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  1. High temperature elastic constant measurements: application to plutonium; Mesure des constantes elastiques a haute temperature application au plutonium

    Energy Technology Data Exchange (ETDEWEB)

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

    1969-03-01

    We present an apparatus with which we have measured the Young's modulus and the Poisson's ratio of several compounds from the resonance frequency of cylinders in the temperature range 0 deg. C-700 deg. C. We especially studied the elastic constants of plutonium and measured for the first time to our knowledge the Young's modulus of Pu{sub {delta}} and Pu{sub {epsilon}}. E{sub {delta}} 360 deg. C = 1.6 10{sup 11} dy/cm{sup 2}; E{sub {epsilon}} 490 deg. C = 1.1 10{sup 11} dy/cm{sup 2}, {sigma}{sub {epsilon}} = 0.25 {+-} 0.03 Using our results, we have calculated the compressibility, the Debye temperature, the Grueneisen constant and the electronic specific heat of Pu{sub {epsilon}}. (author) [French] Nous decrivons un appareil qui permet de mesurer les constantes elastiques (module de Young et module de Poisson) jusqu'a 700 deg. C a partir des frequences de resonance de barreaux cylindriques. Nous avons plus specialement etudie le plutonium et determine pour la premiere fois a notre connaissance le module de Young des phases {delta} et {epsilon}: E{sub {delta}} 360 deg. C = 1.6 10{sup 11} dy/cm{sup 2}; E{sub {epsilon}} 490 deg. C = 1.1 10{sup 11} dy/cm{sup 2}, {sigma}{sub {epsilon}} = 0.25 {+-} 0.03 Nos mesures nous ont permis de calculer la compressibilite, la temperature de Debye, la constante de Gruneisen et la chaleur specifique electronique de Pu{sub {epsilon}}. (auteur)

  2. From the Rydberg constant to the fundamental constants metrology; De la constante de Rydberg a la metrologie des constantes fondamentales

    Energy Technology Data Exchange (ETDEWEB)

    Nez, F

    2005-06-15

    This document reviews the theoretical and experimental achievements of the author since the beginning of his scientific career. This document is dedicated to the spectroscopy of hydrogen, deuterium and helium atoms. The first part is divided into 6 sub-sections: 1) the principles of hydrogen spectroscopy, 2) the measurement of the 2S-nS/nD transitions, 3) other optical frequency measurements, 4) our contribution to the determination of the Rydberg constant, 5) our current experiment on the 1S-3S transition, 6) the spectroscopy of the muonic hydrogen. Our experiments have improved the accuracy of the Rydberg Constant by a factor 25 in 15 years and we have achieved the first absolute optical frequency measurement of a transition in hydrogen. The second part is dedicated to the measurement of the fine structure constant and the last part deals with helium spectroscopy and the search for optical references in the near infrared range. (A.C.)

  3. The determination methods of the velocity constant for electrochemical reactions; Les methodes de determination de la constante de vitesse des reactions electrochimiques

    Energy Technology Data Exchange (ETDEWEB)

    Molina, R

    1963-07-01

    In a brief introduction are recalled the fundamental mechanisms of the electrochemical reaction and the definition of the intrinsic velocity constant of a such reaction. By the nature of the different parameters which enter in this definition are due some experimental problems which are examined. Then are given the principles of the measurement methods of the velocity constant. These methods are developed with the mathematical expression of the different rates of the mass transfer to an electrode. In each case are given the experimental limits of use of the methods and the size order of the velocity constant that can be reached. A list of fundamental works to be consulted conclude this work. (O.M.) [French] Dans une breve introduction sont rappeles les mecanismes fondamentaux de la reaction electrochimique et la definition de la constante de vitesse intrinseque d'une telle reaction. De la nature des differents parametres qui entrent dans celle definition, decoulent un certain nombre de problemes experimentaux qui sont passes en revue. On donne ensuite les principes des methodes de mesure de la constante de vitesse. L'exposition de ces methodes est developpee a l'aide de l'expression mathematique des differents regimes de transfert de masse a une electrode. On s'attache dans chaque cas, a donner les limitations experimentales d'utilisation des methodes et l'ordre de grandeur de la constante de vitesse qu'elles permettent d'atteindre. Une liste des ouvrages fondamentaux a consulter conclut ce travail. (auteur)

  4. Application of general methods for the study of porous materials to the determination of the characteristics of barriers; Application des methodes generales d'etudes des corps poreux a la determination des caracteristiques des barrieres

    Energy Technology Data Exchange (ETDEWEB)

    Plurien, P; Charpin, J; Mommejac, S [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    Barriers foreseen for the separation of uranium isotopes by gaseous diffusion must posses pores of about 100 Angstrom radius and as high an output as possible. They should thus be of small but uniform thickness. In view of these conditions it is necessary to adapt the normal methods available for studying porous materials in order to check the characteristics of the prototypes examined. It has been found that only by cross-comparison of data from various methods can progress in the development of different prototypes be followed. The following account consists of two parts: 1) A review of the main experimental methods we have used: a) various absorption methods, b) electron microscopy, c) X-ray studies, d) mercury porosimetry, e) liquid permeability, f) gas permeability, g) measurement of separation efficiency. 2) Comparison of the results obtained using these various methods and their application with a view to acquiring as complete a knowledge as possible of the structure of the barrier. (author) [French] Les barrieres susceptibles d'etre utilisees pour la separation des isotopes de l'uranium, par diffusion gazeuse, doivent presenter des pores de rayon de l'ordre de 100 Angstrom et un debit aussi grand que possible. Elles doivent donc avoir une epaisseur faible et constante. Ces conditions necessitent une adaptation des methodes usuelles d'etude des corps poreux pour controler les caracteristiques des prototypes etudies. Il est apparu que seul le recoupement entre diverses methodes permet de suivre les progres dans la realisation de differents prototypes. L'expose qui va suivre comprend deux parties: 1) Une revue des principales methodes experimentales que nous utilisons: a) differentes methodes d'absorption, b) microscopie electronique, c) rayons X, d) porosimetrie a mercure, e) permeabilite aux liquides, f) permeabilite aux gaz, g) mesure de l'efficacite de separation. 2) Comparaison des differents resultats obtenus par ces diverses methodes et leur application

  5. Application des TIC à l'atténuation des effets des catastrophes dans ...

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

    L'Amérique centrale est souvent aux prises avec des inondations et des ... (SIG) et de traitement des images, afin de cartographier les dangers et de modéliser les ... de l'Institut d'étude du développement international de l'Université McGill.

  6. Administrateur de programme, Application des connaissances (h/f ...

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

    Le programme découle d'un partenariat conclu entre le Department for International Development du Royaume-Uni, la Fondation William et Flora Hewlett et le CRDI. L'administrateur de programme, Application des connaissances, relevant du chef de programme, travaille à la formulation et au profilage des résultats du ...

  7. The pulsed neutron method applied to the determination of the nuclear constants of graphite (1961); La methode des neutrons pulses appliquee a la determination des constantes nucleaires du graphite (1961)

    Energy Technology Data Exchange (ETDEWEB)

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

    1961-07-01

    A method for determining the nuclear constants {sigma}{sub a} and {lambda}{sub t} of a moderator is described. The disappearance of a burst of neutrons introduced into a finite medium is studied as a function of time. This decrease in the thermal neutron density is the product of two exponentials; one representing the absorption, the other the leakage. By varying one or other of these factors, the constants of the factor left unvaried can be determined, and from this the nuclear constant values are deduced. (author) [French] On decrit une methode permettant de determiner les constantes nucleaires {sigma}{sub a} et {lambda}{sub t} d'un moderateur. On etudie la decroissance dans le temps d'une bouffee de neutrons introduite dans un milieu fini. Cette decroissance de la densite en neutrons thermiques est le produit de deux exponentielles; l'une represente l'absorption, l'autre les fuites. Par variation de l'un ou l'autre de ces facteurs, on determine les constantes du facteur laisse invariant dont on deduit les valeurs des constantes nucleaires. (auteur)

  8. Determination of Peukert's Constant Using Impedance Spectroscopy: Application to Supercapacitors.

    Science.gov (United States)

    Mills, Edmund Martin; Kim, Sangtae

    2016-12-15

    Peukert's equation is widely used to model the rate dependence of battery capacity, and has recently attracted attention for application to supercapacitors. Here we present a newly developed method to readily determine Peukert's constant using impedance spectroscopy. Impedance spectroscopy is ideal for this purpose as it has the capability of probing electrical performance of a device over a wide range of time-scales within a single measurement. We demonstrate that the new method yields consistent results with conventional galvanostatic measurements through applying it to commercially available supercapacitors. Additionally, the novel method is much simpler and more precise, making it an attractive alternative for the determination of Peukert's constant.

  9. Les frameworks au coeur des applications web

    OpenAIRE

    Moro, Arielle; Daehne, Peter

    2010-01-01

    Depuis quelques années, Internet est vraiment entré dans les mœurs : tant dans les entreprises qu’au sein de chaque foyer. En effet, Internet permet de communiquer à travers le monde en quelques secondes, de vendre toute sorte de produits en déployant des solutions e-commerce facilement et bien d’autres choses. Internet est donc un véritable vecteur de communication, de commerce et à présent, avec le Web 2.0, un vrai berceau d’informations (tant des informations personnelles que des informati...

  10. N.M.R. study of organo-phosphorus compounds: non equivalence of methylenic protons in the {alpha} position of an asymmetric phosphorus atom. Application to study of coupling constants J{sub P,H} and J{sub H,H}; R.M.N. de composes organo-phosphores: non equivalence de protons methyleniques en {alpha} d'un phosphore asymetrique. Application a l'etude des constantes de couplage J{sub P,H} et J{sub H,H}

    Energy Technology Data Exchange (ETDEWEB)

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

    1969-07-01

    Non-equivalent methylenic protons, with respect to an asymmetric center, have been observed in the n.m.r. spectra of some three- and tetra-coordinated phosphorus compounds. The analysis of these spectra yield the following results: in the studied secondary phosphines, the inversion rate at the phosphorus atom is slow on the n.m.r. time scale; the geminal coupling constant, for a free-rotating methylene group attached to a phosphorus atom, is negative; in phosphines the non equivalence of methylenic protons reveals two {sup 2}J{sub P-C-H} coupling constants which differ by about 5 Hz. This result is in agreement with previous studies on cyclic phosphines. In phosphine oxides, the {sup 2}J{sub P-C-H} values are negative. The {sup 3}J{sub H-P-C-H} coupling constant is positive in both phosphines and phosphine oxides. In phosphines, the non-equivalent methylenic protons exhibit two nearly equal values for this coupling constant. (author) [French] La non-equivalence de protons methyleniques observee dans quelques composes phosphores tricoordines et tetracoordines a apporte les resultats suivants, concernant la stereochimie et les constantes de couplage dans ces composes: dans les phosphines secondaires, la structure pyramidale des liaisons issues du phosphore est fixe a l'echelle de temps de mesure de la R.M.N.; la constante de couplage {sup 2}J{sub H-C-H}, pour un methylene en libre rotation en {alpha} d'un atome de phosphore, est negative; dans les phosphines etudiees, la non-equivalence. observee pour les protons methyleniques s'accompagne d'une difference importante (5 Hz) entre les deux constantes de couplage {sup 2}J{sub P-C-H} determinees par l'analyse; ce resultat est en accord avec la stereospecificite deja observee pour ce couplage dans les phosphines cycliques. Les valeurs observees pour {sup 2}J{sub P-C-H} dans les oxydes de phosphines sont negatives. Les valeurs de la constante de couplage {sup 3}J{sub H-P-C-H}, dans les phosphines et oxydes de phosphine

  11. Soudage des aciers pour application mécanique

    CERN Document Server

    Deveaux, Dominique

    2016-01-01

    Ce guide détermine les bonnes pratiques pour comprendre les risques d’une forme d’assemblage multimatériaux : celui par soudage de nuances à forte teneur en carbone avec des éléments en acier de construction. Dans un premier temps, le rapport passe en revue l’examen des avaries sur des assemblages soudés pour l’application mécanique mettant en cause les aciers. Fissuration par fatigue, rupture fragile, rupture ductile, fissuration à chaud ou à froid sont autant de causes qui seront analysées. Dans un deuxième temps, il se concentre sur la conception des joints soudés. Du choix des nuances à la tenue vis-à-vis de la rupture fragile en passant par l’analyse en fatigue des assemblages soudés, c’est l’ensemble de la problématique qui est pris en compte.

  12. Applications magnétoélectriques des supraconducteurs

    CERN Document Server

    Mangin, Philippe

    2018-01-01

    La supraconductivité est devenue incontournable, par exemple avec l’IRM qui équipe nos hôpitaux. Elle permet de spectaculaires réalisations tels le LHC du CERN qui a mis en évidence le boson de Higgs, le projet de fusion nucléaire ITER, le train à sustentation magnétique, etc. Ces applications dans divers domaines reposent sur l’aptitude des fils supraconducteurs à transporter de très fortes intensités de courant et sur l’énorme champ magnétique que des bobines supraconductrices peuvent créer. Elles sont l’objet du présent ouvrage avec d’abord l’élaboration des fils supraconducteurs, prouesse technologique tant pour les câbles Nb – Ti et Nb3Sn que pour les rubans de cuprates. Ensuite, pour chaque application, sont présentés les phénomènes physiques et le fonctionnement des dispositifs technologiques ; le lecteur peut ainsi acquérir une vision globale des apports scientifiques de ces technologies et de leurs enjeux, scientifiques, médicaux et sociétaux. Trois autres ouvrag...

  13. Applications magnétoélectriques des supraconducteurs

    CERN Document Server

    Mangin, Philippe

    2018-01-01

    La supraconductivité est devenue incontournable, par exemple avec l’IRM qui équipe nos hôpitaux. Elle permet de spectaculaires réalisations tels le LHC du CERN qui a mis en évidence le boson de Higgs, le projet de fusion nucléaire ITER, le train à sustentation magnétique, etc. Ces applications dans divers domaines reposent sur l’aptitude des fils supraconducteurs à transporter de très fortes intensités de courant et sur l’énorme champ magnétique que des bobines supraconductrices peuvent créer. Elles sont l’objet du présent ouvrage avec d’abord l’élaboration des fils supraconducteurs, prouesse technologique tant pour les câbles Nb – Ti et Nb$_{3}$Sn que pour les rubans de cuprates. Ensuite, pour chaque application, sont présentés les phénomènes physiques et le fonctionnement des dispositifs technologiques ; le lecteur peut ainsi acquérir une vision globale des apports scientifiques de ces technologies et de leurs enjeux, scientifiques, médicaux et sociétaux. Trois autres o...

  14. Study of betatron oscillations in a constant field and alternating gradient accelerator; Etude des oscillations betatron dans l'accelerateur a champ fixe et a gradient alterne

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-07-01

    The conditions for the stability of a constant energy particle beam circulating in the magnetic field of the F.F.A.G. accelerator are studied. By a mathematical study it is possible to derive the equations for the equilibrium orbit and for the low amplitude oscillations, and the expressions for the amplitude stability limits of the beam. For this, approximation methods are used, in particular the linearization of the differential equations of the movement, and the method of gradual approximation. Numerical investigations carried out with the help of the IBM 7090 computer make it possible to judge the precision of the results given by the theory. A systematic variation of the parameters makes it possible to understand more clearly the mechanism of the amplitude variations of the trajectories. Finally, for the radial sector model, the possibility of introducing zones free from the magnetic field is considered. The case of short straight sections, respecting the field periodicity, and of that of long straight sections creating super-periods are considered. For the two cases are given solutions which should lead to a practical machine. (author) [French] On etudie les conditions de stabilite d'un faisceau de particules circulant a energie constante dans le champ magnetique de l'accelerateur F.F.A.G. Une etude mathematique permet d'etablir les equations de l'orbite d'equilibre et des oscillations de faible amplitude, les expressions des limites de stabilite en amplitude du faisceau. On emploie a cet effet des methodes d'approximation, essentiellement la linearisation des equations differentielles du mouvement et la methode de l'approximation douce. Des investigations numeriques effectuees a l'aide de la calculatrice IBM 7090 permettent d'apprecier l'exactitude des resultats fournis par la theorie. Une variation systematique des parametres permet de mieux comprendre le mecanisme des variations d'amplitude des trajectoires. On etudie enfin, pour le modele a secteur radial

  15. Isotopic equilibrium constants of the deuterium exchange between HDO and H{sub 2}S, H{sub 2}Se and H{sub 2}Te; Etude des constantes des equilibres isotopiques du deuterium entre l'eau et les hydrures des metalloides de la deuxieme famille

    Energy Technology Data Exchange (ETDEWEB)

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

    1959-11-15

    We have determined experimentally the equilibrium constant K of each of the following isotope exchanges: SH{sub 2} + OHD {r_reversible} SHD + OH{sub 2}; SeH{sub 2} + OHD {r_reversible} SeHD + OH{sub 2}; TeH{sub 2} + OHD {r_reversible} TeHD + OH{sub 2}. In gaseous phase, statistical thermodynamics leads to the expression: K (Z{sub OHD} x Z{sub RH{sub 2}})/(Z{sub OH{sub 2}} x Z{sub RHD}) x e{sup W/T} (R being the elements S, Se or Te). Z, the partition functions, have been calculated and, through our experimental results, the constant W has been determined. Having obtained W, the equilibrium constant K has been calculated for a series of temperatures. (author) [French] Nous avons determine experimentalement la constante K de chacun des equilibres isotopiques suivants: SH{sub 2} + OHD {r_reversible} SHD + OH{sub 2}; SeH{sub 2} + OHD {r_reversible} SeHD + OH{sub 2}; TeH{sub 2} + OHD {r_reversible} TeHD + OH{sub 2}. En phase gazeuse, la thermodynamique donne l'expression: K = (Z{sub OHD} x Z{sub RH{sub 2}})/(Z{sub OH{sub 2}} x Z{sub RHD}) x e{sup W/T} (R representant un atome de soufre, selenium ou tellure). Les fonctions de partition Z de chacune des molecules ont ete calculees et, grace a nos resultats experimentaux, nous avons determine la constante W. Connaissant W, la constante d'equilibre K a pu etre tabulee en fonction de la temperature. (auteur)

  16. Collection efficiency of charges in ionization chambers in presence of constant or variable radiation intensity; Efficacite de la collection des charges dans les chambres d'ionisation en presence d'une intensite de rayonnement ionisant constante ou variable

    Energy Technology Data Exchange (ETDEWEB)

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

    1970-07-01

    The theoretical and experimental study of the collection of carriers built up by ionization in standard chambers, is made by varying the value of different acting parameters. In the presence of constant ionization intensity and under a D.C. and A.C. voltage, the effect of geometry, recombination, diffusion and attachment is analyzed. The compensation of thermal neutron D.C. chambers is equally considered. Under a time dependent ionization intensity and D.C. voltage, is then studied the effect of recombination on current response, and on the collection efficiency of all formed charges. (author) [French] L'etude theorique et experimentale de la collection des porteurs crees par ionisation dans les chambres couramment utilisees est entreprise en fonction de la valeur des differents parametres agissants. En presence d'une ionisation constante et sous une tension d'alimentation d'abord continue puis alternative, on analyse l'influence de la geometrie, de la recombinaison, de la diffusion et de l'attachement. La compensation des chambres a courant continu de mesure neutronique est egalement examinee. Ensuite, sous une intensite d'ionisation variable dans le temps et en alimentation continue, on etudie l'effet de la recombinaison sur la reponse en courant et sur l'efficacite de la collection de la charge totale liberee. (auteur)

  17. A New Application for Radioimmunoassay: Measurement of Thermodynamic Constants.

    Science.gov (United States)

    Angstadt, Carol N.; And Others

    1983-01-01

    Describes a laboratory experiment in which an equilibrium radioimmunoassay (RIA) is used to estimate thermodynamic parameters such as equilibrium constants. The experiment is simple and inexpensive, and it introduces a technique that is important in the clinical chemistry and research laboratory. Background information, procedures, and results are…

  18. Measurement of the quantity of water in organic solvents by infrared absorption an measurement of the dielectric constants; Dosage de l'eau dans les solvants organiques par absorption infra-rouge et mesure des constantes dielectriques

    Energy Technology Data Exchange (ETDEWEB)

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

    1959-06-15

    Some chemical methods for the analysis of the quantity of water in solvents are first described, their object being the determination of the maximum error for cases where the water content is less than 1 per cent. - The first part of the work consists in describing infrared spectrometry as applied to the analysis of water in carbon tetrachloride, chloroform aniline, acetone and dioxane. A method based on isotopic exchange between heavy and light water is used on the one hand for determining the solubility of water in carbon tetrachloride and on the other hand for establishing standard solutions (sensitivity of the method). - In the second part the dielectric constant of water solvent solutions is measured. A table is presented giving the precision obtained by the two principal methods. These are comparable and further than that the appearance of the spectra suggests an interpretation of the anomalies observed in calibration curves obtained by the dielectric constant method. (author) [French] Quelques methodes chimiques d'analyses de l'eau dissoute dans les solvants sont decrites tout d'abord en vue de determiner l'erreur maxima dans le cas ou la teneur en eau ne depasse pas 1 pour cent. - Une premiere partie du travail expose la technique utilisee en spectrometrie infrarouge pour doser l'eau dans le tetrachlorure de carbone, chloroforme, aniline, acetone et le dioxane. Une methode basee sur l'echange isotopique entre l'eau legere et l'eau lourde permet de determiner d'une part la solubilite de l'eau dans le tetrachlorure de carbone et le chloroforme et d'autre part le titre en valeur absolue des solutions etalons (sensibilite de la methode). - Dans une deuxieme partie, on mesure la constante dielectrique des solutions eau-solvant. On dresse un tableau des precisions obtenues par les deux methodes principales. Celles-ci sont comparables et en outre, l'aspect du spectre suggere une interpretation des anomalies observees dans les courbes d'etalonnage tracees par la

  19. La boîte à outil sur l'application des connaissances | CRDI - Centre ...

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

    1 nov. 2011 ... Gavin Bennett est journaliste, auteur et consultant en communications stratégiques. Nasreen Jessani est conseillère au sein du groupe de l'application des connaissances et des politiques, l'un des deux piliers du groupe de travail chargé des études par pays du Groupe de travail de référence sur ...

  20. Measurement of the Anisotropy of Diffusion Constant in Media with Empty Channels; Mesure de l'Anisotropie de la Constante de Diffusion dans des Milieux a Canaux Vides; Izmerenie anizotropii postoyannoj diffuzii v srede s pustymi kanalami; Medicion de la Anisotropia de la Constante de Difusion en Varios Sistemas con Canales Vacios

    Energy Technology Data Exchange (ETDEWEB)

    Copic, M.; Kalin, T.; Pregl, G.; Zerdin, F. [Nuclear Institute Jozef Stefan, Ljubljana, Yugoslavia (Slovenia)

    1964-04-15

    Using the pulsed-neutron source technique, the diffusion constant was measured in systems with empty channels. Plexiglas was used as the neutron diffusing material. From separate sets of measurements on rectangular blocks the diffusion constants parallel and perpendicular to channels were determined. The average value of the diffusion constant was also obtained experimentally from measurements on cubes. The difference between both diffusion constants, D{sub Double-Up-Tack} - D{sub Up-Tack }, agrees with theoretical predictions inside the limits of experimental errors, yet the average diffusion constant lies systematically below the predictions of Behrens' theory. (author) [French] En se servant de la methode de la source des neutrons puises, les auteurs ont mesure la constante de diffusion dans des systemes a canaux vides. Comme matiere diffusant les neutrons, ils ont utilise du plexiglas. A partir de series de mesures differentes faites sur des blocs rectangulaires, ils ont determine les constantes de diffusion parallele et perpendiculaire aux canaux. Ils ont egalement obtenu experimentalement la valeiir moyenne de la constante de diffusion a i'aide de mesures faites sur des cubes. La difference entre les deux constantes de diffusion, D{sub Double-Up-Tack} - D{sub Up-Tack }, concorde avec les previsions theoriques dans les limites des erreurs d'experience; cependant, la valeur moyenne de la constante de diffusion reste systematiquement inferieure aux previsions etablies par la theorie de Behrens. (author) [Spanish] Utilizando la tecnica de la fuente neutronica pulsada, los autores midieron la constante de difusion en varios sistemas con canales vacios. Como material difusor de neutrones emplearon polimetacrilato de metilo. Basandose en varias series de mediciones efectuadas en bloques rectangulares, los autores determinaron las constantes de difusion Inverted-Question-Mark n sentido paralelo y perpendicular a los canales. Obtuvieron experimentalmente el valor

  1. Contribution to the study of the {sup 31}P, {sup 1}H spin spin coupling constant N. M. R. in three co-ordinated phosphorus compounds. Influence of the bond orientation and of the nature of the substituent around the phosphorus atom; Contribution a l'etude des constantes de couplage {sup 31}P, {sup 1}H en R.M.N. dans les composes organo-phosphores tricoordines. Influence des facteurs geometriques et de la nature des substituants au niveau du phosphore

    Energy Technology Data Exchange (ETDEWEB)

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

    1969-07-01

    In order to investigate the influence of the configuration at the phosphorus atom and the influence of the substituents attached to the phosphorus atom on the J{sub PH} spin spin coupling constant, we have performed the NMR spectrum analysis of some three coordinated organo-phosphorus compounds. The studied coupling constants are {sup 3}J{sub PH} through P-O-C-H and P-C-C-H fragments and {sup 2}J{sub PH} through P-C-H fragment. The results clearly show that on the NMR time scale, in all the studied compounds (1,3,2-dioxaphospholanes, 1,3,2-dioxaphosphorinanes, 3-phospha-cyclopentene and 4-phosphorinanone) there is no inversion of the bonds around phosphorous. This conclusion held also for secondary phosphines. For a given geometry of the bonds joining the P and H atoms, and a given disposition of the bonds around the phosphorus atom, there is only a little influence of the nature of the substituents on the J{sub PH} spin coupling constants. The geometrical dependence of the {sup 3}J{sub PH} cannot be explained by a 'Karplus law'. There is an influence of the bond disposition around phosphorus. In the case of the {sup 2}J{sub P-C-H}, one can plot a curve {sup 2}J{sub P-C-H} = f({alpha}) (0{<=} {alpha} {<=} 180), {alpha} denote the dihedral angle of the two plane defined the first one by the P, C and H atoms, and the second one by the P-C bond together with the three-fold axis of the bond around phosphorus assuming a regular pyramidal arrangement. The function {sup 2}J{sub P-C-H} = f({alpha}) has two maxima, one for {alpha} = 0 degrees and the other for {alpha} = 180 degrees, and also a minimum for {alpha} = 110 degrees. (author) [French] Ce travail consiste en l'analyse par resonance magnetique nucleaire des constantes de couplage phosphore-proton dans des derives organo-phosphores tricoordines dans un double but: examen de la stabilite des liaisons au niveau du phosphore et etude de l'influence de la disposition des liaisons et de la nature de substituants au

  2. Optimisation des proprietes fonctionnelles des alliages a memoire de forme suite a l'application de traitements thermomecaniques

    Science.gov (United States)

    Demers, Vincent

    L'objectif de ce projet est de determiner les conditions de laminage et la temperature de traitement thermique maximisant les proprietes fonctionnelles de l'alliage a memoire de forme Ti-Ni. Les specimens sont caracterises par des mesures de calorimetrie, de microscopie optique, de gene ration de contrainte, de deformation recuperable et des essais mecaniques. Pour un cycle unique, l'utilisation d'un taux d'ecrouissage e=1.5 obtenu avec l'application d'une force de tension FT = 0.1sigma y et d'une huile minerale resulte en un echantillon droit, sans microfissure et qui apres un recuit a 400°C, produit un materiau nanostructure manifestant des proprietes fonctionnelles deux fois plus grandes que le meme materiau ayant une structure polygonisee. Pour des cycles repetes, les memes conditions de laminage sont valables mais le niveau de deformation optimal est situe entre e=0.75-2, et depend particulierement du mode de sollicitation, du niveau de stabilisation et du nombre de cycles a la rupture requis par l'application.

  3. Mécanique des fluides fondements et applications

    CERN Document Server

    Cengel, Yunus A

    2017-01-01

    La mécanique des fluides est un outil performant qui permet d'expliquer les phénomènes qui nous entourent de l'échelle microscopique à l'échelle macroscopique. Elle est aussi à la base du développement de nombreuses technologies. Cet ouvrage à destination des étudiants donne une vision complète de la mécanique des fluides. Bien que la mécanique des fluides puisse souvent paraître rébarbative aux yeux des étudiants, cet ouvrage valorise ce domaine d'enseignement en l'illustrant de nombreux exemples issus de l'ingénierie navale, l'aéronautique, la météorologie, etc.

  4. Statistical treatment of data. Application to nuclear electronics; Traitement des informations en regime statistique. Applications a l'electronique nucleaire

    Energy Technology Data Exchange (ETDEWEB)

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

    1960-07-01

    In this report the data of probability calculations are applied to the analyses of counting losses in experiments on chance events encountered in nuclear physics. The distribution of time intervals according to Poisson's law is studied and various applications of this are given: calculation of counting losses on a scale preceded by a fast de-multiplying circuit, decrease of the counting rate on the multichannel selectors, recording of statistical distribution phenomena on magnetic bands. (author) [French] Ce rapport applique les donnees du calcul des probabilites a l'analyse des pertes de comptage dans les experiences sur des evenements aleatoires rencontres en physique nucleaire. La distribution des intervalles de temps suivant une loi de Poisson est etudiee et differentes applications en sont donnees: calcul des pertes de comptage sur une echelle precedee d'un circuit de demultiplication rapide, diminution du taux de comptage sur les selecteurs multicanaux, enregistrement de phenomenes a distribution statistique sur bandes magnetiques. (auteur)

  5. De l'importance des orbites periodiques: Detection et applications

    Science.gov (United States)

    Doyon, Bernard

    L'ensemble des Orbites Periodiques Instables (OPIs) d'un systeme chaotique est intimement relie a ses proprietes dynamiques. A partir de l'ensemble (en principe infini) d'OPIs cachees dans l'espace des phases, on peut obtenir des quantites dynamiques importantes telles les exposants de Lyapunov, la mesure invariante, l'entropie topologique et la dimension fractale. En chaos quantique (i.e. l'etude de systemes quantiques qui ont un equivalent chaotique dans la limite classique), ces memes OPIs permettent de faire le pont entre le comportement classique et quantique de systemes non-integrables. La localisation de ces cycles fondamentaux est un probleme complexe. Cette these aborde dans un premier temps le probleme de la detection des OPIs dans les systemes chaotiques. Une etude comparative de deux algorithmes recents est presentee. Nous approfondissons ces deux methodes afin de les utiliser sur differents systemes dont des flots continus dissipatifs et conservatifs. Une analyse du taux de convergence des algorithmes est aussi realisee afin de degager les forces et les limites de ces schemes numeriques. Les methodes de detection que nous utilisons reposent sur une transformation particuliere de la dynamique initiale. Cette astuce nous a inspire une methode alternative pour cibler et stabiliser une orbite periodique quelconque dans un systeme chaotique. Le ciblage est en general combine aux methodes de controle pour stabiliser rapidement un cycle donne. En general, il faut connaitre la position et la stabilite du cycle en question. La nouvelle methode de ciblage que nous presentons ne demande pas de connaitre a priori la position et la stabilite des orbites periodiques. Elle pourrait etre un outil complementaire aux methodes de ciblage et de controle actuelles.

  6. Equivalent Electromagnetic Constants for Microwave Application to Composite Materials for the Multi-Scale Problem

    Directory of Open Access Journals (Sweden)

    Keisuke Fujisaki

    2013-11-01

    Full Text Available To connect different scale models in the multi-scale problem of microwave use, equivalent material constants were researched numerically by a three-dimensional electromagnetic field, taking into account eddy current and displacement current. A volume averaged method and a standing wave method were used to introduce the equivalent material constants; water particles and aluminum particles are used as composite materials. Consumed electrical power is used for the evaluation. Water particles have the same equivalent material constants for both methods; the same electrical power is obtained for both the precise model (micro-model and the homogeneous model (macro-model. However, aluminum particles have dissimilar equivalent material constants for both methods; different electric power is obtained for both models. The varying electromagnetic phenomena are derived from the expression of eddy current. For small electrical conductivity such as water, the macro-current which flows in the macro-model and the micro-current which flows in the micro-model express the same electromagnetic phenomena. However, for large electrical conductivity such as aluminum, the macro-current and micro-current express different electromagnetic phenomena. The eddy current which is observed in the micro-model is not expressed by the macro-model. Therefore, the equivalent material constant derived from the volume averaged method and the standing wave method is applicable to water with a small electrical conductivity, although not applicable to aluminum with a large electrical conductivity.

  7. Application of dielectric constant measurement in microwave sludge disintegration and wastewater purification processes.

    Science.gov (United States)

    Kovács, Petra Veszelovszki; Lemmer, Balázs; Keszthelyi-Szabó, Gábor; Hodúr, Cecilia; Beszédes, Sándor

    2018-05-01

    It has been numerously verified that microwave radiation could be advantageous as a pre-treatment for enhanced disintegration of sludge. Very few data related to the dielectric parameters of wastewater of different origins are available; therefore, the objective of our work was to measure the dielectric constant of municipal and meat industrial wastewater during a continuous flow operating microwave process. Determination of the dielectric constant and its change during wastewater and sludge processing make it possible to decide on the applicability of dielectric measurements for detecting the organic matter removal efficiency of wastewater purification process or disintegration degree of sludge. With the measurement of dielectric constant as a function of temperature, total solids (TS) content and microwave specific process parameters regression models were developed. Our results verified that in the case of municipal wastewater sludge, the TS content has a significant effect on the dielectric constant and disintegration degree (DD), as does the temperature. The dielectric constant has a decreasing tendency with increasing temperature for wastewater sludge of low TS content, but an adverse effect was found for samples with high TS and organic matter contents. DD of meat processing wastewater sludge was influenced significantly by the volumetric flow rate and power level, as process parameters of continuously flow microwave pre-treatments. It can be concluded that the disintegration process of food industry sludge can be detected by dielectric constant measurements. From technical purposes the applicability of dielectric measurements was tested in the purification process of municipal wastewater, as well. Determination of dielectric behaviour was a sensitive method to detect the purification degree of municipal wastewater.

  8. Geophysical Well Logs Applied to Geothermal Resource Evaluation Application des diagraphies à l'évaluation des ressources géothermiques

    Directory of Open Access Journals (Sweden)

    Fertl W. H.

    2006-11-01

    Full Text Available Well logging in the petroleum industry has been developed over five decades into a mature industry, whereas geothermal well logging is a relatively new enterprise. Fundamental differences also occur in the geologic environments and key objectives of both logging applications. Geothermal reservoirs are frequently in fractured igneous and metamorphic rocks, which contain hot water or stem at temperature exceeding 150°C. The discussion focuses on present day logging technology, geologic and reservoir engineering objectives, and qualitive and quantitative formation interpretation techniques for geothermal resource evaluation. Specific field case studies illustrate the interpretive state-of-the-art, including examples from the Geysers dry steam field in the Imperial Valley of California, hot water fields in California, Nevada, and Idaho, and the LASL Hot Dry Rock test project in the Valles Caldera of New Mexico. Les diagraphies dans les forages pétroliers ont atteint leur maturité, alors que le contrôle diagraphique des sondages géothermiques est une entreprise relativement nouvelle. Des différences fondamentales apparaissent aussi dans les environnements géologiques et dans les objectifs clés des deux types d'applications des diagraphies. Les réservoirs géothermiques se situent souvent dans les roches ignées ou métamorphiques fracturées qui contiennent de l'eau chaude ou de la vapeur à des températures dépassant 150 °C. L'exposé sera concentré sur les techniques actuelles d'enregistrements, les objectifs géologiques et liés à l'exploitation des réserves et sur les techniques qualitatives et quantitatives d'interprétation des formations pour l'évaluation des ressources géothermiques. Quelques cas particuliers illustrent l'état actuel des techniques d'interprétation avec des exemples pris dans le champ de vapeur sèche des geysers dans Imperial Valley de Californie, des champs d'eau chaude en Californie, Nevada et Idaho et

  9. JENDL reactor constant and its application. The 40th anniversary of Japan nuclear data committee

    International Nuclear Information System (INIS)

    Zukeran, Atsushi

    2004-01-01

    The status of reactor constants about 27 years ago is briefly reviewed from the criticality predictions and nuclear data processing codes. In the second section, status of current users of JENDL-3.3 and/or JENDL-3.2 is consulted with the 2003 Fall Meeting of Atomic Energy Society of Japan. In the third section, the reliabilities of JENDL-3.3 and -3.2 are reviewed mainly from the application to light water reactor (LWR) mockup experiments; MISTRAL and BASALA made on EOLE critical facility of Cadarache Laboratory in France, since an extensive evaluation for nuclear data applicability to LWR have been scarcely performed in relative to for FBR. The results of international benchmark cores and criticality safety analyses are briefly reviewed. In the concluding remarks, overall applicability is shown as a summary with respect to all reactor parameters obtained in the LWR mockup experiment and some remarks are noted. (author)

  10. Sigand : une application SIG sous androïd (tablette de la gestion des chantiers

    Directory of Open Access Journals (Sweden)

    CHAKIB SAFAR BATI

    2016-12-01

    Full Text Available L’introduction de données terrain pour les études environnementales ou de gestion de l’espace, régionales ou locales est une nécessité incontournable pour la validation des traitements et des interprétations mais aussi pour fournir des compléments d’informations aux divers travaux. Mais ce retour terrain est également de plus en plus demandé pour les gestionnaires de chantiers et de projets qui ont une exigence de contrôle ou de suivi et donc d’une information temps réel sur l’avancement des travaux, autrement pour introduire de nouvelles informations sur la base de données géoréférencées. Les avancées technologiques en matière de manipulation de l’information géographique (GPS, tablette graphique, téléphone portable, réalité augmentée permettent d’espérer la mise à dispositiondes professionnels, voire d’un plus large public, des outils adéquats pour de tels travaux. Actuellement, les outils d’élaboration, de gestion et d’exploitation des bases de données géographiques (solutions SIG ne sont pas encore complètement opérationnels en version « tablette » ; des applications telles que Qgis ou ArcGis sous Androïd attendent encore des développements. Nous présentons ici la première version d’une application SIG sous Androïd (disponible sur tablette pour la gestion en temps réel des chantiers qui permet de charger des couches vectorielles et de les mettre à jour sur le terrain en fonction de l’observation directe ; les couches (préalablement géoréférencées sont projetées sur des fonds cartographiques fournis par un serveur cartographique Google Maps (Route, Satellite, terrain; dans le cas d’absence de connexion internet, le fond cartographique est ramené d’un cache. Nous utilisons SpatialiteAndroïd pour le stockage et la manipulation des données géographiques. Le contrôleur de cartes Google Maps est employé pour afficher en mode cartographique les données stockées dans

  11. Measurement of the distribution of anisotropy constants in magnetic nanoparticles for hyperthermia applications

    Science.gov (United States)

    McGhie, A. A.; Marquina, C.; O'Grady, K.; Vallejo-Fernandez, G.

    2017-11-01

    In this work, we have applied theoretical calculations to new experimental measurements of the effect of the anisotropy distribution in magnetite nanoparticles, which in turn controls hysteresis heating for hyperthermia applications. Good agreement between theory and experiment is reported where the theoretical calculation is based upon the detailed measurement of the particle elongation generally observed in the nanoparticles. The elongation has been measured from studies via transmission electron microscopy. We find that particle elongation is responsible for the anisotropy dispersion, which can be obtained by analysis and fitting to a measurement of the temperature decay of remanence. A median value of the anisotropy constant of 1.5  ×  105 erg/cc was obtained. A very wide distribution of anisotropy constants is present with a Gaussian standard deviation of 1.5  ×  105 erg/cc. From our measurements, deviations in the value of the saturation magnetisation from particle to particle are most likely the main factor giving rise to this large distribution, with 33% arising from the error in the measured elongation. The lower limit to the anisotropy constant of the nanoparticles is determined by the magnetocrystalline anisotropy of the material, 1.1  ×  105 erg/cc for magnetite, which was studied in this work.

  12. Application of the pulsed neutron technique on the reactors ALIZE - AQUILON (1963); Application de la methode des neutrons pulses sur les piles ALIZE et AQUILON (1963)

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-07-01

    Different methods of measuring the ratio effective delayed fraction / prompt neutron lifetime, {alpha}{sub c}, are described. According to the classic pulsed neutron technique the negative reactivity due to a localized absorber is given by {rho} / {beta}{sub eff} = {alpha} / {alpha}{sub c} -1 Experiments are reported which show that in this case {alpha}{sub c} can not be considered constant for large reactivities. The absorber element distorts the flux in the system, increasing the importance of the reflector. An application of the pulsed neutron method to the measurement of critical distributed boron concentrations of various absorber elements is described. Less time is required than for the usual super-critical techniques, and the experimental analysis is simplified. It is interesting to note that the results are not influenced by the spectral sensitivity of the control element. A modified pulsed neutron method has been tried out. This procedure was used to determine by measurements at sub-critical the critical water level of uranium-heavy water lattices with a high precision. (author) [French] Differents modes operatoires pour definir la valeur du rapport pourcentage effectif de neutrons retardes / temps de vie, {alpha}{sub c}, sont exposes. La methode classique par neutrons pulses definit l'anti-reactivite d'un element absorbant a partir de la relation: {rho} / {beta}{sub eff} {alpha} / {alpha}{sub c} -1 Les manipulations effectuees montrent qu'on ne peut considerer dans ce cas {alpha}{sub c} constant pour de tres grandes anti-reactivites. L'absorbant introduit dans la pile deforme le flux et augmente l'importance du reflecteur. Une application de la methode des neutrons pulses pour mesurer le titre critique en mg de B/l de divers absorbants est signalee. Les operations sont effectuees en regime sous-critique avec un certain gain de temps et une grande facilite de depouillement. Il est interessant de noter que les resultats ne sont pas

  13. Application of the pulsed neutron technique on the reactors ALIZE - AQUILON (1963); Application de la methode des neutrons pulses sur les piles ALIZE et AQUILON (1963)

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-07-01

    Different methods of measuring the ratio effective delayed fraction / prompt neutron lifetime, {alpha}{sub c}, are described. According to the classic pulsed neutron technique the negative reactivity due to a localized absorber is given by {rho} / {beta}{sub eff} = {alpha} / {alpha}{sub c} -1 Experiments are reported which show that in this case {alpha}{sub c} can not be considered constant for large reactivities. The absorber element distorts the flux in the system, increasing the importance of the reflector. An application of the pulsed neutron method to the measurement of critical distributed boron concentrations of various absorber elements is described. Less time is required than for the usual super-critical techniques, and the experimental analysis is simplified. It is interesting to note that the results are not influenced by the spectral sensitivity of the control element. A modified pulsed neutron method has been tried out. This procedure was used to determine by measurements at sub-critical the critical water level of uranium-heavy water lattices with a high precision. (author) [French] Differents modes operatoires pour definir la valeur du rapport pourcentage effectif de neutrons retardes / temps de vie, {alpha}{sub c}, sont exposes. La methode classique par neutrons pulses definit l'anti-reactivite d'un element absorbant a partir de la relation: {rho} / {beta}{sub eff} {alpha} / {alpha}{sub c} -1 Les manipulations effectuees montrent qu'on ne peut considerer dans ce cas {alpha}{sub c} constant pour de tres grandes anti-reactivites. L'absorbant introduit dans la pile deforme le flux et augmente l'importance du reflecteur. Une application de la methode des neutrons pulses pour mesurer le titre critique en mg de B/l de divers absorbants est signalee. Les operations sont effectuees en regime sous-critique avec un certain gain de temps et une grande facilite de depouillement. Il est interessant de noter que les resultats ne sont pas affectes par la

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1968-07-01

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

  15. Application of Peleg's equation to describe creep responses of potatoes under constant and variable storage conditions.

    Science.gov (United States)

    Solomon, W K; Jindal, V K

    2017-06-01

    The application of Peleg's equation to characterize creep behavior of potatoes during storage was investigated. Potatoes were stored at 25, 15, 5C, and variable (fluctuating) temperature for 16 or 26 weeks. The Peleg equation adequately described the creep response of potatoes during storage at all storage conditions (R 2  = .97to .99). Peleg constant k 1 exhibited a significant (p creep responses during storage or processing will be potentially helpful to better understand the phenomenon. The model parameters from such model could be used to relate rheological properties of raw and cooked potatoes. Moreover, the model parameters could be used to establish relationship between instrumental and sensory attributes which will help in the prediction of sensory attributes from instrumental data. © 2016 Wiley Periodicals, Inc.

  16. Resonant converter topologies for constant-current power supplies and their applications

    International Nuclear Information System (INIS)

    Borage, Mangesh

    2013-01-01

    Power electronics, in general, and power supplies, in particular, is an important field of accelerator technology due to its widespread use, for instance in dc, ramp or pulse magnet power supplies, high voltage power supplies for electrostatic accelerators and RF amplifies, power supplies for vacuum pumps, vacuum gauges, beam diagnostic devices etc. It has been possible to meet stringent performance requirements with the continuing advancement in the field of power electronics. Resonant converters have been an active area of research in power electronics field due to variety of topologies, diverse, peculiar and useful characteristics. While the majority of the previous work on resonant converters has been directed towards developing methods of analysis and control techniques for the mentioned applications, very little has been done to explore their suitability for application as a constant-current power supply, which is either inherently required or can be advantageously applied in power supplies for various accelerator subsystems and other industrial applications such as electric arc welding, laser diode drivers, magnet illumination systems, battery charging, electrochemical processes etc.

  17. L'evolution thermique de la matière organique des sédiments : applications d'une simulation mathématique. Potentiel pétrolier des bassins sédimentaires de reconstitution de l'histoire thermique des sédiments Thermal Evolution of Organic Matter in Sediments : Application of a Mathematical Simulation. Petrleum Potential of Sedimentary Basins and Reconstructing the Thermal History of Sediments

    Directory of Open Access Journals (Sweden)

    Tissot B.

    2006-11-01

    Full Text Available Au moyen d'un modèle mathématique, on simule la dégradation thermique de la matière organique des sédiments. Les applications possibles de ce modèle concernent la recherche des zones favorables pour la prospection de l'huile ou du gaz, la détermination de l'époque de formation des hydrocarbures pour la comparer avec l'âge des pièges et celui des couvertures, l'évaluation des réserves ultimes d'un bassin, ainsi que la pyrogénation des schistes bitumineux. Le type de matière organique est représenté dans le modèle par un jeu de constantes qui sont déterminées par des essais de laboratoire; on discute en particulier la distribution des énergies d'activation et sa signification en rapport avec la composition du kérogène. Les autres données nécessaires sont la reconstitution géologique de l'enfouissement et le gradient géothermique. La reconstitution de la géothermie ancienne pose un problème particulier. En associant la mesure de la réflectance de la vitrinite et la loi d'enfouissement, on peut, au moyen d'un modèle d'évolution de la vitrinite, rétablir dans la plupart des cas l'histoire thermique de la matière organique. Ce résultat présente certes un grand intérêt pour l'exploration pétrolière, mais son champ d'application dépasse largement ce domaine et s'étend aux problèmes de géologie générale géothermie, diagenèse des sédiments, tectonique globale, etc. A mathematical model is used to simulate the thermal degradation of the organic matter in sediments. The possible applications of this model have to do with the seorch for favorable ail or gas prospection zones, determining the period when hydrocarbons were formed so as to compare it with the age of traps and caprocks, and estimating the ultimate reserves of a basin a well as the pyrogenation of ail shales. The type of organic matter is represented in the model by a set of constants that are determined by laboratory tests. This article in

  18. Data processing in gamma spectrometry. Application to the decay schemes study; Traitement des informations en spectrometrie gamma application a l'etude de schemas de desintegration

    Energy Technology Data Exchange (ETDEWEB)

    Boulanger, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires, departement d' electronique generale, service d' instrumentation nucleaire

    1968-06-01

    The purpose of this thesis is the processing of the data issued from a gamma spectrometer, and its applications to the decay schemes study. The mathematical analysis of the full energy peaks, in connection with the very good resolution of semi-conductor detectors, leads to a very accurate determination of the energies. The resolution of complex spectra by the least squares method, completed by a spectra generating process, allows the calculation of branching ratios. Then, the handling of the two dimensional experiments permits the coincidence exam. For each of these methods, the calculation principle, then the systematics tests realized in order to prove their validity and to determine their application ranges as well as some experimental results appropriate to illustrate their possibilities, are presented. The energies of some nuclides, frequently used as standards have been thus measured and the decay schemes of {sup 134}Cs and {sup 110m}Ag determined precisely. (author) [French] Cette these est consacree aux methodes de traitement des informations issues d'un spectrometre {gamma}, et a leur application a l'etude des schemas de desintegration: l'analyse mathematique des pics d'absorption totale, conjuguee avec l'excellent pouvoir de resolution des detecteurs semi-conducteurs, conduit a une determination tres precise des energies. La decomposition des spectres complexes par la methode des moindres carres, completee par un procede de generation de spectres, autorise le calcul des rapports de branchement. Enfin le depouillement des experiences biparametriques permet l'examen des coincidences. Pour chacune de ces methodes, on expose le principe des calculs et les essais systematiques effectues afin d'eprouver leur validite et de definir leurs domaines d'application, ainsi que quelques resultats experimentaux propres a illustrer leurs possibilites. Les energies de quelques isotopes utilises couramment comme etalons ont ainsi ete mesurees, et les schemas de

  19. Contribution to the study of the {sup 31}P, {sup 1}H spin spin coupling constant N. M. R. in three co-ordinated phosphorus compounds. Influence of the bond orientation and of the nature of the substituent around the phosphorus atom; Contribution a l'etude des constantes de couplage {sup 31}P, {sup 1}H en R.M.N. dans les composes organo-phosphores tricoordines. Influence des facteurs geometriques et de la nature des substituants au niveau du phosphore

    Energy Technology Data Exchange (ETDEWEB)

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

    1969-07-01

    In order to investigate the influence of the configuration at the phosphorus atom and the influence of the substituents attached to the phosphorus atom on the J{sub PH} spin spin coupling constant, we have performed the NMR spectrum analysis of some three coordinated organo-phosphorus compounds. The studied coupling constants are {sup 3}J{sub PH} through P-O-C-H and P-C-C-H fragments and {sup 2}J{sub PH} through P-C-H fragment. The results clearly show that on the NMR time scale, in all the studied compounds (1,3,2-dioxaphospholanes, 1,3,2-dioxaphosphorinanes, 3-phospha-cyclopentene and 4-phosphorinanone) there is no inversion of the bonds around phosphorous. This conclusion held also for secondary phosphines. For a given geometry of the bonds joining the P and H atoms, and a given disposition of the bonds around the phosphorus atom, there is only a little influence of the nature of the substituents on the J{sub PH} spin coupling constants. The geometrical dependence of the {sup 3}J{sub PH} cannot be explained by a 'Karplus law'. There is an influence of the bond disposition around phosphorus. In the case of the {sup 2}J{sub P-C-H}, one can plot a curve {sup 2}J{sub P-C-H} = f({alpha}) (0{<=} {alpha} {<=} 180), {alpha} denote the dihedral angle of the two plane defined the first one by the P, C and H atoms, and the second one by the P-C bond together with the three-fold axis of the bond around phosphorus assuming a regular pyramidal arrangement. The function {sup 2}J{sub P-C-H} = f({alpha}) has two maxima, one for {alpha} = 0 degrees and the other for {alpha} = 180 degrees, and also a minimum for {alpha} = 110 degrees. (author) [French] Ce travail consiste en l'analyse par resonance magnetique nucleaire des constantes de couplage phosphore-proton dans des derives organo-phosphores tricoordines dans un double but: examen de la stabilite des liaisons au niveau du phosphore et etude de l'influence de la disposition des liaisons et de la nature de

  20. Application of radioisotopes to studies of crystal imperfections; Application des radioisotopes a l'etude des imperfections des cristaux; Primenenie radioizotopov dlya izucheniya defektov v kristallakh; Aplicaciones de los radioisotopos al estudio de las imperfecciones cristalinas

    Energy Technology Data Exchange (ETDEWEB)

    Sproull, R L; Slack, G A; Moss, M; Pohl, R O; Krumhansl, J A [Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY (United States)

    1962-01-15

    Radioisotopes have been used in two important ways in studying imperfections in alkali halide crystals. The zone refining of the compounds has been monitored by addition of tracers, and segregation coefficients have been determined from such measurements. The other application has been to insert small concentrations of impurity ions into alkali halides in order to study the phonon scattering by such impurities or by the vacancies they introduce; these measurements are carried out at very low temperatures where the phonon mean free path is limited by lattice imperfections. The most commonly used radioisotope in this work has been Ca{sup 45}. This work is reviewed and some current and possible future applications of radioisotopes in this field are mentioned. (author) [French] Les radioisotopes ont recu deux applications importantes dans l'etude des imperfections des cristaux d'halogenures alcalins. Employes comme indicateurs, ils ont permis de controler le raffinage par zones des composes et, par suite, de determiner les coefficients de segregation. La deuxieme application a consiste a introduire dans les halogenures alcalins de faibles concentrations d'ions sous forme d'impuretes afin d'etudier la diffusion des phonons par ces impuretes ou par les lacunes que celles-ci produisent; les mesures sont effectuees a des temperatures tres basses, auxquelles le libre parcours moyen des phonons se trouve limite par les imperfections du reseau. Le radioisotope le plus frequemment employe pour ces operations a ete le {sup 45}Ca. Le memoire passe en revue ces divers travaux et signale quelques applications effectives ou possibles des radioisotopes dans le domaine considere. (author) [Spanish] Los autores han empleado radioisotopos en dos importantes campos del estudio de los cristales de haluros alcalinos. Uno de estos campos es el control de la purificacion por zonas de los compuestos y la determinacion de los coeficientes de segregacion por medida de las actividades de los

  1. Modélisation des processus physiques et biologiques dans des fosses septiques et voies de valorisation des boues de vidange:Application à Bujumbura-Burundi

    OpenAIRE

    Nsavyimana, Gaston

    2014-01-01

    Dans les pays en développement (PED) en général et au Burundi en particulier, la problématique de gestion des eaux usées et des déchets solides constitue un enjeu majeur pour les spécialistes et les autorités locales. En effet, suite à un manque des stations d'épuration collectives au Burundi, les fosses septiques sont les plus utilisées pour gérer les eaux usées produites. Cependant, les processus qui s'y déroulent ne sont pas encore maîtrisés et la gestion des boues de vidange lorsque c...

  2. Calibration of the k- ɛ model constants for use in CFD applications

    Science.gov (United States)

    Glover, Nina; Guillias, Serge; Malki-Epshtein, Liora

    2011-11-01

    The k- ɛ turbulence model is a popular choice in CFD modelling due to its robust nature and the fact that it has been well validated. However it has been noted in previous research that the k- ɛ model has problems predicting flow separation as well as unconfined and transient flows. The model contains five empirical model constants whose values were found through data fitting for a wide range of flows (Launder 1972) but ad-hoc adjustments are often made to these values depending on the situation being modeled. Here we use the example of flow within a regular street canyon to perform a Bayesian calibration of the model constants against wind tunnel data. This allows us to assess the sensitivity of the CFD model to changes in these constants, find the most suitable values for the constants as well as quantifying the uncertainty related to the constants and the CFD model as a whole.

  3. Aspects Topologiques de la Theorie des Champs et leurs Applications

    Science.gov (United States)

    Caenepeel, Didier

    integration. We show that by suitably adjusting the coupling constants the effective theory contains massive non-Abelian gauge fields without any residual scalars or other degrees of freedom.

  4. Application of solar chargers to prospection instruments; Application des chargeurs solaires aux appareils de prospection

    Energy Technology Data Exchange (ETDEWEB)

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

    1960-07-01

    The use of conventional batteries has certain disadvantages, and for this reason high-voltage batteries have been gradually replaced in all prospection instruments by transistor supply systems, using less cumbersome sources of energy. All the same low voltages are still necessary, and in hot or damp countries the use of these batteries leads to consumptions out of all proportion to the services rendered. This is why the use of solar energy possesses real advantages. After a brief review of the basic ideas on semiconductors, this article describes a selenium solar battery which was developed by the Westinghouse brakes and signals society. (author) [French] L'utilisation de piles classiques presente certains inconvenients. C'est pourquoi, dans tous les appareils de prospection, les piles fournissant des tensions elevees ont ete remplacees au fur et a mesure par des alimentations a base de transistors, utilisant des sources d'energie moins encombrantes. Toutefois, il faut tout de meme avoir des tensions faibles et l'utilisation de ces piles entraine dans les pays chauds ou humides une consommation disproportionnee par rapport aux services rendus. C'est pourquoi l'emploi de l'energie solaire presente de reels avantages. Cet expose decrit, apres un rappel de notion de base sur les semi-conducteurs, une batterie solaire a base de selenium qui a ete realisee par la Societe des freins et signaux Westinghouse. (auteur)

  5. Surfactant media for constant-current coulometry. Application for the determination of antioxidants in pharmaceuticals

    Energy Technology Data Exchange (ETDEWEB)

    Ziyatdinova, Guzel, E-mail: Ziyatdinovag@mail.ru [Analytical Chemistry Department, A.M. Butlerov Institute of Chemistry, Kazan (Volga Region) Federal University, Kremlyevskaya, 18, Kazan 420008 (Russian Federation); Ziganshina, Endzhe; Budnikov, Herman [Analytical Chemistry Department, A.M. Butlerov Institute of Chemistry, Kazan (Volga Region) Federal University, Kremlyevskaya, 18, Kazan 420008 (Russian Federation)

    2012-09-26

    Highlights: Black-Right-Pointing-Pointer Applicability of surfactants in constant-current coulometry is shown for the first time. Black-Right-Pointing-Pointer Reactions of antioxidants with electrogenerated titrants in surfactant media are investigated. Black-Right-Pointing-Pointer Water insoluble antioxidants can be determined in water media with addition of surfactants. Black-Right-Pointing-Pointer Coulometric determination of antioxidants in pharmaceutical dosage forms using surfactants media is developed. - Abstract: Effect of surfactant presence on electrochemical generation of titrants has been evaluated and discussed for the first time. Cationic (1-dodecylpyridinium and cetylpyridinium bromide), anionic (sodium dodecyl sulfate) and nonionic (Triton X100 and Brij{sup Registered-Sign} 35) surfactants as well as nonionic high molecular weight polymer (PEG 4000) do not react with the electrogenerated bromine, iodine and hexacyanoferrate(III) ions. The electrogenerated chlorine chemically interact with Triton X100 and Brij{sup Registered-Sign} 35. The allowable range of surfactants concentrations providing 100% current yield has been found. Chain-breaking low molecular weight antioxidants (ascorbic acid, rutin, {alpha}-tocopherol and retinol) were determined by reaction with the electrogenerated titrants in surfactant media. Nonionic and cationic surfactants can be used for the determination of antioxidants by reaction with the electrogenerated halogens. On contrary, cationic surfactants gives significantly overstated results of antioxidants determination with electrogenerated hexacyanoferrate(III) ions. The use of surfactants in coulometry of {alpha}-tocopherol and retinol provides their solubilization and allows to perform titration in water media. Simple, express and reliable coulometric approach for determination of {alpha}-tocopherol, rutin and ascorbic acid in pharmaceuticals using surfactant media has been developed. The relative standard deviation of the

  6. Nouvelle application de control des cavités 200 MHz RF du PS (CERN)

    CERN Document Server

    Cotte, D

    2011-01-01

    Le système Radio Fréquence (RF) 200MHz du PS est un outil essentiel pour la préparation des faisceaux haute intensité du PS. Dans l’anneau PS on trouve 6 cavités 200 MHz utilisées pour contrôler : • l’émittance longitudinale des « bunches » • le processus de « Rebunching » du faisceau avant de l’envoyer au SPS. Chaque cavité est pilotée par des événements appelés « timing » et suit une fonction de tension programmée. Cependant, l’électronique utilisée pour piloter les cavités 200 MHz du PS est obsolète et sa fiabilité non garantie pour cause du manque de pièces de rechange. Ce document décrit le fonctionnement du nouveau programme d’application qui fait abstraction de l’ancienne matrice hardware. Elle suit les recommandations décrites dans l’étude d’une nouvelle structure pour le système RF 200MHz du PS. [1

  7. The application of radioactive isotopes to the study of motion of silt and pebbles in the rivers and in the sea; Application des isotopes radioactifs a l'etude des mouvements des sediments et des galets dans les cours d'eau et en mer

    Energy Technology Data Exchange (ETDEWEB)

    Hours, R [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Jaffry, P [Electricite de France (EDF), 78 - Chatou (France). Lab. National d' Hydraulique

    1959-07-01

    The application of radioactive tracers to the study of sediments drift has received considerable attention since 1954 in various countries. A comparative review is made of a number of techniques of labelling, immersing and detecting silts, sands, and pebbles. The influence of the burying of the active material is emphasized. The different experiments which have been so far carried out are described. (author) [French] L'application des traceurs radioactifs a l'etude des deplacements de sediments a fait depuis 1954 l'objet de travaux nombreux dans divers pays. On passe en revue et on compare differentes techniques de marquage, d'immersion et de detection des vases, sables et galets; on insiste sur l'influence de l'enfouissement du materiau actif. On decrit les differentes experiences effectuees jusqu'a ce jour. (auteur)

  8. Thermodynamic Aspects of Supercritical Fluids Processing: Applications of Polymers and Wastes Treatment Aspects thermodynamiques des procédés mettant en oeuvre des fluides supercritiques : applications aux traitements des polymères et des déchets

    Directory of Open Access Journals (Sweden)

    Beslin P.

    2006-11-01

    Full Text Available Supercritical fluid processes are of increasing interest for many fields : in supercritical fluid separation (petroleum-chemistry separation and purification, food industry and supercritical fluid chromatography (analytical and preparative separation, determination of physicochemical properties; as reaction media with continuously adjustable properties from gas to liquid (low-density polyethylene, waste destruction, polymer recycling; in geology and mineralogy (volcanoes, geothermal energy, hydrothermal synthesis; in particle, fibber and substrate formations (pharmaceuticals, explosives, coatings; in drying materials (gels. This paper presents the unusual physicochemical properties of supercritical fluids in relation to their engineering applications. After a short report of fundamental concepts of critical behavior in pure fluids, we develop in more details the tunable physicochemical properties of fluid in the supercritical domain. The second part of this paper describes the engineering applications of supercritical fluids relevant of chemical reactions and polymer processing. Each application presentation is divided in two parts : the first one recalls the basic concepts including general background, physicochemical properties and the second one develops the engineering applications relevant of the advocated domain. La mise en Suvre des fluides supercritiques est d'un intérêt croissant dans de nombreux domaines : pour la séparation (séparation et purification en pétrochimie, industrie alimentaire et la chromatographie par fluides supercritiques (séparation analytique et préparatoire, détermination des propriétés physicochimiques, comme milieux réactifs aux propriétés continûment ajustables allant du gaz au liquide (polyéthylène de faible densité, élimination des déchets, recyclage des polymères, en géologie et en minéralogie (volcanologie, énergie géothermique, synthèse hydrothermique, dans la formation des particules

  9. Porous Materials with Ultralow Optical Constants for Integrated Optical Device Applications

    Science.gov (United States)

    Chen, Hsuen-Li; Hsieh, Chung-I; Cheng, Chao-Chia; Chang, Chia-Pin; Hsu, Wen-Hau; Wang, Way-Seen; Liu, Po-Tsun

    2005-07-01

    Ultralow dielectric constant (polymers. We demonstrate two structures, ridge waveguides and large-angle Y-branch power splitters, composed of PPSZ and SU8 films to illustrate the use of low dielectric constant (K) cladding materials. The simulation results indicate that the PPSZ films provide better confinement of light. Experimentally, a large-angle Y-branch power splitter with PPSZ cladding can be used to guide waves with the large branching angle of 33.58°.

  10. PREPARATION DES COMPOSITES BENTONITE-DERIVES DE P4VP APPLICATION A LA RETENTION DES COLORANTS TEXTILE

    OpenAIRE

    GADIRI, ANISSA

    2014-01-01

    Les industries du textile rejettent de grandes quantités d‘eaux usées présentant un risque de toxicité. Il existe déjà des traitements tels que l‘adsorption sur charbon actif qui est un processus efficace mais onéreux et qui produit une boue constituant elle même une menace environnementale. Les argiles, les poly (4-vinylpyridine) et ses dérivées pourraient être des matériaux adsorbants alternatifs à la fois économiques et moins polluants. Beaucoup d‘auteurs ont étudié l‘adsorptio...

  11. Le management des risques de l'entreprise cadre de référence, techniques d'application

    CERN Document Server

    Committee of sponsoring organizations of the Treadway commission (Etats-Unis)

    2005-01-01

    Traduction en français du second rapport COSO, ce livre est un véritable outil pour les dirigeants confrontés à la complexité opérationnelle du management des risques. Adaptable à toutes les organisations, il constitue un socle méthodologique indispensable pour tous les professionnels de la gestion des risques ainsi que pour les auditeurs et consultants internes et externes. Il est également un manuel incontournable pour les étudiants et les enseignants. Dans un environnement économique fortement concurrentiel et en constante évolution, cet ouvrage ne s'intéresse pas uniquement à la gestion des risques mais contribue aussi à identifier puis exploiter les opportunités nouvelles, source d'avantages concurrentiels.

  12. Fabrication et applications des reseaux de Bragg ultra-longs

    Science.gov (United States)

    Gagne, Mathieu

    This thesis presents the principal accomplishments realized during the PhD project. The thesis is presented by publication format and is a collection of four published articles having fiber Bragg gratings as a central theme. First achieved in 1978, UV writing of fiber Bragg gratings is nowadays a common and mature technology being present in both industry and academia. The property of reflecting light guided by optical fibers lead to diverse applications in telecommunication, lasers as well as several types of sensors. The conventional fabrication technique is generally based on the use of generally expensive phase masks which determine the obtained characteristics of the fiber Bragg grating. The fiber being photosensitive at those wavelengths, a periodic pattern can be written into it. The maximal length, the period, the chirp, the index contrast and the apodisation are all characteristics that depend on the phase mask. The first objective of the research project is to be able to go beyond this strong dependance on the phase mask without deteriorating grating quality. This is what really sets apart the technique presented in this thesis from other long fiber Bragg grating fabrication techniques available in the literature. The fundamental approach to obtain ultra long fiber Bragg gratings of arbitrary profile is to replace the scheme of scanning a UV beam across a phase mask to expose a fixed fiber by a scheme where the UV beam and phase mask are fixed and where the fiber is moving instead. To obtain a periodic index variation, the interference pattern itself must be synchronized with the moving fiber. Two variations of this scheme were implanted: the first one using electro-optical phase modulator placed in each arm of a Talbot interferometer and the second one using a phase mask mounted on a piezo electric actuator. A new scheme that imparts fine movements of the interferometer is also implemented for the first time and showed to be essential to achieve high

  13. The theory of discrete barriers and its applications to linear boundary-value problems of the 'Dirichlet type'; Theorie des barrieres discretes et applications a des problemes lineaires elliptiques du ''type de dirichlet''

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-07-01

    This report gives a general presentation of barrier theory for finite difference operators, with its applications to some boundary value problems. (author) [French] Ce rapport est un expose synthetique de la theorie des barrieres pour les operateurs aux differences finies et ses applications a certaines classes de problemes lineaires elliptiques du 'type de Dirichlet'. (auteur)

  14. Fundamental study of ionization and dissociation processes caused by electron impact in aromatic molecules; application of the quasi-equilibrium theory to phenanthrene and to methylphenanthrenes; Etudes fondamentales des processus d'ionisation et de dissociation des molecules aromatiques par impact electronique et application de la theorie du quasi-equilibre au phenanthrene et aux methyl-phenanthrenes

    Energy Technology Data Exchange (ETDEWEB)

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

    1969-07-01

    The quasi-equilibrium theory has been applied only to the family of long chain aliphatic hydrocarbons. We have tried to extend it to phenanthrene and methyl-phenanthrenes molecules, i.e. to aromatic molecules possessing a great number of degrees of freedom. In a first part, we have attempted to give a method of interpretation of the ionization and dissociation processes of the phenanthrenic molecules. These preliminary experimental studies of the behaviour under electron impact of the compounds provide us a great wealth of information about important structural transformations of the molecular and fragment ions, and also about auto-ionization and excitation processes of the studied molecules. The experimental study of the metastable peaks has then confirmed the validity of the preceding dissociation processes, while it gave with more accuracy some thermodynamical values in connection with decomposition reactions. The three studies of the ionization, then dissociation processes and of the metastable peaks, represent the three phases of a general method of interpretation of the fragmentation in mass spectrometry. In order to give this method a theoretical basis, we have carried out the molecular diagrams of each of the studied, compounds, showing by this way the aid of Quantum Mechanics to the study of excited and ionic states. In a second part, we have carried out the mass spectra of the phenanthrene and methyl-phenanthrenes molecules by means of the rate constants expression given by ROSENSTOCK. We have proposed new methods of calculation of the frequency factors, for the aliphatic molecules as well as the aromatic ones. If the rather good agreement observed between the experimental and calculated results cannot be surely attributed to the validity of the theory, however it out-lines the interest presented by the application of this theory to large aromatic molecules. Furthermore, the results at which we arrived provide us with interesting information about the

  15. Description of an identification method of thermocouple time constant based on application of recursive numerical filtering to temperature fluctuation

    International Nuclear Information System (INIS)

    Bernardin, B.; Le Guillou, G.; Parcy, JP.

    1981-04-01

    Usual spectral methods, based on temperature fluctuation analysis, aiming at thermocouple time constant identification are using an equipment too much sophisticated for on-line application. It is shown that numerical filtering is optimal for this application, the equipment is simpler than for spectral methods and less samples of signals are needed for the same accuracy. The method is described and a parametric study was performed using a temperature noise simulator [fr

  16. Application of an Artificial Neural Network to the Prediction of OH Radical Reaction Rate Constants for Evaluating Global Warming Potential.

    Science.gov (United States)

    Allison, Thomas C

    2016-03-03

    Rate constants for reactions of chemical compounds with hydroxyl radical are a key quantity used in evaluating the global warming potential of a substance. Experimental determination of these rate constants is essential, but it can also be difficult and time-consuming to produce. High-level quantum chemistry predictions of the rate constant can suffer from the same issues. Therefore, it is valuable to devise estimation schemes that can give reasonable results on a variety of chemical compounds. In this article, the construction and training of an artificial neural network (ANN) for the prediction of rate constants at 298 K for reactions of hydroxyl radical with a diverse set of molecules is described. Input to the ANN consists of counts of the chemical bonds and bends present in the target molecule. The ANN is trained using 792 (•)OH reaction rate constants taken from the NIST Chemical Kinetics Database. The mean unsigned percent error (MUPE) for the training set is 12%, and the MUPE of the testing set is 51%. It is shown that the present methodology yields rate constants of reasonable accuracy for a diverse set of inputs. The results are compared to high-quality literature values and to another estimation scheme. This ANN methodology is expected to be of use in a wide range of applications for which (•)OH reaction rate constants are required. The model uses only information that can be gathered from a 2D representation of the molecule, making the present approach particularly appealing, especially for screening applications.

  17. Application of the variational method for calculation of neutron spectra and group constants - Master thesis

    International Nuclear Information System (INIS)

    Milosevic, M.

    1979-01-01

    One-dimensional variational method for cylindrical configuration was applied for calculating group constants, together with effects of elastic slowing down, anisotropic elastic scattering, inelastic scattering, heterogeneous resonance absorption with the aim to include the presence of a number of different isotopes and effects of neutron leakage from the reactor core. Neutron flux shape P 3 and adjoint function are proposed in order to enable calculation of smaller size reactors and inclusion of heterogeneity effects by cell calculations. Microscopic multigroup constants were prepared based on the UKNDL data library. Analytical-numerical approach was applied for solving the equations of the P 3 approximation to obtain neutron flux moments and adjoint functions

  18. Very high temperature measurements: Applications to nuclear reactor safety tests; Mesures des tres hautes temperatures: Applications a des essais de surete des reacteurs nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Parga, Clemente-Jose

    2013-09-27

    This PhD dissertation focuses on the improvement of very high temperature thermometry (1100 deg. C to 2480 deg. C), with special emphasis on the application to the field of nuclear reactor safety and severe accident research. Two main projects were undertaken to achieve this objective: - The development, testing and transposition of high-temperature fixed point (HTFP) metal-carbon eutectic cells, from metrology laboratory precision (±0.001 deg. C) to applied research with a reasonable degradation of uncertainties (±3-5 deg. C). - The corrosion study and metallurgical characterization of Type-C thermocouple (service temp. 2300 deg. C) prospective sheath material was undertaken to extend the survivability of TCs used for molten metallic/oxide corium thermometry (below 2000 deg. C)

  19. Efficient quantum-classical method for computing thermal rate constant of recombination: application to ozone formation.

    Science.gov (United States)

    Ivanov, Mikhail V; Babikov, Dmitri

    2012-05-14

    Efficient method is proposed for computing thermal rate constant of recombination reaction that proceeds according to the energy transfer mechanism, when an energized molecule is formed from reactants first, and is stabilized later by collision with quencher. The mixed quantum-classical theory for the collisional energy transfer and the ro-vibrational energy flow [M. Ivanov and D. Babikov, J. Chem. Phys. 134, 144107 (2011)] is employed to treat the dynamics of molecule + quencher collision. Efficiency is achieved by sampling simultaneously (i) the thermal collision energy, (ii) the impact parameter, and (iii) the incident direction of quencher, as well as (iv) the rotational state of energized molecule. This approach is applied to calculate third-order rate constant of the recombination reaction that forms the (16)O(18)O(16)O isotopomer of ozone. Comparison of the predicted rate vs. experimental result is presented.

  20. Optical absorption enhancement in silicon nanowire arrays with a large lattice constant for photovoltaic applications.

    Science.gov (United States)

    Lin, Chenxi; Povinelli, Michelle L

    2009-10-26

    In this paper, we use the transfer matrix method to calculate the optical absorptance of vertically-aligned silicon nanowire (SiNW) arrays. For fixed filling ratio, significant optical absorption enhancement occurs when the lattice constant is increased from 100 nm to 600 nm. The enhancement arises from an increase in field concentration within the nanowire as well as excitation of guided resonance modes. We quantify the absorption enhancement in terms of ultimate efficiency. Results show that an optimized SiNW array with lattice constant of 600 nm and wire diameter of 540 nm has a 72.4% higher ultimate efficiency than a Si thin film of equal thickness. The enhancement effect can be maintained over a large range of incidence angles.

  1. Periodic solutions of differential equations with a general piecewise constant argument and applications

    Directory of Open Access Journals (Sweden)

    Kuo-Shou Chiu

    2010-08-01

    Full Text Available In this paper we investigate the existence of the periodic solutions of a quasilinear differential equation with piecewise constant argument of generalized type. By using some fixed point theorems and some new analysis technique, sufficient conditions are obtained for the existence and uniqueness of periodic solutions of these systems. A new Gronwall type lemma is proved. Some examples concerning biological models as Lasota-Wazewska, Nicholson's blowflies and logistic models are treated.

  2. Data processing in gamma spectrometry. Application to the decay schemes study; Traitement des informations en spectrometrie gamma application a l'etude de schemas de desintegration

    Energy Technology Data Exchange (ETDEWEB)

    Boulanger, J.P. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires, departement d' electronique generale, service d' instrumentation nucleaire

    1968-06-01

    The purpose of this thesis is the processing of the data issued from a gamma spectrometer, and its applications to the decay schemes study. The mathematical analysis of the full energy peaks, in connection with the very good resolution of semi-conductor detectors, leads to a very accurate determination of the energies. The resolution of complex spectra by the least squares method, completed by a spectra generating process, allows the calculation of branching ratios. Then, the handling of the two dimensional experiments permits the coincidence exam. For each of these methods, the calculation principle, then the systematics tests realized in order to prove their validity and to determine their application ranges as well as some experimental results appropriate to illustrate their possibilities, are presented. The energies of some nuclides, frequently used as standards have been thus measured and the decay schemes of {sup 134}Cs and {sup 110m}Ag determined precisely. (author) [French] Cette these est consacree aux methodes de traitement des informations issues d'un spectrometre {gamma}, et a leur application a l'etude des schemas de desintegration: l'analyse mathematique des pics d'absorption totale, conjuguee avec l'excellent pouvoir de resolution des detecteurs semi-conducteurs, conduit a une determination tres precise des energies. La decomposition des spectres complexes par la methode des moindres carres, completee par un procede de generation de spectres, autorise le calcul des rapports de branchement. Enfin le depouillement des experiences biparametriques permet l'examen des coincidences. Pour chacune de ces methodes, on expose le principe des calculs et les essais systematiques effectues afin d'eprouver leur validite et de definir leurs domaines d'application, ainsi que quelques resultats experimentaux propres a illustrer leurs possibilites. Les energies de quelques isotopes utilises couramment comme etalons ont ainsi ete

  3. S3 HMBC: Spin-State-Selective HMBC for accurate measurement of homonuclear coupling constants. Application to strychnine yielding thirteen hitherto unreported JHH

    DEFF Research Database (Denmark)

    Kjaerulff, Louise; Benie, Andrew J.; Hoeck, Casper

    2016-01-01

    A novel method, Spin-State-Selective (S3) HMBC, for accurate measurement of homonuclear coupling constants is introduced. As characteristic for S3 techniques, S3 HMBC yields independent subspectra corresponding to particular passive spin states and thus allows determination of coupling constants ...... are demonstrated by an application to strychnine where thirteen JHH coupling constants not previously reported could be measured....

  4. Application of the verona coding definitions of emotional sequences (VR-CoDES) on a pediatric data set.

    Science.gov (United States)

    Vatne, Torun M; Finset, Arnstein; Ørnes, Knut; Ruland, Cornelia M

    2010-09-01

    Adult patients present concerns as defined in the Verona Coding Definitions of Emotional Sequences (VR-CoDES), but we do not know how children express their concerns during medical consultations. This study aimed to evaluate the applicability of VR-CoDES to pediatric oncology consultations. Twenty-eight pediatric consultations were coded with the Verona Coding Definitions of Emotional Sequences (VR-CoDES), and the material was also qualitatively analyzed for descriptive purposes. Five consultations were randomly selected for reliability testing and descriptive statistics were computed. Perfect inter-rater reliability for concerns and moderate reliability for cues were obtained. Cues and/or concerns were present in over half of the consultations. Cues were more frequent than concerns, with the majority of cues being verbal hints to hidden concerns or non-verbal cues. Intensity of expressions, limitations in vocabulary, commonality of statements, and complexity of the setting complicated the use of VR-CoDES. Child-specific cues; use of the imperative, cues about past experiences, and use of onomatopoeia were observed. Children with cancer express concerns during medical consultations. VR-CoDES is a reliable tool for coding concerns in pediatric data sets. For future applications in pediatric settings an appendix should be developed to incorporate the child-specific traits. Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.

  5. La gouvernance des risques naturels et la problematique des ...

    African Journals Online (AJOL)

    Depuis quelques années, la gouvernance des risques naturels dus aux inondations remet en cause les processus de mise en oeuvre des politiques urbaines et la qualité de la structure des aménagements dans les grandes villes du Golfe de Guinée. La perception de la gouvernance et l'application des politiques de ...

  6. Bloch–Siegert shift in application to the astrophysical determination of the fundamental constants variation

    International Nuclear Information System (INIS)

    Solovyev, Dmitry

    2013-01-01

    We have evaluated the Bloch–Siegert shift for the different values of magnetic field's strengths defined at astrophysical conditions, i.e. when the stars with the strong surface magnetic fields are taken as a powerful pumping source of radiation. It is found that the additional shift of resonant frequency should be taken into account in the search for the time variation of the fundamental constants. The main conclusion is that the influence of the electromagnetic field should be considered carefully in each special case of the corresponding frequency determination

  7. Pre-stressed rubber material constant estimation for resilient wheel application

    Czech Academy of Sciences Publication Activity Database

    Šulc, Petr; Pešek, Luděk; Bula, Vítězslav; Cibulka, Jan; Boháč, T.; Tašek, H.

    2017-01-01

    Roč. 113, November (2017), s. 76-83 ISSN 0965-9978 Institutional support: RVO:61388998 Keywords : identification * rubber * viscous-elastic constant * pre-press * dynamic loading Subject RIV: BI - Acoustics OBOR OECD: Applied mechanics Impact factor: 3.000, year: 2016 https://ac.els-cdn.com/S0965997816301922/1-s2.0-S0965997816301922-main. pdf ?_tid=f45f931e-b303-11e7-bccc-00000aab0f01&acdnat=1508221702_e80a18f480ff855769f5eeb99d492c24

  8. New applications of radio-isotopes in France; Quelques nouvelles applications des radioelements en France

    Energy Technology Data Exchange (ETDEWEB)

    Leveque, P; Hours, R; Martinelli, P; May, S; Sandier, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Brillant, J [Societe Soletanche (France)

    1958-07-01

    By measuring the transmission of a flat beam of thermal neutrons, the moisture content of a parallelepiped shaped soil sample can be measured to {+-} 4 per cent and the moisture gradient along the longitudinal axis determined. The method permits the determination of chemically bound water and the measurement of diffusion coefficients of water into low hydrogenated materials. By measuring the intensity of fluorescence excited by 13 radiation it is possible to determine the thickness of metal coatings of less than 20 p. for metals of atomic number less than 40. This method has been applied to chromium, manganese, iron, cobalt, nickel, copper and zinc. By using a suitable metal filter it is possible to measure coating thicknesses of metals differing by only one atomic number from the supporting material. By employing labeled cement it is possible to determine the extent or movement of cement grout used for soil stabilization and waterproofing. The kinetic of ion exchange of different ultramarines in aqueous solutions were studied by tracing the movement of labeled ions in the solution or in the exchanger. Values of the diffusion coefficients and activation energies were determined from the exchange studies. (author)Fren. [French] La mesure de la transmission d'un faisceau plat de neutrons thermiques permet d'evaluer a {+-} 4 pour cent l'humidite d'un echantillon parallelepipedique de sol et d'en effectuer une exploration longitudinale systematique. La methode peut s'appliquer a la determination de l'eau de constitution ainsi qu'a la mesure des coefficients de diffusion de l'eau a travers des substances faiblement hydrogenees. En utilisant la fluorescence X excitee au moyen de rayons {beta} il est possible de mesurer des epaisseurs (< 20) de depots metalliques de faible numero atomique (Z < 40). Ces essais ont porte sur: Cr, Mn, Fe, Co, Ni, Cu et Zn. L'emploi d'ecrans metalliques convenables permet de mesurer l'epaisseur d'un metal dont le numero atomique differe de 1

  9. Diffraction des neutrons : principe, dispositifs expérimentaux et applications

    Science.gov (United States)

    Muller, C.

    2003-02-01

    La diffraction de neutrons, sur monocristal ou sur échantillon polycristallin (ou poudre), est une technique très largement utilisée, en science des matériaux comme en biologie, lorsque l'on souhaite déterminer la structure cristalline d'un composé ou d'une molécule. Toutefois, le degré de précision de la détermination structurale est très corrélé au choix de l'instrument utilisé. Il s'en suit que la question “comment choisir l'instrument le mieux adapté au composé et à la problématique ?" apparaît comme fondamentale. L'objectif de ce cours est de tenter de répondre à cette question en décrivant brièvement les caractéristiques instrumentales de différents diffractomètres, en exposant les avantages spécifiques des expériences de diffraction de neutrons et en donnant quelques exemples d'application.

  10. Rock-Eval 6 Applications in Hydrocarbon Exploration, Production, and Soil Contamination Studies Les applications de Rock-Eval 6 dans l'exploration et la production des hydrocarbures, et dans les études de contamination des sols

    Directory of Open Access Journals (Sweden)

    Lafargue E.

    2006-12-01

    Full Text Available Successful petroleum exploration relies on detailed analysis of the petroleum system in a given area. Identification of potential source rocks, their maturity and kinetic parameters, and their regional distribution are best accomplished by rapid screening of rock samples (cores and/or cuttings using the Rock-Eval apparatus. The technique has been routinely used for about fifteen years and has become a standard tool for hydrocarbon exploration. This paper describes how the new functions of the latest version of Rock-Eval (Rock-Eval 6 have expanded applications of the method in petroleum geoscience. Examples of new applications are illustrated for source rock characterization, reservoir geochemistry, and environmental studies, including quantification. Le succès d'une exploration pétrolière repose sur l'analyse détaillée du système pétrolier dans une zone donnée. L'identification des roches mères potentielles, la détermination de leur maturité, de leurs paramètres cinétiques et de leur répartition sont réalisées au mieux à partir d'examens rapides d'échantillons de roches (carottes ou déblais au moyen de la pyrolyse Rock-Eval. Cette technique a été utilisée en routine pendant une quinzaine d'années et elle est devenue un outil standard pour l'exploration des hydrocarbures. Cet article décrit comment les nouvelles fonctionnalités de la dernière version de l'appareil Rock-Eval (Rock-Eval 6 ont permis une expansion des applications de la méthode en géosciences pétrolières. Des exemples d'applications nouvelles sont illustrés dans les domaines de la caractérisation des roches mères, de la géochimie de réservoir et des études environnementales incluant la quantification et la description des hydrocarbures dans des sols contaminés.

  11. Developmental Times of Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae) at Constant Temperatures and Applications in Forensic Entomology.

    Science.gov (United States)

    Yang, Yong-Qiang; Li, Xue-Bo; Shao, Ru-Yue; Lyu, Zhou; Li, Hong-Wei; Li, Gen-Ping; Xu, Lyu-Zi; Wan, Li-Hua

    2016-09-01

    The characteristic life stages of infesting blowflies (Calliphoridae) such as Chrysomya megacephala (Fabricius) are powerful evidence for estimating the death time of a corpse, but an established reference of developmental times for local blowfly species is required. We determined the developmental rates of C. megacephala from southwest China at seven constant temperatures (16-34°C). Isomegalen and isomorphen diagrams were constructed based on the larval length and time for each developmental event (first ecdysis, second ecdysis, wandering, pupariation, and eclosion), at each temperature. A thermal summation model was constructed by estimating the developmental threshold temperature D0 and the thermal summation constant K. The thermal summation model indicated that, for complete development from egg hatching to eclosion, D0 = 9.07 ± 0.54°C and K = 3991.07 ± 187.26 h °C. This reference can increase the accuracy of estimations of postmortem intervals in China by predicting the growth of C. megacephala. © 2016 American Academy of Forensic Sciences.

  12. Experimental study of heat transfer for parallel flow in tube bundles with constant heat flux and for medium Prandtl numbers; Etude experimentale du transfert de chaleur dans des faisceaux tubulaires en ecoulement parallele pour une densite de flux thermique constante dans le domaine des nombres de Prandtl moyens

    Energy Technology Data Exchange (ETDEWEB)

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

    1968-06-01

    The heat transfer parameters were determined experimentally in electrically heated tube bundles for turbulent flow parallel to the axis. The tubes were arranged in a pattern of equilateral triangles. The ratios of the distance between the axes of the tubes to their external diameter were 1.60 and 1.25 in the two test sections studied. The experiments were carried out with distilled water and with a mixture of 60 per cent ethylene glycol and 40 per cent water. The values obtained for the Prandtl numbers in this way fell within the range from 2.3 to 18. The Reynolds numbers were varied between 10{sup 4} and 2.10{sup 5}. The relation between the mean heat transfer coefficients and the friction factor in the tube bundles was found from the experiments as: Nu = [Re Pr {zeta}/8]/[1+{radical}({zeta}/8) 8.8 (Pr-1.3) Pr{sup -0.22}]. The experimentally determined mean Nusselt numbers were also given by the following function: Nu = (0.0122 + 0.00245 p/d) Re{sup 0.86} Pr{sup 0.4}, with a maximum deviation of {+-}4 per cent. For certain local Nusselt numbers, deviations of up to 20 per cent with respect to the relations given were observed. (author) [French] Dans des faisceaux tubulaires a chauffage electrique parcourus par un ecoulement turbulent parallele a l'axe, on a determine experimentalement les parametres du transfert de chaleur. Les centres des sections droites des tubes etaient des sommets de triangles equilateraux. Les rapports de la distance a l'axe des tubes et leur diametre exterieur dans les deux veines de mesure etudiees etaient de 1.60 et 1.25. Des essais furent effectues avec de l'eau distillee ainsi qu'avec un melange de 60 pour cent de glycol ethylenique et 40 pour cent d'eau. Les valeurs des nombres de Prandtl obtenues ainsi etaient situees entre 2.3 a 18. On a fait varier les nombres de Reynolds entre 10{sup 4} et 2.10{sup 5}. La relation entre les nombres caracteristiques de transfert de chaleur moyens et la perte de charge dans les faisceaux tabulaires

  13. Le tritium de l'écosystème à l'homme : Etude des mécanismes et des constantes qui régissent les équilibres et les différentes voies de transfert

    OpenAIRE

    Le Goff , Pierre ,

    2013-01-01

    Tritium is the radioactive isotope of hydrogen. It can be integrated in most of the biological molecules.Even if its radiotoxicity is weak, effects of tritium could be increased if it can concentrate in somecritical compartments of beings. In order to better understand the tritium circulation in the environment and highlight constants of transfer between compartments, we have studied the tritiationof different agricultural matrices chronically exposed to tritium. The first step of our study i...

  14. Le tritium de l'Ecosystème à l'Homme - Etude des mécanismes et des constantes qui régissent les équilibres et différentes voies de transfert

    OpenAIRE

    Le Goff , Pierre

    2013-01-01

    Tritium is the radioactive isotope of hydrogen. It can be integrated in most of the biological molecules. Even if its radiotoxicity is weak, effects of tritium could be increased if it can concentrate in some critical compartments of beings. In order to better understand the tritium circulation in the environment and highlight constants of transfer between compartments, we have studied the tritiation of different agricultural matrices chronically exposed to tritium. The first step of our stud...

  15. Solid-state fast voltage compensator for pulsed power applications requiring constant AC power consumption

    CERN Document Server

    Magallanes, Francisco Cabaleiro; Viarouge, Philippe; Cros, Jérôme

    2015-01-01

    This paper proposes a novel topological solution for pulsed power converters based on capacitor-discharge topologies, integrating a Fast Voltage Compensator which allows an operation at constant power consumption from the utility grid. This solution has been retained as a possible candidate for the CLIC project under study at CERN, which requires more than a thousand synchronously-operated klystron modulators producing a total pulsed power of almost 40 GW. The proposed Fast Voltage Compensator is integrated in the modulator such that it only has to treat the capacitor charger current and a fraction of the charging voltage, meaning that its dimensioning power and cost are minimized. This topology can be used to improve the AC power quality of any pulsed converters based on capacitor-discharge concept. A prototype has been built and exploited to validate the operating principle and demonstrate the benefits of the proposed solution.

  16. Wave Separation. Part Two: Applications La séparation des ondes. Deuxième partie : applications

    Directory of Open Access Journals (Sweden)

    Glangeaud F.

    2006-11-01

    qui doit être de plus grande amplitude. Le filtrage est effectué sans effet de bord et les variations d'amplitude de l'onde sont préservées. Il permet de séparer les données en un espace signal et un espace bruit. Le filtre SMF (matrice spectrale est coûteux en temps de calcul. Il fait l'hypothèse que l'onde est localement stable. Il ne nécessite pas la mise à plat des données. Il permet de séparer des ondes très voisines sans faire appel à des hypothèses a priori fortes. Il donne une mesure des écarts de temps. Il donne une mesure des variations de spectre d'amplitude et de phase lors de la propagation bien supérieure à celle fournie par la méthode de Wiener puisqu'il opère sur l'ensemble des traces. Il permet également de séparer les données en un espace signal et un espace bruit. La méthode paramétrique est la plus coûteuse en temps. Elle est simple à mettre en oeuvre et ne nécessite ni mise à plat ni préparation de données. Elle extrait les ondes en fonction des paramètres retenus, notamment les écarts de temps. Elle est particulièrement recommandée en profil sismique déporté où la lenteur des ondes montantes n'est pas connue. Elle est robuste vis-à-vis de quelques paramètres d'entrée si le bruit est faible par le rapport au signal à extraire. Les multiples applications à des données réelles ont illustré l'efficacité de ces techniques de séparation d'ondes. Par contre, l'application à un nouveau type de données nécessite souvent un contrôle des performances pour choisir la meilleure méthode.

  17. Biomedical applications of radionuclide generators with equal decay constants for parent and daughter

    International Nuclear Information System (INIS)

    Taylor, D.M.

    1976-01-01

    Reference is made to an article by Spencer and Hosain (Int. J. Appl. Radiat. Isotopes; 27:57 (1976)) on the theoretical aspects of radionuclide generator systems in which the parent and daughter nuclides have equal decay constants in which it was suggested that 'it would be possible to use an appropriate chemical compound of a parent and introduce it in a biological system to study the behaviour of the daughter element'. It is here pointed out that this suggestion assumes that in any biological system the daughter radionuclide produced by the decay of the parent nuclide in vivo will readily enter the general 'metabolic' pool of the daughter element. However studies are cited which have shown that virtually all the daughter radionuclide in many such systems remain within the skeleton and thus it is asserted that the assumption that a daughter radionuclide produced by the decay of a parent nuclide in vivo provides a true tracer for the behaviour of the daughter element is not generally valid, and considerable caution would have to be used in the interpretation of results obtained by this type of study. In a reply, the original authors say that the point made is germane but that the concept was well known to them and hence the use of the expression 'an appropriate chemical compound of a parent...' in their original paper. (U.K.)

  18. Application of the constant rate of pressure change method to improve jet pump performance

    International Nuclear Information System (INIS)

    Long, X P; Yang, X L

    2012-01-01

    This paper adopts a new method named the constant rate of pressure change (CRPC) to improve the jet pump performance. The main contribution of this method is that the diffuser generates uniform pressure gradient. The performance of the jet pump with new diffusers designed by the CRPC method, obtained by CFD methods, was compared with that of the jet pump with traditional conical diffusers. It is found that the CRPC diffuser produces a linear pressure increase indeed. The higher friction loss and the separation decrease the CRPC diffuser efficiency and then lower the pump efficiency. The pump with shorter throats has higher efficiency at small flow ratio while its efficiency is lower than the original pump at lager flow ratio and the peak efficiency of the pumps with the throat length of 5-6 Dt is higher than that of the pumps with other throat length. When the throat length is less than 4 Dt, the CRPC diffuser efficiency is higher than the conical diffuser. The CRPC method could also be used to design the nozzle and other situations needing the pressure change gradually.

  19. Analytic solution of vector model kinetic equations with constant kernel and their applications

    International Nuclear Information System (INIS)

    Latyshev, A.V.

    1993-01-01

    For the first time exact solutions the heif-space boundary value problems for model kinetic equations is obtained. Here x > 0, μ is an element of (-∞, 0) union (0, +∞), Σ = diag {σ 1 , σ 2 }, C = [c ij ] - 2 x 2-matrix, Ψ (x, μ) is vector-column with elements ψ 1 and ψ 2 . Exact solution of the diffusion slip flow of the binary gas mixture as a application for the model Boltzmann equation with collision operator in the McCormack's form is found. 18 refs

  20. Application of mathematical methods to the investigation of uranium deposits; Application des methodes mathematiques a l'etude des gisements d'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Formery, P; Ziegler, V [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    It may be considered approximately that grades, widths and accumulations (grade-width products), in french uranium deposits are distributed according to a lognormal law. This property associated to KRIGE'S and de WIGE'S formulae make a powerful tool in ore deposits surveys. The correlation between radioactivities and grades is realized, in logarithmic coordinates, through a straight line the properties of which are analysed in the paper. MATHERON'S recent works, in association with data of classical statistics and the above mentioned formulae make possible to complete the ore reserves evaluation by computing the accuracy. Statistical methods applied to ore deposits have given birth to a parameter which is as important as the mean grade for characterisation of deposits: the absolute dispersion. (author) [French] On peut considerer en premiere approximation que les teneurs, les puissances et les accumulations se distribuent dans les gisements fran is d'uranium suivant une loi log normale. Cette propriete, associee aux hypotheses de De WIGE et de KRIGE, constitue un puissant instrument d'etude des gisements. La correspondance des radioactivites et des teneurs s'effectue, en coordonnees bilogarithmiques, par une droite dont on etudie les proprietes. Grace aux travaux recents de MATHERON, associes aux donnees de la statistique classique ainsi qu'aux hypotheses enumerees plus haut, il est possible de completer le calcul des reserves d'un gisement par une evaluation de l'erreur commise. Les methodes statistiques ont fait apparaitre un parametre aussi important pour caracteriser un gisement, que la teneur moyenne: la dispersion absolue. (auteur)

  1. Study of formation constant of molybdophosphate and it's application in the product of xenotime sand, tooth and bone

    International Nuclear Information System (INIS)

    Samin; Lahagu, F.; Basuki, K. T.; Ernawati, F.

    1996-01-01

    The formation constant of molybdophosphate complex and it's application in the product of xenotime sand, tooth and bone have been studied by spectrophotometric method. The molybdophosphate complex were formed from reaction between phosphate and molybdate on several of pH in the strong acid condition (pH = 0.45 - 0.71) and several of phosphate mole fraction (0.01 - 0.08). The several of complex formation reactions were determined by matrix disintegration technique. Molybdophosphate complex were founded three forms i.e. (P 2 Mo 18 O 62 ) 6- or 9 MPA, (PMo 11 O 39 ) 7- or 11 MPA and (PMo 12 O 40 ) 3- or 12 MPA. The formation constant of (PMo 12 O 40 ) 3- complex was found β = 10 46.95 ± 10 3.7 , while for (P 2 Mo 18 O 62 ) 6- and (PMo 11 O 39 ) 7- were not detected. The application in samples were found the concentration of P in product of xenotime sand : 5.37±0.08 μg/ml, in canine-tooth: 10.40 - 19.49 % in cutting-tooth : 11.08 - 18.05 % and in bone 10.94 - 14.29 %. (author)

  2. Applications of radionuclides in industry; Applications des radioelements a l'industrie

    Energy Technology Data Exchange (ETDEWEB)

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

    1955-07-01

    After a brief recall of a few concepts (mass number, charge and beams properties) and the description of used detectors (ionization chamber, Geiger-Mueller counter, scintillation counters), some radionuclides applications are described. In a first part, the well-developed applications are presented in three distinct groups: continuous applications such as {beta} and {gamma} gauges (determination hydrogen content of an hydrocarbon and content of an emulsion; discharge of static electricity), discontinuous applications such as radiography and autoradiography, wear or manufacture problems (distribution of a fungicide on tobacco) and finally, applications in research laboratories such as diffusion, exchange and solubility. It also describes the applications which are still in development such as the action of beams on matter (reticulation and degradation of polymers, monomers polymerisation, cold sterilization). In conclusion, few advices on the opportunity of such applications and the choice of the radionuclides are given. (M.P.)

  3. Détermination des radionucléides dans le repas. Application aux ...

    African Journals Online (AJOL)

    40 sont des radionucléides naturels présents dans les riz, les tubercules, les bouillons et les friandises. Dans les quatre échantillons des repas du Riz analysés, les activités spécifiques en potassium-40 sont différentes. Cette différence est ...

  4. Nuclear constants

    International Nuclear Information System (INIS)

    Foos, J.

    1999-01-01

    This paper is written in two tables. The first one describes the different particles (bosons and fermions). The second one gives the isotopes nuclear constants of the different elements, for Z = 1 to 56. (A.L.B.)

  5. Nuclear constants

    International Nuclear Information System (INIS)

    Foos, J.

    2000-01-01

    This paper is written in two tables. The first one describes the different particles (bosons and fermions). The second one gives the isotopes nuclear constants of the different elements, for Z = 56 to 68. (A.L.B.)

  6. Nuclear constants

    International Nuclear Information System (INIS)

    Foos, J.

    1998-01-01

    This paper is made of two tables. The first table describes the different particles (bosons and fermions) while the second one gives the nuclear constants of isotopes from the different elements with Z = 1 to 25. (J.S.)

  7. Nuclear constants

    International Nuclear Information System (INIS)

    Foos, J.

    1999-01-01

    This paper is written in two tables. The first one describes the different particles (bosons and fermions). The second one gives the isotopes nuclear constants of the different elements, for Z = 56 to 68. (A.L.B.)

  8. Stabilized power constant alimentation; Alimentation regulee a puissance constante

    Energy Technology Data Exchange (ETDEWEB)

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

    1968-06-01

    The study and realization of a stabilized power alimentation variable from 5 to 100 watts are described. In order to realize a constant power drift of Lithium compensated diodes, we have searched a 1 per cent precision of regulation and a response time minus than 1 sec. Recent components like Hall multiplicator and integrated amplifiers give this possibility and it is easy to use permutable circuits. (author) [French] On decrit l'etude et la realisation d'une alimentation a puissance constante reglable dans une gamme de 5 a 100 watts. Prevue pour le drift a puissance constante des diodes compensees au lithium, l'etude a ete menee en vue d'obtenir une precision de regulation de 1 pour cent et un temps de reponse inferieur a la seconde. Des systemes recents tels que multiplicateurs a effet Hall et circuits integres ont permis d'atteindre ce but tout en facilitant l'emploi de modules interchangeables. (auteur)

  9. Development of mercury porosimeter. Application to nuclear graphite studies (1961); Mise au point d'un porosimetre a mercure. Application a l'etude des graphites nucleaires (1961)

    Energy Technology Data Exchange (ETDEWEB)

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

    1961-07-01

    A mercury porosimeter, model IFP-CEA, has been developed for application to nuclear graphite studies. The apparatus is based on the capillary depression phenomenon. The relationship between the radius of a pore and the pressure at which mercury fills it is pr = -2 {sigma} cos {theta} ( {sigma} is the surface tension, {theta} the angle of contact of the mercury). After some theoretical consideration, the apparatus is described. The mercury pressure is increased step-wise from 0 to 1000 kg/cm{sup 2} thus yielding the complete distribution of pores from 92 {mu} to 75 A. Results are, then presented concerning nuclear graphites which show the evolution of the porous structure under the effect of bitumen impregnation. In general, the volume of the large pores decreases while that of the small pores increases. The structure of impregnated products appears to depend to a certain extent on that of the starting materials. It has also been possible to study other products with this porosimeter; the range of measurements possible is such that it may be used for the study of the majority of porous materials. (authors) [French] Un porosimetre a mercure modele IFP-CEA a ete mis au point en vue de son application a l'etude de graphites nucleaires. Le fonctionnement de l'appareil repose sur le phenomene de depression capillaire. On etablit la relation existant entre le rayon r d'un pore et la pression p pour laquelle le mercure peut y penetrer: pr = -2 {sigma} cos {theta} ( {sigma} tension superficielle, {theta} angle de contact du mercure). Apres quelques considerations theoriques, l'appareil utilise est decrit. Il permet de faire varier par palier la pression du mercure entre 0 et 1000 kg/cm{sup 2} et d'etablir ainsi la distribution complete des rayons de pores compris entre 92 {mu} et 75 A. Les resultats d'une etude faite sur des graphites nucleaires sont alors presentes faisant apparaitre l'evolution de la structure poreuse sous l'effet des impregnations au brai. D'une facon

  10. Caractérisation intégrée du vignoble alsacien : aspects méthodologiques et application à l'étude des composantes naturelles des principaux terroirs

    Directory of Open Access Journals (Sweden)

    Éric Lebon

    1993-12-01

    Full Text Available Parmi les méthodes utilisées en vue de la définition des potentialités viticoles, l'approche intégrée des terroirs fondée sur la notion de séquence écogéopédologique développée en Moyenne Vallée de la Loire par l'INRA d'Angers s'est révélée particulièrement performante. Son application à la caractérisation du vignoble d'Alsace, fondamentalement différent sur le plan de sa structure géologique, nécessite un certain nombre d'aménagements méthodologiques liés à une variabilité paysagère marquée. Ainsi, une typologie des paysages s'appuyant sur des paramètres tels que l'ouverture du paysage, la répartition et l'orientation des masques est proposée. Elle vient compléter les descripteurs stationnels classiques (altitude, pente et exposition. Le concept de séquence écogéopédologique reste pertinent dans ce contexte moyennant l'adjonction du paramètre exposition, dans le cas des terroirs sur versants. Dans cette optique, les caractéristiques des composantes naturelles des grands types de terroirs alsaciens sont présentées à partir de l'étude de cas concrets.

  11. Applications des techniques de diffusion de la lumière, des rayons X et des neutrons a l'étude des systèmes colloïdaux. Troisième partie : caractérisation des microémulsions et des composés solides. Étude de différents systèmes d'intérêt industriel Application of Light, X-Ray and Neutron Diffusion Techniques to the Study of Colloidal Systems. Part Three: Microemulsions, Solid Materials, Liquids and Miscellaneous Systems with Industrial Uses

    Directory of Open Access Journals (Sweden)

    Espinat D.

    2006-11-01

    Full Text Available Cette troisième partie clôt une revue bibliographique concernant la caractérisation des systèmes colloïdaux par les techniques de diffusion (lumière, rayons X, neutrons (Rev. Inst. Franç. du Pétrole, Vol. 45, No 6, novembre-décembre 1990. Nous poursuivrons cette présentation en nous intéressant aux microémulsions. Après la présentation des informations que l'on peut obtenir sur les systèmes polymériques, les solutions micellaires ou les systèmes fractals, qui ont fait l'objet de multiples travaux, nous reviendrons sur les applications plus restreintes à des systèmes colloïdaux parfois moins bien définis et d'origine industrielle, telles les fractions lourdes des pétroles, les asphaltènes ou encore les additifs de lubrification. Les possibilités de la diffusion des rayons X et des neutrons à l'étude de matériaux solides seront présentées à travers la caractérisation des solides poreux et en particulier des catalyseurs. Nous terminerons cette présentation par les liquides purs ou les mélanges; les techniques de diffusion ont contribué fortement à la description des structures des phases liquides. This article is the second one (the first one was published in Revue de l'Institut Français du Pétrole No. 6, November-December 1990 concerning the application of techniques of light scattering, X rays and neutrons to the analysis of colloidal systems and more specifically to the theoretical description of the three methods. The aim of this second part is to make a nonexhaustive description of several fields of applications. A special effort is made to describe the potential of these methods for characterizing colloidal or divided systems encountered in a great many activities involving the petroleum industry. The first part of this article takes up polymer and colloidal solutions. Particular attention is paid to the importance of scattering techniques for characterizing polymers in solution and micellar solutions. A

  12. Are fundamental constants really constant

    International Nuclear Information System (INIS)

    Norman, E.B.

    1986-01-01

    Reasons for suspecting that fundamental constants might change with time are reviewed. Possible consequences of such variations are examined. The present status of experimental tests of these ideas is discussed

  13. Other applications of neutron beams in material sciences; Autres utilisations des faisceaux de neutrons en science des materiaux

    Energy Technology Data Exchange (ETDEWEB)

    Novion, C.H. de

    1997-12-31

    The various applications of neutron beams are reviewed. The different mechanisms involved in neutron interaction with matter are explained. We notice that generally neutron radiation effects are unfavorable but can be turned into efficient tools to add new structures or properties to materials, silicon doping is an example. The basis principles of neutron activation analysis and neutron radiography are described. (A.C.)

  14. New Recursive Representations for the Favard Constants with Application to Multiple Singular Integrals and Summation of Series

    Directory of Open Access Journals (Sweden)

    Snezhana Georgieva Gocheva-Ilieva

    2013-01-01

    Full Text Available There are obtained integral form and recurrence representations for some Fourier series and connected with them Favard constants. The method is based on preliminary integration of Fourier series which permits to establish general recursion formulas for Favard constants. This gives the opportunity for effective summation of infinite series and calculation of some classes of multiple singular integrals by the Favard constants.

  15. Spectral Matrix Filtering Applied to Vsp Processing Application du filtrage matriciel au traitement des profils sismiques verticaux

    Directory of Open Access Journals (Sweden)

    Glangeaud F.

    2006-11-01

    données et de séparer ces signaux. Nous montrons que les signaux peuvent être automatiquement séparés sans connaissance a priori sur leurs vitesses apparentes, en fonction du produit scalaire (calculé dans le domaine fréquentiel et de l'amplitude relative des signaux. Nous montrons des exemples d'application sur des données de sismique de puits. Le filtrage matriciel est effectué dans le domaine fréquentiel en utilisant la matrice spectrale construite à l'aide des intercorrélations des différents enregistrements constituant les données à traiter. Les méthodes d'estimation de la matrice spectrale sont des méthodes de moyenne : moyenne en fréquence (méthode du périodogramme lissé et/ou moyenne en distance (lissage réalisé le long des diagonales de la matrice spectrale. Le lissage en fréquence est obtenu par l'intermédiaire d'une fonction de pondération (par exemple fenêtre de Hanning élevée à une puissance donnée appliquée à chaque corrélation. Les moyennes sont utilisées pour décorréler les signaux et de ce fait favoriser la séparation. Une fois correctement estimée, la matrice spectrale est diagonalisée sur toutes les fréquences du spectre moyenné, et décomposée selon ses vecteurs propres qui sont orthogonaux entre eux et normalisés. Chaque vecteur propre a une valeur propre associée qui représente la répartition d'énergie en fonction de la fréquence du modèle lié au vecteur propre. Le filtrage est réalisé par projection des données sur les différents vecteurs propres issus de la matrice spectrale. Il est à noter cependant que la séparation des différents signaux (projection sur vecteur propre n'est réalisée en terme d'indicatrice sismique que si les événements sismiques sont naturellement orthogonaux et alignés sur les vecteurs propres. Glangeaud et al (1989 ont étudié l'influence des amplitudes relatives et du produit scalaire de deux ondes. Si la vitesse apparente d'une onde est connue, cette derni

  16. Analytical representation of time correlation functions and application to relaxation problems; Representation analytique des fonctions de correlation temporelle et application a des problemes de relaxation

    Energy Technology Data Exchange (ETDEWEB)

    Dupuis, M [Commissariat a l' Energie Atomique, 91 - Saclay (France). Centre d' Etudes Nucleaires, departement de physico-chimie, services des isotopes stables

    1971-07-01

    Two analytical representations of the Laplace transform of the time autocorrelation of a dynamical variable, namely the moment expansion and Mori's continued fraction expansion, are investigated from the point of view of structure and convergence properties, and the relation between them is established. The general theory is applied first to a dynamical model exactly solvable, the isotopic impurity in a linear chain of coupled harmonic oscillators, and then to two stochastic models recently introduced by Gordon for the rotational diffusion of molecules. In the latter case, the continued fraction expansion yields simple analytical expressions for the infrared absorption band shapes, showing that these models contain all the features of observed shapes in compressed gases, liquids and solutions. (author) [French] Deux representations analytiques de la transformee de Laplace de la fonction d'autocorrelation temporelle d'une variable dynamique, le developpement en moments et le developpement en fraction continue recemment introduit par Mori, sont etudiees du point de vue de leurs proprietes de structure et de convergence, en meme temps que la relation qui existe entre elles est etablie. La theorie generale est appliquee, d'une part, a un modele dynamique exactement soluble, celui d'une particule isotopique dans une chaine lineaire d'oscillateurs harmoniques couples, et, d'autre part, a deux modeles stochastiques recemment proposes par Gordon pour la diffusion rotationnelle des molecules. Dans ce dernier cas, la voie de la fraction continue fournit des expressions analytiques simples pour les formes de bande d'absorption infrarouge, montrant que ces modeles possedent les caracteristiques des formes observees dans les gaz comprimes, les liquides ou les solutions. (auteur)

  17. Contribution to the study of influences in emission spectrography on solutions. Application to a general analysis method for stainless steels (1961); Contribution a l'etude des influences en spectographie d'emission sur solution. Application a une methode generale d'analyse des aciers inoxydables (1961)

    Energy Technology Data Exchange (ETDEWEB)

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

    1961-11-15

    In order to establish a general method of analysis of stainless steels, by means of spark spectroscopy on solutions, a systematic study has been made of the factors involved. The variations in acidity of the solutions, or in the ratio of concentrations of two acids at constant pH, lead to a displacement of the calibration curve. Simple relations have been established between the concentration of the extraneous elements, and the effects produced, for the constituents Fe, Ti, Ni, Cr, Mn; a general method using abacus is proposed for steels containing only these elements. The interactions in the case of the elements Mo, Nb, Ta, W, were more complex, so that the simultaneous separation was studied with the help of ion-exchange resins. A general method of analysis is proposed for stainless steels. (author) [French] En vue d'etablir une methode generale d'analyse des aciers inoxydables par spectrographie d'etincelles sur solution, on a effectue une etude systematique des influences. Les variations de l'acidite des solutions ou du rapport des concentrations de deux acides a pH constant, entrainent un deplacement des courbes d'etalonnage. On a etabli des relations simples entre la teneur des tiers elements et les effets produits pour les constituants Fe, Ti, Ni, Cr, Mn; une methode generale avec abaques est proposee pour les aciers contenant ces seuls elements. Les influences dans le cas des elements Mo, Nb, Ta, W etant plus complexes, on eut a etudier la separation simultanee a l'aide de resines echangeuses d'ions. On propose une methode generale d'analyse des aciers inoxydables. (auteur)

  18. Application of the chemical properties of ruthenium to decontamination processes; L'application des proprietes chimiques du ruthenium a des procedes de decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Fontaine, A.; Berger, D. [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

    1965-07-01

    The chemical properties of ruthenium in the form of an aqueous solution of the nitrate and of organic tributylphosphate solution are reviewed. From this data, some known examples are given: they demonstrate the processes of separation or of elimination of ruthenium from radioactive waste. (authors) [French] Les proprietes chimiques du ruthenium en solutions aqueuses nitriques et en solutions organiques de tributylphosphate, sont passees en revue. A partir de ces donnees, quelques exemples connus sont cites: ils exposent des procedes de separation ou d'elimination du ruthenium de dechets radioactifs. (auteurs)

  19. Application of the chemical properties of ruthenium to decontamination processes; L'application des proprietes chimiques du ruthenium a des procedes de decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Fontaine, A; Berger, D [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

    1965-07-01

    The chemical properties of ruthenium in the form of an aqueous solution of the nitrate and of organic tributylphosphate solution are reviewed. From this data, some known examples are given: they demonstrate the processes of separation or of elimination of ruthenium from radioactive waste. (authors) [French] Les proprietes chimiques du ruthenium en solutions aqueuses nitriques et en solutions organiques de tributylphosphate, sont passees en revue. A partir de ces donnees, quelques exemples connus sont cites: ils exposent des procedes de separation ou d'elimination du ruthenium de dechets radioactifs. (auteurs)

  20. Applications of prospecting geochemical techniques to the search for and to the study of uranium deposits in metropolitan France; Applications des techniques geochimiques de prospection a la recherche et a l'etude des gites uraniferes en France metropolitaine

    Energy Technology Data Exchange (ETDEWEB)

    Grimbert, Arnold

    1957-07-01

    After having recalled facts which leaded the CEA to use new geochemical techniques for the prospecting of uranium deposits through sampling and analysis of soils and waters, the author describes the organisation and methods implemented for this prospecting activity: team composition for sampling and analysis, role of each engineer and technician in the prospecting stages (preliminary study, routine prospecting, result interpretation), sampling and analysis processes. He also reports campaigns of geochemical prospecting: study of the La Chapelle Largeau deposit (objectives, geological context, preliminary study, routine prospecting, study of geochemical anomalies), tactical research on Verneix indices (study of radioactivity anomaly discovered by radio-prospecting), strategical searches in a non prospected area in the South of Avallon. The author discusses the issues of efficiency and cost price of this geochemical prospecting technique in soils and in waters. Appendices present the equipment and operation modality for soil sampling, and for soil sample preparation, and principles, equipment and products for soil analysis and for water analysis [French] A la suite des resultats satisfaisants obtenus dans la recherche de methodes de dosage adaptees au cas de l'uranium, la Direction des Recherches Minieres du Commissariat a l'Energie atomique a decide, en decembre 1954, d'utiliser, conjointement avec les methodes classiques de prospection, les techniques geochimiques pour la recherche et l'etude des gites uraniferes. Ces applications pratiques ont ete confiees a une Section de Geochimie dont l'organisation, les moyens en personnel et en materiel, ainsi que les methodes de travail, font l'objet d'un expose detaille. Quelques exemples de prospection, en France metropolitaine, montrent la nature des problemes poses (etude d'un gisement connu, recherche tactique sur des indices, recherche strategique dans une region non prospectee), les methodes utilisees pour les

  1. A Virtual Mixture Approach to the Study of Multistate Equilibrium: Application to Constant pH Simulation in Explicit Water

    Science.gov (United States)

    Wu, Xiongwu; Brooks, Bernard R.

    2015-01-01

    Chemical and thermodynamic equilibrium of multiple states is a fundamental phenomenon in biology systems and has been the focus of many experimental and computational studies. This work presents a simulation method to directly study the equilibrium of multiple states. This method constructs a virtual mixture of multiple states (VMMS) to sample the conformational space of all chemical states simultaneously. The VMMS system consists of multiple subsystems, one for each state. The subsystem contains a solute and a solvent environment. The solute molecules in all subsystems share the same conformation but have their own solvent environments. Transition between states is implicated by the change of their molar fractions. Simulation of a VMMS system allows efficient calculation of relative free energies of all states, which in turn determine their equilibrium molar fractions. For systems with a large number of state transition sites, an implicit site approximation is introduced to minimize the cost of simulation. A direct application of the VMMS method is for constant pH simulation to study protonation equilibrium. Applying the VMMS method to a heptapeptide of 3 ionizable residues, we calculated the pKas of those residues both with all explicit states and with implicit sites and obtained consistent results. For mouse epidermal growth factor of 9 ionizable groups, our VMMS simulations with implicit sites produced pKas of all 9 ionizable groups and the results agree qualitatively with NMR measurement. This example demonstrates the VMMS method can be applied to systems of a large number of ionizable groups and the computational cost scales linearly with the number of ionizable groups. For one of the most challenging systems in constant pH calculation, SNase Δ+PHS/V66K, our VMMS simulation shows that it is the state-dependent water penetration that causes the large deviation in lysine66’s pKa. PMID:26506245

  2. A Virtual Mixture Approach to the Study of Multistate Equilibrium: Application to Constant pH Simulation in Explicit Water.

    Directory of Open Access Journals (Sweden)

    Xiongwu Wu

    2015-10-01

    Full Text Available Chemical and thermodynamic equilibrium of multiple states is a fundamental phenomenon in biology systems and has been the focus of many experimental and computational studies. This work presents a simulation method to directly study the equilibrium of multiple states. This method constructs a virtual mixture of multiple states (VMMS to sample the conformational space of all chemical states simultaneously. The VMMS system consists of multiple subsystems, one for each state. The subsystem contains a solute and a solvent environment. The solute molecules in all subsystems share the same conformation but have their own solvent environments. Transition between states is implicated by the change of their molar fractions. Simulation of a VMMS system allows efficient calculation of relative free energies of all states, which in turn determine their equilibrium molar fractions. For systems with a large number of state transition sites, an implicit site approximation is introduced to minimize the cost of simulation. A direct application of the VMMS method is for constant pH simulation to study protonation equilibrium. Applying the VMMS method to a heptapeptide of 3 ionizable residues, we calculated the pKas of those residues both with all explicit states and with implicit sites and obtained consistent results. For mouse epidermal growth factor of 9 ionizable groups, our VMMS simulations with implicit sites produced pKas of all 9 ionizable groups and the results agree qualitatively with NMR measurement. This example demonstrates the VMMS method can be applied to systems of a large number of ionizable groups and the computational cost scales linearly with the number of ionizable groups. For one of the most challenging systems in constant pH calculation, SNase Δ+PHS/V66K, our VMMS simulation shows that it is the state-dependent water penetration that causes the large deviation in lysine66's pKa.

  3. A Virtual Mixture Approach to the Study of Multistate Equilibrium: Application to Constant pH Simulation in Explicit Water.

    Science.gov (United States)

    Wu, Xiongwu; Brooks, Bernard R

    2015-10-01

    Chemical and thermodynamic equilibrium of multiple states is a fundamental phenomenon in biology systems and has been the focus of many experimental and computational studies. This work presents a simulation method to directly study the equilibrium of multiple states. This method constructs a virtual mixture of multiple states (VMMS) to sample the conformational space of all chemical states simultaneously. The VMMS system consists of multiple subsystems, one for each state. The subsystem contains a solute and a solvent environment. The solute molecules in all subsystems share the same conformation but have their own solvent environments. Transition between states is implicated by the change of their molar fractions. Simulation of a VMMS system allows efficient calculation of relative free energies of all states, which in turn determine their equilibrium molar fractions. For systems with a large number of state transition sites, an implicit site approximation is introduced to minimize the cost of simulation. A direct application of the VMMS method is for constant pH simulation to study protonation equilibrium. Applying the VMMS method to a heptapeptide of 3 ionizable residues, we calculated the pKas of those residues both with all explicit states and with implicit sites and obtained consistent results. For mouse epidermal growth factor of 9 ionizable groups, our VMMS simulations with implicit sites produced pKas of all 9 ionizable groups and the results agree qualitatively with NMR measurement. This example demonstrates the VMMS method can be applied to systems of a large number of ionizable groups and the computational cost scales linearly with the number of ionizable groups. For one of the most challenging systems in constant pH calculation, SNase Δ+PHS/V66K, our VMMS simulation shows that it is the state-dependent water penetration that causes the large deviation in lysine66's pKa.

  4. Application of accelerated evaluation method of alteration temperature and constant dose rate irradiation on bipolar linear regulator LM317

    International Nuclear Information System (INIS)

    Deng Wei; Wu Xue; Wang Xin; Zhang Jinxin; Zhang Xiaofu; Zheng Qiwen; Ma Wuying; Lu Wu; Guo Qi; He Chengfa

    2014-01-01

    With different irradiation methods including high dose rate irradiation, low dose rate irradiation, alteration temperature and constant dose rate irradiation, and US military standard constant high temperature and constant dose rate irradiation, the ionizing radiation responses of bipolar linear regulator LM317 from three different companies were investigated under the operating and zero biases. The results show that compared with constant high temperature and constant dose rate irradiation method, the alteration temperature and constant dose rate irradiation method can not only very rapidly and accurately evaluate the dose rate effect of three bipolar linear regulators, but also well simulate the damage of low dose rate irradiation. Experiment results make the alteration temperature and constant dose rate irradiation method successfully apply to bipolar linear regulator. (authors)

  5. Application of microhardness measurements to the study of diffusion zones; Application des mesures de microdurete a l'etude des zones de diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Levy, V; Bouchet, P; Siouffi, J; Adda, Y [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    It is well known that the concentration fluctuations in diffusion zones can be determined by microhardness tests. It was therefore interesting to define the experimental conditions leading to the best accuracy. To this end, we have studied the influence of the kind of penetrator used, and of the applied load on the reproducibility of the curves plotting the variation of microhardness values against penetration. This work carried out for diffusion zones of various widths, has enabled us to determine in each case the best experimental procedure. (author) [French] On sait que les variations de concentration existant dans les zones de diffusion peuvent etre determinees au moyen de mesures de microdurete. Il etait donc interessant de definir les conditions experimentales conduisant a la meilleure precision. Dans ce but, nous avons etudie l'influence de la nature du penetrateur et celle de la charge appliquee sur la reproductibilite des courbes representant les variations de durete en fonction de la penetration. Ce travail, effectue pour des zones de diffusion de differentes largeurs, nous a permis de determiner dans chaque cas les conditions experimentales les plus favorables. (auteur)

  6. Continuous surveillance of transformers using artificial intelligence methods; Surveillance continue des transformateurs: application des methodes d'intelligence artificielle

    Energy Technology Data Exchange (ETDEWEB)

    Schenk, A.; Germond, A. [Ecole Polytechnique Federale de Lausanne, Lausanne (Switzerland); Boss, P.; Lorin, P. [ABB Secheron SA, Geneve (Switzerland)

    2000-07-01

    The article describes a new method for the continuous surveillance of power transformers based on the application of artificial intelligence (AI) techniques. An experimental pilot project on a specially equipped, strategically important power transformer is described. Traditional surveillance methods and the use of mathematical models for the prediction of faults are described. The article describes the monitoring equipment used in the pilot project and the AI principles such as self-organising maps that are applied. The results obtained from the pilot project and methods for their graphical representation are discussed.

  7. Implementation en VHDl/FPGA d'afficheur video numerique (AVN) pour des applications aerospatiales

    Science.gov (United States)

    Pelletier, Sebastien

    L'objectif de ce projet est de developper un controleur video en langage VHDL afin de remplacer la composante specialisee presentement utilisee chez CMC Electronique. Une recherche approfondie des tendances et de ce qui se fait actuellement dans le domaine des controleurs video est effectuee afin de definir les specifications du systeme. Les techniques d'entreposage et d'affichage des images sont expliquees afin de mener ce projet a terme. Le nouveau controleur est developpe sur une plateforme electronique possedant un FPGA, un port VGA et de la memoire pour emmagasiner les donnees. Il est programmable et prend peu d'espace dans un FPGA, ce qui lui permet de s'inserer dans n'importe quelle nouvelle technologie de masse a faible cout. Il s'adapte rapidement a toutes les resolutions d'affichage puisqu'il est modulaire et configurable. A court terme, ce projet permettra un controle ameliore des specifications et des normes de qualite liees aux contraintes de l'avionique.

  8. Les filtres plantés de roseaux en assainissement : de la compréhension des mécanismes vers l'optimisation des procédés et la diversification des domaines d'application.

    OpenAIRE

    Molle, P.

    2015-01-01

    / L'usage des végétaux aquatiques dans les filières de traitement des eaux provient de l'observation du rôle des zones humides naturelles dans la préservation de la qualité des milieux aquatiques. En France l'expérience a démarré en 1978. Depuis les premières réalisations jusqu'au début des années 2000 la filière a été évaluée principalement par des bilans 24 h à chaque étape de traitement. Si cette méthode considère les systèmes comme une boîte noire et ne donne pas accès à la quantification...

  9. Determination of correction coefficients for quantitative analysis by mass spectrometry. Application to uranium impurities analysis; Recherche des coefficients de correction permettant l'analyse quantitative par spectrometrie de masse. Application a l'analyse d'impuretes dans l'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Billon, J P [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

    1970-07-01

    Some of basic principles in spark source mass spectrometry are recalled. It is shown how this method can lead to quantitative analysis when attention is paid to some theoretical aspects. A time constant relation being assumed between the analysed solid sample and the ionic beam it gives we determined experimental relative sensitivity factors for impurities in uranium matrix. Results being in fairly good agreement with: an unelaborate theory on ionization yield in spark-source use of theoretically obtained relative sensitivity factors in uranium matrix has been developed. (author) [French] Apres avoir rappele quelques principes fondamentaux regissant la spectrometrie de masse a etincelles, nous avons montre que moyennant un certain nombre de precautions, il etait possible d'utiliser cette methode en analyse quantitative. Ayant admis qu'il existait une relation constante dans le temps entre l'echantillon solide analyse et le faisceau ionique qui en est issu, nous avons d'abord entrepris de determiner des coefficients de correction experimentaux pour des matrices d'uranium. Les premiers resultats pratiques semblant en accord avec une theorie simple relative au rendement d'ionisation dans la source a etincelles, nous avons etudie la possibilite d'appliquer directement les coefficients theoriques ainsi definis, l'application etant toujours faite sur des matrices d'uranium. (auteur)

  10. Utilisation sans risque des eaux usées, des excréta et des eaux ...

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

    Les responsables de ce projet piloteront l'application et l'adaptation des principes directeurs relatifs à l'utilisation sans risque des eaux usées, des excreta et des eaux grises en agriculture et en aquaculture (Guidelines for the Safe Use of Wastewater, Excreta and Greywater in Agriculture and Aquaculture), que ...

  11. La PCR quantitative en temps réel : application à la quantification des OGM

    Directory of Open Access Journals (Sweden)

    Alary Rémi

    2002-11-01

    Full Text Available Suite à l’obligation d’étiquetage, au seuil de 1 %, des aliments contenant des OGM autorisés, il est nécessaire de disposer de méthodes fiables de quantification. Pour répondre à cette obligation, la technique de PCR quantitative en temps réel semble actuellement la mieux adaptée. Son principe, ses avantages et sa mise en oeuvre pour la détermination de la teneur en OGM de farines de soja sont présentés. Les PCR simplex et duplex sont comparées.

  12. Application of transducers to the control of temperatures and of alternating and direct voltages (1962); Application des transducteurs a la regulation des temperatures et des tensions alternatives et continues (1962)

    Energy Technology Data Exchange (ETDEWEB)

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

    1960-11-15

    The temperature regulator and the voltage regulators described have been studied with a view to conferring a high degree of safety to the apparatuses in which they are used. They make use almost exclusively of Transducers which are passive elements acting mainly in these apparatuses as amplifiers and which are entirely satisfactory, ensuring that the regulators studied keep their essential qualities i.e accuracy, reliability, stability and sensitivity. (author) [French] Le regulateur de temperature et les regulateurs de tension decrits ont ete etudies pour donner aux ensembles dans lesquels ils sont inseres une grande securite d'exploitation. Ils utilisent presque exclusivement comme constituants des TRANSDUCTEURS qui sont des elements passifs assurant principalement dans ces appareils une fonction d'amplification ou ils donnent entiere satisfaction en conservant aux regulateurs etudies leurs qualites essentielles qui sont: la precision, la fidelite, la stabilite et la sensibilite. (auteur)

  13. The thermodynamic approach of the pilot-scale purification of refractory metals; Application de la thermodynamique a la mise au point des methodes de purification industrielle des metaux et semi-metaux refractaires

    Energy Technology Data Exchange (ETDEWEB)

    Accary, A [Commissariat a l' Energie Atomique, Dir. des Piles Atomiques, Saclay (France). Centre d' Etudes Nucleaires

    1967-06-15

    The author shows how the thermodynamic can be applied to the prediction of the evolution of impurities from a metal or an alloy being melted and cast at the pilot-scale using electron bombardment and continuous casting in a water cooled copper. He studies this possibility on two examples: - the melting vanadium, - the melting of the uranium monocarbide. He shows using only the constants available in the literature and a few special runs in the pilot-equipment itself it is possible to determine: - the possibility of elimination of anyone impurity by keeping the material in the melting state under vacuum as well as the limit of purification which is achievable under given technological conditions, - the proportion of an impure metal which should be vaporized in order to bring the level of a given impurity down to a predetermined level and the necessary duration of heating. (author) [French] L'auteur montre comment la thermodynamique peut etre appliquee a la prevision de l'evolution d'un metal ou d'un alliage fondu a l'echelle pilote par bombardement d'electrons et coule en continu dans un creuset de cuivre refroidi. Il etudie cette possibilite sur deux cas particuliers: - la fusion de vanadium, - la fusion du monocarbure d'uranium. Il montre que, grace aux constantes disponibles dans la litterature et a des essais simples faits a l'aide de l'appareillage pilote lui-meme, on peut determiner: - la possibilite d'eliminer une impurete par maintien a l'etat fondu ainsi que la limite de purification dans des conditions technologiques donnees, - la proportion d'un metal brut qu'il faut evaporer pour amener sa teneur en une impurete a un niveau donne ainsi que la duree de chauffage necessaire, - la nature des additions propres a favoriser le depart d'une impurete et l'efficacite comparee des additions possibles. (auteur)

  14. Application de principes cognitivistes et constructivistes à l'enseignement de l'écrit assisté par ordinateur : perceptions des étudiants

    Directory of Open Access Journals (Sweden)

    Catherine Caws

    2005-09-01

    Full Text Available Cet article traite des apports des théories cognitives et constructivistes à l'enseignement de l'écrit assisté par ordinateur, en milieu universitaire, chez des apprenants de français langue seconde. À partir des premiers résultats d'un projet pilote mené à l'université de Victoria, au Canada, l'auteure cherche à montrer comment, par le biais d'exercices collaboratifs en réseau Internet, l'application de certains principes-clés des recherches récentes en didactique du français langue seconde peuvent contribuer à un renouveau de l'engagement des étudiants, à une hausse notable de leur motivation et à une prise de conscience de leurs stratégies d'apprentissage. Une analyse des réactions des étudiants face à ce nouveau type d'apprentissage nous permet d'analyser, d'une part, les aspects de l'outil que les étudiants perçoivent comme étant utiles pour leur apprentissage et, d'autre part, les éléments qu'ils voudraient voir améliorer dans l'avenir. La prise de conscience même de ces stratégies nous montre à quel point l'apprenant s'engage activement dans la découverte de la L2, répondant ainsi inconsciemment à un des principes-clés de la psychologie cognitive.

  15. Application of the pM'-pCH diagrams in the determination of hydrolysis constants of the lanthanides

    International Nuclear Information System (INIS)

    Lopez G, H.; Jimenez R, M.; Solache R, M.; Rojas H, A.

    2001-01-01

    The pM ' -pC H diagrams allowed to determine the saturation and non-saturation zones of Lu(OH) 3 in solid phase and those were applied for determining the hydrolysis and lutetium solubility constants, using the radioactive isotope Lu-177. The first constant of hydrolysis was also determined by the potentiometric method in absence of solid phase. (Author)

  16. La Boîte à Outils Sur L'Application Des Connaissances

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

    219. 11. Le résumé de deux pages : Rédaction d'un précis politique. 221. 12. ...... Pour élaborer une stratégie d'AC, plusieurs approches et outils peuvent être utilisés. ...... Le recrutement d'un consultant exige des vérifications approfondies.

  17. Absolute measurement of {beta} activities and application to the determination of neutronic densities; Mesure absolue d'activites {beta} et application a la determination des densites neutronique

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, R [Commissariat a l' Energie Atomique, Lab. du Fort de Chatillon, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1951-01-15

    M. Berthelot, to my entrance to the ''Commissariat a l 'Energie Atomique'', proposed me to study the absolute measurement of neutron densities. Very quickly the problem of the absolute activity of {beta} sources became the central object of this work. In a first part, we will develop the methods of absolute determination for {beta} activities. The use of a 4{pi} counter permits to get the absolute activity of all beta radioactive source, susceptible to be put as thin leaf and of period superior than some minutes. The method is independent of the spectra of the measured radioelement. we will describe in the second part some applications which use neutron densities measurement, neutron sources intensities and ratio of cross sections of capture of thermal neutrons. (M.B.) [French] M. Berthelot, a mon entree au ''Commissariat a l 'Energie Atomique'', m'a propose d'etudier la mesure absolue des densites neutroniques. Tres rapidement le probleme de l'activite absolue des sources beta est devenu l'objet central de ce travail. Dans une premiere partie, on abordera les methodes de determination absolue des activites beta. L'utilisation d'un compteur 4{pi} permet d 'obtenir l'activite absolue de toute source radioactive beta, susceptible d'etre mise sous forme de feuille mince et de periode superieure a quelques minutes. La methode est independante du spectre du radioelement mesure. On decrira dans la seconde partie quelques applications a des mesures de densites neutroniques, d'intensites de sources de neutrons et de rapport de sections efficaces de capture de neutrons thermiques. (M.B.)

  18. Absolute measurement of {beta} activities and application to the determination of neutronic densities; Mesure absolue d'activites {beta} et application a la determination des densites neutronique

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, R. [Commissariat a l' Energie Atomique, Lab. du Fort de Chatillon, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1951-01-15

    M. Berthelot, to my entrance to the ''Commissariat a l 'Energie Atomique'', proposed me to study the absolute measurement of neutron densities. Very quickly the problem of the absolute activity of {beta} sources became the central object of this work. In a first part, we will develop the methods of absolute determination for {beta} activities. The use of a 4{pi} counter permits to get the absolute activity of all beta radioactive source, susceptible to be put as thin leaf and of period superior than some minutes. The method is independent of the spectra of the measured radioelement. we will describe in the second part some applications which use neutron densities measurement, neutron sources intensities and ratio of cross sections of capture of thermal neutrons. (M.B.) [French] M. Berthelot, a mon entree au ''Commissariat a l 'Energie Atomique'', m'a propose d'etudier la mesure absolue des densites neutroniques. Tres rapidement le probleme de l'activite absolue des sources beta est devenu l'objet central de ce travail. Dans une premiere partie, on abordera les methodes de determination absolue des activites beta. L'utilisation d'un compteur 4{pi} permet d 'obtenir l'activite absolue de toute source radioactive beta, susceptible d'etre mise sous forme de feuille mince et de periode superieure a quelques minutes. La methode est independante du spectre du radioelement mesure. On decrira dans la seconde partie quelques applications a des mesures de densites neutroniques, d'intensites de sources de neutrons et de rapport de sections efficaces de capture de neutrons thermiques. (M.B.)

  19. Tailoring the optical constants in single-crystal silicon with embedded silver nanostructures for advanced silicon photonics applications

    International Nuclear Information System (INIS)

    Akhter, Perveen; Huang, Mengbing; Spratt, William; Kadakia, Nirag; Amir, Faisal

    2015-01-01

    Plasmonic effects associated with metal nanostructures are expected to hold the key to tailoring light emission/propagation and harvesting solar energy in materials including single crystal silicon which remains the backbone in the microelectronics and photovoltaics industries but unfortunately, lacks many functionalities needed for construction of advanced photonic and optoelectronics devices. Currently, silicon plasmonic structures are practically possible only in the configuration with metal nanoparticles or thin film arrays on a silicon surface. This does not enable one to exploit the full potential of plasmonics for optical engineering in silicon, because the plasmonic effects are dominant over a length of ∼50 nm, and the active device region typically lies below the surface much beyond this range. Here, we report on a novel method for the formation of silver nanoparticles embedded within a silicon crystal through metal gettering from a silver thin film deposited at the surface to nanocavities within the Si created by hydrogen ion implantation. The refractive index of the Ag-nanostructured layer is found to be 3–10% lower or higher than that of silicon for wavelengths below or beyond ∼815–900 nm, respectively. Around this wavelength range, the optical extinction values increase by a factor of 10–100 as opposed to the pure silicon case. Increasing the amount of gettered silver leads to an increased extinction as well as a redshift in wavelength position for the resonance. This resonance is attributed to the surface plasmon excitation of the resultant silver nanoparticles in silicon. Additionally, we show that the profiles for optical constants in silicon can be tailored by varying the position and number of nanocavity layers. Such silicon crystals with embedded metal nanostructures would offer novel functional base structures for applications in silicon photonics, optoelectronics, photovoltaics, and plasmonics

  20. Dental Encounter System (DES)

    Data.gov (United States)

    Department of Veterans Affairs — Dental Encounter System (DES) is an automated health care application designed to capture critical data about the operations of VA Dental Services. Information on...

  1. Application of quantitative structure-activity relationship to the determination of binding constant based on fluorescence quenching

    Energy Technology Data Exchange (ETDEWEB)

    Wen Yingying [Department of Applied Chemistry, Yantai University, Yantai 264005 (China); Liu Huitao, E-mail: liuht-ytu@163.co [Department of Applied Chemistry, Yantai University, Yantai 264005 (China); Luan Feng; Gao Yuan [Department of Applied Chemistry, Yantai University, Yantai 264005 (China)

    2011-01-15

    Quantitative structure-activity relationship (QSAR) model was used to predict and explain binding constant (log K) determined by fluorescence quenching. This method allowed us to predict binding constants of a variety of compounds with human serum albumin (HSA) based on their structures alone. Stepwise multiple linear regression (MLR) and nonlinear radial basis function neural network (RBFNN) were performed to build the models. The statistical parameters provided by the MLR model (R{sup 2}=0.8521, RMS=0.2678) indicated satisfactory stability and predictive ability while the RBFNN predictive ability is somewhat superior (R{sup 2}=0.9245, RMS=0.1736). The proposed models were used to predict the binding constants of two bioactive components in traditional Chinese medicines (isoimperatorin and chrysophanol) whose experimental results were obtained in our laboratory and the predicted results were in good agreement with the experimental results. This QSAR approach can contribute to a better understanding of structural factors of the compounds responsible for drug-protein interactions, and can be useful in predicting the binding constants of other compounds. - Research Highlights: QSAR models for binding constants of some compounds to HSA were developed. The models provide a simple and straightforward way to predict binding constant. QSAR can give some insight into structural features related to binding behavior.

  2. Application des ondelettes à l'analyse de texture et à l'inspection de surface industrielle

    Science.gov (United States)

    Wolf, D.; Husson, R.

    1993-11-01

    This paper presents a method of texture analysis based on multiresolution wavelets analysis. We discuss the problem of theoretical and experimental choice of the wavelet. Statistical modelling of wavelet images is treated and it results in considering statistical distribution to be a generalized Gaussian law. An algorithm for texture classification is developed with respect of the variances of different wavelet images. An industrial application of this algorithm illustrates its quality and proves its aptitude for automation of certain tasks in industrial control. Nous présentons une méthode d'analyse de texture fondée sur l'analyse multirésolution par ondelettes. Nous discutons du problème du choix théorique et expérimental de l'ondelette. Le problème de la modélisation statistique des images d'ondelettes est traité et aboutit à considérer la distribution statistique comme une loi de Gauss généralisée. Un algorithme de classification de texture est construit à l'aide de la variance des différentes images d'ondelettes. Enfin, une application industrielle de cet algorithme illustre ses qualités et démontre son aptitude à l'automatisation de certaines tâches de contrôle industriel.

  3. Application of the geophysical and geochemical methods to the research for uranium; Application a la recherche de l'uranium des methodes geophysiques et geochimiques

    Energy Technology Data Exchange (ETDEWEB)

    Gangloff, A M; Collin, C R; Grimbert, A; Sanselme, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    Since 1954, at the Commissariat a l'energie atomique, geophysics and geochemistry have been added to routine geological surveying and radiometric observations. Geophysical prospecting reveals the tectonic structures linked with French uranium deposits and gives an idea of favorable zones. Geochemistry adds to the geophysical indirect methods further details on the distribution of uranium traces in the soils. This method is direct and specific. Uranium assay in waters and alluvial deposits find its use in preliminary exploration. (author) [French] Depuis 1954, au CEA, a l'observation geologique directe et aux mesures radiometriques, sont venues s'ajouter des methodes relevant de la geophysique et de la geochimie. La prospection geophysique apporte des precisions sur les structures tectoniques auxquelles sont lies les gisements d'uranium fran is et sur la notion de zones favorables. Aux methodes indirectes de la geophysique, la prospection geochimique ajoute des precisions sur la repartition de l'uranium en traces dans les sols, cette methode est directe et specifique. Le dosage de l'uranium dans les eaux et les alluvions trouve son application dans la prospection de reconnaissance. (auteur)

  4. Partenariat Mexique-Canada en vue de l'application des ...

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

    Le Mexique met en oeuvre de plus en plus de réformes de son système de santé en se fondant directement sur des données probantes découlant de recherches. Toutefois, l'Instituto Nacional de Salud Pública (INSP) du Mexique a récemment modifié les visées de son programme de recherche sur les systèmes de santé ...

  5. Élaboration de protocoles facilitant l'application des lois en matière ...

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

    En Inde, les crimes contre les femmes sont à la hausse. Selon des chiffres récents de l'office national de statistiques sur la criminalité (National Crime Records Bureau), un viol est perpétré toutes les 26 minutes; une agression sexuelle, toutes les 14 minutes; un acte de cruauté de la part du mari ou de la famille, toutes les 6 ...

  6. 10 Détermination des radionucléides dans le repas. Application aux ...

    African Journals Online (AJOL)

    ASIMANANA

    On réalise du tic au tac à l'Agriculture et un système expert des aides aux culinaires. Le Malgache a un art culinaire. Les étrangers, certes, connaissent seulement quelques plats. Malgaches à commencer par le Romazava et le Ravitoto. Or, on constatera que cette cuisine compte de nombreux plats. 2. Matériel et méthodes.

  7. Amélioration des méthodes de protection anticorrosion des structures métalliques : Sous-sujet : Application des systèmes dits de "maintenance" sur préparation de surface UHP

    OpenAIRE

    MAIRE, G; CENTRE D'ETUDES TECHNIQUES DE L'EQUIPEMENT NORMANDIE-CENTRE - CETE NORMANDIE-CENTRE; LABORATOIRE REGIONAL DES PONTS ET CHAUSSEES DE BLOIS - CETE NORMANDIE-CENTRE - LRPC BLOIS

    2005-01-01

    Le problème actuel de l'entretien de la protection anticorrosion des structures métalliques est l'augmentation du coût découlant des contraintes règlementaires récentes sur l'évacuation et le traitement des déchets. Lors d'un chantier d'entretien, le principal poste générateur de déchets est le décapage. Toutes les solutions techniques permettant de diminuer la quantité et/ou la nocivité des déchets de décapage sont donc intéressantes aussi bien du point de vue économique que de celui de la p...

  8. Meson-baryon coupling constants from a chiral-invariant SU(3) Lagrangian and application to NN scattering

    International Nuclear Information System (INIS)

    Stoks, V.G.J.

    1997-01-01

    We present a chiral-invariant meson-baryon Lagrangian which describes the interactions of the baryon octet with the lowest-mass meson nonets. The nonlinear realization of the chiral symmetry generates pair-meson interaction vertices. The corresponding pair-meson coupling constants can all be expressed in terms of the meson-nucleon-nucleon pseudovector, scalar, and vector coupling constants, and their corresponding F/(F+D) ratios, and for which empirical estimates are given. We show that it is possible to construct an NN potential of reasonable quality satisfying these theoretical and empirical constraints. (orig.)

  9. Définition et développement des applications pour smartphones en différentes plateformes (windows8, IOS)

    OpenAIRE

    Lisicic Lopátegui, Claudia

    2013-01-01

    Innovation d’une application d’entreprise, déjà existante et développement de cette application dans une nouvelle plateforme. Gestion et management d’un projet de développement et innovation d’une application pour Smartphones, à travers des études ergonomiques, d’utilisateurs et d’état de l’art.

  10. Application d'une équation d'état à la simulation du comportement thermodynamique des fluides dans les gisements et dans les installations de surface Application of an Equation of State to Simulating the Thermodynamic Behaviour of Fluids in Reservoirs and Surface Installations

    Directory of Open Access Journals (Sweden)

    Jain C.

    2006-11-01

    Full Text Available La connaissance des propriétés thermodynamiques des fluides pétroliers, en particulier des masses volumiques et des coefficients d'équilibre liquide-vapeur, intervient à divers stades de la production : primaire, secondaire par in-jection de gaz (C02 ou hydrocarbures miscibles, vapeur d'eau, séparation, réseau de collecte et de transport. L'ampleur du domaine de pression et de température à l'intérieur duquel on a besoin de connaître les propriétés des huiles et des gaz à condensat, et le fait que la compo-sition d'ensemble des mélanges diphasiques ne cesse de varier au cours de leur déplacement soit dans les gisements, soit dans les installations d'exploitation, rendent mani-feste l'intérêt de pouvoir calculer ces propriétés, en évi-tant d'avoir recours à des travaux de laboratoire beaucoup trop importants. Pour résoudre ces problèmes, une nouvelle équation d'état appelée Redlich-Kwong Développée (RKD a été mise au point. Au cours de cet exposé, nous verrons que cette équation restitue les enveloppes diphasiques de l'équilibre liquide-vapeur avec une qualité au moins égale à celles des méthodes de Soave et de Peng-Robinson qui jouissent actuellement d'une grande notoriété. L'avantage de ce modèle sur ces dernières méthodes est l'évaluation simultanée des propriétés volumétriques des phases en présence avec une bonne précision, ce qui est d'une grande utilité pour l'application de ce modèle aux problèmes industriels. Knowing the thermodynamic properties of petroleum fluids, and in particular the density and liquid-vapor equilibrium coefficients, is important at different stages of production, i. e. primary production, secondary production by gas flooding (CO2 or miscible hydrocarbons, steam, separation, gathering network and transportation. The pressure and temperature range within which the oil and gas-condensate properties must be known coupled with the fact that the overall composition of

  11. Self-consistent random phase approximation - application to systems of strongly correlated fermions; Approximation des phases aleatoires self-consistante - applications a des systemes de fermions fortement correles

    Energy Technology Data Exchange (ETDEWEB)

    Jemai, M

    2004-07-01

    In the present thesis we have applied the self consistent random phase approximation (SCRPA) to the Hubbard model with a small number of sites (a chain of 2, 4, 6,... sites). Earlier SCRPA had produced very good results in other models like the pairing model of Richardson. It was therefore interesting to see what kind of results the method is able to produce in the case of a more complex model like the Hubbard model. To our great satisfaction the case of two sites with two electrons (half-filling) is solved exactly by the SCRPA. This may seem a little trivial but the fact is that other respectable approximations like 'GW' or the approach with the Gutzwiller wave function yield results still far from exact. With this promising starting point, the case of 6 sites at half filling was considered next. For that case, evidently, SCRPA does not any longer give exact results. However, they are still excellent for a wide range of values of the coupling constant U, covering for instance the phase transition region towards a state with non zero magnetisation. We consider this as a good success of the theory. Non the less the case of 4 sites (a plaquette), as indeed all cases with 4n sites at half filling, turned out to have a problem because of degeneracies at the Hartree Fock level. A generalisation of the present method, including in addition to the pairs, quadruples of Fermions operators (called second RPA) is proposed to also include exactly the plaquette case in our approach. This is therefore a very interesting perspective of the present work. (author)

  12. Applications of the automatic meter reading techniques at the Brazilian gas domestic market; Application des techniques de releve automatique des compteurs sur le marche domestique Bresilien du gaz

    Energy Technology Data Exchange (ETDEWEB)

    Venancio, J.; Monteiro, F. [Comgas, Sao Paulo (Brazil); D' Oliveira, R.D. [ORBIS, Curitiba (Brazil)

    2000-07-01

    This article will describe applications of the automation and automatic meter reading techniques at the internal gas pipes installations design, considering residential and commercial buildings, and taking in account the tendency of rapid growth of the activities related to the natural gas industry in Brazil, as well as the recently development of new technologies that can be applied with affordable prices. It will be analysed the application of an automatic meter reading technology in a building of several floors in Sao Paulo, which gas installations design is being carried up, with be purpose of making a comparative cost-effectiveness study with the traditional constructive methods applied in Brazil. As a result, it will be purposed a new commercialization model for the gas in Brazil at the residential and commercial market. (authors)

  13. Stabilized power constant alimentation; Alimentation regulee a puissance constante

    Energy Technology Data Exchange (ETDEWEB)

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

    1968-06-01

    The study and realization of a stabilized power alimentation variable from 5 to 100 watts are described. In order to realize a constant power drift of Lithium compensated diodes, we have searched a 1 per cent precision of regulation and a response time minus than 1 sec. Recent components like Hall multiplicator and integrated amplifiers give this possibility and it is easy to use permutable circuits. (author) [French] On decrit l'etude et la realisation d'une alimentation a puissance constante reglable dans une gamme de 5 a 100 watts. Prevue pour le drift a puissance constante des diodes compensees au lithium, l'etude a ete menee en vue d'obtenir une precision de regulation de 1 pour cent et un temps de reponse inferieur a la seconde. Des systemes recents tels que multiplicateurs a effet Hall et circuits integres ont permis d'atteindre ce but tout en facilitant l'emploi de modules interchangeables. (auteur)

  14. The edition of a personal computer program for determining lattice constants and its application in materials for storage of hydrogen

    International Nuclear Information System (INIS)

    Chen Yongzhong; Bai Chaomao; Lang Dingmu; Zhang Youshou

    1998-01-01

    The equations for finding lattice constants of the 7 crystal systems were completely deduced using the M.U.Cohen least square method. From the deduction process it is obvious that the equation forms had nothing to do with the extrapolation functions so any of them can be used. (But in practice, cos 2 θ and cos 2 θ(1/sinθ + 1/θ) were generally performed.) After a personal computer program was finished using above mathematic model, the lattice constants of materials for storage of hydrogen ZrCo and LaNi 5-x M x (M = Mn, Al) were determined. The results showed that the program is very good for finding lattice parameters and can be used in the 7 crystal systems. The results also showed to the LaNi 5 alloy its lattice constants increase when the elements (such as Mn, Al, etc.) whose atomic radii are larger than that of Ni are substituted for Ni and when the content of the same substitutional element Al goes up. This phenomenon is in accordance with the theory

  15. L'application des normes IAS/IFRS par les entreprises françaises cotées : une décision sous influence institutionnelle

    OpenAIRE

    Barbu, Elena

    2006-01-01

    International audience; Cet article cherche à démontrer le rôle des facteurs institutionnels dans l'application des normes comptables internationales par les entreprises françaises cotées. Pour cela, nous avons analysé les réponses à un questionnaire fondé sur l'approche néo-institutionnelle, envoyé en 2005 aux directeurs financiers des entreprises du CAC 40 et Euronext 100. Les résultats obtenus ont permis de mettre en évidence que la décision d'appliquer les IAS/IFRS est influencée par l'en...

  16. L’Application des Codes de Costas et des Codes a Congruences Quadratiques a la Compression d’Impulsion Numerique (The Application of Cost, Codes and Quadratic Congruence Codes to the Compression of Numeric Impulsion)

    Science.gov (United States)

    1991-12-01

    de produire des diagrammes d’ambigult& en forme de punaise avec de faibles lobes...particularit& de produire des diagrammes d’ambiguiLt6 en forme de punaise tout en ayant de faibles lobes secondaires. Ce rapport traite des diff6rentes m6thodes...les codes de Costas, les r~sultats obtenus mantrent que les codes de Golomb of frent de mains bonnes possibi- lit ~s que les codes de Welch pour

  17. An Appraisal of Analytical Methods for Plutonium and their Applications to the Analysis of Nuclear Materials; Evaluation des Methodes Analytiques de Dosage du Plutonium et de Leur Application a l'Analyse des Matieres Nucleaires; Otsenka analiticheskikh metodov opredeleniya plutoniya i ikh primenenie dlya analiza yadernykh materialov; Metodos Analiticos de Determinacion del Plutonio y su Empleo en el Analisis de Materiales Nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Milner, G. W.C.; Phillips, G. [Atomic Energy Research Establishment, Harwell, Berks. (United Kingdom)

    1966-02-15

    programmes for new nuclear fuels. (author) [French] Il existe plusieurs methodes de dosage de la teneur en plutonium des matieres nucleaires. Pour les quantites de l'ordre du milligramme, les methodes utilisables sont la spectro- photometiie differentielle fondee sur la couleur de Pu (III), la gravimetrie fondee sur PuO{sub 2}, le comptage gamma et les methodes de reduction/oxydation comprenant les titrages poientiometriques et amperemetriques et la coulombmetrie a potentiel constant. Pour les quantites de Tordre du microgramme, le comptage alpha, la dilution isotopique et les methodes polarigraphiques sont a utiliser. Certaines methodes conviennent mieux que d'autres a des types determines d'echantillons et l'analyste soucieux d'obtenir les meilleurs resultats se heurte a un choix difficile. Les auteurs exposent les avantages et les inconvenients des methodes citees tels qu'ils se sont degages de l'experience acquise au cours des annees a l'Atomic Energy Research Establishment, et ils discutent l'exactitude, la precision, la sensibilite de ces methodes, et d'autres caracteristiques presentant un interet particulier. Certaines methodes ne peuvent etre utilisees si l'on n'a, dans une certaine mesure, separe le plutonium des autres constituants de l'echantillon et le memoire commente l'experience acquise avec l'echange d'anions et les procedes de chromatographie a phase inversee utilises a cette fin, en insistant surtout sur la mesure dans laquelle cette methode convient aux echantillons radioactifs. Les auteurs etudient en outre les nombreux problemes qui se sont poses lors de l'application (d'ailleurs couronnee de succes) de ces methodes a l'analyse des alliages de plutonium, des ceramiques et des cermets dans differentes combinaisons contenant de l'uranium, du thorium, du fer, du chrome, du molybdene, du cerium et du cobalt. Us exposent les difficultes de la dissolution des echantillons et de la reduction du plutonium a l'etat de valence voulu, ainsi que les avantages

  18. Systems with a constant heat flux with applications to radiative heat transport across nanoscale gaps and layers

    Science.gov (United States)

    Budaev, Bair V.; Bogy, David B.

    2018-06-01

    We extend the statistical analysis of equilibrium systems to systems with a constant heat flux. This extension leads to natural generalizations of Maxwell-Boltzmann's and Planck's equilibrium energy distributions to energy distributions of systems with a net heat flux. This development provides a long needed foundation for addressing problems of nanoscale heat transport by a systematic method based on a few fundamental principles. As an example, we consider the computation of the radiative heat flux between narrowly spaced half-spaces maintained at different temperatures.

  19. Improving Weak Lensing Mass Map Reconstructions using Gaussian and Sparsity Priors: Application to DES SV

    Science.gov (United States)

    Jeffrey, N.; Abdalla, F. B.; Lahav, O.; Lanusse, F.; Starck, J.-L.; Leonard, A.; Kirk, D.; Chang, C.; Baxter, E.; Kacprzak, T.; Seitz, S.; Vikram, V.; Whiteway, L.; Abbott, T. M. C.; Allam, S.; Avila, S.; Bertin, E.; Brooks, D.; Rosell, A. Carnero; Kind, M. Carrasco; Carretero, J.; Castander, F. J.; Crocce, M.; Cunha, C. E.; D'Andrea, C. B.; da Costa, L. N.; Davis, C.; De Vicente, J.; Desai, S.; Doel, P.; Eifler, T. F.; Evrard, A. E.; Flaugher, B.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gerdes, D. W.; Gruen, D.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Hartley, W. G.; Honscheid, K.; Hoyle, B.; James, D. J.; Jarvis, M.; Kuehn, K.; Lima, M.; Lin, H.; March, M.; Melchior, P.; Menanteau, F.; Miquel, R.; Plazas, A. A.; Reil, K.; Roodman, A.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Sevilla-Noarbe, I.; Smith, M.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Walker, A. R.

    2018-05-01

    Mapping the underlying density field, including non-visible dark matter, using weak gravitational lensing measurements is now a standard tool in cosmology. Due to its importance to the science results of current and upcoming surveys, the quality of the convergence reconstruction methods should be well understood. We compare three methods: Kaiser-Squires (KS), Wiener filter, and GLIMPSE. KS is a direct inversion, not accounting for survey masks or noise. The Wiener filter is well-motivated for Gaussian density fields in a Bayesian framework. GLIMPSE uses sparsity, aiming to reconstruct non-linearities in the density field. We compare these methods with several tests using public Dark Energy Survey (DES) Science Verification (SV) data and realistic DES simulations. The Wiener filter and GLIMPSE offer substantial improvements over smoothed KS with a range of metrics. Both the Wiener filter and GLIMPSE convergence reconstructions show a 12% improvement in Pearson correlation with the underlying truth from simulations. To compare the mapping methods' abilities to find mass peaks, we measure the difference between peak counts from simulated ΛCDM shear catalogues and catalogues with no mass fluctuations (a standard data vector when inferring cosmology from peak statistics); the maximum signal-to-noise of these peak statistics is increased by a factor of 3.5 for the Wiener filter and 9 for GLIMPSE. With simulations we measure the reconstruction of the harmonic phases; the phase residuals' concentration is improved 17% by GLIMPSE and 18% by the Wiener filter. The correlation between reconstructions from data and foreground redMaPPer clusters is increased 18% by the Wiener filter and 32% by GLIMPSE.

  20. Improving Weak Lensing Mass Map Reconstructions using Gaussian and Sparsity Priors: Application to DES SV

    Energy Technology Data Exchange (ETDEWEB)

    Jeffrey, N.; et al.

    2018-01-26

    Mapping the underlying density field, including non-visible dark matter, using weak gravitational lensing measurements is now a standard tool in cosmology. Due to its importance to the science results of current and upcoming surveys, the quality of the convergence reconstruction methods should be well understood. We compare three different mass map reconstruction methods: Kaiser-Squires (KS), Wiener filter, and GLIMPSE. KS is a direct inversion method, taking no account of survey masks or noise. The Wiener filter is well motivated for Gaussian density fields in a Bayesian framework. The GLIMPSE method uses sparsity, with the aim of reconstructing non-linearities in the density field. We compare these methods with a series of tests on the public Dark Energy Survey (DES) Science Verification (SV) data and on realistic DES simulations. The Wiener filter and GLIMPSE methods offer substantial improvement on the standard smoothed KS with a range of metrics. For both the Wiener filter and GLIMPSE convergence reconstructions we present a 12% improvement in Pearson correlation with the underlying truth from simulations. To compare the mapping methods' abilities to find mass peaks, we measure the difference between peak counts from simulated {\\Lambda}CDM shear catalogues and catalogues with no mass fluctuations. This is a standard data vector when inferring cosmology from peak statistics. The maximum signal-to-noise value of these peak statistic data vectors was increased by a factor of 3.5 for the Wiener filter and by a factor of 9 using GLIMPSE. With simulations we measure the reconstruction of the harmonic phases, showing that the concentration of the phase residuals is improved 17% by GLIMPSE and 18% by the Wiener filter. We show that the correlation between the reconstructions from data and the foreground redMaPPer clusters is increased 18% by the Wiener filter and 32% by GLIMPSE. [Abridged

  1. Robust Bayesian linear regression with application to an analysis of the CODATA values for the Planck constant

    Science.gov (United States)

    Wübbeler, Gerd; Bodnar, Olha; Elster, Clemens

    2018-02-01

    Weighted least-squares estimation is commonly applied in metrology to fit models to measurements that are accompanied with quoted uncertainties. The weights are chosen in dependence on the quoted uncertainties. However, when data and model are inconsistent in view of the quoted uncertainties, this procedure does not yield adequate results. When it can be assumed that all uncertainties ought to be rescaled by a common factor, weighted least-squares estimation may still be used, provided that a simple correction of the uncertainty obtained for the estimated model is applied. We show that these uncertainties and credible intervals are robust, as they do not rely on the assumption of a Gaussian distribution of the data. Hence, common software for weighted least-squares estimation may still safely be employed in such a case, followed by a simple modification of the uncertainties obtained by that software. We also provide means of checking the assumptions of such an approach. The Bayesian regression procedure is applied to analyze the CODATA values for the Planck constant published over the past decades in terms of three different models: a constant model, a straight line model and a spline model. Our results indicate that the CODATA values may not have yet stabilized.

  2. Localization of alpha emitters by damage production in a thin film. Application to the study of alpha emitter diffusion in irradiated samples; Localisation des emetteurs alpha par creation de dommages dans un film mince. Application a l'etude de la diffusion des emetteurs alpha dans des echantillons irradies

    Energy Technology Data Exchange (ETDEWEB)

    Houdaille, B; Perrot, M [Commissariat a l' Energie Atomique, 91 - Saclay (France). Centre d' Etudes Nucleaires

    1968-07-01

    The process of recording {alpha} particles on cellulose nitrate films, called alpha-graphy, is applied to the study of the diffusion of {alpha}-emitting elements in irradiated alloys. The existence of diffusion is shown by attacking the film with concentrated caustic soda after exposition. The insensitivity of the recorder to {beta} {gamma} radiation emitted by the sample after passing in the reactor makes it possible to operate with long exposure times and to detect small diffusions. The concentration-penetration curves are drawn up after carrying out a densitometric analysis of the alpha-graphies. - As the cellulose nitrate is affected only by {alpha} particles of energies of between 0.5 and 4 MeV, it was first necessary to determine the yield of the recorder for {alpha} particles emitted by a thick source, i.e. whose energy varies between 0 and E{sub 0}, E{sub 0} being the energy of the alpha emitter. - The concentration C of the {alpha}-emitter, as a function of the optical density D of the alpha-graphy, and of the exposure time t is given by a simple relationship: C = D/at where a is an experimental constant determined by calibration. It depends on the nature of the cellulose nitrate, of the {alpha}-emitting element and of the alloy studied. (authors) [French] Le procede d'enregistrement des particules alpha sur film de nitrate de cellulose, ou alphagraphie, est applique a l'etude de la diffusion d'elements emetteurs alpha dans des alliages irradies. La diffusion est mise en evidence par une attaque du film de nitrate, apres exposition, dans de la soude concentree. L'insensibilite de l'enregistreur au rayonnement {beta} {gamma}, emis par l'echantillon apres son sejour en pile, permet d'operer sur de longs temps de pose et de detecter des diffusions faibles. Les courbes concentration - penetration sont etablies par exploitation densitometrique des alphagraphies. - Comme le nitrate de cellulose n'est impressionne que par des particules alpha dont l'energie est

  3. Renormalization group summation, spectrality constraints, and coupling constant analyticity for phenomenological applications of two-point correlators in QCD

    International Nuclear Information System (INIS)

    Pivovarov, A.A.

    2003-01-01

    The analytic structure in the strong coupling constant that emerges for some observables in QCD after duality averaging of renormalization-group-improved amplitudes is discussed, and the validity of the infrared renormalon hypothesis for the determination of this structure is critically reexamined. A consistent description of peculiar features of perturbation theory series related to hypothetical infrared renormalons and corresponding power corrections is considered. It is shown that perturbation theory series for the spectral moments of two-point correlators of hadronic currents in QCD can explicitly be summed in all orders using the definition of the moments that avoids integration through the infrared region in momentum space. Such a definition of the moments relies on the analytic properties of two-point correlators in the momentum variable that allows for shifting the integration contour into the complex plane of the momentum. For definiteness, an explicit case of gluonic current correlators is discussed in detail

  4. Application of membrane LaF3 electrode in the determination of stability constants of Uranyl Fluoride complex in solution

    International Nuclear Information System (INIS)

    Muzakky; Iswani GS; Mintolo

    1996-01-01

    A membrane electrode LaF 3 has been applied in the determination of uranyl fluoride complex stability constant in solution. The determination is based on the detection of free F ion in solution as a result of hydrolysis reaction (process) of uranyl ions into the uranyl hydroxide form at low pH. The experiment results showed that there was no effect of ammonium carbonate 2 M titran, flow rate on the electrode response. The F release is optimum at pH 1. The free F ion in solution is calculated from the standard curve at pH 1, after the fluoride concentration at the same pH has been corrected. Using the plot of average number of ligand binding (n) versus minus log of free ligand (-log F) the value of β1 = 4.4, β2 = 7.48, β3=9.73, and β4 = 11.67

  5. Numerical solution of fully developed heat transfer problem with constant wall temperature and application to isosceles triangle and parabolic ducts

    International Nuclear Information System (INIS)

    Karabulut, Halit; Ipci, Duygu; Cinar, Can

    2016-01-01

    Highlights: • A numerical method has been developed for fully developed flows with constant wall temperature. • The governing equations were transformed to boundary fitted coordinates. • The Nusselt number of parabolic duct has been investigated. • Validation of the numerical method has been made by comparing published data. - Abstract: In motor-vehicles the use of more compact radiators have several advantages such as; improving the aerodynamic form of cars, reducing the weight and volume of the cars, reducing the material consumption and environmental pollutions, and enabling faster increase of the engine coolant temperature after starting to run and thereby improving the thermal efficiency. For the design of efficient and compact radiators, the robust determination of the heat transfer coefficient becomes imperative. In this study the external heat transfer coefficient of the radiator has been investigated for hydrodynamically and thermally fully developed flows in channels with constant wall temperature. In such situation the numerical treatment of the problem results in a trivial solution. To find a non-trivial solution the problem is treated either as an eigenvalue problem or as a thermally developing flow problem. In this study a numerical solution procedure has been developed and the heat transfer coefficients of the fully developed flow in triangular and parabolic air channels were investigated. The governing equations were transformed to boundary fitted coordinates and numerically solved. The non-trivial solution was obtained by means of guessing the temperature of any grid point within the solution domain. The correction of the guessed temperature was performed via smoothing the temperature profile on a line passing through the mentioned grid point. Results were compared with literature data and found to be consistent.

  6. Injectabilite des coulis de ciment dans des milieux fissures

    Science.gov (United States)

    Mnif, Thameur

    Le travail presente ici est un bilan du travaux de recherche effectues sur l'injectabilite des coulis de ciment dans lu milieux fissures. Un certain nombre de coulis a base de ciment Portland et microfin ont ete selectionnes afin de caracteriser leur capacite a penetrer des milieux fissures. Une partie des essais a ete menee en laboratoire. L'etude rheologique des differents melanges a permis de tester l'influence de l'ajout de superplastifiant et/ou de fumee de silice sur la distribution granulometrique des coulis et par consequent sur leur capacite a injecter des colonnes de sable simulant un milieu fissure donne. La classe granulometrique d'un coulis, sa stabilite et sa fluidite sont apparus comme les trois facteurs principaux pour la reussite d'une injection. Un facteur de finesse a ete defini au cours de cette etude: base sur la classe granulometrique du ciment et sa stabilite, il peut entrer dans la formulation theorique du debit d'injection avant application sur chantier. La deuxieme et derniere partie de l'etude presente les resultats de deux projets de recherche sur l'injection realises sur chantier. L'injection de dalles de beton fissurees a permis le suivi de l'evolution des pressions avec la distance au point d'injection. L'injection de murs de maconnerie a caractere historique a montre l'importance de la definition de criteres de performance des coulis a utiliser pour traiter un milieu donne et pour un objectif donne. Plusieurs melanges peuvent ainsi etre predefinis et mis a disposition sur le chantier. La complementarite des ciments traditionnels et des ciments microfins devient alors un atout important. Le choix d'utilisation de ces melanges est fonction du terrain rencontre. En conclusion, cette recherche etablit une methodologie pour la selection des coulis a base de ciment et des pressions d'injection en fonction de l'ouverture des fissures ou joints de construction.

  7. La recherche en action : des solutions locales, des effets durables ...

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

    15 déc. 2010 ... Le Centre de recherches pour le développement international (CRDI) appuie la production et l'application de connaissances qui améliorent de façon notable la situation des habitants des pays en développement.

  8. Biological Dosimetry Methods Employed at the Boris Kidric Institute of Nuclear Sciences; Application de Quelques Methodes Particulieres de Dosimetrie Biologique a l'Institut des Sciences Nucleaires Boris Kidric

    Energy Technology Data Exchange (ETDEWEB)

    Aleksic, B.; Veljkovic, D.; Djordjevic, O.; Djukic, Z. [Institut des Sciences Nucleaires Boris Kidric, Belgrade, Yugoslavia (Serbia)

    1971-06-15

    In addition to the more usual methods, the following methods are used at the Boris Kidric Institute of Nuclear Sciences in the medical supervision of occupationally exposed staff: analysis of bi nucleated lymphocytes and chromosome aberrations; physical examination (for example, determination of the pain sensitivity threshold, adaptation to pain, discrimination of sensitivity); capillaroscopy. These methods are described briefly and their practical application discussed. (author) [French] Outre les methodes habituelles, on a utilise a l'Institut Boris Kidric, pour le controle medical des travailleurs professionnellement exposes, des methodes d'analyse des lymphocytes binuclees et des aberrations chromosomiques, ainsi que des methodes d'examen physique telles que la determination du seuil de sensibilite douloureuse, de l'adaptation a la douleur et de la discrimination de la sensibilite, et la capillaroscopie. Ces methodes sont brievement decrites et leurs applications pratiques discutees. (author)

  9. The Role of Exponential and PCTR Experiments at Hanford in the Design of Large Power Reactors; Roles Respectifs des Experiences Exponentielles et du Reacteur d'Etude des Constantes Physiques de Hanford dans les Etudes de Grands Reacteurs de Puissance; Znachenie ehksponentsial'nykh opytov i opytov na reaktore PCTR pri proektirovanii bol'shikh ehnergeticheskikh reaktorov v khehnforde; Papel de los Experimentos Exponenciales y del Reactor PCTR de Hanford en el Proyecto de Grandes Reactores de Potencia

    Energy Technology Data Exchange (ETDEWEB)

    Heineman, R. E. [General Electric Company, Richland, WA (United States)

    1964-02-15

    use is described in the light of the trends which are observed. (author) [French] Des mesures exponentielles sont faites aux laboratoires de Hanford sur des reseaux uranium-graphite depuis pres de quinze ans. Les resultats de ces experiences ont ete utilises pour determiner les laplaciens de reacteurs de production que l'on se proposait de construire, mais ils ont servi egalement a ameliorer les connaissances dans le domaine de la physique de ces systemes. On s'est rendu compte tres rapidement qu'en raison des dimensions des assemblages et de leur manque de sensibilite aux petites perturbations localisees du systeme, l'experience exponentielle n'a qu'une utilite limitee. On a donc envisage de mettre au point des experiences integrales avec un reacteur de maniere a reduire au minimum la quantite de matieres necessaires pour se procurer des donnees valables. A cet effet, on a construit une installation critique perfectionnee a plusieurs regions, qu'on a appelee 'reacteur d'etude des constantes physiques' (RECP), dont on s'est servi pour determiner les constantes physiques de plusieurs reacteurs de puissance. On s'en est servi aussi couramment pour mesurer des sections efficaces et determiner des parametres differentiels et integraux de la physique des reacteurs pour divers types de milieux multiplicateurs. Apres la construction de RECP, on a encore employe les experiences exponentielles, bien que RECP ait largement comble les espoirs qui avaient ete places en lui. L'auteur indique quelques donnees caracteristiques obtenues a l'aide de ces deux genres d'installations et compare leurs roles respectifs pour l'etude de nouveaux reacteurs de puissance, pour la modification de reacteurs en fonctionnement, comme moyens de recherche sur la physique des reacteurs et comme moyen de formation. Il compare egalement les montants des capitaux investis dans ces installations et des frais de fonctionnement. Il indique comment ont ete mises au point de nouvelles methodes experimentales

  10. Application des fluides supercritiques à la production d'hydrocarbures. Exploitation des gisements par récupération assistée et applications diverses : pétrole, sables, schistes, charbons Application of Supercritical Fluids to Hydrocarbon Production. Enhanced Oi Recovery and Miscellaneous Applications: Oil, Tar Sands, Shales, Coals

    Directory of Open Access Journals (Sweden)

    Behar E.

    2006-11-01

    Full Text Available Le taux moyen de récupération par drainage naturel des gisements pétroliers atteint à peine 30 %. La récupération assistée désigne l'ensemble des procédés d'exploitation qui permettent d'accroître très sensiblement ce taux. Parmi ces procédés, l'injection de fluides supercritiques joue un rôle prometteur. Les principaux fluides actuellement utilisés sont : le méthane (ou plus généralement les gaz hydrocarbures dits pauvres , l'azote et enfin le gaz carbonique. Les domaines d'application et les mécanismes thermodynamiques mis en jeu sont brièvement exposés, les sources de fluides supercritiques disponibles au voisinage des gisements pétroliers sont rapidement répertoriées et certains problèmes d'exploitation évoqués. Outre leur application en récupération assistée, les fluides supercritiques sont également impliqués dans des procédés de raffinage et d'extraction divers. C'est le procédé de désasphaltage de fractions pétrolières lourdes qui, en 1956, a fait l'objet de la première application industrielle exploitant les fortes variations du pouvoir solvant d'un fluide au voisinage de son point critique. Ce procédé connaît, depuis une dizaine d'années, un regain d'intérêt du fait de l'économie d'énergie qu'il permet de réaliser. D'autre part, les schistes bitumineux, les sables asphaltiques et les charbons, sources d'hydrocarbures considérables pour l'avenir, constituent des domaines d'applications potentielles originales des fluides supercritiques. Les procédés spécifiques, pour la plupart en cours de développement au stade pilote, sont passés en revue. The average recovery by natural drainage from oil fields is barely 30%. Enhanced recovery includes all production processes which appreciably increase this rate. Among such processes, supercritical fluid flooding is quite promising. The main fluids now used are methane (or, more generally, so-called leangaseous hydrocarbons, nitrogen and carbon

  11. Application des techniques de diffusion de la lumière des rayons X et des neutrons à l'étude des systèmes colloïdaux. Première partie : Présentation théorique des trois techniques Application of Light, X-Ray and Neutron Diffusion Techniques to the Study of Colloidal Systems. Part One : Theoretical Description of Three Techniques

    Directory of Open Access Journals (Sweden)

    Espinat D.

    2006-11-01

    Full Text Available Les techniques de diffusion, des rayons X, des neutrons et de la lumière, jouent un rôle très important pour la compréhension des milieux colloïdaux. Peu d'articles de la littérature s'attachent à présenter conjointement les trois méthodes. Nous avons, dans la première partie de cet article, détaillé les principes théoriques en insistent tout particulièrement sur les spécificités de chacune. Après les rappels concernant la diffusion par les systèmes dilués, nous nous sommes intéressés aux systèmes concentrés pour lesquels les entités diffusantes sont en interaction. Les milieux dispersés montrent souvent une certaine polydispersité que l'on cherche à mesurer; les techniques de diffusion permettent cette mesure. Nous terminerons cette revue par une description des appareillages utilisés. La deuxième partie de cet article concernera une large illustration des possibilités de ces méthodes d'analyse à l'étude des systèmes colloïdaux, sur la base de travaux effectués à I'IFP (Institut Français du Pétrole ou dans de nombreux laboratoires de recherche extérieurs. This article aims to describe X-ray, neutron and light scattering techniques with emphasis on their specific nature and their scope of application. Indeed, whereas light diffusion has been used for a long time in research laboratories, in particular for characterizing polymers in solution, small angle X-ray scattering has been the subject of renewed interest in recent years. Neutron scattering, which is obviously more difficultly accessible, has proven to be extremely useful for studying various systems for which light and X-ray scattering remain relatively powerless. Whereas there is an abundant literature concerning various applications of the three methods, it should be noted that only a few articles have attempted to describe all three techniques at the same time. In this article we have tried to make up for this lack, and as such it was

  12. Contribution to the automatic command in robotics - Application to the command by microprocessors of the articulated systems; Contribution a la commande automatique en robotique. Application a la commande par microprocesseurs des manipulateurs articules

    Energy Technology Data Exchange (ETDEWEB)

    Al Mouhamed, Mayez

    1982-01-29

    The first part of the present paper deals with the main methods of changing the coordinates for a general articulated system. After a definition of the coordinates changing, we propose a coordination system designed for easy programming of the movements. Its characteristic is to permit the action anywhere on the manipulated object. The second part deals with the force regulation problem. For this purpose we have developed a general force sensor. The informations delivered by the sensor are used by force regulators which are intended for the automatic assembly of subsystems. In the third part the dynamic problem of the articulated systems is exposed. We present a new method which allows to determine dynamic parameters from appropriate motions of the robot. These parameters are then used to implement the dynamic control. Several applications, using the powerful microprocessor INTEL 8086 and its arithmetic coprocessor 8087, are presented, in order to demonstrate the performances gained. (author) [French] Dans la premiere partie de ce memoire, nous exposons les principales methodes de changement de coordonnees pour un systeme articule general. Apres une definition adequate de ce dernier, nous proposons un systeme de coordination permettant une programmation facile des mouvements. Sa caracteristique est de prendre comme centre d'action un point quelconque de l'objet manipule. Dans la deuxieme partie, nous etudions la regulation en effort. Pour cela nous avons developpe un capteur de forces general. Les informations que delivre ce dernier sont utilisees par des regulateurs d'effort adaptes au contexte de l'assemblage automatique des pieces. Dans la troisieme partie, nous exposons une nouvelle methode de commande dynamique des systemes articules. Nous obtenons des parametres dynamiques du robot a partir de mouvements appropries. Ces derniers sont ensuite utilises dans l'elaboration des commandes. Des applications utilisant le microprocesseur INTEL 8086 avec son

  13. A new Volcanic managEment Risk Database desIgn (VERDI): Application to El Hierro Island (Canary Islands)

    Science.gov (United States)

    Bartolini, S.; Becerril, L.; Martí, J.

    2014-11-01

    One of the most important issues in modern volcanology is the assessment of volcanic risk, which will depend - among other factors - on both the quantity and quality of the available data and an optimum storage mechanism. This will require the design of purpose-built databases that take into account data format and availability and afford easy data storage and sharing, and will provide for a more complete risk assessment that combines different analyses but avoids any duplication of information. Data contained in any such database should facilitate spatial and temporal analysis that will (1) produce probabilistic hazard models for future vent opening, (2) simulate volcanic hazards and (3) assess their socio-economic impact. We describe the design of a new spatial database structure, VERDI (Volcanic managEment Risk Database desIgn), which allows different types of data, including geological, volcanological, meteorological, monitoring and socio-economic information, to be manipulated, organized and managed. The root of the question is to ensure that VERDI will serve as a tool for connecting different kinds of data sources, GIS platforms and modeling applications. We present an overview of the database design, its components and the attributes that play an important role in the database model. The potential of the VERDI structure and the possibilities it offers in regard to data organization are here shown through its application on El Hierro (Canary Islands). The VERDI database will provide scientists and decision makers with a useful tool that will assist to conduct volcanic risk assessment and management.

  14. Analysis of Spain´s competitiveness in the European tomato market: An application of the Constant Market Share method

    Energy Technology Data Exchange (ETDEWEB)

    Capobianco-Uriarte, M.; Aparicio, J.; Pablo-Valenciano, J. de

    2017-07-01

    This paper presents a quantitative analysis of the competitiveness of Spanish tomato export compared with its major competitors in the European Union market countries (EU28). The methodological framework is implemented through Constant Market Share to analyze variations in exports, allowing the portion attributable to competitiveness and segregation into general or specific competitiveness to be quantified. This analysis was carried out with the 2005-2009 and 2010-2014 periods to see if there had been a recovery from the global financial and economic crisis of 2007 in the Spanish tomato trade. Before the global economic and financial crisis, Spain had a positive structural effect of exports which contributed significantly to the growth of tomato sales to the EU, but had a negative change in the volume of exports to the EU28, mainly due to the negative effect of the competitiveness component. According to the segregation effect of competitiveness, a marked general negative competitive effect was evident, that cannot be offset by the positive effect of specific competitiveness. Since 2010, Spain has experienced a positive change in the volume of its tomato exports to the EU28, the competitiveness component also being positive, due to positive investment of the component of general competitiveness and whose greatest contribution was the positive effect of specific competitiveness. Within the group of competitors, Spain is the only country supplying tomatoes to the EU28 that has experienced a positive change in volume when comparing business performance of 2010-2014 vs 2005-2009.

  15. Analysis of Spain´s competitiveness in the European tomato market: An application of the Constant Market Share method

    Directory of Open Access Journals (Sweden)

    Mercedes Capobianco-Uriarte

    2017-12-01

    Full Text Available This paper presents a quantitative analysis of the competitiveness of Spanish tomato export compared with its major competitors in the European Union market countries (EU28. The methodological framework is implemented through Constant Market Share to analyze variations in exports, allowing the portion attributable to competitiveness and segregation into general or specific competitiveness to be quantified. This analysis was carried out with the 2005-2009 and 2010-2014 periods to see if there had been a recovery from the global financial and economic crisis of 2007 in the Spanish tomato trade. Before the global economic and financial crisis, Spain had a positive structural effect of exports which contributed significantly to the growth of tomato sales to the EU, but had a negative change in the volume of exports to the EU28, mainly due to the negative effect of the competitiveness component. According to the segregation effect of competitiveness, a marked general negative competitive effect was evident, that cannot be offset by the positive effect of specific competitiveness. Since 2010, Spain has experienced a positive change in the volume of its tomato exports to the EU28, the competitiveness component also being positive, due to positive investment of the component of general competitiveness and whose greatest contribution was the positive effect of specific competitiveness. Within the group of competitors, Spain is the only country supplying tomatoes to the EU28 that has experienced a positive change in volume when comparing business performance of 2010-2014 vs 2005-2009.

  16. Analysis of Spain´s competitiveness in the European tomato market: An application of the Constant Market Share method

    International Nuclear Information System (INIS)

    Capobianco-Uriarte, M.; Aparicio, J.; Pablo-Valenciano, J. de

    2017-01-01

    This paper presents a quantitative analysis of the competitiveness of Spanish tomato export compared with its major competitors in the European Union market countries (EU28). The methodological framework is implemented through Constant Market Share to analyze variations in exports, allowing the portion attributable to competitiveness and segregation into general or specific competitiveness to be quantified. This analysis was carried out with the 2005-2009 and 2010-2014 periods to see if there had been a recovery from the global financial and economic crisis of 2007 in the Spanish tomato trade. Before the global economic and financial crisis, Spain had a positive structural effect of exports which contributed significantly to the growth of tomato sales to the EU, but had a negative change in the volume of exports to the EU28, mainly due to the negative effect of the competitiveness component. According to the segregation effect of competitiveness, a marked general negative competitive effect was evident, that cannot be offset by the positive effect of specific competitiveness. Since 2010, Spain has experienced a positive change in the volume of its tomato exports to the EU28, the competitiveness component also being positive, due to positive investment of the component of general competitiveness and whose greatest contribution was the positive effect of specific competitiveness. Within the group of competitors, Spain is the only country supplying tomatoes to the EU28 that has experienced a positive change in volume when comparing business performance of 2010-2014 vs 2005-2009.

  17. Application des techniques de diffusion de la lumière des rayons x et des neutrons à l'étude des systèmes colloïdaux. Deuxième partie : étude des différents systèmes : polymères en solution à l'état solide, solutions micellaires, systèmes fractals Application of Light, X-Ray and Neutron Diffusion Techniques to the Study of Colloidal Systems. Part Two: Research on Different Systems: Polymers in Solution in the Solid State, Micellar Solutions, Fractals Systems

    Directory of Open Access Journals (Sweden)

    Espinat D.

    2006-11-01

    Full Text Available Cet article fait suite à la première partie (Revue Inst. Franç. du Pétrole, vol. 45, n°6, novembre-décembre 1990 concernant l'application des techniques de diffusion de la lumière, des rayons X et des neutrons à l'étude des systèmes colloïdaux et plus précisément à la présentation théorique des trois méthodes. L'objet de cette deuxième partie est la présentation non exhaustive de quelques domaines d'applications. Nous nous attacherons tout particulièrement à présenter les potentialités des méthodes pour la caractérisation de systèmes colloïdaux ou divisés rencontrés dans de nombreuses branches d'activité de l'industrie pétrolière. Nous aborderons dans une première partie les solutions polymériques et colloïdales. En particulier nous nous attarderons sur l'importance des techniques de diffusion pour la caractérisation des polymères en solution et des solutions micellaires. Nous verrons également quelles informations la diffusion centrale peut apporter sur la macrostructure des polymères cristallisés ou amorphes à l'état solide. De nombreux systèmes présentent une structure de type fractal ; après présentation de quelques exemples, nous montrerons que les méthodes de diffusion peuvent apporter certaines informations sur ces matériaux, notamment la dimension fractale. This article is the second one (the first one was published in Revue de l'Institut Français du Pétrole No. 6, NovemberDecember 1990 concerning the application of techniques of light scattering, X rays and neutrons to the analysis of colloidal systems and more specifically to the theoretical description of the three methods. The aim of this second part is to make a nonexhaustive description of several fields of applications. A special effort is made to describe the potential of these methods for characterizing colloidal or divided systems encountered in a great many activities involving the petroleum industry. The first part of this

  18. Application of Constant Rate of Supply model (CRS) in dating of Guanabara Bay sediments using 210Pb measures

    International Nuclear Information System (INIS)

    Braganca, Maura Julia Camara da Silva

    1992-09-01

    A geochronological study of the Guanabara Bay (Rio de Janeiro, Brazil) based on 210P b dating technique to determine sedimentation rates and using the Constant Rate of Supply model (CRS) is presented in this work. Sediment samples were collected from river-head of Estrela, Sao Joao de Meriti, Guapimirim, Guaxindiba e Imbuacu. A low energy gamma spectrometry ( 210P b, samples taken from the Estrela and Sao Joao de Meriti rivers. Radiochemical method was applied to determine the amount of 210P b in samples collected near Guapimirim, Guaxindiba and Imbuacu Rivers. Atomic absorption spectrometry with air-acetylene flame technique was used to determine the amount of copper in all these samples. Experimental data shown the following variation in the concentration levels of copper and 210P b: (i) copper; from 2.5 μg/g to 37.1 μg/g (Imbuacu River); from 3.6 to 228.1 μg/g (Estrela River); from 11.6 to 73.4 μg/g (Guapimirim River); from 12.0 to 52.9 μg/g (Guaxindiba River) and from 90.8 to to 237.7 μg/g (Sao Joao de Meriti River), (ti) 210P b; from 2.0 Bq/kg to 27.0 Bq/kg (Imbuacu River); from 25.2 to 136.6 Bq/kg (Estrela River); from 40.0 to 90.0 Bq/kg (Sao Joao de Meriti River); from 7.0 to 70.0 Bq/kg (Guapimirim River); from 10.0 to 48.0 Bq/kg (Guaxindiba River). The sedimentation rates ranged from 0.30 cm/y in the Imbuacu River for a depth below of 35 cm to 1.3 cm/y for 0-30 cm depth in Guaxindiba River. It was concluded that the experimental data found in this work are consistent with those published in the scientific literature and that they can be predicted by the CRS model. (author)

  19. Evaluation des risques-projet par une approche AHP/WPM: Application à un projet réel BTP

    OpenAIRE

    LMOUSSAOUI , Hafida; JAMOULI , Hicham

    2015-01-01

    International audience; La complexité et l'incertitude de l'environnement sont à l'origine de nouveaux défis auxquels les entreprises du domaine BTP font face quotidiennement. La maîtrise des paramètres des projets devient donc une nécessité pour leur pérennité. L'objectif du management des risques est de maîtriser ces paramètres pendant toutes les phases du projet. Il s'appuie sur un processus continu et itératif permettant successivement d'identifier et analyser les risques encourus, les év...

  20. The application of the constants of motion to nonlinear stationary waves in complex plasmas: a unified fluid dynamic viewpoint

    Science.gov (United States)

    McKenzie, J. F.; Dubinin, E.; Sauer, K.; Doyle, T. B.

    2004-08-01

    Perturbation reductive procedures, as used to analyse various weakly nonlinear plasma waves (solitons and periodic waves), normally lead to the dynamical system being described by KdV, Burgers' or a nonlinear Schrödinger-type equation, with properties that can be deduced from an array of mathematical techniques. Here we develop a fully nonlinear theory of one-dimensional stationary plasma waves, which elucidates the common nature of various diverse wave phenomena. This is accomplished by adopting an essentially fluid dynamic viewpoint. In this unified treatment the constants of the motion (for mass, momentum and energy) lead naturally to the construction of the wave structure equations. It is shown, for example, that electrostatic, Hall magnetohydrodynamic and ion cyclotron acoustic nonlinear waves all obey first-order differential equations of the same generic type for the longitudinal flow field of the wave. The equilibrium points, which define the soliton amplitude, are given by the compressive and/or rarefactive roots of a total plasma ‘energy’ or ‘momentum’ function characterizing the wave type. This energy function, which is an algebraic combination of the Bernoulli momentum and energy functions for the longitudinal flow field, is the fluid dynamic counterpart of the pseudo-potentials, which are characteristic of system structure equations formulated in other than fluid variables. Another general feature of the structure equation is the phenomenon of choked flow, which occurs when the flow speed becomes sonic. It is this trans-sonic property that limits the soliton amplitudes and defines the critical collective Mach numbers of the waves. These features are also obtained in multi-component plasmas where, for example, in a bi-ion plasma, momentum exchanges between protons and heavier ions are mediated by the Maxwell magnetic stresses. With a suitable generalization of the concept of a sonic point in a bi-ion system and the corresponding choked flow

  1. Thermoluminescence du quartz naturel et artificiel pur ou dopé des ions Fe++ et Fe+++: application à la datation des poteries

    Directory of Open Access Journals (Sweden)

    1978-01-01

    Full Text Available La thermoluminescence constatée sur les échantillons de poteries et conduisant à la datation archéologique de celles-ci, est due aux inclusions de quartz initialement contenues dans l'argile. Nous présentons une étude de la thermoluminescence d'échantillons de quartz monocristallin synthétique dans lesquels des impuretés ont été volontairement ajoutées et appliquons les résultats à une nouvelle technique de datation, la méthode DATE (différence d'atténuation temporelle des émissions. La termoluminiscencia constatada en muestras de cerámica permite una datación arqueológica es debida a las inclusiones de cuarzo inicialmente contenidas en la arcilla. Se presenta un estudio de la termoluminiscencia de muestras de cuarzo monocristalino sintético en las cuales han sido colocadas voluntariamente impurezas se han aplicado los resultados de una nueva técnica de fechado, el método DATE (Diferencia de atenuación temporal de emisiones. The thermoluminescence observed on samples of pottery and leading to their archaeological dating is a result of the presence of quartz particles originally enclosed in the clay. We offer a study of the termoluminescence of samples of synthetic mono-crystalline quartz doped in with impurities and apply the results to a new dating technique, the 'DATE' method, based upon difference in time attenuation of the emissions.

  2. Universe of constant

    Science.gov (United States)

    Yongquan, Han

    2016-10-01

    The ideal gas state equation is not applicable to ordinary gas, it should be applied to the Electromagnetic ``gas'' that is applied to the radiation, the radiation should be the ultimate state of matter changes or initial state, the universe is filled with radiation. That is, the ideal gas equation of state is suitable for the Singular point and the universe. Maybe someone consider that, there is no vessel can accommodate radiation, it is because the Ordinary container is too small to accommodate, if the radius of your container is the distance that Light through an hour, would you still think it can't accommodates radiation? Modern scientific determinate that the radius of the universe now is about 1027 m, assuming that the universe is a sphere whose volume is approximately: V = 4.19 × 1081 cubic meters, the temperature radiation of the universe (cosmic microwave background radiation temperature of the universe, should be the closest the average temperature of the universe) T = 3.15k, radiation pressure P = 5 × 10-6 N / m 2, according to the law of ideal gas state equation, PV / T = constant = 6 × 1075, the value of this constant is the universe, The singular point should also equal to the constant Author: hanyongquan

  3. Trends in the choice of refrigerants according to the applications; Tendances dans le choix des frigorigenes selon les applications

    Energy Technology Data Exchange (ETDEWEB)

    Billiard, F.

    2002-07-01

    No general rules exist in the choice of refrigerants but five classical criteria: thermo-physical, technological, economical, safety, environmental, some regulations and local standards, and the 'cultural' criteria linked with the professional habits and with the personnel training. The best approach to present the evolutions and trends in this domain consists in reasoning application by application. In this document, 8 applications are analyzed: domestic, commercial, and industrial refrigeration, terrestrial and maritime refrigerating transport, air conditioning and heat pumps, air conditioning with water cooling groups, and mobile air conditioning. For each application, national and worldwide statistical data are given which allow to characterize the economical importance of the sector of application and the trends in the choice of refrigerants (HFC, ammonia, hydrocarbons, CO{sub 2} etc..). Finally, some future trends are briefly evoked. (J.S.)

  4. Light ions radiobiological effects on human tumoral cells: measurements modelling and application to hadron-therapy; Mesures et modelisation des effets radiobiologiques des ions legers sur des cellules tumorales humaines: application a l'hadrontherapie

    Energy Technology Data Exchange (ETDEWEB)

    Jalade, P

    2005-11-15

    In classical radiotherapy, the characteristics of photons interactions undergo limits for the treatment of radioresistant and not well located tumours. Pioneering treatments of patients at the Lawrence Laboratory at Berkeley has demonstrated two advantages of hadrons beams: the Relative Biologic Effect (the RBE) and the ballistic of the beams. Since 1994, the clinical centre at Chiba, has demonstrated successfully the applicability of the method. A physics group, managed by G. Kraft, at Darmstadt in Germany, has underlined the advantages of carbon beams. An European pool, called ENGIGHT (European Network for LIGHt ion Therapy) has been created in which the French ETOILE project appeared. The purpose of the thesis concerns measurements and models of 'in vitro' human cells survival. In the first part, the nowadays situation in particles interactions, tracks and cells structures and radiobiology is presented here. The second is devoted to the models based on the beam tracks and localization of the physical dose. Discussion of sensitivity to various parameters of the model has been realized with the help of numerical simulations. Finally the predictions of the improved model has been compared to experimental irradiations of human cells with argon and carbon beams of the GANIL machine. Conclusion of such study shows the performance and limits of a local model for predicting the radiobiological efficiency of light ions in hadron-therapy. (author)

  5. Light ions radiobiological effects on human tumoral cells: measurements modelling and application to hadron-therapy; Mesures et modelisation des effets radiobiologiques des ions legers sur des cellules tumorales humaines: application a l'hadrontherapie

    Energy Technology Data Exchange (ETDEWEB)

    Jalade, P

    2005-11-15

    In classical radiotherapy, the characteristics of photons interactions undergo limits for the treatment of radioresistant and not well located tumours. Pioneering treatments of patients at the Lawrence Laboratory at Berkeley has demonstrated two advantages of hadrons beams: the Relative Biologic Effect (the RBE) and the ballistic of the beams. Since 1994, the clinical centre at Chiba, has demonstrated successfully the applicability of the method. A physics group, managed by G. Kraft, at Darmstadt in Germany, has underlined the advantages of carbon beams. An European pool, called ENGIGHT (European Network for LIGHt ion Therapy) has been created in which the French ETOILE project appeared. The purpose of the thesis concerns measurements and models of 'in vitro' human cells survival. In the first part, the nowadays situation in particles interactions, tracks and cells structures and radiobiology is presented here. The second is devoted to the models based on the beam tracks and localization of the physical dose. Discussion of sensitivity to various parameters of the model has been realized with the help of numerical simulations. Finally the predictions of the improved model has been compared to experimental irradiations of human cells with argon and carbon beams of the GANIL machine. Conclusion of such study shows the performance and limits of a local model for predicting the radiobiological efficiency of light ions in hadron-therapy. (author)

  6. Determinatin dúne application des betons de balles de riz dans le ...

    African Journals Online (AJOL)

    The obtained concretes are light and have compressive strength between 1 and 8 MPa. An application of these concretes is their use for the manufacture of masonry blocks and interjoists entering in the realization of walls and coffer floor. Key words: Rice husks, lightweight concrete, compressive strength, Masonry blocks, ...

  7. Applications analytiques des films minces de mercure protégés par ...

    African Journals Online (AJOL)

    Analytical application of fibrinogen-coated mercury film electrodes for the detection of lead and cadmium in water samples. The aim of this study was the development of sensor based on fibrinogen (Fbg) coated mercury film electrodes at carbon paste electrode in the perspective of in-field stripping analysis of heavy metals ...

  8. Constant physics and characteristics of fundamental constant

    International Nuclear Information System (INIS)

    Tarrach, R.

    1998-01-01

    We present some evidence which supports a surprising physical interpretation of the fundamental constants. First, we relate two of them through the renormalization group. This leaves as many fundamental constants as base units. Second, we introduce and a dimensional system of units without fundamental constants. Third, and most important, we find, while interpreting the units of the a dimensional system, that is all cases accessible to experimentation the fundamental constants indicate either discretization at small values or boundedness at large values of the corresponding physical quantity. (Author) 12 refs

  9. Applicability of ICRP principles for safety analysis of radioactive waste geological storage; Etude de l'applicabilite des principes de la CIPR a l'analyse de surete du stockage geologique des dechets radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Lombard, J; Hubert, P; Pages, P

    1987-07-01

    modalites de stockage) doit etre determine par un processus comparatif visant a selectionner le niveau conduisant au meilleur compromis entre es depenses de protection et les risques residuels. Ces recommandations, particulierement Ia seconde, s'ecartent des principes des analyses de surete suivis jusqu'a present en France et a l'etranger; cette etude envisage les avantages et inconvenients potentiels lies a l'introduction de ce second principe. Dans ce but on se base sur differentes analyses realisees au niveau international integrant partiellement au moms ces principes. II ressort de cet examen que ces principes sont applicables mais que leur mise en oeuvre necessite une reorientation de modeles d'evaluation en particulier pour s'affranchir d'hypotheses trop conservatrices. Cette mise en oeuvre necessite par ailleurs davantage d'informations que dans le cas d'une approche deterministe de Ia surete puisqu'il faut estimer les consequences et les probabilites de I'ensemble des evenements possibles et ce pour es diverses modalites de stockage que l'on se propose de comparer. L'integration d'evaluation de ce type est cependant plus riche d'enseignements et constitue de ce fait une aide a Ia decision qui peut etre feconde. On peut enfin souligner que cette approche permet un meilleur dialogue entre les differentes instances decisionnelles et plus generalement entre les acteurs du debat, dans Ia mesure ou elle apporte un langage de discussion commun. On notera d'ailleurs que ce souci de clarification s'exprime quelle que soit I'optique de surete adopte (deterministe ou probabiliste), comme en temoignent les interrogations sur le sens du 'scenario central' de I'etude KBS. Par ailleurs, ii semble que ces principes seront vraisemblablement suivis au plan international afin d'uniformiser en outre les modes de gestion de Ia radioprotection dans ses diff?rentes composantes. (author)

  10. The mechanical first law of black hole spacetimes with a cosmological constant and its application to the Schwarzschild-de Sitter spacetime

    International Nuclear Information System (INIS)

    Urano, Miho; Tomimatsu, Akira; Saida, Hiromi

    2009-01-01

    The mechanical first law (MFL) of black hole spacetimes is a geometrical relation which relates variations of the mass parameter and horizon area. While it is well known that the MFL of an asymptotic flat black hole is equivalent to its thermodynamical first law, however we do not know the detail of the MFL of black hole spacetimes with a cosmological constant which possess a black hole and cosmological event horizons. This paper aims to formulate an MFL of the two-horizon spacetimes. For this purpose, we try to include the effects of two horizons in the MFL. To do so, we make use of the Iyer-Wald formalism and extend it to regard the mass parameter and the cosmological constant as two independent variables which make it possible to treat the two horizons on the same footing. Our extended Iyer-Wald formalism preserves the existence of the conserved Noether current and its associated Noether charge, and gives an abstract form of the MFL of black hole spacetimes with a cosmological constant. Then, as a representative application of this formalism, we derive the MFL of the Schwarzschild-de Sitter (SdS) spacetime. Our MFL of the SdS spacetime relates the variations of three quantities: the mass parameter, the total area of the two horizons and the volume enclosed by the two horizons. If our MFL is regarded as a thermodynamical first law of the SdS spacetime, it offers a thermodynamically consistent description of the SdS black hole evaporation process: the mass decreases while the volume and the entropy increase. In our suggestion, a generalized second law is not needed to ensure the second law of SdS thermodynamics for its evaporation process.

  11. Les lipases sont des hydrolases atypiques : principales caractéristiques et applications

    Directory of Open Access Journals (Sweden)

    Fickers P.

    2008-01-01

    Full Text Available ipases are atypical hydrolases: principal characteristics and applications. Due to their kinetic and substrate specificities, triacylglycerol acyl-hydrolases or lipases are atypical enzymes. In function of their microenvironment, lipases are able to act as hydrolases in aqueous solution or as biocatalysts in organic synthesis. As hydrolases, they are responsible of the triglycerids catabolism into fatty acids and glycerol. In many organisms, this reaction plays a major role in the fat and lipid metabolism. In addition, lipases are also able to hydrolyse phospholipids and cholesterol esters. In organic solvent, lipases could catalyse reactions such as esterifications, acidolysis or alcoolysis with enantio-, regio- and chimioselectivity. Lipases form a mixed class of enzyme due to their animal, vegetal or microbial origins. All those properties led to the development of many applications in the food and chemical industries but also in the medical and therapeutic field.

  12. Formation et application des nanoparticules dans les fibres optiques en silice

    OpenAIRE

    Blanc , Wilfried; Dussardier , Bernard

    2016-01-01

    International audience; Optical fibers are the basis for applications that have grown considerably in recent years (telecommunications, sensors, fiber lasers, etc). Despite undeniable successes, it is necessary to develop new generations of amplifying optical fibers that will overcome some limitations typical of silica glass. In this sense, the amplifying Transparent Glass Ceramics (TGC), and particularly the fibers based on this technology, open new perspectives that combine the mechanical a...

  13. Ionizing radiation sources: very diversified means, multiple applications and a changing regulatory environment. Conference proceedings; Les sources de rayonnements ionisants: des moyens tres diversifies, des applications multiples et une reglementation en evolution. Recueil des presentations

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-11-15

    This document brings together the available presentations given at the conference organised by the French society of radiation protection about ionizing radiation source means, applications and regulatory environment. Twenty eight presentations (slides) are compiled in this document and deal with: 1 - Overview of sources - some quantitative data from the national inventory of ionizing radiation sources (Yann Billarand, IRSN); 2 - Overview of sources (Jerome Fradin, ASN); 3 - Regulatory framework (Sylvie Rodde, ASN); 4 - Alternatives to Iridium radiography - the case of pressure devices at the manufacturing stage (Henri Walaszek, Cetim; Bruno Kowalski, Welding Institute); 5 - Dosimetric stakes of medical scanner examinations (Jean-Louis Greffe, Charleroi hospital of Medical University); 6 - The removal of ionic smoke detectors (Bruno Charpentier, ASN); 7 - Joint-activity and reciprocal liabilities - Organisation of labour risk prevention in case of companies joint-activity (Paulo Pinto, DGT); 8 - Consideration of gamma-graphic testing in the organization of a unit outage activities (Jean-Gabriel Leonard, EDF); 9 - Radiological risk control at a closed and independent work field (Stephane Sartelet, Areva); 10 - Incidents and accidents status and typology (Pascale Scanff, IRSN); 11 - Regional overview of radiation protection significant events (Philippe Menechal, ASN); 12 - Incident leading to a tritium contamination in and urban area - consequences and experience feedback (Laurence Fusil, CEA); 13 - Experience feedback - loss of sealing of a calibration source (Philippe Mougnard, Areva); 14 - Blocking incident of a {sup 60}Co source (Bruno Delille, Salvarem); 15 - Triggering of gantry's alarm: status of findings (Philippe Prat, Syctom); 16 - Non-medical electric devices: regulatory changes (Sophie Dagois, IRSN; Jerome Fradin, ASN); 17 - Evaluation of the dose equivalent rate in pulsed fields: method proposed by the IRSN and implementation test (Laurent Donadille

  14. Measurement and analysis of high energy radiation through activation detectors. Application in dosimetry; Sur la mesure et l'analyse des rayonnements de haute energie par detecteurs a activation. Application a la dosimetrie

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-10-15

    This work is concerned with the possibility of measurement and analysis of radiation fluences within objects of small volume submitted to a high energy proton beam. The first part, consecrated to the establishment of a method of analysis, comprises a detailed study of the radiation nature and energy spectra as well as of the various dosimetry methods. In order to select a group of detectors, high energy nuclear reactions were systematically studied and for some of them cross sections were measured or calculated: for example the cross section of the reaction {sup 11}B (p,n) {sup 11}C between 150 and 3000 MeV and of the reaction {sup 34}S (p,2pn) {sup 32}P between 50 and 3000 MeV. The second part is relative to the application of the fore-mentioned analysis to radiation within a tissue equivalent phantom irradiated by 3 GeV protons. This analysis is sufficiently detailed to allow the reconstitution of the absorbed doses, the dose equivalent and, contingent on a better knowledge of the dose due to heavy particles, the quality factors. It allowed also to follow the evolution of the various dosimetric data as a function of the depth inside the phantom and to verify calculations already done by other researchers. The comparison of the measured doses and the corresponding detector activities revealed the possibility that some detectors could give directly the absorbed dose, or even the dose equivalent, by a simple activity measurement. (author) [French] Le travail porte sur la possibilite de mesure et d'analyse, a l'aide de detecteurs a activation, des fluences de rayonnements a l'interieur d'un objet de petit volume soumis a un faisceau de protons de tres haute energie. La premiere partie, consacree a la mise au point de la methode d'analyse des fluences, comporte une etude detaillee de la nature des rayonnements et de leurs spectres energetiques ainsi que des differentes methodes de dosimetrie. Pour arriver au choix d'un groupe de

  15. Measurement and analysis of high energy radiation through activation detectors. Application in dosimetry; Sur la mesure et l'analyse des rayonnements de haute energie par detecteurs a activation. Application a la dosimetrie

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-10-15

    This work is concerned with the possibility of measurement and analysis of radiation fluences within objects of small volume submitted to a high energy proton beam. The first part, consecrated to the establishment of a method of analysis, comprises a detailed study of the radiation nature and energy spectra as well as of the various dosimetry methods. In order to select a group of detectors, high energy nuclear reactions were systematically studied and for some of them cross sections were measured or calculated: for example the cross section of the reaction {sup 11}B (p,n) {sup 11}C between 150 and 3000 MeV and of the reaction {sup 34}S (p,2pn) {sup 32}P between 50 and 3000 MeV. The second part is relative to the application of the fore-mentioned analysis to radiation within a tissue equivalent phantom irradiated by 3 GeV protons. This analysis is sufficiently detailed to allow the reconstitution of the absorbed doses, the dose equivalent and, contingent on a better knowledge of the dose due to heavy particles, the quality factors. It allowed also to follow the evolution of the various dosimetric data as a function of the depth inside the phantom and to verify calculations already done by other researchers. The comparison of the measured doses and the corresponding detector activities revealed the possibility that some detectors could give directly the absorbed dose, or even the dose equivalent, by a simple activity measurement. (author) [French] Le travail porte sur la possibilite de mesure et d'analyse, a l'aide de detecteurs a activation, des fluences de rayonnements a l'interieur d'un objet de petit volume soumis a un faisceau de protons de tres haute energie. La premiere partie, consacree a la mise au point de la methode d'analyse des fluences, comporte une etude detaillee de la nature des rayonnements et de leurs spectres energetiques ainsi que des differentes methodes de dosimetrie. Pour arriver au choix d'un groupe de detecteurs, une etude systematique des

  16. Capacitive Cells for Dielectric Constant Measurement

    Science.gov (United States)

    Aguilar, Horacio Munguía; Maldonado, Rigoberto Franco

    2015-01-01

    A simple capacitive cell for dielectric constant measurement in liquids is presented. As an illustrative application, the cell is used for measuring the degradation of overheated edible oil through the evaluation of their dielectric constant.

  17. Digital Generation of Noise-Signals with Arbitrary Constant or Time-Varying Spectra (A noise generation software package and its application)

    CERN Document Server

    Tückmantel, Joachim

    2008-01-01

    Artificial creation of arbitrary noise signals is used in accelerator physics to reproduce a measured perturbation spectrum for simulations but also to generate real-time shaped noise spectra for controlled emittance blow-up giving tailored properties to the final bunch shape. It is demonstrated here how one can produce numerically what is, for all practical purposes, an unlimited quantity of non-periodic noise data having any predefined spectral density. This spectral density may be constant or varying with time. The noise output never repeats and has excellent statistical properties, important for very long-term applications. It is difficult to obtain such flexibility and spectral cleanliness using analogue techniques. This algorithm was applied both in computer simulations of bunch behaviour in the presence of RF noise in the PS, SPS and LHC and also to generate real-time noise, tracking the synchrotron frequency change during the energy ramp of the SPS and producing controlled longitudinal emittance blow-...

  18. Virtual Reality: State of Military Research and Applications in Member Countries (La realite virutelle: L’etat actuel des travaux de recherche et des applications militaires dans les pays membres de l’Alliance)

    Science.gov (United States)

    2003-02-01

    avec des réglages ergonomiques) avec un casque de Réalité Virtuelle (Kaiser Proview 60) en 1999. Cette équipe est également le chef de file du projet...7B.7.2 Activité Image - ENSAM L’activité Image propose un mastère spécialisé en simulation et Réalité Virtuelle. Le but est de former des chefs de...Large-Scale Virtual Worlds. Conference Companion ACM SIGCHI 󈨣, 45-46. Darken, R.P. (1994). Hands-Off Interaction With Menus in Virtual Spaces

  19. L’IMPACT DE L’APPLICATION DES REFORMES BALE III SUR L’INDUSTRIE BANCAIRE ROUMAINE

    Directory of Open Access Journals (Sweden)

    Maria Halep

    2012-12-01

    Full Text Available Le début du XXIème a connu un essor remarquable des marchés financiers, de l’innovation et des processus de déréglementation. L’inflation faible, la liquidité abondante, la confiance dans les marchés efficaces et autorégulateurs ont conduit à une perception généralisée de risque faible, incitant les acteurs à une prise accrue de risque. Face aux crises qui s’enchaînent depuis maintenant cinq ans, des mesures de ré-réglementation du système ont été proposées, communément appelées Reformes de Bâle.L’article analyse l’évolution des recommandations de Bâle en lien avec l’évolution économique et des marchés financiers et évalue l’impact de ces dernières sur le secteur bancaire roumain.

  20. Workshop on the applications of new computer tools to thermal engineering; Applications a la thermique des nouveaux outils informatiques

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    This workshop on the applications of new computer tools to thermal engineering has been organized by the French society of thermal engineers. Seven papers have been presented, from which two papers dealing with thermal diffusivity measurements in materials and with the optimization of dryers have been selected for ETDE. (J.S.)

  1. Additional application areas of the 3D process information display; Weiterfuehrende Einsatzgebiete des 3-D-Prozessinformationsdisplays

    Energy Technology Data Exchange (ETDEWEB)

    Meissner, K. [Institut fuer Automatisierung und Informatik GmbH, Zentrum fuer industrielle Forschung und Entwicklung, Wernigerode (Germany); Hensel, H. [Hochschule Harz, Fachbereich Automatisierung und Informatik, Wernigerode (Germany)

    2007-07-01

    The current technological progress in the process industry results in a significant increase of the complexity of control systems. The amount of supervised information grows constantly for each operator because of a higher level of automation and an optimized information acquisition of the control systems. This development results in a cognitive overload of the operator which causes incorrect behaviour and responses in alert situations. In technical literature, several approaches are discussed to counteract this problem. This paper presents the newly developed 3-D Process Information Display (3D-PID) and describes which additional application areas as a primary representation method to the supervision of complex process conditions are imaginable. The 3D-PID is based on a cognitive scenic representation of the process values within a 3-D process room. Particularly the problem of the overview and detail presentation known from the literature is discussed. (orig.)

  2. Iminoéthers-1 3 cycliques : chimie et applications dans le domaine des additifs pétroliers et des matériaux organiques Cyclic 1,3-Iminoethers: Chemistry and Applications in the Field of Petroleum Additives and Organic Materials

    Directory of Open Access Journals (Sweden)

    Le Perchec P.

    2006-11-01

    Full Text Available Cet article est consacré aux iminoéthers-1,3 cycliques les plus courants : les oxazines-1,3 et oxazolines-1,3. La première partie rappelle les synthèses de ces composés et quelques aspects récents de leur chimie : réactions d'hydrolyse, réactions de déprotonation avec ouverture de cycle, réactions des organométalliques, réactions d'addition des nucléophiles en positions 2 et 5, des sels d'iminoéthers correspondants, propriétés complexantes vis-à-vis des métaux, réactions d'aminolyse et formation de structures tensioactives, enfin polymérisations et copolymérisations cationiques. La seconde partie est consacrée à l'étude des travaux qui traitent des applications. En ce qui concerne le domaine des additifs pétroliers, on s'intéresse à la stabilité du cycle oxazoline et à son caractère polaire. Les dérivés tensioactifs dérivés d'oxazoline portant des chaînes hydrocarbonées ont été revendiqués comme additifs dispersants et multifonctionnels pour les carburants et les lubrifiants. De nombreuses formulations (dispersants, antioxydants antirouilles, antiusures, extrême pressions, réducteurs de frictions. . . ont été proposées. Certains dérivés d'hydroxyméthyl oxazolines présentent des propriétés lubrifiantes et d'autres ont un intérêt dans les formulations de boues de forage. En ce qui concerne le domaine des matériaux, on s'intéresse à la réactivité du cycle oxazoline pour réaliser soit des extensions de chaînes des thermoplastiques, soit des réticulations pour des applications de peintures et revêtements. Les homopolymères d'oxazoline qui ont un caractère polaire très marqué peuvent trouver des applications comme promoteur d'adhésion, ou tensioactifs pour les polymérisations en émulsion. Enfin, l'utilisation d'oxazolines stables a été revendiquée dans des formulations de vernis d'émaillage. This article deals with the most common cyclic 1,3-iminoethers, i. e. 1,3-oxazines and 1

  3. Image processing. A system for the automatic sorting of chromosomes; Traitement d'images - Applications au classement des chromosomes

    Energy Technology Data Exchange (ETDEWEB)

    Najai, Amor

    1977-05-27

    The present paper deals with two aspects of the system: - an automata (specialized hardware) dedicated to image processing. Images are digitized, divided into sub-units and computations are carried out on their main parameters. - A software for the automatic recognition and sorting of chromosomes is implemented on a Multi-20 minicomputer, connected to the automata. (author) [French] Nous decrivons un systeme automatique de classification de chromosomes. Il se compose de: - l'A.S.T.I., Automate Specialise de Traitement d'Images permettant de numeriser celles-ci, d'isoler des sous-images, d'effectuer des calculs sur leurs parametres principaux. - Un programme de reconnaissance et de classification automatique des chromosomes implante sur un mini-ordinateur MULTI-20, couple a l'A.S.T.I. (auteur)

  4. Cosmological Hubble constant and nuclear Hubble constant

    International Nuclear Information System (INIS)

    Horbuniev, Amelia; Besliu, Calin; Jipa, Alexandru

    2005-01-01

    The evolution of the Universe after the Big Bang and the evolution of the dense and highly excited nuclear matter formed by relativistic nuclear collisions are investigated and compared. Values of the Hubble constants for cosmological and nuclear processes are obtained. For nucleus-nucleus collisions at high energies the nuclear Hubble constant is obtained in the frame of different models involving the hydrodynamic flow of the nuclear matter. Significant difference in the values of the two Hubble constant - cosmological and nuclear - is observed

  5. 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

  6. 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

  7. FORMATION CONSTANTS AND THERMODYNAMIC ...

    African Journals Online (AJOL)

    KEY WORDS: Metal complexes, Schiff base ligand, Formation constant, DFT calculation ... best values for the formation constants of the proposed equilibrium model by .... to its positive charge distribution and the ligand deformation geometry.

  8. Clinical applications of proton magnetic resonance spectroscopy of the brain; Klinische Anwendungen der Protonen-Magnetresonanzspektroskopie des Gehirns

    Energy Technology Data Exchange (ETDEWEB)

    Laubenberger, J.; Bayer, S.; Thiel, T.; Hennig, J.; Langer, M. [Radiologische Universitaetsklinik Freiburg (Germany). Abt. Roentgendiagnostik

    1998-06-01

    In spite of all the scientific advances of the past few years, proton magnetic resonance spectroscopy of the brain has not attained the status of a routine examination technique with clinically accepted indications. The method should be considered as an additional option to MR imaging for inherited and acquired encephalopathic changes as well as, in future, for localization diagnosis of epilepsies. A proton magnetic resonance spectroscopic investigation without a prior intensive clinical and imaging investigation is not useful. Above all, factors influencing metabolite distribution such as for example, serum osmolability must be known. Methodological prerequisites for the clinical application of proton resonance spectroscopy are, first of all, a high stability of the chosen technique as well as a sufficiently certain quantification of metabolites and the availability of a reference group. The use of short echo times is necessary for the quantification of glutamine and the osmolyte myo-inositol. Indications for individual cases in which clinical investigations and MR topography cannot provide sufficient certainty and spectroscopy can furnish additional information are, in addition to uses in neuropediatrics, the suspicion of Alzheimer`s dementia, HIV encephalopathy in early manifestations, and unclarified depressions of consciousness accompanying liver cirrhosis. (orig.) [Deutsch] Die Protonen-Magnetresonanzspektroskopie des Gehirns ist trotz aller wissenschaftlicher Fortschritte der letzten Jahre noch nicht zu einer Routineuntersuchung mit anerkannter klinischer Indikationsstellung geworden. Die Untersuchung muss bei angeborenen und erworbenen enzephalopathischen Veraenderungen sowie in Zukunft in der Lokalisationsdiagnostik von Epilepsien als Zusatzoption zur MR-Bildgebung erachtet werden. Eine protonenspektroskopische Untersuchung ohne ausgiebige klinische und bildgebende Basisuntersuchung ist nicht sinnvoll. Insbesondere muessen Einflussfaktoren, wie z

  9. Ion exchange equilibrium constants

    CERN Document Server

    Marcus, Y

    2013-01-01

    Ion Exchange Equilibrium Constants focuses on the test-compilation of equilibrium constants for ion exchange reactions. The book first underscores the scope of the compilation, equilibrium constants, symbols used, and arrangement of the table. The manuscript then presents the table of equilibrium constants, including polystyrene sulfonate cation exchanger, polyacrylate cation exchanger, polymethacrylate cation exchanger, polysterene phosphate cation exchanger, and zirconium phosphate cation exchanger. The text highlights zirconium oxide anion exchanger, zeolite type 13Y cation exchanger, and

  10. Contribution to the study of aerosol photometers, application to the measurement of filter efficiency; Contribution a l'etude des photometres a aerosols, application a la mesure de l'efficacite des filtres

    Energy Technology Data Exchange (ETDEWEB)

    Billard, F; Hadelaine, G

    1968-01-01

    The measurement of the quantity of diffused light by particulates in suspension in a gas allows to determine the concentration and the size of an aerosol. The aim of this work is to check the answer of the usual photometer in the laboratories, the Phoenix-Sinclair and the Royco-230. The minimum diameter of the particulates detected by these photometers is about 0.3 microns. [French] La mesure de la quantite de lumiere diffusee par des particules en suspension dans un gaz permet de determiner la concentration et les dimensions d'un aerosol. Le but de ce travail est de verifier la reponse du photometres d'usage courant dans les laboratoires, le Phoenix-Sinclair et le Royco-230. Le diametre minimum des particules detectees par ces photometres est d'environ 0, 3 microns. (auteurs)

  11. Realization of a frequency standard at 778 nm: absolute frequency measurement of the 2S-8S/D transitions in hydrogen and deuterium and determination of the Rydberg constant; Realisation d'un etalon de frequence a 778 nm: mesure absolue des frequences 2S-8S/D des atomes d'hydrogene et de deuterium et determination de la constante de rydberg

    Energy Technology Data Exchange (ETDEWEB)

    Beauvoir, B. de

    1996-12-15

    The purpose of this work is to design a 778 nm standard laser for performing an absolute measurement of 2S-8S/D frequencies of hydrogen and deuterium atoms. This frequency calibration is based on a 5S-5D two-photon transition of the rubidium atom. Metrological performance of this laser is 10 times as good as that of He-Ne laser calibrated on iodine. It has been shown that the passage of a laser radiation through an optic fiber does not deteriorate its metrological properties. 2S-8S/8D transitions have been excited in an atomic jet by a titanium-sapphire laser. Spurious effects can shift and broaden lines. In order to prevent these effects, a theoretical line has been shaped and adjusted on experimental signals. The frequency comparison between the excitation laser and the standard laser has led to the measurement of the absolute frequency of the line concerned. The value of the Rydberg constant has been deduced: R{sub {infinity}} = 109737.3156859 (10) cm{sup -1}. The comparison of experimental data between deuterium and hydrogen has allowed us to determine the value of the Lamb shift of the 2S state of deuterium: L(2S-2P) = 1059,230 (9) MHz.

  12. Application of resistivity measurements to research on structural elements in the Nord-Limousin (France) uraniferous basin (1960); Application des mesures de resistivite a la recherche des elements structuraux dans le bassin uranifere du Nord-Limousin (France) (1960)

    Energy Technology Data Exchange (ETDEWEB)

    Sarcia, J A; Bonnet, J; Combe, R [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    The authors discuss the difficulties encountered in the exploration of a typical deposit in the Nord-Limousin, using the resistivity measurement method. In the zone in question the over-thrust was very variable and difficult to predict. The uraniferous deposits had two types of aspect, the passage from one to the other being often very sudden: long thin veins without gangue; short and thick lens-shape deposits which were strongly contaminated by clay towards their edges. After several unsatisfactory attempts, the device known as the 'rectangular map' was adopted and gave an acceptable structural representation rapidly and cheaply. For the placing of the probes however, methods are required which are more refined and sensitive. It is in any case useless to expect to obtain a satisfactory representation and a sufficient accuracy using a single technique; especially in the region under consideration. (author) [French] Les auteurs exposent les difficultes rencontrees pour l'exploration, par la methode des mesures de resistivite, d'un gisement type du Nord-Limousin: il s'agissait d'une zone a recouvrement tres variable et difficilement previsible. Les occurences uraniferes y affectaient deux facies passant brutalement de l'un a l'autre: longs filonnets minces et sans gangue; lentilles courtes et puissantes avec alteration argileuses tres etendue aux epontes. Apres plusieurs essais peu satisfaisants, le dispositif dit 'carte des rectangles' a ete adopte pour obtenir rapidement et a bon compte un schema structural suffisant. Mais des methodes plus fines et plus sensibles sont necessaires pour guider l'implantation des sondages. Il est d'ailleurs vain d'esperer trouver a la fois la representativite d'ensemble et la precision, dans l'utilisation d'une seule technique, surtout dans la region envisagee. (auteur)

  13. The measurement of thermal neutron constants of the soil; application to the calibration of neutron moisture gauges and to the pedological study of soil

    International Nuclear Information System (INIS)

    Couchat, P.; Marcesse, J.; Carre, C.; Le Ho, J.

    1975-01-01

    The neutronic method for measuring the water content of soils is more and more used by agronomists, hydrogeologists and pedologists. On the other hand the studies on the phenomena of slowing down and diffusion process have shown a narrow relation between the thermal absorption (Σ(a)) and diffusion (Σ(d)) constants and the thermal flux developed in the soil around a fast neutron source like Am-Be. Two original applications of the direct measurement of Σ(a) and Σ(d) are then presented. The method described consists in the measurement, in a cube of graphite with Am-Be source in the middle, on one side of the perturbation of the thermal flux, obtained by the introduction of 300g of soil, and on the other side of the transmitted thermal flux measured through the same sample of soil, on a side of the cube. After calibrating the device, these two parameters give Σ(a) and Σ(d) which are easily introduced in the calibration equation of neutron moisture gauge. Also these two values are useful for the pedologists because Σ(d) is connected to clay content in the soil and Σ(a) is connected to the type of clay by the way of rare earth contents [fr

  14. Determination of Paris' law constants and crack length evolution via Extended and Unscented Kalman filter: An application to aircraft fuselage panels

    Science.gov (United States)

    Wang, Yiwei; Binaud, Nicolas; Gogu, Christian; Bes, Christian; Fu, Jian

    2016-12-01

    Prediction of fatigue crack length in aircraft fuselage panels is one of the key issues for aircraft structural safety since it helps prevent catastrophic failures. Accurate estimation of crack length propagation is also meaningful for helping develop aircraft maintenance strategies. Paris' law is often used to capture the dynamics of fatigue crack propagation in metallic material. However, uncertainties are often present in the crack growth model, measured crack size and pressure differential in each flight and need to be accounted for accurate prediction. The aim of this paper is to estimate the two unknown Paris' law constants m and C as well as the crack length evolution by taking into account these uncertainties. Due to the nonlinear nature of the Paris' law, we propose here an on-line estimation algorithm based on two widespread nonlinear filtering techniques, Extended Kalman filter (EKF) and Unscented Kalman filter (UKF). The numerical experiments indicate that both EKF and UKF estimated the crack length well and accurately identified the unknown parameters. Although UKF is theoretical superior to EKF, in this Paris' law application EKF is comparable in accuracy to UKF and requires less computational expense.

  15. Réseau des développeurs - logiciels d'exploitation libre pour ...

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

    Un atelier technique réunissant des utilisateurs, des développeurs et des promoteurs des logiciels libres sera organisé pour mettre au point une application prototype - des formulaires électroniques permettant de saisir des données au moyen d'un ANP puis de les transférer dans un ordinateur - pouvant combler les ...

  16. Fonctionnalisation de la bentonite traitement et applications à léxtraction des colorants et colorants pour mordants.

    OpenAIRE

    MOULESSEHOUL, Hidayet

    2015-01-01

    L'objectif de notre étude est d'améliorer les propriétés de désorption de la bentonite vis à vis les colorants qui sont classés parmi les plus toxiques. La première partie du travail concerne la préparation et la caractérisation des bentonites modifiées avec les sels de diphosphate (porte-parapluie)TPhPMB.

  17. Kinetics of heterogeneous systems; La cinetique des milieux heterogenes

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-07-01

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

  18. Calculation of the nuclear vertex constant for the virtual decay 6LI→α + d in the three- body model and its astrophysical application

    International Nuclear Information System (INIS)

    Blokhintsev, L.D.; Igamov, S.B.; Nishonov, MM; Yarmukhamedov, R; Kamimura, M.

    2003-01-01

    The d(α, γ) 6 Li reaction is one of the sources of 6 Li production in the Big-Bang nuclear synthesis. At present extremely large uncertainties exist on this prediction mainly due to the absence of reliable directly measured cross section (or astrophysical S-factor, S(E)) at astrophysical relevant energies E, including E=0. As far theoretical calculation of the S(E) that have rather large spread. On the other hand, the d(α, γ) 6 Li reaction is predominantly of peripheral character at extremely low energies. Therefore the calculated S(E) at extremely low energies is mainly determined by the nuclear vertex constant (NVC) (or respective asymptotic normalization constant (ANC)) for the virtual decay 6 Li→α + d. Taking into account this circumstance we develop a method of calculation of the NVC for the virtual decay 6 Li→α + d for the subsequent application of the calculated one to the direct radiative capture d(α, γ) 6 Li cross - section (or astrophysical S-factor) calculation at extremely low energies E, including E=0. The developed method is based on the three-body Faddeev approach which is applied for the α-d scattering by using different forms of the NN- and αN-potentials. As a result the values of NVC and respective ANC for 6 Li→α + d virtual decay are obtained using two forms both for NN- and for αN-potential. They are the separable potentials with Yamaguchi type form factor and Paris potential with PEST 16 form factor for the NN- potential and Yamaguchi type form factor and Sack-Biedenharn-Breit potential for the αN- potential. A noticeable sensitivity to used forms of the NN- and αN- potential occurs both for the calculated NVC (or ANC) and astrophysical S- factor S(E) of the direct radiative capture d(α, γ) 6 Li reaction at extremely low energies E (≤100 keV), including the value E=0. The calculated S(E) have been obtained using the information about the NVC values. The obtained values of NVC and S(E) are compared with those of obtained

  19. Applications of Qualitative Microanalysis to the Determination of Secondary Species Associated with Uranium; Application de la microanalyse qualitative a la determination des especes secondaires d'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Agrinier, H

    1959-02-01

    Microanalytical techniques are described which allow rapid determinations of secondary species associated with uranium. They consist in exposing the constituent elements of the ores by means of characteristic microchemical reactions. Because of their rapidity and the small amount of apparatus needed, these techniques can be used either in the field or in the laboratory. (author) [French] Les techniques de microanalyse decrites dans cet ouvrage permettent la determination rapide des especes secondaires d'uranium. Elles consistent a mettre en evidence les elements constitutifs des mineraux par des reactions microchimiques caracteristiques. En raison de leur rapidite et du peu de materiel qu'elles necessitent, ces techniques peuvent etre utilisees aussi bien sur le terrain qu'au laboratoire. (auteur)

  20. Probes and their application to the study of H.F. plasmoids; Les sondes et leur application dans l'etude des plasmoides H.F

    Energy Technology Data Exchange (ETDEWEB)

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

    1960-07-01

    In the first part of this paper, we study the single Langmuir probe and the double-probe method. In the second part, we describe the probe-technique in connection with R.F. plasmoids. (author) [French] Dans la premiere partie de cet article, nous rappelons les principes d'utilisation de la sonde simple de Langmuir ainsi que la methode de la sonde double. La seconde partie est consacree a la pratique des sondes dans l'etude des plasmoides H.F. (auteur)

  1. Contribution a la caracterisation des betons endommages par des methodes de l'acoustique non lineaire. Application a la reaction alcalis-silice

    Science.gov (United States)

    Kodjo, Apedovi

    The aim of this thesis is to contribute to the non-destructive characterization of concrete materials damaged by alkali-silica reaction (ASR). For this purpose, some nonlinear characterization techniques have been developed, as well as a nonlinear resonance test device. In order to optimize the sensitivity of the test device, the excitation module and signal processing have been improved. The nonlinear tests were conducted on seven samples of concrete damaged by ASR, three samples of concrete damaged by heat, three concrete samples damaged mechanically and three sound concrete samples. Since, nonlinear behaviour of the material is often attribute to its micro-defects hysteretic behaviour, it was shown at first that concrete damaged by ASR exhibits an hysteresis behaviour. To conduct this study, an acoustoelastic test was set, and then nonlinear resonance test device was used for characterizing sound concrete and concrete damaged by ASR. It was shown that the nonlinear technique can be used for characterizing the material without knowing its initial state, and also for detecting early damage in the reactive material. Studies were also carried out on the effect of moisture regarding the nonlinear parameters; they allowed understanding the low values of nonlinear parameters measured on concrete samples that were kept in high moisture conditions. In order to find a specific characteristic of damage caused by ASR, the viscosity of ASR gel was used. An approach, based on static creep analysis, performed on the material, while applying the nonlinear resonance technique. The spring-damping model of Maxwell was used for the interpretation of the results. Then, the creep time was analysed on samples damaged by ASR. It appears that the ASR gel increases the creep time. Finally, the limitations of the nonlinear resonance technique for in situ application have been explained and a new applicable nonlinear technique was initiated. This technique use an external source such as a

  2. Solvent purification using a current of water vapour. A continuous process applicable to chemical plants treating irradiated fuels; Purification des solvants par entrainement a la vapeur d'eau. Procede continu applicable aux usines chimiques de traitement des combustibles irradies

    Energy Technology Data Exchange (ETDEWEB)

    Auchapt, P R; Sautray, R R; Girard, B R [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

    1964-07-01

    The pilot plant described in this report is intended for the continuous purification of the solvent used in the plutonium extraction plant at Marcoule, by separating the impurities (fission products). This physical separation is operated by carrying over in a water vapour stream. The contaminating products, only slightly volatile, remain in the form of the droplets and are separated; the vaporised solvent and the water vapour used are condensed and then separated. The originality of the installation resides in the system for pulverising the liquid and in the operating conditions: low working pressure and temperature. The systematic analysis of the various parameters (percentage of residue; flow, pressure and temperature ratios etc...) has shown their influence on the decontamination. The activity due to the zirconium-niobium is undetectable after treatment, and it is easy to obtain decontamination factors of 300 for the ruthenium. The, presence of uranium is favorable for the decontamination. As a conclusion, some extra-technical considerations are given concerning in particular the approximate cost price of the treated solvent per litre. (authors) [French] L'installation pilote decrite dans ce rapport est destinee a purifier, en continu, le solvant utilise a l'usine d'extraction du plutonium de Marcoule, en separant les impuretes (produits de fission). Cette separation physique est realisee par entrainement a la vapeur d'eau. Les produits contaminants, peu volatils, restant sous forme de gouttelettes, sont separes; le solvant vaporise ainsi que la vapeur d'entrainement sont condenses puis separes. L'originalite de l'installation reside dans le systeme de pulverisation du liquide et dans les conditions operatoires: faible pression et basse temperature de fonctionnement. L'analyse systematique des differents parametres (pourcentage de residus, rapport de debits, pression et temperature, etc...) a mis en evidence leur influence sur la decontamination. L'activite en

  3. Application of rank annihilation factor analysis to the spectrophotometric determination of the formation constant of complex of a new synthesized tripodal ligand with Co2+

    Directory of Open Access Journals (Sweden)

    Reza Golbedaghi

    2017-05-01

    Full Text Available The complex formation between a new synthesized tripodal ligand (L22py and the cation Co2+ in water was studied spectrophotometrically using rank annihilation factor analysis (RAFA. According to molar ratio data the stoichiometry of complexation between the ligand and the cation Co2+ was 1:1. Formation constant of this complex was derived using RAFA on spectrophotometric data. In this process the contribution of ligand is removed from the absorbance data matrix when the complex stability constant acts as an optimizing object and simply combined with the pure spectrum of ligand, the rank of original data matrix can be reduced by one by annihilating the information of the ligand from the original data matrix. The effect of ethanol, dimethylformamide (DMF and acetonitrile (AN was investigated on the formation constant of the Co2+ complex. Complex formation constant in water was estimated as log Kf = 5.09 ± 0.02. In mixtures of solvents of water and DMF and water and AN, the formation constant of the complex was increased because of lowering donor number of the solvent and in mixture of water and ethanol, the complex formation constant was decreased because of lowering of dielectric constant of the solvent.

  4. Synthesis, characterization and analytical application of hybrid; Acrylamide zirconium (IV) arsenate a cation exchanger, effect of dielectric constant on distribution coefficient of metal ions

    Energy Technology Data Exchange (ETDEWEB)

    Nabi, Syed A. [Department of Chemistry, Aligarh Muslim University, Aligarh 202002, U.P. (India)], E-mail: sanabi@rediffmail.com; Shalla, Aabid H. [Department of Chemistry, Aligarh Muslim University, Aligarh 202002, U.P. (India)

    2009-04-30

    A new hybrid inorganic-organic cation exchanger acrylamide zirconium (IV) arsenate has been synthesized, characterized and its analytical application explored. The effect of experimental parameters such as mixing ratio of reagents, temperature, and pH on the properties of material has been studied. FTIR, TGA, X-ray, UV-vis spectrophotometry, SEM and elemental analysis were used to determine the physiochemical properties of this hybrid ion exchanger. The material behaves as a monofunctional acid with ion-exchange capacity of 1.65 meq/g for Na{sup +} ions. The chemical stability data reveals that the exchanger is quite stable in mineral acids, bases and fairly stable in organic solvents, while as thermal analysis shows that the material retain 84% of its ion-exchange capacity up to 600 deg. C. Adsorption behavior of metal ions in solvents with increasing dielectric constant has also been explored. The sorption studies reveal that the material is selective for Pb{sup 2+} ions. The analytical utility of the material has been explored by achieving some binary separations of metal ions on its column. Pb{sup 2+} has been selectively removed from synthetic mixtures containing Mg{sup 2+}, Ca{sup 2+}, Sr{sup 2+}, Zn{sup 2+} and Cu{sup 2+}, Al{sup 3+}, Ni{sup 2+}, Fe{sup 3+}. In order to demonstrate practical utility of the material quantitative separation of the Cu{sup 2+} and Zn{sup 2+} in brass sample has been achieved on its columns.

  5. A Fast Hartley Transform based novel optical OFDM system for VLC indoor application with constant envelope PAPR reduction technique using frequency modulation

    Science.gov (United States)

    Singh, Vinay Kumar; Dalal, U. D.

    2017-10-01

    In this research literature we present a unique optical OFDM system for Visible Light Communication (VLC) intended for indoor application which uses a non conventional transform-Fast Hartley Transform and an effective method to reduce the peak to average power ratio (PAPR) of the OFDM signal based on frequency modulation leading to a constant envelope (CE) signal. The proposed system is analyzed by a complete mathematical model and verified by the concurrent simulations results. The use of the non conventional transform makes the system computationally more desirable as it does not require the Hermitian symmetry constraint to yield real signals. The frequency modulation of the baseband signal converge random peaks into a CE signal. This leads to alleviation of the non linearity effects of the LED used in the link for electrical to optical conversion. The PAPR is reduced to 2 dB by this technique in this work. The impact of the modulation index on the performance of the system is also investigated. An optimum modulation depth of 30% gives better results. The additional phase discontinuity incurring on the demodulated signal at the receiver is also significantly reduced. A comparison of the improvement in phase discontinuity of the proposed technique of combating the PAPR with the previously known phase modulation technique is also presented in this work. Based on the channel metrics we evaluate the system performance and report an improvement of 1.2 dB at the FEC threshold. The proposed system is simple in design and computationally efficient and this can be incorporated into the present VLC system without much alteration thereby making it a cost effective solution.

  6. The Fine Structure Constant

    Indian Academy of Sciences (India)

    IAS Admin

    The article discusses the importance of the fine structure constant in quantum mechanics, along with the brief history of how it emerged. Al- though Sommerfelds idea of elliptical orbits has been replaced by wave mechanics, the fine struc- ture constant he introduced has remained as an important parameter in the field of ...

  7. Study and industrial applications of the external slowing-down {beta}{sup -} radiation of the yttrium - 90; Etude et applications industrielles du rayonnement de freinage externe des {beta}{sup -} de l'yttrium - 90

    Energy Technology Data Exchange (ETDEWEB)

    Leveque, P; Martinelli, P; Chauvin, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    Inelastic scattering of the {beta}{sup -} particles on the nucleus gives place to the emission of a X-ray Bremsstrahlung radiation. In view of possible industrial applications, we studied the slowing-down radiation of {sup 90}(Sr + Y) sources in various materials. This pure {beta}{sup -} emitter of long period is in the fission products of uranium. Among of the industrial applications, these sources of weak X-rays energy can be used for the radiography of thin pieces, for measuring the thickness, or for the analysis by fluorescence. (M.B.) [French] La diffusion inelastique des particules {beta}{sup -} sur les noyaux donne lieu a l'emission d'un rayonnement X de freinage. En vue de possibles applications industrielles, nous avons etudie le rayonnement de freinage des sources {sup 90}(Sr + Y) dans divers materiaux. Cet emetteur {beta}{sup -} pur a longue periode se trouve dans les produits de fission de l'uranium. Parmi les applications industrielles a l'etude, ces sources de rayons X de faible energie peuvent etre utilisees pour la radiographie de pieces minces, la mesure d'epaisseurs, ou encore pour l'analyse par fluorescence. (M.B.)

  8. Étude du vieillissement des batteries lithium-ion dans les applications "véhicule électrique" : Combinaison des effets de vieillissement calendaire et de cyclage.

    OpenAIRE

    REDONDO-IGLESIAS, Eduardo

    2017-01-01

    L'étude du vieillissement des batteries est nécessaire car la dégradation de leurs caractéristiques détermine en grande partie le coût, les performances et l'impact environnemental des véhicules électrifiés, notamment des véhicules 100 % électriques. La méthodologie choisie pour cette thèse consiste en deux étapes bien différenciées, à savoir la caractérisation et la modélisation. Pour la première étape, on s'appuie sur des essais de vieillissement accéléré d'éléments de batterie. Malgré leur...

  9. Extraction of sulphates by long chain amines; Extraction des sulfates par les amines a longues chaines

    Energy Technology Data Exchange (ETDEWEB)

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

    1959-05-15

    The extraction of sulphuric acid by long chain amines in organic solution has been studied with a view to determining the value of the stability constants of the amine sulphates and bi-sulphates formed. We have concentrated chiefly on uranium sulphate and thorium sulphate. The formulae of the complexes extractable with amines have been established, as well as the corresponding dissociation constants. We have observed that for uranium sulphate the formula of the complex depends only on the nature of the amine, whereas for thorium this formula varies with the amine structure. From the formulae determined and the value of the constants calculated, we have been able to establish the best conditions for uranium and thorium extraction and also for a separation of these two elements. Finally we propose an application of this study to the determination of uranium in ores, where the separation of uranium by this method is particularly easy and complete. (author) [French] L'extraction de l'acide sulfurique par des amines a longues chaines en solution organique a ete etudiee en vue de la determination de la valeur des constantes de stabilite des sulfates et bisulfates d'amines formes. Parmi les sulfates, nous nous sommes particulierement interesses au sulfate d'uranium et au sulfate de thorium. Nous avons determine les formules des complexes extractibles avec les amines, ainsi que les constantes de dissociation correspondantes. Nous avons remarque que pour le sulfate d'uranium, la formule du complexe ne depend que de la nature de l'amine, alors que pour le thorium cette formule varie avec la structure de l'amine. Les formules determinees et la valeur des constantes calculees, nous ont permis de decrire les meilleures conditions d'extraction de l'uranium et du thorium ainsi que celles d'une separation de ces deux elements. Nous proposons enfin une application de cette etude au dosage de l'uranium dans les minerais, ou la separation de l'uranium par cette methode est

  10. ANALYSE DES PERCEPTIONS LOCALES ET DES FACTEURS ...

    African Journals Online (AJOL)

    AISA

    1Faculté des Sciences Agronomiques (FSA), Université d'Abomey-Calavi (UAC), 01 BP 526 Cotonou Bénin. Email : cgbemavo@yahoo.fr. 2Institut National des Recherches Agricoles du Bénin, Centre de Recherches Agricoles d'Agonkanmey (CRA-A),. Laboratoire des Sciences du Sol, Eau et Environnement (LSSEE).

  11. X-spectrographic method for plutonium detection. Application to contamination measurements in humans; Etude d'une methode de detection du plutonium par spectrographie X. Application a la mesure des contaminations sur l'homme

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-07-01

    After reviewing the radio-toxicology of plutonium 239 and conventional detection methods using its {alpha}-radiation, the author considers the measurement of the X emission spectrum of plutonium 239 using a proportional counter filled with argon under pressure. This preliminary work leads to the third part of this research involving the detailed study of the possibilities of applying thin alkali halide crystal scintillators to the detection of soft plutonium X-rays; there follows a systematic study of all the parameters liable to render the detection as sensitive as possible: movement due to the photomultiplier itself and its accessory electronic equipment, nature and size of the crystal scintillator as well as its mode of preparation, shielding against external parasitic radiation. Examples of some applications to the measurement of contamination in humans give an idea of the sensitivity of this method. (author) [French] Apres un apercu de la radiotoxicologie du plutonium 239 et des methodes classiques de detection par son rayonnement {alpha}, on etudie le spectre d'emission X du plutonium 239 avec un compteur proportionnel rempli avec de l'argon sous pression. Ce travail preliminaire permet d'aborder la troisieme partie de cette etude dans laquelle nous examinons d'une fagon approfondie les possibilites d'application des cristaux scintillateurs minces d'halogenure alcalin a la detection du rayonnement X mou du plutonium; suit une etude systematique de tous les parametres susceptibles de rendre la detection aussi sensible que possible: mouvement propre du photomultiplicateur et de l'electronique associee, nature et dimensions du cristal scintillateur ainsi que son mode de fabrication, blindage contre les rayonnements parasites exterieurs. Quelques applications a la mesure des contaminations sur l'homme permettent d'apprecier la sensibilite de cette methode. (auteur)

  12. utilisation des donnees pour l'evaluation de l'heterogeneite des sols

    African Journals Online (AJOL)

    AISA

    étude a permis de caractériser l'hétérogénéité des sols ferrallitiques, à travers sa couleur. Mots-clés : Couleur ... ainsi qu'à l'application des recommandations des doses de fertilisant. ..... de « système sol » en zone de contact forêt- savane du ...

  13. Cosmological constants and variations

    International Nuclear Information System (INIS)

    Barrow, John D

    2005-01-01

    We review properties of theories for the variation of the gravitation and fine structure 'constants'. We highlight some general features of the cosmological models that exist in these theories with reference to recent quasar data that is consistent with time-variation in the fine structure 'constant' since a redshift of 3.5. The behaviour of a simple class of varying alpha cosmologies is outlined in the light of all the observational constraints. We also discuss some of the consequences of varying 'constants' for oscillating universes and show by means of exact solutions that they appear to evolve monotonically in time even though the scale factor of the universe oscillates

  14. Incidence du contexte sur l'efficacité des think tanks dans les pays ...

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

    indicateurs quantitatifs de mesures clés du contexte et de l'efficacité à la lumière des résultats des études de cas. Le projet devrait aboutir à la formulation de recommandations concrètes et applicables à l'intention des think tanks, des bailleurs de fonds ...

  15. Development of procedures for calculating stiffness and damping properties of elastomers in engineering applications. Part 2: Elastomer characteristics at constant temperature

    Science.gov (United States)

    Gupta, P. K.; Tessarzik, J. M.; Cziglenyi, L.

    1974-01-01

    Dynamic properties of a commerical polybutadiene compound were determined at a constant temperature of 32 C by a forced-vibration resonant mass type of apparatus. The constant thermal state of the elastomer was ensured by keeping the ambient temperature constant and by limiting the power dissipation in the specimen. Experiments were performed with both compression and shear specimens at several preloads (nominal strain varying from 0 to 5 percent), and the results are reported in terms of a complex stiffness as a function of frequency. Very weak frequency dependence is observed and a simple power law type of correlation is shown to represent the data well. Variations in the complex stiffness as a function of preload are also found to be small for both compression and shear specimens.

  16. The cosmological constant problem

    International Nuclear Information System (INIS)

    Dolgov, A.D.

    1989-05-01

    A review of the cosmological term problem is presented. Baby universe model and the compensating field model are discussed. The importance of more accurate data on the Hubble constant and the Universe age is stressed. 18 refs

  17. Applications of sub-optimality in dynamic programming to location and construction of nuclear fuel processing plant; Application de la sous-optimalite en programmation dynamique a la localisation et la cadence optimales de construction des equipements

    Energy Technology Data Exchange (ETDEWEB)

    Thiriet, L; Deledicq, A [Commissariat a l' Energie Atomique, 92 - Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires, section des etudes economiques generales

    1968-09-01

    First, the point of applying Dynamic Programming to optimization and Operational Research problems in chemical industries are recalled, as well as the conditions in which a dynamic program is illustrated by a sequential graph. A new algorithm for the determination of sub-optimal politics in a sequential graph is then developed. Finally, the applications of sub-optimality concept is shown when taking into account the indirect effects related to possible strategies, or in the case of stochastic choices and of problems of the siting of plants... application examples are given. (authors) [French] On rappelle d'abord l'interet de la Programmation Dynamique dans les problemes d'optimisation et de Recherche Operationnelle dans les industries chimiques, et les conditions de representation d'un programme dynamique par un graphe sequentiel. On expose ensuite un nouvel algorithme de determination de politiques sous-optimales dans un graphe sequentiel. On montre enfin les applications du concept de sous-optimalite a la prise en compte d'effets indirects lies aux politiques possibles, aux choix dans l'aleatoire, a des problemes de localisation optimale d'usines... et on donne des exemples d'utilisation. (auteurs)

  18. Use of charge storage tube in the building of a buffer memory; Application des tubes a memoire a la realisation d'une memoire tampon

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-07-01

    The apparatus manufactured is a buffer memory to be located between a detector and a multichannel pulse height analyser which received the pulses at regular times. The buffer memory and the detector have the same order of dead time, then the whole is equivalent to a detector plus an analyser without dead time, but that is true only if the mean time between two consecutive pulses from the detector is greater than the analyser time resolution. The apparatus used two electrostatic barrier grid tubes; the first one stores temporarily the data from the detector during the time necessary to analyse the data recorded on the other one. At the end of the analysis, the roles of the two tubes are permuted. The advantage on similar other apparatus is the uninterrupted recording of the pulse height informations from the detector and the uninterrupted analysis. In addition, the transistorization is interesting for reliability and maintainability. The document presents principles and data on the barrier grid storage tube, considers its conventional uses in nuclear electronics studies statistically the reduction of counting losses. It describes the test equipment and the tests which permits the screening of the best cathode ray storage tube for this application. Finally, it describes the item and gives the wave shapes in various points of the buffer memory. (author) [French] Le dispositif realise est une memoire tampon destinee a etre placee entre un detecteur et un selecteur d'amplitude multicanaux. Elle permet a ce dernier de recevoir et analyser les impulsions a intervalles de temps reguliers. Son temps de resolution est comparable a celui du detecteurs, l'ensemble est donc equivalent a un systeme constitue d'un detecteur suivi d'un selecteur sans temps mort, mais ceci n'est valable que tant que l'intervalle de temps moyen entre deux impulsions issues du detecteur est superieur au temps d'analyse necessite par le selecteur. Ce dispositif est constitue de deux tubes a memoire

  19. Molecular Dynamics Simulation of Spontaneous Imbibition in Nanopores and Recovery of Asphaltenic Crude Oils Using Surfactants for EOR Applications Simulations de dynamique moléculaire d’imbibition spontanée dans des nanopores et pour la récupération d’huiles brutes asphalténiques en utilisant des agents tensioactifs pour des applications d’EOR

    Directory of Open Access Journals (Sweden)

    Stukan M.R.

    2012-12-01

    Full Text Available We present Molecular Dynamics (MD simulations of the imbibition process in nanopores in case of two different mechanisms of the wettability modification. We compare the imbibition of an aqueous surfactant solution into an oil-wet pore driven by surfactant adsorption onto the oil-wet rock surface (coating mechanism and the imbibition of an aqueous surfactants solution driven by surfactants removing the contaminant molecules from the originally water-wet surface (cleaning mechanism. Our results show qualitative difference in the imbibition dynamics in these two cases and indicate that MD simulation is a useful tool to investigate details of the imbibition mechanisms at the pore scale with direct implications for Enhanced Oil Recovery (EOR operations. Nous presentons des simulations de Dynamique Moleculaire (DM du processus d’imbibition dans des nanopores dans le cas de deux mecanismes differents de modification de mouillabilite. Nous comparons l’imbibition d’une solution aqueuse d’agent tensioactif dans un pore mouille d’huile entrainee par une adsorption d’agent tensioactif sur la surface de roche mouillee d’huile (mecanisme de revetement et l’imbibition d’une solution aqueuse d’agent tensioactif entrainee par des agents tensioactifs eliminant les molecules contaminantes de la surface originellement mouillee d’eau (mecanisme de nettoyage. Nos resultats montrent une difference qualitative en matiere de dynamique d’imbibition dans ces deux cas et indiquent que la simulation de DM constitue un outil utile pour etudier les mecanismes d’imbibition a l’echelle des pores avec des implications directes pour des operations de recuperation renforcee d’huile (EOR, Enhanced Oil Recovery.

  20. 12 Conception et réalisation des capteurs hybrides photovoltaïque ...

    African Journals Online (AJOL)

    user

    hybrides photovoltaïque-thermiques à air intégrables en toitures des bâtiments. Pour ces .... de la position du moyen de stockage sur les performances du système. ... propriétés thermo-physiques des matériaux sont supposées constantes et .... L'évolution des températures de tous les éléments des capteurs atteignent le.

  1. Dictionnaire d'analyse et de gestion des risques

    CERN Document Server

    Desroches, Alain

    2005-01-01

    Ce dictionnaire présente les principaux termes utilisés en analyse et gestion des risques, pour tous les secteurs d'activité industrielle ou de service. Il permet de clarifier des terminologies existantes présentant des variations plus ou moins importantes et parfois des contradictions de sens. Il propose : premièrement, la définition des auteurs, définition correspondant à l'usage le plus courant du terme , deuxièmement, les différences avec les terminologies existantes (essentiellement des normes) , troisièmement, des compléments à la définition, lorsque cela semble nécessaire et notamment lorsqu'il est important de préciser le contexte d'utilisation du terme , en dernier lieu, des exemples pratiques d'application, lorsque cela peut apporter un éclairage complémentaire pertinent.

  2. Detection of {alpha} particles using semiconductors. Application to the control of plutonium extraction; Detection des particules {alpha} par semiconducteurs application au controle de l'extraction du plutonium

    Energy Technology Data Exchange (ETDEWEB)

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

    1968-03-01

    A study is made of a particles produced by thick sources, using either diffused junction or surface barrier semiconductor detectors for controlling continuously the plutonium extraction process. For this, a presenting apparatus is described in which the solutions to be analyzed flow in contact with the detector protected by a thin mica membrane. A method is described which gives a precise recording of the spectra and which thus allows the separation of two or more {alpha} emitters present in the same solution. This method has been applied to the measurement of {sup 239}Pu in the the presence of {sup 241}Am with an accuracy of {+-}5 per cent. In the second part of the report is considered the detection of plutonium in solutions of {beta} - {gamma} emitting fission products. Pile-up is reduced by using a fast amplification chain associated to totally depleted thin detectors. Under these conditions a few mg of {sup 239}Pu can be detected in solutions of fission products having an activity of 100 curies/liter. A method is given for discriminating {alpha} and {beta} particles, it is based on the difference in the collection times for the charges liberated by these particles in the detector. (author) [French] On etudie la detection de particules {alpha} issues de sources epaisses par detecteurs semiconducteurs a jonction diffusee ou a barriere de surface pour le controle continu du procede d'extraction du plutonium. A cet effet on decrit un appareil presentateur dans lequel les solutions a analyser circulent au contact du detecteur protege par une membrane mince de mica. On decrit une methode qui permet par le trace precis des spectres de separer deux ou plusieurs emetteurs {alpha} presents dans une meme solution. Cette methode a ete appliquee a la mesure du {sup 239}Pu en presence de {sup 241}Am avec une precision de {+-} 5 pour cent. Dans la deuxieme partie on traite de la detection du plutonium dans des solutions de produits de fission emetteurs {beta} and {gamma}. On

  3. Monte-Carlo method - codes for the study of criticality problems (on IBM 7094); Methode de Monte- Carlo - codes pour l'etude des problemes de criticite (IBM 7094)

    Energy Technology Data Exchange (ETDEWEB)

    Moreau, J; Rabot, H; Robin, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    The two codes presented here allow to determine the multiplication constant of media containing fissionable materials under numerous and divided forms; they are based on the Monte-Carlo method. The first code apply to x, y, z, geometries. The volume to be studied ought to be divisible in parallelepipeds, the media within each parallelepiped being limited by non-secant surfaces. The second code is intended for r, 0, z geometries. The results include an analysis of collisions in each medium. Applications and examples with informations on time and accuracy are given. (authors) [French] Les deux codes presentes dans ce rapport permettent la determination des coefficients de multiplication de milieux contenant des matieres fissiles sous des formes tres variees et divisees, ils reposent sur la methode de Monte-Carlo. Le premier code s'applique aux geometries x, y, z, le volume a etudier doit pouvoir etre decompose en parallelepipedes, les milieux a l'interieur de chaque parallelepipede etant limites par des surfaces non secantes. Le deuxieme code s'applique aux geometries r, 0, z. Les resultats comportent une analyse des collisions dans chaque milieu. Des applications et des exemples avec les indications de temps et de precision sont fournis. (auteurs)

  4. Gestion des risques, valorisation et stratégie : applications aux industries agro-alimentaire et de transport aérien

    OpenAIRE

    Hassane Amadou, Rahila

    2014-01-01

    Ce travail de recherche apporte des éléments de compréhension supplémentaires sur l’impact des stratégies de gestion des risques sur la valeur et sur la stratégie des entreprises. Une première analyse examine un échantillon de 378 observations d’entreprises du secteur agroalimentaire sur 5 ans. Il ressort de cette analyse que l’intensité d’utilisation des produits dérivés pour couvrir les risques de change, taux d’intérêt et prix des matières premières n’influence pas sensiblement la valeur d...

  5. Finance computationnelle et gestion des risques ingénierie financière avec applications Excel (Visual Basic) et Matlab

    CERN Document Server

    Racicot, François-Éric

    2006-01-01

    Ce manuel propose un exposé rigoureux de la gestion des risques en finance. Les aspects théoriques de la question sont abordés par des démonstrations claires et des rappels élaborés des bases mathématiques de la finance computationnelle. Le texte est émaillé de nombreux programmes écrits en langages Visual Basic (Excel), Matlab et EViews qui prépareront l'étudiant à sa carrière de spécialiste en ingénierie financière.

  6. Current algebra; Algebre des courants

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-07-01

    The first three chapters of these lecture notes are devoted to generalities concerning current algebra. The weak currents are defined, and their main properties given (V-A hypothesis, conserved vector current, selection rules, partially conserved axial current,...). The SU (3) x SU (3) algebra of Gell-Mann is introduced, and the general properties of the non-leptonic weak Hamiltonian are discussed. Chapters 4 to 9 are devoted to some important applications of the algebra. First one proves the Adler- Weisberger formula, in two different ways, by either the infinite momentum frame, or the near-by singularities method. In the others chapters, the latter method is the only one used. The following topics are successively dealt with: semi leptonic decays of K mesons and hyperons, Kroll- Ruderman theorem, non leptonic decays of K mesons and hyperons ( {delta}I = 1/2 rule), low energy theorems concerning processes with emission (or absorption) of a pion or a photon, super-convergence sum rules, and finally, neutrino reactions. (author) [French] La premiere partie de ce cours (trois premiers chapitres), traite des generalites concernant l'algebre de courants. Apres une definition rapide des courants faibles et un rappel de leurs proprietes (hypothese V-A, conservation du courant vecteur, regles de selection, courant axial partiellement conserve,...), l'on introduit l'algebre de Gell-Mann SU (3) x SU (3), et discute les proprietes generales de l'Hamiltonien faible non leptonique. Les chapitres IV a IX sont consacres a des applications importantes de l'algebre des courants. En premier lieu l'on demontre la formule de Adler et Weisberger, par deux methodes differentes, celle dite du repere de moment infini et celle des singularites proches. Cette derniere est seule utilisee dans la suite. Puis, l'on traite successivement les problemes suivants: desintegrations semi-leptoniques des mesons K et des hyperons, theoreme de Kroll-Ruderman, desintegrations non leptoniques des mesons

  7. Des universitaires de l'Asie et de l'Afrique échangent des ...

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

    17 oct. 2017 ... Depuis 2007, des conférences de CPRsouth ont eu lieu chaque année; ... de la recherche sur les télécommunications, et des technologies de ... la façon dont les applications mobiles peuvent stimuler l'utilisation d'Internet.

  8. Modelisation des effets physico-techniques pour la conception des ...

    African Journals Online (AJOL)

    automatisation dans les installations industrielles a besoin d'une régulation automatique des commandes des processus technologiques pour lesquelles certaines contraintes sont à relever compte tenu des exigences des innovations scientifiques de ...

  9. The application of {beta}-ray excitation fluorescence to the measurement of the thickness of deposits and to analysis; Applications de la fluorescence excitee au moyen des rayons {beta} a la mesure des epaisseurs des depots et a l'analyse

    Energy Technology Data Exchange (ETDEWEB)

    Martinelli, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Seibel, G [Institut de Recherches de la Siderurgie Francaise (IRSID), 78 - Saint-Germain-en-Laye (France)

    1961-07-01

    Principles of the method are first outlined and the instrumentation used is described. The different types of radiation detectors are subject of a detailed study. As a source of {beta}-radiation {sup 90}(Sr + Y) was used as well as {sup 147}Pm. Great care was taken to eliminate back-diffused electrons by deflection by a strong permanent magnet. The method was applied to the measurement of the thickness of deposits of Cr, Zn, Sn, Cd and Cu on iron as well as Zn, Cr, Ag and Au on copper and the results obtained are discussed. An attempt was made, to use {beta}-X-ray fluorescence for the analysis of minerals, iron ore and glass and for routine control of Si-Mn, Si-Ca, Fe-Mn and Fe-W. Finally the method of {beta}-X-ray fluorescence is compared with normal-X-ray fluorescence and possibilities of further development are cited. (author) [French] Les principes de la methode et l'instrumentation utilisee sont presentes. On decrit en particulier les detecteurs de rayonnement utilises. Comme source de rayonnement on utilise {sup 90}(Sr + Y) et {sup 147}Pm. Pour eliminer les electrons retrodiffuses on utilise un aimant permanent place sur le trajet du faisceau. La methode est appliquee a la mesure des epaisseurs des depots metalliques tels que le Cr, Zn, Sn, Cd et Cu sur fer et le Zn, Cr, Ag et Au sur cuivre. D'autre part, la fluorescence {beta}-X etait utilisee pour l'analyse des minerais et des verres et pour le controle des alliages Fe-Mn, Fe-W, Si-Mn, Si-Ca. Enfin, on passe a une comparaison entre la fluorescence {beta}-X et la fluorescence X normale et on discute les possibilites d'un developpement futur. (auteur)

  10. Application of the variational method for calculation of neutron spectra and group constants - Master thesis; Primena varijacione metode na odredjivanje spektra neutrona i grupnih konstanti - Magistarski rad

    Energy Technology Data Exchange (ETDEWEB)

    Milosevic, M [Institute of Nuclear Sciences Vinca, Beograd (Serbia and Montenegro)

    1979-07-01

    One-dimensional variational method for cylindrical configuration was applied for calculating group constants, together with effects of elastic slowing down, anisotropic elastic scattering, inelastic scattering, heterogeneous resonance absorption with the aim to include the presence of a number of different isotopes and effects of neutron leakage from the reactor core. Neutron flux shape P{sub 3} and adjoint function are proposed in order to enable calculation of smaller size reactors and inclusion of heterogeneity effects by cell calculations. Microscopic multigroup constants were prepared based on the UKNDL data library. Analytical-numerical approach was applied for solving the equations of the P{sub 3} approximation to obtain neutron flux moments and adjoint functions.

  11. Radiographic constant exposure technique

    DEFF Research Database (Denmark)

    Domanus, Joseph Czeslaw

    1985-01-01

    The constant exposure technique has been applied to assess various industrial radiographic systems. Different X-ray films and radiographic papers of two producers were compared. Special attention was given to fast film and paper used with fluorometallic screens. Radiographic image quality...... was tested by the use of ISO wire IQI's and ASTM penetrameters used on Al and Fe test plates. Relative speed and reduction of kilovoltage obtained with the constant exposure technique were calculated. The advantages of fast radiographic systems are pointed out...

  12. 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

    Full Text Available Tracing of injection gas in oil reservoirs is a technique used to improve the description of permeability distributions in situ. Results from dynamic laboratory experiments of gas tracers are reported. Gas tracers are delayed when flooding through a reservoir by the partitioning into the oil phase. A knowledge of this effect is important to optimize the interpretation of field tracer tests. The partition is quantified by the partition coefficient K. Two chemical tracers perfluoromethylcyclopentane (PMCP and perfluoromethylcyclohexane (PMCH and the radioactive 14C labelled ethane have been studied here. The two chemical compounds are new as reservoir tracers and no field results with these tracers are reported in the open literature. Our group has, however, recently applied these compound successfully as tracers in a North Sea reservoir. Les traceurs représentent un outil précieux pour améliorer la description des gisements. On les a utilisés pour obtenir des renseignements sur la configuration de l'écoulement des fluides injectés et sur leur vitesse, sur l'instant de percé des venues d'eau et sur leur origine précise, sur les traitements d'amélioration du balayage, sur les hétérogénéités importantes telles que fractures, barrières d'écoulement et stratifications de la perméabilité. Dans les gisements importants comportant plusieurs puits de production et plusieurs puits d'injection, il est donc souhaitable de disposer de plusieurs traceurs afin de pouvoir injecter différents traceurs ou mélanges de traceurs dans les différents puits. L'article présenté ici est une contribution a l'effort fait pour étendre le nombre de gaz traceurs fiables applicables aux gisements. L'article présente les résultats d'essais dynamiques en laboratoires dans lesquels on injecte des traceurs à travers un milieu poreux. Lorsqu'ils traversent un réservoir, les gaz traceurs sont retardés du fait de leur ségrégation dans la phase huile. La

  13. Calculation of control rods in rectangular reactor, and applications (1960); Calcul des barres de conteole dans un reacteur rectangulaire et applications (1960)

    Energy Technology Data Exchange (ETDEWEB)

    Goshen, S; Pazy, A [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    The aim of this report is to find a method for estimating the anti-reactivity of control rods perpendicular to the axis in a cylindrical pile. The paper is divided into two parts. In the first is given a method of calculating control rods in a rectangular pile, similar to the Nordheim-Scalettar method for cylindrical piles. As an example the formulas are given for the theories of one and two neutron groups, the generalisation for several groups being evident. In the second part we find by a variation method a formula for estimating the Laplacian of a pile, which may be divided into parallelepipeds for which the Laplacian are given. Finally, this formula is used to calculate the anti-reactivity of rods perpendicular to the axis in a cylindrical pile. (author) [French] Le but de ce rapport est de trouver une methode pour estimer l'antireactivite des barres de controle perpendiculaires a l'axe dans pile cylindrique. Le rapport se divise en deux parties. Dans la premiere nous donnons une methode de calcul des barres de controle dans une pile rectangulaire, analogue a la methode de Nordheim-Scalettar pour les piles cylindriques. A titre d'exemple, nous donnons les formules de theories a un et deux groupes de neutrons, la generalisation pour plusieurs groupes est evidente. Dans la deuxieme partie, nous trouvons, par une methode de variation, une formule qui permet d'estimer le laplacien d'une pile, qui peut etre divisee en parallelepipedes dont les laplaciens sont donnes. Nous utilisons enfin, cette formule pour calculer l'antireactivite des barres perpendiculaires a l'axe dans une pile cylindrique. (auteur)

  14. Improved Mask Protected DES using RSA Algorithm

    Directory of Open Access Journals (Sweden)

    Asha Latha S.

    2016-01-01

    Full Text Available The data encryption standard is a pioneering and farsighted standard which helped to set a new paradigm for encryption standards. But now DES is considered to be insecure for some application. Asymmetric mask protected DES is an advanced encryption method for effectively protecting the advanced DES. There are still probabilities to improve its security. This paper propose a method, which introduce a RSA key generation scheme in mask protected DES instead of plain key, which result in enhancement in the security of present asymmetric mask protected DES. We further propose a Vedic mathematical method of RSA implementation which reduce the complexity of computation in RSA block thereby resulting in reduced delay (four timesthat improves the performance of overall system. The software implementation was performed using Xilinx 13.2 and Model-Sim was used for the simulation environment.

  15. Uncertainty and sensitivity analysis of applications of the PARK program system; Unsicherheits- und Sensitivitaetsanalyse von Anwendungen des Programmsystems PARK

    Energy Technology Data Exchange (ETDEWEB)

    Luczak-Urlik, D.; Bleher, M.; Jacob, P.; Mueller, H. [GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany). Inst. fuer Strahlenschutz; Hofer, E.; Krzykacz, B. [Gesellschaft fuer Reaktorsicherheit mbH (Greece)

    1997-11-01

    The (PARK) program package for assessment and abatement of off-site radiological consequences of nuclear accidents establishes radiologic analyses and prognoses on the basis of the measured data obtained by the IMIS system for ambient radiation monitoring. A probabilistic uncertainty and sensitivity analysis has been performed of the PARK-based mean specific activities of fodder and food and the potential radiation exposure of the population. Uncertainties were expressed in model input parameters, i.e. in measured values and radioecologic parameters via subjective probability distributions, within the framework of various emission scenarios (nuclide spectra describing two release modes, dry and wet deposition, and at three times over a one-year period). The resulting output data distributions were determined by Monte Carlo simulations. As a rule, the results of the analyses depend on the selected emission scenario. Measured values proved to be the major source of uncertainties (especially from in-situ soil activity measurements), and also the activity transfer data from fodder to food. As for wet deposition, uncertainties were added by the parameters used for determination of the interception factors. As the measuring stations cannot correlate their measured gamma dose rates with meteorologic data (precipitations), derived information relating to larger areas such as a ``Kreis`` (administrative district) is very much subject to uncertainties. The uncertainties of the PARK results are increasing with assessed increases in rainfall. (orig.) [Deutsch] Das Programmsystem zur Abschaetzung und Begrenzung radiologischer Konsequenzen (PARK) erstellt radiologische Analysen und Prognosen aufgrund von Messdaten, welche im Rahmen des Integrierten Mess- und Informationssystems zur Ueberwachung der Umweltradioaktivitaet (IMIS) erhoben werden. Es wurde eine probabilistische Unsicherheits- und Sensitivitaetsanalyse fuer die in PARK berechneten mittleren spezifischen Aktivitaeten

  16. On the cosmical constant

    International Nuclear Information System (INIS)

    Chandra, R.

    1977-01-01

    On the grounds of the two correspondence limits, the Newtonian limit and the special theory limit of Einstein field equations, a modification of the cosmical constant has been proposed which gives realistic results in the case of a homogeneous universe. Also, according to this modification an explanation for the negative pressure in the steady-state model of the universe has been given. (author)

  17. Cosmological constant problem

    International Nuclear Information System (INIS)

    Weinberg, S.

    1989-01-01

    Cosmological constant problem is discussed. History of the problem is briefly considered. Five different approaches to solution of the problem are described: supersymmetry, supergravity, superstring; anthropic approach; mechamism of lagrangian alignment; modification of gravitation theory and quantum cosmology. It is noted that approach, based on quantum cosmology is the most promising one

  18. The Yamabe constant

    International Nuclear Information System (INIS)

    O Murchadha, N.

    1991-01-01

    The set of riemannian three-metrics with positive Yamabe constant defines the space of independent data for the gravitational field. The boundary of this set is investigated, and it is shown that metrics close to the boundary satisfy the positive-energy theorem. (Author) 18 refs

  19. Study of the magnetic characteristics of ferrites with a view to their application in a proton synchrotron; Etudes des caracteristiques magnetiques des ferrites en vue de leur application dans un synchrotron a protons

    Energy Technology Data Exchange (ETDEWEB)

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

    1966-10-01

    In this report magnetic properties of some Ni Zn ferrites available in France are investigated for the purpose of their use in accelerating cavities of proton synchrotron. An attempt is made to measure permeability and quality factor of ferrite versus various physical parameters such as frequency F, the induction B, the magnetic bias field Hp and the temperature, the investigation ranges being: F {<=} 40 Mc/s; B {<=} 10{sup -2} Tesla; Hp {<=} 5000 AT/m; T {<=} 100 C. The measurements were carried out with the one hand, conventional impedance bridge (Q-meter, RX-meter) and on the other hand, with resonating method using an inductive ferrite loaded cavity in parallel with an external capacity. The latter method is of particular interest for the measurements in function of induction and magnetic bias field. (author) [French] Ce travail consiste a etudier les proprietes magnetiques d'un certain nombre de ferrites de Ni Zn disponibles sur le marche francais en vue de leur utilisation dans les cavites acceleratrices d'un synchrotron a protons. On se propose de mesurer la permeabilite et le facteur de qualite du ferrite en fonction de divers parametres physiques tels que la frequence F, l'induction B, le champ magnetique de polarisation Hp et la temperature T, avec: F {<=} 40 Mc/s; B {<=} 10{sup -2} Tesla; Hp {<=} 5000 AT/m; T {<=} 100 C. On effectue les mesures d'une part a l'aide des ponts d'impedance classiques (Q-metre, RX-metre) et d'autre part par la methode du resonateur qui consiste a mettre en parallele une cavite inductive chargee de ferrite et une capacite exterieure. Cette derniere methode est particulierement interessante pour les mesures en fonction de l'induction et du champ magnetique polarisant. (auteur)

  20. Tubes légers à haute résistance pour des applications pétrolières marines Light High Strength Tubes for Offshore Petroeleum Applications

    Directory of Open Access Journals (Sweden)

    Corteville J.

    2006-11-01

    Full Text Available Les besoins nouveaux en tubes à haute résistance, créés par le développement actuel des gisements pétroliers marins, nous ont conduits à étudier des tubes composites particuliers, élaborés par enrouiement hélicoïdal de rubans d'acier minces à haute résistance enrobés d'une résine époxy polymérisable. Un mode de recouvrement adapté des rubans d'acier confère au composite une bonne étanchéité et des caractéristiques mécaniques élevées. Les propriétés physiques et chimiques de la matrice de résine permettent également d'obtenir une faible densité et une résistance convenable à la corrosion par les fluides pétroliers, l'eau de mer ou les boues de forage. Cette étude préliminaire comporte une analyse théorique simplifiée de ce type de structure composite, puis une partie expérimentale destinée a sélectionner les caractéristiques optimales de l'acier et de la résine et à vérifier les propriétés mécaniques et physico-chimiques obtenues sur ces tubes. Enfin, des exemples d'application en mer profonde destinés à comparer ces tubes composites aux tubes en acier sont présentés. Les premières conclusions de cette étude semblent confirmer l'intérêt de ce type de matériau pour ces applications. The new requirements for high-strength tubes created by thé current development of offshore oilfields led thé authors ta study thé development ot spécial composite tubes formed by thé spiral winding of high-strength thin steel strips coated with a polymerïzable epoxy resin. A particular method of overlapping thé steel strips makes the composite leakproof and leads to good mechanical properties: The physical and chemical properties of thé resin matrix also make for a low specific gravity and suitable résistance to corrosion coused by petroleum fluids, seawater or drilling mud. This preliminary article presents a simplified theoretical analysis of this type of composite structure, followed by an exp

  1. 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

  2. Statutes of limitations: the special problem of DES suits

    International Nuclear Information System (INIS)

    Feigin, C.A.

    1981-01-01

    In 1971, medical studies determined that DES causes a rare type of vaginal cancer in a small number of daughters of mothers who took DES during pregnancy. Subsequently, medical studies determined that exposure to DES can cause other vaginal abnormalities in the daughters, some of which may be precancerous. As a result of these discoveries, many lawsuits have been filed by these daughters against DES manufacturers. Many DES suits may be barred by statutes of limitations, both because the number of years between the daughters' exposure to DES in utero and the discovery that DES can cause injuries exceeds the statutory period, and because the cancer or other injuries caused by DES may not develop for many additional years. This Note discusses two methods that DES plaintiffs may be able to use to overcome the potential statutes of limitations bar: the discovery rule, and state provisions which toll the statute of limitations for minors. The Note contends that courts should apply an expanded discovery rule to DES suits to avoid the unfair result of barring a claim before the plaintiff could have known that she had a cause of action. In addition, the Note argues that the injury which causes the statute of limitations to begin to run in DES suits should not be rigidly defined. Finally, the Note urges that courts allow eligible DES plaintiffs to take advantage of applicable state provisions that toll the statute of limitations for minors

  3. variabilite des productions et des revenus des exploitations

    African Journals Online (AJOL)

    3Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), UMR Innovation,. Montpellier, France. Doubangolo COULIBALY, Email kone_b@yahoo.fr. RESUME. La durabilité des systèmes de production à base de coton dans un contexte de variabilité des prix aux producteurs et de ...

  4. The thin layer technique and its application to electron microscopy; La technique des couches minces et son application a la microscopie electronique

    Energy Technology Data Exchange (ETDEWEB)

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

    1957-10-15

    This work deals with the technique of thin layers obtained by evaporation under vacuum, in the thickness range extending from a few monoatomic layers to several hundred angstroms. The great theoretical and practical interest of these layers has, it is well known, given rise to many investigations from Faraday onwards. Within the necessarily restricted limits of this study, we shall approach the problem more particularly from the point of view of: - their production; - their use in electron microscopy. A critical appraisal is made, in the light of present-day knowledge, based on our personal experience and on an extensive bibliography which we have collected on the subject. (author) [French] Le present travail concerne la technique des couches minces obtenues par evaporation sous vide, dans le domaine d'epaisseur qui s'etend de quelques couches monoatomiques a plusieurs centaines d'angstroms. L'interet theorique et pratique considerable de ces couches a suscite, comme on sait, de nombreux travaux depuis Faraday. Dans le cadre necessairement restreint de cette these, nous aborderons plus particulierement le point de vue de: - leur obtention; - leur utilisation en microscopie electronique. Il s'agit d'une mise au point critique, a la lumiere des connaissances actuelles, appuyee sur notre experience personnelle et sur une importante bibliographie, qu'il nous a ete donne de reunir a ce sujet. (auteur)

  5. The thin layer technique and its application to electron microscopy; La technique des couches minces et son application a la microscopie electronique

    Energy Technology Data Exchange (ETDEWEB)

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

    1957-10-15

    This work deals with the technique of thin layers obtained by evaporation under vacuum, in the thickness range extending from a few monoatomic layers to several hundred angstroms. The great theoretical and practical interest of these layers has, it is well known, given rise to many investigations from Faraday onwards. Within the necessarily restricted limits of this study, we shall approach the problem more particularly from the point of view of: - their production; - their use in electron microscopy. A critical appraisal is made, in the light of present-day knowledge, based on our personal experience and on an extensive bibliography which we have collected on the subject. (author) [French] Le present travail concerne la technique des couches minces obtenues par evaporation sous vide, dans le domaine d'epaisseur qui s'etend de quelques couches monoatomiques a plusieurs centaines d'angstroms. L'interet theorique et pratique considerable de ces couches a suscite, comme on sait, de nombreux travaux depuis Faraday. Dans le cadre necessairement restreint de cette these, nous aborderons plus particulierement le point de vue de: - leur obtention; - leur utilisation en microscopie electronique. Il s'agit d'une mise au point critique, a la lumiere des connaissances actuelles, appuyee sur notre experience personnelle et sur une importante bibliographie, qu'il nous a ete donne de reunir a ce sujet. (auteur)

  6. Chirurgie des grassmanniennes

    CERN Document Server

    Lafforgue, Laurent

    2003-01-01

    Les compactifications diverses de variétés de modules sont un thème important et récurrent des mathématiques modernes, et elles connaissent un grand nombre d'applications. Ce livre traite le cas de cellules de Schubert minces, qui sont de sous-variétés naturelles de grassmanniennes. L'auteur a été amené à traiter ces questions par un cas particulier lié à ses travaux sur le programme de Langlands. Dans cette monographie, il en développe une théorie plus systématique, présentant le fortes similarités avec celle des modules du courbes stables. The various compactifications of moduli spaces are an important recurrent theme of modern mathematics, and they have a large number of applications. This book treats the case of thin Schubert varieties, which are natural subvarieties of Grassmannians. The author was led to these questions by a particular case linked to his work on the Langlands program. In this monograph, he develops the theory in a more systematic way, which exhibits strong similarities...

  7. Évaluation des paysages de l'Hérault: une approche méthodologique et une application SIG adaptée

    Directory of Open Access Journals (Sweden)

    Marie-Cécile FALQUE

    1995-06-01

    Full Text Available L’élaboration d’un outil d’évaluation des paysages a été rendue possible grâce à un partenariat entre l’INRA, la DIREN et l’Observatoire du Territoire, avec le souci commun d’intégrer la réflexion sur les paysages dans les problématiques de gestion de l’espace. Les modules d’analyse élaborés à partir des fonctionnalités des Systèmes d’Information Géographique produisent des résultats très prometteurs en vue de la sensibilisation au paysage des partenaires et acteurs et laissent entrevoir d’intéressantes perspectives de valorisation.

  8. Contribution to the study of physico-chemical properties of surfaces modified by laser treatment. Application to the enhancement of localized corrosion resistance of stainless steels; Contribution a l'etude des proprietes physico-chimiques des surfaces modifiees par traitement laser. Application a l'amelioration de la resistance a la corrosion localisee des aciers inoxydables

    Energy Technology Data Exchange (ETDEWEB)

    Pacquentin, W.

    2011-11-25

    Metallic materials are more and more used in severe conditions with particularly strong request for improving their behavior in aggressive environment and especially over long periods. The objective of this PhD work is to estimate the potentiality of a laser surface melting treatment on the improvement of the stainless steel 304L corrosion resistance, surface treatments by laser can be revisited on the basis of a recent change in the laser technology. In the frame of this work, a nano-pulsed laser fiber was chosen: it allows the treated surface to be melted for few microns in depth, followed by an ultra-fast solidification occurring with cooling rates up to 1011 K/s. The combination of these processes leads to the elimination of the surface defects, the formation (trapping) of metastable phases, the segregation of chemical elements and the growth of a new oxide layer which properties are governed by the laser parameters. To correlate these latter to the electrochemical reactivity of the surface, the influence of two laser parameters on the physico-chemical properties of the surface was studied: the laser power and the overlap of the laser impacts. To support this approach, the pitting corrosion resistance of the samples was determined by standard electrochemical tests. For specific laser parameters, the pitting potential of a 304L stainless steel was increased by more than 500 mV corresponding to an important enhancement in localized corrosion resistance in chloride environment. The interdependence of the different phenomena resulting from the laser treatment lead to a quite complex prioritization of their role on the sensibility of the 304L. However, it was demonstrated that the nature of the thermal oxide formed during the laser surface melting and the induced defects are first-order parameters for the initiation of pits. (author) [French] Les materiaux metalliques sont utilises dans des conditions de plus en plus severes et doivent presenter une parfaite

  9. In situ generation of a hydroxyl radical by nanoporous activated carbon derived from rice husk for environmental applications: kinetic and thermodynamic constants.

    Science.gov (United States)

    Karthikeyan, S; Sekaran, G

    2014-03-07

    The objective of this investigation is to evaluate the hydroxyl radical (˙OH) generation using nanoporous activated carbon (NPAC), derived from rice husk, and dissolved oxygen in water. The in situ production of the ˙OH radical was confirmed through the DMPO spin trapping method in EPR spectroscopy and quantitative determination by a deoxyribose assay procedure. NPAC served as a heterogeneous catalyst to degrade 2-deoxy-d-ribose (a reference compound) using hydroxyl radical generated from dissolved oxygen in water at temperatures in the range 313-373 K and pH 6, with first order rate constants (k = 9.2 × 10(-2) min(-1), k = 1.2 × 10(-1) min(-1), k = 1.3 × 10(-1) min(-1) and k = 1.68 × 10(-1) min(-1)). The thermodynamic constants for the generation of hydroxyl radicals by NPAC and dissolved oxygen in water were ΔG -1.36 kJ mol(-1) at 313 K, ΔH 17.73 kJ mol(-1) and ΔS 61.01 J mol(-1) K(-1).

  10. Production in constant evolution

    International Nuclear Information System (INIS)

    Lozano, T.

    2009-01-01

    The Cofrentes Nuclear Power Plant now has 25 years of operation behind it: a quarter century adding value and demonstrating the reasons why it is one of the most important energy producing facilities in the Spanish power market. Particularly noteworthy is the enterprising spirit of the plant, which has strived to continuously improve with the large number of modernization projects that it has undertaken over the past 25 years. The plant has constantly evolved thanks to the amount of investments made to improve safety and reliability and the perseverance to stay technologically up to date. Efficiency, training and teamwork have been key to the success of the plant over these 25 years of constant change and progress. (Author)

  11. Is the sun constant

    International Nuclear Information System (INIS)

    Blake, J.B.; Dearborn, D.S.P.

    1979-01-01

    Small fluctuations in the solar constant can occur on timescales much shorter than the Kelvin time. Changes in the ability of convection to transmit energy through the superadiabatic and transition regions of the convection zone cause structure adjustments which can occur on a time scale of days. The bulk of the convection zone reacts to maintain hydrostatic equilibrium (though not thermal equilibrium) and causes a luminosity change. While small radius variations will occur, most of the change will be seen in temperature

  12. Stabilized power constant alimentation

    International Nuclear Information System (INIS)

    Roussel, L.

    1968-06-01

    The study and realization of a stabilized power alimentation variable from 5 to 100 watts are described. In order to realize a constant power drift of Lithium compensated diodes, we have searched a 1 per cent precision of regulation and a response time minus than 1 sec. Recent components like Hall multiplicator and integrated amplifiers give this possibility and it is easy to use permutable circuits. (author) [fr

  13. The study by means of a photomultiplier of the scintillations produced by {alpha} particles striking a zinc sulphide screen; Etude, au photomultiplicateur, des scintillations produites par les particules {alpha} dans un ecran de sulfure de zinc. Application a la numeration precise des particules {alpha}

    Energy Technology Data Exchange (ETDEWEB)

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

    1955-06-15

    The object of the study is the accurate counting of {alpha} particles by p-m. detection of their scintillations upon impact with a zinc sulphide screen. The main advantage of the method is the extreme simplicity of the electronics used: the possibility of obtaining a utilizable pulse from the p-m. (EMI5311) without any amplification, and in linear response, is demonstrated. The scintillation produced by an impact on Zn-S has also been studied experimentally. The decrease of light intensity in relation to time may be interpreted by the exponential relation: I = I{sub 0} exp (-t / {tau}) whereby {tau} = (39 {+-} 0,1) 10{sup -6} s. The relation between scintillation intensity and remaining trajectory after travel through a given air-space has also been determined. Possible suitable applications of this method of {alpha} counting are those where good stability and low background are necessary. Results stated bear on air contamination studies, isotopic composition variation measurement of uranium, bismuth content measurement in alloys by irradiation of specimens in a thermal neutron flux and {alpha} count on the Po formed. (author) [French] Ce travail est consacre a l'etude de la numeration precise des particules {alpha} par detection au photomultiplicateur des scintillations produites par ces particules dans un ecran de sulfure de zinc. Le principal avantage de cette methode reside dans l'extreme simplicite de l'appareillage electronique; il est en effet montre qu'il est possible, tout en convoyant une reponse lineaire, d'obtenir du photomultiplicateur (EMI5311) un signal electrique utilisable sans aucune amplification. La scintillation produite par l'impact des particules {alpha} sur un ecran de Zn-S est etudiee experimentalement. La decroissance de l'intensite lumineuse en fonction du temps est interpretable par la relation exponentielle I = I{sub 0} exp (-t / {tau}) avec {tau} = (39 {+-} 0,1) 10{sup -6} s. La relation entre l'intensite de la scintillation et le

  14. Connecting Fundamental Constants

    International Nuclear Information System (INIS)

    Di Mario, D.

    2008-01-01

    A model for a black hole electron is built from three basic constants only: h, c and G. The result is a description of the electron with its mass and charge. The nature of this black hole seems to fit the properties of the Planck particle and new relationships among basic constants are possible. The time dilation factor in a black hole associated with a variable gravitational field would appear to us as a charge; on the other hand the Planck time is acting as a time gap drastically limiting what we are able to measure and its dimension will appear in some quantities. This is why the Planck time is numerically very close to the gravitational/electric force ratio in an electron: its difference, disregarding a π√(2) factor, is only 0.2%. This is not a coincidence, it is always the same particle and the small difference is between a rotating and a non-rotating particle. The determination of its rotational speed yields accurate numbers for many quantities, including the fine structure constant and the electron magnetic moment

  15. Study of deuterons induced nuclear reactions on light elements (N, Al and Si): Application to containment materials of radioactive wastes; Etude des reactions nucleaires induites par des deuterons sur des elements legers (N, Al, Si): application aux materiaux de confinement des dechets radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Pellegrino, St

    2004-03-01

    Nuclear reaction analysis is well adapted to the quantification of light element. Profiles of concentration in order to follow elements migration into materials can be undertaken. This technique is used to study the behavior of the future matrices for nuclear waste containment. This technique is isotopic, characterized by a good signal-to-background ratio and a very low detection limit. The probability of a nuclear reaction is linked to a parameter called 'cross section' we have to know in order to carry out quantitative analysis. We have determined excitation curves for nitrogen, aluminium and silicon. These experiments were done with deuterons from 0.5 to 2 MeV. Two methods for the cross section characterization are presented and are in agreement with each other. The second one reduces uncertainty. Data are incorporated in the simulation software SIMNRA. We have compared the results obtained on different samples when we use data in literature or data of the study. We have noticed a great fit improvement with the data of this study. The new cross sections of this work will be integrated in the general data base SIGMABASE. Applications on materials such as Si{sub 3}N{sub 4}, nano-metric powders, WCN and nuclear glass YLaMgSiAlON studied for radioactive waste containment are also presented. (author)

  16. Civili, langue des Baloango

    DEFF Research Database (Denmark)

    Mavoungou, Paul Achille; Ndinga-Koumba-Binza, Hugues Steve

    , Congo, Angola, etc.) issus de la décolonisation. Il présente de façon succincte quelques phénomènes historiques, phonologiques, morphosyntaxiques, homonymiques et analogiques de la langue. Des faits sémantiques des emprunts linguistiques y sont également décrits dans le cadre des changements...

  17. The Cyrano program. 1 - description and operation of an irradiation device 'Cyrano'. 2 - results of the experiments Cyrano 1 and 2 (study of the EL 4 first-bach pencil); measurement of the thermal conductivity integral for UO{sub 2} sintered up to 2300 deg C; evolution of fission gases at constant power; Programme Cyrano. 1 - description et exploitation d'un dispositif d'irradiation ''cyrano''. 2 - resultats des experiences cyrano 1 et 2 (etude du crayon EL4 1. jeu). Mesure de l'integrale de conductibilite thermique d'UO{sub 2} fritte jusqu'a 2300 deg C. Evolution des gaz de fission a puissance constante

    Energy Technology Data Exchange (ETDEWEB)

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

    1968-07-01

    Two rods of the type 'EL 4 first score' have been irradiated in 'Cyrano' capsules which are suited for continuous measurement of the nuclear power evolved and equipped with thermocouples. The variations of the integral of conductivity of sintered 96 per cent theoretical dense UO{sub 2} has been established until 2300 deg. C; these variations are coherent with those previously measured out-of-pile. The released fission gases have been recovered at different times during the irradiation: the kinetics of release of stable gases is such that, in the experimental conditions (T{sub surface} = 610 deg. C, {integral}{sub T{sub s}}{sup T{sub c}} kdT = 34.7 W cm{sup -1}) the fraction of released gases is still widely increasing after 12 days of irradiation. Numerous observations have been made on concentrations of rare gases locally present in the irradiated fuel. (authors) [French] L'irradiation de deux crayons combustibles type EL 4, 1er jeu, a ete menee a bien dans des capsules 'Cyrano' equipees de dispositifs de mesure continue de la puissance nucleaire et de plusieurs reperes de temperatures; la variation de l'integrale de conductibilite thermique de l'oxyde d'uranium fritte (96 pour cent d. th.) a ete tracee jusqu'a 2300 deg. C; la courbe representative de ces variations est coherente avec celle obtenue precedemment hors pile. Les gaz de fission apparus hors du combustible ont ete extraits du crayon a plusieurs reprises pendant l'experience: la cinetique d'accumulation des gaz stables est telle que dans les conditions etudiees (T{sub surface} = 610 deg. C, {integral}{sub T{sub s}}{sup T{sub c}} kdT = 34.7 W cm{sup -1}) la fraction des gaz degages est encore largement croissante apres 12 jours d'irradiation. De nombreuses observations ont ete recueillies sur la nature et la concentration des gaz rares presents en differents points du combustible irradie. (auteurs)

  18. Application of the Ssub(n)-method for reactors computations on BESM-6 computer by using 26-group constants in the sub-group presentation

    International Nuclear Information System (INIS)

    Rogov, A.D.

    1975-01-01

    Description of the computer program for reactor computation by application of the Ssub(n)-method in the two-dimensional XY and RZ geometries is given. These programs are used with application of the computer library of 26- group constats system taking into account the resonance structure of the cross sections in the subgroup presentation. Results of some systems computations are given and the results obtained are analysed. (author)

  19. Perancangan Enkripsi Pada Citra Bitmap Dengan Algoritma Des, Triple Des, dan Idea

    Directory of Open Access Journals (Sweden)

    Agustinna Yosanny

    2010-12-01

    Full Text Available Rapid development of Information Technology causes information can access easier without space boundaries. Image is a form of information, which contains many information. Some image contains confidential information that cannot distribute to unauthorized persons. Therefore, image encryption application is create to encrypt part of image that has confidential information. The image encryption application is encrypt image by applying DES, Triple DES, and IDEA algorithms. The research was applying analysis and design methodology. The analysis methodology was undertaken through literature study and algorithm research and testing. The design methodology was undertaken through database, features, system, and screen layout design. Results of the research are image encryption application that can encrypt part of image and or all of image by applying three algorithms such as DES, Triple DES, and IDEA. This application is show comparation of these algorithms. In conclusion, method of encryption can apply to image, so that confidential information of the image can protect from unauthorized person. 

  20. Des racines et des ailes

    Directory of Open Access Journals (Sweden)

    Stéphanie Vincent-Geslin

    2012-05-01

    Full Text Available Les mobilités pendulaires semblent être en augmentation en Europe depuis une dizaine d’années. Cette croissance du temps passé à se déplacer amène à remettre en question la conjecture de Zahavi et apparaît relativement inexplicable en regard du paradigme classique de l’acteur rationnel traditionnellement utilisé dans le champ des transports. Si, dans la littérature, les temps de déplacements sont principalement expliqués par le contexte résidentiel, la forme urbaine et le travail, ce cadre explicatif ne dit rien des processus de décision eux-mêmes qui amènent aux pendularités intensives.À partir d’une enquête qualitative menée auprès de pendulaires français, suisses et belges, cette contribution propose d’analyser les arbitrages et les éléments déterminants des processus de la grande pendularité. Les mobilités quotidiennes pendulaires apparaissent comme le résultat de compromis entre activité professionnelle, attachement résidentiel et choix de vie et prennent ainsi la forme de stratégies de conciliation entre vie privée et vie professionnelle. Ces mobilités spatiales permettent alors paradoxalement la préservation des ancrages résidentiels, sociaux et familiaux.Roots and wings. Long-distance commuting patterns, or how to conciliate professional and personal lifeLong-distance commuting patterns appear to be increasing in Europe over the last ten years. These raising mobility patterns lead to reappraise the Zahavi conjecture and appear largely inexplicable by the classical rational actor paradigm traditionally used in transportation research. In literature, commuting is mainly explained by residential contexts, urban forms and job. Nevertheless this theoretical frame says little about the decision-making processes themselves. Based on a qualitative survey conducted in three European countries - France, Belgium and Switzerland – among a population of high commuters, this paper proposes an analysis of

  1. The Hubble Constant

    Directory of Open Access Journals (Sweden)

    Neal Jackson

    2015-09-01

    Full Text Available I review the current state of determinations of the Hubble constant, which gives the length scale of the Universe by relating the expansion velocity of objects to their distance. There are two broad categories of measurements. The first uses individual astrophysical objects which have some property that allows their intrinsic luminosity or size to be determined, or allows the determination of their distance by geometric means. The second category comprises the use of all-sky cosmic microwave background, or correlations between large samples of galaxies, to determine information about the geometry of the Universe and hence the Hubble constant, typically in a combination with other cosmological parameters. Many, but not all, object-based measurements give H_0 values of around 72–74 km s^–1 Mpc^–1, with typical errors of 2–3 km s^–1 Mpc^–1. This is in mild discrepancy with CMB-based measurements, in particular those from the Planck satellite, which give values of 67–68 km s^–1 Mpc^–1 and typical errors of 1–2 km s^–1 Mpc^–1. The size of the remaining systematics indicate that accuracy rather than precision is the remaining problem in a good determination of the Hubble constant. Whether a discrepancy exists, and whether new physics is needed to resolve it, depends on details of the systematics of the object-based methods, and also on the assumptions about other cosmological parameters and which datasets are combined in the case of the all-sky methods.

  2. Automation of ultrasonic testing, instrumentation and rules for application and evaluation. Proceedings; Automatisierung der Ultraschallpruefung, Geraetetechnik und Regeln zur Anwendung und Auswertung. Vortraege des Seminars

    Energy Technology Data Exchange (ETDEWEB)

    Wuestenberg, H. [comp.

    1997-12-31

    The proceedings volume contains 18 lectures of the seminar addressing the following (selected) aspects: Requirements to be met by PC cards for US testing applications, defined by producers and appliers; digital technology and its impact on multichannel US testing instruments; the ALOK and array systems combined into one very efficient testing system (SAPHIR); a testing system combining US radiation source arrays and the pulsed eddy current method by means of highly integrated microelectronics (ASICs); regulatory standards and specifications for automated US testing; requirements for automated US testing in compliance with nuclear engineering codes; state of the art in standardisation for definition of required properties of US testing systems; critical review of the proposed standard relating to the TOFD method; automated evaluation shown with the example of US testing of pipelines. (orig./CB) [Deutsch] Dieser Band enthaelt 18 Vortraege mit folgenden Themen (Auswahl): Anforderungen an Ultraschall-PC-Karten aus der Sicht von Hersteller und Betreiber; Einfluss der Digitaltechnik auf Mehrkanal-Ultraschall-Pruefanlagen; Vereinigung der ALOK- und der Gruppenstrahler-Technik in einem leistungsfaehigen Pruefsystem (SAPHIR); Ein kombiniertes Pruefsystem fuer die Ultraschall-Gruppenstrahler- und Impuls-Wirbelstrom-Technik auf der Basis von hochintegrierter Mikroelektronik (ASICs); Regelwerke und Spezifikationen fuer die automatisierte Ultraschallpruefung; Anforderungen der kerntechnischen Regelwerke an die automatisierte Ultraschallpruefung; Stand der Normung bei der Charakterisierung der Eigenschaften von Ultraschall-Pruefsystemen; Kritische Bewertung des Normungsvorschlages zur Beugungslaufzeittechnik (TOFD); und Automatisierte Auswertung am Beispiel der Ultraschallpruefung von Fernrohrleitungen. (orig.)

  3. 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

  4. The inconstant solar constant

    International Nuclear Information System (INIS)

    Willson, R.C.; Hudson, H.

    1984-01-01

    The Active Cavity Radiometer Irradiance Monitor (ACRIM) of the Solar Maximum Mission satellite measures the radiant power emitted by the sun in the direction of the earth and has worked flawlessly since 1980. The main motivation for ACRIM's use to measure the solar constant is the determination of the extent to which this quantity's variations affect earth weather and climate. Data from the solar minimum of 1986-1987 is eagerly anticipated, with a view to the possible presence of a solar cycle variation in addition to that caused directly by sunspots

  5. A method for determination of X-ray elastic constants of materials showing non-linear sin2ψ diagrams and its application to Zn-Ni-alloy electroplate

    International Nuclear Information System (INIS)

    Sasaki, Toshihiko; Kuramoto, Makoto; Yoshioka, Yasuo.

    1990-01-01

    This paper describes the method and the experiment for the determination of the x-ray elastic constants of Zn-Ni-alloy electroplate. For this material, the sin 2 ψ method is not adequate to use because this material shows severely curved sin 2 ψ diagrams. Therefore, a new method developed by the authors was explained first. This new method is effective for materials showing nonlinear sin 2 ψ diagrams. Secondly, the experiment was made on the application of this method to the Zn-Ni-alloy electroplate. And it was found out that the experimental data agreed well to the theory of this method. As a result, the following values were obtained as the x-ray elastic constants of the sample measured: (1+ν)/E=8.44 TPa -1 ν/E=2.02 TPa -1 (author)

  6. Study of PECVD films containing flourine and carbon and diamond like carbon films for ultra low dielectric constant interlayer dielectric applications

    Science.gov (United States)

    Sundaram, Nandini Ganapathy

    Lowering the capacitance of Back-end-of-line (BEOL) structures by decreasing the dielectric permittivity of the interlayer dielectric material in integrated circuits (ICs) lowers device delay times, power consumption and parasitic capacitance. a:C-F films that are thermally stable at 400°C were deposited using tetrafluorocarbon and disilane (5% by volume in Helium) as precursors. The bulk dielectric constant (k) of the film was optimized from 2.0 / 2.2 to 1.8 / 1.91 as-deposited and after heat treatment. Films, with highly promising k-values but discarded for failing to meet shrinkage rate requirements were salvaged by utilizing a novel extended heat treatment scheme. Film properties including chemical bond structure, F/C ratio, refractive index, surface planarity, contact angle, dielectric constant, flatband voltage shift, breakdown field potential and optical energy gap were evaluated by varying process pressure, power, substrate temperature and flow rate ratio (FRR) of processing gases. Both XPS and FTIR results confirmed that the stoichiometry of the ultra-low k (ULK) film is close to that of CF2 with no oxygen. C-V characteristics indicated the presence of negative charges that are either interface trapped charges or bulk charges. Average breakdown field strength was in the range of 2-8 MV/cm while optical energy gap varied between 2.2 eV and 3.4 eV. Irradiation or plasma damage significantly impacts the ability to integrate the film in VSLI circuits. The film was evaluated after exposure to oxygen plasma and HMDS vapors and no change in the FTIR spectra or refractive index was observed. Film is resistant to attack by developers CD 26 and KOH. While the film dissolves in UVN-30 negative resist, it is impermeable to PGDMA. A 12% increase in dielectric constant and a decrease in contact angle from 65° to 47° was observed post e-beam exposure. The modified Gaseous Electronics Conference (mGEC) reference cell was used to deposit DLC films using CH4 and Argon as

  7. Rational Formulation of Alternative Fuels using QSPR Methods: Application to Jet Fuels Développement d’un outil d’aide à la formulation des carburants alternatifs utilisant des méthodes QSPR (Quantitative Structure Property Relationship: application aux carburéacteurs

    Directory of Open Access Journals (Sweden)

    Saldana D.A.

    2013-06-01

    éveloppement et l’application de méthodes QSPR (Quantitative Structure Property Relationship permettant de relier la structure aux propriétés d’une molécule. Les produits étudiés sont les hydrocarbures (normal et iso-paraffines, naphtènes, aromatiques, etc. et les oxygénés du type alcools et esters. Les propriétés ciblées sont celles figurant dans les spécifications carburants telles que le point d’éclair, l’indice de cétane, la masse volumique et la viscosité. Les modèles prédictifs des propriétés des corps purs ont été établis à partir de données expérimentales de référence provenant en grande partie de la littérature. L’utilité de tels modèles dans la sélection de composés d’intérêt peut être montrée par exemple pour trouver le meilleur compromis pour satisfaire les critères de tenue à froid et de masse volumique des paraffines. Ainsi, si la chaîne carbonée est trop longue alors le critère de tenue à froid risque de ne pas être satisfait. Il est alors nécessaire de favoriser la ramification ou d’ajouter des bases ayant une bonne tenue à froid comme certains naphtènes ou monoaromatiques alkylés. Cependant, cela entraîne bien souvent une masse volumique trop basse par rapport à la spécification. Là encore l’ajout de naphtènes ou de monoaromatiques alkylés issus de la biomasse peut être intéressant.

  8. Reduction of uranium and plutonium oxides by aluminum. Application to the recycling of plutonium; Reduction des oxydes d'uranium et de plutonium par l'aluminium application au recyclage du plutonium

    Energy Technology Data Exchange (ETDEWEB)

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

    1968-07-01

    A process for treating plutonium oxide calcined at high temperatures (1000 to 2000 deg. C) with a view to recovering the metal consists in the reduction of this oxide dissolved in a mixture of aluminium, sodium and calcium fluorides by aluminium at about 1180 deg. C. The first part of the report presents the results of reduction tests carried out on the uranium oxides UO{sub 2} and U{sub 3}O{sub 8}; these are in agreement with the thermodynamic calculations of the exchange reaction at equilibrium. The second part describes the application of this method to plutonium oxides. The Pu-Al alloy obtained (60 per cent Pu) is then recycled in an aqueous medium. (author) [French] Un procede de traitement de l'oxyde de plutonium calcine a haute temperature (1000 deg. C a 2000 deg. C), en vue de la recuperation du metal, consiste a reduire cet oxyde dissous dans un melange de fluorures d'aluminium, de sodium et de calcium, par l'aluminium vers 1180 deg. C. Une premiere partie du rapport presente les resultats des essais de reduction des oxydes d'uranium UO{sub 2} et U{sub 3}O{sub 8}, en accord avec les resultats du calcul thermodynamique de la reaction d'echange a l'equilibre. Une seconde partie rend compte de l'application de cette methode a l'oxyde de plutonium. L'alliage Pu-Al obtenu (60 pour cent Pu) est ensuite recycle par voie aqueuse. (auteur)

  9. Structure of simple liquids; Structure des liquides simples

    Energy Technology Data Exchange (ETDEWEB)

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

    1969-07-01

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

  10. Reactor group constants and benchmark test

    Energy Technology Data Exchange (ETDEWEB)

    Takano, Hideki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-08-01

    The evaluated nuclear data files such as JENDL, ENDF/B-VI and JEF-2 are validated by analyzing critical mock-up experiments for various type reactors and assessing applicability for nuclear characteristics such as criticality, reaction rates, reactivities, etc. This is called Benchmark Testing. In the nuclear calculations, the diffusion and transport codes use the group constant library which is generated by processing the nuclear data files. In this paper, the calculation methods of the reactor group constants and benchmark test are described. Finally, a new group constants scheme is proposed. (author)

  11. Nuclei quadrupole coupling constants in diatomic molecule

    International Nuclear Information System (INIS)

    Ivanov, A.I.; Rebane, T.K.

    1993-01-01

    An approximate relationship between the constants of quadrupole interaction of nuclei in a two-atom molecule is found. It enabled to establish proportionality of oscillatory-rotation corrections to these constants for both nuclei in the molecule. Similar results were obtained for the factors of electrical dipole-quadrupole screening of nuclei. Applicability of these relationships is proven by the example of lithium deuteride molecule. 4 refs., 1 tab

  12. Rôle des germes parasites des bactéries pathogènes dans l'autoépuration des eaux

    Directory of Open Access Journals (Sweden)

    GUELIN A.

    1969-04-01

    Full Text Available Existence dans les eaux polluées de germes parasites qui s'attaquent aux bactéries pathogènes. Le pouvoir bactéricide des eaux polluées dû, en grande partie à la présence dans ces eaux de différents représentants des germes parasites. Possibilité d'application pratique des germes parasites pour l'assainissement des eaux polluées.

  13. Chrono-potentiometry in molten chlorides. Application to the study of the electrochemical properties of uranium and plutonium in the LiCl-KCl eutectic; Chronopotentiometrie dans les chlorures fondus. Application a l'etude des proprietes electrochimiques de l'uranium et du plutonium dans l'eutectique LiCl-KCl

    Energy Technology Data Exchange (ETDEWEB)

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

    1969-05-01

    Using solutions of cadmium chloride in the eutectic LiCl-KCl, a chrono-potentiometric method has been developed with a view to its application to the study of molten solutions. Particular attention has been paid to the choice of the indicator electrodes. The method makes it possible to analyze molten solutions quantitatively and to determine diffusion coefficients and their activation energies; it yields furthermore information about the nature and the behaviour of ionic species in solution. The method has been applied to the study of solutions of uranium and plutonium chloride in the eutectic LiCl-KCl. Linear chrono-amperometry has been used for studying these solutions quantitatively, but chrono-potentiometry, of which the theory is better developed, is better suited to a quantitative study. The results obtained have made it possible to determine the diffusion coefficients of the ions Cd{sup 2+}, U{sup 3+}, U{sup 4+} and U(IV) in the presence of F{sup -} and Pu{sup 3+} ions, as well as the activation energy of the diffusion coefficients. (author) [French] La mise au point de la chronopotentiometrie comme moyen d'etude des solutions fondues a ete effectuee avec des solutions de chlorure de cadmium dans l'eutectique LiCl-KCl. Le probleme du choix des electrodes indicatrices a ete particulierement etudie. La methode permet l'analyse quantitative des solutions fondues ainsi que la determination des coefficients de diffusion et de leurs energies d'activation: elle donne en outre des renseignements sur la nature et le comportement des especes ioniques en solution. Elle a ete appliquee a l'etude des solutions des chlorures d'uranium et de plutonium dans l'eutectique LiCl-KCl. La chronoamperometrie lineaire a ete utilisee pour l'etude qualitative de ces solutions, mais la chronopotentiometrie, dont la theorie est plus complete, convient mieux pour l'etude quantitative. Les resultats obtenus ont permis de determiner les

  14. Computer Applications in Counselor Education: Developing Cultural Competencies Through Online Collaboration of Future School Counselors / L’informatique dans l’éducation des orienteurs : le développement du savoir-faire culturel par la collaboration en

    Directory of Open Access Journals (Sweden)

    Vessela Ilieva

    2012-07-01

    Full Text Available This study examined the applications of computer-mediated student collaboration in a graduate multicultural counseling course. The course work included a reflective cultural competency building assignment that utilized online communication and collaboration using a wiki to extend and improve students’ multicultural counseling and social justice advocacy skills. The online assignment design was aligned with the current call for utilizing technology in the counseling profession. It further considered the needs of the future counselors, the current levels of exposure to and experience with available technology of the class members, and the opportunities for utilization of a variety of online-based tools to extend in-class and out-of-class discussions. Students’ response to this new form of class work and communication confirmed the potential of the online component to other aspects of counselor preparation, and the data analysis showed that the computer-mediated assignment was a valuable addition to developing students’ skills as multiculturally competent professionals. Cette étude a examiné les applications de la collaboration entre étudiants par l’entremise de l’informatique dans le cadre d’un cours d’études supérieures sur l’orientation en contexte multiculturel. Les travaux du cours comprenaient un travail de réflexion pour renforcer le savoir-faire culturel grâce à la communication et à la collaboration en ligne, en utilisant un wiki pour accroître et améliorer les aptitudes des étudiants en orientation en contexte multiculturel et en défense de la justice sociale. La conception du travail en ligne s’alignait sur la tendance actuelle pour une utilisation accrue de la technologie dans le métier de conseiller en orientation. On y tenait également compte des besoins des futurs conseillers, de leur degré d’exposition à la technologie et de leur expérience avec celle-ci, ainsi que des occasions pour l

  15. Code des baux 2018

    CERN Document Server

    Vial-Pedroletti, Béatrice; Kendérian, Fabien; Chavance, Emmanuelle; Coutan-Lapalus, Christelle

    2017-01-01

    Le code des baux 2018 vous offre un contenu extrêmement pratique, fiable et à jour au 1er août 2017. Cette 16e édition intègre notamment : le décret du 27 juillet 2017 relatif à l’évolution de certains loyers dans le cadre d’une nouvelle location ou d’un renouvellement de bail, pris en application de l’article 18 de la loi n° 89-462 du 6 juillet 1989 ; la loi du 27 janvier 2017 relative à l’égalité et à la citoyenneté ; la loi du 9 décembre 2016 relative à la transparence, à la lutte contre la corruption et à la modernisation de la vie économique ; la loi du 18 novembre 2016 de modernisation de la justice du xxie siècle

  16. Determination of a PWR key neutron parameters uncertainties and conformity studies applications; Determination des incertitudes liees aux grandeurs neutroniques d'interet des reacteurs a eau pressurisee a plaques combustible et applications aux etudes de conformite

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, D

    2002-07-01

    The aim of this thesis was to evaluate uncertainties of key neutron parameters of slab reactors. Uncertainties sources have many origins, technologic origin for parameters of fabrication and physical origin for nuclear data. First, each contribution of uncertainties is calculated and finally, a factor of uncertainties is associated to key slab parameter like reactivity, isotherm reactivity coefficient, control rod efficiency, power form factor before irradiation and lifetime. This factors of uncertainties were computed by Generalized Perturbations Theory in case of step 0 and by directs calculations in case of irradiation problems. One of neutronic conformity applications was about fabrication and nuclear data targets precision adjustments. Statistic (uncertainties) and deterministic (deviations) approaches were studied. Then neutronics key slab parameters uncertainties were reduced and so nuclear performances were optimised. (author)

  17. Determination of a PWR key neutron parameters uncertainties and conformity studies applications; Determination des incertitudes liees aux grandeurs neutroniques d'interet des reacteurs a eau pressurisee a plaques combustible et applications aux etudes de conformite

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, D

    2002-07-01

    The aim of this thesis was to evaluate uncertainties of key neutron parameters of slab reactors. Uncertainties sources have many origins, technologic origin for parameters of fabrication and physical origin for nuclear data. First, each contribution of uncertainties is calculated and finally, a factor of uncertainties is associated to key slab parameter like reactivity, isotherm reactivity coefficient, control rod efficiency, power form factor before irradiation and lifetime. This factors of uncertainties were computed by Generalized Perturbations Theory in case of step 0 and by directs calculations in case of irradiation problems. One of neutronic conformity applications was about fabrication and nuclear data targets precision adjustments. Statistic (uncertainties) and deterministic (deviations) approaches were studied. Then neutronics key slab parameters uncertainties were reduced and so nuclear performances were optimised. (author)

  18. Application d’une approche inspirée des colonies de fourmis pour la recommandation des chemins d’apprentissage dans un cours en ligne : modèle et expérience

    Directory of Open Access Journals (Sweden)

    Aziz Dahbi

    2014-01-01

    Full Text Available Dans cet article, nous présentons la mise en œuvre, l’expérimentation et l’évaluation d’une approche pour la recommandation des chemins d’apprentissage dans un cours en ligne. Le processus de recommandation est inspiré de l’intelligence en essaim et plus particulièrement de l’optimisation par colonies de fourmis (OCF (ant colony optimization [ACO]. Dans ce contexte, nous avons considéré une différenciation des chemins d’apprentissage en fonction de l’activité explorée pour l’apprentissage d’un cours. Dans l’objectif de recommander des chemins d’apprentissage considérés optimaux et d’évaluer ainsi leur impact sur l’apprentissage d’un cours en ligne, l’approche proposée est basée à la fois sur la recommandation de chemins pertinents par l’enseignant et sur les résultats stockés au fur et à mesure par les apprenants sur les chemins empruntés. Notre approche a été validée expérimentalement et les résultats obtenus ont montré l’émergence d’un chemin d’apprentissage favorisant la réussite d’un nombre d’apprenants relativement considérable.

  19. Représentations cartographiques des facteurs de vulnérabilité des populations exposées à une menace volcanique. Application à la région du volcan Cotopaxi (Equateur

    Directory of Open Access Journals (Sweden)

    1996-01-01

    Full Text Available Suivant une définition sociale, la vulnérabilité est la propension plus ou moins prononcée à subir des dommages. L’atténuation des risques naturels auxquels les hommes sont confrontés suppose la réduction de la vulnérabilité en matière de vies humaines, de biens et d’activités. Il s’agit au préalable d’identifier les facteurs de vulnérabilité, d’en mesurer la portée, et de localiser dans l’espace les secteurs les plus sensibles. La cartographie de la vulnérabilité et de ses facteurs est une étape indispensable vers une cartographie globale du risque à laquelle de nombreux chercheurs et décideurs aspirent. À partir de l’exemple des régions des provinces du Pichincha et du Cotopaxi exposées aux conséquences de l’activité du volcan Cotopaxi, l’article propose quelques jalons méthodologiques pour une cartographie de la vulnérabilité des populations menacées. Des typologies spatiales de vulnérabilité sont représentées à partir d’une analyse factorielle. La carte intégrée des facteurs de vulnérabilité permet la réalisation de diagnostics locaux, tandis qu’une troisième carte fournit des orientations pour des actions de préparation. Une réflexion est également menée sur l’intérêt et sur les limites d’utilisation de ces cartes. CARTOGRAFÍA DE LOS FACTORES DE VULNERABILIDAD DE LAS POBLACIONES EXPUESTAS A UNA AMENAZA VOLCÁNICA. APLICACIÓN A LA REGIÓN DEL VOLCÁN COTOPAXI (ECUADOR. Según una definición social, la vulnerabilidad es la propensión más o menos pronunciada a sufrir perjuicios cuando ocurre un fenómeno natural destructor. La mitigación de los riesgos naturales que enfrentan los hombres supone la reducción de la vulnerabilidad de éstos, de sus bienes y actividades económicas. Se trata previamente de identificar los factores de vulnerabilidad, medir sus consecuencias y localizar los sectores más sensibles. La cartografía de la vulnerabilidad y sus factores constituye una

  20. Des (bio)nano-composites utilisés dans le traitement d'eaux contaminées par de l'arsenic/gentamicine ou pour des applications médicales

    OpenAIRE

    HE, Jing

    2013-01-01

    Les composés dits 'bionano' (bionanocomposites) apparaissent comme un nouveau groupe de matériaux hybrides nano-structurés. Ils sont issus de la combinaison de polymères naturels et de solides inorganiques et sont de l'ordre du nanomètre dans au moins une direction. Ces matériaux hybrides conservent les structures et les propriétés fonctionnelles des polymères et matériaux inorganiques dont ils sont composés. Parallèlement, la présence de biopolymères permet de diminuer les risques environnem...

  1. Filament instability under constant loads

    Science.gov (United States)

    Monastra, A. G.; Carusela, M. F.; D’Angelo, M. V.; Bruno, L.

    2018-04-01

    Buckling of semi-flexible filaments appears in different systems and scales. Some examples are: fibers in geophysical applications, microtubules in the cytoplasm of eukaryotic cells and deformation of polymers freely suspended in a flow. In these examples, instabilities arise when a system’s parameter exceeds a critical value, being the Euler force the most known. However, the complete time evolution and wavelength of buckling processes are not fully understood. In this work we solve analytically the time evolution of a filament under a constant compressive force in the small amplitude approximation. This gives an insight into the variable force scenario in terms of normal modes. The evolution is highly sensitive to the initial configuration and to the magnitude of the compressive load. This model can be a suitable approach to many different real situations.

  2. Potential constants and centrifugal distortion constants of octahedral hexafluoride molecules

    Energy Technology Data Exchange (ETDEWEB)

    Manivannan, G [Government Thirumagal Mill' s Coll., Gudiyattam, Tamil Nadu (India)

    1981-04-01

    The kinetic constants method outlined by Thirugnanasambandham (1964) based on Wilson's (1955) group theory has been adapted in evaluating the potential constants for SF/sub 6/, SeF/sub 6/, WF/sub 6/, IrF/sub 6/, UF/sub 6/, NpF/sub 6/, and PuF/sub 6/ using the experimentally observed vibrational frequency data. These constants are used to calculate the centrifugal distortion constants for the first time.

  3. Decision threshold associated with multiple measurements. Application to the synthesis of the environment monitoring results; Seuil de decision associe a des mesures multiples. Application a la synthese des resultats de surveillance de l'environnement

    Energy Technology Data Exchange (ETDEWEB)

    Vivier, A. [CEA, Institut national des sciences et techniques nucleaires, Centre de Saclay, 91191 Gif-sur-Yvette Cedex (France); Manificat, G. [IRSN, Direction de l' environnement et de l' intervention, Service d' etude et de surveillance de la radioactivite dans l' environnement, BP 40035, 78116 Le Vesinet Cedex (France); Picolo, J.L.; Fleury, S. [IRSN, Direction de l' environnement et de l' intervention, Service de traitement des echantillons et de metrologie pour l' environnement, BP 40035, 78116 Le Vesinet Cedex (France); Mokili, M. [Laboratoire SUBATECH - UMR 6457, ecole des Mines de Nantes, IN2P3/CNRS, Universite de Nantes, 4 rue Alfred Kastler, La Chantrerie, BP 20722, 44307 Nantes Cedex 03 (France); Guo, X. [ORTEC-AMETEK Inc, 801 S. Illinois Ave., Oak Ridge, TN 37830 (United States)

    2012-01-15

    When the sample activity is measured for various reasons several times, then with each measurement can be associated an individual decision threshold and limit of detection. Each measurement can be analyzed through its own decision threshold. The whole measurements can sometimes present contradictory results, some measurements being lower than the decision threshold and other higher. The problem then arises to build a decision threshold and a detection limit taking into account all the individual results, and to decide if the radioactivity is finally detected or not. It is interesting to note that it is possible sometimes that the decision threshold taking account all results makes it possible to decide that the radioactivity is present whereas the totality of the individual results are negative in terms of individual decision threshold. The purpose of this article is to show how these thresholds and these coherent limits cumulated can be determined in way according to the experimental conditions. In a general way a rigorous method of cumulating makes it possible to systematically decrease the decision threshold and limit of detection in terms of activity. This approach has interesting applications in gamma spectrometry with multi-emitters, discharge or periodical environmental measurements. On the basis of measurements realized by the IRSN within the framework of the national monitoring of the environment, we will see the potential impact of these methods on the final assessments. (authors)

  4. Optimization of the scintillation parameters of the lead tungstate crystals for their application in high precision electromagnetic calorimetry; Optimisation des parametres de scintillation des cristaux de tungstate de plomb pour leur application dans la calorimetrie electromagnetique de haute precision

    Energy Technology Data Exchange (ETDEWEB)

    Drobychev, G

    2000-04-12

    In the frame of this dissertation work scintillation properties of the lead tungstate crystals (PWO) and possibilities of their use were studied foreseeing their application for electromagnetic calorimetry in extreme radiation environment conditions of new colliders. The results of this work can be summarized in the following way. 1. A model of the scintillations origin in the lead tungstate crystals which includes processes influencing on the crystals radiation hardness and presence of slow components in scintillations was developed. 2. An analysis of the influences of the PWO scintillation properties changes on the parameters of the electromagnetic calorimeter was done. 3. Methods of the light collection from the large scintillation elements of complex shape made of the birefringent scintillation crystal with high refraction index and low light yield in case of signal registration by a photodetector with sensitive surface small in compare with the output face of scintillator were Studied. 4. Physical principles of the methodology of the scintillation crystals certification during their mass production foreseeing their installation into a calorimeter electromagnetic were developed. Correlations between the results of measurements of the PWO crystals parameters by different methods were found. (author)

  5. Methods for determining thermal stresses values. Some examples relating to nuclear reactors; Methodes de determination des contraintes thermiques. Quelques exemples d'application aux reacteurs

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, J; Gautier, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Peres, A [Israel Institute of Technology, Dept. of Nuclear Science Technion (Israel)

    1958-07-01

    As modern techniques develop more elaborate machines, and make their way towards higher and higher temperatures and pressures, the thermal stresses become a matter of major importance in the design of mechanical structures. In the first part of this paper, the authors examine the problem from a theoretical standpoint, and try to evaluate the aptitude and limitation of mathematical techniques to attain the quantitative values of thermal stresses. This paper deals mainly with the experimental methods to measure thermal stresses. The authors show some examples relating to nuclear reactors. (author)Fren. [French] Au fur et a mesure que la technique moderne developpe des machines plus poussees et s'oriente vers des temperatures et des pressions toujours plus elevees, les contraintes thermiques deviennent un facteur d'importance capitale dans le calcul des structures mecaniques. Les auteurs examinent d'abord l'aspect theorique du probleme, ainsi que l'aptitude et les limites du calcul pour exprimer quantitativement la valeur des contraintes thermiques. Les auteurs exposent principalement, ensuite, les methodes experimentales qui permettent de mesurer ces contraintes, et illustrent cet expose de quelques exemples relatifs aux installations nucleaires. (auteur)

  6. Global dynamics of shaft lines of turbo-machineries coupled to surrounding fluids: application to the case of fluid sheets; Dynamique globale des lignes d'arbres de turbomachines couplees aux fluides environnants: application au cas des lames fluides

    Energy Technology Data Exchange (ETDEWEB)

    Lornage, D.

    2001-12-15

    Shaft lines of turbo-machineries have to stand increasing reliability, efficiency and safety requirements. A precise modeling of the rotating parts with all possible coupling has become necessary. In this context, this work aims to develop a global modeling of rotating wheel/shaft system inside a surrounding fluid in order to foresee its dynamical behaviour. The use and advantage of Eulerian, Lagrangian and mixed (arbitrary Lagrangian Eulerian - ALE) formulations is recalled first. A bibliographic synthesis of the classical techniques used in structure mechanics and of coupling techniques for rotating machines is presented. The coupling technique retained is presented. It uses fluid and structure models independently developed and validated. The structure domain is discretized by the finite-element method. The fluid domain is discretized by the finite-difference method taking into consideration the hypotheses linked with thin films. A modal base projection combined with a mesh at the fluid-structure interface allows an efficient, adaptable and evolutive coupling. Finally, the method is applied to 3 test-cases. The first two ones comprise a shaft/disc system coupled to a fluid sheet between the disc and the casing and to an hydrodynamic bearing. Both cases allow a first validation of the coupling method. The third case aims to study a structure closer to a real system made of a shaft and a wheel coupled to a fluid sheet between a flange and a casing. These three applications allow to show the trends linked with the fluid effects and the coupling between the flexible sub-parts of the structure. (J.S.)

  7. Spectroscopie d'impédance electrochimique locale : caracterisation de la de lamination des peintures et de la corrosion des alliages Al-Cu

    OpenAIRE

    Jorcin, Jean-Baptiste

    2007-01-01

    Ce travail est consacré à l'étude, au développement et à différentes applications de la spectroscopie d'impédance électrochimique locale ou SIEL. La première partie de ce mémoire se focalise sur la description et le développement de la SIEL tant d'un point de vue expérimental que théorique. La seconde partie présente trois applications différentes dans lesquelles la SIEL apporte des informations déterminantes. La première application est consacrée à l'étude du CPE (constant phase element). Ce...

  8. Couches minces electrochromiques d'oxyde de tungstene dense et poreux pour des applications de controle energetique

    Science.gov (United States)

    Camirand, Hubert

    Nanotechnology has modified the landscape of energy generation, energy storage and energy saving devices. Architectural fenestration can extensively benefit from green nanotechnologies. Amongst them, active fenestration or "smart" windows are able to modify their coloration state upon the application of a small electrical voltage, when based on electrochromic materials. In fact, the amount of visible and near-infrared light that can penetrate through the window can be altered. Therefore, their implementation can allow for a significant reduction in energy consumption in buildings. Furthermore, the capability of optimizing indoor comfort is user-controlled, thus an additional degree of freedom is given by electrochromic-based technology. It is worth mentioning that such devices can be largely advantageous in countries with variable seasons, such as here in Canada. As a matter of fact, the large temperature difference between the hot and cold season influences the requirement of impeding or enabling visible and thermal radiation to pass through. This master's thesis is entirely devoted to tungsten trioxide (WO 3), which is the most widely studied electrochromic material. In the present case, WO3 thin films are synthesized by radiofrequency magnetron sputtering. By varying the deposition pressure and power, the porosity content/packing density of the films is modified. This work's main topic is the characterization of electrochromic samples by in situ spectroscopic ellipsometry simultaneously with the application of an electrical voltage in an aqueous electrolytic medium made of sulfuric acid (H2SO 4). The methodology developed here allows for an in-depth study of electro-active materials. To corroborate this, optical properties of WO3 are obtained for a wide range of coloration levels, and these are subsequently used to model the resulting coloration of electrochromic multilayer systems. However, the interface between the dense and porous films affects the coloration

  9. Les possibilités des turbines de détente dans les industries gazière et pétrolière Application of Expansion Turbines in the Gas and Oil Industry

    Directory of Open Access Journals (Sweden)

    Verneau A.

    2006-11-01

    Full Text Available Utilisées depuis longtemps dans l'industrie cryogénique, les turbines de détente voient leur intérêt augmenter actuellement en tant que turbines de récupération de l'énergie des laminages. Cette énergie peut servir à l'entraînement de compresseurs, pompes ou générateurs électriques. Il existe surtout des turbines dans la gamme de 200 à 20 000 ch. Deux types principaux sont développés : les turbines axiales et les turbines radiales. Les particularités techniques et les domaines d'emploi de chaque type sont discutés. Ue intérêt particulier est porté au domaine des petites puissances (de 100 kW jusqu'à quelques centaines de watts. L'évolution du rendement en fonction de la puissance est étudiée et quelques types spéciaux bien adaptés à cette gamme, tels que les turbines périphériques, sont présentés. Quelques indications sur la récupération de l'énergie des liquides par turbines sont également données. Ensuite, plusieurs exemples d'applications sont exposés tels que : récupération de fractions condensables du gaz naturel (butane, propane, éthane, récupération de gaz perdu, récupération de l'énergie des laminages lors de la distribution et au niveau des stockages souterrains, turbine hydraulique de lavage de gaz, récupération de l'énergie des fumées de cracking catalytique, entraînement de petits générateurs électriques dans la gamme de quelques kilowatts à quelques centaines de watts. Enfin, nous abordons la technologie et les dispositions constructives particulières en nous attachant plus spécialement aux problèmes de régulation, étanchéité, paliers. Des techniques nouvelles telles que l'emploi de paliers à gaz et leurs avantages sont décrites. Les difficultés dues aux basses températures et à la condensation sont examinées. Nous terminons par quelques considérations d'ordre économique destinées à prévoir la rentabilité d'une installation de récupération d

  10. Economic Criteria Applied to Nuclear Materials Management; Criteres Economiques Applicables a la Gestion des Matieres Nucleaires; Ehkonomicheskie kriterii, primenyaemye pri kontrole i uchete yadernykh materialov; Criterios Economicos Aplicados a la Administracion de Materiales Nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Shelley, W. J.; Kuehn, M. N. [Mallinckrodt Chemical Works, St. Charles, MS (United States)

    1966-02-15

    The management of nuclear materials must always be subsidiary to the primary purpose of nuclear material processing, i.e. the generation of power or the production and fabrication of end products. Therefore, those responsible for management of nuclear materials must be constantly responsive to the needs of the primary production purpose and fit the required systems to the process so as to secure the needs of nuclear materials management at optimum costs. The nuclear materials management system must concern itself with careful examination of several factors that influence its costs. The control system evolved must complement the process, providing the lowest costs of personnel, analysis and minimum interruption of the operating process. The control system should be integrated with the process needs so that quantitative information derived is available promptly to those responsible for operating supervision. The recording and reporting system should generate maximum subsidiary data. It should be compatible with the systems employed by suppliers and consumers and carry wherever possible additional information connected with the batches of nuclear material. Data generated for the control of nuclear materials should only be that needed to ensure that no significant losses, theft, misappropriation or diversion occurs. Complementary data should be subject to the same rigid test of need as that applied to the nuclear material management data. Procedures, practices, personnel and techniques have been continuously reviewed and revised to ensure the highest quality of nuclear material management performance. To ensure optimum costs balanced with adequate nuclear material control needs, some general rules have been evolved. It is all-important to determine the real needs for the recording and reporting of data. Real economies are attained by the assignment of nuclear materials management, production control and cost responsibilities to a single group. Reliance must then be

  11. Application de la théorie des graphes au traitement de la carte géologique Applying the Theory of Graphs to the Treatment of Geological Maps

    Directory of Open Access Journals (Sweden)

    Bouillé F.

    2006-11-01

    Full Text Available La saisie des informations d'une carte géologique par les méthodes classiques (grilles ou relevés aléatoires de courbes ne constitue pas une base de données opérationnelle. Par contre, l'assimilation des limites géologiques à un graphe orienté répond aux critères d'optimalité (encombrement très réduit, temps minimal, fiabilité, et permet une digitalisation rationnelle de la carte, une bonne structuration du fichier, et la réalisation d'applications intéressantes : restitutions graphiques sélectives à toutes échelles, calculs de pendages, surfaces, volumes, études de corrélation. Nous avons donc établi une chaîne de traitement de la carte géologique dont chaque maillon (saisie des informations; contrôle, mise à jour, consultation, application opère sur un ou plusieurs graphes. Obtaining data from geological maps by conventional methods (grids or random curve plotting is not an operational data base. However, the comparison of geological boundaries with a directional graph meets criteria of optimalness (very small bulk, minimum time, reliability and makes it possible to digitize the map rationally, to structure the file properly and to achieve significant applications such as selective graph plotting on all scales, calculating dips, areas and volumes, and making correlotion analyses. Therefore, we worked out a geological map processing sequence in which each element (data acquisition, checking, updating, consulting, applications operates on one or several graphs.

  12. Des Connaissances Aux Politiques

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

    Les synergies ont été mises en commun au fur et à mesure des progrès de la recherche. .... Recherche normative (sur le rôle et la performance des institutions .... Système national d'information sur la gestion environnementale connecté à 19 ...... Un fort contrôle centralisé sur l'élaboration des politiques nationales peut ...

  13. An investigation on linear and non-linear optical constants of nano-spherical CuPc thin films for optoelectronic applications

    Science.gov (United States)

    Yahia, I. S.; Ganesh, V.; Shkir, M.; AlFaify, S.; Zahran, H. Y.; Algarni, H.; Abutalib, M. M.; Al-Ghamdi, Attieh A.; El-Naggar, A. M.; AlBassam, A. M.

    2016-09-01

    In the current work, the authors present the systematic study on linear and nonlinear optical properties of Copper-phathalocyanine thin film deposited by thermal evaporation system for the first time. The thickness of the prepared thin film was measured and found to be ~300 nm. X-ray diffraction and AFM study confirms that the prepared thin film possess good quality. The orientation of the grown thin film is found to be along (100). UV-vis-NIR study shows that the deposited thin film is highly transparent (>80%) in the wavelength range of 700-2500 nm. Further, the recorded optical data was used to determine the various linear and nonlinear optical parameters. The calculated value of refractive index is found to be in the range of 0.4-1.0. The direct and indirect band gap value is found to be 2.9 and 3.25 eV, respectively. The value of linear and nonlinear susceptibilities is found to be in order of 10-12. The higher value of linear and nonlinear parameters makes it suitable for optoelectronic applications.

  14. An investigation on linear and non-linear optical constants of nano-spherical CuPc thin films for optoelectronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Yahia, I.S. [Nano-Science & Semiconductor Labs, Metallurgical Lab., Department of Physics, Faculty of Education, Ain Shams University, Roxy, Cairo (Egypt); Advanced Functional Materials & Optoelectronic Laboratory (AFMOL), Department of Physics, Faculty of Science, King Khalid University, P.O. Box 9004, Abha (Saudi Arabia); Ganesh, V. [Advanced Functional Materials & Optoelectronic Laboratory (AFMOL), Department of Physics, Faculty of Science, King Khalid University, P.O. Box 9004, Abha (Saudi Arabia); Shkir, M., E-mail: shkirphysics@gmail.com [Advanced Functional Materials & Optoelectronic Laboratory (AFMOL), Department of Physics, Faculty of Science, King Khalid University, P.O. Box 9004, Abha (Saudi Arabia); AlFaify, S. [Advanced Functional Materials & Optoelectronic Laboratory (AFMOL), Department of Physics, Faculty of Science, King Khalid University, P.O. Box 9004, Abha (Saudi Arabia); Zahran, H.Y. [Nano-Science & Semiconductor Labs, Metallurgical Lab., Department of Physics, Faculty of Education, Ain Shams University, Roxy, Cairo (Egypt); Advanced Functional Materials & Optoelectronic Laboratory (AFMOL), Department of Physics, Faculty of Science, King Khalid University, P.O. Box 9004, Abha (Saudi Arabia); Algarni, H. [Advanced Functional Materials & Optoelectronic Laboratory (AFMOL), Department of Physics, Faculty of Science, King Khalid University, P.O. Box 9004, Abha (Saudi Arabia); Abutalib, M.M.; Al-Ghamdi, Attieh A. [Centre of Nanotechnology, Physics Department-Faculty of Science-AL Faisaliah Campus, King Abdulaziz University, Jeddah (Saudi Arabia); El-Naggar, A.M.; AlBassam, A.M. [Research Chair of Exploitation of Renewable Energy Applications in Saudi Arabia, Physics & Astronomy Dept., College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia)

    2016-09-01

    In the current work, the authors present the systematic study on linear and nonlinear optical properties of Copper-phathalocyanine thin film deposited by thermal evaporation system for the first time. The thickness of the prepared thin film was measured and found to be ~300 nm. X-ray diffraction and AFM study confirms that the prepared thin film possess good quality. The orientation of the grown thin film is found to be along (100). UV–vis-NIR study shows that the deposited thin film is highly transparent (>80%) in the wavelength range of 700–2500 nm. Further, the recorded optical data was used to determine the various linear and nonlinear optical parameters. The calculated value of refractive index is found to be in the range of 0.4–1.0. The direct and indirect band gap value is found to be 2.9 and 3.25 eV, respectively. The value of linear and nonlinear susceptibilities is found to be in order of 10{sup −12}. The higher value of linear and nonlinear parameters makes it suitable for optoelectronic applications.

  15. Beyond the Hubble Constant

    Science.gov (United States)

    1995-08-01

    about the distances to galaxies and thereby about the expansion rate of the Universe. A simple way to determine the distance to a remote galaxy is by measuring its redshift, calculate its velocity from the redshift and divide this by the Hubble constant, H0. For instance, the measured redshift of the parent galaxy of SN 1995K (0.478) yields a velocity of 116,000 km/sec, somewhat more than one-third of the speed of light (300,000 km/sec). From the universal expansion rate, described by the Hubble constant (H0 = 20 km/sec per million lightyears as found by some studies), this velocity would indicate a distance to the supernova and its parent galaxy of about 5,800 million lightyears. The explosion of the supernova would thus have taken place 5,800 million years ago, i.e. about 1,000 million years before the solar system was formed. However, such a simple calculation works only for relatively ``nearby'' objects, perhaps out to some hundred million lightyears. When we look much further into space, we also look far back in time and it is not excluded that the universal expansion rate, i.e. the Hubble constant, may have been different at earlier epochs. This means that unless we know the change of the Hubble constant with time, we cannot determine reliable distances of distant galaxies from their measured redshifts and velocities. At the same time, knowledge about such change or lack of the same will provide unique information about the time elapsed since the Universe began to expand (the ``Big Bang''), that is, the age of the Universe and also its ultimate fate. The Deceleration Parameter q0 Cosmologists are therefore eager to determine not only the current expansion rate (i.e., the Hubble constant, H0) but also its possible change with time (known as the deceleration parameter, q0). Although a highly accurate value of H0 has still not become available, increasing attention is now given to the observational determination of the second parameter, cf. also the Appendix at the

  16. Structure et stabilité des bancs et agrégations de poissons pélagiques côtiers tropicaux : application halieutique

    OpenAIRE

    Soria, Marc

    1994-01-01

    Afin de cerner le rôle du comportement animal dans les problèmes rencontrés lors de l'estimation des stocks de poissons pélagiques en halieutique par les méthodes d'évaluation directes (acoustique) et indirectes, nous avons entrepris l'étude, en milieu naturel, de la structure et de la stabilité des bancs de petits poissons pélagiques côtiers tropicaux (Clupéidés, Engraulidés). Cette étude est basée sur des observations acoustiques et visuelles (aériennes et sous-marines) simultanées... Nous ...

  17. Etude fondamentale des mecanismes de gravure par plasma de materiaux de pointe: Application a la fabrication de dispositifs photoniques

    Science.gov (United States)

    Stafford, Luc

    Advances in electronics and photonics critically depend upon plasma-based materials processing either for transferring small lithographic patterns into underlying materials (plasma etching) or for the growth of high-quality films. This thesis deals with the etching mechanisms of materials using high-density plasmas. The general objective of this work is to provide an original framework for the plasma-material interaction involved in the etching of advanced materials by putting the emphasis on complex oxides such as SrTiO3, (Ba,Sr)TiO 3 and SrBi2Ta2O9 films. Based on a synthesis of the descriptions proposed by different authors to explain the etching characteristics of simple materials in noble and halogenated plasma mixtures, we propose comprehensive rate models for physical and chemical plasma etching processes. These models have been successfully validated using experimental data published in literature for Si, Pt, W, SiO2 and ZnO. As an example, we have been able to adequately describe the simultaneous dependence of the etch rate on ion and reactive neutral fluxes and on the ion energy. From an exhaustive experimental investigation of the plasma and etching properties, we have also demonstrated that the validity of the proposed models can be extended to complex oxides such as SrTiO3, (Ba,Sr)TiO 3 and SrBi2Ta2O9 films. We also reported for the first time physical aspects involved in plasma etching such as the influence of the film microstructural properties on the sputter-etch rate and the influence of the positive ion composition on the ion-assisted desorption dynamics. Finally, we have used our deep investigation of the etching mechanisms of STO films and the resulting excellent control of the etch rate to fabricate a ridge waveguide for photonic device applications. Keywords: plasma etching, sputtering, adsorption and desorption dynamics, high-density plasmas, plasma diagnostics, advanced materials, photonic applications.

  18. Association constants of telluronium salts

    International Nuclear Information System (INIS)

    Kovach, N.A.; Rivkin, B.B.; Sadekov, T.D.; Shvajka, O.P.

    1996-01-01

    Association constants in acetonitrile of triphenyl telluronium salts, which are dilute electrolytes, are determined through the conductometry method. Satisfactory correlation dependence of constants of interion association and threshold molar electroconductivity on the Litvinenko-Popov constants for depositing groups is identified. 6 refs

  19. Anisotropic constant-roll inflation

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Asuka; Soda, Jiro [Kobe University, Department of Physics, Kobe (Japan)

    2018-01-15

    We study constant-roll inflation in the presence of a gauge field coupled to an inflaton. By imposing the constant anisotropy condition, we find new exact anisotropic constant-roll inflationary solutions which include anisotropic power-law inflation as a special case. We also numerically show that the new anisotropic solutions are attractors in the phase space. (orig.)

  20. Quintessence and the cosmological constant

    International Nuclear Information System (INIS)

    Doran, M.; Wetterich, C.

    2003-01-01

    Quintessence -- the energy density of a slowly evolving scalar field -- may constitute a dynamical form of the homogeneous dark energy in the universe. We review the basic idea in the light of the cosmological constant problem. Cosmological observations or a time variation of fundamental 'constants' can distinguish quintessence from a cosmological constant

  1. Les métamatériaux, des micro-ondes à l'optique : théorie et applications

    Science.gov (United States)

    Kante, B.

    2010-04-01

    Cet article constitue une contribution originale et importante à la compréhension à la fois théorique et expérimentale des métamatériaux en micro-ondes et en infrarouge. Nous avons réalisé et caractérisé sur silicium des nano-structures metallo-diélectriques, briques de base des métamatériaux infrarouge et optique. Des caractérisations optiques exhaustives ont été réalisées pour la première fois sur ces structures en amplitude et en phase par interférométrie. Des topologies plus simples de métamatériaux d’un point de vue technologique et des performances optiques ont été introduites, et leur potentiel démontré dans la réalisation de fonctions aussi complexes que la réfraction négative, le couplage de mode plasmoniques, les nano senseurs pour la biologie et l’invisibilité électromagnétique en infrarouge. Les transformations d’espace, et le nouveau paradigme qu’elles offrent à l’optique, rendant possible une ingénierie de l’espace pour les photons ainsi que leur implémentation par métamatériaux ont été présentés par la première démonstration expérimentale d’une cape d’invisibilité non magnétique.

  2. Analysis of the chemical equilibrium of combustion at constant volume

    Directory of Open Access Journals (Sweden)

    Marius BREBENEL

    2014-04-01

    Full Text Available Determining the composition of a mixture of combustion gases at a given temperature is based on chemical equilibrium, when the equilibrium constants are calculated on the assumption of constant pressure and temperature. In this paper, an analysis of changes occurring when combustion takes place at constant volume is presented, deriving a specific formula of the equilibrium constant. The simple reaction of carbon combustion in pure oxygen in both cases (constant pressure and constant volume is next considered as example of application, observing the changes occurring in the composition of the combustion gases depending on temperature.

  3. Problématique de la valorisation agricole des biodéchets dans la ...

    African Journals Online (AJOL)

    SARAH

    30 avr. 2014 ... Conclusion et application de la recherche : La gestion des déchets ... la ville de Lubumbashi, les outils de diagnostic des ... développement participatif des technologies .... sites I, II, IV, V, VI et VII caractérisés par les acteurs.

  4. Inventaire et incidence des insectes inféodes à la culture du fonio ...

    African Journals Online (AJOL)

    importance des insectes capturés sur le fonio est liée à la multitude des adventices qui infestent le fonio et qui favorisent le développement des insectes nuisibles. Conclusion et application : La culture de fonio est infestée par un nombre ...

  5. 7th international conference on Nuclear microprobe technology and applications; 7. conference internationale sur la technologie et les applications des microsondes nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    This colloquium gives an up-to-date report on the continuously advancing applications and development of microbeam technology. It presents abstracts and oral contributions in the following domains: microprobes facilities, analysis techniques, imaging techniques, micro-ion beam modification of materials, microelectronics, applications in Material Sciences in Biology in Medicine in earth and planetary Sciences in environment in art in archaeology, alternative techniques. (A.L.B.)

  6. Contribution à la conception et à la commande des machines synchrones à double excitation. Application au véhicule hybride.

    OpenAIRE

    AMARA , Yacine

    2001-01-01

    This Thesis concerns the design of hybrid excited synchronous machines used for hybrid and/or electric vehicles traction.; Les travaux présentés dans ce mémoire concernent la conception et la commande des machines synchrones à double excitation. Ce concept apparaît viable et améliore les performances des machines synchrones et plus globalement les systèmes d’entraînement où elles s’intègrent.

  7. Caractérisation et simulation des mouvements d'atteinte par un opérateur humain en position assise en vue d'applications ergonomiques

    OpenAIRE

    CHEVALOT, N

    2006-01-01

    La simulation de mouvements d'atteinte effectués par un opérateur assis est particulièrement utile pour les constructeurs d'automobiles. Elle permet d'améliorer l'ergonomie de l'habitacle et des commandes, le plus en amont possible dans la conception. Elle consiste à simuler un mouvement et à prédire son inconfort. Cependant, ce type de simulation se heurte à des problèmes pratiques et théoriques. Pour la partie pratique, une méthode de simulation générique et stable pour tout type de mouveme...

  8. Évaluation des pratiques agricoles des légumes feuilles : le cas des ...

    African Journals Online (AJOL)

    SARAH

    30 sept. 2017 ... ... de Biochimie et Immunologie Appliquée, Centre de Recherche en Sciences Biologiques, Alimentaires et .... l'intoxication des agriculteurs et des consommateurs, ... source d'alimentation en eau et au pouvoir d'achat des.

  9. The ``Grey System`` theory and its application to target cost forecasting at Chinese collieries; Die Theorie des grauen Systems und ihre Anwendung bei der Prognose der Zielkosten des gesamten Bergwerks

    Energy Technology Data Exchange (ETDEWEB)

    Ding Rijia; Yi Maosheng; Wang Shiyuan

    1997-09-01

    A production-cost forecasting system has been developed for use at Chinese collieries. Known as the `Grey System`, the theory and model-based process distinguishes between `white` information, which is human controlled, `black` information, which cannot be controlled by human actions, and `grey information`, which forms the majority component and comprises information which can only be partly or not completely collected. A grey system is therefore one in which the necessary information is absent. Future developments in the system can be forecast by analysing the regularity of the time-series values for the technical and economic characteristics of previous periods. The system employs the GM (1.1) prognostic model, which is a `grey` systematic forecasting model with one variable and one linear differential equation. It can be applied to systems which are affected simultaneously be several factors, with no overriding main factor, or in which no marked regularity exists between the controlling factors. The mathematical model constructed on the basis of the `Grey theory` is designed for large-scale economic systems which are affected by several control factors. A bigger system makes for a greater randomness element, which in turn lessens the influence of subjective interference factors and increases the accuracy of the prognosis. (orig./MSK) [Deutsch] Mit Hilfe der Theorie und von Modellen des `grauen Systems` wird eine Prognose der Produktionskosten von chinesischen Bergwerken erstellt. Die Theorie des `grauen Systems` unterscheidet zwischen den von den Menschen beherrschbaren `weissen` Informationen, den von den Menschen nicht beherrschbaren `schwarzen` Informationen und der ueberwiegenden Anzahl der Informationen, die nur teilweise oder nicht vollstaendig erfasst werden koennen und als `graue` Informationen bezeichnet werden. Ein graues System ist folglich ein System, in dem es an notwendigen Informationen fehlt. Die zukuenftige Entwicklung des Systems kann dadurch

  10. Determination of the form of very short luminous pulses. Application to scintillation phenomena (1962); Determination de la forme des impulsions lumineuses tres breves. Application aux phenomenes de scintillation (1962)

    Energy Technology Data Exchange (ETDEWEB)

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

    1961-12-15

    During studies on photomultipliers and scintillators we have developed a new method of measurement making it possible to determine with precision the form of luminous pulses whose duration may be less that of an anodic photomultiplier pulse. This method, which can be applied to non-recurrent pulses, makes possible the study of scintillations caused by particles of photons in the case where it is possible to operate on a large number of pulses having the same form. We have thus determined the form of the scintillations of various fluorescent liquids excited by {alpha} particles and {gamma} photons. The results obtained are in agreement with the energy transfer theory for organic liquids elaborated by H. Kallmann and M. FURST. The results are used to determine exactly the parameters occurring in the theory. (author) [French] A l'occasion d'etudes sur les photomultiplicateurs et les scintillateurs nous avons mis au point une nouvelle methode de mesure permettant de determiner avec precision la forme des impulsions lumineuses dont la duree peut etre inferieure a celle d'une impulsion anodique de photomultiplicateur. Cette methode, qui peut s'appliquer a des impulsions non recurrentes, permet d'etudier les scintillations provoquees par des particules ou des photons, a la seule condition que l'on puisse operer sur un grand nombre d'impulsions ayant la meme forme. Nous avons determine ainsi la forme des scintillations des divers liquides fluorescents excites par des particules {alpha} et des photons {gamma} Les resultats obtenus sont en accord avec la theorie des transferts d'energie dans les scintillateurs organiques, elaboree par H. KALLMANN et M. FURST. Ils conduisent a une determination precise des parameters intervenant dans cette theorie. (auteur)

  11. La transmission efficace des compétences via Internet : exemple pratique

    NARCIS (Netherlands)

    Caniëls, M.C.J.

    2005-01-01

    Les universités sont de plus en plus nombreuses à adopter des modèles pédagogiques novateurs, plutôt axés sur le développement des compétences que sur la reproduction des connaissances. Ces nouveaux modèles pédagogiques soulignent l’importance de la mise en application des connaissances et du

  12. Influence of extranuclear fields on angular correlations; Influence des champs extranucleaires sur les correlations angulaires

    Energy Technology Data Exchange (ETDEWEB)

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

    1958-07-01

    A general formalism is given for the description of the perturbation of angular correlations by extranuclear fields. An application is made to the case of static interactions in solids and time dependent interactions in liquids. (author) [French] On donne un formalisme general pour la description de la perturbation des correlations angulaires par des champs extranucleaires. Ce formalisme est applique aux cas des interactions statiques dans les solides et des interactions dependantes du temps dans les liquides. (auteur)

  13. Constant force linear permanent magnet actuators

    NARCIS (Netherlands)

    Paulides, J.J.H.; Encica, L.; Meessen, K.J.; Lomonova, E.A.

    2009-01-01

    In applications, such as vibration isolation, gravity compensation, pick-and-place machines, etc., there is a need for (long-stroke) passive constant force actuators combined with tubular permanent magnet actuators to minimize the power consumption, hence, passively counteract the gravitational

  14. L’incertitude dans l’utilisation des médias géolocalisés : étude de deux applications reliées à la mobilité urbaine

    Directory of Open Access Journals (Sweden)

    Julia Salles

    2015-12-01

    Full Text Available À partir de la différentiation entre les pratiques stratégiques et tactiques, développée par Michel de Certeau (1990, et du concept de l’espace hybride (De Souza et Silva, 2006 ; Nova, 2009, ce travail distinguera les différents rapports à l’incertitude lors du déplacement en milieu urbain par les utilisateurs des médias géolocalisés, notamment par l’étude de deux applications pour appareils mobiles, Foursquare/Swarm et Walking the Edit.

  15. Neutron Activation for Studying Hydroelectrolytic Disorders in Child Pathology; Application de l'Activation Neutronique a l'Etude des Troubles Hydroelectrolytiques en Pathologie Infantile

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, J. [Hopital Universitaire St-Pierre, Bruxelles (Belgium); Colard, J. [Centre d' Etude de l' Energie Nucleaire, Mol (Belgium); Vis, H. L. [Institut pour la Recherche Scientifique en Afrique Centrale, Bukavu (Congo, The Democratic Republic of the)

    1967-10-15

    The authors describe a method of determining electrolytes (Na, K, CI) and phosphorus in small fragments of muscle taken from child patients by needle biopsy. This method has been used to study muscular disturbances in hydroelectrolytic illnesses of childhood, whether acute, such as dehydration or toxicosis in infants, or chronic, such as malnutrition or marasmus. The results are discussed in the light of parallel data obtained by other methods of investigation. The authors also discuss the possibility of using this method to estimate intra-cellular hydroelectrolytic disorders in child pathology. (author) [French] Les auteurs presentent la description d'une methode permettant le dosage des electrolytes (Na, K, Cl) et du phosphore sur de petits fragments musculaires preleves par ponction-biopsie chez l'enfant. Cette methode a ete appliquee a l'etude des perturbations du milieu musculaire dans des troubles hydroelectrolytiques aigus (deshydratation et toxicose des nourrissons) et chroniques (malnutrition et denutrition) de l'enfance. Les resultats obtenus sont discutes a la lumiere de donnees recueillies parallelement par d'autres methodes d'investigation. Les auteurs discutent egalement la possibilite d'estimer par cette methode les perturbations hydroelectrolytiques intra-cellulaires en pathologie pediatrique. (author)

  16. The Economical Application of Non-Destructive Testing to Reactor Components, Especially Jacket Tubing; Avantages Economiques du Controle Non Destructif des Pieces de Reacteurs, Notamment des Tubes de Gainage; Ehkonomicheskoe primenenie nedestruktivnykh ispytanij dlya reaktornykh komponentov, v chastnosti obolochechnykh trub; Aplicacion en Condiciones Economicas de Ensayos No Destructivos a las Piezas de los Reactores, en Especial a los Tubos de Revestimiento

    Energy Technology Data Exchange (ETDEWEB)

    Renken, C. J. [Metallurgy Division Argonne National Laboratory Argonne, IL (United States)

    1965-10-15

    electro-magnetic method for technical as well as economic reasons. The optimum area of application of these two methods is explained as well as the large area of overlap where results produced by well- designed and properly operated equipment of both types are essentially equivalent. Spurious defect indications contribute directly to increased component costs, so an evaluation of these effects for both the ultrasonic and the electromagnetic test methods is included for several commonly encountered sources of spurious defect signals. The experience in the application of these methods at Argonne National Laboratory on relatively large quantities of tubing from various sources are recounted from the standpoint of the lowest possible inspection cost per unit length of tubing. This section also summarizes experience gained at Argonne with the newer pulsed electromagnetic test methods. The critical but generally unappreciated role of tube diameter and wall thickness on tube inspection cost is discussed. Since the question of economical inspection is closely related to allowable defect levels, defect levels and standards in use at Argonne are covered. Finally, the practical and theoretical barriers to reduced component inspection costs are enumerated and a projection of what possible reductions in cost might be attainable in the future with the ultrasonic and electromagnetic test methods is attempted. (author) [French] Le reacteur ideal aurait entre autres caracteristiques celle de ne pas exiger de controles non destructifs. Cet ideal, comme tant d'autres, ne sera probablement jamais atteint. Dans l'etude de tout reacteur pour lequel le prix de revient constitue un facteur important, il faudrait envisager la question de savoir si les pieces de ce reacteur pourront etre essayees de facon economique en meme temps que l'on examine les possibilites de fabrication. Cette partie du memoire contient quelques considerations a ce propos ainsi qu'un expose de l'importance des essais non

  17. Gestion des risques

    CERN Document Server

    Louisot, Jean-Paul

    2009-01-01

    Depuis le début du lie siècle, la gestion des risques connaît une véritable révolution culturelle. Jusqu'alors fonction technique, centrée autour de l'achat de couverture d'assurances, elle est devenue une discipline managériale et transversale : une valise d'instruments que chaque manager doit connaître et appliquer quels que soient son domaine de compétence et ses missions au sein de l'organisation. En effet, la gestion des risques est une culture qui doit être assimilée par chacun des acteurs. C'est précisément l'ambition des 101 questions rassemblées dans cet ouvrage : apporter à chaque manager d'entreprise, de collectivité, d'établissement de santé..., des réponses claires au " pourquoi " et au " comment " : Comment identifier les risques ? Comment analyser les risques ? Quels sont les objectifs de la gestion des risques ? Une carte des risques pour quoi faire ? Pourquoi faut-il financer les risques ? Les entreprises ont-elles des responsabilités pénales ? En quoi consiste la gestion...

  18. Sur la reconnaissance de la compétence exclusive des groupements religieux afin d‘instaurer leur structure intrinsèque et les normes intérieures des relations en tant qu’une des garanties ...

    Directory of Open Access Journals (Sweden)

    Philip Ryabykh

    2012-11-01

    SOMMAIRE: 1. Brève histoire de l’affaire – 2. Préambule – 3. Protection de la compétence exclusive des groupements religieux en vue d’instaurer leur structure intrinsèque et les normes intérieures des relations au point de vue de la législation de la Roumanie – 4. Application du principe de l’autonomie des groupements religieux et du principe de l’inadmissibilité d’intervenir pour l’État aux affaires intérieures des groupements religieux – 5. Non-contradiction de la Convention des exigences intérieures des groupements religieux sur la loyauté et la conformité des personnes se trouvant dans les relations de service avec le groupement religieux – 6. Absence des raisons fournies par les faits juridiques suffisantes et justifiant réellement l’assimilation (la mise au même niveau des groupements religieux avec n’importe quelles autres organisations-employeurs dans la sphère de la réglementation des relations de travail – 7. Légalité de l’instauration des restrictions à la création et les activités des syndicats dans les certaines sphères des relations publiques – 8. Compétence de la Roumanie de fixer dans la législation les restrictions à la liberté des syndicats conformément à la sphère des relations religieuses – 9. Signification des résultats du jugement de l’affaire «Syndicat “Le Bon Pasteur” c. Roumanie» (requête 2330/09 pour L’Église Orthodoxe Russe- 10. Conclusion.

  19. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

    Colombet, L

    1994-10-07

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

  1. Determination of the mean free path of the thermal neutrons transport by the measure of a complex diffusion length; Determination du libre parcours moyen de transport des neutrons thermiques par la mesure d'une longueur de diffusion complexe

    Energy Technology Data Exchange (ETDEWEB)

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

    1955-07-01

    The further method is the outcome of a technique used in the study of neutrons in scattering and slowing-down environment. In this technique, we replace the constant sources used in the classic experiences by modulated sources with a variable frequency. The object of this article is to describe the extension of the method for the mean free path for transport of thermal neutrons and also to indicate the possible applications for other sizes, as the slowing length, or the absolute value of the cross-section of the boron. (M.B.) [French] La methode qui va etre decrite est l'aboutissement d'une technique utilisee dans l'etude des milieux ou diffusent et se ralentissent des neutrons. Dans cette technique, on remplace les sources constantes utilisees dans les experiences classiques par des sources modulees, a frequence variable. L'objet de cet article est de decrire l'extension de la methode a la mesure du libre parcours moyen de transport des neutrons thermiques et egalement d'indiquer les applications possibles a la mesure d'autres grandeurs, telles que la longueur de ralentissement, ou la valeur absolue de la section de capture du bore. (M.B.)

  2. The diode pump: its application to nuclear particle counting and to the detection of rapid neutronic power excursions in atomic piles (1962); La pompe a diodes, son application au comptage de particules nucleaires et a la detection des excursions rapides de puissance neutronique d'une pile atomique (1962)

    Energy Technology Data Exchange (ETDEWEB)

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

    1962-05-15

    This work deals in particular with three applications of an electronic device whose principle is based on that of the diode pump. 1- Linear response circuit 2- Logarithmic response circuit 3- Detection of neutronic power excursions in atomic piles using a circuit or a combination of several circuits of the linear response type. Each of the applications has been studied theoretically and experimentally. Finally, the detection of rapid power excursions is extensively discussed with reference to the many methods available, emphasis being laid on the rapidity of the electronic response. (author) [French] Cet ouvrage traite plus particulierement de trois applications d'un dispositif electronique dont le principe de fonctionnement est base sur celui de la pompe a diodes. 1- Circuit a reponse lineaire 2- Circuit a reponse logarithmique 3- Detection des excursions de puissance neutronique d'une pile atomique a l'aide d'un circuit ou d'une association de plusieurs circuits a reponse lineaire. Chacune des applications fait l'objet d'une etude theorique et experimentale. Enfin, la detection des excursions rapides de puissance est tres largement discutee a travers plusieurs methodes, notamment sur la partie concernant la rapidite de reponse de l'electronique. (auteur)

  3. Elongational flow of polymer melts at constant strain rate, constant stress and constant force

    Science.gov (United States)

    Wagner, Manfred H.; Rolón-Garrido, Víctor H.

    2013-04-01

    Characterization of polymer melts in elongational flow is typically performed at constant elongational rate or rarely at constant tensile stress conditions. One of the disadvantages of these deformation modes is that they are hampered by the onset of "necking" instabilities according to the Considère criterion. Experiments at constant tensile force have been performed even more rarely, in spite of the fact that this deformation mode is free from necking instabilities and is of considerable industrial relevance as it is the correct analogue of steady fiber spinning. It is the objective of the present contribution to present for the first time a full experimental characterization of a long-chain branched polyethylene melt in elongational flow. Experiments were performed at constant elongation rate, constant tensile stress and constant tensile force by use of a Sentmanat Extensional Rheometer (SER) in combination with an Anton Paar MCR301 rotational rheometer. The accessible experimental window and experimental limitations are discussed. The experimental data are modelled by using the Wagner I model. Predictions of the steady-start elongational viscosity in constant strain rate and creep experiments are found to be identical, albeit only by extrapolation of the experimental data to Hencky strains of the order of 6. For constant stress experiments, a minimum in the strain rate and a corresponding maximum in the elongational viscosity is found at a Hencky strain of the order of 3, which, although larger than the steady-state value, follows roughly the general trend of the steady-state elongational viscosity. The constitutive analysis also reveals that constant tensile force experiments indicate a larger strain hardening potential than seen in constant elongation rate or constant tensile stress experiments. This may be indicative of the effect of necking under constant elongation rate or constant tensile stress conditions according to the Considère criterion.

  4. Development and application of the discrete ordinate method in orthogonal curvilinear coordinates; Developpement et application de la methode des ordonnees discretes en coordonnees curvilignes orthogonales

    Energy Technology Data Exchange (ETDEWEB)

    Vaillon, R; Lallemand, M; Lemonnier, D [Ecole Nationale Superieure de Mecanique et d` Aerotechnique (ENSMA), 86 - Poitiers (France)

    1997-12-31

    The method of discrete ordinates, which is more and more widely used in radiant heat transfer studies, is mainly developed in Cartesian, (r,z) and (r,{Theta}) cylindrical, and spherical coordinates. In this study, the approach of this method is performed in orthogonal curvilinear coordinates: determination of the radiant heat transfer equation, treatment of the angular redistribution terms, numerical procedure. Some examples of application are described in 2-D geometry defined in curvilinear coordinates along a curve and at the thermal equilibrium. A comparison is made with the discrete ordinates method in association with the finite-volumes method in non structured mesh. (J.S.) 27 refs.

  5. Development and application of the discrete ordinate method in orthogonal curvilinear coordinates; Developpement et application de la methode des ordonnees discretes en coordonnees curvilignes orthogonales

    Energy Technology Data Exchange (ETDEWEB)

    Vaillon, R.; Lallemand, M.; Lemonnier, D. [Ecole Nationale Superieure de Mecanique et d`Aerotechnique (ENSMA), 86 - Poitiers (France)

    1996-12-31

    The method of discrete ordinates, which is more and more widely used in radiant heat transfer studies, is mainly developed in Cartesian, (r,z) and (r,{Theta}) cylindrical, and spherical coordinates. In this study, the approach of this method is performed in orthogonal curvilinear coordinates: determination of the radiant heat transfer equation, treatment of the angular redistribution terms, numerical procedure. Some examples of application are described in 2-D geometry defined in curvilinear coordinates along a curve and at the thermal equilibrium. A comparison is made with the discrete ordinates method in association with the finite-volumes method in non structured mesh. (J.S.) 27 refs.

  6. State of the art of parallel scientific visualization applications on PC clusters; Etat de l'art des applications de visualisation scientifique paralleles sur grappes de PC

    Energy Technology Data Exchange (ETDEWEB)

    Juliachs, M

    2004-07-01

    In this state of the art on parallel scientific visualization applications on PC clusters, we deal with both surface and volume rendering approaches. We first analyze available PC cluster configurations and existing parallel rendering software components for parallel graphics rendering. CEA/DIF has been studying cluster visualization since 2001. This report is part of a study to set up a new visualization research platform. This platform consisting of an eight-node PC cluster under Linux and a tiled display was installed in collaboration with Versailles-Saint-Quentin University in August 2003. (author)

  7. State of the art of parallel scientific visualization applications on PC clusters; Etat de l'art des applications de visualisation scientifique paralleles sur grappes de PC

    Energy Technology Data Exchange (ETDEWEB)

    Juliachs, M

    2004-07-01

    In this state of the art on parallel scientific visualization applications on PC clusters, we deal with both surface and volume rendering approaches. We first analyze available PC cluster configurations and existing parallel rendering software components for parallel graphics rendering. CEA/DIF has been studying cluster visualization since 2001. This report is part of a study to set up a new visualization research platform. This platform consisting of an eight-node PC cluster under Linux and a tiled display was installed in collaboration with Versailles-Saint-Quentin University in August 2003. (author)

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

    Directory of Open Access Journals (Sweden)

    Rubel A.

    2011-02-01

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

  9. Thermoluminescent properties of CVD diamond: applications to ionising radiation dosimetry; Proprietes thermoluminescentes du diamant CVD: applications a la dosimetrie des rayonnements ionisants

    Energy Technology Data Exchange (ETDEWEB)

    Petitfils, A

    2007-09-15

    Remarkable properties of synthetic diamond (human soft tissue equivalence, chemical stability, non-toxicity) make this material suitable for medical application as thermoluminescent dosimeter (TLD). This work highlights the interest of this material as radiotherapy TLD. In the first stage of this work, we looked after thermoluminescent (TL) and dosimetric properties of polycrystalline diamond made by Chemically Vapor Deposited (CVD) synthesis. Dosimetric characteristics are satisfactory as TLD for medical application. Luminescence thermal quenching on diamond has been investigated. This phenomenon leads to a decrease of dosimetric TL peak sensitivity when the heating rate increases. The second part of this work analyses the use of synthetic diamond as TLD in radiotherapy. Dose profiles, depth dose distributions and the cartography of an electron beam obtained with our samples are in very good agreement with results from an ionisation chamber. It is clearly shown that CVD) diamond is of interest to check beams of treatment accelerators. The use of these samples in a control of treatment with Intensity Modulated Radiation Therapy underlines good response of synthetic diamond in high dose gradient areas. These results indicate that CVD diamond is a promising material for radiotherapy dosimetry. (author)

  10. Méthodes de calcul pour la conception des systèmes de protection cathodique des structures longilignes Computing Methods for Designing Cathodic Protection Systemes for Elongate Stuctures

    Directory of Open Access Journals (Sweden)

    Roche M.

    2006-11-01

    Full Text Available Les différentes structures longilignes qu'utilise l'industrie des hydrocarbures sont, dans la plupart des cas, soumises à un système de protection cathodique par anodes sacrificielles ou par courant imposé. La conception de ces systèmes doit être basée sur l'étude de la variation du potentiel et de l'intensité le long de la structure causée par la chute ohmique. La méthode classique de calcul résoud couramment le cas des structures longilignes à diamètre constant traversant un terrain dont la résistivité est considérée comme constante sur toute la longueur. Dans le cas où la constitution de la structure varie, comme celui des casings de puits de forage, ou quand celle-ci traverse plusieurs types de terrain, le problème se complique. Nous proposons une méthode générale permettant de traiter rapidement tout problème de ce type, le nombre de tronçons n'étant pas limité. Cette méthode fait appel à des notions de facteur de réflexion et de résistance équivalente déjà exposées dans la littérature mais dont l'usage ne semble pas s'être répandu. The different elongate structures used by the hydrocarbon industry are, in most cases, subjected ta a cathodic protection system consisting of sacrificial anodes or an impressed current. Desings of such systems must be boséd on an analysis of variations in the potential and intensity along the structure as the result of the ohm drop. The conventional computing method commonly solves cases of elongote structures with a constant diameter, running through ground whose resistivity is considéred to be constant over the entire length. When the~nake-up of the structure varies, as is the case for borehole casings, or when it goes through several types of formations, the problem gets more complicated. We propose a general method for quickly dealing with any problem of this type, with no limit ta the number of lengths involved. This method makes use of reflection factor and

  11. Photonique des Morphos

    CERN Document Server

    Berthier, Serge

    2010-01-01

    La photonique est déjà présente dans notre vie quotidienne, et on attend maintenant que la manipulation des photons permette aussi le traitement logique des informations. Cependant, l’élément de base qui permet cette manipulation de la lumière, le cristal photonique, est d’une réalisation complexe et mal contrôlée. Dans la course à la maîtrise de la lumière, les structures photoniques naturelles ont beaucoup à nous apprendre. C’est ce que nous montre Serge Berthier qui étudie dans ce livre la structure des écailles des Morphos. Tenant compte de l’essor récent des approches biomimétiques, il présente de manière détaillée plus de dix-huit techniques expérimentales utilisées pour ses analyses, ainsi que les diverses approches théoriques développées pour la modélisation de structures multi-échelles complexes. Première étude quasi-exhaustive des structures fines d’un genre et des propriétés optiques ainsi que colorimétriques générées, ce livre fournit aux entomologiste...

  12. Droit des organisations internationales

    CERN Document Server

    Sorel, Jean-Marc; Ndior, Valère

    2013-01-01

    Cet ouvrage collectif offre aux enseignants et chercheurs en droit international, aux praticiens et aux étudiants, une analyse actualisée du droit des organisations internationales. Il dresse en cinq parties un tableau, illustré par des exemples variés, des problématiques que soulève le phénomène polymorphe d institutionnalisation de la société internationale. La première partie est consacrée au phénomène des « organisations internationales », sous l angle à la fois de l institutionnalisation progressive des relations internationales et de la difficulté à cerner une catégorie unifiée. La deuxième partie rend compte de la création, de la disparition et des mutations des organisations internationales, ici envisagées comme systèmes institutionnels et ordres juridiques dérivés. La troisième partie analyse l autonomie que l acquisition de la personnalité juridique et de privilèges et immunités, un organe administratif intégré, un personnel ou un budget propres confèrent aux organi...

  13. Measurement of the lepton {tau} spectral functions and applications to quantum chromodynamic; Mesure des fonctions spectrales du lepton {tau} et applications a la chromodynamique quantique

    Energy Technology Data Exchange (ETDEWEB)

    Hoecker, A [Paris-11 Univ., 91 - Orsay (France). Lab. de l' Accelerateur Lineaire; [Universite de Paris Sud, 91 - Orsay (France)

    1997-04-18

    .9{+-}0.5. The vector spectral functions are used to improve the precision of the experimental determination of the hadronic contribution to the anomalous magnetic moment of the muon a{sub {mu}}=(g - 2)/2 and to the running of the QED fine structure constant {alpha}{sub QED}(M{sub Z}{sup 2}) at the Z mass. They are found to be a{sub {mu}}{sup had}=(701.1{+-}9.4) x 10{sup -10} and {delta}{alpha}{sub had}(M{sub Z}{sup 2})=(281.7{+-}6.2) x 10{sup -4}, where the latter leads to {alpha}{sup -1}(M{sub Z}{sup 2})=128.878{+-}0.085. (author)

  14. Instructions for the use of the methodological tools applicable to polluted sites and soils; Mode d'emploi des outils methodologiques applicables aux sites et sols pollues

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The French policy in the domain of polluted sites and soils is based on a limited number of principles which are: the prevention of future pollutions, the identification of all possible potential risks, a well-suited treatment process which depends on the effective environmental impact and on the intended use of the site. This document aims at identifying the main questions raised by a given situation. It proposed useful methodological tools for the construction of answers to the problems encountered: 1 - general approach (main guidelines for the different steps of the management of a polluted site, different possible approaches); 2 - examples of application (industrial site in use, closing down of an industrial site, accidental situation (recent pollution), fortuitous discovery of a pollution on a site, pollutions with limited surface extension, site involved in a land transaction, polluted site with a sensible use, industrial waste lands). (J.S.)

  15. Mathematical study of chemical kinetics schemes. Application to air pollution models; Etude mathematique de schemas de cinetique chimique. Application a des modeles de pollution atmospherique

    Energy Technology Data Exchange (ETDEWEB)

    Billette, E.

    1997-06-23

    Complex chemical kinetics modelling is relevant in numerous fields related to the petroleum industry, for instance engine combustion, petrochemistry and atmospheric pollution. Many numerical difficulties are encountered in the computation of these models, mainly due to the large size, the non-linearity and the stiffness of the associated ordinary differential systems. We first studied systems that have an asymptotic behaviour which may be derived from an algebraic analysis. Then we reviewed different methods that make possible the reduction of size and stiffness for chemical kinetics-related differential systems, and suggest possible improvements for some of those methods. We also studied their application to atmospheric chemistry models. Finally, we started to extend those reduction methods to partial differential systems that include, in addition to chemical kinetics, other phenomena such as species emission, advection or diffusion. (author) 44 refs.

  16. Industrial applications of membrane processes in chemistry and energy generation; Applications industrielles des procedes membranaires en chimie et production d'energie

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The French membranes club (CFM), with the sustain of the French institute of petroleum (IFP) has organized this meeting which aims to present the most recent industrial realizations in the domain of membrane processes in the chemistry and energy generation sectors. This document gathers the abstracts of the presentations: 1 - hydrogen purification and CO{sub 2} extraction: development of polymer matrix and metal nano-particulate hybrid membranes for selective membrane applications; study of silicone-based mixed matrix membranes for hydrogen purification via inverse selectivity principle; CO{sub 2} capture from gaseous effluents for its sequestration: role and limitations of membrane processes; membranes and processes for the abatement of the acid gas content of smokes; new structural model for Nafion{sup R} membranes, the benchmark polymer for low temperature fuel cells; 2 - molecular screen-based membranes: MFI-alumina nano-composite ceramic membranes: preparation and characterization, gaseous transport and separation; characterization and permeation properties of supported MFI membranes; in-situ measurement of butane isomers diffusion in MFI zeolite membranes through transient permeation tests; 3 - vapors separation: stability of silver particulates in PA12-PTMO/AgBF{sub 4} composite membranes and its effect on the easier ethylene transport inside these membranes; 4 - separation of liquid organic mixtures: isomers separation using cyclo-dextrins bearing membranes: application to the extraction and separation of xylene isomers; electrodialysis in organic environment: application to the electro-synthesis; study of polymer materials permeability; 5 - treatment of industrial waters: use of NanoFlux software in the modeling of nano-filtration membrane processes in the chemical industry: elimination of sulfate impurities from 'Chloralkali' brines; ultra-filtration of a wastewater containing partially emulsified oil; efficiency of a hybrid membrane separation

  17. Spectrophotometric determination of association constant

    DEFF Research Database (Denmark)

    2016-01-01

    Least-squares 'Systematic Trial-and-Error Procedure' (STEP) for spectrophotometric evaluation of association constant (equilibrium constant) K and molar absorption coefficient E for a 1:1 molecular complex, A + B = C, with error analysis according to Conrow et al. (1964). An analysis of the Charge...

  18. La mobilité quotidienne dans les grandes villes du monde : application de la théorie des réseaux bayésiens

    Directory of Open Access Journals (Sweden)

    Giovanni Fusco

    2004-02-01

    Full Text Available À la frontière entre statistiques multivariées et intelligence artificielle, les réseaux bayésiens sont un puissant outil de modélisation de connaissance systémique. Une utilisation particulièrement intéressante est celle de la recherche des liens causaux entre variables dans une base de données. Dans cet article, nous analysons une base de données urbaines sur la mobilité quotidienne couvrant plus de cent grandes villes mondiales. À l'aide d'algorithmes de génération de réseaux bayésiens, nous avons produit deux réseaux reliant les variables et traduisant deux hypothèses différentes sur la hiérarchie causale entre elles. Si l’on introduit l’hypothèse que la mobilité détermine la structure urbaine, on crée alors un réseau qui  identifie la motorisation de la population comme étant une variable cruciale. Ce réseau s’avère plus probable que celui résultant de l’hypothèse opposée. En revanche, les deux réseaux concordent sur l’importance de l’offre de voirie rapide urbaine et de la vitesse moyenne du réseau routier dans l’explication du partage modal et des coûts et des externalités des transports urbains.

  19. Impacts of energy crop cultivation on nature and landscape. Development and application of an evaluation method; Auswirkungen des Energiepflanzenanbaus auf Natur und Landschaft. Entwicklung und Anwendung einer Bewertungsmethode

    Energy Technology Data Exchange (ETDEWEB)

    Wiehe, Julia

    2011-08-15

    For long-term planning, knowledge about the interrelationship of effects of the cultivation method and the sensitivity of ecological balance is essential. Hence, the objective of this thesis is the development of a method for the evaluation of the impacts of bioenergy crop production for biogas use on the natural environment. The developed method is in alignment with existing methods. It is also in alignment with those methods used within the practice of landscape planning, so that the method as well as the derived conclusions can be implemented into landscape planning practice in the future. The evaluation method has been applied in the three model regions Hildesheim, Soltau-Fallingbostel and Emsland. These test areas represent different physical regions in Lower Saxony and typical agricultural production conditions. On the basis of these results, general statements on the impact of bioenergy crop production on the ecological balance of the area can be made. [German] Grundlage fuer eine vorausschauende Steuerung des Ausbaus erneuerbarer Energien ist die Kenntnis der Zusammenhaenge der Wirkung des Energiepflanzenanbaus und der Empfindlichkeit des Naturhaushaltes. Ziel der Arbeit ist daher die Erarbeitung einer Methode zur umfassenden Bewertung dieser Auswirkungen auf den Naturhaushalt. Die Methode orientiert sich an bereits bestehenden und in der Praxis der Landschaftsplanung angewendeten Bewertungsmethoden, so dass sie ebenso wie die daraus abgeleiteten Schlussfolgerungen zukuenftig Eingang in die Planungspraxis finden kann. Die Bewertungsmethode wird in den drei Modellregionen Hildesheim, Soltau-Fallingbostel und Emsland angewendet, mit denen die verschiedenen Naturraeume und fuer Niedersachsen typischen landwirtschaftlichen Produktionsbedingungen abgebildet werden. Auf Grundlage dieser Ergebnisse koennen dann allgemeine Aussagen zu den Auswirkungen des Energiepflanzenanbaus auf den Naturhaushalt gemacht werden.

  20. Outil d'évaluation de l'application des lois sur l'accès à l'information ...

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

    Des essais pilotes de l'IAT ont été réalisés en Afrique du Sud, au Bangladesh et au Mexique, avec l'appui de la Fondation William et Flora Hewlett. Ce financement permettra de réaliser d'autres essais dans jusqu'à sept pays, y compris les trois pays pilotes. Dans les sept pays, on fera appel au commissaire à l'information ...

  1. Adaptative control of aero-acoustic instabilities. Application to propulsion systems; Controle adaptatif des instabilites aeroacoustiques. Application aux systemes de propulsion

    Energy Technology Data Exchange (ETDEWEB)

    Mettenleiter, M.

    2000-02-15

    This work treats active adaptive control of aero-acoustic instabilities. In particular, we are interested in an application to solid propellant rockets. The study is part of the research program ASSM coordinated by CNES and ONERA and the aim is to increase the performance of the P230 segmented solid propellant boosters of the Ariane 5 rocket. The work has been carried out in collaboration with other partners of this program. The main objective of this study is the development of control algorithms, able to diminish low frequency instabilities encountered in propulsion systems. First, the instability phenomenon is analyzed in a simplified experimental setup and similarity is shown with instabilities observed in real propulsion systems. This study enables us to conceive adaptive control strategies, which have been tested on three different levels: - In a simplified dynamical simulation; - During an experimental study; - Using full numerical simulations. The three levels of application made it possible to study the behaviour of the different control strategies. We could show that the actuator signal modifies the behaviour of the system on the acoustic level. But as there is a strong interaction between the pressure fluctuations and the hydrodynamic behaviour, the flow structure is also modified by active control. This behaviour corresponds to the simplified model of the phenomenon, which has been used to define the control algorithms. The control action 'at the noise source' makes it possible to distinguish this kind of algorithms from schemes based on the anti-noise principle. After this first part, where we showed the feasibility of control, we particularly considered algorithms which can act in an unknown environment. The information about the system behaviour. which is necessary for convergence of the controller is now obtained in parallel during control. An identification off-line, used at the beginning of the research, is no longer necessary. Self

  2. Universal equations and constants of turbulent motion

    International Nuclear Information System (INIS)

    Baumert, H Z

    2013-01-01

    This paper presents a parameter-free theory of shear-generated turbulence at asymptotically high Reynolds numbers in incompressible fluids. It is based on a two-fluids concept. Both components are materially identical and inviscid. The first component is an ensemble of quasi-rigid dipole-vortex tubes (vortex filaments, excitations) as quasi-particles in chaotic motion. The second is a superfluid performing evasive motions between the tubes. The local dipole motions follow Helmholtz' law. The vortex radii scale with the energy-containing length scale. Collisions between quasi-particles lead either to annihilation (likewise rotation, turbulent dissipation) or to scattering (counterrotation, turbulent diffusion). There are analogies with birth and death processes of population dynamics and their master equations and with Landau's two-fluid theory of liquid helium. For free homogeneous decay the theory predicts the turbulent kinetic energy to follow t −1 . With an adiabatic wall condition it predicts the logarithmic law with von Kármán's constant as 1/√(2 π)= 0.399. Likewise rotating couples form localized dissipative patches almost at rest (→ intermittency) wherein under local quasi-steady conditions the spectrum evolves into an ‘Apollonian gear’ as discussed first by Herrmann (1990 Correlation and Connectivity (Dordrecht: Kluwer) pp 108–20). Dissipation happens exclusively at scale zero and at finite scales this system is frictionless and reminds of Prigogine's (1947 Etude Thermodynamique des Phenomenes Irreversibles (Liege: Desoer) p 143) law of minimum (here: zero) entropy production. The theory predicts further the prefactor of the 3D-wavenumber spectrum (a Kolmogorov constant) as 1/3 (4 π) 2/3 =1.802, well within the scatter range of observational, experimental and direct numerical simulation results. (paper)

  3. Universal equations and constants of turbulent motion

    Science.gov (United States)

    Baumert, H. Z.

    2013-07-01

    This paper presents a parameter-free theory of shear-generated turbulence at asymptotically high Reynolds numbers in incompressible fluids. It is based on a two-fluids concept. Both components are materially identical and inviscid. The first component is an ensemble of quasi-rigid dipole-vortex tubes (vortex filaments, excitations) as quasi-particles in chaotic motion. The second is a superfluid performing evasive motions between the tubes. The local dipole motions follow Helmholtz' law. The vortex radii scale with the energy-containing length scale. Collisions between quasi-particles lead either to annihilation (likewise rotation, turbulent dissipation) or to scattering (counterrotation, turbulent diffusion). There are analogies with birth and death processes of population dynamics and their master equations and with Landau's two-fluid theory of liquid helium. For free homogeneous decay the theory predicts the turbulent kinetic energy to follow t-1. With an adiabatic wall condition it predicts the logarithmic law with von Kármán's constant as 1/\\sqrt {2\\,\\pi }= 0.399 . Likewise rotating couples form localized dissipative patches almost at rest (→ intermittency) wherein under local quasi-steady conditions the spectrum evolves into an ‘Apollonian gear’ as discussed first by Herrmann (1990 Correlation and Connectivity (Dordrecht: Kluwer) pp 108-20). Dissipation happens exclusively at scale zero and at finite scales this system is frictionless and reminds of Prigogine's (1947 Etude Thermodynamique des Phenomenes Irreversibles (Liege: Desoer) p 143) law of minimum (here: zero) entropy production. The theory predicts further the prefactor of the 3D-wavenumber spectrum (a Kolmogorov constant) as \\frac {1}{3}(4\\,\\pi )^{2/3}=1.802 , well within the scatter range of observational, experimental and direct numerical simulation results.

  4. The n,{gamma} discrimination in recoil-proton proportional counters. Application to the measurement of fast neutron spectra; Discrimination n,{gamma} dans les compteurs proportionnels a protons de recul. Application a la mesure des spectres de neutrons rapides

    Energy Technology Data Exchange (ETDEWEB)

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

    1969-07-01

    A description is given of a spectrometry chain working in the energy range of a few keV to 1 MeV, and designed for measurement of fast neutron spectra. It consists of detectors, recoil proton proportional counters built especially for this work by R. COMTE (DEG/SER) and which make it possible to cover the energy range and also associated electronic equipment. A brief description is first given of the physical processes involved: (n,p) collisions in the gas, influence of {gamma} radiation; the method of discrimination is then presented. It is based on the difference in the rise-times of the pulses. In the experiments described here the use of a bi-parametric system made it possible to employ the most simple discrimination device, based on the fact that the high frequency gamma pulse components are, at a given energy, weaker than those of the neutron pulses. Results are given of measurements carried out on the Van der Graaff (mono-energetic neutrons for testing the linearity of the chain and the resolving power of the counters), and of those made in a sub-critical system Hug at Cadarache. (author) [French] On decrit une chaine de spectrometrie travaillant dans le domaine d'energie de quelques keV a 1 MeV destinee a la mesure des spectres de neutrons rapides. Elle comprend les detecteurs, compteurs proportionnels a protons de recul, realises specialement pour cette etude par M. R. COMTE (DEG/SER), permettant de couvrir la gamme d'energie et l'electronique associee. Apres un rappel des processus physiques mis en jeu: chocs (n,p) dans les gaz, influence des rayonnements {gamma}, on expose la methode de discrimination utilisee. Celle-ci est basee sur la difference des temps de montee des impulsions. Au cours des experiences rapportees ici, la mise en oeuvre d'un ensemble bi-parametrique a permis d'utiliser le dispositif de discrimination le plus simple, base sur la remarque que les composantes a haute frequence des impulsions {gamma} sont, a energie egale, plus faibles

  5. The n,{gamma} discrimination in recoil-proton proportional counters. Application to the measurement of fast neutron spectra; Discrimination n,{gamma} dans les compteurs proportionnels a protons de recul. Application a la mesure des spectres de neutrons rapides

    Energy Technology Data Exchange (ETDEWEB)

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

    1969-07-01

    A description is given of a spectrometry chain working in the energy range of a few keV to 1 MeV, and designed for measurement of fast neutron spectra. It consists of detectors, recoil proton proportional counters built especially for this work by R. COMTE (DEG/SER) and which make it possible to cover the energy range and also associated electronic equipment. A brief description is first given of the physical processes involved: (n,p) collisions in the gas, influence of {gamma} radiation; the method of discrimination is then presented. It is based on the difference in the rise-times of the pulses. In the experiments described here the use of a bi-parametric system made it possible to employ the most simple discrimination device, based on the fact that the high frequency gamma pulse components are, at a given energy, weaker than those of the neutron pulses. Results are given of measurements carried out on the Van der Graaff (mono-energetic neutrons for testing the linearity of the chain and the resolving power of the counters), and of those made in a sub-critical system Hug at Cadarache. (author) [French] On decrit une chaine de spectrometrie travaillant dans le domaine d'energie de quelques keV a 1 MeV destinee a la mesure des spectres de neutrons rapides. Elle comprend les detecteurs, compteurs proportionnels a protons de recul, realises specialement pour cette etude par M. R. COMTE (DEG/SER), permettant de couvrir la gamme d'energie et l'electronique associee. Apres un rappel des processus physiques mis en jeu: chocs (n,p) dans les gaz, influence des rayonnements {gamma}, on expose la methode de discrimination utilisee. Celle-ci est basee sur la difference des temps de montee des impulsions. Au cours des experiences rapportees ici, la mise en oeuvre d'un ensemble bi-parametrique a permis d'utiliser le dispositif de discrimination le plus simple, base sur la remarque que les composantes a haute frequence des impulsions {gamma} sont, a

  6. Application of cubane-type structures to hydro-treatment catalysis; Application des structures d'architecture cubane a la catalyse d'hydrotraitement

    Energy Technology Data Exchange (ETDEWEB)

    Marchand, K.

    2003-11-01

    [Mo{sub 3}S{sub 4}(H{sub 2}O){sub 9}]{sup 4+} has been prepared and supported on zeolites H-USY and NaY. Using this cluster as a precursor for HDT catalysts has many advantages: it is cationic, already in a sulfided form, and a promoter such as a second metal M' such as Cu, Ni or Pd can be incorporated to form Mo{sub 3}M'S{sub 4}{sup 4+}. The cubane structure was found unchanged after loading in the case of NaY (EXAFS, XPS) and although TEM showed that Mo was mainly on the outer surface of the zeolite crystals, DRX confirmed that a modification of the counter ion also occurred, and an isotherm was obtained with NaY zeolite. A thermal stability study was led under N{sub 2} and a mixture of H{sub 2}/H{sub 2}S to optimize the pretreatment of the catalysts. Those were subsequently pre-sulfided and tested in toluene hydrogenation and their activities with both types of zeolites turned out to be the same or even better than that of catalysts prepared by the classical route. An application to mixed cubane-type structures is also reported. (author)

  7. Consumption estimation in system design for real time embedded applications; Estimation de la consommation dans la conception systeme des applications embarquees temps reel

    Energy Technology Data Exchange (ETDEWEB)

    Laurent, J.

    2002-12-15

    Today, power and energy consumption have become, as time and area, an important constraint when you design a system. Indeed modern applications use more and more processing and memory resources so these lead a significant increase of consumption. Furthermore, embedded software impact is preponderant in real time system so the code optimisation has a great impact onto the consumption constraint. Several research teams have already developed estimation methodologies for processor but almost are at instruction level (ILPA). With this kind of method you have to measure the consumption of each instruction of the instruction set and also the inter-instruction consumption overhead. For complex architecture, this kind of methodology is not adapted due to the prohibitive number of consumption measures. So the characterisation time of this kind of architecture is too important furthermore with this method is very difficult to take into account the external environment. For actual architecture another method is needed to reduce the characterisation time while preserving the accuracy. The reduction of the characterisation time have to be realized by increasing the abstraction level. So, we propose here a new approach based on a functional and architectural analysis of the target in consumption point of view (FLPA). Our methodology has two steps: the first one is a modeling step and the second is estimation step. (author)

  8. Santé des adolescents et des jeunes au Burkina Faso : état des ...

    African Journals Online (AJOL)

    Il s'est agi d'une étude évaluative ayant utilisé une revue documentaire associée à une interview des acteurs clés et un atelier de validation et d'identification des interventions pertinentes pour un plan stratégique national. La situation de la santé des adolescents et des jeunes est caractérisée par des grossesses précoces ...

  9. Application of wavelet analysis to the nuclear phase space study; Application de l`analyse en ondelettes a l`etude de l`espace des phases nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Jouault, B. [Nantes Univ., 44 (France)

    1996-11-22

    The objective of this thesis is to present a methodology, based on the projection methods used in statistical physics and on the wavelet approach, which allows to obtain various classes of information. A coherent modelling was elaborated as the tools used for generating and solving the evolution equations, expressed in terms of pertinent variables, are based on common concepts. The property of scale separation of the wavelet analysis allows an approximation hierarchy based on the geometrical structure of phase space to be defined. This information structuration offers the opportunity of solving the evolution equations with various degrees of precision by controlling the information loss and avoiding the sampling methods of Monte Carlo type. The application of this methodology to the case of heavy ion collisions needs an entirely numerical treatment of the density matrix evolution equation. This implies a very precise level of description in order to take into account the important dissipation effects occurring in intermediate energy nuclear dynamics. A proper solution less expensive was adopted by using the wavelets analytically expressed, this entailing also the testing of model validity by comparing its results with the analytical solutions. This model takes into account the structure of the system wave functions, thus conserving the microscopical information. The present methodology can be applied also at other energy domains providing the nuclear systems are subject to transient non steady-state regimes. The wavelet analysis was used extensively in the field of signal processing particularly to extract from background a physical signal and also in the field of turbulence phenomena 152 refs.

  10. Parallelization of learning problems by artificial neural networks. Application in external radiotherapy; Parallelisation de problemes d'apprentissage par des reseaux neuronaux artificiels. Application en radiotherapie externe

    Energy Technology Data Exchange (ETDEWEB)

    Sauget, M

    2007-12-15

    This research is about the application of neural networks used in the external radiotherapy domain. The goal is to elaborate a new evaluating system for the radiation dose distributions in heterogeneous environments. The al objective of this work is to build a complete tool kit to evaluate the optimal treatment planning. My st research point is about the conception of an incremental learning algorithm. The interest of my work is to combine different optimizations specialized in the function interpolation and to propose a new algorithm allowing to change the neural network architecture during the learning phase. This algorithm allows to minimise the al size of the neural network while keeping a good accuracy. The second part of my research is to parallelize the previous incremental learning algorithm. The goal of that work is to increase the speed of the learning step as well as the size of the learned dataset needed in a clinical case. For that, our incremental learning algorithm presents an original data decomposition with overlapping, together with a fault tolerance mechanism. My last research point is about a fast and accurate algorithm computing the radiation dose deposit in any heterogeneous environment. At the present time, the existing solutions used are not optimal. The fast solution are not accurate and do not give an optimal treatment planning. On the other hand, the accurate solutions are far too slow to be used in a clinical context. Our algorithm answers to this problem by bringing rapidity and accuracy. The concept is to use a neural network adequately learned together with a mechanism taking into account the environment changes. The advantages of this algorithm is to avoid the use of a complex physical code while keeping a good accuracy and reasonable computation times. (author)

  11. Diethylstilbestrol (DES) and Cancer

    Science.gov (United States)

    ... DES-exposed grandchildren have? Researchers are also studying possible health effects among women and men who are the children ... for unexposed men. In addition, researchers are studying possible health effects on the grandchildren of mothers who were exposed ...

  12. Table des illustrations

    OpenAIRE

    2016-01-01

    Tableaux Dates d’inauguration des grands hôtels japonais entre 1860 et 1945… 19 Histoire, tourisme et hôtellerie en Corée depuis les années 1870… 59-60 Dates d’inauguration des grands hôtels chinois depuis 1863… 84 Les hôtels de luxe et leurs capacités d’hébergement en Corée en 2000… 103 Les flux de personnes suscités par les hôtels « super luxe » de Séoul en 2000… 105 L’activité des grands hôtels à Séoul en 1999 (en wons)… 106 Propriété et gestion des grands hôtels à Séoul en 1999…. 110 La c...

  13. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    potential and surface properties of their mixtures were investigated, in an ... suppose that the electrostatic repulsive interactions between the two anion ... concentration, et de la conformation des ..... proteins and polysaccharides in solutions,.

  14. Extraction, fractionnement et concentration des huiles marines

    Directory of Open Access Journals (Sweden)

    Linder Michel

    2004-03-01

    Full Text Available Les huiles marines représentent des sources potentielles d’acides gras polyinsaturés (AGPI dont les implications au niveau de la nutrition et de la santé sont avérées. Ces molécules sont extraites à partir de poissons, algues ou co-produits de la filière halieutique par des procédés de cuisson-pression, en présence de solvants ou par des techniques enzymatiques beaucoup moins drastiques. Des fractions plus ou moins purifiées en AGPI sont obtenues par cristallisation à froid, en présence de solvants organiques, complexation avec de l’urée, distillation moléculaire ou extraction par fluide supercritique. L’utilisation de lipases stéréospécifiques dans des procédés d’hydrolyse et d’estérification conduit à une diversité de molécules d’acylglycérols riches en AGPI trouvant de nombreuses applications dans le domaine de l’agroalimentaire et de la santé.

  15. Enseignement Basé sur les Compétences : Manuel d'Application dans le Domaine des Sciences Agronomiques a L'Université d'Abomey-Calavi

    NARCIS (Netherlands)

    Koutinhouin, B.; Hupkes, M.; Gooijer, de G.; Aho, N.; Windmeijer, P.N.

    2011-01-01

    Le présent manuel est produit dans le cadre du Projet d’Appui au Renforcement des Programmes de Formation et de Recherche en Agriculture à la Faculté des Sciences Agronomiques et à l’Ecole Polytechnique d’Abomey-Calavi, financé par le Gouvernement du Royaume des Pays-Bas (Projet NPT/BEN/146). Il est

  16. La revolution des savants

    CERN Document Server

    Chavanne, A

    1989-01-01

    Premiere cassette : - 1666 : impact de la creation de l'Academie des Sciences par Colbert, trente ans apres le proces de Galile, et au moment des disparitions de Pascal, Descartes et Fermat. Elle dirigee par le hollandais Huyggens jusqu'a sa fuite de France au moment de la revocation de l'Edit de Nantes. - 1750 : l'Encyclopedie (ou "Dictionnaire raisonne des Sciences, des Arts et des Metiers") de Diderot et d'Alembert, soutenus par Malherbes, Buffon, Condorcet et Rousseau. - 1789 : Revolution francaise. - 8 aout 1793 : l'Assemblee, par une declaration de Marat, dissout l'Academie des Sciences. Celle-ci continue cependant ses travaux pour les poids et mesures jusqu'en 1795. - la Terreur : la condamnation a mort, pas au nom d'une "Revolution qui n'a pas besoin de savants" mais pour d'autres raisons, de trois grands hommes de science : Lavoisier, Bailly et Condorcet. - 1793-1794 : Au printemps 93, le Comite de Salut Publique s'inquiete du demi-million de soldats etrangers de toutes les pays frontaliers qui essai...

  17. Source oriented modeling of the nitrat pollution of surface waters - application of the immission method for the reporting according to the EC nitrat guideline; Verursacherbezogene Modellierung der Nitratbelastung der Oberflaechengewaesser - Anwendung des Immissionsverfahrens zur Berichterstattung zur EU-Nitratrichtlinie

    Energy Technology Data Exchange (ETDEWEB)

    Behrendt, H.; Opitz, D. [Institut fuer Gewaesseroekologie und Binnenfischerei im Forschungsverbund Berlin e.V. (Germany); Bach, M. [Gesellschaft fuer Boden- und Gewaesserschutz e.V. (Germany); Pagenkopf, W.G. [Geodaten Integration und Analyse, Berlin (Germany)

    2000-09-20

    application of fertilizer seems to be very low. The comparison of long term changes of nitrogen surplus and nitrate concentration within the river basins allows a raw estimation of the residence times of nitrogen from the topsoil to the river. These times were estimated in a range between about 5 years (Rhine) and more than 20 years (Elbe). (orig.) [German] Die Ueberwachung der Oberflaechengewaesser an den 152 Messstellen der Bundeslaender (LAWA-Messstellennetz) ergab im Berichtszeitraum keine Ueberschreitung des Qualitaetsziels fuer Nitrat von 50 mg/l. Aber bei nur 14% der Messstellen wird eine gute Wasserqualitaet bezueglich Nitrat erreicht. Sieht man von abflussbedingten Schwankungen ab, sind eindeutige Trends der Nitratbelastung aus der Landwirtschaft seit der Mitte der 80er Jahre nicht erkennbar. Vertiefende Analysen wurden fuer die 15 EU-Messstellen Deutschlands durchgefuehrt. Fuer den Trend der mittleren Winterkonzentrationen zeigt sich an jeweils der Haelfte dieser Messstellen Stabilitaet bzw. eine schwache Reduktion. Ein aehnliches Ergebnis ergaben die Winterkonzentrationen bei geringen Abfluessen. Die Separation von diffusen und punktuellen Stickstoffquellen auf Basis des Immissionsverfahrens ergab im Berichtszeitraum 1996-1999 bei beiden Anteilen eine leichte Verminderung gegenueber dem vorangegangenen Vierjahres-Zeitraum. Gegenueber der Mitte der 80er Jahre haben die Punktquellen dagegen z.T. erheblich abgenommen und machen heute nur noch 9-24% in den verschiedenen Flussgebieten aus. Das Immissionverfahren zeigt die gleichen Ergebnisse wie die Emissionsschaetzungen. Mitte der 90er Jahre stammten danach ungefaehr 67% der Stickstoffbelastungen der Oberflaechengewaesser aus landwirtschaftlichen Flaechen. Der Weg ueber das Grundwasser war mit 48% der bedeutendste. Die Gesamtemissionen haben vor allem durch Verringerung der Punktquellen um etwa 24% abgenommen. Zur Darstellung der Urachen in der Landwirtschaft wurden die Stickstoffueberschuesse (Flaechenbilanz

  18. Reliability concerns with logical constants in Xilinx FPGA designs

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, Heather M [Los Alamos National Laboratory; Graham, Paul [Los Alamos National Laboratory; Morgan, Keith [Los Alamos National Laboratory; Ostler, Patrick [Los Alamos National Laboratory; Allen, Greg [JPL; Swift, Gary [XILINX; Tseng, Chen W [XILINX

    2009-01-01

    In Xilinx Field Programmable Gate Arrays logical constants, which ground unused inputs and provide constants for designs, are implemented in SEU-susceptible logic. In the past, these logical constants have been shown to cause the user circuit to output bad data and were not resetable through off-line rcconfiguration. In the more recent devices, logical constants are less problematic, though mitigation should still be considered for high reliability applications. In conclusion, we have presented a number of reliability concerns with logical constants in the Xilinx Virtex family. There are two main categories of logical constants: implicit and explicit logical constants. In all of the Virtex devices, the implicit logical constants are implemented using half latches, which in the most recent devices are several orders of magnitudes smaller than configuration bit cells. Explicit logical constants are implemented exclusively using constant LUTs in the Virtex-I and Virtex-II, and use a combination of constant LUTs and architectural posts to the ground plane in the Virtex-4. We have also presented mitigation methods and options for these devices. While SEUs in implicit and some types of explicit logical constants can cause data corrupt, the chance of failure from these components is now much smaller than it was in the Virtex-I device. Therefore, for many cases, mitigation might not be necessary, except under extremely high reliability situations.

  19. Applications of the complex-mass renormalization scheme in effective field theory; Anwendungen des Komplexe-Masse-Renormierungsschemas in effektiver Feldtheorie

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Torsten

    2012-07-11

    In the first part of the this doctoral thesis the perturbative unitarity in the complex-mass scheme (CMS) is analysed. To that end a procedure for calculating cutting rules for loop integrals containing propagators with finite widths is presented. A toy-model Lagrangian describing the interaction of a heavy vector boson with a light fermion is used to demonstrate that the CMS respects unitarity order by order in perturbation theory provided that the renormalized coupling constant remains real. The second part of the thesis deals with various applications of the CMS to chiral effective field theory (EFT). In particular, mass and width of the delta resonance, elastic electromagnetic form factors of the Roper resonance, form factors of the nucleon-to-Roper transition, pion-nucleon scattering, and pion photo- and electroproduction for center-of-mass energies in the region of the Roper mass are calculated. By choosing appropriate renormalization conditions, a consistent chiral power counting scheme for EFT with resonant degrees of freedom can be established. This allows for a systematic investigation of the above processes in terms of an expansion in small quantities. The obtained results can be applied to the extrapolation of corresponding simulations in the context of lattice QCD to the physical value of the pion mass. Therefore, in addition to the Q{sup 2} dependence of the form factors, also the pion-mass dependence of the magnetic moment and electromagnetic radii of the Roper resonance is explored. Both a partial wave decomposition and a multipole expansion are performed for pion-nucleon scattering and pion photo- and electroproduction, respectively. In this connection the P11 partial wave as well as the M{sub 1-} and S{sub 1-} multipoles are fitted via non-linear regression to empirical data.

  20. Models for the Behavior of Offshore Structure Foundations. Part Two: Applications to Structural Design and Quality Assurance Processes Modèles pour le comportement des fondations d'ouvrages types marins. Deuxième partie : applications au calcul d'ouvrage et processus d'assurance qualité

    Directory of Open Access Journals (Sweden)

    Meimon Y.

    2006-11-01

    structure. Prospects opened up by the research are discussed. La conception des fondations de grands ouvrages est une tâche complexe qui requiert à la fois l'expérience de l'expert et l'utilisation de modèles numériques adéquats pour assurer la sécurité et optimiser les coûts de dimensionnement. En fait, prévoir le comportement d'une fondation nécessite de bien évaluer les effets combinés de la technique de mise en place, de la variabilité spatiale des propriétés mécaniques, de l'incertitude sur les chargements et des techniques de modélisation du comportement mécanique des géomatériaux. Ceci est particulièrement vrai pour les plates-formes marines, qu'elles soient destinées à l'exploration ou à la production du pétrole, dans la mesure où les chargements non-monotones dus à l'environnement marin, souvent très sévère, peuvent avoir des effets très néfastes sur le comportement de ces structures. On présente, en deux parties, la synthèse d'une dizaine d'années d'activités de recherche, menées par une équipe de l'Institut Français du Pétrole (IFP, en collaboration avec plusieurs équipes universitaires et des centres techniques et industriels, pour la mise au point de méthodologies et d'outils adaptés au calcul du comportement des fondations d'ouvrages types marins durant toute la durée de vie de la plate-forme. Cet article concerne la deuxième partie qui est dévolue à l'application des modèles développés au calcul d'ouvrage par la méthode des éléments finis et à l'exposé d'un processus de validation des modèles, étape d'une démarche d'assurance qualité. Méthodes pour le calcul des fondations marines : Le système de programmes FONDOF utilisant la méthode des éléments finis a été développé. Il comprend (fig. 1. 1 des interfaces interactives de mise en données et de dépouillement des résultats ainsi que des modules de calcul, opérationnels comme FONGEO pour les calculs bi et tridimensionnels ou FONDAX pour le

  1. Varying Constants, Gravitation and Cosmology

    Directory of Open Access Journals (Sweden)

    Jean-Philippe Uzan

    2011-03-01

    Full Text Available Fundamental constants are a cornerstone of our physical laws. Any constant varying in space and/or time would reflect the existence of an almost massless field that couples to matter. This will induce a violation of the universality of free fall. Thus, it is of utmost importance for our understanding of gravity and of the domain of validity of general relativity to test for their constancy. We detail the relations between the constants, the tests of the local position invariance and of the universality of free fall. We then review the main experimental and observational constraints that have been obtained from atomic clocks, the Oklo phenomenon, solar system observations, meteorite dating, quasar absorption spectra, stellar physics, pulsar timing, the cosmic microwave background and big bang nucleosynthesis. At each step we describe the basics of each system, its dependence with respect to the constants, the known systematic effects and the most recent constraints that have been obtained. We then describe the main theoretical frameworks in which the low-energy constants may actually be varying and we focus on the unification mechanisms and the relations between the variation of different constants. To finish, we discuss the more speculative possibility of understanding their numerical values and the apparent fine-tuning that they confront us with.

  2. Effets du stress salin sur la germination des graines de Gossypium ...

    African Journals Online (AJOL)

    SARAH

    31 août 2014 ... herbeuses et vives tandis que 40 % des graines ont germé sur tanne arbustive en milieu réel. Conclusion et application: l'objectif général de cette étude menée en milieu contrôlé (application des doses de sel) et en milieu réel (tannes) était de montrer les effets du stress salin sur la germination des graines.

  3. Contribution to the experimental survey of the nuclear isomerism. Application of the deferred coincidences method to research and to the survey of metastable states of short period; Contribution a l'etude experimentale de l'isomerie nucleaire. Application de la methode des coincidences differees a la recherche et a l'etude d'etats metastables de periode courte

    Energy Technology Data Exchange (ETDEWEB)

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

    1953-06-15

    Various methods of the physics brought many informations on the nuclear elements which one can arrange some ponderable quantities, what is the case of the steady elements and some, unsteady elements, as most of natural radioelements. On the other hand, elements of shorter life duration, and notably those that are carried to an excited state, are more badly known, and one can get information to their consideration that by the mediator of the properties of the transitions that they undergo, when they give birth has best-known nuclear cash: among these transitions represent the isomeric transitions. The goal of this work is the survey of the isomeric transitions from metastable states of short period, included in the domain of the microsecond to some milliseconds. The method of the deferred coincidences has been put to the point and applied in this goal while using the advantages of the selectors to several channels, under two main aspects where the device to several channels was either a selector of time, either a selector of amplitudes. This method served to study the working of Geiger-Muller counter and to measure with precision the period of {sup 181}Ta{sup *} in of the varied experimental conditions. The adopted value is 17,2 {+-}0,2 {mu}s. This work also found an immediate practical application to the setting in evidence of very weak quantities of hafnium in zirconium, of which it constitutes a tenacious and difficult impurity to analyze by the ordinary ways. (M.B.) [French] Les diverses methodes de la physique ont apporte de nombreux renseignements sur les especes nucleaires dont on peut disposer en quantites ponderables, ce qui est le cas des especes stables et de certaines especes instables, comme la plupart des radioelements naturels. Par contre, les noyaux de duree de vie plus courte, et notamment ceux qui sont portes a un etat excite, sont plus mal connus, et on ne peut obtenir de renseignements a leur egard que par l'intermediaire des proprietes des

  4. Properties of silicium n-i-p junctions - application to the detection of relativist particles; Propriete des jonctions nip de silicium - Application a la detection des particules relativistes; Svojstva perekhoda p-i-n v kremnii - primenenie k obnaruzheniyu relyativistskikh chastits; Propiedades de estructuras nip de silicio - Aplicacion a la deteccion de particulas relativistas

    Energy Technology Data Exchange (ETDEWEB)

    Koch, L; Messier, J; Valin, J [Centre d' Etudes Nucleaires de Saclay (France)

    1962-04-15

    An account is given of experience gained at the CENS on the detection of nuclear particles by semiconductors. One type of detector, of pin structure, has been specially studied. In comparison with the usual p-n or npp{sup +} structures, and given an equal purity of the base material, it has the advantage of permitting a larger effective volume for the following reasons: (a) with an equal potential difference applied to the crystal, the total thickness of the barrier layers is greater; (b) with an equal reverse current, the maximum potential difference which they can withstand is greater; (c) other things being equal, their capacitance per unit of area is smaller and hence the permitted maximum surface is greater. A detailed description is given of methods of obtaining pin structures in silicon, the intermediate zone reaching 1 mm. Lastly, certain applications of these detectors are described: {alpha} and {gamma} spectroscopy and the measurement of dE/dX for relativistic particles. (author) [French] Les auteurs exposent l'experience acquise au CENS sur la detection des particules nucleaires par les semi-conducteurs. Un type de detecteur, de structure pin, a ete particulierement etudie. U presente par rapport aux structures classiques pn ou npp{sup +}, et a purete egale du materiau de depart, l'avantage de permettre un volume sensible plus grand. En effet: a) a difference de potentiel egale appliquee au cristal, l'epaisseur totale des barrieres est plus importante; b) a courant inverse egal, la d.d.p. maximum qu'ils supportent est plus grande; c) toutes choses egales d'ailleurs, leur capacite par unite d'aire est plus faible et la surface maximum permise est donc plus grande. Les auteurs decrivent en detail quelques procedes permettant d'obtenir des structures pin dans le silicium, la zone intermediaire atteignant 1 mm. Enfin, ils decrivent quelques applications de ces detecteurs: spectroscopie {alpha} et {gamma}, mesure de dE/dX pour les particules relativistes

  5. Contribution des radios communautaires a l'education des ...

    African Journals Online (AJOL)

    Contribution des radios communautaires a l'education des populations rurales pour un developpement durable au Benin: etude de cas. ... Journal de la Recherche Scientifique de l'Université de Lomé. Journal Home · ABOUT THIS JOURNAL ...

  6. Simulation of land use evolution by discrete events method: Application to “la chaîne des puys” from XV to XVIII Century

    OpenAIRE

    Y. Michelin; C. Poix

    1998-01-01

    By using a discrete event method, simulation of land use evolution has been applied to a landscape model of “la ChaÎne des Puys” (French Massif Central) during along period (XV–XVIII centuries). The indications concerning the evolution of land use are in conformity with the observation of actual situations but the dynamic changes are faster than in actual facts. In spite of limitations due to necessary simplifications, it is now established that the discrete event method is efficient to simu...

  7. Tourisme et communautés rurales au Venezuela : vers une application des principes du Développement Durable

    Directory of Open Access Journals (Sweden)

    Olivier Dehoorne

    2008-02-01

    Full Text Available L’évolution récente du tourisme international au Venezuela est particulièrement intéressante : l'activité touristique qui reste très largement concentrée sur la côte caribéenne, et notamment l’île de Margarita, se diversifie au profit de nouveaux centres d’intérêt dans les régions intérieures. L’affichage de nouvelles volontés politiques sur la scène régionale et internationale, sous l’impulsion du président Chavez, a perturbé le marché touristique national qui était dominé pour les clientèles nord-américaines ; le Venezuela apparaît désormais aux yeux des Etats-Unis comme un pays à risque, instable. C’est dans ce contexte que s’inscrit le « Programa Andes Tropicales » [PAT] qui soutient le  développement rural dans les parcs nationaux ; ce programme repose sur la participation des populations locales et leur implication dans les politiques de conservation des ressources naturelles et culturelles sources de revenus. Le soutien financier des microprojets familiaux et communautaires doivent permettent de lutter contre la pauvreté.The recent evolution of international tourism in Venezuela is particularly interesting. Even if tourism activity remains heavily concentrated on the Caribbean coast, in particular on the island of Margarita, it is nevertheless diversifying gradually to make way for new areas of interest in the country’s interior. The display of new political will on the regional and international scene, under the leadership of President Chavez, has disrupted the national tourism market which was dominated by North American customers. Venezuela now appears in the eyes of the United States as a country that is at risk,and therefore unstable. It is in this context that the “Programa Andes Tropicales" [PAT] was developed to promote rural development in national parks; This program is based on the participation and involvement of local populations in the development of appropriate

  8. Improved dielectric constant and breakdown strength of γ-phase dominant super toughened polyvinylidene fluoride/TiO2 nanocomposite film: an excellent material for energy storage applications and piezoelectric throughput

    Science.gov (United States)

    Mehebub Alam, Md; Ghosh, Sujoy Kumar; Sarkar, Debabrata; Sen, Shrabanee; Mandal, Dipankar

    2017-01-01

    Titanium dioxide (TiO2) nanoparticles (NPs) embedded γ-phase containing polyvinylidene fluoride (PVDF) nanocomposite (PNC) film turns to an excellent material for energy storage application due to an increased dielectric constant (32 at 1 kHz), enhanced electric breakdown strength (400 MV m-1). It also exhibits a high energy density of 4 J cm-3 which is 25 times higher than that of virgin PVDF. 98% of the electroactive γ-phase has been acheived by the incorporation of TiO2 NPs and the resulting PNC behaves like a super-toughened material due to a dramatic improvement (more than 80%) in the tensile strength. Owing to their electroactive nature and extraordinary mechanical properties, PNC films have a strong ability to fabricate the piezoelectric nanogenerators (PNGs) that have recently been an area of focus regarding mechanical energy harvesting. The feasibility of piezoelectric voltage generation from PNGs is demostrated under the rotating fan that also promises further utility such as rotational speed (RPM) determination.

  9. La convergence des rôles respectifs des relationnistes et des journalistes influence-t-elle la perception qu'ils ont les uns des autres?

    DEFF Research Database (Denmark)

    Valentini, Chiara

    2017-01-01

    la convergence des rôles respectifs des praticiens des relations publiques et des journalistes a un effet favorable sur la perception qu’ils ont les uns des autres. L’effet est plus marqué chez les praticiens des relations publiques, car leur vision de la profession en journalisme correspond à celle...

  10. Application of new fast-electronic techniques to the determination of the exact moment of particle detection; Application des techniques nouvelles de l'electronique rapide a la determination de l'instant precis de detection d'une particule

    Energy Technology Data Exchange (ETDEWEB)

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

    1965-06-01

    Fluctuations in the time response of photomultipliers employed in scintillation counting are studied and experimentally checked. Statistical measurements of the output pulses show that the relative variance of the time fluctuations is minimum for the portion located around the bending point of the leading edge. A shaping circuit using this property is described. Experimental results are given, showing an improvement of the resolving time. (author) [French] Les fluctuations de la reponse temporelle des photomultiplicateurs, utilises dans les detecteurs a scintillations, sont etudiees et mesurees experimentalement. L'etude statistique des signaux de sortie montre que les fluctuations en temps presentent une variance relative minimale pour la region situee autour du point d'inflexion du front de montee. Un circuit de mise en forme utilisant cette propriete est decrit. Des resultats experimentaux sont donnes; ils montrent une amelioration sensible du pouvoir de resolution. (auteur)

  11. From the Rydberg constant to the fundamental constants metrology

    International Nuclear Information System (INIS)

    Nez, F.

    2005-06-01

    This document reviews the theoretical and experimental achievements of the author since the beginning of his scientific career. This document is dedicated to the spectroscopy of hydrogen, deuterium and helium atoms. The first part is divided into 6 sub-sections: 1) the principles of hydrogen spectroscopy, 2) the measurement of the 2S-nS/nD transitions, 3) other optical frequency measurements, 4) our contribution to the determination of the Rydberg constant, 5) our current experiment on the 1S-3S transition, 6) the spectroscopy of the muonic hydrogen. Our experiments have improved the accuracy of the Rydberg Constant by a factor 25 in 15 years and we have achieved the first absolute optical frequency measurement of a transition in hydrogen. The second part is dedicated to the measurement of the fine structure constant and the last part deals with helium spectroscopy and the search for optical references in the near infrared range. (A.C.)

  12. Some aspects of preparation and testing of group constants group constant system ABBN-90

    International Nuclear Information System (INIS)

    Nikolaev, M.N.; Tsiboulia, A.M.; Manturov, G.N.

    1996-01-01

    This paper presents an overview of activities performed to prepare and test the group constants ABBN-90. The ABBN-90 set is designed for application calculations of fast, intermediate and thermal nuclear reactors. The calculations of subgroup parameters are discussed. The processing code system GRUCON is mentioned in comparison to the NJOY code system. Proposals are made for future activities. (author). Figs, tabs

  13. Promouvoir l'entrepreneuriat inclusif des jeunes et des femmes ...

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

    Le projet vise à analyser la contribution réelle et potentielle de l'entrepreneuriat inclusif au bien-être des jeunes et des femmes en Côte d'Ivoire, au Burkina Faso et au Kenya. Après un état des lieux de la pratique de l'entrepreneuriat inclusif dans chacun des pays ciblés, l'équipe de recherche étudiera son incidence sur ...

  14. Learning Read-constant Polynomials of Constant Degree modulo Composites

    DEFF Research Database (Denmark)

    Chattopadhyay, Arkadev; Gavaldá, Richard; Hansen, Kristoffer Arnsfelt

    2011-01-01

    Boolean functions that have constant degree polynomial representation over a fixed finite ring form a natural and strict subclass of the complexity class \\textACC0ACC0. They are also precisely the functions computable efficiently by programs over fixed and finite nilpotent groups. This class...... is not known to be learnable in any reasonable learning model. In this paper, we provide a deterministic polynomial time algorithm for learning Boolean functions represented by polynomials of constant degree over arbitrary finite rings from membership queries, with the additional constraint that each variable...

  15. DES Science Portal: Computing Photometric Redshifts

    Energy Technology Data Exchange (ETDEWEB)

    Gschwend, Julia [LIneA, Rio de Janeiro

    2016-01-01

    An important challenge facing photometric surveys for cosmological purposes, such as the Dark Energy Survey (DES), is the need to produce reliable photometric redshifts (photo-z). The choice of adequate algorithms and configurations and the maintenance of an up-to-date spectroscopic database to build training sets, for example, are challenging tasks when dealing with large amounts of data that are regularly updated and constantly growing. In this paper, we present the first of a series of tools developed by DES, provided as part of the DES Science Portal, an integrated web-based data portal developed to facilitate the scientific analysis of the data, while ensuring the reproducibility of the analysis. We present the DES Science Portal photometric redshift tools, starting from the creation of a spectroscopic sample to training the neural network photo-z codes, to the final estimation of photo-zs for a large photometric catalog. We illustrate this operation by calculating well calibrated photo-zs for a galaxy sample extracted from the DES first year (Y1A1) data. The series of processes mentioned above is run entirely within the Portal environment, which automatically produces validation metrics, and maintains the provenance between the different steps. This system allows us to fine tune the many steps involved in the process of calculating photo-zs, making sure that we do not lose the information on the configurations and inputs of the previous processes. By matching the DES Y1A1 photometry to a spectroscopic sample, we define different training sets that we use to feed the photo-z algorithms already installed at the Portal. Finally, we validate the results under several conditions, including the case of a sample limited to i<22.5 with the color properties close to the full DES Y1A1 photometric data. This way we compare the performance of multiple methods and training configurations. The infrastructure presented here is an effcient way to test several methods of

  16. Stabilization of spectra provided by a gamma-ray spectrometer. Application to the construction of a stabilizer; Stabilisation des spectres fournis par un spectrometre a rayons gamma. Application a la realisation d'un stabilisateur

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-06-15

    This research is concerned with the stabilization of spectra provided by a gamma-ray spectrometer. It is required to hold the calibration straight line of the spectrometer in a position which is fixed initially to better than 5x10{sup -5} channel. A prototype numerical stabilizer has been constructed : the SPECTROSTAB; it is made up of two independent control loops; one of these makes the spectrometer gain depend on the derivatives of a reference peak at high energies; the other makes the origin of the energy scale depend on the derivatives of a second reference peak at low energies A theoretical study of the behaviour of a control loop shows that a direct action stabilizer gives the most accurate stabilization; the loss in resolving power on the theoretical peaks of the spectra attains about 1 % with a scintillation detector, and 10 % with a semi-conductor detector. Various tests show that the expected results are obtained and that the displacement of the spectral peaks produced by the derivatives are hidden by errors in the calculation of the peak abscissae. (author) [French] Cette etude a pour objet la stabilisation des spectres fournis par un spectrometre a rayons gamma. On veut maintenir la droite d'etalonnage du spectrometre dans une position fixee initialement a mieux de 6.10{sup -5} canal pres. On realise un prototype de stabilisateur numerique, le SPECTROSTAB; il comprend deux boucles d'asservissement independantes; l'une d'elles asservit le gain du spectrometre aux derives d'un pic de reference aux hautes energies; l'autre asservit l'origine de l'echelle des energies aux derives d'un second pic de reference aux basses energies. Une etude theorique du comportement d'une boucle d'asservissement montre qu'un stabilisateur a action directe permet la stabilisation la plus precise; la perte en resolution sur les pics theoriques des spectres atteint environ 1 % avec un detecteur a scintillateur et 10 % avec un detecteur a semi-conducteur. Divers essais montrent

  17. Application of alkaline leaching to the extraction of uranium from shale of the Vosges; Application de la lixiviation alcaline a l'extraction de l'uranium du schiste des Vosges

    Energy Technology Data Exchange (ETDEWEB)

    Mouret, P; Pottier, P; Le Bris, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Soudan, P [Centre d' Etude de Lalumine, Compagnie Pechiney (France)

    1958-07-01

    Description of chemical treatment of Vosges shales to obtain uranium by alkaline leaching. Mineralogy aspects of ore, physical and chemical conditions of leaching, solid/liquid separation, uranium recovery by either ion exchange process or electrolytic precipitation. (author)Fren. [French] Description du traitement chimique des schistes des Vosges pour extraire l'uranium en milieu alcalin. L'aspect mineralogique, les conditions physiques et chimiques de la lixiviation, la separation solide/liquide et la recuperation de l'uranium soit par echangeurs d'ions, soit par precipitation electrolytique y sont exposes. (auteur)

  18. La fabrique des sciences des institutions aux pratiques

    CERN Document Server

    Benninghoff, Martin; Crettaz von Roten, Fabienne; Merz, Martina

    2006-01-01

    Aujourd'hui, les façons de produire, d'organiser, d'évaluer et d'utiliser les savoirs sont en profond débat. De plus en plus, l'Etat, la société civile et l'économie tentent d'influencer les activités des universités et des laboratoires de recherche. Ces développements mettent à l'épreuve tout à la fois les fondements des systèmes d'enseignement supérieur et de recherche, l'autonomie des institutions scientifiques, la définition des frontières des savoirs et l'acceptation des sciences. Dans des contextes suisses et européens, cet ouvrage s'intéresse aux manières dont les sciences et les technologies sont fabriquées, en analysant leurs institutions et les pratiques. A partir d'une approche relationnelle, les sciences et les technologies sont conçues comme des phénomènes profondément sociaux, culturels et politiques. Une telle démarche déstabilise les visions parfois idéalisées et stéréotypées de la construction des savoirs. Des études de cas détaillées décrivent des phénomè...

  19. Effets des extraits vegetaux sur la dynamique de populations des ...

    African Journals Online (AJOL)

    La présente étude se propose de trouver une alternative de l'utilisation des pesticides chimiques en testant l'effet insecticide des extraits aqueux des feuilles de Hyptis suaveolens, graines de Ricinus communis et de Azadirachta indica contre les ravageurs du niébé en conditions de champ en utilisant le cyperméthrine ...

  20. Stimulation des réservoirs gréseux. Interprétation des courbes de réponse à l'acide Sandstone Acidizing. Acid Response Curves Interpretation

    Directory of Open Access Journals (Sweden)

    Labrid J.

    2006-11-01

    Full Text Available Les problèmes d'acidification des réservoirs gréseux sont abordés en introduisant une grandeur cinétique caractéristique du milieu à stimuler appelée réactivité dont la détermination est nécessaire pour l'interprétation complète des courbes de réponse à l'acide; ce concept de réactivité prend en compte la morphologie du milieu poreux (dimension et forme des- grains, distribution des minéraux, et les constantes de vitesse de dissolution des différentes espèces minéralogiques. Les effets de l'acidification sont évalués en établissant une relation liant la porosité, la perméabilité et la réactivité; cette relation est indépendante des conditions de l'expérience : débit, concentration et volume d'acide injecté. Par ailleurs, un modèle mathématique de l'acidification a été conçu et mis au point en géométrie radiale et unidimensionnelle. Ce modèle, alimenté par les données tirées de l'expérience, restitue de manière très satisfaisante l'évolution des propriétés pétrophysiqués du milieu ; son application à la géométrie radiale (cas de l'opération de chantier conduit à des recommandations sur la procédure à adopter en fonction des caractéristiques de la formation. Problems in the acid treatment of sandstone reservoirs are approached by introducing a kinetic parameter, called reactivity, thot is characteristic of the medium to be stimulated. This reactivity must be determined fora complete interpretation of the acid response curves. The concept of reactivity tokes into consideration the morphology of the porous medium (grain size and shape, distribution of minerals and the dissolution rate constants of the différent mineralogical species. The effects of acid treatment are evaluated by establishing a relationship linking porosity, permeability and reactivity. This relationship is independent of the experimental conditions such as flowrate and concentration and volume of acid injected. In

  1. Modélisation des sources de bruit dans les dispositifs MOS Résumé ...

    African Journals Online (AJOL)

    AKA Boko Mathieu

    basse fréquence) et le bruit thermique. En radiofréquence le bruit en 1/f est ... Où : KF : constante dépendant de la technologie utilisée n : concentration des électrons q : la charge de l'électron. ID. : le courant du drain k : la constante de ...

  2. Systematics of constant roll inflation

    Science.gov (United States)

    Anguelova, Lilia; Suranyi, Peter; Wijewardhana, L. C. R.

    2018-02-01

    We study constant roll inflation systematically. This is a regime, in which the slow roll approximation can be violated. It has long been thought that this approximation is necessary for agreement with observations. However, recently it was understood that there can be inflationary models with a constant, and not necessarily small, rate of roll that are both stable and compatible with the observational constraint ns ≈ 1. We investigate systematically the condition for such a constant-roll regime. In the process, we find a whole new class of inflationary models, in addition to the known solutions. We show that the new models are stable under scalar perturbations. Finally, we find a part of their parameter space, in which they produce a nearly scale-invariant scalar power spectrum, as needed for observational viability.

  3. Contribution to the geochemical knowledge of the uranium-radium and thorium families in the southern Vosges. Applications of some results in the prospecting of uranium deposits; Contribution a la connaissance geochimique des familles uranium-radium et du thorium dans les Vosges meridionales. Application de certains resultats en prospection des gisements d'uranium

    Energy Technology Data Exchange (ETDEWEB)

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

    1962-07-01

    This work's aim is to lead to a more accurate knowledge of the geochemistry of the Uranium-Radium and Thorium families in the Southern Vosges and to apply some of the results to the prospecting of uraniferous deposits: It has been showed: a bond between Calcium-Magnesium and Uranium-Thorium in the calco-alkaline granites. The host minerals of Uranium and Thorium are hornblende, biotite, titanite and epidote. a concentration of Uranium, at present time with secular disequilibrium in a thermal zone where the satellite mineralizations form an epithermal paragenesis. a disequilibrium of the Uranium-Radium family in the supergene minerals of the lead (phosphate and vanadate) showing the present circulations of Uranium. a bond between the radon grade of the spring waters and Uranium-Radium of the rocks. Such a relation allow to realize a prospecting method based on the determination of radioactive gases from the cold spring-waters of a common country. (author) [French] L'etude presentee ici a pour but de conduire a une connaissance plus precise de la geochimie des familles Uranium-Radium et Thorium dans les Vosges meridionales et d'appliquer certains resultats a la prospection des gites uraniferes. Il a ete mis en evidence: une liaison Calcium-Magnesium et Uranium-Thorium dans des granites calco-alcalins. Les mineraux hotes de l'Uranium et du Thorium sont: la hornblende, la biotite, le sphene, l'epidote. une concentration actuelle de l'Uranium en desequilibre seculaire dans une zone thermale ou les mineralisations satellites constituent une paragenese epithermale. un desequilibre de la famille Uranium-Radium dans des mineraux supergenes du plomb (phosphates et vanadates) prouvant les circulations actuelles de l'Uranium. une liaison entre la teneur en Radon des eaux de sources et celle en Uranium-Radium des roches. Une telle liaison permet de realiser une methode de prospection fondee sur le dosage du gaz radioactif des eaux de sources froides d'une region quelconque

  4. Contribution to the geochemical knowledge of the uranium-radium and thorium families in the southern Vosges. Applications of some results in the prospecting of uranium deposits; Contribution a la connaissance geochimique des familles uranium-radium et du thorium dans les Vosges meridionales. Application de certains resultats en prospection des gisements d'uranium

    Energy Technology Data Exchange (ETDEWEB)

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

    1962-07-01

    This work's aim is to lead to a more accurate knowledge of the geochemistry of the Uranium-Radium and Thorium families in the Southern Vosges and to apply some of the results to the prospecting of uraniferous deposits: It has been showed: a bond between Calcium-Magnesium and Uranium-Thorium in the calco-alkaline granites. The host minerals of Uranium and Thorium are hornblende, biotite, titanite and epidote. a concentration of Uranium, at present time with secular disequilibrium in a thermal zone where the satellite mineralizations form an epithermal paragenesis. a disequilibrium of the Uranium-Radium family in the supergene minerals of the lead (phosphate and vanadate) showing the present circulations of Uranium. a bond between the radon grade of the spring waters and Uranium-Radium of the rocks. Such a relation allow to realize a prospecting method based on the determination of radioactive gases from the cold spring-waters of a common country. (author) [French] L'etude presentee ici a pour but de conduire a une connaissance plus precise de la geochimie des familles Uranium-Radium et Thorium dans les Vosges meridionales et d'appliquer certains resultats a la prospection des gites uraniferes. Il a ete mis en evidence: une liaison Calcium-Magnesium et Uranium-Thorium dans des granites calco-alcalins. Les mineraux hotes de l'Uranium et du Thorium sont: la hornblende, la biotite, le sphene, l'epidote. une concentration actuelle de l'Uranium en desequilibre seculaire dans une zone thermale ou les mineralisations satellites constituent une paragenese epithermale. un desequilibre de la famille Uranium-Radium dans des mineraux supergenes du plomb (phosphates et vanadates) prouvant les circulations actuelles de l'Uranium. une liaison entre la teneur en Radon des eaux de sources et celle en Uranium-Radium des roches. Une telle liaison permet de realiser une methode de prospection fondee sur le dosage du gaz radioactif des eaux de sources

  5. Strain fluctuations and elastic constants

    Energy Technology Data Exchange (ETDEWEB)

    Parrinello, M.; Rahman, A.

    1982-03-01

    It is shown that the elastic strain fluctuations are a direct measure of elastic compliances in a general anisotropic medium; depending on the ensemble in which the fluctuation is measured either the isothermal or the adiabatic compliances are obtained. These fluctuations can now be calculated in a constant enthalpy and pressure, and hence, constant entropy, ensemble due to recent develpments in the molecular dynamics techniques. A calculation for a Ni single crystal under uniform uniaxial 100 tensile or compressive load is presented as an illustration of the relationships derived between various strain fluctuations and the elastic modulii. The Born stability criteria and the behavior of strain fluctuations are shown to be related.

  6. Charte du Conseil des Gouverneurs

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

    Office 2004 Test Drive User

    7. favoriser des communications ouvertes et franches entre le personnel, la direction ..... de dresser le procès-verbal des réunions du Conseil et de ses comités et de veiller à ce ... et des résultats qu'il obtient, et non de sa gestion quotidienne.

  7. Development and Testing of Xanthan Products for Eor-Applications in the North Sea Développement et essais des produits à base de xanthane pour les applications de RAH en mer du Nord

    Directory of Open Access Journals (Sweden)

    Foss P.

    2006-11-01

    Full Text Available A program for development and evaluation of xanthan for use in enhanced oil recovery projects in the North Sea has been performed. Xanthan was produced using different fermentation conditions. Rheological measurements and filterability tests have been done. Xanthan products, which readily dissolve in sea water and give high viscosity and low aggregation have been produced. The fermentation process used for this type of product was scaled up from 10 litres to 20,000 litres production volume without significant changes in polymer solution properties. Un programme de développement et d'évaluation du xanthane pour utilisation dans les projets de récupération assistée des hydrocarbures en mer du Nord a été réalisé. Le xanthane est obtenu par différents procédés de fermentation. On a effectué des mesures rhéologiques et des essais de filtrabilité. Les produits à base de xanthane se dissolvent facilement dans l'eau de mer, ils donnent une forte viscosité et une faible agrégation. Avec le procédé de fermentation utilisé pour ce type de produit, on a pu faire passer la production de 10 litres à 20000 litres sans modification notable des propriétés de la solution de polymère.

  8. Le statut vitaminique des individus et des populations…

    Directory of Open Access Journals (Sweden)

    Icart Jean-Claude

    2000-05-01

    Full Text Available Comme le souligne un récent rapport du Haut comité de santé publique, le statut vitaminique des individus et des populations demeure une question d’actualité. Si les études ne révèlent plus de signes évocateurs de carence, au plus des problèmes de déficiences pour certains groupes à risque, des interrogations, demeurent malgré le contexte d’abondance, concernant la couverture des besoins, laquelle pourrait s’avérer inférieure aux valeurs considérées comme satisfaisantes.

  9. Les lueurs des sables

    CERN Multimedia

    Les lueurs des sables

    2013-01-01

    Two CERN ladies are getting ready for the “Trophée Roses des Sables” rally adventure: Julie and Laetitia are finalizing the last details before setting off on Monday 7th October 2013. Julie from EN-MEF group and Laetitia from DGS-SEE group, met at the CERN Rugby club. This year, they are participating in the 100 % female rally which will take place in Morocco from 10 to 20 October. They will be carrying along 100 kg of humanitarian donation for children such as some clothes, books and medical material. Do not hesitate to show your support at their farewell party to be held on Monday 7 October, from 4 to 6 pm in front of the St Genis-Pouilly Mairie (city Hall). Follow their exciting adventure on the blog leslueursdessables.trophee-roses-des-sables.org and on their association’s Facebook page Les Lueurs des Sables.

  10. Liste des auteurs

    OpenAIRE

    2016-01-01

    Madeleine Akrich      Ecole des Mines – Centre de Sociologie de l’innovation – Paris Noël Barbe      Association comtoise des Arts et Traditions populaires – Besançon Lucien Bernot      Ecole des hautes études en sciences sociales (EHESS) – Paris Anni Borzeix      Centre national de la recherche scientifique (CNRS) –     Groupement d’intérêt public (GIP) « Mutations industrielles » – Paris François Boudarias      Laboratoire d’Anthropologie et de sociologie de Tours (LAST) Dominique Boullier ...

  11. Multiphoton amplitude in a constant background field

    Science.gov (United States)

    Ahmad, Aftab; Ahmadiniaz, Naser; Corradini, Olindo; Kim, Sang Pyo; Schubert, Christian

    2018-01-01

    In this contribution, we present our recent compact master formulas for the multiphoton amplitudes of a scalar propagator in a constant background field using the worldline fomulation of quantum field theory. The constant field has been included nonperturbatively, which is crucial for strong external fields. A possible application is the scattering of photons by electrons in a strong magnetic field, a process that has been a subject of great interest since the discovery of astrophysical objects like radio pulsars, which provide evidence that magnetic fields of the order of 1012G are present in nature. The presence of a strong external field leads to a strong deviation from the classical scattering amplitudes. We explicitly work out the Compton scattering amplitude in a magnetic field, which is a process of potential relevance for astrophysics. Our final result is compact and suitable for numerical integration.

  12. Gestion des déchets dangereux et responsabilité sociale des firmes

    Directory of Open Access Journals (Sweden)

    Faouzi Bensebaa

    2010-10-01

    Full Text Available Prenant les déchets électriques et électroniques comme terrain d’observation, cette recherche étudie les fondements du commerce illégal de déchets dangereux des pays développés vers les PED. En effet, malgré la multiplication des législations, le problème des déchets dans les pays développés, loin d’être traité en amont, l’est en grande partie en aval par leur délocalisation dans les PED. Les deux lectures proposées, économique et institutionnelle, permettent de montrer comment les contraintes de coût de gestion des déchets dans les pays développés conjuguées à l’imperfection et à la non-application des législations conduisent à des comportements socialement irresponsables. À partir de là, l’implication des parties prenantes est suggérée comme solution pour éliminer ce type de comportements.Based on the analysis of the waste electrical and electronic equipments (WEEE, the research investigates the motivations for the illegal cross-border trade in hazardous wastes from developed countries to developing countries. Although many developed countries have implemented waste shipment regulations, they are passing the risks and costs of E-waste to developing countries. Indeed, E-waste is often sent for recycling and refurbishing in developing countries. The two-side proposed approach (i.e. economical and institutional suggests that both the cost for firms to comply with increasing regulations and the imperfect implementation of regulatory restrictions lead to socially irresponsible behaviours. An increasing and better involvement of stakeholders may be put forward as a solution.

  13. Évaluation des pratiques agricoles des légumes feuilles : le cas des ...

    African Journals Online (AJOL)

    Face à ce constat, le défi de la recherche serait la détermination du niveau actuel de contamination des légumes feuilles et des eaux du barrage et celui de l'État serait l'initiation de programmes de sensibilisation des producteurs par rapport à une gestion plus rigoureuse des pesticides. Mots-clés : pratiques paysannes, ...

  14. Universal relation between spectroscopic constants

    Indian Academy of Sciences (India)

    (3) The author has used eq. (6) of his paper to calculate De. This relation leads to a large deviation from the correct value depending upon the extent to which experimental values are known. Guided by this fact, in our work, we used experimentally observed De values to derive the relation between spectroscopic constants.

  15. Tachyon constant-roll inflation

    Science.gov (United States)

    Mohammadi, A.; Saaidi, Kh.; Golanbari, T.

    2018-04-01

    The constant-roll inflation is studied where the inflaton is taken as a tachyon field. Based on this approach, the second slow-roll parameter is taken as a constant which leads to a differential equation for the Hubble parameter. Finding an exact solution for the Hubble parameter is difficult and leads us to a numerical solution for the Hubble parameter. On the other hand, since in this formalism the slow-roll parameter η is constant and could not be assumed to be necessarily small, the perturbation parameters should be reconsidered again which, in turn, results in new terms appearing in the amplitude of scalar perturbations and the scalar spectral index. Utilizing the numerical solution for the Hubble parameter, we estimate the perturbation parameter at the horizon exit time and compare it with observational data. The results show that, for specific values of the constant parameter η , we could have an almost scale-invariant amplitude of scalar perturbations. Finally, the attractor behavior for the solution of the model is presented, and we determine that the feature could be properly satisfied.

  16. Implementation Cryptography Data Encryption Standard (DES) and Triple Data Encryption Standard (3DES) Method in Communication System Based Near Field Communication (NFC)

    Science.gov (United States)

    Ratnadewi; Pramono Adhie, Roy; Hutama, Yonatan; Saleh Ahmar, A.; Setiawan, M. I.

    2018-01-01

    Cryptography is a method used to create secure communication by manipulating sent messages during the communication occurred so only intended party that can know the content of that messages. Some of the most commonly used cryptography methods to protect sent messages, especially in the form of text, are DES and 3DES cryptography method. This research will explain the DES and 3DES cryptography method and its use for stored data security in smart cards that working in the NFC-based communication system. Several things that will be explained in this research is the ways of working of DES and 3DES cryptography method in doing the protection process of a data and software engineering through the creation of application using C++ programming language to realize and test the performance of DES and 3DES cryptography method in encrypted data writing process to smart cards and decrypted data reading process from smart cards. The execution time of the entering and the reading process data using a smart card DES cryptography method is faster than using 3DES cryptography.

  17. Simulation of land use evolution by discrete events method: Application to “la chaîne des puys” from XV to XVIII Century

    Directory of Open Access Journals (Sweden)

    Y. Michelin

    1998-01-01

    Full Text Available By using a discrete event method, simulation of land use evolution has been applied to a landscape model of “la ChaÎne des Puys” (French Massif Central during along period (XV–XVIII centuries. The indications concerning the evolution of land use are in conformity with the observation of actual situations but the dynamic changes are faster than in actual facts. In spite of limitations due to necessary simplifications, it is now established that the discrete event method is efficient to simulate land use evolution during a long period. The model is immediately able to describe actual dynamics and to show sensitive variables with their critical values. Although oversimplified, it shows how far factors such as level of crops production and taxation can influence land use and landscape changes with a more or less lengthy period. In the future, the model should be bettered by introducing other determined and/or stochastic events.

  18. Note: Determination of torsional spring constant of atomic force microscopy cantilevers: Combining normal spring constant and classical beam theory

    DEFF Research Database (Denmark)

    Álvarez-Asencio, R.; Thormann, Esben; Rutland, M.W.

    2013-01-01

    A technique has been developed for the calculation of torsional spring constants for AFM cantilevers based on the combination of the normal spring constant and plate/beam theory. It is easy to apply and allow the determination of torsional constants for stiff cantilevers where the thermal power s...... spectrum is difficult to obtain due to the high resonance frequency and low signal/noise ratio. The applicability is shown to be general and this simple approach can thus be used to obtain torsional constants for any beam shaped cantilever. © 2013 AIP Publishing LLC....

  19. Realization of an electromagnetic isotope separator. Application to the isotopes of the mass 93 from the molybdenum and the technetium; Realisation d'un separateur electromagnetique d'isotope. Application a l'etude des isotopes de masse 93 du molybdene et du technetium

    Energy Technology Data Exchange (ETDEWEB)

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

    1954-07-15

    Analysis of focusing properties of a homogeneous magnetic field leads the author to use a magnetic sector of 60 deg, for the realization of an electromagnetic separator. The sources of realized ions provide ionic debits of 10 mA. The currents ionic detached isotopes to the collector vary from 1 to 5 mA. The separation efficiency is of 125 for a current collected of 1 mA. A survey of the neutralization of the space charge permitted to specify the role of the negative ions in this phenomenon. A method of neutralization of the space charge is proposed and gave excellent results. A report will be given of the separations of some elements: mercury, bromine, thorium, etc... The application of the separator to the study of the isomeric transfers in the molybdenum and the technetium permitted to assign definitely for {sup 93}Mo and {sup 93}Tc two radiances {gamma} of respective energies 260 and 390 keV. A new process of fast chemical separation Mo/Tc is described. (author) [French] L'analyse des proprietes de focalisation d'un champ magnetique homogene conduit l'auteur, pour la realisation d'un separateur electromagnetique, a employer un secteur magnetique de 60 deg. Les sources d'ions realisees fournissent des debits ioniques de 10 mA. Les courants ioniques d'isotopes separes au collecteur varient de 1 a 5 mA. Le pouvoir separateur est de 125 pour un courant collecte de 1 mA. Une etude de la neutralisation de la charge d'espace a permis de preciser le role des ions negatifs dans ce phenomene. Une methode de neutralisation de la charge d'espace est proposee et a donne d'excellents resultats. On donne le compte rendu des separations de quelques elements: mercure, brome, thorium, etc... L'application du separateur a l'etude des translations isomeriques dans le molybdene et le technetium a permis d'attribuer definitivement a {sup 93}Mo et a {sup 93}Tc deux rayonnements {gamma} d'energies respectives 260 et 390 keV. Un nouveau procede de separation chimique rapide Mo c est

  20. Realization of an electromagnetic isotope separator. Application to the isotopes of the mass 93 from the molybdenum and the technetium; Realisation d'un separateur electromagnetique d'isotope. Application a l'etude des isotopes de masse 93 du molybdene et du technetium

    Energy Technology Data Exchange (ETDEWEB)

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

    1954-07-15

    Analysis of focusing properties of a homogeneous magnetic field leads the author to use a magnetic sector of 60 deg, for the realization of an electromagnetic separator. The sources of realized ions provide ionic debits of 10 mA. The currents ionic detached isotopes to the collector vary from 1 to 5 mA. The separation efficiency is of 125 for a current collected of 1 mA. A survey of the neutralization of the space charge permitted to specify the role of the negative ions in this phenomenon. A method of neutralization of the space charge is proposed and gave excellent results. A report will be given of the separations of some elements: mercury, bromine, thorium, etc... The application of the separator to the study of the isomeric transfers in the molybdenum and the technetium permitted to assign definitely for {sup 93}Mo and {sup 93}Tc two radiances {gamma} of respective energies 260 and 390 keV. A new process of fast chemical separation Mo/Tc is described. (author) [French] L'analyse des proprietes de focalisation d'un champ magnetique homogene conduit l'auteur, pour la realisation d'un separateur electromagnetique, a employer un secteur magnetique de 60 deg. Les sources d'ions realisees fournissent des debits ioniques de 10 mA. Les courants ioniques d'isotopes separes au collecteur varient de 1 a 5 mA. Le pouvoir separateur est de 125 pour un courant collecte de 1 mA. Une etude de la neutralisation de la charge d'espace a permis de preciser le role des ions negatifs dans ce phenomene. Une methode de neutralisation de la charge d'espace est proposee et a donne d'excellents resultats. On donne le compte rendu des separations de quelques elements: mercure, brome, thorium, etc... L'application du separateur a l'etude des translations isomeriques dans le molybdene et le technetium a permis d'attribuer definitivement a {sup 93}Mo et a {sup 93}Tc deux rayonnements {gamma} d'energies respectives 260 et 390

  1. Connaissance des pharmaciens d'officine à propos du droit de prescription des sages-femmes

    OpenAIRE

    Gache, Brune

    2012-01-01

    Introduction : La profession de sage-femme est une profession médicale à compétences définies. L'une d'entre elles nous intéresse particulièrement : le droit de prescription. Nous avons voulu évaluer les connaissances des pharmaciens d'officine, principaux intéressés de la mise en application de cette compétence. Matériel et méthode : L'objectif de ce travail de recherche était d'évaluer les connaissances des pharmaciens d'officine à propos du droit de prescription des sages-femmes ainsi que ...

  2. The Technology and Applications of Large Fission Product Beta Sources; Technologie et applications des grandes sources beta de fission; Tekhnologiya i primenenie krupnykh istochnikov beta-izluchenij, ispuskaemykh produktami deleniya; Tecnologia y utilizacion de los productos de fision como fuentes de irradiacion beta de elevada intensidad

    Energy Technology Data Exchange (ETDEWEB)

    Silverman, Joseph [Radiation Applications Incorporated (United States)

    1960-07-15

    test the validity of the calculations. 4. An engineering cost analysis indicates that fission product beta power can be competitive with alternative sources of radiation. (author) [French] Si les emetteurs beta ne sont pas entres en ligne de compte en tant que sources de rayonnement de grandes dimensions, c'est que dans le passe les procedes sous irradiation presentant un interet pour l'industrie etaient bases sur l'utilisation de particules a grand pouvoir de penetration; de la l'importance considerable que l'on accordait aux rayons gamma et aux electrons artificiellement acceleres. Il y a environ quatre ans, il devint evident que de vastes perspectives s'ouvraient aux applications pratiques des rayonnements beta dans le domaine du traitement par irradiation superficielle, par exemple, la modification par copolymerisation greffee de la surface des moulages en matiere plastique et la pasteurisation superficielle des aliments. En effet, l'irradiation en profondeur occasionne dans ces cas des pertes et peut meme presenter des dangers. D'autre part, il y a deux autres domaines dans lesquels l'utilisation des electrons artificiellement acceleres ne semble pas indiquee; ce sont les syntheses chimiques amorcees par irradiation dans des cuves sous pression et certaines categories de reactions en chaine provoquees par des radicaux libres pour lesquels le taux de production par kilowatt decroit en fonction de la racine carree de l'intensite d'irradiation. Dans tous ces domaines, les sources beta de grandes dimensions presentent des avantages potentiels evidents; puisque la fission nucleaire permet d'en obtenir en quantites importantes, elles meritent que leurs- possibilites d'utilisation fassent l'objet d'un examen approfondi. Compte tenu de ces considerations, on a procede - sous l'egide de la Commission de l'energie atomique - a une etude des applications'et de la technologie des sources beta de fission. Cette etude a permis d'aboutir aux conclusions suivantes: 1. Des

  3. Use of geothermal heat by means of energetic geostructures. Methodology to identify potential zones of application; Exploitation de la chaleur terrestre par des geostructures energetiques. Methodologie de determination des zones potentielles

    Energy Technology Data Exchange (ETDEWEB)

    Joliquin, P.

    2002-07-01

    This study focuses on the realisation of earth heat exchangers by means of so-called geostructures. These geostructures are works of concrete being in close contact with the ground and which are used for foundation or as retaining structures. The three main types of geostructures are piles, the walls and the foundation slabs. These structures can be equipped with a network of tubes where a liquid circulates to permit a heat exchange with the ground. In this case, they can be called energetic geostructures. To date, the use of this technology is rather limited in Switzerland. Therefore, the aim of this study is to increase its development, and a methodology to identify potential zones of application will be given for the purpose of energy planning. The correct land planning and the geotechnical properties of the ground are the two basic criteria to select the type of geostructure and its foundation conditions. Additional criteria like the thermal properties of the ground and the presence of groundwater will determine whether geostructures can be equipped with heat exchangers. Finally, the protection of the groundwater and thermal ground disturbances are possible criteria which could limit the application of energetic geostructures. To validate this methodology, six sites were selected in the canton of Geneva. Two of them ('La Chapelle - Les Sciers' and 'Frontenex - Gradelle'), were investigated by applying the above mentioned criteria. The conclusion is that the two sites represent potential zones for using energetic geostructures. Nevertheless, within the site 'La Chapelle - Les Sciers', the presence of an important groundwater resource was identified. To protect it, it is not permitted to pierce the impermeable layer above the aquifer, and therefore foundation depths must carefully be chosen by controlling the lengths of piles. (author)

  4. REPRISE DES COURS - Yoga

    CERN Multimedia

    Club de Yoga

    2015-01-01

    REPRISE DES COURS – Venez nombreux ! Yoga, Sophrologie, Tai Chi La liste des cours pour le semestre allant du 1er septembre 2015 au 31 janvier 2016 est disponible sur notre site web : http://club-yoga.web.cern.ch Lieu Les cours ont lieu dans la salle des clubs, à l’entresol du restaurant No 2, Bât. 504 (dans la salle no 3 pour la Sophrologie). Prix des cours Le prix pour le semestre (environ 18 leçons) est fixé à 220 CHF plus 10 CHF d’adhésion annuelle au Club. Couple : 200 CHF par personne. 2 cours par semaine : 400 CHF. Inscriptions Les inscriptions aux cours seront prises directement auprès du professeur, lors de la 1ère séance. Avant de s’inscrire pour le semestre, il est possible d’essayer une séance gratuitement. Informations : http://club-yoga.web.cern.ch ----------------------------------------- cern.ch/club-yoga/

  5. Praxis des Klebens

    CERN Document Server

    Theuerkauff, Petra

    1989-01-01

    Bei diesem Buch handelt es sich um einen Leitfaden fur Klebepraktiker. Es werden die verschiedenen Einzelschritte beim kleben beschrieben, als auch die vorbereitenden Massnahmen und anschliessenden Prufverfahren auf Festigkeit behandelt. Das Buch sollte an keinem Arbeitsplatz fehlen, wo man sich mit Problemen der Fugetechnik des Klebens beschaftigt.

  6. Dimensions des stabulations 2018

    OpenAIRE

    Früh, Barbara; Maurer, Veronika; Schneider, Claudia; Schürmann, Stefan; Spengler Neff, Anet; Werne, Steffen

    2018-01-01

    Les «Dimensions des stabulations» contiennent toutes les dimensions pour les stabulations et les parcours pour la production animale en agriculture biologique. Cette liste sert d’instrument de planification pour les éleveurs, d’outil de travail pour la vulgarisation et d’ouvrage de référence pour le contrôle bio.

  7. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    économique des services rendus par les écosystèmes marins. La richesse ... croissance plus rapide que la moyenne de l‟économie ...... services and natural capital. Nature. 387, 253-260. .... d‟interactions où l‟humain est partie prenante. In.

  8. La physique des infinis

    CERN Document Server

    Bernardeau, Francis; Laplace, Sandrine; Spiro, Michel

    2013-01-01

    Écrire l'histoire de l'Univers, tel est l'objectif commun des physiciens des particules et des astrophysiciens. Pour y parvenir, deux approches s'épaulent : la voie de l'infiniment petit, que l'on emprunte via de gigantesques accélérateurs de particules, et celle de l'infiniment grand, dont le laboratoire est l'Univers. Un Univers qui est bien loin d'avoir livré tous ses secrets. On connaît à peine 4,8 % de la matière qui le constitue, le reste étant composé de matière noire (25,8 %) et d'énergie noire (69,4 %), toutes deux de nature inconnue. Et si la récente découverte du boson de Higgs valide le Modèle standard de la physique des particules, celui-ci est toujours incomplet et doit être étendu à ou dépassé. Est-on arrivé au bout du jeu de poupées russes de la matière ? Quelles sont les particules manquantes ? Faut-il revoir les lois fondamentales ? Quels instruments faut-il mettre en œuvre pour accéder à cette « nouvelle physique » ? Comment parler de Super Big Science aux citoye...

  9. Evolution of the solar constant

    International Nuclear Information System (INIS)

    Newman, M.J.

    1978-01-01

    The ultimate source of the energy utilized by life on Earth is the Sun, and the behavior of the Sun determines to a large extent the conditions under which life originated and continues to thrive. What can be said about the history of the Sun. Has the solar constant, the rate at which energy is received by the Earth from the Sun per unit area per unit time, been constant at its present level since Archean times. Three mechanisms by which it has been suggested that the solar energy output can vary with time are discussed, characterized by long (approx. 10 9 years), intermediate (approx. 10 8 years), and short (approx. years to decades) time scales

  10. Calculation of magnetic hyperfine constants

    International Nuclear Information System (INIS)

    Bufaical, R.F.; Maffeo, B.; Brandi, H.S.

    1975-01-01

    The magnetic hyperfine constants of the V sub(K) center in CaF 2 , SrF 2 and BaF 2 have been calculated assuming a phenomenological model, based on the F 2 - 'central molucule', to describe the wavefunction of the defect. Calculations have shown that introduction of a small degree of covalence, between this central molecule and neighboring ions, is necessary to improve the electronic structure description of the defect. It was also shown that the results for the hyperfine constants are strongly dependent on the relaxations of the ions neighboring the central molecule; these relaxations have been determined by fitting the experimental data. The present results are compared with other previous calculations where similar and different theoretical methods have been used

  11. On the gravitational constant change

    International Nuclear Information System (INIS)

    Milyukov, V.K.

    1986-01-01

    The nowadays viewpoint on the problem of G gravitational constant invariability is presented in brief. The methods and results of checking of the G dependence on the nature of substance (checking of the equivalence principle), G dependepce on distance (checking of Newton gravity law) and time (cosmological experiments) are presented. It is pointed out that all performed experiments don't give any reasons to have doubts in G constancy in space and time and G independence on the nature of the substance

  12. Photodissociation constant of NO2

    International Nuclear Information System (INIS)

    Nootebos, M.A.; Bange, P.

    1992-01-01

    The velocity of the dissociation of NO 2 into ozone and NO mainly depends on the ultraviolet sunlight quantity, and with that the cloudiness. A correct value for this reaction constant is important for the accurate modelling of O 3 - and NO 2 -concentrations in plumes of electric power plants, in particular in the case of determination of the amount of photochemical summer smog. An advanced signal processing method (deconvolution, correlation) was applied on the measurements. The measurements were carried out from aeroplanes

  13. Screening phytochimique et identification spectroscopique des ...

    African Journals Online (AJOL)

    Origin

    plante, effectuée pour la première fois, a révélé la présence des alcaloïdes, des flavonoïdes, des tanins catéchiques, des terpènes, des coumarines et des composés cyanogénétiques. Quant aux saponines et les quinones libres, ils sont présents chez les fleurs et absents chez les feuilles. La caractérisation des molécules.

  14. Mass spectrometer introduction line: application to the analysis of impurities in uranium hexafluoride; Ligne d'introduction pour spectrometre de masse: application a l'analyse des impuretes contenues dans l'UF{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Besson, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires. Departement de physico-chimie, service des isotopes stables, section de spectrometrie de masse

    1967-01-01

    The continuous mass-spectrometric analysis of impurities in UF{sub 6} is possible industrially if certain conditions imposed by the nature of the gas are respected. The gas introduction line arriving at the spectrometer's source makes it possible to fix the flow-rate, to control the inlet pressure and to selectively destroy the gas containing the impurities. The operational conditions for the line are defined and a description is given of the theoretical and experimental study of the various elements of which it is composed, i.e. the leak valve, the flow-meter, the chemical trap and the servo-mechanism making it possible to regulate and control the gas flow. The dynamic characteristics of the line's various components and the performance of the equipment in the case of the analyses considered are given. (author) [French] L'analyse en continu par spectrometrie de masse des impuretes contenus dans l'UF{sub 6} est possible industriellement moyennant certaines conditions imposees par la nature du gaz. La ligne d'introduction des gaz dans la source du spectrometre permet de regler le debit, de controler la pression d'introduction et de detruire selectivement le gaz porteur d'impuretes. Les conditions de fonctionnement de la ligne etant definies, on decrit l'etude theorique et experimentale des differents elements qui la composent, c'est-a-dire: le robinet a fuite, le debitmetre, le piege chimique et l'ensemble d'asservissement permettant la regulation et le controle du debit. On donne les caracteristiques dynamiques des differents constituants de la ligne et les performances de l'ensemble pour les analyses considerees. (auteur)

  15. Mass spectrometer introduction line: application to the analysis of impurities in uranium hexafluoride; Ligne d'introduction pour spectrometre de masse: application a l'analyse des impuretes contenues dans l'UF{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Besson, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires. Departement de physico-chimie, service des isotopes stables, section de spectrometrie de masse

    1967-01-01

    The continuous mass-spectrometric analysis of impurities in UF{sub 6} is possible industrially if certain conditions imposed by the nature of the gas are respected. The gas introduction line arriving at the spectrometer's source makes it possible to fix the flow-rate, to control the inlet pressure and to selectively destroy the gas containing the impurities. The operational conditions for the line are defined and a description is given of the theoretical and experimental study of the various elements of which it is composed, i.e. the leak valve, the flow-meter, the chemical trap and the servo-mechanism making it possible to regulate and control the gas flow. The dynamic characteristics of the line's various components and the performance of the equipment in the case of the analyses considered are given. (author) [French] L'analyse en continu par spectrometrie de masse des impuretes contenus dans l'UF{sub 6} est possible industriellement moyennant certaines conditions imposees par la nature du gaz. La ligne d'introduction des gaz dans la source du spectrometre permet de regler le debit, de controler la pression d'introduction et de detruire selectivement le gaz porteur d'impuretes. Les conditions de fonctionnement de la ligne etant definies, on decrit l'etude theorique et experimentale des differents elements qui la composent, c'est-a-dire: le robinet a fuite, le debitmetre, le piege chimique et l'ensemble d'asservissement permettant la regulation et le controle du debit. On donne les caracteristiques dynamiques des differents constituants de la ligne et les performances de l'ensemble pour les analyses considerees. (auteur)

  16. Processing of data issued from {gamma} spectrometer. Application to the study of decay schemes; Traitement des informations issues d'un spectrometre {gamma}. Application a l'etude de schemas de desintegration

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-07-01

    The main purpose of the following report is the study of a generation method of {gamma} spectra corresponding to any energy, from a library of some basic spectra. Then we point out how to establish the decay scheme of a radio-nuclide, in using an accurate analysis of full-energy peaks which appear in its complex spectrum, followed by a generation of plain spectra corresponding to the energies of the different transitions, and ending with a least-squares fitting procedure of the complex spectrum. The accuracy of the process is examined comparing the calculated spectra to the ones issued from two kinds of spectrometers (Na I(Tl) and Ge(Li)). The method is then applied to the study of {sup 134}Cs and {sup 95}Zr - {sup 95}Nb. (authors) [French] Le present rapport a pour principal objet l'etude d'une methode de generation de spectres {gamma} correspondant a n'importe quelle energie, a partir d'une bibliotheque de quelques spectres de reference. On montre ensuite comment on peut etablir le schema de desintegration d'un radionucleide, a l'aide d'une analyse precise des pics d'absorption totale apparaissant dans son spectre complexe, suivie d'une generation des spectres simples correspondant aux energies des diverses transitions, et en terminant par une decomposition du spectre complexe par la methode des moindres carres. On examine la validite du procede en comparant les spectres calcules a ceux obtenus avec deux types de detecteurs (scintillateurs et semi-conducteurs). On applique alors la methode a l'etude du {sup 134}Cs et du {sup 95}Zr - {sup 95}Nb. (auteurs)

  17. Efficacité des néonicotinoïdes et des pyréthrinoïdes utilisés contre le ...

    African Journals Online (AJOL)

    Efficacité des néonicotinoïdes et des pyréthrinoïdes utilisés contre le foreur des tiges du cacaoyer ( Eulophonotus myrmeleon Felder : Lepidoptera, Cossidae). Implications dans la stratégie de protection de la cacaoculture en Côte d'Ivoire.

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

    Science.gov (United States)

    Dolez, Patricia

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

  19. Fine-structure constant: Is it really a constant

    International Nuclear Information System (INIS)

    Bekenstein, J.D.

    1982-01-01

    It is often claimed that the fine-structure ''constant'' α is shown to be strictly constant in time by a variety of astronomical and geophysical results. These constrain its fractional rate of change alpha-dot/α to at least some orders of magnitude below the Hubble rate H 0 . We argue that the conclusion is not as straightforward as claimed since there are good physical reasons to expect alpha-dot/α 0 . We propose to decide the issue by constructing a framework for a variability based on very general assumptions: covariance, gauge invariance, causality, and time-reversal invariance of electromagnetism, as well as the idea that the Planck-Wheeler length (10 -33 cm) is the shortest scale allowable in any theory. The framework endows α with well-defined dynamics, and entails a modification of Maxwell electrodynamics. It proves very difficult to rule it out with purely electromagnetic experiments. In a cosmological setting, the framework predicts an alpha-dot/α which can be compatible with the astronomical constraints; hence, these are too insensitive to rule out α variability. There is marginal conflict with the geophysical constraints: however, no firm decision is possible because of uncertainty about various cosmological parameters. By contrast the framework's predictions for spatial gradients of α are in fatal conflict with the results of the Eoetvoes-Dicke-Braginsky experiments. Hence these tests of the equivalence principle rule out with confidence spacetime variability of α at any level

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-02-01

    The purification of uranium has been achieved by zone melting. Because of the high affinity of uranium towards elements such as oxygen, contamination has been avoided by adopting the floating zone technique and by working under high vacuum. The difficulties created by the deformations of uranium rod, which are caused by anisotropy of dilatation of phases {alpha} and {beta} and allotropic transformations {alpha} {r_reversible} {beta} and {beta} {r_reversible} {alpha}, have been overcome by the use of electron bombardment stabilized by feedback. A rough control of the purification was obtained by micrographic examination, microhardness measurements, and tests of secondary recrystallization, allowed us to appreciate the new degree of purity of the uranium obtained. The investigation of the purity degree was pursued by electrical resistivity measurements at 20 deg. K. But one had to take care in the interpretation of those measurements of the anisotropy of the uranium resistivity and the influence of structure on residual resistivity. Those measurements have led us, by determination of single crystal and uranium resistivity, to be able to distinguish between the principal resistivity against axis [100] and [010]. (author) [French] La purification de l'uranium a ete realisee par l'application de la methode dite de la zone fondue. L'uranium etant particulierement reactif vis-a-vis d'elements tels que l'oxygene, les risques de contamination ont ete supprimes en adoptant la technique de la zone flottante et en operant sous vide eleve. Les difficultes creees par les deformations du barreau d'uranium, dues a l'anisotropie de dilatation des phases {alpha} et {beta} et ou passage des deux points de transformation allotropiques {alpha} {r_reversible} {beta} et {beta} {r_reversible} {alpha}, ont pu etre surmontees par l'emploi du chauffage par bombardement electronique, stabilise par un systeme tres simple de contre reaction. Un premier controle de la purification effectue par

  1. La gestion des résultats des entreprises innovantes

    OpenAIRE

    Dumas, Guillaume

    2014-01-01

    Cette thèse s’intéresse à la gestion des résultats dans le cadre des entreprises innovantes. Elle est constituée de trois articles. Dans le premier, il s’agit d’examiner si les résultats des entreprises innovantes sont gérés et si le stade de développement des innovations influence cette gestion des résultats. Il apparaît que les résultats des entreprises innovantes sont gérés à la hausse. Cette gestion ne semble intervenir qu’au cours de l’activité d’innovation (c’est-à-dire lorsque les entr...

  2. Evaluation de l'efficacité vis-à-vis du ruissellement de surface et des transferts latéraux dans le sol de différentes options de gestion utilisant (ou non) un couvert enherbé : Application en vue de limiter la contamination des eaux par les pesticides dans le contexte du Beaujolais viticole de coteaux

    OpenAIRE

    Gouy, V.; Peyrard, X.; Liger, L.

    2015-01-01

    / Cette étude apporte des éléments de réponse aux questions suivantes dans le contexte du Nord Beaujolais : - dans quelle mesure une zone tampon enherbée rivulaire recevant un ruissellement concentré de surface est-elle capable de réduire significativement le transfert des pesticides associés sans engendrer une contamination de nappe sous-jacente ? - dans quelle mesure une infiltration en amont en parcelle de vigne peut-elle contribuer à l'atténuation des transferts de pesticides ou engendrer...

  3. Inverse method for effects characterization from ultrasonic b-scan images; Caracterisation des defauts par une methode d'inversion lors d'un controle ultrasonore. Application au controle des defauts en paroi externe

    Energy Technology Data Exchange (ETDEWEB)

    Faur, M. [Paris-11 Univ., 91 - Orsay (France)

    1999-02-01

    In service inspections of French nuclear pressure water reactor vessels are carried out automatically in complete immersion from the inside by means of ultrasonic focused probes working in the pulse echo mode. Concern has been expressed about the capabilities of performing non destructive evaluation of the Outer Surface Defects (OSD), i.e. defects located in the vicinity of the outer surface of the inspected components. OSD are insonified by both a direct field that passes through the inner surface (water/steel) of the component containing the defect and a secondary field reflected from the outer surface. Consequently, the Bscan images, containing the signatures of such defects, are complicated and their interpretation is a difficult task. This work deals with extraction of the maximum available information for characterizing OSD from ultrasonic Bscan images. Our main objectives are to obtain the type of OSD and their geometric parameters by means of two specific inverse methods. The first method is used for the identification of the geometrical parameters of the equivalent planar OSD from segmented Bscan images. Ultrasonic equivalent defect sizing model-based methods may be used to size a defect in a material by obtaining a best-fit simple equivalent shape that matches the ultrasonic observed data. We illustrate the application of such an equivalent sizing OSD method that is based on a simplified direct model. The major drawback of this identification method, as used to date, is that only a part of the useful information contained into original Bscan image, i.e. segmented Bscan image, is used for defect characterization. Moreover, it requires the availability of defect classification information (i.e. if the defect is volumetric or planer, e. g. a crack or a lack of fusion), which, generally, may be as difficult to obtain as the defect parameters themselves. Therefore, we propose a parameter estimation method for extracting complementary information on the defect

  4. Safeguards Implementation Guide for States with Small Quantities Protocols (French Edition); Guide d'application des garanties pour les Etats ayant des protocoles relatifs aux petites quantites de matieres

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-10-15

    The International Atomic Energy Agency (IAEA) works to enhance the contribution of nuclear energy for peace and prosperity around the world, while helping to ensure that nuclear material is not diverted to nuclear weapons or other nuclear explosive devices. In implementing safeguards, the IAEA plays an instrumental independent verification role, providing credible assurances that States' safeguards commitments are being respected. Most of the world's non-nuclear-weapon States (NNWSs) have concluded comprehensive safeguards agreements (CSAs) with the IAEA, pursuant to the Treaty on the Non- Proliferation of Nuclear Weapons (NPT). The IAEA and States are required to cooperate in the implementation of such agreements. Effective cooperation demonstrates a State's commitment to the peaceful use of nuclear energy and furthers the State's national interests by reducing the risk of unauthorized use of nuclear material. Over 100 NNWSs party to the NPT have very limited quantities of nuclear material and have concluded protocols to their CSAs which hold in abeyance many procedures in Part II of a CSA. These protocols are referred to as 'small quantities protocols' or 'SQPs' and remain in effect as long as the State meets certain eligibility criteria. The purpose of an SQP is to reduce the burden of safeguards implementation for States with little or no nuclear activities, while retaining the integrity of the safeguards system. States with SQPs have very important obligations they must fulfil under their CSAs. In 1997, as part of the IAEA's efforts to strengthen its safeguards system, the Model Additional Protocol to the Agreement(s) between State(s) and the International Atomic Energy Agency for the Application of Safeguards was developed to provide the IAEA with broader access to information and locations, thus significantly increasing the IAEA's ability to provide assurance of the absence of undeclared nuclear material and activities in States. Many States with SQPs have

  5. Detection of {alpha} particles using semiconductors. Application to the control of plutonium extraction; Detection des particules {alpha} par semiconducteurs application au controle de l'extraction du plutonium

    Energy Technology Data Exchange (ETDEWEB)

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

    1968-03-01

    A study is made of a particles produced by thick sources, using either diffused junction or surface barrier semiconductor detectors for controlling continuously the plutonium extraction process. For this, a presenting apparatus is described in which the solutions to be analyzed flow in contact with the detector protected by a thin mica membrane. A method is described which gives a precise recording of the spectra and which thus allows the separation of two or more {alpha} emitters present in the same solution. This method has been applied to the measurement of {sup 239}Pu in the the presence of {sup 241}Am with an accuracy of {+-}5 per cent. In the second part of the report is considered the detection of plutonium in solutions of {beta} - {gamma} emitting fission products. Pile-up is reduced by using a fast amplification chain associated to totally depleted thin detectors. Under these conditions a few mg of {sup 239}Pu can be detected in solutions of fission products having an activity of 100 curies/liter. A method is given for discriminating {alpha} and {beta} particles, it is based on the difference in the collection times for the charges liberated by these particles in the detector. (author) [French] On etudie la detection de particules {alpha} issues de sources epaisses par detecteurs semiconducteurs a jonction diffusee ou a barriere de surface pour le controle continu du procede d'extraction du plutonium. A cet effet on decrit un appareil presentateur dans lequel les solutions a analyser circulent au contact du detecteur protege par une membrane mince de mica. On decrit une methode qui permet par le trace precis des spectres de separer deux ou plusieurs emetteurs {alpha} presents dans une meme solution. Cette methode a ete appliquee a la mesure du {sup 239}Pu en presence de {sup 241}Am avec une precision de {+-} 5 pour cent. Dans la deuxieme partie on traite de la detection du plutonium dans des solutions de produits de fission emetteurs {beta} and {gamma

  6. Des dispositions responsables à prendre pour la protection des ...

    African Journals Online (AJOL)

    En considérant l'effet néfaste des maladies, des parasites, du changement climatique et d'autres facteurs environnementaux (les OGM par exemple) sur la survie des abeilles, la baisse de leurs populations dans certaines parties du monde ne saurait être attribuée aux seules pesticides. En plus, l'impact de ces derniers sur ...

  7. Aspects des Onychomycoses chez des patients camerounais de ...

    African Journals Online (AJOL)

    ... biologiques et évolutifs des onychomycoses chez des patients camerounais. Méthode : Il s'agit d'une étude rétrospective et descriptive menée de mars 2011 à mars 2014 dans l'unité de dermatologie de l'hôpital général de Douala (HGD), incluant des patients chez lesquels le diagnostic d'onychomycose avait été posé.

  8. Advances in constant-velocity Moessbauer instrumentation

    International Nuclear Information System (INIS)

    Veiga, A.; Martinez, N.; Zelis, P. Mendoza; Pasquevich, G. A.; Sanchez, F. H.

    2006-01-01

    A prototype of a programmable constant-velocity scaler is presented. This instrument allows the acquisition of partial Moessbauer spectra in selected energy regions using standard drivers and transducers. It can be fully operated by a remote application, thus data acquisition can be automated. The instrument consists of a programmable counter and a constant-velocity reference. The reference waveform generator is amplitude modulated with 13-bit resolution, and is programmable in a wide range of frequencies and waveforms in order to optimize the performance of the transducer. The counter is compatible with most standard SCA, and is configured as a rate-meter that provides counts per selectable time slice at the programmed velocity. As a demonstration of the instrument applications, a partial Moessbauer spectrum of a natural iron foil was taken. Only positive energies were studied in 512 channels, accumulating 20 s per channel. A line width of 0.20 mm/s was achieved, performing with an efficiency of 80%.

  9. Neutron spin echo spectroscopy. Its application to the study of the dynamics of polymers in solution; La spectrometrie par echos de spins de neutrons. Application a l'etude de la dynamique des polymeres en solution

    Energy Technology Data Exchange (ETDEWEB)

    Papoular, Robert

    1992-06-15

    This work focuses on Neutron Spin Echo (NSE) spectroscopy and on the NSE spectrometer MESS, which we have built at the L.L.B. (CE Saclay). After analyzing in detail the classical and quantum principles of this type of instrument, and illustrated them with optical analogies, we expound a simple formalism for the interpretation of polarized neutron experiments of the most general type. In a second part, we describe the MESS spectrometer extensively; its characteristics and performances as well as the first results obtained with this instrument. In particular, we include two papers showing how the neutron depolarization, spin rotation and echoes can be used to investigate high-Tc superconductors. The last part deals with the dynamics of Polymer-Polymer-Solvent ternary solutions and demonstrates how the Neutron Spin Echo technique becomes a privileged tool for such physico-chemical studies thanks to the joint use of NSE and contrast variation methods, coupled with the adequate ranges of time and scattering vectors accessible. Finally, we describe the specific case of partially deuterated polydimethyl-siloxane (PDMS) in semi-dilute solution in Toluene. We have experimentally and separately evidenced the cooperative and inter-diffusive diffusion modes predicted by the theory of Akcasu, Benoit, Benmouna et al. These results, obtained at the L.L.B. (CE Saclay) are the subject matter of the last paper included in this work. (author) [French] Ce memoire est centre sur la spectroscopie par echos de spins de neutrons, et plus particulierement, sur le spectrometre a echos de spins MESS que nous avons construit au L.L.B (CE/Saclay). Apres avoir detaille les principes classique et quantique de ce type d'instrument et les avoir illustres par des analogies optiques, nous detaillons un formalisme simple permettant d'interpreter les experiences utilisant les neutrons polarises dans le cas le plus general. Une seconde partie decrit de maniere approfondie le spectrometre MESS de Saclay

  10. Chandra Independently Determines Hubble Constant

    Science.gov (United States)

    2006-08-01

    A critically important number that specifies the expansion rate of the Universe, the so-called Hubble constant, has been independently determined using NASA's Chandra X-ray Observatory. This new value matches recent measurements using other methods and extends their validity to greater distances, thus allowing astronomers to probe earlier epochs in the evolution of the Universe. "The reason this result is so significant is that we need the Hubble constant to tell us the size of the Universe, its age, and how much matter it contains," said Max Bonamente from the University of Alabama in Huntsville and NASA's Marshall Space Flight Center (MSFC) in Huntsville, Ala., lead author on the paper describing the results. "Astronomers absolutely need to trust this number because we use it for countless calculations." Illustration of Sunyaev-Zeldovich Effect Illustration of Sunyaev-Zeldovich Effect The Hubble constant is calculated by measuring the speed at which objects are moving away from us and dividing by their distance. Most of the previous attempts to determine the Hubble constant have involved using a multi-step, or distance ladder, approach in which the distance to nearby galaxies is used as the basis for determining greater distances. The most common approach has been to use a well-studied type of pulsating star known as a Cepheid variable, in conjunction with more distant supernovae to trace distances across the Universe. Scientists using this method and observations from the Hubble Space Telescope were able to measure the Hubble constant to within 10%. However, only independent checks would give them the confidence they desired, considering that much of our understanding of the Universe hangs in the balance. Chandra X-ray Image of MACS J1149.5+223 Chandra X-ray Image of MACS J1149.5+223 By combining X-ray data from Chandra with radio observations of galaxy clusters, the team determined the distances to 38 galaxy clusters ranging from 1.4 billion to 9.3 billion

  11. Cryptography in constant parallel time

    CERN Document Server

    Applebaum, Benny

    2013-01-01

    Locally computable (NC0) functions are 'simple' functions for which every bit of the output can be computed by reading a small number of bits of their input. The study of locally computable cryptography attempts to construct cryptographic functions that achieve this strong notion of simplicity and simultaneously provide a high level of security. Such constructions are highly parallelizable and they can be realized by Boolean circuits of constant depth.This book establishes, for the first time, the possibility of local implementations for many basic cryptographic primitives such as one-way func

  12. Low power constant fraction discriminator

    International Nuclear Information System (INIS)

    Krishnan, Shanti; Raut, S.M.; Mukhopadhyay, P.K.

    2001-01-01

    This paper describes the design of a low power ultrafast constant fraction discriminator, which significantly reduces the power consumption. A conventional fast discriminator consumes about 1250 MW of power whereas this low power version consumes about 440 MW. In a multi detector system, where the number of discriminators is very large, reduction of power is of utmost importance. This low power discriminator is being designed for GRACE (Gamma Ray Atmospheric Cerenkov Experiments) telescope where 1000 channels of discriminators are required. A novel method of decreasing power consumption has been described. (author)

  13. Can coupling constants be related

    International Nuclear Information System (INIS)

    Nandi, Satyanarayan; Ng, Wing-Chiu.

    1978-06-01

    We analyze the conditions under which several coupling constants in field theory can be related to each other. When the relation is independent of the renormalization point, the relation between any g and g' must satisfy a differential equation as follows from the renormalization group equations. Using this differential equation, we investigate the criteria for the feasibility of a power-series relation for various theories, especially the Weinberg-Salam type (including Higgs bosons) with an arbitrary number of quark and lepton flavors. (orig./WL) [de

  14. Exact constants in approximation theory

    CERN Document Server

    Korneichuk, N

    1991-01-01

    This book is intended as a self-contained introduction for non-specialists, or as a reference work for experts, to the particular area of approximation theory that is concerned with exact constants. The results apply mainly to extremal problems in approximation theory, which in turn are closely related to numerical analysis and optimization. The book encompasses a wide range of questions and problems: best approximation by polynomials and splines; linear approximation methods, such as spline-approximation; optimal reconstruction of functions and linear functionals. Many of the results are base

  15. Hydrodynamic constants from cosmic censorship

    International Nuclear Information System (INIS)

    Nakamura, Shin

    2008-01-01

    We study a gravity dual of Bjorken flow of N=4 SYM-theory plasma. We point out that the cosmic censorship hypothesis may explain why the regularity of the dual geometry constrains the hydrodynamic constants. We also investigate the apparent horizon of the dual geometry. We find that the dual geometry constructed on Fefferman-Graham (FG) coordinates is not appropriate for examination of the apparent horizon since the coordinates do not cover the trapped region. However, the preliminary analysis on FG coordinates suggests that the location of the apparent horizon is very sensitive to the hydrodynamic parameters. (author)

  16. Usages des TIC et socialisation professionnelle des enseignants-chercheurs

    OpenAIRE

    Lavielle-Gutnik, Nathalie; Massou, Luc

    2013-01-01

    En prenant appui sur une nouvelle analyse des données recueillies dans l’enquête Tec-Meus (2008-2011, MSH Lorraine) sur la place accordée par des enseignants-chercheurs en sciences humaines et sociales aux technologies de l’information et de la communication (TIC) dans leur activité d’enseignement, nous souhaitons nous focaliser dans cet article sur la compréhension des processus de socialisation professionnelle en jeu dans leur usage déclaré des TIC. Par socialisation professionnelle, nous e...

  17. Relaxing a large cosmological constant

    International Nuclear Information System (INIS)

    Bauer, Florian; Sola, Joan; Stefancic, Hrvoje

    2009-01-01

    The cosmological constant (CC) problem is the biggest enigma of theoretical physics ever. In recent times, it has been rephrased as the dark energy (DE) problem in order to encompass a wider spectrum of possibilities. It is, in any case, a polyhedric puzzle with many faces, including the cosmic coincidence problem, i.e. why the density of matter ρ m is presently so close to the CC density ρ Λ . However, the oldest, toughest and most intriguing face of this polyhedron is the big CC problem, namely why the measured value of ρ Λ at present is so small as compared to any typical density scale existing in high energy physics, especially taking into account the many phase transitions that our Universe has undergone since the early times, including inflation. In this Letter, we propose to extend the field equations of General Relativity by including a class of invariant terms that automatically relax the value of the CC irrespective of the initial size of the vacuum energy in the early epochs. We show that, at late times, the Universe enters an eternal de Sitter stage mimicking a tiny positive cosmological constant. Thus, these models could be able to solve the big CC problem without fine-tuning and have also a bearing on the cosmic coincidence problem. Remarkably, they mimic the ΛCDM model to a large extent, but they still leave some characteristic imprints that should be testable in the next generation of experiments.

  18. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    Unité de Recherche des Matériaux et des Energies Renouvelables (U.R.M.E.R). Université Abou –Baker Belkaid B.p : 119 Tlemcen 13000 Algerie. 2. Unité de Développement de la Technologie Du Silicium. UDTS, BP 399, Alger, Algérie. Accepté le : 08/06/2011. صخلم. داوﻣﻟا نﻣ ﻲﺗﻟا ﺔﺻﺎﺧو ،ﺔﻋﺎﻧﺻ يأ رﯾوطﺗ ﻲﻓ ﺎﯾﺳﯾﺋر ﻼﻣﺎﻋ ةرﯾﺧﻷا تاوﻧﺳﻟا ...

  19. Mykotische Infektionen des Penis

    Directory of Open Access Journals (Sweden)

    Mayser P

    1999-01-01

    Full Text Available Die häufigste mykotische Infektion des Penis stellt die Balanitis/Balonoposthitis durch Candida albicans dar. Sie weist eine steigende Inzidenz auf und scheint vornehmlich durch Genitalverkehr übertragen zu werden. Penile Infektionen durch Dermatophyten sind sehr selten, obwohl die Tinea inguinalis zu den häufigeren Erkrankungen zählt. Eine Mitbeteiligung des Penis im Rahmen von Systemmykosen kennzeichnet zumeist ein schwer verlaufende Erkrankung. Ursächlich kann beim immunoinkompetenten Patienten nahezu jeder Erreger in Frage kommen. Biopsie sowie Gewebekultur aus den meist ulzerativen Veränderungen können die Diagnose sichern. Die meisten superfiziellen Infektionen sprechen zufriedenstellend auf eine topische antimykotische Behandlung an, insbesondere wenn Provokationsfaktoren und die Möglichkeit der sexuellen Transmission berücksichtigt werden. Ausgedehnte Infektionen durch Dermatophyten, Hefen und natürlich systemische Infektionen erfordern eine systemische antimykotische Therapie.

  20. Chimie des processus biologiques

    OpenAIRE

    Fontecave, Marc

    2014-01-01

    Cours : Chimie biologique radicalaire : de l’origine de l’ADN au métabolisme d’aujourd’hui Il est généralement admis que les radicaux libres, espèces chimiques très réactives, sont des poisons pour les systèmes vivants qui ont élaboré des mécanismes efficaces pour s’en protéger et s’en débarrasser lorsqu’ils viennent à se former, par accident. Par exemple ce qu’on appelle communément le stress oxydant est une situation caractérisée par une accumulation de radicaux issus de l’oxygène moléculai...

  1. Formas estructurales de fuerza constante

    Directory of Open Access Journals (Sweden)

    Zalewski, Waclaw

    1963-05-01

    Full Text Available The author seeks to prove the need to obtain the most essential form in the various types of structures by applying a number of rational principles, of which the constant stress principle is one of the most decisive. The structural form should be a logical consequence of all its functional circumstances, and this requires a clear understanding of the general behaviour of each part of the structure, and also of the main stresses which operate on it, considered as a unitary whole. To complete his theoretical argument, the author gives some examples, in the design of which the criterion of constant stress has been adopted. The author considers the various aspects which are involved in obtaining a structural design that satisfies given functional and aesthetic requirements. In doing so he refers to his personal experience within Poland, and infers technical principles of general validity which should determine the rational design of the form, as an integrated aspect of the structural pattern. The projects which illustrate this paper are Polish designs of undoubted constructive significance, in which the principle of constant stress has been applied. Finally the author condenses his whole theory in a simple and straightforward practical formula, which should be followed if a truly rational form is to be achieved: the constancy of stress in the various structural elements.El autor se esfuerza en mostrar la necesidad de llegar a la forma real en las distintas estructuras siguiendo una serie de principios racionales, entre los que domina el criterio de la fuerza constante. La forma ha de ser una consecuencia lógica en todos sus aspectos, y esto exige un claro conocimiento del comportamiento general de cada una de las partes de la estructura, y de los esfuerzos generales que dominan en la misma al considerarla como un todo. Para completar la exposición de orden teórico, el autor presenta algunos ejemplos en cuyo proyecto se ha seguido el criterio de

  2. La cogestion des Ressources naturelles

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

    L'eau, le sol, les nutriments, la lumière du soleil — ce sont des choses de la vie. .... habitent encore ces régions, soit de 9 % à 14 % de la population mondiale. ...... La guerre civile a fait vivre au Cambodge des années de chaos, d'anarchie et ...... et les allégeances politiques sont des facteurs qu'il est impossible d'ignorer.

  3. Des Ogle's old stump

    International Nuclear Information System (INIS)

    Jones, M.; Sutton, D.; Wallace, R.

    1998-01-01

    On 17 October 1997 Sylvia Bryan of RD4 Kaitaia wrote to 'Dear Somebody-Everybody' at the Anthropology Department, University of Auckland, urging further examination of an adzed stump found by Des Ogle during planting out of the Te Aupouri forest. The authors have since sought out relevant information and present it here for the interests of our readers. (author). 7 refs., 1 fig

  4. Grundlagen des Tissue Engineering

    Science.gov (United States)

    Mayer, Jörg; Blum, Janaki; Wintermantel, Erich

    Die Organtransplantation stellt eine verbreitete Therapie dar, um bei krankheitsoder unfallbedingter Schädigung eines Organs die Gesamtheit seiner Funktionen wieder herzustellen, indem es durch ein Spenderorgan ersetzt wird. Organtransplantationen werden für die Leber, die Niere, die Lunge, das Herz oder bei schweren grossflächigen Verbrennungen der Haut vorgenommen. Der grosse apparative, personelle und logistische Aufwand und die Risiken der Transplantationschirurgie (Abstossungsreaktionen) sowie die mangelnde Verfügbarkeit von immunologisch kompatiblen Spenderorganen führen jedoch dazu, dass der Bedarf an Organtransplantaten nur zu einem sehr geringen Teil gedeckt werden kann. Sind Spenderorgane nicht verfügbar, können in einzelnen Fällen lebenswichtige Teilfunktionen, wie beispielsweise die Filtrationsfunktion der Niere durch die Blutreinigung mittels Dialyse ersetzt oder, bei mangelnder Funktion der Bauchspeicheldrüse (Diabetes), durch die Verabreichung von Insulin ein normaler Zustand des Gesamtorganismus auch über Jahre hinweg erhalten werden. Bei der notwendigen lebenslangen Anwendung apparativer oder medikamentöser Therapie können für den Patienten jedoch häufig schwerwiegende, möglicherweise lebensverkürzende Nebenwirkungen entstehen. Daher werden in der Forschung Alternativen gesucht, um die Funktionen des ausgefallenen Organs durch die Implantation von Zellen oder in vitro gezüchteten Geweben möglichst umfassend wieder herzustellen. Dies erfordert biologisch aktive Implantate, welche die für den Stoffwechsel des Organs wichtigen Zellen enthalten und einen organtypischen Stoffwechsel entfalten.

  5. Dictionnaire des risques psychosociaux

    CERN Document Server

    Zawieja, Philippe

    2014-01-01

    Stress, suicide, harcèlement, épuisement professionnel, workaholism... Au-delà de la souffrance qu'elles désignent, ces notions souvent récentes constituent une approche inédite, et demandent à mieux être comprises, dans leur ensemble et isolément. C'est tout l'enjeu de ce dictionnaire, pionnier en son genre. Le lecteur y trouvera représentés, avec les 314 entrées (rédigées par 251 contributeurs) qui le composent, tous les champs disciplinaires s'intéressant à la souffrance au travail : psychologie du travail et des organisations, psychologie sociale et psychosociologie, psychanalyse, psychopathologie et psychiatrie, ergonomie, sociologie du travail et des organisations, médecine du travail, droit du travail et de la sécurité sociale, sciences de gestion, philosophie... Y sont détaillés les principaux concepts, notions, approches, méthodes, théories, outils, études, etc., ayant cours dans l'étude des risques psychosociaux, mais aussi certaines professions emblématiques (infirmières,...

  6. Le vernis des apparences

    Directory of Open Access Journals (Sweden)

    Grazia Nicosia

    2010-04-01

    Full Text Available Le but de cet article est de comprendre l’incidence sémiotique du nettoyage d’un tableau ainsi que la résultante cognitive induite sur l’observateur. Cette étude confronte l’analyse des phénomènes visuels engendrés par le jaunissement du vernis et son retrait, à des entretiens réalisés à dessein. Le retrait d’un vernis jauni change considérablement l’image. L’heure, le climat, la saison et l’activité même des personnages s’en trouvent ainsi modifié. La patine peut être perçue, soit comme un obstacle à l’exploration, soit pour ceux qui l’apprécient, comme le medium d’une relation plus intime entre l’œuvre et l’observateur.The purpose of this article is to understand the semiotic impact of the cleaning of a painting and the cognitive effects induced on the observer. This study analyses conjointly the visual phenomenon generated by yellowing varnish and its removal and controlled interviews of observers.The removal of yellowing varnish modifies considerably the perception of the picture. Daytime, climate, season and characters activities are modified. The patina may be perceived either as an obstacle to the painting exploration, or, for those who appreciate it, as a medium for a closer relationship between the painting and the observer.

  7. Extraction liquide-liquide des sels minéraux. Approximation analytique des isothermes de partage. Application au calcul sur ordinateur d'une installation Liquid-Liquid Extraction of Mineral Salts. Analytical Approximation of Partition Isotherms. Application to the Computer Designing of an Installation

    Directory of Open Access Journals (Sweden)

    Chaid M. T.

    2006-11-01

    Full Text Available Cet article comporte deux parties -dans la première on a calculé les isothermes de partage en partant des considérations thermodynamiques basées sur les travaux de Guggenheim. Les résultats ne sont bons que dans le cas des solutions idéales. On a donc simulé les isothermes par des fonctions analytiques. Celles-ci permettent de représenter convenablement tous les faisceaux d'isothermes quelles que soient l'acidité de la solution aqueuse et les concentrations dans les deux phases; - la deuxième partie est réservée au calcul d'une installation complète d'extraction avec colonne de récupération; le calcul, mené sur ordinateur, utilise les fonctions analytiques précédentes et permet d'obtenir les débits et les concentrations à chaque plateau. This article contains two parts: - the first part discusses the calculating of partition isotherms using thermodynamic considerations based on research by Guggenheim. The results are good only in the case of ideal solutions. Therefore, isotherms were simulated by ànalyticfunctionswhich are suitable for representing all isotherm bundles no matter what the acidity of the aqueous solution and the concentrations in both phases moy be. - the second part 'deals' with designing a complete extraction installation with a recovery column. Computerized designing makes use of the preceding analytic functions and enables flowrates and concentrations ta be determined at each plate.

  8. Harmonische Reduktion des linken Ventrikels

    OpenAIRE

    Atila, M. (Mehmet)

    2005-01-01

    In der vorliegenden Arbeit wurde die harmonische Reduktion des linken Ventrikels am Modell des ausgewachsenen Hausschweins, unter Verwendung von Saugkappen variabler Größe untersucht. In 10 Schweinen mit Herzen normaler Größe und Funktion wurde eine Saugkappe, in Größe und Form an das abzufaltende Wandsegment angepasst, auf die epikardiale Oberfläche des schlagenden Herzens gesetzt. Wir führten Messungen der linksventrik. und der pulmonalart. Drücke, des ventrikulären Durchmessers und der Her...

  9. Solvent purification using a current of water vapour. A continuous process applicable to chemical plants treating irradiated fuels; Purification des solvants par entrainement a la vapeur d'eau. Procede continu applicable aux usines chimiques de traitement des combustibles irradies

    Energy Technology Data Exchange (ETDEWEB)

    Auchapt, P.R.; Sautray, R.R.; Girard, B.R. [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

    1964-07-01

    The pilot plant described in this report is intended for the continuous purification of the solvent used in the plutonium extraction plant at Marcoule, by separating the impurities (fission products). This physical separation is operated by carrying over in a water vapour stream. The contaminating products, only slightly volatile, remain in the form of the droplets and are separated; the vaporised solvent and the water vapour used are condensed and then separated. The originality of the installation resides in the system for pulverising the liquid and in the operating conditions: low working pressure and temperature. The systematic analysis of the various parameters (percentage of residue; flow, pressure and temperature ratios etc...) has shown their influence on the decontamination. The activity due to the zirconium-niobium is undetectable after treatment, and it is easy to obtain decontamination factors of 300 for the ruthenium. The, presence of uranium is favorable for the decontamination. As a conclusion, some extra-technical considerations are given concerning in particular the approximate cost price of the treated solvent per litre. (authors) [French] L'installation pilote decrite dans ce rapport est destinee a purifier, en continu, le solvant utilise a l'usine d'extraction du plutonium de Marcoule, en separant les impuretes (produits de fission). Cette separation physique est realisee par entrainement a la vapeur d'eau. Les produits contaminants, peu volatils, restant sous forme de gouttelettes, sont separes; le solvant vaporise ainsi que la vapeur d'entrainement sont condenses puis separes. L'originalite de l'installation reside dans le systeme de pulverisation du liquide et dans les conditions operatoires: faible pression et basse temperature de fonctionnement. L'analyse systematique des differents parametres (pourcentage de residus, rapport de debits, pression et temperature, etc...) a mis en evidence leur influence

  10. Study of problems arising from the use of thermal neutron detectors in a pulsed regime. Application to the development of a digital transferometer adapted to receive signals from these detectors; Etude des problemes poses par l'utilisation des detecteurs de neutrons thermiques fonctionnant en regime impulsionnel. Application a la realisation d'un transferometre numerique adapte aux signaux fournis par ces detecteurs

    Energy Technology Data Exchange (ETDEWEB)

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

    1966-12-01

    The instantaneous value of the counting rate of the pulses given by a fission detector settled in a reactor follows the neutron flux, but it is shown that the counter adds a white noise to the measured signal. This report deals with some possibilities of on line numerical handling afforded by this kind of signals. One considers first the influence of a by N numerical divider and one shows that, acting like a quantifier, it adds to the signal a white noise with the power N{sup 2}/{sub 12}. One, studies afterwards the principle of a digital filter aimed to Fourier analyse the signal. The realization of this device is described. It can be used in transfer function measurements at frequencies below 125 kHz. Some examples of experiments performed with this apparatus are presented. One discusses finally the design, according to the same principle, of a power spectral density analyser in the frequency range 0,01 - 10 000 Hz for random signal of the same kind. (author) [French] La valeur instantanee de la frequence de recurrence des impulsions issues d'un detecteur a fission place dans un reacteur est proportionnelle au flux neutronique. Apres avoir montre que le detecteur ajoute un bruit blanc au signal mesure, on etudie clans ce rapport certaines possibilites de traitement numerique en temps reel offertes par ce type de signaux. On examine d'abord l'influence d'un diviseur numerique par N, et l'on montre que son action, semblable a une quantification, ajoute au signal un bruit blanc de puissance N{sup 2}/{sub 12}. On, etudie ensuite le principe d'un filtre numerique destine a effectuer l'analyse de Fourier du signal, et l'on decrit la realisation de cet appareil qui peut etre utilise pour mesurer des fonctions de transfert a une frequence quelconque inferieure a 10 kHz. Des exemples de mesures faites avec cet appareil sont presentes. On discute enfin la possibilite de realiser suivant le meme principe un analyseur de densite spectrale dans la bande de frequence 0,01 Hz

  11. Study of the anodic process in the electrolysis of molten chlorides. Application to the chlorine electrode; Contribution a l'etude du processus anodique dans l'electrolyse des chlorures fondus. Application a l'electrode de chlore

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-05-01

    The oxidation reaction of Cl{sup -} ions on a carbon electrode occurs with a very low over-voltage in molten LiCl-KCl, NaCl-KCl, CaCl{sub 2} and AgCl electrolytes and therefore the properties of the electrode 'polarized' anodically with a current density I are, as a first approximation, identical to those which it possesses at a chlorine pressure P (produced by the addition of external chlorine). This property of the Cl{sup -} ion oxidation reaction has enabled us to propose an electrochemical method for the study of the absorption equilibrium of the chlorine between a solid and a liquid phase. We can in effect replace this addition of outside chlorine at a pressure P by an electrolysis at a current density I. We have developed a mechanism which accounts for the reaction kinetic of the discharge of Cl{sup -} ions. It has been checked with the help of intensity-potential curves and potential-time curves which characterize the carbon depolarization in an open circuit. Two methods have been used for measuring the amount of chlorine adsorbed on the carbon. It has been possible to determine the nature of the bonds linking the adsorbed chlorine to the carbon, and the electrode-electrolyte surface exchange by varying the temperature and the nature of the electrode and of the electrolyte. Certain anomalies and in particular certain transient phenomena have been explained by the influence of the oxygen present in the molten salt in the form of O{sup 2-} ions and, on the electrode surface, in the form of chemisorption complexes. (author) [French] La reaction d'oxydation des ions Cl{sup -} sur une electrode de carbone s'effectue avec une surtension tres faible dans les electrolytes fondus LiCl-KCl, NaCl-KCl, CaCl{sub 2} et AgCl et par consequent les proprietes de l'electrode ''polarisee'' anodiquement avec une densite de courant I sont, en premiere approximation, identiques a celles qu'elle possede sous une pression de chlore P (creee par un apport exterieur de chlore). Cette

  12. Computing the Gromov hyperbolicity constant of a discrete metric space

    KAUST Repository

    Ismail, Anas

    2012-07-01

    Although it was invented by Mikhail Gromov, in 1987, to describe some family of groups[1], the notion of Gromov hyperbolicity has many applications and interpretations in different fields. It has applications in Biology, Networking, Graph Theory, and many other areas of research. The Gromov hyperbolicity constant of several families of graphs and geometric spaces has been determined. However, so far, the only known algorithm for calculating the Gromov hyperbolicity constant δ of a discrete metric space is the brute force algorithm with running time O (n4) using the four-point condition. In this thesis, we first introduce an approximation algorithm which calculates a O (log n)-approximation of the hyperbolicity constant δ, based on a layering approach, in time O(n2), where n is the number of points in the metric space. We also calculate the fixed base point hyperbolicity constant δr for a fixed point r using a (max, min)−matrix multiplication algorithm by Duan in time O(n2.688)[2]. We use this result to present a 2-approximation algorithm for calculating the hyper-bolicity constant in time O(n2.688). We also provide an exact algorithm to compute the hyperbolicity constant δ in time O(n3.688) for a discrete metric space. We then present some partial results we obtained for designing some approximation algorithms to compute the hyperbolicity constant δ.

  13. Transformation des découvertes en génomique pour soigner les ...

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

    ... des composés préventifs et thérapeutiques ciblés pour des essais précliniques ... IDRC is pleased to announce the results of its 2017 call for proposals to establish Cyber ... IDRC invites applications for the IDRC Doctoral Research Awards.

  14. 黏性防冲锚索支护技术及其在冲击地压矿井中的应用%Application of impact-constant resistance anchor support theory in rock burst mine

    Institute of Scientific and Technical Information of China (English)

    黄自伟; 韩雪峰; 连小勇; 时晓东; 周辰辰

    2016-01-01

    为解决现行的支护方法及材料(金属支架、锚网等)在冲击性高应力巷道支护中出现的支护材料破断、支护体失效等问题,提出了黏性支护方法,即在支护系统中加入黏弹性材料,利用附加在锚索尾端的阻尼器增加支护系统黏性,将冲击地压产生的机械能转化为热能,减弱冲击破坏程度;研发了一种新的黏性支护材料——抗冲击恒阻锚索,该支护材料具有高恒阻力让压和抗冲击特性,以阻尼器型号为skp18-1/500的抗冲击恒阻锚索为例,其恒阻力保持在220 kN左右、抗冲击能量大于50 kJ,并通过力学性能实验得以验证;论述了新型支护方法及材料的理论依据及实施措施,通过力学特性检验及现场应用,证实了新型支护体能够通过可控变形吸收转化冲击能量,使围岩从一种稳定状态过渡到另一种稳定状态.%The theory of viscous support was put forward to solve the problems with current support methods and materials (metal stent,bolting-wire mesh) which were extremely prone to failure and fracture when they were used in impact roadway with high stress.The core of viscous support theory required the support system to add viscoelastic materials.The damper was installed on the one end of the anchor cable to increase the viscosity of support system because viscoelastic materials could absorb and consume energy.Thus,it could be used to transfer energy to achieve the purpose of reducing damage,in other words,the mechanical energy caused by rock burst was converted into internal energy.Based on the theory above,the authors had developed a new viscous support product which was named as an impact-constant resistance anchor cable.The cable could have a large deformation when it was pulled to a certain forced state and absorbed the impact energy caused by rock burst.Using skpl8-1/500 damper as an example,when it was pulled up to 220 kN,it would yield a large deformation,when the rock burst occurred

  15. How Molecular Evolution Technologies can Provide Bespoke Industrial Enzymes: Application to Biofuels Comment les technologies d’évolution moléculaire peuvent fournir des enzymes industrielles sur mesure : application aux biocarburants

    Directory of Open Access Journals (Sweden)

    Fourage L.

    2013-08-01

    est l’un des principaux goulets d’étranglement dans le développement de la conversion biologique de la biomasse lignocellulosique en biocarburants. L’un des organismes les plus efficaces pour la production d’enzymes cellulolytiques est le champignon Trichoderma reesei, principalement grâce à sa capacité importante de sécrétion. La conversion de la cellulose en glucose implique trois types de cellulases travaillant en synergie : les endoglucanases (EC 3.2.1.4 clivant de façon aléatoire les liaisons glycosidiques en (3-1,4, les cellobiohydrolases (EC 3.2.1.91 attaquant la chaîne de cellulose aux deux extrémités afin de produire le cellobiose, dimère qui sera converti en glucose par l’action des (3-glucosidases (EC 3.2.1.21. De façon inattendue, la quantité de 3-glucosidase (BGL1 sécrétée par les souches de T. reesei représente un très faible pourcentage de la quantité totale des protéines sécrétées qui en fait donc une activité limitante du cocktail. Cette faible activité limite d’autant plus les performances du cocktail que le cellobiose représente le principal inhibiteur de la réaction cellulolyse par les cellobiohydrolases. Ce goulot d’étranglement peut être atténué soit par une surexpression de la (3-glucosidase chez T. reesei, soit par une amélioration de son activité spécifique. Après un bref aperçu des principales technologies existantes, cet exemple sera utilisé dans cette revue pour illustrer le potentiel des technologies d’évolution dirigée pour développer des enzymes répondant aux besoins de l’industrie des biotechnologies. Nous décrivons comment la mise en oeuvre d’une stratégie d’évolution dirigée par le L-ShufflingTM avec trois gènes parentaux provenant de la biodiversité microbienne permet d’obtenir des activités (3-glucosidases très améliorées par rapport à la Cel3a (3-glucosidase de T. reesei (activité spécifique 242 fois plus élevée pour le substrat pNPGIc. Cette am

  16. Constant Proportion Debt Obligations (CPDOs)

    DEFF Research Database (Denmark)

    Cont, Rama; Jessen, Cathrine

    2012-01-01

    be made arbitrarily small—and thus the credit rating arbitrarily high—by increasing leverage, but the ratings obtained strongly depend on assumptions on the credit environment (high spread or low spread). More importantly, CPDO loss distributions are found to exhibit a wide range of tail risk measures......Constant Proportion Debt Obligations (CPDOs) are structured credit derivatives that generate high coupon payments by dynamically leveraging a position in an underlying portfolio of investment-grade index default swaps. CPDO coupons and principal notes received high initial credit ratings from...... the major rating agencies, based on complex models for the joint transition of ratings and spreads for all names in the underlying portfolio. We propose a parsimonious model for analysing the performance of CPDO strategies using a top-down approach that captures the essential risk factors of the CPDO. Our...

  17. Energy, stability and cosmological constant

    International Nuclear Information System (INIS)

    Deser, S.

    1982-01-01

    The definition of energy and its use in studying stability in general relativity are extended to the case when there is a nonvanishing cosmological constant Λ. Existence of energy is first demonstrated for any model (with arbitrary Λ). It is defined with respect to sets of solutions tending asymptotically to any background space possessing timelike Killing symmetry, and is both conserved and of flux integral form. When Λ O, small excitations about De Sitter space are stable inside the event horizon. Outside excitations can contribute negatively due to the Killing vector's flip at the horizon. This is a universal phenomenon associated with the possibility of Hawking radiation. Apart from this effect, the Λ>O theory appears to be stable, also at the semi-classical level. (author)

  18. Evolution of the solar 'constant'

    Energy Technology Data Exchange (ETDEWEB)

    Newman, M J

    1980-06-01

    Variations in solar luminosity over geological time are discussed in light of the effect of the solar constant on the evolution of life on earth. Consideration is given to long-term (5 - 7% in a billion years) increases in luminosity due to the conversion of hydrogen into helium in the solar interior, temporary enhancements to solar luminosity due to the accretion of matter from the interstellar medium at intervals on the order of 100 million years, and small-amplitude rapid fluctuations of luminosity due to the stochastic nature of convection on the solar surface. It is noted that encounters with dense interstellar clouds could have had serious consequences for life on earth due to the peaking of the accretion-induced luminosity variation at short wavelengths.

  19. Asympotics with positive cosmological constant

    Science.gov (United States)

    Bonga, Beatrice; Ashtekar, Abhay; Kesavan, Aruna

    2014-03-01

    Since observations to date imply that our universe has a positive cosmological constant, one needs an extension of the theory of isolated systems and gravitational radiation in full general relativity from the asymptotically flat to asymptotically de Sitter space-times. In current definitions, one mimics the boundary conditions used in asymptotically AdS context to conclude that the asymptotic symmetry group is the de Sitter group. However, these conditions severely restricts radiation and in fact rules out non-zero flux of energy, momentum and angular momentum carried by gravitational waves. Therefore, these formulations of asymptotically de Sitter space-times are uninteresting beyond non-radiative spacetimes. The situation is compared and contrasted with conserved charges and fluxes at null infinity in asymptotically flat space-times.

  20. The fundamental constants a mystery of physics

    CERN Document Server

    Fritzsch, Harald

    2009-01-01

    The speed of light, the fine structure constant, and Newton's constant of gravity — these are just three among the many physical constants that define our picture of the world. Where do they come from? Are they constant in time and across space? In this book, physicist and author Harald Fritzsch invites the reader to explore the mystery of the fundamental constants of physics in the company of Isaac Newton, Albert Einstein, and a modern-day physicist

  1. Etude des phenomenes dynamiques ultrarapides et des caracteristiques impulsionnelles d'emission terahertz du supraconducteur YBCO

    Science.gov (United States)

    Savard, Stephane

    choisi, nous avons mesure les proprietes intrinseques du meme echantillon de YBa2Cu3O7- delta avec la technique pompe-visible et sonde-terahertz donnant, elle aussi, acces aux temps caracteristiques regissant l'evolution hors-equilibre de ce materiau. Dans le meilleur scenario, ces temps caracteristiques devraient correspondre a ceux evalues grace a la modelisation des antennes. Un bon controle des parametres de croissance des couches minces supraconductrices et de fabrication du dispositif nous a permis de realiser des antennes d'emission terahertz possedant d'excellentes caracteristiques en terme de largeur de bande d'emission (typiquement 3 THz) exploitables pour des applications de spectroscopie resolue dans le domaine temporel. Le modele developpe et retenu pour le lissage du spectre terahertz decrit bien les caracteristiques de l'antenne supraconductrice pour tous les parametres d'operation. Toutefois, le lien avec la technique pompe-sonde lors de la comparaison des proprietes intrinseques n'est pas direct malgre que les deux techniques montrent que le temps de relaxation des porteurs augmente pres de la temperature critique. Les donnees en pompe-sonde indiquent que la mesure du temps de relaxation depend de la frequence de la sonde, ce qui complique la correspondance des proprietes intrinseques entre les deux techniques. De meme, le temps de relaxation extrait a partir du spectre de l'antenne terahertz augmente en s'approchant de la temperature critique (T c) de YBa2Cu 3O7-delta. Le comportement en temperature du temps de relaxation correspond a une loi de puissance qui est fonction de l'inverse du gap supraconducteur avec un exposant 5 soit 1/Delta 5(T). Le travail presente dans cette these permet de mieux decrire les caracteristiques des antennes supraconductrices a haute temperature critique et de les relier aux proprietes intrinseques du materiau qui les compose. De plus, cette these presente les parametres a ajuster comme le courant applique, la puissance de

  2. Les déterminants de l’attractivité territoriale des entreprises manufacturières et logistiques étrangères : application à la ville de Tanger – Maroc

    Directory of Open Access Journals (Sweden)

    Abbes Elhasbi

    2017-03-01

    Full Text Available L’objectif de cet article est de proposer les principaux facteurs d’attractivité des investisseurs étrangers dans les secteurs manufacturiers et logistiques de la ville de Tanger au Maroc. Notre modèle conceptuel a été élaboré à partir d’une revue de littérature et d’entretiens avec un échantillon de dirigeants des petites et moyennes entreprises (PME étrangères. Notre analyse empirique est réalisée à partir des données issues d’une enquête menée auprès des dirigeants des entreprises étrangères (manufacturières et logistiques installées à la ville de Tanger. L’utilisation de l’approche Partial least squares (PLS nous a permis de tester les liens de causalité entre les divers facteurs politiques, économiques, sociaux, technologiques, environnementaux et juridiques (Pestel. L’intérêt scientifique de notre modèle est de présenter aux décideurs de la ville de Tanger des recommandations afin d’améliorer le développement et l’attractivité des investissements étrangers dans les deux secteurs logistique et manufacturier.

  3. Analyse des caractéristiques structurelles et des performances ...

    African Journals Online (AJOL)

    SARAH

    28 févr. 2014 ... performances technico-économiques de la riziculture irriguée en Côte d' .... en nous basant sur les prix des intrants et des produits en vigueur au cours ..... la recherche et de la vulgarisation et le transfert de technologies ; (2) ...

  4. Evaluation des pratiques de gestion des adventices en riziculture

    African Journals Online (AJOL)

    Les résultats ont montré que les méthodes de gestion de l'enherbement ont .... Le contrôle des adventices en riziculture irriguée a principalement .... mesurer la hauteur des plantes et la longueur ..... Performance agronomique du Sys- tème de ...

  5. Diversification des moyens de subsistance des petits producteurs de ...

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

    L'économie du Malawi repose essentiellement sur la culture du tabac, qui représente plus de 70 % des revenus d'exportation. Pour 60 % des 100 000 membres de la National Smallholder Farmers' Association of Malawi (NASFAM), le tabac est la seule et unique source de revenus. Les cultivateurs de tabac, au Malawi ...

  6. Culture du bambou : diversification des moyens de subsistance des ...

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

    Culture du bambou : diversification des moyens de subsistance des petits producteurs de tabac du sud de la province de Nyanza, au Kenya - phase II. Au cours de la première phase du projet (projet no 103765), les chercheurs ont effectué une analyse de marché pour le bambou et les produits du bambou, comparé les ...

  7. Roles et taches des accompagnateurs des patients hospitalises ...

    African Journals Online (AJOL)

    Roles et taches des accompagnateurs des patients hospitalises dans le service de pneumo-phtysiologie au Centre Hospitalier Universitaire Yalgado Ouedraogo de ... Logistical support represented by material support, drug supply, cleaning of premises, and littering occupied respectively 100%, 91%, 42% and 73%.

  8. Application de la méthode des éléments finis hiérarchiquesà l’analyse thermo- élastique d’unpanneau solaire d’un satellite

    OpenAIRE

    hamzA-CHERIF, Sidi Mohammed

    2013-01-01

    Dans l'ère actuelle, Les satellites sont devenus des outils incontournables dans le développement économique (télécommunications, positionnement, prévision météorologique), militaire (renseignement) et scientifique (observation astronomique, microgravité, observation de la Terre, océanographie, altimétrie). Les satellites en orbite sont soumis à des conditions de fonctionnement très sévères, en plus des effets de l’oxygène atomique, le rayonnement ultraviolet, la radiation é...

  9. Communication Received from the Permanent Mission of the Netherlands regarding Certain Member States' Guidelines for the Export of Nuclear Material, Equipment and Technology; Communication recue de la mission permanente des Pays-Bas concernant les Directives de certains Etats Membres applicables a l'exportation de matieres, d'equipements et de technologie nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-09-05

    The Agency has received a Note Verbale from the Permanent Mission of the Kingdom of the Netherlands, dated 12 July 2011, in which it requests that the Agency circulate to all Member States a letter of 12 July 2011 from the Chairman of the Nuclear Suppliers Group, Ambassador Piet de Klerk, to the Director General, on behalf of the Governments of Argentina, Australia, Austria, Belarus, Belgium, Brazil, Bulgaria, Canada, China, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Japan, Kazakhstan, Republic of Korea, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, New Zealand, Norway, Poland, Portugal, Romania, Russian Federation, Slovakia, Slovenia, South Africa, Spain, Sweden, Switzerland, Turkey, Ukraine, the United Kingdom of Great Britain and Northern Ireland and the United States of America, providing further information on those Governments' Guidelines for Nuclear Transfers [French] L'Agence a recu une note verbale de la mission permanente du Royaume des Pays-Bas, en date du 12 juillet 2011, lui demandant de communiquer a tous les Etats Membres une lettre du 12 juillet 2011 du president du Groupe des fournisseurs nucleaires, l'ambassadeur Piet de Klerk, adressee au Directeur general au nom des gouvernements des Etats suivants : Afrique du Sud, Allemagne, Argentine, Australie, Autriche, Belarus, Belgique, Bresil, Bulgarie, Canada, Chine, Croatie, Chypre, Danemark, Espagne, Estonie, Etats-Unis d'Amerique, Federation de Russie, Finlande, France, Grece, Hongrie, Irlande, Islande, Italie, Japon, Kazakhstan, Lettonie, Lituanie, Luxembourg, Malte, Norvege, Nouvelle-Zelande, Pays-Bas, Pologne, Portugal, Republique de Coree, Republique tcheque, Roumanie, Royaume-Uni de Grande-Bretagne et d'Irlande du Nord, Slovaquie, Slovenie, Suede, Suisse, Turquie et Ukraineb. Cette lettre apporte des informations supplementaires sur les Directives de ces gouvernements applicables aux transferts nucleaires.

  10. Application of radioisotopes to the investigation of the kinetics and mechanism of reactions of some inorganic complex compounds; Application des radioisotopes a l'etude de la cinetique et du mecanisme des reactions de certains complexes inorganiques; Primenenie radioizotopov k issledovaniyam kinetiki i mekhanizma reaktsij nekotorykh neorganicheskikh slozhnykh soedinenij; Aplicacion de los radioisotopos al estudio de la cinetica y del mecanismo de las reacciones de algunos complejos inorganicos

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Gordon M [Department of Chemistry, University of Buffalo, Buffalo 14, NY (United States)

    1962-03-15

    cyanide is an important end-product. (author) [French] Les radioisotopes sont particulierement precieux dans l'etude de nombreux types de reactions de chimie minerale, notamment de reactions ou interviennent des ions complexes en solution aqueuse. Les recherches sur la vitesse et le mecanisme des echanges isotopiques constituent un aspect important de ces applications. C'est ainsi qu'on a fait une serie d'etudes sur l'echange entre du carbonate ''libre'' marque au carbone-14 et le carbonate qui joue le role de coordinafc dans les ions complexes octaedriques du type CoA{sub 2}CO{sub 3}{sup +}, ou A represente le 2NH{sub 3}, ou l'ethylene-diamine (en), ou la propylene-diamine (pn) ou la trimethylene-diamine (tn). Grace aux etudes ainsi effectuees, on connait assez exactement la nature de ces reactions par substitution de coordinate, ainsi que le role joue par les coordinais amines qui ne participent pas a l'echange. Des etudes analogues sur l'echange entre oxalates dans les complexes tri-oxaliques de forme M (C{sub 2}O{sub 4}){sub 3}{sup 3-}, ou M=Co (III), Cr (III), ou Rh (III), n'ont pas ete moins fecondes en resultats. Une autre technique, applicable seulement lorsqu'on utilise des radioisotopes de faible poids atomique comme le carbone-14, consiste a observer les effets d'equilibre ou les effets cinetiques que les isotopes exercent sur la reaction etudiee. C'est ainsi qu'il a ete possible d'interpreter des differences dans le mecanisme d'echange du coordinat carbonate dans le Coen{sub 2}CO{sub 3}{sup +} et le Cotn{sub 2}CO{sub 3}{sup +}, par mesure de l'effet isotopique a l'etat d'equilibre dans la reaction d'echange des carbonates. De meme, des donnees sur l'effet isotopique cinetique dans l'hydratation avec catalyseur acide de l'ion Co(NH{sub 3}){sub 4}CO{sub 3}{sup +} ont confirme les deductions faites en ce qui concerne l'etape a laquelle se rompt la liaison, etape qui determine la vitesse de ces reactions. Enfin, la determination des positions successives de

  11. Arrhenius Rate: constant volume burn

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-12-06

    A constant volume burn occurs for an idealized initial state in which a large volume of reactants at rest is suddenly raised to a high temperature and begins to burn. Due to the uniform spatial state, there is no fluid motion and no heat conduction. This reduces the time evolu tion to an ODE for the reaction progress variable. With an Arrhenius reaction rate, two characteristics of thermal ignition are illustrated: induction time and thermal runaway. The Frank-Kamenetskii approximation then leads to a simple expression for the adiabatic induction time. For a first order reaction, the analytic solution is derived and used to illustrate the effect of varying the activation temperature; in particular, on the induction time. In general, the ODE can be solved numerically. This is used to illustrate the effect of varying the reaction order. We note that for a first order reaction, the time evolution of the reaction progress variable has an exponential tail. In contrast, for a reaction order less than one, the reaction completes in a nite time. The reaction order also affects the induction time.

  12. Markov constant and quantum instabilities

    Czech Academy of Sciences Publication Activity Database

    Pelantová, E.; Starosta, Š.; Znojil, Miloslav

    2016-01-01

    Roč. 49, č. 15 (2016), s. 155201 ISSN 1751-8113 R&D Projects: GA ČR GA16-22945S Institutional support: RVO:61389005 Keywords : renormalizable quantum theories with ghosts * Pais-Uhlenbeck model * singular spectra * square-well model * number theory analysis * physical applications Subject RIV: BE - Theoretical Physics Impact factor: 1.857, year: 2016

  13. Measurement of the {pi}{sup +} p and {pi}{sup -} p total cross-section from 700 to 1700 MeV, and applications to the dispersion relationships; Mesure des sections efficaces totales {pi}{sup +} p et {pi}{sup -} p entre 700 a 1700 MeV et applications aux relations de dispersion

    Energy Technology Data Exchange (ETDEWEB)

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

    1966-07-01

    The {pi}{sup +} P and {pi}{sup -} P total cross sections have been measured between 500 and 1700 MeV to eliminate discrepancies in the experimental data. These new values have permitted a more precise calculation of the forward dispersion relation. These relations are well satisfied by the experimental data up to 18 GeV for charge exchange scattering. The dispersion relation for the spin-flip amplitude gives an efficient test for the phase-shift analysis solutions. (author) [French] Les sections efficaces totales {pi}{sup +} P et {pi}{sup -} P ont ete mesurees entre 500 et 1700 MeV pour eliminer les divergences qui existaient entre les resultats experimentaux anterieurs. Ces nouvelles valeurs ont permis de preciser le calcul des relations de dispersion vers l'avant. Dans le cas de la diffusion avec echange de charge ces relations sont en bon accord avec les resultats experimentaux entre 0 et 18 GeV. L'application des relations de dispersion vers l'avant a l'amplitude de spin-flip fournit une methode tres sensible pour comparer differentes series de dephasages en fonction de l'energie. (auteur)

  14. Multiplexeurs numériques haut débit sur arséniure de gallium pour des applications au-delà de 1,5 Gbit/s

    OpenAIRE

    Kamdem , J.; Le Rouzic , M.; Thébault , C.

    1988-01-01

    Deux types de circuits intégrés GaAs de multiplexage haut débit (multiplexeurs à rang fixe et à rang programmable sur 2, 3 ou 4 entrées), capables de fournir des débits numériques jusqu'à 1,9 Gbit/s, ont été conçus et réalisés en logique BFL à grille de 1 μm. On présente ici la méthode de conception mise en oeuvre, et les performances des circuits obtenus. L'architecture de ces multiplexeurs est basée sur des compteurs de type Johnson, sans logique d'établissement de cycle, utilisant des basc...

  15. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    mélange pulvérulent de coke et de calcaire. La réduction est assurée par le gaz CO à 1250°C [2]. Le procédé Kawazaki iron powder utilise la calamine comme matière première et aussi CO comme gaz réducteur pour élaborer des poudres de fer. [3]. Un autre procédé plus connu qui fabrique les poudres de fer à partir de la.

  16. Glossaire des sigles

    OpenAIRE

    2015-01-01

    ABM Anti-ballistic missile = Missile antimissile balistique AGM Air-to-ground missile = Missile air-sol AIEA Agence Internationale de l’Energie Atomique ALCM Air-launched cruise missile = Missile de croisière air-sol ANSEA Association des Nations du Sud-Est asiatique ANT* Arme nucléaire tactique ASAT Anti-satellite = Arme antisatellite ASW Anti-submarine warfare = Guerre anti-sous-marine AWACS Airborne warning and control system = Système aérien de contrôle et d’alerte BMD Ballistic missile d...

  17. Magnetic resonance studies of solid polymers; Etude des polymeres solides par resonance magnetique

    Energy Technology Data Exchange (ETDEWEB)

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

    1969-07-01

    This paper is a review of the application of nuclear magnetic resonance (NMR) to solid polymers. In the first, theoretical part, the elements of the theory of NMR, which are necessary for the study of the properties of solid polymers are discussed: the moments method, nuclear relaxation and the distribution of correlation times. In the second part the experimental results are presented. (author) [French] Cette etude est une recherche bibliographique sur l'application de la resonance magnetique nucleaire (RMN) aux polymeres solides. Dans la premiere partie theorique on discute les elements de la theorie de RMN, necessaires pour l'etude des proprietes des polymeres solides: la methode des moments, la relaxation nucleaire et la distribution des temps de correlation. La deuxieme partie presente les resultats des experiences. (auteur)

  18. Studies on the gamma-gamma method. Definition of an apparatus for on-the-spot measurement of uranium ore densities; Etudes sur la methode gamma-gamma. Determination d'un appareillage pour la mesure en place de la densite des minerais d'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Czubek, J A [Institut de Recheches Nucleaires, Dept. 6, Cracovie (Poland); Guitton, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-07-01

    The work described follows on to the research published in report CEA-R--2720 in march 1965. It includes: - experimental results obtained with a model composed of a constant density material (graphite); - the drawing-up of calibration curves using the similitude principle; - determination of the characteristics of a gamma-gamma probe, together with a discussion. The influence is studied of a certain number of parameters on the shape of the energy spectra of scattered radiation, and of the calibration curves: nature of the radioactive source, diameter of the probe area, source detector distance, geometrical shape of shielding between the source and the detector. An attempt is made to find a mathematical model for the calibration curve, for given conditions. Numerical applications make it possible to establish the optimum technical characteristics for a probe measuring the density with the smallest statistical error. (authors) [French] Les travaux decrits font suite aux etudes presentees dans le rapport CEA-R--2720 de mars 1965. Ils portent sur: - les resultats experimentaux obtenus sur un modele constitue d'un materiau de densite constante (graphite) ; - l'etablissement de courbes d'etalonnage a l'aide du principe de similitude; - la recherche et la discussion des caracteristiques d'une sonde gamma-gamma. L'influence d'un certain nombre de parametres sur la forme des spectres d'energie du rayonnement diffuse et des courbes d'etalonnage est etudiee: nature de la source radioactive, diametre du sondage, distance source-detecteur, forme geometrique du blindage entre la source et le detecteur. Pour des conditions determinees, le modele mathematique de la courbe d'etalonnage est recherche. Des applications numeriques permettent d'etablir les caracteristiques techniques optimales d'une sonde mesurant la densite avec la plus faible erreur statistique. (auteurs)

  19. Modelling solar radiation interception in row plantation. 3. Application to a traditional vineyard; Modélisation de l’interception des rayonnements solaires dans une culture en rangs. 3. Application à une vigne traditionnelle

    Energy Technology Data Exchange (ETDEWEB)

    Sinoquet, H. [Institut National de la Recherche Agronomique, Pointe a Pitre (France); Valancogne, C.; Lescure, A.; Bonhomme, R.

    1992-07-01

    A previously described model of solar radiation interception was applied to a spatially discontinuous canopy: that of a traditional vineyard in which the classical terms of the radiative balance and the spatial distribution of the radiation transmitted to the soil were measured. Comparison of measured and simulated data gave satisfactory agreement for reflected radiation (fig 4), but major discrepancies appeared for mean transmitted radiation (fig 5). The use of small stationary sensors for measuring the transmitted radiation explains the latter observation, since most of the time they measured radiation received on the ground in the sunflecks or in the shaded area rather than mean radiation. This was verified by comparing the measured and simulated spatial distribution of transmitted radiation (figs 7, 8). Finally, the influence of the woody parts which were not taken into consideration in the model was clearly identified : it significantly reduced the transmission of incident radiation (fig 9), and to a greater degrees the closer the sensor was to the vegetation row. (author) [French] Un modèle d’interception du rayonnement solaire décrit précédemment est appliqué à un couvert spatialement discontinu : une vigne traditionnelle sur laquelle ont été mesurés les termes classiques du bilan radiatif et la distribution spatiale du rayonnement transmis au sol. La comparaison des mesures au modèle révèle un ajustement satisfaisant pour le rayonnement réfléchi (fig 4), mais assez médiocre pour le rayonnement transmis moyen (fig 5). Ceci est expliqué par l’utilisation de capteurs ponctuels qui, en raison de leur taille, mesurent plus souvent le rayonnement reçu au sol dans les taches de soleil ou les zones d’ombre qu’un rayonnement moyen. Ceci est vérifié en comparant les distributions mesurées et calculées du rayonnement transmis au sol (figs 7 et 8). Enfin, l’influence des parties ligneuses, non prise en compte dans le modèle, est

  20. Étude des distributions de contraintes autour d'un puits pétrolier. Application au calcul des pressions d'initiation de fracturation hydraulique Research on Stress Distribution Around an Oil Or Gas Well. Application to Calculating Pressures for Initiating Hydraulic Fracturing

    Directory of Open Access Journals (Sweden)

    Skoczylas F.

    2006-11-01

    Full Text Available Des méthodes de résolution analytiques et numériques ont été proposées, pour déterminer les distributions de contraintes autour de forages pétroliers dans le cas de matériaux peu résistants. Le calcul de ces distributions aboutit à la détermination des pressions de fracturation. Le critère de plasticité de Mohr-Coulomb a été choisi pour la résolution analytique. Cette étude permet d'établir trois schémas types de distribution de contraintes, au moment de la fracturation, pour un régime permanent d'écoulement. La géométrie axisymétrique du modèle a permis d'utiliser une méthode numérique par schéma aux différences finies. La loi de comportement du matériau est déduite du critère de plasticité de Drucker. Cette résolution permet le chargement incrémental en pression dans le forage et de simuler une injection rapide par un couplage simplifié fluide-squelette. Le modèle élastoplastique à deux surfaces de charge de Lade-Shao a finalement été retenu pour décrire l'écrouissage du matériau. La comparaison des résultats des différentes méthodes de calcul s'effectue sur la base de l'influence respective du coefficient de poussée au repos Ko, du coefficient de Poisson et de la résistance à la compression, Co, du matériau. Analytical and numerical methods are proposed, in order to determine stresses distribution around borehole for axisymetric problems in the case of low strengh materials. Calculation of these distributions leads to the determination of hydraulic fracture-pressure. Analytical solutions were found in the case of Mohr-Coulomb criterion and steady flow. These solutions leads to three typical stresses distributions when hydraulic fracture takes place. Because problem's axisymetry, the finite difference method was used. The constitutive law was deduced using Drücker plasticity criterion with an associated flow rule for elastic perfectly plastic behaviour. Such a numerical method can take into

  1. Isolement et identification des levures.

    Directory of Open Access Journals (Sweden)

    S. DOMERCQ

    1967-06-01

    Full Text Available La fermentation du moût de raisin est assurée par les levures qui se trouvent sur la pellicule du raisin, sur les rafles, et aussi, par celles qui envahissent le matériel de vendange et de vinification dès que la récolte est commencée. L'apparition deLa fermentation du moût de raisin est assurée par les levures qui se trouvent sur la pellicule du raisin, sur les rafles, et aussi, par celles qui envahissent le matériel de vendange et de vinification dès que la récolte est commencée. L'apparition des signes de la fermentation est spontanée. La fermentation est rapide dans la majorité des cas, si elle devient trop violente et que la température s'élève dangeureusement, il faut la « canaliser », la calmer. Des accidents peuvent se produire; des arrêts de fermentation laissant des sucres non fermentés pouvant être attaqués par d'autres microorganismes, des développements de levures formant des substances nuisibles à la qualité; par la suite, il s'agit d'obtenir la stabilité du vin, en particulier, éviter les refermentations des vins doux. L'étude de ces problèmes nécessite une étude préliminaire, celle des levures responsables de la fermentation alcoolique du jus de raisin, qui ne peut être faite que sur des cultures pures, isolées au préalable à l'aide de prélèvements soigneusement réalisés.s signes de la fermentation est spontanée. La fermentation est rapide dans la majorité des cas, si elle devient trop violente et que la température s'élève dangeureusement, il faut la « canaliser », la calmer. Des accidents peuvent se produire; des arrêts de fermentation laissant des sucres non fermentés pouvant être attaqués par d'autres microorganismes, des développements de levures formant des substances nuisibles à la qualité; par la suite, il s'agit d'obtenir la stabilité du vin, en particulier, éviter les refermentations des vins doux. L'étude de ces problèmes nécessite une étude pr

  2. Le Débat des semences

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

    Solutions pour les lois nationales régissant le contrôle des ressources génétiques et des ...... des pouvoirs) qui reconnaissent, dans une certaine mesure, les droits de gestion collectifs des ...... documentés, les performances physiques, etc.

  3. The Dielectric Constant of Lubrication Oils

    National Research Council Canada - National Science Library

    Carey, A

    1998-01-01

    The values of the dielectric constant of simple molecules is discussed first, along with the relationship between the dielectric constant and other physical properties such as boiling point, melting...

  4. Globally Coupled Chaotic Maps with Constant Force

    International Nuclear Information System (INIS)

    Li Jinghui

    2008-01-01

    We investigate the motion of the globally coupled maps (logistic map) with a constant force. It is shown that the constant force can cause multi-synchronization for the globally coupled chaotic maps studied by us.

  5. STABILITY CONSTANT OF THE TRISGLYCINATO METAL ...

    African Journals Online (AJOL)

    DR. AMINU

    overall stability constants of the complexes were found to be similar. Keywords: Glycinato, titration ... +. −. = 1 where Ka = dissociation constant of the amino acid. [ ]+. H = concentration of the .... Synthesis and techniques in inorganic chemistry.

  6. Mécanique des sols et des roches

    CERN Document Server

    Vullier, Laurent; Zhao, Jian

    2016-01-01

    La mécanique des sols et la mécanique des roches sont des disciplines généralement traitées séparément dans la littérature. Pour la première fois, un traité réunit ces deux spécialités, en intégrant également les connaissances en lien avec les écoulements souterrains et les transferts thermiques. A la fois théorique et pratique, cet ouvrage propose tout d'abord une description détaillée de la nature et de la composition des sols et des roches, puis s'attache à la modélisation de problèmes aux conditions limites et présente les essais permettant de caractériser les sols et les roches, tant d'un point de vue mécanique qu'hydraulique et thermique. La problématique des sols non saturés et des écoulements multiphasiques est également abordée. Une attention particulière est portée aux lois de comportement mécanique et à la détermination de leurs paramètres par des essais in situ et en laboratoire, et l'ouvrage offre également une présentation détaillée des systèmes de classi...

  7. Convexity and concavity constants in Lorentz and Marcinkiewicz spaces

    Science.gov (United States)

    Kaminska, Anna; Parrish, Anca M.

    2008-07-01

    We provide here the formulas for the q-convexity and q-concavity constants for function and sequence Lorentz spaces associated to either decreasing or increasing weights. It yields also the formula for the q-convexity constants in function and sequence Marcinkiewicz spaces. In this paper we extent and enhance the results from [G.J.O. Jameson, The q-concavity constants of Lorentz sequence spaces and related inequalities, Math. Z. 227 (1998) 129-142] and [A. Kaminska, A.M. Parrish, The q-concavity and q-convexity constants in Lorentz spaces, in: Banach Spaces and Their Applications in Analysis, Conference in Honor of Nigel Kalton, May 2006, Walter de Gruyter, Berlin, 2007, pp. 357-373].

  8. Binary analysis: 1. part: definitions and treatment of binary functions; 2. part: applications and functions of trans-coding; Analyse binaire: 1ere partie: definitions et traitements des fonctions binaires; 2eme partie: applications et fonctions de transcodage

    Energy Technology Data Exchange (ETDEWEB)

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

    1968-07-01

    The study of binary groups under their mathematical aspects constitutes the matter of binary analysis, the purpose of which consists in developing altogether simple, rigorous and practical methods needed by the technicians, the engineers and all those who may be mainly concerned by digital processing. This subject, fast extending if not determining, however tends actually to play a main part in nuclear electronics as well as in several other research areas. (authors) [French] L'analyse binaire a pour objet l'etude mathematique des proprietes d'ensembles binaires algebriques et pour but l'elaboration de methodes simples, rigoureuses et pratiques, destinees aux techniciens, aux ingenieurs et a tous ceux qu'interesse directement le traitement numerique de l'information, discipline en expansion rapide qui, deja, en electronique nucleaire comme dans de nombreux autres domaines de la recherche, tend a jouer un role essentiel sinon determinant. (auteurs)

  9. La micro-entreprise moyen de lutte contre la pauvreté: mise en évidence par application au niveau des régions tunisiennes = Micro-enterprises are the medium against poverty: Its application in Tunisian regions

    Directory of Open Access Journals (Sweden)

    Makram Gaaliche

    2013-12-01

    Full Text Available La contribution du secteur des micro-entreprises en Tunisie, dans la lutte contre la pauvreté, s’est manifestée de telle sorte que, tout accroissement du nombre d’unité de micro-entreprise entraîne une réduction du taux de pauvreté. En outre, il s’est avérée que la participation de ces petites unités dans la lutte contre la pauvreté, varie d’une région à une autre, selon le secteur d’activité y exerçantes. La détection d’une telle spécialisation sectorielle au niveau de la lutte contre la pauvreté, permet l’adoption de politiques régionales ciblées, destinées à encourager la création de micro-entreprises, au niveau des secteurs d’activité les plus pertinents.In Tunisia, the contribution of the microentreprises sector, in the fight against poverty, has appeared so that, every increasing in the number of the microentreprises involves a reduction of the poverty rate. In addition, it proved that the participation of these small unities in the fight against poverty varies from one area to another, according to the activity sectors. The detection of such sectoral specialization on the level of the fight against poverty, allows the adoption of targeted regional policies, intended to encourage the creation of microentreprises, in the most relevant activity sectors.

  10. Comportement des polluants des eaux pluviales urbaines en ...

    African Journals Online (AJOL)

    développement et la croissance des organismes vivant dans l'eau et particulièrement les micro- organismes. Le suivi des températures enregistrées oscille entre 9 et 16°C dans les trois sites d'observation durant la période ... de la lumière du soleil. Le site C est bien aéré et .... Effets de différents modes de gestion des eaux ...

  11. Approche historique des classifications en psychiatrie

    OpenAIRE

    Garrabé , J.

    2011-01-01

    Resume Des le milieu du xixe siecle s?est posee la question des criteres de classification des maladies. Pour les maladies mentales, diverses classifications ont alors ete proposees par des auteurs francais (Morel) et allemands (Kahlbaum, Kraepelin). A partir de la fin du xixe siecle, le Bureau International de Statistique (Paris) a publie a une Classification Internationale des Maladies, a revision decennale (J. Bertillon). Cette tache a ete poursuivie dans l?entre-deux-guerres pa...

  12. Complications du traitement traditionnel des fractures : aspects ...

    African Journals Online (AJOL)

    Tous les patients reçus avec des complications du traitement traditionnel des fractures ont été inclus dans ce travail. Le diagnostic des lésions était clinique et radiologique. Nous avions reçu 51 patients porteurs de complications suite à des traitements de médecine traditionnelle, soit 13,7% du total des patients hospitalisés ...

  13. Réduction des vibrations de structures composites complexes par dispositifs piézoélectriques shuntés : application aux aubes de turbomachines

    OpenAIRE

    Thierry , Olivier

    2016-01-01

    This thesis concerns the vibration reduction in the low frequency range of a composite fan blade of a turbojet engine with piezoelectric devices. The interest is to increase lifespan and avoid flutter phenomena by reducing the vibration amplitude. The purpose of this thesis is to study several shunted piezoelectric devices, in the low frequency range, that can be applied to a woven composite turbojet fan blade. The targeted applications are the LEAP fan blades or the “open-rotor” fan blade, b...

  14. GESTION DES FLUX ÉNERGÉTIQUE DANS UN SYSTÈME PHOTOVOLTAÏQUE AVEC STOCKAGE CONNECTER AU RÉSEAU – Application à l'habitat

    OpenAIRE

    Riffonneau , Yann

    2009-01-01

    The work done during this thesis contributes to the intensive penetration of the photovoltaic electricity production into the electric grid. Photovoltaic energy holds an immense potential, in particular in the housing sector, but intermittent nature limits its large scale development. In this thesis, we propose to add a storage element to the grid connected photovoltaic system (housing application). First, we introduce the notion of energy management in these systems called « hybrids systems ...

  15. Modélisation de l'anisotropie plastique et application à la mise en forme des tôles métalliques

    OpenAIRE

    RABAHALLAH , Meziane

    2007-01-01

    This research work, realized in two laboratories (LPMM of ENSAM of Metz and LPMTM of Paris 13 university) proposed to study the plastic anisotropy of sheet metals during forming operations. The applications in mind concern the prediction, through the forming process numerical simulation, of the initial plastic anisotropy and its influence on the global behaviour of the sheet. An anisotropy that manifest, during forming operation, by the apparition of undulations on the sheet edge. To do this,...

  16. Evaluation and optimization of the bandwidth of static converters: application to multi-cell converters; Evaluation et optimisation de la bande passante des convertisseurs statiques

    Energy Technology Data Exchange (ETDEWEB)

    Aime, M.

    2003-11-15

    Thanks to the technological progress achieved in the field of power electronics, the use of static converters has spread to new applications. In particular, some applications such as active filtering or the supply of special AC machines require power converters having good dynamic performances. The subject of this thesis is to evaluate systematically the dynamic performances of multi-cell converters, and then to optimize these performances. This document is organized in four chapters. The first one summarizes the main multilevel converter structures, and some control strategies dedicated to these structures. The second chapter presents the evaluation criteria chosen to quantify the dynamic performances of static converters. These criteria are then used to compare the performances obtained with two different PWM strategies. An optimized strategy which results from a trade-off between the two former strategies is then introduced. The third chapter shows a new control strategy of multi-cell voltage source converters. This new strategy enables to control the peak current at a fixed switching frequency. The operation of this controller is explained, and the results obtained by digital simulations are presented and discussed. The fourth chapter deals with the experimental achievement of the peak current control. In particular, the implementation of the control algorithm within a FPGA is demonstrated. Finally, the conclusion of this thesis presents some orientations for further developments, in order to improve the current control strategy and to widen its field of applications. (author)

  17. Les étudiantes et étudiants en écosanté : tisser des liens | IDRC ...

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

    9 mai 2011 ... De plus, une nouvelle application de réseautage social appelée Ning, semblable à Facebook, a été personnalisée pour former un réseau écosanté où les étudiantes et étudiants créent des profils, présentent des photos et partagent des renseignements sur leur recherche. Entre autres initiatives futures ...

  18. Des cartes dans la classe…

    Directory of Open Access Journals (Sweden)

    R. Gimeno

    1990-09-01

    Full Text Available La majorité des enseignants qui veulent faire des cartes — et les faire réaliser aux élèves — pour répondre aux exigences des instructions officielles, doivent surmonter leur manque de compétences en cartographie et en didactique ainsi que les difficultés propres aux logiciels de cartographie encore peu performants. Ces compétences et la réflexion qui les accompagne sont pourtant accessibles aux enfants de l’école élémentaire…

  19. Diversification des moyens de subsistance des petits producteurs de ...

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

    Cette subvention permettra à l'Institut international de recherche sur les cultures des zones tropicales ... In ROSSA's latest bulletin issue: A farewell message from Simon Carter, the Regional Director of the ... Cigarette Taxation in Tanzania.

  20. Validity of the breast imaging reporting and data system BI-RADS{sup TM} for clinical mammography in men; Anwendbarkeit des Breast Imaging Reporting and Data System (BI-RADS{sup TM}) auf die klinische Mammographie des Mannes

    Energy Technology Data Exchange (ETDEWEB)

    Bock, K.; Duda, V.F.; Bonwetsch, C.; Hadji, P.; Schulz, K.D. [Marburg Univ. (Germany). Klinik fuer Gynaekologie, Gynaekologische Endokrinologie und Onkologie; Iwinska-Zelder, J.; Klose, K.J. [Marburg Univ. (Germany). Klinik fuer Diagnostische Radiologie; Rode, G. [Diagnostische Gemeinschaftspraxis Marburg (Germany)

    2001-11-01

    Aim: The implementation of diagnostic standards enhances quality assurance. The American College of Radiology's breast imaging-reporting and data system (BI-RADS{sup TM}) is intended to standardize terminology in the mammography report, the assessment of the findings, and the recommendation af action to be taken. The purpose of this study was to assess the value of the standardized system for clinically apparent male breast tumors. Do the special male anatomy and physiology limit the applicability of an evaluation system designed for female screening mammograms? Methods: 4 investigators with different degrees of experience retrospectively evaluated 160 male mammograms. Our study was based on the 36 cases which could be correlated to histopathological findings: gynecomastia in the majority of cases, but also 4 invasive ductal carcinoma, 1 leiomyosarcoma and 1 ductal carcinoma in situ. Results: Assessment of the mammograms by BI-RADS{sup TM} (3{sup rd} Edition 1998) correctly placed all cases of malignancy into categories 4 and 5 without respect to the investigators's level of experience. Conclusion: Therefore, we conclude that the BI-RADS{sup TM}-classification can successfully be used to classify male mammograms with a high positive predictive value for malignancy. Knowledge of gender-specific imaging characteristics increases the specificity at a constant high level of sensitivity. (orig.) [German] Ziel: In der apparativen Diagnostik dient die Einfuehrung von Standards der Qualitaetssicherung. Das breast imaging-reporting and data system (BI-RADS{sup TM}) des American College of Radiology standardisiert den Sprachgebrauch in der Befundbeschreibung, die Befundbewertung und die resultierenden Empfehlungen in der Mammographie. Unser Interesse galt der Frage, inwieweit dieses System der Kategorisierung von Screening-Mammographien der Frau uebertragbar ist auf klinische Mammographien des Mannes. Begrenzen Anatomie und Physiologie der maennlichen Brustdruese