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Sample records for refroidis par gaz

  1. Containment for Heavy-Water Gas-Cooled Reactors; Le Confinement des Reacteurs a Eau Lourde Refroidis par Gaz

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    Verstraete, P.; Lehmann, D.; Lafitte, R. [Bonard et Gardel, Ingenieurs-Conseils, Lausanne (Switzerland)

    1967-09-15

    par gaz sont passes en revue dans le but d'etablir les specifications des enceintes de confinement en fonction des conditions des sites disponibles en Suisse pour la construction de centrales nucleaires. Ces specifications sont etablies d'apres les taux de dose consideres comme admissibles pour les populations vivant aux environs de la centrale en cas d 'accident grave du reacteur, en se basant sur des conditions meteorologiques et demographiques representatives de la plupart des sites du pays. Differents modes de construction de l ' enceinte de confinement, prenant en consideration les conditions qui s'etablissent dans l'enceinte a la suite de l'accident maximal concevable du reacteur, sont consideres. Les enceintes etudiees sont les suivantes: beton precontraint; beton precontraint avec coupole d'acier; beton precontraint avec peau d' etancheite interieure en acier; acier avec ecran lateral en beton pour la protection contre les radiations; et double confinement. Le degre d'etancheite des enceintes etudiees a ete considere comme une caracteristique lie e au mode de construction particulier et non comme une valeur prescrite en vue de laquelle la construction devait etre adaptee. Les caracteristiques d'etancheite de chaque enceinte sont estimees et les prix de chaque construction ont ete determines sur la base de plans precis avec le concours de diverses entrepises specialisees. L'estimation de l'efficacite des differentes enceintes, sous l'an gle de la securite, a ete faite en prenant en consideration differentes procedures en cas d' accident parmi lesquelles on citera principalement le rejet atmospherique, au travers de filtres adequats, et la decontamination de l 'atmosphere de l 'enceinte par recyclage dans des batteries de filtres. Une dizaine de cas, correspondant a differentes combinaisons de modes de construction et procedures en cas d'accident, font l 'objet d'une comparaison tres detaillee qui a ete realisee grace a un programme pour ordinateur electronique

  2. Can-rupture detection in gas-cooled nuclear reactors; La detection des ruptures de gaine dans les piles nucleaires refroidies par gaz

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    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

  3. Can-rupture detection in gas-cooled nuclear reactors; La detection des ruptures de gaine dans les piles nucleaires refroidies par gaz

    Energy Technology Data Exchange (ETDEWEB)

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

    1965-07-01

    Can-rupture detection (DRG) is one important aspect of pile safety, more particularly so in the case of gas-cooled reactors. A rapid and sure detection constitutes also an improvement as far as the efficiency of electricity-producing nuclear power stations are concerned. Among the numerous can-rupture detection methods, that based on the measurement of the concentration of short-lived fission gases in the heat-carrying fluid has proved to be the most sensitive and the most rapid. A systematic study of detectors based on the electrostatic collection of the daughter products of fission gases has been undertaken with a view to equip the reactors EL 2, G 3, EDF 1, EDF 2 and EDF 3, the gas loops of PEGASE and EL 4. The different parameters are studied in detail in order to obtain a maximum sensitivity and to make it possible to construct detection devices having the maximum operational reliability and requiring the minimum maintenance. The primary applications of these devices are examined in the case of the above-mentioned reactors. (author) [French] La Detection des Ruptures de Gaines (D. R. G.) est un aspect important de la securite des piles et plus particulierement des piles refroidies par un gaz. Une detection rapide et sure constitue aussi un element d'amelioration du rendement des centrales nucleaires productrices d'energie electrique. Parmi les nombreuses methodes de detection des ruptures de gaines, la mesure de la concentration dans le fluide caloporteur des gaz de fission a vie courte s'est revelee comme la plus sensible et la plus rapide. Une etude systematique des detecteurs a collection electrostatique des descendants des gaz de fission a ete entreprise en vue d'equiper les piles EL 2, G 3, EDF 1, EDF 2 et EDF 3, les boucles a gaz de la pile Pegase et la pile EL 4. Les divers parametres sont etudies en detail pour obtenir une sensibilite maximum et permettre la realisation de dispositifs de detection ayant le maximum de securite de fonctionnement et le

  4. Corrosion of magnesium and some magnesium alloys in gas cooled reactors; Corrosion du magnesium et de certains de ses alliages dans les piles refroidies par gaz

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

    1958-07-01

    The results of corrosion tests on magnesium and some magnesium alloys (Mg-Zr and Mg-Zr-Zn) in moist air (like G1 reactor) and in CO{sub 2}: (like G2, G3, EDF1 reactors) are reported. The maximum temperature for exposure of magnesium to moist air without any risk of corrosion is 350 deg. C. Indeed, the oxidation rate follows a linear law above 350 deg. C although it reaches a constant level and keeps on very low under 350 deg. C. However, as far as corrosion is concerned this temperature limit can be raised up to 500 deg. C if moist air is very slightly charged with fluorinated compounds. Under pressure of CO{sub 2}, these three materials oxidate much more slowly even if 500 deg. C is reached. The higher is the temperature, the higher is the constant level of the weight increase and the quicker is reached this one. However, Mg-Zr alloy behaves quite better than pure magnesium and especially than Mg-Zr-Zn alloy. (author)Fren. [French] On expose essentiellement les resultats d'etudes sur la corrosion du magnesium et de certains de ses alliages (Mg-Zr et Mg-Zr-Zn) dans l'air humide (cas de la pile G1) et dans le gaz carbonique (cas des piles G2, G3, EDF1, etc...). La temperature limite d'exposition du magnesium dans l'air humide sans risque de corrosion se situe a 350 deg. C; en effet l'oxydation a un caractere lineaire au-dessus de cette temperature, alors qu'elle atteint un palier et reste tres limitee au-dessous de 350 deg. C. Du point de vue de la corrosion, cette temperature limite d'emploi peut cependant etre elevee jusqu'a 500 deg. C si l'on introduit dans l'air humide de tres faibles teneurs de composes fluores. Dans le gaz carbonique sous pression, l'oxydation est beaucoup plus faible, meme jusqu'a 50g. C pour les trois materiaux: l'augmentation de poids atteint un palier d'autant plus eleve et ceci d'autant plus rapidement que la temperature est elle-meme plus elevee. Cependant, l'alliage Mg-Zr se comporte nettement mieux que le magnesium pur et surtout que l

  5. Corrosion of magnesium and some magnesium alloys in gas cooled reactors; Corrosion du magnesium et de certains de ses alliages dans les piles refroidies par gaz

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

    1958-07-01

    The results of corrosion tests on magnesium and some magnesium alloys (Mg-Zr and Mg-Zr-Zn) in moist air (like G1 reactor) and in CO{sub 2}: (like G2, G3, EDF1 reactors) are reported. The maximum temperature for exposure of magnesium to moist air without any risk of corrosion is 350 deg. C. Indeed, the oxidation rate follows a linear law above 350 deg. C although it reaches a constant level and keeps on very low under 350 deg. C. However, as far as corrosion is concerned this temperature limit can be raised up to 500 deg. C if moist air is very slightly charged with fluorinated compounds. Under pressure of CO{sub 2}, these three materials oxidate much more slowly even if 500 deg. C is reached. The higher is the temperature, the higher is the constant level of the weight increase and the quicker is reached this one. However, Mg-Zr alloy behaves quite better than pure magnesium and especially than Mg-Zr-Zn alloy. (author)Fren. [French] On expose essentiellement les resultats d'etudes sur la corrosion du magnesium et de certains de ses alliages (Mg-Zr et Mg-Zr-Zn) dans l'air humide (cas de la pile G1) et dans le gaz carbonique (cas des piles G2, G3, EDF1, etc...). La temperature limite d'exposition du magnesium dans l'air humide sans risque de corrosion se situe a 350 deg. C; en effet l'oxydation a un caractere lineaire au-dessus de cette temperature, alors qu'elle atteint un palier et reste tres limitee au-dessous de 350 deg. C. Du point de vue de la corrosion, cette temperature limite d'emploi peut cependant etre elevee jusqu'a 500 deg. C si l'on introduit dans l'air humide de tres faibles teneurs de composes fluores. Dans le gaz carbonique sous pression, l'oxydation est beaucoup plus faible, meme jusqu'a 50g. C pour les trois materiaux: l'augmentation de poids atteint un palier d'autant plus eleve et ceci d'autant plus rapidement que la temperature est elle-meme plus elevee. Cependant, l

  6. Aerodynamic and thermal studies of cans of gas cooled fuel elements; Etudes aerodynamiques et thermiques de gaines d'elements combustibles refroidis par gaz

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

    1964-07-01

    l'amelioration des grappes et s'est ensuite poursuivie dans les deux Laboratoires pour le refroidissement interne des elements combustibles annulaires. Au fur et a mesure de l'avancement de ces etudes, les moyens d'essais se sont amplifies tandis que les methodes experimentales n'ont cesse de s'ameliorer. Actuellement, les deux Laboratoires, qui travaillent en pleine collaboration, disposent de moyens puissants. Pour les grappes, l'effort a surtout porte sur les pertes de charge dues aux pieces d'assemblage et sur les variations de temperature autour des elements de la grappe. On est arrive ainsi a determiner d'une facon satisfaisante les points chauds de gaine, les deformations des crayons et les conditions de stabilite de ces deformations. Pour les gaines a chevrons, les etudes ont porte, d'une part sur l'evolution des performances en fonction des parametres geometriques, et, d'autre part sur les singularites aerodynamiques et thermiques creees tant par les ailettes que par les interruptions de cartouche. Ces etudes ont abouti a une connaissance tres complete des cartouches choisies pour les reacteurs EDF2 et EDF3, et ouvrent maintenant des perspectives tres encourageantes pour les reacteurs a venir, en particulier les reacteurs equipes d'elements annulaires; parmi les solutions convenant a la gaine interne de l'element annulaire, les corrugations et les ailettes longitudinales ont fait l'objet d'essais assez etendus dans une large plage de nombre de Reynolds. (auteurs)

  7. Detection of burst cans in the reactors cooled by gaseous phase; Detection des ruptures de gaine dans les reacteurs refroidis par phase gazeuse

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    Labeyrie, J; Roguin, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    In a nuclear reactor including the bars or plates cooled by a gaseous fluid, burst risks to occur in the sheath assuring the tightness separation between the cooling gas and the fissile materials. It is necessary to be able to detect the formation of these cracks as possible in order to avoid all risk of fission products release or any reaction of uranium to the contact of the refrigerating gas. It is however the increase of the radioactivity in the cooling gas due to the scattering of the fission products that permits to signal the apparition of a crack or to follow its evolution. It is possible to detect cracks of the order of the square millimeter. In this report, we will detail the principle and the realization of a device used for the surveillance of a natural uranium reactor cooled by air circulation. (M.B.) [French] Dans un reacteur nucleaire comportant des barres ou des plaques refroidies par un fluide gazeux des fissures risquent de se produire dans les gaines assurant la separation etanche entre le gaz de refroidissement et les materiaux fissiles. II est necessaire de pouvoir detecter la formation de ces fissures des que possible afin d'eviter tout risque de liberation de produits de fission ou de reaction de l'uranium au contact du gaz refrigerant. C'est cependant l'augmentation de la radioactivite du gaz de refroidissement due a la dispersion des produits de fission qui permet de signaler l'apparition d'une fissure ou de suivre son evolution. On peut ainsi detecter des fissures de l'ordre du millimetre carre. Dans ce rapport, nous detaillerons le principe et la realisation d'un appareil utilise pour la surveillance d'un reacteur a uranium naturel refroidi par circulation d'air. (M.B.)

  8. Development of Non-Metallic Fuel Elements for a High-Temperature Gas-Cooled Reactor; Mise au point d'elements combustibles non metalliques pour un reacteur a haute temperature, refroidi par un gaz; Razrabotka nemetallicheskikh teplovydelyashchikh ehlementov dlya vysokotemperaturnogo reaktora s gazovym okhlazhdeniem; Elementos combustibles no metalicos para un reactor de temperatura elevada refrigerado por gas

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    Liebmann, B.; Schafer, L.; Spener, G. [NUKEM, Nuklear-Chemie und -Metallurgie G.m.b.H., Wolfgang bei Hanau, Federal Republic of Germany (Germany)

    1963-11-15

    In connection with fuel element development work for the high-temperature gas-coolcd reactor of the Brown-Boveri/Krupp Reaktorbau G.m.b.H., two different fuel element concepts were considered and developed. In both cases the fuel element consists of a graphite ball of 6 cm in diam. which contains the fuel insert, a cylindrical pellet of about 20 mm in diam. and 16 mm in height. The two concepts differ in the type of the.fuel insert as well as in the preparation of the graphite ball. In the first concept the fuel insert consists of a mixture of UC{sub 2} and graphite which is prepared by blending U{sub 3}O{sub 8} and graphite, pressing them into pellets and reacting the two components in a vacuum furnace at 1800{sup o}C. The atomic ratio of U : C is 1:45. Since this type of fuel pellet does not retain the fission products completely the surrounding graphite sphere had to be made impervious to fission products by impregnation in order to obtain a fission-product retaining element. Permeabilities of the order of 10{sup -6}cm{sup 2}/s could be achieved. In the second concept the fuel insert consists of a solid solution of UC in ZrC and is coated with a layer of ZrC. The molar ratio of UC to ZrC is 1 : 20. The fuel pellet preparation was accomplished by the following procedure: UO{sub 2}, ZrO{sub 2}, and graphite were mixed and pressed into pellets. The pellets were reacted to the carbides. Ball milling of the carbides was followed by hot pressing at temperatures o f 2000{sup o}C. Densities of more than 95% of the theoretical density could be achieved. A full description of the preparation and of some physical properties of the fuel pellets is given in the paper. A sufficient fission gas retention behaviour of this type of fuel insert which allows it to be put into unimpregnated graphite balls is expected. Other advantages of this kind of fuel are discussed. (author) [French] Dans le cadre des etudes de combustibles destines au reacteur a haute temperature, refroidi par

  9. Reactor Physics Development for Advanced Gas-Cooled Reactors; Recherches en Physique des Reacteurs, pour des Reacteurs Perfectionnes Refroidis par un Gaz; Razrabotka metodov v oblasti reaktornoj fiziki dlya usovershenstvovannogo reaktora s gazovym okhlazhdeniem; Progresos de la Fisica de los Reactores de Tipo Avanzado Refrigerados por Gas

    Energy Technology Data Exchange (ETDEWEB)

    Moore, J. [United Kingdom Atomic Energy Authority (United Kingdom)

    1964-04-15

    effects in APEX, HERO and AGR and for determining fine structure data and power distribution in the complex fuel assemblies are of particular interest. Current and future theoretical work is concentrated primarily on development of an alternative method to hetrecontrol and FTD2 for dealing with reactor cores after considerable burn-up of the fuel. The experimental programme on HERO is designed to test these methods with complex cores including plutonium bearing fuel. Additional information on the effect of plutonium will be derived from operation of AGR and physics measurements on fuel after irradiation. (author) [French] Le memoire relate les recherches experimentales et theoriques auxquelles on a procede lois de l'etude, de la realisation et de la mise en service du reacteur perfectionne refroidi par un gaz (AGR) de Windscale et, d'une facon generale, pour la mise au point d'un filiere de ce type en vue de la production d'energie electrique industrielle. Il decrit l'important volume de travail qui a ete necessaire en vue d'elaborer les methodes theoriques voulues pour calculer: a) la repartition du flux et l'equilibre de la reactivite dans un coeur complexe; b) la repartition de la puissance dans des geometries de combustible complexes-, c) les effets de l'irradiation sur le cycle du combustible et la repartition de la puissance. A titre d'introduction, le memoire resume la documentation experimentale et les methodes theoriques qui sont le resultat des recherches sur la filiere a uranium gaine de magnox et decrit la documentation experimentale obtenue par le programme commun des industries britanniques (BICEP); toutes ces donnees ont servi de point de depart pour l'elaboration de methodes theoriques applicables a l'AGR. On s'est servi de l'ensemble critique APEX et du reacteur HERO de puissance zero avec des configurations de reseau regulieres et diverses combinaisons de perturbateurs (notamment des barres de commande) pour calculer les parametres de reseau de l'AGR et

  10. Study of the consequences of the rupture of a pressure tube in the tank of a gas-cooled, heavy-water moderated reactor; Etude des consequences de la rupture d'un tube de force dans la cuve d'un reacteur modere a l'eau lourde et refroidi au gaz

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    Hareux, F; Roche, R; Vrillon, B [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    Bursting of a pressure tube in the tank of a heavy water moderated-gas cooled reactor is an accident which has been studied experimentally about EL-4. A first test (scale 1) having shown that the burst of a tube does not cause the rupture of adjacent tubes, tests on the tank resistance have been undertaken with a very reduced scale model (1 to 10). It has been found that the tank can endure many bursts of tube without any important deformation. Transient pressure in the tank is an oscillatory weakened wave, the maximum of which (pressure peak) has been the object of a particular experimental study. It appears that the most important parameters which affect the pressure peak are; the pressure of the gas included in the bursting pressure tube, the volume of this gas, the mass of air included in the tank and the nature of the gas. A general method to calculate the pressure peak value in reactor tanks has been elaborated by direct application of experimental data. (authors) [French] L'eclatement d'un tube de force dans la cuve d'un reacteur de puissance modere a l'eau lourde et refroidi par un gaz sous pression est un accident qui a ete etudie experimentalement a propos d'EL-4. Un premier essai a l'echelle 1 ayant montre que l'eclatement d'un tube ne provoque pas celui des tubes voisins, des essais relatifs a la tenue de la cuve ont ete effectues sur maquettes a echelle tres reduite (l/lO). Il a ete trouve que la cuve peut supporter plusieurs eclatements de tubes sans deformations notables. La pression transitoire dans la cuve a une allure oscillatoire amortie dont le maximum (pression de pic) a fait l'objet d'une etude experimentale detaillee. Il apparait que les parametres essentiels influant sur cette pression sont: la pression du gaz contenu dans le tube de force, le volume du gaz qui participe a l'eclatement, la flexibilite de la cuve, la masse d'air empoisonnee dans la cuve, la nature du gaz explosant. Une methode generale d'estimation des pics de pression dans

  11. High-Temperature Gas-Cooled Reactor Critical Experiment and its Application to Thorium Absorption Rates; Experience Critique pour l'Etude d'un Reacteur a Haute Temperature, Refroidi par un Gaz et son Application a la Determination des Taux d'Absorption du Thorium; Kriticheskij opyt, postavlennyj na vysokotemperaturnom reaktore s gazovym okhlazhdeniem, i primenenie ego dlya opredeleniya stepeni pogloshcheniya toriya; Experimento Critico Efectuado en un Reactor de Elevada Temperatura Refrigerado por Gas y su Aplicacion para Calcular los Indices de Absorcion del Torio

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    Bardes, R. G.; Brown, J. R.; Drake, M. K.; Fischer, P. U.; Pound, D. C.; Sampson, J. B.; Stewart, H. B. [General Dynamics Corporation,San Diego, CA (United States)

    1964-04-15

    the fact that the thorium is dispersed in graphite and the usual cadmium-ratio technique is difficult to apply. Comparison of experimental and theoretical results shows excellent agreement over a range of variables. In addition, the results of both activation and reactivity measurements of Doppler coefficient are in agreement, a fact which is felt to be significant in view of the disparity between results from these two techniques in the literature. (author) [French] Lors de l'etude du reacteur HTGR a haute temperature refroidi par un gaz, et de son premier prototype a Peach Bottom, la General Atomic Division de la societe General Dynamics a decide qu'il fallait proceder a une experience critique pour obtenir certaines donnees d'entree necessaires pour l'analyse nucleaire. Aux fins de l'etude nucleaire theorique, les besoins particuliers en donnees d'entree relatives aux absorptions par le thorium ont amene les ingenieurs a concevoir un assemblage experimental critique compose d'un reseau central entoure d*une region tampon et d'une region de commande. Ce type.d'assemblage, dans lequel on peut creer le spectre a mesurer dans le reseau central relativement petit ayant la geometrie voulue, permet d'obtenir des donnees d'entree tres diverses pour les etudes de projets nouveaux, au point de vue de l'analyse nucleaire. Le memoire indique les avantages particuliers que presente cette methode par rapport a celle qiu consiste a construire une maquette, ainsi que le role de la theorie pour determiner quelles experiences sont le plus utiles et comment utiliser ensuite ces experiences dans la verification des procedes d'etude. Les auteurs ont mis au point deux methodes relativement nouvelles qui peuvent etre utilisees avec l'assemblage decrit ci-dessus: une methode d'oscillation de la reactivite pour determiner le coefficient Doppler pour le thorium; une methode d'activation pour determiner a la fois l'integrale de resonance pour le thorium disperse dans le graphite et ses

  12. Contribution to the study of the stability of water-cooled reactors; Contribution a l'etude de la stabilite des reacteurs refroidis par de l'eau

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

    1969-06-01

    This work is devoted to the study of the stability of reactors cooled by water subjected only to natural convection. It is made up of two parts, a theoretical study and experimental work, each of these parts being devoted to a consideration of linear and non-linear conditions: - calculation of the transfer function of the reactor using neutronic and hydrodynamic linear equations with the determination of the instability threshold; - demonstration of the existence of the limiting oscillation cycle in the case of a linear feedback using MALKIN'S method; - measurement and interpretation of the reactor's transfer functions and of the hydrodynamic transfer functions; and - analysis of the noise due to boiling. (author) [French] Dans ce travail on etudie la stabilite des piles refroidies par de l'eau circulant en convection naturelle. Cette etude se divise en deux parties: un travail theorique et un travail experimental, chacune de ces parties comportant une etude lineaire et une etude non-lineaire: - calcul de la fonction de transfert du reacteur a partir des equations lineaires de la neutronique et de l'hydrodynamique avec determination du seuil d'instabilite; - demonstration de l'existence du cycle limite des oscillations dans le cas d'une retroaction lineaire en utilisant la methode de MALKIN; - mesure et interpretation de la fonction de transfert du reacteur et des fonctions de transfert hydrodynamiques; et - analyse du bruit d'ebullition. (auteur)

  13. Les techniques de séparation de gaz par membranes Gas Separation Techniques by Membranes

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    Avrillon R.

    2006-11-01

    Full Text Available Deux types de membranes peuvent être utilisés pour la séparation des gaz. Les unes sont poreuses et séparent les gaz sur la base de leur masse moléculaire selon un mécanisme de diffusion de Knudsen dans des micropores. Les facteurs de séparation obtenus sont généralement trop faibles pour présenter un intérêt industriel. Les autres, appelées membranes non poreuses, mettent en oeuvre un mécanisme de dissolution-diffusion des gaz dans une fine couche de polymère dénuée de toute porosité. C'est de ces dernières que nous allons parler. Commencé il y a une vingtaine d'années, le développement de ce type de membranes a conduit aux premières applications industrielles en 1979 avec l'introduction par Monsanto des séparateurs PRISM pour la récupération d'hydrogène à partir de différents gaz de raffinerie et de pétrochimie. Après des débuts modestes par suite de la compétition avec des technologies éprouvées comme la cryogénie, l'adsorption et l'absorption, la perméation gazeuse est en train de conquérir sa place parmi les techniques de séparation de gaz. Elle est aujourd'hui l'une des techniques membranaires présentant le plus fort taux de progression (30 % par an. Après un rappel des principes de base de la perméation gazeuse on abordera successivement les points suivants : - le choix du polymère constituant la couche séparatrice, - l'élaboration des membranes à structure asymétrique présentant une peau dense et fine, - les principales applications industrielles. Cela permettra de mettre en évidence les avantages et les limitations actuelles de la perméation gazeuse et de souligner les différents domaines où les efforts de R et D peuvent amener des progrès significatifs. Principle of Gas permeation - Gas permeation is a technique for fractionating gas mixtures by using nonporous polymer membranes having a selective permeability to gas according to a dissolution-diffusion mechanism. Gas is made to pass

  14. Les recherches menées par le Gaz de France dans le domaine de l'hydrogène Research on Hydrogen by Gaz de France

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    Donat G.

    2006-11-01

    Full Text Available Les besoins en énergie de l'humanité allant croissant et les ressources en combustibles de la Terre étant obligatoirement limitées, le temps viendra où la demande en hydrocarbures excédera la capacité mondiale de production; cette situation s'aggravera encore ultérieurement du fait de l'épuisement des réserves récupérables. Un recours massif aux énergies nucléaire et solaire semble donc indispensable et l'utilisation de l'hydrogène comme vecteur de ces énergies retient depuis quelques années l'attention, notamment en France où les ressources propres en pétrole sont faibles. Le Gaz de France a entrepris des recherches sur la production massive de l'hydrogène par décomposition de l'eau et vient de parvenir à des conclusions pessimistes quant à la compétitivité, par rapport à la voie électrolytique, de la filière utilisant des cycles thermochimiques. Par contre, l'électrolyse de l'eau offre des perspectives intéressantes à condition d'améliorer ses performances et son économie. D'autre part, des études concernant le stockage et le transport de l'hydrogène ont permis d'ores et déjà de tirer quelques conclusions dans ces domaines où les vecteurs gazeux disposent d'excellents atouts. With the increasing energy needs of mankind and the earth's necessarily limited resources of fuel, the time will come when the demand for hydrocarbons will exceed the world production capacity. This situation will subsequently get even worse becouse of the depletion of recoverable reserves. Massive recourse ta nuclear and solar energy thus appears indispensable, and the use of hydrogen as a vector for such energies has been under consideration for several years, especially in France where petroleum resources are very limited. Gaz de France has been doing research on the mass production of hydrogen by the decomposition of water and has just come ta rather pessimistic conclusions as ta the competitiveness of thermochemical processes in

  15. Modélisation d'une détente quasi-isotherme d'un gaz par contact direct avec un fluide caloporteur

    OpenAIRE

    Blaise , Mathilde; Maillet , Denis; Feidt , Michel; Alemany , Antoine; Forcinetti , Renato

    2015-01-01

    National audience; Les besoins en électricité sont croissants, cependant, les rejets thermiques industriels sont peu valorisés. La reconsidération des moteurs à apport de chaleur externe est un enjeu d'actualité pour la valorisation des rejets thermiques. Dans ces derniers, la phase de détente motrice offre des possibilités d'amélioration. L'idée ici est d'accompagner cette étape par un apport de chaleur par contact direct avec un fluide caloporteur. En effet, la détente d'un gaz entre une ha...

  16. Dosage du mercure dans le gaz naturel par absorption atomique sans flammes Mercury Titration in Natural Gas by Flameless Atomic Absorption

    Directory of Open Access Journals (Sweden)

    La Villa F.

    2006-11-01

    Full Text Available Cet article présente la méthode mise au point par l'Institut Français du Pétrole pour déterminer par absorption atomique sans flamme, les traces de mercure métallique contenu dans un gaz naturel. La méthode d'analyse nécessite une extraction du mercure soit sous forme d'ion mercurique en faisant passer le gaz dans une solution oxydante, soit sous forme d'amalgame avec de l'or ou de l'argent. Le premier mode opératoire s'applique aux échantillons dont la concentration en mercure est supérieure à I ttg/Nm3, le second pour des concentrations inférieures à 5 pg/Nm3. Les seuils de détection sont respectivement 10 ng (en solution et 0,3 ng (en amalgame. La répétabilité pour 100 ng de mercure (en amalgame est de ± 7% pour une probabilité de.95 %. En conclusion, dans un échantillon de gaz naturel, compte tenu du volume des prélèvements effectués, il est possible de détecter des concentrations de l'ordre du nanogramme de mercure par mètre cube de gaz. This article describes the method developed by IFP using flameless atomic absorption to determine metallic mercury traces in a natural gas. The analyst method requires a mercury extraction either in the form of mercuric ions by making the gas pass through an oxidizing solution or in the form of an amalgam with gold or silver. The former operating method applies ta samples having a mercury concentration greater than I !ag/Nm3, and the latter for concentrations smaller than 5 (-Lg/Nm3. Detection thresholds are respectively 10 ng (in solution and 0.3 ng (in amalgam. The repeatability for 100 ng of mercury (in amalgam is ± 7 % with a probability of 95%. To conclude, in a sample of natural gas, considering the volume of the samples taken, it is possible ta detect concentrations in the vicinity of one nanogrom of mercury per cubic meter of gas.

  17. Oxidation of steel heated in CO{sub 2} medium under pressure; Oxydation d'un acier ordinaire chauffe dans le gaz carbonique sous pression

    Energy Technology Data Exchange (ETDEWEB)

    Darras, R.; Leclercq, D.; Bunard, C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    Behaviour of low-alloyed steels heated in CO{sub 2} medium under pressure is reported. Tests are carried out in the range of erature reached in the CO{sub 2} cooled reactors (vessel, thermal shield, pipes). The observed weight increases are small, even after more than a thousand hours of heating at 350 deg. C, but oxidation curve looks like progressing linearly. Furthermore, the oxide formed under a pressure of 15 kg/cm{sup 2} is undoubtedly more compact and adherent than the one formed under a pressure of 1 kg/cm{sup 2}. Finally, for practical use, CO{sub 2} steel pipes surface has to be sand blast and pickled. A following phosphatizing protects it from atmospheric corrosion during assembling, but these treatments have no influence on the behaviour of these steels heated in CO{sub 2}. (author)Fren. [French] On etudie le comportement d'aciers au carbone faiblement allies, chauffes dans le gaz carbonique sous pression, aux temperatures atteintes dans les reacteurs refroidis par ce gaz (caisson, bouclier thermique, canalisations). Les augmentations de poids observees sont faibles, meme apres plus de 1000 heures de chauffage a 350 deg. C, mais l'oxydation semble se poursuivre lineairement. De plus, l'oxyde forme dans le gaz carbonique sous pression de 15 kg/cm{sup 2} est nettement plus compact et adherent que celui forme sous pression atmospherique de gaz carbonique. Enfin, dans la pratique, les surfaces d'acier du circuit de gaz carbonique sont necessairement sablees ou decapees; une phosphatation ulterieure le protege de la corrosion atmospherique pendant le montage. Ces traitements sont sans influence sur le comportement de ces aciers dans le gaz carbonique a chaud. (auteur)

  18. Oxidation of steel heated in CO{sub 2} medium under pressure; Oxydation d'un acier ordinaire chauffe dans le gaz carbonique sous pression

    Energy Technology Data Exchange (ETDEWEB)

    Darras, R; Leclercq, D; Bunard, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    Behaviour of low-alloyed steels heated in CO{sub 2} medium under pressure is reported. Tests are carried out in the range of erature reached in the CO{sub 2} cooled reactors (vessel, thermal shield, pipes). The observed weight increases are small, even after more than a thousand hours of heating at 350 deg. C, but oxidation curve looks like progressing linearly. Furthermore, the oxide formed under a pressure of 15 kg/cm{sup 2} is undoubtedly more compact and adherent than the one formed under a pressure of 1 kg/cm{sup 2}. Finally, for practical use, CO{sub 2} steel pipes surface has to be sand blast and pickled. A following phosphatizing protects it from atmospheric corrosion during assembling, but these treatments have no influence on the behaviour of these steels heated in CO{sub 2}. (author)Fren. [French] On etudie le comportement d'aciers au carbone faiblement allies, chauffes dans le gaz carbonique sous pression, aux temperatures atteintes dans les reacteurs refroidis par ce gaz (caisson, bouclier thermique, canalisations). Les augmentations de poids observees sont faibles, meme apres plus de 1000 heures de chauffage a 350 deg. C, mais l'oxydation semble se poursuivre lineairement. De plus, l'oxyde forme dans le gaz carbonique sous pression de 15 kg/cm{sup 2} est nettement plus compact et adherent que celui forme sous pression atmospherique de gaz carbonique. Enfin, dans la pratique, les surfaces d'acier du circuit de gaz carbonique sont necessairement sablees ou decapees; une phosphatation ulterieure le protege de la corrosion atmospherique pendant le montage. Ces traitements sont sans influence sur le comportement de ces aciers dans le gaz carbonique a chaud. (auteur)

  19. Contribution to the activation analysis of the rare gases. Contribution to the analysis of carbon monoxide and water vapour in gases (1963); Contribution a l'analyse par activation des gaz rares. Contribution a l'analyse de l'oxyde de carbone et de la vapeur d'eau dans les gaz (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Diebolt, J [Commisariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1963-07-15

    In the present work, we have applied radioactive analysis to the general technique of rare gas separation. This separation is carried out on active charcoal, at constant pressure. The desorption of the gas is caused by an increase in the initial temperature of adsorption. These separations are quantitative and can be confirmed by chemical analysis. The volumes of desorbed gas are measured by radioactive counting. We have also used radioactivation to study the reduction of palladous chloride by carbon monoxide. Since this reduction is quantitative, we can have a knowledge of the mass of palladium reduced by measuring its activity. We have used the property which have organic chlorides of being hydrolysed by water vapour and of liberating hydrochloric acid to study quantitatively the amount of water vapour which a gas contains. The hydrochloric acid formed is measured by activation of the chlorine in the acid. (author) [French] Dans les travaux que nous presentons, nous avons applique l'analyse par radioactivation, a la technique generale de separation des gaz rares. Cette separation est faite sur charbon active, a pression constante. La desorption des gaz est provoquee par une augmentation de la temperature initiale d'adsorption. Ces separations sont quantitatives, et peuvent etre exploitees par l'analyse chimique. Les volumes de gaz dedorbes sont mesures par comptage de la radioactivite. Nous avons egalement utilise la radioactivation pour l'etude de la reduction du chlorure palladeux par l'oxyde de carbone. Cette reduction etant quantitative, nous pouvons connaitre la masse de palladium reduit par la mesure de son activite. Nous avons exploite la propriete que possede un chlorure organique d'etre hydrolise par la vapeur d'eau et de liberer de l'acide chlorhydrique pour etudier quantitativement la vapeur d'eau contenue dans un gaz. L'acide chlorhydrique forme est mesure par l'activation du chlore de l'acide. (auteur)

  20. Etude du déplacement de l'huile par le gaz Analysis of Oil Displacement by Gas

    Directory of Open Access Journals (Sweden)

    Delclaud J.

    2006-11-01

    Full Text Available Les ingénieurs « réservoir u prévoient avec beaucoup de difficultés l'exploitation des gisements en utilisant les relations perméabilités relatives-saturations fournies par les laboratoires. Ceci amène à se demander si le concept est valide en écoulement transitoire, si les mesures sont effectuées selon des procédures convenables, si la relation statique entre la pression capillaire et la saturation est conservée en régime variable, si enfin la méconnaissance des lois de combinaison de ces fonctions n'est pas la cause de l'insatisfaction des ingénieurs. Le travail présenté ici traite des trois premiers points. Deux séries d'expériences sont réalisées à cet effet : - d'une part, des expériences de déplacement de l'huile par le gaz, où l'on s'intéresse à l'établissement et à la caractérisation de phénomènes pseudo-stationnaires. Les échantillons poreux choisis sont de faibles dimensions. Ils permettent ainsi de réduire la durée des périodes transitoires; - d'autre part, des expériences de déplacement sur des échantillons homogènes de grandes dimensions où l'on étudie les phénomènes transitoires. On mesure, tout au long du massif, la pression dans les deux phases et la saturation. Les perméabilités relatives sont calculées en tout point et à tout instant, à partir des équations de continuité. II ressort de ces travaux que la relation perméabilité relative-saturation est la même en tout point du milieu poreux, tout au long de l'écoulement transitoire, qu'elle ne dépend pas de la vitesse d'écoulement et que la relation pression capillaire-saturation coïncide avec celle établie par la méthode des états restaurés. La validité du concept en écoulement transitoire est donc prouvée. La méthode de WELGE, JOHNSON, BOSSLER et NAUMANN conduit à des résultats différents de ceux obtenus. On montre, pour expliquer ces écarts, que les hypothèses théoriques de cette méthode sont

  1. Mass-spectrometric analysis of trace oxygen in carbon dioxide; Analyse de traces d'oxygene dans le gaz carbonique par spectrometrie de masse

    Energy Technology Data Exchange (ETDEWEB)

    Nief, G; Severin, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    The mass spectrum of pure CO{sub 2} contains a peak of weight 32 whose relationship to peak at 44 varies greatly depending on the previous history of the source of ions and even during the course of an analysis. The fact that this peak is more or less proportional to the pressure and that its appearance potential is the same as that of oxygen leads us to suppose that it is produced from oxygen formed by dissociation of the carbon dioxide on the tungsten filament. A prior treatment of the ion source with acetylene reduces the ratio 32/44 to a value of about 15.10{sup -5}. This same treatment also stabilises the spectrometer's sensitivity to oxygen. Two lines of introduction enable pure carbon dioxide, the specimen to be estimated and a reference mixture of known oxygen content to be sent into the mass spectrometer in quick succession. Oxygen in the carbon dioxide in amounts ranging between 0 and 500 p.p.m. can thus be determined to an accuracy of {+-} 5 p.p.m., the analysis taking 30 minutes. (author) [French] Le spectre de masse de CO{sub 2} pur contient un pic de masse 32 dont le rapport au pic 44 varie enormement suivant l'histoire anterieure de la source d'ions et meme au cours d'une analyse. Le fait que ce pic soit grossierement proportionnel a la pression et que son potentiel d'apparition soit le meme que celui de l'oxygene permet de supposer qu'il est engendre a partir de l'oxygene produit par dissociation du gaz carbonique sur le filament de tungstene. Un conditionnement prealable de la source d'ions avec de l'acetylene reduit le rapport 32/44 a une valeur d'environ 15.10{sup -5}. Ce meme traitement stabilise egalement la sensibilite du spectrometre vis-a-vis de l'oxygene. Une double ligne d'introduction de gaz permet d'envoyer en successions rapides dans le spectrometre de masse le gaz carbonique pur, l'echantillon a doser et un melange de reference de teneur en oxygene connue. On arrive ainsi a doser l'oxygene dans le gaz carbonique dans la gamme de 0 a

  2. Spectral study of the luminescence produced by the excitation of noble gases by alpha-rays; Etude spectrale de la luminescence due a l'excitation des gaz rares par les rayons alpha

    Energy Technology Data Exchange (ETDEWEB)

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

    1960-07-01

    Luminescence spectra of the noble gases He, A, Kr and Xe are studied under excitation by {alpha} rays. It is shown that the energy is transferred from excited levels of these gases to Hg and N{sub 2} impurities for impurity concentrations respectively less than 10{sup 6} and 10{sup 4}. These results confirm previous measurements concerning the period of luminescence and its variations versus nitrogen concentration in noble gases. (author) [French] On etudie les spectres de luminescence des gaz rares, He, A, Kr et Xe excites par une source intense de rayons {alpha}. Le transfert d'energie des etats excites des gaz rares sur les impuretes mercure et azote pour des concentrations respectives de ces impuretes inferieures a 1 ppm et 100 ppm est demontre. Ces resultats confirment les mesures anterieures concernant la duree de luminescence et ses variations avec la concentration d'azote dans les gaz rares. (auteur)

  3. Contribution to the study on the flow rate adjustment for gas cooled power reactors (1964); Contributiom a l'etude de reglage du debit pour les reacteurs industriels refroidis par gaz (1964)

    Energy Technology Data Exchange (ETDEWEB)

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

    1961-06-15

    1. This original study firstly defines the problem of the adjustment of the coolant flow rate in a reactor channel as a function of the corresponding heat transfer equations and of the local and temporal neutron flux. The necessity of such an adjustment is pointed out and the modifying parameters are studied. An adjustment study using the envelope of the possible flux curves is developed. A short study on the technology and the economical advantage of this adjustment is presented. Some measurements, made on G-1 and G-2, show the precision one can obtain from adjustment apparatus itself as well as from the complete reactor adjustment system. 2. Evolution of nuclear properties of fuel in an heterogeneous thermal reactor. In the first port of this paper, the phenomena of fuel evolution have been mainly pointed out. Now a bibliographical study more qualitatively than quantitatively has been done. This survey specifies the present theories and relates to a real effective cross section and also yields to the bases of such a nuclear calculation. (author) [French] 1. Cette etude originale definit d'abord le probleme du reglage du debit de refrigerant dans un canal de reacteur en fonction de la formulation du calcul des performances thermodynamiques de ce canal et des variations du flux neutronique dans l'espace et le temps. La necessite du reglage est ensuite mise en evidence et les parametres le modifiant sont etudies. Une methode de reglage, basee sur l'emploi d 'une courbe enveloppe des courbes de flux possibles, est donnee. Une breve etude de la technologie et des incidences economiques du reglage est presentee. Des mesures effectuees sur les reacteurs G-1 et G-2 montrent la precision que l'on peut attendre des dispositifs de reglage comme du reglage d'ensemble du reacteur lui-meme. 2. Evolution des proprietes nucleaires du combustible dans un reacteur heterogene a neutrons thermiques. Les phenomenes d'evolution du combustible tiennent une place importante dans l'etude precedente. Une etude bibliographique plus qualitative que quantitative a donc ete effectuee sur ce point. Cet examen expose les theories actuelles, se refere en particulier a l'emploi d'une section efficace dite effective et fournit ainsi les principes d'un tel calcul neutronique. (auteur)

  4. Contribution to the study on the flow rate adjustment for gas cooled power reactors (1964); Contributiom a l'etude de reglage du debit pour les reacteurs industriels refroidis par gaz (1964)

    Energy Technology Data Exchange (ETDEWEB)

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

    1961-06-15

    1. This original study firstly defines the problem of the adjustment of the coolant flow rate in a reactor channel as a function of the corresponding heat transfer equations and of the local and temporal neutron flux. The necessity of such an adjustment is pointed out and the modifying parameters are studied. An adjustment study using the envelope of the possible flux curves is developed. A short study on the technology and the economical advantage of this adjustment is presented. Some measurements, made on G-1 and G-2, show the precision one can obtain from adjustment apparatus itself as well as from the complete reactor adjustment system. 2. Evolution of nuclear properties of fuel in an heterogeneous thermal reactor. In the first port of this paper, the phenomena of fuel evolution have been mainly pointed out. Now a bibliographical study more qualitatively than quantitatively has been done. This survey specifies the present theories and relates to a real effective cross section and also yields to the bases of such a nuclear calculation. (author) [French] 1. Cette etude originale definit d'abord le probleme du reglage du debit de refrigerant dans un canal de reacteur en fonction de la formulation du calcul des performances thermodynamiques de ce canal et des variations du flux neutronique dans l'espace et le temps. La necessite du reglage est ensuite mise en evidence et les parametres le modifiant sont etudies. Une methode de reglage, basee sur l'emploi d 'une courbe enveloppe des courbes de flux possibles, est donnee. Une breve etude de la technologie et des incidences economiques du reglage est presentee. Des mesures effectuees sur les reacteurs G-1 et G-2 montrent la precision que l'on peut attendre des dispositifs de reglage comme du reglage d'ensemble du reacteur lui-meme. 2. Evolution des proprietes nucleaires du combustible dans un reacteur heterogene a neutrons thermiques. Les phenomenes d'evolution du combustible tiennent une place importante dans l'etude precedente. Une etude bibliographique plus qualitative que quantitative a donc ete effectuee sur ce point. Cet examen expose les theories actuelles, se refere en particulier a l'emploi d'une section efficace dite effective et fournit ainsi les principes d'un tel calcul neutronique. (auteur)

  5. Preparation and properties of carbonaceous products prepared by the cracking of natural gas; Fabrication et proprietes de corps carbones prepares par craquage de gaz naturel

    Energy Technology Data Exchange (ETDEWEB)

    Blum, P L; Bochirol, L; Rappeneau, J; Cornuault, P; Blanchard, R; Moreau, C [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1964-07-01

    . Plusieurs voies ont ete etudiees: 1 - En utilisant comme supports des graphites industriels de qualite courante (densite voisine de 1,50) on obtient des corps d'une densite proche de 1,80. Leur porosite ouverte (6 a 7 pour cent) est inferieure a celle des graphites traditionnels, et plusieurs de leurs proprietes sensiblement egales ou superieures a celles resultant habituellement d'une double inpregnation au brai. 2 - L'utilisation comme supports de demi-produits ('cuits') cycle traditionnel de fabrication des graphites ne conduit pas a des resultats satisfaisants. On en donne les raisons principales. 3 - Un procede nouveau, dit 'BB5', a ete mis au point. Il part, directement des matieres de corps pulverulentes (coke de petrole ou graphite) mises en forme au moyen d'un liant dispersable dans l'eau. Les supports ainsi constitues permettent, du fait de leur structure poreuse, de tirer le meilleur parti de la densification par craquage, en dessous de 1000 deg. C: du gaz naturel. Les produits obtenus, composes a parts a peu pres egales de la matiere de corps et de pyrocarbone, peuvent avoir des densites depassant 1,90. Leur porosite ouverte, tres faible, peut etre rendue pratiquement nulle, leur impermeabilite etant alors excellente (k = 10{sup -8} cm{sup 2}sec{sup -1}). Ils sont egalement remarquables par leur resistance elevee a la compression, qui peut se situer entre 15 et 20 kg/mm{sup 2} pour les versions ne subissant pas un traitement final de graphitation. On indique quelques exemples d'applications possibles, dans le domaine, nucleaire, des materiaux ainsi prepares. (auteurs)

  6. Corrosion by cooling gases in nuclear reactors; la corrosion par les gaz caloporteurs dans les reacteurs nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Darras, R. [Commissariat a l' energie atomique et aux energies alternatives - CEA, Centre de Saclay, Section d' etude de la corrosion par gaz et metaux liquides (France)

    1960-07-01

    This article begins with a review of the various materials which can be used and the cooling gases in which they may be heated, emphasis being placed on the importance of reaching temperatures as high as possible. This is followed by a few general remarks on the dry oxidation of metals and alloys, particularly with regard to diffusion phenomena and their various possible mechanisms, and also the methods of investigation employed. Finally, the behaviour of the chief nuclear materials heated in the various gases is studied successively. Materials used for fuel (metallic uranium, uranium oxide, carbides and silicides), canning materials (magnesium, aluminium, zirconium, beryllium, stainless and refractory steels), structural materials (ordinary or slightly alloyed steels), and finally moderators (graphite, beryllium oxide) are deal with in this way. This account is backed up both by the results obtained at the CEA and by work published outside or abroad up to the present day. In conclusion, every effort has been made to direct future research on the basis of the foregoing. Reprint of a paper published in Industries Atomiques - no. 9/10, 1959, p. 3-23 [French] Dans cet article, on passe tout d'abord en revue les divers materiaux utilisables et les gaz de refroidissement dans lesquels ils peuvent etre chauffes, en insistant sur l'interet d'atteindre des temperatures aussi elevees que possible. On rappelle ensuite quelques generalites sur l'oxydation seche des metaux et alliages, notamment en ce qui concerne les phenomenes de diffusion et leurs divers mecanismes possibles ainsi que les methodes d'etude. Enfin, le comportement des principaux materiaux nucleaires chauffes dans les divers gaz est etudie successivement. On traita ainsi des materiaux combustibles (uranium metallique, oxyde, carbures et siliciures d'uranium), des materiaux de gainage (magnesium, aluminium, zirconium, beryllium, aciers inoxydables et refractaires), des materiaux de structure (aciers ordinaires

  7. A study on the isotope effects in the reduction of carbon dioxide by zinc; Etude des effets isotopiques dans la reduction du gaz carbonique par le zinc

    Energy Technology Data Exchange (ETDEWEB)

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

    1957-06-15

    We have determined the isotope effects which occur in the reduction of carbon dioxide by zinc. It has been shown that in the case of irreversible surface reactions, Bernstein's equation which permits the calculation of the fractionation factor is still valid. These experimental factors are in good agreement with those obtained by calculating the partition functions of the adsorbed activated complexes. In the reaction mechanism used, the model of the activated complex corresponds to the dissociation of one of the carbon oxygen bonds CO{sub 2} {yields} CO + O. Perturbations arising from the slight reversibility of the reaction Zn + CO{sub 2} {r_reversible} ZnO + CO on the isotope effects on the carbon and oxygen atoms have also been calculated. (author) [French] Nous avons etudie les effets isotopiques qui ont lieu dans la reduction du gaz carbonique par le zinc. La validite de l'equation de Bernstein qui permet de calculer le facteur de fractionnement a ete demontree pour le cas d'une reaction irreversible de surface. Ces facteurs de fractionnement experimentaux sont en bon accord avec ceux obtenus par le calcul des fonctions de partition isotopiques des complexes actives adsorbes. Dans le mecanisme de reaction utilise, le modele du complexe active correspond a la dissociation d'une des liaisons carbone oxygene CO{sub 2} {yields} CO + O. Les effets perturbateurs de la reversibilite de la reduction Zn + CO{sub 2} {r_reversible} ZnO + CO sur les effets isotopiques du carbone et ceux de l'oxygene ont ete egalement evalues. (auteur)

  8. A study on the isotope effects in the reduction of carbon dioxide by zinc; Etude des effets isotopiques dans la reduction du gaz carbonique par le zinc

    Energy Technology Data Exchange (ETDEWEB)

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

    1957-06-15

    We have determined the isotope effects which occur in the reduction of carbon dioxide by zinc. It has been shown that in the case of irreversible surface reactions, Bernstein's equation which permits the calculation of the fractionation factor is still valid. These experimental factors are in good agreement with those obtained by calculating the partition functions of the adsorbed activated complexes. In the reaction mechanism used, the model of the activated complex corresponds to the dissociation of one of the carbon oxygen bonds CO{sub 2} {yields} CO + O. Perturbations arising from the slight reversibility of the reaction Zn + CO{sub 2} {r_reversible} ZnO + CO on the isotope effects on the carbon and oxygen atoms have also been calculated. (author) [French] Nous avons etudie les effets isotopiques qui ont lieu dans la reduction du gaz carbonique par le zinc. La validite de l'equation de Bernstein qui permet de calculer le facteur de fractionnement a ete demontree pour le cas d'une reaction irreversible de surface. Ces facteurs de fractionnement experimentaux sont en bon accord avec ceux obtenus par le calcul des fonctions de partition isotopiques des complexes actives adsorbes. Dans le mecanisme de reaction utilise, le modele du complexe active correspond a la dissociation d'une des liaisons carbone oxygene CO{sub 2} {yields} CO + O. Les effets perturbateurs de la reversibilite de la reduction Zn + CO{sub 2} {r_reversible} ZnO + CO sur les effets isotopiques du carbone et ceux de l'oxygene ont ete egalement evalues. (auteur)

  9. Some results on the fluorescence of gases excited by high-energy charged particles; Quelques resultats concernant la fluorescence de gaz excites par des particules chargees de grande energie

    Energy Technology Data Exchange (ETDEWEB)

    Koch, L; Lesureur, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The essential characteristics of rare gases for use as scintillators are as follows: a very brief period of luminescence, generally less than 10{sup -8} s; a linear response as a function of the energy lost by the nuclear particle in the gas, even in the case of strongly ionising particles (fission fragments). In the gaseous or condensed state therefore, they are of great interest in nuclear physics. (author) [French] Les caracteristiques essentielles des gaz rares en tant que scintillateurs sont: une duree de luminescence tres breve, inferieure a 10{sup -8} s en general; une reponse lineaire en fonction de l'energie perdue par la particule nucleaire dans le gaz, meme dans le cas de particules fortement ionisantes (fragments de fission). A l'etat gazeux ou condense, ils presentent donc un grand interet en physique nucleaire. (auteur)

  10. Detection and location of can rupture in reactors cooled by a flow of water; Detection et localisation des ruptures de gaines sur les reacteurs refroidis par circulation d'eau

    Energy Technology Data Exchange (ETDEWEB)

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

    1968-07-01

    This report brings together the principal methods of fission-product detection used for water reactors. The position, type and method of adjustment is given for each detector. The methods for localizing the defective elements are explained, in particular those using water sampling or decreases in the flux. A few installations are briefly described. They correspond to particular types of reactors using boiling, pressurized or cold water. Amongst the many methods used, it can be noted that when the fuel is resistant, the installations are fairly compact. In nuclear super-heated reactors on the other hand, the study of fuel behaviour calls for larger installations. An identification of defective elements exists when the reactor structure allows it. If this is not possible, a localization in a group of elements is obtained by a flux depression. (author) [French] Ce rapport rassemble les principales methodes de detection de produits de fission utilisees pour des reacteurs a eau. On indique pour les detecteurs leurs emplacements, leurs types, leurs reglages. On explique quelles sont les methodes de localisation des elements defectueux, en particulier celles utilisant des prelevements d'eau ou des depressions de flux. Quelques installations sont decrites sommairement. Elles correspondent a des types particuliers de reacteurs a eau bouillante, pressurisee ou froide. Parmi les nombreuses methodes utilisees, on constate que les installations sont peu importantes, lorsque le combustible est resistant. Par contre dans les reacteurs a surchauffe nucleaire l'etude du comportement du combustible necessite des installations plus importantes. Une identification d'elements defectueux existe lorsque la structure du reacteur le permet. A defaut une localisation dans un groupe d'elements est obtenue par depression de flux. (auteur)

  11. General design and main problems of a gas-heavy-water power reactor contained in a pressure vessel; Conception generale et principaux problemes d'un reacteur de puissance eau lourde-gaz contenu dans un caisson resistant

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-07-01

    In the framework of research carried out on a CO{sub 2}-cooled power reactor moderated by heavy water, the so-called 'pressure vessel' solution involves the total integration of the core, of the primary circuit (exchanges and blowers) and of the fuel handling machine inside a single, strong, sealed vessel made of pre-stressed concrete. A vertical design has been chosen: the handling 'attic' is placed above the core, the exchanges being underneath. This solution makes it possible to standardize the type of reactor which is moderated by heavy-water or graphite and cooled by a downward stream of carbon dioxide gas; it has certain advantages and disadvantages with respect to the pressure tube solution and these are considered in detail in this report. Extrapolation presents in particular.problems due specifically to the heavy water (for example its cooling,its purification, the balancing of the pressures of the heavy water and of the gas, the assembling of the internal structures, the height of the attic, etc. (authors) [French] Dans le cadre des etudes d'un reacteur de puissance modere a l'eau lourde et refroidi-au gaz carbonique, la solution dite 'en caisson' consiste en une integration totale du coeur, du circuit primaire (echangeurs et soufflantes) et du dispositif de manutention du combustible a l'interieur d'un meme caisson etanche et resistant en beton precontraint. La disposition envisagee est verticale; le grenier de manutention est dispose au-dessus du coeur, les echangeurs en dessous. Cette solution, qui permet d'uniformiser les types de reacteurs moderes a l'eau lourde ou au graphite et refroidis par une circulation descendante de gaz carbonique presente, par rapport a la solution a tube de force, des avantages et des inconvenients qui sont analyses dans cette etude. L'extrapolation pose, en particulier, des problemes specifiques a l'eau lourde (tels que son refroidissement, son epuration, l'equilibrage des pression entre l'eau lourde et le gaz, le montage

  12. General design and main problems of a gas-heavy-water power reactor contained in a pressure vessel; Conception generale et principaux problemes d'un reacteur de puissance eau lourde-gaz contenu dans un caisson resistant

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-07-01

    In the framework of research carried out on a CO{sub 2}-cooled power reactor moderated by heavy water, the so-called 'pressure vessel' solution involves the total integration of the core, of the primary circuit (exchanges and blowers) and of the fuel handling machine inside a single, strong, sealed vessel made of pre-stressed concrete. A vertical design has been chosen: the handling 'attic' is placed above the core, the exchanges being underneath. This solution makes it possible to standardize the type of reactor which is moderated by heavy-water or graphite and cooled by a downward stream of carbon dioxide gas; it has certain advantages and disadvantages with respect to the pressure tube solution and these are considered in detail in this report. Extrapolation presents in particular.problems due specifically to the heavy water (for example its cooling,its purification, the balancing of the pressures of the heavy water and of the gas, the assembling of the internal structures, the height of the attic, etc. (authors) [French] Dans le cadre des etudes d'un reacteur de puissance modere a l'eau lourde et refroidi-au gaz carbonique, la solution dite 'en caisson' consiste en une integration totale du coeur, du circuit primaire (echangeurs et soufflantes) et du dispositif de manutention du combustible a l'interieur d'un meme caisson etanche et resistant en beton precontraint. La disposition envisagee est verticale; le grenier de manutention est dispose au-dessus du coeur, les echangeurs en dessous. Cette solution, qui permet d'uniformiser les types de reacteurs moderes a l'eau lourde ou au graphite et refroidis par une circulation descendante de gaz carbonique presente, par rapport a la solution a tube de force, des avantages et des inconvenients qui sont analyses dans cette etude. L'extrapolation pose, en particulier, des problemes specifiques a l'eau lourde (tels que son refroidissement, son epuration

  13. Performance Analysis of Compositional and Modified Black-Oil Models For a Gas Lift Process Analyse des performances de modèles black-oil pour le procédé d’extraction par injection de gaz

    Directory of Open Access Journals (Sweden)

    Mahmudi M.

    2013-03-01

    Full Text Available Artificial gas lift is frequently used to boost production rate of mature oil fields. An integrated mathematical model was developed in order to track the spatial and temporal changes in various components of the continuous gas lift process. The computational demand for solving the comprehensive gas lift model highly depends on the thermodynamic treatment of the hydrocarbon fluids involved. A full compositional treatment using an equation of state provides the most accurate results but at a high computational cost. The results of this article showed that the computational cost can be halved without sacrificing accuracy by using reduced parameter stability and flash calculation procedures. It was also demonstrated that a Modified Black-Oil treatment of the fluids can provide reasonable accuracy at a much-reduced computational cost. The Modified Black-Oil treatment provides a valuable tool when the model has to be solved many hundreds of times to find the optimal combination of the gas lift parameters. Les procédés artificiels d’extraction par injection de gaz sont utilisés pour améliorer le taux de récupération des champs pétroliers matures. Un modèle mathématique intégré a été développé pour détecter de faibles changements temporels et spatiaux dans plusieurs composants des procédés continus d’extraction par injection de gaz. La solution numérique utilisée pour résoudre le modèle du procédé d’extraction dépend fortement du comportement thermodynamique des hydrocarbures impliqués. Un traitement complet de la composition utilisant une équation d’état offre les résultats les plus précis, mais à un coût de calcul très élevé. Les résultats de nos travaux de recherche montrent que l’implication des paramètres de stabilité et des procédures de calcul flash, peut diviser par deux le coût du calcul tout en gardant la précision attendue. Ces travaux montrent que la précision admissible peut être

  14. 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

    modeles neutroniques 2D et 3D du coeur du reacteur ont ete crees, bases sur le schema de calculs de reference ERANOS-2.0/ERALIB1. Pour l'analyse thermo-hydraulique, le code COPERNIC du CEA a ete utilise. Le travail de design a ete poursuivi par l'etude d'un schema de l'implantation des assemblages de controle (nombre et position dans le coeur). Des etudes detaillees de neutronique ont reveles l'existence de grands effets d'interaction entre les AC, appeles effets d'ombre/d'anti-ombre, conduisant a une amplification/reduction de l'antireactivite des AC. Les interactions entre les barreaux absorbants a l'interieur d'un AC, ainsi qu'entre les AC eux-memes, ont ete investiguees dans le detail, dans le but d'optimiser l'efficacite des AC (en terme de la fraction d'absorbant et la minimisation des effets d'heterogeneite associes). Resultant d'investigations detaillees, le diametre des pastilles absorbantes a ete choisi de maniere a minimiser l'influence 'barreau-a-barreau' a l'interieur de l'assemblage. En particulier, une partie centrale de l'assemblage a ete concue sans aucun barreau absorbant (zone remplie d'helium statique). Par ce biais, une reduction, a 13%, des effets d'heterogeneite, a ete obtenue. Les investigations neutroniques effectuees pour le coeur RNR-G de reference ('2004-Coeur'), specialement, celles liees a l'Etude des interactions entre les AC, ont directement contribue au nouveau design du coeur ('2007-Coeur'). Le rapport hauteur sur diametre a ete augmente a 0.6, compare a la valeur de 0.3 pour le coeur de reference. Pendant la troisieme phase, des modeles couples et detailles, cinetiques 3D et thermohydrauliques 1D, ont ete developpes pour le coeur RNR-G; le but etait d'arriver a une comprehension, en profondeur, du comportement 3D du coeur pendant des transitoires induits par le mouvement d

  15. Contribution to the study of the ionization and heating of gases by laser radiation; Contribution a l'etude de l'ionisation et du chauffage des gaz par le rayonnement d'un laser declenche

    Energy Technology Data Exchange (ETDEWEB)

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

    1968-01-01

    The ionization and heating of gases by the concentrated radiation of a neodymium laser is studied. The power is 300 MW, the gas studied is primarily deuterium between 300 mm and 2280 mm. The first part concerns a certain number of experimental results on the absorption of the radiation and on changes produced in the plasma as a function of time. From these results are deduced a certain number of consequences, amongst which may be mentioned the definition of a pre-ionization threshold. These experimental results are interpreted in the second part. A calculation is made of the length of the period during which the electrons multiply up to when the absorption becomes measurable. The last phase corresponds to the hydrodynamics evolution, the calculations are compared with the experiments. The agreement between theory and experiment is satisfactory for the different phases. (author) [French] On etudie l'ionisation et le chauffage des gaz par le rayonnement concentre d'un laser au neodyme. La puissance est de 300 MW, le gaz etudie est principalement le deuterium entre 300 mm et 2280 mm. La premiere partie concerne un certain nombre de resultats experimentaux. Il s'agit de l'absorption du rayonnement et de l'evolution chronologique du plasma. De ces resultats on deduit un certain nombre de consequences parmi lesquelles il faut citer la definition d'un seuil de preionisation. Ces resultats experimentaux sont interpretes dans la deuxieme partie. On calcule la duree de la phase pendant laquelle se multiplient les electrons jusqu'a ce que l'absorption soit mesurable. La derniere phase correspond a l'evolution hydrodynamique. Les calculs sont confrontes avec l'experience. L'accord entre theorie et experience est satisfaisant pour les differentes phases. (auteur)

  16. Contribution to the study of the ionization and heating of gases by laser radiation; Contribution a l'etude de l'ionisation et du chauffage des gaz par le rayonnement d'un laser declenche

    Energy Technology Data Exchange (ETDEWEB)

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

    1968-01-01

    The ionization and heating of gases by the concentrated radiation of a neodymium laser is studied. The power is 300 MW, the gas studied is primarily deuterium between 300 mm and 2280 mm. The first part concerns a certain number of experimental results on the absorption of the radiation and on changes produced in the plasma as a function of time. From these results are deduced a certain number of consequences, amongst which may be mentioned the definition of a pre-ionization threshold. These experimental results are interpreted in the second part. A calculation is made of the length of the period during which the electrons multiply up to when the absorption becomes measurable. The last phase corresponds to the hydrodynamics evolution, the calculations are compared with the experiments. The agreement between theory and experiment is satisfactory for the different phases. (author) [French] On etudie l'ionisation et le chauffage des gaz par le rayonnement concentre d'un laser au neodyme. La puissance est de 300 MW, le gaz etudie est principalement le deuterium entre 300 mm et 2280 mm. La premiere partie concerne un certain nombre de resultats experimentaux. Il s'agit de l'absorption du rayonnement et de l'evolution chronologique du plasma. De ces resultats on deduit un certain nombre de consequences parmi lesquelles il faut citer la definition d'un seuil de preionisation. Ces resultats experimentaux sont interpretes dans la deuxieme partie. On calcule la duree de la phase pendant laquelle se multiplient les electrons jusqu'a ce que l'absorption soit mesurable. La derniere phase correspond a l'evolution hydrodynamique. Les calculs sont confrontes avec l'experience. L'accord entre theorie et experience est satisfaisant pour les differentes phases. (auteur)

  17. A study of the fluorescence of the rare gases excited by nuclear particles. Use of the principle for the detection of nuclear radiation by scintillation; Etude de la fluorescence des gaz rares excites par des particules nucleaires. Utilisation pour la detection des rayonnements nucleaires par scintillation

    Energy Technology Data Exchange (ETDEWEB)

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

    1959-12-15

    In the first part is studied the properties of atoms excited by the passage of {alpha} particles through the various rare gases at atmospheric pressure. A spectral analysis of the emitted light showed that certain impurities play an important part in producing the fluorescence, and it has led to the conclusion that the light emission contains at least two components - one very short - lived due to the direct deexcitation of the rare gas, the other relatively slower due to the energy transfers to the impurity. The measurement of the life-time of the excited states has confirmed this foregoing hypothesis, the rapid part of the impulse is extremely short: less than 2,25.10{sup -9} s in the case of xenon; the slower part has a life-time depending directly on the nitrogen concentration, nitrogen being the impurity giving the largest effect in all cases. The study of rare gases under the influence of an electric field has made it possible to show that the amount of light produced by an {alpha} particle can be multiplied (by 60, for example, in a field of 600 V:cm) so that the luminescent efficiency is greater than in the case of INaTI. In the second part the characteristics of the rare gases acting as scintillators is examined, the most important property being the absence of fluorescence saturation when the intensity of the excitation incident on the gas is very large. This, together with the very short time of scintillation has made it possible to study a certain number of nuclear physical applications (heavy particle energy-measurements, kinetic studies on nuclear reactors, neutron spectroscopy). (author) [French] On etudie dans la premiere partie les proprietes des atomes excites par le passage de particules {alpha} dans les differents gaz rares a la pression atmospherique. L'etude spectrale de la lumiere emise a montre que certaines impuretes jouent un role considerable dans la fluorescence et on a ete amene a penser que l'emission de lumiere comporte au moins deux

  18. Heat transfer by gas-liquid mixture in forced turbulent flow with weak vaporization of the liquid phase (1962); Transfert de chaleur par melange de liquide et de gaz en convection forcee turbulente avec faible vaporisation de la phase liquide (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Huyghe, J; Mondin, G [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1962-07-01

    The present study deals with measures of heat transfer and pressure drop in two-phase liquid flow. The stream is of annular dispersed type, obtained by introducing a small quantity of liquid in a gas turbulent flow. The heat transfer experiments are performed without vaporization of the liquid phase. A notable improvement of the heat transfer coefficient of such a stream is observed, compared with a gas-alone or liquid-alone flow. The improvement concerning the gas-alone is of about 20 when it is compared with the same gas Reynolds's number, of about 8 when it is compared with the same total mass flow rate. A hydrodynamic study of the flow pattern lets us know the original structure of the flow, and allows to foresee the experimental results by means of a simplified theory. (authors) [French] II est fait etat de mesures de transfert thermique et de perte de charge dans un ecoulement en double phase gaz-liquide. L'ecoulement est du type annulaire disperse, obtenu par injection d'une faible quantite de liquide dans un ecoulement gazeux en regime turbulent. Les experiences de transfert thermique sont menees sans vaporisation de la phase liquide. On note une amelioration sensible du coefficient de transfert thermique dans un tel ecoulement par rapport a un ecoulement de gaz seul ou de liquide seul. L'augmentation est de l'ordre de 20 par rapport au gaz seul si on opere a meme nombre de REYNOLDS du gaz, de l'ordre de 8 si on opere a meme debit massique total. Une etude hydrodynamique rapide de l'ecoulement permet de connaitre la structure originale de l'ecoulement, puis de prevoir par une theorie simplifiee le phenomene thermique observe. (auteurs)

  19. Vibrational and cascade dissociation of H{sub 2}{sup +} ions by collision with gas molecules; Dissociation vibrationnelle et dissociation en cascade d'ions H{sub 2}{sup +} par collisions avec les molecules d'un gaz

    Energy Technology Data Exchange (ETDEWEB)

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

    1966-07-01

    Protons produced by collisional dissociation of H{sub 2}{sup +} ions have an energy spectrum with a narrow central peak. For a part the protons in this peak are produced by vibrational dissociation and for another part by a cascade of two collisions. For H{sub 2}{sup +} ions of 50 to 150 keV the cross section for vibrational dissociation is about 4.1 10{sup -19} cm{sup 2}/molecule in hydrogen and 1.1 10{sup -18} cm{sup 2}/molecule in argon. (author) [French] Les protons resultant de la dissociation par collisions d'ions H{sub 2}{sup +} dans un gaz ont un spectre d'energie qui presente un pic central tres etroit. Les protons dans ce pic proviennent, pour une part de la dissociation vibrationnelle et pour l'autre part d'une suite de deux collisions. Dans le domaine d'energie des ions H{sub 2}{sup +} de 50 a 150 keV la section efficace de dissociation vibrationnel vaut 4.1 10{sup -19} cm{sup 2}/molecule pour l'hydrogene et 1,1 10{sup -18} cm{sup 2}/molecule pour l'argon.

  20. Gas Well Testing Analysis Using Finite-Difference Models and Optimization Techniques Analyse d'essais de puits de gaz par des modèles utilisant la méthode des différences finies et par des techniques d'optimisation

    Directory of Open Access Journals (Sweden)

    Darderes E. A.

    2006-11-01

    Full Text Available In reservoir engineering studies of gas fields, three important parameters are needed: the permeability-thickness product, the skin factor, and the inertial-turbulent factor. Several methods have been proposed to determine these parameters from gas well tests. The most powerful one is the pseudo-steady state analysis, where a linear dependence on a semilogarithmic plot is found between the real gas pseudo-pressure and time. Another one is the type-curve matching. Both have drawbacks because they can be rigorously applied only to specific cases. An automated type-curve match, which provides a general method to analyze well test data, is presented in this paper. It is based on the adjustment of a numerical model to gas well test data, by means of optimization techniques. The numerical model is the solution of the second order strongly non-linear partial differential equation which rules the radial flow of real gases towards a well. The differential equation is solved by finite-differences, taking into account the variation of gas properties with pressure. In order to simulate any gas well test, appropriate initial and boundary conditions are imposed. The least squares method is used to minimize residual differences between actual pressures measured during test and computed pressures. Two optimization techniques are applied to obtain the best estimate of parameters that minimize the sum of the square of the residuals: the univariate method of Fibonacci [1] and the multivariate method of Marquardt [1, 2]. This procedure is applied to a single-rate and a two-rate drawdown test. Numerical results showed excellent agreement with well test data. Les études de gisements de gaz rendent indispensables la connaissance de trois paramètres importants : la capacité de flux (produit de la perméabilité par l'épaisseur de la couche productrice, l'effet de peau et le facteur d'inertie et de turbulence. On connaît plusieurs méthodes pour déterminer ces

  1. Enjeux juridiques du contrôle des émissions personnelles de gaz à effet de serre par un dispositif de carte carbone

    Directory of Open Access Journals (Sweden)

    Sandrine Rousseaux

    2011-02-01

    Full Text Available La carte carbone individuelle est un dispositif innovant, qui permet d’impliquer les particuliers dans la lutte face au changement climatique. Ce dispositif consiste à limiter leurs émissions de gaz à effet de serre, ce qui suppose de suivre leur consommation de certains produits et services. Ce mode de contrôle des émissions personnelles soulève parfois des controverses, la carte carbone pouvant être perçue comme un instrument de rationnement potentiellement liberticide. Ces deux aspects sont discutés sur la base d’une analyse comparative de la conception et des modalités de mise en œuvre des différents dispositifs de carte carbone, établis ou envisagés en Europe et aux États-Unis. Il en ressort que les controverses ne sont pas réellement fondées.The individual carbon card is an innovative mechanism that helps involve individuals in the fight against climate change. It consists in limiting their greenhouse gas emissions, which requires monitoring a part of their goods and services consumption. This method of personal emissions control is much debated since the carbon card may be perceived as a rationing tool and raises civil liberty issues. Both of these controversial aspects are discussed on the basis of a comparative analysis of how the various carbon card programs, established or contemplated in Europe and in the USA, are designed and implemented. The findings are these controversies are somewhat groundless.

  2. Improvements in gas supply systems for heavy-water moderated reactors; Etudes de perfectionnements aux systemes d'alimentation en gaz d'un reacteur modere a l'eau lourde

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, G; Hassig, J M; Laurent, N; Thomas, B [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    In a heavy-water moderated reactor cooled by pressurized gas, an important problem from the point of view, of the reactor block and its economics is the choice of the gas supply system. In the pressure tube solution, the whole of the reactor block structure is at a relatively low temperature, whereas the gas supply equipment is at that of the gas, which is much higher. These parts, through which passes the heat carrying fluid have to present as low a resistance as possible to it so as to avoid costly extra blowing power. Finally, they may only be placed in the reactor block after it has been built; the time required for putting them in position should therefore not be too long. The work reported here concerns the various problems arising in the case of each channel being supplied individually by a tube at the entry and the exit which is connected to a main circuit made up of large size collectors. This individual tubing is sufficiently flexible to absorb the differential expansion and the movement of its ends without stresses or prohibitive reactions being produced; the tubing is also of relatively short length so as to reduce the pressure head of the pressurized gas outside the channels; the small amount of space taken up by the tubing makes it possible to assemble it in a manner which is satisfactory from the point of view both of the time required and of the technical quality. (authors) [French] Dans un reacteur modere a l'eau lourde et refroidi au gaz sous pression, un probleme important du point de vue du trace du bloc pile et de son economie est le choix du systeme d'alimentation en gaz. Pour une solution a tubes de force, l'ensemble des structures du bloc reacteur est a temperature relativement faible, alors que les organes d'alimentation en gaz sont a celle, notablement plus elevee, du gaz. Ces organes, traverses par le debit du caloporteur, doivent lui opposer le minimum de resistance afin de ne pas necessiter un supplement onereux de puissance de

  3. Heavy water moderated gas-cooled reactors; Filiere eau lourde - gaz

    Energy Technology Data Exchange (ETDEWEB)

    Bailly du Bois, B; Bernard, J L; Naudet, R; Roche, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    France has based its main effort for the production of nuclear energy on natural Uranium Graphite-moderated gas-cooled reactors, and has a long term programme for fast reactors, but this country is also engaged in the development of heavy water moderated gas-cooled reactors which appear to present the best middle term prospects. The economy of these reactors, as in the case of Graphite, arises from the use of natural or very slightly enriched Uranium; heavy water can take the best advantages of this fuel cycle and moreover offers considerable development potential because of better reactor performances. A prototype plant EL 4 (70 MW) is under construction and is described in detail in another paper. The present one deals with the programme devoted to the development of this reactor type in France. Reasons for selecting this reactor type are given in the first part: advantages and difficulties are underlined. After reviewing the main technological problems and the Research and Development carried out, results already obtained and points still to be confirmed are reported. The construction of EL 4 is an important step of this programme: it will be a significant demonstration of reactor performances and will afford many experimentation opportunities. Now the design of large power reactors is to be considered. Extension and improvements of the mechanical structures used for EL 4 are under study, as well as alternative concepts. The paper gives some data for a large reactor in the present state of technology, as a result from optimization studies. Technical improvements, especially in the field of materials could lead to even more interesting performances. Some prospects are mentioned for the long run. Investment costs and fuel cycles are discussed in the last part. (authors) [French] La France, qui a base son effort principal pour la production d'energie nucleaire sur la filiere des reacteurs a uranium naturel et graphite refroidis par gaz, et qui a un programme a plus

  4. Natural gas news; Gaz actualites

    Energy Technology Data Exchange (ETDEWEB)

    Anon,

    1998-12-01

    This brochure is a compilation of practical information concerning the Gaz de France group: organization chart, daughter companies, services, economical activity, natural gas market, trade, regulations etc. A list of partners, directions, centres, groups, associations and other various organisms in relation with Gaz de France company is given. (J.S.)

  5. Gaz de France. Operation note

    International Nuclear Information System (INIS)

    2003-01-01

    This note was published for the public at the occasion of the admission to Euronext's Eurolist of the existing shares that make the capital of Gaz de France company, the French gas utility. The note gives some informations about Gaz de France activity, and about its strategy of development in the European gas market. Then it describes the offer relative to the opening of Gaz de France capital. Some selected financial data and some precision about the risk factors and the management of the company complete the document. (J.S.)

  6. Gaz de France. Source document

    International Nuclear Information System (INIS)

    2005-01-01

    This document was issued by Gaz de France, the French gas utility, at the occasion of the opening of the capital of the company. It is intended to shareholders and presents some informations relative to the stocks admitted to Euronext's Eurolist, some general informations about the company and its capital, some informations about the activities of Gaz de France group, about its financial situation and results, about its management, and about its recent evolution and future perspectives. (J.S.)

  7. Can rupture detector for water cooled piles; Detecteur de rupture de gaine pour piles refroidies a l'eau

    Energy Technology Data Exchange (ETDEWEB)

    Choudens, H de; Guitton, P

    1962-07-01

    The object of this study was to develop a simple, easy to-build, apparatus for showing the appearance of a defect on a fuel element can of a swimming pool reactor. The apparatus used consists of a coil of activated carbon around a NaI(Tl) crystal. Through this coil pass the gases obtained by degassing a sample of water from the reactor; the fission gases which appear when a can leaks are trapped in the carbon; the NaI(Tl) crystal is coupled with a photomultiplier followed by a single-channel selector fixed on a photo-electric peak characteristic of the {gamma} spectrum of fission gases. Preliminary experiments were carried out in laboratory; a more complete device was then built and is now working in the reactor Melusine. (author) [French] Le but de cette etude a ete la realisation d'un appareil simple et facile a realiser destine a indiquer l'apparition d'un defaut sur une gaine des elements combustibles d'une pile piscine. A cet effet, l'appareillage utilise est compose d'un serpentin de charbon active entourant un cristal de NaI (Tl). Ce serpentin est parcouru par les gaz provenant du degazage d'un prelevement d'eau de la piscine du reacteur; les gaz de fission apparaissant lors d'une rupture de gaine sont retenus dans le charbon; le cristal INa (Tl) est couple avec un PM suivi d'un selecteur monocanal cale sur un pic photoelectrique caracteristique du spectre {gamma} des gaz de fission. Des manipulations preliminaires ont ete faites en laboratoire, un dispositif plus complet a ete ensuite monte et fonctionne a la Pile Melusine. (auteurs)

  8. Study of total ionization by {alpha} particles, in pure gases and gaseous mixtures containing metastable atoms, as a function of temperature; Etude de l'ionisation totale par les paricules {alpha}, dans les gaz purs et les melanges gazeux contenant des atomes metastables, en fonction de la temperature

    Energy Technology Data Exchange (ETDEWEB)

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

    1969-07-01

    Experiments have been carried out on the total ionization by alpha particles, in pure gases and gaseous mixtures containing metastable atoms, as a function of temperature. Using a different experimental method, the results for the mean ionization energy at 300 K given by Jesse in 1953 have been confirmed to within 1 per cent. It is established that in pure gases the mean energy W required to form a pair of ions remains constant as the temperature varies from 77 to 300 K. It is shown that there is a temperature effect for W in binary gas mixtures of the type A-B containing meta-stable atoms A{sup *} and an 'impurity' B. A systematic study is made of the change {delta}W in W as a function of the temperature and of the B 'impurity' concentration in the mixtures Ne - Ar, Ne - Kr, Ne - H{sub 2}, Ne - N{sub 2}, Ne - CH{sub 4} and He - Ar. Experiments have been carried out on a ternary gas mixture of the type A - B - C, where C is a second ionizable 'impurity' added to the binary mixture A - B; they show the existence of excited atoms B{sup *} formed from the 'impurity' B. Finally, it is shown that the amount of metastable atoms formed in a pure gas must be very close to the number N{sub 0} of ion pairs, and that there must exist a correlation between the number N{sub 0} of ion pairs and the number {approx_equal} N{sub 0} of metastable atoms created in the pure rare gases. (author) [French] On realise des experiences sur l'ionisation totale par les particules alpha, dans les gaz purs et les melanges gazeux contenant des atomes metastables, en fonction de la temperature. Avec une methode experimentale differente, on retrouve a mieux que 1 pour cent pres les valeurs de l'energie moyenne d'ionisation que JESSE a obtenues en 1953 et a 300 K. On etablit que dans les gaz purs, l'energie moyenne W pour creer une paire d'ions demeure constante, quand la temperature varie entre 77 et 300 K. On met en evidence un effet de temperature sur W, dans les melanges gazeux binaires du type

  9. Proposition d'explication de la formation d'hydrogène sulfuré dans les stockages souterrains de gaz naturel par réduction des sulfures minéraux de la roche magasin Proposed Explanation of Hydrogen-Sulfide Formation in Underground Natural-Gas Storage Structures by Reduction of Mineral Sulfides in the Reservoir Rock.

    Directory of Open Access Journals (Sweden)

    Bourgeois J. P.

    2006-11-01

    Full Text Available La formation d'hydrogène sulfuré dans les structures de stockage peu expliquer autrement que par l'action de bactéries sulfato-réductrices. La contenue dans la roche magasin constitue une source de sulfures capable d'alimenter en H2S le gaz naturel. La réduction de la pyrite en sulfures du type Fe 1-x S et l'équilibre de dissolution précipitation, lié principalement à la pression de CO2, dans les structures stockages, constituent un processus de formation d'H2S capable d'expliquer tativement et quantitativement les phénomènes observés sur le terrain. Un modèle simplifié de stockage reprend ce schéma et teste la sensibililté de la teneur en H2S à la valeur des paramètres physiques et chimiques définissant le stockage. Cette étude permet de proposer un certain nombre d'actions susceptibles de limiter la formation d'H2S et d'orienter les choix futurs du couple gaz naturel - structures de stockage. The formation of hydrogen sulfide in storage structures can be explained otherwise thon by the action of sulfate-reducing bacteria. The pyrite contained in the reservoir rock makes up a source of sulfides capable of supplying the natural gas with H2S.Reduction of pyrite ta sulfides of the Fe,-,S type and the dissolution precipitation equilibrium, linked mainly ta C02 pressure in storage structures, make up an H2S for-mation process capable of qualitatively and quantitatively explained phenomena observed in the field.A simplified storage model reflects this scheme and can be used ta test the sensi-tivity of the H2S content ta the value of the physical and chemical parameters defining the storage structure.This investigation can be used to propose various means of action (sable ta "mit H2S formation and ta guide future choices of natural gas/storage-structure pairs.

  10. Experimental study of improvement of exchanged power in gases by catalytic dissociation: ammonia (1961); Etude experimentale de l'amelioration des echanges de chaleur avec les gaz par dissociation catalytique: ammoniac (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Perroud, P [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires; De La Harpe, A [Centre National de la Recherche Scientifique(CNRS), 75 - Paris (France)

    1961-07-01

    Rates of ammonia dissociation and resulting coefficients of improvement of exchanged power have been measured in an annular channel under following conditions: mean wall temperature until 1500 deg. C (tungsten rod, diameter 3 mm), mass velocity until 11 g/cm{sup 2}.s and absolute pressure between 1.5 and 7 kg/cm{sup 2}. Rate of dissociation is mainly function of wall temperature and total mass flow rate of ammonia; it depends little on entrance gas temperature and is practically independent of pressure. Apparent coefficients of improvement of exchanged power under above conditions (including radiation) have reached 1.8; this maximum was obtained for a mean wall temperature of 1250 deg. C. These coefficients decrease when Reynolds number increases. Finally, a theoretical analysis of the phenomenon is given as well as possibilities of application. (authors) [French] Les taux de dissociation d'ammoniac et les coefficients d'amelioration de puissance echangee resultants ont ete mesures en espace annulaire dans les conditions suivantes: temperature moyenne de paroi jusqu'a 1500 deg. C (barreau de tungstene de diametre 3 mm), vitesse massique jusqu'a 11 g/cm{sup 2}.s et pression absolue comprise entre 1,5 et 7 kg/cm{sup 2}. Le taux de dissociation est surtout fonction de la temperature de paroi et du debit en masse total d'ammoniac; il depend peu de la temperature d'entree du gaz et est pratiquement independant de la pression. Les coefficients d'amelioration apparents de la puissance echangee dans les conditions d'experience (rayonnement compris) ont atteint 1,8. Ce maximum observe se place vers une temperature moyenne de la paroi de 1250 deg. C. Ces coefficients decroissent quand le nombre de Reynolds de l'ecoulement croit. Finalement, une analyse theorique du phenomene est donnee ainsi que les perspectives d'applications. (auteurs)

  11. Improvement of heat transfer by the use of corrugated surfaces; Amelioration du transfert de chaleur par l'emploi de surfaces corruguees

    Energy Technology Data Exchange (ETDEWEB)

    Gargaud, J; Paumard, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    This experimental work is designed to determine the friction coefficient and the Margoulis number of internally or externally corrugated cans cooled by air or CO{sub 2} under forced convection, when the Reynolds' number is between 1.5 * 10{sup 4} and 3.5 * 10{sup 6} Different corrugation profiles have been examined; they are made up of variously shaped threading, of rings, of transverse fins, of very small 'herring-bone fins, of undulations. Two types of test have been carried out: 1. tests in annular spaces using CO{sub 2} or air, where the gas circulates between an electrically heated corrugated nucleus having a constant flux and a smooth exterior channel. 2. tests on internally corrugated tubes heated by an external water current and cooled by an internal current of pressurized CO{sub 2}. The first type of test requires probe-measurement of the speeds and the temperatures in the fluid in order to obtain a friction coefficient and a Margoulis' number which are characteristic of the corrugated surface. These coefficients, on the other hand, are given directly by the second, type of test. This work shows the role and the importance of the various geometric and aerodynamic parameters such as relative roughness, the reduced pitch (ratio of the pitches at the height of the corrugation) and the Reynolds' number. (authors) [French] Ce travail experimental a pour objet la determination du coefficient de frottement et du nombre de Margoulis de gaines corruguees exterieurement ou interieurement, refroidies par de l'air ou du CO{sub 2} en convection forcee turbulente, pour des nombres de Reynolds compris entre 1,5.10{sup 4} et 3,5.10{sup 6}. Divers profils de corrugations ont ete examines; ils comprennent des filetages de formes variees, des anneaux, des ailettes transversales et des ailettes en chevrons de tres petites dimensions, des ondulations. Deux types d'essais ont ete realises: 1. des essais en espace annulaire, au CO{sub 2} ou a l'air, ou le gaz circule entre un

  12. Absolute analysis of uranium isotopic concentrations with a gas ion source mass spectrometer; Analyses absolues des concentrations isotopiques de l'uranium par spectrometre de masse equipe d'une source a gaz

    Energy Technology Data Exchange (ETDEWEB)

    Chaussy, L.; Boyer, R. [Commissariat a l' Energie Atomique, Pierrelatte (France)

    1969-07-01

    Mass spectrometer with electronic bombardment ions source for routine uranium isotopic analysis are used like relative measurements apparatus. We show that such mass spectrometers can be used for absolute measurements with a very high sensitivity and precision which are ten times better than theses of thermo-ionic ions source mass spectrometer. We examine the causes of systematic errors and we give experimental data. In particular natural uranium sample used as reference give: U{sub 5} = 0.7202 {+-} 0.0005 atoms per cent; U{sub 4} = 0.00552 {+-} 0.0003 atoms per cent. The use of this method is justified for standards control. (authors) [French] Les spectrometres de masse a source par bombardement electronique pour l'analyse de l'uranium sous forme d'hexafluorure, sont utilises en routine comme des appareils de mesure relative. On montre que l'on peut utiliser de tels appareils pour effectuer des mesures absolues avec une excellente sensibilite et reproductibilite, dix fois superieure a celle des spectrometres a source thermoionique. On examine en detail les causes d'erreurs systematiques et on donne des resultats experimentaux. En particulier, l'analyse d'un echantillon d'uranium naturel donne: U{sub 5} = 0.7202 {+-} 0.0005 atomes pour cent; U{sub 4} = 0.00552 {+-} 0.0003 atomes pour cent. La technique de mesure est utile pour le controle d'etalons isotopiques. (auteurs)

  13. Pollution atmospherique par emission de gaz d'echappement des ...

    African Journals Online (AJOL)

    The objective of the present work is to study the air pollution generated by the gases of exhaust in the city of Porto-Novo to Benin. The quantification of the different pollutants or particles given out on the one hand by the vehicles, and the determination of the level of the pollution of every particle on the other hand, allowed us ...

  14. Gaz de France. Operation note; Gaz de France. Note d'operation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    This note was published for the public at the occasion of the admission to Euronext's Eurolist of the existing shares that make the capital of Gaz de France company, the French gas utility. The note gives some informations about Gaz de France activity, and about its strategy of development in the European gas market. Then it describes the offer relative to the opening of Gaz de France capital. Some selected financial data and some precision about the risk factors and the management of the company complete the document. (J.S.)

  15. Gaz de France annual report 2003

    International Nuclear Information System (INIS)

    2003-01-01

    Today, Gaz de France Group ranks as one of the largest gas utilities in Europe. This success is the fruit of a growth strategy that fuses economic, social and environmental imperatives. To respond more efficiently to fluctuations in the natural gas market and continue to expand its range of competitive products and services, Gaz de France has committed to integrated development across the full spectrum of natural gas activities, from exploration and production to the sale of energy and related services. As the leading supplier of natural gas in France, Gaz de France has honed a targeted policy to acquire equity interests and assets, mainly in Europe, assuring the Group of a privileged place at the heart of the European gas grid. As European energy markets continue to open more widely to competition, the Group intends to benefit from its presence in all the sectors of the natural gas industry and in the European market to confirm its position as an integrated energy operator, focused on gas, among Europe's leaders. To achieve this goal, Gaz de France will concentrate in a balanced fashion on activities linked to infrastructures and activities related to energy supply and services. While assuming its public service responsibilities, the Group will expand the range of products and services to customers. This activity report presents: consolidated financial highlights, profile, corporate governance, Gaz de France's ambition, panorama of activities: energy supply and services (exploration - production, purchase and sale of energy, services), infrastructures (transmission and storage - France, distribution - France, transmission and distribution - international), Commitments of Gaz de France (human resources, research and development, sustainable development, map of main subsidiaries and affiliates)

  16. Le Gaz Naturel Véhicule Natural Gas for Vehicles

    Directory of Open Access Journals (Sweden)

    De Chauveron S.

    2006-11-01

    Full Text Available Cet article présente le GNV (Gaz Naturel Véhicule. Le GNV a en effet de sérieux atouts, à la fois comme carburant de substitution et comme carburant propre. Ces atouts sont aussi bien économiques que techniques. La première partie est consacrée aux enjeux du développement du GNV. Les premiers pays utilisateurs ont été ceux qui disposent sur leur sol de ressources de gaz naturel. Aujourd'hui, alors que de nombreux pays doivent faire face à l'inquiétude croissante relative à l'augmentation de la pollution urbaine, le gaz naturel apparaît également comme un carburant propre, permettant de réduire rapidement les émissions de polluants des véhicules. Dans une deuxième partie, nous donnons une description technique sommaire des stations GNV et des véhicules GNV. Il s'agit de familiariser le lecteur avec les quelques spécificités techniques du GNV, par rapport à l'essence et au gazole. On constatera d'ailleurs que les technologies GNV sont très proches des technologies classiques. Enfin, la dernière partie est consacrée aux actions en cours, qui permettront le développement du GNV en France et en Europe : programmes de recherche, réduction des coûts de la filière, actions réglementaires, communication, etc. This article presents compressed natural gas for vehicles (CNG, which can provide considerable advantages both as an alternative fuel and as a clean fuel. These assets are not only economic but also technical. The first part deals with what is at stake in developing natural gas as a motor fuel. The first countries to use CNG were those with natural gas resources in their subsoil. Today, with a large number of countries having to cope with growing concern about increasing urban pollution, natural gas is also seen as a clean fuel that can help cut vehicle pollutant emissions dramatically. In the second part a brief technical description is given of CNG stations and vehicles, with the aim of acquainting the reader with

  17. Gaz de France. Source document; Gaz de France. Document de base

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This document was issued by Gaz de France, the French gas utility, at the occasion of the opening of the capital of the company. It is intended to shareholders and presents some informations relative to the stocks admitted to Euronext's Eurolist, some general informations about the company and its capital, some informations about the activities of Gaz de France group, about its financial situation and results, about its management, and about its recent evolution and future perspectives. (J.S.)

  18. Energy of solution of rare gases in metals; Energie de dissolution des gaz rares dans les metaux

    Energy Technology Data Exchange (ETDEWEB)

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

    1959-07-01

    In order to calculate the energy of solution of rare gases in metals, a method which has given good results in the case of solid solutions in metals has been applied. Nevertheless, it was necessary for this, to know the compressibility of gases under conditions which are not feasible in a laboratory. H. Jensen has studied this compressibility in a precise way for the rare gases Ar, Kr, Xe. It has thus been possible to calculate the energy of solution of these gases in different metals. These calculations have been carried out most thoroughly for the case of uranium. (author) [French] Nous avons applique au calcul de l'energie de dissolution des gaz rares dans les metaux, une methode qui a donne de bons resultats dans le cas des solutions solides metalliques. Il fallait pour cela connaitre la compressibilite des gaz rares dans des conditions impossibles a realiser en laboratoire. Cette compressibilite a ete etudiee par H. Jensen de facon precise pour les gaz rares A, Kr, Xe. Nous avons pu, de ce fait, calculer les energies de dissolution de ces gaz dans les differents metaux. Les calculs ont ete faits plus completement dans le cas de l'uranium. (auteur)

  19. Energy of solution of rare gases in metals; Energie de dissolution des gaz rares dans les metaux

    Energy Technology Data Exchange (ETDEWEB)

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

    1959-07-01

    In order to calculate the energy of solution of rare gases in metals, a method which has given good results in the case of solid solutions in metals has been applied. Nevertheless, it was necessary for this, to know the compressibility of gases under conditions which are not feasible in a laboratory. H. Jensen has studied this compressibility in a precise way for the rare gases Ar, Kr, Xe. It has thus been possible to calculate the energy of solution of these gases in different metals. These calculations have been carried out most thoroughly for the case of uranium. (author) [French] Nous avons applique au calcul de l'energie de dissolution des gaz rares dans les metaux, une methode qui a donne de bons resultats dans le cas des solutions solides metalliques. Il fallait pour cela connaitre la compressibilite des gaz rares dans des conditions impossibles a realiser en laboratoire. Cette compressibilite a ete etudiee par H. Jensen de facon precise pour les gaz rares A, Kr, Xe. Nous avons pu, de ce fait, calculer les energies de dissolution de ces gaz dans les differents metaux. Les calculs ont ete faits plus completement dans le cas de l'uranium. (auteur)

  20. Gaz de France annual report 2001

    International Nuclear Information System (INIS)

    2001-01-01

    One of Europe's leading gas utilities, the Gaz de France Group operates in all sectors of the natural gas industry, from exploration and production to energy distribution and services, to respond to customer demand efficiently and achieve sustained and profitable growth. To this end, the Group is organized in five lines of business: exploration and production, supply and trading, transmission, distribution and services. Active in 33 countries, the Gaz de France Group first targets growth in Europe, its natural environment. The opening of energy markets and its position at the center of Europe's gas grids offers the Group many opportunities in trading, transmission for third parties, distribution and services. Since August 10, 2000, Gaz de France has made it possible for other gas operators to access its transmission system. The Group capitalizes on its expertise at the global level as well, in emerging markets like Mexico and in fields in which it has recognized know-how, such as liquefied natural gas (LNG). To ensure this growth and pursue its penetration of European and world markets, the Gaz de France Group implements a policy of cooperation and partnership with other energy sector operators, demonstrates its well-developed ability to innovate and practices a customer-focused organization that offers competitive, tailored services to residential users, companies and local governments. The Group has chosen to pursue this growth through a strategy of sustainable development. By making natural gas more accessible and promoting its uses, Gaz de France integrates demand-side management of energy, fosters human development and ensures environmental protection in France, Europe and the world. This activity report presents: the corporate profile of the group, the international natural gas businesses, the financial highlights, the growth objectives of the group in all its businesses (exploration and production, supply and trading, transmission, distribution, services

  1. A Geochemical Approach for Monitoring a CO2 Pilot Site: Rousse, France. A Major gases, CO2-Carbon Isotopes and Noble Gases Combined Approach Une méthode géochimique pour la surveillance d’un site pilote de stockage de CO2 : Rousse, France. Approche combinant les gaz majeurs, l’isotopie du carbone du CO2 et les gaz rares

    Directory of Open Access Journals (Sweden)

    Garcia B.

    2012-02-01

    storage pilot suggest that noble gas compositions produced by oxyfuel process are sufficiently exotic compared to compositions found in nature (reservoir, aquifer and air to be directly used as tracers of the injected CO2, and to detect and quantify leaks at soil and aquifer levels. Ce papier presente la caracterisation geochimique des differents gaz, naturels et anthropogeniques, impliques dans un pilote de stockage de CO2 en champ de gaz naturel appauvri (Rousse, France. Dans ce pilote, le CO2 est produit par oxycombustion d’un gaz naturel transforme en gaz domestique a l’usine de Lacq. Ce CO2 est transporte dans un pipeline de 30 km de longueur jusqu’au reservoir de gaz appauvri de Rousse. Les gaz produits a Rousse avant injection de CO2, le gaz commercial de Lacq et le CO2 resultant de l’oxycombustion ont ete echantillonnes, ainsi que les gaz situes dans un puits de surveillance (a une profondeur de 45 m et les gaz du sol situes au voisinage de Rousse. Pour tous ces echantillons, la composition en gaz majeurs, la signature isotopique du carbone ainsi que l’abondance et signature isotopique des gaz rares ont ete determinees. Les compositions gazeuses du gaz naturel de Rousse sont comparables a celle du gaz domestique de Lacq avec le methane comme compose principal et la fraction C2-C5 et CO2 comme gaz residuels. Les gaz des sols refletent typiquement des melanges entre l’air (pole pur et le CO2 d’origine biogenique (avec des teneurs maximales de l’ordre de 9-10 %, tandis que les gaz presents dans le puits de monitoring refletent typiquement la composition de l’air sans exces de CO2. Le gaz de Rousse et le gaz domestique du site de Lacq ont une composition isotopique δ13CCH4 egale a –41,0 ‰ et –43,0 ‰ respectivement. Le CO2 injecte sur Rousse a une composition isotopique δ13CCO2 egale a –40,0 ‰ a la sortie de la chambre d’oxycombustion, tandis que la composition isotopique δ13CCO2 des gaz des sols est comprise entre –15 et –25

  2. Unstable fluid flow in a water-cooled heating channel; Instabilites d'ecoulement du fluide dans un canal chauffant refroidi a l'eau

    Energy Technology Data Exchange (ETDEWEB)

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

    1961-07-01

    Experimental investigations of the instable behavior of a pressurized water flow in forced convection in a heating channel, with subcooled or bulk boiling have been carried. Tests were conducted at 1140, 850 and 570 psi. The test section was 35 in. high, surmounted by a 25.4 in. riser, these sections were by-passed by a pipe where the flow was between 1 and 4 times the flow in the test section. The water velocity (in the test section) was between 1.6 and 6.6 ft/s. Under certain conditions oscillations with a period of several seconds and perfectly stable have been observed. A mathematical model has been defined and a good agreement obtained for the main characteristics of the oscillations. It seems that the dimensions of the riser have a determining effect: the inception of bulk boiling gives an important variation of the driving head which can generate oscillations due to the non-zero delay for the system to reach its equilibrium. (author) [French] Une investigation experimentale des risques d'instabilite d'ecoulement d'eau sous pression dans un canal chauffant, avec ebullition sous refroidie ou en masse a ete faite. Les essais ont ete effectues a des pressions de 40, 60 et 80 kg/cm{sup 2}. La section d'essais d'une hauteur de 1,37m etait surmontee d'une cheminee de 1 m, le tout by-passe par une conduite ou le debit pouvait varier entre 1 et 4 fois le debit dans la section d'essais. La vitesse dans la section variait entre 0,5 et 2 m/s. Dans certaines conditions, des oscillations de periode de l'ordre de quelques secondes et parfaitement stables sont apparues. Un modele mathematique a permis de retrouver les principales caracteristiques de ces oscillations. Il semble que l'influence des dimensions de la cheminee soit determinante: en effet, l'apparition de l'ebullition de masse entraine une importante variation de la hauteur motrice qui peut engendrer des oscillations entretenues a cause du retard non nul a la mise en equilibre du systeme. (auteur)

  3. Gaz de France annual report 2003; Gaz de France rapport annuel 2003

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    Today, Gaz de France Group ranks as one of the largest gas utilities in Europe. This success is the fruit of a growth strategy that fuses economic, social and environmental imperatives. To respond more efficiently to fluctuations in the natural gas market and continue to expand its range of competitive products and services, Gaz de France has committed to integrated development across the full spectrum of natural gas activities, from exploration and production to the sale of energy and related services. As the leading supplier of natural gas in France, Gaz de France has honed a targeted policy to acquire equity interests and assets, mainly in Europe, assuring the Group of a privileged place at the heart of the European gas grid. As European energy markets continue to open more widely to competition, the Group intends to benefit from its presence in all the sectors of the natural gas industry and in the European market to confirm its position as an integrated energy operator, focused on gas, among Europe's leaders. To achieve this goal, Gaz de France will concentrate in a balanced fashion on activities linked to infrastructures and activities related to energy supply and services. While assuming its public service responsibilities, the Group will expand the range of products and services to customers. This activity report presents: consolidated financial highlights, profile, corporate governance, Gaz de France's ambition, panorama of activities: energy supply and services (exploration - production, purchase and sale of energy, services), infrastructures (transmission and storage - France, distribution - France, transmission and distribution - international), Commitments of Gaz de France (human resources, research and development, sustainable development, map of main subsidiaries and affiliates)

  4. Cell for studying electron-adsorbed gas interactions; Cellule d'etudes des interactions electron-gaz adsorbe

    Energy Technology Data Exchange (ETDEWEB)

    Golowacz, H; Degras, D A [Commissariat a l' Energie Atomique, 91 - Saclay (France). Centre d' Etudes Nucleaires, Deptartement de Physique des Plasmas et de la Fusion Controlee, Service de Physique Appliquee, Service de Physique des Interractions Electroniques, Section d' Etude des Interactions Gaz-Solides

    1967-07-01

    The geometry and the technology of a cell used for investigations on electron-adsorbed gas interactions are described. The resonance frequencies of the surface ions which are created by the electron impact on the adsorbed gas are predicted by simplified calculations. The experimental data relative to carbon monoxide and neon are in good agreement with these predictions. (authors) [French] Les caracteristiques geometriques et technologiques generales d'une cellule d'etude des interactions entre un faisceau d'electrons et un gaz adsorbe sont donnees. Un calcul simplifie permet de prevoir les frequences de resonance des ions de surface crees par l'impact des electrons sur le gaz adsorbe. Les donnees experimentales sur l'oxyde de carbone et le neon confirment les previsions du calcul. (auteurs)

  5. Gaz de France annual report 2000

    International Nuclear Information System (INIS)

    2000-01-01

    A leader in the natural gas market in Europe, Gaz de France is an integrated group active in all sectors of the natural gas industry. In exploration and production, trading of natural gas, transmission, storage, distribution, energy management, air conditioning and heating, the Group has developed recognized skills and know-how both upstream and down to assure its customers of diversified, efficient and competitive services. A leader in liquefied natural gas, storage and distribution technologies, the Gaz de France Group has strong positions in Europe and operates throughout the world by promoting a strategy of alliances and partnerships at all levels of the gas industry. The goal of the Gaz de France Group is to continue to expand and develop its activities from the wellhead to the burner tip, and to seize, in France and throughout the world, the best opportunities offered to capitalize on its strengths. This activity report presents: the corporate profile, the financial highlights, the principal subsidiaries and affiliates, the major European trunk lines the responsive, customer-focused services (exploration-production, trading, transmission, distribution, services), the actions to ensure performance (productive research, comprehensive quality assurance, mobilized workforce ready for the opening of the markets)

  6. Gaz de France 2006 sustainable development report

    International Nuclear Information System (INIS)

    2006-01-01

    A major European energy utility, the Gaz de France Group produces, purchases, transports, distributes and sells natural gas, electricity and related services for its residential, corporate and local government customers. this report presents the actions implemented by the group to incorporate sustainable development into its strategy. From the point of view of risks and opportunities, the group analyzes what it takes to ensure development that respects people and the environment, and it implements them in all its business lines and management systems. Content: Gaz de France, portrait of a major energy utility, highlights of 2006, challenges and strategy (defining strategy and sustainable development policy, specific risks and opportunities, activities of the Gaz de France group: challenges, impact for stakeholders, transparency and independence in governing), ranking and implementing (defining sustainable development policy: reviewing priorities, meeting all the challenges, publicizing and defending positions, increasing awareness, overseeing and monitoring results), results of the 2004-2006 sustainable development action plan, dialogue and action with stakeholders, performance assessment, performance in response to challenges: energy challenges (guaranteeing regular supplies, controlling atmospheric emissions, promoting energy conservation, developing renewable energy), industrial challenges (ensuring health and safety, limiting the overall environmental impact of group activities), social responsibility challenges (advocating corporate social responsibility, promoting human rights and fighting corruption, encouraging commitment to solidarity, promoting regional development through local initiatives, reconciling acquisitions, procurement and sustainable development, ensuring transparency in natural gas rates, providing shareholders with quality information, promoting diversity, a source of enrichment, making working conditions a performance factor), indicators and

  7. Gaz de France annual report 2001; Gaz de France rapport annuel 2001

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    One of Europe's leading gas utilities, the Gaz de France Group operates in all sectors of the natural gas industry, from exploration and production to energy distribution and services, to respond to customer demand efficiently and achieve sustained and profitable growth. To this end, the Group is organized in five lines of business: exploration and production, supply and trading, transmission, distribution and services. Active in 33 countries, the Gaz de France Group first targets growth in Europe, its natural environment. The opening of energy markets and its position at the center of Europe's gas grids offers the Group many opportunities in trading, transmission for third parties, distribution and services. Since August 10, 2000, Gaz de France has made it possible for other gas operators to access its transmission system. The Group capitalizes on its expertise at the global level as well, in emerging markets like Mexico and in fields in which it has recognized know-how, such as liquefied natural gas (LNG). To ensure this growth and pursue its penetration of European and world markets, the Gaz de France Group implements a policy of cooperation and partnership with other energy sector operators, demonstrates its well-developed ability to innovate and practices a customer-focused organization that offers competitive, tailored services to residential users, companies and local governments. The Group has chosen to pursue this growth through a strategy of sustainable development. By making natural gas more accessible and promoting its uses, Gaz de France integrates demand-side management of energy, fosters human development and ensures environmental protection in France, Europe and the world. This activity report presents: the corporate profile of the group, the international natural gas businesses, the financial highlights, the growth objectives of the group in all its businesses (exploration and production, supply and trading, transmission, distribution, services

  8. Gaz de France annual report 2001; Gaz de France rapport annuel 2001

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    One of Europe's leading gas utilities, the Gaz de France Group operates in all sectors of the natural gas industry, from exploration and production to energy distribution and services, to respond to customer demand efficiently and achieve sustained and profitable growth. To this end, the Group is organized in five lines of business: exploration and production, supply and trading, transmission, distribution and services. Active in 33 countries, the Gaz de France Group first targets growth in Europe, its natural environment. The opening of energy markets and its position at the center of Europe's gas grids offers the Group many opportunities in trading, transmission for third parties, distribution and services. Since August 10, 2000, Gaz de France has made it possible for other gas operators to access its transmission system. The Group capitalizes on its expertise at the global level as well, in emerging markets like Mexico and in fields in which it has recognized know-how, such as liquefied natural gas (LNG). To ensure this growth and pursue its penetration of European and world markets, the Gaz de France Group implements a policy of cooperation and partnership with other energy sector operators, demonstrates its well-developed ability to innovate and practices a customer-focused organization that offers competitive, tailored services to residential users, companies and local governments. The Group has chosen to pursue this growth through a strategy of sustainable development. By making natural gas more accessible and promoting its uses, Gaz de France integrates demand-side management of energy, fosters human development and ensures environmental protection in France, Europe and the world. This activity report presents: the corporate profile of the group, the international natural gas businesses, the financial highlights, the growth objectives of the group in all its businesses (exploration and production, supply and trading, transmission, distribution

  9. Gaz de France. 2006 reference document

    International Nuclear Information System (INIS)

    2006-01-01

    This document was issued by Gaz de France, the French gas utility, at the occasion of the opening of the capital of the company. It is intended to shareholders and presents the relevant informations relative to the annual consolidated financial statements of the group according to IFRS and French standards for the year 2005 (selected financial information, business overview, liquidity and capital resources, profit forecasts or estimates, compensation and benefits, issuer assets etc..). It includes also some complementary information about the activities of the group, its estate property, plants and equipments, its R and D and patenting activities, its management and administration, its 2005 and 2006 contracts etc.. (J.S.)

  10. Law project modified by the Senate after urgency declaration relative to the electric and gas public utilities and to the power and gas companies; Projet de loi modifie par le Senat apres declaration d'urgence relatif au service public de l'electricite et du gaz et aux entreprises electriques et gazieres

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This document is the modifications made by the French Senate after the first reading of the law project adopted by the House of Commons and relative to the change of status of the power and gas public utilities in the framework of the deregulation of European energy markets. This law changes the juridical status of the two state monopolies Electricite de France (EdF) and Gaz de France (GdF) into two anonymous companies and creates two additional companies for the management of the power and gas networks. It ensures also the transposition of the European directives from June 26, 2003 (2003/54/CE and 2003/55/CE). It contains some proper dispositions and modifies various existing French laws, in particular the law no. 46-628 from April 8, 1946 about the electricity and gas nationalization and the law no. 2000-108 from February 10, 2000 relative to the modernization and development of the electric public utility. The document lists the modifications made by the Senate article by article. (J.S.)

  11. Project of law modified by the Senate relative to the electric and gas public utilities and to the electric and gas companies; Projet de loi modifie par le Senat relatif au service public de l'electricite et du gaz et aux entreprises electriques et gazieres

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This project of law aims to adapt the electricity and gas sector to the new economical context of opening of the energy markets to competition. It gives to energy companies the internal organization base necessary to warrant a high level of service and a transparent and non-discriminatory access of third parties to transport and distribution networks. These evolutions will allow Electricite de France (EdF) and Gaz de France (GdF) companies to compete on equal terms with their European competitors. It confirms first the prime role of public utility of both companies and then transposes the dispositions of the European directives relative to the organization of EdF and GdF integrated companies. It foresees the creation of two daughter companies for the management of energy transport activities. The project of law foresees also the change of the status of EdF and GdF companies and the reform of the retirement pensions of the personnel. This report presents the modifications added by the Senate to the text of law adopted at first reading by the House of Commons. (J.S.)

  12. Ecoulements intermittents de gaz et de liquide en conduite verticale Intermittent Gas and Liquid Flows in a Vertical Pipe.

    Directory of Open Access Journals (Sweden)

    Line A.

    2006-11-01

    Full Text Available Le modèle présenté ici permet la pré-détermination du gradient de pression, du taux global de gaz, et de grandeurs caractéristiques de l'intermittence, dans un écoulement à poches et bouchons en conduite verticale. L'écriture des lois de conservation en moyenne phasique conditionnelle conduit à la définition d'une cellule moyenne équivalente. La fermeture du modèle est assurée par des lois de contrainte de cisaillement film-paroi, film-poche, bouchon-paroi, par une loi d'arrachage du gaz au culot de la poche, une loi de glissement du gaz dans les bouchons et par une loi de la vitesse moyenne de propagation des fronts de poches. Le calibrage et la qualification du modèle s'appuient sur deux banques de données, dont l'une a été obtenue avec des fluides pétroliers dans des conditions proches des situations industrielles (boucle diphasique de Boussens. The model described here can be used to predetermine the pressure gradient, the overall gas rate and the characteristic intermittence magnitudes in pocket and slug flow in a vertical pipe. The way governing equations in the conditional phase average are written defines an equivalent average cell. The model is closed by film/wall, film/pocket and slug/wall shear-stress laws, by a pulloff law for the gas at the bottom of the pocket, a slippage law for the gas in the slugs, and a mean propagation velocity law for the pocket fronts. The calibration and qualification of the model are based on two data banks, one of which contains data on petroleum fluids under conditions close to industrial situations (two-phase loop at Boussens.

  13. Behaviour of rare gases in solids at high temperature; Comportement des gaz rares dans les solides a haute temperature

    Energy Technology Data Exchange (ETDEWEB)

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

    1960-07-01

    In this article a number of simple results regarding the solubility and displacement of rare gases in solids have been assembled. These results were obtained from elementary considerations on highly compressed gases and on dislocations. They provide a better understanding of the now fairly numerous experiments dealing with the swelling of irradiated fuels, this swelling being due to the presence of a high proportion of gases in the fission products. Finally, the chances of success of the various methods which may be devised to diminish the swelling are examined. (author) [French] Nous avons rassemble dans ce texte un certain nombre de resultats simples relatifs a la solubilite et au deplacement des gaz rares dans les solides. Ces resultats ont ete obtenus par des considerations elementaires sur les gaz tres comprimes et sur les dislocations. Ils permettent de mieux comprendre les experiences, maintenant assez nombreuses, qui ont trait au gonflement des combustibles irradies; gonflement qui est du a la presence d'une forte proportion de gaz dans les produits de fission. On examine finalement les chances de succes des differents moyens que l'on peut imaginer pour attenuer le gonflement. (auteur)

  14. Contribution to the chromatography of atmospheric gases (1963); Contribution a la chromatographie des gaz de l'air (1963)

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-06-15

    In the first part, the author studies the gas-phase chromatographic separation of the atmospheric rare gases, of hydrogen, and of some gaseous compounds of carbon (CO, CO{sub 2}, CH{sub 4}) using inactive gases to obtain the most favourable operational conditions far this separation. In the second part, the optimum conditions for detecting non-active gases using an ionisation chamber and a {sup 239}Pu radioactive source emitting 5.15 MeV {alpha} particles are determined. (author) [French] Dans une premiere partie, l'auteur etudie la separation par chromatographie en phase gazeuse des gaz rares de l'air, de l'hydrogene, et de quelques composes gazeux du carbone (CO, CO{sub 2}, CH{sub 4}) en utilisant des gaz inactifs an vue d'obtenir les conditions experimenales les plus favorables en vue de cette separation. Dans une deuxieme partie, les conditions optimales de detection de gaz non actifs a l'aide d'une chambre d'ionisation, en utilisant comme source radioactive du {sup 239}Pu qui emet des particules {alpha} de 5,15 MeV, sont determinees. (auteur)

  15. Gaz de France interim financial report 2007

    International Nuclear Information System (INIS)

    2007-01-01

    This financial report contains the unaudited condensed financial statements of Gaz de France Group for the first half ended June 30, 2007, which were reviewed by the audit committee on August 27, 2007 and by the board of directors at its meeting on August 28, 2007. It includes forward-looking statements concerning the objectives, strategies, financial position, future operating results and the operations of Gaz de France Group. These statements reflect the Group's current perception of its activities and the markets in which it operates, as well as various estimates and assumptions considered to be reasonable. Content: interim management report (highlights of the first half of 2007, revenues and results for the period, financial structure, data on outstanding stock, outlook); interim consolidated financial statements (consolidated statements of income, consolidated balance sheets, consolidated statements of cash flows, recognized income and expenses, statements of changes in shareholders' equity, note to the consolidated financial statements); statement by the person responsible for the interim financial report; statutory auditors' report. (J.S.)

  16. Gaz de France 2006 annual report

    International Nuclear Information System (INIS)

    2006-01-01

    Gaz de France is major European energy utility, which produces, purchases, transports, distributes and sells natural gas, electricity and related services for its residential, corporate and local government customers. Its strategic focuses are to develop an ambitious marketing strategy, pursue a supply and procurement policy that guarantees the Group's competitiveness, confirm its position as a benchmark infrastructure manager, and speed up its profitable growth in Europe. Gaz de France aligns its strategy with a concrete and ambitious sustainable development policy. Its growth model is based on responsiveness to customers and constructive dialogue with its employees and partners. This document is the activity report of the group for the year 2006. It presents: 1 - the corporate profile of the group; 2 - its strategies (energy, energy supply, infrastructures); 3 - its financial highlights; 4 - its governance, shareholders and human resources; 5 - the activities of the group (exploration and production, energy procurement, energy sales, services, transmission France, storage France, LNG terminals, distribution France, transmission and distribution international, research and development); 6 - its 2006 financial data and financial summary

  17. Les perspectives du gaz naturel dans le Monde World Natural Gas Prospects

    Directory of Open Access Journals (Sweden)

    Valais M.

    2006-11-01

    Full Text Available Dans un monde en quête de diversification énergétique, le gaz naturel apparaît comme une source d'énergie particulièrement attrayante. Par son abondance, sa facilité de substitution aux produits pétroliers dans une gamme très large d'usages, il pourrait assurément jouer un rôle beaucoup plus important dans la couverture des besoins énergétiques mondiaux. Toutefois, de nombreux obstacles semblent devoir ralentir sa progression. Cet article dégage les grands paramètres techniques et économiques qui devraient conditionner le développement de l'industrie du gaz dans le monde et présente des perspectives d'évolution de sa production et de son commerce international d'ici à la fin du siècle. For a world in search of energy diversification, natural gas is a particularly attractive source. Its abundance and its facility for being substituted for petroleum products over a wide range of uses should certainly mean that it will play a much more important rote in filling world energy needs. Nonetheless, many obstacles are hindering its progress. This article outlines the leading technical and economic parameters which should influence the development of the world gas industry, and the prospects for its production and international trade evolution between now and the end of the century.

  18. Gaz de France and the sustainable development in 2005

    International Nuclear Information System (INIS)

    2006-01-01

    This booklet provides information on the Gaz de France group involvement in the sustainable development: the stakes, the approach, the energy challenge answers, the security and the solidarity and the active part in the territories development. (A.L.B.)

  19. Gaz de France annual report 2000; Gaz de France rapport annuel 2000

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    A leader in the natural gas market in Europe, Gaz de France is an integrated group active in all sectors of the natural gas industry. In exploration and production, trading of natural gas, transmission, storage, distribution, energy management, air conditioning and heating, the Group has developed recognized skills and know-how both upstream and down to assure its customers of diversified, efficient and competitive services. A leader in liquefied natural gas, storage and distribution technologies, the Gaz de France Group has strong positions in Europe and operates throughout the world by promoting a strategy of alliances and partnerships at all levels of the gas industry. The goal of the Gaz de France Group is to continue to expand and develop its activities from the wellhead to the burner tip, and to seize, in France and throughout the world, the best opportunities offered to capitalize on its strengths. This activity report presents: the corporate profile, the financial highlights, the principal subsidiaries and affiliates, the major European trunk lines the responsive, customer-focused services (exploration-production, trading, transmission, distribution, services), the actions to ensure performance (productive research, comprehensive quality assurance, mobilized workforce ready for the opening of the markets)

  20. Gaz de France 2006 sustainable development report; Gaz de France 2006 rapport developpement durable

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    A major European energy utility, the Gaz de France Group produces, purchases, transports, distributes and sells natural gas, electricity and related services for its residential, corporate and local government customers. this report presents the actions implemented by the group to incorporate sustainable development into its strategy. From the point of view of risks and opportunities, the group analyzes what it takes to ensure development that respects people and the environment, and it implements them in all its business lines and management systems. Content: Gaz de France, portrait of a major energy utility, highlights of 2006, challenges and strategy (defining strategy and sustainable development policy, specific risks and opportunities, activities of the Gaz de France group: challenges, impact for stakeholders, transparency and independence in governing), ranking and implementing (defining sustainable development policy: reviewing priorities, meeting all the challenges, publicizing and defending positions, increasing awareness, overseeing and monitoring results), results of the 2004-2006 sustainable development action plan, dialogue and action with stakeholders, performance assessment, performance in response to challenges: energy challenges (guaranteeing regular supplies, controlling atmospheric emissions, promoting energy conservation, developing renewable energy), industrial challenges (ensuring health and safety, limiting the overall environmental impact of group activities), social responsibility challenges (advocating corporate social responsibility, promoting human rights and fighting corruption, encouraging commitment to solidarity, promoting regional development through local initiatives, reconciling acquisitions, procurement and sustainable development, ensuring transparency in natural gas rates, providing shareholders with quality information, promoting diversity, a source of enrichment, making working conditions a performance factor), indicators and

  1. Natural Gas Storage Seismic Monitoring Suivi sismique des stockages de gaz naturel

    Directory of Open Access Journals (Sweden)

    Mari J.L.

    2011-02-01

    té conçues et utilisées de façon continue pendant plusieurs années pour suivre le cycle remplissage/extraction du stockage. Les dispositifs permanents ont permis d’améliorer la précision des mesures de temps d’arrivée jusqu’au dixième de milliseconde. L’arrivée de gaz dans un aquifère se traduit par une rapide variation de vitesse, qui a un impact à la fois sur les temps d’arrivée des réflexions sous les réservoirs et sur les amplitudes aux limites du réservoir. Les mouvements ultérieurs du contact gaz/eau avec le cycle de remplissage/soutirage sont plus difficiles à suivre et nécessitent une excellente précision des mesures de temps d’arrivée des réflexions. L’inversion de ces mesures pour l’estimation des saturations en gaz et en eau est délicate. Cette inversion a été tentée, avec un certain succès, dans le cas de Céré-la-Ronde. Du fait de la densité du dioxyde de carbone, au-delà d’une profondeur de 800 mètres environ, cette inversion risque d’être encore plus délicate pour les stockages de CO2 que pour les stockages de gaz naturel.

  2. Synthesis Gas Purification Purification des gaz de synthèse

    Directory of Open Access Journals (Sweden)

    Chiche D.

    2013-10-01

    Full Text Available Fischer-Tropsch (FT based B-XTL processes are attractive alternatives for future energy production. These processes aim at converting lignocellulosic biomass possibly in co-processing with petcoke, coal, or vacuum residues into synthetic biofuels. A gasification step converts the feed into a synthesis gas (CO and H2 mixture , which undergoes the Fischer-Tropsch reaction after H2/CO ratio adjustment and CO2 removal. However synthesis gas also contains various impurities that must be removed in order to prevent Fischer-Tropsch catalyst poisoning. Due to the large feedstocks variety that can be processed, significant variations of the composition of the synthesis gas are expected. Especially, this affects the nature of the impurities that are present (element, speciation, as well as their relative contents. Moreover, due to high FT catalyst sensitivity, severe syngas specifications regarding its purity are required. For these reasons, synthesis gas purification constitutes a major challenge for the development of B-XTL processes. In this article, we focus on these major hurdles that have to be overcome. The different kinds of syngas impurities are presented. The influence of the nature of feedstocks, gasification technology and operating conditions on the type and content of impurities is discussed. Highlight is given on the fate of sulfur compounds, nitrogen compounds, halides, transition and heavy metals. Main synthesis gas purification technologies (based on adsorption, absorption, catalytic reactions, etc. are finally described, as well as the related challenges. Les procédés de synthèse de biocarburants par voie Fischer-Tropsch (FT, voies B-XTL, représentent des alternatives prometteuses pour la production d’énergie. Ces procédés permettent la conversion en carburants de synthèse de biomasse lignocellulosique, éventuellement mise en oeuvre en mélange avec des charges fossiles telles que petcoke, charbons ou résidus sous vide. Pour

  3. Gaz de France and the sustainable development in 2005; Gaz de France et le developpement durable en 2005

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This booklet provides information on the Gaz de France group involvement in the sustainable development: the stakes, the approach, the energy challenge answers, the security and the solidarity and the active part in the territories development. (A.L.B.)

  4. Research on hydrogen by Gaz de France

    International Nuclear Information System (INIS)

    Donat, G.; Lecoanet, A.; Roncato, J.-P.

    1978-01-01

    With the increasing energy needs of mankind and the earth's necessarily limited resources of fuel, the time will come when the demand for hydrocarbons will exceed the world production capacity. This situation will subsequently get even worse because of the depletion of recoverable reserves. Massive recourse to nuclear and solar energy thus appears indispensable, and the use of hydrogen as a vector for such energies has been under consideration for several years, especially in France where petroleum resources are very limited. Gaz de France has been doing research on the mass production of hydrogen by the decomposition of water and has just come to rather pessimistic conclusions as to the competitiveness of thermochemical processes in comparison with electrolytic methods. However, the electrolysis of water offers interesting prospects providing its efficiency and economics can be improved. Furthermore research on the storage and transportation of hydrogen has already enabled some conclusions to be drawn in these fields where gaseous vectors have very encouraging possibilities [fr

  5. MODELISATION DE LA CINETIQUE CHIMIQUE DANS LA REDUCTION DES OXYDES D4AZOTE PAR DECHARGE COURONNE.

    OpenAIRE

    MEDJAHDI, Sarah ines

    2015-01-01

    CE TRAVAIL DE recherche rentre dans le cadre général de modélisation de la réduction des oxydes d'azote . l'utilisation des réacteurs a plasma froid non-thermique généré par des décharges couronnes est actuellement l'une des techniques les puis promettre .ses pour la destruction des oxydes d'azote .en effet , le traitement des gaz pollués par les décharges couronnes est notamment rendu possible par la multiplication des décharges Électriques .

  6. Gaz de France. 2006 reference document; Gaz de France. Document de reference 2006

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This document was issued by Gaz de France, the French gas utility, at the occasion of the opening of the capital of the company. It is intended to shareholders and presents the relevant informations relative to the annual consolidated financial statements of the group according to IFRS and French standards for the year 2005 (selected financial information, business overview, liquidity and capital resources, profit forecasts or estimates, compensation and benefits, issuer assets etc..). It includes also some complementary information about the activities of the group, its estate property, plants and equipments, its R and D and patenting activities, its management and administration, its 2005 and 2006 contracts etc.. (J.S.)

  7. Contribution of Gaz de France offers to the environmental quality of buildings; Les offres de Gaz de France au service de la qualite environnementale des batiments

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    Cegibat, the information-recommendation agency of Gaz de France for building engineering professionals, has organized this conference meeting to present the contributions of Gaz de France offers in the improvement of the environmental quality of residential and tertiary buildings: environmental quality in France and in Europe, Gaz de France and the 'high environmental quality' (HQE) approach, experience feedback: combined solar-gas systems, examples of realizations. (J.S.)

  8. Gaz de France 2006 annual report; Gaz de France 2006 rapport d'activite

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    Gaz de France is major European energy utility, which produces, purchases, transports, distributes and sells natural gas, electricity and related services for its residential, corporate and local government customers. Its strategic focuses are to develop an ambitious marketing strategy, pursue a supply and procurement policy that guarantees the Group's competitiveness, confirm its position as a benchmark infrastructure manager, and speed up its profitable growth in Europe. Gaz de France aligns its strategy with a concrete and ambitious sustainable development policy. Its growth model is based on responsiveness to customers and constructive dialogue with its employees and partners. This document is the activity report of the group for the year 2006. It presents: 1 - the corporate profile of the group; 2 - its strategies (energy, energy supply, infrastructures); 3 - its financial highlights; 4 - its governance, shareholders and human resources; 5 - the activities of the group (exploration and production, energy procurement, energy sales, services, transmission France, storage France, LNG terminals, distribution France, transmission and distribution international, research and development); 6 - its 2006 financial data and financial summary.

  9. Gaz de France and market regulation

    International Nuclear Information System (INIS)

    Carriere, J.F.; Balard, Th.

    2004-01-01

    Following an overview of the specific features of the European gas sector (characterised by highly concentrated production and increasing levels of production outside Europe and over long distances), the article describes the lead up to the opening of the market place in France. Following the application of the first directive in 2000, Gaz de France has carried out various measures, the aim of which was to achieve immediate efficiency (with the organizational separation of the transport and trading divisions, the separation of activities from an accounting viewpoint and the publication of a transparent TPA tariff as opposed to a discriminatory one). This opening of the gas sector has seen the start of a gradual process based on this experience. In addition to these initial measures, the opening of the gas markets has been subject to a regulatory framework as from January 2003, and the task of regulating the French gas sector has been given to the CRE (Commission de regulation de l'electricite). Thanks to the ongoing dialogue initiated by the latter with all key players in the market, progress has been achieved in various fields related to regulation. Even if this process is not complete, the French example demonstrates that the combined actions of the regulator and the market operators working together in a constructive manner and in stages, makes it possible to successfully introduce a genuinely open market. (authors)

  10. Gaz de France: first half 2007 results

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    Paris, 29 August 2007, Gaz de France Group presents its first half 2007 results (billion euros): Sales revenue 13.78 (-11% with respect to 2006), EBITDA 3.11 (-4.9%), Operating income 2.33 ( -8.7%), Net income Group share 1.51 (-11%), Net income Group share per share 1.53 euro (-11%). The half-year results are attributable primarily to three factors: - A very difficult environment with exceptionally mild climate conditions in the first half, impacting nearly all of the businesses, and unfavourable market conditions, reflected in particular in the low gas prices on the markets; - A tariff context which did not negatively impact the sales margins following a very difficult year 2006; - Good performance in international activities. Despite the environment, the Group is maintaining its financial target for 2007, as announced in March this year: 2007 will be a year of consolidation. EBITDA is expected to be in line with that of 2006. This target assumes average climate conditions during the second half 2007.

  11. Gaz de France: first half 2007 results

    International Nuclear Information System (INIS)

    2007-01-01

    Paris, 29 August 2007, Gaz de France Group presents its first half 2007 results (billion euros): Sales revenue 13.78 (-11% with respect to 2006), EBITDA 3.11 (-4.9%), Operating income 2.33 ( -8.7%), Net income Group share 1.51 (-11%), Net income Group share per share 1.53 euro (-11%). The half-year results are attributable primarily to three factors: - A very difficult environment with exceptionally mild climate conditions in the first half, impacting nearly all of the businesses, and unfavourable market conditions, reflected in particular in the low gas prices on the markets; - A tariff context which did not negatively impact the sales margins following a very difficult year 2006; - Good performance in international activities. Despite the environment, the Group is maintaining its financial target for 2007, as announced in March this year: 2007 will be a year of consolidation. EBITDA is expected to be in line with that of 2006. This target assumes average climate conditions during the second half 2007

  12. Activities of Gaz de France Group

    International Nuclear Information System (INIS)

    Anon.

    2003-01-01

    The Board of Directors of Gaz de France approved the Group's consolidated accounts for 2004. In a more dynamic economic environment than in 2003, the Gaz de France Group reports enhanced results and has continued to pursue its growth in Europe. Increase in net sales driven by sustained growth in sales (+ 8.9%): In 2004, net sales rose 8.9% compared with the 2003 financial year to reach a total of euro 18,129 m. This strong increase in business activities was driven by sustained growth in sales volumes both in France and Europe. Total Group sales volumes amounted to 730 TWh (approximately 66 billion cubic metres), equal to growth of 10.3%. Natural gas sales volumes increased by approximately 10% in France, and are almost 18% higher in Europe, notably in the United Kingdom, Italy, Belgium and the Netherlands. The Group has pursued the profitable development of its activities outside France. As a result, international activities account for 29% of total sales in 2004, against 23% in 2003. The contribution made by international subsidiaries - particularly those specializing in exploration and production - grew by a very substantial 44.3% to reach a total of euro 502 m in 2004. Energy and Services Offering Branch: this core business line, which includes natural gas and oil exploration and production, energy trading and sales, and services associated with the supply of energy, boasts net sales of euro 16,498 m, equal to growth of 10.8% compared with 2003. Infrastructures Branch: this division, which groups together all activities related to the management of transmission and distribution infrastructures in both the French domestic and international markets, generated net sales of euro 6,794 m in 2004, virtually unchanged from the previous year. This situation is the result of higher sales generated by the distribution subsidiaries operating outside France (+9.2%) offset by a decline in the sales performance of the Transmission, Storage and Distribution in France

  13. EdF-Gaz de France. No merger without dismembering

    International Nuclear Information System (INIS)

    Lepetit, V.

    2007-01-01

    Gathering together the two historical French energy monopolies, Electricite de France (EdF) and Gaz de France (GdF), and warranting low electricity and gas prices is still an attractive idea for some political and syndicate representatives. However, such a merger would create a dominating position which is forbidden with respect to Brussels criteria. (J.S.)

  14. The results of Gaz de France in 1996

    International Nuclear Information System (INIS)

    Gadonneix, P.

    1997-01-01

    The principle results of the national company activity for 1996 have been presented by Mr Gadonneix, president of Gaz de France. These results will allow to face in the best economic conditions the realisation of the next contract which has to be signed with the government. Financial results, commercial results, supplies, transport and storage, distribution system, research and development are detailed. (N.C.)

  15. Optimal use of the Gaz de France underground gas storage facilities; Utilisation optimale des stockages souterrains de Gaz de France

    Energy Technology Data Exchange (ETDEWEB)

    Favret, F.; Rouyer, E.; Bayen, D.; Corgier, B. [Gaz de France (GDF), 75 - Paris (France)

    2000-07-01

    This paper describes the tools developed by Gaz de France to optimize the use of its whole set of underground gas storage facilities. After a short introduction about the context and the purposes, the methodology and the models are detailed. The operational results obtained during the last three years are presented, and some conclusions and perspectives are given. (authors)

  16. The merging of Suez and 'Gaz de France'

    International Nuclear Information System (INIS)

    Anon.

    2008-01-01

    The merging of 'Gaz de France' and Suez has been approved by the shareholders on the 16 july 2008, and the decree for the privatization of 'Gaz de France' has been published to the 'Journal Officiel'. The French state will hold 35.6% of the capital of the new group GDF-Suez. The board of directors will be composed of 24 members: 7 officials from the state, 1 representative of the share-holding staff, 3 representatives of the elected employees and 13 members named by the general assembly of the shareholders. This group, which is officially born on the 22. of july 2008, is the fourth bigger group worldwide in the domain of energy. (A.C.)

  17. Experimental contribution to the study of gas bearings; Contribution experimentale a l'etude des paliers a gaz

    Energy Technology Data Exchange (ETDEWEB)

    Gobert, G

    1962-07-01

    Developments for gas-lubricated bearings are discussed. The study of how the fluid film behaves compared to what one can expect is discussed. Various devices are described which have allowed us to go up to peripheral velocity greater than 400 m/s, leading to rotational speed of several thousand revolutions per second. This is obtained by using an automatic setting for the distance between fixed and rotating walls. (author) [French] Le present travail debute par un apercu de l'etat actuel des connaissances sur le processus de la lubrification, notamment sur les paliers a lubrification par gaz. Apres une analyse effectuee au moyen des recentes theories de R. Comolet sur le film fluide entre disques paralleles, nous decrivons des machines dont les charges axiales et radiales specialement etudiees ont permis, au moyen d'un reglage automatique des jeux entre parois fixes et parois tournantes, d'atteindre des vitesses peripheriques superieures a 400 m/s correspondant a des vitesses de plusieurs milliers de tours par seconde. (auteur)

  18. Experimental contribution to the study of gas bearings; Contribution experimentale a l'etude des paliers a gaz

    Energy Technology Data Exchange (ETDEWEB)

    Gobert, G

    1962-07-01

    Developments for gas-lubricated bearings are discussed. The study of how the fluid film behaves compared to what one can expect is discussed. Various devices are described which have allowed us to go up to peripheral velocity greater than 400 m/s, leading to rotational speed of several thousand revolutions per second. This is obtained by using an automatic setting for the distance between fixed and rotating walls. (author) [French] Le present travail debute par un apercu de l'etat actuel des connaissances sur le processus de la lubrification, notamment sur les paliers a lubrification par gaz. Apres une analyse effectuee au moyen des recentes theories de R. Comolet sur le film fluide entre disques paralleles, nous decrivons des machines dont les charges axiales et radiales specialement etudiees ont permis, au moyen d'un reglage automatique des jeux entre parois fixes et parois tournantes, d'atteindre des vitesses peripheriques superieures a 400 m/s correspondant a des vitesses de plusieurs milliers de tours par seconde. (auteur)

  19. Gaz Metropolitain's experience in regards to transmission access

    International Nuclear Information System (INIS)

    Noel, J.-P.

    1994-01-01

    The natural gas industry in Canada is briefly reviewed as it applies to the sale of transported gas in Quebec. The deregulation of the industry which occurred in 1985 brought many changes to the relationships among natural gas consumers, suppliers, transmission companies, and distribution utilities. It is noted that only the producers' natural gas sale price has been deregulated, not the rates of transmission companies or distributors. Deregulation offered two possibilities for natural gas users in Quebec: the client can contract a transmission service between the Alberta (source of supply) and Quebec borders, separately from contracting a delivery service from Gaz Metropolitain, the company supplying the vast majority of natural gas in Quebec; or the client can contract those two services from Gaz Metropolitain who then gathers the gas at the Alberta border. The adoption of Gaz Metropolitain services to meet the need for transmission access are discussed in the areas of supply contracts, and services offered (buy/sell, rate unbundling, delivery). The opportunities and risks for the customer are assessed in the areas of costs, speculation on transportation capacity, operational flexibility, and the possiblity of unused capacities. Opportunities and issues for the distributor include maintenance of client satisfaction, shortening of the duration of contracts, maintenance of the role of the distributor in natural gas sales, take-or-pay commitments, rate unbundling, accounting methods, inventories, and pricing

  20. A contribution from Gaz de France to the economic performance of industries; Contribution de Gaz de France a la perfomance economique des industriels

    Energy Technology Data Exchange (ETDEWEB)

    Depail, J.C. [Gaz de France (GDF), 75 - Paris (France)

    1996-12-31

    The aim of the policy of the French national gas utility, Gaz de France, towards industries, is to promote natural gas as a competitive fuel compared to fuels and electric power, with energy efficient solutions that are easy to implement and maintain: space heating, paint curing, surface cleaning, bath heating, vapour generation, waste treatment (especially for molding sand and volatile organic compounds, sludge drying). Gaz de France proposes also expertise schemes and audits

  1. Fractionation of Hydrocarbons Between Oil and Gas Phases Fractionnement des hydrocarbures entre les phases huile et gaz

    Directory of Open Access Journals (Sweden)

    Ruffier-Meray V.

    2006-12-01

    expliquer certains phénomènes de migration. Lors de l'injection de gaz, la dissolution préférentielle de certains constituants dans le gaz peut modifier la composition et le comportement le l'huile en place. Le stockage souterrain de gaz dans des réservoirs contenant encore de l'huile peut également être concerné par ce problème. Des études ont été menées à l'IFP, dans le cadre de différents projets, de façon à mettre en évidence ce phénomène et à le quantifier. Deux d'entre elles, qui concernent la géochimie de réservoir, ont été menées sur des fluides réels. La troisième étude, qui est un test de gonflement, concerne l'injection de gaz, le fluide considéré est un mélange synthétique comprenant des hydrocarbures jusqu'à C30. Les équipements utilisés sont, d'une part, une cellule saphir ayant une pression maximale d'utilisation de 400 bar, et d'autre part un équipement appelé Hercule dont la pression maximale d'utilisation est de 1500 bar. Pour chacun des fluides étudiés, la pression de saturation a été mesurée. Pour plusieurs paliers, inférieurs à la pression de saturation, les phases liquides et gazeuses à l'équilibre ont été prélevées à pression constante et analysées. Dans le cas de l'injection de gaz, les compositions à l'équilibre ont été déterminées pour des mélanges contenant des quantités variables de gaz. Par rapport aux n-alcanes de même nombre d'atomes de carbone, les hydrocarbures aromatiques restent préférentiellement dans la phase liquide, de même que les cycloalcanes pour lesquels ce phénomène est moins net toutefois. Par contre, la phase gazeuse s'enrichit légèrement en isoalcanes. Ces phénomènes de fractionnement sont moins marqués au voisinage de la région critique. Ils ont été modélisés au moyen d'une équation d'état cubique assortie d'une règle de mélange par contribution de groupes.

  2. Research into zirconium alloys resistant to carbon dioxide under pressure at temperatures of up to 600 deg C (1963); Recherche d'alliages de zirconium compatibles avec le gaz carbonique sous pression jusqu'a 500 ou 600 deg C (1063)

    Energy Technology Data Exchange (ETDEWEB)

    Baque, P; Dominget, R; Bossard, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1963-07-01

    Zirconium is a metal having a relatively low neutron capture cross-section and a high melting point; it is thus possible to consider its use in particular as a canning material for fuel elements in CO{sub 2}-cooled nuclear reactors. A preliminary study of several types of zirconium showed that the metal is already strongly oxidised in this gas at 500 deg C. The 'breakaway' phenomenon is generalised; the oxidation rate is then linear and depends on the carbon dioxide pressure. An attempt was therefore made to find binary and tertiary alloys in order to improve the metal behaviour. Several interesting compositions were found: 1, 1.6 and 2.5 per cent of copper, 2 per cent of vanadium, and 0.05 and 0.5 per cent of calcium. Tertiary copper-molybdenum and copper-phosphorus alloys are also less liable to oxidation and in particular do not exhibit the 'breakaway' phenomenon even after a prolonged treatment at 600 deg C. (authors) [French] Le zirconium se trouve parmi les metaux a section de capture neutronique relativement faible et possede une temperature de fusion elevee; aussi peut on songer a l'employer notamment comme materiau de gainage d'elements combustibles pour reacteurs nucleaires refroidis au gaz carbonique. Une etude prealable de plusieurs qualites de zirconium a montre que le metal est deja assez fortement oxyde dans ce gaz des 500 deg C. En effet, le phenomene de ''breakaway'' est general; la vitesse d'oxydation devient alors lineaire et depend de la pression du gaz carbonique. La recherche d'alliages binaires et ternaires a donc ete entreprise afin de tenter d'ameliorer le comportement du metal. Elle a permis d'aboutir a quelques compositions interessantes: cuivre 1, 1,6 et 2,5 pour cent, vanadium 2 pour cent, et calcium 0,05 et 0,5 pour cent. Des alliages ternaires au cuivre-molybdene et cuivre-phosphore sont egalement moins oxydables, et en particulier ne presentent pas le phenomene de ''breakaway'', meme apres une longue exposition a 600 deg C. (auteurs)

  3. Study of a device for the direct measurement of the fission gas pressure inside an in-pile fuel element; Etude d'un dispositif pour la mesure directe de la pression des gaz de fission a l'interieur d'un element combustible en pile

    Energy Technology Data Exchange (ETDEWEB)

    Lavaud, B; Uschanoff, S [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    The fission gas pressure inside a fuel element made of a refractory fuel constitutes an important limiting factor for the burn-up. Although it is possible to calculate approximately the volume of gas produced outside the fuel during its life-time; it is nevertheless very difficult to evaluate the pressure since the volume allowed to the fission gases, as well as their temperature are known only very approximately. This physical value, which is essential for the technologist, can only be known by direct in-pile measurement of the pressure. The report describes the equipment which has been developed for this test. (authors) [French] La pression des gaz de fission a l'interieur d'un element combustible a combustible refractaire constitue une des limitations importantes du taux de combustion. Si on peut approcher par calcul la determination du volume, des gaz degages hors du combustible au cours de sa vie, il est par contre tres difficile d'evaluer la pression car le volume alloue aux gaz de fission et leur temperature sont tres mal connus. Cette donnee essentielle pour le technologue ne peut etre atteinte que par une mesure directe en pile de la pression. Le rapport decrit l'appareillage qui a ete mis au point pour cet essai. (auteurs)

  4. Mortal waiting for EdF and Gaz de France

    International Nuclear Information System (INIS)

    Jemain, A.

    2003-01-01

    Electricite de France (EdF) and Gaz de France (GdF) utilities have announced important investment programs for the forthcoming opening of gas and electricity markets to 2.5 millions of professionals by July 1, 2004. However, nothing can be done before the approval of the French government has been given for the change of their statuses (from the industrial and commercial public company status to the anonymous company status) and for the opening of their capital. Short paper. (J.S.)

  5. Contribution to the dosimetry of tritium in the presence of inactive or active gases; Contribution a la dosimetrie du tritium en presence de gaz inactifs ou actifs

    Energy Technology Data Exchange (ETDEWEB)

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

    1966-07-01

    Tritium is a dangerous gas for man and the maximum admissible doses in the atmosphere are sufficiently low for the dosage to be fairly difficult. We have developed an apparatus for measuring selectively the contamination of air by this gas when it is alone or when it is associated with other gaseous contaminants. The differential apparatus using two ionization chambers makes it possible to eliminate a parasitic {gamma} radiation field. In a few particular cases, the presence of the radio-active gas has been studied. From the practical point of view, the use of these chambers made of stainless steel makes for easier use since the problems connected with wall adsorption have been satisfactorily resolved. The method can be applied without restriction and very easily to the dosage of traces tritium in air or in the form of tritiated water or tritiated steam in the atmosphere. (author) [French] Le tritium est un gaz dangereux pour l'homme et les concentrations maximales admissibles dans l'atmosphere sont suffisamment basses pour que le dosage soit delicat. Nous avons etudie et realise un appareil qui permet de mesurer selectivement la contamination de l'air par ce gaz lorsqu'il est seul ou lorsqu'il est associe a d'autres agents gazeux contaminants. Le montage differentiel a deux chambres d'ionisation permet d'eliminer un champ de rayonnement {beta} parasite. Dans certains cas particuliers, la presence du gaz radioactif a ete etudiee. Sur le plan pratique, l'utilisation des chambres en acier inoxydable facilite les applications car les problemes d'adsorption aux parois ont ete bien resolus. La methode peut s'appliquer sans restriction et tres pratiquement au dosage des traces de tritium dans l'air ou encore sous forme d'eau tritiee ou de vapeur d'eau tritiee dans l'atmosphere. (auteur)

  6. Unconventional Gas Resources in the Paleozoic of Central Europe Ressources de gaz non conventionnels dans le Paléozoïque de l’Europe Centrale

    Directory of Open Access Journals (Sweden)

    Littke R.

    2011-05-01

    shales et du gaz de houille (coalbed methane, CBM. Les grès de faible perméabilité se trouvent surtout parmi les couches permiennes (Rotliegend aux Pays-Bas et dans le nord de l’Allemagne, mais aussi dans les couches du Carbonifère supérieur. La production est déjà active dans quelques-uns de ces réservoirs. Pour l’avenir, le développement dépendra principalement de l’amélioration de la compréhension du gaz en place et de la distribution régionale de la porosité et la perméabilité qui, d’ailleurs, dépendent du faciès lithologique et la diagénèse. La recherche de gaz dans les roches argileuses, par contre, vient juste de commencer. Les roches argileuses mésozoïques dans le sud du bassin de Basse-Saxe (Lower Saxony Basin sont des objets d’exploration prioritaire à cause de leur épaisseur, de leur maturité et de leur teneur en matière organique. Mais il existe d’autres séries intéressantes dans le carbonifère inférieur et des couches plus anciennes. Actuellement, un projet de recherche international vise à acquérir des données géologiques sur ces systèmes. La recherche du gaz de houille (CBM a commencé dans la bassin de la Ruhr il y a une vingtaine d’années, mais avec un succès très limité à cause de faibles débits de gaz. En revanche, le captage de grisou des mines de charbon abandonnées a fourni de considérables quantités de gaz. De par la multitude des filons houillers et des conditions de maturité et de teneurs en gaz favorables, il existe dans cette région un potentiel considérable de gaz de houille.

  7. Detection of radioactive gases in the CO{sub 2} cooling the reactors G 2 - G 3; Detection des gaz radioactifs dans le CO{sub 2} de refroidissement des piles G2 - G3

    Energy Technology Data Exchange (ETDEWEB)

    Pouthier, J; Rossi, J [Commissariat a l' Energie Atomique, Chusclan (France). Centre de Production de Plutonium de Marcoule

    1968-07-01

    The carbon dioxide cooling the reactors G2 - G3 contains activation gases and fission gases. It is of interest to know their concentration, for example to be able to deduce rapidly the norms which would have to be applied in the case of an incident in the circuit. Gas-phase chromatography is applied daily for carrying out analyses. The chromatogram has separate peaks due to tritium, argon 41, krypton 85 and the 133 and 135 isotopes of xenon. By integrating each peak it is possible to calculate the specific activity of each product. The construction of an apparatus for carrying out continuous measurements is under consideration. (authors) [French] Le gaz carbonique, refroidissant les reacteurs G2 - G3, contient des gaz d'activation et des gaz de fission. Il est interessant de connaitre leur teneur par exemple pour etre en mesure de deduire rapidement les normes qu'il y aurait lieu d'appliquer en cas d'incidents sur le circuit. La methode de chromatographie en phase gazeuse est employee quotidiennement pour faire des analyses. Le chromatogramme se presente sous forme de pics distincts dus au tritium, a l'argon 41, au krypton 85 et aux isotopes 133 et 135 du xenon. L'integration de chaque pic permet de calculer l'activite specifique de chaque compose. Il est envisage de construire un appareil pour des mesures en continu. (auteurs)

  8. Canning by the diffusion caused by a heated die; Gainage par diffusion par filiere chauffante

    Energy Technology Data Exchange (ETDEWEB)

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

    1959-07-01

    In this process, the uranium fuel is clad with a zirconium can by passing the element through a die. The operation takes place at a temperature varying between 500 and 1000 deg. C. The heating is obtained by passing low voltage electric current through the can. This process differs from the co-extrusion process in that the uranium is not deformed. The uranium is therefore machined to the final dimensions before canning, it can also be hollow. Two types of processes can be adopted for the extrusion: a) Process in which the binding of the can to the uranium is obtained without diffusion (here the can is at high temperature - subsequently cooled - and the uranium is at a low temperature); b) Process in which uranium-zirconium diffusion is initiated. No matter which process is adopted the element is subsequently heat treated in an over at 800 deg. C in order to obtain the final diffusion. The quality of this diffusion is dependent on the initial state of the surfaces and on the degree of vacuum maintained during the operation. (author) [French] Dans ce procede, la gaine zirconium est plaquee sur le combustible uranium par passage dans une filiere. L'operation a lieu a chaud, a une temperature variant entre 500 et 1000 deg. C. Le chauffage est assure par passage d'un courant basse tension dans la gaine. A la difference du procede de cofilage, l'uranium ne subit pas de deformation durant l'operation. Il est donc prealablement usine aux cotes definitives et peut etre creux. Deux processus sont possibles pendant le passage dans la filiere: a) Obtention d'un frettage de la gaine sur l'uranium sans diffusion (avec une gaine a haute temperature et un tube d'uranium a basse temperature, eventuellement refroidi); b) Obtention d'un commencement de diffusion uranium-zirconium. Quelque soit le processus adopte, la cartouche est ensuite traitee dans un four a 800 deg. C pour obtenir la diffusion definitive. La qualite de celle-ci depend essentiellement des etats de surface initiaux

  9. Gaz Metropolitain 2002 report : connecting with the future

    International Nuclear Information System (INIS)

    2003-01-01

    Gaz Metropolitain is the major natural gas distributor in Quebec. In 2002, the utility had its best year ever in terms of Partners' income of $154.6 million, representing a 9.5 per cent increase from 2001. Income from its core business, the distribution of natural gas in Quebec and Vermont, was $7.5 million higher than in 2001. This increase in income was due in part to better transportation and load balancing transactions. The main business effort in 2002 was on cogeneration plant projects developed with Boralex and Hydro Quebec. The projects, however, were not retained. This annual report presented consolidated financial and operating data for the distribution and transmission sectors of the company. It included information about Gaz Metropolitain's customers, the transmission and supply system, mission objectives, partnerships, corporate structure, and the year in review. The consolidated financial statements included income and cash flows, consolidated normalized volumes, and consolidated balance sheets. Revenue and expenditure statements were summarized by source. tabs., figs

  10. Contribution to the study of the fission-gas release in metallic nuclear fuels; Contribution a l'etude du degagement des gaz de fission dans les combustibles nucleaires metalliques

    Energy Technology Data Exchange (ETDEWEB)

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

    1969-10-01

    In order to study the effect of an external pressure on the limitation of swelling due to fission-gas precipitation, some irradiations have been carried out at burn-ups of about 35.000 MWd/ton, and at average sample temperatures of 575 Celsius degrees, of non-alloyed uranium and uranium 8 per cent molybdenum gained in a thick stainless steel can. A cylindrical central hole allows a fuel swelling from 20 to 33 per cent according to the experiment. After irradiation, the uranium samples showed two types of can rupture: one is due to the fuel swelling, and the other, to the pressure of the fission gases, released through a network of microcracks. The cans of the uranium-molybdenum samples are all undamaged and it is shown that the gas release occurs by interconnection of the bubbles for swelling values higher than those obtained in the case of uranium. For each type of fuel, a swelling-fission gas release relationship is established. The results suggest that good performances with a metallic fuel intended for use in fast reactor conditions can be obtained. (author) [French] Afin d'etudier l'effet d'une pression exterieure sur la limitation du gonflement due a la precipitation des gaz de fission, on a irradie a des taux de combustion d'environ 35.000 MWj/t et a des temperatures moyennes de 575 degres des echantillons d'uranium non allie et d'uranium-molybdene 8 pour cent contenus dans une gaine en acier inoxydable epaisse. Un trou cylindrique central permet au combustible de gonfler librement de 20 a 33 pour cent suivant les cas. Apres irradiation les echantillons d'uranium presentent deux types de ruptures de gaine: l'une due au gonflement du combustible, l'autre a la pression des gaz degages, ce degagement des gaz etant provoque par un reseau de micro-fissures. Les gaines des echantillons d'alliage uranium-molybdene sont toutes intactes et l'on montre que le relachement des gaz opere par interconnexion des bulles pour des valeurs de gonflement plus elevees que dans

  11. Plasmas pour valorisation totale ou partielle des gaz contenant de l'H2S Plasmas for Total Or Partial Upgrading of H2s Containing Gases

    Directory of Open Access Journals (Sweden)

    Czernichowski A.

    2006-12-01

    Full Text Available Des procédés par plasmas alternatifs au procédé Claus sont proposés pour produire de l'hydrogène et récupérer du soufre à partir des gaz contenant une forte teneur en H2S. Quand la teneur en H2S est moins importante, des techniques plasma peuvent également être utiles pour assister certains étages du procédé classique Claus ou réaliser ce procédé pour des gaz non conventionnels. Les tests allant jusqu'à l'échelle industrielle sont menés dans divers réacteurs à plasmas et les résultats encourageants rapportés de la littérature et de la recherche propre laissent envisager des prochaines applications. Plasma assisted processes are proposed to act as an alternative to the Claus process in order to recover hydrogen and sulphur from high H2S gases. For less concentrated gases plasma techniques may also be inserted into classical Claus plant or may allow treatment of non conventional gases. Up to industrial scale tests are performed using different plasma reactors. The literature-based results as well as our own ones make the future applications quite optimistic.

  12. The compatibility of chromium-aluminium steels with high pressure carbon dioxid at intermediate- temperatures; Compatibilite des aciers au chrome-aluminium avec le gaz carbonique sous pression aux temperatures moyennes

    Energy Technology Data Exchange (ETDEWEB)

    Leclercq, D; Loriers, H; David, R; Darras, E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    With a view to their use in the exchangers of nuclear reactors of the graphite-gas or heavy water-gas types, the behaviour of chromium-aluminium steels containing up to 7 per cent chromium and 1.5 per cent aluminium has been studied in the presence of high-pressure carbon dioxide at temperatures of between 400 and 700 deg. C. The two most interesting grades of steel (2 per cent Cr - 0.35 per cent Al - 0.35 per cent Mo and 7 per cent Cr - 1.5 per cent Al - 0.6 per cent Si) are still compatible with carbon dioxide up to 550 and 600 deg. C respectively. A hot dip aluminised coating considerably increases resistance to oxidation of the first grade and should make possible its use up to temperatures of at least 600 deg. C. (authors) [French] Dans l'optique de leur emploi dans les echangeurs de reacteurs nucleaires des filieres graphite-gaz ou eau lourde-gaz, le comportement en presence de gaz carbonique sous pression d'aciers au chrome-aluminium, contenant jusqu'a 7 pour cent de chrome et 1,5 pour cent d'aluminium a ete etudie entre 400 et 700 deg. C. Les deux nuances les plus interessantes (2 pour cent Cr - 0,35 pour cent Al - 0,35 pour cent Mo et 7 pour cent Cr - 1,5 pour cent Al - 0,6 pour cent Si) restent compatibles avec le gaz carbonique jusqu'a 550 et 600 deg. C respectivement. Un revetement d'aluminium, effectue par immersion dans un bain fondu, ameliore notablement la resistance a l'oxydation de la premiere et doit permettre son empioi jusqu'a 600 deg. C au moins. (auteurs)

  13. Isotopic analysis of plutonium by optical spectroscopy; Analyse isotopique du plutonium par spectroscopie optique

    Energy Technology Data Exchange (ETDEWEB)

    Artaud, J; Chaput, M; Gerstenkorn, S [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    Isotopic analysis of mixtures of plutonium 239 and 240 has been carried out by means of the photo-electric spectrometer Fabry-Perot, the source being a hollow cathode cooled by liquid nitrogen. This first research has been concerned with finding among the spectral lines given by the hollow cathode, those suitable for use in analysis. Actually, the relative precision is of the order of 2 per cent (for samples containing 3 per cent of {sup 240}Pu). The study of the reproducibility of the measurements should make it possible to increase the precision; the relative precision which can be expected from this method should be 1 per cent for mixtures containing 1 per cent of {sup 240}Pu. (author) [French] L'analyse isotopique des melanges de plutonium 239 et 240 a ete effectuee a l'aide du spectrometre photoelectrique Fabry-Perot, la source etant une cathode creuse refroidie a l'azote liquide. Ce premier travail a eu pour but de discerner parmi les raies spectrales emises par la cathode creuse, celles susceptibles de servir de raies d'analyse. Actuellement, la precision relative est de l'ordre de 2 pour cent (pour des echantillons contenant 3 pour cent de {sup 240}Pu). L'etude de la reproductibilite des mesures devrait permettre d'ameliorer la precision; la precision relative que l'on pourrait atteindre par cette methode serait de 1 pour cent pour des melanges contenant 1 pour cent de {sup 240}Pu. (auteur)

  14. Starting up a programme of atomic piles using compressed gas; Le demarrage d'un programme de piles atomiques a gaz comprime

    Energy Technology Data Exchange (ETDEWEB)

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

    1959-07-01

    1) An examination of the intellectual and material resources which have directed the French programme towards: a) the natural uranium and plutonium system, b) the use of compressed gas as heat transfer fluid (primary fluid). 2) The parts played in exploring the field by the pile EL2 and G1, EL2 a natural uranium, heavy water and compressed gas pile, G1 a natural uranium, graphite and atmospheric air pile. 3) Development of the neutronics of graphite piles: physical study of G1. 4) The examination of certain problem posed by centres equipped with natural uranium, graphite and compressed carbon dioxide piles: structure, special materials, fluid circuits, maximum efficiency. Economic aspects. 5) Aids to progress: a) piles for testing materials and for tests on canned fuel elements, b) laboratory and calculation facilities. 6) Possible new orientations of compressed gas piles: a) raising of the pressure, b) enriched fuel, c) higher temperatures, d) use of heavy water. (author) [French] 1) Examen des ressources - intellectuelles et materielles - qui ont oriente le programme fran is vers: a) la voie de l'uranium naturel et du plutonium; b) l'emploi comme fluide pour le transfert de la chaleur (fluide primaire) d'un gaz comprime. 2) Le role d'exploration des piles EL2 et G1, EL2 pile a uranium naturel, eau lourde et gaz comprime, G1 pile a uranium naturel, graphite et air atmospherique. 3) Developpement de la neutronique des piles a graphite: l'etude physique de G1. 4) Examen de certains problemes poses par les centrales equipees de piles a uranium naturel, graphite et gaz carbonique comprime: structure, materiaux speciaux, circuits de fluides, optimisation. Aspects economiques. 5) Les auxiliaires du progres: a) piles pour essai de materiaux et pour essais de cartouches, b) moyens de laboratoire et moyens de calcul. 6) Orientations nouvelles possibles des piles a gaz comprime: a) elevation de la pression, b) combustible enrichi, c) temperatures elevees, d) emploi de l

  15. World Gas Prospects: Which Role for the Middle East? Perspectives mondiales du gaz naturel : quel rôle pourrait jouer le Moyen-Orient ?

    Directory of Open Access Journals (Sweden)

    Chabrelie M. F.

    2006-12-01

    vingt dernières années, le gaz naturel a enregistré le taux de croissance le plus élevé parmi les énergies fossiles, et sa part de marché est progressivement passée de 18,9 % en 1975 à 23 % en 1997. Aujourd'hui, des facteurs d'ordres économiques et environnementaux font du gaz naturel l'énergie de choix sur de nombreux marchés. Le gaz jouit en effet d'un certain nombre d'atouts (réserves importantes, flexibilité, utilisations performantes qui lui confèrent une place majeure dans tous les scénarios de prévision de demande énergétique. Le développement le plus spectaculaire se fera sans conteste dans le secteur électrique. Doté de réserves gazières considérables, le Moyen-Orient représentera une source d'approvisionnement essentielle pour bon nombre de pays industrialisés et plusieurs projets d'exportation de gaz par méthaniers ou par gazoducs sont déjà à l'étude. Par ailleurs, au cours des dix dernières années, la contribution du gaz naturel dans le bilan énergétique a augmenté de façon significative dans la plupart des pays du Moyen-Orient. La croissance de l'utilisation du gaz devrait se poursuivre à un rythme soutenu, en particulier sous l'influence du secteur électrique, de la pétrochimie et de l'autoconsommation de l'industrie pétrolière. Ces perspectives prometteuses de demande de gaz sur la plupart des marchés de la région pourraient conduire au développement d'un réseau de transport intrarégional. Toutefois, bien que des opportunités existent, elles ne doivent pas masquer les nombreux défis que cette région devra relever pour contribuer plus largement au bilan gazier mondial dans les années à venir.

  16. Apparatus for studying the diffusion of rare gases in stainless steel; Appareil pour etude de la diffusion des gaz rares dans l'acier inoxydable

    Energy Technology Data Exchange (ETDEWEB)

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

    1959-07-01

    This apparatus enables measurements to be carried out on the diffusion of gaseous fission products and of gases in general across thin metallic walls at high temperatures. This work was initially intended to solve the problems involved in systems for detecting the rupture of a fuel element can (D.R.G.) by the diffusion of fission products through the cans at high temperatures. The extension of the work to other fields is envisaged. (author) [French] Cet appareil permet d'effectuer des mesures sur la diffusion des produits de fission gazeux, et des gaz en general, au travers de parois metalliques minces a haute temperature. Au depart, ce procede devait contribuer a resoudre les problemes poses aux systemes detecteurs de rupture de gaine (D.R.G.), par la diffusion des produits de fission au travers des gaines de cartouches a haute temperature. Son extension a d'autres etudes est envisagee. (auteur)

  17. Study of new structures adapted to gas-graphite and gas-heavy water reactors; Etude de structures nouvelles adaptees aux reacteurs graphite-gaz et eau lourde-gaz

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-07-01

    'EDF d'une part, les conclusions des etudes et essais effectues hors pile d'autre part, conduisent a un changement considerable de la physionomie des reacteurs de la filiere Graphite-Gaz, Les principales modifications envisagees sont analysees dans la communication. L'adoption d'un element combustible annulaire et d'un soufflage descendant permettront d'accroitre considerablement la puissance specifique et la puissance developpee par canal; il en resultera une reduction sensible du nombre des canaux et un accroissement correlatif de la maille du reseau - L'empilement de graphite devra etre adapte a ces nouvelles conditions - Des raisons de securite conduisent a generaliser l'emploi du beton precontraint pour la construction du caisson; elles pourront amener a integrer a l'interieur de celui-ci les echangeurs et l'appareil de manutention du combustible (dispositif dit: 'en grenier'). Une maquette en vraie grandeur de ce grenier a ete construite a Saclay avec la participation d'EURATOM; les resultats d'exploitation en sont presentes, ainsi que des idees de barres de controle de conception nouvelle. En ce qui concerne la filiere Eau-Lourde-Gaz, les etudes sont poursuivies dans deux voies principales; la premiere, qui conserverait l'usage de tubes de force horizontaux, tient compte de l'experience acquise au cours de la construction du reacteur EL4 dont elle constituerait une extrapolation; la seconde, inspiree des etudes poursuivies au titre de la filiere Graphite-Gaz, ferait appel a un caisson en beton precontraint pour tenir la pression, le moderateur etant sensiblement a la pression du fluide refrigerant et le combustible etant dispose dans des canaux verticaux. Les merites respectifs de ces deux variantes sont analyses dans la communication. (auteurs)

  18. Detection of high energy gamma radiations with liquid rare gases as scintillators; Detection des rayonnements Gamma de grande energie avec les gaz rares liquides comme scintillateurs

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Phan Xuan

    1965-11-25

    This research thesis reports the study of a sensor based on a liquid scintillator for the detection of high energy (10 to 30 MeV) gamma radiations. The scintillator is a liquefied argon or xenon rare gas. The author first studies the process of energy transfer from the particle to the sensing medium. He addresses the different involved elements and phenomena: electromagnetic radiations (Compton Effect, photoelectric effect, pair production, and total gamma absorption), charged particles (braking radiation, collisions) and application to gamma spectrometry. He describes and discusses the scintillation mechanisms (scintillation of organic and inorganic materials), the general characteristics of scintillators (impurities, converters), and then reports the practical realisation of the sensor. Results are presented and discussed [French] Dans ce travail, nous nous proposons d'etudier une technique. Il s'agit d'un detecteur a scintillateur liquide pour la detection des rayonnements gamma energiques (10 a 30 MeV). Le scintillateur utilise est un gaz rare liquefie argon ou xenon. Nous examinerons d'abord les processus de transfert de l'energie de la particule au milieu detecteur puis les mecanismes de scintillation en general pour pouvoir exploiter au mieux les phenomenes favorables. Nous presenterons ensuite la realisation pratique du detecteur. Ses qualites (et defauts) trouveront leur place dans la fin de ce memoire. Bien qu'a l'heure actuelle, par la methode de Kyropoulos, on puisse faire pousser des gros cristaux d'iodure de sodium, l'utilisation des 'gaz rares' liquefies comme scintillateurs est, grace a la brievete de la scintillation, tres utile lorsqu'on recherche un fort taux de comptage (jusqu'a 10 impulsions par seconde) ou lorsqu'on veut resoudre certains problemes de coincidence. Les cristaux NaI(Tl) de grandes dimensions sont d'un montage facile mais leur manipulation requiert beaucoup de precautions du fait qu'ils supportent tres mal les chocs thermiques

  19. MODÉLISATION DES FLUX DE CHALEUR GÉNÉRÉS PAR FROTTEMENT GLISSANT DANS UN CONTACT CUIVRE-ACIER TRAVERSÉ PAR UN COURANT ÉLECTRIQUE

    Directory of Open Access Journals (Sweden)

    A BOUCHOUCHA

    2001-06-01

    Full Text Available Le problème de la conduction de la chaleur dans un contact électrique glissant cuivre–acier est étudié. Le couple fonctionne dans des conditions atmosphériques et est donc refroidi par convection naturelle à travers les faces latérales. En utilisant l'équation de la chaleur, un modèle de calcul de la température interfaciale a été élaboré. A l'aide de la méthode des volumes finis, les résultats de la température en fonction de la charge normale, la vitesse de glissement et le courant électrique sont donnés. Une comparaison avec la méthode d'Archard est faite. Les résultats montrent une bonne concordance. Une discussion globale du modèle élaboré et son application dans les contacts électriques glissants a été dégagée.

  20. Modélisation et analyse exergetique d'un système de gazéification des résidus de bois en vue de la production d'électricité

    OpenAIRE

    Razanajatovo , Tahiry Landry; Morau , Dominique; Rakotondramiarana , Hery Tiana

    2016-01-01

    International audience; Cette étude s'est focalisée sur l'opportunité de l'utilisation des ressources renouvelables, comme le bois, dans le domaine énergétique. La modélisation de chaque étape de transformation de l'énergie des résidus bois en électricité est présentée : transformation du bois en gaz de synthèse par le biais d'un gazogène – conversion de l'énergie calorifique du syngaz en énergie mécanique par l'utilisation d'un moteur à combustion interne – conversion de l'énergie mécanique ...

  1. Cycle e-business: the e-business of Gaz De France; Cycle e-business: l'e-business de Gaz de France

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This paper deals with the Gaz De France Group position in the e-business context. In terms of e-business, all is done to put Internet at the marketing service. Three examples of Internet sites realization and the future policy are presented. (A.L.B.)

  2. Detector for the liquid carried over in a gas; Detecteur d'entrainement de liquide dans un gaz

    Energy Technology Data Exchange (ETDEWEB)

    Delisle, J P; Eperonnat, P; Lions, N [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

    1965-07-01

    This report describes an optical detector for the detection of a liquid carried over by a gas. The device is sensitive to a cumulated quantity of liquid equal to a few cubic millimetres and is capable of operating an alarm from a distance. The prototype was constructed and tested as detector for the oil leaking in the argon compressed by a diaphragm compressor. A patent for this apparatus under the number: P.V.954.703, has been deposited on 22.11.1963. (authors) [French] Ce rapport decrit un detecteur optique d'entrainement de liquide dans un gaz, sensible a une quantite cumulee de liquide entraine egale a quelques millimetres cubes. L'appareil peut actionner une alarme a distance. Le prototype a ete construit et essaye comme detecteur de fuites d'huile dans l'argon refoule par un compresseur a membranes. Une demande de brevet a ete deposee pour cet appareil sous le numero: P.V.954.703, le 22.11.1963. (auteur)

  3. Toprak Radon (222Rn Gazı Anomalilerinin ARIMA Analizi

    Directory of Open Access Journals (Sweden)

    Miraç KAMIŞLIOĞLU

    2014-12-01

    Full Text Available Özet: Zaman serileri analizi, istatistik, ekonomi, fizik ve mühendislik gibi bilim dallarında geniş uygulama alanına sahiptir. Zaman serisi analizi, değişkenlerin gelecekteki değerlerinin doğru bir şekilde tahmin edilmesi için kullanılan bir yöntemdir. Bu çalışmada, bir deprem öncüsü olarak bilinen toprak radon gazı (222Rn ölçümleri ile bir zaman serisi oluşturulmuştur. Bu veriler kullanılarak, otoregresif süreçler (ARIMA yardımıyla dinamik sistem modellemesi yapılmıştır. ARIMA; zaman serileri analizinde, zaman içerisinde rastgele gerçekleşen bir stokastik (olasılıksal sürecin veya hatalarının modellenmesidir. ARIMA modeli, temelde Box-Jenkins modeline dayanmaktadır. Box-Jenkins modeli, tek değişkenli zaman serilerinin ileriye dönük tahmin ve kontrolünde kullanılan istatistiksel tabanlı bir yöntemdir. Elde edilen sonuçlar, ARIMA modellerinin tahmin konusundaki başarısını göstermektedir. Anahtar kelimeler: Zaman Serileri Analizi, Radon Gazı (222Rn, ARIMA ARIMA Analysis of Soil Radon (222Rn Gas Anomalies Abstract: Time series analysis, has wide applications in statistics, economics, physics and engineering such disciplines. This method used for estimate correctly future values of the variables. In this study, is formed a time series with soil radon gas (222Rn measurements known as a pioneer of an earthquake. Dynamic system modelling was performed with autoregressive (ARIMA modelling process by used these measurements. ARIMA; time series analysis is modelled of the recoverable over time a random stochastic (probabilistic process or its errors. ARIMA model is based on Box-Jenkins model. Box-Jenkins model is a statistically based method which is used forward-looking forecasting and control of univariate time series. The obtained results, ARIMA model is indicating success in predict subject. Key words: Time Series Analysis, Radon Gas (222Rn, ARIMA

  4. Risk Analysis of Flare Flame-out Condition in a Gas Process Facility Analyse des risques des conditions d’extinction de torche au sein d’une installation de traitement de gaz

    Directory of Open Access Journals (Sweden)

    Zadakbar O.

    2011-02-01

    Full Text Available Flaring is a common method of disposal of flammable waste gases in the downstream industries. Flare flame out (flame lift-off or blow-outs often occurs causing toxic vapors to discharge. The toxic gases released may have hazardous effects on the surrounding environment. To study the effect of inhalation exposure of these toxic gases on human health, the four steps of the EPA (Environmental Protection Agency framework with the field data to quantify the cancer and non-cancer health risks are integrated in this paper. As a part of exposure assessment, gas dispersion modeling using AERMOD and UDM-PHAST is applied in two different conditions of normal flaring and flare flame out during a particular climate condition in Khangiran region. Recommendations to avoid flare flame out conditions are also presented here. Le torchage est un procédé courant d’élimination des gaz résiduaires inflammables dans les industries de traitement. L’extinction de la torche (par décollage ou soufflage de flamme provoque souvent une émission de vapeurs toxiques. Ces gaz toxiques libérés peuvent présenter des effets dangereux sur le milieu environnant. Pour étudier l’effet d’une exposition par inhalation de ces gaz toxiques sur la santé, cet article croise les quatre étapes de la démarche de l’EPA (Environmental Protection Agency, Agence de protection de l’environnement avec les données d’exploitation afin de quantifier le risque sanitaire cancérologique et non cancérologique. Dans le cadre de l’estimation d’exposition, une modélisation de dispersion des gaz utilisant AERMOD et UDM-PHAST est évaluée dans deux configurations différentes de torchage normal et d’extinction de torche à l’occasion de conditions climatiques particulières dans la région du Khangiran. L’article propose également des recommandations destinées à éviter les conditions d’une extinction de flamme de torche.

  5. New results concerning the behaviour of fission gases in in-pile UO{sub 2} at high temperatures; Resultats nouveaux sur le comportement des gaz de fission a haute temperature dans l'UO{sub 2} en pile

    Energy Technology Data Exchange (ETDEWEB)

    Soulhier, R; Schurenkamper, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    The authors consider in the first part the various phenomena giving rise to the production of fission gases towards the exterior of nuclear fuels. The following aspects are dealt with: diffusion, for which is considered the influence of the predecessors of the radioactive gases, the fission recoil, atom expulsion along the fission paths and the evaporation. In the second part the authors present the results obtained on UO{sub 2} samples subjected to irradiation at temperatures of between 150 and 2000 deg C: - At low temperatures the variation of the amount produced as a function of the half-life of the isotopes studied shows that recoil is hot the only cause of gas production. - Above 1800 deg C, a weight loss by evaporation has been observed and the influence of this phenomenon on gas liberation has been studied; thus the fraction of {sup 135}Xe liberated at 2000 deg C by processes other than evaporation is of the order of 10 per cent. - The influence of the various mechanism on the overall effect as a function of temperature is discussed. (authors) [French] Dans une premiere partie, les auteurs etudient les differents phenomenes pouvant donner lieu au degagement des gaz de fission hors d'un combustible. Sont traites successivement: la diffusion, pour laquelle on discute l'influence des predecesseurs des gaz radioactifs, le recul de fission, l'expulsion des atomes le long des trajets de fission et l'evaporation. Dans une deuxieme partie ils exposent les resultats obtenus sur des echantillons d'UO{sub 2} portes sous irradiation a des temperatures comprises entre 150 deg C et 2000 deg C: - A basse temperature la variation de la quantite degagee suivant la periode des isotopes etudies montre que le recul n'est pas la seule cause du degagement des gaz. - Au-dessus de 1800 deg C on a note une perte de poids par evaporation et on a evalue l'influence de ce phenomene sur la liberation des gaz: ainsi la fraction du {sup 135}Xe liberee a 2000 deg C par d'autres processus

  6. Le problème des hydrates dans le contexte de la production et du transport polyphasiques des pétroles bruts et des gaz naturels. Deuxième partie : les solutions possibles aux difficultés d'exploitation générées par les hydrates Hydrates Problem Within the Framework of Multiphase Production and Transport of Crude Oils and Natural Gases. Part Two: Possible Solutions to Exploitation Difficulties Generated by Hydrates

    Directory of Open Access Journals (Sweden)

    Behar E.

    2006-11-01

    Full Text Available L'exploitation en mer des gisements de combustibles fossiles fluides a amplifié le besoin d'accroître nos connaissances sur les hydrates qui sont susceptibles de boucher les installations de production, de traitement et de transport. La première partie rappelait la structure moléculaire des hydrates I, Il et H et décrivait ensuite succinctement l'analyse physico-chimique de leur formation, tant sur les plans thermodynamique que cinétique. Dans cette deuxième partie, les remèdes possibles aux problèmes rencontrés par les compagnies opératrices sont indiqués, essentiellement les inhibiteurs thermodynamiques classiques tels que les alcools ou les sels qui diminuent la température de formation des hydrates, et les additifs dispersants qui évitent la croissance et/ou l'agglomération des cristaux. Pour terminer, une boucle pilote de circulation originale est présentée, ses caractéristiques qui permettent la validation des additifs dispersants dans des conditions hydrodynamiques et physico-chimiques représentatives étant soulignées. Offshore exploitation of fossil fluid fuels has emphasized the need of improving our knowledge on hydrates which can plug production, treatment and transport facilities. The first part recalled the molecular structure of I, II and H hydrates, then the physical-chemistry of their formation was briefly reviewed from both the thermodynamic and the kinetic points of view. In this second part, the possible remedies to the problems met by operating companies are described, mainly classical thermodynamic inhibitors such as alcohols or salts which decrease the hydrates formation temperature, and dispersant additives which avoid crystals growth and/or agglomeration. At last an original circulation loop at pilot scale is presented, its characteristics which allow the testing of dispersant additives under representative hydrodynamic and physico-chemical conditions being outlined.

  7. suPAR

    DEFF Research Database (Denmark)

    Hodges, Gethin W; Bang, Casper N; Wachtell, Kristian

    2015-01-01

    The fundamental role of inflammation in cardiovascular disease (CVD) has prompted interest in numerous biomarkers that detect subclinical levels of inflammation. Soluble urokinase plasminogen activator receptor (suPAR) is a novel biomarker that correlates significantly with cardiovascular events ...... comprehensive review of suPAR in CVD and explore its function and usefulness in predicting cardiovascular events....

  8. Recent and future developments at the Regie du gaz naturel

    International Nuclear Information System (INIS)

    Giroux, J.

    1995-01-01

    The history of the Quebec Regie du gaz naturel, dating back to 1932, and its role in distributing natural gas in Quebec was described. Among more recent developments construction of a natural gas distribution system on the south shore of Quebec City was discussed. Unlinked mini-systems were built in St-Romuald and Levis. Gas was delivered by truck until an underwater crossing was completed. The federal-provincial infrastructures program was also summarized. The most important ruling by the Regie was the D-94-19 decision on GMi's supply policy and the concept of u mbrella buy-sell . Although this policy was originally approved by the Regie, after consideration of all factors, it was decided that this system was not in line with the deregulation trend and that buyers and sellers could do without GMi's intrusion in their contractual agreements. Issues to be addressed by the Regie in the coming months included transportation service, unbundling, cost allocation and rate of return adjustments mechanism in regards to the recent National Energy Board (NEB) decision on the subject, and separation of (LDC) distribution activities from LDC sales

  9. Natural gas and laundry: an efficient duo; Conference Cegibat: Gaz naturel et blanchisserie

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    Cegibat, the information-recommendation agency of Gaz de France for building engineering professionals, has organized this conference about the use of natural gas in the laundry sector. This document summarizes the content of the different talks dealing with: the history and evolution of laundry activity, the energy consumption problem, the gas appliances (dryers) and their advantages, some testimonies in the health sector (hospitals), the regulatory aspects, the economic aspects (tariffs), Gaz de France energy diagnostic offer, and the testimony of a launderette. (J.S.)

  10. Ecoulements diphasiques gaz-liquide à poches et à bouchons en conduites Two-Phase Gas-Liquid Slug Flow in Pipes

    Directory of Open Access Journals (Sweden)

    Ferschneider G.

    2006-11-01

    Full Text Available Les écoulements diphasiques gaz-liquide ont été étudiés afin de contribuer à développer des modèles de calculs prédictifs des pertes de charge dans les conduites de production des bruts pétroliers. Les expériences nécessaires ont été réalisées sur la boucle diphasique de Boussens dans les conditions suivantes représentatives des conditions industrielles : diamètre 6 , longueur 120 m, disposition de la conduite horizontale ou faiblement ascendante, couple de fluide gaz naturel-huile légère. Le gradient de pression, le contenu global, et la distribution locale des phases ont été mesurés. Le traitement des équations de conservation phasique intégrées sur la section par différents types de moyennes a permis de développer un modèle cellulaire qui inclue un nombre limité d'équations constitutives nécessaires à sa fermeture. Ce modèle prédétermine convenablement le gradient de pression, le contenu gaz global et la longueur des poches et des bouchons. Two-phase gas-liquid flows were analyzed so as to develop models for prediction of pressure drops in crude-oil production lines. The experiments were performed on the two-phase loop at Boussens under the following representative industrial conditions: 6 diameter, 120 m length, horizontal or slightly rising pipe, couple of fluids natural gas and light oil. The pressure gradient, average content and local phase distribution were measured. Conservation phase equations integrated along the cross-section were processed by different time-averaged operators so as to develop a cellular model including a limited number of constitutive equations required for its closure. This model suitably predetermines the pressure gradient, the average gas content and the length of gas and liquid slug.

  11. Model-Based Throttle Control using Static Compensators and Pole Placement Commande des gaz basée sur un modèle utilisant des compensateurs statiques et un placement de pôles

    Directory of Open Access Journals (Sweden)

    Thomasson A.

    2011-10-01

    Full Text Available In modern spark ignited engines, the throttle is controlled by the Electronic Control Unit (ECU, which gives the ECU direct control of the air flow and thereby the engine torque. This puts high demands on the speed and accuracy of the controller that positions the throttle plate. The throttle control problem is complicated by two strong nonlinear effects, friction and limp-home torque. This paper proposes the use of two, simultaneously active, static compensators to counter these effects and approximately linearize the system. A PID controller is designed for the linearized system, where pole placement is applied to design the PD controller and a gain scheduled I-part is added for robustness against model errors. A systematic procedure for generating compensator and controller parameters from open loop experiments is also developed. The controller performance is evaluated both in simulation, on a throttle control benchmark problem, and experimentally. A robustness investigation pointed out that the limp-home position is an important parameter for the controller performance, this is emphasized by the deviations found in experiments. The proposed method for parameter identification achieves the desired accuracy. Au sein des moteurs à allumage commandé modernes, les gaz sont régulés par le boîtier de commande électronique (ECU; Electronic Control Unit, qui permet la régulation directe par l’ECU du flux d’air et ainsi du couple moteur. Cela conduit à des exigences élevées quant à la vitesse et à la précision du régulateur qui positionne le papillon des gaz. Le problème de commande des gaz est compliqué par deux forts effets non linéaires, le frottement et le couple de mode de secours (“limp-home”. Cet article propose l’utilisation de deux compensateurs statiques, actifs simultanément, pour contrer ces effets et linéariser approximativement le système. Un régulateur PID est conçu pour le système linéarisé, où un

  12. 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 surete de fonctionnement sont

  13. Transport diphasique de gaz et de condensat. Aspects techniques et économiques Technical and Economic Aspects of Two-Phase Pipelining of Gas and Condensate

    Directory of Open Access Journals (Sweden)

    Bourgeois T.

    2006-11-01

    Full Text Available L'évacuation diphasique de la production d'un gisement de gaz à condensat présente des avantages importants, en particulier sur le plan économique. Les caractéristiques des écoulements diphasiques sont exposées, avec les conséquences principales sur la définition d'un schéma d'exploitation. Une comparaison économique est ensuite présentée, pour illustrer la réduction des investissements qui peut être apportée par l'évacuation diphasique de la production. Enfin, les recherches françaises sur les écoulements diphasiques dans les conduites pétrolières sont brièvement décrites, ainsi qu'un exemple de calcul sur une conduite de gaz à condensat en exploitation diphasique. The two-phase pipelining of a wet gas field production presents many advantages, especially from an economic point of view. The characteristics of two-phase flow are described, together with their main consequences on the operational scheme. Then an economic comparison is made to illustrate the reduction in investment costs that can by achieved with two-phase pipelining. Research in France on two-phase flow in gas and condensate pipelines is briefly described, and an example is given of the designing of a wet-gas pipeline currently being operated in the two-phase mode.

  14. Par Pond water balance

    International Nuclear Information System (INIS)

    Hiergesell, R.A.; Dixon, K.L.

    1996-06-01

    A water budget for the Par Pond hydrologic system was established in order to estimate the rate of groundwater influx to Par Pond. This estimate will be used in modeling exercises to predict Par Pond reservoir elevation and spillway discharge in the scenario where Savannah River water is no longer pumped and discharged into Par Pond. The principal of conservation of mass was used to develop the water budget, where water inflow was set equal to water outflow. Components of the water budget were identified, and the flux associated with each was determined. The water budget was considered balanced when inflow and outflow summed to zero. The results of this study suggest that Par Pond gains water from the groundwater system in the upper reaches of the reservoir, but looses water to the groundwater system near the dam. The rate of flux of groundwater from the water table aquifer into Par Pond was determined to be 13 cfs. The rate of flux from Par Pond to the water table aquifer near the dam was determined to be 7 cfs

  15. FooPar

    DEFF Research Database (Denmark)

    Hargreaves, F. P.; Merkle, D.

    2013-01-01

    We present FooPar, an extension for highly efficient Parallel Computing in the multi-paradigm programming language Scala. Scala offers concise and clean syntax and integrates functional programming features. Our framework FooPar combines these features with parallel computing techniques. Foo......, results based on a empirical analysis on two supercomputers are given. We achieve close-to-optimal performance wrt. theoretical peak performance. Based on this result we conclude that FooPar allows programmers to fully access Scalas design features without suffering from performance drops when compared...

  16. Contribution to the study of the desorption of fission gases formed in irradiated uranium oxide; Contribution a l'etude de la desorption des gaz de fission formes dans l'oxyde d'uranium irradie

    Energy Technology Data Exchange (ETDEWEB)

    Berry, J -L; Darras, R; Roger, B [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

    1966-09-01

    The release of {sup 133}Xe from irradiated UO{sub 2} has been studied in the temperature range 1300 to 1900 deg C, using various monocrystalline or sintered samples. Up to 1600 deg C, this release is proportional to the square root of the time and thus occurs essentially by diffusion. The apparent diffusion constant D' decreases and the activation energy of the corresponding process increases as the integrated neutron flux received by the fuel increases. As the density of the sintered samples decreases however, the activation energy of the release also decreases, so that the difference between D' values for sintered samples of different densities decreases as the temperature rises. Finally, above 1600 deg C, the fission gas release phenomenon is governed by UO{sub 2} evaporation, and all the different types of oxide studied have similar behaviors, characterized by poor retention of these gases. (authors) [French] La desorption du xenon 133 forme dans le bioxyde d'uranium irradie a ete etudiee dans l'intervalle de 1300 a 1900 C, a l'aide de differents echantillons monocristallins ou frittes. Jusqu'a 1600 C, elle s'effectue proportionnellement a la racine carree du temps, donc essentiellement par diffusion. La pseudo-constante de desorption D' decroit et l'energie d'activation du processus correspondant croit lorsque le flux de neutrons integre recu par le combustible augmente. Cependant, lorsque la densite des frittes diminue, l'energie d'activation de desorption diminue egalement, de sorte que l'ecart entre les valeurs de D' relatives a des frittes de densites differentes se restreint lorsque, la temperature s'eleve. Finalement, au-dessus de 1600 C, l'evaporation de l'UO{sub 2} regit le phenomene de liberation des gaz de fission, et toutes les qualites d'oxyde etudiees presentent alors des comportements voisins a cet egard, caracterises par une mediocre retention de ces gaz. (auteurs)

  17. Algeria facing the challenges of Europe natural gas supply and the respect of the environment.; L'Algerie face aux defis de l'approvisionnement de l'Europe en gaz naturel et le respect de l'environnement

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Nadia Nait

    2010-09-15

    Taking into account the expectations, for the next decades, of a strong increase in the demand for gas in Europe, Algeria has committed to large structuring projects, adding to the two gas pipeline linking Algeria to Spain via Morocco and Algeria to Italy via Tunisia. Two more undertakings are added linking Algeria directly to two European partners. Sonatrach will play an important role in global environment protection, natural gas being less polluting than oil and coal and emitting less co2. Substitution of coal by natural gas will generate socio economical advantages and will preserve the environment. [French] Compte tenu des attentes, pour les decennies prochaines, d'une forte croissance de la demande de gaz en Europe, l'Algerie s'est engagee dans de grands projet structurants s'ajoutant aux deux gazoducs reliant l'Algerie a l'Espagne via le Maroc et l'Algerie a l'Italie via la Tunisie, viennent s'ajouter deux autres ouvrages reliant directement l'Algerie a deux partenaires europeens. Sonatrach Jouera un role important dans la protection de l'environnement a l'echelle mondiale, le gaz naturel est moins polluants que le petrole, le charbon et emet moins de co2. La substitution du charbon par le gaz naturel generera des avantages socio-economiques, preservation de l'environnement.

  18. Approche économique de l'exploration des stockages souterrains de gaz en nappe aquifère Economic Approach to Exploration for Underground Gas Storage Facilities in Aquifers

    Directory of Open Access Journals (Sweden)

    Colonna J.

    2006-11-01

    Full Text Available Dans le cadre de la recherche des stockages souterrains de gaz, le Département Réservoirs Souterrains de Gaz de France est amené à établir un programme d'exploration destiné à sélectionner définitivement, et au moindre coût, les structures capables de satisfaire la demande. Cette sélection passe par une estimation des probabilités de rejet ou d'abandon affectant les différentes structures susceptibles de donner lieu à une exploration. Il faut ensuite constituer le programme d'exploration de chacun des sites retenus après cet examen; ce programme consiste en une liste d'opérations (forage, sismique, essai hydraulique, forage à faible profondeur etc. qui mettront le plus vite possible en évidence : - d'une part les défauts; - d'autre part les principales caractéristiques techniques de la structure étudiée. La règle est d'atteindre la décision sur la faisabilité du site au stockage avec le moindre coût d'exploration. Pour ce faire, une analyse détaillée des causes potentielles d'abandon (recensement des défauts permet de choisir les opérations à effectuer, et d'associer à chacun des défauts recensés, l'opération ou l'ensemble d'opérations permettant de le détecter de façon certaine. Alors les estimateurs économiques tels que l'espérance de dépense, le risque financier, l'espérance de gain, sont calculés pour chacun des programmes, en vue de déterminer l'ordre d'exécution optimal des opérations. L'intérêt d'une telle approche, en ce qui concerne la réduction des dépenses d'exploration, est illustré par un exemple. As part of its work concerning the search for underground gas storage sites, the Underground Storage Department of Gaz de France has established an exploration program for the definitive and lowcost selection of suitable geological structures. This selection involves estimating probabilities of rejecting or abandoning different structures liable to be targets for exploration. The

  19. Black and blue gas, the Gaz de France story during the last forty years

    International Nuclear Information System (INIS)

    Beltran, A.; Williot, J.P.

    1992-01-01

    This book narrates Gaz de France story during the last forty years. The author describes the great events such change from coal gas to methane (black and blue gas), building of a national distribution network, natural gas promoting, negotiating on great supply contracts, research programs. 61 refs., 12 figs., 29 photos

  20. Report of visiting Laboratoire de Physique des Gaz et des Plasmas, Universite Paris-Sud

    International Nuclear Information System (INIS)

    Ferreira, J.L.

    1991-03-01

    The activities carried out by identification mission to the Laboratoire de Physique des Gaz et des Plasmas (LPGP) of Paris-Sud University are related. The mission is part of the project of Study on Plasma wave and Plasma turbulence which is part of international agreement between CAPES and COFECUB in France. (M.C.K.)

  1. Measurement, with steady pressure rise, of the permeability of a gas through a porous membrane; Mesure, en montee continue de pression, de la permeabilite d'un gaz a travers une membrane poreuse

    Energy Technology Data Exchange (ETDEWEB)

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

    1969-07-01

    This study concerns a device for following the variations in the permeability of a gas across a porous membrane as a function of the average pressure, increasing steadily, which is applied to the membrane: P-bar; from these variations is deduced a value of an equivalent pore radius. A constant gas flow is introduced into an enclosure separated into two compartments by the membrane; the simultaneous variations of the pressure in the enclosure and of the pressure difference {delta} P between the two compartments are followed. After a transient period, {delta} P is given by an asymptotic expansion as a function of a dimensionless variable, w, whose expression includes several parameters (ratio of the compartment volumes, physical properties of the gas, pore radius, value of {delta} P in the steady state) and the variable pressure P. When w is large compared to unity, condition which gives an upper limit to the flow for a given membrane, the expansion is practically equal to its first term; the changes in {delta} P and in the permeability are then inversely proportional. The perturbing influences of various secondary effects (e. g. changes in the enclosure temperature) on the pore radius measurement have been estimated. (author) [French] Cette etude concerne un dispositif permettant de suivre les variations de permeabilite d'un gaz a travers une membrane poreuse en fonction de la pression moyenne, continument croissante, appliquee a cette membrane: P-bar; de ces variations se deduit la valeur d'un rayon de pore equivalent. Un debit de gaz constant est introduit dans une enceinte separee par la membrane en deux compartiments, et l'on suit les variations simultanees de la pression dans l'enceinte et de la difference de pression entre ces compartiments, {delta} P. A l'issue d'un stade transitoire, {delta}P est donne par un developpement asymptotique en fonction d'une variable sans dimensions, w, dont l'expression groupe plusieurs parametres (rapport des volumes des

  2. Irreversibility of Gas-Condensate Flow in Gas Cycling Projects: Kinetically Stable Saturation Patterns Irréversibilité des écoulements de gaz à condensat dans les projets de recyclage de gaz : profils stationnaires de saturation

    Directory of Open Access Journals (Sweden)

    Mitlin V.

    2006-12-01

    Full Text Available The dynamics of a two-phase multicomponent reservoir system which is approaching the steady-state flow regime are studied. First, the compositional model is analyzed in the linear approximation, for the case of a small initial deviation from the steady-state regime. An analytical expression is obtained for the characteristic relaxation time. Next, numerical simulations are performed for situations where there is a substantial deviation from the steady-state regime. The linear injection of an enriched gas into a gas-condensate reservoir, followed by the extraction regime, is simulated. It is shown that the change in phase compositions and pressure on the way to equilibrium proceeds with characteristic times of the order of the injection time. However, the change in the saturation and overall composition takes approximately 200 times longer than the injection time. Thus, the reservoir system manifests a spatially inhomogeneous saturation distribution for an abnormally long time. Similar kinetically stable patterns have been also discovered in the nonlinear dynamics of phase transitions, plasma, and thin films. The question of the existence of discontinuous steady states for this multicomponent flow is considered. In the case of a binary mixture, it is shown that such solutions do not exist. Cet article présente une étude de la dynamique d'un réservoir biphasique multiconstituant approchant le régime d'écoulement stationnaire. En premier lieu, nous procédons à une approximation linéaire du modèle compositionnel dans le cas des petites fluctuations autour du régime permanent. Une expression analytique est ainsi obtenue pour le temps caractéristique de transition. Des simulations numériques sont ensuite effectuées pour les déviations importantes par rapport au régime permanent. Nous avons ainsi pu étudier le déplacement linéaire d'un mélange gaz/condensat par un gaz enrichi suivi d'un régime de production. On montre alors que le

  3. Analysis of Simultaneous Gas-Liquid Flow Through an Orifice and Its Application to Flow Metering Etude de l'écoulement simultané d'un mélange gaz-liquide à travers un orifice et son application à la mesure du débit

    Directory of Open Access Journals (Sweden)

    Pascal H.

    2006-11-01

    Full Text Available The purpose of this article is to show a more accurate orifice equation for a two-phase flow, such a compressible mixture of gas and liquid. The orifice equation given here con be used for the measurement of a gas-liquid mixture of fine emulsions by the orificemeter method. From the thermodynamic point of view, an equation of state has been formulated which provides the relationship between the specific mass of the mixture and pressure, under conditions of adiabatic expansion. The results obtained enable the mass flow rates of gas and liquid ta be determined without separation of the phases, provided thot the gas liquid mass ratio is known. The critical pressure ratio corresponding ta sonic velocity is also determined. Cet article présente une relation plus précise pour l'écoulement d'un système à deux phases, tel qu'un mélange compressible gaz-liquide, à travers un diaphragme. Cette relation peut être utilisée pour des mesures de mélanges gaz-liquide très finement divisés, c'est-à-dire des émulsions ou brouillards, par la méthode du diaphragme en paroi mince. Du point de vue thermodynamique, on a formulé une équation d'état donnant la relation entre la masse spécifique du mélange et la pression dans des conditions d'expansion adiabatique. Les résultats obtenus per-mettent de déterminer le débit massique du gaz et du liquide, sans séparation des deux phases, à condition que le rapport de masse gaz-liquide soit connu. On détermine également le rapport de pression critique correspondantà la vitesse du son.

  4. Reconsideration of Methane Isotope Signature As a Criterion for the Genesis of Natural Gas: Influence of Migration on Isotopic Signatures Reconsidération de la signature isotopique du méthane comme critère pour la genèse du gaz naturel : influence de la migration sur les signatures isotopiques

    Directory of Open Access Journals (Sweden)

    Pernaton E.

    2006-11-01

    Full Text Available Experiments were performed in the purpose of studying the isotopic consequences of the diffusional transport of hydrocarbon gases through sediment rocks. Linked to a numerical model, these gas diffusion experiments through a shale porous plug allowed us to correlate porosity and diffusivity of the migration medium. Significant isotopic fractionations (carbon and hydrogen of methane, and ethane at a lesser degree were observed. This is in contradiction with the actual dogma of isotope geochemistry of natural gases which claims that no fractionation occurs during gas migration. The genetic characterization of natural gases by using the isotopic signature of methane appears as an ambiguous method. Plusieurs expériences ont été réalisées dans le but d'étudier les conséquences isotopiques du transport par diffusion des gaz hydrocarbures au travers des roches sédimentaires. Associées à un modèle numérique, ces expériences de diffusion au travers d'une membrane d'argile reconstituée nous ont permis de corréler deux paramètres pétrophysiques du milieu de migration : la porosité et la diffusivité. D'importants fractionnements isotopiques ont été observés au cours de la diffusion du méthane et, à plus petite échelle, lors de la diffusion de l'éthane. Ces résultats remettent en cause le dogme actuel de la géochimie isotopique des gaz naturels qui stipule que la migration des gaz ne peut induire de fractionnements isotopiques. En conséquence, les méthodes de caractérisation génétique des gaz naturels utilisant la signature isotopique du méthane apparaissent comme insuffisantes.

  5. Oil and Gas Prospects in Egypt Recherches d'huile et de gaz en Égypte

    Directory of Open Access Journals (Sweden)

    El Ayouti M. K.

    2006-10-01

    étrolière. La province du golfe de Suez réunissait des conditions très favorables à la formation et au piégeage des hydrocarbures, mais elle présentait en même temps une grande complexité tectonique qui rendait l'exploration très difficile. Le delta du Nil par contre a été exploré relativement récemment. Un travail extensif sera nécessaire pour une véritable évaluation de ce bassin. Jusqu'à maintenant, du gaz a été mis en évidence à divers emplacements dans des réservoirs du Miocène ou du Pliocène inférieur. Des travaux ultérieurs indiqueront-ils si la formation d'huile a été possible ? Le désert occidental n'a pas encore répondu favorablement à l'effort d'exploration consenti. De petits champs d'huile et de gaz ont seulement été découverts dans le Crétacé inférieur et supérieur. Les progrès récents des méthodes sismiques aident à déceler des éléments structuraux plus profonds qui pourront contribuer à améliorer le potentiel pétrolier de la région. A l'heure actuelle, l'exploration est active dans les différentes provinces d'huile et de gaz d'Égypte. Ces activités devraient s'accroître et s'étendre à l'est du golfe de Suez, à terre et en mer, au nord du Sinai et sous le plateau continental méditerranéen. Ces nouvelles zones sont sensées contenir d'excellentes possibilités qui seront testées dans un proche avenir. On compte également sur les progrès des outils et techniques sismiques pour augmenter les chances de trouver plus d'huile et de gaz.

  6. The use of beryllium as a canning material the problems arising from the brittleness of the metal and their present solution; L'utilisation du beryllium comme materiau de gaine les problemes poses par la fragilite du metal et leurs solutions actuelles

    Energy Technology Data Exchange (ETDEWEB)

    Weisz, M; Mallen, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    not solved, an attempt was made to overcome it by a stricter control of metallurgical factors. It has thus been possible to increase by a factor of 10 the low-temperature ductility of tubes (of commercial purity beryllium or even of corrosion-resisting alloys). This is sufficient for the present purpose. Experiments under way will show whether this is still true after exposure to significant irradiation doses. (authors) [French] Le beryllium est envisage comme materiau de gainage dans les reacteurs du type EL 4 (refroidi au gaz carbonique, temperature de fonctionnement 600 C). On peut considerer schematiquement deux cas: - soit la gaine est indeformable sous l'action des forces exterieures, mais on peut alors tolerer une faible ductilite; - soit la resistance au fluage n'est pas suffisante; la ductilite doit etre importante a chaud et egalement a froid pour la resistance au cyclage thermique. Il est apparu rapidement que le beryllium ordinaire avait une resistance au fluage trop faible et qu'il paraissait difficile de l'augmenter suffisamment pour EL 4 (5 kg/mm{sup 2}). D'autres facteurs non metallurgiques ont contribue egalement a l'abandon de cette voie de recherche. On s'est donc oriente vers la deuxieme possibilite en s'efforcant d'augmenter la ductilite du metal qui etait notablement insuffisante. On a d'abord cherche a determiner dans quelle mesure celle-ci dependait de la purete. Il n'est pas encore possible de decider si la fragilite a l'ambiante est due a la presence d'un faible taux d'une impurete particuliere. Dans le Beryllium le plus pur qu'il ait ete possible d'obtenir par distillation, fusion sous vide, fusion de zone ou la combinaison de ces procedes, les scissions critiques des deux modes de glissement possibles ((0001) et (10 1-bar 0)) suivant (11 2-bar 0) sont encore plus differentes que dans le metal moins pur. Ceci signifie que dans le polycristal les grains qui se deforment sont ceux qui peuvent le faire par glissement basal et le mode de rupture

  7. Possibilités de contribution de la gazéification Lurgi à notre approvisionnement énergétique futur Potential Contribution of Lurgi Gasification to Our Future Energy Supplies

    Directory of Open Access Journals (Sweden)

    Eckert G.

    2006-11-01

    Full Text Available Pour la valorisation du charbon, la gazéification est une possibilité immédiatement utilisable et industriellement éprouvée, qui présente l'avantage de permettre la production des formes d'énergie secondaire, auxquelles nous sommes habitués. Indépendamment du produit final, une unité de conversion du charbon est toujours constituée d'étapes de transformation successives, mettant en oeuvre des procédés adaptés, parmi lesquels la gazéification de charbon proprement dite constitue la première étape qui n'est cependant qu'une opération parmi d'autres. Le traitement des gaz et la séparation des produits secondaires sont mis en oeuvre également et sont importants dans l'ensemble du complexe de traitement. Dans la communication présentée, trois possibilités différentes sont évoquées : - production de gaz de chauffage de différents pouvoirs calorifiques ; - production de méthanol et transformation éventuelle de celui-ci en essence ; - production d'hydrocarbures par la synthèse de Fischer-Tropsch. Une approche économique générale dégage une idée d'ensemble sur la situation et l'intérêt des techniques de conversion du charbon à l'heure actuelle. For the upgrading of coal, gasification is an immediately available and industrially well-proven possibility which has the advantage of making it possible to produce the types of secondary energy to which we have become accustomed. Independently of the end product, a coal conversion plant always consists of successive transformation steps making use of suitable processes, among which coal gasification itself is the first such step, although being only one operation among others. Gas processing and secondary products separation are also implemented and are important in the overall processing complex. This article brings out three different possibilities: (a production of fuel gas with different heating values; (b production of methanol and eventual transformation into gasoline

  8. Compatibility problems of canning materials with carbon dioxide at high temperatures; Problemes de comptabilite des materiaux de gainage avec le gaz carbonique aux temperatures elevees

    Energy Technology Data Exchange (ETDEWEB)

    Darras, R; Loriers, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    and iron-aluminium alloys should increase as a result of the research carried out with a view to improving their technological and mechanical properties. (authors) [French] L'adoption, en France, du gaz carbonique sous pression comme fluide caloporteur dans les reacteurs avances des filieres graphite-gaz et eau lourde-gaz, a impose la recherche de materiaux de gainage susceptibilite prendre la releve des alliages de magnesium. En effet, ces derniers deviennent inutilisables au dessus de 500 C environ, en raison de la proximite de leur point de fusion et de leurs proprietes mecaniques alors defaillantes, quoique leur compatibilite avec le gaz carbonique reste relativement bonne. Le beryllium, particulierement seduisant en raison de sa faible section de capture pour les neutrons thermiques, presente, entre autres, un inconvenient grave: son utilisation dans le gaz carbonique n'est possible, des 600 C, que si ce gaz est rigoureusement desseche, la pression partielle de vapeur d'eau etant le facteur determinant imposant une dessication d'autant plus poussee que la pression nominale est plus elevee. Dans le cas contraire, apres une courte periode d'incubation, l'oxydation s'accelere, conduisant a une corrosion intergranulaire rapidement destructrice. Neanmoins, les alliages beryllium-calcium ou beryllium-magnesium, a 0,5 pour cent environ d'element d'addition, permettent de surmonter cette difficulte; ils restent utilisables en presence de quelques centaines de vpm de vapeur d'eau jusqu'a 700 C au moins. Les problemes metallurgiques lies a la mise en oeuvre du beryllium ou de ses alliages ont cependant conduit a envisager provisoirement l'utilisation d'aciers inoxydables austenitiques. Ces materiaux sont intrinsequement tres resistants a l'oxydation; mais, comme ils ne peuvent etre employes qu'en faible epaisseur, etant donne leur section de capture importante, il y a lieu de choisir les nuances comparativement les moins oxydables. Au dessus de 600 C, les nuances

  9. La formation de l'oxyde azotique dans les flammes de diffusion de gaz naturel Nitrogen. Oxyde Formation in Natural-Gas Diffusion Flams

    Directory of Open Access Journals (Sweden)

    Portrait L. M.

    2006-11-01

    Full Text Available L'étude de la formation de l'oxyde azotique dans des flammes de diffusion de ga naturel est effectuée depuis deux ans sur le four expérimental du Groupe d'Etude des Flammes de Gaz Naturel situé à Toulouse. Un certain nombre de variables ont été explorées : type de flamme, excès d'air, préchauffage de l'air, teneur en oxygène du comburant, puissance calorifique, et débit de moment cinétique. L'étude a mis en évidence une corrélation générale, quelle que soit la variable considérée, entre la quantité maximale d'oxyde d'azote formé et la température maximale de la flamme. Certains des résultats précédents ont été exploités à l'Institut Français du Pétrole, en vue d'établir une équation de vitesse de formation de NO applicable aux flammes axiales de diffusion de gaz naturel. Les calculs s'appuient sur les connaissances obtenues lors de l'étude cinétique de formation de NO effectuée au Laboratoire d'Aérothermique Fondamentale. Les résultats du calcul théorique confirment ceux de l'étude sur le four expérimental en ce qui concerne l'influence prépondérante de la température sur la formation de l'oxyde azotique. Par ailleurs, le calcul théorique retrouve bien les résultats obtenus lors de l'étude fondamentale, selon lesquels la cinétique de formation de NO évolue le long de la flamme depuis le front de flamme jusqu'aux gaz brûlés. La généralisation à un grand nombre de flammes de l'équation cinétique expérimentale obtenue nécessite maintenant de prendre en compte certains phénomènes de diffusion négligés jusqu'à présent. Research on the formation of nitrogen oxide in natural-gas diffusion flammes has been going on for two years in the experimental furnace of the Groupe d'Etude des Flammes de Gaz Naturel located in Toulouse. Different variables have been investigoted such as type of flamme, air excess, air preheating, oxygen content in the oxidant, heating power and kinetic moment output

  10. Study of heat transfer in superconducting cable electrical insulation of accelerator magnet cooled by superfluid helium; Etude des transferts de chaleur dans les isolations electriques de cables supraconducteurs d'aimant d'accelerateur refroidi par helium superfluide

    Energy Technology Data Exchange (ETDEWEB)

    Baudouy, B

    1996-10-04

    Heat transfer studies of electrical cable insulation in superconducting winding are of major importance for stability studies in superconducting magnets. This work presents an experimental heat transfer study in superconducting cables of Large Hadron Collider dipoles cooled by superfluid helium and submitted to volume heat dissipation due to beam losses. For NbTi magnets cooled by superfluid helium the most severe heat barrier comes from the electrical insulation of the cables. Heat behaviour of a winding is approached through an experimental model in which insulation characteristics can be modified. Different tests on insulation patterns show that heat transfer is influenced by superfluid helium contained in insulation even for small volume of helium (2 % of cable volume). Electrical insulation can be considered as a composite material made of a solid matrix with a helium channels network which cannot be modelled easily. This network is characterised by another experimental apparatus which allows to study transverse and steady-state heat transfer through an elementary insulation pattern. Measurements in Landau regime ({delta}T{approx}10{sup -5} to 10{sup -3} K) and in Gorter-Mellink regime ({delta}T>10{sup -3} K) and using assumptions that helium thermal paths and conduction in the insulation are decoupled allow to determine an equivalent channel area (10{sup -6} m{sup 2}) and an equivalent channel diameter (25 {mu}). (author)

  11. Study of heat transfer in superconducting cable electrical insulation of accelerator magnet cooled by superfluid helium; Etude des transferts de chaleur dans les isolations electriques de cables supraconducteurs d'aimant d'accelerateur refroidi par helium superfluide

    Energy Technology Data Exchange (ETDEWEB)

    Baudouy, B

    1996-10-04

    Heat transfer studies of electrical cable insulation in superconducting winding are of major importance for stability studies in superconducting magnets. This work presents an experimental heat transfer study in superconducting cables of Large Hadron Collider dipoles cooled by superfluid helium and submitted to volume heat dissipation due to beam losses. For NbTi magnets cooled by superfluid helium the most severe heat barrier comes from the electrical insulation of the cables. Heat behaviour of a winding is approached through an experimental model in which insulation characteristics can be modified. Different tests on insulation patterns show that heat transfer is influenced by superfluid helium contained in insulation even for small volume of helium (2 % of cable volume). Electrical insulation can be considered as a composite material made of a solid matrix with a helium channels network which cannot be modelled easily. This network is characterised by another experimental apparatus which allows to study transverse and steady-state heat transfer through an elementary insulation pattern. Measurements in Landau regime ({delta}T{approx}10{sup -5} to 10{sup -3} K) and in Gorter-Mellink regime ({delta}T>10{sup -3} K) and using assumptions that helium thermal paths and conduction in the insulation are decoupled allow to determine an equivalent channel area (10{sup -6} m{sup 2}) and an equivalent channel diameter (25 {mu}). (author)

  12. It's quicker "Par Avignon"!

    CERN Multimedia

    2005-01-01

    For a few years, the CERN Library has been receiving books from the University of Hanover sent via Avignon, at least that's what it says on the envelope. Such a detour would mean that parcels were travelling 720 km more than the distance separating Geneva and Hanover, which would be a very strange state of affairs. The explanation lies in a spelling mistake. The sender has been stamping parcels with a stamp that says "Par Avignon prioritaire" (first-class via Avignon) instead of "Par Avion prioritaire" (First Class Air Mail), a source of much amusement to the librarians!

  13. Gas data transmission system by satellite telephone; Systeme de transmission de donnees sur le gaz utilisant le telephone par satellite

    Energy Technology Data Exchange (ETDEWEB)

    Ogasawara, S.; Tanji, A. [Dengineer Co., Ltd (Japan); Akiyama, S. [Buyo Gas Company (Japan)

    2000-07-01

    Dengineer Co., Ltd. and Buyo Gas Co., Ltd. had been developing and using the data and alarm transmission system by public telephone since 1984, that was first practical use in Japan. It is very important for business management that adjusts the production value of gas by measuring gas pressures in each governor. Also, it is indispensable to know the accident of gas leakage or abnormal gas pressure quickly. But this convenient system is not spread yet in Japanese market cause of the following reasons. - Take time and cost for installation of terminal station. - Terminal station is apt to damage by thunder. - Big disaster must stop working this system. In order to solve those problems, we have developed and tested the system organized of the satellite telephone system and solar cells for power. This system will be very useful for wide place, not only Japanese market but also the area, which has no electricity and phone. Also, it will be convenient for international rescue as is able to access it from the foreign countries. (authors)

  14. Contribution to the study of the reactivity of graphite with respect to carbon dioxide and air; Contribution a l'etude de la reactivite du graphite vis-a-vis du gaz corbonique et de l'air

    Energy Technology Data Exchange (ETDEWEB)

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

    1959-09-15

    The oxidation of nuclear-quality graphite by air and carbon dioxide has been studied at temperatures at which the reaction becomes measurable. These experiments have been carried out on graphites differing in the concentration and nature of their ash, and in their mode of preparation. The reaction velocities measured have been compared in an attempt to correlate these two factors. Ten types of graphite have thus been studied. Since the oxidation reactions are of the type gas-solid, their velocities have also been compared to the BET surface areas of the graphite studied and to the diameter distribution of the pores of this surface. The conclusion is that, even for these low impurity contents, the law relating the reaction velocity to the surface is masked by the impurities which appear to behave as preferential reaction sites. This has been shown by carrying out successive purifications on various types of graphite, which treatment results in an important decrease in the reactivity of all the samples studied. (author) [French] On a etudie l'oxydation de graphites de qualites nucleaires par l'air et par le gaz carbonique, a des temperatures telles que la reaction commence a etre mesurable. Ces essais ont porte sur des graphites differents aux points de vue de la concentration et de la nature des cendres, et differents par le mode de preparation. Les vitesses de reaction mesurees ont ete comparees afin de tenter de les relier a ces deux facteurs. Dix qualites de graphite ont ainsi ete etudiees. Les reactions d'oxydation etant des reactions gaz-solide, les vitesses ont ete egalement comparees aux surfaces specifiques B.E.T. des echantillons de graphite etudies et a la repartition par diametres des pores de cette surface. La conclusion est que, meme a ces teneurs faibles en impuretes, la loi de variation de la vitesse de reaction en fonction de la surface est masquee par les impuretes qui paraissent jouer le role de sites privilegies de reaction comme l'ont montre les

  15. The reactions of magnesium and its alloys with moist gases at high temperatures; Les reactions du magnesium et de ses alliages avec les gaz humides aux temperatures elevees

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-02-15

    The kinetics and mechanisms of the reaction of pure or low alloyed magnesium with various gas saturated by water vapor: oxygen, argon, nitrogen, air, carbon dioxide, have been studied and compared in the temperature range 350-600 deg C. After picturing the large chemical reactivity of magnesium surface, the more or less properties of the oxide film, always made of magnesia, have been shown depending on the nature of the gas carrying water vapor; in fact, metal sublimation occurs the more easily as the surrounding atmosphere is less oxidizing. Moreover, an activation energy change is systematic, but at a temperature which depends also on the latter. In the case of the alloys, the linear oxidation rate is generally obtained only after short induction periods, parabolic in nature. Two possibilities of corrosion inhibition of magnesium by water vapor are then demonstrated and explained: either by a partial superficial fluoridation, or when the carrier gas is carbon dioxide. Also, the extreme conditions of oxidation were studied, that is the ignition processes that occur at a particular temperature in every gas mixture. Finally, it is tried to evolve the fundamental and practical significance of all the results. (author) [French] On a etudie et compare par voie thermogravimetrique, micrographique et radiocristallographique, les cinetiques et les mecanismes de reaction du magnesium et de certains de ses alliages avec diverses atmospheres saturees en vapeur d'eau: oxygene, argon, azote, air, gaz carbonique, dans un domaine de temperatures s'etendant de 350 a 600 deg C, Apres avoir illustre l'extreme sensibilite chimique de la surface du magnesium, on a tout d'abord montre que la valeur plus ou moins protectrice de la couche d'oxyde formee, pourtant toujours constituee de magnesie normale, depend de la nature du gaz porteur de la vapeur d'eau; en effet, la sublimation du metal intervient d'autant plus facilement que les atmospheres en presence sont moins oxydantes. De plus

  16. Perspectives de développement de la production industrielle d'hydrogène par électrolyse alcaline avancée Development Outlook for Industrial Hydrogen Production by Advanced Alkaline Electrolysis

    OpenAIRE

    Derive C.; Pottier J.; Montet A.; Avallet M.; Robin J. -Y.

    2006-01-01

    Dans les conditions du développement du programme nucléaire français qui permettent une production d'électricité à un coût intéressant en heures creuses, la production d'hydrogène par électrolyse de l'eau peut être envisagée à moyen terme en compétition avec les autres procédés de fabrication d'hydrogène tels que le reformage de gaz naturel. Dans le cadre de leur coopération, Électricité de France (EDF) et le Gaz de France (GDF) conduisent, depuis 1976, un programme de recherches et développe...

  17. Globalization of the natural gas industry; La mondialisation de l`industrie du gaz naturel

    Energy Technology Data Exchange (ETDEWEB)

    Deyirmendjan, J. [Gaz de France (GDF), 75 - Paris (France)

    1997-05-01

    After presenting a panorama of the international gas industry, a description of changes affecting the world gas industry, and an analysis of how environment-related demands give gas an opportunity to become the leading source of energy in the 21. century, Mr Jacques Deyirmendjan, Senior Executive-Vice-President of Gaz de France, tells his interviewer how French industry and national companies are designing their strategies to respond effectively to these changes.

  18. Gaz de France and Ruhrgas have made commitments towards the European commission

    International Nuclear Information System (INIS)

    Anon.

    2004-01-01

    The European Commission's DG Competition has decided to close its investigation into the alleged refusal by the French and German gas companies Gaz de France and Ruhrgas to grant the Norwegian subsidiary of the US gas producer Marathon access to their gas networks. Both companies have offered commitments to improve third party access to their respective transport networks in order to allow customers in France and Germany to benefit more effectively from the opening of the gas markets to competition. (author)

  19. Gasification in Petroleum Refinery of 21st Century La gazéification dans la raffinerie du pétrole du XXIe siècle

    Directory of Open Access Journals (Sweden)

    Furimsky E.

    2006-12-01

    goudrons, le coke et l'asphalte, résultant respectivement de la viscoréduction, de la carbonisation et du désasphaltage. Les résidus finaux peuvent être, à leur tour, convertis en produits utilisables comme l'hydrogène, la vapeur, l'électricité, l'ammoniac et des produits chimiques. Dans ce contexte, la gazéification est apparue comme la technologie de choix pour la valorisation des résidus en raison de ses meilleures performances. De même, les boues de raffinerie peuvent être cogazéifiées avec les résidus finaux et devenir alors des produits valorisables. Intégrée à la raffinerie de pétrole, la gazéification peut aider à résoudre les problèmes environnementaux liés à l'élimination des résidus et des boues. Les résultats économiques de la raffinerie peuvent également être améliorés. Les tendances de déréglementation du marché de l'énergie permettent aux raffineries de pétrole d'y pénétrer, soit toutes seules, soit en partenariat avec les fournisseurs d'utilités. Le potentiel de coproduction de produits chimiques et de vapeur avec l'électricité offre une souplesse de réaction permettant de répondre aux demandes du marché. L'intérêt de la technologie de la gazéification est commercialement démontré. Parmi d'autres, les gazéificateurs à lit entraîné sont les gazéificateurs de prédilection. Plusieurs projets commerciaux en Europe, en Asie et aux États-Unis font appel à un gazéificateur utilisant soit un système d'alimentation en suspension, soit un système d'alimentation par voie sèche.

  20. La pelade par plaques

    Science.gov (United States)

    Spano, Frank; Donovan, Jeff C.

    2015-01-01

    Résumé Objectif Présenter aux médecins de famille des renseignements de base pour faire comprendre l’épidémiologie, la pathogenèse, l’histologie et l’approche clinique au diagnostic de la pelade par plaques. Sources des données Une recension a été effectuée dans PubMed pour trouver des articles pertinents concernant la pathogenèse, le diagnostic et le pronostic de la pelade par plaques. Message principal La pelade par plaques est une forme de perte pileuse auto-immune dont la prévalence durant une vie est d’environ 2 %. Des antécédents personnels ou familiaux de troubles auto-immuns concomitants, comme le vitiligo ou une maladie de la thyroïde, peuvent être observés dans un petit sous-groupe de patients. Le diagnostic peut souvent être posé de manière clinique en se fondant sur la perte de cheveux non cicatricielle et circulaire caractéristique, accompagnée de cheveux en « point d’exclamation » en périphérie chez ceux dont le problème en est aux premiers stades. Le diagnostic des cas plus complexes ou des présentations inhabituelles peut être facilité par une biopsie et un examen histologique. Le pronostic varie largement et de mauvais résultats sont associés à une apparition à un âge précoce, une perte importante, la variante ophiasis, des changements aux ongles, des antécédents familiaux ou des troubles auto-immuns concomitants. Conclusion La pelade par plaques est une forme auto-immune de perte de cheveux périodiquement observée en soins primaires. Les médecins de famille sont bien placés pour identifier la pelade par plaques, déterminer la gravité de la maladie et poser le diagnostic différentiel approprié. De plus, ils sont en mesure de renseigner leurs patients à propos de l’évolution clinique de la maladie ainsi que du pronostic général selon le sous-type de patients.

  1. Description d'un nouveau brûleur compact. Fonctionnement en régime de gaz prémélangés Description of a New Compact Premixed Gas Burner

    Directory of Open Access Journals (Sweden)

    Minetti R.

    2006-11-01

    Full Text Available On décrit un nouveau brûleur compact à gaz, de haut rendement et d'une puissance variable de 1 à 5 kW. La source de chaleur est une flamme plate d'un prémélange stoechiométrique de gaz naturel et d'air stabilisé sur une grille d'une surface de 100 cm2. Plusieurs grilles en acier inoxydable sont comparées. Elles diffèrent par leur épaisseur, le nombre et la dimension des trous. Un échangeur de chaleur en laiton à circulation d'eau peut être approché jusqu'à 7 mm de la surface du brûleur. La température des gaz frais, le débit et la position de l'échangeur ont été modifiés et les conditions optimales de fonctionnement sont décrites. Les températures à travers les gaz frais, la flamme, les gaz brûlés et les fumées, ont été mesurées. Un modèle simple des échanges de chaleurs est présenté. Il permet une meilleure compréhension des processus de transfert et facilite le choix des conditions opératoires. Dans les meilleures conditions, 93 % du contenu thermique du mélange gazeux est transféré à l'échangeur. Some general characteristics of a compact and efficient gas burner are described (1-5 kW. The heat source is a premixed flat flame stabilized on a 100 cm2 grid fed by a stoechiometric mixture of air and natural gas. Various types of stainless steel grids have been investigated. They differ according to their thickness and to the number and size of the holes. A circulating water heat exchanger made of brass can be approached to the flame as close as 7 mm above the burner surface. The temperature of the inlet gas mixture, the flow rate, and the position of the heat exchanger have been varied. The best working conditions are given as well as the temperature through the fresh gaseous mixture, the temperature profiles of the flame and the temperature of the fumes. From heat transfer calculations a simple model is presented. It gives better insight into the heat transfer processes and facilitates a judicious

  2. suPAR

    DEFF Research Database (Denmark)

    Eugen-Olsen, Jesper; Giamarellos-Bourboulis, Evangelos J

    2015-01-01

    Investigation of biomarkers that can promptly predict unfavourable outcome of critically illness is an emerging necessity taking into consideration the need for early intervention, the shortage of available beds in intensive care units and the considerable cost of hospitalisation. The most...... promising biomarker is soluble urokinase-type plasminogen activator receptor (suPAR). Three studies in large populations of critically ill patients and patients admitted to the emergency department have shown that concentrations >12ng/mL can safely predict unfavourable outcome. This review presents...

  3. Kinetic study of the reaction of uranium with various carbon-containing gases; Etude cinetique de la reaction sur l'uranium de differents gaz carbones

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-09-15

    The kinetic study of the reaction U + CO{sub 2} and U + CO has been performed by a thermogravimetric method on a spherical uranium powder, in temperature ranges respectively from 460 to 690 deg. C and from 570 to 850 deg. C. The reaction with carbon dioxide leads to uranium dioxide. A carbon deposition takes place at the same time. The global reactions is the result of two reactions: U + 2 CO{sub 2} {yields} UO{sub 2} + 2 CO U + CO{sub 2} {yields} UO{sub 2} + C The reaction with carbon monoxide leads to a mixture of dioxide UO{sub 2}, dicarbide UC{sub 2} and free carbon. The main reaction can be written. U + CO {yields} 1/2 UO{sub 2} + 1/2 UC{sub 2} The free carbon results of the disproportionation of the carbon monoxide. A remarkable separation of the two phases UO{sub 2} and UC{sub 2} can be observed. A mechanism accounting for the phenomenon has been proposed. The two reactions U + CO{sub 2} and U + CO begin with a long germination period, after which, the reaction velocity seems to be limited in both cases by the ionic diffusion of oxygen through the uranium dioxide. (author) [French] L'etude cinetique des reactions U sol + CO{sub 2} gaz et U sol + CO gaz a ete effectuee par thermogravirnetrie sur une poudre d'uranium a grains spheriques, les domaines de temperature etudies s'etendant respectivement de 460 a 690 deg. C et de 570 a 850 deg. C. L'action du dioxyde de carbone conduit au dioxyde d'uranium UO{sub 2}; il se produit en meme temps un depot de carbone. La reaction globale resulte des deux reactions: U + 2 CO{sub 2} {yields} UO{sub 2} + 2 CO U + CO{sub 2} {yields} UO{sub 2} + C Le mono-oxyde de carbone conduit a un melange de dioxyde UO{sub 2}, de dicarbure UC{sub 2} et de carbone libre. La reaction principale s'ecrit: U + CO {yields} 1/2 UO{sub 2} + 1/2 UC{sub 2} Le carbone libre provient de la dismutation du mono-oxyde de carbone. On observe une separation remarquable des deux phases UO{sub 2} et UC{sub 2}; un mecanisme rendant compte de ce phenomene a

  4. Parálisis cerebral :

    OpenAIRE

    Cabrero Izquierdo, María del Carmen

    2012-01-01

    Se aborda el tema de la parálisis cerebral definiendo qué es, clasificando los tipos de parálisis dependiendo de la afectación y las características principales. Se explican algunos de sus tratamientos, se dan sistemas alternativos y/o aumentativos de comunicación para un alumno con PC (parálisis cerebral).

  5. Together on the same planet. Gaz de France and sustainable development in 2006; Ensemble sur la meme planete. Gaz de France et le developpement durable en 2006

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This document presents the sustainable development policy of Gaz de France group. It identifies the challenges the group has to face in order to control the environmental impact of the Group's activities (exploration, production, procurement, re-gasification, transmission, storage, distribution, marketing and shares, services). The approach used is based on a voluntary commitment of the Group to dialogue and share current challenges with all its stakeholders, and to imagine other roads to development. The initiatives consist in clean production practices, development of renewable energy sources, energy conservation, investment in research, safety improvement, solidarity with underprivileged people, respect of local environment and of codes of conduct, accompanying local economic development and development of clean transport systems. (J.S.)

  6. Together on the same planet. Gaz de France and sustainable development in 2006; Ensemble sur la meme planete. Gaz de France et le developpement durable en 2006

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This document presents the sustainable development policy of Gaz de France group. It identifies the challenges the group has to face in order to control the environmental impact of the Group's activities (exploration, production, procurement, re-gasification, transmission, storage, distribution, marketing and shares, services). The approach used is based on a voluntary commitment of the Group to dialogue and share current challenges with all its stakeholders, and to imagine other roads to development. The initiatives consist in clean production practices, development of renewable energy sources, energy conservation, investment in research, safety improvement, solidarity with underprivileged people, respect of local environment and of codes of conduct, accompanying local economic development and development of clean transport systems. (J.S.)

  7. Measurement of the activity of beta emitting gases using an ionisation chamber; Mesure de l'activite des gaz emetteurs beta au moyen d'une chambre d'ionisation

    Energy Technology Data Exchange (ETDEWEB)

    Lebouleux, P [Commissariat a l' Energie Atomique. Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

    1962-07-01

    An ionization chamber was developed for measuring directly the activity of a {beta}-emitting gas whatever the gas may be. The following two parameters are defined and determined: p, the average specific ionization produced by a {beta} disintegration, and i, the average {beta} path in the chamber. It was shown, during the determination of i, that the {beta} particles are reflected on the walls of the ionization chamber when the latter are made of a high atomic number material. It was possible to eliminate this effect by constructing an electrode chamber made of graphite. With this chamber a direct measurement can be made of the activity of a gaseous {beta} emitter with a precision of about {+-}10%. Some applications are given of the graphite electrode chamber (calibration of the chambers built industrially and determination of the activation cross section of a gaseous emitter). It was possible to determine the activation cross section of {sup 134}Xe; a value of 0.18 {+-} 0.03 barn was found. (author) [French] Le but de l'etude est de realiser une chambre d'ionisation permettant d'effectuer une mesure directe de l'activite d'un gaz emetteur {beta} quel que soit l'emetteur considere. On definit et l'on determine les deux parametres suivants: p: ionisation specifique moyenne produite par une desintegration {beta}. La determination est effectuee par une methode graphique, i: moyenne des parcours des {beta} dans la chambre. La determination est effectuee experimentalement par introduction dans la chambre d'un gaz radioactif dont on peut calculer l'activite. On a mis en evidence, au cours de la determination de i, la reflexion des particules {beta} sur les parois des chambres d'ionisation lorsque celles-ci sont constituees d'un materiau de numero atomique eleve. La construction d'une chambre a electrodes de graphite nous a permis d'eliminer ce phenomene. Avec cette chambre, on effectue une mesure directe de l'activite d'un emetteur {beta} gazeux avec une precision de l

  8. 2006 annual results: Gaz de France announces record-high results and exceeds its objectives

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    Paris, 13 March 2007 - In fiscal year 2006, Gaz de France had the best operational performance in its history. The Group confirms the strength of its business model, with sound Infrastructure business and sharp growth in Exploration - Production, Trading and Sales: - Net income, Group share: 2.3 billion euros; - EBITDA: 5.15 billion euros; - Dynamic dividend policy: 1.1 euro per share (+62%); - Investments at stepped-up pace: 4 billion euros (+38%); - Contribution of Group's international activities doubled in two years (39% of sales); - Many operational advances: strengthened operations, Exploration-Production, LNG Infrastructures and Electricity; - Major steps completed in merger project with Suez.

  9. 2006 annual results: Gaz de France announces record-high results and exceeds its objectives

    International Nuclear Information System (INIS)

    2007-01-01

    Paris, 13 March 2007 - In fiscal year 2006, Gaz de France had the best operational performance in its history. The Group confirms the strength of its business model, with sound Infrastructure business and sharp growth in Exploration - Production, Trading and Sales: - Net income, Group share: 2.3 billion euros; - EBITDA: 5.15 billion euros; - Dynamic dividend policy: 1.1 euro per share (+62%); - Investments at stepped-up pace: 4 billion euros (+38%); - Contribution of Group's international activities doubled in two years (39% of sales); - Many operational advances: strengthened operations, Exploration-Production, LNG Infrastructures and Electricity; - Major steps completed in merger project with Suez

  10. Annual report on theoretical work of the S.T.G.I. (Section de theorie des gaz ionises)

    International Nuclear Information System (INIS)

    1984-01-01

    This report presents in a detailed form the theoretical work of the STGI (Section Theorie des Gaz Ionises). It is thus hoped that the present report will be useful for physicists interested in additional information. Works an plasma equilibrium and its evolution are shortly presented together with works on plasma heating and current drive. Kinetic theory and spectroscopy are not forgotten

  11. Evolution dans la gestion de la détection gaz

    CERN Document Server

    Bonthond, F

    1999-01-01

    Cet article présente l'interface graphique qui a été développée pour gérer d'une façon visuelle et globale la détection des gaz inflammables utilisés dans les expériences du hall EHN1 (NA49, NA56, tests pour ATLAS, CMS, Alice, etc.). A cet effet, on utilise des détecteurs catalytiques connectés à une centrale. Afin de retransmettre les alarmes à la salle de contrôle des pompiers, cette centrale est couplée à un automate programmable connecté au réseau Ethernet du CERN. Une liaison filaire entre l'automate et le synoptique câblé des alarmes de niveau 3 assure la redondance nécessaire à ce type d'alarmes. Le logiciel de contrôle LabView a été utilisé pour développer l'interface graphique. Elle permet de visualiser sur n'importe quel PC ou X-Terminal le taux de remplissage des bouteilles de gaz, la position des électrovannes ainsi que les asservissements qui pilotent lors d'une alarme, notamment les ventilations, les panneaux de signalisation et les arrêts d'urgence.

  12. Replacing Sugar by Date Syrup in Gaz and Investigation of Texture Properties

    Directory of Open Access Journals (Sweden)

    Fateme Raiesi Ardali

    2013-10-01

    Full Text Available Date Syrup is a natural sweetener that is suitable replacement for sugar in food stuffs formulation. In this Research Amounts of 25-100 percent of sugar in Gaz formulation were replaced with date syrup and to study effect of its use in product formulation, characteristics of texture, color and sensory analyse of treatments were investigated. Statistical analyse of data was also done by SPSS software and Dankan test. The results of this research showed that amount of used date syrup in formulation had a significant effect on  color parameters  (L*,a*,b*, texture characteristics and sensory analyse of samples. By increase of date syrup in Gaz formulation, samples texture became softer than control sample and yellowness and redness index of samples were increasedDoi: DOI: 10.12777/ijse.6.1.11-15 [How to cite this article:  Shafiei, Z., Hojjatoleslami, M.,  Soha, S., and Shariati, M.A. 2014. The Influence of Malt Extraction Adding to UF Fresh Low Fat Cheese on Its Textural Properties. International Journal of Science and Engineering, 6(1:57-60. Doi: 10.12777/ijse.6.1.11-15

  13. Natural gas cogeneration in the residential sector; La cogeneration au gaz naturel en residentiel

    Energy Technology Data Exchange (ETDEWEB)

    Lancelot, C.; Gaudin, S. [Gaz de France, GDF, Dir. de la Recherche, 75 - Paris (France)

    2000-07-01

    The natural gas cogeneration offer is now available and operational in the industrial sector. It is based on technologies of piston engines and gas turbines. Currently, this offer is sufficiently diversified, so much from the point of view of the range of powers available (from 1 MW to more than 40 MW electric) that number of manufacturers. In order to widen the cogeneration market in France to the markets of the commercial and residential sectors, Gaz De France has undertaken a technical economic study to validate the potential of those markets. This study led to work on the assembly of a french die to cogeneration packages of low power (less than 1 MW electric). This step has emerged at the beginning of 1999 with the launching of a commercial offer of cogeneration packages. In margin to this work Gaz De France Research division also initiated a study in order to evaluate the offer of micro cogeneration, products delivering an electric output lower than 10 kW. (authors)

  14. The take-over of Gaz Metropolitain by Hydro-Quebec

    International Nuclear Information System (INIS)

    Bernard, J-T.

    1997-01-01

    The implications of a take-over of Gaz Metropolitain by Hydro-Quebec in early 1997 and the pricing of electricity and natural gas in Quebec were discussed. In January 1997, Hydro-Quebec purchased all the shares in Noverco that were formerly owned by SOQUIP. With this purchase, Hydro-Quebec became the major share holder in Noverco, the company that controls Gaz Metropolitain. This type of take-over, where an electrical utility purchases the interests in a natural gas distributor, has also been observed in the United States and is believed to be a consequence of the recent deregulation of the electricity market. In the near future, it is believed that consumers will probably pay for equivalent energy use (like heating or cooling) rather than separate tariffs for electricity or natural gas consumption. The recent popularity of gas-fueled electrical cogenerating stations is also believed to be an important factor in this take-over. 1 ref., 3 tabs

  15. Fixation à haute et moyenne température de l'hydrogène sulfuré par des masses de captation régénérables Hydrogen-Sulfide Fixation At High and Medium Temperature by Regenerable Capture Masses

    OpenAIRE

    Hotier G.

    2006-01-01

    L'intérêt de la désulfuration haute température comparée à la même opération conduite à basse température est renforcé quand la désulfuration a lieu entre deux opérations de niveau thermique élevé comme la gazéification du charbon et la production d'électricité par cycles combinés turbine à gaz-turbine à vapeur. Les masses absorbantes à base d'oxyde de fer peuvent réaliser une bonne désulfuration mais résistent mal aux chocs thermiques. Un agent de régénération particulièrement efficace est l...

  16. The performance of the natural gas solutions in the accommodation; La performance des solutions gaz naturel dans l'habitat

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This paper presents the Gaz De France Group policy concerning the utilization of the gas as energy source in residential buildings for heating and cooking. The market and more specially the manufacturers importance are discussed. (A.L.B.)

  17. Methods for continuous or semi-continuous analysis of gases dissolved in pressurized water; Methodes d'analyses continue et semi-continue de gaz dissous dans l'eau surpressee

    Energy Technology Data Exchange (ETDEWEB)

    Vignet, P; Gabilly, R; Lutz, J; Zermizogilou, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    }/kg of water. (authors) [French] Trois appareils ont ete mis au point pour permettre la mesure de gaz en solution dans l'eau sous une pression pouvant atteindre 200 kg/cm{sup 2}. 1 - Analyseur d'hydrogene: On mesure la variation relative de resistance d'un filament immerge dans l'eau, constitue par du palladium pur ou par un alliage palladium-platine 75.25, lors de l'absorption de l'hydrogene. On a trace les courbes d'etalonnage pour un fil de palladium pour des temperatures allant de 180 a 280 deg. C. A temperature ambiante, on a utilise un ruban en alliage palladium-platine. L'etude theorique et experimentale de la cinetique d'absorption de l'hydrogene dissous dans l'eau par un metal a permis de definir les meilleures conditions de fonctionnement de l'analyseur pour obtenir une reponse rapide, de l'ordre de quelques minutes. On utilise actuellement pour la mesure un pont alimente en courant alternatif (pont de Kohlrausch) avec compensation de temperature et systeme de regeneration periodique du filament. 2 - Analyseur d'oxygene: On sait que l'oxygene dissous dans l'eau reagit sur le thallium pour former l'hydroxyde de thallium, compose soluble dont la presence augmente la conductibilite electrique de l'eau. Pour realiser une methode de dosage basee sur ce principe, on a mis au point un conductimetre differentiel dont les caracteristiques permettent d'atteindre une excellente precision dans une gamme de 0,001 ppm a quelques dizaines de ppm d'oxygene. On examine dans quelles conditions le bruit de fond de l'appareil, du a des reactions parasites, peut etre rendu negligeable; puis on etudie la cinetique de la reaction d'oxydation du thallium par l'oxygene dissous, qui est de type diffusionnel. On a ainsi pu relier quantitativement le taux de transformation aux parametres physiques et hydrodynamiques. 3 - Analyse globale des gaz en solution: On isole, dans une bombe placee en derivation sur un circuit surpresse un volume d'eau a pression et temperature elevees. Apres

  18. Mobility of Rb{sup +} and Cs{sup +} ions in gases at high pressures; Mobilite des ions Rb{sup +} et Cs{sup +} dans les gaz a haute pression

    Energy Technology Data Exchange (ETDEWEB)

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

    1965-07-01

    A theoretical study and mobility measurements have been made of Rb{sup +} and Cs{sup +} ions moving in gases at high pressures (10{sup -2} to 25 kg/cm{sup 2}). The theoretical study has been effected using the results of P. Langevin who considers the ions and molecules as elastic spheres and takes into account the electrical polarization forces. The practical work has been carried out using the Rb{sup +} and Cs{sup +} ions emitted by a thermal source; for the measurement of their velocity the method using an ionic beam cut by four grids was employed. Since the source does not work in atmospheres containing oxygen (even in the combined state) the tests only involved pure gases: nitrogen, argon, helium at pressures of from 10{sup -2} to 12 kg/cm{sup 2}. The overall results show that the Rb{sup +} and Cs{sup +} ionic mobilities are very similar and that for fairly-short times spent by the ions in the gas, the measurement results are in agreement with theory. An increase in these times favours a degradation of the ions, which always leads to a decrease in the mobility. This effect is most marked in helium. The gases argon and nitrogen behave identically towards Rb{sup +} and Cs{sup +} ions. (author) [French] Une etude theorique et des mesures de mobilite ont ete effectuees pour des ions Rb{sup +} et Cs{sup +} se deplacant dans des gaz a haute pression (10{sup -2} a 25 kg/cm{sup 2}). L'etude theorique a ete effectuee en utilisant les resultats de P. Langevin qui assimile les ions et les molecules a des spheres elastiques et tient compte des forces de polarisation electrique. L'etude pratique a ete realisee en utilisant des ions Rb{sup +} et Cs{sup +} emis par une source thermique et pour la mesure de leur vitesse, la methode de coupure du faisceau ionique au moyen de quatre grilles a ete adoptee. La source ne fonctionnant pas dans des atmospheres contenant de l'oxygene (meme a l'etat combine) les essais ont seulement porte sur des gaz purs: azote

  19. Mobility of Rb{sup +} and Cs{sup +} ions in gases at high pressures; Mobilite des ions Rb{sup +} et Cs{sup +} dans les gaz a haute pression

    Energy Technology Data Exchange (ETDEWEB)

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

    1965-07-01

    A theoretical study and mobility measurements have been made of Rb{sup +} and Cs{sup +} ions moving in gases at high pressures (10{sup -2} to 25 kg/cm{sup 2}). The theoretical study has been effected using the results of P. Langevin who considers the ions and molecules as elastic spheres and takes into account the electrical polarization forces. The practical work has been carried out using the Rb{sup +} and Cs{sup +} ions emitted by a thermal source; for the measurement of their velocity the method using an ionic beam cut by four grids was employed. Since the source does not work in atmospheres containing oxygen (even in the combined state) the tests only involved pure gases: nitrogen, argon, helium at pressures of from 10{sup -2} to 12 kg/cm{sup 2}. The overall results show that the Rb{sup +} and Cs{sup +} ionic mobilities are very similar and that for fairly-short times spent by the ions in the gas, the measurement results are in agreement with theory. An increase in these times favours a degradation of the ions, which always leads to a decrease in the mobility. This effect is most marked in helium. The gases argon and nitrogen behave identically towards Rb{sup +} and Cs{sup +} ions. (author) [French] Une etude theorique et des mesures de mobilite ont ete effectuees pour des ions Rb{sup +} et Cs{sup +} se deplacant dans des gaz a haute pression (10{sup -2} a 25 kg/cm{sup 2}). L'etude theorique a ete effectuee en utilisant les resultats de P. Langevin qui assimile les ions et les molecules a des spheres elastiques et tient compte des forces de polarisation electrique. L'etude pratique a ete realisee en utilisant des ions Rb{sup +} et Cs{sup +} emis par une source thermique et pour la mesure de leur vitesse, la methode de coupure du faisceau ionique au moyen de quatre grilles a ete adoptee. La source ne fonctionnant pas dans des atmospheres contenant de l'oxygene (meme a l'etat combine) les essais ont seulement porte sur des gaz purs: azote, argon, helium et pour

  20. Elusloom lennukiga puhkusele / Inge Parring

    Index Scriptorium Estoniae

    Parring, Inge

    2003-01-01

    Ilmunud ka: Delovõje Vedomosti 1. okt. lk. 13. Air Cargo Estonia/ACE Logisticsi müügijuht Inge Parring tutvustab elusloomade transpordivõimalusi. Vt. samas: Loomade transportimiseks vajalikud dokumendid

  1. Possibilities of gas-phase radio-chromatography application to permanent-gas analysis; Possibilites de la radiochromatographie en phase gazeuse applications a l'analyse des gaz permanents

    Energy Technology Data Exchange (ETDEWEB)

    Dupuis, M C; Charrier, G; Alba, C; Massimino, D [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

    1970-07-01

    The gas-phase radio-chromatography technique has been applied to the rapid analysis of permanent gases (H{sub 2}, O{sub 2}, N{sub 2}, A, Kr, Xe, CO, CH{sub 4}) labelled with radioactive indicators ({sup 3}H, {sup 37}A, {sup 85}Kr, {sup 133}Xe). After calibration, the components of such a mixture can be identified and their concentrations measured in less than two hours, using a sample volume of from 0.1 to 10 cm{sup 3}. The minimum detectable activity is of the order of 10{sup -4} {mu}C for each radioactive isotope. The measurements are reproducible to about 2 to 3 per cent. This work has been mainly concerned with the influence of parameters affecting the response of the radioactivity detector (ionization chamber or gas flow proportional counter). The method has very numerous applications both theoretically, for the study of chromatographic phenomena under ideal conditions (infinitesimal concentrations made possible by the use of radioactive tracers), and practically, for rapid and accurate radiochemical analysis of radioactive gas mixtures. (authors) [French] La technique de radiochromatographie en phase gazeuse est appliquee a l'analyse rapide de gaz permanents (H{sub 2}, O{sub 2}, N{sub 2}, A, Kr, Xe, CO, CH{sub 4}) marques par des indicateurs radioactifs ({sup 3}H, {sup 37}A, {sup 85}Kr, {sup 133}Xe). Apres etalonnage, l'identification et la mesure des concentrations des constituants d'un tel melange requierent moins de deux heures, sur un volume d'echantillon de 0.1 a 10 cm{sup 3}. L'activite minimum detectable est de l'ordre de 10{sup -4} {mu}C pour chaque isotope radioactif. La reproductibilite des mesures est de l'ordre de 2 a 3 pour cent. L'etude porte principalement sur l'influence des parametres affectant la reponse du detecteur de radioactivite (chambre d'ionisation, ou compteur proportionnel a circulation). La methode est extremement fertile en applications tant sur le plan theorique pour l'etude du phenomene chromatographique dans les conditions

  2. Possibilities of gas-phase radio-chromatography application to permanent-gas analysis; Possibilites de la radiochromatographie en phase gazeuse applications a l'analyse des gaz permanents

    Energy Technology Data Exchange (ETDEWEB)

    Dupuis, M.C.; Charrier, G.; Alba, C.; Massimino, D. [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

    1970-07-01

    The gas-phase radio-chromatography technique has been applied to the rapid analysis of permanent gases (H{sub 2}, O{sub 2}, N{sub 2}, A, Kr, Xe, CO, CH{sub 4}) labelled with radioactive indicators ({sup 3}H, {sup 37}A, {sup 85}Kr, {sup 133}Xe). After calibration, the components of such a mixture can be identified and their concentrations measured in less than two hours, using a sample volume of from 0.1 to 10 cm{sup 3}. The minimum detectable activity is of the order of 10{sup -4} {mu}C for each radioactive isotope. The measurements are reproducible to about 2 to 3 per cent. This work has been mainly concerned with the influence of parameters affecting the response of the radioactivity detector (ionization chamber or gas flow proportional counter). The method has very numerous applications both theoretically, for the study of chromatographic phenomena under ideal conditions (infinitesimal concentrations made possible by the use of radioactive tracers), and practically, for rapid and accurate radiochemical analysis of radioactive gas mixtures. (authors) [French] La technique de radiochromatographie en phase gazeuse est appliquee a l'analyse rapide de gaz permanents (H{sub 2}, O{sub 2}, N{sub 2}, A, Kr, Xe, CO, CH{sub 4}) marques par des indicateurs radioactifs ({sup 3}H, {sup 37}A, {sup 85}Kr, {sup 133}Xe). Apres etalonnage, l'identification et la mesure des concentrations des constituants d'un tel melange requierent moins de deux heures, sur un volume d'echantillon de 0.1 a 10 cm{sup 3}. L'activite minimum detectable est de l'ordre de 10{sup -4} {mu}C pour chaque isotope radioactif. La reproductibilite des mesures est de l'ordre de 2 a 3 pour cent. L'etude porte principalement sur l'influence des parametres affectant la reponse du detecteur de radioactivite (chambre d'ionisation, ou compteur proportionnel a circulation). La methode est extremement fertile en applications tant sur le plan theorique pour l

  3. Par Pond vegetation status 1996

    International Nuclear Information System (INIS)

    Mackey, H.E. Jr.; Riley, R.S.

    1996-12-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the newly emergent, shoreline aquatic plant communities of Par Pond began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level. These surveys continued in July, September, and late October, 1995, and into the early spring and late summer of 1996. Communities similar to the pre-drawdown, Par Pond aquatic plant communities continue to become re-established. Emergent beds of maidencane, lotus, waterlily, watershield, and Pontederia are extensive and well developed. Measures of percent cover, width of beds, and estimates of area of coverage with satellite data indicate regrowth within two years of from 40 to 60% of levels prior to the draw down. Cattail occurrence continued to increase during the summer of 1996, especially in the former warm arm of Par Pond, but large beds common to Par Pond prior to the draw down still have not formed. Lotus has invaded and occupies many of the areas formerly dominated by cattail beds. To track the continued development of macrophytes in Par Pond, future surveys through the summer and early fall of 1997, along with the evaluation of satellite data to map the extent of the macrophyte beds of Par Pond, are planned

  4. Fluctuations Magnetiques des Gaz D'electrons Bidimensionnels: Application AU Compose Supraconducteur LANTHANE(2-X) Strontium(x) Cuivre OXYGENE(4)

    Science.gov (United States)

    Benard, Pierre

    Nous presentons une etude des fluctuations magnetiques de la phase normale de l'oxyde de cuivre supraconducteur La_{2-x}Sr _{x}CuO_4 . Le compose est modelise par le Hamiltonien de Hubbard bidimensionnel avec un terme de saut vers les deuxiemes voisins (modele tt'U). Le modele est etudie en utilisant l'approximation de la GRPA (Generalized Random Phase Approximation) et en incluant les effets de la renormalisation de l'interaction de Hubbard par les diagrammes de Brueckner-Kanamori. Dans l'approche presentee dans ce travail, les maximums du facteur de structure magnetique observes par les experiences de diffusion de neutrons sont associes aux anomalies 2k _{F} de reseau du facteur de structure des gaz d'electrons bidimensionnels sans interaction. Ces anomalies proviennent de la diffusion entre particules situees a des points de la surface de Fermi ou les vitesses de Fermi sont tangentes, et conduisent a des divergences dont la nature depend de la geometrie de la surface de Fermi au voisinage de ces points. Ces resultats sont ensuite appliques au modele tt'U, dont le modele de Hubbard usuel tU est un cas particulier. Dans la majorite des cas, les interactions ne determinent pas la position des maximums du facteur de structure. Le role de l'interaction est d'augmenter l'intensite des structures du facteur de structure magnetique associees a l'instabilite magnetique du systeme. Ces structures sont souvent deja presentes dans la partie imaginaire de la susceptibilite sans interaction. Le rapport d'intensite entre les maximums absolus et les autres structures du facteur de structure magnetique permet de determiner le rapport U_ {rn}/U_{c} qui mesure la proximite d'une instabilite magnetique. Le diagramme de phase est ensuite etudie afin de delimiter la plage de validite de l'approximation. Apres avoir discute des modes collectifs et de l'effet d'une partie imaginaire non-nulle de la self-energie, l'origine de l'echelle d'energie des fluctuations magnetiques est examinee

  5. A Comprehensive Numerical Study on Effects of Natural Gas Composition on the Operation of an HCCI Engine Une étude numérique complète sur les effets de la composition du gaz naturel carburant sur le réglage d’un moteur HCCI

    Directory of Open Access Journals (Sweden)

    Jahanian O.

    2011-11-01

    Full Text Available Homogeneous Charge Compression Ignition (HCCI engine is a promising idea to reduce fuel consumption and engine emissions. Natural Gas (NG, usually referred as clean fuel, is an appropriate choice for HCCI engines due to its suitable capability of making homogenous mixture with air. However, varying composition of Natural Gas strongly affects the auto-ignition characteristics of in-cylinder mixture and the performance of the HCCI engine. This paper has focused on the influence of Natural Gas composition on engine operation in HCCI mode. Six different compositions of Natural Gas (including pure methane have been considered to study the engine performance via a thermo-kinetic zero-dimensional model. The simulation code covers the detailed chemical kinetics of Natural Gas combustion, which includes Zeldovich extended mechanism to evaluate NOx emission. Validations have been made using experimental data from other works to ensure the accuracy needed for comparison study. The equivalence ratio and the compression ratio are held constant but the engine speed and mixture initial temperature are changed for comparison study. Results show that the peak value of pressure/temperature of in-cylinder mixture is dependent of fuel Wobbe number. Furthermore, engine gross indicated power is linearly related to fuel Wobbe number. Gross indicated work, gross mean effective pressure, and NOx are the other parameters utilized to compare the performance of engine using different fuel compositions. Le moteur HCCI (Homogeneous Charge Compression Ignition, ou à allumage par compression d’une charge homogène est une idée prometteuse pour réduire la consommation de carburant et les émissions polluantes. Le gaz naturel, considéré généralement comme un carburant propre, est un choix approprié pour les moteurs HCCI en raison de sa capacité à former avec l’air un mélange homogène. Cependant, la composition du gaz naturel influe fortement sur les caract

  6. Together on the same planet. Gaz de France and sustainable development in 2006

    International Nuclear Information System (INIS)

    2006-01-01

    This document presents the sustainable development policy of Gaz de France group. It identifies the challenges the group has to face in order to control the environmental impact of the Group's activities (exploration, production, procurement, re-gasification, transmission, storage, distribution, marketing and shares, services). The approach used is based on a voluntary commitment of the Group to dialogue and share current challenges with all its stakeholders, and to imagine other roads to development. The initiatives consist in clean production practices, development of renewable energy sources, energy conservation, investment in research, safety improvement, solidarity with underprivileged people, respect of local environment and of codes of conduct, accompanying local economic development and development of clean transport systems. (J.S.)

  7. Fusion special: E.ON/Ruhrgas, EDF/Gaz de France? Trends. Interview. Inquiry. Portrait

    International Nuclear Information System (INIS)

    Schneid, O.; Carbier, M.Ch.

    2003-01-01

    This issue of 'Energies news' newsletter comprises 6 articles dealing with: the E.ON/Ruhrgas fusion and the birth of a leader of the gas-electric power convergence in Europe (the serial story of the fusion, the compromise with the adverse parties); the key economical data of RWE; the proposal of fusion between EdF (Electricite de France) and Gaz de France (interview of M. Boiteux, honorary president of EdF); the reorganization of RWE activities in France (interview of R. Felgentreff, head of RWE Solutions France); travel inside the French power market (part.2: opening of the power market to all professionals); portrait of J. Masdeu-Arus, co-president of a study group at the French house of commons, who made a report about the economical and financial situation of EdF. (J.S.)

  8. Theory and Practice of a New Class of Equipment for Separation of Particulates from Gases: the Turbulent Flow Precipitator Le précipitateur turbulent : un nouveau type de dispositif de séparation de particules présentes dans un courant de gaz. Théorie et technologie

    Directory of Open Access Journals (Sweden)

    Dullien F. A. L.

    2006-12-01

    Full Text Available The main classes of separators of particulates from gases comprise inertial separators, filters, (wet scrubbers and electrostatic precipitators, each of which technique has its proper niche and each has its advantages and its disadvantages. In the present paper a new class of equipment, the turbulent flow precipitator (TFP for gas cleaning is described that, though at the present only in its infancy, is rapidly gaining popularity because it has some advantages over each and every known type of separator and it has very few limitations. TFPs are far more efficient for the removal of fine particles than inertial separators, unlike filters they do not plug up, they do not present secondary disposal problems and they require less maintenance (and are less expensive than electrostatic precipitators. They can be very efficient also in the submicron range of particle size and there are no practical limitations as far as high temperatures and/or corrosive atmospheres are concerned. They are equally suitable for the removal of solid and liquid particles from gases. Turbulent flow precipitators work on the principle of turbulent eddy penetration into deep regions where there is no net flow, where the eddies die out and where the fine particulates carried by the eddies deposit on collector surfaces. TFPs comprise two well defined regions:- straight, uniform and unobstructed flow passages in which the gas carrying the suspended fine particulates is passed in turbulent flow;- and adjacent collection regions where there is no net gas flow and where all of the separation of particles from the gas takes place. Hence, a TFP is a filter in which the separation of the particulates from the gas takes place outside the passages where the gas flows. Les principaux séparateurs de particules dans un courant de gaz existants sur le marché sont les séparateurs par inertie, les filtres, les laveurs et les électrofiltres. Chaque type de séparateur est destiné à une

  9. New combustion, environment regulations: the answers for natural gas; Nouvelles reglementations, combustion, environnement: les reponses pour le gaz naturel

    Energy Technology Data Exchange (ETDEWEB)

    Le Peltier-Marc, A. [Gaz de France (GDF), 75 - Paris (France)

    1997-12-31

    This paper reports on the point of view from Gaz de France (GdF) company concerning the potential consequences of the use of natural gas in combustion systems with respect to the new regulations about combustion and environment. Details concerning the measures relative to the limitation of pollutants in small combustion installations (2 - 20 MW) are given (chimney height, SO{sub x}, NO{sub x} and dusts content in exhaust gases). (J.S.)

  10. Visual Investigation of Retrograde Phenomena and Gas Condensate Flow in Porous Media Étude visuelle des phénomènes rétrogrades et de l'écoulement des gaz de condensat en milieux poreux

    Directory of Open Access Journals (Sweden)

    Danesh A.

    2006-11-01

    és avec des mélanges synthétiques d'hydrocarbures gazeux multicomposants, mais aussi avec un condensat naturel provenant de la mer du Nord. Le comportement en écoulement polyphasique des systèmes soumis à l'essai, observé et enregistré en vidéo, est présenté ici, accompagné des données mesurées. En milieu poreux mouillé à l'eau, on a observé que le condensat se forme en film mince continu sur l'eau connée, site préférentiel de condensation. En abaissant la pression au-dessous de la cricondenbar du système, on a provoqué la croissance du condensat presque exclusivement sur les anneaux d'eau à l'entrée des pores et sur les pores aveugles. On a constaté que le condensat passe à travers les films minces même en cas de saturation faible, sans que cela améliore sa récupération. Le rythme de la baisse de pression influence le cisaillement de l'écoulement de gaz et influence fortement, on l'a constaté, la propagation du condensat. Des instabilités localisées pourraient entraîner des mouvements importants du condensat dans certaines zones poreuses, mais en aval les effets capillaires exerceraient une action retardatrice qui diminuerait la récupération du condensat. On ne doit pas penser que les rapports entre la perméabilité relative et la saturation du gaz de condensat prendront la même forme que la perméabilité relative pétrole-gaz dans le cas de récupération par un gaz en solution ou un gaz injecté.

  11. Energy Equation Derivation of the Oil-Gas Flow in Pipelines Dérivation de l’équation d’énergie de l’écoulement huile-gaz dans des pipelines

    Directory of Open Access Journals (Sweden)

    Duan J.M

    2012-09-01

    well describe the oil-gas two-phase flow. Lors de la simulation d’un écoulement multiphasique huile-gaz dans une conduite, le calcul thermodynamique représente un processus important en interaction avec le calcul hydraulique; il influence la convergence du programme et la précision des résultats. La forme de l’équation d’énergie constitue la clef du calcul thermodynamique. Basée sur l’équation d’énergie de l’écoulement huile-gaz dans un pipeline, la formule de chute de température explicite (ETDF; Explicit Temperature Drop Formula est dérivée pour un calcul de température d’état stable huile-gaz. Cette nouvelle équation d’énergie prend en compte de nombreux facteurs, tels que l’effet Joule-Thomson, le travail de pression, le travail de frottement, ainsi que l’incidence des ondulations de terrain et le transfert de chaleur avec le milieu extérieur le long de la ligne. Ainsi, il s’agit d’une forme globale de l’équation d’énergie, laquelle pourrait décrire précisément la réalité d’un pipeline à phases multiples. Pour cette raison, un certain nombre de points de vue de la littérature à propos du calcul de température d’un écoulement diphasique huile-gaz dans des pipelines sont passés en revue. L’élimination de la boucle d’itération de température et l’intégration de l’équation de température explicite, au lieu de l’équation d’énergie d’enthalpie, dans le calcul conjugué hydraulique et thermique, se sont avérées améliorer l’efficacité de l’algorithme. Le calcul a été appliqué non seulement au modèle de composants mais aussi au modèle Black-Oil. Ce modèle est incorporé respectivement dans le modèle de composants ainsi que le modèle Black-Oil et deux simulations sont effectuées sur deux pipelines en service, les pipelines multiphasiques Yingmai-Yaha et Lufeng; les résultats de température sont comparés à la simulation calculée par OLGA et aux résultats mesurés. Il

  12. Vote par sondage uniforme incorruptible

    OpenAIRE

    Blanchard , Nicolas

    2016-01-01

    International audience; Introduit en 2012 par David Chaum, le vote par sondage uniforme (random-sample voting) est un protocole de vote basé sur un choix d'une sous-population représentative , permettant de limiter les coûts tout en ayant de nombreux avantages, principalement lorsqu'il est couplé a d'autres techniques comme ThreeBallot. Nous analysons un problème de corruptibilité potentielle où les votants peuvent vendre leur vote au plus offrant et proposons une variation du protocole reméd...

  13. Production of Methanol-Higher Alcohol Mixtures from Natural Gas via Syngas Chemistry Production de mélanges méthanol-alcools supérieurs à partir du gaz, via (CO + H2

    Directory of Open Access Journals (Sweden)

    Courty P.

    2006-11-01

    Full Text Available Despite the prevailing position of ethers (MTBE, TAME as octane boosters, and the low oil prices at present, alcohol synthesis remains one of the near future means of natural gas upgrading via syngas chemistry. After a review of the available process development data in the field, this paper focuses on the IFP process studies, based on the CuCo and CuNi catalysts developed by Institut Français du Pétrole (IFR, France and Idemitsu Kosan (Japan. The adequacy between the product specifications, and the optimization of the performances is then discussed in a technico-economic context, together with a presentation of lab scale, pilot scale and demonstration scale test results. As a conclusion, a prospective overall view brings together todays economics and some improvement guidelines dealing with investments, operating cost and catalyst performances. Cette publication présente les travaux de R & D (Recherche et Développement menés par l'Institut Français du Pétrole (IFP, France et Idemitsu Kosan (Japon en synthèse d'alcools. Elle situe les résultats dans le contexte technique et économique actuel. L'accroissement constant des ressources prouvées en gaz et, chronologiquement, les deux crises pétrolières, la suppression du plomb dans les essences, ont conduit le monde industriel à intensifier les recherches concernant la synthèse d'alcools. Très récemment, les effets bénéfiques de l'addition d'alcools sur les émissions de polluants ont été mis en évidence. Toutefois, l'additivation de carburants par les alcools est en voie de disparition au profit des éthers, alors que, indépendamment, les procédés de production d'ammoniac, de méthanol, d'acide acétique, également fondés sur le gaz, se sont seuls développés. La synthèse d'alcools a fait l'objet de nombreux travaux, résumés dans les tableaux 1 et 2. L'étude des différents aspects réactionnels amène à prendre en compte l'exothermicité importante des r

  14. Study of gases contained in an Antarctica glacier; Etude des gaz contenus dans un glacier antarctique

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-07-15

    This report presents a study of gases contained in ice samples taken from a drilling 97.8 meters deep in the coastal zone of Adelie Land (Antarctica). Simultaneously, a study has been made of the composition of the atmospheric air and of the gases extracted in situ from the firn. Carbon dioxyde was analysed by means of gas-phase chromatography and argon, oxygen and nitrogen by means of mass spectrometry. The results obtained show that for the most part the oxygen concentration decreases with an increase in the depth of the drilling. The values range from a maximum of 20,83 per cent of the volume at the surface to a minimum of 19,46 per cent of the volume at a depth of 87 meters. The results also show that the distribution of carbon dioxide concentration does not vary with the depth. These concentrations are either in the same range as or lower than the concentration of CO{sub 2} found in atmospheric air. The different results are discussed. (author) [French] Le present travail rend compte d'analyses de gaz contenus dans des echantillons de glace provenant d'un forage de 97,8 m de profondeur, realise dans la zone cotiere de la Terre Adelie (Antarctique). Parallelement, la composition d'air atmospherique et de gaz extraits in situ du neve a ete etudiee. La chromatographie en phase gazeuse a ete utilisee pour analyser le CO{sub 2} et la spectrometrie de masse pour analyser l'argon, l'oxygene et l'azote. Les resultats obtenus indiquent essentiellement le long du forage: - une decroissance de la teneur en oxygene avec la profondeur, les valeurs extremes etant de 20.83 pour cent en volume a la surface et de 19,46 pour cent en volume a - 87 metres, - une repartition des teneurs en CO{sub 2} sans correlation nette avec la profondeur, ces teneurs etant de l'ordre ou inferieures a la teneur atmospherique. Les differents resultats sont discutes. (auteur)

  15. Oxidation of iron and steels by carbon dioxide under pressure (1962); Oxydation du fer et des aciers par l'anhydride carbonique sous pression (1962)

    Energy Technology Data Exchange (ETDEWEB)

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

    1962-07-01

    After having developed one of the first thermo-balances to operate under pressure, we have studied the influence of the pressure on the corrosion of iron and steels by carbon dioxide. The corrosion was followed by three different methods simultaneously: by the oxidation kinetics, by micrographs, and by radiocrystallography. We have been able to show that the influence of the pressure is not negligible and we have provided much experimental evidence: oxidation kinetics, micrographic aspects, surface precipitation of carbon, metal carburization, the texture of the magnetite layer. All these phenomena are certainly modified by changes in the carbon dioxide pressure. In order to interpret most of our results we have been led to believe that the phenomenon of corrosion by CO{sub 2} depends on secondary reactions localised at the oxide-gas interface. This would constitute a major difference between the oxidation by CO{sub 2} and that by oxygen. (author) [French] Apres avoir etudie et mis au point une des premieres thermobalances fonctionnant sous pression, nous avons etudie l'influence de la pression sur la corrosion du fer et des aciers par l'anhydride carbonique. Notre etude a ete conduite simultanement sur trois plans differents: etude des cinetiques d'oxydation, etude micrographique et etude radiocristallographique. Nous avons pu montrer que l'influence de la pression n'etait pas negligeable et nous en avons fourni un faisceau de preuves experimentales important: cinetiques d'oxydation, aspect micrographique, precipitation superficielle de carbone, carburation du metal, texture de la couche de magnetite. Tous ces phenomenes sont sans aucun doute modifies par une variation de pression du gaz carbonique. Pour interpreter la plupart de nos resultats, nous avons ete conduits a penser que le phenomene de corrosion par CO{sub 2} etait tributaire de reactions secondaires localisees a l'interface oxyde-gaz. Ce serait la une des differences fondamentales entre l'oxydation par

  16. Par Pond Fish, Water, and Sediment Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Paller, M.H. [Westinghouse Savannah River Company, AIKEN, SC (United States); Wike, L.D.

    1996-06-01

    The objectives of this report are to describe the Par Pond fish community and the impact of the drawdown and refill on the community, describe contaminant levels in Par Pond fish, sediments, and water and indicate how contaminant concentrations and distributions were affected by the drawdown and refill, and predict possible effects of future water level fluctuations in Par Pond.

  17. Par Pond Fish, Water, and Sediment Chemistry

    International Nuclear Information System (INIS)

    Paller, M.H.; Wike, L.D.

    1996-06-01

    The objectives of this report are to describe the Par Pond fish community and the impact of the drawdown and refill on the community, describe contaminant levels in Par Pond fish, sediments, and water and indicate how contaminant concentrations and distributions were affected by the drawdown and refill, and predict possible effects of future water level fluctuations in Par Pond

  18. Gas transport through porous media; Sur le transport des gaz a travers les milieux poreux

    Energy Technology Data Exchange (ETDEWEB)

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

    1968-06-01

    In the first part of this work we derive a rigorous transport theory for a mixture of gases passing through a bed of spheres, when the temperature is uniform. We solve the Boltzmann equation, putting boundary conditions in the solution. Two different methods are used, according to the nature of the flow. The second part deals with the experimental work: measurements of permeability, of separation and of interdiffusion. In the last part, with the help of the new theory presented here, we are for the first time able to explain all the experimental data. (author) [French] Dans la premiere partie de ce travail nous developpons une theorie rigoureuse du transport d'un melange de gaz a travers un lit de spheres, quand la temperature est uniforme. Nous integrons l'equation de Boltzmann en introduisant des conditions aux limites dans la solution. Nous utilisons deux methodes differentes selon le regime d'ecoulement. La seconde partie est consacree a l'etude experimentale: mesures de permeametrie, de separation et d'interdiffusion. Dans la derniere partie, a l'aide de la nouvelle theorie developpee ici, nous expliquons tous les resultats experimentaux, ce qui n'avait pas ete fait jusque la. (auteur)

  19. Gas market is today strategical; Le marche du gaz est aujourd'hui strategique

    Energy Technology Data Exchange (ETDEWEB)

    Darricarrere, Y.L. [Total, 92 - Courbevoie (France)

    2006-07-01

    The energy market, and in particular the gas market, is today seething with excitement. In France, in Europe and in the rest of the world, the energy stakes are in the center of preoccupations. This article is an interview of Y.L. Darricarrere, general director of the gas and electricity division of Total group, who explains his opinions about the opening of European and French energy markets, presents the ambitions of Total group on these markets, and comments some recent events of the European energy scene: concentration between gas and electric utilities, the Suez and Gaz de France (GdF) project of merger, the risks linked with the coming in of national companies from producing countries, like Gazprom and Sonatrach, on the European market, the restriction of access of foreign companies to hydrocarbon reserves in Russia and Latin America (come back of the 'energy nationalism'), Total's policy for anticipating the increase of the world energy demand and the depletion of fossil fuel reserves. (J.S.)

  20. La projection par plasma : une revue

    Science.gov (United States)

    Fauchais, P.; Grimaud, A.; Vardelle, A.; Vardelle, M.

    are presented in the fields of aeronautics and mechanics. La qualité d'un dépôt projete par plasma dépend de nombreux paramètres que l'on commence à mieux appréhender du fait des progrès de la modélisation et de la métrologie tant des écoulements plasmas que des transferts plasma-particules ou que des conditions d'écrasement et de refroidissement des particules lors de leur impact sur le substrat ou les couches déjà déposées. Les techniques de mesure utilisdes et leurs limitations sont d'abord rappelées tant pour les jets de plasma que pour les particules en vol et l'importance des différents phénomènes intervenant dans les transferts plasma-particules est soulignée : gradients de température et de concentration d'espèces chimiques très élevés autour des particules, effets de propagation de la chaleur, notamment pour les particules céramiques, effet d'évaporation, effet de raréfaction sensible dès la pression atmosphérique. Les problèmes de distribution de taille et de vitesse d'injection des particules sont également abordés car ils conditionnent les distributions de trajectoires et donc le traitement des particules dans le jet de plasma. La génération du plasma montre d'une part 1'influence considérable de l'injection du gaz, de sa nature, du dessin de la chambre d'arc et de la tuyère ainsi que du pompage de l'air ambiant sur la longueur des jets de plasma d'arc et d'autre part les problèmes d'injection pour éviter le couplage avec la décharge dans les jets de plasmas R.E Tout ceci est illustré avec des exemples de dépôt d'alumine, de zircone, de cermet carbure et de nickel. L'écrasement des particules est ensuite abordé avec les problèmes de réactions chimiques, de trempe ultra-rapide et donc de structure cristalline des dépôts, d'adhdsion mais aussi de containtes résiduelles et de leur contrôle via les gradients de température dans les dépôts pendant le tir. Enfin quelques applications actuelles sont pr

  1. Dépollution des gaz d'échappement des moteurs diesel au moyen de pots catalytiques Depolluting Exhaust Gases from Diesel Engines by Catalytic Mufflers

    Directory of Open Access Journals (Sweden)

    Goldenberg E.

    2006-11-01

    Full Text Available On présente dans cet article les résultats d'une première série de recherches sur la dépollution des gaz d'échappement des moteurs diesel au moyen de pots catalytiques. L'efficacité des catalyseurs à base de platine pour l'oxydation du monoxyde de carbone et des hydrocarbures imbrûlés a pu être établie par des essais sur banc moteur et sur véhicule. L'emploi de certaines phases actives à base de métaux non nobles permet d'autre part d'abaisser la température de début d'oxydation des particules de suie de 380 à 250 °C environ, avec, entre 250 et 350 °C, élimination de 15 à 20 % des produits piégés. L'essai de divers media filtrants a mis en évidence l'importance des phénomènes d'adsorption des revêtements en alumine et a orienté la recherche vers de nouveaux supports pour filtres catalytiques. This article describes the results of a first series of research on the depollution of exhaust gases from diesel engines by catalytic mufflers. The effectiveness of platinum-base catalysts for the oxidation of carbon monoxide and unburned hydrocarbons was determined by test on an engine test bed and on vehicles on the road. The use of some active non-noble metal phases reduced on the other hand the starting oxidation temperature of soot particulates from 380°C to about 250°C, eliminating 15 to 20% of the trapped products between 250 and 350° C. Tests of different filtering media revealed the importance of adsorption phenomena on alumina coatings and directed research toward new supports for catalytic filters.

  2. Analytical methods used in plutonium purification cycles by trilaurylamine; Methodes analytiques utilisees dans les cycles de purification du plutonium par la trilaurylamine

    Energy Technology Data Exchange (ETDEWEB)

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

    1965-07-01

    The utilisation of trilaurylamine as a solvent extractant for the purification of plutonium has entailed to perfect a set of analytical methods which involves, various techniques. The organic impurities of the solvent can be titrated by gas-liquid chromatography. The titration of the main degradation product, the di-laurylamine, can be accomplished also by spectro-colorimetry. Potentiometry is used for the analysis of the different salts of amine-nitrate-sulfate-bisulfate as also the extracted nitric acid. The determination of the nitrate in aqueous phase is carried out by constant current potentiometry. The range of application, the accuracy and the procedure of these analysis are related in the present report. (author) [French] L'utilisation de la trilaurylamine comme solvant d'extraction pour la purification du plutonium a necessite la mise au point d'un ensemble de methodes analytiques qui ressortent de techniques diverses. Les impuretes organiques du solvant peuvent etre dosees par chromatographie gaz-liquide. Le dosage du principal produit de degradation, la dilaurylamine, peut egalement etre effectue par spectrocolorimetrie. La potentiometrie est utilisee pour les analyses des differents sels d'amine: nitrate, sulfate, bisulfate, ainsi que de l'acide nitrique extrait. La determination des nitrates en phase aqueuse est executee par potentiometrie a courant impose. Le domaine d'application, la precision et le mode operatoire de ces analyses sont indiques dans le present rapport. (auteur)

  3. Directed and persistent movement arises from mechanochemistry of the ParA/ParB system.

    Science.gov (United States)

    Hu, Longhua; Vecchiarelli, Anthony G; Mizuuchi, Kiyoshi; Neuman, Keir C; Liu, Jian

    2015-12-22

    The segregation of DNA before cell division is essential for faithful genetic inheritance. In many bacteria, segregation of low-copy number plasmids involves an active partition system composed of a nonspecific DNA-binding ATPase, ParA, and its stimulator protein ParB. The ParA/ParB system drives directed and persistent movement of DNA cargo both in vivo and in vitro. Filament-based models akin to actin/microtubule-driven motility were proposed for plasmid segregation mediated by ParA. Recent experiments challenge this view and suggest that ParA/ParB system motility is driven by a diffusion ratchet mechanism in which ParB-coated plasmid both creates and follows a ParA gradient on the nucleoid surface. However, the detailed mechanism of ParA/ParB-mediated directed and persistent movement remains unknown. Here, we develop a theoretical model describing ParA/ParB-mediated motility. We show that the ParA/ParB system can work as a Brownian ratchet, which effectively couples the ATPase-dependent cycling of ParA-nucleoid affinity to the motion of the ParB-bound cargo. Paradoxically, this resulting processive motion relies on quenching diffusive plasmid motion through a large number of transient ParA/ParB-mediated tethers to the nucleoid surface. Our work thus sheds light on an emergent phenomenon in which nonmotor proteins work collectively via mechanochemical coupling to propel cargos-an ingenious solution shaped by evolution to cope with the lack of processive motor proteins in bacteria.

  4. Case-book of all decisions taken by the Regie du gaz naturel from April 1, 1995 - March 31, 1996

    International Nuclear Information System (INIS)

    Precourt, L.; L'Heureux, L.

    1996-01-01

    All decisions taken by the Regie du gaz naturel du Quebec during the period of April 1, 1995 to March 31, 1996 were presented. The case-book includes all legal decisions concerning the supply, transmission and storage of natural gas delivered or intended for delivery by pipeline distribution in the Province of Quebec. The text of the Act, amendments and revisions to the Act, and summaries of Board decisions are provided in French and English. Also included are a number of indexes for ease of reference and a glossary of relevant terms

  5. Price cap regulation: the case of natural gas transport in the UK; La reglementation par price cap: le cas du transport de gaz naturel au Royaume Uni

    Energy Technology Data Exchange (ETDEWEB)

    David, L. [ATER, Paris-1 Univ., 75 (France)

    1999-09-01

    The transport and storage activities of British Gas company are controlled by a distinct organization named Transco. The access charges paid by the suppliers for the use of Transco's network are regulated by a price cap since October 1, 1994. However, Ofgas, the office of gas supply which is the regulation authority in charge of the control of competition and of British Gas activities, considers this control system as inefficient and has chosen a RPI (retail price index)-X (expected productivity factor)-type price cap for the control of gas transport tariffs. This has led to a disagreement between Transco and Ofgas which has delayed the implementation of the new system up to February 1998. This article compares the choices made by Ofgas for the control of gas transport tariffs with the economical theory. It recalls first, the reasons why the price cap appears as more efficient than the service cost regulation, the alternate method used by regulation authorities to control the tariffs of natural monopolies. Then, the difficulties linked with the implementation of the price cap for the transport of natural gas in the UK are analyzed in order to explain the reasons that led Ofgas to change its formula. Finally, the bases of an optimum hybrid formula are proposed. (J.S.)

  6. Craquage thermique des vapeurs de pyrolyse-gazéification de la biomasse en réacteur parfaitement auto-agité par jets gazeux

    OpenAIRE

    Baumlin , Sébastien

    2006-01-01

    Pyrolysis and gasification processes give rise to gases containing by-products such as condensable vapors (tars), aerosols, dust, sulfur compounds and inorganics which may considerably lower the efficiency of catalysts (if chemical synthesis is foreseen) or cause severe damages to motors and turbines (in case of electricity production). Hence, efficient gas treatments are needed. The experiments reported in the present work are related to thermal cracking of condensable vapors. These vapors a...

  7. Gazéification du GNL par cycle de Brayton associé à une boucle caloportrice et une pompe à chaleur

    OpenAIRE

    Hadid , Zoheir

    2012-01-01

    The market of liquefied natural gas (LNG) is growing and presents the advantage of diversifying supplies. The LNG is fed at a temperature of -162°C and at atmospheric pressure. The main objective of the thesis aims at the valorization of the LNG exergy during its gasification and heating before being delivered through the network. The thesis investigates a new concept of gasification that differs from the current developments by the use of ambient air as the only heat source and by partial va...

  8. Dust extraction from gas in cement kilns, using bag filters; Depoussierage des gaz de four cimentier par les filtres a manches

    Energy Technology Data Exchange (ETDEWEB)

    Harmegnies, M. [CALCIA, 78 - Guerville (France). Direction Technique

    1996-12-31

    After a review of regulations concerning cement plant emissions, the two main cement production techniques (dry and semi-dry processes) are described and the electrostatic and bag filter de-dusting techniques are compared. Examples of pilot applications of these techniques in two French cement plants are presented and operating results (performances, transient procedures, costs) are discussed

  9. Évolution d'un gaz quantique unitaire dans un potentiel harmonique variable: solution par changement d'échelle

    Science.gov (United States)

    Castin, Yvan

    2004-04-01

    A unitary quantum gas is a gas of quantum particles with a binary interaction of infinite scattering length and negligible range. It has been produced in recent experiments with gases of fermionic atoms by means of a Feshbach resonance. Using the Fermi pseudo-potential model for the atomic interaction, we show that the time evolution of such a gas in an isotropic three-dimensional time dependent harmonic trap is exactly given by a gauge and scaling transform. To cite this article: Y. Castin, C. R. Physique 5 (2004).

  10. Recherche documentaire par titrage automatique

    OpenAIRE

    Lopez , Cédric; Prince , Violaine; Roche , Mathieu

    2011-01-01

    Nous proposons dans cet article un système facilitant la recherche d'information dans un ensemble de documents textuels, basé sur le titrage (et sous-titrage) automatique. Ce dernier peut se révéler crucial, par exemple, dans le cadre de la problématique de l'accessibilité des pages web (norme W3C). Notre processus de titrage automatique consiste à extraire des syntagmes nominaux pertinents dans les textes, pouvant constituer des titres ou sous-titres candidats. Une approche originale combina...

  11. Comportment of various magnesium alloys in carbon dioxide under pressure, between 400 and 600 deg; Compatibilite de divers alliages de magnesium avec le gaz carbonique sous pression entre 400 et 600 deg

    Energy Technology Data Exchange (ETDEWEB)

    Darras, R; Baque, P; Chevilliard, C [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    'magnesium oxyde fritte'. Les echantillons, preleves dans des produits files, sont convenablement polis, deux etats de surface reproductibles etant realises a titre comparatif. Les essais ont ete effectues dans le gaz carbonique purifie, aux pressions de 25 et 60 atmospheres, et a des temperatures allant de 400 a 600, au moyen d'autoclaves speciaux en acier inoxydable, chauffes exterieurement. Leur duree est en general superieure a 1000 heures. Les equations des courbes d'augmentation de poids obtenues sont du type ({delta}p){sup n} = k.t (({delta}p en mg/cm{sup 2} et t en heures), l'exposant n etant voisin de 2, du moins jusqu'a 500 deg. C. En se referant a des resultats precedemment acquis quant a certains de ces materiaux exposes dans le gaz carbonique sous pression atmospherique et sous 15 atmospheres, il apparait que: 1) Pour un materiau determine: - a une pression donnee, l'oxydation augmente avec la temperature, - a une temperature donnee, l'oxydation augmente avec la pression, - dans les memes conditions de temperature et de pression, les resultats obtenus varient peu suivant les deux etats de surface etudies; 2) les alliages Mg-Zr presentent une resistance a l'oxydation amelioree par rapport au magnesium non allie; 3) l'alliage magnox est beaucoup moins avantageux dans le gaz carbonique que dans l'air, par rapport aux autres alliages. D'une facon generale, les courbes d'oxydation tendant vers un palier apres un certain temps d'exposition, la compatibilite de tous les alliages consideres avec le gaz carbonique apparait satisfaisante jusqu'a une temperature voisine de 500 deg. C, dans les conditions operatoires presentement definies; au dessus de 500 deg. C, des differences notables apparaissent entre les divers alliages, mais des phenomenes de sublimation interferent avec ceux d'oxydation, de sorte qu'un classement des divers materiaux ne peut etre base que sur leur resultante. (auteur)

  12. SECHAGE DE PRODUITS GRANULAIRES PAR DESHYDRATATION PAR DETENTES SUCCESSIVES (DDS)

    OpenAIRE

    Abdulla , Galal; Mellouk , Hamid; Belghit , Abdelhamid; Allaf , Karim

    2009-01-01

    International audience; Dans cette étude, nous avons évalué les performances d'un nouveau procédé de séchage dans le cas du liège en granulés. Ce procédé (La déshydratation par détentes successives : DDS) consiste à soumettre le matériau liège dans une chambre hermétique aux variations cycliques de la pression. Chaque cycle est composé d'une compression et d'une décompression. La phase de compression est réalisée en injectant de l'air comprimé à température ambiante provenant d'un compresseur...

  13. Construction of the core of the 'heavy water-gas' reactor EL 4; Structures du coeur du reacteur 'eau- lourde-gaz EL 4'

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, J L; Foulquier, H; Thome, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    problem of thermal insulation around a zirconium alloy liner tube. The neutron absorption equivalent is about 1, 1 mm of Al, and the mean loss around 2 p. 100 of the thermal power of the reactor. The methods proposed have proved practicable as a result of important research and developments on automatic remote control for all the operations which make up the sequences of mounting, demounting and repairing of the construction components. In particular the possibilities opened up by the new techniques of welding tubes from the inside have been extended to other problems connected with the assembling of a reactor. (authors) [French] Le coeur de ce reacteur est constitue par une cuve contenant l'eau lourde, cuve traversee d'une serie de tubes de force dans lesquels circule le gaz caloporteur sous pression de 60 at. Les specifications de depart qui ont joue un role important dans la conception de ces structures concernent des aspects de securite de fonctionnement (chargement du combustible par les deux faces du reacteur, remplacement des structures sur les deux faces du reacteur), des necessites neutroniques (absorption des structures minimum, pas du reseau, diametre des tubes de force) et des considerations thermiques (temperature de sortie 500 C). Ces specifications ont entraine une disposition horizontale des tubes de force et des problemes d'encombrement tres delicats qui ont elimine (pour les dimensions d'EL 4) toute possibilite de recourir a des compensateurs de dilatation sur les tubes de force. II s'ensuit un dessin de cuve semi-rigide dans lequel les tubes de force contribuent pour une part importante a la resistance mecanique de l'ensemble en jouant le role de tirant, d'ou des contraintes elevees sur les jonctions et tubes de force (et le choix des alliages de zirconium). Les structures comprennent le tube de force, les jonctions, l'isolement thermique et le tube de guidage. On expose brievement les moyens d'essais mis en oeuvre et les performances de ces diverses

  14. La preuve par le nombre

    Directory of Open Access Journals (Sweden)

    Hélène Verdier

    2012-04-01

    Full Text Available S’il en était besoin, la question des usages et de la finalité des résultats de l’inventaire général pourrait être abordée par le nombre : nombre d’œuvres répertoriées, de communes inventoriées, de clichés photographiques réalisés, de dossiers, de consultations des notices dans les bases de données… Les additions aujourd’hui sont éloquentes, mais elles laissent dans l’ombre le rôle de l’inventaire qui, en mettant en œuvre une démarche systématique de connaissance, participe à l’ identificatio...

  15. Etude d'un procédé d'hydroliquéfaction du charbon pour la production simultanée de gaz et de carburant . . . . . Studies of a Coal Hydrogenation Process to Produce CO-Currently Gas and Gasoline

    Directory of Open Access Journals (Sweden)

    Franckowiak S.

    2006-11-01

    Full Text Available Un des principaux moyens de réintroduire le charbon dans le marché énergétique français est de le transformer en produits utiles comme le gaz de réseau ou les carburants. Les procédés d'oxyvapogazéification permettent d'obtenir un gaz de synthèse qui peut être ensuite converti en gaz riche ou en produits liquides. L'hydrogénation en phase liquide (ou hydroliquéfaction se présente pour le long terme comme une seconde voie qui offre des avantages spécifiques - taux de conversion du charbon et rendement élevés, - production directe de gaz de substitution (GNS et de carburant, - possibilité d'utilisation d'hydrogène provenant de l'électricité nucléaire. Un programme d'étude a été lancé avec la participation du Gaz de France (GDF, du Centre d'études et de recherches des Charbonnages de France (Cerchar, de l'institut Français du Pétrole (lFP et du Centre National de la Recherche Scientifique (CNRS dans le cadre du Groupe d'Étude de la Conversion du Charbon par Hydrogénation (GECH. Un banc d'essai d'hydroliquéfaction situé au Cerchar, d'un débit de 10 kg/h de mélange charbon-solvant, permet d'obtenir des hydrogénats dans des conditions variées et en présence de divers catalyseurs. L'étude de la valorisation de ces hydrogénats est effectuée dans les laboratoires de l'lFP. Les essais et les études effectués permettent d'envisager la production à volonté du GNS, de carburants ou des deux ensemble. Un modèle d'optimisation a été réalisé au GDF pour étudier et comparer les différentes filières en prenant en compte l'utilisation d'hydrogène d'électrolyse ou d'hydrogène produit sur place à partir du résidu de liquéfaction. One of the main ways to bring coal in the future french energy market is to transform it into valuable products. The oxygen steam gasification processes give a synthesis gas which can be converted into SNG or gasoline in a catalytic stage. The liquid phase hydrogenation process is a

  16. Par Pond vegetation status Summer 1995 -- Summary

    International Nuclear Information System (INIS)

    Mackey, H.E. Jr.; Riley, R.S.

    1996-01-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the newly emergent, shoreline aquatic plant communities of Par Pond began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level. These surveys continued in July, September, and late October, 1995. Communities similar to the pre-drawdown, Par Pond aquatic plant communities are becoming re-established. Emergent beds of maidencane, lotus, waterlily, and watershield are extensive and well developed. Cattail occurrence continued to increase during the summer, but large beds common to Par Pond prior to the drawdown have not formed. Estimates from SPOT HRV, remote sensing satellite data indicated that as much as 120 hectares of emergent wetlands vegetation may have been present along the Par Pond shoreline by early October, 1995. To track the continued development of macrophytes in Par Pond, future surveys throughout 1996 and 1997, along with the continued evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned

  17. Dehumidification by dessiccant regenerated by natural gas at the Campeau ice rink in Gatineau; La deshumidification par dessiccant regenere par le gaz naturel a l'Arena Campeau de Gatineau

    Energy Technology Data Exchange (ETDEWEB)

    Lajoie, S.

    2003-03-01

    As air quality gains in importance, dehumidification by dessiccant represents an interesting technological solution, especially in ice rinks where bad air quality (carbon monoxide) is not unknown. Contrary to conventional technologies, dehumidification by dessiccant allows to maintain adequate levels of air quality and optimum humidity levels. Three major advantages are: improved user comfort, the building structure is protected from corrosion, and superior air quality levels are achieved. The document first provided the reader with a brief overview of conventional mechanical dehumidification systems before discussing dehumidification by natural gas dessiccant. A quick historical review of the Campeau ice rink in Gatineau, Quebec was provided, including results obtained. The article concluded by indicating that the technology offers interesting potential for ice rinks. Energy savings are made possible through the utilization of this technology, and improves revenues by stretching operations for longer periods. 1 tab., 1 fig.

  18. Contribution to the analysis of light elements using x fluorescence excited by radio-elements; Contribution a l'analyse des elements legers par fluorescence x excitee au moyen de radioelements

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-07-01

    In order to study the possibilities of using radioactive sources for the X-fluorescence analysis of light elements, the principle is given, after a brief description of X-fluorescence, of the excitation of this phenomenon by X, {beta} and {alpha} emission from radio-elements. The operation and use of the proportional gas counter for X-ray detection is described. A device has been studied for analysing the elements of the 2. and 3. periods of the Mendeleev table. It makes it possible to excite the fluorescence with a radioactive source emitting X-rays or a particles; the X-ray fluorescence penetrates into a window-less proportional counter, this being made possible by the use of an auxiliary electric field in the neighbourhood of the sample. The gas detection pressure leading to the maximum detection yield is given. The spectra are given for the K{sub {alpha}} lines of 3. period elements excited by {sup 55}Fe, {sup 3}H/Zr and {sup 210}Po sources; for the 2. period the K{sub {alpha}} spectra of carbon and of fluorine excited by the {alpha} particles of {sup 210}Po. (author) [French] Afin d'etudier les possibilites d'emploi de sources radioactives a l'analyse par fluorescence X des elements legers, on presente apres rappel de notions generales sur la fluorescence X, le principe de l'excitation de ce phenomene par emission X, {beta}, {alpha} de radioelements. Le fonctionnement et l'utilisation du compteur proportionnel a gaz a la detection du rayonnement X est developpe. Un dispositif permettant l'analyse des elements des 2eme et 3eme periodes de la classification de Mendeleev est etudie. Il permet l'excitation de la fluorescence par source radioactive emettrice de rayons X ou de particules {alpha}; le rayonnement X de fluorescence penetre dans un compteur proportionnel depourvu de fenetre, ceci est rendu possible en creant un champ electrique auxiliaire au voisinage de l'echantillon. On definit une pression du gaz de detection pour un rendement de detection maximal

  19. Contribution to the analysis of light elements using x fluorescence excited by radio-elements; Contribution a l'analyse des elements legers par fluorescence x excitee au moyen de radioelements

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-07-01

    In order to study the possibilities of using radioactive sources for the X-fluorescence analysis of light elements, the principle is given, after a brief description of X-fluorescence, of the excitation of this phenomenon by X, {beta} and {alpha} emission from radio-elements. The operation and use of the proportional gas counter for X-ray detection is described. A device has been studied for analysing the elements of the 2. and 3. periods of the Mendeleev table. It makes it possible to excite the fluorescence with a radioactive source emitting X-rays or a particles; the X-ray fluorescence penetrates into a window-less proportional counter, this being made possible by the use of an auxiliary electric field in the neighbourhood of the sample. The gas detection pressure leading to the maximum detection yield is given. The spectra are given for the K{sub {alpha}} lines of 3. period elements excited by {sup 55}Fe, {sup 3}H/Zr and {sup 210}Po sources; for the 2. period the K{sub {alpha}} spectra of carbon and of fluorine excited by the {alpha} particles of {sup 210}Po. (author) [French] Afin d'etudier les possibilites d'emploi de sources radioactives a l'analyse par fluorescence X des elements legers, on presente apres rappel de notions generales sur la fluorescence X, le principe de l'excitation de ce phenomene par emission X, {beta}, {alpha} de radioelements. Le fonctionnement et l'utilisation du compteur proportionnel a gaz a la detection du rayonnement X est developpe. Un dispositif permettant l'analyse des elements des 2eme et 3eme periodes de la classification de Mendeleev est etudie. Il permet l'excitation de la fluorescence par source radioactive emettrice de rayons X ou de particules {alpha}; le rayonnement X de fluorescence penetre dans un compteur proportionnel depourvu de fenetre, ceci est rendu possible en creant un champ electrique auxiliaire au voisinage de l'echantillon. On definit une pression du gaz de detection

  20. ¡París!

    Directory of Open Access Journals (Sweden)

    Beatriz Caballero

    2003-01-01

    Full Text Available El día no le alcanzaba para caminarlo. Conocía cada puente, cada calle,plaza, museo, rincón, iglesia, café, y la mesa con el mejor ángulo para mirar siempre una iglesia, ojalá Saint-Germain-des-Pres, o Notre-Dame. Siempre contaba la impresión que le había causado a Bolívar ver allí cuando el papa coronó a Napoleón. Él se iba para la oficina todos los días, Luis a un taller a pintar, Antonio a estudiar ciencias políticas, yo al colegio y mamá hacía las cosas prácticas. Aprendíamos francés todos al tiempo y por la noche nos contábamos lo nuevo que cada uno había aprendido. Mamá después, cuando ya se quería volver, decía que París nos había maleado a todos. Estaba en pleno furor el cine francés de la "nueva ola", pero ella sólo me llevaba a ver películas de vaqueros pues no se fiaba de la clasificación de los periódicos.

  1. Suez-Gaz de France merger, E.ON's public takeover bid on Endesa... The new energy fight

    International Nuclear Information System (INIS)

    Lepetit, V.; Rouaud, P.O.; Mairet, C.

    2006-01-01

    The energy sector is in fever. In less than a week (February 21 to 26, 2006), the Europe of energy has fallen into a frenzy of mergers and acquisitions: the German E.ON offered 29.1 billion euros to get the Spanish Endesa, Electricite de France (EdF), who already got the Italian Edison in 2005, is ready for more major acquisitions, the Italian Enel is candidate for the repurchasing of Suez, while Gaz de France (GdF) and Suez have started a surprise merger. The stake of this match between giants is their growing up and the penetration of foreign markets before their complete liberalization in July 2007. The potential victims of these actions are the competition and the clients, the industrial ones first. (J.S.)

  2. Some economic aspects of natural uranium graphite gas reactor types. Present status and trends of costs in France; Quelques aspects economiques de la filiere uranium naturel - Graphite - gaz. Etat actuel et tendance des couts en France

    Energy Technology Data Exchange (ETDEWEB)

    Gaussens, J; Tanguy, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Leo, B [Electricite de France (EDF), 75 - Paris (France)

    1964-07-01

    reduction in investment costs can be obtained without relying on fuel enrichment, and that this development is accompanied moreover by improvements in the operational safety of the reactor. The economic aspects of the main technical problems entailed by these developments are discussed: loading and unloading machines, blowers etc... (authors) [French] Dans une premiere partie, on situe l'interet economique de l'utilisation de l'uranium naturel comme combustible. Cet interet reside a la fois dans le nombre limite et la simplicite relative des operations de mise en forme des elements combustibles, dans le faible cout du produit fini par kwh et dans les immobilisations modestes en capital qu'implique ce cycle par rapport ou cycle de l'uranium enrichi. Tous ces elements permettent de reduire le caractere aleatoire des evaluations des couts, particulierement marque dans le cas de l'uranium enrichi, en raison de la complexite de son cycle et des incertitudes concernant le prix du plutonium. Enfin, la diversite des sources d'approvisionnement en concentre d'uranium naturel opposee au quasi monopole actuel de la separation isotopique, et le faible cout du stockage de ce concentre, offrent des garanties en matiere de securite d'approvisionnement et d'independance economique et politique appreciables par rapport a l'uranium enrichi. En ce qui concerne l'ensemble des capitaux immobilises, on montre que si le cout des centrales au graphite-gaz est plus eleve que celui des centrales eau legere pour certaines gammes de puissance, ce resultat est fortement nuance des que l'on fait intervenir dans un souci d'independance nationale le cout de l'equipement de production des combustibles de l'une et l'autre filiere. Enfin, le cout marginal de la puissance du reacteur au graphite est faible, ses limitations technologiques ont considerablement recule (grace en particulier a l'utilisation du beton precontraint). On sait que la tendance actuelle est a l'accroissement de la puissance unitaire des

  3. 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

    Full Text Available sAn indirect method to map the burned gases in SI engine has been developed. It is based on visualisation by Laser Induced Fluorescence of the unburned mixture seeded with biacetyl. Both internally and externally recirculated burned gases are monitored. This diagnostic is complementary to the LIF technique applied to measure the gasoline distribution. These LIF gasoline and burned gases measurements are applied in a 4-valve optical access SI engine for a large range of operating conditions. These include variations of both fuel injection and burned gas recirculation modes causing different types of stratification leading to very distinct heat release and exhaust emissions characteristics. Tumble level and spark location are also modified. The observation of the actual stratification in the engine forms a sound basis explanation of the engine performance. Parameters allowing an optimisation of NOx and HC levels can be inferred, and in particular the effectiveness of recirculation and fuel injection strategies. The conclusions are confirmed by measurements in a single engine cylinder conventional head with the same geometry. Une méthode indirecte pour cartographier les gaz brûlés dans un moteur à allumage commandé a été développée. Elle est fondée sur une visualisation à partir de la fluorescence induite par laser (LIF du mélange air-carburant non brûlé et ensemencé avec du biacétyl. Les gaz brûlés provenant à la fois des recirculations internes et externes sont observés. Ce type de diagnostic est complémentaire des techniques de LIF utilisées pour observer la distribution du carburant. Ces mesures de concentration sont réalisées dans un moteur à 4 soupapes avec accès optiques, pour une gamme étendue de conditions opératoires. Celles-ci comprennent des variations des modes d'injection du carburant et des modes de recirculation des gaz brûlés, provoquant ainsi différents types de stratifications qui correspondent

  4. Natural gas air conditioning in the tertiary sector. Ambitions, realizations and tools; Climatisation au gaz naturel dans le tertiaire. Ambitions, realisations et outils

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-04-01

    This meeting, organized by the research center of Gaz de France (Cegibat), makes a status of the market of natural gas air conditioning in office and public buildings: experience feedback, improvements of the technology, available tools. After a brief presentation of the status and perspectives of this market in France, the representatives of different companies involved in the fitting of natural gas air conditioning systems present their point of view about this technology. A last part presents the 'climogaz.com' tool launched by Gaz de France. It consists in a web site devoted to the share of knowledge and experience about this technology between professionals and applied to hotels, swimming pools, office buildings, food trade and other trades. (J.S.)

  5. Graphite suspension in carbon dioxide; Suspension de graphite dans le gaz carbonique

    Energy Technology Data Exchange (ETDEWEB)

    Roche, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Moussez, C; Rouvillois, X; Brevet, R [Societe Nationale d' Etude et de Construction de Moteurs d' Aviation (SNECMA), 75 - Paris (France)

    1965-07-01

    Since 1963 the Atomic Division of SNECMA has been conducting, under a contract with the CEA, an experimental work with a two-component fluid comprised of carbon dioxide and small graphite particles. The primary purpose was the determination of basic engineering information pertaining to the stability and the flowability of the suspension. The final form of the experimental loop consists mainly of the following items: a light-phase compressor, a heavy-phase pump, an electrical-resistance type heater section, a cooling heat exchanger, a hairpin loop, a transparent test section and a separator. During the course of the testing, it was observed that the fluid could be circulated quite easily in a broad range of variation of the suspension density and velocity - density from 30 to 170 kg/m{sup 3} and velocity from 2 to 24 m/s. The system could be restarted and circulation maintained without any difficulty, even with the heavy-phase pump alone. The graphite did not have a tendency to pack or agglomerate during operation. No graphite deposition was observed on the wall of the tubing. A long period run (250 hours) has shown the evolution of the particle dimensions. Starting with graphite of surface area around 20 m{sup 2}/g (graphite particles about 1 {mu}), the powder surface area reaches an asymptotic value of 300 m{sup 2}/g (all the particles less than 0.3 {mu}). Moisture effect on flow stability, flow distribution between two parallel channels, pressure drop in straight tubes, recompression ratio in diffusers were also investigated. (author) [French] Depuis 1963 la Division Atomique de la SNECMA conduit, dans le cadre d'un contrat avec le Commissariat A l'Energie Atomique, l'etude experimentale d'une suspension de fines particules de graphite dans le gaz carbonique. L'objectif principal est d'obtenir des informations d'ordre mecanique et technologique sur la mise en oeuvre de l'ecoulement de ce fluide diphase. Le circuit experimental comprend principalement: un

  6. Fixation à haute et moyenne température de l'hydrogène sulfuré par des masses de captation régénérables Hydrogen-Sulfide Fixation At High and Medium Temperature by Regenerable Capture Masses

    Directory of Open Access Journals (Sweden)

    Hotier G.

    2006-11-01

    Full Text Available L'intérêt de la désulfuration haute température comparée à la même opération conduite à basse température est renforcé quand la désulfuration a lieu entre deux opérations de niveau thermique élevé comme la gazéification du charbon et la production d'électricité par cycles combinés turbine à gaz-turbine à vapeur. Les masses absorbantes à base d'oxyde de fer peuvent réaliser une bonne désulfuration mais résistent mal aux chocs thermiques. Un agent de régénération particulièrement efficace est le dioxyde de soufre qui peut réoxyder le sulfure de fer par une réaction légèrement endothermique. Un des principaux avantages de cette réaction est la production directe de soufre élémentaire. Ses désavantages sont une faible conversion par passe et la sulfatation de l'oxyde de calcium (une des nombreuses impuretés des boues rouges qui composent la masse. Lorsque l'on emploie de la vapeur pour diluer le SO2 deux autres réactions ont lieu. La production de soufre est augmentée et la sulfatation disparaît. Les productions principales du procédé sont du soufre élémentaire et de la vapeur haute pression. On rencontre deux zones de réactions (l'une de captation, l'autre de régénération séparées par un tampon de gaz inerte et une circulation de la masse. Aucune autre unité de traitement de soufre n'est requise sur le site. Une évaluation économique préliminaire montre que ce procédé est compétitif lorsqu'on le compare à un lavage des gaz par solvant, à froid. The interest of a high temperature unit compared to a low temperature one is enhanced when desulphurization takes place between two hotoperations like coal gasification and power generation by combined cycles. Iron oxide based sorbents such as redmuds can achieve good desulphurization but cannot withstand high temperature gradients. An efficient regenerating agent is sulphur dioxide. SO2 can regenerate iron sulphide with a slightly endothermic

  7. The performances of natural gas infrared radiation in paints baking; Les performances de l`infrarouge gaz pour la cuisson des peintures

    Energy Technology Data Exchange (ETDEWEB)

    Lourdou, I. [Gaz de France, 75 - Paris (France). Centre d`essais de recherches sur les utilisations du gaz

    1998-04-01

    The direction of research of Gaz de France (GdF) company, in association with the centre for technical studies of aeraulic and thermal industries (CETIAT), has carried out infrared radiation baking tests on real painted parts using natural gas burners. Tests were performed on the Erica test facility. The development of the use of infrared gas burners in the mechanical industry requires an optimum use of this technology in the baking cycle. (J.S.)

  8. C9.A/14 steelwork joints de poutres par plaque frontale : assemblages par gousset

    CERN Document Server

    2015-01-01

    Les Tables de résistances ultimes des assemblages boulonnés par plaque frontale et par gousset, complétées par une description des modèles de calcul et des exemples d’application, ont pour but de faciliter la tâche de l'ingénieur et du constructeur. Cette première partie C9.A/14 contient les chapitres suivants: - Joints de poutres par plaque frontale en acier S235 et S355 - Assemblages par gousset en acier S235 et S355 Les Tables contiennent des données relatives à la géométrie ainsi que les valeurs de calcul correspondantes des résistances ultimes des assemblages ; elles remplacent le chapitre « Assemblages par plaques frontales et boulons HR » des anciennes Tables C9.1 de 1983 / 2002. Le calcul de ces assemblages par plaque frontale est basé sur les hypothèses du modèle de la méthode des composants décrite dans la norme SN EN 1993-1-8. Les vérifications sont effectuées selon la norme SIA 263:2013. Les assemblages par gousset remplacent les assemblages par double cornière, (telle...

  9. Séparation par membranes organiques : applications et prévisions de marché dans l'industrie pétrolière et pétrochimique Separation by Organic Membranes: Applications and Market Outlook in the Petroleum and Petrochemical Industry

    Directory of Open Access Journals (Sweden)

    Arlie J. P.

    2006-11-01

    Full Text Available Les principales applications des membranes en séparation portent aujourd'hui sur la perméation gazeuse : récupération de l'hydrogène sous haute pression en raffinage (hydrocraquage, en pétrochimie (synthèse de l'ammoniac, enrichissement du gaz de synthèse; traitement du gaz naturel (élimination des gaz acides, récupération du CO2 pour récupération assistée, extraction de l'hélium. En matière de purification de l'eau de mer, la technique d'osmose inverse est limitée à des capacités de 10 000 m3/j pour des raisons d'économie d'échelle. Le marché des membranes est en forte croissance, 10 % et plus en moyenne annuelle, essentiellement pour les applications déjà implantées industriellement, qui déplacent ou complètent par association les technologies classiques de séparation. The principal applications of separation membranes now have to do with gaseous permeation such as high-pressure hydrogen recovery in refining (hydrocracking and in petrochemistry (ammonia synthesis, enrichment of synthetic gas; the processing of natural gas (sour-gas removal, CO2 recovery for enhanced recovery, helium extraction. For seawater purification, the technique of reverse osmosis is limited to capacities of 10 000 m3/d for reasons of economy of scale. The market for membranes is increasing strongly, at a rate of 10% and more for the yearly average, mainly for applications that are already industrially installated and that are moved or completed by the adding on of conventional separation technologies.

  10. Influence de la pression et de la non-idéalité des gaz dans le calcul d'un réacteur d'ammoniac Influence of Gas Pressure and Non-Iddeality on Designing an Ammonia Reactor

    Directory of Open Access Journals (Sweden)

    Scheiderman B.

    2006-11-01

    Full Text Available Le mélange gazeux qui parcourt un réacteur de synthèse d'ammoniac présente des écarts notables par rapport aux gaz idéaux. On a établi les équations de calcul d'un réacteur à gradient thermique optimum en tenant compte de l'influence de ces écarts sous trois pressions d'opération (150, 300 et 500 atm.. On a vérifié que les corrections principales à effectuer sont dues à la fugacité; les autres sont d'une importance moindre, et affectent surtout le contrôle du réacteur. En outre, on a mis en évidence l'influence considérable de la pression totale. The gaseous mixture flowing through an ommonia synthesis reactor shows considerable divergences from the behovior of ideal gases. These divergences are examined at three operating pressures (150, 300 and 500 atm, and the corresponding design equations for an optimum temperature progression are determined. The main diver gences are those caused by fugacity. The others are of lesser importance. At the same time, the great influence of total pressure is demonstrated.

  11. The Hydrodynamic Characteristics of Cocurrent Downflow and Cocurrent Upflow Gas-Liquid-Solid Catalytic Fixed Bed Reactors: the Effect of Pressure Les caractéristiques hydrodynamiques des réacteurs gaz-liquide-solide à lit de catalyseur fixe à écoulement cocourant montant et descendant : l'influence de la pression

    Directory of Open Access Journals (Sweden)

    Wild G.

    2006-11-01

    ésultats de quelques années de recherches expérimentales sur les caractéristiques hydrodynamiques des réacteurs à écoulement cocourant ruisselant et enfin de réacteurs en cocourant montant. Au cours des dernières années, des résultats ont également pu être obtenus sous des pressions pouvant aller jusqu'à 8 MPa, les mesures étant faites à petite échelle (23 mm de diamètre dans une maquette froide. Différents liquides aqueux et organiques plus ou moins visqueux, éventuellement inhibiteurs de coalescence, 4 gaz et un certain nombre de particules plus ou moins mouillables non poreuses ont été utilisés. La rétention liquide a, dans tous les cas, été déterminée en mesurant la distribution des temps de séjour de la phase liquide, à l'aide de différents traceurs. Les conclusions suivantes ont pu être tirées : - Pour le régime à forte interaction, c'est l'inertie du gaz et des phases liquides qui constitue la cause principale de la dissipation d'énergie mécanique. Dans ce régime, les résultats obtenus en cocourant montant et descendant sont à peu près identiques. - La plupart des corrélations relevées dans la littérature ne permettent pas de prévoir l'influence de la pression sur la chute de pression ou la retenue liquide. - La viscosité du gaz n'influence pas l'hydrodynamique. Il est donc possible de simuler, par exemple, l'hydrogène sous forte pression par un autre gaz de même densité (à pression beaucoup plus basse. Une étude critique des corrélations et/ou des modèles de la littérature est présentée du point de vue de leur aptitude à représenter les différentes caractéristiques en fonction de la pression.

  12. Protease-activated receptor (PAR)-2 is required for PAR-1 signalling in pulmonary fibrosis

    NARCIS (Netherlands)

    Lin, Cong; von der Thüsen, Jan; Daalhuisen, Joost; ten Brink, Marieke; Crestani, Bruno; van der Poll, Tom; Borensztajn, Keren; Spek, C. Arnold

    2015-01-01

    Idiopathic pulmonary fibrosis is the most devastating diffuse fibrosing lung disease of unknown aetiology. Compelling evidence suggests that both protease-activated receptor (PAR)-1 and PAR-2 participate in the development of pulmonary fibrosis. Previous studies have shown that bleomycin-induced

  13. Apport de la géostatistique à la description des stockages de gaz en aquifère Contribution of Geostatistics to Describing Aquifer Gas-Storage Reservoirs

    Directory of Open Access Journals (Sweden)

    Delhomme J. P.

    2006-11-01

    Full Text Available L'étude du comportement d'un réservoir de gaz en nappe aquifère réclame une connaissance aussi précise que possible des caractéristiques géométriques et pétrophysiques des couches réservoirs. Les moyens d'investigation sont de deux natures : - forages permettant une connaissance locale des roches réservoirs ; - mesures sismiques conduisant à une estimation approximative des cotes de certains repères stratigraphiques, en des points situés le long de profils. Les données recueillies sont donc, par nature, fragmentaires et discrètes : là où elles sont absentes, il y a lieu d'estimer les grandeurs étudiées en tenant compte au mieux de notre connaissance de leur variabilité spatiale. Ce problème d'interpolation optimale a donné lieu, depuis une vingtaine d'années, à l'élaboration et la mise en pratique d'un outil théorique particulièrement bien adapté aux besoins exprimés par les techniciens des sciences de la terre : la théorie des variables régionalisées due à G. Matheron. Des programmes informatiques mettant en oeuvre cette théorie sont actuellement opérationnels. Des exemples d'application en sont donnés : - tracé automatique de cartes structurales à partir des données de forages et des mesures sismiques ; - estimation des incertitudes de prévision sur les profondeurs ; - tracé de plusieurs variantes de carte compatibles avec les données ; - établissement d'éléments statistiques relatifs à une grandeur caractéristique d'un stockage : volume stockable par exemple ; - génération automatique des données nécessaires à la mise en oeuvre d'un modèle maillé de réservoir. Predicting and monitoring the behavior of an aquifer gas-storage reservoir requires as precise a knowledge as possible of the geometric and petrophysical properties of the reservoir layer. Two ways of obtaining this information can be given: (a Boreholes which provide local knowledge of the reservoir, and (b Seismic measurements

  14. Production of Olefins and Higher Hydrocarbons by Thermal Coupling of Methane Production d'oléfines et d'hydrocarbures supérieurs par couplage thermique du méthane

    Directory of Open Access Journals (Sweden)

    Weill J.

    2006-11-01

    Full Text Available Thermal coupling of methane or methane pyrolysis, which is a possible way for the direct chemical conversion of natural gas, can be used to produce ethylene, acetylene and benzene. But the high stability of methane requires a very high pyrolysis temperature (1200°C. To perform this reaction, IFP decided to build and elecric pilot furnace with an overall capacity of 10 m3/h. The design of this furnace is based on shell-and-tube heat exchanger technology with the use of new materials such as ceramics. This furnace has now been operating for more than one year without any noteworthy incident. First we will describe the technological and parametric study that has now been completed. In conclusion, we will make a short economic assessment of the production of ethylene and acetylene in France. Dans le domaine de la conversion du gaz naturel en hydrocarbures supérieurs, il nous a paru intéressant de reconsidérer la pyrolyse du méthane. Contrairement au couplage oxydant [1, 2], il s'agit d'une réaction très ancienne [3] n'ayant fait l'objet que de travaux épisodiques dans le passé [4, 5]. En effet, compte-tenu de sa réactivité très faible, le méthane doit être porté à très haute température, de l'ordre de 1 200°C, pour produire par couplage thermique principalement de l'éthylène de l'acétylène, du benzène, du coke et de l'hydrogène. Ce qui a gouverné notre démarche et la reprise de travaux sur cette réaction, était l'idée que les nouvelles technologies et spécialement les nouveaux matériaux réfractaires tels que les matériaux céramiques devaient permettre de réaliser de nouveaux designs de réacteurs pour mettre en oeuvre cette réaction. Lors d'une étude paramétrique préliminaire [8], réalisée sur un micro-pilote de faible capacité (50 l/h, nous avons pu obtenir des résultats intéressants, parmi lesquels nous avons sélectionné un bilan matière moyen , qui représente un compromis entre les imp

  15. No 3017. Resolution proposal aiming at creating an inquiry commission relative to the project of merger between Gaz de France and Suez, to the conditions of its preparation and announcement and to the consequences of Gaz de France privatization on users and on the energy market balance

    International Nuclear Information System (INIS)

    Balligand, J.P.; Ayrault, J.M.; Hollande, F.; Besson, E.; Migaud, D.; Emmanuelli, H.; Brottes, F.; Bataille, Ch.; Ducout, P.; Gaubert, J.; Habib, D.

    2006-04-01

    On February 25, 2006, the French government took the decision of merging together Gaz de France and Suez energy companies as an answer to Enel's project of takeover bid on Suez. This document wonders about: the real motivations of Gaz de France (the French gas utility) privatization, the possible intervention of public authorities in Enel and Veolia companies project of controlling the Suez group, the governing way of the share-holding government and the preservation of its industrial interests, and the consequences for consumers. Therefore, the creation of a parliamentary inquiry commission is requested to shade light on these different points and to give notice of any bad practices in this affair. (J.S.)

  16. ParA and ParB coordinate chromosome segregation with cell elongation and division during Streptomyces sporulation

    Science.gov (United States)

    Donczew, Magdalena; Mackiewicz, Paweł; Wróbel, Agnieszka; Flärdh, Klas; Zakrzewska-Czerwińska, Jolanta

    2016-01-01

    In unicellular bacteria, the ParA and ParB proteins segregate chromosomes and coordinate this process with cell division and chromosome replication. During sporulation of mycelial Streptomyces, ParA and ParB uniformly distribute multiple chromosomes along the filamentous sporogenic hyphal compartment, which then differentiates into a chain of unigenomic spores. However, chromosome segregation must be coordinated with cell elongation and multiple divisions. Here, we addressed the question of whether ParA and ParB are involved in the synchronization of cell-cycle processes during sporulation in Streptomyces. To answer this question, we used time-lapse microscopy, which allows the monitoring of growth and division of single sporogenic hyphae. We showed that sporogenic hyphae stop extending at the time of ParA accumulation and Z-ring formation. We demonstrated that both ParA and ParB affect the rate of hyphal extension. Additionally, we showed that ParA promotes the formation of massive nucleoprotein complexes by ParB. We also showed that FtsZ ring assembly is affected by the ParB protein and/or unsegregated DNA. Our results indicate the existence of a checkpoint between the extension and septation of sporogenic hyphae that involves the ParA and ParB proteins. PMID:27248800

  17. Contamination potentielle des aliments par des ...

    African Journals Online (AJOL)

    SARA Computers

    la notion de la pollution et de l'exposition aux PCBs, lorsque 77% n'ont pas conscience de cette situation de risque ... 2018). Quoique la contamination par les. PCBs soit de faible niveau, elle est ...... Université Paris-Est, Paris, France ; 183.

  18. Geochemical Study of Natural CO2 Emissions in the French Massif Central: How to Predict Origin, Processes and Evolution of CO2 Leakage Étude géochimique des émissions naturelles de CO2 du Massif Central : origine et processus de migration du gaz

    Directory of Open Access Journals (Sweden)

    Battani A.

    2010-05-01

    de surveillance des futurs sites de stockage de CO2. Au cours des campagnes de terrain, nous avons analysé des flux de CO2 entre le sol et l’atmosphère, et nous avons prélevé et analysé à la fois des gaz des sols, et du gaz provenant de sources carbo-gazeuses, présentes dans toute la région. Un dispositif de « monitoring continu » dans le temps a également été testé, afin d’enregistrer conjointement les teneurs en CO2 de l’atmosphère et dans le sol en un point précis. Nous avons pu mettre au point un suivi géochimique basé sur la composition isotopique des gaz rares prélevés dans les sols. L’ensemble de nos résultats, confronté à la géologie de terrain, nous a permis de mettre en évidence l’origine mantellique du CO2. Ce CO2 remonte rapidement à la surface à l’état gazeux, le long de failles normales et/ou décrochantes, actives actuellement. Les teneurs et flux de CO2 dans le sol sont spatialement variables et élevés, et montrent également une origine mantellique. Les teneurs atmosphériques semblent faiblement augmenter par rapport à l’important dégazage observé dans la région.

  19. CFD analysis of PAR performance as function of inlet design

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kweonha, E-mail: khpark@kmou.ac.kr [Division of Mechanical and Energy systems Engineering, Korea Maritime University, Dongsam-dong, Yeongdo-gu, Busan 606-791 (Korea, Republic of); Khor, Chong Lee, E-mail: itachi_829@hotmail.com [Department of Mechanical Engineering, Korea Maritime University (Korea, Republic of)

    2016-01-15

    Highlights: • The new concept of PAR (passive autocatalytic recombiner) was proposed and analyzed. • Guidance wall was added at the bottom of PAR to enhance the flow rate through the catalyst. • The new concept of PAR was proved to have a better hydrogen removal performance. - Abstract: Passive autocatalytic recombiner (PAR) is very useful hydrogen mitigation measurement. It is widely implemented in the current and advanced light water reactors (ALWRs). The design of the PARs should be optimized for the specific use under severe accident scenarios. Several techniques and innovations have been fused into the PAR, as an effort to increase its efficiency of hydrogen mitigation. This study proposes different concepts of PAR, which applied some changes to the honeycomb catalyst PAR made by the Korea Nuclear Technology (KNT) Inc. Two slices of plate are added to the bottom of PAR model, which intended to act as a reflection wall and promote the gas flow into PAR. Hydrogen volume fraction was given 4 vol. % which tested by KNT to investigate the performance of PAR in different direction gas flow conditions to see maximum hydrogen recombination rate. The new concept of PAR was proved to have a better hydrogen removal performance compared to the original honeycomb catalyst PAR.

  20. CFD analysis of PAR performance as function of inlet design

    International Nuclear Information System (INIS)

    Park, Kweonha; Khor, Chong Lee

    2016-01-01

    Highlights: • The new concept of PAR (passive autocatalytic recombiner) was proposed and analyzed. • Guidance wall was added at the bottom of PAR to enhance the flow rate through the catalyst. • The new concept of PAR was proved to have a better hydrogen removal performance. - Abstract: Passive autocatalytic recombiner (PAR) is very useful hydrogen mitigation measurement. It is widely implemented in the current and advanced light water reactors (ALWRs). The design of the PARs should be optimized for the specific use under severe accident scenarios. Several techniques and innovations have been fused into the PAR, as an effort to increase its efficiency of hydrogen mitigation. This study proposes different concepts of PAR, which applied some changes to the honeycomb catalyst PAR made by the Korea Nuclear Technology (KNT) Inc. Two slices of plate are added to the bottom of PAR model, which intended to act as a reflection wall and promote the gas flow into PAR. Hydrogen volume fraction was given 4 vol. % which tested by KNT to investigate the performance of PAR in different direction gas flow conditions to see maximum hydrogen recombination rate. The new concept of PAR was proved to have a better hydrogen removal performance compared to the original honeycomb catalyst PAR.

  1. Measurement of a neutral particle flux by a thermal method using the junction temperature effect; Mesure d'un flux de particules neutres par une methode thermique mettant a contribution l'effet de temperature des jonctions

    Energy Technology Data Exchange (ETDEWEB)

    Caron, Anthime [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires. Services Scientifiques

    1966-07-01

    Among all the methods suitable for measuring neutral particle fluxes obtained by proton charge exchange in an organic gas, the thermal method has been chosen. The energy imparted by the neutral particles to the target in the form of heat leads to the latter temperature increasing; this temperature is usually followed with a thermocouple. In order to increase the sensitivity and the elegance of the apparatus the thermocouple has been replaced by a junction whose characteristics are known to vary with temperature. A calibration is carried out using a beam of charged particles. The response obtained is linear. Measurements have been made with a power of up to 1 mW; the accuracy increases with the energy provided; for 4 joules an accuracy of 10 per cent is obtained. The apparatus may be improved in particular by extending the measurement range towards low power values, and by increasing the accuracy. (author) [French] Parmi toutes les methodes utilisees pour la mesure d'un flux de particules neutres, obtenues par echange de charge de protons dans un gaz organique, nous avons choisi la methode thermique. L'energie cedee par les particules neutres a la cible sous forme de chaleur provoque une elevation de temperature de celle-ci; cette temperature est habituellement reperee par thermocouple. Pour accroitre la sensibilite et la finesse de l'appareillage, nous avons substitue au thermocouple une jonction dont on sait que les caracteristiques varient avec la temperature. Un etalonnage est realise par un faisceau de particules chargees. La reponse obtenue est lineaire. Des puissances de l'ordre du mW ont ete mesurees; la precision croit avec l'energie apportee; elle est de 10 pour cent quand celle-ci est de 4 joules. L'appareillage peut etre notablement perfectionne, pour reculer la gamme des mesures vers les basses puissances et accroitre la precision. (auteur)

  2. SAFARI 2000 PAR Measurements, Kalahari Transect, Botswana, Wet Season 2000

    Data.gov (United States)

    National Aeronautics and Space Administration — Ceptometer data from a Decagon AccuPAR (Model PAR-80) were collected at four sites in Botswana during the SAFARI 2000 Kalahari Transect Wet Season Campaign (March,...

  3. Theory of the separation of a gaseous mixture by diffusion through a porous wall (1962); Theorie de la separation d'un melange gazeux par diffusion a travers une paroi poreuse (1962)

    Energy Technology Data Exchange (ETDEWEB)

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

    1962-06-15

    The present-day theories of separation by gaseous diffusion (Present and de BETHUNE, KYNCH, BOSANQUET) are all based on the same model in which the pores are cylindrical capillaries. In the theory presented here, we substitute for this model that of a disordered and isotropic bed of identical spheres, which describes more accurately most of the porous media. We take as our starting point DERIAGUINE and BAKANOV'S permeability theory, which expresses the flow of a simple gas in such a bed when the latter is of high porosity. We first generalise this theory in the case of medium and low porosities; then, we go on to a mixture of two gases, from which we deduce our separation theory. Finally we compare our results with those of Present and de BETHUNE. (author) [French] Les theories actuelles de la separation par diffusion gazeuse (PRESENT et de BETHUNE, KYNCH, BOSANQUET) reposent toutes sur le modele des pores capillaires cylindriques. Dans la theorie presentee ici, nous substituons a ce modele celui d'un empilement desordonne et isotropes de spheres identiques, qui decrit plus correctement la plupart des milieux poreux. Nous partons de la theorie de la permeabilite de DERIAGUINE et BAKANOV, qui exprime l'ecoulement d'un gaz simple dans un tel empilement dans le cas ou la porosite en est elevee. Nous generalisons d'abord cette theorie du cas des porosites moyennes ou faibles, puis, passant a un melange de deux gaz, nous en deduisons une theorie de la separation. Pour terminer, nous comparons nos resultats a ceux de PRESENT et de BETHUNE. (auteur)

  4. Heat transfer in gas-cooled piles; Echanges thermiques dans les piles a gaz

    Energy Technology Data Exchange (ETDEWEB)

    Le Foll, J; Gelin, P; Robert, E de [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    . Technological studies led to such developments as special machining of the caps, using high conductibility metanes, anodic oxidation of thin discs. They provided the basis for solving the problem by removing the more trouble-some heat sources and providing heat insulation of the caps. Experimental study of convection around the fuel rod extremities led then to formulate specific boundary conditions of conduction inside the caps for any given geometry. Conduction in turn was studied by electrical analogy and permitted to map the temperature distribution of the critical region. (author) [French] Des mesures de coefficients d'echange locaux effectuees en regime etabli sur une gaine a ailettes longitudinales montrent que la distribution de ces coefficients le long du contour chauffant d'une section droite presente en general des singularites tres accentuees qui rendent inapplicables les calculs classiques de conduction dans les ailettes. Une etude systematique de cette distribution etablit cependant que deux coefficients numeriques calcules par integration dans le plan de section droite suffisent a rattacher les proprietes thermiques globales a celles d'un canal circulaire de contour isotherme, avec une approximation suffisante dans la plupart des cas. Bien qu'assez delicat, le calcul de ces deux coefficients est rendu accessible par deux analogies rheoelectriques et on peut meme atteindre directement l'influence d'une petite deformation du contour de gaine. Pour une valeur donnee de la temperature limite de gaine, le calcul des performances du canal entier est effectue en considerant que cette limite est effectivement atteinte dans une section droite courante. En pratique, la division du combustible en cartouches courtes risque d'introduire des singularites importantes par rapport a ce cas ideal et le probleme se pose de determiner la forme des extremites de cartouches pour eviter que ces singularites n'affectent les performances. Or, les bouchons qui assurent la fermeture des

  5. Compatibility of various magnesium alloys with pressurized carbon dioxide at high temperatures; Compatibilite de divers alliages de magnesium avec le gaz carbonique sous pression aux temperatures elevees

    Energy Technology Data Exchange (ETDEWEB)

    Dewanckel, B; David, R; Hulin, C; Leclercq, D [Commissariat a l' Energie Atomique, 38 - Grenoble (France). Centre d' Etudes Nucleaires

    1968-07-01

    This work on the compatibility of magnesium alloys with pressurized carbon dioxide has been carried out along three lines: - testing of special alloys containing additions of zirconium, manganese, cerium, zinc, beryllium and yttrium. The results are satisfactory, generally speaking, and the corrosion kinetics are often comparable to those of conventional magnesium-zirconium alloy; - influence of the quality of the carbon dioxide, in particular the presence of water vapour or of carbon monoxide in this gas. It appears that oxidation is reduced if the carbon dioxide contains traces of water vapour, but is more pronounced if carbon monoxide is also present; - study of certain phenomena related to corrosion: size changes in the samples during tests, structural modifications in the alloys (grain-size changes, formation of a cortical zone in the case of alloys containing zirconium). The influence of thermal cycling has also been studied in a few specific tests. The results obtained make it possible to compare the behaviour of various alloys under varying conditions of long-term use, and to choose, if required, the best composition for a given application. (authors) [French] Ce travail sur la compatibilite des alliages de magnesium avec le gaz carbonique sous pression a ete particulierement oriente dans trois directions: - epreuve, d'alliages speciaux comportant des additions de zirconium, manganese, cerium, zinc, beryllium et yttrium. Les resultats sont generalement satisfaisants et les cinetiques de corrosion souvent comparables a celles de l'alliage magnesium-zirconium classique; - influence de la qualite du gaz carbonique, et notamment de la presence de vapeur d'eau ou d'oxyde de carbone dans ce gaz. Il est apparu que l'oxydation est reduite si le gaz carbonique contient des traces d'eau, mais accrue si l'oxyde de carbone est egalement present; - etude de certains phenomenes lies a la corrosion: variations dimensionnelles des echantillons au cours des essais

  6. Effects of hydrogen on the tensile strength characteristics of stainless steels; Effets de l'hydrogene sur les caracteristiques de rupture par traction d'aciers inoxydables

    Energy Technology Data Exchange (ETDEWEB)

    Blanchard, R; Pelissier, J; Pluchery, M [Commissariat a l' Energie Atomique, Grenoble (France).Centre d' Etudes Nucleaires; Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1961-07-01

    This paper deals with the effects of hydrogen on stainless steel, that might possibly be used as a canning material in hydrogen-cooled reactors. Apparent ultimate-tensile strength is only 80 per cent of initial value for hydrogen content about 50 cc NTP/ 100 g, and reduction in area decreases from 80 to 55 per cent. A special two-stage replica technique has been developed which allows fracture surface of small tensile specimens (about 0.1 mm diam.) to be examined in an electron microscope. All the specimens showed evidence of ductile character throughout the range of hydrogen contents investigated, but the aspect of the fracture surfaces gradually changes with increasing amounts. (author) [French] On etudie les effets de l'hydrogene sur des aciers inoxydables, qui sont des materiaux de gainage possibles pour des reacteurs utilisant l'hydrogene comme gaz de refroidissement. On montre que la charge apparente de rupture a la traction n'est plus que 80 pour cent de sa valeur initiale lorsque la teneur en hydrogene atteint 50 cc TPN/ 100 g, et que la striction passe dans ces conditions de 80 a 55 pour cent. L'examen microfractographique qui a ete effectue avec succes par une technique de double replique malgre la petitesse des echantillons (0,3 mm de diametre environ), revele que tout en gardant un caractere ductile, l'aspect des surfaces de rupture evolue notablement avec la teneur en hydrogene. (auteur)

  7. Plasma suPAR is lowered by smoking cessation

    DEFF Research Database (Denmark)

    Eugen-Olsen, Jesper; Ladelund, Steen; Sørensen, Lars Tue

    2016-01-01

    BACKGROUND: Soluble urokinase plasminogen activator receptor (suPAR) is a stable inflammatory biomarker. In patients, suPAR is a marker of disease presence, severity and prognosis. In the general population, suPAR is predictive of disease development, such as diabetes and cardiovascular disease a...

  8. Copenhagen uPAR prostate cancer (CuPCa) database

    DEFF Research Database (Denmark)

    Lippert, Solvej; Berg, Kasper D; Høyer-Hansen, Gunilla

    2016-01-01

    AIM: Urokinase plasminogen activator receptor (uPAR) plays a central role during cancer invasion by facilitating pericellular proteolysis. We initiated the prospective 'Copenhagen uPAR Prostate Cancer' study to investigate the significance of uPAR levels in prostate cancer (PCa) patients. METHODS...

  9. The inflammatory marker suPAR after cardiac arrest

    DEFF Research Database (Denmark)

    Rundgren, Malin; Lyngbaek, Stig; Fisker, Helle

    2015-01-01

    . This pilot study aimed at investigating suPAR levels in relation to outcome after CA and mild induced hypothermia. METHODS: suPAR levels were measured at 6, 36, and 72 hours in patients treated with hypothermia after CA. suPAR levels were analyzed in relation to survival after 6 months. Receiver operating...

  10. Phosphorylation of Mycobacterium tuberculosis ParB participates in regulating the ParABS chromosome segregation system.

    Science.gov (United States)

    Baronian, Grégory; Ginda, Katarzyna; Berry, Laurence; Cohen-Gonsaud, Martin; Zakrzewska-Czerwińska, Jolanta; Jakimowicz, Dagmara; Molle, Virginie

    2015-01-01

    Here, we present for the first time that Mycobacterium tuberculosis ParB is phosphorylated by several mycobacterial Ser/Thr protein kinases in vitro. ParB and ParA are the key components of bacterial chromosome segregation apparatus. ParB is a cytosolic conserved protein that binds specifically to centromere-like DNA parS sequences and interacts with ParA, a weak ATPase required for its proper localization. Mass spectrometry identified the presence of ten phosphate groups, thus indicating that ParB is phosphorylated on eight threonines, Thr32, Thr41, Thr53, Thr110, Thr195, and Thr254, Thr300, Thr303 as well as on two serines, Ser5 and Ser239. The phosphorylation sites were further substituted either by alanine to prevent phosphorylation or aspartate to mimic constitutive phosphorylation. Electrophoretic mobility shift assays revealed a drastic inhibition of DNA-binding by ParB phosphomimetic mutant compared to wild type. In addition, bacterial two-hybrid experiments showed a loss of ParA-ParB interaction with the phosphomimetic mutant, indicating that phosphorylation is regulating the recruitment of the partitioning complex. Moreover, fluorescence microscopy experiments performed in the surrogate Mycobacterium smegmatis ΔparB strain revealed that in contrast to wild type Mtb ParB, which formed subpolar foci similar to M. smegmatis ParB, phoshomimetic Mtb ParB was delocalized. Thus, our findings highlight a novel regulatory role of the different isoforms of ParB representing a molecular switch in localization and functioning of partitioning protein in Mycobacterium tuberculosis.

  11. Phosphorylation of Mycobacterium tuberculosis ParB participates in regulating the ParABS chromosome segregation system.

    Directory of Open Access Journals (Sweden)

    Grégory Baronian

    Full Text Available Here, we present for the first time that Mycobacterium tuberculosis ParB is phosphorylated by several mycobacterial Ser/Thr protein kinases in vitro. ParB and ParA are the key components of bacterial chromosome segregation apparatus. ParB is a cytosolic conserved protein that binds specifically to centromere-like DNA parS sequences and interacts with ParA, a weak ATPase required for its proper localization. Mass spectrometry identified the presence of ten phosphate groups, thus indicating that ParB is phosphorylated on eight threonines, Thr32, Thr41, Thr53, Thr110, Thr195, and Thr254, Thr300, Thr303 as well as on two serines, Ser5 and Ser239. The phosphorylation sites were further substituted either by alanine to prevent phosphorylation or aspartate to mimic constitutive phosphorylation. Electrophoretic mobility shift assays revealed a drastic inhibition of DNA-binding by ParB phosphomimetic mutant compared to wild type. In addition, bacterial two-hybrid experiments showed a loss of ParA-ParB interaction with the phosphomimetic mutant, indicating that phosphorylation is regulating the recruitment of the partitioning complex. Moreover, fluorescence microscopy experiments performed in the surrogate Mycobacterium smegmatis ΔparB strain revealed that in contrast to wild type Mtb ParB, which formed subpolar foci similar to M. smegmatis ParB, phoshomimetic Mtb ParB was delocalized. Thus, our findings highlight a novel regulatory role of the different isoforms of ParB representing a molecular switch in localization and functioning of partitioning protein in Mycobacterium tuberculosis.

  12. [Ambroise Paré in French literature].

    Science.gov (United States)

    Dumaitre, P

    1995-01-01

    The 16th century by its passionate side has been the favourite one of authors of historical novels in which among the heroes of "cloak and dagger stories" appears sometime Ambroise Paré. Alexandre Dumas (the father) has shown him at the court of Charles IX in La Reine Margot (1845) where he does not however play a great role. On the contrary, Balzac in Le Martyr calviniste (1842) has given him a capital part close to the dying François II, whom he intended to trepanize but had to give up this idea as a consequence of the opposition of the queen-mother Catherine de Médicis. In the present century, Robert Merle in Paris ma bonne ville (Fortune de France, 3, 1980) shows Paré at the time of the Saint Barthélemy.

  13. Étude des équilibres thermodynamiques des réactions de gazéification en vue de l'optimisation du rapport vapeur/comburant injecté dans un gazogène souterrain Study of Thermodynamic Equilibria in Gasification Reactions So As to Optimise the Steam/Oxidizer Ratio Injected Into an Underground Gas Generator

    OpenAIRE

    Pirard J. P.

    2006-01-01

    Le but de cette étude est de déterminer sur la base des équilibres thermodynamiques des réactions de gazéification le rapport vapeur/comburant à injecter dans un gazogène fonctionnant sous pression pour optimaliser les compositions, les pouvoirs calorifiques, les rendements de gazéification et la consommation d'agent gazéifiant. The aim of this study is to determine, on the basis of the thermodynamic equilibria of gazification reactions, the steam/oxidizer ratio to be injected into a gas g...

  14. Par Pond refill water quality sampling

    International Nuclear Information System (INIS)

    Koch, J.W. II; Martin, F.D.; Westbury, H.M.

    1996-08-01

    This study was designed to document anoxia and its cause in the event that the anoxia caused a fish kill. However, no fish kill was observed during this study, and dissolved oxygen and nutrient concentrations generally remained within the range expected for southeastern reservoirs. Par Pond water quality monitoring will continue during the second summer after refill as the aquatic macrophytes become reestablished and nutrients in the sediments are released to the water column

  15. Simplified theory of gas-jet pumps and experimental verification; Theorie simplifiee des trompes a gaz et verification experimentale

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-07-01

    With a view to using the gas-jet pump in the fuel-study loops of gas reactors, a theory is developed for an unidimensional mixer, applicable to the case of low compression ratios in the induced current. This theory makes it possible to optimize the diameter of the mixer if the pressure-drop coefficient {alpha} of the mixer is known with respect to the induced current. An experimental study has made it possible to define the geometry suitable for such pumps, and to provide a remarkably constant value of {alpha} for the economically advantageous designs; this makes it possible to define simply the geometry of the optimized pump as a function of the geometry of the circuit in use, and independently of the flow-rate conditions. (author) [French] Dans le but d'utiliser la pompe a jet (ou trompe) dans des boucles d'etude de combustible des piles a gaz, on etablit une theorie du melangeur unidimensionnel, applicable dans la cas des faibles rapports de compression dans le courant induit. Cette theorie permet l'optimisation du diametre de melangeur, moyennant la connaissance du coefficient {alpha} de pertes de charge de celui-ci, relativement au courant induit. Une recherche experimentale a permis de preciser la geometrie a adopter dans de telles pompes, et fourni pour {alpha} une valeur remarquablement constante dans les configurations economiquement interessantes, ce qui permet de definir simplement la geometrie de la pompe optimisee en fonction de la geometrie du circuit d'utilisation et independamment des conditions de debit. (auteur)

  16. Liberalization of energy markets, reorganization of work and collective mobilization in the company. The case of Gaz de Bordeaux

    International Nuclear Information System (INIS)

    Dif-Pradalier, M.

    2009-01-01

    Formerly in a monopolistic situation and running on a politico-administrative mode, Gaz de Bordeaux is a network industry now part of a competitive market. The present case study of this local public utility is meant to identify the nature of its modernisation and to measure its effects as well on the system of social regulations and professional identities, as on the capacities of action and forms of appropriation/resistance developed by the various categories of actors within the company. From a methodological point of view, we pledged ourselves with a combination of qualitative and quantitative approaches, aiming at articulating analysis of the work being done with that of collective action, both considered as linked realities. As work gains in intensity, in both senses of productive pressure (do more in less time and with fewer staff) and interest (given the need expressed by every person to come true by the reality of its work), the company appears as disrespectful of the quality of work possible and the capacities mobilized by individuals that modern management precisely contributed to develop. Faced with this reorganisation of work, labor unions struggle to grasp the issues at stake in modern employment relationships and translate individual complaints in renewed collective claims. Despite increasing individual withdrawal behaviours, working collectives recompose on new bases. We therefore revisit the origin of suffering at work; from its contemporary mutations, we present evidence for what we believe is one of its current major problems: the one at stake around what employees call a 'well done work', at the very moment when management is concerned with quality. (author)

  17. Centromere pairing by a plasmid-encoded type I ParB protein

    DEFF Research Database (Denmark)

    Ringgaard, Simon; Löwe, Jan; Gerdes, Kenn

    2007-01-01

    The par2 locus of Escherichia coli plasmid pB171 encodes two trans-acting proteins, ParA and ParB, and two cis-acting sites, parC1 and parC2, to which ParB binds cooperatively. ParA is related to MinD and oscillates in helical structures and thereby positions ParB/parC-carrying plasmids regularly......, hence identifying the N terminus of ParB as a requirement for ParB-mediated centromere pairing. These observations suggest that centromere pairing is an important intermediate step in plasmid partitioning mediated by the common type I loci....

  18. Seminar on the news energy utilization in rural area of April 3 to March 24 , 1980 in Reo, Upper Volta[Energie renouvelable ; Zone rurale ; Gaz biologique ; Energie solaire ; Sechoir solaire]; Seminaire sur l'utilisation des energies nouvelles en zone rurale du 24 mars au3 avril 1980 a Reo, Haute Volta

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1980-04-15

    volume of transport much more reduced. Mastering these new technologies will help fight efficiently against desertification, and fruits and vegetables rotting. [French] L'acces a l'energie par toutes les populations reste une des preoccupations du Gouvernement de Haute Volta (Burkina Faso). C'est ainsi que sous l'egide de la Communaute Economique de l Afrique de l'Ouest (CEAO), de l'Agence Canadienne de Developpement International et du Mouvement Scout, un seminaire sur l'utilisation des energies renouvelables en zone rurale y a ete organise. Il s'agit pour les participants venus de plusieurs pays, d'apprendre a mettre en pratique, l'utilisation des energies nouvelles telles la cuisiniere a feu ferme, le gaz biologique, le chauffe- eau solaire et le sechoir solaire. L'adoption de ces nouvelles sources d'energie par les populations permettrait de pallier les problemes de desertification lies au deboisement intensif dans le pays. Tous les participants a cette rencontre sont donc sensibilises pour qu'ils apportent leur contribution et celle des populations de leurs terroirs respectifs pour une meilleure conservation des ressources naturelles disponibles. Cela passe aussi par la construction de cuisinieres a feu ferme qui permettent d'avoir deux sources d'energie. Ce type de foyer est d'une construction facile et utilisable seulement trois jours apres. Il permet d'eviter la perte d'energie qui caracterisait le foyer traditionnel (pres de 95% de perte d'energie) ; ce qui revient a consommer moins de bois tout en assurant un rendement de l'ordre de 60 a 70%. Il s'est agi pour les participants aux travaux de s'initier a l'installation de gaz suivant des modeles chinois et indien . Ils ont donc ete inities a la realisation des technologies de production de gaz biologique a travers la maitrise du schema de principe du procede de fermentation discontinue. De meme, ils ont acquis le savoir- faire sur les techniques de mise en place du chauffe- eau solaire par insolateur et du

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-07-01

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

  20. Ortaçağlardan 21. Yüzyıla Gazâlî’nin Kozmolojisinin Batılı Alımlanışı

    OpenAIRE

    GRIFFEL, Frank

    2011-01-01

    İslam teolojisinin konuları arasında özellikle Gazâlî’nin kozmolojisi Batı’da oldukça dikkat çekmiştir. Rönesans dönemi ilim adamları Gazâlî’nin Filozofların Tutarsızlığı (Tehâfütü’l-felâ- sife) adlı eserinin 17. meselesinde filozofların nedensellik teorilerine yönelttiği eleştirilere aşinaydılar. İslam teolojisine dair akademik araştırmaların başladığı 19. yüzyılın ilk yarısında ilim adamları, Gazâlî’nin sözkonusu meselede nedensel ilişkilerin varlığını reddettiği sonucuna ulaştılar. Gazâlî’...

  1. Magnesium and uranium ignition in different gaseous atmospheres; Inflammabilite du magnesium et de l'uranium dans l'air et le gaz carbonique

    Energy Technology Data Exchange (ETDEWEB)

    Darras, R; Baque, P; Leclercq, D [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    Magnesium, uranium and some of their alloys burning temperatures have been systematically determined in an air or carbon dioxide atmosphere, either dry or wet. Two different ways of heating have been used: either continuously rising up the temperature, or heating to and then maintaining a constant temperature. The results are clearly different in the two cases. Besides, if moisture has little effect on the magnesium burning temperatures in air, it does lower them by about 130-140 deg. C in CO{sub 2}. The differences of sight between the burning of magnesium and uranium have been noticed; this leads to distinguish between an 'ignition' and an 'inflammation'. (author) [French] Les temperatures auxquelles apparait la combustion vive du magnesium, de l'uranium et certains de leurs alliages ont ete determinees systematiquement dans l'air et le gaz carbonique, soit secs, soit humidifies. On a mis en evidence l'influence du mode de chauffage sur les resultats: soit montee en temperature continue, soit stabilisation a partir d'une certaine temperature. En outre, si la presence d'humidite affecte peu les temperatures de combustion vive du magnesium dans l'air, elle les abaisse de 130 a 140 deg. C dans le gaz carbonique. Les differences d'aspect entre la combustion vive du magnesium et de l'uranium ont egalement ete remarquees, ce qui amene notamment a distinguer une 'ignition' d'une 'inflammation'. (auteur)

  2. Recent progress in the detection of bursts in the canning in French reactors; Progres recents de la detection des ruptures de gaines dans les reacteurs francais G1, EL2, G3, EL3

    Energy Technology Data Exchange (ETDEWEB)

    Goupil, J; Grenon, M; Raffailhac, J; Roguin, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-07-01

    method. A scintillator and an electronic system provide a specific signal of the fission products which is then marked on a recorder. In a case where the activity threshold is exceeded, the cell involved is isolated from the prospection system and taker, over by a 'follow-up' detector which follows the evolution of the crack. A year of working on the pile G{sub 1}, which is cooled by air at atmospheric pressure, has made it possible to obtain results on the operation of the canning-burst detection appliance, which has led us to perfect the original device by installing an 'evolution-meter' of the type described above for G{sub 3}. The reactor EL{sub 3}, cooled by heavy water, uses a detection system based on the measurement by GM counters of the activity of the fission gases carried by diluted helium into the heavy water, then extracted by hydro-cyclones. The selectivity of the system gives it a low sensitivity to parasite activities, and an excellent performance. (author) [French] Dans les piles refroidies par gaz carbonique sous pression, du type G{sub 3}, la radioactivite principale du gaz est celle de l'azote 16 creee par reaction {sup 16}O(n, p) {sup 16}N des neutrons rapides sur l'oxygene. Cette activite, de vie courte et de forte energie {beta}, masque l'activite des gaz de fission s'echappant par une fissure de gaine dans le gaz carbonique et oblige a utiliser une methode de separation materielle des produits de fission solides avant la detection proprement dite. Cette detection est faite par une chaine electronique speciale dont l'entree est un scintillateur associe a un photomultiplicateur. Un systeme de mesure d'evolution de fissure avec compensation des variations de puissance permet de suivre la vitesse d'evolution d'une fissure. Cet appareil, baptise evolumetre, est destine a ramener a une methode de zero la mesure de l'activite du gaz de refroidissement des canaux, il permet de s'affranchir: 1) de l'activite propre du gaz restant apres la discrimination

  3. Childhood Pars Planitis; Clinical Features and Outcomes

    Directory of Open Access Journals (Sweden)

    Homayoon Nikkhah

    2011-01-01

    Full Text Available Purpose: To evaluate the demographic and clinical features of childhood pars planitis, and to determine the therapeutic and visual outcomes of the disease. Methods: Medical records of pediatric patients (less than 16 years of age at diagnosis with pars planitis and at least 6 months of follow-up who were referred to Labbafinejad Medical Center, Tehran, Iran over a 22 year period were reviewed. Results: Overall, 117 eyes of 61 patients including 51 (83.6% male subjects were included. Mean age at the time of diagnosis was 7.8΁3.2 (range, 3-16 years. Mean best corrected visual acuity (BCVA was 0.88΁0.76 logMAR at presentation which improved to 0.39΁0.51 logMAR at final visit (P<0.001. Endotheliitis was present in 23 (19.6% eyes and was significantly more prevalent in subjects younger than 9 years (P=0.025. Cataract formation (41.9% and cystoid macular edema (19.7% were the most prevalent complications. Univariate regression analysis showed that better baseline visual acuity (OR=0.38, 95%CI 0.21-0.70, P=0.002, age older than 5 years at disease onset (OR=0.36, 95%CI 0.14-0.9, P=0.029, absence of endotheliitis (OR=0.39, 95%CI 0.15-0.99, P=0.047 and female gender (OR=3.77, 95%CI 1.03-13.93, P=0.046 were significantly associated with final BCVA of 20/40 or better. Conclusion: Childhood pars planitis was much more common among male subjects. Endotheliitis may be a sign of inflammation spillover and is more prevalent in younger patients. Visual prognosis is favorable in most patients with appropriate treatment.

  4. La fonction logistique, un outil performant d'analyse et de prévision à moyen terme. Application à la production de pétrole et de gaz aux Etats-Unis, en URSS et dans d'autres pays The Logistic Function, an Efficient Medium-Range Analysis and Forecasting Method

    Directory of Open Access Journals (Sweden)

    Seguret J.

    2006-11-01

    Full Text Available A partir de la similitude observée entre l'évolution de la production pétrolière d'un pays et celle de la pénétration d'un produit dans un marché (fonction logistique, l'auteur expose le principe d'une méthode originale qui permet, sous certaines conditions, de prévoir quelle sera la production annuelle probable d'un pays producteur à un horizon de 10 à 15 ans. La validité de cette méthode est d'abord démontrée sur l'exemple de la production pétrolière aux Etats-Unis. Elle est ensuite illustrée par les résultats obtenus pour un certain nombre de pays : production future de gaz aux Etats-Unis, production pétrolière future du Canada, de l'URSS, du Venezuela et de l'ensemble du monde hors Moyen-Orient. On the basis of the similarity observed between the variation in the petroleum production of a country and that of the penetration of a product into the market (logistic function, this article describes the principle of an original method that can be used, under certain conditions, to forecast the probable annual production of a producing country in 10 to 15 years. The validity of this method is first demonstrated for the example of oil production in the United States. It is then illustrated by results obtained for various other countries, i. e. future gas production in the United States, future oil production of Canada, the Soviet Union, Venezuela and the world as a whole outside of the Middle East.

  5. Corrosion of copper by chlorine trifluoride; Corrosion du cuivre par le trifluorure de chlore

    Energy Technology Data Exchange (ETDEWEB)

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

    1966-07-01

    The research described called for a considerable amount of preliminary development of the test methods and equipment in order that the various measurements and observations could be carried out without contaminating either the samples or this highly reactive gas. The chlorine trifluoride was highly purified before use, its purity being checked by gas-phase chromatography, micro-sublimation and infrared spectrography. The tests were carried out on copper samples of various purities, in particular a 99.999 per cent copper in the form of mono-crystals. They involved kinetic measurements and the characterization of corrosion products under different temperature and pressure conditions. The kinetics showed reactions of the same order of magnitude as those obtained with elementary fluorine. At atmospheric pressure there occurs formation of cupric fluoride and cuprous chloride. The presence of this latter product shows that it is not possible to consider ClF{sub 3} simply as a fluorinating agent. At low pressures an unknown product has been characterized. There are strong grounds for believing that it is the unstable cuprous fluoride which it has not yet been possible to isolate. A germination phenomenon has been shown to exist indicating an analogy between the initial phases of fluorination and those of oxidation. Important effects resulting from the dissociation of the copper fluorides and the solubility of chlorine in this metal have been demonstrated. Finally, tests have shown the considerable influence of the purity of the gas phase and of the nature of the reaction vessel walls on the rates of corrosion which can in certain cases be increased by a factor of several powers of ten. (author) [French] Le travail a comporte une importante mise au point des appareillages et methodes d'essai, en vue de pouvoir effectuer differentes mesures et observations sans contaminer les echantillons, ni polluer ce gaz hautement reactif. Une purification poussee du trifluorure de

  6. Measurements and Application of Partition Coefficients of Compounds Suitable for Tracing Gas Injected Into Oil Reservoirs Mesures et applications des coefficients de partage de composants utilisables comme gaz traceurs injectés dans des réservoirs de pétrole

    Directory of Open Access Journals (Sweden)

    Dugstad O.

    2006-11-01

    connaissance de ce phénomène est importante pour une interprétation optimale des essais de traceurs réalisés in-situ. Cette ségrégation est quantifiée à l'aide du coefficient de partage. On présente un modèle mono-dimensionnel permettant de prévoir la vitesse d'écoulement du traceur en fonction du coefficient de saturation, du coefficient de partage et de la fraction écoulée lors de l'injection discontinue d'un traceur dans un milieu poreux. On a étudié deux traceurs chimiques, le perfluorométhylcyclopentane (PMCP et le perfluorométhylcyclohexane (PMCH, ainsi qu'un composé radioactif, de l'éthane marqué au 14C. Les deux composés chimiques sont nouveaux comme traceurs appliqués aux réservoirs; la littérature disponible ne fait état d'aucun résultat in-situ qui aurait été obtenu avec ces substances. Les hydrocarbures fluorés sont intéressants comme traceurs potentiels du fait de leur stabilité, y compris dans les conditions caractéristiques des réservoirs, et de leur très faible seuil de détection lorsqu'ils sont analysés par chromatographie en phase gazeuse associée à un détecteur à capture d'électrons. La meilleure sensibilité à la détection est obtenue pour les composés cycliques polyfluorés comportant une ou plusieurs chaînes latérales, ce qui est le cas pour le PMCP et le PLCH. Notre groupe a récemment utilisé avec succès ses deux composés comme traceurs dans un réservoir de la mer du Nord. Le PMCP, le PMCH et l'éthane marqué au 14C ont été étudiés à l'aide d'essais dynamiques. Le milieu poreux utilisé est un tube de 6 m de long, d'un diamètre intérieur, de 0,5 cm rempli de sable d'Ottawa. On rince le tube jusqu'à l'obtention de decane puis on injecte une quantité finie de traceur dans le gaz vecteur, juste à l'amont de l'entrée du tube mince. Les figures 4 et 5 donnent les courbes de réponse types de traceur dans le gaz effluent. Les figures montrent que le traceur de référence, du méthane marqué au

  7. Kinetic study of the fluorination by fluorine of some uranium and plutonium compounds; Etude cinetique de la fluoration par le fluor de quelques composes de l'uranium et du plutonium

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-12-15

    The study of fluorination reactions of uranium and plutonium compounds with elementary fluorine, has been carried out using a thermogravimetric method. These reactions are heterogeneous ones, and of the following type: S(solid) + G{sub 1}(gas) - G{sub 2}(gas). The kinetics of these reactions correspond to a uniform attack of the entire surface of the sample. {alpha}: being the degree of completion of the reaction, k(rel): being the relative rate of penetration of the reaction interface, t: being the time, one have the relation: (1-{alpha}){sup 1/3} = 1 - k(rel)*t. The mechanism of the reaction varies according to the nature of the compound: 1) with uranium tetrafluoride and plutonium tetrafluoride, the reaction proceeds in a single step; 2) with uranium oxides, the reaction proceeds in two steps, uranium oxyfluoride being the intermediate compound; 3) with plutonium oxide, the reaction proceeds in two steps, plutonium tetrafluoride being the intermediate compound; and 4) with uranium trichloride, the mechanism is complex: chlorine trifluoride is formed. (author) [French] L'etude des reactions de fluoration par le fluor, de composes de l'uranium et du plutonium a ete faite par thermogravimetrie. Ce sont des reactions heterogenes du type: S(solide) + G{sub 1}(gaz) - G{sub 2}(gaz). La cinetique de ces reactions est celle correspondant a une attaque uniforme de toute la surface de l'echantillon. Si {alpha}: est le degre d'avancement de la reaction, k(rel): est la vitesse relative d'avancement d'un interface reactionnel, t: le temps. On a la relation: (1-{alpha}){sup 1/3} = 1-k(rel)*t. Le mecanisme de la reaction varie selon la nature du compose: 1) tetrafluorure d'uranium et tetrafluorure de plutonium, la reaction s'effectue en un seul stade; 2) Oxydes d'uranium: la reaction s'effectue en deux stades, l'oxyfluorure d'uranium est le compose intermediaire; 3) oxyde de plutonium, la reaction s'effectue en deux stades, la tetrafluorure de plutonium est le compose

  8. Single Pellet String Reactor for Intensification of Catalyst Testing in Gas/Liquid/Solid Configuration Réacteur catalytique de type “filaire” pour l’intensification de tests catalytiques en configuration gaz/liquide/solide

    Directory of Open Access Journals (Sweden)

    Hipolito A.I.

    2010-09-01

    . Ce probleme est particulierement critique pour les reactions rapides et tres exothermiques. Une nouvelle geometrie de reacteur est proposee pour intensifier les transferts de matieres autour des grains de catalyseur et accelerer les vitesses superficielles des fluides : le “reacteur filaire”. Pour caracteriser cette nouvelle geometrie de reacteur, une etude hydrodynamique a ete menee avec un reacteur filaire horizontal de section carree de 4,0 × 4,0 mm2 rempli de particules spheriques de diametre compris entre 2 et 4 mm et simulant des grains de catalyseur. Les regimes d’ecoulement ontete etudies a partir d’analyses d’images, des mesures de perte de pression et de distribution de temps de sejour qui ont ete effectuees en ecoulement monophasique liquide et diphasique gaz/liquide. Deux principaux regimes d’ecoulements ont ete observes: un regime de “bulles isolees” et un regime de type “stratifie”. Les retentions liquides sont toujours superieures a 60 %, ce qui indique en complement d’observations visuelles que le catalyseur est toujours correctement irrigue par l’ecoulement liquide. En ecoulement diphasique gaz/liquide, l’ecoulement est de type piston puisque les nombres de Peclet sont toujours superieurs a 40. La perte de pression est principalement controlee par les forces de frottement liquide/solide et les valeurs de perte de pression restent tres faibles en conditions de tests catalytiques (< 0,1 bar. Les caracteristiques hydrodynamiques indiquent donc que ce reacteur est approprie pour des tests catalytiques. Enfin, ce type de reacteur a ete mis en oeuvre en conditions de reactions catalytiques pour effectuer des tests d’un catalyseur commercial pour une reaction d’hydrogenation de l’allene. Le reacteur a permis d’effectuer des tests en conditions isothermes avec une tres faible quantite de catalyseur (inferieure a 2 cc et d’acceder aux performances catalytiques pour des temps de contact tres courts impossible a atteindre

  9. Accouchement par forceps: indications et pronostic materno-foetal ...

    African Journals Online (AJOL)

    L'accouchement par voie basse, peut être parfois compromis par des facteurs maternels, foetaux ou materno-foetaux nécessitant des moyens thérapeutiques comme le forceps pour achever l'accouchement par voie naturelle. Le forceps, une méthode qui n'est pas sans risque pour la mère et le nouveau-né. Nous avons ...

  10. 2001-2003 ''public utility'' contract between the French government and Gaz de France; Contrat de ''service public'' 2001-2003 entre l'etat et Gaz de France

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    The ''public utility'' contract aims at specifying the actions of Gaz de France (GdF), the French gas utility, in terms of national development and public utility presence at the local scale. It extends and completes the 'contract of group' established between the government and GdF in the domain of quality of the services offered to clients, development of gas infrastructures and extension of gas supplies, and sustainable development. (J.S.)

  11. Influence of the heat flux and of the gas on heat transfer and friction coefficients in a smooth cylindrical tube; Influence du flux de chaleur et de la nature du gaz sur les coefficients d'echange et le frottement dans un tube cylindrique lisse

    Energy Technology Data Exchange (ETDEWEB)

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

    1962-12-15

    The stainless steel tube used for the experiments is heated by means of d.c current; its inside diameter is 40 mm; its length is about 5.80 meters. Special core has been taken (heated rocket) to avoid heat loss and to provide very accurate measurements. The cooling gases tested are air and carbon dioxide at a pressure of 2.6 to 19 psi; the Reynolds number ranges from 70,000 to 10{sup 6}, the wall temperature and the heat flux reach respectively 430 deg C and 16 watts/cm{sup 2}. The Reynolds number Re{sub m}, Stanton number M{sub m} and friction coefficient f are computed by evaluating the physical properties of the gases at the mean temperature T{sub m}. For a given Reynolds number, a decrease of M{sub m} and of f is observed hen the heat flux increases, this decrease reaches 10 per cent in the experiments described. A formulation is proposed to express this effect in terms of a heat flow parameter (T{sub m} - T{sub m}) / T{sub p} used as a corrective factor (T{sub p} = wall temperature). The correlation formulae are: M{sub m} = 0.0168 Re{sub m}{sup -0.18} P{sub m}{sup -0.6} (1 - 0.4 [(T{sub p} - T{sub m}) / T{sub p}]) for air f = f{sub 0} (1 0.25 [(T{sub p} - T{sub m}) / T{sub p}]) for air M{sub m} = 0.0171 Re{sub m}{sup -0.18} P{sub m}{sup -0.6} (1 - 0.2 [(T{sub p} - T{sub m}) / T{sub p}]) for carbon dioxide f = f{sub 0} (1 - 0.20 [(T{sub p} - T{sub m}) / T{sub p}]) for carbon dioxide where f{sub 0} = the friction coefficient for isotherm flow. (author) [French] Le tube utilite a un diametre interieur de 40 mm; sa longueur est de 5,80 m environ; il est en acier inoxydable et chauffe par un courant continu. Des precautions particulieres (enceinte chauffante exterieure) ont ete prises pour eviter tout echange de chaleur avec le milieu exterieur et permettre des mesures extremement precises. Les gaz de refroidissement experimentes sont l'air et le gaz corbonique sous une pression de 1,8 a 13 hpz; les nombres de Reynolds vont de 70 000 a 10{sup 6}, la temperature de

  12. Un nouveau moyen de mesure absolue du taux gazeux des mélanges gaz-liquides : le SMAC A New Absolute Measurement of the Volumetric Gas Ratio of Gas-Liquid Mixture: the Smac

    Directory of Open Access Journals (Sweden)

    Porot P.

    2006-11-01

    Full Text Available Du graphe (P, V de la compression d'un mélange gaz-liquide, on peut tirer la valeur du taux volumique de gaz dans le mélange. La vérification théorique et expérimentale de ce principe ainsi que ses limites d'application comme moyen de mesure sont présentées. Ce résultat a été utilisé pour développer un système de mesure de l'aération de l'huile moteur, le SMAC (Système de Mesure d'Aération par Compressibilité. Des exemples d'application, tels que l'étude de la sensibilité de certaines huiles à l'aération, sont exposés. Oil aeration can be a real problem in engine oil circuit. The involved lubrication power decrease and thermic properties changes can damage the engine. Furthermore, the increased compressibility is very dangerous for hydraulic systems like valve lash adjusters. A first step to control this aeration is to be able to measure it. Gammametry is often used but this measurement needs a very precise calibration and is quite complicated and dangerous. A new absolute measurement has been discovered, based on the difference of compressibility between air and oil. It is absolute because the measurement principle is independant of the conditions, The system does not need a new calibration at each new environment. It is valid for any gas-liquid mixture. From the (P, V graph of a gas-liquid mixture compression, one can derive the gas-liquid volumetric ratio. The log-log graph (P/PO, 1-V/VO of a mixture sample pressurization always shows an inflexion point. The y value of this inflexion point (1-V/VO is equal to the volumetric gas ratio of the sample (before compression. This phenomenon is obvious on hydraulic curves (see Annexe 1. To check it, we have proceeded to a theoretical demonstration and an experimental verification. The theoretical demonstration of this principle concludes that the principle is verified as long as the ration P index 0 / alpha B is small. B is the oil bulk modulus, alpha is the volumetric gas ratio

  13. PAR1 activation affects the neurotrophic properties of Schwann cells.

    Science.gov (United States)

    Pompili, Elena; Fabrizi, Cinzia; Somma, Francesca; Correani, Virginia; Maras, Bruno; Schininà, Maria Eugenia; Ciraci, Viviana; Artico, Marco; Fornai, Francesco; Fumagalli, Lorenzo

    2017-03-01

    Protease-activated receptor-1 (PAR1) is the prototypic member of a family of four G-protein-coupled receptors that signal in response to extracellular proteases. In the peripheral nervous system, the expression and/or the role of PARs are still poorly investigated. High PAR1 mRNA expression was found in the rat dorsal root ganglia and the signal intensity of PAR1 mRNA increased in response to sciatic nerve transection. In the sciatic nerve, functional PAR1 receptor was reported at the level of non-compacted Schwann cell myelin microvilli of the nodes of Ranvier. Schwann cells are the principal population of glial cells of the peripheral nervous system which myelinate axons playing an important role during axonal regeneration and remyelination. The present study was undertaken in order to determine if the activation of PAR1 affects the neurotrophic properties of Schwann cells. Our results suggest that the stimulation of PAR1 could potentiate the Schwann cell ability to favour nerve regeneration. In fact, the conditioned medium obtained from Schwann cell cultures challenged with a specific PAR1 activating peptide (PAR1 AP) displays increased neuroprotective and neurotrophic properties with respect to the culture medium from untreated Schwann cells. The proteomic analysis of secreted proteins in untreated and PAR1 AP-treated Schwann cells allowed the identification of factors differentially expressed in the two samples. Some of them (such as macrophage migration inhibitory factor, matrix metalloproteinase-2, decorin, syndecan 4, complement C1r subcomponent, angiogenic factor with G patch and FHA domains 1) appear to be transcriptionally regulated after PAR1 AP treatment as shown by RT-PCR. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Spatial flux instabilities, and their control in the graphite gas power reactors; Les instabilites spatiales du flux et leur controle dans les reacteurs de puissance graphite-gaz

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-07-01

    Radial-azimuthal and axial spatial flux instabilities in graphite-gas reactors are studied by means of an analytical approach. Results are checked with those which are given by two dimensional (r, z and r, {theta}) kinetic models programmed for an IBM 7094 computer. At least, conclusions on the control of instabilities obtained from these models are reported. (author) [French] Les instabilites spatiales du flux dans les reacteurs graphite-gaz, radiales et azimutales d'une part, axiales d'autre part, sont etudiees au moyen d'une formulation analytique. Les resultats sont confrontes avec ceux que fournissent des modeles cinetiques a deux dimensions (r, z et r, {theta}) programmes sur IBM 7094. On donne enfin les conclusions relatives au controle de ces instabilites que ces modeles ont permis de degager. (auteur)

  15. Installation of a bitumen coating plant for high-activity concentrates; Installation pilote d'enrobage par le bitume de concentrats de haute activite

    Energy Technology Data Exchange (ETDEWEB)

    Rodier, J; Lefillatre, G; Seyfried, P [Commissariat a l' Energie Atomique, Chusclan (France). Centre de Production de Plutonium de Marcoule

    1969-07-01

    Following the excellent results obtained on the industrial coating of radioactive sludges, the possibility of solidifying also the evaporation concentrates with bitumen has been considered. For high activity concentrates, the use of bitumen is however limited by two main parameters: temperature resistance, irradiation resistance. By making use of the characteristics of a blown bitumen, it has been possible to design a high activity coating pilot plant treating concentrations of several tens of curies per litre. This plant will make use of a screw-type extrusion machine capable of coating treated concentrates at a rate of 20 l/hr. Before being coated, the concentrates will be subjected to a coprecipitation treatment designed to make the radioelements insoluble. This installation will make possible, apart from technological studies, laboratory experiments on the coated material (measurements on self-heating, on electrical charges, on radiolytic gases, and also lixiviation tests. It is at present believed, on the basis of available data, that it is possible to coat concentrates having an activity of 20 Ci/l at a price of 1840 F per cubic metre. (authors) [French] A la suite des excellents resultats obtenus pour l'enrobage industriel des boues radioactives, il a ete envisage de solidifier egalement les concentrats d'evaporation par le bitume. Pour les concentrats de haute activite, l'emploi du bitume est cependant limite par deux parametres essentiels: tenue a la temperature, tenue a l'irradiation. Grace aux caracteristiques d'un bitume souffle, il a ete possible de concevoir une installation pilote d'enrobage haute activite contenant plusieurs dizaines de curies par litre. Cette installation utilisera une machine du type extrudeuse a vis qui peut enrober 20 l/h de concentrats traites. Avant leur enrobage, les concentrats subiront un traitement de coprecipitation destine a insolubiliser les radioelements. En dehors des etudes technologiques, cette installation

  16. Taare Zameen Par and dyslexic savants.

    Science.gov (United States)

    Chakravarty, Ambar

    2009-04-01

    The film Taare Zameen Par (Stars upon the Ground) portrays the tormented life at school and at home of a child with dyslexia and his eventual success after his artistic talents are discovered by his art teacher at the boarding school. The film hints at a curious neurocognitive phenomenon of creativity in the midst of language disability, as exemplified in the lives of people like Leonardo da Vinci and Albert Einstein, both of whom demonstrated extraordinary creativity even though they were probably affected with developmental learning disorders. It has been hypothesized that a developmental delay in the dominant hemisphere most likely 'disinhibits' the nondominant parietal lobe, unmasking talents-artistic or otherwise-in some such individuals. It has been suggested that, in remedial training, children with learning disorders be encouraged to develop such hidden talents to full capacity, rather than be subjected to the usual overemphasis on the correction of the disturbed coded symbol operations.

  17. Soudage de bois feuillus par friction rotationnelle

    OpenAIRE

    Belleville, Benoît

    2012-01-01

    Les différentes colles utilisées actuellement par l’industrie du meuble au Canada nécessitent des temps de polymérisation constituant un goulot dans la production des meubles et limitant l’atteinte de la production unitaire. Ces adhésifs synthétiques généralement issus de la pétrochimie nécessitent énormément d’énergie lors de leur confection. L’utilisation de connecteurs métalliques ou plastiques, quant à elle, limite les phases de découpage et sablage subséquentes. La présence d’adhésifs et...

  18. The analysis on of the effect of urea, iron sulfate and vermicompost fertilizers on the growth characteristics and yield of sunflower (Helianthus annuus L. The city Darreh Gaz

    Directory of Open Access Journals (Sweden)

    mahdiyeh zomorrodi

    2015-12-01

    Full Text Available To study the effect of vermicompost and urea and iron sulfate fertilizers on the growth characteristics and yield of sunflower seed (Helianthus annuus L. an pediment was conducted in Darreh Gaz located in Khorasan Razavi province in 2012. Factorial experiment in a randomized complete block design with three factors and three repetition. In this experiment three levels of urea (50; 150 and 250 kg per hectare as the first factor and two level of vermicompost (7 tons per hectare consumption and non-consumption as the second factor and two iron sulfate (80 kilogram per hectare consumption and non- consumption were considered as the third factor. The results showed that the effect of urea × vermicompost treatment combination on stem height, head diameter, stem dry weight and yield was significantly at one percent probability level. The treatment combination of 250 kg. ha-1 × iron sulfate× vermicompost increased plant height, head diameter, petiole dry weight. Vermicompost × iron sulfate treatment combination on the dry weight’s leaf, petiole, stem and head were the highest significant (p≤0.01. The application of vermicompost × iron sulfate treatment combination resulted in the highest rate of stem diameter, leaf dry weight and stem the highest yield belonged to 250 kg.ha-1 × vermicompost. Iron sulfate use different amounts of urea fertilizer redact yield. The lowest yield of 250 kg.ha-1× iron sulfate was related to treatment combination. So it seems that the combined application of organic vermicompost fertilizer and urea and iron sulfate fertilizers on the growth and yield of sunflower Darreh Gaz can be effective in improving properties.

  19. Mécanisme de l'usure par polissage des cylindres de moteurs diesel Bore Polishing Wear Mechanism in Diesel Engine Cylinders

    Directory of Open Access Journals (Sweden)

    Fayard J. C.

    2006-11-01

    particulier, l'usure des segments ainsi que les débits de gaz de soufflage, sont plus faibles qu'avec une chemise normale. Enfin, le mécanisme de l'usure par polissage par abrasion douce à deux et à trois corps est parfaitement confirmé par une exploration micrographique et une microanalyse des surfaces polies. A fast and economical method for evaluating lubricants and fuels in relation to the bore polishing wear of super charged diesel-engine cylinders has been developed using a single-cylinder laboratory engine within the framework of an Société Nationale Elf Aquitaine - Institut Français du Pétrole (SNEA-lFP research agreement. This method bears the reference IFP-UP-4/80.It also serves to evaluate the deposit-forming and sticking tendency, ring wear and the oil-consumption tendency of lubricants. It is in good correlation with the CEC-Ford Tornado test and makes an excellent discrimination between the Coordinating European Council (CEC reference cils RL 47 and RL 48. The method is used for investigating the bore polishingwear mechanism by searching for the influence exerted by the principal parameters: (a Composition of the lubricant: the phenomenon is influenced by the base oil and its viscosity, by the amount of polymers improving the viscosity index and especially by the choice of detergent additives. As a first approximation and for homogeneous oil familles, polishing wear increases when the thermal stability of the oil decreases. (b Engine running: polishing increases very fart with the engine load after a certain threshold, and its evolution in time as observed by endoscopic rating shows a characteristic S shape as polishing begins on the thrust side and at the top of the cylinder. (c Composition of the fuel: the increase in the sulfur content of diesel fuel considerably decreases polishing wear caused by an oil reputed to be poorfrom this standpoint but has no effect on a goodoil. (d Surface finish of the cylinder: prepolishing the liner by extremely fine

  20. TMS suppression of right pars triangularis, but not pars opercularis, improves naming in aphasia

    Science.gov (United States)

    Naeser, Margaret A.; Martin, Paula I.; Theoret, Hugo; Kobayashi, Masahito; Fregni, Felipe; Nicholas, Marjorie; Tormos, Jose M.; Steven, Megan S.; Baker, Errol H.; Pascual-Leone, Alvaro

    2011-01-01

    This study sought to discover if an optimum 1 cm2 area in the non-damaged right hemisphere (RH) was present, which could temporarily improve naming in chronic, nonfluent aphasia patients when suppressed with repetitive transcranial magnetic stimulation (rTMS). Ten minutes of slow, 1 Hz rTMS was applied to suppress different RH ROIs in eight aphasia cases. Picture naming and response time (RT) were examined before, and immediately after rTMS. In aphasia patients, suppression of right pars triangularis (PTr) led to significant increase in pictures named, and significant decrease in RT. Suppression of right pars opercularis (POp), however, led to significant increase in RT, but no change in number of pictures named. Eight normals named all pictures correctly; similar to aphasia patients, RT significantly decreased following rTMS to suppress right PTr, versus right POp. Differential effects following suppression of right PTr versus right POp suggest different functional roles for these regions. PMID:21864891

  1. ParABS system in chromosome partitioning in the bacterium Myxococcus xanthus.

    Directory of Open Access Journals (Sweden)

    Antonio A Iniesta

    Full Text Available Chromosome segregation is an essential cellular function in eukaryotic and prokaryotic cells. The ParABS system is a fundamental player for a mitosis-like process in chromosome partitioning in many bacterial species. This work shows that the social bacterium Myxococcus xanthus also uses the ParABS system for chromosome segregation. Its large prokaryotic genome of 9.1 Mb contains 22 parS sequences near the origin of replication, and it is shown here that M. xanthus ParB binds preferentially to a consensus parS sequence in vitro. ParB and ParA are essential for cell viability in M. xanthus as in Caulobacter crescentus, but unlike in many other bacteria. Absence of ParB results in anucleate cells, chromosome segregation defects and loss of viability. Analysis of ParA subcellular localization shows that it clusters at the poles in all cells, and in some, in the DNA-free cell division plane between two chromosomal DNA masses. This ParA localization pattern depends on ParB but not on FtsZ. ParB inhibits the nonspecific interaction of ParA with DNA, and ParA colocalizes with chromosomal DNA only when ParB is depleted. The subcellular localization of ParB suggests a single ParB-parS complex localized at the edge of the nucleoid, next to a polar ParA cluster, with a second ParB-parS complex migrating after the replication of parS takes place to the opposite nucleoid edge, next to the other polar ParA cluster.

  2. Concerning the dynamic instability of actin homolog ParM

    International Nuclear Information System (INIS)

    Popp, David; Yamamoto, Akihiro; Iwasa, Mitsusada; Narita, Akihiro; Maeda, Kayo; Maeda, Yuichiro

    2007-01-01

    Using in vitro TIRF- and electron-microscopy, we reinvestigated the dynamics of native ParM, a prokaryotic DNA segregation protein and actin homolog. In contrast to a previous study, which used a cysteine ParM mutant, we find that the polymerization process of wild type ATP-ParM filaments consists of a polymerization phase and a subsequent steady state phase, which is dynamically unstable, like that of microtubules. We find that the apparent bidirectional polymerization of ParM, is not due to the intrinsic nature of this filament, but results from ParM forming randomly oriented bundles in the presence of crowding agents. Our results imply, that in the bacterium, ParM filaments spontaneously form bipolar bundles. Due to their intrinsic dynamic instability, ParM bundles can efficiently 'search' the cytoplasmic lumen for DNA, bind it equally well at the bipolar ends and segregate it approximately symmetrically, by the insertion of ParM subunits at either end

  3. The protein kinase SIK downregulates the polarity protein Par3

    DEFF Research Database (Denmark)

    Vanlandewijck, Michael; Dadras, Mahsa Shahidi; Lomnytska, Marta

    2018-01-01

    on Par3. Functionally, this mechanism impacts on tight junction downregulation. Furthermore, SIK contributes to the loss of epithelial polarity and examination of advanced and invasive human cancers of diverse origin displayed high levels of SIK expression and a corresponding low expression of Par3...

  4. Recombination in the human Pseudoautosomal region PAR1.

    Directory of Open Access Journals (Sweden)

    Anjali G Hinch

    2014-07-01

    Full Text Available The pseudoautosomal region (PAR is a short region of homology between the mammalian X and Y chromosomes, which has undergone rapid evolution. A crossover in the PAR is essential for the proper disjunction of X and Y chromosomes in male meiosis, and PAR deletion results in male sterility. This leads the human PAR with the obligatory crossover, PAR1, to having an exceptionally high male crossover rate, which is 17-fold higher than the genome-wide average. However, the mechanism by which this obligatory crossover occurs remains unknown, as does the fine-scale positioning of crossovers across this region. Recent research in mice has suggested that crossovers in PAR may be mediated independently of the protein PRDM9, which localises virtually all crossovers in the autosomes. To investigate recombination in this region, we construct the most fine-scale genetic map containing directly observed crossovers to date using African-American pedigrees. We leverage recombination rates inferred from the breakdown of linkage disequilibrium in human populations and investigate the signatures of DNA evolution due to recombination. Further, we identify direct PRDM9 binding sites using ChIP-seq in human cells. Using these independent lines of evidence, we show that, in contrast with mouse, PRDM9 does localise peaks of recombination in the human PAR1. We find that recombination is a far more rapid and intense driver of sequence evolution in PAR1 than it is on the autosomes. We also show that PAR1 hotspot activities differ significantly among human populations. Finally, we find evidence that PAR1 hotspot positions have changed between human and chimpanzee, with no evidence of sharing among the hottest hotspots. We anticipate that the genetic maps built and validated in this work will aid research on this vital and fascinating region of the genome.

  5. Revue des aspects hydrodynamiques des réacteurs catalytiques gaz-liquide-solide à lit fixe arrosé Hydrodynamics of Gas-Liquid-Solid Trickle-Bed Reactors: a Critical Review

    Directory of Open Access Journals (Sweden)

    Attou A.

    2006-12-01

    Full Text Available Bien que les aspects hydrodynamiques soient d'une importance primordiale lors de la conception et du fonctionnement d'un réacteur gaz-liquide-solide à lit fixe arrosé, les méthodes de calcul prédictif proposées sont restées fort rudimentaires. La plupart des études portant sur ce sujet ont été menées dans des conditions quasi atmosphériques alors que les réacteurs industriels fonctionnent à des pressions élevées. C'est seulement récemment que quelques résultats expérimentaux ont été obtenus à des hautes pressions, et des corrélations ont été proposées dans ces conditions pour prédire la transition entre les régimes ruisselant et pulsé, la perte de pression et le taux de rétention de liquide. L'objectif de cet article est double. D'une part, une synthèse y est présentée ; elle fait état des connaissances acquises sur les divers aspects hydrodynamiques du réacteur triphasique à lit fixe, incluant les récents développements réalisés à hautes pressions. D'autre part, les modèles et les corrélations actuels de transitions de régimes, de la perte de pression et du taux de rétention de liquide sont soumis à une analyse critique en confrontant leurs prédictions à l'ensemble des données expérimentales obtenues pour un large intervalle de la pression de fonctionnement du réacteur. Des conclusions objectives ont pu être tirées concernant les aptitudes des corrélations et des modèles actuels à être utilisées pour les calculs de conception des réacteurs triphasiques à lit fixe industriels. Malheureusement, il apparaît qu'aucun modèle de transitions entre les régimes ruisselant et pulsé n'est satisfaisant. Seule la corrélation empirique de Larachi et al. (1993 s'avère être jusqu'à présent la méthode la plus précise pour prédire la position de la frontière entre les régimes ruisselant et pulsé dans un large domaine de la pression de fonctionnement. Par ailleurs, aucune corr

  6. Gas and electric power opening of the markets. Reality, limits and paradoxes the position of the cogeneration; Gaz electricite ouverture des marches. Realite, limites et paradoxes place de la cogeneration

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    During these two days of the colloquium on gas and electric power market opening, industrial and french administration discussed about the new market deregulation impacts and the cogeneration position in this context. The position of EDF and Gaz De France, the european competition and the government policy are presented. These nineteen papers proposed an economic analysis and the state of the art of the situation. (A.L.B.)

  7. Realisation and tests of a compressed gas Cherenkov counter. Study of the pollution of a beam (1961); Realisation et essais d'un compteur cherenkov a gaz comprime etude de la pollution d'un faisceau (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Duboc, J; Banaigs, J; Detoeuf, J F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    The realisation of a compressed as Cherenkov counter permits the study of the pollution of a beam of {pi} mesons with momentum varying from 220 to 11000 MeV/c. (authors) [French] La realisation d'un compteur Cherenkov a gaz sous pression permet l'etude de la pollution d'un faisceau de mesons {pi} d'impulsions comprise entre 220 et 1100 MeV/c. (auteurs)

  8. Investigation of Methane Hydrate Formation in a Recirculating Flow Loop: Modeling of the Kinetics and Tests of Efficiency of Chemical Additives on Hydrate Inhibition Étude de la formation de l'hydrate de méthane dans une conduite de recirculation : modélisation de la cinétique et tests d'efficacité d'additifs chimiques inhibiteurs d'hydrates de gaz

    Directory of Open Access Journals (Sweden)

    Peytavy J. L.

    2006-12-01

    obstruer les lignes de transport et les installations de traitement d'effluents pétroliers. Pour contrôler ces dépôts d'hydrates, on utilise fréquemment, comme inhibiteurs, le méthanol ou les glycols. Aujourd'hui, les équilibres thermodynamiques des hydrates de gaz sont bien connus ; par contre, les cinétiques de formation et de croissance doivent être étudiées afin de mettre en évidence de nouveaux moyens de contrôle grâce à l'étude des mécanismes de formation des hydrates hors équilibre. Le présent travail propose une étude de la cinétique de formation de l'hydrate de méthane dans une boucle de recirculation de laboratoire dans laquelle le mélange liquide, saturé de méthane, circule à une pression maximum de 75 bar. La pression constante au cours des expériences est maintenue par ajout de gaz frais. Dans un premier temps, nous avons étudié les effets de la pression (35-75 bar, de la vitesse d'écoulement du liquide (0,5-3 m/s, de la rampe de refroidissement (2-15°C/h et de la quantité d'hydrocarbure présent dans la charge (0-96 % sur les cinétiques de formation de l'hydrate. Nous proposons ensuite une nouvelle méthode de prédiction, en premier lieu, des conditions thermodynamiques (pression et température correspondant aux valeurs de vitesse de croissance maximum de l'hydrate, puis de ces vitesses de croissance maximum. Nous avons obtenu un bon accord entre valeurs expérimentales et calculées. Enfin, nous avons évalué, en utilisant la procédure expérimentale décrite précédemment, l'efficacité de quelques inhibiteurs cinétiques et tensioactifs mis au point pour éviter, soit la nucléation, soit la croissance des cristaux et l'agglomératon de particules d'hydrates de méthane.

  9. Depo Gazı Enerji Üretim Tesisi Baca Gazı Atık Isısının Seralarda Değerlendirilmesi: İstanbul Örneği / Utilization of Waste Heat in Energy Production Plant from Landfill Gas at Greenhouses – Case Study in Istanbul

    Directory of Open Access Journals (Sweden)

    Volkan Enç

    2012-12-01

    Full Text Available Evsel atık düzenli depolama sahaları kullanım ömrü dolduktan sonra yararlı kullanım alanları sınırlı sahalardır. Çoğunlukla yeşil alan olarak kullanılan bu yerler ekonomik ve çevresel anlamda atıl durumda bulunmaktadır. Depolama sahalarının İstanbul gibi arazi sıkıntısı çeken bir şehirde yararlı amaçlar için kullanılması elzemdir. Depolama sonrası sahalarda metan gazı oluşmakta ve farklı yöntemlerle kontrol altına alınmaktadır. Bu gazların toplanması, taşınması ve özel motorlarda yakılması ile elektrik enerjisi üretilmektedir. Tesislerde gazın yakılması, depo gazı içerisinde bulunan CH4 (metan gazının CO2’e indirgenmesini sağlayarak sera etkisini azaltmakta, elektrik enerjisi üreterek ekonomiye katkı sağlamaktadır. Çevresel ve ekonomik yarar göz önüne alındığında, depo gazından enerji üretim tesislerinde, enerji üretiminde mümkün olabilecek maksimum verime ulaşılmalıdır. Bu düşünce ile bakıldığında, depo gazı enerji üretim tesisinde oluşan atık ısının değerlendirilemeden atmosfere verilmesi önemli bir sorun olarak ortaya çıkmaktadır. Oldukça yüksek debi ve sıcaklığa sahip bu ısı, enerji bakımından önemli bir potansiyele sahiptir. Bu sıcaklıktaki ve debideki ısının değerlendirilmeden atmosfere verilmesi, çevreyi olumsuz etkilemesinin yanında ekonomik kayıplara yol açmaktadır. Seralarda mevsimlik çiçek üretimi, maliyeti yüksek bir faaliyettir. Maliyetlerin önemli bir kısmını sera ısıtılması ve gübre kullanımı oluşturmaktadır. Isıtma işlemi için Türkiye’nin büyük bir bölümünde kömür ve doğalgaz kullanılmaktadır. Kışın seraların ısıtılması için kullanılan fosil yakıtların hem maliyeti yüksek, hem de çevresel standardı düşüktür. Bu çalışma, İstanbul Kalkınma Ajansı (İSTKA tarafından desteklenen “Depo Gazı Enerji Üretim Tesisi Atık Isının ve Kompostun Seralarda

  10. Measurement of the electron density of a plasma by interferometry with a He - Ne laser ({lambda} = 3.39 {mu}); Mesure de la densite electronique d'un plasma par interferometrie avec un laser He - Ne ({lambda} = 3.39 {mu})

    Energy Technology Data Exchange (ETDEWEB)

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

    1968-07-01

    The characteristics of the He-Ne gas laser used in a simple interferometric technique have been studied. After passing through the plasma, the beam is reflected back into the laser cavity, and the intensity of the laser itself, modulated by this optical feedback, is used to observe the fringes. Furthermore, owing to the coupling of the two laser transitions 0.63{mu} (red) and 3.39{mu} (infra red), interferences in the infra red can be detected by a simple photomultiplier monitoring the red line. This method has been applied to two plasma machines (E.P.P.E. and SABLIER) for spatial and temporal measurements of the mean electron density. (author) [French] Nous avons etudie les caracteristiques d'un laser a gaz He-Ne utilise dans une technique simple d'interferometrie. La lumiere qui traverse le plasma est reinjectee dans le laser, et l'intensite propre de celui-ci, modulee par cette reinjection, sert a observer les franges. De plus, a cause du couplage des deux transitions laser: 0.63{mu} (rouge) et 3.39{mu} (infrarouge), les interferences dans l'infrarouge peuvent etre detectees par un simple photomultiplicateur sensible au rouge. Nous avons applique cette methode a deux machines a plasma (E.P.P.E. et SABLIER) pour la mesure de la densite electronique moyenne en fonction du temps et de l'espace. (auteur)

  11. Catalytic removal of methane and NO{sub x} in lean-burn natural-gas engine exhaust; Elimination par catalyse du methane et des NO{sub x} dans les echappements de moteur au gaz naturel a basse combustion

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, H.; Satokawa, S.; Yahagi, M.; Yamaseki, K.; Hoshi, F.; Uchida, H.; Yokota, H. [Tokyo Gas Co., Ltd. (Japan)

    2000-07-01

    We have developed a new catalytic system to reduce the emissions of hydrocarbons, carbon monoxide (CO), and nitrogen oxides (NO{sub x}) contained in the exhaust gases from a lean-burn natural-gas engine. Catalytic oxidation of unburned hydrocarbons and CO in the exhaust has been studied for noble metals supported on alumina. (1) A low-loading catalyst comprising platinum supported on alumina (Pt/alumina) was efficient for the oxidation of CO and hydrocarbons without methane. The CO conversions were maintained at more than 98 % for 20,000 hours over the Pt/alumina. (2) A catalyst comprising platinum and palladium supported on alumina (Pt-Pd/alumina) exhibited higher levels of oxidation of hydrocarbons (including methane) than a catalyst comprising only palladium supported on alumina (Pd/alumina). Its oxidation also lasted longer. The combined effects of the platinum and palladium metals achieved high sulfur dioxide resistance. Increasing the palladium content in the Pt-Pd/alumina catalyst increased the level of oxidation and extended the lifetime of the catalyst. (3) A catalyst comprising silver supported on alumina (Ag/alumina) was effective at reducing the amount of NO{sub X} by using the unburned hydrocarbons in the exhaust gas. The NO{sub x} conversions over Ag/alumina were maintained at more than 30 % for 3,500 hours. We describe a total clean-up system consisting of a Ag/alumina catalyst and a Pt-Pd/alumina catalyst in series on the exhaust gas stream. (authors)

  12. Study of gas-solid contact in an ultra-rapid reactor for cumene catalytic cracking; Etude du contact gaz-solide dans un reacteur a co-courant descendant par la mise en oeuvre du craquage catalytique du cumene

    Energy Technology Data Exchange (ETDEWEB)

    Bayle, J

    1996-11-05

    Few studies have been carried out on the notion of gas-solid contact in ultra-rapid reactors. Both gas and solid move in the reactor and the contact can be directly estimated when using a chemical reaction such as cumene cracking. It`s a pure and light feedstock whose kinetics can be determined in a fixed bed. The study was carried out on a downflow ultra-rapid reactor (ID = 20 mm, length = 1 m) at the University of Western Ontario. It proved that the quench and the ultra-rapid separation of gas and solid must be carefully designed in the pilot plant. Cumene conversion dropped when reducing gas-solid contact, which led to push the temperature over 550 deg. C and increase the cat/oil ratio at 25 working at solid mass fluxes below 85 kg/m{sup 2}.s. Change of selectivity at very short residence time were also observed due to deactivation effects. Experiments made by Roques (1994) with phosphorescent pigments on the Residence Time Distribution of solids gave Hydrodynamic data on a cold flow copy of the pilot plant. Experiments made on packed bed gave kinetic data on the cracking of cumene. These data were combined to optimize a mono dimensional plug flow model for cumene cracking. (author)

  13. Catalytic N{sub 2}O decomposition in a model tail gas from nitric acid plants; Decomposition catalytique du protoxyde d'azote dans un modele de gaz de queue produits par un atelier d'acide nitrique

    Energy Technology Data Exchange (ETDEWEB)

    Mul, G.; Xu, X.; Perez Ramirez, J.; Vaccaro, A.R.; Kapteijn, F.; Moulijn, J.A. [Delft University of Technology, Faculty of Chemical Technology and Materials Sciences, Delft (Netherlands)

    2001-07-01

    In this study direct catalytic decomposition of N{sub 2}O in simulated tail-gas from nitric acid plants, containing water, oxygen, NO{sub x}, was investigated. Three groups of catalysts were prepared: oxide-supported catalysts; zeolite-based catalysts; mixed oxides derived from hydrotalcites-like (HTLc) materials. The activity of these types of catalysts was tested in an advanced automated six-flow reactor system. Nobel metal (Ru, Rh) based catalysts, either supported on zeolites or ex-hydrotalcite compositions (Mg-Al or Co-Al mixed oxides), and Fe-ZSM-5 effectively decompose N{sub 2}O in tail-gas conditions at temperatures of about 400-450 deg C, typical for certain nitric acid plants. Catalysts active for tail gas temperatures of 230-250 deg C, typical for other nitric acid plants, were not found. This is mainly due to the dramatic negative effect of especially water and NO{sub x} on the conversion of N{sub 2}O. The negative effect of NO{sub x} observed for many catalysts might be related to the formation of surface nitrites and nitrates, blocking active sites for N{sub 2}O decomposition in the 200-300 deg C temperature range. (authors)

  14. Solar process for cold production at low temperature (-28 deg) by solid-gas sorption; Procede solaire de production de froid basse temperature (-28 deg) par sorption solide-gaz

    Energy Technology Data Exchange (ETDEWEB)

    Le Pierres, N.

    2005-09-15

    The aim of this work is the design and experimentation of a thermochemical process for cold production purpose at -28 deg. C using low grade heat (70 deg. C) supplied by flat plate solar collectors. An exergetic analysis of the thermo-chemical dipole and of ideal thermodynamic cycles led to the definition of an original solar process. This process involves two cascaded cycles functioning in parallel. The cycle is discontinuous and presents a day phase of heating and regeneration and a night phase of cold production. A dynamic simulation allowed the study of its functioning depending on the weather conditions and on the dimensions of the process. A prototype covering the needs of a cold chamber loosing 40 W of cold continuously was built and tested in real conditions in Perpignan. It demonstrated the feasibility of this innovative concept and validated the hypothesis used to develop the model. A study of the process functioning was lead by simulation in different meteorological conditions and for different heat sources (solar, geothermal or industrial waste). It showed the potentialities of the concept. (author)

  15. The hydrogen state: from the solid to the gas taking into account the liquid; L'hydrogene dans tous ses etats: du solide au gaz en passant par le liquide

    Energy Technology Data Exchange (ETDEWEB)

    Latroche, M.; Joubert, J.M.; Cuevas, F.; Paul-Boncour, V.; Percheron-Guegan, A. [Centre National de la Recherche Scientifique (CNRS), Institut de Chimie et des Materiaux Paris-Est (CMTR-ICMPE-UMR7182), 94 - Thiais (France)

    2007-07-01

    Hydrogen is considered as a future energy vector. To become a viable solution, the hydrogen storage processes must be safe, economic and adapted to the use possibilities. Today many storage modes offer interesting possibilities but need also more researches before realization of prototypes. These modes are described taking into account the physical (compression, liquefaction) and chemical (adsorption in porous solids and absorption in chemical hydrides) solutions. (A.L.B.)

  16. Two-phase flows during draining of liquefied gases initially undersaturated. Validation by water and CFC11; Ecoulements diphasiques lors de la vidange de gaz liquifies initialement sous satures. Validation par l`eau et le CFC11

    Energy Technology Data Exchange (ETDEWEB)

    May, L.

    1996-12-11

    In petroleum industry, the safety studies require to estimate the two-phase flow during accidental draining of pressurized liquefied gas storages. Meanwhile the mass flow strongly depends of initial conditions. Then it is primordial to be able to reckon it in the case where it is the highest, that is to say when the fluid is initially undersaturated. An experimental installation has been carried out. The used fluids are water and CFC11. The experimental measures show that the thermodynamic conditions at the inlet of the pipe (P at +/- 15 mbar and T at +/- 0.15 degrees Celsius) are well controlled. The measured mass flows are compared to different models. The frictions in the monophase domain have been taken into account. It has been shown that the extensive H.E.M. model perfectly estimates the mass flow (as well as for water than for CFC11) for large deviations to saturation. In order to correctly predict the domain of weak variation to saturation, D.E.M. (out of equilibrium) models or H.R.M. (homogeneous model of relaxation) models have to be used. (O.M.) 50 refs.

  17. Geochemical monitoring using noble gases and carbon isotopes: study of a natural reservoir; Monitoring geochimique par couplage entre les gaz rares et les isotopes du carbone: etude d'un reservoir naturel

    Energy Technology Data Exchange (ETDEWEB)

    Jeandel, E

    2008-12-15

    To limit emissions of greenhouse gases in the atmosphere, CO{sub 2} geological sequestration appears as a solution in the fight against climate change. The development of reliable monitoring tools to ensure the sustainability and the safety of geological storage is a prerequisite for the implementation of such sites. In this framework, a geochemical method using noble gas and carbon isotopes geochemistry has been tested on natural and industrial analogues. The study of natural analogues from different geological settings showed systematic behaviours of the geochemical parameters, depending on the containment sites, and proving the effectiveness of these tools in terms of leak detection and as tracers of the behaviour of CO{sub 2}. Moreover, an experience of geochemical tracing on a natural gas storage has demonstrated that it is possible to identify the physical-chemical processes taking place in the reservoir to a human time scale, increasing interest in the proposed tool and providing general information on its use. (author)

  18. Modeling of gas condensates properties using continuous distribution functions for the characterization of the plus fraction; Modelisation des proprietes thermodynamiques des gaz a condensat par representation de la fraction lourde a l`aide de fonctions de distribution

    Energy Technology Data Exchange (ETDEWEB)

    Sportisse, M.

    1996-12-20

    The modeling of thermodynamic behaviour for gas condensates is not yet satisfactory and it involves an adjustment of thermodynamic models. We propose here a fitting based on the characterization of the plus fraction using three continuous distribution functions associated to the following families: n-alkanes, n-alkylbenzenes and poly-aromatics. No continuous thermodynamic model is used and PVT calculations are made with the Peng-Robinson equation of state. For poly-aromatics, a simple correlation of {l_brace} T{sub c}, P{sub c}, {omega} {r_brace} is given. The parameters of the distributions are fitted in order to improve the accuracy of the liquid deposit curve calculation. A continuous minimization by simulated annealing has been used to avoid local minima. Good results on fitting PVT properties have been obtained with more than twenty gas condensates from different areas. Moreover, the prediction of tank liquid and heavy-plus fraction densities are given with an average deviation of 1.2 % and 3.6 %. Tests on temperature extrapolation show that our modeling yields a good representation of pressure and temperature influence on gas condensates behaviour. (author) 89 refs.

  19. Saclay Reactor: acquired knowledge by two years experience in heat transfer using compressed gas; La pile de Saclay experience acquise en deux ans sur le transfert de chaleur par gaz comprime

    Energy Technology Data Exchange (ETDEWEB)

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

    1955-07-01

    Describes the conception and functioning of a new reactor (EL-2) using compressed gas as primary coolant. The aim of the use of compressed gas as primary coolant is to reduce the quantity of heavy water used in the functioning of the reactor. Description of the reactor vessel (dimensions, materials, reflector and protection). Description of the cells and the circulation of the gas within the cells. A complete explanation of the control and regulating of the reaction by the ionization chamber is given. Heavy water is used as modulator: it describes the heavy water system and its recombination system. The fuel slugs are cooled by compressed gas: its system is described as well as the blower and the heat exchanger system. Water is supplied by a cooling tower which means the reactor power is dependant of the atmospheric conditions. Particular attention has been given to the tightness of the different systems used. The relation between neutron flow and the thermal output is discussed: the thermal output can be calculated by measuring the gas flow and its heating or by measuring the neutron flow within the reactor, both methods gives closed results. Reactivity study: determination of the different factors which induce a variation of reactivity. Heat transfer: discussion on the use of different heat transfer systems, determination of the required chemical and physical properties of the primary coolant as well as the discussion of the nuclear and thermal requirements for the choice of it. A comparison between the use of nitrogen and carbon dioxide gas shows an advantage in using nitrogen with the existing knowledge. Reflexion on the relevance of this work and the future perspectives of the use of compressed gas as primary coolant. (M.P.)

  20. Recent progress in the determination of gases in metals by emission spectrography (1963); Progres recents dans la determination des gaz dans les metaux par spectrographie d'emission (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, G; Melamed, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1963-07-01

    The Fassel method for analysis of bases in metals was used. By employing a smaller, completely cooled chamber greater sensitivity and lover blank values were obtained. A straight calibration curve, independent of the sample nature was established for oxygen using graphite pellets containing known amounts of ZnO and SnO{sub 2}. The calibration curve for hydrogen was obtained from previously analysed Zircaloy samples. In bath cases a lower limit of sensitivity of 15 {mu}g was attained. (authors) [French] On a utilise la methode Fassel pour l'analyse des metalloides dans les metaux. En employant une chambre de volume reduit avec refroidissement des parois, ou a pu abaisser la limite de sensibilite et reduire le blanc a une valeur negligeable. Une courbe de dosage pour l'oxygene, lineaire jusqu'a environ 15 {mu}g et independante de la nature de l'echantillon, a ete obtenue a partir des melanges oxyde de zinc + graphite et oxyde d'etain + graphite. Une courbe de dosage pour l'hydrogene lineaire jusqu'a 15 {mu}g a ete obtenue en partant d'echantillons de Zircaloy a teneur connue en hydrogene. (auteurs)

  1. Production de vapeur d'uranium par pulverisation cathodique dans une cathode creuse: efficacites relatives des gaz Ne, Ar, Kr et concentration a l'etat 5L06

    International Nuclear Information System (INIS)

    Gagne, J.M.; Mongeau, B.; Leblanc, B.; Saint-Dizier, J.P.; Pianarosa, P.; Bertrand, L.

    1978-01-01

    We have investigate the production of uranium vapors in the 5 L 0 6 ground state using a sputtering technique. We have also compared the performance of the Ne, Ar, Kr gases as carrier agents. We have found that the krypton gas gives a maximum yield with minimum energy. Finally the density of U vapors has been found to be of the order of 10 12 atmos cm -3

  2. Adsorption process analysis at the solid-gas interface by the polarization phenomenon study; Analyse des processus d`adsorption a l`interface solide - gaz par l`etude du phenomene de polarisation

    Energy Technology Data Exchange (ETDEWEB)

    Mouton-Chazel, V

    1994-10-05

    In order to improve the safety of anti-gas filters users, the Cogema (Nuclear Materials General Company) has developed a gaseous pollutants saturation detection technology for respiratory protection masks. As a matter of fact, the problem consists in studying the surface properties of a solid. In this study the adsorption has been considered as a phenomenon which can be followed by a relatively simple electrical measure technology. A microscopic description of the adsorption phenomenon has been given at first and explained by the thermodynamics laws. Then a theoretical model has been elaborated. The developments which have been brought to this model in this work have allowed to give a satisfactory interpretation of the phenomena observed during the adsorption of a polar gas on a zeolite. (O.M.). 169 refs.

  3. PARs for combustible gas control in advanced light water reactors

    International Nuclear Information System (INIS)

    Hosler, J.; Sliter, G.

    1997-01-01

    This paper discusses the progress being made in the United States to introduce passive autocatalytic recombiner (PAR) technology as a cost-effective alternative to electric recombiners for controlling combustible gas produced in postulated accidents in both future Advanced Light Water Reactors (ALWRs) and certain U. S. operating nuclear plants. PARs catalytically recombine hydrogen and oxygen, gradually producing heat and water vapor. They have no moving parts and are self-starting and self-feeding, even under relatively cold and wet containment conditions. Buoyancy of the hot gases they create sets up natural convective flow that promotes mixing of combustible gases in a containment. In a non-inerted ALWR containment, two approaches each employing a combination of PARs and igniters are being considered to control hydrogen in design basis and severe accidents. In pre-inerted ALWRs, PARs alone control radiolytic oxygen produced in either accident type. The paper also discusses regulatory feedback regarding these combustible gas control approaches and describes a test program being conducted by the Electric Power Research Institute (EPRI) and Electricite de France (EdF) to supplement the existing PAR test database with performance data under conditions of interest to U.S. plants. Preliminary findings from the EPRI/EdF PAR model test program are included. Successful completion of this test program and confirmatory tests being sponsored by the U. S. NRC are expected to pave the way for use of PARs in ALWRs and operating plants. (author)

  4. Gaz - almaz / Jekaterina Rodina

    Index Scriptorium Estoniae

    Rodina, Jekaterina

    2008-01-01

    Venemaa Energiapoliitika Instituudi arvutuste kohaselt võib maagaasi tootmise ja nõudluse vahe ulatuda 2010. aastaks 100 miljardi kuupmeetrini, Kui maagaasi tarned Eestisse ära jäävad, saab meie riik omal jõul hakkama kõige rohkem kuu aega. Vt. samas: Gaas arvudes

  5. Gas mission; Mission gaz

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This preliminary report analyses the desirable evolutions of gas transport tariffing and examines some questions relative to the opening of competition on the French gas market. The report is made of two documents: a synthesis of the previous report with some recommendations about the tariffing of gas transport, about the modalities of network access to third parties, and about the dissociation between transport and trade book-keeping activities. The second document is the progress report about the opening of the French gas market. The first part presents the European problem of competition in the gas supply and its consequences on the opening and operation of the French gas market. The second part presents some partial syntheses about each topic of the mission letter of the Ministry of Economics, Finances and Industry: future evolution of network access tariffs, critical analysis of contractual documents for gas transport and delivery, examination of auxiliary services linked with the access to the network (modulation, balancing, conversion), consideration about the processing of network congestions and denied accesses, analysis of the metering dissociation between the integrated activities of gas operators. Some documents are attached in appendixes: the mission letter from July 9, 2001, the detailed analysis of the new temporary tariffs of GdF and CFM, the offer of methane terminals access to third parties, the compatibility of a nodal tariffing with the presence of three transport operators (GdF, CFM and GSO), the contract-type for GdF supply, and the contract-type for GdF connection. (J.S.)

  6. uPAR as anti-cancer target

    DEFF Research Database (Denmark)

    Lund, Ida K; Illemann, Martin; Thurison, Tine

    2011-01-01

    , and a potential diagnostic and predictive impact of the different uPAR forms has been reported. Hence, pericellular proteolysis seems to be a suitable target for anti-cancer therapy and numerous approaches have been pursued. Targeting of this process may be achieved by preventing the binding of uPA to u...... using mouse monoclonal antibodies (mAbs) against mouse uPA or uPAR. These reagents will target uPA and uPAR in both stromal cells and cancer cells, and their therapeutic potential can now be assessed in syngenic mouse cancer models....

  7. Limnological database for Par Pond: 1959 to 1980

    International Nuclear Information System (INIS)

    Tilly, L.J.

    1981-03-01

    A limnological database for Par Pond, a cooling reservoir for hot reactor effluent water at the Savannah River Plant, is described. The data are derived from a combination of research and monitoring efforts on Par Pond since 1959. The approximately 24,000-byte database provides water quality, primary productivity, and flow data from a number of different stations, depths, and times during the 22-year history of the Par Pond impoundment. The data have been organized to permit an interpretation of the effects of twenty years of cooling system operations on the structure and function of an aquatic ecosystem

  8. Protease-activated receptor (PAR2, but not PAR1, is involved in collateral formation and anti-inflammatory monocyte polarization in a mouse hind limb ischemia model.

    Directory of Open Access Journals (Sweden)

    Lisa G van den Hengel

    Full Text Available AIMS: In collateral development (i.e. arteriogenesis, mononuclear cells are important and exist as a heterogeneous population consisting of pro-inflammatory and anti-inflammatory/repair-associated cells. Protease-activated receptor (PAR1 and PAR2 are G-protein-coupled receptors that are both expressed by mononuclear cells and are involved in pro-inflammatory reactions, while PAR2 also plays a role in repair-associated responses. Here, we investigated the physiological role of PAR1 and PAR2 in arteriogenesis in a murine hind limb ischemia model. METHODS AND RESULTS: PAR1-deficient (PAR1-/-, PAR2-deficient (PAR2-/- and wild-type (WT mice underwent femoral artery ligation. Laser Doppler measurements revealed reduced post-ischemic blood flow recovery in PAR2-/- hind limbs when compared to WT, while PAR1-/- mice were not affected. Upon ischemia, reduced numbers of smooth muscle actin (SMA-positive collaterals and CD31-positive capillaries were found in PAR2-/- mice when compared to WT mice, whereas these parameters in PAR1-/- mice did not differ from WT mice. The pool of circulating repair-associated (Ly6C-low monocytes and the number of repair-associated (CD206-positive macrophages surrounding collaterals in the hind limbs were increased in WT and PAR1-/- mice, but unaffected in PAR2-/- mice. The number of repair-associated macrophages in PAR2-/- hind limbs correlated with CD11b- and CD115-expression on the circulating monocytes in these animals, suggesting that monocyte extravasation and M-CSF-dependent differentiation into repair-associated cells are hampered. CONCLUSION: PAR2, but not PAR1, is involved in arteriogenesis and promotes the repair-associated response in ischemic tissues. Therefore, PAR2 potentially forms a new pro-arteriogenic target in coronary artery disease (CAD patients.

  9. Novel role for proteinase-activated receptor 2 (PAR2) in membrane trafficking of proteinase-activated receptor 4 (PAR4).

    Science.gov (United States)

    Cunningham, Margaret R; McIntosh, Kathryn A; Pediani, John D; Robben, Joris; Cooke, Alexandra E; Nilsson, Mary; Gould, Gwyn W; Mundell, Stuart; Milligan, Graeme; Plevin, Robin

    2012-05-11

    Proteinase-activated receptors 4 (PAR(4)) is a class A G protein-coupled receptor (GPCR) recognized through the ability of serine proteases such as thrombin and trypsin to mediate receptor activation. Due to the irreversible nature of activation, a fresh supply of receptor is required to be mobilized to the cell surface for responsiveness to agonist to be sustained. Unlike other PAR subtypes, the mechanisms regulating receptor trafficking of PAR(4) remain unknown. Here, we report novel features of the intracellular trafficking of PAR(4) to the plasma membrane. PAR(4) was poorly expressed at the plasma membrane and largely retained in the endoplasmic reticulum (ER) in a complex with the COPI protein subunit β-COP1. Analysis of the PAR(4) protein sequence identified an arginine-based (RXR) ER retention sequence located within intracellular loop-2 (R(183)AR → A(183)AA), mutation of which allowed efficient membrane delivery of PAR(4). Interestingly, co-expression with PAR(2) facilitated plasma membrane delivery of PAR(4), an effect produced through disruption of β-COP1 binding and facilitation of interaction with the chaperone protein 14-3-3ζ. Intermolecular FRET studies confirmed heterodimerization between PAR(2) and PAR(4). PAR(2) also enhanced glycosylation of PAR(4) and activation of PAR(4) signaling. Our results identify a novel regulatory role for PAR(2) in the anterograde traffic of PAR(4). PAR(2) was shown to both facilitate and abrogate protein interactions with PAR(4), impacting upon receptor localization and cell signal transduction. This work is likely to impact markedly upon the understanding of the receptor pharmacology of PAR(4) in normal physiology and disease.

  10. Contribution to the study and to the development of continuous infrared absorption analyzers; Contribution a l'etude et a la mise au point des analyseurs en continu par absorption infrarouge

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-12-01

    The continuous infra-red absorption determination of corrosive gases implies the construction of an original single-beam spectrometer. The use of a vibration-rotation line means that the apparatus function has to undergo an alternating displacement: for one position this function is centered on the line, for other position it is placed close by, but away from any absorption. A non-linear relationship is derived between the concentration of the impurity under consideration, the optical density measured at the centre of the line and the total pressure of the gas mixture. The problem is then solved using an associated specific analog computer. The system is applicable to the determination of low concentrations. The principle proposed in then adapted to an analysis using a non-resolved vibration-rotation band. (authors) [French] Le dosage en continu par absorption infrarouge des gaz corrosifs, implique la construction d'un spectrometre original en simple faisceau. L'utilisation d'une raie de vibration - rotation, conduit a effectuer un deplacement alternatif de la fonction d'appareil: pour une position, celle-ci est centree sur la raie, pour l'autre position elle est placee a proximite mais en dehors de toute absorption. On etablit une relation non lineaire entre la concentration de l'impurete consideree, la densite optique mesuree au centre de la raie et la pression totale du melange gazeux. Le probleme est alors resolu par un calculateur analogique specifique associe. Le systeme s'applique au dosage des faibles concentrations. Le principe propose est ensuite adapte a l'analyse a partir d'une bande de vibration - rotation non resolue. (auteurs)

  11. Fast Plasma from a Coaxial Gun; Plasma Rapide Produit par un Canon Coaxial; Bystraya plazma iz koaksial'nogo inzhektora; Produccion de Plasma Rapido Mediante un Inyector Coaxial

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, J.; Henins, I. [Los Alamos Scientific Laboratory, Los Alamos, NM (United States)

    1966-04-15

    volume around the jet. Fast plasma is emitted in a narrow conical distribution with an open centre. The high voltage which accelerates the fast deuterohs also accelerates wall material ions if the fast plasma bombards a glass wall and evaporates it. (author) [French] Le canon coaxial utilise dans cette experience est une source de deux plasmas differents produits par des mecanismes separes. Un plasma de deuterium abondant et lent ( Tilde-Operator 10{sup 7} cm/s) est produit directement par l'interaction du type j xli ou j est le courant de plasma radial et if le champ magnetique produit par le courant d'alimentation le long de l'electrode centrale. La perturbation de courant se deplace, a travers le gaz injecte, vers l'ouverture du canon, a une vitesse d'environ 2,5 * 10{sup 7} cm/s et emmagasine de l'energie a l'arriere sous forme de champ magnetique et d'energie cinetique de plasma. Par son energie emmagasinee, le canon fonctionne comme un generateur electrique de basse impedence et de grande puissance de maniere a lancer dans le vide au-dela de l'ouverture du canon un jet de courant qui est la source de plasma rapide ( Tilde-Operator 5 x 10{sup 17} deuterons, Tilde-Operator 10{sup 8} cm/s). Le jet de courant ainsi que le plasma qu'il produit font l'objet des experiences decrites dans ce memoire. Le mecanisme de l'acceleration est complique et n'est pas parfaitement connu, mais beaucoup d'enseignements ont ete tires d'un grand nombre d'experiences dans lesquelles ont ete utilises les diagnostics suivants: boucles de captage diamagnetique externes, boucles Rogowsky sous vide, sondes electriques, electrode de captage capacitive externe, analyse de la deflection magnetique et electrostatique de particules, spectroscopic, photographie de la lumiere emise par les cibles, mesure de temps de vol avec ou sans champ de guidage, neutrons emis par le volume,du plasma par suite de la reaction d-d, etc. Il en resulte que le mecanisme d'acceleration consiste en un processus magneto

  12. Positron Accumulator Ring (PAR) power supply

    International Nuclear Information System (INIS)

    Fathizadeh, M.

    1995-01-01

    The Positron Accumulator Ring (PAR) consists of 8 dipole magnets connected in series. These magnets are energized via one 12-pulse dc power supply. The power supply consists of four phase controlled half-wave wye group converters. Each of the two half-wave converters are connected through an interphase transformer to obtain a full-wave converter with 120 degrees conduction. The input voltage for these two half-wave converters are 180 degrees apart. The two full-wave converters are connected in parallel through a third interphase transformer. This type of connection of the converters not only provides the required output current, it also improves the input power factor of the power supply. The output of the wye group converters is filtered through a passive L-R-C filter to reduce the ripple content of the output current. At low current values of the power supply the current ripple is high, thus a large filter is needed, which adds to the cost of the power supply, however at high output current levels, the current ripple is less severe. The large size of the filter can be reduced by adding an anti-parallel rectifier diode(D1) to the output of the power supply. A freewheeling diode(D2) is connected before the choke to circulate the current once the power supply is turned off. In order to measure the current in the magnet a high precision, low drift, zero flux current transductor is used. This transductor senses the magnet current which provides a feedback signal to control the gating of the converter's thyristors. A true 14 bit Digital to Analog Converter (DAC) is programmed by the control computer for the required current value, providing a reference for the current regulator. Fast correction of the line transients is provided by a relatively fast voltage loop controlled by a high gain slow response current loop

  13. First-in-human uPAR PET

    DEFF Research Database (Denmark)

    Persson, Morten; Skovgaard, Dorthe; Brandt-Larsen, Malene

    2015-01-01

    A first-in-human clinical trial with Positron Emission Tomography (PET) imaging of the urokinase-type plasminogen activator receptor (uPAR) in patients with breast, prostate and bladder cancer, is described. uPAR is expressed in many types of human cancers and the expression is predictive...... for targeted molecular imaging with PET. The safety, pharmacokinetic, biodistribution profile and radiation dosimetry after a single intravenous dose of (64)Cu-DOTA-AE105 were assessed by serial PET and computed tomography (CT) in 4 prostate, 3 breast and 3 bladder cancer patients. Safety assessment...... of invasion, metastasis and indicates poor prognosis. uPAR PET imaging therefore holds promise to be a new and innovative method for improved cancer diagnosis, staging and individual risk stratification. The uPAR specific peptide AE105 was conjugated to the macrocyclic chelator DOTA and labeled with (64)Cu...

  14. Peptide-Based Optical uPAR Imaging for Surgery

    DEFF Research Database (Denmark)

    Juhl, Karina; Christensen, Anders; Persson, Morten

    2016-01-01

    Near infrared intra-operative optical imaging is an emerging technique with clear implications for improved cancer surgery by enabling a more distinct delineation of the tumor margins during resection. This modality has the potential to increase the number of patients having a curative radical...... tumor resection. In the present study, a new uPAR-targeted fluorescent probe was developed and the in vivo applicability was evaluated in a human xenograft mouse model. Most human carcinomas express high level of uPAR in the tumor-stromal interface of invasive lesions and uPAR is therefore considered...... an ideal target for intra-operative imaging. Conjugation of the flourophor indocyanine green (ICG) to the uPAR agonist (AE105) provides an optical imaging ligand with sufficiently high receptor affinity to allow for a specific receptor targeting in vivo. For in vivo testing, human glioblastoma xenograft...

  15. Contribution de la tomographie par coherence optique au diagnostic ...

    African Journals Online (AJOL)

    Contribution de la tomographie par coherence optique au diagnostic de la neuropathie optique toxique. C.O.A. Abouki, S Alamou, C.R.A. Assavedo, L Odoulami-Yehouessi, I Sounouvou, S Hounnou-Tchabi ...

  16. Analysis of ParB-centromere interactions by multiplex SPR imaging reveals specific patterns for binding ParB in six centromeres of Burkholderiales chromosomes and plasmids.

    Directory of Open Access Journals (Sweden)

    Flavien Pillet

    Full Text Available Bacterial centromeres-also called parS, are cis-acting DNA sequences which, together with the proteins ParA and ParB, are involved in the segregation of chromosomes and plasmids. The specific binding of ParB to parS nucleates the assembly of a large ParB/DNA complex from which ParA-the motor protein, segregates the sister replicons. Closely related families of partition systems, called Bsr, were identified on the chromosomes and large plasmids of the multi-chromosomal bacterium Burkholderia cenocepacia and other species from the order Burkholeriales. The centromeres of the Bsr partition families are 16 bp palindromes, displaying similar base compositions, notably a central CG dinucleotide. Despite centromeres bind the cognate ParB with a narrow specificity, weak ParB-parS non cognate interactions were nevertheless detected between few Bsr partition systems of replicons not belonging to the same genome. These observations suggested that Bsr partition systems could have a common ancestry but that evolution mostly erased the possibilities of cross-reactions between them, in particular to prevent replicon incompatibility. To detect novel similarities between Bsr partition systems, we have analyzed the binding of six Bsr parS sequences and a wide collection of modified derivatives, to their cognate ParB. The study was carried out by Surface Plasmon Resonance imaging (SPRi mulitplex analysis enabling a systematic survey of each nucleotide position within the centromere. We found that in each parS some positions could be changed while maintaining binding to ParB. Each centromere displays its own pattern of changes, but some positions are shared more or less widely. In addition from these changes we could speculate evolutionary links between these centromeres.

  17. Analysis of ParB-centromere interactions by multiplex SPR imaging reveals specific patterns for binding ParB in six centromeres of Burkholderiales chromosomes and plasmids.

    Science.gov (United States)

    Pillet, Flavien; Passot, Fanny Marie; Pasta, Franck; Anton Leberre, Véronique; Bouet, Jean-Yves

    2017-01-01

    Bacterial centromeres-also called parS, are cis-acting DNA sequences which, together with the proteins ParA and ParB, are involved in the segregation of chromosomes and plasmids. The specific binding of ParB to parS nucleates the assembly of a large ParB/DNA complex from which ParA-the motor protein, segregates the sister replicons. Closely related families of partition systems, called Bsr, were identified on the chromosomes and large plasmids of the multi-chromosomal bacterium Burkholderia cenocepacia and other species from the order Burkholeriales. The centromeres of the Bsr partition families are 16 bp palindromes, displaying similar base compositions, notably a central CG dinucleotide. Despite centromeres bind the cognate ParB with a narrow specificity, weak ParB-parS non cognate interactions were nevertheless detected between few Bsr partition systems of replicons not belonging to the same genome. These observations suggested that Bsr partition systems could have a common ancestry but that evolution mostly erased the possibilities of cross-reactions between them, in particular to prevent replicon incompatibility. To detect novel similarities between Bsr partition systems, we have analyzed the binding of six Bsr parS sequences and a wide collection of modified derivatives, to their cognate ParB. The study was carried out by Surface Plasmon Resonance imaging (SPRi) mulitplex analysis enabling a systematic survey of each nucleotide position within the centromere. We found that in each parS some positions could be changed while maintaining binding to ParB. Each centromere displays its own pattern of changes, but some positions are shared more or less widely. In addition from these changes we could speculate evolutionary links between these centromeres.

  18. Prise en charge des intoxications par envenimation chez les enfants ...

    African Journals Online (AJOL)

    Les signes cliniques étaient dominés par les douleurs (98%) suivies des hémorragies (73,80%) pour les morsures de serpent, la douleur pour les piqures de scorpion (100%) et les oedèmes pour les piqures d'abeilles (100%). Les cas de morsure de serpent ont été traités par le sérum antivenimeux polyvalent. Conclusion: ...

  19. Intoxication par la paraphényléne-diamine

    African Journals Online (AJOL)

    raoul

    9 mars 2011 ... remède contre la douleur par Averbukh [8], ou contre la constipation par Schemesh [9], mais l´utilisation à des fins autolytique reste toujours prédominante. Le tableau clinique de l´intoxication à ... une anurie ayant nécessité le recours à l´hémodialyse. Ce taux de survenue d´IRA anurique est relativement ...

  20. Croissance epitaxiale de GaAs sur substrats de Ge par epitaxie par faisceaux chimiques

    Science.gov (United States)

    Belanger, Simon

    La situation energetique et les enjeux environnementaux auxquels la societe est confrontee entrainent un interet grandissant pour la production d'electricite a partir de l'energie solaire. Parmi les technologies actuellement disponibles, la filiere du photovoltaique a concentrateur solaire (CPV pour concentrator photovoltaics) possede un rendement superieur et mi potentiel interessant a condition que ses couts de production soient competitifs. La methode d'epitaxie par faisceaux chimiques (CBE pour chemical beam epitaxy) possede plusieurs caracteristiques qui la rendent interessante pour la production a grande echelle de cellules photovoltaiques a jonctions multiples a base de semi-conducteurs III-V. Ce type de cellule possede la meilleure efficacite atteinte a ce jour et est utilise sur les satellites et les systemes photovoltaiques a concentrateur solaire (CPV) les plus efficaces. Une des principales forces de la technique CBE se trouve dans son potentiel d'efficacite d'utilisation des materiaux source qui est superieur a celui de la technique d'epitaxie qui est couramment utilisee pour la production a grande echelle de ces cellules. Ce memoire de maitrise presente les travaux effectues dans le but d'evaluer le potentiel de la technique CBE pour realiser la croissance de couches de GaAs sur des substrats de Ge. Cette croissance constitue la premiere etape de fabrication de nombreux modeles de cellules solaires a haute performance decrites plus haut. La realisation de ce projet a necessite le developpement d'un procede de preparation de surface pour les substrats de germanium, la realisation de nombreuses sceances de croissance epitaxiale et la caracterisation des materiaux obtenus par microscopie optique, microscopie a force atomique (AFM), diffraction des rayons-X a haute resolution (HRXRD), microscopie electronique a transmission (TEM), photoluminescence a basse temperature (LTPL) et spectrometrie de masse des ions secondaires (SIMS). Les experiences ont permis

  1. Some equipment for graphite research in swimming pool reactors; Quelques dispositifs d'etude du graphite dans les piles piscines

    Energy Technology Data Exchange (ETDEWEB)

    Seguin, M; Arragon, Ph; Dupont, G; Gentil, J; Tanis, G [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1964-07-01

    The irradiation devices described are used for research concerning reactors of the natural uranium type, moderated by graphite and cooled by carbon dioxide. The devices are generally designed for use in swimming pool reactors. The following points have been particularly studied: - maximum use of the irradiation volume, - use of the simplest technological solutions, - standardization of certain constituent parts. This standardization calls for precision machining and careful assembling; these requirements are also true when a relatively low irradiation temperature is required and the nuclear heating is pronounced. Finally, the design of these devices is suitable for the irradiation of other fissile or non-fissile materials. (authors) [French] Les dispositifs d'irradiation decrits servent aux etudes relatives a la filiere des reacteurs a uranium naturel, moderes au graphite et refroidis par le gaz carbonique. Ils sont generalement concus pour etre utilises dans des piles piscines. L'accent a ete mis sur: - l'utilisation au maximum du volume d'irradiation, - le recours aux solutions technologiques les plus simples, - la standardisation de certaines parties constitutives. Cette standardisation impose un usinage precis et un montage soigne, lesquels sont egalement necessaires lorsqu'on doit obtenir une temperature d'irradiation relativement basse alors que l'echauffement nucleaire est important. Enfin, la conception de ces dispositifs est valable pour irradier d'autres materiaux non fissiles ou fissiles. (auteurs)

  2. Thermo-pneumatic canning; Le gainage thermopneumatique

    Energy Technology Data Exchange (ETDEWEB)

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

    1958-07-01

    In the thermo-pneumatic canning, the fuel is enclosed in its can with a clearance that must be reduced by external heated gas pressure. The principal applications are: a) binding magnesium cans on to uranium in fuel elements of reactors cooled by CO{sub 2} under pressure, b) application of a can to a hollow bar of uranium too thin to resist the pressure of cold hydraulic canning, c) application of an aluminium can to a bar, with an initial diametrical clearance between uranium and can too great to sustain cold hydraulic canning without buckling, d) detection of major leakage in the slugs. (author) [French] Ce procede consiste a appliquer une gaine sur une barre d'uranium par pression hydrostatique d'un gaz chaud. Les principales applications sont: a) le frettage des gaines de magnesium des elements combustibles des piles refroidies au CO{sub 2} sous pression, b) le gainage d'un barreau creux qui serait ecrase a froid, c) le gainage avec un jeu initial trop fort pour etre effectue a froid sans plisser, d) la detection des fuites de cartouches. (auteur)

  3. A Study of the Diffusion and Precipitation of Rare Gases in Metals; Étude de la diffusion et de la précipitation des gaz rares dans les métaux; ИЗУЧЕНИЕ РАСПРОСТРАНЕНИЯ И ОСАЖДЕНИЯ ИНЕРТНЫХ ГАЗОВ В МЕТАЛЛАХ; Estudio de la difusion y de la precipitacion de los gases nobles en los metales

    Energy Technology Data Exchange (ETDEWEB)

    Brebec, M. Gilbert; Levy, Viviane; Leteurtre, Jean; Adda, Yves [Centre d' Études Nucléaires de Saclay, Gif-sur-Yvette (S. et O.) (France)

    1963-08-15

    In an attempt to explain the mechanism of swelling of irradiated uranium, we studied the behaviour ol various rare gases(helium, argon, krypton, xenon) in several metals (silver, zirconium, uranium). Rare-gas/metal alloys of different concentrations were produced by electric discharge. It was shown that the introduction mechanism is probably based on the penetration of rare gas ions into the metallic lattice combined with redeposition. Using these alloys we studied: (a) Changes in the crystal lattice, including variations in crystal parameter due to introduction of rare gases into the lattice, and formation of defects through bombardment by the rare gas ions. (b) Diffusion of the Xe and Kr fission gases in various metals (silver, uranium). (c) Precipitation of rare gases (helium, argon, xenon, krypton) in the form of bubbles in various metals (silver, uranium, zirconium). These studies were carried out partly by optical microscopy and partly by transmission electron microscopy. (author) [French] En vue d'essayer de préciser les mécanismes du gonflement de l'uranium irradié nous avons étudié le comportement de différents gaz rares (hélium, argon, krypton, xénon) dans différents métaux (argent, zirconium, uranium). Des alliages gaz rare-métal de différentes concentrations ont été réalisés par décharge électrique. On a montré que le mécanisme d'introduction est probablement basé sur une pénétration des ions gaz rare dans le réseau métallique combinée à une redéposition. Sur de tels alliages nous avons étudié: a) Les modifications du réseau cristallin. - Variations de paramètre cristallin dû à l'introduction des gaz rares dans le réseau. - Création de défauts dus au bombardement par les ions gaz rares. b) La diffusion des gaz de fission Xe et Kr dans différents métaux (argent, uranium). c) La précipitation des gaz rares (hélium, argon, xénon, krypton) sous forme de bulles dans différents métaux (argent, uranium, zirconium

  4. Instrument for continuous supervision of the radioactivity of CO{sub 2} coolant in piles - DCCA -CO{sub 2} (1960); Dispositif de controle continu de la radioactivite du CO{sub 2} de refroidissement des piles - DCCA - CO{sub 2} (1960)

    Energy Technology Data Exchange (ETDEWEB)

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

    1960-07-01

    This paper describes an apparatus for continuous measurement of CO{sub 2} activity, which can be used on piles cooled by circulation of gas. The first part is devoted mainly to describing the apparatus used and the character of the radioactivity and thermodynamic measurements carried out, and giving the general characteristics of the gas circuit required if the instrument is to be suitably gas-tight. In the second part theoretical calculations are given, particularly on the determination of the ionisation current in an ionisation chamber with circulating gas. Several parameters enter into this determination, such as the mean path of {beta} particles in the ionisation chamber, the linear number of ion pairs formed in the gas by these {beta} particles as a function of their energy, the temperature and pressure of the gas in the ionisation chamber. This part also evaluates the sensitivity areas of the apparatus for measuring the concentrations of radioactive gases such as argon-41 and fission gases from uranium-235 in the CO{sub 2} coolant. In the last part are described the results of measurements performed with such an apparatus on the pile EL2, the special investigations carried out on the CO{sub 2} coolant of this pile, and the information gained during normal operation and during accidents. The DCCA - CO{sub 2} which has just been put in operation at G2 is briefly presented. In the conclusion the possibilities offered by this apparatus are underlined. (author) [French] Ce rapport a pour but de presenter le Dispositif de Controle continu de l'Activite du CO{sub 2} pouvant etre utilise aupres des piles refroidies par une circulation de gaz. La premiere partie du rapport consiste essentiellement a decrire l'ensemble de l'appareillage mis en oeuvre, a preciser la nature des mesures de radioactivite et de thermodynamique effectuees et a citer les caracteristiques generales du circuit de gaz pour avoir un dispositif presentant une etancheite efficace. Dans la seconde

  5. Instrument for continuous supervision of the radioactivity of CO{sub 2} coolant in piles - DCCA -CO{sub 2} (1960); Dispositif de controle continu de la radioactivite du CO{sub 2} de refroidissement des piles - DCCA - CO{sub 2} (1960)

    Energy Technology Data Exchange (ETDEWEB)

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

    1960-07-01

    This paper describes an apparatus for continuous measurement of CO{sub 2} activity, which can be used on piles cooled by circulation of gas. The first part is devoted mainly to describing the apparatus used and the character of the radioactivity and thermodynamic measurements carried out, and giving the general characteristics of the gas circuit required if the instrument is to be suitably gas-tight. In the second part theoretical calculations are given, particularly on the determination of the ionisation current in an ionisation chamber with circulating gas. Several parameters enter into this determination, such as the mean path of {beta} particles in the ionisation chamber, the linear number of ion pairs formed in the gas by these {beta} particles as a function of their energy, the temperature and pressure of the gas in the ionisation chamber. This part also evaluates the sensitivity areas of the apparatus for measuring the concentrations of radioactive gases such as argon-41 and fission gases from uranium-235 in the CO{sub 2} coolant. In the last part are described the results of measurements performed with such an apparatus on the pile EL2, the special investigations carried out on the CO{sub 2} coolant of this pile, and the information gained during normal operation and during accidents. The DCCA - CO{sub 2} which has just been put in operation at G2 is briefly presented. In the conclusion the possibilities offered by this apparatus are underlined. (author) [French] Ce rapport a pour but de presenter le Dispositif de Controle continu de l'Activite du CO{sub 2} pouvant etre utilise aupres des piles refroidies par une circulation de gaz. La premiere partie du rapport consiste essentiellement a decrire l'ensemble de l'appareillage mis en oeuvre, a preciser la nature des mesures de radioactivite et de thermodynamique effectuees et a citer les caracteristiques generales du circuit de gaz pour avoir un dispositif presentant une etancheite efficace

  6. Mesure et modélisation multidimensionnelle des transferts thermiques gaz-paroi dans le cas des moteurs à allumage commandé Measurement and Multidimensional Modeling of Gas-Wall Heat Transfers in Spark-Ignition Engines

    Directory of Open Access Journals (Sweden)

    Gilaber P.

    2006-11-01

    Full Text Available A cette fin, deux étapes de recherche ont été mises en oeuvre : une phase expérimentale et une phase calcul. Dans la phase expérimentale, des mesures ont été faites sur un moteur monocylindre équipé de flux-mètres à réponse rapide. Chaque flux-mètre est composé d'un cylindre d'acier, contenant deux thermocouples. Dans le but de montrer l'influence de l'aérodynamique sur les échanges thermiques, un anémomètre à Laser a été utilisé à l'aide d'une entretoise placée entre culasse et cylindre. L'entretoise comportait deux hublots et deux flux-mètres permettant la mesure simultanée des flux thermiques et des paramètres aérodynamiques à l'extérieur de la couche limite. Deux flux-mètres supplémentaires ont été placés dans la culasse et le système d'acquisition permettait d'enregistrer simultanément dix voies de mesure à chaque degré vilebrequin, parmi lesquelles deux composantes de vitesse et la pression cylindre. Une étude paramétrique a révélé les tendances suivantes : - les pertes globales aux parois au cours d'un cycle thermodynamique diminuent lorsque le régime augmente, mais la valeur maximale des flux locaux augmente en raison de l'élévation du niveau de turbulence; - le remplissage a peu d'effet sur l'aérodynamique; son influence sur les transferts thermiques est due principalement à l'augmentation de la densité des gaz, qui se traduit par une augmentation des flux. Dans la phase calcul, deux idées de base ont guidé notre travail : - pour des raisons de temps de calcul prohibitif, il est impossible de mailler la couche limite; les échanges thermiques ont donc été estimés à l'aide d'une loi de paroi; - on fait l'hypothèse que les champs locaux de densité, vitesse et turbulence conditionnent fortement les flux thermiques; ce seront les paramètres de la loi de paroi. Dans cet esprit, le modèle de transferts thermiques de DIWAKAR a été introduit dans le code multi-dimensionnel KIVA. Une

  7. The behaviour of some polyatomic gases in nuclear reactors; Le comportement de quelques gaz polyatomiques dans les reacteurs nucleaires

    Energy Technology Data Exchange (ETDEWEB)

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

    1958-07-01

    'influence des radiations. La radiolyse de NH{sub 3}, procede par un mecanisme complexe, et la cinetique obeit a une loi d'ordre 2,5 environ qui augmente avec le taux de decomposition. La decomposition de l'hydrogene sulfure est notablement plus rapide que celle de NH{sub 3}. Le seul produit gazeux de la reaction est l'hydrogene. Le soufre, qui se depose sur les parois des ampoules, est nettement perceptible a l'oeil. On a obtenu jusqu'ici des decompositions allant jusqu'a 84 pour cent. L'influence de la reaction {sup 32}S (n, p) {sup 32}P est consideree. La decomposition radiochimique du protoxyde d'azote N{sub 2}O se fait avec des rendements eleves. La reaction est compliquee des ses debuts par la formation d'oxydes superieurs de l'azote que nous identifions et mesurons. Le methane donne par decomposition radiochimique des quantites d'hydrocarbures superieurs. Certains de ces systemes gazeux pourraient trouver des applications dans la mesure de fortes doses de rayonnement. Ce probleme est discute en conclusion. (auteur)

  8. Serum suPAR in patients with FSGS: trash or treasure?

    NARCIS (Netherlands)

    Maas, R.J.H.; Deegens, J.K.J.; Wetzels, J.F.M.

    2013-01-01

    The urokinase-type plasminogen activator receptor (uPAR) has important functions in cell migration. uPAR can be shed from the cell membrane resulting in soluble uPAR (suPAR). Further cleavage gives rise to shorter fragments with largely unknown functions. Recent studies have demonstrated that both

  9. Étude des équilibres thermodynamiques des réactions de gazéification en vue de l'optimisation du rapport vapeur/comburant injecté dans un gazogène souterrain Study of Thermodynamic Equilibria in Gasification Reactions So As to Optimise the Steam/Oxidizer Ratio Injected Into an Underground Gas Generator

    Directory of Open Access Journals (Sweden)

    Pirard J. P.

    2006-11-01

    Full Text Available Le but de cette étude est de déterminer sur la base des équilibres thermodynamiques des réactions de gazéification le rapport vapeur/comburant à injecter dans un gazogène fonctionnant sous pression pour optimaliser les compositions, les pouvoirs calorifiques, les rendements de gazéification et la consommation d'agent gazéifiant. The aim of this study is to determine, on the basis of the thermodynamic equilibria of gazification reactions, the steam/oxidizer ratio to be injected into a gas generator operating under pressure so as to optimize the compositions, the heating values, the gasification efficiencies and the consumption of gasifying agent.

  10. Une terreur par l’image

    Directory of Open Access Journals (Sweden)

    Annie DULONG

    2011-09-01

    Full Text Available Si d’autres événements — Hiroshima, la découverte des camps de concentration, la chute du mur de Berlin — ont, au cours du XXe siècle, marqué suffisamment l’imaginaire pour trouver leur réponse dans des œuvres d’art, le 11 septembre 2001 pose la question de la fictionnalisation autrement : il ne s’agit plus tant de combler les manques de la représentation, liés à l’absence d’images ou au délai dans leur dévoilement, mais bien de composer avec l’omniprésence d’une représentation martelée à la télévision et sur Internet. Que cette représentation soit partielle, tronquée et qu’il lui manque la présence des corps, ces grands absents des photographies et des images tournées par les journalistes, ne change rien au fait que c’est avec le trop-plein que les artistes doivent maintenant négocier.Cet article s’intéresse aux romans qui traitent l’événement de front au lieu de l’aborder sur un mode mineur, et a pour objectif de tracer un portrait de la représentation des médias dans les romans du 11 septembre 2001. Ces romans, outre le fait qu’ils traitent des événements de New York, ont comme point commun un personnage, ou décor : les médias, représentés par la télévision, l’Internet, les photographies de presse, interviennent dans les récits d’une manière significative et témoignent de la force brute des images. À travers une étude de certains des mécanismes à l’œuvre dans The Writing on the Wall (Lynne Sharon Schwartz, Extremely Loud and Incredibly Close (Jonathan Safran Foer, Falling Man (Don DeLillo et A Disorder Peculiar to the Country (Ken Kalfus, il s’agira de proposer des réponses à ces quelques questions : quel rôle les médias jouent-ils, et comment participent-ils au récit ? Quelle pression les images exercent-elles sur les personnages ? Que révèlent les personnages enfants dans leur rapport aux médias ? Quelle critique, finalement, les romans

  11. Par Pond vegetation status Summer 1995 -- June survey descriptive summary

    International Nuclear Information System (INIS)

    Mackey, H.E. Jr.; Riley, R.S.

    1995-06-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the shoreline aquatic plant communities in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level, indicated that much of the original plant communities and the intermediate shoreline communities present on the exposed sediments have been lost. The extensive old-field and emergent marsh communities that were present on the exposed shoreline during the drawdown have been flooded and much of the pre-drawdown Par Pond aquatic plant communities have not had sufficient time for re-establishment. The shoreline does, however, have extensive beds of maidencane which extend from the shoreline margin to areas as deep as 2 and perhaps 3 meters. Scattered individual plants of lotus and watershield are common and may indicate likely directions of future wetland development in Par Pond. In addition, within isolated coves, which apparently received ground water seepage and/or stream surface flows during the period of the Par Pond draw down, extensive beds of waterlilies and spike rush are common. Invasion of willow and red maple occurred along the lake shoreline as well. Although not absent from this survey, evidence of the extensive redevelopment of the large cattail and eel grass beds was not observed in this first survey of Par Pond. Future surveys during the growing seasons of 1995, 1996, and 1997 along with the evaluation of satellite date to map the areal extent of the macrophyte beds of Par Pond are planned

  12. Epidemiological Surveillance at Electricite de France and Gaz de France: Health Assessment of Nuclear Power Plant Employers between 1993 and 1998

    Energy Technology Data Exchange (ETDEWEB)

    Chevalier, A.; Gros, H.; Carrier, E.; Labon, G.

    2004-07-01

    Because the 17,500 employees working in nuclear power plants at Electricite de France, the national power company, may be exposed to a wide variety of industrial hazards, the health insurance department of the company has set up an epidemiologic surveillance programme for them. This descriptive, cross-sectional,and exhaustive study examined sick-leaves, mortality and cancer incidence to assess the health of the employees working from 1993 through 1998. The analysis comparing the employees in nuclear power plants, considered exposed, to the rest of the personnel of Electricite de France-Gaz de France, the non-exposed (125,000 persons) showed that globally, the employees in the nuclear sector appeared to have fewer health problems than the other company employees. This was true regardless of age and especially for men, operating employees, and supervisory employees. Nonetheless three points must be noted: non-work accidents generated a non-significant excess of absenteeism and mortality among these employees, especially among management and supervisory personnel; suicides affected supervisors in particular; and an excess of primary malignant brain tumors affected both mortality (RR{sub 1}.96, NS) and incidence, especially among operating employees (RR=2.87, 95% CL=(1.00-8.43)). No excess of malignant blood disease was observed. (Author) 38 refs.

  13. Preparation and characterization of mechanically alloyed AB3-type based material LaMg2Ni5Al4 and its solid-gaz hydrogen storage reaction

    Science.gov (United States)

    Jaafar, Hassen; Aymard, Luc; Dachraoui, Walid; Demortière, Arnaud; Abdellaoui, Mohieddine

    2018-04-01

    We developed in the present paper the synthesis of a new AB3-type compound LaMg2Ni5Al4 by mechanical alloying (MA) process. ​​X-ray diffraction analysis (XRD) was used to determine the structural properties and the phase evolution of the powder mixtures. Two different synthesis pathways have been investigated. The first starting from elemental metals and the second from a mixture of two binary compounds LaNi5 (CaCu5-type structure, P6/mmm space group) and Al(Mg) solid solution (cubic Fm-3 m space group). The results show multiphase alloys which contain LaMg2Ni5Al4 main phase with hexagonal PuNi3-type structure (R-3 m space group). Rietveld analysis shows that using a planetary ball mill, we obtain a good yield of LaMg2Ni5Al4 compound after 5 h of mechanical alloying for both synthesis pathways. TEM analysis confirmed XRD results. SEM-EDX analysis of the final product was in agreement with the nominal chemical formula. A setup of possible solid-gaz hydrogenation reaction will be described so far at the end of this work. Electrochemical results demonstrate evidence on hydrogen absorption in the AB3 material and the discharge capacity was equal to 5.9 H/f.u.

  14. Oxidation of ordinary steels or alloys heated in carbon dioxide under pressure; Oxydation d'aciers ordinaires ou allies chauffes dans le gaz carbonique sous pression

    Energy Technology Data Exchange (ETDEWEB)

    Leclercq, D; Chevilliard, C; Darras, R [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    Selection tests were carried out on commercial steels from the viewpoint of their resistance to oxidation in carbon dioxide, under 25 atmospheres pressure, between 350 and 600 deg. C. Comparative curve of oxidation kinetics were obtained, from which the influence of various additive elements can be found; small amounts of aluminium particularly seem to be favourable in the case of only slightly alloyed steels. (author) [French] Des essais de selection d'aciers commerciaux ont ete effectues quant a leur resistance a l'oxydation dans le gaz carbonique, sous pression de 25 atmospheres, ente 350 et 600 deg. C. Des courbes comparatives de cinetique d'oxydation ont ete obtenues, ce qui permet de degager l'influence de divers elements d'addition; de faibles teneurs en aluminium apparaissent notamment favorables dans le cas des aciers peu allies. L'acier inoxydable 18-8 a egalement ete etudie, notamment sous forme de tubes minces. Son comportement est bon jusqu'au moins 600 deg. C dans ces conditions. (auteur)

  15. Epidemiological Surveillance at Electricite de France and Gaz de France: Health Assessment of Nuclear Power Plant Employers between 1993 and 1998

    International Nuclear Information System (INIS)

    Chevalier, A.; Gros, H.; Carrier, E.; Labon, G.

    2004-01-01

    Because the 17,500 employees working in nuclear power plants at Electricite de France, the national power company, may be exposed to a wide variety of industrial hazards, the health insurance department of the company has set up an epidemiologic surveillance programme for them. This descriptive, cross-sectional,and exhaustive study examined sick-leaves, mortality and cancer incidence to assess the health of the employees working from 1993 through 1998. The analysis comparing the employees in nuclear power plants, considered exposed, to the rest of the personnel of Electricite de France-Gaz de France, the non-exposed (125,000 persons) showed that globally, the employees in the nuclear sector appeared to have fewer health problems than the other company employees. This was true regardless of age and especially for men, operating employees, and supervisory employees. Nonetheless three points must be noted: non-work accidents generated a non-significant excess of absenteeism and mortality among these employees, especially among management and supervisory personnel; suicides affected supervisors in particular; and an excess of primary malignant brain tumors affected both mortality (RR 1 .96, NS) and incidence, especially among operating employees (RR=2.87, 95% CL=(1.00-8.43)). No excess of malignant blood disease was observed. (Author) 38 refs

  16. Une installation expérimentale pour l'étude du traitement par combustion des fumées industrielles An Experimental Plant for Processing Industrial Fumes by Combustion

    Directory of Open Access Journals (Sweden)

    Morillon R.

    2006-11-01

    Full Text Available Le rejet à l'atmosphère d'effluents gazeux d'origine industrielle entraîne un accroissement sensible de la pollution atmosphérique ; en outre, il s'accompagne souvent d'une perte d'énergie lorsque l'élément polluant est un hydrocarbure. Dans ce cas, l'utilisation du gaz naturel pour le traitement par combustion des fumées industrielles apporte une solution élégante et souvent peu coûteuse grâce à la récupération d'énergie qu'il est possible de faire. La première partie de l'article rappelle les aspects théoriques de ce traitement ; en particulier, l'influence des divers éléments sur son efficacité y est discutée (composition de l'atmosphère polluée, température, temps de séjour, etc.. II apparaît ainsi que diverses conditions doivent être remplies simultanément pour obtenir une efficacité satisfaisante. Afin de disposer d'éléments d'ingénierie permettant de construire les unités de traitement les plus efficaces et les plus sûres possible, au coût le plus bas possible, la Direction des études et techniques nouvelles du Gaz de France a réalisé une installation expérimentale qui est présentée dans la deuxième partie de l'article. Enfin, quelques examples d'utilisation de cette installation expérimentale, qui constitue un nouvel outil de travail mis à la disposition des utisitateurs et des constructeurs, sont décrits dans la troisième partie de l'article. The discharge into the atmosphere of industrial waste gases causes substantially increased air pollution. Moreover, it is often accompanied by loss of energy when the polluting element is a hydrocarbon. In such cases, the use of natural gas for processing industrial fumes by combustion provides an elegant solution, which moy often prove economical too becouse of the recovery of energy it makes possible. The first part of this article reviews the theoretical aspects of such processing. The way in which its effectiveness is affected by various parameters

  17. Contribution to the study of can deformations in the fuel elements of gas-graphite reactors during thermal cycling; Contribution a l'etude des deformations des gaines des elements combustibles de reacteur graphite-gaz au cours du cyclage thermique

    Energy Technology Data Exchange (ETDEWEB)

    Gauthron, M; Boudouresques, B; Delpeyroux, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    The cans of fuel cartridges used in reactors of the gas-graphite type have either longitudinal fins of variable thickness, short herring-bone fins, or else a mixture of the two. An important test of the strength of these cartridges is their behaviour during thermal cycling carried out in cells reproducing in-pile conditions. It has been observed during with rapid cooling that there occurs a shortening at the base of the fins which can be accompanied in particular by a compression effect at the fin type, which has a tendency to curl, and by a tractive force acting on the body of the can at the ends of the longitudinal fins; this last phenomenon can result in a fracturing of the welds at the extremities or of the ends of the cartridge. This report presents first of all the way in which the stress diagram can be drawn for a can touching the fuel, and then the effect of the ratchet along a fin fixed to a bar with or without grooves. Finally the importance is shown of the test cycling variables (temperature, heating and cooling rates). (authors) [French] Les gaines des cartouches combustibles des reacteurs de la filiere graphite-gaz comportent soit des ailettes longitudinales plus ou moins epaisses, soit de courtes ailettes a chevrons, soit un ensemble des deux. Un test important de la tenue des cartouches, est la tenue au cyclage thermique en cellule pour reproduire le comportement en pile. On a observe au cours des cyclages a refroidissement rapide, un raccourcissement a la base des ailettes qui peut s'accompagner notamment d'une mise en compression du sommet de l'ailette qui a tendance a friser, et d'une traction exercee sur le corps des gaines au bout des ailettes longitudinales; ce dernier phenomene peut se traduire par des ruptures de soudures d'extremites ou des parties terminales de la cartouche. Ce rapport presente d'abord la maniere dont peut etre trace le diagramme des contraintes dans une gaine liee au combustible, puis l'effet du rochet le long d

  18. Contribution to the study of isotopic exchange of oxygen between nickel oxide and the gases arising from the oxidation reaction of carbon monoxide; Contribution a l'etude de l'echange isotopique de l'oxygene entre l'oxyde de nickel et les gaz de la reaction d'oxydation de l'oxyde de carbone

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-12-01

    The 3 isotopic reactions of oxygen: C{sup 18}O + Ni{sup 16}O {r_reversible} C{sup 16}O + Ni{sup 18}O, {sup 16}O{sup 18}O + Ni{sup 16}O {r_reversible} {sup 16}O{sub 2} + Ni{sup 18}O, and C{sup 16}O{sup 18}O + Ni{sup 16}O {r_reversible} C{sup 16}O{sub 2} + Ni{sup 18}O between CO, CO{sub 2}, O{sub 2} and NiO are studied using a mass spectrometer. The isotopic gaseous mixtures are prepared from oxygen-18 enriched water. A first order kinetic law has been found for these reactions in the gaseous phase, and the activation energies have been determined. Only CO and CO{sub 2} exchange oxygen, at room temperature, but only with part of the oxide surface. Gaseous O{sub 2} reacts with the whole surface at 250 C, the slow step of the exchange process, in the gaseous phase, being certainly the mobility of oxygen ions on the surface of NiO. (author) [French] Les 3 reactions d'echange isotopique de l'oxygene: C{sup 18}O + Ni{sup 16}O {r_reversible} C{sup 16}O + Ni{sup 18}O, {sup 16}O{sup 18}O + Ni{sup 16}O {r_reversible} {sup 16}O{sub 2} + Ni{sup 18}O, et C{sup 16}O{sup 18}O + Ni{sup 16}O {r_reversible} C{sup 16}O{sub 2} + Ni{sup 18}O entre l'oxyde de carbone, l'oxygene gazeux, le gaz carbonique et l'oxyde de nickel sont etudiees par spectrometrie de masse. Les melanges isotopiques gazeux sont prepares a partir d'une eau enrichie en isotope 18 de l'oxygene. Une loi cinetique du premier ordre a ete trouvee pour les trois reactions d'echange en phase gazeuse, et des energies d'activation de ces reactions ont ete determinees. Seuls CO et CO{sub 2} echangent l'oxygene, des la temperature ambiante, mais avec une fraction seulement de la surface de l'oxyde. O{sub 2} gazeux reagit avec toute la surface du solide a 250 C, l'etape lente du processus d'echange en phase gazeuse etant vraisemblablement liee a la mobilite des ions oxygene superficiels de NiO. (auteur)

  19. Perspectives de développement de la production industrielle d'hydrogène par électrolyse alcaline avancée Development Outlook for Industrial Hydrogen Production by Advanced Alkaline Electrolysis

    Directory of Open Access Journals (Sweden)

    Derive C.

    2006-11-01

    Full Text Available Dans les conditions du développement du programme nucléaire français qui permettent une production d'électricité à un coût intéressant en heures creuses, la production d'hydrogène par électrolyse de l'eau peut être envisagée à moyen terme en compétition avec les autres procédés de fabrication d'hydrogène tels que le reformage de gaz naturel. Dans le cadre de leur coopération, Électricité de France (EDF et le Gaz de France (GDF conduisent, depuis 1976, un programme de recherches et développement sur la production d'hydrogène par électrolyse alcaline de l'eau ayant pour but, par comparaison avec des installations existantes, de réduire le coût d'investissement et de conserver un rendement identique. Les études préalables ont montré que ces objectifs pouvaient être atteints par une électrolyse avancée avec élévation de la densité de courant et de la température. Ces contraintes techniques ont conduit EDF et le GDF à lancer des études sur la tenue chimique et la résistance mécanique des matériaux, sur une sélection de composants de cellules adaptés et sur l'amélioration de la conception d'ensemble des installations. Les deux groupements industriels français - pilotés par Alsthom-Atlantique et Creusot-Loire - associés à ces travaux depuis 1979, ont fixé les conditions de fonctionnement suivantes : - électrolyte à base de potasse (40 % en masse; - température de 120 et 160°C; - pression de 30 et 70 bar. Dans un premier temps, les constructeurs ont réalisé une étude technico-économique sur la production massive d'hydrogène à partir d'usines de puissance d'environ 300 MWe, fourni les plans de détail d'une installation pilote de 2 MWe et entrepris la qualification de leurs choix technologiques sur des boucles-prototypes de 25-30 kWe. Afin de valider plus complètement les choix retenus et d'approfondir les problèmes d'extrapolation à des électrolyseurs de grande taille, les essais sur boucles

  20. Par Pond vegetation status Summer 1995 -- September survey descriptive summary

    International Nuclear Information System (INIS)

    Mackey, H.E. Jr.; Riley, R.S.

    1995-09-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the emergent shoreline aquatic plant communities began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level and continued with this mid-September survey. Communities similar to the pre-drawdown Par Pond aquatic plant communities are becoming re-established; especially, beds of maidencane, lotus, waterlily, and watershield are now extensive and well established. Cattail occurrence continues to increase, but large beds common to Par Pond prior to the drawdown have not formed. Future surveys during the late growing seasons of 1995, and throughout 1996 and 1997, along with the evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned

  1. Par Pond vegetation status Summer 1995 -- October survey descriptive summary

    International Nuclear Information System (INIS)

    Mackey, H.E. Jr.; Riley, R.S.

    1995-11-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the emergent shoreline aquatic plant communities began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level and continued with this late October survey. Communities similar to the pre-drawdown Par Pond aquatic plant communities are becoming re-established; especially, beds of maiden cane, lotus, waterlily, and watershield are now extensive and well established. Cattail occurrence continues to increase, but large beds common to Par Pond prior to the drawdown have not formed. Future surveys throughout 1996 and 1997, along with the continued evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned

  2. [Ambroise Paré, his death and his historians].

    Science.gov (United States)

    Dumaître, P

    2001-01-01

    Ambroise Paré died December the 20th., 1590. What happened after his death and what are we knowing about his life? Never forgotten, though a lack of care, we were waiting till the XIXth. century to get recollection upon a subject sustained only by accounts of his travels. After Percy, a surgeon who tried to write Paré's biography through the "Biographie universelle ancienne et moderne, de Michaud (1822)" and some second rank authors, Malgaigne is the first who inside a printing of the "Oeuvres complétes de Paré (1840-41)" has a fine look upon the question, though his work is incomplete and allows many mistakes. Doctors Chéreau and Jal, an historian, analysing civil status records, gave new information enlarged by doctors Le Paulmier, Turner and the U.S. native Janet Doe.

  3. Keratometric alterations following the 25-gauge transconjunctival sutureless pars plana vitrectomy versus the conventional pars plana vitrectomy.

    Science.gov (United States)

    Citirik, Mehmet; Batman, Cosar; Bicer, Tolga; Zilelioglu, Orhan

    2009-09-01

    To assess the alterations in keratometric astigmatism following the 25-gauge transconjunctival sutureless pars plana vitrectomy versus the conventional pars plana vitrectomy. Sixteen consecutive patients were enrolled into the study. Conventional vitrectomy was applied to eight of the cases and 25-gauge transconjunctival sutureless vitrectomy was performed in eight patients. Keratometry was performed before and after the surgery. In the 25-gauge transconjunctival sutureless pars plana vitrectomy group, statistically significant changes were not observed in the corneal curvature in any post-operative follow-up measurement (p > 0.05); whereas in the conventional pars plana vitrectomy group, statistically significant changes were observed in the first postoperative day (p = 0.01) and first postoperative month (p = 0.03). We noted that these changes returned to baseline in three months (p = 0.26). Both 25-gauge transconjunctival sutureless and conventional pars plana vitrectomy are effective surgical modalities for selected diseases of the posterior segment. Surgical procedures are critical for the visual rehabilitation of the patients. The post-operative corneal astigmatism of the vitrectomised eyes can be accurately determined at least two months post-operatively.

  4. Cellular properties of slug flow in vertical co-current gas-liquid flow: slug-churn transition; Caracteristiques cellulaires du regime a poches en ecoulement gaz-liquide co-courant vertical. Transition vers le regime destructure

    Energy Technology Data Exchange (ETDEWEB)

    Lusseyran, Francois

    1990-12-13

    This research thesis reports the study and description of the structure of a slug flow regime in a co-current vertical cylindrical duct, and the characterization and prediction of its transition towards a slug-churn (de-structured) regime. Flow physical mechanisms highlighted by the measurement of two important dynamics variables (wall friction and thickness of liquid films) are related to hypotheses of cellular models. The author first proposes an overview of slug flow regimes: theoretical steady and one-dimensional analysis, mass assessment equations of cellular models, application to the assessment of the flow rate and of the thickness of the film surrounding the gas slug. In the second part, the author addresses the slug flow regime transition towards the slug-churn regime: assessment of the evolution of flow dynamic properties, use of average wall friction analysis to obtain a relevant transition criterion. The third part presents experimental conditions, and measurement methods: conductometry for thickness measurement, polarography for wall friction measurement, and gas phase detection by using an optic barrier or optic fibres [French] Les ecoulements gaz-liquide en conduite verticale presentent quatre configurations ou regimes d'ecoulement. Ce travail porte sur le regime a poches et sur la transition vers la configuration qui lui succede: le regime destructure (churn flow). Les mesures sont effectuees a 200D du point d'injection du gaz, dans une conduite de 12.2 mm de diametre et pour le couple de fluides eau-azote. Les deux principales grandeurs mesurees en fonction des flux d'entree sont: le frottement parietal instantane (methode electrochimique) et l'epaisseur de film instantanee (methode conductimetrique). Une detection optique simultanee de la presence des phases permet un traitement conditionnel de la base de donnees. Les caracteristiques de la cellule moyenne representative de chaque point de fonctionnement en sont deduites: longueur de la cellule

  5. Economical and geopolitical aspects bond to the foreseen development of the natural gas in an open market; Aspects economiques et geopolitiques lies au developpement prevu du gaz naturel dans un marche ouvert

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-12-15

    For the first time in 2000, the part of natural gas is equal to those of coal in the world energy accounting. The economy and the geo-policy of this developing energy is analyzed, showing an economy dominated by the transport costs, the specificity of the european sector and the opening market since 1980. The european market opening incertitudes and opportunities are detailed. In conclusion the Gaz De France role in the european energy pole and the new regulations are discussed. (A.L.B.)

  6. The gas market opens out to competition: how will the French system of distributions evolve?; Ouverture a la concurrence du marche du gaz: quelle evolution pour le systeme francais des concessions de distribution?

    Energy Technology Data Exchange (ETDEWEB)

    Carbonnier, R. [Strasbourg-3 Universite, Robert Schuman, 67 (France)]|[Strasbourg-1 Univ. Louis Pasteur, 67 (France)

    1998-10-01

    Th public distribution of natural gas in France is organised around a system of franchises allocated by the communes to a unique designated distributor (Gaz de France in most cases). This system, which was recently eased by a legislative provision, seems to have an uncertain future faced with the opening of competition that is encouraged by the European authorities and with the demands of some local communities which would like to lay a greater role in the future organisational plan for gas. This article looks at the possible evolutions, from the reactivation of franchises to their complete disappearance. (author)

  7. Cyclanthaceae no estado do Pará, Brasil Cyclanthaceae in Pará State, Brazil

    Directory of Open Access Journals (Sweden)

    Eduardo da Silva Leal

    2012-12-01

    Full Text Available Cyclanthaceae apresenta distribuição exclusiva na região neotropical sendo bem diversificada nas terras baixas das florestas pluviais tropicais, ocorrendo do sul do México até a Mata Atlântica do sul do Brasil. Consistem de ervas terrestres, epífitas, hemiepífitas ou lianas. O tratamento taxonômico de Cyclanthaceae no Pará foi baseado em coleções de herbário, trabalhos de campo e consulta a bibliografia referente à família. Foram registradas 11 espécies: Asplundia altiscandens E.S. Leal, A. fanshawei (Maguire Harling, A. glandulosa (Gleason Harling, A. heteranthera Harling, A. latifrons (Drude Harling, A. schizotepala Harling, A. xiphophylla Harling, Cyclanthus bipartitus Poit. ex A. Rich., Evodianthus funifer (Poit. Lindm., Ludovia lancifolia Brongn. e Thoracocarpus bissectus (Vell. Harling. São apresentadas chave de identificação, descrições e ilustrações das espécies, além de comentários sobre distribuição geográfica, hábitat e período de floração e frutificação.Cyclanthaceae is a family with a distribution exclusively in the Neotropics and is well diversified in lowland rainforests, occurring from southern Mexico to the Atlantic Forest of southern Brazil. The family consists of terrestrial herbs, epiphytes, hemiepiphytes and lianas. This taxonomic treatment of the Cyclanthaceae from the state of Pará was based on herbarium specimens, fieldwork, and the literature. Eleven species were recorded: Asplundia altiscandens E.S. Leal, A. fanshawei (Maguire Harling, A. glandulosa (Gleason Harling, A. heteranthera Harling, A. latifrons (Drude Harling, A. schizotepala Harling, A. xiphophylla Harling, Cyclanthus bipartitus Poit. ex A. Rich., Evodianthus funifer (Poit. Lindm., Ludovia lancifolia Brongn. and Thoracocarpus bissectus (Vell. Harling. An identification key, descriptions and illustrations of species are presented. Additional information on the geographic distribution, habitat, and flowering and

  8. Parasitisme de Dacryodes edulis par le genre Tapinanthus ...

    African Journals Online (AJOL)

    SARAH

    31 août 2013 ... Parasitisme de Dacryodes edulis par le genre. Tapinanthus (Loranthaceae) et répartition de la myrmécofaune associée à Logbessou Plateau. (Douala, Cameroun). Massako F1*, Tchatat M2, Mony R3, Ladoh Yemeda CF1, Dibong SD1,4,5. 1Laboratoire de Biologie et Physiologie des Organismes ...

  9. Parasitisme des champs semenciers de cacaoyers par les ...

    African Journals Online (AJOL)

    SARAH

    30 janv. 2015 ... J. Appl. Biosci. Parasitisme des champs semenciers de cacaoyers par les loranthaceae dans la localité de Nkoemvone (sud Cameroun). 7795 to the various clones, Phragmanthera capitata was the most abundant Loranthaceae; the level of parasitism of cacao trees is more important at the cacao trees of ...

  10. Den eneste ene - hvordan etniske minoritetsunge i Danmark danner par

    DEFF Research Database (Denmark)

    Singla, Rashmi

    Rapporten handler om etniske unges måde at danne par på. Rapporten er baseret på en større empirisk undersøgelse gennemført af forfatteren i 2003 og er desuden inspireret af forfatterens egen ph.d.-afhandling: "Ungdom, etnicitet og psychosocial intervention" (2000, Københavns Universitet). Rappor...

  11. Indications and visual outcome of first hundred pars plana ...

    African Journals Online (AJOL)

    Objective: To review the indications and visual outcome of the first one hundred pars plana vitrectomies performed at the newly established surgical retina unit of Makkah Specialist Eye Hospital, Kano, Kano State, Nigeria. Materials and Methods: Aretrospective chart review was performed. Data recorded from the patient ...

  12. Epuration des effluents industriels par électroflottation Belkacem ...

    African Journals Online (AJOL)

    étudié la séparation de quelques métaux lourds tels que le fer, le nickel, ... the separation of some heavy metals such as iron, nickel, copper, zinc, lead and ... généralement basées sur l'adsorption (par ... Différents essais de concentration en.

  13. Predicting spectral and PAR light attenuation in Greenlandic coastal waters

    DEFF Research Database (Denmark)

    Murray, Ciarán; Markager, Stiig; Stedmon, Colin

    (CDOM), phytoplankton pigments and inorganic particles. These differences are due in part to hydrography and to the sources of meltwater: respectively, fjord-terminating and land-terminating glaciers. We present a model to explain the variation in spectral and PAR irradiance in terms of the variation...

  14. Priapisme induit par la chlorpromazine: A propos de deux cas

    Directory of Open Access Journals (Sweden)

    I. Marrag

    2016-06-01

    Le priapisme veineux est une urgence urologique. Il constitue un des effets secondaires des neuroleptiques parmi les quels la chlorpromazine. Cet effet iatrogène, qui est rare mais grave, doit être connu par les cliniciens afin d’être mieux prévenu pour éviter les séquelles érectiles.

  15. La lecture de Merleau-Ponty par Renaud Barbaras

    Czech Academy of Sciences Publication Activity Database

    Pechar, Jiří

    2015-01-01

    Roč. 11, č. 2 (2015), s. 1-6 ISSN 1336-6556 Institutional support: RVO:67985955 Keywords : Merleau-Ponty * Husserl * phenomenology * linguistics of Ferdinand de Saussure Subject RIV: AA - Philosophy ; Religion http://www.ostium.sk/sk/la-lecture-de-merleau-ponty-par-renaud-barbaras/

  16. Par Pond vegetation status summer 1995 - July survey descriptive summary

    International Nuclear Information System (INIS)

    Mackey, H.E. Jr.; Riley, R.S.

    1995-07-01

    A survey of the emergent shoreline aquatic plant, communities began in June 1995, three months after the refilling of Par Pond to approximately 200 feet (61 meters) above mean sea level, and continued with this July survey. Aquatic plant communities, similar to the pre-drawdown Par Pond communities, are becoming reestablished. Beds of maidencane (Panicum hemitomon), lotus (Nelumbo lutea), water lily (Nymphaea odorata), and watershield (Brasenia schreberi) are now extensive and well established. In addition, within isolated coves, extensive beds of water lilies and spike-rush (Eleocharis sp.) are common. Cattail occurrence has increased since refill, but large beds common to Par Pond prior to the drawdown have not formed. Invasion of willow (Salix sp.) and red maple (Acer rubrum) occurred along the lake shoreline during drawdown. The red maples along the present shoreline are beginning to show evidence of stress and mortality from flooding over the past four months. Some of the willows appear to be stressed as well. The loblolly pines (Pinus taeda), which were flooded in all but the shallow shoreline areas, are now dead. Future surveys are planned for the growing seasons of 1995, 1996, and 1997, along with the evaluation of satellite data for mapping the areal extent of the macrophyte beds of Par Pond

  17. fortification des farines tropicales par l'introduction de proteines ...

    African Journals Online (AJOL)

    2Université d'Abomey Calavy, Faculté des Sciences et Techniques, Bénin ... valeur recommandée par le Codex Alimentarius pour ce type de complément alimentaire destiné aux enfants. ..... neurotransmission, coagulation sanguine et.

  18. Theoretical interpretations and experimental verifications of a radioelectric resonance method for measuring the electronic density and collision frequency in a discharge plasma in gases; Interpretations theoriques et verifications experimentales d'une methode de resonance radioelectrique pour la mesure de la densite d'une decharge dans les gaz

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen Trong, Khoi [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    Theoretical discussions and experimental verifications of one radioelectric resonance method for measuring plasma electronic density and collision frequency. (author) [French] Discussions theoriques et verifications experimentales sur une methode de resonance radioelectrique pour la mesure de la densite electronique et de la frequence de collision d'un plasma d'une decharge dans le gaz. (auteur)

  19. Méthode analytique généralisée pour le calcul du coning. Nouvelle solution pour calculer le coning de gaz, d'eau et double coning dans les puits verticaux et horizontaux Generalized Analytical Method for Coning Calculation. New Solution to Calculation Both the Gas Coning, Water Coning and Dual Coning for Vertical and Horizontal Wells

    Directory of Open Access Journals (Sweden)

    Pietraru V.

    2006-11-01

    Full Text Available Une nouvelle méthode analytique d'évaluation du coning d'eau par bottom water drive et/ou de gaz par gas-cap drive dans les puits horizontaux et verticaux a été développée pour les réservoirs infinis [1]. Dans cet article, une généralisation de cette méthode est présentée pour les réservoirs confinés d'extension limitée dont le toit est horizontal. La généralisation proposée est basée sur la résolution des équations différentielles de la diffusivité avec prise en compte des effets de drainage par gravité et des conditions aux limites pour un réservoir confiné. La méthode est applicable aux réservoirs isotropes ou anisotropes. L'hypothèse de pression constante à la limite de l'aire de drainage dans l'eau et/ou dans le gaz a été adoptée. Les pertes de charge dans l'aquifère et dans le gas-cap sont donc négligées. Les principales contributions de cet article sont : - L'introduction de la notion de rayon de cône, différent du rayon de puits. La hauteur du cône et le débit critique dépendent du rayon de cône alors qu'ils sont indépendants du rayon du puits. - Une nouvelle corrélation pour le calcul du débit critique sous forme adimensionnelle en fonction de trois paramètres : le temps, la longueur du drain horizontal (nulle pour un puits vertical et le rayon de drainage. - Des corrélations pour le calcul du rapport des débits gaz/huile (GOR ou de la fraction en eau (fw, pendant les périodes critique et postcritique, qui tiennent compte de la pression capillaire et des perméabilités relatives. - Des corrélations pour le calcul des rapports de débits gaz/huile et eau/huile pendant les périodes pré, post et supercritique en double coning. - Des critères pour le calcul du temps de percée au puits en simple coning de gaz ou d'eau, ou en double coning de gaz et d'eau. A new analytical method for assessing water and/or gas coning in horizontal and vertical wells has been developed for infinite

  20. The role of pars flaccida in human middle ear sound transmission.

    Science.gov (United States)

    Aritomo, H; Goode, R L; Gonzalez, J

    1988-04-01

    The role of the pars flaccida in middle ear sound transmission was studied with the use of twelve otoscopically normal, fresh, human temporal bones. Peak-to-peak umbo displacement in response to a constant sound pressure level at the tympanic membrane was measured with a noncontacting video measuring system capable of repeatable measurements down to 0.2 micron. Measurements were made before and after pars flaccida modifications at 18 frequencies between 100 and 4000 Hz. Four pars flaccida modifications were studied: (1) acoustic insulation of the pars flaccida to the ear canal with a silicone rubber baffle, (2) stiffening the pars flaccida with cyanoacrylate cement, (3) decreasing the tension of the pars flaccida with a nonperforating incision, and (4) perforation of the pars flaccida. All of the modifications (except the perforation) had a minimal effect on umbo displacement; this seems to imply that the pars flaccida has a minor acoustic role in human beings.

  1. FIRST trial: Lemay park collection plan

    Science.gov (United States)

    2007-12-01

    expériences : une expé- rience de détection de panache de gaz, une de plastique simulant un panache de gaz, DRDC Valcartier TN 2007-435 i une de...panache de gaz, une de plastique simulant un panache de gaz, une de poudre chimique et une d’artilleries non explosées. Objectifs : Par cet exercice

  2. Apoplejía pituitaria con parálisis del III par craneal: Reporte de caso

    Directory of Open Access Journals (Sweden)

    Miguel Pinto Valdivia

    2011-10-01

    Full Text Available Se describe el caso de un varón de 65 años de edad, sin antecedentes patológicos de importancia, que acudió a emergencia del Hospital Nacional Cayetano Heredia por presentar cefalea intensa y ptosis palpebral izquierda. El examen físico mostró parálisis aislada del III par craneal izquierdo. Los análisis de laboratorio mostraron hiponatremia e hipopituitarismo y la resonancia magnética nuclear un adenoma pituitario con áreas de hemorragia e invasión de los senos cavernosos. El tratamiento incluyó glucocorticoides y descompresión quirúrgica transesfenoidal. La anatomía patológica confirmó el diagnóstico de infarto hemorrágico de un adenoma pituitario. El paciente fue dado de alta con terapia sustitutiva de levotiroxina y prednisona. La ptosis palpebral izquierda se recuperó en forma parcial. La apoplejía pituitaria es un síndrome clínico producido por un proceso expansivo dentro de la silla turca, secundario a hemorragia o infarto de un adenoma pituitario, que se caracteriza por cefalea, déficit visual, oftalmoplejía y alteración del nivel de conciencia. Este proceso expansivo puede comprimir los pares craneales en los senos cavernosos, produciendo diferentes grados de parálisis de los músculos oculomotores. La parálisis aislada del III par craneal es rara.(Rev Med Hered 2011;22:186-189.

  3. Épidémiologie de l'intoxication par envenimation chez les enfants ...

    African Journals Online (AJOL)

    Introduction: L'intoxication par envenimation est l'ensemble des manifestations locales et générales induites par la pénétration dans l'organisme d'une substance toxique produite par un animal venimeux. Le but de notre travail était d'étudier les signes cliniques des intoxications par envenimation chez les enfants de 0 à 15 ...

  4. Contribution to the study of a method for measuring continuously the isotopic effect. The search for an isotopic effect during the reduction of cuprous oxide by a {sup 12}CO - {sup 14}CO mixture (1962); Contribution a l'etude d'une methode de mesure continue de l'effet isotopique. Recherche d'un effet isotopique dans la reduction de l'oxyde cuivreux par le melange {sup 12}CO - {sup 14}CO (1962)

    Energy Technology Data Exchange (ETDEWEB)

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

    1961-07-15

    The determination of an isotopic effect between the two reactions: {sup 12}CO + Cu{sub 2}O {yields} {sup 12}CO{sub 2} + 2 Cu 'light' reaction {sup 14}CO + Cu{sub 2}O {yields} {sup 14}C{sub O}2 + 2 Cu 'heavy' reaction is possible if the respective kinetics are known. The condensation, during the reaction, of the carbon dioxide formed, and the measurement as a function of time of the residual carbon monoxide pressure, makes it possible to deduce, uninterruptedly, the 'light' reaction kinetics. The 'heavy' reaction kinetics are obtained by measuring continuously, in situ, the radioactivity of the residual reactant gas as a function of the time. The apparatus used for this is a plastic scintillator counter. A calibration curve of the measured radioactivity as a function of the reactant gas pressure in the absence of reaction makes it possible to compare the kinetics of the 'light' and 'heavy' reactions. The reaction temperature is chosen such that the reaction rate is sufficiently slow, so that the variation of the radioactivity during unit counting time is negligible. (author) [French] La determination d'un effet isotopique entre les deux reactions: {sup 12}CO + Cu{sub 2}O {yields} {sup 12}CO{sub 2} + 2 Cu reaction 'legere' {sup 14}CO + Cu{sub 2}O {yields} {sup 14}C{sub O}2 + 2 Cu reaction 'lourde' est rendue possible par la connaissance de leurs cinetiques respectives. La condensation, au cours de la reaction, du gaz carbonique forme et la mesure en fonction du temps de la pression de l'oxyde de carbone residuel, permet d'obtenir, de facon continue, la cinetique de la reaction 'legere'. La cinetique de la reaction lourde est determinee par la mesure continue, in situ, du taux de radioactivite du reactif gazeux residuel en fonction du temps. Le dispositif employe dans ce but est un compteur a scintillateur plastique. Une courbe d'etalonnage, du taux mesure de radioactivite en fonction de la pression du gaz reactif, en l'absence de reaction, permet de comparer les

  5. Soluble urokinase plasminogen activator receptor (suPAR) in acute care

    DEFF Research Database (Denmark)

    Rasmussen, Line Jee Hartmann; Ladelund, Steen; Haupt, Thomas Huneck

    2016-01-01

    for age, sex, Charlson score and C reactive protein. Area under the curve for receiver operating characteristics curve analysis of suPAR for 30-day mortality was 0.84 (95% CI 0.81 to 0.86). Furthermore, in the entire cohort, women had slightly higher suPAR compared with men, and suPAR was associated...

  6. Movement and equipositioning of plasmids by ParA filament disassembly

    DEFF Research Database (Denmark)

    Ringgaard, Simon; van Zon, Jeroen; Howard, Martin

    2009-01-01

    , plasmids consistently migrate behind disassembling ParA cytoskeletal structures, suggesting that ParA filaments pull plasmids by depolymerization. The perpetual cycles of ParA assembly and disassembly result in continuous relocation of plasmids, which, on time averaging, results in equidistribution...

  7. Protease-Activated Receptor 4 (PAR4): A Promising Target for Antiplatelet Therapy.

    Science.gov (United States)

    Rwibasira Rudinga, Gamariel; Khan, Ghulam Jilany; Kong, Yi

    2018-02-14

    Cardiovascular diseases (CVDs) are currently among the leading causes of death worldwide. Platelet aggregation is a key cellular component of arterial thrombi and major cause of CVDs. Protease-activated receptors (PARs), including PAR1, PAR2, PAR3 and PAR4, fall within a subfamily of seven-transmembrane G-protein-coupled receptors (GPCR). Human platelets express PAR1 and PAR4, which contribute to the signaling transduction processes. In association with CVDs, PAR4 not only contributes to platelet activation but also is a modulator of cellular responses that serve as hallmarks of inflammation. Although several antiplatelet drugs are available on the market, they have many side effects that limit their use. Emerging evidence shows that PAR4 targeting is a safer strategy for preventing thrombosis and consequently may improve the overall cardiac safety profile. Our present review summarizes the PAR4 structural characteristics, activation mechanism, role in the pathophysiology of diseases and understanding the association of PAR4 targeting for improved cardiac protection. Conclusively, this review highlights the importance of PAR4 antagonists and its potential utility in different CVDs.

  8. Protease-Activated Receptor 4 (PAR4: A Promising Target for Antiplatelet Therapy

    Directory of Open Access Journals (Sweden)

    Gamariel Rwibasira Rudinga

    2018-02-01

    Full Text Available Cardiovascular diseases (CVDs are currently among the leading causes of death worldwide. Platelet aggregation is a key cellular component of arterial thrombi and major cause of CVDs. Protease-activated receptors (PARs, including PAR1, PAR2, PAR3 and PAR4, fall within a subfamily of seven-transmembrane G-protein-coupled receptors (GPCR. Human platelets express PAR1 and PAR4, which contribute to the signaling transduction processes. In association with CVDs, PAR4 not only contributes to platelet activation but also is a modulator of cellular responses that serve as hallmarks of inflammation. Although several antiplatelet drugs are available on the market, they have many side effects that limit their use. Emerging evidence shows that PAR4 targeting is a safer strategy for preventing thrombosis and consequently may improve the overall cardiac safety profile. Our present review summarizes the PAR4 structural characteristics, activation mechanism, role in the pathophysiology of diseases and understanding the association of PAR4 targeting for improved cardiac protection. Conclusively, this review highlights the importance of PAR4 antagonists and its potential utility in different CVDs.

  9. Par3L enhances colorectal cancer cell survival by inhibiting Lkb1/AMPK signaling pathway

    International Nuclear Information System (INIS)

    Li, Taiyuan; Liu, Dongning; Lei, Xiong; Jiang, Qunguang

    2017-01-01

    Partitioning defective 3-like protein (Par3L) is a recently identified cell polarity protein that plays an important role in mammary stem cell maintenance. Previously, we showed that high expression of Par3L is associated with poor survival in malignant colorectal cancer (CRC), but the underlying mechanism remained unknown. To this end, we established a Par3L knockout colorectal cancer cell line using the CRISPR/Cas system. Interestingly, reduced proliferation, enhanced cell death and caspase-3 activation were observed in Par3L knockout (KO) cells as compared with wildtype (WT) cells. Consistent with previous studies, we showed that Par3L interacts with a tumor suppressor protein liver kinase B1 (Lkb1). Moreover, Par3L depletion resulted in abnormal activation of Lkb1/AMPK signaling cascade. Knockdown of Lkb1 in these cells could significantly reduce AMPK activity and partially rescue cell death caused by Par3L knockdown. Furthermore, we showed that Par3L KO cells were more sensitive to chemotherapies and irradiation. Together, these results suggest that Par3L is essential for colorectal cancer cell survival by inhibiting Lkb1/AMPK signaling pathway, and is a putative therapeutic target for CRC. - Highlights: • Par3L knockout using the CRISPR/Cas system induces apoptosis in colorectal cancer cells. • Par3L interacts with Lkb1 and regulates the activity of AMPK signaling cascade. • Par3L knockout cells are more sensitive to treatment of different chemotherapy drugs and irradiation.

  10. Brésil : La contamination par le mercure en Amazonie | CRDI ...

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

    11 janv. 2011 ... En tentant de déceler la source de la contamination de l'Amazone par le ... par Jean-Rémy Davy Guimaraes de l'Université fédérale de Rio de Janeiro ... ces mattes est circonscrite par la conservation et la restauration en rive.

  11. Problems presented by the filtration and sampling of aerosols in the atomic energy programme; Problemes poses par la filtration et le prelevement des aerosols dans le cadre de l'energie atomique

    Energy Technology Data Exchange (ETDEWEB)

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

    1959-07-01

    The maximum permissible limits for radioactive aerosols are much lower than those for aerosols encountered in the non-nuclear industries. These limits depend on numerous factors such as: nature of the radiation, half-life, etc. The radioactive aerosols can be prepared by various methods. The filtering of the air in high activity laboratories or in plutonium treatment factories necessitates an installation consisting of: - aspiration filters, - extraction filters of very high efficiency (those used for {alpha} emitter cells: designed to be replaced without incurring contamination risks; those used for {gamma} emitter cells: designed to be replaced by remote control). The filtering in nuclear reactors is also effectuated by filter papers: - the G1 reactor with open circuit: the air coolant is entirely filtered at the entry and on leaving; - the G2, G3 and EDF1 reactors with closed circuits: filtering under pressure of a small portion of the coolant gas. (author) [French] Les limites maxima permises des aerosols radioactifs sont beaucoup plus faibles que celles des aerosols rencontres dans l'industrie classique. Elles dependent de nombreux facteurs tel que: nature du rayonnement, periode radioactive, etc... La formation des aerosols radioactifs est de nature diverse. La filtration des laboratoires de haute activite, ou d'usines d'elaboration de plutonium conduit a des types d'installations comportant: - des filtres d'aspiration; - des filtres d'extraction a rendement extremement eleve (type pour cellules emettrices {alpha} concu pour etre change sans risque de contamination, type pour cellules emettrices {gamma}: concu pour etre change a distance) La filtration des reacteurs nucleaires sont egalement effectuee par des papiers filtres: - reacteur G1 a circuit ouvert: air de refroidissement totalement filtre a l'aspiration et a l'extraction; - reacteurs G2, G3, EDF1: a circuit ferme: filtration sous pression d'une faible partie du gaz de refroidissement. (auteur)

  12. La syphilis congenitale revelee par une fracture spontanee

    Directory of Open Access Journals (Sweden)

    Mounia Lakhdar Idrissi

    2011-11-01

    Full Text Available Alors qu�elle est actuellement oubliee dans les pays developpes, la syphilis congenitale se voit encore chez nous faute du depistage antenatal. Ses formes cliniques sont polymorphes et orientent a tord vers d�autres pathologies surtout en periode neonatale. Le diagnostic n�est donc pas toujours facile. La revelation d�une syphilis congenitale par une fracture spontanee est exceptionnellement decrite. Nous rapportons dans ce travail le cas d�un nourrisson de 2 mois ramene en consultation pour limitation douloureuse des mouvements du bras droit. Le diagnostic est evoque sur les donnees radiologiques et confirme par la serologie syphilitique. Le traitement a repose essentiellement sur l�administration de la penicilline G avec une bonne evolution clinique.

  13. Results of Preliminary Tests of PAR Bunch Cleaning

    CERN Document Server

    Yao, Chihyuan; Grelick, Arthur; Lumpkin, Alex H; Sereno, Nicholas S

    2005-01-01

    A particle accumulator ring (PAR) is used at the Advanced Photon Source (APS) to collect multiple linac bunches and compress them into a 0.3-ns (rms) single bunch for booster injection. A 9.77-MHz fundamental rf system and a 117.3-MHz harmonic rf system are employed for initial beam capture and bunch length compression. Satellite bunches with very low charge form due to rf phase drifts or beam loading change. These satellites, when injected into the booster and then into the storage ring (SR), cause bunch impurity at three buckets from the target bucket. Storage ring and booster bunch cleaning was tried but proved to be difficult due to the top-up mode of operation in the storage ring and tune drift in the booster synchrotron. Recently we implemented a PAR bunch-cleaning system with tune-modulated harmonic rf knockout. Preliminary tests gave a measured SR bunch purity of better than 10

  14. Avis 6 sur la formation à et par la recherche

    OpenAIRE

    Centre de Coopération Internationale en Recherche Agronomique pour le Développement

    2015-01-01

    La formation à et par la recherche s’appuie sur la démarche scientifique, les savoirs, les connaissances à transmettre, tout autant que l’acquisition de compétences en gestion de projet, de capacités au travail en équipe, d’une ouverture d’esprit qui favorisera la créativité. Elle doit permettre de prendre conscience de la responsabilité endossée par la communauté scientifique vis-à-vis de la société et de l’environnement, mais aussi préparer l’avenir professionnel de celle ou de celui qu...

  15. Evaluation of the Stability After Orthodontic Treatment Using PAR Index

    Directory of Open Access Journals (Sweden)

    Chaitra Ramanathan

    2006-01-01

    Full Text Available The aim of the present study is to establish the results using the scores obtained from the methodology that was applied for assessing the stability after 2 years post orthodontic treatment and stability in a sample of 69 individuals. After applying PAR index to the collected group of patients, a series of scores were obtained, which were then needed to be evaluated further to establish the results. The scores were evaluated using the nomogram. A comparison was done between the post treatment and the 2 years post treatment PAR weighting scores to determine if the results were stable after orthodontic treatment. The majority of the orthodontic patients were treated to a good standard and that the results appeared to be stable.

  16. La parálisis cerebral en el contexto escolar /

    OpenAIRE

    González Vara, Azucena

    2012-01-01

    Se analiza el concepto de parálisis cerebral, los diferentes tipos y sus características. También las adaptaciones que se deben realizar a nivel de centro, de aula, y a nivel individual para estos alumnos, conocer los diferentes sistemas alternativos y aumentativos de comunicación y aplicar las ayudas técnicas que precisa este alumnado

  17. Tuberculose lymphonodale cervicale chez les enfants vaccines par ...

    African Journals Online (AJOL)

    La tuberculose ganglionnaire cervicale est une localisation extrapulmonaire relativement fréquente chez l'enfant. Elle pose essentiellement des difficultés de prévention. L'objectif de ce travail est d'étudier les particularités diagnostiques et thérapeutiques chez des enfants vaccinés par le BCG. Matériel et méthodes: Nôtre ...

  18. Traitement De La Peripneumonie Contagieuse Bovine Par L ...

    African Journals Online (AJOL)

    Traitement De La Peripneumonie Contagieuse Bovine Par L'oxyteTracycline Longe Action Et Transmission Experimentale de la Maladie A Partir de Bovins Traites. ... Tous les 14 animaux ont séroconverti et l'analyse post-mortem a montré la présence des lésions chroniques dont des séquestres pulmonaires chez 4 d'entre ...

  19. Adoption d'innovations agricoles par le truchement de services ...

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

    L'agriculture est le fer de lance de nombreuses économies en développement, mais la capacité des petits agriculteurs privés de ressources à adopter des innovations agricoles est freinée par le manque d'accès à des services financiers adéquats. Des experts internationaux estiment qu'il existe un manque à gagner ...

  20. Candido: Uma Leitura Paródica de Candide

    Directory of Open Access Journals (Sweden)

    Maria Gloria Cusumano Mazzi

    2010-12-01

    Full Text Available O presente artigo estuda a leitura paródica que Leonardo Sciascia (1921-1989 faz de Voltaire (1694-1778 mediante o cotejo das obras: o hipertexto Candido ovvero Un sogno fatto in Sicilia (1977 e o hipotexto Candide ou l’optimisme (1759. Apresenta ainda outra possibilidade de leitura, ou seja, Candido como metáfora da própria intertextualidade.

  1. Solution volumes finis polynomiale par morceaux pour les ...

    African Journals Online (AJOL)

    Nous présentons dans ce papier un concept de solution volumes finis continue pour des problèmes de diffusion-convection avec des données régulières. Nous comparons dans certains cas particuliers la solution proposée avec la solution volumes finis classiques (qui est une fonction constante par morceaux) et la ...

  2. Preliminary Analysis For Wolsong Par Effects Using ISACC Calculations

    International Nuclear Information System (INIS)

    Song, Yong Mann; Kim, Dong Ha

    2012-01-01

    In the paper, hydrogen control effects using PARs only are analyzed for severe SBO station blackout (SBO) sequences beyond the design basis accidents in WS-1 which are of CANDU6 type reactor. As a computational tool, the latest version of ISAAC4.3 (Integrated Severe Accident Analysis Code for CANDU), which is a fully integrated and lumped severe accident computer code, is used to simulate hydrogen generation and transport inside the reactor building (R/B) before its failure. For the performance of hydrogen removal, the depletion rate equation of K-PAR developed in Korea is applied. In a CANDU reactor, three areas are identified as sources of hydrogen under severe accidents: fuel-coolant interactions in intact channels, suspended fuel or debris interactions in-calandria tank and debris interactions in-calandria vault. The first two origins provide source for the late ('late' terminology is used because it takes more than one day before calandria tank failure) potential hydrogen combustion before calandria tank failure and all the three origins would provide source for the very late potential hydrogen combustion occurring at or after calaria tank failure. If the hydrogen mitigation system fails, the AICC (adiabatic isochoric complete combustion) burning of highly flammable hydrogen may cause Wolsong R/B failure. So hydrogen induced failure possibility is evaluated, using preliminary ISAAC calculations, under several SBO conditions with and without PAR for both late and very late accident periods

  3. Protease activated receptors (PARS) mediation in gyroxin biological activity

    International Nuclear Information System (INIS)

    Silva, Jose Alberto Alves da

    2009-01-01

    Gyroxin is a serine protease enzyme from the South American rattlesnake (Crotalus durissus terrificus) venom; it is only partially characterized and has multiple activities. Gyroxin induces blood coagulation, blood pressure decrease and a neurotoxic behavior named barrel rotation. The mechanisms involved in this neurotoxic activity are not known. Whereas gyroxin is a member of enzymes with high potential to become a new drug with clinical applications such as thrombin, batroxobin, ancrod, tripsyn and kalicrein, it is important to find out how gyroxin works. The analysis on agarose gel electrophoresis and circular dichroism confirmed the molecules' integrity and purity. The gyroxin intravenous administration in mice proved its neurotoxicity (barrel rotation). In vivo studies employing intravital microscopy proved that gyroxin induces vasodilation with the participation of protease activated receptors (PARs), nitric oxide and Na+K+ATPase. The leukocytes' adherence and rolling counting indicated that gyroxin has no pro inflammatory activity. Gyroxin induced platelet aggregation, which was blocked by inhibitors of PAR1 and PAR4 receptors (SCH 79797 and tcY-NH 2 , respectively). Finally, it was proved that the gyroxin temporarily alter the permeability of the blood brain barrier (BBB). Our study has shown that both the protease-activated receptors and nitric oxide are mediators involved in the biological activities of gyroxin. (author)

  4. A Bipolar Spindle of Antiparallel ParM Filaments Drives Bacterial Plasmid Segregation

    DEFF Research Database (Denmark)

    Gayathri, P; Fujii, T; Møller-Jensen, Jakob

    2012-01-01

    the spindle between ParRC complexes on sister plasmids. Using a combination of structural work and total internal reflection fluorescence microscopy, we show that ParRC bound and could accelerate growth at only one end of polar ParM filaments, mechanistically resembling eukaryotic formins. The architecture...... of ParM filaments enabled two ParRC-bound filaments to associate in an antiparallel orientation, forming a bipolar spindle. The spindle elongated as a bundle of at least two antiparallel filaments, thereby pushing two plasmid clusters toward the poles....

  5. First (18)F-labeled ligand for PET imaging of uPAR

    DEFF Research Database (Denmark)

    Persson, Morten; Liu, Hongguang; Madsen, Jacob

    2013-01-01

    Urokinase-type plasminogen activator receptor (uPAR) is overexpressed in human prostate cancer and uPAR has been found to be associated with metastatic disease and poor prognosis. AE105 is a small linear peptide with high binding affinity to uPAR. We synthesized an N-terminal NOTA......-conjugated version (NOTA-AE105) for development of the first (18)F-labeled uPAR positron-emission-tomography PET ligand using the Al(18)F radiolabeling method. In this study, the potential of (18)F-AlF-NOTA-AE105 to specifically target uPAR-positive prostate tumors was investigated....

  6. Intact and cleaved uPAR forms: diagnostic and prognostic value in cancer

    DEFF Research Database (Denmark)

    Rasch, M.G.; Lund, I.K.; Hoyer-Hansen, G.

    2008-01-01

    identified in tissue and body fluids. It is well-established, that the total amount of all uPAR forms is a strong prognostic marker in different types of cancer. Using immunoassays, measuring the individual uPAR forms, has revealed that the cleaved uPAR forms are even stronger prognostic markers and have...... diagnostic utility. This review will focus on the mechanism of uPAR cleavage and the functional consequences, as well as the clinical applicability of cleaved uPAR forms Udgivelsesdato: 2008...

  7. Dynamic Filament Formation by a Divergent Bacterial Actin-Like ParM Protein.

    Directory of Open Access Journals (Sweden)

    Anthony J Brzoska

    Full Text Available Actin-like proteins (Alps are a diverse family of proteins whose genes are abundant in the chromosomes and mobile genetic elements of many bacteria. The low-copy-number staphylococcal multiresistance plasmid pSK41 encodes ParM, an Alp involved in efficient plasmid partitioning. pSK41 ParM has previously been shown to form filaments in vitro that are structurally dissimilar to those formed by other bacterial Alps. The mechanistic implications of these differences are not known. In order to gain insights into the properties and behavior of the pSK41 ParM Alp in vivo, we reconstituted the parMRC system in the ectopic rod-shaped host, E. coli, which is larger and more genetically amenable than the native host, Staphylococcus aureus. Fluorescence microscopy showed a functional fusion protein, ParM-YFP, formed straight filaments in vivo when expressed in isolation. Strikingly, however, in the presence of ParR and parC, ParM-YFP adopted a dramatically different structure, instead forming axial curved filaments. Time-lapse imaging and selective photobleaching experiments revealed that, in the presence of all components of the parMRC system, ParM-YFP filaments were dynamic in nature. Finally, molecular dissection of the parMRC operon revealed that all components of the system are essential for the generation of dynamic filaments.

  8. Proteinase-Activated Receptor 1 (PAR1 regulates leukemic stem cell functions.

    Directory of Open Access Journals (Sweden)

    Nicole Bäumer

    Full Text Available External signals that are mediated by specific receptors determine stem cell fate. The thrombin receptor PAR1 plays an important role in haemostasis, thrombosis and vascular biology, but also in tumor biology and angiogenesis. Its expression and function in hematopoietic stem cells is largely unknown. Here, we analyzed expression and function of PAR1 in primary hematopoietic cells and their leukemic counterparts. AML patients' blast cells expressed much lower levels of PAR1 mRNA and protein than CD34+ progenitor cells. Constitutive Par1-deficiency in adult mice did not affect engraftment or stem cell potential of hematopoietic cells. To model an AML with Par1-deficiency, we retrovirally introduced the oncogene MLL-AF9 in wild type and Par1-/- hematopoietic progenitor cells. Par1-deficiency did not alter initial leukemia development. However, the loss of Par1 enhanced leukemic stem cell function in vitro and in vivo. Re-expression of PAR1 in Par1-/- leukemic stem cells delayed leukemogenesis in vivo. These data indicate that Par1 contributes to leukemic stem cell maintenance.

  9. Proteinase-Activated Receptor 1 (PAR1) regulates leukemic stem cell functions.

    Science.gov (United States)

    Bäumer, Nicole; Krause, Annika; Köhler, Gabriele; Lettermann, Stephanie; Evers, Georg; Hascher, Antje; Bäumer, Sebastian; Berdel, Wolfgang E; Müller-Tidow, Carsten; Tickenbrock, Lara

    2014-01-01

    External signals that are mediated by specific receptors determine stem cell fate. The thrombin receptor PAR1 plays an important role in haemostasis, thrombosis and vascular biology, but also in tumor biology and angiogenesis. Its expression and function in hematopoietic stem cells is largely unknown. Here, we analyzed expression and function of PAR1 in primary hematopoietic cells and their leukemic counterparts. AML patients' blast cells expressed much lower levels of PAR1 mRNA and protein than CD34+ progenitor cells. Constitutive Par1-deficiency in adult mice did not affect engraftment or stem cell potential of hematopoietic cells. To model an AML with Par1-deficiency, we retrovirally introduced the oncogene MLL-AF9 in wild type and Par1-/- hematopoietic progenitor cells. Par1-deficiency did not alter initial leukemia development. However, the loss of Par1 enhanced leukemic stem cell function in vitro and in vivo. Re-expression of PAR1 in Par1-/- leukemic stem cells delayed leukemogenesis in vivo. These data indicate that Par1 contributes to leukemic stem cell maintenance.

  10. Fabrication of the 4. set of fuel elements for the experimental pile EL2; Fabrication du 4. jeu de barreaux de la pile d'essai EL2

    Energy Technology Data Exchange (ETDEWEB)

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

    1958-07-01

    The reactor EL2 is the second atomic reactor built in France. It is a laboratory reactor using heavy water and natural uranium. Its cooling circuit operates with compressed CO{sub 2} gas at 8 kg/cm{sup 2} pressure. The subject of this lecture is the manufacturing of the fourth set of rods. The principle of uranium-can connection is exposed: that is the principle of a pre-pressed bound can. The EL2 reactor has been a prototype with respect to this aspect of the question, and a prototype which has been quite satisfactory. The main steps of the fabrication are exposed: the {gamma} phase extension of uranium, the machining, the three canning (die canning, hydraulic canning, compressed air treatment), the automatic argon arc welding of cups and the different manufacturing controls. (author) [French] Le reacteur EL2 est le deuxieme reacteur construit en France. C'est un reacteur de recherches qui utilise de l'eau lourde et de l'uranium naturel. Il est refroidi par du gaz carbonique sous 8 kg/cm{sup 2} de pression. On etudie dans cet expose la fabrication du quatrieme jeu d'elements combustibles. Le principe de la liaison uranium-gaine est expose: c'est celui d'une gaine precontrainte. La pile EL2 a constitue un prototype a ce point de vue, prototype qui a donne entiere satisfaction. Les principales etapes de la fabrication sont ensuite expliquees: le filage {gamma} de l'uranium, l'usinage des barreaux, les trois operations de gainages (gainage par filiere, gainage hydraulique, gainage a chaud), la soudure automatique des bouchons a l'argon-arc et les differents controles de fabrication. (auteur)

  11. Heat exchange and pressure drop of herring-bone fin surfaces. Experimental cell results at constant wall temperature; Echange de chaleur et perte de charge de surfaces a ailettes en chevrons. Resultats experimentaux en cellule a temperature de paroi constante

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1968-07-01

    The increase in the specific power of nuclear reactors of the gas-graphite type has necessitated the use of high performance exchange surfaces for canning the fuel (natural uranium). For this, experiments were carried out on cans fitted with herring-bone fins, at constant wall temperature; a flow of water at 100 deg. C passes inside the can which is cooled externally by a flow of CO{sub 2} at 15 bars pressure. This experimental set-up makes it possible to compare the aero-thermal performances of the different cans with an accuracy of 5 per cent. This report presents the results obtained in the form of a friction coefficient f{sub 0} and mean Margoulis number m{sub 0} as a function of the Reynolds number Re{sub 0}, this latter varying from 3 x 10{sup 5} to 9 x 10{sup 5}. (authors) [French] L'augmentation de la puissance specifique des reacteurs nucleaires de la filiere graphite-gaz a necessite l'utilisation de surfaces d'echange a hautes performances pour gainer le combustible (uranium naturel). Dans cette optique, des gaines munies d'ailettes disposees en chevron ont ete experimentees a temperature de paroi constante: un courant d'eau a 100 deg. C circule a l'interieur de la gaine qui est refroidie exterieurement par un ecoulement de CO{sub 2} sous une pression de 15 bars. Cette methode experimentale permet de situer les performances aerothermiques des gaines les unes par rapport aux autres a 5 pour cent pres. Ce rapport presente les resultats obtenus sous la forme d'un coefficient de frottement f{sub 0} et d'un nombre de Margoulis moyen m{sub 0} en fonction du nombre de Reynolds Re{sub 0}, ce dernier pouvant varier de 3. 10{sup 5} a 9. 10{sup 5}. (auteurs)

  12. Aerodynamic study of the fluid flow in the channel of a reactor filled with internally and externally cooled fuel elements; Etude aerodynamique de l'ecoulement fluide dans un canal de reacteur charge en elements combustibles annulaires refroidis interieurement et exterieurement

    Energy Technology Data Exchange (ETDEWEB)

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

    1965-07-01

    A study is made of the problem of the flow-rate and pressure distributions along the length of two volumes, internal and external, bounded by a series of non-continuous annular elements placed along the channel axis. It is observed that the phenomenon can easily be represented by equations. The theoretical expressions observed are particularly simple when the distances between the elements are above a certain minimum value. The experimental work has made it possible to show that the theoretical formulation derived is valid with a very great accuracy. The experimental study has also been carried out in the case of a very small spacing between the elements. It has been possible to show in this case that the hypothesis made for deriving the theoretical expressions was perfectly justified. In the last part finally, we consider the practical problem of evaluating the pressure-drops between the ends of a series of annular elements. (author) [French] On etudie le probleme de la repartition des debits et des pressions le long des deux espaces, interne et externe, delimites par une succession d'elements annulaires non jointifs, disposes suivant l'axe d'un canal. On constate que le phenomene peut etre mis aisement en equation. Les relations theoriques obtenues prennent en particulier une forme simple lorsque les intervalles entre elements sont superieurs a une valeur minimum. L'etude experimentale a permis de constater que cette formulation theorique etablie etait alors valable avec une precision excellente. L'etude experimentale a ete egalement effectuee dans le cas de tres faibles intervalles entre elements consecutifs. On a pu alors verifier que l'hypothese adoptee dans l'etablissement des relations theoriques etait parfaitement justifiee. Dans un dernier chapitre enfin, nous abordons le point de vue pratique de l'evaluation des pertes de charge aux bornes d'un train d'elements annulaires. (auteur)

  13. Aerodynamic study of the fluid flow in the channel of a reactor filled with internally and externally cooled fuel elements; Etude aerodynamique de l'ecoulement fluide dans un canal de reacteur charge en elements combustibles annulaires refroidis interieurement et exterieurement

    Energy Technology Data Exchange (ETDEWEB)

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

    1965-07-01

    A study is made of the problem of the flow-rate and pressure distributions along the length of two volumes, internal and external, bounded by a series of non-continuous annular elements placed along the channel axis. It is observed that the phenomenon can easily be represented by equations. The theoretical expressions observed are particularly simple when the distances between the elements are above a certain minimum value. The experimental work has made it possible to show that the theoretical formulation derived is valid with a very great accuracy. The experimental study has also been carried out in the case of a very small spacing between the elements. It has been possible to show in this case that the hypothesis made for deriving the theoretical expressions was perfectly justified. In the last part finally, we consider the practical problem of evaluating the pressure-drops between the ends of a series of annular elements. (author) [French] On etudie le probleme de la repartition des debits et des pressions le long des deux espaces, interne et externe, delimites par une succession d'elements annulaires non jointifs, disposes suivant l'axe d'un canal. On constate que le phenomene peut etre mis aisement en equation. Les relations theoriques obtenues prennent en particulier une forme simple lorsque les intervalles entre elements sont superieurs a une valeur minimum. L'etude experimentale a permis de constater que cette formulation theorique etablie etait alors valable avec une precision excellente. L'etude experimentale a ete egalement effectuee dans le cas de tres faibles intervalles entre elements consecutifs. On a pu alors verifier que l'hypothese adoptee dans l'etablissement des relations theoriques etait parfaitement justifiee. Dans un dernier chapitre enfin, nous abordons le point de vue pratique de l'evaluation des pertes de charge aux bornes d'un train d'elements annulaires. (auteur)

  14. Purification by high vacuum fusion and progressive solidification of uranium from electrolytic origin; Purification par fusion sous vide eleve et solidification progressive d'uranium d'origine electrolytique

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-01-15

    grain observed, so-called secondary recrystallisation. in appendix, the method for measuring the electrical resistance by induction (with direct current)is studied from the fundamental and experimental point of view. The author applied it to the particular case of uranium for measuring the low-temperature resistance of the bars from the same which solidified first to the least pure ended the ingot. (author) [French] Dans le cadre de recherches generales sur la purification de l'uranium par fusion de zone, on a entrepris de determiner le degre de purification que l'on pourrait atteindre par une simple solidification progressive a vitesse et direction soigneusement controlees d'un uranium de purete nucleaire courante. Cet uranium de purete intermediaire fournirait un materiau de depart approprie au mode de purification ultime qu'est la fusion a zone verticale, dite ''flottante''. Dans ce but, des lingots d'uranium d'origine electrolytique ont ete refondus sous vide (2 a 5 x 10{sup -6} mm) dans une longue nacelle en UO{sub 2} apres une monte lente en temperature pour eliminer le maximum de gaz et d'impuretes volatiles. Ce degazage et cette volatilisation d'impuretes sont completes par maintien prolonge a haute temperature du bais liquide. Celui-ci est ensuite solidifie d'une extremite a l'autre de la nacelle par deplacement a vitesse lente et constante du front de solidification de facon a obtenir une repartition des impuretes selon les lois etablies par PFANN. Differentes methodes experimentales ont permis de montrer que le metal solidifie en premier lieu est nettement plus pur que celui de la partie solidifie a l'extremite opposee du lingot. Le degre de purification du metal en tete du lingot a ete apprecie, soit quantitativement par mesure du rapport des resistivites electriques a la temperature ambiante et a celle de l'azote liquide, soit qualitativement par l'examen de la structure micrographique et par l'etude de la recristallisation du metal. D'une part, le metal

  15. The double par locus of virulence factor pB171: DNA segregation is correlated with oscillation of ParA

    DEFF Research Database (Denmark)

    Ebersbach, G; Gerdes, K; Charbon, Gitte Ebersbach

    2001-01-01

    Prokaryotic plasmids and chromosomes encode partitioning (par) loci that segregate DNA to daughter cells before cell division. Recent database analyses showed that almost all known par loci encode an ATPase and a DNA-binding protein, and one or more cis-acting regions where the proteins act. All...

  16. Surface and Subsurface Geochemical Monitoring of an EOR-CO2 Field: Buracica, Brazil Monitoring géochimique en surface et sub-surface d’un gisement en production par récupération assistée et injection de CO2 : le champ de Buracica, Brésil

    Directory of Open Access Journals (Sweden)

    Magnier C.

    2012-04-01

    Full Text Available This paper presents a surface and subsurface geochemical survey of the Buracica EOR-CO2 field onshore Brazil. We adopted a methodology coupling the stable isotopes of carbon with noble gases to investigate the adequacy of geochemical monitoring to track deep fluid leakage at the surface. Three campaigns of CO2 flux and concentration in soils were performed to understand the CO2 variability across the field. The distribution of the CO2 soil contents between 0.8 and 14% is in great part controlled by the properties of the soil, with a first-order topographic dependency. These results, together with a δ13CCO2 between –15 and –23‰, suggest that the bulk of the soil CO2 flux is biological. The gas injected and produced at numerous wells across the field showed a great spatial and somewhat temporal heterogeneity with respect to molecular, δ13CCO2 and noble gas compositions. This heterogeneity is a consequence of the EOR-induced sweeping of the petroleum fluids by the injected CO2, producing a heterogeneous mixing controlled by the production scheme and the distribution in reservoir permeability. In light of the δ13CCO2 found in the reservoir, the stable isotopic composition of carbon was insufficient to track CO2 leaks at the surface. We demonstrate how noble gases may be powerful leak discriminators, even for CO2 abundances in soils in the bottom range of the biological baseline (~1%. The results presented in this study show the potential of geochemical monitoring techniques, involving stable isotopes and noble gases at the reservoir and soil levels, for tracing CO2 in CCS projects. Le monitoring géochimique du gisement de Buracica, qui produit des hydrocarbures par récupération assistée et injection de dioxyde de carbone, est présenté dans cet article. Une méthodologie permettant de coupler l’utilisation des isotopes stables du carbone et des isotopes des gaz rares pour étudier la faisabilité de traçage d’une fuite de CO2 du r

  17. ParABS Systems of the Four Replicons of Burkholderia cenocepacia: New Chromosome Centromeres Confer Partition Specificity†

    Science.gov (United States)

    Dubarry, Nelly; Pasta, Franck; Lane, David

    2006-01-01

    Most bacterial chromosomes carry an analogue of the parABS systems that govern plasmid partition, but their role in chromosome partition is ambiguous. parABS systems might be particularly important for orderly segregation of multipartite genomes, where their role may thus be easier to evaluate. We have characterized parABS systems in Burkholderia cenocepacia, whose genome comprises three chromosomes and one low-copy-number plasmid. A single parAB locus and a set of ParB-binding (parS) centromere sites are located near the origin of each replicon. ParA and ParB of the longest chromosome are phylogenetically similar to analogues in other multichromosome and monochromosome bacteria but are distinct from those of smaller chromosomes. The latter form subgroups that correspond to the taxa of their hosts, indicating evolution from plasmids. The parS sites on the smaller chromosomes and the plasmid are similar to the “universal” parS of the main chromosome but with a sequence specific to their replicon. In an Escherichia coli plasmid stabilization test, each parAB exhibits partition activity only with the parS of its own replicon. Hence, parABS function is based on the independent partition of individual chromosomes rather than on a single communal system or network of interacting systems. Stabilization by the smaller chromosome and plasmid systems was enhanced by mutation of parS sites and a promoter internal to their parAB operons, suggesting autoregulatory mechanisms. The small chromosome ParBs were found to silence transcription, a property relevant to autoregulation. PMID:16452432

  18. Project of law relative to the electricity and gas public utilities and to the power and gas companies; Projet de loi relatif au service public de l'electricite et du gaz et aux entreprises electriques et gazieres

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This document is the definitive text of this project of law adopted by the French house of commons. The aim of this law is to allow the administrations to avoid to use their eligibility right with the opening of the electricity and gas markets to competition. It changes the juridical status of the two public utilities Electricite de France (EdF) and Gaz de France (GdF) into two anonymous companies and creates two additional companies for the management of the power and gas networks. It ensures also the transposition of the European directives from June 26, 2003 (2003/54/CE and 2003/55/CE). It contains some proper dispositions and modifies various existing French laws, in particular the law no. 46-628 from April 8, 1946 about the electricity and gas nationalization and the law no. 2000-108 from February 10, 2000 relative to the modernization and development of the electric public utility. (J.S.)

  19. Serum suPAR in patients with FSGS: trash or treasure?

    Science.gov (United States)

    Maas, Rutger J H; Deegens, Jeroen K J; Wetzels, Jack F M

    2013-07-01

    The urokinase-type plasminogen activator receptor (uPAR) has important functions in cell migration. uPAR can be shed from the cell membrane resulting in soluble uPAR (suPAR). Further cleavage gives rise to shorter fragments with largely unknown functions. Recent studies have demonstrated that both overexpression of uPAR on podocytes and the administration of suPAR cause proteinuria in mice. The common pathogenic mechanism involves the activation of podocyte β3-integrin. Increased activation of β3-integrin is also observed in patients with focal and segmental glomerulosclerosis (FSGS). These observations form the basis for the hypothesis that suPAR may be the circulating factor causing FSGS. A recent study fosters this idea by demonstrating increased suPAR levels in the serum of patients with FSGS and reporting an association with recurrence after transplantation and response to plasmapheresis. However, this study was heavily biased, and subsequent studies have given conflicting results. Although the experimental work is very suggestive, at present there is no proof that any known human suPAR fragment causes FSGS in humans. We therefore suggest that the measurement of suPAR using currently available assays has absolutely no value at the present time in decision-making in routine clinical practice.

  20. PAR-2 expression in the gingival crevicular fluid reflects chronic periodontitis severity

    Directory of Open Access Journals (Sweden)

    Henrique FUKUSHIMA

    Full Text Available Abstract Recent studies investigating protease-activated receptor type 2 (PAR-2 suggest an association between the receptor and periodontal inflammation. It is known that gingipain, a bacterial protease secreted by the important periodontopathogen Porphyromonas gingivalis can activate PAR-2. Previous studies by our group found that PAR-2 is overexpressed in the gingival crevicular fluid (GCF of patients with moderate chronic periodontitis (MP. The present study aimed at evaluating whether PAR-2 expression is associated with chronic periodontitis severity. GCF samples and clinical parameters, including plaque and bleeding on probing indices, probing pocket depth and clinical attachment level, were collected from the control group (n = 19 at baseline, and from MP patients (n = 19 and severe chronic periodontitis (SP (n = 19 patients before and 6 weeks after periodontal non-surgical treatment. PAR-2 and gingipain messenger RNA (mRNA in the GCF of 4 periodontal sites per patient were evaluated by Reverse Transcription Polymerase Chain Reaction (RT-qPCR. PAR-2 and gingipain expressions were greater in periodontitis patients than in control group patients. In addition, the SP group presented increased PAR-2 and gingipain mRNA levels, compared with the MP group. Furthermore, periodontal treatment significantly reduced (p <0.05 PAR-2 expression in patients with periodontitis. In conclusion, PAR-2 is associated with chronic periodontitis severity and with gingipain levels in the periodontal pocket, thus suggesting that PAR-2 expression in the GCF reflects the severity of destruction during periodontal infection.

  1. Structures of actin-like ParM filaments show architecture of plasmid-segregating spindles.

    Science.gov (United States)

    Bharat, Tanmay A M; Murshudov, Garib N; Sachse, Carsten; Löwe, Jan

    2015-07-02

    Active segregation of Escherichia coli low-copy-number plasmid R1 involves formation of a bipolar spindle made of left-handed double-helical actin-like ParM filaments. ParR links the filaments with centromeric parC plasmid DNA, while facilitating the addition of subunits to ParM filaments. Growing ParMRC spindles push sister plasmids to the cell poles. Here, using modern electron cryomicroscopy methods, we investigate the structures and arrangements of ParM filaments in vitro and in cells, revealing at near-atomic resolution how subunits and filaments come together to produce the simplest known mitotic machinery. To understand the mechanism of dynamic instability, we determine structures of ParM filaments in different nucleotide states. The structure of filaments bound to the ATP analogue AMPPNP is determined at 4.3 Å resolution and refined. The ParM filament structure shows strong longitudinal interfaces and weaker lateral interactions. Also using electron cryomicroscopy, we reconstruct ParM doublets forming antiparallel spindles. Finally, with whole-cell electron cryotomography, we show that doublets are abundant in bacterial cells containing low-copy-number plasmids with the ParMRC locus, leading to an asynchronous model of R1 plasmid segregation.

  2. PAR-1 contributes to the innate immune response during viral infection

    Science.gov (United States)

    Antoniak, Silvio; Owens, A. Phillip; Baunacke, Martin; Williams, Julie C.; Lee, Rebecca D.; Weithäuser, Alice; Sheridan, Patricia A.; Malz, Ronny; Luyendyk, James P.; Esserman, Denise A.; Trejo, JoAnn; Kirchhofer, Daniel; Blaxall, Burns C.; Pawlinski, Rafal; Beck, Melinda A.; Rauch, Ursula; Mackman, Nigel

    2013-01-01

    Coagulation is a host defense system that limits the spread of pathogens. Coagulation proteases, such as thrombin, also activate cells by cleaving PARs. In this study, we analyzed the role of PAR-1 in coxsackievirus B3–induced (CVB3-induced) myocarditis and influenza A infection. CVB3-infected Par1–/– mice expressed reduced levels of IFN-β and CXCL10 during the early phase of infection compared with Par1+/+ mice that resulted in higher viral loads and cardiac injury at day 8 after infection. Inhibition of either tissue factor or thrombin in WT mice also significantly increased CVB3 levels in the heart and cardiac injury compared with controls. BM transplantation experiments demonstrated that PAR-1 in nonhematopoietic cells protected mice from CVB3 infection. Transgenic mice overexpressing PAR-1 in cardiomyocytes had reduced CVB3-induced myocarditis. We found that cooperative signaling between PAR-1 and TLR3 in mouse cardiac fibroblasts enhanced activation of p38 and induction of IFN-β and CXCL10 expression. Par1–/– mice also had decreased CXCL10 expression and increased viral levels in the lung after influenza A infection compared with Par1+/+ mice. Our results indicate that the tissue factor/thrombin/PAR-1 pathway enhances IFN-β expression and contributes to the innate immune response during single-stranded RNA viral infection. PMID:23391721

  3. Par-4-mediated recruitment of Amida to the actin cytoskeleton leads to the induction of apoptosis

    International Nuclear Information System (INIS)

    Boosen, Meike; Vetterkind, Susanne; Koplin, Ansgar; Illenberger, Susanne; Preuss, Ute

    2005-01-01

    Par-4 (prostate apoptosis response-4) sensitizes cells to apoptotic stimuli, but the exact mechanisms are still poorly understood. Using Par-4 as bait in a yeast two-hybrid screen, we identified Amida as a novel interaction partner, a ubiquitously expressed protein which has been suggested to be involved in apoptotic processes. Complex formation of Par-4 and Amida occurs in vitro and in vivo and is mediated via the C-termini of both proteins, involving the leucine zipper of Par-4. Amida resides mainly in the nucleus but displays nucleo-cytoplasmic shuttling in heterokaryons. Upon coexpression with Par-4 in REF52.2 cells, Amida translocates to the cytoplasm and is recruited to actin filaments by Par-4, resulting in enhanced induction of apoptosis. The synergistic effect of Amida/Par-4 complexes on the induction of apoptosis is abrogated when either Amida/Par-4 complex formation or association of these complexes with the actin cytoskeleton is impaired, indicating that the Par-4-mediated relocation of Amida to the actin cytoskeleton is crucial for the pro-apoptotic function of Par-4/Amida complexes in REF52.2 cells. The latter results in enhanced phosphorylation of the regulatory light chain of myosin II (MLC) as has previously been shown for Par-4-mediated recruitment of DAP-like kinase (Dlk), suggesting that the recruitment of nuclear proteins involved in the regulation of apoptotic processes to the actin filament system by Par-4 represents a potent mechanism how Par-4 can trigger apoptosis

  4.  Standardy rachunkowości stanowiące podstawę sporządzania sprawozdań finansowych przez jednostki wydobywające gaz łupkowy w Polsce i w Stanach Zjednoczonych

    Directory of Open Access Journals (Sweden)

    Anna Galimska

    2015-12-01

    Full Text Available Celem artykułu jest analiza oraz porównanie standardów rachunkowości wykorzystywanych przez przedsiębiorstwa poszukujące i wydobywające gaz łupkowy w Stanach Zjednoczonych i w Polsce. Autorka dokonała zestawienia regulacji służących do sporządzania i prezentacji sprawozdań finansowych, na których opierają się jednostki eksploatujące węglowodory niekonwencjonalne. Wciąż postępujący rozwój rynków kapitałowych znajduje swoje odzwierciedlenie w intensyfikacji oczekiwań interesariuszy względem atrybutów, którymi winny charakteryzować się sprawozdania finansowe. Rozważania zawarte w artykule ukazują wysoki poziom specjalizacji amerykańskich standardów rachunkowości, na których bazują podmioty wydobywające gaz łupkowy w Stanach Zjednoczonych. Natomiast standardy międzynarodowe poruszają jedynie kwestię początkowego stadium procesu wydobycia alternatywnych węglowodorów, co rzutuje na spójność przygotowywanych na ich podstawie sprawozdań finansowych. Ponadto istotna jest kwestia rozbieżności merytorycznych czy też interpretacyjnych analizowanych standardów zarówno w zakresie identyfikacji kosztów oraz ich klasyfikacji, jak i określania wysokości odpisów z tytułu utraty wartości.

  5. Bacterial mitosis: Partitioning protein ParA oscillates in spiral-shaped structures and positions plasmids at mid-cell

    DEFF Research Database (Denmark)

    Ebersbach, G.; Gerdes, Kenn

    2004-01-01

    The par2 locus of Escherichia coli plasmid pB171 encodes oscillating ATPase ParA, DNA binding protein ParB and two cis-acting DNA regions to which ParB binds (parC1 and parC2). Three independent techniques were used to investigate the subcellular localization of plasmids carrying par2. In cells......A-GFP oscillated in spiral-shaped structures. Amino acid substitutions in ParA simultaneously abolished ParA spiral formation, oscillation and either plasmid localization or plasmid separation at mid-cell. Therefore, our results suggest that ParA spirals position plasmids at the middle of the bacterial nucleoid...

  6. Tests on dynamic corrosion by water. Influence of the passage of a heat flux on the corrosion kinetics. pH measurement in water at high temperature; Essais de corrosion dynamique par l'eau. Influence du passage d'un flux thermique sur la cinetique de corrosion. Mesure du pH dans l'eau a haute temperature

    Energy Technology Data Exchange (ETDEWEB)

    Coriou, H.; Grall, L.; Hure, J.; Saint-James, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Berthod [Societe Grenobloise d' Etudes et d' Applications Hydrauliques, 38 (France); Le peintre [Centre National de la Recherche Scientifique (CNRS), 38 - Grenoble (France)

    1958-07-01

    The passage of a heat flux through the surface of a metal placed in a corrosive medium influences the rate of corrosion, these being higher than under adiabatic conditions. The apparatus developed for corrosion tests is described, it is possible to obtain with this equipment: 1) Heat fluxes greater than 200 W/cm{sup 2}, across aluminium canning, which is cooled by water (temperature 50 deg. C), circulating with flow rates of the order of 5 to 6 m/s. 2) Heat fluxes which can go up to 150 W/cm{sup 2}, across canning of zircaloy or stainless steel. The cooling fluid is pressurized water at a temperature around 280 deg. C, the flow-rate of circulation reaching 6 m/s. The results obtained on aluminium canning are studied from the viewpoint of corrosion, paying particular attention to cavitation phenomena which can cause serious damage in certain special circumstances. After developing a glass electrode system capable of supporting high pressures, the authors have investigated materials capable of functioning as a hydrogen electrode and of resisting satisfactorily corrosion by water at 200 deg. C. Various possibilities have been examined: electrodes of special glasses, quartz, metals, with a membrane etc... The results of the various tests and the practical limits of utilisation are given. (author)Fren. [French] Le passage d'un flux thermique a travers la surface d'un metal place dans un milieu corrosif influence les vitesses de corrosion, celles-ci etant plus elevees que dans des conditions adiabatiques. On decrit les appareils mis au point, pour essais de corrosion. Ils permettent d'obtenir: 1) A travers des gaine aluminium des flux thermiques depassant 200 W /cm{sup 2}. Les gaines sont refroidies par l'eau (temperature 50 deg. C), circulant a des vitesses de l'ordre de 5 a 6 m/s. 2) A travers des gaines en zircaloy ou acier inoxydable des flux thermiques pouvant s'elever a 150 W/cm{sup 2}. Le fluide de refroidissement est de l

  7. Tests on dynamic corrosion by water. Influence of the passage of a heat flux on the corrosion kinetics. pH measurement in water at high temperature; Essais de corrosion dynamique par l'eau. Influence du passage d'un flux thermique sur la cinetique de corrosion. Mesure du pH dans l'eau a haute temperature

    Energy Technology Data Exchange (ETDEWEB)

    Coriou, H; Grall, L; Hure, J; Saint-James, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Berthod, [Societe Grenobloise d' Etudes et d' Applications Hydrauliques, 38 (France); peintre, Le [Centre National de la Recherche Scientifique (CNRS), 38 - Grenoble (France)

    1958-07-01

    The passage of a heat flux through the surface of a metal placed in a corrosive medium influences the rate of corrosion, these being higher than under adiabatic conditions. The apparatus developed for corrosion tests is described, it is possible to obtain with this equipment: 1) Heat fluxes greater than 200 W/cm{sup 2}, across aluminium canning, which is cooled by water (temperature 50 deg. C), circulating with flow rates of the order of 5 to 6 m/s. 2) Heat fluxes which can go up to 150 W/cm{sup 2}, across canning of zircaloy or stainless steel. The cooling fluid is pressurized water at a temperature around 280 deg. C, the flow-rate of circulation reaching 6 m/s. The results obtained on aluminium canning are studied from the viewpoint of corrosion, paying particular attention to cavitation phenomena which can cause serious damage in certain special circumstances. After developing a glass electrode system capable of supporting high pressures, the authors have investigated materials capable of functioning as a hydrogen electrode and of resisting satisfactorily corrosion by water at 200 deg. C. Various possibilities have been examined: electrodes of special glasses, quartz, metals, with a membrane etc... The results of the various tests and the practical limits of utilisation are given. (author)Fren. [French] Le passage d'un flux thermique a travers la surface d'un metal place dans un milieu corrosif influence les vitesses de corrosion, celles-ci etant plus elevees que dans des conditions adiabatiques. On decrit les appareils mis au point, pour essais de corrosion. Ils permettent d'obtenir: 1) A travers des gaine aluminium des flux thermiques depassant 200 W /cm{sup 2}. Les gaines sont refroidies par l'eau (temperature 50 deg. C), circulant a des vitesses de l'ordre de 5 a 6 m/s. 2) A travers des gaines en zircaloy ou acier inoxydable des flux thermiques pouvant s'elever a 150 W/cm{sup 2}. Le fluide de refroidissement est de l'eau sous pression a une temperature

  8. Envenimation mortelle par morsure de serpent chez une femme ...

    African Journals Online (AJOL)

    Les auteurs rapportent un cas de morsure de serpent au niveau de la face chez une femme enceinte, dont l'évolution a été marquée par l'installation d'un oedème cervico-facial nécessitant une trachéotomie en urgence, et une mort foetale in utero avec troubles de l'hémostase responsable du décès maternel dans un ...

  9. Analysis of clinical features and visual outcomes of pars planitis.

    Science.gov (United States)

    Berker, Nilufer; Sen, Emine; Elgin, Ufuk; Atilgan, Cemile Ucgul; Dursun, Erdem; Yilmazbas, Pelin

    2018-04-01

    To evaluate the demographic characteristics, clinical features, treatment and outcomes of patients with pars planitis in a tertiary referral center in Turkey. Medical records of patients with pars planitis were retrospectively reviewed. The data including demographic and ocular features and treatment outcomes were recorded. The distribution of clinical findings and complications were evaluated according to age and gender groups. The changes in final BCVA compared to the initial BCVA were noted. Statistical analysis was performed using SPSS software (Version 18.0, SPSS Inc., Chicago, USA). Twenty-seven patients (54 eyes) were included in this study. 16 patients were male (59.3%), and 11 were female (40.7%). Mean age at diagnosis was 12.84 ± 8.26 (range 4-36) years. Mean follow-up period was 61.3 ± 52.15 (range 9-172) months. Mean BCVA was 0.58 ± 0.36 (range 0.03-1.00) (0.40 ± 0.45 logMAR) at presentation, and 0.81 ± 0.28 (range 0.10-1.00) (0.14 ± 0.27 logMAR) at final visit (P = 0.001). Vitreous inflammation (100%), vitreous haze (92.6%), snowballs (74.1%), snowbanks (66.7%), anterior chamber cells (66.7%) and peripheral retinal vascular sheathing (48.1%) were the most common presentations. Ocular complications included vitreous condensation (51.9%), cystoid macular edema (22.2%), cataract (18.5%), inferior peripheral retinal detachment (11.1%), glaucoma (5.6%) and vitreous hemorrhage (3.7%). Treatments included topical, periocular, intravitreal and systemic corticosteroids, immunosuppressives, peripheral laser photocoagulation and pars plana vitrectomy when needed. Pars planitis is an idiopathic chronic intermediate uveitis mostly affecting children and adolescents. In spite of its chronic nature with high potential of causing ocular complications, adequate treatment and close follow-up lead to favorable visual outcomes.

  10. Cartographie par carroyage et précision spatiale

    Directory of Open Access Journals (Sweden)

    Patrice LANGLOIS

    1998-03-01

    Full Text Available Dans le cadre d'une cartographie par carroyage, on étudie la désagrégation de variables zonales, en revenant sur l'hypothèse de l'équirépartition spatiale des populations. L'objectif est d'approcher des règles différenciées de désagrégation des variables en fusionnant des plans d'information de nature morphologique, topologique et environnementale.

  11. Karabük İlindeki Hava Kirliliğinin Doğal Gaz Kullanımı İle Değişimi

    Directory of Open Access Journals (Sweden)

    Abdülaziz YILDIZ

    2012-12-01

    Full Text Available ÖzetFosil kaynaklı yakıtların kullanımı, hava kirliliğine sebebiyet veren en önemli unsurlardan bir tanesidir. Bu yakıtların bilinçsizce kullanılması sonucunda çevre problemlerine özellikle de hava kirliliğine neden olmaktadır. Yapılan bu çalışmada, Karabük ilinin doğalgaz kullanmaya başlamadan önceki ve doğalgaza geçiş ile hava kirlilik parametreleri (SO2 ve PM10 incelenmiştir. Doğal gaz kullanımının hava kalitesine etkisi araştırılmıştır. İlde ısınma ihtiyacını karşılamak için kömür, fuel-oil ve mazot kullanılırken 2010 yılı itibariyle doğal gaza geçilmiştir. Doğal gazın kullanılmaya başlanmasıyla bu yakıtların kullanımı azalmıştır. Çalışmanın sonunda, Hava Kalitesi Değerlendirme ve Yönetimi Yönetmeliğinde (HKDYY belirtilen, SO2 için 250 μg/m3 değerinin doğal gaz kullanımına geçilmeden önce bazı aylarda üzerinde olduğu görülmüş ve doğal gaz kullanılmaya başlanmasından sonraki dönemlerde ise 250 μg/m3 değerinin aşılmadığı görülmüştür. PM10 için yönetmelikte belirtilen 200 μg/m3 değerinin kış sezonunda aşıldığı tespit edilmiştir. 2010 yılında Doğal gaz kullanımına geçiş ile birlikte bu değerde tekrar bir düşüş gözlenmiştir. Doğal gaz kullanım oranı artıkça havadaki SO2 ve PM10 değerlerinde ciddi düşüşler olduğu gözlenmiştir.AbstractThe Usage of fossil origin fuels is one of the most important cause of air pollution. The usage of these fuels unconsciously causes environmental problems especially air pollution. In this study air pollution parameters (SO2 ve PM10 were analyzed before and after the usage of natural gas in Karabuk. The effect of usage natural gas on air quality is researched. In this city before 2010 coal, foul-oil and diesel were used to provide heat demanded then it is started using natural gas by 2010.With starting the usage of natural gas, the usage of these kind of fuels (coal, foul

  12. PET imaging of urokinase-type plasminogen activator receptor (uPAR) in prostate cancer

    DEFF Research Database (Denmark)

    Skovgaard, Dorthe; Persson, Morten; Kjaer, Andreas

    2016-01-01

    Overexpression of urokinase-type plasminogen activator receptors (uPAR) represents an important biomarker for aggressiveness in most common malignant diseases, including prostate cancer (PC). Accordingly, uPAR expression either assessed directly in malignant PC tissue or assessed directly in plasma...... and prognostic imaging method. In this review, we will focus on the recent development of uPAR PET and the relevance within prostate cancer imaging. Novel antibody and small-molecule radiotracers-targeting uPAR, including a series of uPAR-targeting PET ligands, based on the high affinity peptide ligand AE105......, have been synthesized and tested in vitro and in vivo in preclinical murine xenograft models and, recently, in a first-ever clinical uPAR PET study in cancer patients, including patients with PC. In this phase I study, a high and specific uptake of the tracer 64Cu-DOTA-AE105 was found in both primary...

  13. Paracrine Apoptotic Effect of p53 Mediated by Tumor Suppressor Par-4

    Directory of Open Access Journals (Sweden)

    Ravshan Burikhanov

    2014-01-01

    Full Text Available The guardian of the genome, p53, is often mutated in cancer and may contribute to therapeutic resistance. Given that p53 is intact and functional in normal tissues, we harnessed its potential to inhibit the growth of p53-deficient cancer cells. Specific activation of p53 in normal fibroblasts selectively induced apoptosis in p53-deficient cancer cells. This paracrine effect was mediated by p53-dependent secretion of the tumor suppressor Par-4. Accordingly, the activation of p53 in normal mice, but not p53−/− or Par-4−/− mice, caused systemic elevation of Par-4, which induced apoptosis of p53-deficient tumor cells. Mechanistically, p53 induced Par-4 secretion by suppressing the expression of its binding partner, UACA, which sequesters Par-4. Thus, normal cells can be empowered by p53 activation to induce Par-4 secretion for the inhibition of therapy-resistant tumors.

  14. Impact environnemental d'une désulfuration poussée des gazoles Environmental Impact of Gaz Oil Desulfurization

    Directory of Open Access Journals (Sweden)

    Armengol C.

    2006-11-01

    Full Text Available En une dizaine d'années, le diesel a connu un développement spectaculaire sur les marchés automobile français et européen et pourrait atteindre, en 1995, la moitié des immatriculations de véhicules particuliers en France et le quart en Europe de l'Ouest. Cette situation n'est évidemment pas sans poser de problèmes. Problèmes environnementaux puisque le moteur diesel est une source plus importante d'émissions d'oxydes d'azote et de particules que le convertisseur essence, mais également au niveau de l'industrie du raffinage qui, en France, n'est plus en mesure de satisfaire la demande en gazole. De plus, à compter du 1er octobre 1996, la teneur en soufre du gazole routier ne devra pas excéder 0,05 %, conformément aux nouvelles spécifications européennes. Cette perspective de production de carburants fortement désulfurés va affecter directement l'équilibre en hydrogène de la raffinerie et donc les autoconsommations et les émissions de CO2. L'objectif de cette étude est de mesurer l'impact sur l'environnement d'une réduction de la teneur en soufre des gazoles de 0,3 à 0,05 %. Le bilan est réalisé sur l'ensemble de la filière énergétique, depuis l'extraction du pétrole jusqu'à la combustion du carburant dans le moteur. Les gains et les pertes en termes de pollution locale ou globale sont évalués suivant la nature de l'hydrogène utilisé (oxydation partielle de résidus sous vide ou de charbon, reformage à la vapeur de gaz naturel ou de naphta électrolyse et la nature de la charge à traiter (gazole straight run ou light cycle oil lors de l'hydrodésulfuration. Over the past decade, diesel had made large advances in the French and European automobile markets. In 1995, diesel could account for half of all private vehicle registrations in France, and a quarter in Western Europe. This situation inevitably raises a number of problems : environmental problems, because the diesel engine emits more nitrogen oxides and

  15. Four cases of endophthalmitis after 25-gauge pars plana vitrectomy

    Directory of Open Access Journals (Sweden)

    Mutoh T

    2012-08-01

    Full Text Available Tetsuya Mutoh, Koji Kadoya, Makoto ChikudaDepartment of Ophthalmology, Dokkyo Medical University Koshigaya Hospital, Koshigaya, Saitama, JapanAbstract: We report our recent experience with four cases of endophthalmitis (one male, three females after 25-gauge pars plana vitrectomy (PPV. One was a case of persistent cystoid macular edema caused by branch retinal vein occlusion, whereas the remaining three were cases of epiretinal membrane. Preoperative antibiotics before the first PPV procedure were not administered in three of the four cases. Endophthalmitis occurred 2–4 days after the first procedure in all cases, for which ceftazidime 2.0 mg/0.1 mL and vancomycin 1.0 mg/0.1 mL were injected into the vitreous cavity. This was followed by emergent 20-gauge PPV and intraocular lens removal using an infusion fluid containing ceftazidime and vancomycin. After the second PPV procedure, progress was good in three cases while retinal detachment occurred in the remaining case one month after surgery; this case required a third PPV procedure. Final best-corrected visual acuity ranged from 20/100 to 20/25 for the four cases. Bacterial cultures were negative after the second PPV procedure in all cases. In conclusion, postoperative endophthalmitis occurred in four of 502 cases (0.80% that underwent 25-gauge PPV at our hospital. It is important to minimize the incidence of endophthalmitis after 25-gauge PPV.Keywords: 25-gauge pars plana vitrectomy, endophthalmitis, incidence

  16. Stress reactions involving the pars interarticularis in young athletes

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, D.W.; Wiltse, L.L.; Dingeman, R.D.; Hayes, M.

    A stress reaction involving the pars interarticularis of the lumbar spine was confirmed in seven young athletes with a positive technetium pyrophosphate bone scan. No pars defects were detectable on their lumbosacral roentgenograms, which included oblique views. The return to normal levels of radioactive uptake on repeat bone scans correlated closely with their clinical course. If the bony reaction is recognized early, it may heal at a subroentgenographic level and prevent the development of lumbar spondylolysis. These early lesions usually show unilateral increased uptake at one lumbar level on the bone scan and, initially, the athlete localizes the pain to the corresponding unilateral lumbar paraspinous area. The ''one-legged hyperextension test'' is positive on the ipsilateral side and aggravates the pain. Treatment consists of avoiding the aggravating activities and resting. The average time for return to pain-free competition was 7.3 months. These developing defects may be the source of considerable prolonged disability in the young athlete, particularly if undiagnosed and untreated.

  17. Stress reactions involving the pars interarticularis in young athletes

    International Nuclear Information System (INIS)

    Jackson, D.W.; Wiltse, L.L.; Dingeman, R.D.; Hayes, M.

    1981-01-01

    A stress reaction involving the pars interarticularis of the lumbar spine was confirmed in seven young athletes with a positive technetium pyrophosphate bone scan. No pars defects were detectable on their lumbosacral roentgenograms, which included oblique views. The return to normal levels of radioactive uptake on repeat bone scans correlated closely with their clinical course. If the bony reaction is recognized early, it may heal at a subroentgenographic level and prevent the development of lumbar spondylolysis. These early lesions usually show unilateral increased uptake at one lumbar level on the bone scan and, initially, the athlete localizes the pain to the corresponding unilateral lumbar paraspinous area. The ''one-legged hyperextension test'' is positive on the ipsilateral side and aggravates the pain. Treatment consists of avoiding the aggravating activities and resting. The average time for return to pain-free competition was 7.3 months. These developing defects may be the source of considerable prolonged disability in the young athlete, particularly if undiagnosed and untreated

  18. Réduction du risque d'infection par le VIH au Botswana - essais ...

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

    Au Botswana, ce sont les jeunes femmes qui sont le plus touchées par les nouvelles infections par le VIH. Le présent projet a pour but de réduire le nombre de nouveaux cas d'infection par le VIH, en particulier chez les femmes de 15 à 29 ans. Bien que l'on recense des cas de VIH/sida dans la plupart des régions du ...

  19. Improved Oxidation Resistance of Zirconium Resulting from Addition of Small Amounts of Copper; Amelioration de la Resistance a l'Oxydation du Zirconium par de Faibles Additions de Cuivre; Povyshenie soprotivlyaemosti k okisleniyu tsirkoniya posle dobavlenij nebol'shikh kolichestv medi; Aumento de la Resistencia del Circonio a la Oxidacion por Agregado de Pequenas Cantidades de Cobre

    Energy Technology Data Exchange (ETDEWEB)

    Loriers, H.; Darras, R.; Baque, P. [Centre d' Etudes Nucleaires de Saclay (France)

    1966-02-15

    The authors have tried to explain the process by which the addition of small amounts of copper improves the resistance of zirconium to oxidation by pressurized carbon dioxide between 600 and 700 Degree-Sign C. The resulting alloys, particularly that with 2.5% copper, seem to offer interesting possibilities as cladding or structural materials for the fuel elements of reactors of the heavy water-carbon dioxide type. The corrosion of zirconium by carbon dioxide amounts essentially to oxidation, in which two processes are involved: (1) the building up of a layer of monoclinic zirconia, through which oxygen diffuses by migration of the anionic vacancies: (2) the dissolution and diffusion of oxygen, which penetrates into the metal. The combination of gravimetric data and measurements of the thickness of the oxide layers permits evaluation of the two corresponding diffusion coefficients. This calculation has been extended, by analogy, to the case of binary zirconium-copper alloys with a concentration of copper less than or equal to 4% by weight. Comparison of the results obtained shows that the apparent diffusion coefficient of oxygen in the oxide layer that is formed decreases as the copper content of the alloy in question increases; as regards the apparent diffusion coefficient of the oxygen in the alloy, though this is only slightly modified at 600 Degree-Sign C, at 700 Degree-Sign C it too decreases when the copper content is increased to 2.5%. The improved oxidation resistance associated with slowing down of the diffusion processes results, in particular, in prolongation of parabolic-type kinetics whereas, in the case of non-alloyed zirconium or other alloys, cracking in the oxide layer rapidly leads to linear oxidation kinetics as a result of the phenomenon of peeling. (author) [French] Les auteurs ont cherche a interpreter l'amelioration apportee par de faibles additions de cuivre a la resistance a l'oxydation du zirconium par le gaz carbonique sous pression entre

  20. Glaz da glaz ili gaz da gaz? / Jevgenija Garanzha

    Index Scriptorium Estoniae

    Garanža, Jevgenija, 1979-

    2005-01-01

    Euroopa Liidu ja Venemaa tippkohtumisest Londonis, kõnealusteks teemadeks lihtsustatud viisarežiim, piirilepingud Eesti ja Lätiga, vähemusrahvuste olukord nendes riikides, põhiteemaks kujuneb Euroopa sõltuvus Venemaa gaasist ja naftast

  1. Heavy water reactors physics; Physique des reacteurs a eau lourde

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-07-01

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

  2. PAR-2 expression in the gingival crevicular fluid reflects chronic periodontitis severity.

    Science.gov (United States)

    Fukushima, Henrique; Alves, Vanessa Tubero Euzebio; Carvalho, Verônica Franco de; Ambrósio, Lucas Macedo Batitucci; Eichler, Rosangela Aparecida Dos Santos; Carvalho, Maria Helena Catelli de; Saraiva, Luciana; Holzhausen, Marinella

    2017-01-26

    Recent studies investigating protease-activated receptor type 2 (PAR-2) suggest an association between the receptor and periodontal inflammation. It is known that gingipain, a bacterial protease secreted by the important periodontopathogen Porphyromonas gingivalis can activate PAR-2. Previous studies by our group found that PAR-2 is overexpressed in the gingival crevicular fluid (GCF) of patients with moderate chronic periodontitis (MP). The present study aimed at evaluating whether PAR-2 expression is associated with chronic periodontitis severity. GCF samples and clinical parameters, including plaque and bleeding on probing indices, probing pocket depth and clinical attachment level, were collected from the control group (n = 19) at baseline, and from MP patients (n = 19) and severe chronic periodontitis (SP) (n = 19) patients before and 6 weeks after periodontal non-surgical treatment. PAR-2 and gingipain messenger RNA (mRNA) in the GCF of 4 periodontal sites per patient were evaluated by Reverse Transcription Polymerase Chain Reaction (RT-qPCR). PAR-2 and gingipain expressions were greater in periodontitis patients than in control group patients. In addition, the SP group presented increased PAR-2 and gingipain mRNA levels, compared with the MP group. Furthermore, periodontal treatment significantly reduced (p periodontitis. In conclusion, PAR-2 is associated with chronic periodontitis severity and with gingipain levels in the periodontal pocket, thus suggesting that PAR-2 expression in the GCF reflects the severity of destruction during periodontal infection.

  3. Reactivity coefficients by perturbation theory; Calcul des coefficients de re activite par la theorie des perturbations; Koehffitsienty reaktivnosti, opredelennye pri pomoshchi teorii vozmushchenij; Determinacion, de coeficientes de reactividad con ayuda de la teoria de las perturbaciones

    Energy Technology Data Exchange (ETDEWEB)

    Webster, J W [International Atomic Energy Agency, Vienna (Austria)

    1962-03-15

    lethargie, en procedant par analogie a partir de l'equation differentielle a un groupe relative au flux adjoint. b) Montre comment appliquer la forme a deux groupes de la theorie des perturbations au cas d'un reacteur surgenerateur a neutrons rapides, refroidi au mercure. Lors de l'essai preliminaire du reacteur, on a constate que la variation de reactivite accompagnant une variation de densite du mercure est telle que le coefficient net de la reactivite est negatif pour certaines regions et positif pour d'autres. Il est negatif pour les regions de poids statistique le plus eleve et ou une variation de puissance entrainerait le changement de densite le plus important. Le coefficient global de densite du mercure est donc negatif, et par consequent le coefficient cavitaire est positif, ce qui est dangereux. On peut facilement voir, en employant la forme a deux groupes, quelles modifications doivent etre apportees aux plans du reacteur etudie pour obtenir un coefficient cavitaire negatif. Au cours de recherches ulterieures, il s'est revele possible d'apporter certaines de ces modifications, et l'on est finalement parvenu a etablir des plans tels que le coefficient cavitaire du reacteur soit negatif. (author) [Spanish] Las formulas de la teoria de las perturbaciones pueden establecerse empleando uno de los procedimientos mas importantes de la heuristica matematica, que consiste en partir de una expresion sencilla para llegar por analogia a una expresion mas compleja. La presente memoria: (a) Formula la teoria de las perturbaciones como metodo para calcular los coeficientes de reactividad. Consiste principalmente en desarrollar la ecuacion diferencial del flujo adjunto como funcion continua de la posicion y del letargo, procediendo por analogia a partir de la ecuacion diferencial de un solo grupo para el flujo adjunto. (b) Presenta una aplicacion de la forma de dos grupos de la teoria de las perturba ciones a un reactor reproductor rapido, refrigerado por mercurio hirviente

  4. La catalyse d'épuration des gaz d'échappement automobiles. Situation actuelle et nouvelles orientations Catalytic Automotive Exhaust Gas Depollution. Present Status and New Trends

    Directory of Open Access Journals (Sweden)

    Prigent M.

    2006-11-01

    Full Text Available Cet article passe en revue les différents systèmes catalytiques de post-traitement utilisés actuellement sur la plupart des automobiles pour limiter leurs rejets de polluants. Les systèmes sont différenciés par leur mode de fonctionnement, le type de moteur à dépolluer (deux-temps, quatre-temps, diesel ou essence ou par leur mode de réalisation. Les nouvelles orientations, prévues pour respecter les futures réglementations antipollution, sont également décrites. On montre que certains véhicules prototypes, équipés de moteurs à combustion interne, sont capables d'avoir des émissions très proches de zéro tout comme les véhicules électriques. A review is made of the various types of exhaust gas aftertreatment systems presently used on most vehicles to reduce pollutant emissions. The systems are differentiated by their mode of action, according to the engine type to be depolluted (two-stroke, four-stroke, diesel or spark-ignition, and by their type of make-up. The major developments foreseen in the future, in view of compliance with the new legislations, are described. It is shown that some prototype vehicles with internal combustion engines are able to emit pollutant quantities really close to zero, such as electric cars.

  5. Un « gouvernement des journalistes par le Pouvoir politique » par défaut ?

    Directory of Open Access Journals (Sweden)

    Matthieu Lardeau

    2013-12-01

    Full Text Available Cet article présente les interactions de deux mouvements concomitants apparusprincipalement dans les décennies 1950 à 1970 dans le champ de la presse française : d’un côté les initiatives – consécutives à la démarche pionnière, en 1951, de création de la première Société des journalistes (SDJ au sein du Monde – menées par les journalistes de rédactions de quotidiens pour créer des SDJ dont la destination peut aller jusqu’à gouverner les journaux; de l’autre côté, les « réponses » apportées par les Pouvoirs politique et public pour contenir ces initiatives visant à étendre le pouvoir des journalistes dans la gestion et la gouvernance de leurs journaux. Cette étude exploratoire repose principalement sur l’analyse de deux types de littérature, souvent déconsidérés ou négligés par le champ académique, en dépit de leur grande richesse : (1 la littérature professionnelle, ayant pour principaux auteurs les journalistes et managers de presse (Périer Daville, Boegner, Pigasse, etc., florissante depuis 1944 et singulièrement durant les décennies 1960 et 1970 ; (2 la littérature grise constituée notamment par des rapports publics rédigés par des institutions comme les services du Premier ministre (commissions Lindon de 1970 et Serisé de 1972, le Conseil économique et social, etc. Nos principaux résultats montrent que les propositions ou actions menées par les journalistes (1 restent le plus souvent inexploitées in concreto par les journalistes eux-mêmes; (2 entrent le plus souvent en opposition avec les politiques de nouveaux actionnaires ou directions de journaux et avec les projets des autorités politiques et publiques qui cherchent à encadrer l’autonomie de la profession journalistique pour mieux gouverner celle-ci ; (3 combien in fine les représentants des différents acteurs impliqués s’accordent pour contenir l’émergence d’un « gouvernement des journalistes » par les

  6. The polarity protein Par6 is coupled to the microtubule network during molluscan early embryogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Homma, Taihei [Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Shimizu, Miho [Kuroda Chiromorphology Team, ERATO-SORST, JST, Komaba, Meguro-ku, Tokyo 153-8902 (Japan); Kuroda, Reiko, E-mail: ckuroda@mail.ecc.u-tokyo.ac.jp [Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Kuroda Chiromorphology Team, ERATO-SORST, JST, Komaba, Meguro-ku, Tokyo 153-8902 (Japan); Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902 (Japan)

    2011-01-07

    Research highlights: {yields} The cDNAs encoding Par6 and aPKC homologues were cloned from the snail Lymnaea stagnalis. {yields} L. stagnalis Par6 directly interacts with tubulin and microtubules and localizes to the microtubule cytoskeleton during the early embryogenesis. {yields} Identical sequence and localization of LsPar6 for the dextral and the sinistral snails exclude the possibility of the gene being the primary determinant of body handedness. -- Abstract: Cell polarity, which directs the orientation of asymmetric cell division and segregation of fate determinants, is a fundamental feature of development and differentiation. Regulators of polarity have been extensively studied, and the critical importance of the Par (partitioning-defective) complex as the polarity machinery is now recognized in a wide range of eukaryotic systems. The Par polarity module is evolutionarily conserved, but its mechanism and cooperating factors vary among different systems. Here we describe the cloning and characterization of a pond snail Lymnaea stagnalis homologue of partitioning-defective 6 (Lspar6). The protein product LsPar6 shows high affinity for microtubules and localizes to the mitotic apparatus during embryonic cell division. In vitro assays revealed direct binding of LsPar6 to tubulin and microtubules, which is the first evidence of the direct interaction between the two proteins. The interaction is mediated by two distinct regions of LsPar6 both located in the N-terminal half. Atypical PKC, a functional partner of Par6, was also found to localize to the mitotic spindle. These results suggest that the L. stagnalis Par complex employs the microtubule network in cell polarity processes during the early embryogenesis. Identical sequence and localization of LsPar6 for the dextral and the sinistral snails exclude the possibility of the gene being the primary determinant of handedness.

  7. The polarity protein Par6 is coupled to the microtubule network during molluscan early embryogenesis

    International Nuclear Information System (INIS)

    Homma, Taihei; Shimizu, Miho; Kuroda, Reiko

    2011-01-01

    Research highlights: → The cDNAs encoding Par6 and aPKC homologues were cloned from the snail Lymnaea stagnalis. → L. stagnalis Par6 directly interacts with tubulin and microtubules and localizes to the microtubule cytoskeleton during the early embryogenesis. → Identical sequence and localization of LsPar6 for the dextral and the sinistral snails exclude the possibility of the gene being the primary determinant of body handedness. -- Abstract: Cell polarity, which directs the orientation of asymmetric cell division and segregation of fate determinants, is a fundamental feature of development and differentiation. Regulators of polarity have been extensively studied, and the critical importance of the Par (partitioning-defective) complex as the polarity machinery is now recognized in a wide range of eukaryotic systems. The Par polarity module is evolutionarily conserved, but its mechanism and cooperating factors vary among different systems. Here we describe the cloning and characterization of a pond snail Lymnaea stagnalis homologue of partitioning-defective 6 (Lspar6). The protein product LsPar6 shows high affinity for microtubules and localizes to the mitotic apparatus during embryonic cell division. In vitro assays revealed direct binding of LsPar6 to tubulin and microtubules, which is the first evidence of the direct interaction between the two proteins. The interaction is mediated by two distinct regions of LsPar6 both located in the N-terminal half. Atypical PKC, a functional partner of Par6, was also found to localize to the mitotic spindle. These results suggest that the L. stagnalis Par complex employs the microtubule network in cell polarity processes during the early embryogenesis. Identical sequence and localization of LsPar6 for the dextral and the sinistral snails exclude the possibility of the gene being the primary determinant of handedness.

  8. Paternal age related schizophrenia (PARS): Latent subgroups detected by k-means clustering analysis.

    Science.gov (United States)

    Lee, Hyejoo; Malaspina, Dolores; Ahn, Hongshik; Perrin, Mary; Opler, Mark G; Kleinhaus, Karine; Harlap, Susan; Goetz, Raymond; Antonius, Daniel

    2011-05-01

    Paternal age related schizophrenia (PARS) has been proposed as a subgroup of schizophrenia with distinct etiology, pathophysiology and symptoms. This study uses a k-means clustering analysis approach to generate hypotheses about differences between PARS and other cases of schizophrenia. We studied PARS (operationally defined as not having any family history of schizophrenia among first and second-degree relatives and fathers' age at birth ≥ 35 years) in a series of schizophrenia cases recruited from a research unit. Data were available on demographic variables, symptoms (Positive and Negative Syndrome Scale; PANSS), cognitive tests (Wechsler Adult Intelligence Scale-Revised; WAIS-R) and olfaction (University of Pennsylvania Smell Identification Test; UPSIT). We conducted a series of k-means clustering analyses to identify clusters of cases containing high concentrations of PARS. Two analyses generated clusters with high concentrations of PARS cases. The first analysis (N=136; PARS=34) revealed a cluster containing 83% PARS cases, in which the patients showed a significant discrepancy between verbal and performance intelligence. The mean paternal and maternal ages were 41 and 33, respectively. The second analysis (N=123; PARS=30) revealed a cluster containing 71% PARS cases, of which 93% were females; the mean age of onset of psychosis, at 17.2, was significantly early. These results strengthen the evidence that PARS cases differ from other patients with schizophrenia. Hypothesis-generating findings suggest that features of PARS may include a discrepancy between verbal and performance intelligence, and in females, an early age of onset. These findings provide a rationale for separating these phenotypes from others in future clinical, genetic and pathophysiologic studies of schizophrenia and in considering responses to treatment. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Electron microscope study of vacancy clusters produced by quenching in magnesium; Etude par microscopie electronique des amas de lacunes crees par trempe dans le magnesium

    Energy Technology Data Exchange (ETDEWEB)

    Levy, V; Espinasse, J; Mairy, C; Hillairet, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    Vacancy clustering in quenched magnesium has been studied by transmission electron microscopy. The nature of the vacancy loops observed, seems to depend essentially on the impurity content of the metal; this effect can be attributed to a variation of the stacking fault energy of magnesium due to impurities. (authors) [French] On a etudie par microscopie electronique en transmission les defauts crees par trempe dans le magnesium. Un effet considerable des impuretes du metal sur la nature des boucles obtenues par condensation de lacunes a ete mis en evidence; cet effet semble s'expliquer de facon satisfaisante par un abaissement de l'energie de faute d'empilement du magnesium du aux impuretes. (auteur)

  10. Study of a micro-sublimation apparatus with removal of the vapours by pumping; application to the analysis of fluorinated products (1963); Etude d'un appareillage de microsublimation avec entrainement des vapeurs par pompage et application a l'analyse des produits fluores (1963)

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-07-01

    Micro-sublimation analysis presents definite advantages both from the qualitative and quantitative points of view. An automatic micro-sublimation analysis apparatus has been developed for the analysis of fluorinated products (ClF{sub 3}, HF, UF{sub 6}, etc.) but this is only one particular application of a method which has a far wider field of possible applications. We give first the most favorable conditions for the operation of such an apparatus. These conditions are the use of a detector which is linear and independent of the nature of the gas, the flow of the sublimed vapours in the conditions of molecular flow, and finally a reproducible and linear re-heating of the separating trap. The apparatus thus built has the advantage of yielding any analysis without prior calibration. It also makes possible the easy identification of an unknown product by the determination of its vapour pressure curve and its molecular weight. The analysis of fluorinated products with this apparatus has shown that the experimental results agree well with what is expected. (author) [French] L'analyse par microsublimation presente un interet certain tant au point de vue qualitatif que quantitatif. Nous avons mis au point un appareillage automatique d'analyse par microsublimation pour l'analyse des produits fluores (CIF{sub 3}, HF, UF{sub 6}, etc.) mais il ne s'agit que de l'application a un cas particulier d'une methode ayant un champ d'applications bien plus vaste. Nous exposons tout d'abord les conditions les plus favorables au bon fonctionnement d'un tel appareil. Ces conditions sont l'emploi d'un detecteur lineaire et independant de la nature du gaz, l'ecoulement des vapeurs sublimees en regime moleculaire et enfin un rechauffage reproductible et lineaire du piege separateur. L'appareil ainsi realise presente l'avantage d'effectuer une analyse quelconque sans etalonnage prealable. Il permet en outre d'identifier aisement un corps inconnu par la determination de sa courbe de tension

  11. Neutrons detection by scintillation; Detection de neutrons par scintillations

    Energy Technology Data Exchange (ETDEWEB)

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

    1955-01-15

    The absence of charge of neutrons and their elevated penetration power make difficult their detection. Techniques vary otherwise with the energy of the particle. The author proposes the realization of a scintillation detector with a big volume of liquid scintillator and containing boron for the detection of slowing-down neutrons in the domain of intermediate energies from 1 to 10{sup 5} eV about. (M.B.) [French] L'absence de charge du neutron et son pouvoir de penetration eleve rendent difficile sa detection. Les techniques par ailleurs varient avec l'energie de cette particule. L'auteur propose la realisation d'un detecteur a scintillations comprenant un grand volume de scintillateur liquide et contenant du bore pour la detection des neutrons en ralentissement dans le domaine des energies intermediaires de 1 a 10{sup 5} eV environ. (M.B.)

  12. Cancro em mogno africano no estado do Pará

    Directory of Open Access Journals (Sweden)

    Célia Regina Tremacoldi

    2013-06-01

    Full Text Available Sintomas de cancro foram observados em plantios de mogno africano, no município de Dom Eliseu, Pará. Os fungos associados aos tecidos sintomáticos foram identificados como Lasiodiplodia theobromae e Fusarium subglutinans. Culturas puras desses fungos foram testadas quanto à patogenicidade em mudas de mogno africano sadias. Apenas L. theobromae produziu cancro, por meio de inoculação por ferimento e alta umidade. A confirmação de L. theobromae como agente causal do cancro ocorreu após o reisolamento do fungo a partir das plantas inoculadas em casa de vegetação, concluindo a primeira verificação do postulado de Koch para esse patossistema.

  13. IMPROVEMENT OF PRODUCTION PLANNING IN COMPANY PARS KOMPONENTY

    Directory of Open Access Journals (Sweden)

    René Klega

    2014-03-01

    Full Text Available The article analyzes the current status of production planning in company Pars Komponenty s.r.o., proposes a new method of planning based on application of the principle of MRP. It is a discrete type of production with high complexity of BOM and MTO (Make-to-Order and ETO (Engineering-to-Order from the point of decoupling point. The original planning system plans according to production capacity backward without collisions, but for a given type of production does not work in practice. Planning system was analyzed and the main problems were identified, which were high work in progress and material stocks. This article target is to propose a new planining system based on the inclusion of time reserves of purchased material items. New planning system was tested in practise with benefit in reducing both the material inventory and work in progress.

  14. Pierre Vilar Frontinhan 1906 - París 2003

    Directory of Open Access Journals (Sweden)

    Pablo Rodríguez

    2003-01-01

    Full Text Available En el pasado mes de agosto falleció en París el historiador y maestro de tantas generaciones Pierre Vilar. Aunque había mantenido una intensa actividad de reflexión sobre los sucesos contemporáneos, ésta se vio afectada en 1991 luego que una grave enfermedad le negó la visión. Fue entonces cuando decidió con la ayuda de Rosa Congost escribir sus reflexiones y recuerdos, especie de memoria de juventud. Pensar Históricamente (Barcelona: Editorial Crítica, 1997, el libro que reúne estos ejercicios, es una obra de sumo interés para conocer la infancia, adolescencia y juventud de este connotado historiador.

  15. Neutrons detection by scintillation; Detection de neutrons par scintillations

    Energy Technology Data Exchange (ETDEWEB)

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

    1955-01-15

    The absence of charge of neutrons and their elevated penetration power make difficult their detection. Techniques vary otherwise with the energy of the particle. The author proposes the realization of a scintillation detector with a big volume of liquid scintillator and containing boron for the detection of slowing-down neutrons in the domain of intermediate energies from 1 to 10{sup 5} eV about. (M.B.) [French] L'absence de charge du neutron et son pouvoir de penetration eleve rendent difficile sa detection. Les techniques par ailleurs varient avec l'energie de cette particule. L'auteur propose la realisation d'un detecteur a scintillations comprenant un grand volume de scintillateur liquide et contenant du bore pour la detection des neutrons en ralentissement dans le domaine des energies intermediaires de 1 a 10{sup 5} eV environ. (M.B.)

  16. Determination of tritium by counting; Dosage du tritium par comptage

    Energy Technology Data Exchange (ETDEWEB)

    Schott, R; Froment, G; Pinson, J; Genty, C [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

    1968-07-01

    Ionisation chamber assay of tritium in any gaseous mixture is a simple, fast and accurate method. We used the method of relative determination by comparison to a standard rather than the method of absolute assay in which case the constants are known with too little accuracy. The efficiency of the chamber was studied in connection to the pressure inside the chamber and its total volume. The calibration is linear in the range we are taking into account (1 to 80 millicuries). The reproducibility of the method is good: 13 runs gave a coefficient of variation of 1.6 per cent. The relative accuracy was found equal to {+-} 1.3 per cent. To end the paper, we describe in detail the apparatus and the ways of proceedings. (authors) [French] Le comptage du tritium par chambre d'ionisation est une methode simple, rapide et precise pour determiner la teneur en tritium d'un melange gazeux quelconque. Nous avons prefere utiliser la methode de determination relative par rapport a un etalon car, dans le cas d'une determination absolue, les constantes sont connues avec une trop grande incertitude. L'efficacite de la chambre a ete etudiee en fonction de la variation de la pression d'argon a l'interieur de la chambre et du volume total, de cette derniere. L'etalonnage s'est revele lineaire dans le domaine de mesures qui nous interessaient (1 a 80 millicuries). La reproductibillte de la methode est tres bonne, le coefficient de variation pour une serie de 13 essais etant de 1,6 pour cent, quant a la precision relative, elle a ete evaluee a {+-} 1,3 pour cent. Pour terminer, nous donnons une description detaillee de l'appareillage utilise et du mode operatoire suivi. (auteurs)

  17. Clinical outcomes of pars plicata anterior vitrectomy: 2-year results

    Directory of Open Access Journals (Sweden)

    Priya Narang

    2015-01-01

    Full Text Available Purpose: To demonstrate the safety and outcome of a surgical approach that uses pars plicata site for anterior vitrectomy during phacoemulsification procedure complicated by posterior capsule rupture and residual cortical matter. Design: Single center, retrospective, interventional, noncomparative study. Materials and Methods: Medical records of a consecutive series of 35 eyes of 35 patients who underwent pars plicata anterior vitrectomy (PPAV were reviewed. The main outcome measures were corrected and uncorrected distance visual acuity (CDVA, UDVA, early and late postoperative complications and intraocular pressure (IOP. Ultrasound biomicroscopic (UBM evaluation of sclerotomy site and spectral domain optical coherence tomography analysis for central macular thickness (CMT was performed. The final visual outcome at 2 years was evaluated. Results: At 2 years follow-up, the mean postoperative UDVA (logarithm of the minimum angle of resolution [logMAR] and CDVA (logMAR was 0.49 ± 0.26 and 0.19 ± 0.14, respectively. There was no significant change in the IOP (P = 0.061 and the mean CMT at 2 years was 192.5 ± 5.54 mm. The postoperative UBM image of the sclerotomy site at 8 weeks demonstrated a clear wound without any vitreous adhesion or incarceration. Intraoperative hyphema was seen in 1 (2.8% case and postoperative uveitis was seen in 2 (5.7% cases, which resolved with medications. No case of an iatrogenic retinal break or retinal detachment was reported. Conclusions: PPAV enables a closed chamber approach, allows thorough cleanup of vitreous in the pupillary plane and anterior chamber and affords better access to the subincisional and retropupillary cortical remnant with a significant visual outcome and an acceptable complication rate.

  18. Urokinase-type plasminogen activator receptor (uPAR) as a promising new imaging target

    DEFF Research Database (Denmark)

    Persson, Morten; Kjaer, Andreas

    2013-01-01

    modalities such as optical imaging, magnetic resonance imaging, single photon emission computer tomography (SPECT) and positron emission topography (PET). In this review, we will discuss recent advances in the development of uPAR-targeted imaging ligands according to imaging modality. In addition, we...... will discuss the potential future clinical application for uPAR imaging as a new imaging biomarker....

  19. Pars plana vitrectomy for disturbing primary vitreous floaters: clinical outcome and patient satisfaction

    NARCIS (Netherlands)

    Nie, K.F. de; Crama, N.; Tilanus, M.A.D.; Klevering, B.J.; Boon, C.J.F.

    2013-01-01

    BACKGROUND: Primary vitreous floaters can be highly bothersome in some patients. In the case of persistently bothersome floaters, pars plana vitrectomy may be the most effective treatment. The aim of this study is to evaluate the incidence of complications, and patient satisfaction, after pars plana

  20. Solar PAR and UVR modify the community composition and photosynthetic activity of sea ice algae.

    Science.gov (United States)

    Enberg, Sara; Piiparinen, Jonna; Majaneva, Markus; Vähätalo, Anssi V; Autio, Riitta; Rintala, Janne-Markus

    2015-10-01

    The effects of increased photosynthetically active radiation (PAR) and ultraviolet radiation (UVR) on species diversity, biomass and photosynthetic activity were studied in fast ice algal communities. The experimental set-up consisted of nine 1.44 m(2) squares with three treatments: untreated with natural snow cover (UNT), snow-free (PAR + UVR) and snow-free ice covered with a UV screen (PAR). The total algal biomass, dominated by diatoms and dinoflagellates, increased in all treatments during the experiment. However, the smaller biomass growth in the top 10-cm layer of the PAR + UVR treatment compared with the PAR treatment indicated the negative effect of UVR. Scrippsiella complex (mainly Scrippsiella hangoei, Biecheleria baltica and Gymnodinium corollarium) showed UV sensitivity in the top 5-cm layer, whereas Heterocapsa arctica ssp. frigida and green algae showed sensitivity to both PAR and UVR. The photosynthetic activity was highest in the top 5-cm layer of the PAR treatment, where the biomass of the pennate diatom Nitzschia frigida increased, indicating the UV sensitivity of this species. This study shows that UVR is one of the controlling factors of algal communities in Baltic Sea ice, and that increased availability of PAR together with UVR exclusion can cause changes in algal biomass, photosynthetic activity and community composition. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Spectral variations of UV-A and PAR solar radiation in estuarine waters of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Talaulikar, M.; Suresh, T.; Silveira, N.; Desa, E.; Matondkar, S; Lotlikar, A

    radiation (400 to 700 nm), PAR and ultraviolet radiation in the range 350-400 nm (UV-A) are presented here. The mean PAR values at the surface were 327 W/m sup(2) and reduced to 84 W/m sup(2) at first optical depth, Z sub(90) (m) in water. The first optical...

  2. Modular plants with high power gas engines (1 to 30 MWe); Centrales modulaires a moteurs gaz de forte puissance (de 1 a 30 MWe)

    Energy Technology Data Exchange (ETDEWEB)

    Haushalter, J. [Wartsila (France)

    1997-12-31

    This paper is a series of transparencies about the high power gas engines manufactured by Waertsilae NSD Corporation company. The first par recalls the NO{sub x} and CO air pollution regulations worldwide, the German TA-Luft standards and the French 2910 by-law according to the engine type (2 and 4 stroke, dual-fuel, natural gas, LPG, others..) and to the type of pollutants (NO{sub x}, dusts, SO{sub 2}, CO, noise..). The second part presents the Waertsilae NSD Corporation concept of gas-fueled spark ignition engines (Otto cycle, emissions, performances, technology, fuel system, combustion optimization, fuel-air ratio regulation, pollution control equipment) and of the `pure energy` global concept of plants. (J.S.)

  3. Narrative Identities and the Plebiscite in Pará: An Analysis of the Front Pages for O Liberal and Diário do Pará

    Directory of Open Access Journals (Sweden)

    Alda Cristina Silva da Costa

    2017-05-01

    Full Text Available On December 11, 2011, a plebiscite was held in Pará proposing to create two separatist states, Carajás and Tapajós, out of the state of Pará. The public voted against both projects. This article analyzes the narrative identities found on the front pages of O Liberal and Diário do Pará newspapers about the plebiscite in Pará. Depth Hermeneutics (DH, as proposed by Thompson (2011, was used as the methodological reference. DH emphasizes the object of analysis as a meaningful symbolic construction requiring interpretation. Narrative analysis, as proposed by Motta (2007, was the main research technique used to highlight the movement of construction of journalistic (discursive characters. The narrative identities built by the two newspapers showed that both were against the creation of the new states, but for very different reasons. The flag of Pará was the main object used to induce the idea of unity. Em 11 de dezembro de 2011, o plebiscito no Pará propôs a criação dos estados de Carajás e de Tapajós a partir da divisão do estado do Pará. O resultado da consulta pública foi negativo aos dois projetos. O artigo analisa as identidades narrativas constituídas pelas primeiras páginas dos jornais O Liberal e Diário do Pará sobre o plebiscito no Pará. Utilizou-se como referencial metodológico a Hermenêutica em Profundidade (HP, proposta por Thompson (2011. A HP evidencia o fato de que o objeto de análise é uma construção simbólica significativa, que exige uma interpretação. Como principal técnica de pesquisa, a análise narrativa, proposta por Motta (2007, com ênfase no movimento de construção de personagens jornalísticas (discursivas. As identidades narrativas construídas pelos dois jornais indicaram que ambos eram contrários à criação dos novos estados, porém por motivos divergentes. A bandeira do Pará foi o principal elemento utilizado para evocar a ideia de unidade. En 11 de diciembre de 2011, el plebiscito en

  4. The urokinase receptor (uPAR) and the uPAR-associated protein (uPARAP/Endo180)

    DEFF Research Database (Denmark)

    Behrendt, Niels

    2004-01-01

    The breakdown of the barriers formed by extracellular matrix proteins is a pre-requisite for all processes of tissue remodeling. Matrix degradation reactions take part in specific physiological events in the healthy organism but also represent a crucial step in cancer invasion. These degradation...... on the surface of various cell types that serves to bind the urokinase plasminogen activator and localize the activation reactions in the proteolytic cascade system of plasminogen activation. uPARAP is an integral membrane protein with a pronounced role in the internalization of collagen for intracellular...... degradation. Both receptors have additional functions that are currently being unraveled. The present discussion of uPAR and uPARAP is centered on their protein structure and molecular and cellular function....

  5. Effect of simvastatin and ezetimibe on suPAR levels and outcomes

    DEFF Research Database (Denmark)

    Hodges, Gethin W; Bang, Casper N; Forman, Julie L

    2018-01-01

    -lowering therapy also lowers suPAR levels is unknown. METHODS: We investigated whether treatment with Simvastatin 40 mg and Ezetimibe 10 mg lowered plasma suPAR levels in 1838 patients with mild-moderate, asymptomatic aortic stenosis, included in the Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) study, using...... and Ezetimibe treatment impeded the progression of the time-related increase in plasma suPAR levels. Year-1 suPAR was associated with all-cause mortality, MCE, and AVE irrespective of baseline levels (SEAS study: NCT00092677)....... cardiovascular events (MCE) composed of ischemic cardiovascular events (ICE) and aortic valve related events (AVE). RESULTS: After 4.3 years of follow-up, suPAR levels had increased by 9.2% (95% confidence interval [CI]: 7.0%-11.5%) in the placebo group, but only by 4.1% (1.9%-6.2%) in the group with lipid...

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

    Science.gov (United States)

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

    2010-01-01

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

  7. par genes in Mycobacterium bovis and Mycobacterium smegmatis are arranged in an operon transcribed from "SigGC" promoters

    Directory of Open Access Journals (Sweden)

    Casart Yveth

    2008-03-01

    Full Text Available Abstract Background The ParA/Soj and ParB/Spo0J proteins, and the cis-acting parS site, participate actively in chromosome segregation and cell cycle progression. Genes homologous to parA and parB, and two putative parS copies, have been identified in the Mycobacterium bovis BCG and Mycobacterium smegmatis chromosomes. As in Mycobacterium tuberculosis, the parA and parB genes in these two non-pathogenic mycobacteria are located near the chromosomal origin of replication. The present work focused on the determination of the transcriptional organisation of the ~6 Kb orf60K-parB region of M. bovis BCG and M. smegmatis by primer extension, transcriptional fusions to the green fluorescence protein (GFP and quantitative RT-PCR. Results The parAB genes were arranged in an operon. However, we also found promoters upstream of each one of these genes. Seven putative promoter sequences were identified in the orf60K-parB region of M. bovis BCG, whilst four were identified in the homologous region of M. smegmatis, one upstream of each open reading frame (ORF. Real-time PCR assays showed that in M. smegmatis, mRNA-parA and mRNA-parB levels decreased between the exponential and stationary phases. In M. bovis BCG, mRNA-parA levels also decreased between the exponential and stationary phases. However, parB expression was higher than parA expression and remained almost unchanged along the growth curve. Conclusion The majority of the proposed promoter regions had features characteristic of Mycobacterium promoters previously denoted as Group D. The -10 hexamer of a strong E. coli σ70-like promoter, located upstream of gidB of M. bovis BCG, overlapped with a putative parS sequence, suggesting that the transcription from this promoter might be regulated by the binding of ParB to parS.

  8. MODIS-derived daily PAR simulation from cloud-free images and its validation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Liangfu; Gu, Xingfa; Tian, Guoliang [State Key Laboratory of Remote Sensing Science, Jointly Sponsored by Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University, Beijing 100101 (China); The Center for National Spaceborne Demonstration, Beijing 100101 (China); Gao, Yanhua [State Key Laboratory of Remote Sensing Science, Jointly Sponsored by Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University, Beijing 100101 (China); Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China); Yang, Lei [State Key Laboratory of Remote Sensing Science, Jointly Sponsored by Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University, Beijing 100101 (China); Jilin University, Changchun 130026 (China); Liu, Qinhuo [State Key Laboratory of Remote Sensing Science, Jointly Sponsored by Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University, Beijing 100101 (China)

    2008-06-15

    In this paper, a MODIS-derived daily PAR (photosynthetically active radiation) simulation model from cloud-free image over land surface has been developed based on Bird and Riordan's model. In this model, the total downwelling spectral surface irradiance is divided into two parts: one is beam irradiance, and another is diffuse irradiance. The attenuation of solar beam irradiance comprises scattering by the gas mixture, absorption by ozone, the gas mixture and water vapor, and scattering and absorption by aerosols. The diffuse irradiance is scattered out of the direct beam and towards the surface. The multiple ground-air interactions have been taken into account in the diffuse irradiance model. The parameters needed in this model are atmospheric water vapor content, aerosol optical thickness and spectral albedo ranging from 400 nm to 700 nm. They are all retrieved from MODIS data. Then, the instantaneous photosynthetically available radiation (IPAR) is integrated by using a weighted sum at each of the visible MODIS wavebands. Finally, a daily PAR is derived by integration of IPAR. In order to validate the MODIS-derived PAR model, we compared the field PAR measurements in 2003 and 2004 against the simulated PAR. The measurements were made at the Qianyanzhou ecological experimental station, Chinese Ecosystem Research Network. A total of 54 days of cloud-free MODIS L1B level images were used for the PAR simulation. Our results show that the simulated PAR is consistent with field measurements, where the correlation coefficient of linear regression between calculated PAR and measured PAR is 0.93396. However, there were some uncertainties in the comparison of 1 km pixel PAR with the tower flux stand measurement. (author)

  9. Texture study of divided solids by gas adsorption: application to beryllia, alumina and to gels and oxides; Contribution a l'etude, par adsorption gazeuse, de la texture des solides divises. Application a l'alumine, a la glucine et a differents gels et oxydes

    Energy Technology Data Exchange (ETDEWEB)

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

    1965-12-01

    particulier dans le cas des solides mtcroporeux) pour la determination du volume de gaz adsorbe dans une couche monomoleculaire et que l'azote est sensible aux interactions chimiques ou electriques avec l'adsorbant: il convient de le remplacer par l'argon. Les methodes de calcul de la distribution de taille des pores sont analysees et discutees. Nos resultats experimentaux ont montre que l'epaisseur de la couche multimoleculaire doit etre calculee a partir du nombre de couches donne par Shull et d'une epaisseur de 3,6 angstrom par couche. Enfin, nous proposons une nouvelle methode d'analyse de la branche de desorption. Nous montrons que certains systemes lamellaires, non poreux, tels que Be(OH){sub 2}, donnent une hysteresis sur une isotherme d'adsorption du type I ou II. En nous basant sur les resultats numeriques fournis par notre methode ainsi que sur des observations obtenues par microscopie electronique, nous concluons que cette hysteresis est due au manque de rigidite du solide. Inversement, nous avons caracterise des solides poreux qui ne donnent pas lieu au phenomene d'hysteresis. C'est le cas des echantillons de glucine de texture microporeuse (r < 20 A). Les conclusions precedentes nous permettent de decrire l'evolution de texture subie par deux series d'echantillons (glucine et alumine) au cours de leur deshydratation progressive (traitement thermique allant de 150 a 1100 C). (auteur)

  10. Texture study of divided solids by gas adsorption: application to beryllia, alumina and to gels and oxides; Contribution a l'etude, par adsorption gazeuse, de la texture des solides divises. Application a l'alumine, a la glucine et a differents gels et oxydes

    Energy Technology Data Exchange (ETDEWEB)

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

    1965-12-01

    solides mtcroporeux) pour la determination du volume de gaz adsorbe dans une couche monomoleculaire et que l'azote est sensible aux interactions chimiques ou electriques avec l'adsorbant: il convient de le remplacer par l'argon. Les methodes de calcul de la distribution de taille des pores sont analysees et discutees. Nos resultats experimentaux ont montre que l'epaisseur de la couche multimoleculaire doit etre calculee a partir du nombre de couches donne par Shull et d'une epaisseur de 3,6 angstrom par couche. Enfin, nous proposons une nouvelle methode d'analyse de la branche de desorption. Nous montrons que certains systemes lamellaires, non poreux, tels que Be(OH){sub 2}, donnent une hysteresis sur une isotherme d'adsorption du type I ou II. En nous basant sur les resultats numeriques fournis par notre methode ainsi que sur des observations obtenues par microscopie electronique, nous concluons que cette hysteresis est due au manque de rigidite du solide. Inversement, nous avons caracterise des solides poreux qui ne donnent pas lieu au phenomene d'hysteresis. C'est le cas des echantillons de glucine de texture microporeuse (r < 20 A). Les conclusions precedentes nous permettent de decrire l'evolution de texture subie par deux series d'echantillons (glucine et alumine) au cours de leur deshydratation progressive (traitement thermique allant de 150 a 1100 C). (auteur)

  11. Urine suPAR levels compared with plasma suPAR levels as predictors of post-consultation mortality risk among individuals assumed to be TB-negative: a prospective cohort study

    DEFF Research Database (Denmark)

    Rabna, Paulo; Andersen, Andreas; Wejse, Christian

    2010-01-01

    -suPAR was measured using a commercial ELISA (suPARnostic®). We found that U-suPAR carried significant prognostic information on mortality for HIV-infected subjects with an area under the ROC curve of 0.75. For HIV-negative individuals, little or no prognostic effect was observed. However, in both HIV positives...... and negatives, the predictive effect of U-suPAR was found to be inferior to that of P-suPAR....

  12. Thermodynamic study of sulphur hemi-oxide using mass spectrometry (1963); Etude thermodynamique de l'hemioxyde de soufre par spectrometry de masse (1963)

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-01-15

    have also examined the work concerning the heat of formation of SO to discover whether the formation of SO is possible between 1000 deg K and 1500 deg K starting from sulphur and SO{sub 2}. (author) [French] L'action de l'oxygene sur le soufre, a basse pression, dons une decharge haute frequence, a ete etudiee en analysant en continu, les produits de la reaction par spectrometrie de masse. Les spectres de masse du gaz issu de la decharge correspondent a un melange SO{sub 2}, S{sub 2}O, S{sub 2} et O{sub 2}. Nous avons mesure jusqu'a 75 pour rent de SO{sub 2} dans le melange SO{sub 2} + S{sub 2}O. Nous avons conclu a l'absence des molecules S{sub 2}O{sub 2}, et SO dans le melange. Les potentiels d'ionisation des molecules, et d'apparition des ions fragments du melange issu de la decharge, ont ete etudies par spectrometrie de masse. La chaleur de formation de S{sub 2}O a ete estimee a partir des mesures des potentiels d'apparition des ions SO{sup +} provenant de SO{sub 2}, et S{sub 2}O. (- 18.5 kcal/mole - < {delta}H, (S{sub 2}O{sub g}) < - 7 kcal/mole). Nous avons ete amenes a mesurer les potentiels d'ionisation des molecules S{sub 2}, S{sub 4}, S{sub 6} et S{sub 8} dont les valeurs sont respectivement: 9,7 {+-} 0,1 eV; 10,4 {+-} 0,5 eV; 8,5 {+-} 0,3 eV et 7,3 {+-} 0,3 eV. Nous avons enfin etudie l'equilibre de formation de StO a partir de soufre et de S{sub 2}O, dans un reacteur a filaments chauds. La mesure de la variation, entre 1100 deg K et 1500 deg K. de h constante d'equilibre de la reaction: SO{sub 2} + 3/2 S{sub 2} {r_reversible} 2 S{sub 2}O a permis de determiner la variation d'enthalpie de cette reaction ({delta}H = 5310 {+-} 370 calories) La somme d'etats de la molecule S{sub 2}O, Z{sup 0}, a ete calculee a partir des donnees bibliographiques. En appliquant a l'equilibre de formation de S{sub 2}O l'equation: Log K{sub p} = {delta}Log Z{sup 0}/N - {delta}H{sup 0}{sub 0}/RT nous avons calcule l'enthalpie de ia reaction au zero absolu ({delta}H{sup 0}{sub 0

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1962-07-01

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

  14. Proteinase-Activated Receptor-1 and Immunomodulatory Effects of a PAR1-Activating Peptide in a Mouse Model of Prostatitis

    Science.gov (United States)

    Stanton, M. Mark; Nelson, Lisa K.; Benediktsson, Hallgrimur; Hollenberg, Morley D.; Buret, Andre G.; Ceri, Howard

    2013-01-01

    Background. Nonbacterial prostatitis has no established etiology. We hypothesized that proteinase-activated receptor-1 (PAR1) can play a role in prostatitis. We therefore investigated the effects of PAR1 stimulation in the context of a new model of murine nonbacterial prostatitis. Methods. Using a hapten (ethanol-dinitrobenzene sulfonic acid- (DNBS-)) induced prostatitis model with both wild-type and PAR1-null mice, we examined (1) the location of PAR1 in the mouse prostate and (2) the impact of a PAR1-activating peptide (TFLLR-NH2: PAR1-TF) on ethanol-DNBS-induced inflammation. Results. Ethanol-DNBS-induced inflammation was maximal at 2 days. In the tissue, PAR1 was expressed predominantly along the apical acini of prostatic epithelium. Although PAR1-TF on its own did not cause inflammation, its coadministration with ethanol-DNBS reduced all indices of acute prostatitis. Further, PAR1-TF administration doubled the prostatic production of interleukin-10 (IL-10) compared with ethanol-DNBS treatment alone. This enhanced IL-10 was not observed in PAR1-null mice and was not caused by the reverse-sequence receptor-inactive peptide, RLLFT-NH2. Surprisingly, PAR1-TF, also diminished ethanol-DNBS-induced inflammation in PAR1-null mice. Conclusions. PAR1 is expressed in the mouse prostate and its activation by PAR1-TF elicits immunomodulatory effects during ethanol-DNBS-induced prostatitis. However, PAR1-TF also diminishes ethanol-DNBS-induced inflammation via a non-PAR1 mechanism by activating an as-yet unknown receptor. PMID:24459330

  15. Profiling gene expression induced by protease-activated receptor 2 (PAR2 activation in human kidney cells.

    Directory of Open Access Journals (Sweden)

    Jacky Y Suen

    Full Text Available Protease-Activated Receptor-2 (PAR2 has been implicated through genetic knockout mice with cytokine regulation and arthritis development. Many studies have associated PAR2 with inflammatory conditions (arthritis, airways inflammation, IBD and key events in tumor progression (angiogenesis, metastasis, but they have relied heavily on the use of single agonists to identify physiological roles for PAR2. However such probes are now known not to be highly selective for PAR2, and thus precisely what PAR2 does and what mechanisms of downstream regulation are truly affected remain obscure. Effects of PAR2 activation on gene expression in Human Embryonic Kidney cells (HEK293, a commonly studied cell line in PAR2 research, were investigated here by comparing 19,000 human genes for intersecting up- or down-regulation by both trypsin (an endogenous protease that activates PAR2 and a PAR2 activating hexapeptide (2f-LIGRLO-NH(2. Among 2,500 human genes regulated similarly by both agonists, there were clear associations between PAR2 activation and cellular metabolism (1,000 genes, the cell cycle, the MAPK pathway, HDAC and sirtuin enzymes, inflammatory cytokines, and anti-complement function. PAR-2 activation up-regulated four genes more than 5 fold (DUSP6, WWOX, AREG, SERPINB2 and down-regulated another six genes more than 3 fold (TXNIP, RARG, ITGB4, CTSD, MSC and TM4SF15. Both PAR2 and PAR1 activation resulted in up-regulated expression of several genes (CD44, FOSL1, TNFRSF12A, RAB3A, COPEB, CORO1C, THBS1, SDC4 known to be important in cancer. This is the first widespread profiling of specific activation of PAR2 and provides a valuable platform for better understanding key mechanistic roles of PAR2 in human physiology. Results clearly support the development of both antagonists and agonists of human PAR2 as potential disease modifying therapeutic agents.

  16. Comparaison du Pangola (Digitaria decumbens) et du Stargrass (Cynodon nlemfluensis) exploités par des ovins

    OpenAIRE

    Boval, Maryline

    1989-01-01

    A la Martinique l'utilisation comparée de Digitaria decumbens (Dd) et de Cynodon nlemfuensis (Cn) par des brebis allaitantes a été étudiée pendant une période d'observation de 6 mois. Le cheptel est à un taux élevé de 1 600 kg de poids vif par hectare et par an, obtenu par une fertilisation de 450 kg/ha/an en azote.

  17. Nonlinear EGR and VGT Control with Integral Action for Diesel Engines Régulation de Recirculation des Gaz d’Echappement (RGE et de Turbine à Géométrie Variable (TGV non linéaire avec action intégrée pour moteurs Diesel

    Directory of Open Access Journals (Sweden)

    Wahlström J.

    2011-10-01

    Full Text Available A nonlinear multivariable control design with integral action is proposed and investigated for control of Exhaust Gas Recirculation (EGR and Variable Geometry Turbine (VGT in heavy duty Diesel engines. The main control goal is to regulate oxygen/fuel ratio and intake manifold EGR-fraction, and they are specified in an outer loop. These are chosen as main performance variables since they are strongly coupled to the emissions. An existing nonlinear control design based on feedback linearization is extended with integral action. In particular, the control design method utilizes a control Lyapunov function, inverse optimal control, and a nonlinear input transformation. Comparisons between different control structures are performed in simulations showing the following four points. Firstly, integral action is necessary to handle model errors so that the controller can track the performance variables specified in the outer loop. Secondly, the proposed control design handles the nonlinear effects in the Diesel engine that results in less control errors compared to a control structure with PID controllers. Thirdly, it is important to use the input transformation and it is sufficient to use a control structure with PID controllers and input transformation to handle the nonlinear effects. Fourthly, the proposed control design is sensitive to model errors in the input transformation while a control structure with PID controllers and input transformation handles these model errors. Une conception de régulation non linéaire à variables multiples avec action intégrée est proposée et étudiée pour une régulation de la Recirculation des Gaz d’Echappement (RGE et une Turbine à Géométrie Variable (TGV au sein de moteurs Diesel à usage industriel. L’objectif principal de la régulation consiste à réguler le rapport oxygène / carburant et la fraction de RGE de tubulure d’admission, qui sont spécifiés au sein d’une boucle extérieure. Ceux

  18. Improved Satellite-based Photosysnthetically Active Radiation (PAR) for Air Quality Studies

    Science.gov (United States)

    Pour Biazar, A.; McNider, R. T.; Cohan, D. S.; White, A.; Zhang, R.; Dornblaser, B.; Doty, K.; Wu, Y.; Estes, M. J.

    2015-12-01

    One of the challenges in understanding the air quality over forested regions has been the uncertainties in estimating the biogenic hydrocarbon emissions. Biogenic volatile organic compounds, BVOCs, play a critical role in atmospheric chemistry, particularly in ozone and particulate matter (PM) formation. In southeastern United States, BVOCs (mostly as isoprene) are the dominant summertime source of reactive hydrocarbon. Despite significant efforts in improving BVOC estimates, the errors in emission inventories remain a concern. Since BVOC emissions are particularly sensitive to the available photosynthetically active radiation (PAR), model errors in PAR result in large errors in emission estimates. Thus, utilization of satellite observations to estimate PAR can help in reducing emission uncertainties. Satellite-based PAR estimates rely on the technique used to derive insolation from satellite visible brightness measurements. In this study we evaluate several insolation products against surface pyranometer observations and offer a bias correction to generate a more accurate PAR product. The improved PAR product is then used in biogenic emission estimates. The improved biogenic emission estimates are compared to the emission inventories over Texas and used in air quality simulation over the period of August-September 2013 (NASA's Discover-AQ field campaign). A series of sensitivity simulations will be performed and evaluated against Discover-AQ observations to test the impact of satellite-derived PAR on air quality simulations.

  19. Pars plana Ahmed valve and vitrectomy in patients with glaucoma associated with posterior segment disease.

    Science.gov (United States)

    Wallsh, Josh O; Gallemore, Ron P; Taban, Mehran; Hu, Charles; Sharareh, Behnam

    2013-01-01

    To assess the safety and efficacy of a modified technique for pars plana placement of the Ahmed valve in combination with pars plana vitrectomy in the treatment of glaucoma associated with posterior segment disease. Thirty-nine eyes with glaucoma associated with posterior segment disease underwent pars plana vitrectomy combined with Ahmed valve placement. All valves were placed in the pars plana using a modified technique, without the pars plana clip, and using a scleral patch graft. The 24 eyes diagnosed with neovascular glaucoma had an improvement in intraocular pressure from 37.6 mmHg to 13.8 mmHg and best-corrected visual acuity from 2.13 logarithm of minimum angle of resolution to 1.40 logarithm of minimum angle of resolution. Fifteen eyes diagnosed with steroid-induced glaucoma had an improvement in intraocular pressure from 27.9 mmHg to 14.1 mmHg and best-corrected visual acuity from 1.38 logarithm of minimum angle of resolution to 1.13 logarithm of minimum angle of resolution. Complications included four cases of cystic bleb formation and one case of choroidal detachment and explantation for hypotony. Ahmed valve placement through the pars plana during vitrectomy is an effective option for managing complex cases of glaucoma without the use of the pars plana clip.

  20. Effects of solar PAR and UV radiation on tropical biofouling communities

    KAUST Repository

    Dobretsov, SV

    2010-03-08

    We investigated the effect of solar ultraviolet radiation (UVR) and photosynthetically active radiation (PAR) on the development of tropical micro- and macrofouling communities for 30 d. The experimental design involved 3 treatments: full spectrum (PAR+UVR), PAR only, and minimal light (reduced PAR and UVR). Terminal restriction fragment length polymorphism analysis demonstrated that different light conditions resulted in the formation of highly different microbial communities. The lowest densities of bacteria were found under the full spectrum treatment, while the lowest densities of diatoms were found in the minimal light treatment. Macrofouling communities consisted of 13 species and differed among light treatments. In the presence of UVR, communities had low species diversity, evenness, and richness, while in minimal light and PAR treatments, communities had high species diversity, evenness, and richness. Similarity percentage (SIMPER) analysis revealed that the tubeworm Hydroides elegans, the alga Ulva (Enteromorpha) sp., and the bivalve Perna viridis were the species responsible for most of the dissimilarities in macrofouling communities among treatments. While densities of H. elegans were similar in the PAR and minimal light treatments, this polychaete had higher growth rates under minimal light conditions. We conclude that UVR and PAR directly control the development of shallow micro- and macrofouling communities by inhibiting the recruitment and growth of sensitive species and promoting the growth of resistant species, but also that these forms of solar radiation influence the surface cues available to competent larvae by altering the development of the microbial community.

  1. The pars intermedia: an anatomic basis for a coordinated vascular response to female genital arousal.

    Science.gov (United States)

    Shih, Cheryl; Cold, Christopher J; Yang, Claire C

    2013-06-01

    The pars intermedia is an area of the vulva that has been inconsistently described in the literature. We conducted anatomic studies to better describe the tissues and vascular structures of the pars intermedia and proposed a functional rationale of the pars intermedia in the female sexual response. Nine cadaveric vulvectomy specimens were used. Each was serially sectioned and stained with hematoxylin and eosin and Masson's trichrome. Histologic ultrastructural description of the pars intermedia. The pars intermedia contains veins traveling longitudinally in the angle of the clitoris, supported by collagen-rich stromal tissues. These veins drain the different vascular compartments of the vulva, including the clitoris, the bulbs, and labia minora; also, the interconnecting veins link the different vascular compartments. The pars intermedia is not composed of erectile tissue, distinguishing it from the erectile tissues of the corpora cavernosa of the clitoris as well as the corpus spongiosum of the clitoral (vestibular) bulbs. The venous communications of the pars intermedia, linking the erectile tissues with the other vascular compartments of the vulva, appear to provide the anatomic basis for a coordinated vascular response during female sexual arousal. © 2012 International Society for Sexual Medicine.

  2. Hunger amidst plenty along the coast of Pará

    Directory of Open Access Journals (Sweden)

    Ivete Nascimento

    2006-08-01

    Full Text Available In this work one analyzes some referring questions to the new significações of the temporality constructed socially enters the artisan fishing of the coast, in the city of Maracanã, using as boundary-maker the concepts the concepts of abundance and famitura the one that they send themselves to the speech in way of life of the past and the gift. It will see as the typical way of life of the rescued past of the memory of old and the meaning of the abundance in the time of the fishing-farmer, the counterpoint with the concept of famitura of the fishing-exclusive of the gift, where the loss surpasses the scope of the strict survival reaching the proper way of life with the weakness of solidarity. This analysis will be given mecanicamente in the conceptual field of the time measured for the tasks and of the time chronometered for the clock. The intensive field work ocurred on Fortaleza of the Mocooca community incorporating data gotten a long the author's experience in the fish artisan thematic of the Pará coast.

  3. Le Web pour enseigner par projets et favoriser la collaboration

    Directory of Open Access Journals (Sweden)

    Sylvie Ratté

    2004-01-01

    Full Text Available L’utilisation du Web présentée dans cet article vient appuyer une démarche pédagogique fondée sur le partage des savoirs. Dans le contexte d’une simulation industrielle, les étudiants d’un cours de programmation avancée doivent apprendre à partager leur expertise, à communiquer clairement leurs questions, à décrire des problèmes et à faire face à des retournements inattendus. Le Web devient un espace de collaboration pour diffuser les requêtes d’un client fictif, les directives, les travaux préliminaires et les ententes. Les résultats obtenus tendent à suggérer que cette approche globale force l’étudiant à mieux planifier, l’invite à mieux formuler et décrire les problèmes, augmente le niveau de collaboration et facilite la production d’analogies. Un système facilitant la logistique entourant la revue par les pairs (récupération des travaux, construction d’une grille d’évaluation et diffusion des résultats est également présenté.

  4. Design of 118 MHz twelfth harmonic cavity of APS PAR

    International Nuclear Information System (INIS)

    Kang, Y.W.; Kustom, R.L.; Bridges, J.F.

    1992-01-01

    Two radio frequency (RF) cavities are needed in the Positron Accumulator Ring (PAR) of the Advanced Photon Source. One is for the first harmonic frequency at 9.8 MHz, and the other is for the twelfth harmonic frequency at 118 MHz. This note reports on the design of the 118 MHz RF cavity. Computer models are used to find the mode frequencies, impedances, Q-factors, and field distributions in the cavity. The computer codes MAFIA, URMEL, and URMEL-T are useful tools which model and simulate the resonance characteristics of a cavity. These codes employ the finite difference method to solve Maxwell's equations. MAFIA is a three-dimensional problem solver and uses square patches to approximate the inner surface of a cavity. URMEL and URMEL-T are two-dimensional problem solvers and use rectangular and triangular meshes, respectively. URMEL-T and MAFIA can handle problems with arbitrary dielectric materials located inside the boundary. The cavity employs a circularly cylindrical ceramic window to limit the vacuum to the beam pipe. The ceramic window used in the modeling will have a wall thickness of 0.9 cm. This wall thickness is not negligible in determining the resonant frequencies of the cavity. In the following, results of two- and three-dimensional modeling of the cavities using the URMEL-T and MAFIA codes are reported

  5. Characterization of ParTI Phoswiches Using Charged Pion Beams

    Science.gov (United States)

    Churchman, Emily; Zarrella, Andrew; Youngs, Michael; Yennello, Sherry

    2017-09-01

    The Partial Truncated Icosahedron (ParTI) detector array consists of 15 phoswiches. Each phoswich is made of two scintillating components - a thallium-doped cesium iodide (CsI(Tl)) crystal and an EJ-212 scintillating plastic - coupled to a photomultiplier tube. Both materials have different scintillation times and are sensitive to both charged and neutral particles. The type of particle and amount of energy deposited determine the shape of the scintillation pulse as a function of time. By integrating the fast and slow signals of the scintillation pulses, a ``Fast vs. Slow Integration'' plot can be created that produces particle identification lines based on the energy deposited in the scintillating materials. Four of these phoswiches were taken to the Paul Scherrer Institute (PSI) in Switzerland where π + , π-, and proton beams were scattered onto the phoswiches to demonstrate their particle identification (PID) capabilities. Using digitizers to record the detector response waveforms, pions can also be identified by the characteristic decay pulse of the muon daughters.

  6. Monitoreo de parásitos en efluentes domiciliarios

    Directory of Open Access Journals (Sweden)

    Semenas Liliana

    1999-01-01

    Full Text Available OBJETIVO: Evaluar la presencia de parásitos en efluentes semisólidos y líquidos en distintas localidades de la Patagonia argentina considerando que ésta es una de las restricciones para su uso. MÉTODOS: Las muestras tomadas en 4 Plantas de Tratamiento de Efluentes Domiciliarios se analizaron siguiendo las normativas de Environmental Protection Agency, Organización Mundial de la Salud, Standard Methods for Examination of Water and Wastewater y de algunas clasificaciones. RESULTADOS: Solamente 2 de las 6 muestras de semisólidos analizadas tenían huevos de Ascaris lumbricoides no viables. De las 10 muestras líquidas, solamente 2 no tenían huevos mientras las restantes tenían patógenos de las categorías I (Giardia sp., Hymenolepis diminuta y Enterobius vermicularis y III (Ascaris lumbricoides, Ancylostoma duodenale y Trichuris trichiura. CONCLUSIONES: Todas las muestras de semisólidos analizadas fueron aptas para su uso como fertilizantes porque no se registró en ninguna de ellas la presencia de huevos viables de Ascaris lumbricoides y solamente 6 de las muestras líquidas fueron aptas para riego por carecer de huevos o por ser su concentración igual o inferior a 1 huevo por litro.

  7. MMP-1/PAR-1 signal transduction axis and its prognostic impact in esophageal squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Hong-hua Peng

    2012-01-01

    Full Text Available The matrix metalloprotease-1 (MMP-1/protease-activated receptor-1 (PAR-1 signal transduction axis plays an important role in tumorigenesis. To explore the expression and prognostic value of MMP-1 and PAR-1 in esophageal squamous cell carcinoma (ESCC, we evaluated the expression of two proteins in resected specimens from 85 patients with ESCC by immunohistochemistry. Sixty-two (72.9% and 58 (68.2% tumors were MMP-1- and PAR-1-positive, respectively, while no significant staining was observed in normal esophageal squamous epithelium. MMP-1 and PAR-1 overexpression was significantly associated with tumor node metastasis (TNM stage and regional lymph node involvement. Patients with MMP-1- and PAR-1-positive tumors, respectively, had poorer disease-free survival (DFS than those with negative ESCC (P = 0.002 and 0.003, respectively. Univariate analysis showed a significant relationship between TNM stage [hazard ratio (HR = 2.836, 95% confidence interval (CI = 1.866-4.308], regional lymph node involvement (HR = 2.955, 95%CI = 1.713-5.068, MMP-1 expression (HR = 2.669, 95%CI = 1.229-6.127, and PAR-1 expression (HR = 1.762, 95%CI = 1.156-2.883 and DFS. Multivariate analysis including the above four parameters identified TNM stage (HR = 2.035, 95%CI = 1.167-3.681, MMP-1 expression (HR = 2.109, 95%CI = 1.293-3.279, and PAR-1 expression (HR = 1.967, 95%CI = 1.256-2.881 as independent and significant prognostic factors for DFS. Our data suggest for the first time that MMP-1 and PAR-1 were both overexpressed in ESCC and are novel predictors of poor patient prognosis after curative resection. The MMP-1/PAR-1 signal transduction axis might be a new therapeutic target for future therapies tailored against ESCC.

  8. MMP-1/PAR-1 signal transduction axis and its prognostic impact in esophageal squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Hong-hua; Zhang, Xi; Cao, Pei-guo [Department of Oncology, the Third Xiangya Hospital, Central South University, Changsha, Hunan Province (China)

    2011-11-18

    The matrix metalloprotease-1 (MMP-1)/protease-activated receptor-1 (PAR-1) signal transduction axis plays an important role in tumorigenesis. To explore the expression and prognostic value of MMP-1 and PAR-1 in esophageal squamous cell carcinoma (ESCC), we evaluated the expression of two proteins in resected specimens from 85 patients with ESCC by immunohistochemistry. Sixty-two (72.9%) and 58 (68.2%) tumors were MMP-1- and PAR-1-positive, respectively, while no significant staining was observed in normal esophageal squamous epithelium. MMP-1 and PAR-1 overexpression was significantly associated with tumor node metastasis (TNM) stage and regional lymph node involvement. Patients with MMP-1- and PAR-1-positive tumors, respectively, had poorer disease-free survival (DFS) than those with negative ESCC (P = 0.002 and 0.003, respectively). Univariate analysis showed a significant relationship between TNM stage [hazard ratio (HR) = 2.836, 95% confidence interval (CI) = 1.866-4.308], regional lymph node involvement (HR = 2.955, 95%CI = 1.713-5.068), MMP-1 expression (HR = 2.669, 95%CI = 1.229-6.127), and PAR-1 expression (HR = 1.762, 95%CI = 1.156-2.883) and DFS. Multivariate analysis including the above four parameters identified TNM stage (HR = 2.035, 95%CI = 1.167-3.681), MMP-1 expression (HR = 2.109, 95%CI = 1.293-3.279), and PAR-1 expression (HR = 1.967, 95%CI = 1.256-2.881) as independent and significant prognostic factors for DFS. Our data suggest for the first time that MMP-1 and PAR-1 were both overexpressed in ESCC and are novel predictors of poor patient prognosis after curative resection. The MMP-1/PAR-1 signal transduction axis might be a new therapeutic target for future therapies tailored against ESCC.

  9. 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.

  10. Prognostic value of suPAR and hs-CRP on cardiovascular disease

    DEFF Research Database (Denmark)

    Diederichsen, Marie Zöga; Diederichsen, Søren Zöga; Mickley, Hans

    2018-01-01

    Background and ai