes combustible material comprising a fuel metal and a metal oxide. The fuel metal is present in the combustible material at a weight ratio from 1:9 to 1:1 of the fuel metal to the metal oxide. The fuel metal and the metal oxide are capable of exothermically reacting upon application of energy at or above a threshold value to support self-sustaining combustion of the combustible material within the combustible structural composite. Structural-reinforcing fibers are present in the composite at a weight ratio from 1:20 to 10:1 of the structural-reinforcing fibers to the combustible material. Other embodiments and aspects are disclosed.

  6. Les paradoxes du littoral Swahili

    Directory of Open Access Journals (Sweden)

    François Bart

    2008-10-01

    Full Text Available Le contact entre l'océan Indien occidental et le continent africain a forgé l'identité et l'originalité du littoral swahili. Cette interface, longue d'environ 2 000 kilomètres, du sud de la Somalie au nord du Mozambique, constitue un monde original où, au gré de traditions anciennes de circulation maritime et continentale se sont diffusées et mêlées des influences culturelles venues du continent africain, de la péninsule arabique et de la péninsule indienne. Le développement du continent, du littoral et des archipels s'inscrit dans une double logique de fragmentation et d'ouverture au monde. Dans cette vaste aire géographique, le rôle de relais des îles et des axes de pénétration continentale à partir des ports est essentiel.The identity and the original features of the Swahili seashore mainly proceed from the contact of African mainland and western indian Ocean. This coastal interface, stretching over 2 000 kilometres from southern Somalia to northern Mozambique, is characterized by ancient traditions of trade movements through maritime areas and mainland as well, which spread and mixed different cultural influences originating from Africa and both Arabic and Indian peninsulas. The development of this area is linked to both fragmentation and opening dynamics. In such a wide area, the relaying function of islands and continental corridors from main harbours is very important.

  7. Combustion and regulation; Combustion et reglementation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    This conference was organized after the publication of the French by-law no 2010 relative to combustion installations and to the abatement of atmospheric pollution. Five topics were discussed during the conference: the new regulations, their content, innovations and modalities of application; the means of energy suppliers to face the new provisions and their schedule; the manufacturers proposals for existing installations and the new equipments; the administration control; and the impact of the new measures on exploitation and engineering. Twenty papers and 2 journal articles are reported in these proceedings. (J.S.)

  8. 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)

  9. Study of the behaviour of artificial radioactive aerosols. Applications to some problems of atmospheric circulation (1963); Etude du comportement dcs aerosols radioactifs artificiels. Applications a quelques problemes de circulation atmospherique (1963)

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-11-15

    The aim of this work, consists in the examination of the behaviour of radioactive aerosols produced in the atmosphere by nuclear explosions, in order to deduce the most general laws governing atmospheric circulation and diffusion. After having given a general table of the radioactive aerosols present the authors consider the validity and the precision of the measurement methods and the concentration of the aerosols at ground level and in the upper atmosphere, as well as their deposition on the ground. The existence is thus demonstrated of a tropospheric equatorial barrier and of discontinuous and seasonal aspects of stratosphere-troposphere transfers. The role is shown of precipitations and dry auto-filtration in the lower atmosphere cleaning processes. This work makes it possible to describe the general behaviour of dust from the stratosphere, and to improve the total radioactive contamination of the globe. (author) [French] L'objectif de ce travail consiste a examiner le comportement des aerosols radioactifs introduits dans l'atmosphere par les explosions nucleaires, pour en deduire les lois les plus generals de la circulation et diffusion atmospheriques. Apres avoir dresse un tableau d'ensemble des aerosols radioactifs presents, on examine la validite et la precision des methodes de mesure de leur concentration, au niveau du sol et en haute atmosphere, ainsi que de leur depot a la surface du sol. On met ainsi en evidence l'existence d'une barriere equatoriale tropospherique; l'aspect discontinu et saisonnier des transferts stratosphere-troposphere; le role des precipitations et de l'auto-filtration seche, dans les processus de nettoyage de la basse atmosphere. Ces etudes permettent de decrire le comportement general des poussieres d'origine stratospherique et d'ameliorer le bilan de la contamination radioactive du globe. (auteur)

  10. ETUDE GEOCHIMIQUE ET ISOTOPIQUE DES EAUX SUPERFICIELLES DU BASSIN VERSANT DU FURAN ET DES EAUX MINERALES DU GRABEN DU FOREZ, EST DU MASSIF CENTRAL FRANÇAIS

    OpenAIRE

    Gal, Frédérick

    2005-01-01

    Ce travail est basé sur l'étude d'un continuum eau de pluie – eau de surface – eau minérale, en utilisant différents outils chimiques et géochimiques. La zone d'étude se situe en bordure Est du Massif Central Français. Elle comprend des entités géographiques et géologiques variées (complexe granito-gneissique et cristallophyllien – Monts du Forez et du Lyonnais d'âge hercynien, graben Oligocène du Forez à venues volcaniques miocènes).La première partie repose sur l'étude en isotopes stables (...

  11. From the coupling between ion beam analysis techniques and physico-chemical characterization methods to the study of irradiation effects on materials behaviour; Du couplage des techniques d'analyse par faisceaux d'ions et des methodes de caracterisation physico-chimique a l'etude des effets d'irradiation sur le comportement des materiaux

    Energy Technology Data Exchange (ETDEWEB)

    Millard-Pinard, N

    2003-07-01

    The general purpose of my research work is to follow and to interpret the surface evolution of materials, which have received several treatments. During my PhD and my post-doc work, my field of research was tribology. Since I arrived in the 'Aval du Cycle Electronucleaire' group of the Institut de Physique Nucleaire de Lyon, my research activities are in line with the CNRS program 'PACE ' (Programme sur l'Aval du Cycle Electronucleaire) within the ACTINET network. They are coordinated by the PARIS (Physico-chimie des actinides et autres radioelements en solution et aux interfaces) and NOMADE (NOuveaux MAteriaux pour les DEchets) GDR with ANDRA (Agence Nationale pour la gestion des Dechets RAdioactifs), EDF and IRSN (Institut de Radioprotection et de Surete Nucleaire) as partner organisations. My work focused on the study of fission products and actinides migration in barrier materials, which may be capable of assuring the long term safety of deep geological repositories. Until now, it was necessary to use the coupling of ion beam analysis techniques and physico-chemical characterization techniques. During the last few months, I have became interested in understanding radiolytic effects. This new orientation has led us to use ion beams as an irradiating tool. These irradiation experiments are pursued in three major projects. The study of cobalt sulfide inhibition effects of radiolysis gas production during the irradiation of model organic molecules. This is a collaboration with the IRSN, the Institut de Recherche sur la Catalyse and the Ecole Nationale Superieure des Mines de Saint-Etienne. A PhD, co-directed by M. Pijolat from ENSMSE and myself, concerning this study will start in October 2003. Water radiolysis effects on iron corrosion are also studied in the particular case of vitrified nuclear waste containers, which will be stored in deep geological repositories. One ANDRA financed PhD, co-directed by Nathalie Moncoffre and myself, is

  12. Studies in combustion dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Koszykowski, M.L. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    The goal of this program is to develop a fundamental understanding and a quantitative predictive capability in combustion modeling. A large part of the understanding of the chemistry of combustion processes comes from {open_quotes}chemical kinetic modeling.{close_quotes} However, successful modeling is not an isolated activity. It necessarily involves the integration of methods and results from several diverse disciplines and activities including theoretical chemistry, elementary reaction kinetics, fluid mechanics and computational science. Recently the authors have developed and utilized new tools for parallel processing to implement the first numerical model of a turbulent diffusion flame including a {open_quotes}full{close_quotes} chemical mechanism.

  13. Alcohol combustion chemistry

    KAUST Repository

    Sarathy, Mani

    2014-10-01

    Alternative transportation fuels, preferably from renewable sources, include alcohols with up to five or even more carbon atoms. They are considered promising because they can be derived from biological matter via established and new processes. In addition, many of their physical-chemical properties are compatible with the requirements of modern engines, which make them attractive either as replacements for fossil fuels or as fuel additives. Indeed, alcohol fuels have been used since the early years of automobile production, particularly in Brazil, where ethanol has a long history of use as an automobile fuel. Recently, increasing attention has been paid to the use of non-petroleum-based fuels made from biological sources, including alcohols (predominantly ethanol), as important liquid biofuels. Today, the ethanol fuel that is offered in the market is mainly made from sugar cane or corn. Its production as a first-generation biofuel, especially in North America, has been associated with publicly discussed drawbacks, such as reduction in the food supply, need for fertilization, extensive water usage, and other ecological concerns. More environmentally friendly processes are being considered to produce alcohols from inedible plants or plant parts on wasteland. While biofuel production and its use (especially ethanol and biodiesel) in internal combustion engines have been the focus of several recent reviews, a dedicated overview and summary of research on alcohol combustion chemistry is still lacking. Besides ethanol, many linear and branched members of the alcohol family, from methanol to hexanols, have been studied, with a particular emphasis on butanols. These fuels and their combustion properties, including their ignition, flame propagation, and extinction characteristics, their pyrolysis and oxidation reactions, and their potential to produce pollutant emissions have been intensively investigated in dedicated experiments on the laboratory and the engine scale

  14. Radiative Augmented Combustion.

    Science.gov (United States)

    1985-08-12

    86-0085 In 00I to RADIATIVE AUGMENTED COMBUSTION MOSHE LAVID M.L. ENERGIA , INC. P.O. BOX 1468 1 PRINCETON, NEW JERSEY 08542 AUGUST 1985 *.. plo...Combustion conducted at M.L. ENERGIA . It is funded by the Air Force Office of Scientific Research under Contract No. F49620-83-C-0133, with Dr. J.M...reported. It covers the second year of the contract, from July 15, 1984 through July 14, 1985. The work was performed at ENERGIA , Princeton, New Jersey

  15. Transition nozzle combustion system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Won-Wook; McMahan, Kevin Weston; Maldonado, Jaime Javier

    2016-11-29

    The present application provides a combustion system for use with a cooling flow. The combustion system may include a head end, an aft end, a transition nozzle extending from the head end to the aft end, and an impingement sleeve surrounding the transition nozzle. The impingement sleeve may define a first cavity in communication with the head end for a first portion of the cooling flow and a second cavity in communication with the aft end for a second portion of the cooling flow. The transition nozzle may include a number of cooling holes thereon in communication with the second portion of the cooling flow.

  16. Toxicology of Biodiesel Combustion products

    Science.gov (United States)

    1. Introduction The toxicology of combusted biodiesel is an emerging field. Much of the current knowledge about biological responses and health effects stems from studies of exposures to other fuel sources (typically petroleum diesel, gasoline, and wood) incompletely combusted. ...

  17. Réflexion sur l’origine du processus de segmentation du marche du travail

    Directory of Open Access Journals (Sweden)

    Attia Nicole

    2006-01-01

    Full Text Available (francuski Ce travail propose une réflexion sur l'origine du processus de segmentation du marché du travail par rapport à l'entreprise. Se situe-t-elle au sein même de l'entreprise ou en amont, c'est à dire entre les entreprises? Cela revient à se demander si on peut avoir une approche microéconomique ou macroéconomique de la segmentation et, à s'interroger sur le rôle réel tenu par les firmes dans le processus. Déterminant pour la théorie, ce rôle est à repenser selon la réponse apportée à notre question.

  18. Cri-du-chat syndrome

    NARCIS (Netherlands)

    Didden, H.C.M.; Curfs, L.M.G

    2013-01-01

    Cri-du-chat syndrome is a genetic disease resulting from a deletion occurring on the short arm of chromosome 5 (5p-). The incidence ranges from 1:15 000 to 1:50 000 live-born infants. Its main clinical features are a high-pitched monochromatic cry, microcephaly, broad nasal bridge, epicanthal folds,

  19. A simplified proof of a conjecture for the perturbed Gelfand equation from combustion theory

    Science.gov (United States)

    Korman, Philip; Li, Yi; Ouyang, Tiancheng

    2017-09-01

    For the perturbed Gelfand's equation on the unit ball in two dimensions, Y. Du and Y. Lou [5] proved that the curve of positive solutions is exactly S-shaped, for sufficiently small values of the secondary parameter. We present a simplified proof and some extensions. This problem is prominent in combustion theory, see e.g., the book of J. Bebernes and D. Eberly [1].

  20. Experimental combustion an introduction

    CERN Document Server

    Mishra, D P

    2014-01-01

    ""… other books available in this area do not cover the detailed topics covered here. Energy and combustion is a hot issue. It is expected to be even hotter with more demand in this area as we search for cleaner methods of energy conversion from chemical to thermal energy.""-Ashwani K. Gupta, Department of Mechanical Engineering, University of Maryland, College Park, USA

  1. Coal combustion research

    Energy Technology Data Exchange (ETDEWEB)

    Daw, C.S.

    1996-06-01

    This section describes research and development related to coal combustion being performed for the Fossil Energy Program under the direction of the Morgantown Energy Technology Center. The key activity involves the application of chaos theory for the diagnosis and control of fossil energy processes.

  2. Optical Tomography in Combustion

    DEFF Research Database (Denmark)

    Evseev, Vadim

    . JQSRT 113 (2012) 2222, 10.1016/j.jqsrt.2012.07.015] included in the PhD thesis as an attachment. The knowledge and experience gained in the PhD project is the first important step towards introducing the advanced optical tomography methods of combustion diagnostics developed in the project to future...

  3. Combustion Models in Finance

    CERN Document Server

    Tannous, C

    2001-01-01

    Combustion reaction kinetics models are used for the description of a special class of bursty Financial Time Series. The small number of parameters they depend upon enable financial analysts to predict the time as well as the magnitude of the jump of the value of the portfolio. Several Financial Time Series are analysed within this framework and applications are given.

  4. Flameless Combustion Workshop

    Science.gov (United States)

    2005-09-20

    operating hours, to produce low emission levels of NOx, CO and UHC . Gas turbine combustion stability has increasingly become a crucial design issue as...achieved proved: "* Safe and reliable operation ofgas turbine combustors "* Low emissions of NO., CO and UHC These results have clear economically

  5. Cross-correlation of two detectors in a nuclear reactor; Intercorrelation de deux detecteurs dans un reacteur nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Dalfes, A.; Beliard, L.; Cazemajou, J.; Froelicher, B. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    Auto and cross-correlation functions of signals given by neutron detectors situated in a subcritical nuclear reactor are determined by a numerical method. Values of the prompt neutrons decay constant obtained by means of the autocorrelation function of each detector and the cross-correlation function of the two detectors are compared to the reference value given by a classical pulsed neutrons measurement. Agreement between results seems to be satisfactory. (authors) [French] Les fonctions d'autocorrelation et d'intercorrelation des signaux issus de deux detecteurs de neutrons places dans un reacteur nucleaire sous critique sont determinees par une methode numerique. On compare les valeurs de la constante de decroissance des neutrons prompts donnees par les fonctions d'autocorrelation de chaque detecteur et la fonction d'intercorrelation des deux detecteurs au resultat de reference fourni par une manipulation dite de 'neutrons pulses'. L'accord entre les resultats parait satisfaisant. (auteurs)

  6. Combustion calorimetry experimental chemical thermodynamics

    CERN Document Server

    Sunner, Stig

    1979-01-01

    Combustion Calorimetry deals with expertise knowledge concerning the calorimetry of combustion reactions of an element or compound. After defining the use of units and physical constants, the book discusses the basic principles of combustion calorimetry and the various instruments and calorimeters used in the experiments to measure operations concerning temperatures and its time variations. One paper discusses the theory and design criteria of combustion calorimeter calibration. Another paper discusses the results obtained from a combustion calorimeter after it has measured the energy or entha

  7. Modelling of CWS combustion process

    Science.gov (United States)

    Rybenko, I. A.; Ermakova, L. A.

    2016-10-01

    The paper considers the combustion process of coal water slurry (CWS) drops. The physico-chemical process scheme consisting of several independent parallel-sequential stages is offered. This scheme of drops combustion process is proved by the particle size distribution test and research stereomicroscopic analysis of combustion products. The results of mathematical modelling and optimization of stationary regimes of CWS combustion are provided. During modeling the problem of defining possible equilibrium composition of products, which can be obtained as a result of CWS combustion processes at different temperatures, is solved.

  8. Caractérisation des sables et morphologie du fond du lac du ...

    African Journals Online (AJOL)

    Administrateur

    Map of this lake 26 years after its setting in water. Key words : Dam .... La méthode d'interpolation retenue est l'IDW (Inverse Distance Weighting) avec un pas .... Figure 2 : Répartition des faciès de surface des sédiments du lac de Taabo. 3.3.

  9. LES GITES PLOMBO-ZINCIFERES DU DISTRICT MINIER DU KOUDIAT SIDU AUSUD DU KEF EN TUNISIE

    Directory of Open Access Journals (Sweden)

    Ivan Jurković

    1992-12-01

    Full Text Available Les auteurs ont dćcrit l:i stratigiaphie. I.i tectonique, le corps de minerals, la paragenese et la genese dcs gttes Koudiat Sidri situ&s environ 20 km au sud de la ville du Kef en Tunisie.

  10. Le parcours migratoire de jeunes ruraux du bled du kif

    Directory of Open Access Journals (Sweden)

    Khalid Mouna

    2015-06-01

    Full Text Available Cet article analyse le parcours migratoire des jeunes ruraux originaires des zones de production du cannabis, jeunes qui cherchent à briser les chaînes de soumission et d’humiliation vécues au quotidien. Pour les jeunes concernés par notre étude, la migration constitue un moyen de s’intégrer dans des réseaux transnationaux et ainsi d’entamer une carrière de beznass (commerçant du cannabis. Ce parcours « initiatique » permet à ces jeunes de revenir au bled avec de nouvelles idées, des moyens accrus, et de jouer un rôle actif dans l’économie locale – qui reste pour eux focalisée sur la production de cannabis, cette dernière restant néanmoins officiellement interdite.

  11. Paul Celan in Translation: "Du sei wie du"

    Directory of Open Access Journals (Sweden)

    John Felstiner

    1983-09-01

    Full Text Available Translating the lyric poetry of Paul Celan, especially his later poems, carries not only the endemic challenge and difficulty of any verse translation, but the added incentive of doing justice to a writer whose whole recourse after the Holocaust—whose sanctuary, if he was to have any at all—he sought in language itself, specifically in the Muttersprache , the mother tongue that was as well the tongue of those who murdered his mother and father. This essay exposes a process of translating "Du sei wie du" (1970, which perhaps more than any other poem by Celan, at once solicits and defies translation, moving as it does from modern to medieval German, and closing with Hebrew words from Isaiah— a messianic imperative that shows Celan verging as ever on his Jewish identity.

  12. Dynamique narrative du texte, du film et de la musique

    OpenAIRE

    Wildgen, Wolfgang

    2015-01-01

    La narrativité est foncièrement liée à la dynamique des événements et des actions représentés, et elle dépend du champ pragmatique narrateur/récepteur, c’est-à-dire du discours narratif. Cette dynamique demande une théorisation adéquate, par exemple au sein de la théorie des systèmes dynamiques ou de l’analyse vectorielle, et elle se manifeste dans des modalités différentes. Nous présentons des exemples d’analyse dans la modalité linguistique (récit oral spontané, conte populaire), dans la mo...

  13. Plutonium isotopes and their decay products in civil nuclear engineering; Les isotopes du plutonium et leurs descendants dans le nucleaire civil

    Energy Technology Data Exchange (ETDEWEB)

    Dautray, R

    2005-07-01

    This book is the continuation and conclusion of a previous book from the same author, entitled 'civil nuclear energy in the temporal framework of climatic changes' (Tec and Doc editions). It focusses on plutonium and on its daughter products. A synthesis of the scientific and technical data gathered so far is presented, together with the different choices offered to political authorities in the light of present-day knowledge. The authors starts from existing and firmly implemented scientific and technical data and presents some ways to solve the pending questions about the management of radioactive wastes. He shows that in our democratic system, the choice belongs to people. Beside the storage and deep disposal facilities, still necessary, some processes and problems are reviewed and explored. Of course new scientific data will be obtained, which would change the ways to discover and evaluate the ways to follow up. (J.S.)

  14. The today situation and the nuclear sector perspectives in Usa; La situation actuelle et les perspectives du secteur nucleaire aux Etats-Unis

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    In this analysis the author details and discusses the nuclear energy situation in the Usa: the park and the electric power production, the nuclear safety and the radiation protection, the licenses prolongation, the power increase, the regulation relative to the construction of new reactors, the combined construction permit and operating license, the uncertainties on the Yucca Mountain storage site and the Global Nuclear Energy Partnership initiative, the 2006 perspectives and the IV generation reactors. (A.L.B.)

  15. The technology of the bearings used in the nuclear power generation system turbine generator units; Technologie des paliers equipant les groupes turbo-alternateurs du parc nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Vialettes, J.M.; Rossato, M. [Service Ensembles de Production, Departement Machines, Direction des Etudes et Recherches, Electricite de France (EDF), 92 - Clamart (France)

    1997-01-01

    A bearing consists of all the stationary part which allow the relative motion in rotation or in translation, of a shaft line. Inside the bearing there is a journal bearing with a metallic anti-friction coating (the babbitt metal). The high power turbine generator unit rotors are supported by smooth transversal journal bearings fed with oil which fills the empty space and runs along the shaft. The technologies used for the bearings and the thrust bearings of the turbine generator units and the various shaft lines of the French CP0/CP1- and CP2/1300 MW-type nuclear power plants are described. The experience feedback is then discussed in terms of the dynamics of the shaft line, i.e. vibrational problems, the influence of the alignment and the babbitt metal incidents. (author) 4 refs., 11 figs.

  16. Nuclear trade and non-proliferation: report by working group; Commerce nucleaire et non-proliferation: rapport du groupe de travail

    Energy Technology Data Exchange (ETDEWEB)

    Kerever, M.

    1995-12-31

    The paper is organized in three parts. The first one analyses the Treaty on the Non-proliferation of Nuclear Weapons (NPT) mentioning the arrangements and registered agreements between the IAEA and Member States. Also, the most important international legal instruments concerned the peaceful uses of nuclear energy are considered. In the second part, other international, regional or national legal instruments are discussed, particularly the London Club Guidelines, Treaty of Tlatelolco, the EURATOM and the Commission of the European Communities (CEC) Treaties, besides the American law of 18 Mars, 1978 - Nuclear Non-proliferation Act (NNPA) about the exportation of materials and services or nuclear technology; An appreciation about the laws and treaties are presented in the third part. Special attention is given to reinforce the non-proliferation dispositives face the actions after Iraq`s event (1990): new installations and nuclear activities moratorium extension export controls extension established by the London Club Guidelines and full scope safeguards adoption to accomplish controls and protect of dual-use nuclear-related technologies. 3 refs.

  17. Investigating the irradiation behavior of nuclear materials: the contribution of the JANNUS platform; Etude du comportement sous irradiation des materiaux nucleaires: apport de la plateforme JANNUS

    Energy Technology Data Exchange (ETDEWEB)

    Trocellier, P.; Miro, S.; Serruys, Y. [Departement des materiaux pour le nucleaire, Direction de l' energie nucleaire, CEA Centre de Saclay, 91191 Gif-sur-Yvette (France)

    2010-07-01

    The JANNUS platform (Joint Accelerators for Nano-sciences and Nuclear Simulation) comprises two experimental facilities, one located at Saclay, the other nearby at Orsay. The Saclay facility brings together 3 electrostatic particle accelerators: a single-ended, 3-MV Pelletron-accelerator (EPIMETHEE), a tandem 2-MV Pelletron (JAPET), and a single-ended 2.5-MV Van de Graaff accelerator (YVETTE), set up around a common experiment chamber. The Orsay facility features a mixed-mode 2-MV accelerator (ARAMIS), and a 190-kV ion implanter (IRMA), both being coupled to a 200-kV transmission electron microscope. This setup allows the evolution of the sample's microstructure to be observed in situ, while it is undergoing irradiation, in single- or dual-beam configuration. A typical irradiation experiment, in triple-beam configuration, matches the conditions required, e.g., by applications in the area of fusion. The multicharged heavy-ion beam delivered by EPIMETHEE serves to simulate the atomic displacements caused, within the material, by neutrons. YVETTE provides helium ({sup 4}He), and JAPET hydrogen ({sup 1}H), as yielded by nuclear reactions (n, {alpha}) and (n, p). This characterization - whether structural, chemical, or mechanical - may be carried out during irradiation (in situ), or immediately subsequent to it (ex situ). Materials science can now avail itself of an altogether comprehensive panoply of physicochemical analysis techniques, e.g. electron microscopy, atom-probe tomography, X-ray diffraction and absorption... 2 examples illustrate the contribution made by the JANNUS platform to our understanding of the irradiation behavior of nuclear materials. The first example concerns hexagonal silicon carbide (6H-SiC), the second one an ODS (Oxide Dispersion Strengthened) ferritic-martensitic alloy. (A.C.)

  18. On needs for particular isotopes with future advanced nuclear reactors; Quelques besoins en isotopes particuliers pour les reacteurs nucleaires avances du futur

    Energy Technology Data Exchange (ETDEWEB)

    Asou, M.; Porta, J. [CEA Centre d`Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. d`Etudes des Reacteurs

    1994-12-31

    This paper is concerned with two essential points with innovative approaches for nuclear reactors: utilization of {sup 15}N in uranium nitride fuels in order to avoid carbon 14 generation; utilization of rare earths, and especially gadolinium, for the control of the potential reactivity in the core in the case of a cycle lengthening from 12 to 18 months, and in the case of a water reactor operating without soluble boron. 1 tab., 17 refs.

  19. Nuclear systems of the future. Stakes, R and D strategy, and international cooperation; Les systemes nucleaires du futur. Enjeux, strategie de recherche et developpement, et cooperation internationale

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    As demonstrated by prospective studies, nuclear energy will represent a decisive contribution in the future energy mix. The long-term strategy of development of nuclear energy requires to foresee a new generation of nuclear systems, named generation 4. The goal of these new systems is to optimize the use of nuclear fuels, to minimize the generation of wastes and to enlarge the field of applications of nuclear energy to other applications like: hydrogen and synthetic fuels generation, heat generation for the industry etc. This document presents the French R and D strategy on nuclear systems of 4. generation that has been approved by the public authorities. This strategy follows three axes: a priority research on fast neutron systems with fuel recycle (sodium fast reactors (SFR) and gas fast reactors (GFR)), a research on key-technologies for the supply of very high temperature heat (very high temperature reactor (VHTR), fast and thermal neutron reactors, and water decomposition processes), and a continuation of researches on PWR reactors improvement. An integral recycling of all actinides in fast neutron reactors requires the development of new fuel reprocessing and fuel re-fabrication processes. A reference scenario for the progressive renewal of French nuclear facilities foresees the simultaneous development of fast neutron systems and the start-up of a new spent fuel reprocessing plant. France in involved in the development of the SFR, GFR and VHTR systems thanks to its participation to the Generation 4 international forum and to bilateral cooperation with other big nuclear partners like Russia and China. One of the main stakes of the French nuclear industry is to be able to invest in the R and D of future nuclear systems in order to valorize the experience gained so far in sodium FBR systems and in fuel cycle processes. (J.S.)

  20. Symmetry and geometry of the N-body problem. Application to the nuclear physics; Symetrie et geometrie du probleme a N-corps. Application a la physique nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Chau, H.T.P

    2002-10-01

    One of the main goals of classical and quantum physics is to solve the many-body problem. In nuclear theory, several methods have been developed and provide accurate results. In this thesis, we remind how symmetry can be used to obtain analytical solutions of the quantum many-body problem. We emphasize that unitary Lie algebras play a crucial role in quantum mechanics and propose and implement a method to build irreducible representations of this algebra from its highest-weight state. Calculations of bosonic and fermionic spectra are performed with realistic and with random interactions. Studies with rotational invariant two-body random interactions have unveiled high degree of order (a marked statistical preference is found for ground states with angular momentum equal to zero). In the second chapter of this thesis, it is argued that the spectral properties of this kind of interaction depend on the choice of the valence space. In particular, we propose a geometrical method to predict the properties of the ground state in certain cases. We also present numerical results when the geometrical approach can not be applied. In the third chapter, we study the link between quantum chaos and nuclear spectra calculated with realistic interactions. (author)

  1. Thermal stability of the French nuclear waste glass - long term behavior modeling; Etude de la stabilite thermique du verre nucleaire. Modelisation de son evolution a long terme

    Energy Technology Data Exchange (ETDEWEB)

    Orlhac, X

    2000-07-01

    The thermal stability of the French nuclear waste glass was investigated experimentally and by modeling to predict its long-term evolution at low temperature. The crystallization mechanisms were analyzed by studying devitrification in the supercooled liquid. Three main crystalline phases were characterized (CaMoO{sub 4}, CeCO{sub 2}, ZnCr{sub 2}O{sub 4}). Their crystallisation was TO 4.24 wt%, due to the low concentration of the constituent elements. The nucleation and growth curves showed that platinoid elements catalysed nucleation but did not affect growth, which was governed by volume diffusion. The criteria of classic nucleation theory were applied to determine the thermodynamic and diffusional activation energies. Viscosity measurements illustrate the analogy between the activation energy of viscous flow and diffusion, indicating control of crystallization by viscous flow phenomena. The combined action of nucleation and growth was assessed by TTT plots, revealing a crystallization equilibrium line that enables the crystallized fractions to be predicted over the long term. The authors show that hetero-genetics catalyze the transformation without modifying the maximum crystallized fraction. A kinetic model was developed to describe devitrification in the glass based on the nucleation and growth curves alone. The authors show that the low-temperature growth exhibits scale behavior (between time and temperature) similar to thermo-rheological simplicity. The analogy between the resulting activation energy and that of the viscosity was used to model growth on the basis of viscosity. After validation with a simplified (BaO{sub 2}SiO{sub 2}) glass, the model was applied to the containment glass. The result indicated that the glass remained completely vitreous after a cooling scenario with the one measured at the glass core. Under isothermal conditions, several million years would be required to reach the maximum theoretical crystallization fraction. (author)

  2. The role of the nuclear industry in the Brazil's electricity system; Le role du nucleaire dans le systeme electrique Bresilien

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro Da Silva, O.L.; Dos Santos Guimaraes, L. [Electronuclear - Electrobras Termonuclear (Brazil)

    2009-11-15

    No form of energy - renewable, clean or whatever other name it is given - can constitute the sole solution to the challenge of ensuring electric power supplies that are compatible with a country's economic and social growth. Brazilian consumption and installed electrical generation capacity per capita are stiller low, below the world average - that is the main factor that needs to be stressed. The catch-up requires that the country benefit it as much as possible and as soon as possible from all available sources to increase electricity generation capacity allowing increased consumption compatible with the way of life that Brazilians aspire to. A country's electrical system planning requires the efficient management of a diversified array of energy sources. Regarding Brazil, hydro power will be or several decades the main component in its electricity generation portfolio. Nonetheless, it already needs to be complemented by thermal sources - uranium, coal, bio-mass, natural gas and petroleum-based oil - in that order of importance, taking account of such actors as availability on the home territory, costs, environmental impacts and uses in other applications. (authors)

  3. The threat of nuclear terrorism: from analysis to caution measures; La menace du terrorisme nucleaire: de l'analyse aux mesures de precaution

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, M

    2001-12-15

    In this work are analysed the different cases of terrorism attacks, the potential sources of risks, such reprocessing plants, nuclear power plants, every facility where is stored radioactive material. The vulnerability of these facilities is also evoked. Some solutions are recommended but more specially, further thought needs to be given to that kind of problems. (N.C.)

  4. How many to bring the nuclear part to 50% in 2020?; Quel cout pour ramener la part du nucleaire a 50% en 2020?

    Energy Technology Data Exchange (ETDEWEB)

    Nifenecker, H

    2007-02-15

    The author aims to evaluate the cost of a reduction of 50% of the nuclear part in the energy production in France. This evaluation, realized for 2020 gives a total of 42 giga euros. The consequences on the CO{sub 2} emissions are also calculated. (A.L.B.)

  5. Present day situation and perspectives of the nuclear sector in the USA; La situation actuelle et les perspectives du secteur nucleaire aux Etats-Unis

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    With the restart-up of Browns Ferry NPP on May 22, 2007, the US nuclear park comprises now 104 reactors in operation: 35 BWR-type and 69 PWR-type. NPPs are present in only 31 states and mainly in the eastern half of the country. Nuclear energy represents 20% of the US energy mix (coal: 50%, gas: 19%, hydro-power: 6%, petroleum: 3% and other renewable energies: 2%). The highest average availability rate in power generation is reached by nuclear energy (89.9%). The nuclear power generation reached 787.2 TWh in 2006, i.e. the second best result after the 2004 record (788.5 TWh). This document presents also some nuclear safety and radioprotection indicators (number of unplanned outages, failures, injury frequency rate), the programme of licenses extension, the permissions for power increase, the demands for design certification, for early site permit, and for combined construction permit and operating license. The regulation may be different from one state to the other and sometimes not favorable to a re-launch of nuclear energy. The situation of each state in this domain is presented in appendix. (J.S.)

  6. The nuclear energy of the future: the researches and the objectives; L'energie nucleaire du futur: quelles recherches pour quels objectifs?

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    Today energy problems are global problems. That is why the new generation of energy production by nuclear power must be realized basely on serious forecasts at a world scale. The nuclear energy presents many trumps for an energetic answer, at long-dated, concerning the environment and the resources. This will be for two main conditions: the ability to answer the public opinion anxiety and the development of new systems more high- performance in terms of safety and economy in the framework of the sustainable development and the non proliferation policy. These subjects are at the earth of the CEA missions. This document proposes a detailed presentation of the nuclear origins, the fuel and its cycle, the radioactive wastes and their management,the dismantling and the decommissioning of the nuclear installations, the challenges of the nuclear safety, the energy in the world, the nuclear economy, the nuclear in the world, the researches of the future, the third generation reactors, the research on radioactive wastes, the fuel cycle of the nuclear systems of the future, the uranium resources, the generation four forum, the gas coolant reactors, the thorium, hybrid systems and the thermonuclear fusion. (A.L.B.)

  7. Pollution with an underlying of corruption. How Russia is becoming the world nuclear sewer; Pollution sur fond de corruption. Comment la Russie devient la poubelle nucleaire du monde

    Energy Technology Data Exchange (ETDEWEB)

    Melis, N

    2002-02-01

    Following the new laws decided by the Russian Government, concerning the radioactive wastes importation, many ecologist organizations fight against the future environmental and biological impacts of such a policy. This paper presents the legal situation, the Government attitude and the actions of russian and international organizations. (A.L.B.)

  8. Inventory of chemical releases of nuclear installations in the North-Cotentin; Inventaire des rejets chimiques des installations nucleaires du Nord-Cotentin

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-05-15

    The nuclear installations concerned by this study are Cogema La Hague, the Flamanville nuclear power plant, the Manche plant and the National Navy of Cherbourg.The objective followed by the ' source term ' work group has consisted in counting and examining the whole of existing measures relative to the releases of chemical substances in the liquid and gaseous effluents. Then because of the lack of measures for the operation first years of installations, the work group has estimated the order of magnitude of these chemical releases (essentially for Cogema La Hague). This report presents a review of the literature looking at the background levels of chemicals in different environmental compartments: air, soil, plants and animals products. these values have been summarized here to be available for comparisons with concentrations input by the North Cotentin nuclear installations, calculated by the G.R.N.C. (radioecology group of Nord Cotentin)

  9. United Kingdom from past leadership to the renaissance of nuclear industry; Le Royaume-Uni: a l'avant-garde de la renaissance du nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Capdevila, J.M. [CEA/Ambassade de France a Londres (United Kingdom)

    2010-07-15

    United-Kingdom has developed a long tradition of know-how in the domain of nuclear energy since 1956 when the first power reactor entered into service at Calder Hall site. From 1956 till now 45 reactors have been successively connected to the grid. All the sectors of nuclear industry were developed: uranium conversion, enrichment, fuel fabrication, MOX fabrication, spent fuels reprocessing and radioactive waste management. Now British nuclear industry is slowly getting out of a 20 year long period of lethargy due mainly to the lost competition with the oil and gas from the North sea fields. Since 2008 and because the North sea resources are waning, U.K. has become again an oil importer. The new energy policy of the government is to favor renewable energies and to support at least the renewal of the today's reactors. 19 reactors are operating but most are old: 14 reactors will have to be stopped by 2018 unless service life extensions are allowed. The French EDF company who purchased British-Energy in 2009 has announced the construction of 4 EPR by 2025. The renaissance of the nuclear industry in U.K. is all the easier as the past was glorious. (A.C.)

  10. Ascouf: an industrial software for the engineering of nuclear facilities in operation; Ascouf: un outil numerique industriel pour l`ingenierie nucleaire du parc en exploitation

    Energy Technology Data Exchange (ETDEWEB)

    Genette, P.; Martelet, B. [Electricite de France (EDF), 69 - Villeurbanne (France). Div. Mecanique des Structures du Septen; Debost-Eymart, I. [Electricite de France (EDF), 92 - Clamart (France). Dept. Mecanique et Modeles Numeriques

    1998-10-01

    The ASCOUF software has been developed par EDF to facilitate the quick analysis of defects contained in pipes or elbows of the primary loop. This preprocessing tool of Code Aster, the structural analysis finite element code of EDF, has been used to carry out, with an increase of productivity a series of numerical studies proving the mechanical strength of these components. Its validation, taking into account the feed-back from previous studies, leads us to rely on the results. ASCOUF has afterwards been extended to solve the problems of lack of thickness of pipes of the secondary loop. (authors)

  11. Crisis assistance to nuclear operators: the manufacturer missions and methods; L`assistance de crise a l`exploitant nucleaire: missions et methodes du constructeur

    Energy Technology Data Exchange (ETDEWEB)

    Touati, J. [Societe Franco-Americaine de Constructions Atomiques (FRAMATOME), 92 - Paris-La-Defense (France)

    1995-12-31

    Since 1985, the Framatome Company has provided to Electricite de France (EDF) a technical assistance in the case of major accident on a nuclear power plant. During the accident crisis, Framatome establishes a diagnosis and a forecast about the installation state and proposes the safest solutions to the operator for a limitation of accident consequences. Different tools have been developed by Framatome to identify the consequences of electric power outages or to control the state of coolant circuits using expert systems and a data base about reactor component characteristics. A thermo-hydraulic analysis of the accident is performed by the system, using data transmitted to the crisis center, and hypotheses about the origin of the accident are proposed by the expert. After validation, a classification of risks is established and the best strategy to follow is determined by the system, in particular when non-conventional means are required. (J.S.). 1 fig.

  12. Correlations between nuclear data and results of integral slab experiments. Case of hafnium; Correlations entre donnees nucleaires et experiences integrales a plaques: le cas du hafnium

    Energy Technology Data Exchange (ETDEWEB)

    Palau, J.M

    1997-10-22

    The aim of this thesis was to evaluate how much integral slab experiments can both reduce discrepancies between experimental results and calculations, and improve the knowledge of hafnium isotopes neutronic parameters by an adapted sensitivity and uncertainty method. A statistical approach, based on the generalized least squares method and perturbation theory, has been incorporated into our calculation system in order to deduce microscopic cross-section adjustments from observed integral measurements on this particular `mock-up` reactor. In this study it has been established that the correlations between integral parameters and hafnium capture cross-sections enable specific variations in the region of resolved resonances at the level of multigroup and punctual cross-sections recommended data (JEF-2.2 evaluation) to be highlighted. The use of determinist methods (APOLLO2 code) together with Monte Carlo- type simulations (TRIPOLI4 code) enabled a depth analysis of the modelling approximations to be carried out. Furthermore, the sensitivity coefficient validation technique employed leads to a reliable assessment of the quality of the new basic nuclear data. In this instance, the adjustments proposed for certain isotope {sup 177}Hf resonance parameters reduce, after error propagation, by 3 to 5 per cent the difference between experimental results and calculations related to this absorbent`s efficiency. Beyond this particular application, the qualification methodology integrated in our calculation system should enable other basic sizing parameters to be treated (chemical / geometric data or other unexplored nuclear data) to make technological requirements less stringent. (author) 128 refs.

  13. Correlations between nuclear data and integral slab experiments: the case of hafnium; Correlations entre donnees nucleaires et experiences integrales a plaques: le cas du hafnium

    Energy Technology Data Exchange (ETDEWEB)

    Palau, J.M

    1999-07-01

    The aim of this work was to evaluate how much integral slab experiments can both reduce discrepancies between experimental results and calculations, and improve the knowledge of hafnium isotopes neutronic parameters by an adapted sensitivity and uncertainty method. A statistical approach, based on the generalized least squares method and perturbation theory, has been incorporated into our calculation system in order to deduce microscopic cross-section adjustments from observed integral measurements on this particular 'mock-up' reactor.In this study it has been established that the correlations between integral parameters and hafnium capture cross-sections enable specific variations in the region of resolved resonances at the level of multigroup and punctual cross-sections recommended data (JEF-2.2 evaluation) to be highlighted. The use of determinist methods together with Monte Carlo- type simulations enabled a depth analysis of the modelling approximations to be carried out. Furthermore, the sensitivity coefficient validation technique employed leads to a reliable assessment of the quality of the new basic nuclear data. In this instance, the adjustments proposed for certain isotope {sup 177}Hf resonance parameters reduce, after error propagation, by 3 to 5 per cent the difference between experimental results and calculations related to this absorbent's efficiency. Beyond this particular application, the qualification methodology integrated in our calculation system should enable other basic sizing parameters to be treated (chemical / geometric data or other unexplored nuclear data) to make technological requirements less stringent. (author)

  14. Study of nuclear glasses alteration gel and synthesis of some model gels; Etude du gel d`alteration des verres nucleaires et synthese de gels modeles

    Energy Technology Data Exchange (ETDEWEB)

    Ricol, S.

    1995-10-05

    This work deals with the general problem of alteration of the reference nuclear glass R7T7. Attention is paid particularly to the altered layer formed at the glass surface during alteration process. In opposition to previous works, related essentially to glass dissolution kinetics based on chemical analyses of lixiviated elements, this thesis deals with alteration problems through structural studies of the reference glass and derived gel. This approach allows the determination of mechanisms for the gel formation and a better understanding of the behaviour of glasses towards lixiviation. Both approaches appeared complementary. Based on several spectroscopic techniques, this work showed the particular role of cations such as calcium, zirconium and iron. Studies of silica-based synthetic gels showed the synergic effect of formers cation and of one highly coordinated cation. The variation of the wavenumber related to Si-O-Si asymmetric stretching vibration can be correlated to O/Si ratio for ternary systems Si/Na/Zr. On the contrary, the Si losses of the materials depend on the number of non-bridging oxygen atoms. In the perspective of long-term behaviour, the alteration gel presents better characteristics than initial glass. It is therefore a highly stable material in static conditions. In the same way, synthetic gels are materials with very low solubilities (much lower than the alteration gel) and could be used as confining matrices. (authors). refs., 71 figs., 37 tabs.

  15. Correlations between nuclear data and results of integral slab experiments. Case of hafnium; Correlations entre donnees nucleaires et experiences integrales a plaques: le cas du hafnium

    Energy Technology Data Exchange (ETDEWEB)

    Palau, J.M

    1997-10-22

    The aim of this thesis was to evaluate how much integral slab experiments can both reduce discrepancies between experimental results and calculations, and improve the knowledge of hafnium isotopes neutronic parameters by an adapted sensitivity and uncertainty method. A statistical approach, based on the generalized least squares method and perturbation theory, has been incorporated into our calculation system in order to deduce microscopic cross-section adjustments from observed integral measurements on this particular `mock-up` reactor. In this study it has been established that the correlations between integral parameters and hafnium capture cross-sections enable specific variations in the region of resolved resonances at the level of multigroup and punctual cross-sections recommended data (JEF-2.2 evaluation) to be highlighted. The use of determinist methods (APOLLO2 code) together with Monte Carlo- type simulations (TRIPOLI4 code) enabled a depth analysis of the modelling approximations to be carried out. Furthermore, the sensitivity coefficient validation technique employed leads to a reliable assessment of the quality of the new basic nuclear data. In this instance, the adjustments proposed for certain isotope {sup 177}Hf resonance parameters reduce, after error propagation, by 3 to 5 per cent the difference between experimental results and calculations related to this absorbent`s efficiency. Beyond this particular application, the qualification methodology integrated in our calculation system should enable other basic sizing parameters to be treated (chemical / geometric data or other unexplored nuclear data) to make technological requirements less stringent. (author) 128 refs.

  16. Etude de l'influence du champ magnetique dans une section d'essais thermohydraulique d'un canal de reacteur nucleaire CANDU 6

    Science.gov (United States)

    Landry-Lavoie, Renaud

    This memoir deals with the effects of the magnetic fields present in a thermal hydraulic test section of the Canadian nuclear industry. This test section is used to determine the thermal hydraulic conditions that can lead to critical heat flux in a channel of a CANDU 6 nuclear reactor. To perform their series of experiments the STERN Company used strong electric currents to heat the simulation bundles with a thermal power similar to the one found in a channel of a CANDU reactor. The materials constituting the simulation channel and its supports are of ferromagnetic nature. The strong magnetic field generated by the bundles implies that they are subjected to a magnetostatic force due to the magnetization of the ferromagnetic materials. The nuclear industry wants to know if these efforts, combined with the force of gravity, are sufficient to maintain the bundles in place in the simulation channel. The question also arises whether or not the magnetic field present in the channel can affect the parameters of boiling heat transfer. To determine the magnetic field distribution in the simulation channel, we had recourse to the magnetostatic image method and the integral method of calculation of magnetization. The results of the calculations show that the magnetostatic forces exerted by the ferromagnetic elements of the test section are inferior in magnitude to the one estimated by the STERN laboratorie. We used the mechanistic model of Sullivan et al. (1964) to evaluate the possible influence of the magnetic fields on the departure diameter of the vapor bubbles. The deviation in the frequency of bubble emission was evaluated by using the correlations of Zuber et al. (1959) and Cole (1960). By introducing a magnetostatic force in the boiling model and in the correlations, we demonstrated that the magnetic field present in the STERN test section has a negligible effect on the bubble departure diameter and their emission frequency. We conclude that the conditions in the test section are consistent with those prevailing in the channel of a CANDU 6 reactor.

  17. Non-proliferation and nuclear disarmament: speech of the president Obama at Prague; Non-proliferation et desarmement nucleaires: discours de Prague du president Obama

    Energy Technology Data Exchange (ETDEWEB)

    Hautecouverture, B. [Centre d' Etudes de Securits Internationale et de Maitrise des armements (CESIM), 75 - Paris (France)

    2009-10-15

    Introduced by the Prague speech of april 7 2009, the Obama President program towards the non proliferation and the nuclear disarmament was pointed out by its optimism ambition and determination. But a more detailed lecture shows concurrent positions. The author analyzes the political aspects of the President speech. (A.L.B.)

  18. Nuclear non-proliferation and disarmament: the President Obama's Prague speech; Non-proliferation et desarmement nucleaires: discours de Prague du president Obama

    Energy Technology Data Exchange (ETDEWEB)

    Hautecouverture, B. [Centre d' Etudes de Securite Internationale et de Maitrise des Armements (CESIM), 75 - Paris (France)

    2010-07-15

    The author comments the content and the consequences of President Obama's speech on the future of nuclear weapons in the 21. century. After a recall of the political context, the author shows how this declaration sounded with a real new tone, defined a new direction and introduced a new method, but may reach its objectives only on a long term. Then, he comments how these objectives are challenged by the present context and events, and outlines how the US Nuclear Posture Review will be important

  19. By-law from December 12, 2005 relative to nuclear pressure systems; Arrete du 12 decembre 2005 relatif aux equipements sous pression nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-01-15

    This by-law deals with the specifications relative to the design, fabrication and conformability evaluations of nuclear pressure system, i.e. systems that may lead to a radioactive contamination in the case of failure. The main safety requirements of these systems are recalled in appendixes (nondestructive testing and qualification). (J.S.)

  20. Obligation of information and nuclear medicine after the law of march 4. 2002; Obligation d'information en medecine nucleaire apres la loi du 4 mars 2002

    Energy Technology Data Exchange (ETDEWEB)

    Bloch, L. [Universite Montesquieu, ATER, 33 - Bordeaux (France)

    2002-06-01

    The default of the obligation of information, which should only be a deontological fault, had begun to intrude on the area of responsibility, whether it be criminal or indeed civil. 'Ethical' responsibility took over a 'technical' responsibility limited by the primacy of fault. The law of March 4, 2002 prepared the ground for a return of this sword of Damocles towards its natural area, that is to say deontological fault which comes within ordinal jurisdictions. Thus the main contribution of this law is to be found in the definition of medical responsibility which, by limiting responsibility to a technical fault, seems to rule out the default of the obligation of information. The law of March 4, 2002 has not stirred up the content of the obligation of information for all that. The question of the information on exceptional risks is the only one to have noticeably evolved, since information now concerns only predictable risks. Therefore, the law of March 4, 2002, in no way leads to the death of the obligation of information, quite the reverse: the quality requirements in the information of the patient are even reinforced in some of their aspects, but in compensation for these requirements, there is no exacerbated responsibility anymore. (author)

  1. Contribution to the optimization of the coupling of nuclear reactors to desalination processes; Contribution a l'optimisation du couplage des reacteurs nucleaires aux procedes de dessalement

    Energy Technology Data Exchange (ETDEWEB)

    Dardour, S

    2007-04-15

    This work deals with modelling, simulation and optimization of the coupling between nuclear reactors (PWR, modular high temperature reactors) and desalination processes (multiple effect distillation, reverse osmosis). The reactors considered in this study are PWR (Pressurized Water Reactor) and GTMHR (Gas Turbine Modular Helium Reactor). The desalination processes retained are MED (Multi Effect Distillation) and SWRO (Sea Water Reverse Osmosis). A software tool: EXCELEES of thermodynamic modelling of coupled systems, based on the Engineering Algebraic Equation Solver has been developed. Models of energy conversion systems and of membrane desalination processes and distillation have been developed. Based on the first and second principles of thermodynamics, these models have allowed to determine the optimal running point of the coupled systems. The thermodynamic analysis has been completed by a first economic evaluation. Based on the use of the DEEP software of the IAEA, this evaluation has confirmed the interest to use these types of reactors for desalination. A modelling tool of thermal processes of desalination in dynamic condition has been developed too. This tool has been applied to the study of the dynamics of an existing plant and has given satisfying results. A first safety checking has been at last carried out. The transients able to jeopardize the integrated system have been identified. Several measures aiming at consolidate the safety have been proposed. (O.M.)

  2. Time Resolved FTIR Analysis of Combustion of Ethanol and Gasoline Combustion in AN Internal Combustion Engine

    Science.gov (United States)

    White, Allen R.; Sakai, Stephen; Devasher, Rebecca B.

    2011-06-01

    In order to pursue In Situ measurements in an internal combustion engine, a MegaTech Mark III transparent spark ignition engine was modified with a sapphire combustion chamber. This modification will allow the transmission of infrared radiation for time-resolved spectroscopic measurements by an infrared spectrometer. By using a Step-scan equipped Fourier transform spectrometer, temporally resolved infrared spectral data were acquired and compared for combustion in the modified Mark III engine. Measurements performed with the FTIR system provide insight into the energy transfer vectors that precede combustion and also provides an in situ measurement of the progress of combustion. Measurements were performed using ethanol and gasoline.

  3. Experimental chemical thermodynamics. Volume I. Combustion calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Sunner, S.; Mansson, M. (eds.)

    1979-01-01

    This book contains 18 chapters. The information included is: units and physical constants; basic principles of combustion calorimetry; calibration of combustion calorimeters; test and auxiliary substances in combustion calorimetry; strategies in the calculation of standard-state energies of combustion from the experimentally determined quantities; assignments of uncertainties; presentation of combustion calorimetric data in the primary literature; general techniques for combustion of liquid/solid organic compounds by oxygen bomb calorimetry; combustion of liquid/solid organic compounds with non-metallic hetero-atoms; combustion calorimetry of metals and simple metallic compounds; combustion calorimetry of organometallic compounds; combustion in fluorine and other halogens; bomb combustion of gaseous compounds in oxygen; oxygen flame calorimetry; fluorine flame calorimetry; combustion calorimetry as a technological service; trends in combustion calorimetry; and from the history of combustion calorimetry. (DP)

  4. Aerosols from biomass combustion

    Energy Technology Data Exchange (ETDEWEB)

    Nussbaumer, T.

    2001-07-01

    This report is the proceedings of a seminar on biomass combustion and aerosol production organised jointly by the International Energy Agency's (IEA) Task 32 on bio energy and the Swiss Federal Office of Energy (SFOE). This collection of 16 papers discusses the production of aerosols and fine particles by the burning of biomass and their effects. Expert knowledge on the environmental impact of aerosols, formation mechanisms, measurement technologies, methods of analysis and measures to be taken to reduce such emissions is presented. The seminar, visited by 50 participants from 11 countries, shows, according to the authors, that the reduction of aerosol emissions resulting from biomass combustion will remain a challenge for the future.

  5. Combustion science and engineering

    CERN Document Server

    Annamalai, Kalyan

    2006-01-01

    Introduction and Review of Thermodynamics Introduction Combustion Terminology Matter and Its Properties Microscopic Overview of Thermodynamics Conservation of Mass and Energy and the First Law of Thermodynamics The Second Law of Thermodynamics Summary Stoichiometry and Thermochemistry of Reacting Systems Introduction Overall Reactions Gas Analyses Global Conservation Equations for Reacting Systems Thermochemistry Summary Appendix Reaction Direction and Equilibrium Introduction Reaction Direction and Chemical Equilibrium Chemical Equilibrium Relations Vant Hoff Equation Adi

  6. Combustion Characteristics of Sprays

    Science.gov (United States)

    1989-08-01

    regarded by implication or otherwise, or in any way licensing the holder or any other person or corporation, or conveying any rights or permission to...00 _’N 1. TI TLE inctuat Security CZaaafication5 Combustion Characteristics of Sprays 12. PERSONAL AUTHOR(S) Sohrab, Siavash H. 13& TYPE OF REPORT...to ?!HF of rich butane/air 3unsen flames. .lso, the rotacion speed and :he oerodic temDeracure fluc:uations of rotacfng ?HF are examined. :’!naily

  7. Combustible Cartridge Case Characterization

    Science.gov (United States)

    1984-02-01

    University (NYU) has resulted in the selection of two cross-linked melamine / formaldehyde acrylic styrene resin systems that can be used in the beater additive... melamine resin Akaradit II stabilizer 20. ABSTRACT (con) Test coupons of combustible cartridge case material were fabricated using these recommended...and agitated for 30 min before the pH was slowly lowered to 3 with p-toluene sulfonic acid. In order to maintain this pH in the felting tank, it was

  8. High Gravity (g) Combustion

    Science.gov (United States)

    2006-02-01

    required thrust-to-weight ratio goals. Shorter residence times in the combustion chamber may reduce the NOx emissions, but the CO and UHC emissions then...Emissions analyzing equipment is available to detect CO, CO2, NOx, O2, and total unburned hydrocarbons ( UHC ) at the combustor exit plane. Emissions... UHC ) emissions along with the CO data, as seen in Fig. 24, shows that Configuration 1 had much higher UHC levels. The reactions from hydrocarbons to

  9. Eléments d'analyse du cliquetis et de ses effets Elements for Analyzing Knocking and Its Effects

    Directory of Open Access Journals (Sweden)

    Douaud A.

    2006-11-01

    Full Text Available On présente dans cet article une synthèse des travaux théoriques et expérimentaux relatifs à la génération du cliquetis et à ses effets sur le fonctionnement du moteur. L'apparition du cliquetis est décrite par un mécanisme global de délai d'auto-inflammation. Des exemples d'application portant sur l'identification du délai de carburants quelconques et sur l'optimisation de l'ensemble moteurs-carburants documentent cette approche. Le cliquetis a pour conséquence un accroissement de sollicitations mécaniques et thermiques des parois de la chambre de combustion. Des méthodes et résultats d'investigation de ces phénomènes sont présentés. A synthesis is presented of theoretical and experimental research concerning the generating of knocking and its effects on engine running. The appearance of knocking is described by an overall mechanism of autoignition delay. This approach is documented by applied examples concerning the identification of the delay involved with any type of fuel and the optimizing of engine-fuel systems. Knocking causes an increase in mechanical and thermal stresses on combustion-chamber walls. Investigational methods and results concerning these phenomena are described.

  10. L’Harmonie du monde

    Directory of Open Access Journals (Sweden)

    Martine Clouzot

    2003-11-01

    Full Text Available La Bourgogne est particulièrement bien présente et représentée dans l’exposition sur la musique et ses représentations au Moyen Âge organisée par Isabelle Marchesin (université de Poitiers, Christine Laloue (conservatrice du Patrimoine au Musée et Martine Clouzot (université de Bourgogne, au Musée de la Musique à Paris du 26 mars au 27 juin 2004. En Côte-d’Or, à Dijon, la Bibliothèque municipale a donné son accord officiel pour le prêt de la Bible d’Etienne Harding, les Moralia in Job et u...

  11. Internal combustion engine using premixed combustion of stratified charges

    Science.gov (United States)

    Marriott, Craig D.; Reitz, Rolf D. (Madison, WI

    2003-12-30

    During a combustion cycle, a first stoichiometrically lean fuel charge is injected well prior to top dead center, preferably during the intake stroke. This first fuel charge is substantially mixed with the combustion chamber air during subsequent motion of the piston towards top dead center. A subsequent fuel charge is then injected prior to top dead center to create a stratified, locally richer mixture (but still leaner than stoichiometric) within the combustion chamber. The locally rich region within the combustion chamber has sufficient fuel density to autoignite, and its self-ignition serves to activate ignition for the lean mixture existing within the remainder of the combustion chamber. Because the mixture within the combustion chamber is overall premixed and relatively lean, NO.sub.x and soot production are significantly diminished.

  12. The Diesel Combustion Collaboratory: Combustion Researchers Collaborating over the Internet

    Energy Technology Data Exchange (ETDEWEB)

    C. M. Pancerella; L. A. Rahn; C. Yang

    2000-02-01

    The Diesel Combustion Collaborator (DCC) is a pilot project to develop and deploy collaborative technologies to combustion researchers distributed throughout the DOE national laboratories, academia, and industry. The result is a problem-solving environment for combustion research. Researchers collaborate over the Internet using DCC tools, which include: a distributed execution management system for running combustion models on widely distributed computers, including supercomputers; web-accessible data archiving capabilities for sharing graphical experimental or modeling data; electronic notebooks and shared workspaces for facilitating collaboration; visualization of combustion data; and video-conferencing and data-conferencing among researchers at remote sites. Security is a key aspect of the collaborative tools. In many cases, the authors have integrated these tools to allow data, including large combustion data sets, to flow seamlessly, for example, from modeling tools to data archives. In this paper the authors describe the work of a larger collaborative effort to design, implement and deploy the DCC.

  13. Internal combustion piston engines

    Energy Technology Data Exchange (ETDEWEB)

    Segaser, C.L.

    1977-07-01

    Current worldwide production of internal combustion piston engines includes many diversified types of designs and a very broad range of sizes. Engine sizes range from a few horsepower in small mobile units to over 40,000 brake horsepower in large stationary and marine units. The key characteristics of internal combustion piston engines considered appropriate for use as prime movers in Integrated Community Energy Systems (ICES) are evaluated. The categories of engines considered include spark-ignition gas engines, compression-ignition oil (diesel) engines, and dual-fuel engines. The engines are evaluated with respect to full-load and part-load performance characteristics, reliability, environmental concerns, estimated 1976 cost data, and current and future status of development. The largest internal combustion piston engines manufactured in the United States range up to 13,540 rated brake horsepower. Future development efforts are anticipated to result in a 20 to 25% increase in brake horsepower without increase in or loss of weight, economy, reliability, or life expectancy, predicated on a simple extension of current development trends.

  14. Issues in waste combustion

    Energy Technology Data Exchange (ETDEWEB)

    Gustavsson, Lennart; Robertson, Kerstin; Tullin, Claes [Swedish National Testing and Research Inst., Boraas (Sweden); Sundquist, Lena; Wrangensten, Lars [AaF-Energikonsult AB, Stockholm (Sweden); Blom, Elisabet [AaF-Processdesign AB, Stockholm (Sweden)

    2003-05-01

    The main purpose of this review is to provide an overview of the state-of-the-art on research and development issues related to waste combustion with relevance for Swedish conditions. The review focuses on co-combustion in grate and fluidised bed furnaces. It is primarily literature searches in relevant databases of scientific publications with to material published after 1995. As a complement, findings published in different report series, have also been included. Since the area covered by this report is very wide, we do not claim to cover the issues included completely and it has not been possitile to evaluate the referred studies in depth. Basic knowledge about combustion issues is not included since such information can be found elsewhere in the literature. Rather, this review should be viewed as an overview of research and development in the waste-to-energy area and as such we hope that it will inspire scientists and others to further work in relevant areas.

  15. L'energie du moustique

    CERN Document Server

    Augereau, J F

    2002-01-01

    ENSEMBLE DE QUATRE ARTICLES - LARGE HADRON COLLIDER: Le dernier accelerateur de particules du CERN, le LEP, produisait des faisceaux d'electrons de 100 GeV chacun. Le LHC, qui accelere des faisceaux de protons, leur communiquera une energie de 7 TeV chacun. Une energie a la fois colossale et derisoire. Un TeV represente a peu pres l'energie cinetique d'un moustique (1/2 page).

  16. Revision du Genre Aseraggodes Kaup

    NARCIS (Netherlands)

    Chabanaud, P.

    1930-01-01

    Le présent travail comprend la définition du genre Aseraggodes Kaup et la revision, sous forme d'une clef dichotomique, de toutes les espèces qui le composent, revision établie d'après les types eux-mêmes de ces espèces. Ce genre Aseraggodes appartient à la famille des Soleidae et à la sousfamille

  17. Collecting uncollectables: Joachim Du Bellay

    Directory of Open Access Journals (Sweden)

    Gro Bjørnerud Mo

    2017-09-01

    Full Text Available Lists of wonders have circulated for millennia. Over and over, such inventories of spectacular man made constructions have been rewritten, re-edited and reimagi-ned. Both the wonders and the lists of wonders, preferably of the seven, have had a profound and long-lasting effect, and have been abundantly imitated, copied and reworked. Renaissance creative thinking was obsessed with the seven wonders of the ancient world, and early-modern Europe experienced a surge of visual and verbal depictions of wonders. This article is about a remarkable list of seven wonders, included in one of Joachim Du Bellay's canonical poems on Roman antiquities (Antiquités de Rome, published in Paris in 1558. Du Bellay shapes his list of wonders by exploring pat-terns of both repetition and mutability. Almost imperceptibly, he starts suggesting connections between 16th-century Rome and distant civilizations. Through the eyes of a fictive traveller and collector, the poet venerates the greatness and la-ments the loss of ancient buildings, sites and works of art, slowly developing a ver-bal, visual and open-ended gallery, creating a collection of crumbling or vanished, mainly Roman, architecture. This poetic display of ruins and dust in the Eternal City is nourished by the attraction of the inevitable destruction of past splendour and beauty. In the sonnets, Du Bellay imitates classical models and patterns. Whi-le compiling powerful images and stories of destruction, he combines techniques associated with both a modern concept of copy and more ancient theories of co-pia. In this context, this article also explores whether Pliny's Natural History might be a source for the imaginary collection of lost sites and wonders in Du Bellay's Antiquit's.

  18. Development of flameless combustion; Desarrollo de la combustion sin flama

    Energy Technology Data Exchange (ETDEWEB)

    Flores Sauceda, M. Leonardo; Cervantes de Gortari, Jaime Gonzalo [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)]. E-mail: 8344afc@prodigy.net.mx; jgonzalo@servidor.unam.mx

    2010-11-15

    The paper intends contribute to global warming mitigation joint effort that develops technologies to capture the CO{sub 2} produced by fossil fuels combustion and to reduce emission of other greenhouse gases like the NO{sub x}. After reviewing existing combustion bibliography is pointed out that (a) touches only partial aspects of the collective system composed by Combustion-Heat transfer process-Environment, whose interactions are our primary interest and (b) most specialists think there is not yet a clearly winning technology for CO{sub 2} capture and storage. In this paper the study of combustion is focused as integrated in the aforementioned collective system where application of flameless combustion, using oxidant preheated in heat regenerators and fluent gas recirculation into combustion chamber plus appropriated heat and mass balances, simultaneously results in energy saving and environmental impact reduction. [Spanish] El trabajo pretende contribuir al esfuerzo conjunto de mitigacion del calentamiento global que aporta tecnologias para capturar el CO{sub 2} producido por la combustion de combustibles fosiles y para disminuir la emision de otros gases invernadero como NOx. De revision bibliografica sobre combustion se concluye que (a) trata aspectos parciales del sistema compuesto por combustion-proceso de trasferencia de calor-ambiente, cuyas interacciones son nuestro principal interes (b) la mayoria de especialistas considera no hay todavia una tecnologia claramente superior a las demas para captura y almacenaje de CO{sub 2}. Se estudia la combustion como parte integrante del mencionado sistema conjunto, donde la aplicacion de combustion sin flama, empleando oxidante precalentado mediante regeneradores de calor y recirculacion de gases efluentes ademas de los balances de masa y energia adecuados, permite tener simultaneamente ahorros energeticos e impacto ambiental reducido.

  19. Désulfuration : avant, pendant ou après la combustion ? Synthèse bibliographique Desulfurization: Before, During Or After Combustion? Bibliographic Synthesis

    Directory of Open Access Journals (Sweden)

    Benchecroun N.

    2006-11-01

    Full Text Available Les perspectives d'applications de nouvelles normes aux émissions des grandes installations de combustion, tant aux Etats-Unis qu'en Europe de l'Ouest ont suscité de nombreuses recherches. Les diverses publications qui leur sont consacrées traitent le plus souvent de la combustion de charbons et, beaucoup plus rarement, de l'adaptabilité de ces procédés à des combustibles liquides ou de techniques spécifiques. Les principaux points technico-économiques qui se dégagent sur la désulfuration des combustibles liquides sont donnés dans cet article. Enfin, au-delà des aspects techniques, on notera que la désulfuration des combustibles liquides, et plus particulièrement du fuel lourd, est liée à deux aspects plus politiques : - l'application de normes sur les émissions des installations de combustion (ou les dérogations possibles qui concernent non seulement les oxydes de soufre mais aussi les oxydes d'azote et les particules contenues dans les fumées; - l'avenir des fuels lourds tant sur le plan quantitatif (marché que qualitatif (constitution du pool fuel et spécifîcations. The prospects that new emission standards will be applied to large combustion installations, both in the United States and Western Europe, have given rise to extensive research. The different publications devoted to this research usually deal with coal combustion and more rarely with the suitability of such processes for liquid fuels or specific techniques. The leading technico-economic points involved in the desulfurization of liquid fuels are given in this article. Likewise, over and beyond the technical aspects, it can be seen that the desulfurization of liquid fuels, and more particularly of heavy fuel oil, is linked to two more politicalaspects:(a the application of standards on emissions from combustion installations (or possible derogations concerning not only sulfur oxides but also nitrogen oxides and particles contained in fumes;(b the future of

  20. Prairie du Chien: A Historical Study,

    Science.gov (United States)

    1976-10-01

    Naudouwessee with whom this governor made peace and introduced trade and commerce among the whole nation. His son the successor told me that some of the...Nicholas Perrot, French Commandant of the West, with a party of couriers du bois and voyageurs descended the Wisconsin River and erected Fort St...number of traders and voyageurs settled at Prairie du Chien. Thomas Anderson who settled at Prairie du Chien in 1800 described the conditions on his

  1. Genetics Home Reference: cri-du-chat syndrome

    Science.gov (United States)

    ... Health Conditions cri-du-chat syndrome cri-du-chat syndrome Enable Javascript to view the expand/collapse ... PDF Open All Close All Description Cri-du-chat (cat's cry) syndrome, also known as 5p- (5p ...

  2. Post combustion in converter steelmaking

    Energy Technology Data Exchange (ETDEWEB)

    Oghbasilasie, H.; Holappa, L.

    1997-12-31

    The purpose of this work is to study the fundamentals of post combustion and the effect of different process parameters on the post combustion ratio (PCR) and heat transfer efficiency (HTE) in converter steelmaking process. The PCR and HTE have been determined under normal operating conditions. Trials assessed the effect of lance height, vessel volume, foaming slag and pellet additions on PCR and HTE. Based on enthalpy considerations, post combustion of CO gas is regarded as one of the most effective means of increasing the heat supply to the BOP. The thermodynamic study of gas-metal-slag reactions gives the limiting conditions for post combustion inside the converter reactor. Different process parameters influencing both thermodynamic equilibria and kinetic conditions can greatly affect the post combustion ratio. Different features of converter processes as well smelting reduction processes utilizing post combustion have been reviewed. (orig.) SULA 2 Research Programme; 26 refs.

  3. Au fil du temps (1976 ou la loi du seuil

    Directory of Open Access Journals (Sweden)

    Isabelle Singer

    2010-04-01

    Full Text Available Ayant choisi de vivre dans un camion, les héros d’Au fil du temps (film de Wim Wenders de 1976 font du seuil une expérience particulière. Celle de la rupture avec toute idée de foyer et celle du refus d’appartenance à la terre natale, cette terre allemande traversée par une frontière le long de laquelle ils vont voyager, et qui les renvoie à chaque instant aux traumatismes de l’Histoire. Sur le pare-brise du camion, l’extérieur (campagnes indifférenciées, villes à l’abandon… et l’intérieur se superposent. Au fil du temps questionne le paysage : il s’agit d’en décoller un à un les mythes qui le recouvrent. L’image alors n’est plus surface mais volume à traverser, à lacérer et découvrir ce qui est tissé dans le paysage. La démarche de Wenders est alors proche de celle d’un de ses contemporains : Anselm Kiefer. Le paysage allemand provoque le rejet parce qu’il y a là toujours plus que le visible : des strates et des strates de culpabilité que le mythe - et c’est sa fonction - a recouvert. Et qu’il s’agira ici, de soulever. Le choix du nomadisme, c’est celui d’un état de l’humanité antérieur à l’idée de patrie. Et c’est aussi celui de la solitude, comme prix à payer à ce refus d’appartenance et à cette mise à jour des mythes. L’appartenance à la terre allemande et à son Histoire est profondément problématique parce que les pères sont fondamentalement coupables. On se reconnaîtra alors des pères de substitution : des pères de cinéma (Nicholas Ray ou Fritz Lang. Et l’on substituera l’Histoire du cinéma à l’Histoire. Bruno est réparateur ambulant de projecteurs et Au fil du temps dressera, au gré de ses pérégrinations, un état des lieux du cinéma allemand des années soixante-dix : déliquescent, colonisé par les images hollywoodiennes. Il faut que cela change : état du cinéma ; état des protagonistes solitaires en quête d’une identit

  4. Sulfur Chemistry in Combustion I

    DEFF Research Database (Denmark)

    Johnsson, Jan Erik; Glarborg, Peter

    2000-01-01

    of the sulphur compounds in fossil fuels and the possibilities to remove them will be given. Then the combustion of sulphur species and their influence on the combustion chemistry and especially on the CO oxidation and the NOx formation will be described. Finally the in-situ removal of sulphur in the combustion...... process by reaction between SO2 and calcium containing sorbents and the influence on the NOx chemistry will be treated....

  5. Pulsating combustion - Combustion characteristics and reduction of emissions

    Energy Technology Data Exchange (ETDEWEB)

    Lindholm, Annika

    1999-11-01

    In the search for high efficiency combustion systems pulsating combustion has been identified as one of the technologies that potentially can meet the objectives of clean combustion and good fuel economy. Pulsating combustion offers low emissions of pollutants, high heat transfer and efficient combustion. Although it is an old technology, the interest in pulsating combustion has been renewed in recent years, due to its unique features. Various applications of pulsating combustion can be found, mainly as drying and heating devices, of which the latter also have had commercial success. It is, however, in the design process of a pulse combustor, difficult to predict the operating frequency, the heat release etc., due to the lack of a well founded theory of the phenomenon. Research concerning control over the combustion process is essential for developing high efficiency pulse combustors with low emissions. Natural gas fired Helmholtz type pulse combustors have been the experimental objects of this study. In order to investigate the interaction between the fluid dynamics and the chemistry in pulse combustors, laser based measuring techniques as well as other conventional measuring techniques have been used. The experimental results shows the possibilities to control the combustion characteristics of pulsating combustion. It is shown that the time scales in the large vortices created at the inlet to the combustion chamber are very important for the operation of the pulse combustor. By increasing/decreasing the time scale for the large scale mixing the timing of the heat release is changed and the operating characteristics of the pulse combustor changes. Three different means for NO{sub x} reduction in Helmholtz type pulse combustors have been investigated. These include exhaust gas recirculation, alteration of air/fuel ratio and changed inlet geometry in the combustion chamber. All used methods achieved less than 10 ppm NO{sub x} emitted (referred to stoichiometric

  6. The modes of gaseous combustion

    CERN Document Server

    Rubtsov, Nickolai M

    2016-01-01

    This book provides an analysis of contemporary problems in combustion science, namely flame propagation, detonation and heterophaseous combustion based on the works of the author. The current problems in the area of gas combustion, as well as the methods allowing to calculate and estimate limiting conditions of ignition, and flame propagation on the basis of experimental results are considered. The book focuses on the virtually inaccessible works of Russian authors and will be useful for experienced students and qualified scientists in the area of experimental studies of combustion processes.

  7. Combustion from basics to applications

    CERN Document Server

    Lackner, Maximilian; Winter, Franz

    2013-01-01

    Combustion, the process of burning, is defined as a chemical reaction between a combustible reactant (the fuel) and an oxidizing agent (such as air) in order to produce heat and in most cases light while new chemical species (e.g., flue gas components) are formed. This book covers a gap on the market by providing a concise introduction to combustion. Most of the other books currently available are targeted towards the experienced users and contain too many details and/or contain knowledge at a fairly high level. This book provides a brief and clear overview of the combustion basics, suitable f

  8. Mathematical Modeling in Combustion Science

    CERN Document Server

    Takeno, Tadao

    1988-01-01

    An important new area of current research in combustion science is reviewed in the contributions to this volume. The complicated phenomena of combustion, such as chemical reactions, heat and mass transfer, and gaseous flows, have so far been studied predominantly by experiment and by phenomenological approaches. But asymptotic analysis and other recent developments are rapidly changing this situation. The contributions in this volume are devoted to mathematical modeling in three areas: high Mach number combustion, complex chemistry and physics, and flame modeling in small scale turbulent flow combustion.

  9. Active Combustion Control Valve Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Over the past decade, research into active combustion control has yielded impressive results in suppressing thermoacoustic instabilities and widening the...

  10. Active Combustion Control Valve Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Over the past decade, research into active combustion control has yielded impressive results in suppressing thermoacoustic instabilities and widening the operational...

  11. Basic Aerodynamics of Combustion Chambers,

    Science.gov (United States)

    1981-05-20

    8217, tie imnrulse foree eyuilibr-um c’ the bomd’~ leye - is 173 pv-:irJ p~76vJbK 2sO) IL !-. = Zn pT -- a , bV T. z -,,r y.re C era 3oia * ~~I" onc art-=e...heat by combustion all have very large influences on the capabilities of a combustion chamber. A yellow- colored flame represents diffusion combustion in...the wakes of fuel droplets. Blue- colored flames represent gaseous combustion of evaporated vapors which have already left the fuel droplets. The

  12. Numerical and Experimental Study on the Combustion and Emission Characteristics of a Dimethyl Ether (DME Fueled Compression Ignition Engine Études numériques et expérimentales sur les caractéristiques de combustion et d’émissions d’un éther diméthylique (EDM- moteur à auto-allumage rempli de combustible

    Directory of Open Access Journals (Sweden)

    Kim Hyung Jun

    2012-05-01

    Full Text Available A numerical investigation was carried out to study on the combustion and emission characteristics of dimethyl ether (DME with wide ranges of injection timings in compression ignition engines. In order to simulate DME combustion processes, a KIVA-3V code coupled with a chemistry solver was used to solve the detailed chemical kinetics model of DME oxidation. In addition, the Kelvin-Helmholtz-Rayleigh-Taylor (KH-RT hybrid breakup model and Renormalization Group (RNG k-ε  models were applied to analyze the spray characteristics and turbulent flow, respectively. To predict the NOx formation during DME combustion, a reduced Gas Research Institute (GRI NO mechanism was used. From these results on the combustion and emission, the calculated results were compared with experimental ones for the same operating conditions. In the combustion characteristics, the calculated combustion pressure and heat release rates agreed well with experimental results. The levels of experimental NOx emissions was reduced as the start of the injection timing retarded, and also these trends appeared in calculated emission characteristics. Additionally, the calculated CO and HC emissions show an increasing trend as the start of the injection is retarded. Dans cette étude, nous considérons la simulation de la combustion du dimethyl ether (DME dans un moteur à allumage par compression. Les caractéristiques de la combustion ainsi que les émissions polluantes sont analysées sur une large gamme d’avance à l’injection. Afin de simuler le processus de combustion du EDM, le code KIVA-3V couplé à un solveur chimique a été utilisé pour résoudre la cinétique détaillée de l’oxydation du EDM. Le modèle de rupture de Kelvin-Helmholtz-Rayleigh- Taylor (KH-RT ainsi que le modèle de turbulence k-ε  RNG ont été appliqués pour analyser respectivement les caractéristiques du jet et l’écoulement turbulent. Pour prévoir la formation de NOx pendant la combustion

  13. Combustion Branch Website Development

    Science.gov (United States)

    Bishop, Eric

    2004-01-01

    The NASA combustion branch is a leader in developing and applying combustion science to focused aerospace propulsion systems concepts. It is widely recognized for unique facilities, analytical tools, and personnel. In order to better communicate the outstanding research being done in this Branch to the public and other research organization, a more substantial website was desired. The objective of this project was to build an up-to-date site that reflects current research in a usable and attractive manner. In order to accomplish this, information was requested from all researchers in the Combustion branch, on their professional skills and on the current projects. This information was used to fill in the Personnel and Research sections of the website. A digital camera was used to photograph all personnel and these photographs were included in the personnel section as well. The design of the site was implemented using the latest web standards: xhtml and external css stylesheets. This implementation conforms to the guidelines recommended by the w3c. It also helps to ensure that the web site is accessible by disabled users, and complies with Section 508 Federal legislation (which mandates that all Federal websites be accessible). Graphics for the new site were generated using the gimp (www.gimp.org) an open-source graphics program similar to Adobe Photoshop. Also, all graphics on the site were of a reasonable size (less than 20k, most less than 2k) so that the page would load quickly. Technologies such as Macromedia Flash and Javascript were avoided, as these only function on some clients which have the proper software installed or enabled. The website was tested on different platforms with many different browsers to ensure there were no compatibility issues. The website was tested on windows with MS IE 6, MSIE 5 , Netscape 7, Mozilla and Opera. On a Mac, the site was tested with MS IE 5 , Netscape 7 and Safari.

  14. Alternate fuels; Combustibles alternos

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes R, Hernando; Ambriz G, Juan Jose [Universidad Autonoma Metropolitana. Iztapalapa (Mexico)

    2003-07-01

    In the definition and description of alternate fuels we must center ourselves in those technological alternatives that allow to obtain compounds that differ from the traditional ones, in their forms to be obtained. In this article it is tried to give an overview of alternate fuels to the conventional derivatives of petroleum and that allow to have a clear idea on the tendencies of modern investigation and the technological developments that can be implemented in the short term. It is not pretended to include all the tendencies and developments of the present world, but those that can hit in a relatively short term, in accordance with agreed with the average life of conventional fuels. Nevertheless, most of the conversion principles are applicable to the spectrum of carbonaceous or cellulosic materials which are in nature, are cultivated or wastes of organic origin. Thus one will approach them in a successive way, the physical, chemical and biological conversions that can take place in a production process of an alternate fuel or the same direct use of the fuel such as burning the sweepings derived from the forests. [Spanish] En la definicion y descripcion de combustibles alternos nos debemos centrar en aquellas alternativas tecnologicas que permitan obtener compuestos que difieren de los tradicionales, al menos en sus formas de ser obtenidos. En este articulo se pretende dar un panorama de los combustibles alternos a los convencionales derivados del petroleo y que permita tener una idea clara sobre las tendencias de la investigacion moderna y los desarrollos tecnologicos que puedan ser implementados en el corto plazo. No se pretende abarcar todas las tendencias y desarrollos del mundo actual, sino aquellas que pueden impactar en un plazo relativamente corto, acordes con la vida media de los combustibles convencionales. Sin embargo, la mayor parte de los principios de conversion son aplicables al espectro de materiales carbonaceos o celulosicos los cuales se

  15. Combustion Stratification for Naphtha from CI Combustion to PPC

    KAUST Repository

    Vallinayagam, R.

    2017-03-28

    This study demonstrates the combustion stratification from conventional compression ignition (CI) combustion to partially premixed combustion (PPC). Experiments are performed in an optical CI engine at a speed of 1200 rpm for diesel and naphtha (RON = 46). The motored pressure at TDC is maintained at 35 bar and fuelMEP is kept constant at 5.1 bar to account for the difference in fuel properties between naphtha and diesel. Single injection strategy is employed and the fuel is injected at a pressure of 800 bar. Photron FASTCAM SA4 that captures in-cylinder combustion at the rate of 10000 frames per second is employed. The captured high speed video is processed to study the combustion homogeneity based on an algorithm reported in previous studies. Starting from late fuel injection timings, combustion stratification is investigated by advancing the fuel injection timings. For late start of injection (SOI), a direct link between SOI and combustion phasing is noticed. At early SOI, combustion phasing depends on both intake air temperature and SOI. In order to match the combustion phasing (CA50) of diesel, the intake air temperature is increased to 90°C for naphtha. The combustion stratification from CI to PPC is also investigated for various level of dilution by displacing oxygen with nitrogen in the intake. The start of combustion (SOC) was delayed with the increase in dilution and to compensate for this, the intake air temperature is increased. The mixture homogeneity is enhanced for higher dilution due to longer ignition delay. The results show that high speed image is initially blue and then turned yellow, indicating soot formation and oxidation. The luminosity of combustion images decreases with early SOI and increased dilution. The images are processed to generate the level of stratification based on the image intensity. The level of stratification is same for diesel and naphtha at various SOI. When O concentration in the intake is decreased to 17.7% and 14

  16. AIR EMISSIONS FROM SCRAP TIRE COMBUSTION

    Science.gov (United States)

    The report discusses air emissions from two types of scrap tire combustion: uncontrolled and controlled. Uncontrolled sources are open tire fires, which produce many unhealthful products of incomplete combustion and release them directly into the atmosphere. Controlled combustion...

  17. Path planning during combustion mode switch

    Science.gov (United States)

    Jiang, Li; Ravi, Nikhil

    2015-12-29

    Systems and methods are provided for transitioning between a first combustion mode and a second combustion mode in an internal combustion engine. A current operating point of the engine is identified and a target operating point for the internal combustion engine in the second combustion mode is also determined. A predefined optimized transition operating point is selected from memory. While operating in the first combustion mode, one or more engine actuator settings are adjusted to cause the operating point of the internal combustion engine to approach the selected optimized transition operating point. When the engine is operating at the selected optimized transition operating point, the combustion mode is switched from the first combustion mode to the second combustion mode. While operating in the second combustion mode, one or more engine actuator settings are adjusted to cause the operating point of the internal combustion to approach the target operating point.

  18. Métastases gastro-intestinales du cancer du sein: à propos de 2 cas

    Science.gov (United States)

    Loubna, Mezouar; Mohamed, El Hfid; Tijani, El Harroudi; Fouzia, Ghadouani; Hanane, Haj Kacem; Zouhour, Bourhaleb; Asmae, Ouabdelmoumen

    2013-01-01

    Le cancer du sein est le cancer le plus fréquent chez la femme, notamment au Maroc, avec un taux de mortalité élevé. Les métastases gastro-intestinales d'un carcinome canalaire du sein sont rares. Leur diagnostic est difficile du fait de la nature non spécifique des symptômes. Nous rapportons deux observations originales de métastases gastroduodénales d'un cancer canalaire infiltrant du sein. Les métastases gastro-intestinales du cancer du sein sont très rares; la présence de symptômes gastro-intestinaux chez une malade ayant un antécédent de cancer du sein doit faire suspecter une atteinte métastatique gastro-intestinale. PMID:24198876

  19. Session du Conseil du CERN : le ministre britannique, Robert Jackson, souligne l'intérêt de on pays pour l'avenir du CERN : décisions du Conseil pour la mise en oeuvre des recommandations du Comité d'évaluation du CERN: départ anticipé pour 200 membres au moins du personnel - mise à jour de la méthode de calcule pour les contributions des Etats Membres au budget

    CERN Multimedia

    CERN Press Office. Geneva

    1988-01-01

    Session du Conseil du CERN : le ministre britannique, Robert Jackson, souligne l'intérêt de on pays pour l'avenir du CERN : décisions du Conseil pour la mise en oeuvre des recommandations du Comité d'évaluation du CERN: départ anticipé pour 200 membres au moins du personnel - mise à jour de la méthode de calcule pour les contributions des Etats Membres au budget

  20. Des Taiwanais dans Ie sud du Fujian

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Se trouvant dans le sud-est de la Chine au bord dela mer, la province du Fujian s’appelle aussi toutsimplement "Min". Les anc(?)tres d’une grande partie de lapopulation de Taiwan sont venus du Fujian (Min). Les deux

  1. Chemical Looping Combustion of Solid Fuels in a Laboratory Fluidized-bed Reactor Combustion de charges solides avec la boucle chimique dans un lit fluidisé de laboratoire

    Directory of Open Access Journals (Sweden)

    Leion H.

    2011-02-01

    Full Text Available When using solid fuel in a chemical looping system, the char fraction of the fuel needs to be gasified before syngas react with the oxygen carrier. This can be done inside the fuel reactor with fuel and oxygen carriers well mixed, and, since this gasification is comparably slow, this will be the time limiting step of such a system. An option is to use an oxygen carrier that is able to release gas-phase oxygen which can react with the fuel by normal combustion giving a significantly faster overall fuel conversion. This last option is generally referred to as Chemical Looping combustion with Oxygen Un-coupling (CLOU. In this work, an overview is given of parameters that affect the fuel conversion in laboratory CLC and CLOU experiments. The main factor determining the fuel conversion, in both CLC and CLOU, is the fuel itself. High-volatile fuels are generally more rapidly converted than low volatile fuels. This difference in fuel conversion rate is more pronounced in CLC than in CLOU. However, the fuel conversion is also, both for CLC and CLOU, increased by increasing temperature. Increased steam and SO2 fraction in the surrounding gas will also enhance the fuel conversion in CLC. CO2 gasification in CLC appears to be very slow in comparison to steam gasification. H2 can inhibit fuel gasification in CLC whereas CO did not seem to have any effect. Possible deactivation of oxygen carriers due to SO2 or ash also has to be considered. Lorsque l’on utilise des combustibles solides dans la boucle chimique (CLC pour Chemical Looping Combustion, il est nécessaire de gazéifier le char avant de faire la combustion du gaz de synthèse au contact du transporteur d’oxygène. Ces réactions peuvent s’effectuer dans le réacteur fuel, dans lequel le combustible et le transporteur d’oxygène sont bien mélangés. Cependant, la gazéification du charbon est lente et reste l’étape limitante du processus de combustion dans ces conditions. Une alternative

  2. Le vide univers du tout et du rien

    CERN Document Server

    Diner, Simon

    1997-01-01

    Pourquoi l'Univers plutôt que le vide ? Le temps et l'espace existent-ils en l'absence de l'Univers ? Que reste-t-il quand tout est enlevé ? Pourquoi quelque chose plutôt que rien ? Depuis des siècles, ces interrogations mobilisent philosophes et physiciens. Mais aujourd'hui, le vide n'est pas le rien. Il serait même l'acteur central de l'histoire de la matière et de l'Univers, le partenaire privilégié de la physique. Vide et matière ne sont plus deux manifestations séparées de la nature, mais deux aspects d'une même réalité. Le vide est l'état de base dont la matière émerge, sans couper son cordon ombilical Le vide comme Univers du rien cède la place au vide comme Univers du tout. Que le vide puisse être conçu par les physiciens comme réservoir potentiel d'univers, voici qui ne devrait laisser personne indifférent. Ce livre ouvre un débat et nous convie à une réflexion surprenante.

  3. Image du savoir, image du pouvoir dans le Lapidaire

    Directory of Open Access Journals (Sweden)

    Marta LACOMBA

    2007-01-01

    Full Text Available À travers le prologue et les enluminures de présentation, le Lapidaire d’Alphonse X oriente l’interprétation de l’œuvre. Ces paratextes mettent en avant le rôle capital du savoir, représenté par la métaphore du trésor caché, qui a ici une valeur topique. Ils mettent également en exergue le rôle que s’attribue le roi dans la transmission de ce savoir, et placent cette nouvelle attribution royale au cœur de son projet politique.A través del prólogo y las miniaturas de presentación, el Lapidario de Alfonso X orienta la interpretación de la obra. Estos paratextos subrayan el papel capital del saber, representado por la metáfora del tesoro escondido, que tiene aquí un valor tópico. Ponen asimismo de manifiesto el papel que se atribuye el monarca en la transmisión de ese saber y colocan esta nueva atribución real en el centro de su proyecto político.

  4. Les esclaves du commandant Quiquandon

    OpenAIRE

    Tymowski, Michal

    2003-01-01

    Le 10 janvier 1895, Albert Grodet, gouverneur général du Soudan français, adressa au ministère des Colonies une dépêche accusant le commandant Quiquandon, dirigeant de la région Nord-Est (Ségou), d'exploiter illégalement un domaine sur lequel travaillent 140 esclaves. À partir de ce cas particulier, l'auteur analyse les conflits qui existaient à l'époque entre l'administration civile et un groupe d'officiers soudanais. Il se demande si la possession d'esclaves par des officiers, prenant...

  5. Du comptoir à la toge

    OpenAIRE

    Buti, Gilbert

    2007-01-01

    Descendant d’une famille de petits notables du Dauphiné, Antoine Anthoine (1749-1826) qui n’a pas pu accéder à la magistrature se destine à la marchandise. Après un apprentissage à Marseille au comptoir des Seimandy, il est nommé, par ces négociants, régisseur pour leur commandite de Constantinople. La mobilisation de sa proche parenté et les soutiens des pouvoirs politiques locaux, nationaux et internationaux lui permettent d’obtenir une mission destinée à ouvrir le commerce de la Russie mér...

  6. Aventures radiophoniques du Nouveau Roman

    Directory of Open Access Journals (Sweden)

    Beatrice Nickel

    2015-12-01

    Full Text Available  Aventures radiophoniques du Nouveau Roman Colloque international organisé par l’Université Paul-Valéry Montpellier, en partenariat avec l’Université de Stuttgart 19-20 novembre 2015   Organisateurs :  Pierre-Marie Héron, Annie Pibarot, Université Paul-Valéry Montpellier, centre de recherche Rirra21. Françoise Joly, Beatrice Nickel, Universität Stuttgart 

  7. Description of methods for making activation detectors for use in nuclear reactors; Description des procedes de fabrication des detecteurs d'activation utilises dans les reacteurs nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Barbalat, R.; Le Coguie, R.; Leger, P.; Salon, L.; Thierry, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1968-07-01

    A brief description of methods currently used for making activation detectors, thin films and various deposits used in nuclear reactors. The thicknesses required vary from about a few tenths of a micron to a few tenths of a millimeter. Different techniques are used for fixing the large variety of elements: rolling, moulding, painting, electrolysis, vacuum deposition, thin films, wires, enamels, protective linings, etc. (authors) [French] Expose succinct des procedes actuellement mis en oeuvre pour la realisation des detecteurs d'activation, feuilles minces et depots divers utilises dans les reacteurs nucleaires. La gamme des epaisseurs necessaires s'etendant approximativement des dixiemes de micrometre aux dixiemes de millimetre. La diversite des elements a fixer justifiant les techniques differentes selon les cas: laminage, moulage, peinture, electrolyse, depot sous vide, couches minces, fils, emaux, revetements protecteurs, etc. (auteurs)

  8. Manifold methods for methane combustion

    Energy Technology Data Exchange (ETDEWEB)

    Yang, B.; Pope, S.B. [Cornell Univ., Ithaca, NY (United States)

    1995-10-01

    Great progresses have been made in combustion research, especially, the computation of laminar flames and the probability density function (PDF) method in turbulent combustion. For one-dimensional laminar flames, by considering the transport mechanism, the detailed chemical kinetic mechanism and the interactions between these two basic processes, today it is a routine matter to calculate flame velocities, extinction, ignition, temperature, and species distributions from the governing equations. Results are in good agreement with those obtained for experiments. However, for turbulent combustion, because of the complexities of turbulent flow, chemical reactions, and the interaction between them, in the foreseeable future, it is impossible to calculate the combustion flow field by directly integrating the basic governing equations. So averaging and modeling are necessary in turbulent combustion studies. Averaging, on one hand, simplifies turbulent combustion calculations, on the other hand, it introduces the infamous closure problems, especially the closure problem with chemical reaction terms. Since in PDF calculations of turbulent combustion, the averages of the chemical reaction terms can be calculated, PDF methods overcome the closure problem with the reaction terms. It has been shown that the PDF method is a most promising method to calculate turbulent combustion. PDF methods have been successfully employed to calculate laboratory turbulent flames: they can predict phenomena such as super equilibrium radical levels, and local extinction. Because of these advantages, PDF methods are becoming used increasingly in industry combustor codes.

  9. Spent fuel, plutonium and nuclear waste: long-term management; Le combustible use et le plutonium en tant que dechets nucleaires: gestion a long terme

    Energy Technology Data Exchange (ETDEWEB)

    Collard, G

    1998-11-01

    Different options for the management of nuclear waste arising from the nuclear fuel cycle are discussed. Special emphasis is on reprocessing followed by geological disposal, geological disposal of reprocessing waste, direct geological disposal of spent nuclear fuel, long term storage. Particular emphasis is on the management of plutonium including recycling, immobilisation and disposal, partitioning and transmutation.

  10. The future of the nuclear wastes and the spent fuels at the United States; Le devenir des dechets nucleaires et des combustibles uses aux Etats-Unis

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    The USA regulation distinguishes three classes of nuclear wastes: the low activity wastes under the federal states control, the wastes contaminated by long life radionuclides (transuranic elements) and the high activity wastes. The two last classes are controlled by the DOE (Department of energy). The different classes management are discussed as the DOE obligations towards the operators, the storage project of Yucca Mountain and Private fuel storage of Skull Valley. (A.L.B.)

  11. Physicochemical state of the spent fuel leaving the reactors; Le combustible nucleaire et son etat physico-chimique a la sortie des reacteurs

    Energy Technology Data Exchange (ETDEWEB)

    Dehaut, Ph

    2000-07-01

    This report focuses on the current knowledge, updated at the end of 1999, about the physicochemical state of the fuels leaving light water reactors, and particularly pressurized water reactors. Lessons are withdrawn from it making it possible to determine the points which require a necessary deepening of the data and coherence of interpretations. Lastly, evolution of the sailed fuel rod as well as the potential availability of gases and volatile fission products, during a secular storage or of a multi-millennium disposal, are the subject of an attempt at forecast. Accessible data in the scientific literature, or those acquired at the CEA, are particularly numerous. Their analysis and their synthesis are joined together to constitute a collection of references intended to the specialists in nuclear fuel and for all those which contribute to the reflexion on the storage or final disposal of the irradiated fuel. This memory is structured in ten chapters. The last chapter makes it possible to retain on some pages, the essential lessons of this study. Chapter I: Introduction; Chapter II: Characteristics of assemblies and fuels before irradiation; Chapter III: Transformations in reactor; Chapter IV: State of rods leaving the reactor; Chapter V: State of pellets; Chapter VI: Chemical and structural composition of the fuel; Chapter VII: Fuel fragmentation and density; Chapter VIII: Phenomena at the pellet periphery. Formation, characteristics and structure of the rim.Chemical interaction between pellet and cladding; Chapter IX: Location of fission gases and volatile fission products; Chapter X: Review, lessons and predictions. (authors)

  12. Report on the possibilities of long-term storage of irradiated nuclear fuels; Rapport sur les possibilites d'entreposage a long terme de combustibles nucleaires irradies

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This report aims at giving a legislative aspect to the many rules that govern the activities of the back-end of the fuel cycle in France. These activities concern the unloading of spent nuclear fuels, their reprocessing, storage, recycling and definitive disposal. The following points are reviewed and commented: the management of non-immediately reprocessed fuels (historical reasons of the 'all wastes reprocessing' initial choice, evolution of the economic and political context, the future reprocessing or the definitive disposal of spent fuels in excess); the inevitable long-term storage of part of the spent fuels (quantities and required properties of long-term stored fuels, the eventuality of a definitive disposal of spent fuels); the criteria that long-term storage facilities must fulfill (confinement measures, reversibility, surveillance and control during the whole duration of the storage); storage concept to be retained (increase of storage pools capacity, long-term storage in pools of reprocessing plants, centralized storage in pools, surface dry-storage on power plant sites, reversible underground storage, subsurface storage and storage/disposal in galleries, surface dry-storage facilities); the preliminary studies for the creation of long-term storage facilities (public information, management by a public French organization, clarifying of the conditions of international circulation of spent fuels); problems linked with the presence of foreign spent fuels in France (downstream of the reprocessing cycle, foreign plutonium and wastes re-shipment); conclusions and recommendations. (J.S.)

  13. Combustion & Laser Diagnostics Research Complex (CLDRC)

    Data.gov (United States)

    Federal Laboratory Consortium — Description: The Combustion and Laser Diagnostics Research Complex (CLRDC) supports the experimental and computational study of fundamental combustion phenomena to...

  14. Mission Success for Combustion Science

    Science.gov (United States)

    Weiland, Karen J.

    2004-01-01

    This presentation describes how mission success for combustion experiments has been obtained in previous spaceflight experiments and how it will be obtained for future International Space Station (ISS) experiments. The fluids and combustion facility is a payload planned for the ISS. It is composed of two racks: the fluids Integrated rack and the Combustion INtegrated Rack (CIR). Requirements for the CIR were obtained from a set of combustion basis experiments that served as surrogates for later experiments. The process for experiments that fly on the ISS includes proposal selection, requirements and success criteria definition, science and engineering reviews, mission operations, and postflight operations. By following this process, the microgravity combustion science program has attained success in 41 out of 42 experiments.

  15. Sociologie et sociolinguistique du franbreu

    Directory of Open Access Journals (Sweden)

    Ben-Rafael Eliezer

    2014-07-01

    Full Text Available Des enquêtes ont montré que plus de 20 % des adultes israéliens ont quelque connaissance du français. Parmi cette population, 250 000 à 300 000 personnes pouvaient être considérées comme francophones. Le français a affirmé une présence importante – pas toujours reconnue – dès la phase cruciale du développement de cette société. Une immigration de masse suivit la création de l’État (1948 dont la population a quasiment triplé en moins de deux décennies, avec l’arrivée de plus de 200 000 immigrants d’Afrique du Nord et des dizaines de milliers des Balkans et du Moyen-Orient. Beaucoup parmi ces immigrants étaient francophones – le français étant pour eux soit la première langue soit une deuxième qu’ils contrôlaient. C’est depuis lors que la présence du français est devenue démographiquement significative dans la société israélienne, se prolongeant de nos jours dans l’immigration en provenance de France qui se poursuit jusqu’à aujourd’hui. Comme nous l’avons montré ailleurs (Ben-Rafael et Ben-Rafael 2013, Israël fait l’expérience simultanée de plusieurs francophonies originales qui diffèrent par leurs sources aussi bien que leurs expressions (Ben-Rafael et Ben-Rafael 2013. Un premier modèle est le « français vernaculaire » (voir Boudras-Chapon 2008 amené par les immigrants de classes défavorisées arrivant d’Afrique du nord qui se sont regroupés en Israël. Leur français n’a offert qu’une faible résistance à l’hébreu qui s’est imposée dans le processus d’intégration. Un bilinguisme fonctionnant sur un mode additif au début qui s’est mué progressivement en modèle soustractif. Un second modèle concerne les immigrants de même origine ainsi que des immigrants francophones d’autres pays (pays balkaniques, Turquie ou Egypte formant une strate instruite de classe moyenne, pour qui le français était d’utilisation quotidienne aussi bien que de langue de

  16. Rejets et environnement du CERN

    CERN Document Server

    Vojtyla, P

    2007-01-01

    La radioactivité de l’environnement autour de l’Organisation Européenne pour la Recherche Nucléaire (CERN) et les doses de rayonnements qui en résultent pour la population avoisinante sont contrôlées par la Commission de Sécurité du CERN et de manière indépendante par les autorités compétentes des deux États Hôtes, l’Institut de Radioprotection et de Sûreté Nucléaire (IRSN) côté France et l’Office Fédéral de la Santé Publique (OFSP) côté Suisse (voire Chapitre 8.6). Dans ce rapport, les résultats de mesures concernent en particulier le territoire suisse. L’ensemble des mesures effectuées en 2006 prouve que le fonctionnement des installations du CERN était sans conséquence radiologique sur l’environnement et la population. Le contrôle des émissions montre que les rejets effectifs se situent, également en 2006, nettement en dessous des limites réglementaires. Ce constat est confirmé par le contrôle des immissions dans l’environnement. Le CERN a bien respecté en 2...

  17. Bases en technique du vide

    CERN Document Server

    Rouviere, Nelly

    2017-01-01

    Cette seconde édition, 20 ans après la première, devrait continuer à aider les techniciens pour la réalisation de leur système de vide. La technologie du vide est utilisée, à présent, dans de nombreux domaines très différents les uns des autres et avec des matériels très fiables. Or, elle est souvent bien peu étudiée, de plus, c'est une discipline où le savoir-faire prend tout son sens. Malheureusement la transmission par des ingénieurs et techniciens expérimentés ne se fait plus ou trop rapidement. La technologie du vide fait appel à la physique, à la chimie, à la mécanique, à la métallurgie, au dessin industriel, à l'électronique, à la thermique, etc. Cette discipline demande donc de maîtriser des techniques de domaines très divers, et ce n'est pas chose facile. Chaque installation est en soi un cas particulier avec ses besoins, sa façon de traiter les matériaux et celle d'utiliser les matériels. Les systèmes de vide sont parfois copiés d'un laboratoire à un autre et le...

  18. Report 2000 of EDF nuclear park '' Humans, architects of the progress; Bilan 2000 du parc nucleaire d'EDF ''les hommes, artisans du progres''

    Energy Technology Data Exchange (ETDEWEB)

    Stricker, L.

    2001-03-01

    This report presents the results of the EDF nuclear park, during 2000, in matter of safety, environment and competitiveness. In 2000, the EDF nuclear installations safety still improved. Hopeful the nuclear energy part in its power production, EDF avoids the carbon dioxide diffusion in the atmosphere. EDF also commits itself to reduce the liquid effluents, the gaseous emissions and the solid wastes. At the same time EDF remained competitive with a decrease of the kWh price of 7%. (A.L.B.)

  19. Nuclear systems of the future: international forum generation 4 and research and development projects at the Cea; Systemes nucleaires du futur: forum international generation 4 et projets de R et D du CEA

    Energy Technology Data Exchange (ETDEWEB)

    Carre, F

    2003-07-01

    To advance nuclear energy to meet future energy needs, ten countries have agreed to develop a future generation of nuclear energy systems, known as Generation 4. A technology road map to guide the Generation 4 effort was begun. This document presents the goals for these nuclear systems and the research programs of the Cea on the gas technology, GT-MHR, VHTR and GFR and the other systems as sodium Fast Neutron reactors, supercritical water and space nuclear. (A.L.B.)

  20. The nuclear core of sun: theoretical perspectives and characterization of the scientific performances of the GOLF / SOHO experiment detector; La region nucleaire du soleil: perspectives theoriques et caracterisation des performances scientifiques du detecteur de l`experience GOLF / SOHO

    Energy Technology Data Exchange (ETDEWEB)

    Dzitko, H.

    1995-06-23

    The subject of this thesis is the nuclear core of the sun. The first part is theoretical and concerns neutrino flux predictions. A precise description of the solar plasma is necessary to predict boron, beryllium and CNO cycle neutrinos. We treat here the nuclear reaction rates. They are mainly determined by the cross sections and the enhancement factors due to plasma particles, the co-called screening factors. We have discussed the various possible formalisms that could be used in stellar evolution and performed direct calculations of screened cross sections. We concluded that the screening prescriptions which have been used so far in stellar evolution should be replaced by the Mitler formalism. Next, we examine the cross section uncertainties and we show that it is possible to get a better agreement between theory and experiment. Discrepancies between the gallium experiments and the calculations suggest that we should go beyond the classical solar model. This has motivated our study on possible magnetic fields deeply buried in the solar core. We discuss here the influence of a magnetic pressure perturbation on solar evolution. In the experimental part of this work, we deal with the GOLF experiment, one of the three helio-seismological experiments on board the space probe SOHO. The purpose of this instrument is the study of the global oscillation modes in the frequency range 10{sup -7} to 6 10{sup -3} Hz with a sensitivity for frequencies higher than 2 10{sup -4} Hz of about 1 mm/s over 20 days of continuous integration at counting rates of 12 10{sup 6} cs/s. One part of this work was devoted to the precise characterization of the photomultipliers and their associated electronics in order to select them according to their intrinsic performances. This step was followed by long duration tests of three weeks simulating as well as possible the flight conditions. We show that the detection chain effectively meets the stability requirements of around 10{sup -7} by velocity measurement. (Abstract Truncated)

  1. Reinforced concrete corrosion: application of Bayesian networks to the risk management of cooling towers in nuclear plants; Corrosion du beton arme: application des reseaux bayesiens a la gestion du risque des aerorefrigerants des centrales nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Capra, B.; Le Drogo, J.; Wolff, V. [OXAND S.A., 77 - Avon (France)

    2007-07-01

    Degradation modeling of concrete structures uses uncertain variables and leads, using reliability assessment, to time dependant evolution of failure probabilities. However, only few data are generally available to feed models leading to two types of uncertainties: an intrinsic one depending on the modeled phenomena and one related to the precision of the measurements. Each new data available is a piece of information which allows updating the initial prediction. In this article, an example of updating process, based on a Bayesian network, is presented and applied on the corrosion risk of a cooling tower in a nuclear plant. (authors)

  2. Is the nuclear phaseout compatible with the respect of the Kyoto protocol? The example of Belgium; La sortie du nucleaire est-elle compatible avec le respect du protocole de Kyoto? l'exemple de la Belgique

    Energy Technology Data Exchange (ETDEWEB)

    Berger, A

    2008-12-15

    This document provides data and operations needed to evaluate the impacts of the nuclear phaseout on the respect of the Kyoto protocol. The data are based on the belgium electricity production. The author concludes that the nuclear power plants shutdown will lead to a non respect of the kyoto protocol in unacceptable limits. To respect the protocol, he presents two possibilities: the today nuclear park and the use of 1600 wind turbines of 2 MW, or the improvement of the energy efficiency of the thermal power plants. (A.L.B.)

  3. The first turbulent combustion

    CERN Document Server

    Gibson, C H

    2005-01-01

    The first turbulent combustion arises in a hot big bang cosmological model Gibson (2004) where nonlinear exothermic turbulence permitted by quantum mechanics, general relativity, multidimensional superstring theory, and fluid mechanics cascades from Planck to strong force freeze out scales with gravity balancing turbulent inertial-vortex forces. Interactions between Planck scale spinning and non-spinning black holes produce high Reynolds number turbulence and temperature mixing with huge Reynolds stresses driving the rapid inflation of space. Kolmogorovian turbulent temperature patterns are fossilized as strong-force exponential inflation stretches them beyond the scale of causal connection ct where c is light speed and t is time. Fossil temperature turbulence patterns seed nucleosynthesis, and then hydro-gravitational structure formation in the plasma epoch, Gibson (1996, 2000). Evidence about formation mechanisms is preserved by cosmic microwave background temperature anisotropies. CMB spectra indicate hydr...

  4. De Sumer à Seattle, le voyage du bout du monde

    Directory of Open Access Journals (Sweden)

    Olivier Walther

    2008-12-01

    Full Text Available « Les affaires qui se nouent par-dessus les frontières qui séparent les peuples ne font pas que ces frontières n'existent pas » notait Émile Durkheim en 1895 (1895 : 113. Un peu plus d’un siècle plus tard, l’ouvrage de William J. Bernstein intitulé A Splendid Exchange et sous-titré de manière inspirée How Trade Shaped the World vient apporter une confirmation étayée au sociologue français. De Sumer où fut introduit le commerce du cuivre 3000 ans avant Jésus-Christ, à Seattle où se tint la tr...

  5. Le cas du Haut-Adige ou Tyrol du Sud

    Directory of Open Access Journals (Sweden)

    Licia Bagini Scantamburlo

    2007-06-01

    Full Text Available La situation de cette région italienne est vraiment emblématique des rapports entre « les territoires et l’identité » à cause de la présence de différentes communautés linguistiques autochtones, dont les plus importantes sont les minorités germanophone et latine. S’il est vrai que cette situation existe également dans d’autres régions italiennes, il est incontestable que dans le Haut-Adige/Tyrol du Sud elle présente des caractéristiques très spécifiques et uniques pour l’Italie, car les italo...

  6. COMMUNICATION DU CREDIT AGRICOLE - French version only

    CERN Multimedia

    2003-01-01

    La Direction du Crédit Agricole informe son aimable clientèle du CERN des jours et heures d'ouverture de l'agence du site de Prévessin à compter du mardi 14 janvier 2003 : 1. Horaires pour les opérations bancaires courantes 7 jours sur 7 et 24h/24 avec l'espace libre service bancaire. 2. Horaires conseil du mardi au vendredi - Mardi, de 9h. à 12h. et de 14h.15 à 16h.30. - Mercredi, jeudi et vendredi, de 9h. à 12h. et de 13h.30 à 16h.30. Deux collaboratrices au lieu d'une seront désormais présentes toute la journée du mardi au vendredi pour vous accueillir, vous informer et vous conseiller en crédits et placements (réception conseil sur rendez-vous). Autre nouveauté : les mêmes conseillers seront aussi à votre disposition le samedi, sur notre agence de Gex, de 8h.15 à 13h.05, notamment pour les études de financements habitat. La Direction et toute l'équipe de l'agence du Crédit Agricole vous souhaitent une excellent année 2003.

  7. Filtration combustion: Smoldering and SHS

    Science.gov (United States)

    Matkowsky, Bernard J.

    1995-01-01

    Smolder waves and SHS (self-propagating high-temperature synthesis) waves are both examples of combustion waves propagating in porous media. When delivery of reactants through the pores to the reaction site is an important aspect of the process, it is referred to as filtration combustion. The two types of filtration combustion have a similar mathematical formulation, describing the ignition, propagation and extinction of combustion waves in porous media. The goal in each case, however, is different. In smoldering the desired goal is to prevent propagation, whereas in SHS the goal is to insure propagation of the combustion wave, leading to the synthesis of desired products. In addition, the scales in the two areas of application may well differ. For example, smoldering generally occurs at a relatively low temperature and with a smaller propagation velocity than SHS filtration combustion waves. Nevertheless, the two areas of application have much in common, so that mechanisms learned about in one application can be used to advantage in the other. In this paper we discuss recent results in the areas of filtration combustion.

  8. Combustion Properties of Straw Briquettes

    Directory of Open Access Journals (Sweden)

    Zhao Qing-ling

    2013-05-01

    Full Text Available The low bulk density of straw is one of the major barriers, which blocks the collection, handling, transportation and storage. Densification of biomass into briquettes/pellets is a suitable method of increasing the bulk density of biomass. Yet in the process, a tremendous amount of air is ejected from biomass grind, which brings substantial specific variation including combustion property. Among them, combustion property is critical for proper design and operation of burning facilities. Therefore, a series of tests about combustion properties of 75mm diameter corn briquettes were done. First, the combustion process (ignition, full flaming and glowing phases., precipitation of tar were investigated by a heating stove, then, Some ash sample from the muffle burner was subjected to an ash melting characteristic test. The results show the combustion of briquettes takes more time than that of raw straw from ignition to complete combustion; in order to meet complete combustion in a short time, the raw straw needs more supply air volume than briquettes under the same α value; the temperature of furnace chamber should been controlled under 900°C, which help to reduce the dark smoke, tar and slag.

  9. Approche de prise en charge du trouble du spectre de l’autisme

    Science.gov (United States)

    Lee, Patrick F.; Thomas, Roger E.; Lee, Patricia A.

    2015-01-01

    Résumé Objectif Se pencher sur les critères diagnostiques du trouble du spectre de l’autisme (TSA) comme les définit le Manuel diagnostique et statistique des troubles mentaux, cinquième édition (DSM-V), et concevoir une approche de prise en charge du TSA à l’aide du cadre CanMEDS–Médecine familiale (CanMEDS-MF). Sources d’information Le DSM-V, publié par l’American Psychiatric Association en mai 2013, énonce de nouveaux critères diagnostiques du TSA. Le cadre CanMEDS-MF du Collège des médecins de famille du Canada fournit un plan d’orientation pour la prise en charge complexe du TSA. Nous avons utilisé des données recueillies par le Centers for Disease Control and Prevention afin de déterminer la prévalence du TSA, ainsi que la revue systématique et méta-analyse détaillée effectuée par le National Institute for Health and Care Excellence du R.-U. pour ses lignes directrices sur le TSA dans le but d’évaluer les données probantes issues de plus de 100 interventions. Message principal Selon les données du Centers for Disease Control and Prevention, la prévalence du TSA se chiffrait à 1 sur 88 en 2008 aux États-Unis. La classification du TSA dans la quatrième édition du DSM incluait l’autisme, le syndrome d’Asperger, le trouble envahissant du développement et le trouble désintégratif de l’enfance. La dernière révision du DSM-V réunit tous ces troubles sous la mention TSA, avec différents niveaux de sévérité. La prise en charge du TSA est complexe; elle exige les efforts d’une équipe multidisciplinaire ainsi que des soins continus. Les rôles CanMEDS-MF fournissent un cadre de prise en charge. Conclusion Les médecins de famille sont au cœur de l’équipe de soins multidisciplinaire pour le TSA, et le cadre CanMEDS-MF tient lieu de plan détaillé pour guider la prise en charge d’un enfant atteint de TSA et aider la famille de cet enfant.

  10. Nouvelles du Centre Aéré de l’Association du Personnel du CERN

    CERN Multimedia

    Jardin d'enfants

    2015-01-01

    Cet été 2015, durant quatre semaines d’été, le Centre Aéré a accueilli plus de 40 enfants âgés de 4 à 6 ans. Devant le succès rencontré, et à la demande des parents, il a été décidé d’en doubler la capacité maximale. A l'été 2016, du 4 au 29 juillet, la structure pourra accueillir les enfants de 4 ans révolus et de moins de 7 ans (nés après le 31/07/2009 mais avant  01/07/2012). Les inscriptions se feront à la semaine durant le mois d'Avril 2016. Les programmes sont en cours d'élaboration cependant nous pouvons déjà vous communiquer le thème conducteur du centre qui sera : à la découverte d'un continent différent chaque ...

  11. Catalytic Combustion of Gasified Waste

    Energy Technology Data Exchange (ETDEWEB)

    Kusar, Henrik

    2003-09-01

    This thesis concerns catalytic combustion for gas turbine application using a low heating-value (LHV) gas, derived from gasified waste. The main research in catalytic combustion focuses on methane as fuel, but an increasing interest is directed towards catalytic combustion of LHV fuels. This thesis shows that it is possible to catalytically combust a LHV gas and to oxidize fuel-bound nitrogen (NH{sub 3}) directly into N{sub 2} without forming NO{sub x} The first part of the thesis gives a background to the system. It defines waste, shortly describes gasification and more thoroughly catalytic combustion. The second part of the present thesis, paper I, concerns the development and testing of potential catalysts for catalytic combustion of LHV gases. The objective of this work was to investigate the possibility to use a stable metal oxide instead of noble metals as ignition catalyst and at the same time reduce the formation of NO{sub x} In paper II pilot-scale tests were carried out to prove the potential of catalytic combustion using real gasified waste and to compare with the results obtained in laboratory scale using a synthetic gas simulating gasified waste. In paper III, selective catalytic oxidation for decreasing the NO{sub x} formation from fuel-bound nitrogen was examined using two different approaches: fuel-lean and fuel-rich conditions. Finally, the last part of the thesis deals with deactivation of catalysts. The various deactivation processes which may affect high-temperature catalytic combustion are reviewed in paper IV. In paper V the poisoning effect of low amounts of sulfur was studied; various metal oxides as well as supported palladium and platinum catalysts were used as catalysts for combustion of a synthetic gas. In conclusion, with the results obtained in this thesis it would be possible to compose a working catalytic system for gas turbine application using a LHV gas.

  12. Sylvain Fagot, Le cirque. Entre culture du corps et culture du risque

    OpenAIRE

    Crochet-Giacometti, Nicolas

    2011-01-01

    Cet ouvrage écrit par Sylvain Fagot, chercheur en sociologie associé à l'université du Québec, et auteur d'une thèse soutenue en 2003 intitulée « Ethno-sociologie du cirque. Arts de la piste / Arts du corps / Arts du risque », s'intéresse à un monde peu connu : celui du cirque. L'objectif y est de montrer comment chaque forme du cirque, le cirque dit « classique » et le cirque dit « nouveau », ont des stratégies sociales et économiques différentes mais surtout un rapport au corps et au risque...

  13. On Lean Turbulent Combustion Modeling

    Directory of Open Access Journals (Sweden)

    Constantin LEVENTIU

    2014-06-01

    Full Text Available This paper investigates a lean methane-air flame with different chemical reaction mechanisms, for laminar and turbulent combustion, approached as one and bi-dimensional problem. The numerical results obtained with Cantera and Ansys Fluent software are compared with experimental data obtained at CORIA Institute, France. First, for laminar combustion, the burn temperature is very well approximated for all chemical mechanisms, however major differences appear in the evaluation of the flame front thickness. Next, the analysis of turbulence-combustion interaction shows that the numerical predictions are suficiently accurate for small and moderate turbulence intensity.

  14. Regulation possibilities of biomass combustion

    Science.gov (United States)

    Suzdalenko, Vera; Gedrovics, Martins; Zake, Maija; Barmina, Inesa

    2012-11-01

    The focus of the recent experimental research is to analyze the regulation possibilities of biomass combustion. Three possibilities were chosen as part of this research: a) biomass cofiring with propane, b) swirling flow with re-circulation zone, and c) use of a permanent magnet. The aim of the research is to provide stable, controllable and effective biomass combustion with minimum emissions. The special pilot device was created where biomass can be combusted separately and co-fired with propane. Wood pellets were used during the experiments.

  15. Combustion-gas recirculation system

    Science.gov (United States)

    Baldwin, Darryl Dean

    2007-10-09

    A combustion-gas recirculation system has a mixing chamber with a mixing-chamber inlet and a mixing-chamber outlet. The combustion-gas recirculation system may further include a duct connected to the mixing-chamber inlet. Additionally, the combustion-gas recirculation system may include an open inlet channel with a solid outer wall. The open inlet channel may extend into the mixing chamber such that an end of the open inlet channel is disposed between the mixing-chamber inlet and the mixing-chamber outlet. Furthermore, air within the open inlet channel may be at a pressure near or below atmospheric pressure.

  16. THE COMBUSTION ACTION VERIFICATION AND ESTIMATE OF COMBUSTION EFFICIENCY IN AVIATION GAS#TURBINE ENGINE COMBUSTION CHAMBERS

    OpenAIRE

    2011-01-01

    Verification results of combustion action simulating and estimate of calculation combustion efficiency that was given by simulating were shown. Mathematical model and its assumption are described. Execution calculations method was shown. Results of simulating are shown; their comparative analyses with results of experiment were executed. Accuracy of combustion action mathematical modeling by combustion efficiency in model with oneand two-stage reactions of combustion was estimated. The infere...

  17. Measures for a quality combustion (combustion chamber exit and downstream); Mesures pour une combustion de qualite (sortie de chambre de combustion et en aval)

    Energy Technology Data Exchange (ETDEWEB)

    Epinat, G. [APAVE Lyonnaise, 69 (France)

    1996-12-31

    After a review of the different pollutants related to the various types of stationary and mobile combustion processes (stoichiometric, reducing and oxidizing combustion), measures and analyses than may be used to ensure the quality and efficiency of combustion processes are reviewed: opacimeters, UV analyzers, etc. The regulation and control equipment for combustion systems are then listed, according to the generator capacity level

  18. Computational Modeling of Turbulent Spray Combustion

    NARCIS (Netherlands)

    Ma, L.

    2016-01-01

    The objective of the research presented in this thesis is development and validation of predictive models or modeling approaches of liquid fuel combustion (spray combustion) in hot-diluted environments, known as flameless combustion or MILD combustion. The goal is to combine good physical insight,

  19. Computational Modeling of Turbulent Spray Combustion

    NARCIS (Netherlands)

    Ma, L.

    2016-01-01

    The objective of the research presented in this thesis is development and validation of predictive models or modeling approaches of liquid fuel combustion (spray combustion) in hot-diluted environments, known as flameless combustion or MILD combustion. The goal is to combine good physical insight, a

  20. Chapitre VI. Prudence du financement

    OpenAIRE

    Jambard, Pierre

    2015-01-01

    L’histoire financière de la société permet de comprendre bien des traits de son histoire. Comme toutes les entreprises du bâtiment et des travaux publics, la Société Auxiliaire s’est trouvée devant la nécessité de disposer d’importants capitaux circulants. Grâce à une gestion financière efficace, elle est, en général, parvenue à dégager de son activité les fonds nécessaires, bien que l’aisance de la trésorerie quotidienne n’ait été acquise qu’avec la reconversion. Les années 1927-1946 sont ce...

  1. DU COTÉ DE CHEZ SOI

    OpenAIRE

    Marc Smeets

    2013-01-01

    Le voyage en Hollande, au XIXe siècle, s'inscrit dans une longue tradition où résonnent les notions de liberté, tolérance et commerce, mais il acquiert aussi une spécificité étant donné l’importance que prend la figure du « chez soi » : les Pays-Bas, terre d'agrément où le voyageur français se sent à l'aise et où il aimerait, si possible, vivre. Proust, de ce point de vue-là, ne fait rien de neuf quand il rêve dans la Recherche d'une « vie domestique » en terre batave. Les Pays-Bas, pour le v...

  2. L’abolition du vieillissement

    Directory of Open Access Journals (Sweden)

    Josef Reindl

    2012-02-01

    Full Text Available I « L’humanité vieillit à un rythme inimaginable. (... »« L’humanité vieillit à un rythme inimaginable. Nous devons résoudre le problème de notre propre vieillissement pour résoudre celui du monde entier. » M. Schirrmacher, l’un des intellectuels médiatiques les plus connus de l’Allemagne, joue comme toujours de façon magistrale la partition de l’effroi. Il ne se contente nullement de s’arranger avec son propre vieillissement, mais il veut sauver le monde à travers « une révolution militante...

  3. Sulphite metabolism; Metabolisme du sulfite

    Energy Technology Data Exchange (ETDEWEB)

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

    1960-07-01

    Although the formation of sulphite by micro-organisms was observed as early as 1914 by Neuberg, it was only in 1932 that Nightingale showed it to be present inside cells, in the case of tomato leaf stalks, its formation being due to the reaction: SO{sub 3}H{sup -} + (S{sub 2}O{sub 3}){sub 2}{sup --} {yields} S{sub 2}O{sub 3}{sup --} + O{sub 3}S{sub 2}O{sub 3}{sup --}. The presence of the thiosulphate formed was shown by the high refractive index of its barium salt. Today we have a certain amount of data concerning the formation and use of sulphite in the living cell, even through the knowledge is still incomplete. In this article we will describe and discuss the facts which are known, with particular reference to the oxidation of sulphite. (author) [French] Si la formation de sulfite par des micro-organismes a ete observee des 1914 par Neuberg, sa presence a l'interieur des cellules a ete demontree pour la premiere fois par Nightingale en 1932, dans des tiges et des feuilles de tomates, par la reaction: SO{sub 3}H{sup -} + (S{sub 2}O{sub 3}){sub 2}{sup --} {yields} S{sub 2}O{sub 3}{sup --} + O{sub 3}S{sub 2}O{sub 3}{sup --}. Le thiosulfate forme etait mis en evidence par l'indice de refraction eleve de son sel de baryum. Aujourd'hui on possede un certain nombre de donnees, cependant encore tres incompletes, sur la formation du sulfite et son utilisation par la cellule vivante. Dans cet expose nous decrirons et discuterons quelques-unes de ces acquisitions, tout particulierement celles relatives a l'oxydation du sulfite. (auteur)

  4. Sulphite metabolism; Metabolisme du sulfite

    Energy Technology Data Exchange (ETDEWEB)

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

    1960-07-01

    Although the formation of sulphite by micro-organisms was observed as early as 1914 by Neuberg, it was only in 1932 that Nightingale showed it to be present inside cells, in the case of tomato leaf stalks, its formation being due to the reaction: SO{sub 3}H{sup -} + (S{sub 2}O{sub 3}){sub 2}{sup --} {yields} S{sub 2}O{sub 3}{sup --} + O{sub 3}S{sub 2}O{sub 3}{sup --}. The presence of the thiosulphate formed was shown by the high refractive index of its barium salt. Today we have a certain amount of data concerning the formation and use of sulphite in the living cell, even through the knowledge is still incomplete. In this article we will describe and discuss the facts which are known, with particular reference to the oxidation of sulphite. (author) [French] Si la formation de sulfite par des micro-organismes a ete observee des 1914 par Neuberg, sa presence a l'interieur des cellules a ete demontree pour la premiere fois par Nightingale en 1932, dans des tiges et des feuilles de tomates, par la reaction: SO{sub 3}H{sup -} + (S{sub 2}O{sub 3}){sub 2}{sup --} {yields} S{sub 2}O{sub 3}{sup --} + O{sub 3}S{sub 2}O{sub 3}{sup --}. Le thiosulfate forme etait mis en evidence par l'indice de refraction eleve de son sel de baryum. Aujourd'hui on possede un certain nombre de donnees, cependant encore tres incompletes, sur la formation du sulfite et son utilisation par la cellule vivante. Dans cet expose nous decrirons et discuterons quelques-unes de ces acquisitions, tout particulierement celles relatives a l'oxydation du sulfite. (auteur)

  5. Decree no 2007-1557 from November 2, 2007, relative to basic nuclear facilities and to the nuclear safety control of nuclear materials transport; Decret no 2007-1557 du 2 novembre 2007 relatif aux installations nucleaires de base et au controle, en matiere de surete nucleaire, du transport de substances radioactives

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-11-15

    This decree concerns the enforcement of articles 5, 17 and 36 of the law 2006-686 from June 13, 2006, relative to the transparency and safety in the nuclear domain. A consultative commission of basic nuclear facilities is established. The decree presents the general dispositions relative to basic nuclear facilities, the dispositions relative to their creation and operation, to their shutdown and dismantling. It precises the dispositions in the domain of public utility services, administrative procedures and sanctions. It stipulates also the particular dispositions relative to other facilities located in the vicinity of nuclear facilities, relative to the use of pressure systems, and relative to the transport of radioactive materials. (J.S.)

  6. Decontamination of nuclear liquid wastes using ion exchange. Case of the treatment of the water of the storage pond of the EDF Bugey 1 nuclear reactor; Decontamination d'effluents nucleaires par echange d'ions. Cas du traitement de l'eau de la piscine d'entreposage du reacteur nucleaire EDF Bugey-1

    Energy Technology Data Exchange (ETDEWEB)

    Doury-Berthod, M. [CEA Saclay, 91 - Gif-sur-Yvette (France). Institut National des Sciences et Techniques Nucleaires

    2006-12-15

    The paper explains in detail the works carried out in order to decontaminate before dismantling the water contained in a cooling pond where were stored spent nuclear fuels from the Bugey 1 reactor. The studies included laboratory tests, the design and the operation of pilot and industrial units. The process was based on the use of ion exchange resins on several steps in order to completely fix the contaminating elements, especially cesium, strontium and plutonium.The procedure applied and the detailed results are given. (authors)

  7. Combustion Process Modelling and Control

    Directory of Open Access Journals (Sweden)

    Vladimír Maduda

    2007-10-01

    Full Text Available This paper deals with realization of combustion control system on programmable logic controllers. Control system design is based on analysis of the current state of combustion control systems in technological device of raw material processing area. Control system design is composed of two subsystems. First subsystem is represented by software system for measured data processing and for data processing from simulation of the combustion mathematical model. Outputs are parameters for setting of controller algorithms. Second subsystem consists from programme modules. The programme module is presented by specific control algorithm, for example proportional regulation, programmed proportional regulation, proportional regulation with correction on the oxygen in waste gas, and so on. According to the specific combustion control requirements it is possible built-up concrete control system by programme modules. The programme modules were programmed by Automation studio that is used for development, debugging and testing software for B&R controllers.

  8. Putting combustion optimization to work

    Energy Technology Data Exchange (ETDEWEB)

    Spring, N.

    2009-05-15

    New plants and plants that are retrofitting can benefit from combustion optimization. Boiler tuning and optimization can complement each other. The continuous emissions monitoring system CEMS, and tunable diode laser absorption spectroscopy TDLAS can be used for optimisation. NeuCO's CombustionOpt neural network software can determine optimal fuel and air set points. Babcock and Wilcox Power Generation Group Inc's Flame Doctor can be used in conjunction with other systems to diagnose and correct coal-fired burner performance. The four units of the Colstrip power plant in Colstrips, Montana were recently fitted with combustion optimization systems based on advanced model predictive multi variable controls (MPCs), ABB's Predict & Control tool. Unit 4 of Tampa Electric's Big Bend plant in Florida is fitted with Emerson's SmartProcess fuzzy neural model based combustion optimisation system. 1 photo.

  9. Flameless Combustion for Gas Turbines

    Science.gov (United States)

    Gutmark, Ephraim; Li, Guoqiang; Overman, Nick; Cornwell, Michael; Stankovic, Dragan; Fuchs, Laszlo; Milosavljevic, Vladimir

    2006-11-01

    An experimental study of a novel flameless combustor for gas turbine engines is presented. Flameless combustion is characterized by distributed flame and even temperature distribution for high preheat air temperature and large amount of recirculating low oxygen exhaust gases. Extremely low emissions of NOx, CO, and UHC are reported. Measurements of the flame chemiluminescence, CO and NOx emissions, acoustic pressure, temperature and velocity fields as a function of the preheat temperature, inlet air mass flow rate, exhaust nozzle contraction ratio, and combustor chamber diameter are described. The data indicate that larger pressure drop promotes flameless combustion and low NOx emissions at the same flame temperature. High preheated temperature and flow rates also help in forming stable combustion and therefore are favorable for flameless combustion.

  10. Experimental validation of calculated capture rate for nucleus involved in fuel cycle; Validation experimentale du calcul du taux de capture des noyaux intervenant dans le cycle du combustible

    Energy Technology Data Exchange (ETDEWEB)

    Benslimane-Bouland, A

    1997-09-01

    The framework of this study was the evaluation of the nuclear data requirements for Actinides and Fission Products applied to current nuclear reactors as well as future applications. This last item includes extended irradiation campaigns, 100 % Mixed Oxide fuel, transmutation or even incineration. The first part of this study presents different types of integral measurements which are available for capture rate measurements, as well as the methods used for reactor core calculation route design and nuclear data library validation. The second section concerns the analysis of three specific irradiation experiments. The results have shown the extent of the current knowledge on nuclear data as well as the associated uncertainties. The third and last section shows both the coherency between all the results, and the statistical method applied for nuclear data library adjustment. A relevant application of this method has demonstrated that only specifically chosen integral experiments can be of use for the validation of nuclear data libraries. The conclusion is reached that even if co-ordinated efforts between reactor and nuclear physicists have made possible a huge improvement in the knowledge of capture cross sections of the main nuclei such as uranium and plutonium, some improvements are currently necessary for the minor actinides (Np, Am and Cm). Both integral and differential measurements are recommended to improve the knowledge of minor actinide cross sections. As far as integral experiments are concerned, a set of criteria to be followed during the experimental conception have been defined in order to both reduce the number of required calculation approximations, and to increase as much as possible the maximum amount of extracted information. (author)

  11. Combustion of boron containing compositions

    Energy Technology Data Exchange (ETDEWEB)

    Frolov, Y.; Pivkina, A. [Institute of Chemical Physics, Russian Academy of Science, Moscow (Russian Federation)

    1996-12-31

    Boron is one of the most energetic components for explosives, propellants and for heterogeneous condensed systems in common. The combustion process of mixtures of boron with different oxidizers was studied. The burning rate, concentration combustion limits, the agglomeration and dispersion processes during reaction wave propagation were analysed in the respect of the percolation theory. The linear dependence of the burning rate on the contact surface value was demonstrated. The percolative model for the experimental results explanation is proposed. (authors) 5 refs.

  12. Smoldering Combustion Experiments in Microgravity

    Science.gov (United States)

    Walther, David C.; Fernandez-Pello, A. Carlos; Urban, David L.

    1997-01-01

    The Microgravity Smoldering Combustion (MSC) experiment is part of a study of the smolder characteristics of porous combustible materials in a microgravity environment. Smoldering is a non-flaming form of combustion that takes place in the interior of porous materials and takes place in a number of processes ranging from smoldering of porous insulation materials to high temperature synthesis of metals. The objective of the study is to provide a better understanding of the controlling mechanisms of smolder, both in microgravity and normal-gravity. As with many forms of combustion, gravity affects the availability of oxidizer and transport of heat, and therefore the rate of combustion. Microgravity smolder experiments, in both a quiescent oxidizing environment, and in a forced oxidizing flow have been conducted aboard the NASA Space Shuttle (STS-69 and STS-77 missions) to determine the effect of the ambient oxygen concentration and oxidizer forced flow velocity on smolder combustion in microgravity. The experimental apparatus is contained within the NASA Get Away Special Canister (GAS-CAN) Payload. These two sets of experiments investigate the propagation of smolder along the polyurethane foam sample under both diffusion driven and forced flow driven smoldering. The results of the microgravity experiments are compared with identical ones carried out in normal gravity, and are used to verify present theories of smolder combustion. The results of this study will provide new insights into the smoldering combustion process. Thermocouple histories show that the microgravity smolder reaction temperatures (Ts) and propagation velocities (Us) lie between those of identical normal-gravity upward and downward tests. These observations indicate the effect of buoyancy on the transport of oxidizer to the reaction front.

  13. Daphne du Maurier' unustatud jutud / Udo Uibo

    Index Scriptorium Estoniae

    Uibo, Udo, 1956-

    2011-01-01

    Ajalehe "The Independent" teatel kavatseb kirjastus "Virago" maikuus avaldada Daphne Du Maurier lühiproosa kogumiku "Nukk" (The Doll), mille on koostanud tema loomingu suur austaja Ann Willmore ja mis sisaldab 13 unustatud ja seni avaldamata novelli

  14. Flaubert et Du Camp : quelques remarques

    Directory of Open Access Journals (Sweden)

    Michel Brix

    2016-12-01

    Full Text Available Les spécialistes de Flaubert ont fait de nombreux reproches à Maxime Du Camp et ne prêtent plus guère d’attention à ce qu’il a écrit. C’est une situation très regrettable, qui prive les lecteurs d’informations nombreuses, susceptibles d’éclairer les enjeux mais aussi les impasses et les contradictions du projet esthétique de Flaubert. Quelques cas significatifs sont évoqués dans le présent article, qui se penche plus particulièrement sur la ressemblance entre un passage du livre de Du Camp Le Nil (1854 et les lignes de L’Éducation sentimentale (1869 qui rapportent l’“apparition” de Mme Arnoux.

  15. Inauguration du C/R Forum (Belgique

    Directory of Open Access Journals (Sweden)

    2009-04-01

    Full Text Available Le 16 février dernier, la Vlaamse beroepsvereniging Conservatie en Restauratie Forum (C/R Forum a été constituée à l'initiative de 18 personnes du milieu de la conservation/restauration et du secteur de la protection du patrimoine. Etant donné que la conservation et la gestion du patrimoine culturel mobilier et immobilier de même que la formation et la recherche relèvent des communautés et des régions, la nécessité est apparue depuis un certain temps de créer une organisation Flamande au sei...

  16. Daphne du Maurier' unustatud jutud / Udo Uibo

    Index Scriptorium Estoniae

    Uibo, Udo, 1956-

    2011-01-01

    Ajalehe "The Independent" teatel kavatseb kirjastus "Virago" maikuus avaldada Daphne Du Maurier lühiproosa kogumiku "Nukk" (The Doll), mille on koostanud tema loomingu suur austaja Ann Willmore ja mis sisaldab 13 unustatud ja seni avaldamata novelli

  17. DU-127090 Solvay/H Lundbeck.

    Science.gov (United States)

    Wolf, William

    2003-01-01

    DU-127090 is a mixed dopamine antagonist/serotonin agonist in development by Solvay and H Lundbeck as a potential treatment for psychosis and schizophrenia, for which it is in phase II clinical trials. In August 2002, phase II trials were ongoing and Lundbeck expected to commence phase III trials in 2003 and file an NDA after 2004. DU-127090 is also under development for Parkinson's disease, for which it is in phase I clinical trials.

  18. La fin du risque zéro : du homegrown jihadism au terrorisme du loup solitaire

    Directory of Open Access Journals (Sweden)

    Rémi Baudouï

    2015-09-01

    Full Text Available Le risque zéro représente un moment historique particulier dans la conceptualisation de la socio-politique du risque. Son application repose au début des années 1980 sur l’hypothèse de la possibilité de progresser dans le domaine de l’anticipation et de la gestion sécuritaire des crises potentielles au point de pouvoir prémunir les populations contre toute forme de menace. Il fut employé dans les domaines de la protection civile et de la sécurité militaire. Comme élément de gouvernance politique, il réfutait l’idée selon laquelle le risque existe en préalable comme catégorie d’acceptabilité collective de la menace.

  19. Aux frontières du politique et du religieux

    Directory of Open Access Journals (Sweden)

    Frédéric Sylvanise

    2006-05-01

    Full Text Available The Autobiography of Miss Jane Pittman met en scène de manière spectaculaire deux figures de leadership noir-américain au XIXe siècle (Ned et au XXe siècle (Jimmy. Ned, fils adoptif de Jane Pittman, se rebaptise Professor Douglass en hommage au leader abolitionniste Frederick Douglass. S’il est fondamentalement laïc (il est instituteur, le texte lui confère néanmoins une dimension religieuse, notamment dans le chapitre intitulé « The Sermon at the River » , qui renvoie à la fois à Moïse (le fleuve et à Jésus (le sermon sur la montagne. Abattu par un tueur à gages, Ned est un martyr dont l’histoire était déjà écrite. Le personnage de Jimmy, attendu par toute une communauté comme le messie (alors que lui aussi est un laïc et un homme qui perd la foi, s’inscrit dans la même histoire. Lettré, éloquent et impliqué dans le mouvement pour les droits civils, il est assassiné comme son prédécesseur. Dans les deux cas, le texte lie donc le politique et le biblique comme s’il ne faisait qu’un : être un leader politique, c’est être un preacher et un messie qui guide le peuple. Il est possible de lire l’évocation de ces deux hommes à la lumière d’une certaine actualité. Ned et Jimmy connaissent en effet un sort proche de celui de Malcolm X et de Martin Luther King, récemment assassinés au moment de l’écriture de The Autobiography of Miss Jane Pittman. C’est l’histoire de la répression du leadership noir, au travers du portrait de deux de ses avatars, qui peut donc se lire en creux ici.

  20. Rotary internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Witkowski, J.

    1989-12-05

    This patent describes an internal combustion engine assembly. It includes: a central rotor means formed with at least one peripheral fuel cavity. The cavity having a first surface defining a thrust surface and a second surface defining a contoured surface; a housing means enclosing the rotor and having an internal wall encircling the rotor. The internal wall being intercepted by at least two recesses defining cylinder means. The housing means and the rotor means being relatively rotatable; piston means individual to each the cylinder means and reciprocable therein; each piton means having a working face complementary to aid contoured surface; and power means for urging the working face into intimate areal contact with the contoured surface to create a first seal means. The housing means having at lest one fuel inlet port, at least one fuel ignition means and at least one exhaust port whereby during the course of a revolution of the rotor means relative to the housing means, the first seal means, the power means, the respective ports, the ignition means and the fuel cavity cooperate to develop fuel compression, fuel ignition and exhaust functions.

  1. Internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Laskaris, M.A.; Broitman, K.; Natale, S.E.

    1991-08-27

    This patent describes improvement in a two-stroke internal combustion engine adapted to run on a diesel or a kerosene type of fuel, and including a piston connected to the crankshaft of the engine to move within a cylinder through a first stroke from a top dead center position to a bottom dead center position and through a second stroke from the bottom dead center position back to the top dead center position. The improvement comprises: means providing a cylinder head at the top end of the engine cylinder in the shape of an open bowl having a generally cup-shaped configuration including a sidewall portion, a spark plug positioned centrally within the bowl at the top end of the cylinder, and means for injecting fuel into the top end of the engine cylinder at a location between the spark plug and the sidewall portion, the fuel injecting means including an injection nozzle having a plurality of nozzle openings therein, the nozzle openings being constructed and arranged to discharge a plurality of plume-like sprays into the top end of the cylinder at a location within the bowl, two of the sprays being directed from the nozzle to diverge and pass along opposite sides of the spark plug, and additional sprays being directed from the nozzle against the sidewall portion or the cylinder head to be deflected therefrom back toward the piston and the spark plug to thereby form a cloud of fuel over the spark plug for good ignition.

  2. Perspectives d'amélioration du rendement à très faible charge des moteurs d'automobile Prospects for Lmprovinq the Very-Low-Load Efficiency of Automotive Engines

    Directory of Open Access Journals (Sweden)

    Douaud A.

    2006-11-01

    Full Text Available Le mauvais rendement énergétique des véhicules utilisés à très faible charge (circulation urbaine, vitesses limitées provient entre autres des combustions non optimales. Celles-ci sont de plusieurs types : combustion lente et/ou tardive, ratés de propagation. L'acquisition de cycles de pression au moyen du système DIGITAP développé à l'In-titut Français du Pétrole (IFP est décrite et le calcul instantané du travail cycle-à-cycle permet de définir un critère de stabilité de fonctionnement du moteur. L'analyse thermodynamique des cycles montre que la composition du mélange air + carburant + gaz résiduels, trop proche des limites de propagabilité de flamme, est à l'origine des phénomènes observés. Des voies d'action portant sur les gaz résiduels, la turbulence et les paramètres du système d'allumage sont dégagées et permettent des améliorations importantes du rendement. The poor energy efficiency of vehicles used at very low engine load (urban traffic, limited speeds comes from non-optimum combustion, among other causes. Such combustion may be of several types, i. e. slow and/or late combustion, propagation misfiring. The recording of pressure cycles by the DIGITAP system developed at Institut Français du Pétrole (IFP is described, and the instantaneous computing of the cycle-to-cycle work enables a stability criterion for engine operating to be described. The thermodynamic analysis of the cycles shows that the composition of the air + fuel + residuel gas mixture which is too close to flame propagation limits is at the origin of the phenomena observed. Methods of action concerning residual gases, turbulence and the parameters of the ignition system are determined and make for great improvements in efficiency and stability for such types of running.

  3. Chemical Looping Combustion with Different Types of Liquid Fuels Combustion en boucle chimique avec différentes charges liquides

    Directory of Open Access Journals (Sweden)

    Hoteit A.

    2011-02-01

    Full Text Available CLC is a new promising combustion process for CO2 capture with less or even no energy penalty compared to other processes. Up to now, most of the work performed on CLC was conducted with gaseous or solid fuels, using methane and coal and/or pet coke. Liquid fuels such as heavy fuels resulting from oil distillation or conversion may also be interesting feedstocks to consider. However, liquid fuels are challenging feedstock to deal with in fluidized beds. The objective of the present work is therefore to investigate the feasibility of liquid feed injection and contact with oxygen carrier in CLC conditions in order to conduct partial or complete combustion of hydrocarbons. A batch experimental fluidized bed set-up was developed to contact alternatively oxygen carrier with liquid fuels or air. The 20 mm i.d. fluidized bed reactor was filled up with 45 g of NiAl0.44O1.67 and pulses of 1-2 g of liquid were injected in the bed at high temperatures up to 950˚C. Different feedstocks have been injected, from dodecane to heavy fuel oils No.2. Results show that, during the reduction period, it is possible to convert all the fuel injected and there is no coke remaining on particles at the end of the reduction step. Depending upon oxygen available in the bed, either full combustion or partial combustion can be achieved. Similar results were found with different liquid feeds, despite their different composition and properties. Le CLC est un nouveau concept prometteur appliqué à la combustion qui permet le captage de CO en minimisant la pénalité énergétique liée au captage. Jusqu’à présent, l’essentiel des travaux de recherche dans le domaine du CLC concerne les charges gazeuses (méthane et solides (charbon et coke. Les charges liquides, et particulièrement les résidus pétroliers, sont des charges également intéressantes à considérer a priori. La mise en oeuvre de ces charges en lit fluidisé est cependant délicate. L’objet de ce

  4. Some problems on the aqueous corrosion of structural materials in nuclear engineering; Problemes de corrosion aqueuse de materiaux de structure dans les constructions nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Coriou, H.; Grall, L. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    The purpose of this report is to give a comprehensive view of some aqueous corrosion studies which have been carried out with various materials for utilization either in nuclear reactors or in irradiated fuel treatment plants. The various subjects are listed below. Austenitic Fe-Ni-Cr alloys: the behaviour of austenitic Fe-Ni-Cr alloys in nitric medium and in the presence of hexavalent chromium; the stress corrosion of austenitic alloys in alkaline media at high temperatures; the stress corrosion of austenitic Fe-Ni-Cr alloys in 650 C steam. Ferritic steels: corrosion of low alloy steels in water at 25 and 360 C; zirconium alloys; the behaviour of ultrapure zirconium in water and steam at high temperature. (authors) [French] On presente un ensemble d'etudes de corrosion en milieu aqueux effectuees sur des materiaux utilises, soit dans la construction des reacteurs soit pour la realisation des usines de traitement des combustibles irradies. Les differents sujets etudies sont les suivants. Les alliages austenitiques Fer-Nickel-Chrome: comportement d'alliages austenitiques fer-nickel-chrome en milieu nitrique en presence de chrome hexavalent; Corrosion sous contrainte d'alliages austenitiques dans les milieux alcalins a haute temperature; Corrosion sous contrainte dans la vapeur a 650 C d'alliages austenitiques fer-nickel-chrome. Les aciers ferritiques; Corrosion d'aciers faiblement allies dans l'eau a 25 et 360 C; le zirconium et ses alliages; Comportement du zirconium tres pur dans l'eau et la vapeur a haute temperature. (auteurs)

  5. Baltic states: self-sufficiency through nuclear electricity; Pays Baltes: une independance par le nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Sainte Catherine, C. [CEA/Ambassade de France a Helsinki (Finland)

    2010-07-15

    The Baltic states are connected to the Russian power grid and direct connection to the European grid are scheduled through the ENTSO-E (European Network of Transmission System Operators for Electricity). In end 2009 Lithuania closed its last RBMK reactor on the Ignalina site, this plant provided Lithuania with 70% of its electricity demand. A project of new reactors on the Ignalina site has been considered since 2004 but this complex regional project including Estonia, Latvia but also Poland, lacks momentum to go ahead. Nevertheless, the project shows that a nuclear plant of 3400 MW would be necessary to assure 1000 MW to Poland and 500 MW to Latvia. Latvia has not nuclear plant and produces most of its electricity by hydro-energy and bio-energy (70%) and by natural gas combustion (30%). A share in the construction of the Lithuanian nuclear power plant will allow Latvia to be less dependent on Russian gas imports. The production of electricity of Estonia is based on the burning of oil shale which is very polluting. Estonia has committed itself to use only no-emitting CO{sub 2} energy sources to generate its electricity by 2030. A share in the Lithuanian power plant or in a new nuclear power plant in Finland might be an adequate solution. Since the end of 2008 Estonia authorities are studying the construction of a mid-size reactor whose power output would range between 400 and 900 MW. (A.C.)

  6. The distribution, atmospheric transfer, and assessment of krypton-85; Distribution, transfert atmospherique et bilan du krypton-85

    Energy Technology Data Exchange (ETDEWEB)

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

    1968-06-01

    Techniques for sampling and measuring krypton-85 have been developed which allowed to determine its geographical distribution. From its use as a tracer, an evaluation of the air masses which cross over the subtropical fronts has been derived. Besides, the stratospheric character of air pollution by krypton-85 at the level of the antarctic soil has been shown out. Levels of krypton-85 seem to point out to an underestimation of the assessment of nuclear explosion fission energies as adopted by the United Nations Scientific committee on the effects of atomic radiation and emphasize the need to set limits as soon as possible to the amounts of krypton-85 released to the atmosphere by fuel-reprocessing plants. (author) [French] La mise au point de techniques de prelevement et de mesure du krypton-85 atmospherique a permis de determiner sa repartition geographique. De son utilisation comme traceur on deduit une evaluation des masses d'air qui traversent les fronts subtropicaux. Par ailleurs, le caractere stratospherique de la pollution de l'air par le krypton-85 au niveau du sol antarctique est mis en evidence. Le bilan du krypton-85 semble reveler une sous-estimation du bilan des energies de fission des explosions adopte par le Comite scientifique des Nations Unies et souligne la necessite de limiter des que possible les quantites de krypton-85 rejetees dans l'atmosphere par les usines de traitement de combustibles irradies. (auteur)

  7. Two further years of operation of the reactor G1 (july 1958 - july 1960); Deux nouvelles annees de fonctionnement du reacteur G1. (juillet 1958 - Juillet 1960)

    Energy Technology Data Exchange (ETDEWEB)

    Mathot, P.; Bauzit, J.; Cante, R.; Hebrard, L. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    The aim of the present report is to present certain observations and to give the results obtained during the period from july the 1{sup st} 1958 to july the 1{sup st} 1960. The main operations carried out during this period were, chronologically: - From july the 5{sup th} to october the 18{sup th} 1958: preparation and execution of the first annealing of the graphite. - From dec. the 15{sup th} 1958 to july the 15{sup th} 1959: a discharging campaign which resulted in the complete renewal of the fuel elements. During the monthly stoppages of this campaign, it was possible to make certain observations concerning the packing of the graphite, while at the same time measurements of the temperature of the element cans were made at an increased number of points. - From september the 25{sup th} 1959 to december the 9{sup th} 1959: preparation and execution of the second annealing. At the end of the annealing, the thorium lattice was modified and extra thermocouples were installed for measuring the temperature of the body of the graphite. An apparatus was built for measuring the radial flux. - From december the 9{sup th} 1959 to july 1960: a continuous operation campaign, with a minimum of stoppages. The experimental results are re-assembled, independently of their chronological order, under three main headings which describe the reactors history: - continuous operation, - discharges, - annealing of the reactor. (author) [French] Le but du present rapport est d'exposer certaines observations faites et les resultats obtenus au cours de la periode du 1{sup er} juillet 1958 au 1{sup er} juillet 1960. Cette periode a ete marquee chronologiquement par les operations essentielles suivantes: - du 5 juillet au 18 octobre 1958: preparation et execution du premier recuit du graphite. - du 15 decembre 1958 au 15 juillet 1959: campagne de dechargement entrainant un renouvellement total des cartouches de combustibles. Au cours des arrets mensuels de cette campagne, certaines

  8. Original Paper Performances comparées du HDL-cholestérol et du ...

    African Journals Online (AJOL)

    CT/HDL-C) et du HDL-Cholestérol est le meilleur prédicteur du SMet chez les adultes béninois. L'étude de ..... d'hypertension artérielle avaient observé qu'une ... facteurs tels que l'alimentation et l'activité physique sur les lipides sanguins.

  9. Engagez-vous, devenez délégué(e) du personnel du CERN

    CERN Multimedia

    Staff Association

    2017-01-01

    Dans notre ECHO N° 275, nous avons annoncé les élections à venir au Conseil du personnel du CERN. Dans le présent ECHO, nous vous informons du lancement du processus des élections qui débute par le dépôt des candidatures. Tous les titulaires, boursiers et associés, qui sont aussi membres de l’Association du personnel, peuvent s’engager et déposer leur candidature entre le 11 septembre à 08 h 00 et le 13 octobre 2017 à 17 h 00. N’hésitez plus, remplissez le formulaire de candidature, présentez-vous aux élections au Conseil du personnel afin de pouvoir représenter et défendre vos collègues du personnel du CERN. ÊTRE DÉLÉGUÉ(E), C’EST QUOI ? Poser la question à plusieurs d...

  10. Twenty-second symposium (international) on combustion

    Energy Technology Data Exchange (ETDEWEB)

    1989-01-01

    The following research areas were discussed at the symposium: coal combustion: carbon burnout, pyrolysis, furnaces, laboratory-scale combustion, and fluidized bed combustion; combustion-generated particulates: soot inception, growth, and soot formation in diffusion flames; engine combustion; turbulent combustion: flames in vortices, fractals and cellular automations, nonpremixed flames, premixed flames, premixed flame structure, and lifted flames; reaction kinetics: hydrocarbon oxidation, free radical chemistry, unsaturated species, aromatics, and nitrogen compounds/pollutant formation; combustion generated NO/sub x/ and SO/sub x/; fires: flame spread, radiation, characterization, and unsteady flames; Laminar flames: structure, opposed-flow combustion, shape, propagation/extinction, and inhibition, oscillations, microgravity; ignition; detonations; dusts; propellants; diagnostics; combustion of drops, sprays, and dispersions, and slurries. Individual projects are processed separately for the data bases. (CBS)

  11. Combustion iron distribution and deposition

    Science.gov (United States)

    Luo, Chao; Mahowald, N.; Bond, T.; Chuang, P. Y.; Artaxo, P.; Siefert, R.; Chen, Y.; Schauer, J.

    2008-03-01

    Iron is hypothesized to be an important micronutrient for ocean biota, thus modulating carbon dioxide uptake by the ocean biological pump. Studies have assumed that atmospheric deposition of iron to the open ocean is predominantly from mineral aerosols. For the first time we model the source, transport, and deposition of iron from combustion sources. Iron is produced in small quantities during fossil fuel burning, incinerator use, and biomass burning. The sources of combustion iron are concentrated in the industrialized regions and biomass burning regions, largely in the tropics. Model results suggest that combustion iron can represent up to 50% of the total iron deposited, but over open ocean regions it is usually less than 5% of the total iron, with the highest values (ocean biogeochemistry the bioavailability of the iron is important, and this is often estimated by the fraction which is soluble (Fe(II)). Previous studies have argued that atmospheric processing of the relatively insoluble Fe(III) occurs to make it more soluble (Fe(II)). Modeled estimates of soluble iron amounts based solely on atmospheric processing as simulated here cannot match the variability in daily averaged in situ concentration measurements in Korea, which is located close to both combustion and dust sources. The best match to the observations is that there are substantial direct emissions of soluble iron from combustion processes. If we assume observed soluble Fe/black carbon ratios in Korea are representative of the whole globe, we obtain the result that deposition of soluble iron from combustion contributes 20-100% of the soluble iron deposition over many ocean regions. This implies that more work should be done refining the emissions and deposition of combustion sources of soluble iron globally.

  12. Combustion Byproducts Recycling Consortium

    Energy Technology Data Exchange (ETDEWEB)

    Paul Ziemkiewicz; Tamara Vandivort; Debra Pflughoeft-Hassett; Y. Paul Chugh; James Hower

    2008-08-31

    The Combustion Byproducts Recycling Consortium (CBRC) program was developed as a focused program to remove and/or minimize the barriers for effective management of over 123 million tons of coal combustion byproducts (CCBs) annually generated in the USA. At the time of launching the CBRC in 1998, about 25% of CCBs were beneficially utilized while the remaining was disposed in on-site or off-site landfills. During the ten (10) year tenure of CBRC (1998-2008), after a critical review, 52 projects were funded nationwide. By region, the East, Midwest, and West had 21, 18, and 13 projects funded, respectively. Almost all projects were cooperative projects involving industry, government, and academia. The CBRC projects, to a large extent, successfully addressed the problems of large-scale utilization of CCBs. A few projects, such as the two Eastern Region projects that addressed the use of fly ash in foundry applications, might be thought of as a somewhat smaller application in comparison to construction and agricultural uses, but as a novel niche use, they set the stage to draw interest that fly ash substitution for Portland cement might not attract. With consideration of the large increase in flue gas desulfurization (FGD) gypsum in response to EPA regulations, agricultural uses of FGD gypsum hold promise for large-scale uses of a product currently directed to the (currently stagnant) home construction market. Outstanding achievements of the program are: (1) The CBRC successfully enhanced professional expertise in the area of CCBs throughout the nation. The enhanced capacity continues to provide technology and information transfer expertise to industry and regulatory agencies. (2) Several technologies were developed that can be used immediately. These include: (a) Use of CCBs for road base and sub-base applications; (b) full-depth, in situ stabilization of gravel roads or highway/pavement construction recycled materials; and (c) fired bricks containing up to 30%-40% F

  13. Biokinetics and dosimetry of depleted uranium (DU) in rats implanted with DU fragments.

    Energy Technology Data Exchange (ETDEWEB)

    Guilmette, Ray A.; Hahn, Fletcher F.; Durbin, P. W.

    2004-01-01

    A number of U. S. veterans of the Persian Gulf War were wounded with depleted uranium (DU) metal fragments as a result of 'friendly fire' incidents, in which Abrams tanks and Bradley fighting vehicles were struck by DU anti-armor munitions. Some of the crew members who survived were left with multiple small fragments of DU in their muscles and soft tissues. The number, size and location of the fragments made them inoperable in general, and therefore subject to long-term retention. Because there was inadequate data to predict the potential carcinogenicity of DU fragments in soft tissues, Hahn et al. (2003) conducted a lifespan cancer study in rats. As part of that study, a number of rats were maintained to study the biokinetics and dosimetry of DU implanted intramuscularly in male Wistar rats. Typically, four metal fragments, either as cylindrical pellets or square wafers were implanted into the biceps femoris muscles of the rats. Urine samples were collected periodically during their lifespans, and DU was analyzed in kidneys and eviscerated carcass (minus the implant sites) at death. The daily DU urinary excretion rate increased steeply during the first 30 d after implantation peaking at about 90 d at 3-10 x 10{sup -3}%/d. During the first 150 d, the average excretion rate was 2.4 x 10{sup -3}%/d, decreasing thereafter to about 1 x 10{sup -3}%/d. Serial radiographs were made of the wound sites to monitor gross morphologic changes in the DU implant and the surrounding tissue. As early as 1 w after implantation, radiographs showed the presence of surface corrosion and small, dense bodies near the original implant, presumably DU. This corrosion from the surface of the implant continued with time, but did not result in an increasing amount of DU reaching the blood and urine after the first 3 mo. During this 3-mo period, connective tissue capsules formed around the implants, and are hypothesized to have reduced the access of DU to tissue fluids by limiting the

  14. Comportement du carbone aux joints de grains du molybdène

    OpenAIRE

    1994-01-01

    Pas de résumé en anglais; La mise en évidence et l'interprétation du rôle bénéfique du carbone et du rôle néfaste de l'oxygène sur la cohésion intergranulaire du molybdène en l'absence de précipitation visible au MEB constituaient le but de cette étude. Une méthode efficace de purification du molybdène a été mise au point. Les mesures de la concentration intergranulaire de carbone en fonction de la température de carburation et de la teneur volumique ont été effectuées à l'aide d'un spectromè...

  15. Modélisation de la combustion dans un moteur diesel d'automobile

    Science.gov (United States)

    Pinchon, Philippe

    La plupart des moteurs diesels utilisés pour la traction des véhicules automobiles sont des moteurs à préchambre. Le combustible y est introduit sous forme liquide, à haute pression, se vaporise, auto-inflamme et brûle dans un espace confiné dans lequel règnent des vitesses d'écoulement très élevées. La vitesse de combustion, et donc le rendement du moteur, sont très sensibles à divers paramètres liés à l'injection ou à la géométrie de la chambre. Cette dernière joue un rôle prédominant sur l'aérodynamique interne et son interaction avec la propagation de la flamme.

  16. Subgrid Combustion Modeling for the Next Generation National Combustion Code

    Science.gov (United States)

    Menon, Suresh; Sankaran, Vaidyanathan; Stone, Christopher

    2003-01-01

    In the first year of this research, a subgrid turbulent mixing and combustion methodology developed earlier at Georgia Tech has been provided to researchers at NASA/GRC for incorporation into the next generation National Combustion Code (called NCCLES hereafter). A key feature of this approach is that scalar mixing and combustion processes are simulated within the LES grid using a stochastic 1D model. The subgrid simulation approach recovers locally molecular diffusion and reaction kinetics exactly without requiring closure and thus, provides an attractive feature to simulate complex, highly turbulent reacting flows of interest. Data acquisition algorithms and statistical analysis strategies and routines to analyze NCCLES results have also been provided to NASA/GRC. The overall goal of this research is to systematically develop and implement LES capability into the current NCC. For this purpose, issues regarding initialization and running LES are also addressed in the collaborative effort. In parallel to this technology transfer effort (that is continuously on going), research has also been underway at Georgia Tech to enhance the LES capability to tackle more complex flows. In particular, subgrid scalar mixing and combustion method has been evaluated in three distinctly different flow field in order to demonstrate its generality: (a) Flame-Turbulence Interactions using premixed combustion, (b) Spatially evolving supersonic mixing layers, and (c) Temporal single and two-phase mixing layers. The configurations chosen are such that they can be implemented in NCCLES and used to evaluate the ability of the new code. Future development and validation will be in spray combustion in gas turbine engine and supersonic scalar mixing.

  17. DU COTÉ DE CHEZ SOI

    Directory of Open Access Journals (Sweden)

    Marc Smeets

    2013-12-01

    Full Text Available Le voyage en Hollande, au XIXe siècle, s'inscrit dans une longue tradition où résonnent les notions de liberté, tolérance et commerce, mais il acquiert aussi une spécificité étant donné l’importance que prend la figure du « chez soi » : les Pays-Bas, terre d'agrément où le voyageur français se sent à l'aise et où il aimerait, si possible, vivre. Proust, de ce point de vue-là, ne fait rien de neuf quand il rêve dans la Recherche d'une « vie domestique » en terre batave. Les Pays-Bas, pour le voyageur français au XIXe, c'est le home sweet home.

  18. Turbulent Combustion in SDF Explosions

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, A L; Bell, J B; Beckner, V E

    2009-11-12

    A heterogeneous continuum model is proposed to describe the dispersion and combustion of an aluminum particle cloud in an explosion. It combines the gas-dynamic conservation laws for the gas phase with a continuum model for the dispersed phase, as formulated by Nigmatulin. Inter-phase mass, momentum and energy exchange are prescribed by phenomenological models. It incorporates a combustion model based on the mass conservation laws for fuel, air and products; source/sink terms are treated in the fast-chemistry limit appropriate for such gasdynamic fields, along with a model for mass transfer from the particle phase to the gas. The model takes into account both the afterburning of the detonation products of the C-4 booster with air, and the combustion of the Al particles with air. The model equations were integrated by high-order Godunov schemes for both the gas and particle phases. Numerical simulations of the explosion fields from 1.5-g Shock-Dispersed-Fuel (SDF) charge in a 6.6 liter calorimeter were used to validate the combustion model. Then the model was applied to 10-kg Al-SDF explosions in a an unconfined height-of-burst explosion. Computed pressure histories are compared with measured waveforms. Differences are caused by physical-chemical kinetic effects of particle combustion which induce ignition delays in the initial reactive blast wave and quenching of reactions at late times. Current simulations give initial insights into such modeling issues.

  19. Explosion limits for combustible gases

    Institute of Scientific and Technical Information of China (English)

    TONG Min-ming; WU Guo-qing; HAO Ji-fei; DAI Xin-lian

    2009-01-01

    Combustible gases in coal mines are composed of methane, hydrogen, some multi-carbon alkane gases and other gases. Based on a numerical calculation, the explosion limits of combustible gases were studied, showing that these limits are related to the concentrations of different components in the mixture. With an increase of C4H10 and C6H14, the Lower ExplosionLimit (LEL) and Upper Explosion-Limit (UEL) of a combustible gas mixture will decrease clearly. For every 0.1% increase in C4H10 and C6H14, the LEL decreases by about 0.19% and the UEL by about 0.3%. The results also prove that, by increasing the amount of H2, the UEL of a combustible gas mixture will increase considerably. If the level of H2 increases by 0.1%, the UEL will increase by about 0.3%. However, H2 has only a small effect on the LEL of the combustible gas mixture. Our study provides a theoretical foundation for judging the explosion risk of an explosive gas mixture in mines.

  20. New Combustion Regimes and Kinetic Studies of Plasma Assisted Combustion

    Science.gov (United States)

    2012-11-01

    Tasks 8 and 9: Kinetic model validation) Today’s Presentation 2. Multispecies diagnostics in a flow reactor with Mid-IR and molecular beam mass...S-Curve Competition between low T RO2 kinetics high T chain branching reactions 0.00 0.02 0.04 0.06 0.08 0.10 0.12 1x10 5 2x10 5 3x10 5 4x10...in Plasma assisted combustion • LTC in turbulent combustion at engine time scales 0-D modeling of DME /O2/He (0.03/0.1/0.896) ignition, P = 72

  1. A comprehensive fractal char combustion model☆

    Institute of Scientific and Technical Information of China (English)

    Yuting Liu; Rong He

    2016-01-01

    The char combustion mechanisms were analyzed and a comprehensive fractal char combustion model was developed to give a better understanding and better predictions of the char combustion characteristics. Most of the complex factors affecting the char combustion were included, such as the coupling effects between the pore diffusion and the chemical reactions, the evolution of the char pore structures and the variation of the apparent reaction order during combustion, the CO/CO2 ratio in the combustion products and the correction for oxy-char combustion. Eleven different chars were then combusted in two drop tube furnaces with the conversions of the partly burned char samples measured by thermogravimetric analysis. The combustion processes of these chars were simulated with the predicted char conversions matching very well with the measured data which shows that this char combustion model has good accuracy. The apparent reaction order of the char combustion decreases, stabilizes and then increases during the combustion process. The combustion rates in the oxy-mode are general y slower than in the air-mode and the effect of the char-CO2 gasification reac-tion becomes obvious only when the temperature is relatively high and the O2 concentration is relatively low.

  2. Cirque du Monde as a health intervention

    Science.gov (United States)

    Fournier, Cynthia; Drouin, Mélodie-Anne; Marcoux, Jérémie; Garel, Patricia; Bochud, Emmanuel; Théberge, Julie; Aubertin, Patrice; Favreau, Gil; Fleet, Richard

    2014-01-01

    Abstract Objective To present Cirque du Soleil’s social circus program, Cirque du Monde, to explore its potential as a primary health care tool for family physicians. Data sources A review of the literature in PubMed, the Cochrane Library, PsycINFO, LaPresse, Eureka, Google Scholar, and Érudit using the key words circus, social circus, Cirque du Monde, and Cirque du Soleil; a Montreal-based initiative, Espace Transition, modeled on Cirque du Monde; and personal communication with Cirque du Soleil’s Social Circus Training Advisor. Study selection The first 50 articles or websites identified for each key word in each of the databases were examined on the basis of their titles and abstracts in the case of articles, and on the basis of their titles and page content in the case of websites. Articles and websites that explored an aspect of social circuses or that described an intervention that involved circuses were then retained for analysis. Because all literature on social circuses was searched, no criterion for year of publication was used. Synthesis No articles on the social circus as a health intervention were found. One study on the use of the circus as an intervention in schools was identified. It demonstrated an increase in self-esteem in the children who took part. One study on the use of the circus in a First Nations community was found; it contained nonspecific, qualitative findings. The other articles identified were merely descriptions of social circuses. One website was identified on the use of the social circus to help youth who had been treated in a hospital setting for major psychiatric disorders to re-enter the community. The team in the pediatric psychiatry department at Centre Hospitalier Universitaire Sainte-Justine, the children’s hospital in Montreal, Que, was contacted; they were leading this project, called Espace Transition. The unpublished preliminary findings of its pilot project demonstrate substantial improvements in overall patient

  3. Novel Active Combustion Control Valve

    Science.gov (United States)

    Caspermeyer, Matt

    2014-01-01

    This project presents an innovative solution for active combustion control. Relative to the state of the art, this concept provides frequency modulation (greater than 1,000 Hz) in combination with high-amplitude modulation (in excess of 30 percent flow) and can be adapted to a large range of fuel injector sizes. Existing valves often have low flow modulation strength. To achieve higher flow modulation requires excessively large valves or too much electrical power to be practical. This active combustion control valve (ACCV) has high-frequency and -amplitude modulation, consumes low electrical power, is closely coupled with the fuel injector for modulation strength, and is practical in size and weight. By mitigating combustion instabilities at higher frequencies than have been previously achieved (approximately 1,000 Hz), this new technology enables gas turbines to run at operating points that produce lower emissions and higher performance.

  4. Établissements recevant du public

    CERN Document Server

    2014-01-01

    Synthèse pour les installations électriques, des règles de sécurité contre les risques d’incendie et de panique dans les établissements recevant du public (ERP), selon l’arrêté du 25 juin 1980 modifié. L'ouvrage traite à la fois des dispositions communes aux établissements du 1er groupe (1ère à 4ème catégorie), du 2ème groupe (5ème catégorie) et des règles particulières applicables aux différents types d'établissements (structures d'accueil pour personnes âgées ou handicapées, hôtels, magasins de vente, restaurants et débit de boisson, établissements de soins, administration, châpiteaux, etc...) Sont ainsi notamment traités, dans le cadre des dispositions communes aux établissements du 1er groupe, pour les installations électriques normales : les installations des appareils, tableaux et canalisations, les locaux électriques et installation de machines, l'éclairage normal des locaux accessibles au public, le chauffage et la ventilation, l'installation d'eau chaude sanita...

  5. L’internationalisation du roman arabe

    Directory of Open Access Journals (Sweden)

    Dr Dalia Khraibani

    2016-09-01

    Full Text Available La littérature arabe est presque invisible dans l’espace littéraire mondiale pour des raisons diverses. Pourtant, des écrivains réussissent à s’imposer sur la scène littéraire internationale et leurs œuvres deviennent des chefs d’œuvre de la littérature mondiale. Parmi ces écrivains, nous citons Tayeb Saleh qui connaît un succès international surtout avec la parution de son second roman "Saison de migration vers le Nord". Notre étude vise à montrer comment ce roman par son contenu et sa forme, occupe une place de choix dans la littérature mondiale. En effet, nous allons examiner le contexte historique de l’émergence du roman qui joue un rôle dans sa diffusion au niveau mondial. L’une des clés de réussite du roman est la technique narrative qui retient l’haleine du lecteur dès la première page. De plus, le roman répond à l’horizon d’attente du lectorat occidental en représentant des images particulières de la société arabo-africaine qui correspondent aux stéréotypes et clichés du public occidental vis-à-vis des Arabes.

  6. Influence du pH, d'acides aminés et de diverses substances organiques sur la fongitoxicité du pyriméthanil, du glufosinate, du captafol, du cymoxanil et du fenpiclonil vis-à-vis de certaines souches de Botrytis cinerea

    OpenAIRE

    1994-01-01

    L’effet du pyriméthanil, du fenpiclonil, du captafol, du glufosinate et du cymoxanil sur l’élongation des filaments germinatifs des spores de Botrytis cinerea est étudié dans diverses conditions culturales du champignon. Si le fenpiclonil présente un niveau d’activité stable entre pH 3,6 et 7,3, en revanche les autres pesticides voient leur toxicité chuter dans des milieux acides (ex pyriméthanil) ou neutres à faiblement basiques (ex captafol, cymoxanil, glufosinate). L’adjonction d’extrait d...

  7. De Gainsborough à Turner : l'âge d'or du paysage et du portrait anglais dans les collections du musée du Louvre

    OpenAIRE

    Adrien, Muriel

    2015-01-01

    L’exposition De Gainsborough à Turner : l'âge d'or du paysage et du portrait anglais dans les collections du musée du Louvre co-organisée par le Musée du Louvre, le Musée d’Art et d’Archéologie de Valence et le Musée des Beaux-arts de Quimper présentait une sélection de 35 peintures de la collection du Louvre, complétée par 38 dessins du département des Arts Graphiques. Les commissaires de l'exposition étaient : Guillaume Faroult, conservateur en charge des peintures françaises du 18ème siècl...

  8. Combustion synthesis method and products

    Science.gov (United States)

    Holt, J.B.; Kelly, M.

    1993-03-30

    Disclosed is a method of producing dense refractory products, comprising: (a) obtaining a quantity of exoergic material in powder form capable of sustaining a combustion synthesis reaction; (b) removing absorbed water vapor therefrom; (c) cold-pressing said material into a formed body; (d) plasma spraying said formed body with a molten exoergic material to form a coat thereon; and (e) igniting said exoergic coated formed body under an inert gas atmosphere and pressure to produce self-sustained combustion synthesis. Also disclosed are products produced by the method.

  9. Chemical kinetics and combustion modeling

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J.A. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    The goal of this program is to gain qualitative insight into how pollutants are formed in combustion systems and to develop quantitative mathematical models to predict their formation rates. The approach is an integrated one, combining low-pressure flame experiments, chemical kinetics modeling, theory, and kinetics experiments to gain as clear a picture as possible of the process in question. These efforts are focused on problems involved with the nitrogen chemistry of combustion systems and on the formation of soot and PAH in flames.

  10. Fundamentals of premixed turbulent combustion

    CERN Document Server

    Lipatnikov, Andrei

    2012-01-01

    Lean burning of premixed gases is considered to be a promising combustion technology for future clean and highly efficient gas turbine engines. This book highlights the phenomenology of premixed turbulent flames. The text provides experimental data on the general appearance of premixed turbulent flames, physical mechanisms that could affect flame behavior, and physical and numerical models aimed at predicting the key features of premixed turbulent combustion. The author aims to provide a simple introduction to the field for advanced graduate and postgraduate students. Topics covered include La

  11. Autodesk Combustion 4 fundamentals courseware

    CERN Document Server

    Autodesk,

    2005-01-01

    Whether this is your first experience with Combustion software or you're upgrading to take advantage of the many new features and tools, this guide will serve as your ultimate resource to this all-in-one professional compositing application. Much more than a point-and-click manual, this guide explains the principles behind the software, serving as an overview of the package and associated techniques. Written by certified Autodesk training specialists for motion graphic designers, animators, and visual effects artists, Combustion 4 Fundamentals Courseware provides expert advice for all skill le

  12. Free Energy and Internal Combustion Engine Cycles

    CERN Document Server

    Harris, William D

    2012-01-01

    The performance of one type (Carnot) of Internal Combustion Engine (ICE) cycle is analyzed within the framework of thermodynamic free energies. ICE performance is different from that of an External Combustion Engine (ECE) which is dictated by Carnot's rule.

  13. Scramjet Combustion Stability Behavior Modeling Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A recent breakthrough in combustion stability analysis (UCDS) offers the means to accurately predict the combustion stability of a scramjet. This capability is very...

  14. Scramjet Combustion Stability Behavior Modeling Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A recent breakthrough in combustion stability analysis (UCDS) offers the potential to predict the combustion stability of a scramjet. This capability is very...

  15. Analyse énonciative du point du vue, narration et analyse de discours

    Directory of Open Access Journals (Sweden)

    Alain Rabatel

    2007-01-01

    Full Text Available Cet article montre que l’analyse énonciative du point de vue (PDV, en rupture avec la typologie des focalisations de Genette, peut renouveler partiellement la narratologie, à la condition de substituter à l’approche immanentiste du récit une analyse interactionnelle de la narration. L’article présente d’abord l’approche énonciative du PDV, en appui des théories de Ducrot, et, sur cette base, propose diverses modalités de PDV (représenté, raconté, asserté qui donnent corps au point de vue des personnages ou du narrateur en modifiant sensiblement les analyses de Genette. Dans une deuxième partie, l’article envisage le rôle des PDV dans la narration, notamment dans la réévaluation des dimensions cognitive et pragmatique de la mimésis, puis dans les mécanismes inférentiels-interprétatifs, proches du système de sympathie de Jouve, enfin, dans la revalorisation du rôle du narrateur •puisque ce dernier se construit dans le même temps qu’il construit ses personnages.

  16. Development of a Premixed Combustion Capability for Scramjet Combustion Experiments

    Science.gov (United States)

    Rockwell, Robert D.; Goyne, Christopher P.; Rice, Brian E.; Chelliah, Harsha; McDaniel, James C.; Edwards, Jack R.; Cantu, Luca M. L.; Gallo, Emanuela C. A.; Cutler, Andrew D.; Danehy, Paul M.

    2015-01-01

    Hypersonic air-breathing engines rely on scramjet combustion processes, which involve high speed, compressible, and highly turbulent flows. The combustion environment and the turbulent flames at the heart of these engines are difficult to simulate and study in the laboratory under well controlled conditions. Typically, wind-tunnel testing is performed that more closely approximates engine testing rather than a careful investigation of the underlying physics that drives the combustion process. The experiments described in this paper, along with companion data sets being developed separately, aim to isolate the chemical kinetic effects from the fuel-air mixing process in a dual-mode scramjet combustion environment. A unique fuel injection approach is taken that produces a nearly uniform fuel-air mixture at the entrance to the combustor. This approach relies on the precombustion shock train upstream of the dual-mode scramjet combustor. A stable ethylene flame anchored on a cavity flameholder with a uniformly mixed combustor inflow has been achieved in these experiments allowing numerous companion studies involving coherent anti-Stokes Raman scattering (CARS), particle image velocimetry (PIV), and planar laser induced fluorescence (PLIF) to be performed.

  17. Science et technologie du collage

    CERN Document Server

    Cognard, Jacques

    2003-01-01

    L'Homme a su coller avant de savoir écrire et compter. Le collage est en effet l'une des premières techniques d'assemblage d'une structure que l'homme ait utilisée, technique qui n'est devenue science qu'au début du 20e siècle avec la fabrication des premières colles synthétiques. Cette science de l'adhésion a considérablement progressé ces dix dernières années et ce livre présente l'état actuel des connaissances en décrivant les progrès considérables réalisés dans la compréhension des phénomènes fondamentaux qui font qu'un collage tient bien et durablement. Après l'exposé des bases scientifiques nécessaires et des modèles théoriques récents, l'auteur introduit la distinction entre collages faibles et collages forts puis expose les difficultés rencontrées dans les cas pratiques, difficultés souvent dues à la complexité de la chimie des surfaces et des réactions surface-polymère. L'ouvrage se termine par la présentation de quelques applications récentes, en particulier dans...

  18. High Frequency Combustion Instabilities of LOx/CH4 Spray Flames in Rocket Engine Combustion Chambers

    NARCIS (Netherlands)

    Sliphorst, M.

    2011-01-01

    Ever since the early stages of space transportation in the 1940’s, and the related liquid propellant rocket engine development, combustion instability has been a major issue. High frequency combustion instability (HFCI) is the interaction between combustion and the acoustic field in the combustion c

  19. High Frequency Combustion Instabilities of LOx/CH4 Spray Flames in Rocket Engine Combustion Chambers

    NARCIS (Netherlands)

    Sliphorst, M.

    2011-01-01

    Ever since the early stages of space transportation in the 1940’s, and the related liquid propellant rocket engine development, combustion instability has been a major issue. High frequency combustion instability (HFCI) is the interaction between combustion and the acoustic field in the combustion c

  20. Combustion Chemistry Diagnostics for Cleaner Processes.

    Science.gov (United States)

    Kohse-Höinghaus, Katharina

    2016-09-12

    Climate change, environmental problems, urban pollution, and the dependence on fossil fuels demand cleaner, renewable energy strategies. However, they also ask for urgent advances in combustion science to reduce emissions. For alternative fuels and new combustion regimes, crucial information about the chemical reactions from fuel to exhaust remains lacking. Understanding such relations between combustion process, fuel, and emissions needs reliable experimental data from a wide range of conditions to provide a firm basis for predictive modeling of practical combustion processes.

  1. Simulation study on combustion of biomass

    Science.gov (United States)

    Zhao, M. L.; Liu, X.; Cheng, J. W.; Liu, Y.; Jin, Y. A.

    2017-01-01

    Biomass combustion is the most common energy conversion technology, offering the advantages of low cost, low risk and high efficiency. In this paper, the transformation and transfer of biomass in the process of combustion are discussed in detail. The process of furnace combustion and gas phase formation was analyzed by numerical simulation. The experimental results not only help to optimize boiler operation and realize the efficient combustion of biomass, but also provide theoretical basis for the improvement of burner technology.

  2. Les métamorphoses du pouvoir

    OpenAIRE

    Adler, Alfred

    2004-01-01

    On sait que la sorcellerie en Afrique peut s'exercer du faible au fort ou l'inverse. Les situations qui sont ici analysées sont celles où les rois ou les chefs sont expressément désignés comme sorciers, soit qu'ils le deviennent du fait même de leur investiture, soit qu'il leur ait fallu le devenir pour accéder au pouvoir et le conserver face à des rivaux usant des mêmes moyens. Quoi qu'il en soit, un roi-sorcier offre une figure paradoxale du pouvoir, et cela doublement : garant de l'...

  3. Au fond de la logique du lieu.

    Directory of Open Access Journals (Sweden)

    Augustin Berque

    2009-03-01

    Full Text Available L’école de Kyôto ( Kyôto gakuha est cette mouvance philosophique, née dans l’entre-deux-guerres, dont le Nihonshi jiten ( Dictionnaire historique du Japon des éditions Iwanami donne la présentation suivante : 1 École centrée sur la Faculté de philosophie de l’Université de Kyôto dans les années Taishô et Shôwa. Elle débuta autour de Nishida Kitarô et de Tanabe Hajime, mais on la connaît plutôt du fait que peu après le début de la guerre du Pacifique, en 1942, ...

  4. Method and device for diagnosing and controlling combustion instabilities in internal combustion engines operating in or transitioning to homogeneous charge combustion ignition mode

    Science.gov (United States)

    Wagner, Robert M [Knoxville, TN; Daw, Charles S [Knoxville, TN; Green, Johney B [Knoxville, TN; Edwards, Kevin D [Knoxville, TN

    2008-10-07

    This invention is a method of achieving stable, optimal mixtures of HCCI and SI in practical gasoline internal combustion engines comprising the steps of: characterizing the combustion process based on combustion process measurements, determining the ratio of conventional and HCCI combustion, determining the trajectory (sequence) of states for consecutive combustion processes, and determining subsequent combustion process modifications using said information to steer the engine combustion toward desired behavior.

  5. Oncoplastie avec conservation mammaire dans le traitement du cancer du sein: à propos de 16 cas

    OpenAIRE

    2015-01-01

    Le cancer du sein est actuellement le cancer le plus fréquent chez la femme, et pose un véritable problème diagnostique et thérapeutique. Le dépistage des lésions à un stade de plus en plus précoce, a permis une extension des indications du traitement conservateur radiochirurgical, qui était initialement limitées aux tumeurs de moins de 3 cm, unifocales, non inflammatoires. Par ailleurs, l'utilisation de traitements préopératoires permet d’étendre les indications du traitement conservateur à ...

  6. Combustor nozzle for a fuel-flexible combustion system

    Science.gov (United States)

    Haynes, Joel Meier [Niskayuna, NY; Mosbacher, David Matthew [Cohoes, NY; Janssen, Jonathan Sebastian [Troy, NY; Iyer, Venkatraman Ananthakrishnan [Mason, OH

    2011-03-22

    A combustor nozzle is provided. The combustor nozzle includes a first fuel system configured to introduce a syngas fuel into a combustion chamber to enable lean premixed combustion within the combustion chamber and a second fuel system configured to introduce the syngas fuel, or a hydrocarbon fuel, or diluents, or combinations thereof into the combustion chamber to enable diffusion combustion within the combustion chamber.

  7. 30 CFR 56.4104 - Combustible waste.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Combustible waste. 56.4104 Section 56.4104... Control Prohibitions/precautions/housekeeping § 56.4104 Combustible waste. (a) Waste materials, including... properly, waste or rags containing flammable or combustible liquids that could create a fire hazard shall...

  8. Straw combustion on slow-moving grates

    DEFF Research Database (Denmark)

    Kær, Søren Knudsen

    2005-01-01

    Combustion of straw in grate-based boilers is often associated with high emission levels and relatively poor fuel burnout. A numerical grate combustion model was developed to assist in improving the combustion performance of these boilers. The model is based on a one-dimensional ‘‘walking...

  9. The ``SILVA`` program; Le cycle du combustible (evolution des techniques d`enrichissement isotopique)

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, M.

    1996-12-31

    The ``SILVA`` process (Uranium Atomic Vapor Laser Isotopic Separation) is an innovating system of enriched uranium (electronuclear reactors fuel) production. Its great interest comes from its selectivity. The aim is to divide by a factor of three the costs of production compared with those of the current plants. The stakes of this research program, its principle, the main research axis, the material means and the future prospects beyond 1997 are given as well as its technical advancement state. (O.M.).

  10. Optimisation de la gestion du combustible dans les reacteurs CANDU refroidis a l'eau legere

    Science.gov (United States)

    Chambon, Richard

    This research has two main goals. First, we wanted to introduce optimization tools in the diffusion code DONJON, mostly for fuel management. The second objective is more practical. The optimization capabilities are applied to the fuel management problem for different CANDU reactors at refueling equilibrium state. Two kinds of approaches are considered and implemented in this study to solve optimization problems in the code DONJON. The first methods are based on gradients and on the quasi-linear mathematical programming. The method initially developed in the code OPTEX is implemented as a reference approach for the gradient based methods. However, this approach has a major drawback. Indeed, the starting point has to be a feasible point. Then, several approaches have been developed to be more general and not limited by the initial point choice. Among the different methods we developed, two were found to be very efficient: the multi-step method and the mixte method. The second kind of approach are the meta-heuristic methods. We implemented the tabu search method. Initially, it was designed to optimize combinatory variable problems. However, we successfully used it for continuous variables. The major advantage of the tabu method over the gradient methods is the capability to exit from local minima. Optimisation of the average exit burnup has been performed for CANDU-6 and ACR-700 reactors. The fresh fuel enrichment has also been optimized for ACR-700. Results match very well what the reactor physics can predict. Moreover, a comparison of the two totally different types of optimization methods validated the results we obtained.

  11. Sulfur Chemistry in Combustion II

    DEFF Research Database (Denmark)

    Johnsson, Jan Erik; Kiil, Søren

    2000-01-01

    Several options are available to control the emission of SO2 from combustion processes. One possibility is to use a cleaner technology, i.e. fuel switching from oil and coal to natural gas or biomass, or to desulphurize coal and oil. Another possibility is to change to a different technology for ...

  12. Leaching from biomass combustion ash

    DEFF Research Database (Denmark)

    Maresca, Alberto; Astrup, Thomas Fruergaard

    2014-01-01

    The use of biomass combustion ashes for fertilizing and liming purposes has been widely addressed in scientific literature. Nevertheless, the content of potentially toxic compounds raises concerns for a possible contamination of the soil. During this study five ash samples generated at four...

  13. Les perspectives du commerce international de gaz naturel d'ici 2000 The World Natural Gas Trade Outlook to 2000

    Directory of Open Access Journals (Sweden)

    Valais M.

    2006-11-01

    Full Text Available L'abondance des ressources gazières mondiales et l'excellence des qualités du gaz naturel, comme combustible et matière première pétrochimique, devraient lui permettre d'accroître sa pénétration sur les marchés énergétiques internationaux. Toutefois, la répartition géographique de ses réserves prouvées coïncide de moins en moins avec celle de sa consommation. En conséquence, la croissance du commerce international de gaz naturel apparaît comme une nécessité de plus en plus vitale du développement mondial de ses marchés. A partir d'une étude prospective menée au sein de l'Association Technique de l'industrie du Gaz en France (ATG, le présent mémoire se propose d'analyser les perspectives des échanges gaziers internationaux d'ici l'horizon 2000. The abundance of the world reserves of natural gas and the excellence of its qualities as a fuel and a petrochemical feedstock should enable natural gas to increase its penetration on international energy markets. However the geographic distribution of its proved reserves coincides less and less with the distribution of its consumption. Therefore, the increase in international gas trade appears more and more to be of vital necessity for the world development of its markets. On the basis of a study carried out within the Association Technique de l'industrie du Gaz en France (ATG, the present paper will attempt to analyse the outlook for international gas trade between now and the year 2000.

  14. Environmental optimisation of waste combustion

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, Robert [AaF Energikonsult, Stockholm (Sweden); Berge, Niclas; Stroemberg, Birgitta [TPS Termiska Processer AB, Nykoeping (Sweden)

    2000-12-01

    The regulations concerning waste combustion evolve through R and D and a strive to get better and common regulations for the European countries. This study discusses if these rules of today concerning oxygen concentration, minimum temperature and residence time in the furnace and the use of stand-by burners are needed, are possible to monitor, are the optimum from an environmental point of view or could be improved. No evidence from well controlled laboratory experiments validate that 850 deg C in 6 % oxygen content in general is the best lower limit. A lower excess air level increase the temperature, which has a significant effect on the destruction of hydrocarbons, favourably increases the residence time, increases the thermal efficiency and the efficiency of the precipitators. Low oxygen content is also necessary to achieve low NO{sub x}-emissions. The conclusion is that the demands on the accuracy of the measurement devices and methods are too high, if they are to be used inside the furnace to control the combustion process. The big problem is however to find representative locations to measure temperature, oxygen content and residence time in the furnace. Another major problem is that the monitoring of the operation conditions today do not secure a good combustion. It can lead to a false security. The reason is that it is very hard to find boilers without stratifications. These stratifications (stream lines) has each a different history of residence time, mixing time, oxygen and combustible gas levels and temperature, when they reach the convection area. The combustion result is the sum of all these different histories. The hydrocarbons emission is in general not produced at a steady level. Small clouds of unburnt hydrocarbons travels along the stream lines showing up as peaks on a THC measurement device. High amplitude peaks has a tendency to contain higher ratio of heavy hydrocarbons than lower peaks. The good correlation between some easily detected

  15. Fluidized-bed combustion of gasification residue

    Energy Technology Data Exchange (ETDEWEB)

    Kudjoi, A.; Heinolainen, A.; Hippinen, I.; Lu, Y. [Helsinki University of Technology, Espoo (Finland). Lab. of Energy Economics and Power Plant Engineering

    1998-12-31

    Hybrid combined cycle processes have been presented as possibilities for power generation in the future. In the processes based on partial gasification of coal, the solid materials removed from a gasifier (i.e. fly ash and bed char) contain unburned fuel, which is burned either in an atmospheric or a pressurised fluidised-bed. Pressurised fluidised-bed (PFB) combustion of gasification residues were studied experimentally by Helsinki University of Technology. The gasification residues, i.e. cyclone fines and bed chars, came from pilot scale PFB gasification tests of bituminous coals. The combustion efficiency was high in cyclone fines combustion. The calcium sulphide oxidised effectively to calcium sulphate in the combustion of cyclone fines. In bed char combustion the residual sulphide contents in solids after combustion were still relatively high. In general, sulphur dioxide emissions in residue combustion were low. The recarbonation of calcium oxide was observed in bed char combustion. Fuel-N conversion to NO{sub x} during bed char combustion and in most of the test runs with cyclone fines was higher than in bituminous coal combustion. In bed char combustion the conversion was significantly higher than in cyclone fines combustion. NO{sub x} emissions increased with increasing excess air for both residues, as was expected. In bed char combustion the highest NO{sub x} emissions were measured at higher pressure. Calculated mass reactivity values of equal particle size of all bed chars studied had similar trends with burnout. The biggest particles had the lowest reactivity values throughout the combustion, while reactivity for finer particles was at considerably higher level and sharply increases with burnout. In the constant combustion conditions used in the tests, no significant differences were observed in rate-controlling mechanisms for bed char fractions studied. 25 refs., 13 figs., 15 tab.

  16. Le Flaubert de Charles Du Bos

    Directory of Open Access Journals (Sweden)

    Jacques Neefs

    2009-01-01

    Full Text Available Charles Du Bos a porté une attention constante à l’œuvre de Flaubert (à l’exclusion de Bouvard et Pécuchet qui semble ne pas exister pour lui, à Madame Bovary et à L’Éducation sentimentale en particulier. La mise en relation de son étude : « Sur le milieu intérieur chez Flaubert », écrite en 1921, avec des textes du Journal de 1923 et de 1937, les rapprochements avec Gogol, Thomas Hardy, Tolstoï, Baudelaire, Henry James qui traversent les écrits de Du Bos, permettent de suivre ce que celui-ci décrit comme « l’expérience spirituelle » d’une matérialité comprise dans la conquête de la triple exigence du Beau, du Vivant et du Vrai. Du Bos décèle la force de l’œuvre de Flaubert dans la « disproportion » du style, et dans la puissance d’absorption qui fait la densité de cette prose, et qui désigne un extraordinaire travail de conversion. L’obscure expérience spirituelle ainsi poursuivie est celle d’un absolu de l’art, expérience paradoxale d’un « mystique qui ne croit à rien » (comme se désignait Flaubert lui-même, que le critique lie à une interrogation sur sa propre conversion.Charles Du Bos devoted an unflagging attention to Flaubert’s work (except for Bouvard et Pécuchet, which, apparently, according to him did not exist, to Madame Bovary and in particular L’Éducation sentimentale. The connection between his essay “Sur le milieu intérieur chez Flaubert”, written in 1921, and extracts from his Journal, from 1923 to 1937, the comparisons with Gogol, Thomas Hardy, Tolstoy, Baudelaire, and Henry James that run through the writings of Du Bos, allow us to follow what he terms “the spiritual experience” of a materiality encompassed in the conquest of the triple demand of the Beautiful, the Living, the Truth. Du Bos detects the power of Flaubert’s work in the “disproportion” of his style, and the power of absorption that forms the density of his prose, showing an

  17. Combustive management of oil spills

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    Extensive experiments with in situ incineration were performed on a desert site at the University of Arizona with very striking results. The largest incinerator, 6 feet in diameter with a 30 foot chimney, developed combustion temperatures of 3000, F, and attendant soot production approximately 1000 times less than that produced by conventional in situ burning. This soot production, in fact, is approximately 30 times less than current allowable EPA standards for incinerators and internal combustion engines. Furthermore, as a consequence of the high temperature combustion, the bum rate was established at a very high 3400 gallons per hour for this particular 6 foot diameter structure. The rudimentary design studies we have carried out relative to a seagoing 8 foot diameter incinerator have predicted that a continuous burn rate of 7000 gallons per hour is realistic. This structure was taken as a basis for operational design because it is compatible with C130 flyability, and will be inexpensive enough ($120,000 per copy) to be stored at those seaside depots throughout the US coast line in which the requisite ancillary equipments (booms, service tugs, etc.) are already deployed. The LOX experiments verified our expectations with respect to combustion of debris and various highly weathered or emulsified oils. We have concluded, however, that the use of liquid oxygen in actual beach clean up is not promising because the very high temperatures associated with this combustion are almost certain to produce environmentally deleterious effects on the beach surface and its immediately sublying structures. However, the use of liquid oxygen augmentation for shore based and flyable incinerators may still play an important role in handing the problem of accumulated debris.

  18. L’ombre du Condor

    Directory of Open Access Journals (Sweden)

    Franck Gaudichaud

    2003-09-01

    Full Text Available Si l’on observe aujourd’hui, avec un regard d’historien, le Cône Sud à la fin des années soixante soixante-dix et que par, la suite, on tourne une page de quelques années, pour fixer la même partie du monde, le constat est sans appel : le sous-continent latino-américain est passé, en général, d’une phase de forte mobilisation et politisation sociale, montée en puissance de partis et organisations révolutionnaires, surgissements de gouvernements populistes de gauche ou progressistes – appelant à une rupture avec l’impérialisme –, à un reflux généralisé du mouvement ouvrier, une ère de violence politique étatisée, la destruction massive de tous les espaces d’expression et de participation démocratiques, l’écrasement physique et idéologique sans relâche des militants et mouvements révolutionnaires, la mise en place de modèles économiques capitalistes dirigistes puis/ou néolibéraux. Que s’est-il passé ? Quel fil conducteur a été rompu et par quels moyens l’Amérique Latine a été conduite à ce reflux des luttes sociales ? Pour répondre à cette question, nous nous contenterons dans cet article de focaliser notre objectif sur un aspect spécifique et essentiel de ce retournement de tendance que vit alors l���Amérique Latine : celui de la mise en place d’un terrorisme d’Etat contre-révolutionnaire transnational, appuyé par l’impérialisme américain, nommé « l’Opération Condor ». Dans cet article, il s’agit de montrer le fonctionnement d’un terrorisme hégémonique dont l’impact sur les sociétés latino-américaines est considérable en termes de destruction du mouvement social, des activités culturelles et de l’ensemble de la vie sociale et politique qui restent marquées, encore aujourd’hui à des degrés divers, par la violence, la peur et l’atomisation structurelle.Si miramos hoy en día, desde una perspectiva histórica, el Cono Sur hacia finales de

  19. Stravinsky : figures clownesques du spectacle dansé

    OpenAIRE

    Frey, Leonard H.

    2013-01-01

    L’origine du mot clown remonte au vieux Scandinave klunni (lourdaud / benêt). Comme nous avons pu en juger au cours de ces rencontres, la sémantique historique du terme a connu de nombreuses variations, a été, au fil du temps, soumise aux fluctuations plus ou moins heureuses imposées par le théâtre. Dans cette étude, je me propose d’étudier l’iconographie de la représentation du clown à travers l’une des variantes du spectacle, la danse, le ballet et les musiques d’Igor Stravinsky. Au cours d...

  20. Study of a method of detection for natural carbon-14 using a liquid scintillator, recent variations in the natural radio-activity due to artificial carbon-14 (1963); Etude d'une methode de detection du carrons 14 naturel, utilisant un scintillateur liquide - variations recentes de l'activite naturelle dues au carbone 14 artificiel (1963)

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-06-15

    Among the various natural isotopes of carbon, a radioactive isotope, carbon-14, is formed by the action of secondary neutrons from cosmic rays on nitrogen in the air. Until 1950, the concentration of this isotope in ordinary carbon underwent weak fluctuations of about 2-3 per cent. The exact measurement of this concentration 6 X 10{sup 12} Ci/gm of carbon, and of its fluctuations, are difficult and in the first part of this report a highly sensitive method is given using a liquid scintillator. Since 1950 this natural activity has shown large fluctuations because of the carbon-14 formed during nuclear explosions, and in the second part, the evolution in France of this specific activity of carbon in the atmosphere and biosphere is examined. In the last part is studied the local increase in carbon activity in the atmosphere around the Saclay site, an increase caused by the carbon-14 given off as C{sup 14}O{sub 2}, by the reactors cooled partially with exterior air. (author) [French] Parmi les differents isotopes naturels du carbone, un isotope radioactif, le carbone 14, est forme par l'action de neutrons secondaires due aux rayons cosmiques sir l'azote de l'air. Jusqu'en 1950, la concentration de cet isotope dans le carbone ordinaire est soumise a des fluctuations de faible amplitude, de l'ordre de 2 a 3 pour cent. Les mesures precises de cette concentration, 6. 10{sup -12} Ci/g de carbone, et de ses fluctuations sont delicates, et dans la premiere partie de ce rapport, on decrit une methode de detection a grande sensibilite utilisant un scintillateur liquide. Depuis 1950, cette activite naturelle subit des fluctuations importantes dues au carbone 14 forme lors des explosions nucleaires, et dans la seconde partie, on examine l'evolution en France de l'activite specifique du carbone de l'atmosphere et ce la biosphere. Dans la derniere partie, on etudie l'accroissement local de l'activite du carbone de l'air aux

  1. Une force venant du futur chercherait à saboter l'expérience du LHC...

    CERN Multimedia

    Scappaticci, Bruno

    2009-01-01

    "A quelques jours de la reprise de l'expérience du LHC, on ne parle plus de la menace d'un trou noir, mais deux physicines souteinnent aujourd'hui une tout autres hypothèse: la nature, depuis le futur, va continuer de contrarier les travaux du Cern, afin d'éviter à l'Homme de mettre le doigt là où il ne faut pas..." (1.5 pages)

  2. OGM : vers une définition commune du contenu du problème ?

    Directory of Open Access Journals (Sweden)

    Icart Jean-Claude

    2001-07-01

    Full Text Available Les divergences croissantes depuis des années entre experts, responsables économiques, et acteurs sociaux et « citoyens » au sujet des OGM, ont pu être analysées à juste titre, comme exprimant la difficulté de dégager une « définition commune du contenu du problème »1.

  3. Utilisation du langage signal pour l'etude d'algorithmes de traitement du Signal electrocardiographique

    OpenAIRE

    Médigue, Claire; Clairambault, Jean; Kauffmann, François; Sorine, Michel; Cursi-Dascalova, Lilia

    1992-01-01

    Projet SOSSO; Pour etudier la maturation du Systeme Nerveux Autonome (SNA) chez les nouveaux nes, on analyse la Variabilite du Rythme Cardiaque (VRC), en relation avec d'autres informations biologiques telles que les changements de stades de sommeil. La VRC est calculee par la Transformee de Fourier a Court Terme dans trois bandes de frequence : la haute frequence, refletant le controle para sympathique seul et liee au cycle respiratoire ; les moyenne et basse frequences, refletant a la fois ...

  4. Secondary combustion device for woodburning stove

    Energy Technology Data Exchange (ETDEWEB)

    Craver, R.D.

    1989-08-08

    This patent describes in a wood burning stove including an exhaust flue opening, a combustion chamber for primary combustion having an access door, a support for wood to be burned and a primary air inlet means for supplying air to support primary combustion of the wood to produce flue gases containing combustible particulate material, plenum means for directing the flue gases in a direction from the combustion chamber to the flue opening in a preselected path, and secondary combustion means for burning the particulate material in the flue gases before flue gases through the exhaust flue opening. The improvement comprising: the combustion chamber having a flue gas exit opening extending laterally across the top of the combustion chamber and communicating the combustion chamber with the plenum means, an elongated manifold extending laterally across and above the combustion chamber substantially coextensively with the flue gas exit opening, a number of air opening spaced longitudinally along the manifold and facing opposite the direction of the flue gases closely adjacent the flue gas exit opening, and an air inlet means for supplying ambient, secondary combustion air to the manifold for counterflow thereof from the openings into the path of the flue gases in a plurality of distinct jets.

  5. Measurement and simulation of swirling coal combustion

    Institute of Scientific and Technical Information of China (English)

    Liyuan Hu; Lixing Zhou; Yonghao Luo; Caisong Xu

    2013-01-01

    Particle image velocimetry (PIV),thermocouples and flue gas analyzer are used to study swirling coal combustion and NO formation under different secondary-air ratios.Eulerian-Lagrangian large-eddy simulation (LES) using the Smagorinsky-Lilly sub-grid scale stress model,presumed-PDF fast chemistry and eddy-break-up (EBU) gas combustion models,particle devolatilization and particle combustion models,are simultaneously used to simulate swirling coal combustion.Statistical LES results are validated by measurement results.Instantaneous LES results show that the coherent structures for swirling coal combustion are stronger than those for swirling gas combustion.Particles are shown to concentrate along the periphery of the coherent structures.Combustion flame is located in the high vorticity and high particle concentration zones.Measurement shows that secondary-air ratios have little effect on final NO formation at the exit of the combustor.

  6. Combustion diagnostic for active engine feedback control

    Science.gov (United States)

    Green, Jr., Johney Boyd; Daw, Charles Stuart; Wagner, Robert Milton

    2007-10-02

    This invention detects the crank angle location where combustion switches from premixed to diffusion, referred to as the transition index, and uses that location to define integration limits that measure the portions of heat released during the combustion process that occur during the premixed and diffusion phases. Those integrated premixed and diffusion values are used to develop a metric referred to as the combustion index. The combustion index is defined as the integrated diffusion contribution divided by the integrated premixed contribution. As the EGR rate is increased enough to enter the low temperature combustion regime, PM emissions decrease because more of the combustion process is occurring over the premixed portion of the heat release rate profile and the diffusion portion has been significantly reduced. This information is used to detect when the engine is or is not operating in a low temperature combustion mode and provides that feedback to an engine control algorithm.

  7. ESTIMATION DU MODELE LINEAIRE GENERALISE ET APPLICATION

    Directory of Open Access Journals (Sweden)

    Malika CHIKHI

    2012-06-01

    Full Text Available Cet article présente  le modèle linéaire généralisé englobant les  techniques de modélisation telles que la régression linéaire, la régression logistique, la régression  log linéaire et la régression  de Poisson . On Commence par la présentation des modèles  des lois exponentielles pour ensuite estimer les paramètres du modèle par la méthode du maximum de vraisemblance. Par la suite on teste les coefficients du modèle pour voir leurs significations et leurs intervalles de confiances, en utilisant le test de Wald qui porte sur la signification  de la vraie valeur du paramètre  basé sur l'estimation de l'échantillon.

  8. Clinical Application of the Du Channel

    Institute of Scientific and Technical Information of China (English)

    刘淑娅; 王世杰

    2003-01-01

    @@ The authors have, in recent years, obtained quite good therapeutic results in their acupuncture treatment of mental diseases, heat syndromes and cerebrovascular diseases through treating mainly the Du Channel with the methods of resuscitating and regulating the mind, and clearing and activating the channels and collaterals. The illustrative cases are reported below.

  9. Annonce du diagnostic et rupture biographique

    African Journals Online (AJOL)

    du cancer en Tunisie , maladie chronique identifiée parmi les plus répandues ... et quelques tentatives de redéploiement des activités des praticiens .... appréhendant ainsi la nature de la souffrance physique mais aussi morale, ces cliniciens.

  10. Prejudice: From Allport to DuBois.

    Science.gov (United States)

    Gaines, Stanley O., Jr.; Reed, Edward S.

    1995-01-01

    Examines the differences between Gordon Allport's and W. E. B. DuBois's theories on the origins of prejudice and the impact of discrimination on the personality and social development of blacks. The article argues that prejudice is a historically developed process, not a universal feature of human psychology. Implications for U.S. race relations…

  11. Le PT à la conquête du pouvoir

    OpenAIRE

    Mendes, Candido

    2014-01-01

    LES PREMIERS PAS DU PT AU POUVOIR La première victoire du PT pour l′accès à un exécutif fut celle de la candidate Maria Luiza, en 1989, dans la capitale du Ceará, Fortaleza. Son arrivée au pouvoir démontra à la fois un certain manque d′expérience personnel ainsi qu′un bégaiement des cadres du parti, trop empreints de la radicalité, de l′utopie de gauche, du culte des « razzias » de pureté politique, du changement complet de tous les acteurs du pouvoir, tant la victoire était marquée par le dé...

  12. Technical and Economic Problems Associated with the Development of Methods of Processing and Using Radioactive Waste; Problemes techniques et economiques lies au developpement des methodes de traitement et d'utilisation des dechets radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Thiriet, L.; Sauteron, J.; Oger, C. [Commissariat a l' Energie Atomique, Fontenay-Aux-Roses (France). Centre d' Etudes Nucleaires

    1968-07-01

    The paper briefly reviews the various techniques used in processing the radioactive wastes which unavoidably result from the generation of electric power from nuclear sources. The paper goes on to define the relative importance, in nuclear fuel cycles, of the problem raised by these wastes. Emphasis is placed on the economic influence of management policies on the cost of power generation, and hence on the relative position of nuclear energy. A substantial percentage of these wastes can be economically utilized. Attention is drawn to the major technical and economic features of the industry which will come into being as a result of this utilization. The major uses anticipated are discussed: radiation sources, heat sources, auxiliary power generation. The paper concludes that satisfactory solutions have already been found to these problems, and describes possible improvements. (author) [French] La communication rappelle d'abord succinctement les differentes techniques de traitement des dechets radioactifs resultant necessairement de la production d'electricite d'origine nucleaire. On situe ensuite l'importance du probleme pose par ces residus dans le cycle du combustible nucleaire. On fait ressortir l'influence economique du choix des methodes de gestion sur le cout de production de l'energie, et par consequent sur la place devolue a l'energie nucleaire. Une part importante de ces dechets peut faire l'objet d'une utilisation rentable de l'industrie qui naitra de cette utilisation. Les principales applications envisagees sont evoquees: sources d'irradiation, sources chauffantes, generateurs auxiliaires d'energie. On conclut que d'ores et deja des solutions satisfaisantes ont ete apportees a ces problemes, et l'on decrit les perspectives d'amelioration concevables. (auteur)

  13. Distributed Low Temperature Combustion: Fundamental Understanding of Combustion Regime Transitions

    Science.gov (United States)

    2016-09-07

    Excellent optical access for laser- based diagnostic measurements ; (ii) Accurate experimental control of boundary conditions; (iii) Aerodynamic flame...potential to extend methods based on bimodal approximations, such as the BML [21] framework , by permitting inter- mediate fluid states, which is of...identify the impact of the major chemical pathways on combustion mode transitions. The conceptual multifluid approach of Spalding can be used to avoid

  14. 77 FR 37361 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Science.gov (United States)

    2012-06-21

    ... Reciprocating Internal Combustion Engines; New Source Performance Standards for Stationary Internal Combustion... Combustion Engines; New Source Performance Standards for Stationary Internal Combustion Engines.'' The EPA... Internal Combustion Engines; New Source Performance Standards for Stationary Internal Combustion Engines...

  15. Sébastien Broca, Utopie du logiciel libre. Du bricolage informatique à la réinvention sociale

    OpenAIRE

    Goëta, Samuel

    2014-01-01

    Traitant des pratiques et des conceptions du logiciel libre mais aussi, plus largement, du mouvement pour l’ouverture des savoirs, Utopie du logiciel libre ambitionne, premièrement, de nourrir une réflexion critique sur l’ethos du libre au sens d’un « ensemble de valeurs qui constituent un cadre pour l’action et s’actualisent dans des pratiques » (p. 24) et, deuxièmement, d’élaborer une sociologie critique du libre. Reprenant la notion d’utopie concrète chez Ernst Bloch (Le principe Espérance...

  16. Néotoponymie contestée à Potchefstroom / Tlokwe (Province du Nord-Ouest, Afrique du Sud

    Directory of Open Access Journals (Sweden)

    Myriam Houssay-Holzschuch

    2010-09-01

    Full Text Available Illustration 1 - Extrait du site de la municipalité de Potchefstroom / TlokweSource : http://www.potch.co.za/newsarchive/streetnames.htmlIllustration 2- Potchefstroom (Afrique du SudAuteur : Béatrice Obry-Guyot, début décembre 2007.Illustration 3 - Extrait du plan Google Map de PotchefstroomSource : Google Map.La question toponymique en Afrique du Sud sur la longue durée porte sur deux thèmes essentiels porteurs de controverses : le plurilinguisme et le marquage symbolique et mémoriel du te...

  17. Esquisse du parlementarisme et du monopartisme en Afrique: le cas du Togo

    Directory of Open Access Journals (Sweden)

    E. A. B. van Rouveroy van Nieuwaal

    1989-01-01

    Full Text Available Witnessed the last hundred years profound political and constitutional changes. In this respect there are many differences between African States depending on which kind of colonial overlord has been the ruling power. The African State was a juridical entity in international law, but was it also, at the time of independence, an empirical entity in national fact?In almost all cases the empirical reality as a functioning government was still primarily the presence of European bureaucrats who has embodied the colonial state. Independence therefore opened a gap between the international legitimacy and the internal marginality of many emergent African State. The gap often presented a real political dilemma to the new African rulers: they usually could retain European officials only by compromising their national independence and could dispense with them only at the risk of undermining governmental performance. After adoption of European constitutional law and with, initially, a high degree of similarity between most constitutions in French-speaking Africa, nowadays these constitutions differ widely, contrary to the Commonwealth Africa that has experienced fewer innovations and constitutional breakdowns.Parliamentary systems of government gave way to One Party Systems, introduced in many cases by the national army, as the best equiped, trained, paid and organised power in the country. This has been the political and constitutional development in Togo as well. Since 1969, it has a One Party System, the Rassemblement du Peuple Togolais, founded by the President of the Togolese Republic, Gen. Gnassingbé Eyadéma. But, as everywhere else, doubts are growing about the effectiveness of the One Party System. Are the Togolese perspectives such that Eyadéma is willing to have an open mind and to be all ears for the critics to his own creation? Another intriguing question is to know in which way the Africantraditional authorities (" chieftancy", as the core

  18. L'évolution des combustibles pour moteurs thermiques Evolution of Fuels for Thermal Engines

    Directory of Open Access Journals (Sweden)

    Balaceanu J. C.

    2006-11-01

    Full Text Available Depuis la crise pétrolière, l'accroissement des prix et les craintes de pénurie ont conduit à adapter les moteurs aux combustibles disponibles. Si la situation apparaît comme moins tendue, l'industrie des machines thermiques, qui pendant longtemps a eu comme partenaire une industrie du pétrole très sûre, se trouve cependant confrontée à un marché des combustibles incertain dans son ravitaillement et surtout dans ses prix. Les progrès des moteurs diesel et des turbines à gaz, dûs à une meilleure adaptation à leur usage et aussi à l'évolution de la technologie, supposent que les combustibles n'apporteront aucune contrainte majeure en quantité ou en qualité. La modification des usages dévolus désormais au pétrole entraînera une réduction de la coupe lourde et un raffinage plus profond des bruts avec en particulier un développement du craquage catalytique et de la viscoréduction. Or, ces différentes opérations de conversion peuvent conduire à une détérioration de la qualité des combustibles moins grave pour le gazole que pour le fuel lourd. Dans les différents domaines impliqués, les parades technologiques sont en cours de développement. L'industrie des machines thermiques, qui poursuit l'amélioration des engins, et l'industrie du pétrole, qui recherche une réduction des prix des combustibles, sont donc conduites à un compromis optimal auquel elles ne peuvent accéder efficacement qu'en définissant les règles du jeu c'est-à-dire des spécifications internationales rigoureuses des combustibles. Since the oil crisis, the increase in prices and fears of a shortage have led to the adapting of engines to what fuels are available. Whereas the situation now seems somewhat less tense, the thermal machinery industry, which for a long time had a very reliable petroleum industry as its partner, nonetheless finds itself confronted with an uncertain fuel market with regard to supplies and especially to prices. Progress

  19. Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ojeda, William de

    2010-07-31

    The project which extended from November 2005 to May of 2010 demonstrated the application of Low Temperature Combustion (LTC) with engine out NOx levels of 0.2 g/bhp-hr throughout the program target load of 12.6bar BMEP. The project showed that the range of loads could be extended to 16.5bar BMEP, therefore matching the reference lug line of the base 2007 MY Navistar 6.4L V8 engine. Results showed that the application of LTC provided a dramatic improvement over engine out emissions when compared to the base engine. Furthermore LTC improved thermal efficiency by over 5% from the base production engine when using the steady state 13 mode composite test as a benchmark. The key enablers included improvements in the air, fuel injection, and cooling systems made in Phases I and II. The outcome was the product of a careful integration of each component under an intelligent control system. The engine hardware provided the conditions to support LTC and the controller provided the necessary robustness for a stable combustion. Phase III provided a detailed account on the injection strategy used to meet the high load requirements. During this phase, the control strategy was implemented in a production automotive grade ECU to perform cycle-by-cycle combustion feedback on each of the engine cylinders. The control interacted on a cycle base with the injection system and with the Turbo-EGR systems according to their respective time constants. The result was a unique system that could, first, help optimize the combustion system and maintain high efficiency, and secondly, extend the steady state results to the transient mode of operation. The engine was upgraded in Phase IV with a Variable Valve Actuation system and a hybrid EGR loop. The impact of the more versatile EGR loop did not provide significant advantages, however the application of VVA proved to be an enabler to further extend the operation of LTC and gain considerable benefits in fuel economy and soot reduction. Finally

  20. 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

    A number of different possible programs for nuclear power stations of various types are presented in this survey. These programs are established in relation to the use of uranium and thorium in amounts similar to those that shall probably be produced in France during the next fifteen years. As it is possible to draw plans for nuclear power stations in which several processes exist simultaneously, an unlimited number of variations being thinkable, this survey is limited to successive analysis of the results obtained by use of only one of each of the following three systems: - system natural uranium-graphite, - system natural uranium-heavy water, -system enriched uranium-pressurised light water. All schemes are considered as assemblages of these three simple systems. The effects of plutonium recycling are also considered for each system. The electric power installed and the capacity of stations situated up-stream and down-stream have been calculated by this method and an attempt has been made to establish the sum to be invested during the fifteen years necessary for the launching of the programs scheduled. A table of timing for the investments groups the results obtained. Considering the fact that French availabilities in capital shall not be unlimited during the coming years, this way of presenting the results seems to be interesting. (author)Fren. [French] L'etude presentee comporte l'examen d'un certain nombre d'hypotheses de programmes de centrales nucleaires de types differents. Ces programmes correspondent a l'utilisation de tonnages d'uranium et de thorium de l'ordre de grandeur de ceux qui seront probablement produits par la France dans les quinze prochaines annees. Comme il est possible de batir un programme de centrales nucleaires, comportant a la fois plusieurs filieres suivant des variantes en nombre infini, on s'est contente d'examiner successivement les resultats ous si on utilisait exclusivement l

  1. Oxy-coal Combustion Studies

    Energy Technology Data Exchange (ETDEWEB)

    Wendt, J. [Univ. of Utah, Salt Lake City, UT (United States); Eddings, E. [Univ. of Utah, Salt Lake City, UT (United States); Lighty, J. [Univ. of Utah, Salt Lake City, UT (United States); Ring, T. [Univ. of Utah, Salt Lake City, UT (United States); Smith, P. [Univ. of Utah, Salt Lake City, UT (United States); Thornock, J. [Univ. of Utah, Salt Lake City, UT (United States); Y Jia, W. Morris [Univ. of Utah, Salt Lake City, UT (United States); Pedel, J. [Univ. of Utah, Salt Lake City, UT (United States); Rezeai, D. [Univ. of Utah, Salt Lake City, UT (United States); Wang, L. [Univ. of Utah, Salt Lake City, UT (United States); Zhang, J. [Univ. of Utah, Salt Lake City, UT (United States); Kelly, K. [Univ. of Utah, Salt Lake City, UT (United States)

    2012-01-06

    The objective of this project is to move toward the development of a predictive capability with quantified uncertainty bounds for pilot-scale, single-burner, oxy-coal operation. This validation research brings together multi-scale experimental measurements and computer simulations. The combination of simulation development and validation experiments is designed to lead to predictive tools for the performance of existing air fired pulverized coal boilers that have been retrofitted to various oxy-firing configurations. In addition, this report also describes novel research results related to oxy-combustion in circulating fluidized beds. For pulverized coal combustion configurations, particular attention is focused on the effect of oxy-firing on ignition and coal-flame stability, and on the subsequent partitioning mechanisms of the ash aerosol.

  2. Steady state HNG combustion modeling

    Energy Technology Data Exchange (ETDEWEB)

    Louwers, J.; Gadiot, G.M.H.J.L. [TNO Prins Maurits Lab., Rijswijk (Netherlands); Brewster, M.Q. [Univ. of Illinois, Urbana, IL (United States); Son, S.F. [Los Alamos National Lab., NM (United States); Parr, T.; Hanson-Parr, D. [Naval Air Warfare Center, China Lake, CA (United States)

    1998-04-01

    Two simplified modeling approaches are used to model the combustion of Hydrazinium Nitroformate (HNF, N{sub 2}H{sub 5}-C(NO{sub 2}){sub 3}). The condensed phase is treated by high activation energy asymptotics. The gas phase is treated by two limit cases: the classical high activation energy, and the recently introduced low activation energy approach. This results in simplification of the gas phase energy equation, making an (approximate) analytical solution possible. The results of both models are compared with experimental results of HNF combustion. It is shown that the low activation energy approach yields better agreement with experimental observations (e.g. regression rate and temperature sensitivity), than the high activation energy approach.

  3. Fundamental studies of spray combustion

    Energy Technology Data Exchange (ETDEWEB)

    Li, S.C.; Libby, P.A.; Williams, F.A. [Univ. of California, San Diego, CA (United States)

    1997-12-31

    Our research on spray combustion involves both experiment and theory and addresses the characteristics of individual droplets and of sprays in a variety of flows: laminar and turbulent, opposed and impinging. Currently our focus concerns water and fuel sprays in two stage laminar flames, i.e., flames arising, for example from a stream of fuel and oxidizer flowing opposite to an air stream carrying a water spray. Our interest in these flames is motivated by the goals of reducing pollutant emissions and extending the range of stable spray combustion. There remains considerable research to be carried out in order to achieve these goals. Thus far our research on the characteristics of sprays in turbulent flows has been limited to nonreacting jets impinging on a plate but this work will be extended to opposed flows with and without a flame. In the following we discuss details of these studies and our plans for future work.

  4. SPECIFIC EMISSIONS FROM BIOMASS COMBUSTION

    Directory of Open Access Journals (Sweden)

    Pavel Skopec

    2014-02-01

    Full Text Available This paper deals with determining the specific emissions from the combustion of two kinds of biomass fuels in a small-scale boiler. The tested fuels were pellets made of wood and pellets made of rape plant straw. In order to evaluate the specific emissions, several combustion experiments were carried out using a commercial 25 kW pellet-fired boiler. The specific emissions of CO, SO2 and NOx were evaluated in relation to a unit of burned fuel, a unit of calorific value and a unit of produced heat. The specific emissions were compared with some data acquired from the reference literature, with relatively different results. The differences depend mainly on the procedure used for determining the values, and references provide no information about this. Although some of our experimental results may fit with one of the reference sources, they do not fit with the other. The reliability of the references is therefore disputable.

  5. Fluidized bed coal combustion reactor

    Science.gov (United States)

    Moynihan, P. I.; Young, D. L. (Inventor)

    1981-01-01

    A fluidized bed coal reactor includes a combination nozzle-injector ash-removal unit formed by a grid of closely spaced open channels, each containing a worm screw conveyor, which function as continuous ash removal troughs. A pressurized air-coal mixture is introduced below the unit and is injected through the elongated nozzles formed by the spaces between the channels. The ash build-up in the troughs protects the worm screw conveyors as does the cooling action of the injected mixture. The ash layer and the pressure from the injectors support a fluidized flame combustion zone above the grid which heats water in boiler tubes disposed within and/or above the combustion zone and/or within the walls of the reactor.

  6. The FCF Combustion Integrated Rack: Microgravity Combustion Science Onboard the International Space Station

    Science.gov (United States)

    OMalley, Terence F.; Weiland, Karen J.

    2002-01-01

    The Combustion Integrated Rack (CIR) is one of three facility payload racks being developed for the International Space Station (ISS) Fluids and Combustion Facility (FCF). Most microgravity combustion experiments will be performed onboard the Space Station in the Combustion Integrated Rack. Experiment-specific equipment will be installed on orbit in the CIR to customize it to perform many different scientific experiments during the ten or more years that it will operate on orbit. This paper provides an overview of the CIR, including a description of its preliminary design and planned accommodations for microgravity combustion science experiments, and descriptions of the combustion science experiments currently planned for the CIR.

  7. CSIR helps prevent spontaneous combustion

    Energy Technology Data Exchange (ETDEWEB)

    Vuuren, M. van (CSIR Energy Technology (South Africa))

    1992-03-01

    Heaps of stockpiled coal could present a fire hazard due to the risk of spontaneous combustion. Regular monitoring of stockpiles and bunker testing of coals help to prevent stockpile fires. This brief article describes the recent upgrading of the CSIR's bunker test facility that enables coal producers, users and exporters to test their products under simulated conditions that duplicate the actual conditions under which coal is stored. 2 photos.

  8. Radiation/Catalytic Augmented Combustion.

    Science.gov (United States)

    1980-09-01

    NATIO& NAk H(fJI At tl TANUAHTOb 19 A ~omm.81-0287 LVL RADIATION/CATALYTIC AUGMENTED COMBUST ION MOSHE LAVID CORPORATE RESEARCH-TECHNOLOGY FEASIBILITY...refinements as necessary. i. Perform cannular combustor experiments to Investigate ignition and flame attachment in flowing, liquid -fuel, unpremixed...stabilizer, with a sintered metal disk on the downstream side through which hot gases or products of partial fuel oxidation can be passed. Experimental

  9. Laser Optics/Combustion Diagnostics.

    Science.gov (United States)

    1986-07-01

    been demonstrated. CARS measurements of axial and 0.12 radial temperature profiles in a highly sooting flame compared favorably with profiles...of Number-Density Equation ’Eckbreth. A.C. and Hatt. R.., "CARS Thermomrry in a The third-order susceptibility can be rewritten to show its Sooting ... Flame ." Combustion and Homie, Vol. 36. 1979, pp. 87-98. explcitdepndece ponthenumer ensty Roh. %W.B.. "Coherent Anti-Stokcs Raman Scattering ofexpici

  10. ABB Combustion Engineering nuclear technology

    Energy Technology Data Exchange (ETDEWEB)

    Matzie, R.A.

    1994-12-31

    The activities of ABB Combustion Engineering in the design and construction of nuclear systems and components are briefly reviewed. ABB Construction Engineering continues to improve the design and design process for nuclear generating stations. Potential improvements are evaluated to meet new requirements both of the public and the regulator, so that the designs meet the highest standards worldwide. Advancements necessary to meet market needs and to ensure the highest level of performance in the future will be made.

  11. Vortex Simulation of Turbulent Combustion

    Science.gov (United States)

    1992-11-19

    TURBULENT COMBUSTION (AFOSR Grant No. 89-0491) Principal Investigator: Ahmed F. Ghoniem Department of Mechanical Engineering Massachusetts Institute of...Heavy Industries, Nagoya, Japan.(talk and discussion). 17. 1990, Mazda Motor Co., Yokohama, Japan, (talk and discussion). 18. 1990, American Math Society...VORTICITY LAYERS UNDER NON-SYMMETRIC CONDITIONS Omar M. Kniot and Ahmed F. Ghoniem Department of Mechanical Engineering Massachusetts Institute of

  12. Nitrogen release during coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, L.L.; Mitchell, R.E.; Fletcher, T.H.; Hurt, R.H.

    1995-02-01

    Experiments in entrained flow reactors at combustion temperatures are performed to resolve the rank dependence of nitrogen release on an elemental basis for a suite of 15 U.S. coals ranging from lignite to low-volatile bituminous. Data were obtained as a function of particle conversion, with overall mass loss up to 99% on a dry, ash-free basis. Nitrogen release rates are presented relative to both carbon loss and overall mass loss. During devolatilization, fractional nitrogen release from low-rank coals is much slower than fractional mass release and noticeably slower than fractional carbon release. As coal rank increases, fractional nitrogen release rate relative to that of carbon and mass increases, with fractional nitrogen release rates exceeding fractional mass and fractional carbon release rates during devolatilization for high-rank (low-volatile bituminous) coals. At the onset of combustion, nitrogen release rates increase significantly. For all coals investigated, cumulative fractional nitrogen loss rates relative to those of mass and carbon passes through a maximum during the earliest stages of oxidation. The mechanism for generating this maximum is postulated to involve nascent thermal rupture of nitrogen-containing compounds and possible preferential oxidation of nitrogen sites. During later stages of oxidation, the cumulative fractional loss of nitrogen approaches that of carbon for all coals. Changes in the relative release rates of nitrogen compared to those of both overall mass and carbon during all stages of combustion are attributed to a combination of the chemical structure of coals, temperature histories during combustion, and char chemistry.

  13. Combustion char characterisation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Rosenberg, P.; Ingermann Petersen, H.; Sund Soerensen, H.; Thomsen, E.; Guvad, C.

    1996-06-01

    The aim was to correlate reactivity measures of raw coals and the maceral concentrates of the coals obtained in a previous project with the morphology of the produced chars by using a wire grid devolatilization method. Work involved determination of morphology, macroporosity and a detailed study by Scanning Electron Microscopy (SEM). Systematic variations in the texture of chars produced in different temperature domains and heating rates were demonstrated by using incident light microscopy on polished blocks and by SEM studies directly on the surfaces of untreated particles. Results suggest that work in the field of char reactivity estimates and correlations between char morphology and coal petrography can be accomplished only on chars produced under heating rates and temperatures comparable to those for the intended use of coal. A general correlation between the coals` petrography and the the morphology of high temperature chars was found. The SEM study of the chars revealed that during the devolatilization period the particles fuse and the macroporosity and thus the morphotypes are formed. After devolatilization ceases, secondary micropores are formed. These develop in number and size throughout the medium combustion interval. At the end of the combustion interval the macrostructure breaks down, caused by coalescence of the increased number of microspores. This can be observed as a change in the morphology and the macroporosity of the chars. Results indicate that char reactivity is a function of the macroporosity and thus the morphology of combustion chars. (AB) 34 refs.

  14. Demonstration of Active Combustion Control

    Science.gov (United States)

    Lovett, Jeffrey A.; Teerlinck, Karen A.; Cohen, Jeffrey M.

    2008-01-01

    The primary objective of this effort was to demonstrate active control of combustion instabilities in a direct-injection gas turbine combustor that accurately simulates engine operating conditions and reproduces an engine-type instability. This report documents the second phase of a two-phase effort. The first phase involved the analysis of an instability observed in a developmental aeroengine and the design of a single-nozzle test rig to replicate that phenomenon. This was successfully completed in 2001 and is documented in the Phase I report. This second phase was directed toward demonstration of active control strategies to mitigate this instability and thereby demonstrate the viability of active control for aircraft engine combustors. This involved development of high-speed actuator technology, testing and analysis of how the actuation system was integrated with the combustion system, control algorithm development, and demonstration testing in the single-nozzle test rig. A 30 percent reduction in the amplitude of the high-frequency (570 Hz) instability was achieved using actuation systems and control algorithms developed within this effort. Even larger reductions were shown with a low-frequency (270 Hz) instability. This represents a unique achievement in the development and practical demonstration of active combustion control systems for gas turbine applications.

  15. Combustion instability modeling and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Santoro, R.J.; Yang, V.; Santavicca, D.A. [Pennsylvania State Univ., University Park, PA (United States)] [and others

    1995-10-01

    It is well known that the two key elements for achieving low emissions and high performance in a gas turbine combustor are to simultaneously establish (1) a lean combustion zone for maintaining low NO{sub x} emissions and (2) rapid mixing for good ignition and flame stability. However, these requirements, when coupled with the short combustor lengths used to limit the residence time for NO formation typical of advanced gas turbine combustors, can lead to problems regarding unburned hydrocarbons (UHC) and carbon monoxide (CO) emissions, as well as the occurrence of combustion instabilities. Clearly, the key to successful gas turbine development is based on understanding the effects of geometry and operating conditions on combustion instability, emissions (including UHC, CO and NO{sub x}) and performance. The concurrent development of suitable analytical and numerical models that are validated with experimental studies is important for achieving this objective. A major benefit of the present research will be to provide for the first time an experimentally verified model of emissions and performance of gas turbine combustors.

  16. Modeling the internal combustion engine

    Science.gov (United States)

    Zeleznik, F. J.; Mcbride, B. J.

    1985-01-01

    A flexible and computationally economical model of the internal combustion engine was developed for use on large digital computer systems. It is based on a system of ordinary differential equations for cylinder-averaged properties. The computer program is capable of multicycle calculations, with some parameters varying from cycle to cycle, and has restart capabilities. It can accommodate a broad spectrum of reactants, permits changes in physical properties, and offers a wide selection of alternative modeling functions without any reprogramming. It readily adapts to the amount of information available in a particular case because the model is in fact a hierarchy of five models. The models range from a simple model requiring only thermodynamic properties to a complex model demanding full combustion kinetics, transport properties, and poppet valve flow characteristics. Among its many features the model includes heat transfer, valve timing, supercharging, motoring, finite burning rates, cycle-to-cycle variations in air-fuel ratio, humid air, residual and recirculated exhaust gas, and full combustion kinetics.

  17. Optical Engines as Representative Tools in the Development of New Combustion Engine Concepts Moteurs transparents comme outils représentatifs dans le développement de nouveaux concepts des moteurs à combustion interne

    Directory of Open Access Journals (Sweden)

    Kashdan J.

    2011-11-01

    (EGR. A comparison has been made between simulated EGR (using pure nitrogen with real EGR under Diesel LTC conditions. Finally, “pure”, single component fuels are often employed in optical Diesel engines due to laser diagnostic constraints. However, these fuels generally differ from standard Diesel fuel in terms of cetane number and fuel volatility which can significantly influence the combustion and emissions characteristics in optical engines. These aspects have also been investigated within the present study. An improved understanding of the differences between optical and all-metal engines has allowed us to develop appropriate strategies to compensate for these differences on the optical engine. It is shown here that combustion phasing (and engine-out emissions matching between optical and all-metal engines can be achieved even for advanced LTC Diesel combustion strategies. The ability to ensure fully representative combustion and emissions behaviour of optical engines ultimately increases the value of optical engine data, highlighting the importance of using such engines as research tools for the further development of innovative, low emission combustion concepts. Les moteurs monocylindres transparents sont employés comme outils de recherche et de développement des moteurs à combustion interne. Ils permettent l’utilisation de techniques de diagnostics non-intrusifs (qualitatifs et quantitatifs pour étudier des phénomènes comme l’aérodynamique interne, la préparation du mélange, la combustion et la formation de polluants. Ces données expérimentales sont importantes pour la validation des modèles numériques et permettent également d’obtenir une compréhension détaillée des phénomènes physiques se déroulant dans la chambre. Les données recueillies aident au développement des nouvelles stratégies de combustion telles que la combustion homogène (HCCI et la combustion Diesel à basse température (LTC. Dans ce contexte, il est important

  18. COMBUSTION SIMULATION IN A SPARK IGNITION ENGINE CYLINDER: EFFECTS OF AIR-FUEL RATIO ON THE COMBUSTION DURATION

    OpenAIRE

    2010-01-01

    Combustion is an important subject of internal combustion engine studies. To reduce the air pollution from internal combustion engines and to increase the engine performance, it is required to increase combustion efficiency. In this study, effects of air/fuel ratio were investigated numerically. An axisymmetrical internal combustion engine was modeled in order to simulate in-cylinder engine flow and combustion. Two dimensional transient continuity, momentum, turbulence, energy, and combustion...

  19. CO{sub 2} direct cycles suitable for AGR type reactors; Cycles directs de gaz carbonique applicables aux reacteurs du genre AGR

    Energy Technology Data Exchange (ETDEWEB)

    Maillet, E. [Commissariat a l' Energie Atomique. Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

    1967-10-01

    The perspectives given by the gas turbines under pressure, to build simple nuclear power plants and acieving significantly high yield, are specified. The CO{sub 2} is characterised by by good efficiency under moderate temperature (500 to 750 Celsius degrees), compactness and the simpleness of machines and the safe exploitation (supply, storage, relief cooling, thermosyphon). The revision of thermal properties of the CO{sub 2} and loss elements show that several direct cycles would fit in particular to the AGR type reactors. Cycles that would diverge a little from classical models and able to lead to power and heat generation can lead by simple means to the best results. Several satisfying solutions present for the starting up, the power regulation and the stopping. The nuclear power plant components and the functioning safety are equally considered in the present report. The conclusions stimulate the studies and realizations of carbon dioxide gas turbines in when approprite. [French] Les perspectives offertes par la turbine a gaz sous pression, pour construire des centrales nucleaires simples et de rendement progressivement eleve, se precisent actuellement. le CO{sub 2} se distingue par sa bonne efficacite a temperature moderee (500 a 750 degres celsius), la compacite et la simplicite des machines, et la surete qu'il apporte a l'exploitation ( approvisionnement, stockage, refroidissement de secours, thermosiphon). La revision des proprietes thermophysiques du CO{sub 2} et des elements de pertes montre que divers cycles directs conviendraient en particulier aux reacteurs agr ou derives. Des cycles s'ecartant peu des modeles classiques, et se pretant ulterieurement a la production simultanee d'electricite et de chaleur, peuvent conduire par des moyens simples aux meilleurs resultats d'ensemble. Plusieurs solutions satisfaisantes se presentent pour le demarrage, le reglage de la puissance et l'arret. Les composants de la centrale et la

  20. Particle Emissions from Biomass Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Szpila, Aneta; Bohgard, Mats [Lund Inst. of Technology (Sweden). Div. of Ergonomics and Aerosol Technology; Strand, Michael; Lillieblad, Lena; Sanati, Mehri [Vaexjoe Univ. (Sweden). Div. of Bioenergy Technology; Pagels, Joakim; Rissler, Jenny; Swietlicki, Erik; Gharibi, Arash [Lund Univ. (Sweden). Div. of Nuclear Physics

    2003-05-01

    We have shown that high concentrations of fine particles of the order of 2-7x10{sup -7} particles per cm{sup 3} are being formed in all the combustion units studied. There was a higher difference between the units in terms of particle mass concentrations. While the largest differences was found for gas-phase constituents (CO and THC) and polyaromatic hydrocarbons. In 5 out of 7 studied units, multi-cyclones were the only measure for flue-gas separation. The multicyclones had negligible effect on the particle number concentration and a small effect on the mass of particles smaller than 5 {mu}m. The separation efficiency was much higher for the electrostatic precipitators. The boiler load had a dramatic influence on the coarse mode concentration during combustion of forest residue. PM0.8-6 increased from below 5 mg/m{sup 3} to above 50 mg/m{sup 3} even at a moderate change in boiler load from medium to high. A similar but less pronounced trend was found during combustion of dry wood. PM0.8-PM6 increased from 12 to 23 mg/m{sup 3} when the load was changed from low to high. When increasing the load, the primary airflow taken through the grate is increased; this itself may lead to a higher potential of the air stream to carry coarse particles away from the combustion zone. Measurements with APS-instrument with higher time-resolution showed a corresponding increase in coarse mode number concentration with load. Additional factor influencing observed higher concentration of coarse mode during combustion of forest residues, could be relatively high ash content in this type of fuel (2.2 %) in comparison to dry wood (0.3 %) and pellets (0.5 %). With increasing load we also found a decrease in PM1 during combustion of forest residue. Whether this is caused by scavenging of volatilized material by the high coarse mode concentration or a result of a different amount of volatilized material available for formation of fine particles needs to be shown in future studies. The

  1. TOXIC SUBSTANCES FROM COAL COMBUSTION

    Energy Technology Data Exchange (ETDEWEB)

    A KOLKER; AF SAROFIM; CL SENIOR; FE HUGGINS; GP HUFFMAN; I OLMEZ; J LIGHTY; JOL WENDT; JOSEPH J HELBLE; MR AMES; N YAP; R FINKELMAN; T PANAGIOTOU; W SEAMES

    1998-12-08

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. With support from the Federal Energy Technology Center (FETC), the Electric Power Research Institute, the Lignite Research Council, and VTT (Finland), Physical Sciences Inc. (PSI) has teamed with researchers from USGS, MIT, the University of Arizona (UA), the University of Kentucky (UK), the University of Connecticut (UC), the University of Utah (UU) and the University of North Dakota Energy and Environmental Research Center (EERC) to develop a broadly applicable emissions model useful to regulators and utility planners. The new Toxics Partitioning Engineering Model (ToPEM) will be applicable to all combustion conditions including new fuels and coal blends, low-NO combustion systems, and new power generation x plants. Development of ToPEM will be based on PSI's existing Engineering Model for Ash Formation (EMAF). This report covers the reporting period from 1 July 1998 through 30 September 1998. During this period distribution of all three Phase II coals was completed. Standard analyses for the whole coal samples were also completed. Mössbauer analysis of all project coals and fractions received to date has been completed in order to obtain details of the iron mineralogy. The analyses of arsenic XAFS data for two of the project coals and for some high arsenic coals have been completed. Duplicate splits of the Ohio 5,6,7 and North Dakota lignite samples were taken through all four steps of the selective leaching procedure. Leaching analysis of the Wyodak coal has recently commenced. Preparation of polished coal/epoxy pellets for probe/SEM studies is underway. Some exploratory mercury LIII XAFS work was

  2. Sandia Combustion Research Program: Annual report, 1986

    Energy Technology Data Exchange (ETDEWEB)

    1986-01-01

    This report presents research results of the past year, divided thematically into some ten categories. Publications and presentations arising from this work are included in the appendix. Our highlighted accomplishment of the year is the announcement of the discovery and demonstration of the RAPRENOx process. This new mechanism for the elimination of nitrogen oxides from essentially all kinds of combustion exhausts shows promise for commercialization, and may eventually make a significant contribution to our nation's ability to control smog and acid rain. The sections of this volume describe the facility's laser and computer system, laser diagnostics of flames, combustion chemistry, reacting flows, liquid and solid propellant combustion, mathematical models of combustion, high-temperature material interfaces, studies of engine/furnace combustion, coal combustion, and the means of encouraging technology transfer. 182 refs., 170 figs., 12 tabs.

  3. Straw combustion on slow-moving grates

    DEFF Research Database (Denmark)

    Kær, Søren Knudsen

    2005-01-01

    Combustion of straw in grate-based boilers is often associated with high emission levels and relatively poor fuel burnout. A numerical grate combustion model was developed to assist in improving the combustion performance of these boilers. The model is based on a one-dimensional ‘‘walking......-column’’ approach and includes the energy equations for both the fuel and the gas accounting for heat transfer between the two phases. The model gives important insight into the combustion process and provides inlet conditions for a computational fluid dynamics analysis of the freeboard. The model predictions...... indicate the existence of two distinct combustion modes. Combustion air temperature and mass flow-rate are the two parameters determining the mode. There is a significant difference in reaction rates (ignition velocity) and temperature levels between the two modes. Model predictions were compared...

  4. Présentation du volume

    Directory of Open Access Journals (Sweden)

    Ana Zwitter Vitez

    2012-12-01

    Full Text Available Dans de nombreuses disciplines scientifiques, le discours parlé représente depuis quelques décennies un objet de recherche proéminent. Ce fait s’explique probablement par deux caractéristiques principales du discours parlé: la structure complexe de sa matérialité et les fonctions variées de différentes pratiques langagières. C’est pourquoi le présent numéro réunit les articles basés sur les approches actuelles du discours parlé et sur les pratiques langagières spécifiques. Le volume est introduit par deux articles interdisciplinaires: Peter Garrard et Ahmed Samrah présentent le domaine de la pathologie du langage en donnant une revue fouillée sur les approches actuelles de l’analyse linguistique lors de la détection de la maladie d’Alzheimer, tandis que Harry Hollien donne un aperçu structuré sur le domaine de la phonétique judiciaire destiné à dévoiler l’identité des locuteurs et de détecter la déception dans le discours parlé. Les analyses explorant l’acquisition du langage commencent par l’article de Katharina Zipser qui examine la progression de structures grammaticales en les mettant en comparaison avec la compétence des apprenants et continuent par l’étude de Meta Lah proposant une évaluation des documents audiovisuels proposés aux apprenants de langue étrangère. Vesna Požgaj Hadži, Damir Horga et Tatjana Balažic Bulc remettent en question la corrélation entre la compétence linguistique et la fluence linguistique auprès de locuteurs non-maternels et l'analyse de Gemma Santiago Alonso aborde l'acquisition de l'article défini dans le langage enfantin. Les articles suivants se réunissent autour du domaine de l'interprétation: Jana Zidar Forte présente une approche actuelle dans l'entrainement d'interprètes, Lea Burjan analyse les phénomènes issus de la pratique de l'interprétation juridique et Simona  Šumrada traite de la reformulation dans le discours de la traduction et de

  5. Optimization of Gas Turbine Cogeneration Systemfor Various Heat Exchanger Configurations Optimisation des systèmes de turbine à combustion en cogénération pour différentes configurations des échangeurs de chaleur

    Directory of Open Access Journals (Sweden)

    Costea M.

    2011-11-01

    Full Text Available The present paper investigates and compares the performance of three configurations of Gas Turbine systems allowing cogeneration of heat and electricity, on the basis of an irreversible regenerative Brayton-Joule cycle. The proposed model is developed for two different cycle constraints, namely, an imposed heat transfer rate released by the fuel combustion, or an imposed maximum cycle temperature. The model also includes the irreversibility due to the friction in the compressor and turbine, and due to the heat losses in the combustion chamber and heat exchangers. Energy efficiency for the system without and with cogeneration, and the exergetic efficiency are used in order to emphasize the cogeneration advantages, but also to help the designer to choose the best configuration of the Gas Turbine system that suits to his needs. Experimental data from a real operating microturbine were used to validate the model. The power output and the energy and exergetic efficiencies are optimized with respect to a set of operating parameters. The optimum values of the Gas Turbine engine parameters corresponding to maximum power output and respectively to maximum thermodynamic efficiency are discussed. The results show same optimal values of the compression ratio corresponding to almost all maximum performances for an imposed heat transfer rate released by the fuel combustion, excepting the maximum exergetic efficiency that requires higher optimal values of the compression ratio than the maximum exergy rate one. A performance comparison of the three configurations is done and future perspectives of the work are proposed. Cet article explore et compare les performances des trois configurations de systèmes de turbine à combustion permettant la production combinée de chaleur et d’électricité, sur la base du cycle irréversible régénératif de Brayton-Joule. Le modèle proposé est développé pour deux contraintes différentes sur le cycle, notamment le

  6. Experimental research on combustion fluorine retention using calcium-based sorbets during coal combustion (Ⅰ)

    Institute of Scientific and Technical Information of China (English)

    QI Qing-jie; LIN Zhi-yan; LIU Jian-zhong; WU Xian; ZHOU Jun-hu; CEN Ke-fa

    2008-01-01

    In order to provide experimental guide to commercial use of fluorine pollution control during coal combustion, with fluorine pollution control during coal combustion in mind, this paper proposed the theory of combustion fluorine retention technology. Feasibility of fluorine retention reaction with calcium-based fluorine retention agent was analyzed through thermo-dynamic calculation during coal combustion. By simulating the restraining and retention effects and influential factors of calcium-based sorbets on vaporized fluoride during experimental combustion using fixed bed tube furnace, the paper systematically explored the influential law of such factors as combustion temperature, retention time, and added quantities of calcium-based sorbets on effects of fluorine retention. The research result shows that adding calcium-based fluorine retention agent in coal combustion has double effects of fluorine retention and sulfur retention, it lays an experimental foundation for commercial test of combustion fluorine retention.

  7. Fuel combustion test in constant volume combustion chamber with built-in adaptor

    Institute of Scientific and Technical Information of China (English)

    JEONG; DongSoo; CHO; GyuBack; CHOI; SuJin; LEE; JinSoo

    2010-01-01

    Combustion tests of pre-mixture of methane and air in constant volume combustion chamber(CVCC) have been carried out by means of flame propagation photo and gas pressure measurement,the effects of CVCC body temperature,intake pressure of pre-mixture of methane and air,equivalence ratio and location of the built-in adaptor have been investigated.The whole combustion chamber can be divided into two parts,i.e.the upper combustion chamber and the lower combustion chamber,by the built-in adaptor with through hole.Owing to the built-in adaptor with through hole,jet ignition or compression ignition(auto-ignition) phenomena may occur in the lower combustion chamber,which is helpful to getting higher flame propagation velocity,higher combustion peak pressure,low cycle-to-cycle variation and more stable combustion process.

  8. Combustion Behavior of Free Boron Slurry Droplets,

    Science.gov (United States)

    2014-09-26

    weak disruptive behavior while pure JP-1t burn quiescently, except for a flash extinction which occurs at the termination of combustion. The...I AD-R158 628 COMBUSTION BEHAVIOR OF FREE BORON SLURRY DROPLETS(U) i/i I PRINCETON UNIV NJ DEPT OF MECHANICAL AND AEROSPACE ENINEERIN., F TAKAHASHI...COMBUSTION BEHAVIOR OF FREE BORON SLURRY DROPLETS TAM by F. Takahashi, F.L. Dryer, and F.A. Williams Department of M~echanical and keyosase Engineering

  9. Materials for High-Temperature Catalytic Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ersson, Anders

    2003-04-01

    Catalytic combustion is an environmentally friendly technique to combust fuels in e.g. gas turbines. Introducing a catalyst into the combustion chamber of a gas turbine allows combustion outside the normal flammability limits. Hence, the adiabatic flame temperature may be lowered below the threshold temperature for thermal NO{sub X} formation while maintaining a stable combustion. However, several challenges are connected to the application of catalytic combustion in gas turbines. The first part of this thesis reviews the use of catalytic combustion in gas turbines. The influence of the fuel has been studied and compared over different catalyst materials. The material section is divided into two parts. The first concerns bimetallic palladium catalysts. These catalysts showed a more stable activity compared to their pure palladium counterparts for methane combustion. This was verified both by using an annular reactor at ambient pressure and a pilot-scale reactor at elevated pressures and flows closely resembling the ones found in a gas turbine combustor. The second part concerns high-temperature materials, which may be used either as active or washcoat materials. A novel group of materials for catalysis, i.e. garnets, has been synthesised and tested in combustion of methane, a low-heating value gas and diesel fuel. The garnets showed some interesting abilities especially for combustion of low-heating value, LHV, gas. Two other materials were also studied, i.e. spinels and hexa aluminates, both showed very promising thermal stability and the substituted hexa aluminates also showed a good catalytic activity. Finally, deactivation of the catalyst materials was studied. In this part the sulphur poisoning of palladium, platinum and the above-mentioned complex metal oxides has been studied for combustion of a LHV gas. Platinum and surprisingly the garnet were least deactivated. Palladium was severely affected for methane combustion while the other washcoat materials were

  10. The combustion of solid fuels and wastes

    CERN Document Server

    Tillman, David

    1991-01-01

    Careful organization and empirical correlations help clarify the prodigious technical information presented in this useful reference.Key Features* Written for practicing engineers, this comprehensive book supplies an overall framework of the combustion process; It connects information on specific reactions and reaction sequences with current applications and hardware; Each major group of combustion solids is evaluated; Among the many topics covered are:* Various biomass forms* The coalification process* Grate, kiln, and suspension firing* Fluidized bed combustion

  11. Basic theory research of coal spontaneous combustion

    Institute of Scientific and Technical Information of China (English)

    WANG Ji-ren; SUN Yan-qiu; ZHAO Qing-fu; DENG Cun-bao; DENG Han-zhong

    2008-01-01

    Discussed latest research results of basic theory research of coal spontaneous combustion in detail, with quantum chemical theory and method and experiment systematically studied chemical structure of coal molecule, adsorption mechanism of coal surface to oxygen molecule and chemical reaction mechanism and process of spontaneous combustion of organic macromolecule and low molecular weight compound in coal from microcosmic view, and established complete theoretical system of the mechanism of coal spontaneous combustion.

  12. Nitrous Oxide from Combustion and Industry: Chemistry, Emissions and Control Protoxyde d'azote provenant de la combustion et de l'industrie : chimie, émissions et techniques de réduction

    Directory of Open Access Journals (Sweden)

    De Soete G.

    2006-11-01

    'industrie chimique, d'autre part il s'interroge sur les technologies possibles de destruction de N2O dans les cas où sa teneur dans les fumées ou autres effluves industriels pose des problèmes. Comme les émissions, aussi bien que les moyens de les abattre, sont fortement tributaires des mécanismes chimiques responsables de la production et de la destruction du N2O, une introduction substantielle sur la cinétique homogène et hétérogène de sa formation/réduction, telle qu'elle apparaît dans un contexte de combustion, est fournie, permettant au lecteur de comprendre le pourquoi de ces émissions et le comment des technologies d'abattement suggérées. Dans une première section de l'introduction, on rappelle brièvement la chimie du N2O en phase gazeuse et ses relations avec la chimie du monoxyde d'azote NO (fig. 1 ; l'effet de la température sur la production nette de N2O est accentué, puisqu'elle expliquera en grande partie les émissions relativement élevées de la combustion à basse température, telle qu'elle est mise en oeuvre dans les lits fluidisés (fig. 2. On mentionne pour finir les réactions du système rédox SO2/NO (fig. 3, responsable de la formation artificiellede N2O dans les échantillons de fumées stockés. La deuxième section de l'introduction traite de la chimie hétérogène du protoxyde d'azote, dont la compréhension est actuellement encore relativement fragmentaire. Parmi les mécanismes hétérogènes non catalytiques, figurent principalement : la réduction de N2O sur le carbone constitutif du charbon et du coke, la formation de N2O à partir de l'azote constitutif de ces derniers et la production de N2O par des réactions entre carbone, NO et sulfates. Les deux premiers mécanismes sont traités en parallèle avec ceux, similaires, qui opèrent sur le NO, auxquels ils sont intimement liés (voir tableau 1 et réactions S1 à S8 dans le texte. La réduction de N20 sur carbone constitutif ne produit que peu de N2O, au moins en absence d

  13. L’écologie du coupable.

    Directory of Open Access Journals (Sweden)

    André Ourednik

    2006-04-01

    Full Text Available « Denn dass der Mensch erlöst werde von der Rache  : das ist mir die Brücke zur höchsten Hoffnung und ein Regenbogen nach langen Unwettern. » 1 Nous l’aurions presque oublié, en fouillant parmi les fondations du rapport moral au monde de nos sociétés, nous trouverons encore bien en place deux piliers érigés au cours du processus de la chrétienté : celui de l’ empathie et celui de la culpabilité . Le premier semble offrir le seul appui plausible à notre vivre ...

  14. Les Nymphes dans les rites du mariage

    OpenAIRE

    2013-01-01

    Le champ du mariage (où l’on rencontre à la fois les Nymphes puissances surnaturelles et les numphai humaines) peut se révéler intéressant pour croiser des données littéraires, archéologiques et épigraphiques sur le culte des Nymphes. Lors des préliminaires, ces puissances peuvent être l’objet des protéléia (sacrifices prénuptiaux) ou être associées avec la loutrophorie et le bain prénuptial. Les Nymphes n’interviennent guère pendant la journée de célébration du mariage, sauf dans des textes ...

  15. High Frequency Combustion Instabilities of LOx/CH4 Spray Flames in Rocket Engine Combustion Chambers

    OpenAIRE

    Sliphorst, M.

    2011-01-01

    Ever since the early stages of space transportation in the 1940’s, and the related liquid propellant rocket engine development, combustion instability has been a major issue. High frequency combustion instability (HFCI) is the interaction between combustion and the acoustic field in the combustion chamber. It destroys the thermal boundary layer wall increasing heat transfer and could lead to compromised performance, and ultimately to destruction of the engine and mission loss. The main object...

  16. Hydrodynamique, transfert de chaleur et combustion de gaz naturel en lit fluidisé circulant Hydrodynamics, Heat Transfer and Combustion of Natural Gas in a Circulating Fluidized Bed

    Directory of Open Access Journals (Sweden)

    Feugier A.

    2006-11-01

    Full Text Available L'hydrodynamique, les transferts de chaleur et la combustion du gaz naturel ont été étudiés dans un réacteur à lit circulant de 15 cm de diamètre et de 7 m de haut. Ce réacteur peut opérer avec des vitesses de gaz allant jusqu'à 15 m/s, jusqu'à des températures de 880-900°C et avec des débits de solides compris entre 0 et 15t/h. Les charges utilisées sont des sables de granulométrie allant de 95 à 625 microns. Le profil de concentration en solides dans le réacteur est déterminé à partir du profil de pression. Une corrélation reliant la vitesse de glissement des particules aux principaux paramètres opératoires, rend compte de façon très satisfaisante de l'ensemble des résultats expérimentaux. La mise en place d'un échangeur en paroi dans la partie supérieure du réacteur a permis la détermination de coefficients d'échange thermique. Ces derniers sont essentiellement fonction de la, concentration en particules au droit de l'échangeur et de la granulométrie des particules. Des valeurs allant jusqu'à 200 W/m2 K peuvent, être obtenues. Enfin, la combustion du méthane s'avère très sensible à la présence de particules dans le réacteur. Ces particules ont un effet inhibiteur. Hydrodynamics, heat transfer and combustion of natural gas have been investigated in a circulating-bed reactor 15 cm in diameter and 7 m high. This reactor can operate with gas velocities up to 15 m/s, at temperature up to 880-900°C and with solids flow rates of between 0 and 15 t/h. The solids used are sands with a particle size ranging from 95 to 625 microns. The solids concentration profile in the reactor is determined from the pressure profile. A correlation linking the slippage velocity of particles to the principal operating parameters very satisfactorily takes into consideration the overall experimental results. The installation of a wall heat exchanger in the upper part of the reactor enabled the heat exchange coefficients to be

  17. Fuel gas combustion research at METC

    Energy Technology Data Exchange (ETDEWEB)

    Norton, T.S.

    1995-06-01

    The in-house combustion research program at METC is an integral part of many METC activities, providing support to METC product teams, project managers, and external industrial and university partners. While the majority of in-house combustion research in recent years has been focussed on the lean premixed combustion of natural gas fuel for Advanced Turbine Systems (ATS) applications, increasing emphasis is being placed on issues of syngas combustion, as the time approaches when the ATS and coal-fired power systems programs will reach convergence. When the METC syngas generator is built in 1996, METC will have the unique combination of mid-scale pressurized experimental facilities, a continuous syngas supply with variable ammonia loading, and a team of people with expertise in low-emissions combustion, chemical kinetics, combustion modeling, combustion diagnostics, and the control of combustion instabilities. These will enable us to investigate such issues as the effects of pressure, temperature, and fuel gas composition on the rate of conversion of fuel nitrogen to NOx, and on combustion instabilities in a variety of combustor designs.

  18. Secondary combustion device for woodburning stove

    Energy Technology Data Exchange (ETDEWEB)

    Craver, R.D.

    1987-06-16

    This patent describes a wood burning stove including an exhaust flue opening, a combustion chamber for primary combustion having an access door, a support for wood to be burnt and a primary air inlet means for supplying air to support primary combustion of the wood to produce flue gases containing combustible particulate material. A conduit means for directing the flue gases is included from the combustion chamber to the flue opening in a preselected path. Also included is a secondary combustion means for burning particulate material in flue gases before flue gases pass through the exhaust flue opening. The improvement comprises: secondary combustion means including an elongated manifold extending laterally across and above the combustion chamber at a preselected position on the preselected path; a number of air openings spaced longitudinally along the manifold and facing the path of the flue gases and an air inlet means for supplying ambient; secondary combustion air to the manifold for flow from openings into the path of the flue gases in distinct jets; and a laterally elongated passageway above the manifold with upper and lower portions and defined at its upper portion by a sheet metal wall, and a layer of extremely low heat conducting insulation in the passageway. On the sheet metal wall the layer of insulation prevents appreciable conduction of heat from the passageway into the sheet metal wall and flue gases flow through the passageway and from passageway in a generally wide thin flow pattern.

  19. Determining Heats of Combustion of Gaseous Hydrocarbons

    Science.gov (United States)

    Singh, Jag J.; Sprinkle, Danny R.; Puster, Richard L.

    1987-01-01

    Enrichment-oxygen flow rate-ratio related to heat of combustion. Technique developed for determining heats of combustion of natural-gas samples. Based on measuring ratio m/n, where m is (volmetric) flow rate of oxygen required to enrich carrier air in which test gas flowing at rate n is burned, such that mole fraction of oxygen in combustion-product gases equals that in carrier air. The m/n ratio directly related to heats of combustion of saturated hydrocarbons present in natural gas.

  20. Sustainable growth, the DuPont way.

    Science.gov (United States)

    Holliday, C

    2001-09-01

    Like many manufacturers, DuPont traditionally has grown by making more and more "stuff." And its business growth has been proportional to the amount of raw materials and energy used--as well as the resulting waste and emissions from operations. Over the years, though, DuPont became aware that cheap supplies of nonrenewable resources wouldn't be endlessly available and that the earth's ecosystems couldn't indefinitely absorb the waste and emissions of production and consumption. Chad Holliday, chairman and CEO of DuPont, believes strongly in the challenge of sustainable growth and makes the business case for it: By using creativity and scientific knowledge effectively, he says, companies can provide strong returns for shareholders and grow their businesses--while also meeting the human needs of societies around the world and reducing the environmental footprint of their operations and products. In fact, a focus on sustainability can help identify new products, markets, partnerships, and intellectual property and lead to substantial business growth. Holliday describes how DuPont developed a three-pronged strategy to translate the concept of sustainability into nuts-and-bolts business practices. Focusing on integrated science, knowledge intensity, and productivity improvement, the strategy was accompanied by a new way to measure progress quantitatively. Sustainable growth should be viewed not as a program for stepped-up environmental performance but as a comprehensive way of doing business, one that delivers tremendous economic value and opens up new opportunities. Ultimately, companies will find that they can generate substantial business value through sustainability while both enhancing the quality of life around the world and protecting the environment.