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

NASA Astrophysics Data System (ADS)

Metiche, Slimane

La demande croissante en poteaux pour les differents reseaux d'electricite et de telecommunications a rendu necessaire l'utilisation de materiaux innovants, qui preservent l'environnement. La majorite des poteaux electriques existants au Canada ainsi qu'a travers le monde, sont fabriques a partir de materiaux traditionnels tel que le bois, le beton ou l'acier. Les motivations des industriels et des chercheurs a penser a d'autres solutions sont diverses, citons entre autre: La limitation en longueur des poteaux en bois ainsi que la vulnerabilite des poteaux fabriques en beton ou en acier aux agressions climatiques. Les nouveaux poteaux en materiaux composites se presentent comme de bons candidats a cet effet, cependant; leur comportement structural n'est pas connu et des etudes theoriques et experimentales approfondies sont necessaires avant leur mise en marche a grande echelle. Un programme de recherche intensif comportant plusieurs projets experimentaux, analytiques et numeriques est en cours a l'Universite de Sherbrooke afin d'evaluer le comportement a court et a long termes de ces nouveaux poteaux en Polymeres Renforces de Fibres (PRF). C'est dans ce contexte que s'inscrit la presente these, et notre recherche vise a evaluer le comportement a la flexion de nouveaux poteaux tubulaires coniques fabriques en materiaux composites par enroulement filamentaire et ce, a travers une etude theorique, ainsi qu'a travers une serie d'essais de flexion en "grandeur reelle" afin de comprendre le comportement structural de ces poteaux, d'optimiser la conception et de proposer une procedure de dimensionnement pour les utilisateurs. Les poteaux en Polymeres Renforces de Fibres (PRF) etudies dans cette these sont fabriques avec une resine epoxyde renforcee de fibres de verre type E. Chaque type poteaux est constitue principalement de trois zones ou les proprietes geometriques (epaisseur, diametre) et les proprietes mecaniques sont differentes d'une zone a l'autre. La difference entre ces proprietes est due au nombre de couches utilisees dans chaque zone ainsi qu'a l'orientation des fibres de chaque couche. Un total de vingt-trois prototypes de dimensions differentes; ont ete testes en flexion jusqu'a la rupture. Deux types de fibres de verre de masses lineaires differentes, ont ete utilisees afin d'evaluer l'effet du type de fibres sur le comportement a la flexion. Un nouveau montage experimental permettant de tester tous les types de poteaux en PRF a ete dimensionne et fabrique selon les recommandations decrites dans les normes ASTM D 4923-01 et ANSI C 136.20-2005. Un modele analytique base sur la theorie des poutres en elasticite lineaire est propose dans cette these. Ce modele predit avec une bonne precision le comportement experimental charge---deflexion ainsi que la deflexion maximale au sommet des poteaux en PRF; constitues de plusieurs zones de caracteristiques geometriques et mecaniques differentes. Une procedure de dimensionnement des poteaux en PRF, basee sur les resultats experimentaux obtenus dans le cadre de la presente these, est egalement proposee. Les resultats obtenus dans le cadre de la presente these permettront le developpement et l'amelioration des regles de conception utiles et pratiques a l'usage des concepteurs et des industriels du domaine des poteaux en PRF. Les retombees de cette recherche sont a la fois economiques et technologiques, car les resultats obtenus constitueront une banque de donnees qui contribueront au developpement des normes de calcul, et par consequent a l'optimisation des materiaux utilises, et serviront a valider de futurs resultats et modeles theoriques.

Le niobate de lithium a haute temperature pour les applications ultrasons =

NASA Astrophysics Data System (ADS)

De Castilla, Hector

L'objectif de ce travail de maitrise en sciences appliquees est de trouver puis etudier un materiau piezoelectrique qui est potentiellement utilisable dans les transducteurs ultrasons a haute temperature. En effet, ces derniers sont actuellement limites a des temperatures de fonctionnement en dessous de 300°C a cause de l'element piezoelectrique qui les compose. Palier a cette limitation permettrait des controles non destructifs par ultrasons a haute temperature. Avec de bonnes proprietes electromecaniques et une temperature de Curie elevee (1200°C), le niobate de lithium (LiNbO 3) est un bon candidat. Mais certaines etudes affirment que des processus chimiques tels que l'apparition de conductivite ionique ou l'emergence d'une nouvelle phase ne permettent pas son utilisation dans les transducteurs ultrasons au-dessus de 600°C. Cependant, d'autres etudes plus recentes ont montre qu'il pouvait generer des ultrasons jusqu'a 1000°C et qu'aucune conductivite n'etait visible. Une hypothese a donc emerge : une conductivite ionique est presente dans le niobate de lithium a haute temperature (>500°C) mais elle n'affecte que faiblement ses proprietes a hautes frequences (>100 kHz). Une caracterisation du niobate de lithium a haute temperature est donc necessaire afin de verifier cette hypothese. Pour cela, la methode par resonance a ete employee. Elle permet une caracterisation de la plupart des coefficients electromecaniques avec une simple spectroscopie d'impedance electrochimique et un modele reliant de facon explicite les proprietes au spectre d'impedance. Il s'agit de trouver les coefficients du modele permettant de superposer au mieux le modele avec les mesures experimentales. Un banc experimental a ete realise permettant de controler la temperature des echantillons et de mesurer leur impedance electrochimique. Malheureusement, les modeles actuellement utilises pour la methode par resonance sont imprecis en presence de couplages entre les modes de vibration. Cela implique de posseder plusieurs echantillons de differentes formes afin d'isoler chaque mode principal de vibration. De plus, ces modeles ne prennent pas bien en compte les harmoniques et modes en cisaillement. C'est pourquoi un nouveau modele analytique couvrant tout le spectre frequentiel a ete developpe afin de predire les resonances en cisaillement, les harmoniques et les couplages entre les modes. Neanmoins, certains modes de resonances et certains couplages ne sont toujours pas modelises. La caracterisation d'echantillons carres a pu etre menee jusqu'a 750°C. Les resultats confirment le caractere prometteur du niobate de lithium. Les coefficients piezoelectriques sont stables en fonction de la temperature et l'elasticite et la permittivite ont le comportement attendu. Un effet thermoelectrique ayant un effet similaire a de la conductivite ionique a ete observe ce qui ne permet pas de quantifier l'impact de ce dernier. Bien que des etudes complementaires soient necessaires, l'intensite des resonances a 750°C semble indiquer que le niobate de lithium peut etre utilise pour des applications ultrasons a hautes frequences (>100 kHz).

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

NASA Astrophysics Data System (ADS)

Maamri, Ilyes

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

Fuel-Air Explosive Simulation of Far-Field Nuclear Airblasts.

DTIC Science & Technology

1979-12-31

Blastwave Simulator," Sixieme Symposium International sur Les A19 plications Militaires de La Simulation de Souffle, Centre D’Etudes de Gramat , Gramat ... Gramat , Gramat , France, p. 4.2.1, June 1979. 207 7............................. 64. Cooperwaithe, M. and Zwisler, W. H., "TIGER Computer Program

Folds and Etudes

ERIC Educational Resources Information Center

Bean, Robert

2007-01-01

In this article, the author talks about "Folds" and "Etudes" which are images derived from anonymous typing exercises that he found in a used copy of "Touch Typing Made Simple". "Etudes" refers to the musical tradition of studies for a solo instrument, which is a typewriter. Typing exercises are repetitive attempts to type words and phrases…

Introduction A l'Etude de la Médecine Expérimentale--surgical revolution part II.

PubMed

Toledo-Pereyra, Luis H

2009-01-01

The book that Claude Bernard (1813-1878) published in 1865, the Introduction à l'Etude de la Médecine Expérimentale, fostered a revolution that we believe influenced the practice of surgery when the discipline became a scientific enterprise. In Part I, we set the stage by presenting the life and accomplishments of Bernard, by reviewing his science, and introducing his experimental medicine work. In this issue in Part II, we further analyze his book and determine the "why" of a genuine surgical revolution. What were the factors that generated this revolution, and how a new generation of surgeons learned to become better researchers, and thus better surgeons, were the main objectives of this work. Science, research, and surgery became highly intertwined and the surgeon pursued these fields of knowledge more effectively.

Experimental Study of the Shock Waves Produced by Condenser Discharge in a Gas Tube (thesis); ETUDE EXPERIMENTALE DES ONDES DE CHOC PRODUITES PAR DECHARGES D'UN CONDENSATEUR DANS UN TUBE A GAZ (thesis)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Der Agobian, R.

1964-10-31

The shock waves Droduced by condenser discharge in a gas tube were investigated. The study was limited to wave velocities less than five times the speed of sound, propagated in gas at low pressure (several mm Hg). A method was designed and perfected for the detection of the shock waves that are insufficiently rapid to produce gas ionization. This method consisted of the creation of an autonomous plasma, before the arrival of the wave, which was then modified by the wave passage. two methods were used for the detection of phenomena accompanying the passage of the shock waves, an opticalmore » method and a radioelectric method. The qualitative study of the modifications produced on the wave passage showed the remarkable correlation existing between the results obtained by the two methods. The experimental results on the propagation laws for shock waves in a low-diameter tube agreed with theory. The variations of the coefficient oi recombination were determined as a iunction of the electron temperature, and the results were in good agreement with the Bates theory. It was shown that the electron gas of the plasma had the same increase of density as a neutral gas during the passage of a shock wave. The variations of the frequency of electron collisions on passage of the shock wave could be explained by considering the electron--ion collisions with respect to electron-- atom collisions. (J.S.R.)« less

L'etude de l'InP et du GaP suite a l'implantation ionique de Mn et a un recuit thermique

NASA Astrophysics Data System (ADS)

Bucsa, Ioan Gigel

Cette these est dediee a l'etude des materiaux InMnP et GaMnP fabriques par implantation ionique et recuit thermique. Plus precisement nous avons investigue la possibilite de former par implantation ionique des materiaux homogenes (alliages) de InMnP et GaMnP contenant de 1 a 5 % atomiques de Mn qui seraient en etat ferromagnetique, pour des possibles applications dans la spintronique. Dans un premier chapitre introductif nous donnons les motivations de cette recherche et faisons une revue de la litterature sur ce sujet. Le deuxieme chapitre decrit les principes de l'implantation ionique, qui est la technique utilisee pour la fabrication des echantillons. Les effets de l'energie, fluence et direction du faisceau ionique sur le profil d'implantation et la formation des dommages seront mis en evidence. Aussi dans ce chapitre nous allons trouver des informations sur les substrats utilises pour l'implantation. Les techniques experimentales utilisees pour la caracterisation structurale, chimique et magnetique des echantillons, ainsi que leurs limitations sont presentees dans le troisieme chapitre. Quelques principes theoriques du magnetisme necessaires pour la comprehension des mesures magnetiques se retrouvent dans le chapitre 4. Le cinquieme chapitre est dedie a l'etude de la morphologie et des proprietes magnetiques des substrats utilises pour implantation et le sixieme chapitre, a l'etude des echantillons implantes au Mn sans avoir subi un recuit thermique. Notamment nous allons voir dans ce chapitre que l'implantation de Mn a plus que 1016 ions/cm 2 amorphise la partie implantee du materiau et le Mn implante se dispose en profondeur sur un profil gaussien. De point de vue magnetique les atomes implantes se trouvent dans un etat paramagnetique entre 5 et 300 K ayant le spin 5/2. Dans le chapitre 7 nous presentons les proprietes des echantillons recuits a basses temperatures. Nous allons voir que dans ces echantillons la couche implantee est polycristalline et les atomes de Mn sont toujours dans un etat paramagnetique. Dans les chapitres 8 et 9, qui sont les plus volumineux, nous presentons les resultats des mesures sur les echantillons recuits a hautes temperatures: il s'agit d'InP et du GaP implantes au Mn, dans le chapitre 8 et d'InP co-implante au Mn et au P, dans le chapitre 9. D'abord, dans le chapitre 8 nous allons voir que le recuit a hautes temperatures mene a une recristallisation epitaxiale du InMnP et du GaMnP; aussi la majorite des atomes de Mn se deplacent vers la surface a cause d'un effet de segregation. Dans les regions de la surface, concentres en Mn, les mesures XRD et TEM identifient la formation de MnP et d'In cristallin. Les mesures magnetiques identifient aussi la presence de MnP ferromagnetique. De plus dans ces mesures on trouve qu'environ 60 % du Mn implante est en etat paramagnetique avec la valeur du spin reduite par rapport a celle trouvee dans les echantillons non-recuits. Dans les echantillons InP co-implantes au Mn et au P la recristallisation est seulement partielle mais l'effet de segregation du Mn a la surface est beaucoup reduit. Dans ce cas plus que 50 % du Mn forme des particules MnP et le restant est en etat paramagnetique au spin 5/2, dilue dans la matrice de l'InP. Finalement dans le dernier chapitre, 10, nous presentons les conclusions principales auxquels nous sommes arrives et discutons les resultats et leurs implications. Mots cles: implantation ionique, InP, GaP, amorphisation, MnP, segregation, co-implantation, couche polycristalline, paramagnetisme, ferromagnetisme.

Effets des electrons secondaires sur l'ADN

NASA Astrophysics Data System (ADS)

Boudaiffa, Badia

Les interactions des electrons de basse energie (EBE) representent un element important en sciences des radiations, particulierement, les sequences se produisant immediatement apres l'interaction de la radiation ionisante avec le milieu biologique. Il est bien connu que lorsque ces radiations deposent leur energie dans la cellule, elles produisent un grand nombre d'electrons secondaires (4 x 104/MeV), qui sont crees le long de la trace avec des energies cinetiques initiales bien inferieures a 20 eV. Cependant, il n'y a jamais eu de mesures directes demontrant l'interaction de ces electrons de tres basse energie avec l'ADN, du principalement aux difficultes experimentales imposees par la complexite du milieu biologique. Dans notre laboratoire, les dernieres annees ont ete consacrees a l'etude des phenomenes fondamentaux induits par impact des EBE sur differentes molecules simples (e.g., N2, CO, O2, H2O, NO, C2H 4, C6H6, C2H12) et quelques molecules complexes dans leur phase solide. D'autres travaux effectues recemment sur des bases de l'ADN et des oligonucleotides ont montre que les EBE produisent des bris moleculaires sur les biomolecules. Ces travaux nous ont permis d'elaborer des techniques pour mettre en evidence et comprendre les interactions fondamentales des EBE avec des molecules d'interet biologique, afin d'atteindre notre objectif majeur d'etudier l'effet direct de ces particules sur la molecule d'ADN. Les techniques de sciences des surfaces developpees et utilisees dans les etudes precitees peuvent etre etendues et combinees avec des methodes classiques de biologie pour etudier les dommages de l'ADN induits par l'impact des EBE. Nos experiences ont montre l'efficacite des electrons de 3--20 eV a induire des coupures simple et double brins dans l'ADN. Pour des energies inferieures a 15 eV, ces coupures sont induites par la localisation temporaire d'un electron sur une unite moleculaire de l'ADN, ce qui engendre la formation d'un ion negatif transitoire dans un etat electronique dissociatif, cette localisation est suivie d'une fragmentation. A plus haute energie, la dissociation dipolaire (i.e., la formation simultanee d'un ion positif et negatif) et l'ionisation jouent un role important dans le dommage de l'ADN. L'ensemble de nos resultats permet d'expliquer les mecanismes de degradation de l'ADN par les EBE et d'obtenir des sections efficaces effectives des differents types de dommages.

French Research in Acoustics and Signal Processing: Report on Introductory Visit

DTIC Science & Technology

1986-05-01

CEPHAG (Centre d’Etude des Phenomenes Aleatoires et Geophysiques ), which is associated with the Institut National Polytechnique at Grenoble. We were...measurement programs. Centre d’Etude des Phenomenes Aleatoires et Geophysiques (CEPHAG), Institut National Polytechnique, Universite de Grenoble, 23 May...69288 Lyon Cedex, France, Tel 72.32.50.67. CENTRE D’ETUDE DES PHENOMENES ALEATOIRES ET GEOPHYSIQUES (CEPHAG), Grenoble. Prof. J. L. Lacoume

Synthese de champs sonores adaptative

NASA Astrophysics Data System (ADS)

Gauthier, Philippe-Aubert

La reproduction de champs acoustiques est une approche physique au probleme technologique de la spatialisation sonore. Cette these concerne l'aspect physique de la reproduction de champs acoustiques. L'objectif principal est l'amelioration de la reproduction de champs acoustiques par "synthese de champs acoustiques" ("Wave Field Synthesis", WFS), une approche connue, basee sur des hypotheses de champ libre, a l'aide du controle actif par l'ajout de capteurs de l'erreur de reproduction et d'une boucle fermee. Un premier chapitre technique (chapitre 4) expose les resultats d'appreciation objective de la WFS par simulations et mesures experimentales. L'effet indesirable de la salle de reproduction sur les qualites objectives de la WFS fut illustre. Une premiere question de recherche fut ensuite abordee (chapitre 5), a savoir s'il est possible de reproduire des champs progressifs en salle dans un paradigme physique de controle actif: cette possibilite fut prouvee. L'approche technique privilegiee, "synthese de champs adaptative" ("Adaptive Wave Field Synthesis" [AWFS]), fut definie, puis simulee (chapitre 6). Cette approche d'AWFS comporte une originalite en controle actif et en reproduction de champs acoustiques: la fonction cout quadratique representant la minimisation des erreurs de reproduction inclut une regularisation de Tikhonov avec solution a priori qui vient de la WFS. L'etude de l'AWFS a l'aide de la decomposition en valeurs singulieres (chapitre 7) a permis de comprendre les mecanismes propres a l'AWFS. C'est la deuxieme principale originalite de la these. L'algorithme FXLMS (LMS et reference filtree) est modifie pour l'AWFS (chapitre 8). Le decouplage du systeme par decomposition en valeurs singulieres est illustre dans le domaine du traitement de signal et l'AWFS basee sur le controle independant des modes de rayonnement est simulee (chapitre 8). Ce qui constitue la troisieme originalite principale de cette these. Ces simulations du traitement de signal montrent l'efficacite des algorithmes et la capacite de l'AWFS a attenuer les erreurs attribuables a des reflexions acoustiques. Le neuvieme chapitre presente des resultats experimentaux d'AWFS. L'objectif etait de valider la methode et d'evaluer les performances de l'AWFS. Un autre algorithme prometteur est aussi teste. Les resultats demontrent la bonne marche de l'AWFS et des algorithmes testes. Autant dans le cas de la reproduction de champs harmoniques que dans le cas de la reproduction de champs a large bande, l'AWFS reduit l'erreur de reproduction de la WFS et les effets indesirables causes par les lieux de reproduction.

Advances in X-Ray Simulator Technology

DTIC Science & Technology

1995-07-01

d’Etudes de Gramat ; I. Vitkovitsky, Logicon RDA INTRODUCTION DNA’s future x-ray simulators are based upon inductive energy storage, a technology which...switch. SYRINX, a proposed design to be built by the Centre d’Etudes de Gramat (CEG) in France would employ a modular approach, possibly with a...called SYRINX, would be built at the Centred’ Etudes de Gramat (CEG). It would employ a modular.long conduction time current source to drive a PRS

Evolution des quasiparticules nodales du cuprate supraconducteur YBa2Cu3Oy en conductivite thermique

NASA Astrophysics Data System (ADS)

Rene de Cotret, Samuel

Ce memoire presente des mesures de conductivite thermique sur les supraconducteurs YBCO et Tl-2201 afin de statuer sur la presence possible d'un point critique quantique (QCP) dans le diagramme de phase de cuprates. Ce point critique quantique serait a l'origine de la reconstruction de la surface de Fermi, d'un large cylindre de trous en de petites poches de trous et d'electrons. La conductivite thermique dans le regime T → 0 permet d'extraire une quantite purement electronique liee aux vitesses de Fermi et du gap, au noeud. Une discontinuite dans cette quantite pourrait signaler la traversee du dopage critique qui reconstruit la surface de Fermi. Plusieurs sondes experimentales distinguent une transition de phase ou un crossover a T* a temperature finie. D'autres sondes mettent en evidence une transition de phase sous l'effet d'un champ magnetique. La presence ou non de cet ordre, a temperature et champ magnetique nul questionne la communaute depuis plusieurs annees. Dans cette etude, nous detectons une variation brusque de kappa0/T a p = 0.18 dans YBCO et a p = 0.20 dans Tl-2201. Ces sauts sont interpretes comme un signe de la transition a temperature nulle et sont en faveur d'un QCP. Le manque de donnees d'un meme materiau a ces dopages ne permet pas de valider hors de tout doute l'existence d'un point critique quantique. Le modele theorique YRZ decrit aussi bien les donnees de conductivite thermique. Des pistes de travaux experimentaux a poursuivre sont proposees pour determiner la presence ou non du QCP de facon franche. Mots-cles : Supraconducteurs, cuprates, conductivite thermique, point critique quantique.

Modelisation par elements finis du muscle strie

NASA Astrophysics Data System (ADS)

Leonard, Mathieu

Ce present projet de recherche a permis. de creer un modele par elements finis du muscle strie humain dans le but d'etudier les mecanismes engendrant les lesions musculaires traumatiques. Ce modele constitue une plate-forme numerique capable de discerner l'influence des proprietes mecaniques des fascias et de la cellule musculaire sur le comportement dynamique du muscle lors d'une contraction excentrique, notamment le module de Young et le module de cisaillement de la couche de tissu conjonctif, l'orientation des fibres de collagene de cette membrane et le coefficient de poisson du muscle. La caracterisation experimentale in vitro de ces parametres pour des vitesses de deformation elevees a partir de muscles stries humains actifs est essentielle pour l'etude de lesions musculaires traumatiques. Le modele numerique developpe est capable de modeliser la contraction musculaire comme une transition de phase de la cellule musculaire par un changement de raideur et de volume a l'aide des lois de comportement de materiau predefinies dans le logiciel LS-DYNA (v971, Livermore Software Technology Corporation, Livermore, CA, USA). Le present projet de recherche introduit donc un phenomene physiologique qui pourrait expliquer des blessures musculaires courantes (crampes, courbatures, claquages, etc.), mais aussi des maladies ou desordres touchant le tissu conjonctif comme les collagenoses et la dystrophie musculaire. La predominance de blessures musculaires lors de contractions excentriques est egalement exposee. Le modele developpe dans ce projet de recherche met ainsi a l'avant-scene le concept de transition de phase ouvrant la porte au developpement de nouvelles technologies pour l'activation musculaire chez les personnes atteintes de paraplegie ou de muscles artificiels compacts pour l'elaboration de protheses ou d'exosquelettes. Mots-cles Muscle strie, lesion musculaire, fascia, contraction excentrique, modele par elements finis, transition de phase

Modelisation de la diffusion sur les surfaces metalliques: De l'adatome aux processus de croissance

NASA Astrophysics Data System (ADS)

Boisvert, Ghyslain

Cette these est consacree a l'etude des processus de diffusion en surface dans le but ultime de comprendre, et de modeliser, la croissance d'une couche mince. L'importance de bien mai triser la croissance est primordiale compte tenu de son role dans la miniaturisation des circuits electroniques. Nous etudions ici les surface des metaux nobles et de ceux de la fin de la serie de transition. Dans un premier temps, nous nous interessons a la diffusion d'un simple adatome sur une surface metallique. Nous avons, entre autres, mis en evidence l'apparition d'une correlation entre evenements successifs lorsque la temperature est comparable a la barriere de diffusion, i.e., la diffusion ne peut pas etre associee a une marche aleatoire. Nous proposons un modele phenomenologique simple qui reproduit bien les resultats des simulations. Ces calculs nous ont aussi permis de montrer que la diffusion obeit a la loi de Meyer-Neldel. Cette loi stipule que, pour un processus active, le prefacteur augmente exponentiellement avec la barriere. En plus, ce travail permet de clarifier l'origine physique de cette loi. En comparant les resultats dynamiques aux resultats statiques, on se rend compte que la barriere extraite des calculs dynamiques est essentiellement la meme que celle obtenue par une approche statique, beaucoup plus simple. On peut donc obtenir cette barriere a l'aide de methodes plus precises, i.e., ab initio, comme la theorie de la fonctionnelle de la densite, qui sont aussi malheureusement beaucoup plus lourdes. C'est ce que nous avons fait pour plusieurs systemes metalliques. Nos resultats avec cette derniere approche se comparent tres bien aux resultats experimentaux. Nous nous sommes attardes plus longuement a la surface (111) du platine. Cette surface regorge de particularites interessantes, comme la forme d'equilibre non-hexagonale des i lots et deux sites d'adsorption differents pour l'adatome. De plus, des calculs ab initio precedents n'ont pas reussi a confirmer la forme d'equilibre et surestiment grandement la barriere. Nos calculs, plus complets et dans un formalisme mieux adapte a ce genre de probleme, predisent correctement la forme d'equilibre, qui est en fait due a un relachement different du stress de surface aux deux types de marches qui forment les cotes des i lots. Notre valeur pour la barriere est aussi fortement diminuee lorsqu'on relaxe les forces sur les atomes de la surface, amenant le resultat theorique beaucoup plus pres de la valeur experimentale. Nos calculs pour le cuivre demontre en effet que la diffusion de petits i lots pendant la croissance ne peut pas etre negligee dans ce cas, mettant en doute la valeur des interpretations des mesures experimentales. (Abstract shortened by UMI.)

Le vocabulaire disponible du francais, Tome 1. Le vocabulaire concret usuel des enfants francais et acadiens: Etude temoin (The Working French Vocabulary, Volume 1. Common Generic Terms Used by French and Acadian Children: A Field Study).

ERIC Educational Resources Information Center

Mackey, William F.; And Others

The first of a two-volume study of the relative accessibility of French vocabulary in French-speaking Canada presents statistical data concerning the frequency, distribution, valence, and accessibility of vocabulary related to 16 fundamental centers of interest found in normal conversation. The scope, procedures, and results of the study are…

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

NASA Astrophysics Data System (ADS)

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 supraconductrice qui restent fixes a l'interface coeur-enveloppe, et le revetement en alliage d'argent. L'interet d'une methode calorimetrique par rapport a la technique electrique, plus rapide, plus sensible et maintenant fiable, reside dans la possibilite de realiser des mesures de pertes ac dans des environnements complexes, reproduisant la situation presente par exemple dans un cable de transport d'energie ou dans un transformateur. En particulier, la superposition d'un courant dc en plus du courant ac habituel nous a permis d'observer experimentalement, pour la premiere fois a notre connaissance, un comportement particulier des pertes ac en fonction de la valeur du courant dc decrit theoriquement par LeBlanc. Nous avons pu en deduire la presence d'un courant d'ecrantage Meissner de 16 A, ce qui nous permet de determiner les conditions dans lesquelles une reduction du niveau de pertes ac pourrait etre obtenue par application d'un courant dc, phenomene denomme "vallee de Clem".

Mesure de haute resolution de la fonction de distribution radiale du silicium amorphe pur

NASA Astrophysics Data System (ADS)

Laaziri, Khalid

1999-11-01

Cette these porte sur l'etude de la structure du silicium amorphe prepare par irradiation ionique. Elle presente des mesures de diffraction de rayons X sur de la poudre de silicium cristallin, du silicium amorphe relaxe et non relaxe, ainsi que tous les developpements mathematiques et physiques necessaires pour extraire la fonction de distribution radiale correspondant a chaque echantillon. Au Chapitre I, nous presentons une methode de fabrication de membranes minces de silicium amorphe pur. Il y a deux etapes majeures lors du processus de fabrication: l'implantation ionique, afin de creer une couche amorphe de plusieurs microns et l'attaque chimique, pour enlever le reste du materiau cristallin. Nous avons caracterise premierement les membranes de silicium amorphe par spectroscopie Raman pour verifier qu'il ne reste plus de trace de materiau cristallin dans les films amorphes. Une deuxieme caracterisation par detection de recul elastique (ERD-TOF) sur ces memes membranes a montre qu'il y a moins de 0.1% atomique de contaminants tels que l'oxygene, le carbone, et l'hydrogene. Au Chapitre II, nous proposons une nouvelle methode de correction de la contribution inelastique "Compton" des spectres de diffusion totale afin d'extraire les pics de diffusion elastique, responsable de la diffraction de Bragg. L'article presente tout d'abord une description simplifiee d'une theorie sur la diffusion inelastique dite "Impulse Approximation" (IA) qui permet de calculer des profils de Compton en fonction de l'energie et de l'angle de diffusion 2theta. Ces profils sont utilises comme fonction de lissage de la diffusion Compton experimentale. Pour lisser les pics de diffusion elastique, nous avons utilise une fonction pic de nature asymetrique. Aux Chapitre III, nous exposons de maniere detaillee les resultats des experiences de diffraction de rayons X sur les membranes de silicium amorphe et la poudre de silicium cristallin que nous avons preparees. Nous abordons aussi les differentes etapes experimentales, d'analyse ainsi que les methodes de determination et de filtrage des transformees de Fourier des donnees de diffraction. Une comparaison des fonctions de distribution radiale du silicium amorphe relaxe et non relaxe indique que la relaxation structurelle dans le silicium amorphe est probablement due en grande partie a une annihilation des defauts plutot qu'a une reorganisation atomique globale du reseau de silicium amorphe. La deduction de la coordination des pics correspondants au premiers voisins atomiques par lissage de fonctions gaussienne indique que la coordination du silicium amorphe relaxe est de 3.88, celle du non-relaxe est de 3.79, alors que la mesure de reference sur la poudre de silicium cristallin donne une valeur de 4 tel que prevu. La sous-coordination du silicium amorphe expliquerait pourquoi sa densite est inferieure a celle du silicium cristallin. (Abstract shortened by UMI.)

Experiences of CNES and SEP on space mechanisms rotating at low speed

NASA Technical Reports Server (NTRS)

Atlas, G.; Thomin, G.

1987-01-01

Some aspects of knowledge acquired in the field of space mechanisms by Societe Europeenne de Propulsion and Centre National d'Etudes Spatiales in International and French National space programs are described. The experience described centers on the development of these programs: The MEGS (Mechanisme d'Etrainement du Generateur Solaire), and the MOGS (Mechanisme d'Orientation de Generateur Solaire), both solar array drive mechanisms. Key design areas and the mechanism performance obtained are highlighted. Some test problems with the MEGS sliprings are discussed.

Effets Seebeck et Nernst dans les cuprates: Etude de la reconstruction de la surface de Fermi sous champ magnetique intense

NASA Astrophysics Data System (ADS)

Laliberte, Francis

2010-06-01

Ce memoire presente des mesures de transport thermoelectrique, les effets Seebeck et Nernst, dans une serie d'echantillons de supraconducteurs a haute temperature critique. Des resultats obtenus recemment au Laboratoire National des Champs Magnetiques Intenses a Grenoble sur La1.7Eu0.2Sr0.1 CuO4, La1.675Eu0.2Sr0.125CuO 4, La1.64Eu0.2Sr0.16CuO4, La1.74Eu0.1Sr0.16CuO4 et La 1.4Nd0.4Sr0.2CuO4 sont analyses. Une attention particuliere est accordee aux equations de la theorie semi-classique du transport et leur validite est verifiee. La procedure experimentale et les materiaux utilises pour concevoir les montages de mesures sont expliques en detail. Enfin, un chapitre est dedie a l'explication et l'interpretation des resultats de transport thermoelectrique sur YBa2Cu3O6+delta publies au cours de l'hiver 2010 dans les revues Nature et Physical Review Letters. Les donnees d'effet Seebeck dans les echantillons de La 1.8-x,Eu0.2SrxCuO 4, ou un changement de signe est observe, permettent de conclure a la presence d'une poche d'electrons dans la surface de Fermi qui domine le transport a basse temperature dans la region sous-dopee du diagramme de phase. Cette conclusion est similaire a celle obtenue par des mesures d'effet Hall dans YBa 2Cu3O6+delta et elle cadre bien dans un scenario de reconstruction de la surface de Fermi. Les donnees d'effet Nernst recueillies indiquent que la contribution des fluctuations supraconductrices est limitee a un modeste intervalle de temperature au-dessus de la temperature critique.

Singing as a Therapeutic Agent, inThe Etude, 1891-1949.

PubMed

Hunter

1999-01-01

The Etude music magazine, founded by Theodore Presser, was one of a number of popular music magazines published in the years prior to the establishment of the music therapy profession in 1950. During its publication run from 1883 to 1957, over 100 music therapy related articles appeared, including 13 on the health benefits of singing published between 1891 and 1949. Written by authors with diverse backgrounds, such as the famous Battle Creek, Michigan physician John Harvey Kellogg and Boston music critic Louis C. Elson, the articles contained consistent and adamant support regarding the health benefits of singing. The advantages described were both physical and psychological, and were recommended prophylactically for well persons and therapeutically for ill persons. Although the articles varied in perspective, from philosophical to theoretical to pedagogical, there is a consistent holistic medicine theme that appeared almost ahead of its time and no doubt linked to the push for vocal music education in that era. The importance of The Etude in promulgating ideas that helped shape the early practice of music therapy should not be underestimated. For much of its publication run The Etude was the largest music periodical in print, reaching its peak circulation of 250,000 copies per month in 1924.

Evaluation d'une approche pedagogique respectant les facons d'apprendre des filles en sciences et en TIC en 9e annee au Nouveau-Brunswick

NASA Astrophysics Data System (ADS)

Lirette-Pitre, Nicole T.

2009-07-01

La reussite scolaire des filles les amene de plus en plus a poursuivre une formation postsecondaire et a exercer des professions qui demandent un haut niveau de connaissances et d'expertise scientifique. Toutefois, les filles demeurent toujours tres peu nombreuses a envisager une carriere en sciences (chimie et physique), en ingenierie ou en TIC (technologie d'information et de la communication), soit une carriere reliee a la nouvelle economie. Pour plusieurs filles, les sciences et les TIC ne sont pas des matieres scolaires qu'elles trouvent interessantes meme si elles y reussissent tres bien. Ces filles admettent que leurs experiences d'apprentissage en sciences et en TIC ne leur ont pas permis de developper un interet ni de se sentir confiante en leurs habiletes a reussir dans ces matieres. Par consequent, peu de filles choisissent de poursuivre leurs etudes postsecondaires dans ces disciplines. La theorie sociocognitive du choix carriere a ete choisie comme modele theorique pour mieux comprendre quelles variables entrent en jeu lorsque les filles choisissent leur carriere. Notre etude a pour objet la conception et l'evaluation de l'efficacite d'un materiel pedagogique concu specifiquement pour ameliorer les experiences d'apprentissage en sciences et en TIC des filles de 9e annee au Nouveau-Brunswick. L'approche pedagogique privilegiee dans notre materiel a mis en oeuvre des strategies pedagogiques issues des meilleures pratiques que nous avons identifiees et qui visaient particulierement l'augmentation du sentiment d'auto-efficacite et de l'interet des filles pour ces disciplines. Ce materiel disponible par Internet a l'adresse http://www.umoncton.ca/lirettn/scientic est directement en lien avec le programme d'etudes en sciences de la nature de 9e annee du Nouveau-Brunswick. L'evaluation de l'efficacite de notre materiel pedagogique a ete faite selon deux grandes etapes methodologiques: 1) l'evaluation de l'utilisabilite et de la convivialite du materiel et 2) l'evaluation de l'effet du materiel en fonction de diverses variables reliees a l'interet et au sentiment d'auto-efficacite des filles en sciences et en TIC. Cette recherche s'est inscrite dans un paradigme pragmatique de recherche. Le pragmatisme a guide nos choix en ce qui a trait au modele de recherche et des techniques utilisees. Cette recherche a associe a la fois des techniques qualitatives et quantitatives, particulierement en ce qui concerne la collecte et l'analyse de donnees. Les donnees recueillies dans la premiere etape de l'evaluation de l'utilisabilite et de la convivialite du materiel par les enseignantes et les enseignants de sciences et les filles ont revele que le materiel concu est tres utilisable et convivial. Toutefois quelques petites ameliorations seront apportees a une version subsequente afin de faciliter davantage la navigation. Quant a l'evaluation des effets du materiel concu sur les variables reliees au sentiment d'auto-efficacite et aux interets lors de l'etape quasi experimentale, nos donnees qualitatives ont indique que ce materiel a eu des effets positifs sur le sentiment d'auto-efficacite et sur les interets des filles qui l'ont utilise. Toutefois, nos donnees quantitatives n'ont pas permis d'inferer un lien causal direct entre l'utilisation du materiel et l'augmentation du sentiment d'auto-efficacite et des interets des filles en sciences et en TIC. A la lumiere des resultats obtenus, nous avons conclu que le materiel a eu les effets escomptes. Donc, nous recommandons la creation et l'utilisation de materiel de ce genre dans toutes les classes de sciences de la 6e annee a la 12e annee au Nouveau-Brunswick.

Microgenerateurs electriques a base d'oscillateurs thermiques

NASA Astrophysics Data System (ADS)

Leveille, Etienne

Dans un contexte de developpement durable et d'automatisation de notre environnement, l'utilisation de capteurs sans-fil distribues est croissante. Hors l'usage et le remplacement de piles s'avere couteux. La consommation energetique de plus en plus faible de l'electronique rend l'extraction energetique de l'energie ambiante envisageable. La chaleur residuelle est une source d'energie interessante puisqu'elle est la forme finale de la majeure partie de l'energie utilisee par l'humain. Cependant, a petite echelle, seuls les elements thermoelectriques sont disponibles. Les presents travaux s'interessent donc a explorer et comparer des mecanismes de generation alternatifs. Puisque la majorite des mecanismes de transduction alternatifs sont dynamiques, leur utilisation requiert une transformation de l'energie thermique continue en oscillations. Les mecanismes etudies ont donc tous en commun de posseder un oscillateur thermique en plus d'un mecanisme de transduction vers la forme d'energie electrique. Parmi les divers mecanismes identifies, deux sont etudies en details pour comprendre leurs comportements ainsi que connaitre leur efficacite et leur puissance potentielle. Le premier generateur etudie theoriquement est base sur le changement de ferromagnetisme d'une masse suspendue par des ressorts au-dessus d'un aimant. Les comportements du modele developpe correspondent aux comportements reportes dans la litterature. Deux parametres de conception principaux ont ete identifies, permettant un controle de la frequence, de la plage de temperatures d'operation. De plus le mecanisme peut operer avec de faibles differences de temperature et des temperatures proches de l'ambiant, ouvrant la porte a des applications utilisant la chaleur du corps humain. L'utilisation de materiau pyroelectrique comme mecanisme de transduction pourrait offrir des densites de puissance electrique envisageables de l'ordre de 1mW/cm3. Le second generateur etudie experimentalement est base sur l'evaporation explosive d'un liquide surchauffe en absence de sites de nucleation. Un premier prototype a permis de demontrer, pour la premiere fois, le fonctionnement d'un tel cycle. Une etude de l'effet de la temperature de la source de chaleur et de l'effet du debit de liquide montre qu'une zone d'operation ideale est presente. La puissance de sortie maximale mesuree est de l'ordre de 1.6muW. Des ameliorations sont proposees pour faire croitre cette puissance de deux ordres de grandeur. Finalement, l'utilisation du pompage capillaire pour rendre le systeme autonome est demontre, mais reste sensible aux variations de conditions. Finalement, l'etude des dispositifs montre que les microgenerateurs a base d'oscillateurs thermiques peuvent presenter un interet, par rapport aux elements thermoelectriques, dans les applications ou les temperatures sont faibles ou incertaines. Cependant, ces mecanismes souffrent d'une tres faible efficacite causee par les multiples transformations energetiques a faible couplage. Mots-cles : microgenerateur, oscillateur thermique, cycle thermodynamique, thermoelectricite, microsystemes electromecaniques, MEMS

Actes du colloque sur le bilinguisme, Universite de Neuchatel, 14/15 Septembre, 1981 (Proceedings of the Colloquium on Bilingualism, University of Neuchatel, September 14-15, 1981).

ERIC Educational Resources Information Center

TRANEL, 1982

1982-01-01

This issue contains proceedings of a colloquium on linguistics at the University of Neuchatel: (1) "Propositions epistemologiques pour une etude du bilinguisme (Epistemological Propositions for a Study of Bilingualism)," by B. Py; (2) "Comment on di ca? Prolegomenes a une etude de la composante semantique du langage des migrants (How Do You Say…

Plates-formes de microscopie et fluorescence par resonance de plasmons de surface appliquees a l'imagerie cellulaire

NASA Astrophysics Data System (ADS)

Chabot, Vincent

L'elaboration de nouveaux medicaments repose sur les etudes pharmacologiques, dont le role est d'identifier de nouveaux composes actifs ou de nouvelles cibles pharmacologiques agissant entre autres au niveau cellulaire. Recemment, la detection basee sur la resonance des plasmons de surface (SPR) a ete appliquee a l'etude de reponses cellulaires. Cette methode de detection, permettant d'observer des variations d'indice de refraction associes a de faibles changements de masse a la surface d'un metal, a l'avantage de permettre l'etude d'une population de cellules vivantes en temps reel, sans necessiter l'introduction d'agents de marquage. Pour effectuer la detection au niveau de cellules individuelles, on peut employer la microscopie SPR, qui consiste a localiser spatialement la detection par un systeme d'imagerie. Cependant, la detection basee sur la SPR est une mesure sans marquage et les signaux mesures sont attribues a une reponse moyennee des differentes sources cellulaires. Afin de mieux comprendre et identifier les composantes cellulaires generant le signal mesure en SPR, il est pertinent de combiner la microscopie SPR avec une modalite complementaire, soit l'imagerie de fluorescence. C'est dans cette problematique que s'insere ce projet de these, consistant a concevoir deux plates-formes distinctes de microscopie SPR et de fluorescence optimisees pour l'etude cellulaire, de sorte a evaluer les possibilites d'integration de ces deux modalites en un seul systeme. Des substrats adaptes pour chaque plate-forme ont ete concus et realises. Ces substrats employaient une couche d'argent passivee par l'ajout d'une mince couche d'or. La stabilite et la biocompatibilite des substrats ont ete validees pour l'etude cellulaire. Deux configurations permettant d'ameliorer la sensibilite en sondant les cellules plus profondement ont ete evaluees, soit l'emploi de plasmons de surface a longue portee et de guides d'onde a gaine metallique. La sensibilite accrue de ces configurations a aussi ete demontree pour un usage en biodetection cellulaire. Une plate-forme permettant de mesurer la spectroscopie SPR simultanement avec l'acquisition d'images de fluorescence a ete realisee. Cette plate-forme a ensuite ete validee par l'etude de reponses cellulaires suite a une stimulation pharmacologique. Puis, un systeme base sur la microscopie SPR a ete concu et caracterise. Son emploi pour l'etude de reponses au niveau de cellules individuelles a ete demontre. Finalement, les forces et faiblesses des substrats et des plates-formes realisees au cours de la these ont ete evaluees. Des possibilites d'amelioration sont mises de l'avant et l'integration des modalites de microscopie SPR et de fluorescence suite aux travaux de la these est discutee. Les realisations au cours de cette etude ont donc permis d'identifier les composantes cellulaires impliquees dans la generation du signal mesure en biodetection SPR. Mots-cles : Resonance des plasmons de surface, microscopie SPR, plasmons de surface a longue portee LRSPR, guide d'onde a gaine metallique MCWG, fluorescence exaltee par plasmons de surface SPEF, biodetection cellulaire, imagerie SPR.

Propulsion and Energetics Panel Working Group 14 on Suitable Averaging Techniques in Non-Uniform Internal Flows

DTIC Science & Technology

1983-06-01

PANEL WORKING GROUP 14 on SUITABLE AVERAGING TECHNIQUES IN NON-UNIFORM INTERNAL FLOWS Edited by M.Pianko Office National d’Etudes et de...d’Etudes et de Recherches Aerospatiales Pratt and Whitney Government Products Division Rocketdyne Division of Rockwell International , Inc. Teledyne CAE...actions exerted by individual components on the gas flow must be known. These specific component effects are distributed internally within the

Reanalysis of European Flight Loads Data

DTIC Science & Technology

1994-05-01

DATA 6. Pulornig Ogaiation Cods 7. Authus) 8. Peronming Organization Report No. J. B. de Jonge, P.A. Hol and P.A. van Gelder NLR TP 93�L 9...containing data on aircraft operated by British Airways was obtained from the Office National d’etudes et de researches aerospatiales in France. A database...by British Airways. This data base was kept at Office National d’etudes et de recherches aerospatiales (ONERA) and was acquired from that institute

An Integrated Approach to Estimate Instantaneous Near-Surface Air Temperature and Sensible Heat Flux Fields during the SEMAPHORE Experiment.

NASA Astrophysics Data System (ADS)

Bourras, Denis; Eymard, Laurence; Liu, W. Timothy; Dupuis, Hélène

2002-03-01

A new technique was developed to retrieve near-surface instantaneous air temperatures and turbulent sensible heat fluxes using satellite data during the Structure des Echanges Mer-Atmosphere, Proprietes des Heterogeneites Oceaniques: Recherche Experimentale (SEMAPHORE) experiment, which was conducted in 1993 under mainly anticyclonic conditions. The method is based on a regional, horizontal atmospheric temperature advection model whose inputs are wind vectors, sea surface temperature fields, air temperatures around the region under study, and several constants derived from in situ measurements. The intrinsic rms error of the method is 0.7°C in terms of air temperature and 9 W m2 for the fluxes, both at 0.16° × 0.16° and 1.125° × 1.125° resolution. The retrieved air temperature and flux horizontal structures are in good agreement with fields from two operational general circulation models. The application to SEMAPHORE data involves the First European Remote Sensing Satellite (ERS-1) wind fields, Advanced Very High Resolution Radiometer (AVHRR) SST fields, and European Centre for Medium-Range Weather Forecasts (ECMWF) air temperature boundary conditions. The rms errors obtained by comparing the estimations with research vessel measurements are 0.3°C and 5 W m2.

Etude de l'influence de la temperature et de l'humidite sur les proprietes mecaniques en traction des fibres de chanvre et de coco

NASA Astrophysics Data System (ADS)

Ho Thi, Thu Nga

L'objectif de cette etude fut d'etablir l'effet de l'humidite et de la temperature sur la resistance en traction et le module elastique des fibres de chanvre et de coco. Deux etudes ont ete realisees afin d'atteindre cet objectif. La premiere vise l'absorption de l'humidite dans ces fibres en exposition dans l'air (de 0%RH a 80%RH) ainsi que l'absorption de l'eau dans ces fibres immergees dans l'eau aux differentes temperatures. La deuxieme consiste a mesurer la resistance en traction et le module elastique de ces fibres sous differentes conditions d'humidite et de temperature. En basant sur les resultats experimentaux obtenus, les methodes semi empiriques et de reseaux de neurones ont ete utilisees pour but de predire les proprietes en traction (resistance et module d'elasticite) des fibres de chanvre et de coco sous l'influence de l'humidite et de la temperature.

Amelioration de l'efficacite energetique du procede d'electrolyse de l'aluminium conception d'un nouveau bloc cathodique

NASA Astrophysics Data System (ADS)

Blais, Mathieu

Au Quebec, les alumineries sont de grandes consommatrices d'energie electrique, soit pres de 14 % de la puissance installee d'Hydro-Quebec. Dans ce contexte, des petits gains en efficacite energetique des cuves d'electrolyse pourraient avoir un impact important sur la reduction globale de la consommation d'electricite. Le projet de maitrise decrit dans cette etude repond a la problematique suivante : comment l'optimisation de la geometrie d'un bloc cathodique en vue d'uniformiser la densite de courant peut augmenter l'efficacite energetique et la duree de vie de la cuve d'aluminium? Le but premier du projet est de modifier la geometrie en vue d'ameliorer le comportement thermoelectrique des blocs cathodiques et d'accroitre par le fait meme l'efficacite energetique du procede de production d'aluminium. La mauvaise distribution de la densite de courant dans la cuve est responsable de certains problemes energetiques ayant des impacts negatifs sur l'economie et l'environnement. Cette non-uniformite de la distribution du courant induit une usure prematuree de la surface de la cathode et contribue a reduire la stabilite magnetohydrodynamique de la nappe de metal liquide. Afin de quantifier les impacts que peut avoir l'uniformisation de la densite de courant a travers le bloc cathodique, un modele d'un bloc cathodique d'une cuve de la technologie AP-30 a ete concu et analyse par elements finis. A partir de son comportement thermoelectrique et de donnees experimentales d'une cuve AP-30 tirees de la litterature, une correlation entre le profil de densite de courant a la surface du bloc et le taux d'erosion local au meme endroit a ete creee. Cette relation correspond au modele predictif de la duree de vie de tout bloc du meme materiau a partir de son profil de densite de courant. Ensuite, une programmation a ete faite incorporant dans une meme fonction cout les impacts economiques de la duree de vie, de la chute de voltage cathodique et de l'utilisation de nouveaux materiaux. Ceci a permis d'evaluer les benefices faits a partir d'un bloc modifie par rapport au bloc de reference. Plusieurs parametres geometriques du bloc sont variables sur un domaine realiste et l'integration d'un composant en materiau plus conducteur y a egalement ete etudiee. Utilisant des outils mathematiques d'optimisation, un design de bloc optimal a pu etre trouve. Les resultats demontrent qu'il est possible de generer des economies a partir de la modification du bloc. Il est egalement prouve que l'uniformisation de la densite de courant a travers le bloc peut apporter de grands avantages economiques et environnementaux dans le procede d'electrolyse de l'aluminium. Les resultats de cette etude serviront d'arguments pour les chercheurs dans l'industrie a savoir s'il vaut la peine d'investir ou non dans la fabrication d'un prototype experimental souvent tres couteux. Mots-cles : Efficacite energetique, electrolyse de l'aluminium, cathode, simulation thermoelectrique, uniformisation de la densite de courant, optimisation.

Etude Experimentale du Photo-Injecteur de Fermilab (in French)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carneiro, Jean-Paul

2001-01-01

TESLA (TeV Superconducting Linear Accelerator) is an international collaboration which is studying the feasibility of anmore » $e^+e^-$ collider of energy 0.8 TeV in the center of mass. One of the first goals of this collaboration was to construct a prototype linear accelerator at the DESY Laboratory in Hamburg, the TESLA Test Facility (TTF), in order to establish the technical basis for the collider. Two injectors were developed for TTF: a thermionic injector (developed by LAL-Orsay, IPN-Orsay, and CEA-Saclay) and a photo-injector (developed by Fermilab). The thermionic injector was used from February 1997 to October 1998, and then it was replaced by the photo-injector, which was first operated in December 1998. Another photo-injector, identical to the one delivered to TTF, was installed at Fermilab in the $$A{\\emptyset}$$ Building. The first beam from the latter was produced on 3 March 1999. The photo-injector consists of an RF gun, followed by a superconducting cavity. The RF gun is a 1.625-cell copper cavity with a resonant frequency of 1.3 GHz. The gun contains a cesium telluride ($$C_{s_2}$$Te) photo-cathode, which is illuminated by UV pulses from a Nd:YLF laser. The system can produce trains of 800 bunches of photo-electrons of charge 8 nC per bunch with spacing between bunches of 1$$\\mu$$s and 10 Hz repetition rate. Upon emerging from the RF gun, the beam energy is 4 to 5 MeV; the beam is then rapidly accelerated by the superconducting cavity to an energy of 17 to 20 MeV. Finally, a magnetic chicane, consisting of 4 dipoles, produces longitudinal compression of the electron bunches. This thesis describes the installation of the photo-injector at Fermilab and presents the experimentally-measured characteristics of the injector. The principal measurements were quantum eciency, dark current, transverse emittance, and bunch length. The conclusion from these studies is that the quality of the photo-injector beam fullls the design goals. The photo-injector at Fermilab is presently available for user experiments, including the production of at beams and plasma wake eld acceleration.« less

Etude theorique et experimentale de la correlation entre la resistance aux chocs thermiques et aux chocs mecaniques des materiaux refractaires utilises dans les fours de traitement de l'aluminium

NASA Astrophysics Data System (ADS)

Sebbani, Mohamed Jamal Eddine

2001-07-01

This work is a theoretical and experimental study of the correlation between the resistance to thermal shock and mechanical shock of refractory materials. The study of thermal shock showed that the Bahr and Hasselman approaches are alike and that they can be combined into a single, more general approach. This generalisation allowed the division of the theoretical models into two groups: the Hasselman model and the Harmuth model. However, neither of these approaches can predict the behaviour of all refractory materials submitted to thermal shock. Therefore, the generalisation of the Hasselman approach is more appropriate for more dense materials while the Hartmuth approach is more appropriate for less dense materials. The influence of porosity on the energy of rupture helped to explain the behaviour of the less dense material. The absence of generalisation in this case allows those parameters that could be correlated with thermal shock resistance to be dependent on the type of refractory. The study of mechanical shock provided a better understanding of this mechanism. The work performed showed, theoretically and experimentally, that the resistance of the refractory materials could be correlated with the parameter s20 Egwof n-22 . This new parameter helped to explain the statistical correlation between the resistance to mechanical impact and the soxRst parameter established in earlier work. The sintering influence, which makes the refractories more resistant to this type of demand, notably by reducing the "n" coefficient, was shown. This part of the study allowed the establishment of equivalence between thermal fatigue and fatigue by mechanical impact. An evaluation of the correlation between the two mechanisms demonstrated, theoretically and experimentally, that the mechanical and thermal demands could only be exceptionally correlated. In the case of thermal shock, which are imposed deformation demands, it is the shorter cracks which are the most dangerous. However, in the case of mechanical shock, which is constraint imposed, it is the longer cracks that are the most harmful. (Abstract shortened by UMI.)

Formability Extension of Aerospace Alloys for Tube Hydroforming Applications =

NASA Astrophysics Data System (ADS)

Anderson, Melissa

L'hydroformage de tube est un procede novateur de mise en forme du metal qui utilise la pression d'un fluide, generalement de l'eau, dans une matrice fermee pour deformer plastiquement des pieces d'epaisseur faible et fabriquer ainsi des composants tubulaires de geometries complexes. Ce procede possede de nombreux avantages tels que la reduction du poids des pieces, la diminution des couts lies a l'outillage et l'assemblage, la reduction du nombre d'etapes de fabrication et l'excellent etat de surface des pieces hydroformees. Cependant, malgre tous ces atouts, l'hydroformage reste un procede marginal dans le domaine aerospatial a cause de plusieurs facteurs dont la formabilite limitee des alliages aeronautiques. L'objectif principal de la recherche conduite dans le cadre de cette these est d'etudier une methode pour augmenter la formabilite de deux alliages aeronautiques designes par l'utilisation d'un procede de mise en forme multi-etapes qui inclue des cycles de mise en forme suivis d'etapes de traitement thermique intermediaires. Une revue de litterature exhaustive sur les methodes existantes pour ameliorer la formabilite des materiaux vises ainsi que les traitements thermiques d'adoucissement disponibles a permis d'etablir une procedure experimentale appropriee. Ce procede comprend plusieurs sequences de mise en forme suivie de traitement thermique successives jusqu'a l'obtention de la piece finale. L'insertion d'etapes de traitements thermiques intermediaires ainsi que la combinaison " deformation + traitement thermique " influencent le comportement mecanique et metallurgique des alliages. De ce fait, une caracterisation complete des materiaux a ete conduite a chaque etape du procede. D'un point de vue mecanique, l'effet des traitements thermiques et plus generalement du procede multi-etapes sur les proprietes mecaniques et lois constitutives des alliages a ete etudie en detail. Au niveau metallurgique, l'influence du procede sur les caracteristiques microstructurales des alliages tels la taille de grains, les phases en presence et la texture a ete analysee. Ces deux etudes paralleles ont permis de comprendre de facon complete et detaillee l'impact des modifications metallurgiques induites par le procede multietapes sur le comportement mecanique macroscopique et les proprietes finales de la piece.

Programmable wide field spectrograph for earth observation

NASA Astrophysics Data System (ADS)

Zamkotsian, Frédéric; Lanzoni, Patrick; Liotard, Arnaud; Viard, Thierry; Costes, Vincent; Hébert, Philippe-Jean

2017-11-01

In Earth Observation, Universe Observation and Planet Exploration, scientific return of the instruments must be optimized in future missions. Micro-Opto-Electro-Mechanical Systems (MOEMS) could be key components in future generation of space instruments. These devices are based on the mature micro-electronics technology and in addition to their compactness, scalability, and specific task customization, they could generate new functions not available with current technologies. French and European space agencies, the Centre National d'Etudes Spatiales (CNES) and the European Space Agency (ESA) have initiated several studies with LAM and TAS for listing the new functions associated with several types of MEMS, and developing new ideas of instruments.

La Methode Experimentale en Pedagogie (The Experimental Method in Pedagogy)

ERIC Educational Resources Information Center

Rouquette, Michel-Louis

1975-01-01

The pedagogue is caught between the qualitative and quantitative or regularized aspects of his work, a situation not automatically conducive to scientific study. The article refreshes the instructor on the elementary principles of experimentation: observation, systematization, elaboration of hypothesis, and startegies of comparison. (Text is in…

[Grmek, the "thunderbolt", "thunder-clapp" (as testimony)].

PubMed

Lellouch, A

2001-01-01

The paper details how the author (who was a young physician) met, ... by a mere chance. Prof. Grmek a "Sorbonne", in November 1978, how he felt the "Leçons du Jeudi" at the Ecole Pratique des Hautes Etudes (Fourth Section : "Historical and Philological Sciences"). Grmek was both Croatian and French. Other testimonies are given coming from the disciple (who had Prof. Grmek as director of thesis at Paris I - Panthéon - Sorbonne, in 1986) and coming also from Prof. Vera Gavrilovic (Serbia) who met Grmek when he as in "Yugoslavia". Grmek's quotings and photographies, devoted to this exceptional searcher in the field of History of Medicine and History of Sciences, are reported and showed.

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

NASA Astrophysics Data System (ADS)

Amrani, Salah

La fabrication de l'aluminium est realisee dans une cellule d'electrolyse, et cette operation utilise des anodes en carbone. L'evaluation de la qualite de ces anodes reste indispensable avant leur utilisation. La presence des fissures dans les anodes provoque une perturbation du procede l'electrolyse et une diminution de sa performance. Ce projet a ete entrepris pour determiner l'impact des differents parametres de procedes de fabrication des anodes sur la fissuration des anodes denses. Ces parametres incluent ceux de la fabrication des anodes crues, des proprietes des matieres premieres et de la cuisson. Une recherche bibliographique a ete effectuee sur tous les aspects de la fissuration des anodes en carbone pour compiler les travaux anterieurs. Une methodologie detaillee a ete mise au point pour faciliter le deroulement des travaux et atteindre les objectifs vises. La majorite de ce document est reservee pour la discussion des resultats obtenus au laboratoire de l'UQAC et au niveau industriel. Concernant les etudes realisees a l'UQAC, une partie des travaux experimentaux est reservee a la recherche des differents mecanismes de fissuration dans les anodes denses utilisees dans l'industrie d'aluminium. L'approche etait d'abord basee sur la caracterisation qualitative du mecanisme de la fissuration en surface et en profondeur. Puis, une caracterisation quantitative a ete realisee pour la determination de la distribution de la largeur de la fissure sur toute sa longueur, ainsi que le pourcentage de sa surface par rapport a la surface totale de l'echantillon. Cette etude a ete realisee par le biais de la technique d'analyse d'image utilisee pour caracteriser la fissuration d'un echantillon d'anode cuite. L'analyse surfacique et en profondeur de cet echantillon a permis de voir clairement la formation des fissures sur une grande partie de la surface analysee. L'autre partie des travaux est basee sur la caracterisation des defauts dans des echantillons d'anodes crues fabriquees industriellement. Cette technique a consiste a determiner le profil des differentes proprietes physiques. En effet, la methode basee sur la mesure de la distribution de la resistivite electrique sur la totalite de l'echantillon est la technique qui a ete utilisee pour localiser la fissuration et les macro-pores. La microscopie optique et l'analyse d'image ont, quant a elles, permis de caracteriser les zones fissurees tout en determinant la structure des echantillons analyses a l'echelle microscopique. D'autres tests ont ete menes, et ils ont consiste a etudier des echantillons cylindriques d'anodes de 50 mm de diametre et de 130 mm de longueur. Ces derniers ont ete cuits dans un four a UQAC a differents taux de chauffage dans le but de pouvoir determiner l'influence des parametres de cuisson sur la formation de la fissuration dans ce genre de carottes. La caracterisation des echantillons d'anodes cuites a ete faite a l'aide de la microscopie electronique a balayage et de l'ultrason. La derniere partie des travaux realises a l'UQAC contient une etude sur la caracterisation des anodes fabriquees au laboratoire sous differentes conditions d'operation. L'evolution de la qualite de ces anodes a ete faite par l'utilisation de plusieurs techniques. L'evolution de la temperature de refroidissement des anodes crues de laboratoire a ete mesuree; et un modele mathematique a ete developpe et valide avec les donnees experimentales. Cela a pour objectif d'estimer la vitesse de refroidissement ainsi que le stress thermique. Toutes les anodes fabriquees ont ete caracterisees avant la cuisson par la determination de certaines proprietes physiques (resistivite electrique, densite apparente, densite optique et pourcentage de defauts). La tomographie et la distribution de la resistivite electrique, qui sont des techniques non destructives, ont ete employees pour evaluer les defauts internes des anodes. Pendant la cuisson des anodes de laboratoire, l'evolution de la resistivite electrique a ete suivie et l'etape de devolatilisation a ete identifiee. Certaines anodes ont ete cuites a differents taux de chauffage (bas, moyen, eleve et un autre combine) dans l'objectif de trouver les meilleures conditions de cuisson en vue de minimiser la fissuration. D'autres anodes ont ete cuites a differents niveaux de cuisson, cela dans le but d'identifier a quelle etape de l'operation de cuisson la fissuration commence a se developper. Apres la cuisson, les anodes ont ete recuperees pour, a nouveau, faire leur caracterisation par les memes techniques utilisees precedemment. L'objectif principal de cette partie etait de reveler l'impact de differents parametres sur le probleme de fissuration, qui sont repartis sur toute la chaine de production des anodes. Le pourcentage de megots, la quantite de brai et la distribution des particules sont des facteurs importants a considerer pour etudier l'effet de la matiere premiere sur le probleme de la fissuration. Concernant l'effet des parametres du procede de fabrication sur le meme probleme, le temps de vibration, la pression de compaction et le procede de refroidissement ont ete a la base de cette etude. Finalement, l'influence de la phase de cuisson sur l'apparition de la fissuration a ete prise en consideration par l'intermediaire du taux de chauffage et du niveau de cuisson. Les travaux realises au niveau industriel ont ete faits lors d'une campagne de mesure dans le but d'evaluer la qualite des anodes de carbone en general et l'investigation du probleme de fissuration en particulier. Ensuite, il s'agissait de reveler les effets de differents parametres sur le probleme de la fissuration. Vingt-quatre anodes cuites ont ete utilisees. Elles ont ete fabriquees avec differentes matieres premieres (brai, coke, megots) et sous diverses conditions (pression, temps de vibration). Le parametre de la densite de fissuration a ete calcule en se basant sur l'inspection visuelle de la fissuration des carottes. Cela permet de classifier les differentes fissurations en plusieurs categories en se basant sur certains criteres tels que le type de fissures (horizontale, verticale et inclinee), leurs localisations longitudinales (bas, milieu et haut de l'anode) et transversales (gauche, centrale et droite). Les effets de la matiere premiere, les parametres de fabrication des anodes crues ainsi que les conditions de cuisson sur la fissuration ont ete etudies. La fissuration des anodes denses en carbones cause un serieux probleme pour l'industrie d'aluminium primaire. La realisation de ce projet a permis la revelation de differents mecanismes de fissuration, la classification de fissuration par plusieurs criteres (position, types localisation) et l'evaluation de l'impact de differents parametres sur la fissuration. Les etudes effectuees dans le domaine de cuisson ont donne la possibilite d'ameliorer l'operation et reduire la fissuration des anodes. Le travail consiste aussi a identifier des techniques capables d'evaluer la qualite d'anodes (l'ultrason, la tomographie et la distribution de la resistivite electrique). La fissuration des anodes en carbone est consideree comme un probleme complexe, car son apparition depend de plusieurs parametres repartis sur toute la chaine de production. Dans ce projet, plusieurs nouvelles etudes ont ete realisees, et elles permettent de donner de l'originalite aux travaux de recherches faits dans le domaine de la fissuration des anodes de carbone pour l'industrie de l'aluminium primaire. Les etudes realisees dans ce projet permettent d'ajouter d'un cote, une valeur scientifique pour mieux comprendre le probleme de fissuration des anodes et d'un autre cote, d'essayer de proposer des methodes qui peuvent reduire ce probleme a l'echelle industrielle.

Structural Basis for Methylarginine-dependent Recognition of Aubergine by Tudor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, H.; Wang, J; Huang, Y

2010-01-01

Piwi proteins are modified by symmetric dimethylation of arginine (sDMA), and the methylarginine-dependent interaction with Tudor domain proteins is critical for their functions in germline development. Cocrystal structures of an extended Tudor domain (eTud) of Drosophila Tudor with methylated peptides of Aubergine, a Piwi family protein, reveal that sDMA is recognized by an asparagine-gated aromatic cage. Furthermore, the unexpected Tudor-SN/p100 fold of eTud is important for sensing the position of sDMA. The structural information provides mechanistic insights into sDMA-dependent Piwi-Tudor interaction, and the recognition of sDMA by Tudor domains in general.

Team Modelling: Survey of Experimental Platforms (Modelisation d’equipes : Examen de plate-formes experimentales)

DTIC Science & Technology

2006-09-01

Control Force Agility Shared Situational Awareness Attentional Demand Interoperability Network Based Operations Effect Based Operations Speed of...Command Self Synchronization Reach Back Reach Forward Information Superiority Increased Mission Effectiveness Humansystems® Team Modelling...communication effectiveness and Distributed Mission Training (DMT) effectiveness . The NASA Ames Centre - Distributed Research Facilities platform could

Modeles numeriques de la stimulation optique de neurones assistee par nanoparticules plasmoniques

NASA Astrophysics Data System (ADS)

Le Hir, Nicolas

La stimulation de neurones par laser emerge depuis plusieurs annees comme une alternative aux techniques plus traditionnelles de stimulation artificielle. Contrairement a celles-ci, la stimulation lumineuse ne necessite pas d'interagir directement avec le tissu organique, comme c'est le cas pour une stimulation par electrodes, et ne necessite pas de manipulation genetique comme c'est le cas pour les methodes optogenetiques. Plus recemment, la stimulation lumineuse de neurones assistee par nanoparticules a emerge comme un complement a la stimulation simplement lumineuse. L'utilisation de nanoparticules complementaires permet d'augmenter la precision spatiale du procede et de diminuer la fluence necessaire pour observer le phenomene. Ceci vient des proprietes d'interaction entre les nanoparticules et le faisceau laser, comme par exemple les proprietes d'absorption des nanoparticules. Deux phenomenes princpaux sont observes. Dans certains cas, il s'agit d'une depolarisation de la membrane, ou d'un potentiel d'action. Dans d'autres experiences, un influx de calcium vers l'interieur du neurone est detecte par une augmentation de la fluorescence d'une proteine sensible a la concentration calcique. Certaines stimulations sont globales, c'est a dire qu'une perturbation se propage a l'ensemble du neurone : c'est le cas d'un potentiel d'action. D'autres sont, au contraire, locales et ne se propagent pas a l'ensemble de la cellule. Si une stimulation lumineuse globale est rendue possible par des techniques relativement bien maitrisees a l'heure actuelle, comme l'optogenetique, une stimulation uniquement locale est plus difficile a realiser. Or, il semblerait que les methodes de stimulation lumineuse assistees par nanoparticules puissent, dans certaines conditions, offrir cette possibilite. Cela serait d'une grande aide pour conduire de nouvelles etudes sur le fonctionnement des neurones, en offrant de nouvelles possibilites experimentales en complement des possibilites actuelles. Cependant, le mecanisme physique a l'origine de la stimulation lumineuse de neurones, ainsi que celui a l'orgine de la stimulation lumineuse assistee par nanoparticules, n'est a ce jour pas totalement compris. Des hypotheses ont ete formulees concernant ce mecanisme : il pourrait etre photothermique, photomecanique, ou encore photochimique. Il se pourrait egalement que plusieurs mecanismes soient a l'oeuvre conjointement, etant donne la variete des observations. La litterature ne converge pas a ce sujet et l'existence d'un mecanisme commun aux differentes situations n'a pas ete demontree.

Study of African Trypanosomiasis.

DTIC Science & Technology

1979-09-30

received foot and mouth vaccine (Wellcome-Kenya). In general, the experimental animals were kept out- side and supplemental food was provided during... vaccinant dans le plasma de souris experimentalement infectees par Trypanosoma gaibiense et par Trypanosoma concolense. Bullitin de la Society...Medicine and Hyciene, 35: 165-176. Jchnson, P., Neal, R.A. and Gall, D., 1963. Protective effect of killed trypanosome vaccines with incorporated

Inertial dissipation method applied to derive turbulent fluxes over the ocean during the Surface of the Ocean, Fluxes and Interactions with the Atmosphere/Atlantic Stratocumulus Transition Experiment (SOFIA/ASTEX) and Structure des Echanges Mer-Atmosphere, Proprietes des Heterogeneites Oceaniques: Recherche Experimentale (SEMAPHORE) experiments with low to moderate wind speeds

NASA Astrophysics Data System (ADS)

Dupuis, HéLèNe; Taylor, Peter K.; Weill, Alain; Katsaros, K.

1997-09-01

The transfer coefficients for momentum and heat have been determined for 10 m neutral wind speeds (U10n) between 0 and 12 m/s using data from the Surface of the Ocean, Fluxes and Interactions with the Atmosphere (SOFIA) and Structure des Echanges Mer-Atmosphere, Proprietes des Heterogeneites Oceaniques: Recherche Experimentale (SEMAPHORE) experiments. The inertial dissipation method was applied to wind and pseudo virtual temperature spectra from a sonic anemometer, mounted on a platform (ship) which was moving through the turbulence field. Under unstable conditions the assumptions concerning the turbulent kinetic energy (TKE) budget appeared incorrect. Using a bulk estimate for the stability parameter, Z/L (where Z is the height and L is the Obukhov length), this resulted in anomalously low drag coefficients compared to neutral conditions. Determining Z/L iteratively, a low rate of convergence was achieved. It was concluded that the divergence of the turbulent transport of TKE was not negligible under unstable conditions. By minimizing the dependence of the calculated neutral drag coefficient on stability, this term was estimated at about -0.65Z/L. The resulting turbulent fluxes were then in close agreement with other studies at moderate wind speed. The drag and exchange coefficients for low wind speeds were found to be Cen × 103 = 2.79U10n-1 + 0.66 (U10n < 5.2 m/s), Cen × 103 = Chn × 103 = 1.2 (U10n ≥ 5.2 m/s), and Cdn × 103 = 11.710n-2 + 0.668 (U10n < 5.5 m/s), which imply a rapid increase of the coefficient values as the wind decreased within the smooth flow regime. The frozen turbulence hypothesis and the assumptions of isotropy and an inertial subrange were found to remain valid at these low wind speeds for these shipboard measurements. Incorporation of a free convection parameterization had little effect.

Variación temporal de las constantes fundamentales

NASA Astrophysics Data System (ADS)

Landau, S. J.; Vucetich, H.

La variación temporal de las constantes fundamentales es un problema que ha motivado numerosos trabajos teóricos y experimentales desde la hipótesis de los grandes números de Dirac en 1937. Entre los métodos experimentales y observacionales para establecer restricciones sobre la variación de las constantes fundamentes es importante mencionar: comparación entre relojes atómicos[1], métodos geofísicos[2][3], análisis de sistemas de absorción en quasares[4][5][6] y cotas provenientes de la nucleosíntesis primordial[7]. En un trabajo reciente[5], se reportó una significativa variación en la constante de estructura fina. Intentos de unificar las cuatro interacciones fundamentales dieron como resultado teorías con múltiples dimensiones como las teorías de Kaluza-Klein y teorías de supercuerdas. Estas teorías proporcionan un marco teórico natural para el estudio de la variación temporal de las constantes fundamentales. A su vez, un modelo sencillo para estudiar la variación de la constante de estructura fina, fue propuesto en [8], a partir de premisas muy generales como ser covarianza, invarianza de gauge, causalidad y invarianza ante reversiones temporales en el electromagnetismo. Diferentes versiones de las teorías antes mencionadas coinciden en predecir variaciones temporales de las constantes fundamentales pero difieren en la forma de esta variación[9][10]. De esta manera, las restricciones establecidas experimentalmente sobre la variación de las constantes fundamentales pueden ser una herramienta importante para testear estas diferentes teorías. En este trabajo, utilizamos las cotas provenientes de diversas técnicas experimentales, para testear si las mismas son consistentes con alguna de las teorías antes mencionadas. En particular, establecemos cotas sobre la variación de los parámentros libres de las diferentes teorías como por ejemplo el radio de las dimensiones extras en las teorías tipo Kaluza-Klein.

SITELLE: a wide-field imaging Fourier transform spectrometer for the Canada-France-Hawaii Telescope

NASA Astrophysics Data System (ADS)

Drissen, L.; Bernier, A.-P.; Rousseau-Nepton, L.; Alarie, A.; Robert, C.; Joncas, G.; Thibault, S.; Grandmont, F.

2010-07-01

We describe the concept of a new instrument for the Canada-France-Hawaii telescope (CFHT), SITELLE (Spectromètre Imageur à Transformée de Fourier pour l'Etude en Long et en Large de raies d'Emission), as well as a science case and a technical study of its preliminary design. SITELLE will be an imaging Fourier transform spectrometer capable of obtaining the visible (350 nm - 950 nm) spectrum of every source of light in a field of view of 15 arcminutes, with 100% spatial coverage and a spectral resolution ranging from R = 1 (deep panchromatic image) to R = 104 (for gas dynamics). SITELLE will cover a field of view 100 to 1000 times larger than traditional integral field spectrographs, such as GMOS-IFU on Gemini or the future MUSE on the VLT. It is a legacy from BEAR, the first imaging FTS installed on the CFHT and the direct successor of SpIOMM, a similar instrument attached to the 1.6-m telescope of the Observatoire du Mont-Mégantic in Québec. SITELLE will be used to study the structure and kinematics of HII regions and ejecta around evolved stars in the Milky Way, emission-line stars in clusters, abundances in nearby gas-rich galaxies, and the star formation rate in distant galaxies.

Intercomparison and Assessment of GRACE Temporal Gravity Solutions Performance

NASA Astrophysics Data System (ADS)

Choe, J.; Nerem, R. S.; Leuliette, E. W.

2006-12-01

The GRACE mission has been producing monthly estimates of changes in the Earth's gravity field since April 2002. Converting the raw GRACE range, accelerometer, and GPS measurements into estimates of the gravity field is a complex process, and therefore different analysis groups use various "recipes" resulting in different models of the time-varying gravity field. We have intercompared the solutions generated by a number of groups: Center for Space Research (CSR), Jet Propulsion Laboratory (JPL), Goddard Space Flight Center (GSFC), Centre National d'Etudes Spatiales (CNES) and GeoForschungsZentrum (GFZ), to determine the characteristics of each group's solutions as applied to different scientific applications. For different scales of gaussian smoothing, we have examined the power spectrum of each model, the pattern of seasonal gravity variations, the residuals from a seasonal fit, and results from locations in the Sahara desert and Atlantic Ocean where the signals are known to be small. We have also characterized the level of "striping" in each center's solutions. In addition, we have compared each center's solutions for changes in Greenland and Antarctic ice mass, global ocean mass, and hydrologic changes over the continents. Using these tests and evaluations, we have been able to characterize the performance of each center's gravity solutions.

Computational and Experimental Assessment of Jets in Cross Flow (Evaluation Numerique et Experimentale des Jets dans des Courants Transversaux)

DTIC Science & Technology

1993-11-01

sont caracterises par la striosconic continue tic la la partie tie la couche tie melange situde sous le jet figure 3 ainsi que par la tomoscopie tie... caracterisent les ondzs). Ces ondes un disque; de Mach. Sur la figuire 4, on observe la semblent proveriir tie la r6gion tie l’jccteur, juste trace du

Etude de faisabilite d'un systeme eolien diesel avec stockage d'air comprime

NASA Astrophysics Data System (ADS)

Benchaabane, Youssef

Le Systeme Hybride Eolien-Diesel avec Stockage d'Air Comprime (SHEDAC) utilise l'hybridation pneumatique pour remplacer la consommation des combustibles fossiles par de l'energie renouvelable, plus particulierement de l'energie eolienne. Le surplus de l'energie eolienne est utilise pour comprimer et stocker de l'air qui est utilise ensuite pour suralimenter le moteur diesel. Le memoire de maitrise est constitue de deux articles scientifiques. Le premier article presente le developpement d'un logiciel dedie a l'etude de faisabilite d'un systeme eolien-diesel avec stockage d'air comprime. Cette etude est basee sur l'analyse des couts et des revenus, des couts des equipements (eolienne, moteur diesel, systeme de stockage d'air). Elle est completee par une analyse de sensibilite aux differents parametres, une analyse des risques et des emissions des gaz a effet de serre (GES). Le deuxieme article est une application de ce logiciel pour l'installation d'un systeme SHEDAC au camp minier Esker au Quebec en remplacement des sources actuelles de production d'energie. L'utilisation du stockage d'air comprime a l'aide d'un systeme SHEDAC est le plus rentable par rapport a l'utilisation de l'energie eolienne seule ou d'une centrale thermique au diesel seule ou des deux combinees. Avec une valeur actuelle nette et un taux de rendement interne plus eleves, cette solution permet d'obtenir le plus bas cout de l'energie pour cette region eloignee. None None None

Progress in NMR Studies of Liquid Ceramic Materials

NASA Astrophysics Data System (ADS)

Marzke, Robert F.; Piwowarczyk, Jeremy; Boucher, Susan; Wolf, George H.

2003-10-01

The availability of molten, levitated samples of Al-containing ceramics at temperatures of 2,000^oC and higher permits a broad range of important materials to be investigated by the powerful techniques of NMR.footnote Coutures, J-P., Massiot, D., Bessada, C., Echegut, P., Rifflet, J-C. & Taulelle F., Etude par RMN 27Al daluminates liquides dans le domaine 1600-2100 ^oC. C.R. Acad. Sci. Paris, 1990, 310, 1041. Standard measurements of chemical shift as a function of composition yield information concerning the bonding of Al and the structure of liquid phases, for both novel and well-studied refractory materials. Studies of incoherent motions in a sample, such as Al diffusion or time-dependent convective currents, may also be performed when magnetic field gradients are incorporated into the experimental NMR probe. Recent advances are reviewed, in several research areas.

Wedge filter imaging spectrometer

NASA Astrophysics Data System (ADS)

Bernardi, Pernelle; Bonafous, M.; Motisi, M.; Reess, J.-M.; Tanrin, J.; Laubier, D.

2017-11-01

LESIA (Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique, Observatoire de Paris-Meudon) has an extensive experience in visible and infrared imaging spectrometry with several instruments onboard planetary space missions (MarsExpress/OMEGA, VenusExpress/VIRTIS, Rosetta/VIRTIS).

Prediction of Aerodynamic Loads on Rotorcraft.

DTIC Science & Technology

1982-09-01

CALCULATION ON HORIZONTAL AXIS WIND TURBINE IN NON UNIFORM FLOW by E.Lupo 6 PREDICTION ET VERIFICATION EXPERIMENTALE DU CHAMP DES VITESSES D’UN ROTOR...calculs, do plus en plus sophistiqugs, tridimensionnols quasi -stationnairos ou instationnaires non portants ou portents, mime our pale isolfe do rotor...exemple d’dquations de Ia mdcanique des pales. Ces 6quationa sont quasi lin~aires en fonc- tion des portances mgme non lindaires. L’a6rodynamique examinde

Official portrait of STS-65 backup Payload Specialist Jean-Jacques Favier

NASA Image and Video Library

1993-09-30

Official portrait of STS-65 International Microgravity Laboratory 2 (IML-2) backup Payload Specialist Jean-Jacques Favier. Favier is a member of the Centre National D'Etudes Spatiales (CNES), the French space agency.

French research program on the physiological problems caused by weightlessness. Use of the primate model

NASA Astrophysics Data System (ADS)

Pesquies, P. C.; Milhaud, C.; Nogues, C.; Klein, M.; Cailler, B.; Bost, R.

The need to acquire a better knowledge of the main biological problems induced by microgravity implies—in addition to human experimentation—the use of animal models, and primates seem to be particularly well adapted to this type of research. The major areas of investigation to be considered are the phospho-calcium metabolism and the metabolism of supporting tissues, the hydroelectrolytic metabolism, the cardiovascular function, awakeness, sleep-awakeness cycles, the physiology of equilibrium and the pathophysiology of space sickness. Considering this program, the Centre d'Etudes et de Recherches de Medecine Aerospatiale, under the sponsorship of the Centre National d'Etudes Spatiales, developed both a program of research on restrained primates for the French-U.S. space cooperation (Spacelab program) and for the French-Soviet space cooperation (Bio-cosmos program), and simulation of the effects of microgravity by head-down bedrest. Its major characteristics are discussed in the study.

Fractal dimension analysis of complexity in Ligeti piano pieces

NASA Astrophysics Data System (ADS)

Bader, Rolf

2005-04-01

Fractal correlation dimensional analysis has been performed with whole solo piano pieces by Gyrgy Ligeti at every 50ms interval of the pieces. The resulting curves of development of complexity represented by the fractal dimension showed up a very reasonable correlation with the perceptional density of events during these pieces. The seventh piece of Ligeti's ``Musica ricercata'' was used as a test case. Here, each new part of the piece was followed by an increase of the fractal dimension because of the increase of information at the part changes. The second piece ``Galamb borong,'' number seven of the piano Etudes was used, because Ligeti wrote these Etudes after studying fractal geometry. Although the piece is not fractal in the strict mathematical sense, the overall structure of the psychoacoustic event-density as well as the detailed event development is represented by the fractal dimension plot.

Conception d'un outil d'aide a la decision de technologies de fabrication additive en milieu aeronautique

NASA Astrophysics Data System (ADS)

Buvat, Gael

La fabrication additive offre une opportunite d'amelioration des methodes de productions de pieces. Cependant, les technologies de fabrication additive sont diverses, les fournisseurs de services sont multiples et peu de personnel est forme pour operer sur ces technologies. L'objectif de cette etude est d'emettre une suggestion de concepts d'outils d'aide a la decision de technologies, de materiaux et de post-traitements de fabrication additive en milieu aeronautique. Trois sous-objectifs sont employes. Premierement, la definition des criteres de decision de technologies, de materiaux et de post-traitements de fabrication additive. Ensuite, l'elaboration d'un cahier des charges de l'outil d'aide a la decision en accord avec les besoins industriels du secteur aeronautique. Et enfin, la suggestion de trois concepts d'outils d'aide a la decision et leur evaluation par comparaison au cahier des charges etabli. Les criteres captures aupres de 11 industriels concernent des criteres de couts, de qualite, de conception et de delai d'obtention. Ensuite, nous avons elabore un cahier des charges permettant de reunir les besoins des industriels du secteur aeronautique selon trois axes qui constituent la colonne vertebrale des outils d'aide a la decision : une suggestion d'interface utilisateur, une suggestion de bases de donnees et un moteur de selection des technologies, des materiaux et des post-traitements de fabrication additive. La convivialite de l'interface utilisateur, l'evaluation de la qualite souhaitee par l'utilisateur et la prise en compte des etudes de cas realisees par le moteur de selection sont exemples de besoins que nous avons identifie au sein de cette etude. Nous avons ensuite transcrit ces besoins en specifications techniques pour permettre une evaluation du niveau de satisfaction des industriels au travers d'un pointage des trois concepts suggeres. Ces trois concepts d'outils d'aide a la decision ont ete realises respectivement grâce a Microsoft ExcelRTM, Microsoft AccessRTM ainsi qu'une plateforme en ligne associee a l'outil d'apprentissage statistique RapidMinerRTM. Ce dernier outil en ligne a retenu l'attention des ingenieurs qui l'ont evalue principalement du fait de la prise en compte des etudes de cas dans la suggestion preferentielle de technologies, de materiaux et de post-traitements.

Etude experimentale et optimisation d'un systeme hybride hydraulique pour camions a ordures et amelioration des performances par raffinement de sa logique de controle

NASA Astrophysics Data System (ADS)

Lacroix, Benoit

The aim of this thesis is to demonstrate experimentally the operation of a hydraulic hybrid system specifically dedicated to the application of refuse trucks in addition to proposing solutions to improve its control strategy. The developed hybrid system recovers the vehicle's kinetic energy during braking. A variable displacement hydraulic motor then uses the energy stored in a hydraulic accumulator to assist the internal combustion engine (ICE) at suitable times. The particular aspect of this system is that assistance to the ICE can occur when it operates at idle and drives the auxiliary hydraulic equipment of the refuse truck. Essentially, the control strategy initially developed maximizes the recovery of braking energy and uses that energy to minimize the solicitation of the ICE at idle. The experimental results obtained with two prototypes tested in real operating conditions show that the hybrid system can recover a significant portion of braking energy. In addition, the results show that it is possible to reduce the load on the ICE during idle with the application of an assisting torque. However, the advantage of assisting the ICE in specific areas of the operating range is slim since the ICE's gross efficiency varies only slightly depending on conditions of operation. This is confirmed by the optimization of the control logic using deterministic dynamic programming. Indeed, by managing the pressure in the accumulator to maximize the amount of energy recovered during braking and by dosing the assistance to the ICE in an ideal fashion, the optimal control only managed to improve fuel savings by 6% in comparison to the original control. Therefore, since the efforts that would be required to emulate the ideal behavior in real time are significant for a relatively small and uncertain gain, the initial control logic is considered near optimal. Finally, this thesis proposes an improved version of the torque assisting hybrid system that could shut down the ICE when the vehicle is stopped while maintaining functional the auxiliary hydraulic equipment. An optimization of the control logic indicates that proper management of the pressure in the accumulator would allow turning off the ICE most of the time at stop and thus, would increase the fuel savings by over 40% compared to the original system. The simulation of a basic control strategy shows that such pressure management may be feasible in real time and that the potential gain in fuel savings is achievable. Keywords: hybrid system, hydraulic, control, refuse truck.

Le modele de Hubbard bidimensionnel a faible couplage: Thermodynamique et phenomenes critiques

NASA Astrophysics Data System (ADS)

Roy, Sebastien

Une etude systematique du modele de Hubbard en deux dimensions a faible couplage a l'aide de la theorie Auto-Coherente a Deux Particules (ACDP) dans le diagramme temperature-dopage-interaction-sauts permet de mettre en evidence l'influence des fluctuations magnetiques sur les proprietes thermodynamiques du systeme electronique sur reseau. Le regime classique renormalise a temperature finie pres du dopage nul est marque par la grandeur de la longueur de correlation de spin comparee a la longueur thermique de de Broglie et est caracterisee par un accroissement drastique de la longueur de correlation de spin. Cette croissance exponentielle a dopage nul marque la presence d'un pic de chaleur specifique en fonction de la temperature a basse temperature. Une temperature de crossover est alors associee a la temperature a laquelle la longueur de correlation de spin est egale a la longueur thermique de de Broglie. C'est a cette temperature caracteristique, ou est observee l'ouverture du pseudogap dans le poids spectral, que se situe le maximum du pic de chaleur specifique. La presence de ce pic a des consequences sur l'evolution du potentiel chimique avec le dopage lorsque l'uniformite thermodynamique est respectee. Les contraintes imposees par les lois de la thermodynamique font en sorte que l'evolution du potentiel chimique avec le dopage est non triviale. On demontre entre autres que le potentiel chimique est proportionnel a la double occupation qui est reliee au moment local. Par ailleurs, une derivation de la fonction de mise a l'echelle de la susceptibilite de spin a frequence nulle au voisinage d'un point critique marque sans equivoque la presence d'un point critique quantique en dopage pour une valeur donnee de l'interaction. Ce point critique, associe a une transition de phase magnetique en fonction du dopage a temperature nulle, induit un comportement non trivial sur les proprietes physiques du systeme a temperature finie. L'approche quantitative ACDP permet de calculer une echelle de temperature concrete pour laquelle ce point critique a des repercussions. Dans le regime critique, la longueur de correlation enregistre plutot une dependance en 1T Finalement, une synthese de ces resultats permet d'aborder une mise en application pratique de ces methodes d'analyse pour les supraconducteurs a haute temperature critique dopes aux electrons tels que le Nd2--xCe xCuO4+/-delta. Une comparaison entre les resultats theoriques et les mesures experimentales pour ce materiau est effectuee.

Investigation experimentale de l'ecoulement et des performances thermiques du nanofluide eau-oxyde de cuivre dans un Micro-Canal Chauffe

NASA Astrophysics Data System (ADS)

Rimbault, Benjamin

Cette these de maitrise presentee par articles visait a etudier le comportement hydraulique et thermique d'un ecoulement de nanofluides en micro-canal chauffe. Nous avons etudie premierement de l'eau distillee, ensuite des melanges de particules d'oxyde de cuivre (taille 29nm) avec de l'eau distillee en concentrations particulaires volumiques 4.5%, 1.03%, et 0.24% (CuO-H2O). L'ecoulement force des differents fluides a ete realise au moyen de pompes a engrenages au sein d'un circuit ferme, comprenant un micro-canal a section rectangulaire (e=1.116mm,1=25.229mm) chauffe sur deux faces paralleles via des cartouches electriques, deux echangeurs de chaleurs en serie, ainsi qu'un debitmetre magnetique. A notre connaissance peu d'etudes sur l'ecoulement de nanofluides d'oxyde de cuivre-eau en micro-canal rectangulaire chauffe sont disponibles dans la litterature, cette recherche sert de contribution. Premierement, une validation avec la litterature a ete effectuee pour le cas d'un ecoulement d'eau entre plaques planes paralleles chauffees. Des essais hydrauliques ont ete realises pour une gamme du nombre de Reynolds allant jusqu'a Re=5000 a temperature constante. Par la suite des essais thermiques jusqu'a Re=2500 ont consiste en une elevation de temperature fixe (20.5°C a 30.5°C) a travers la longueur du micro-canal sous un regime stationnaire. Les resultats ont demontre une augmentation de la perte de pression et du coefficient de frottement des nanofluides sur l'eau pour un meme debit. Une telle augmentation de perte de pression etait de +70%, +25%, et +0 a 30% respectivement pour les concentrations 4.50%, 1.03%, et 0.24%. Concernant la transition laminaire a turbulent les comportements semblaient indiquer une valeur critique semblable entre l'eau et les differentes concentrations avec et sans chauffage a un nombre de Reynolds critique Rem 1000. Nous avons observe une legere augmentation du coefficient de convection thermique avec le debit massique pour les faibles concentrations (1.03% et 0.24%), alors que la concentration 4.5% demontre une nette diminution. En general la performance energetique globale definie par la chaleur transferee sur la puissance de pompage, reste inferieure compare a l'eau pour un meme Reynolds et un meme debit massique egalement. L'eau semble etre la meilleure solution en termes de performance energetique globale.

Mesures experimentales de l'impact des revetements hydrophobeset superhydrophobes sur la trainee et la portance d'un profil aerodynamique propre et glace

NASA Astrophysics Data System (ADS)

Villeneuve, Eric

Ce projet, realise a la demande du Laboratoire International des Materiaux Antigivre, a pour but de mesurer et definir experimentalement l'impact de revetements hydrophobes sur les coefficients de trainee et de portance d'un profil NACA 0012. Pour ce faire, la balance aerodynamique du LIMA devait tout d'abord etre amelioree afin d'offrir une sensibilite suffisante pour realiser le projet. Plusieurs ameliorations ont ete faites, comme le changement des cellules de charge, la diminution du nombre de cellules de charge, le changement du cadre de la balance, etc. Une fois ces ameliorations terminees, la reproductibilite, l'exactitude et la sensibilite ont ete valides afin de s'assurer de la fiabilite des resultats offerts par la balance. Pour les angles d'attaque etudies avec les revetements, soient -6° et 0°, la balance a une reproductibilite de +/-2,06% a 360 000 de nombre de Reynolds. Pour valider la sensibilite, des essais a -6° et 0° d'angle d'attaque et des nombres de Reynolds de 360 000 et 500 000 ont ete faits avec des papiers sables. Les resultats de ces essais ont permis de, tracer des courbes de tendances du coefficient de trainee du NACA 0012 en fonction de la rugosite de surface et d'etablir la valeur de la sensibilite de la balance a +/-8 mu m. Cinq revetements populaires ont ete choisis pour l'experimentation, soient le Wearlon, le Staclean, le Hirec, le Phasebreak ainsi que le Nusil. Les revetements sont soumis aux memes conditions experimentales que les papiers sables, et une rugosite equivalente est trouvee par extrapolation des resultats. Cependant, les rugosites equivalentes de surfaces different entre -6° et 0°. Les essais avec le Staclean et le Hirec donnent des coefficients de trainee equivalent a ceux avec l'aluminium, alors que le Wearlon, le Nusil et le Phasebreak donnent une augmentation du coefficient de trainee de 13%, 17% et 25% respectivement par rapport a l'aluminium. Pour les coefficients de portance, la balance ne detecte pas l'effet des revetements, ni des papiers sables, sur la force de portance ce qui signifie qu'il entre dans l'insensibilite de la balance. La derniere etape experimentale consistait a mesurer l'impact des revetements sur la formation de la glace ainsi que sur l'evolution des coefficients de trainee et de portance du NACA 0012 en fonction de l'accumulation de glace sur celui-ci. Le Wearlon a ete choisi comme revetement en raison de sa grande popularite. Des essais a -5°C et -20°C ont ete faits et les resultats ont montres que le Wearlon n'apporte pas d'effet benefique au NACA 0012 en conditions d'accumulations de glace. L'augmentation du coefficient de trainee du profil muni du Wearlon debutait plus rapidement que sur l'aluminium et de l'eau gelait legerement plus loin vers l'arriere du profil pendant les essais, ce qui n'est pas souhaitable. Le coefficient de trainee est superieur d'environ 13% pour le Wearlon par rapport a l'aluminium pendant toute l'accumulation de glace, ce qui correspond au meme ecart lorsque la glace n'est pas en cause. Pour le coefficient de portance, les resultats ne peuvent etre utilises pour une raison qui doit etre investiguee.

Study of selective heating at ion cyclotron resonance for the plasma separation process

NASA Astrophysics Data System (ADS)

Compant La Fontaine, A.; Pashkovsky, V. G.

1995-12-01

The plasma separation process by ion cyclotron resonance heating (ICRH) is studied both theoretically and experimentally on two devices: the first one called ERIC (Ion Cyclotron Resonance Experiment) at Saclay (France) [P. Louvet, Proceedings of the 2nd Workshop on Separation Phenomena in Liquids and Gases, Versailles, France, 1989, edited by P. Louvet, P. Noe, and Soubbaramayer (Centre d'Etudes Nucléaires de Saclay and Cité Scientifique Parcs et Technopoles, Ile de France Sud, France, 1989), Vol. 1, p. 5] and the other one named SIRENA at the Kurchatov Institute, Moscow, Russia [A. I. Karchevskii et al., Plasma Phys. Rep. 19, 214 (1993)]. The radio frequency (RF) transversal magnetic field is measured by a magnetic probe both in plasma and vacuum and its Fourier spectrum versus the axial wave number kz is obtained. These results are in agreement with the electromagnetic (EM) field calculation model based on resolution of Maxwell equations by a time-harmonic scheme studied here. Various axial boundary conditions models used to compute the EM field are considered. The RF magnetic field is weakly influenced by the plasma while the electric field components are strongly disturbed due to space-charge effects. In the plasma the transversal electric field is enhanced and the kz spectrum is narrower than in vacuum. The calculation of the resonant isotope heating is made by the Runge-Kutta method. The influence of ion-ion collisions, inhomogeneity of the static magnetic field B0, and the RF transversal magnetic field component on the ion acceleration is examined. These results are successfully compared with experiments of a minor isotope 44Ca heating measurements, made with an energy analyzer.

Hypersonic Experimental and Computational Capability, Improvement and Validation. Volume 2. (l’Hypersonique experimentale et de calcul - capacite, ameliorafion et validation)

DTIC Science & Technology

1998-12-01

Soft Sphere Molecular Model for Inverse-Power-Law or Lennard Jones Potentials , Physics of Fluids A, Vol. 3, No. 10, pp. 2459-2465. 42. Legge, H...information; — Providing assistance to member nations for the purpose of increasing their scientific and technical potential ; — Rendering scientific and...nal, 34:756-763, 1996. [22] W. Jones and B. Launder. The Prediction of Laminarization with a Two-Equation Model of Turbulence. Int. Journal of Heat

La Aventura de las Partículas

Science.gov Websites

ciertas formas fundamentales. Explore las siguientes rutas que le explicarán la materia del universo! La grande del logo de la Ruta SM) La ruta de las evidencias experimentales : aprenda como los físicos diseà explicación de los "por qué" de las interacciones físicas hay todavía muchos misterios por

French payload specialist Patrick Baudry prepares a meal

NASA Image and Video Library

1985-06-17

51G-08-021 (17-24 June 1985) --- Patrick Baudry, payload specialist representing the Centre National d'Etudes Spatiales of France, prepares to open a can of lobster. The bag attached to a nearby locker door appears to contain several other French snacks.

Des journees d'etudes sur les techniques d'expression (Days of Study on Expression Techniques)

ERIC Educational Resources Information Center

Roumette, Sylvain

1975-01-01

Describes the discussions which took place at a two-day conference on the instruction of expression techniques. Discussion centered around the role of linguistics, of the media, and of psychological factors. (Text is in French.) (AM)

Spall Strength of Tungsten Carbide

DTIC Science & Technology

2004-09-01

1 PCS GROUP CAVENDISH LABORATORY W G PROUD MADINGLEY RD CAMBRIDGE UNITED KINGDOM 1 CENTRE D ETUDES DE GRAMAT J Y TRANCHET...46500 GRAMAT FRANCE 1 MINISTERE DE LA DEFENSE DR G BRAULT DGA DSP STTC 4 RUE DE LA PORTE DISSY 75015 PARIS FRANCE 1 SPART

Stochastic Pseudo-Boolean Optimization

DTIC Science & Technology

2011-07-31

Right-Hand Side,” 2009 IN- FORMS Annual Meeting, San Diego, CA, October 11-14, 2009. 113 References [1] A.-Ghouila-Houri. Caracterisation des matrices...Optimization, 10:7–21, 2005. [30] P. Camion. Caracterisation des matrices unimodulaires. Cahiers Centre Etudes Rech., 5(4), 1963. [31] P. Camion

Study of the Tributyl Phosphate--30 Percent Dodecane Solvent; ETUDE DU SOLVANT PHOSPHATE TRIBUTYLIQUE 30 PERCENT--DODECANE (in French)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leroy, P.

1967-07-01

This study, originating mainly from a literature survey, gives the principal chemical and physical features of the tributyl-phosphate (TBP) agent diluted at 30 volumes per cent in dodecane. The mixture is a very commonly used extractant in nuclear fuel processing. In this paper, the main following points are reported: -) the components (TBP and diluents) -) the TBP-diluents systems (non-loaded), -) the TBP-diluents-water systems, -) TBP-diluents-water-nitric acid systems, and -) industrial solvents. (author) [French] Cette etude, d'origine bibliographique, regroupe les caracteristiques physico-chimiques essentielles du phosphate tributylique (TBP) dilue a 30% en volume dans du dodecane. Ce melange constitue un agentmore » d'extraction tres utilise dans le traitement des combustibles nucleaires. Les principaux points traites sont les suivants: -) les constituants (TBP et diluants), -) les systemes TBP-diluants non charges, -) les systemes TBP-diluants-eau, -) les systemes TBP-diluants-eau-acide nitrique, et -) les solvants industriels. (auteur)« less

Etude spectroscopique des collisions moleculaires (hydrogene-azote et hydrogene-oxygene) a des energies de quelques MeV

NASA Astrophysics Data System (ADS)

Plante, Jacinthe

1998-09-01

Les resultats presentes ici proviennent d'une etude systematique portant sur les collisions a vitesse constante, entre les projectiles d'hydrogene (H+, H2+ et H3+ a 1 MeV/nucleon) et deux cibles gazeuses (N2 et O2), soumises a differentes pressions. Les collisions sont analysees a l'aide des spectres d'emission (de 400 A a 6650 A) et des graphiques intensite/pression. Les spectres ont revele la presence des raies d'azote atomique, d'azote moleculaire, d'oxygene atomique, d'oxygene moleculaire et d'hydrogene atomique. Les raies d'hydrogene sont observees seulement avec les projectiles H2+ et H3+. Donc les processus responsables de la formation de ces raies sont des mecanismes de fragmentation des projectiles. Pour conclure, il existe une difference notable entre les projectiles et les differentes pressions. Les raies d'azote et d'oxygene augmentent selon la pression et les raies d'hydrogene atomique presentent une relation non lineaire avec la pression.

Reconstruction de la surface de Fermi dans l'etat normal d'un supraconducteur a haute Tc: Une etude du transport electrique en champ magnetique intense

NASA Astrophysics Data System (ADS)

Le Boeuf, David

Des mesures de resistance longitudinale et de resistance de Hall en champ magnetique intense transverse (perpendiculaire aux plans CuO2) ont ete effectuees au sein de monocristaux de YBa2Cu3Oy (YBCO) demacles, ordonnes et de grande purete, afin d'etudier l'etat fondamental des supraconducteurs a haute Tc dans le regime sous-dope. Cette etude a ete realisee en fonction du dopage et de l'orientation du courant d'excitation J par rapport a l'axe orthorhombique b de la structure cristalline. Les mesures en champ magnetique intense revelent par suppression de la supraconductivite des oscillations magnetiques des resistances longitudinale et de Hall dans YBa2Cu 3O6.51 et YBa2Cu4O8. La conformite du comportement de ces oscillations quantiques au formalisme de Lifshitz-Kosevich, apporte la preuve de l'existence d'une surface de Fermi fermee a caractere quasi-2D, abritant des quasiparticules coherentes respectant la statistique de Fermi-Dirac, dans la phase pseudogap d'YBCO. La faible frequence des oscillations quantiques, combinee avec l'etude de la partie monotone de la resistance de Hall en fonction de la temperature indique que la surface de Fermi d'YBCO sous-dope comprend une petite poche de Fermi occupee par des porteurs de charge negative. Cette particularite de la surface de Fermi dans le regime sous-dope incompatible avec les calculs de structure de bande est en fort contraste avec la structure electronique presente dans le regime surdope. Cette observation implique ainsi l'existence d'un point critique quantique dans le diagramme de phase d'YBCO, au voisinage duquel la surface de Fermi doit subir une reconstruction induite par l'etablissement d'une brisure de la symetrie de translation du reseau cristallin sous-jacent. Enfin, l'etude en fonction du dopage de la resistance de Hall et de la resistance longitudinale en champ magnetique intense suggere qu'un ordre du type onde de densite (DW) est responsable de la reconstruction de la surface de Fermi. L'analogie de la phenomenologie entourant le comportement des resistances longitudinale et de Hall dans YBa2Cu3Oy, avec des systemes dans lesquels l'existence d'un ordre du type DW est etablie, notamment des cuprates a structure tetragonale a basse temperature ("Low Temperature Tetragonal", LTT), indique que l'ordre causant la reconstruction de la surface de Fermi est stabilise au voisinage du dopage p = 1/8, et est en competition directe avec la supraconductivite.

Propagating Waves Transverse to the Magnetic Field in a Solar Prominence

NASA Astrophysics Data System (ADS)

Schmieder, B.; Kucera, T. A.; Knizhnik, K.; Luna, M.; Lopez-Ariste, A.; Toot, D.

2013-11-01

We report an unusual set of observations of waves in a large prominence pillar that consist of pulses propagating perpendicular to the prominence magnetic field. We observe a huge quiescent prominence with the Solar Dynamics Observatory Atmospheric Imaging Assembly in EUV on 2012 October 10 and only a part of it, the pillar, which is a foot or barb of the prominence, with the Hinode Solar Optical Telescope (SOT; in Ca II and Hα lines), Sac Peak (in Hα, Hβ, and Na-D lines), and THEMIS ("Télescope Héliographique pour l' Etude du Magnétisme et des Instabilités Solaires") with the MTR (MulTi-Raies) spectropolarimeter (in He D3 line). The THEMIS/MTR data indicates that the magnetic field in the pillar is essentially horizontal and the observations in the optical domain show a large number of horizontally aligned features on a much smaller scale than the pillar as a whole. The data are consistent with a model of cool prominence plasma trapped in the dips of horizontal field lines. The SOT and Sac Peak data over the four hour observing period show vertical oscillations appearing as wave pulses. These pulses, which include a Doppler signature, move vertically, perpendicular to the field direction, along thin quasi-vertical columns in the much broader pillar. The pulses have a velocity of propagation of about 10 km s-1, a period of about 300 s, and a wavelength around 2000 km. We interpret these waves in terms of fast magnetosonic waves and discuss possible wave drivers.

ERRATUM: Propagating Waves Transverse to the Magnetic Field in a Solar Prominence

NASA Technical Reports Server (NTRS)

Schmieder, B.; Kucera, T. A.; Knizhnik, K.; Luna, M.; Lopez-Ariste, A.; Toot, D.

2014-01-01

We report an unusual set of observations of waves in a large prominence pillar that consist of pulses propagating perpendicular to the prominence magnetic field. We observe a huge quiescent prominence with the Solar Dynamics Observatory Atmospheric Imaging Assembly in EUV on 2012 October 10 and only a part of it, the pillar, which is a foot or barb of the prominence, with the Hinode Solar Optical Telescope (SOT; in Ca II and Halpha lines), Sac Peak (in Ha, Hß, and Na-D lines), and THEMIS ("Télescope Héliographique pour l' Etude du Magnétisme et des Instabilités Solaires") with the MTR (MulTi-Raies) spectropolarimeter (in He D3 line). The THEMIS/MTR data indicates that the magnetic field in the pillar is essentially horizontal and the observations in the optical domain show a large number of horizontally aligned features on a much smaller scale than the pillar as a whole. The data are consistent with a model of cool prominence plasma trapped in the dips of horizontal field lines. The SOT and Sac Peak data over the four hour observing period show vertical oscillations appearing as wave pulses. These pulses, which include a Doppler signature, move vertically, perpendicular to the field direction, along thin quasi-vertical columns in the much broader pillar. The pulses have a velocity of propagation of about 10 km/s, a period of about 300 s, and a wavelength around 2000 km. We interpret these waves in terms of fast magnetosonic waves and discuss possible wave drivers.

The Normative Effects of Higher Education Policy in France

ERIC Educational Resources Information Center

Langan, Elise

2012-01-01

This student survey was a response to the French youth unrest in 2005 and 2006. It considers the degree to which French higher and secondary education institutions create social cohesion. Focusing on three distinct higher-education institutions: "L'institut d'etudes politiques de Paris" (Sciences Po), "Ecole Normale…

The Effect of Material Strength on Segment Penetration Behavior

DTIC Science & Technology

1993-04-01

Muenchen GERMANY Royal Armament R&D Establishment ATTN: I. Cullis Fort Halstead Sevenoaks, Kent TN14 7BJ ENGLAND Centre d’Etudes de Gramat ATTN...SOLVE Gerald 46500 Gramat FRANCE 2 Defense Research Establishment Suffield ATTN: C. Weickert D. Mackay Ralston, Alberta, TOJ 2N0 Ralston CANADA Defense

Initial Evaluation of Advanced Powder Metallurgy Magnesium Alloys for Armor Development

DTIC Science & Technology

2009-05-01

28911 LEGANES MADRID SPAIN 1 CELIUS MATERIAL TEKNIK KARLSKOGA AB L HELLNER S 69180 KARLSKOGA SWEDEN 3 CENTRE D’ETUDES GRAMAT ...J CAGNOUX C GALLIC J TRANCHET GRAMAT 46500 FRANCE 1 MINISTRY OF DEFENCE DGA DSP STTC G BRAULT 4 RUE DE LA PORTE D’ISSY

On Comparing Precision Orbit Solutions of Geodetic Satellites Given Several Atmospheric Density Models

DTIC Science & Technology

2014-08-01

Astrodynamics, drag, atmospheric density, geodesy 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18. NUMBER OF PAGES 12 19a...Translation of ’Le satellite de geodesie ’Starlette’,’ Groupe de Recherches de Geodesie Spatiale, Centre National d’Etudes Spatiales, Bretigny-sur-Orge

Methode d’Identification des Forces Aerodynamiques Instationnaires sur les Essais en Vol, Validation Experimentale (Method of Mathematical Identification of Unsteady Airloads From Flight Measurements, Experimental Validation)

DTIC Science & Technology

2000-05-01

gage en vol de rdponses de jauges de contraintes en responses in maneuver, illustrated by an example manoeuvre, illustrd par un exemple issu de la coming...sous ddrapage, ... , braquages gouvernes,..) la forme: -Les mesures sont directement les rkponses de - minimiser Z = Q(k - Xj tb) 2 jauges de...3, la rdponse - les facteurs de ponddration des mesures, fli ou incidence de l’avion, la rdponse de la jauge plus ou momns subjectifs, sont remplacds

Methode de Calcul du Flutter en Presence de jeu Mecanique et Verification Experimentale (Flutter Analysis Method in Presence of Mechanical Play and Experimental Verification)

DTIC Science & Technology

2000-05-01

Flexible Aircraft Control", held in Ottawa, Canada, 18-20 October 1999, and published in RTO MP-36. 9-2 INTRODUCTION 2. PRINCIPES DE LA METHODE DE CALCUL...constitude par un .les pressions sur la gouveme et le ensemble de 17 pouts de jauge , de 20 moment de charni~re sont surestimds accildrom~tes, de 5...les corrdlations calcul-essais 130 mm). des rdponses dc jauges de contraintes A 12 Le calcul, comme les essais, permettent chargements statiques. Cette

Initial results of experimental studies of prairie dogs in arid grasslands: Implications for landscape conservation and the importance of scale (Resultados Iniciales de Estudios Experimentales en Perros Llaneros de Pastizales Aridos: Implicaciones Para la Conservacion del Paisaje y la Importancia de Escala)

Treesearch

Charles Curtin

2006-01-01

Numerous ecologists and conservationists believe that prairie dogs increase ecosystem diversity and preserve the function of grasslands (Whicker and Detling 1988, Miller et al. 1994, Jones et al. 1994, Power et al. 1996, Weltzin et al. 1997, Miller et al. 2000), yet this perspective is controversial (Stapp 1998). In contrast, many ranchers and land owners view prairie...

Microwave Interferometric Radiometry in Remote Sensing: an Invited Historical Review

NASA Technical Reports Server (NTRS)

Martin-Neira, M.; LeVine, D. M.; Kerr, Y.; Skou, N.; Peichl, M.; Camps, A.; Corbella, I.; Hallikainen, M.; Font, J.; Wu, J.;

Environmental Indicators. A Preliminary Set = Indicateurs d'environnement. Une etude pilote.

ERIC Educational Resources Information Center

Organisation for Economic Cooperation and Development, Paris (France).

This document provides a preliminary set of environmental indicators by which to measure environmental performance. The indicators are patterned on the outline of the Organisation for Economic Cooperation and Development (OECD) "Report on the State of the Environment," a companion volume published in the same year. This volume is…

Centenary Birth Anniversary of E. W. Beth (1908-1964)

ERIC Educational Resources Information Center

Bagni, Giorgio T.

2008-01-01

Evert Willem Beth (1908-1964) was a Dutch logician, mathematician and philosopher, whose work mainly concerned the foundations of mathematics. Beth was among the founders of the Commission Internationale pour l'Etude et l'Amelioration de l'Enseignement des Mathematiques and was a member of the Central Committee of the International Commission on…

An Analysis of Magnesium Alloy AZ31B-H24 for Ballistic Applications

DTIC Science & Technology

2007-12-01

CELIUS MATERIAL TEKNIK KARLSKOGA AB L HELLNER S 69180 KARLSKOGA SWEDEN 3 CENTRE D’ETUDES GRAMAT J CAGNOUX C GALLIC J TRANCHET... GRAMAT 46500 FRANCE 1 MINISTRY OF DEFENCE DGA DSP STTC G BRAULT 4 RUE DE LA PORTE D’ISSY 00460 ARMEES F 75015 PARIS FRANCE 1

Radiolocation Techniques (Les Techniques de Radiolocalisation

DTIC Science & Technology

1992-11-01

Dr R. Klemm DrD Rother FGAN- FFM SEL/LS/E Neuenahrer Strasse 20 Lorenzstrasse 10 D-5307 Wachtberg 7 D-7000 Stuttgart 40 Germany Germany Prof. G...des solutions. accas I lFionograinme, donc: aui profil. Cat article rapporte tine partie des Etudes mendes an La indthodo proposde s’inspirc de cette

Pratique d'apprentissage en ligne aux etudes superieures (Online Learning for Higher Education).

ERIC Educational Resources Information Center

Marchand, Louise

2001-01-01

Online learning requires new approaches to teaching and learning. At the University of Montreal, 28 graduate students in education and adult students specializing in educational technology attended an experimental distance education course. Students identified advantages and disadvantages of online learning/teaching and reflected on how the course…

Etude de l'affaiblissement du comportement mecanique du pergelisol du au rechauffement climatique

NASA Astrophysics Data System (ADS)

Buteau, Sylvie

Le rechauffement climatique predit pour les prochaines decennies, aura des impacts majeurs sur le pergelisol qui sont tres peu documentes pour l'instant. La presente etude a pour but d'evaluer ces impacts sur les proprietes mecaniques du pergelisol et sa stabilite a long terme. Une nouvelle technique d'essai de penetration au cone a taux de deformation controle, a ete developpee pour caracteriser en place le pergelisol. Ces essais geotechniques et la mesure de differentes proprietes physiques ont ete effectues sur une butte de pergelisol au cours du printemps 2000. Le developpement et l'utilisation d'un modele geothermique 1D tenant compte de la thermodependance du comportement mecanique ont permis d'evaluer que les etendues de pergelisol chaud deviendraient instables a la suite d'un rechauffement de l'ordre de 5°C sur cent ans. En effet, la resistance mecanique du pergelisol diminuera alors rapidement jusqu'a 11,6 MPa, ce qui correspond a une perte relative de 98% de la resistance par rapport a un scenario sans rechauffement.

Investigation de l'anisotropie du gap supraconducteur dans les composes Ba(Fe(1-x)Co(x))2As2, Ba(1-x)K(x)Fe2As2, LiFeAs et Fe1-deltaTe(1-x)Se(x)

NASA Astrophysics Data System (ADS)

Reid, Jean-Philippe

ommaire La structure du gap supraconducteur et sa modulation sont intimement liees au potentiel d'interaction responsable de l'appariement des electrons d'un supraconducteur. Ainsi, l'etude de la structure du gap-SC et de sa modulation permettent de faire la lumiere sur la nature du mecanisme d'appariement des electrons. A cet egard, les resultats experimentaux des supraconducteurs a base de fer ne cadrent pas dans un seul ensemble, ce qui est en opposition au gap-SC universel des cuprates. Dans ce qui suit, nous presenterons une etude systematique du gap-SC pour plusieurs pnictides. En effet, en utilisant la conductivite thermique, une sonde directionnelle du gap-SC, nous avons ete en mesure de reveler la structure du gap-SC pour les composes suivants : Ba1-xKxFe 2As2, Ba(Fe1-xCo x)2As2, LiFeAs et Fe1-deltaTe 1-xSex. L'etude de ces quatre composes, de trois differentes familles structurales, a pu etablir un tableau partiel mais tres exhaustif de la structure du gap-SC de pnictides. En effet, tel qu'illustre dans cette these, ces quatre composes ne possedent aucun noeud dans leur structure du gap-SC a dopage optimal. Toutefois, a une concentration differente de celle optimale pour les composes K-Ba122 et Co-Ba122, des noeuds apparaissent sur la surface de Fermi, aux extremites 'du dome supraconducteur. Ceci suggere fortement que, pour ces composes, la presence de noeuds sur la surface de Fermi est nuisible a la phase supraconductrice. Mots-cles: Supraconducteurs a base de fer, Pnictides, Structure du gap supraconducteur, Conductivite thermique

Methodes d'amas quantiques a temperature finie appliquees au modele de Hubbard

NASA Astrophysics Data System (ADS)

Plouffe, Dany

Depuis leur decouverte dans les annees 80, les supraconducteurs a haute temperature critique ont suscite beaucoup d'interet en physique du solide. Comprendre l'origine des phases observees dans ces materiaux, telle la supraconductivite, est l'un des grands defis de la physique theorique du solide des 25 dernieres annees. L'un des mecanismes pressentis pour expliquer ces phenomenes est la forte interaction electron-electron. Le modele de Hubbard est l'un des modeles les plus simples pour tenir compte de ces interactions. Malgre la simplicite apparente de ce modele, certaines de ses caracteristiques, dont son diagramme de phase, ne sont toujours pas bien etablies, et ce malgre plusieurs avancements theoriques dans les dernieres annees. Cette etude se consacre a faire une analyse de methodes numeriques permettant de calculer diverses proprietes du modele de Hubbard en fonction de la temperature. Nous decrivons des methodes (la VCA et la CPT) qui permettent de calculer approximativement la fonction de Green a temperature finie sur un systeme infini a partir de la fonction de Green calculee sur un amas de taille finie. Pour calculer ces fonctions de Green, nous allons utiliser des methodes permettant de reduire considerablement les efforts numeriques necessaires pour les calculs des moyennes thermodynamiques, en reduisant considerablement l'espace des etats a considerer dans ces moyennes. Bien que cette etude vise d'abord a developper des methodes d'amas pour resoudre le modele de Hubbard a temperature finie de facon generale ainsi qu'a etudier les proprietes de base de ce modele, nous allons l'appliquer a des conditions qui s'approchent de supraconducteurs a haute temperature critique. Les methodes presentees dans cette etude permettent de tracer un diagramme de phase pour l'antiferromagnetisme et la supraconductivite qui presentent plusieurs similarites avec celui des supraconducteurs a haute temperature. Mots-cles : modele de Hubbard, thermodynamique, antiferromagnetisme, supraconductivite, methodes numeriques, larges matrices

PROPAGATING WAVES TRANSVERSE TO THE MAGNETIC FIELD IN A SOLAR PROMINENCE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmieder, B.; Kucera, T. A.; Knizhnik, K.

2013-11-10

We report an unusual set of observations of waves in a large prominence pillar that consist of pulses propagating perpendicular to the prominence magnetic field. We observe a huge quiescent prominence with the Solar Dynamics Observatory Atmospheric Imaging Assembly in EUV on 2012 October 10 and only a part of it, the pillar, which is a foot or barb of the prominence, with the Hinode Solar Optical Telescope (SOT; in Ca II and Hα lines), Sac Peak (in Hα, Hβ, and Na-D lines), and THEMIS ({sup T}élescope Héliographique pour l' Etude du Magnétisme et des Instabilités Solaires{sup )} with themore » MTR (MulTi-Raies) spectropolarimeter (in He D{sub 3} line). The THEMIS/MTR data indicates that the magnetic field in the pillar is essentially horizontal and the observations in the optical domain show a large number of horizontally aligned features on a much smaller scale than the pillar as a whole. The data are consistent with a model of cool prominence plasma trapped in the dips of horizontal field lines. The SOT and Sac Peak data over the four hour observing period show vertical oscillations appearing as wave pulses. These pulses, which include a Doppler signature, move vertically, perpendicular to the field direction, along thin quasi-vertical columns in the much broader pillar. The pulses have a velocity of propagation of about 10 km s{sup –1}, a period of about 300 s, and a wavelength around 2000 km. We interpret these waves in terms of fast magnetosonic waves and discuss possible wave drivers.« less

Engine Response to Distorted Inflow Conditions: Conference Proceedings of the Propulsion and Energetics Specialists’ Meeting (68th) Held in Munich, Germany on 8-9 September 1986.

DTIC Science & Technology

1987-03-01

DISTORTION UNSTEADY INLET DISTORTION CHARACTERISTICS WITH THE B-1 B by C.J.MacMiler and W.R.Haagenson 16 DETERMINATION EXPERIMENTALE DES LOIS DE TRANSFERT DE...compresseurs. Dens ce domaine. los trois principaux objectifs du motoriste sont los suivants (a) - d6mont rer avant los essais en vol. la compatibilitA...ann~es sur la conception des moteurs deavions. 2 - ETHODES DE CALCUL 2.1. METNODES DES SECTEURS DE COMPRESSEUR EN PARALLELE 2.1.1. Description do la m

The Relationship between Musical Instrumental Performance Skills and Postsecondary Musical Independence (How Important Are Scales, Etudes, Solos, Sight-Reading, Improvisation, Etc.?)

ERIC Educational Resources Information Center

Bobbett, Gordon C.; And Others

This study examines the relationships among a variety of secondary/postsecondary experiences and activities and postsecondary students' musical independence (MI). The paper reports on the impact Instrumental Performance Skills (IPSs) have on the students" MI development during private lessons, band rehearsal, and individual practicing. The study…

Ballistic Performance Testing of Aluminum Alloy 5059-H131 and 5059-H136 for Armor Applications

DTIC Science & Technology

2008-05-01

LEGANES MADRID SPAIN 1 CELIUS MATERIAL TEKNIK KARLSKOGA AB L HELLNER S 69180 KARLSKOGA SWEDEN 3 CENTRE D’ETUDES GRAMAT J...CAGNOUX C GALLIC J TRANCHET GRAMAT 46500 FRANCE 1 MINISTRY OF DEFENCE DGA DSP STTC G BRAULT 4 RUE DE LA PORTE D’ISSY 00460 ARMEES

International Symposium on Military Applications of Blast Simulation (5th)

DTIC Science & Technology

1977-06-22

Centre d’Etudes de Grainat, Gramat , France, de- scribed their work in designing a blast simulator with a test section of 12—rn width and 7—rn height...de Gramat , Gramat , France) on the dynamic behavior of limestone. Through a series of high—pressure experiments of the type developed in the recent

Mathematics for Vocational Students in France and England: Contrasting Provision and Consequences. Discussion Paper No. 23.

ERIC Educational Resources Information Center

Wolf, Alison

French postsecondary education for 16- to 19-year-olds is divided into programs that lead to the Baccalaureats--general, technical, and vocational--and to the lower-level Certificat d'Aptitude Professionnel (CAP) and Brevet d'Etudes Professionnelles (BEP). A common mathematics core curriculum is specified for all CAP students, regardless of…

Pedagogy of Notation: Learning Styles Using a Constructivist, Second-Language Acquisition Approach to Dance Notation Pedagogy

ERIC Educational Resources Information Center

Heiland, Teresa L.

2015-01-01

Four undergraduate dance majors learned Motif Notation and Labanotation using a second-language acquisition, playful, constructivist approach to learning notation literacy in order to learn and dance the "Parsons Etude." Qualitative outcomes were gathered from student journals and pre- and post-tests that assessed for levels of improved…

La Parabole du Gaucher et de la Casserole a Bec Verseur: Etude des Processus d'Apprentissage dans un Environnement de Calculatrices Symboliques.

ERIC Educational Resources Information Center

Trouche, Luc

2000-01-01

Discusses the problems of conceptualization of the function limit in technological environments (principally graphing calculators today and symbolic calculators tomorrow) that are gradually being adopted in precalculus teaching. Explains how the instrumentation process and the conceptualization process are dependent on each other. Sets forth a…

Modern Data Analysis techniques in Noise and Vibration Problems

DTIC Science & Technology

1981-11-01

Hilbert l’une de l’autre. Cette propriete se retrouve dans l’etude de la causalite : ce qui de- finit un critere pratique caracterisant un signal donc, par...entre Ie champ direct et Ie champ reflechi se caracterisent loca- lement par l’existence de frequences pour lesquelles l’interference est totale

Problemes en enseignement fonctionnel des langues (Problems in the Functional Teaching of Languages). Publication B-103.

ERIC Educational Resources Information Center

Alvarez, Gerardo, Ed.; Huot, Diane, Ed.

Articles include: (1) "L'elaboration du materiel pedagogique pour des publics adultes" (The Elaboration of Teaching Materials for the Adult Public) by G. Painchaud-Leblanc, (2) "L'elaboration d'un programme d'etudes en francais langue seconde a partir des donnees recentes en didactique des langues" (The Elaboration of a Program…

The Work of Ambroise Tardieu: The First Definitive Description of Child Abuse

ERIC Educational Resources Information Center

Roche, A.J.; Fortin, G.; Labbe, J.; Brown, J.; Chadwick, D.

2005-01-01

The first important monograph describing the battered child syndrome was written in 1860 by Ambroise Tardieu, a French forensic physician. Here is a translation of his article, published in the Annales d'hygiene publique et de medecine legale, with the title ''Etude medico-legale sur les sevices et mauvais traitements exerces sur des enfants.''…

Mutations des roles techniques et formation. Etude documentaire (Changes in the Roles and Education of Technicians. Documentary Study).

ERIC Educational Resources Information Center

Pinard, Helene

Drawing from research conducted in 1990-91, this report examines trends affecting the future work of technicians in Quebec, their pre-employment education, and the link between college and work. Part 1 focuses on aspects of the economic, technological, and social environment that will influence the future role of technicians. Economic concerns…

The Role of Women in Foreign-Language Textbooks: A Collection of Essays. Collection d'"Etudes linguistiques" No. 24.

ERIC Educational Resources Information Center

Freudenstein, R., Ed.

Essays that consider the way that women are portrayed in foreign language textbooks are presented. The selected essays were submitted to a competition sponsored by the Federation Internationale des Professeurs de Langues Vivantes, which requested that language teachers assess such concerns as: (1) whether women were described in a stereotyped way;…

Etude RICH Nursing. Plus de connaissances et de preuves scientifiques

PubMed Central

SCHUBERT, MARIA

2009-01-01

L’importance et la validité des résultats de l’étude RICH-Nursing* ont été récemment mises en cause par certains milieux, ce qui a provoqué certaines incertitudes chez les infirmières. Les auteurs reviennent sur l’impact actuel de cette étude et évoquent les perspectives d’avenir. PMID:25221376

Primary and Secondary Vestibular Connections in the Brain Stem and Cerebellum: An Axoplasmic Transport Study in the Monkey and Cat

DTIC Science & Technology

1983-08-25

Edinger-Westphal nucleus in the cat, Brain Research, 141 (1978) 153-159. Lorente de No, R., Etudes sur le cerveau posterieur. Ill, Sur 1 es connexions...extra-cerebelleuses des fascicules afferents au cerveau , et sur la fontion de cet organe, Trav. Lab. Rech. Biol. Univ. Madrid, 22 (1924) 51-65

L'ilot du reservoir: etude de voisinage en milieu urbain (The Reservoir Block: A Study of a Neighborhood in an Urban Setting).

ERIC Educational Resources Information Center

Rey, Jean-Noel

1983-01-01

An analysis of a small neighborhood of Paris looks at its layout and spatial constraints, habitats, symbols, sense of territory, and rhythms and styles of the inhabitants and their roles in the group. The description, including photos, is intended for use in the French language classroom. (MSE)

Canadian Mathematics Education Study Group = Groupe Canadien d'etude en didactique des mathematiques. Proceedings of the Annual Meeting (22nd, Vancouver, British Columbia, Canada, May 29-June 2, 1998).

ERIC Educational Resources Information Center

Pothier, Yvonne M., Ed.

This proceedings includes the following papers: (1) "Structure of Attention in Teaching Mathematics" (John Mason); (2) "Communicating Mathematics or Mathematics Storytelling" (Kathy Heinrich); (3) "Assessing Mathematical Thinking" (Florence Glanfield and Pat Rogers); (4) "From Theory to Observational Data (and…

Zone Nationale D'Etude de L'Environnment: Un Guide (National Environmental Study Area: A Guide).

ERIC Educational Resources Information Center

National Park Service (Dept. of Interior), Washington, DC.

This booklet, the French version of SE 014 817, is a guide for teachers and resource managers who are interested in establishing National Environmental Study Areas (NESA) or interested in receiving NESA recognition for their on-going environmental study area programs. It outlines the characteristics and procedures of the program; the nature,…

The COROT telescope

NASA Astrophysics Data System (ADS)

Viard, Thierry

2017-11-01

The COROT telescope, of which the customer is the French "INSU" / "CNES" (Institut National des Sciences de l'Univers / Centre National des Etudes Spatiales) is in fact a very precise and stable imaging instrument, which will be pointed towards fixed areas in the sky (each containing more than 3000 target stars) for periods of at least 5 months, in order to carry out its two missions.

Etude de l'apprentissage par la lecture d'etudiants en contexte d'apprentissage par problemes (APP) (A Study of Student Text-Learning Strategy).

ERIC Educational Resources Information Center

Cartier, Sylvie

2002-01-01

Examined strategies reported by students during reading to develop knowledge in their area of professional training. Discovered the reading, encoding, self-regulation, and resource management strategies used most often by students, which were not sufficient to attain effective learning. Less frequently used strategies added nuances to the…

Symetrie en energie des spectres de l'onde de densite de charge dans le 2-hydrogene seleniure de niobium

NASA Astrophysics Data System (ADS)

Behmand, Behnaz

Les mecanismes qui menent a la supraconductivite dans les supraconducteurs a haute temperature critique sont encore aujourd'hui mal compris contrairement a ceux dans les supraconducteurs conventionnels. Dans les hauts-Tc, certaines modulations de la densite d'etats electroniques coexistant avec la phase supraconductrice ont ete observees, ce qui engendre des questionnements sur leur role dans la supraconductivite. En fait, plusieurs types de modulation de la densite d'etats electroniques existent, comme par exemple l'onde de densite de charge et l'onde de densite de paires. Ces deux modulations, d'origines differentes et mesurables avec la technique de spectroscopie par effet tunnel, peuvent etre differenciees avec une etude de leur symetrie. Ce memoire consistera donc a presenter l'etude de la symetrie de l'onde de densite de charge dans le 2H-NbSe2 qui est presente dans la phase supraconductrice a 300 mK. Par contre, certaines difficultes liees au principe de mesure, soit l'effet de normalisation, nuisent a l'identification de cette symetrie. La methode, pour contourner ce probleme sera alors l'element clef de ce travail.

A microcosm of musical expression: II. Quantitative analysis of pianists' dynamics in the initial measures of Chopin's Etude in E major.

PubMed

Repp, B H

1999-03-01

Patterns of expressive dynamics were measured in bars 1-5 of 115 commercially recorded performances of Chopin's Etude in E major, op. 10, No. 3. The grand average pattern (or dynamic profile) was representative of many performances and highly similar to the average dynamic profile of a group of advanced student performances, which suggests a widely shared central norm of expressive dynamics. The individual dynamic profiles were subjected to principal components analysis, which yielded Varimax-rotated components, each representing a different, nonstandard dynamic profile associated with a small subset of performances. Most performances had dynamic patterns resembling a mixture of several components, and no clustering of of performances into distinct groups was apparent. Some weak relationships of dynamic profiles with sociocultural variables were found, most notably a tendency of female pianists to exhibit a greater dynamic range in the melody. Within the melody, there were no significant relationships between expressive timing [Repp, J. Acoust. Soc. Am. 104, 1085-1100 (1998)] and expressive dynamics. These two important dimensions seemed to be controlled independently at this local level and thus offer the artist many degrees of freedom in giving a melody expressive shape.

A microcosm of musical expression. III. Contributions of timing and dynamics to the aesthetic impression of pianists' performances of the initial measures of Chopin's Etude in E major.

PubMed

Repp, B H

1999-07-01

Four judges repeatedly assessed the overall aesthetic quality of more than 100 recorded performances of the opening of Chopin's Etude in E major on a 10-point scale. The judgments, which exhibited reasonable reliability and modest intercorrelations, were entered into regression analyses with 16 independent variables derived from earlier objective analyses of the expressive timing and dynamics of the performances [Repp, J. Acoust. Soc. Am. 104, 1085-1100 (1998); 105, 1972-1988 (1999)]. Only between 9% and 18% of the variance in the judges' ratings was accounted for. By contrast, timing variables accounted for 53% of the variance in one judge's ratings of synthesized performances that varied in timing only and mimicked the timing patterns of the original performances. These results indicate, first, that the aesthetic impression of the original recordings rested primarily on aspects other than those measured (such as texture, tone, or aspects of timing and dynamics that eluded the earlier analyses) and, second, that very different patterns of timing and dynamics are aesthetically acceptable for the same music, provided that other, aesthetically more crucial performance aspects are present.

STRUCTURE OF PROMINENCE LEGS: PLASMA AND MAGNETIC FIELD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levens, P. J.; Labrosse, N.; Schmieder, B.

We investigate the properties of a “solar tornado” observed on 2014 July 15, and aim to link the behavior of the plasma to the internal magnetic field structure of the associated prominence. We made multi-wavelength observations with high spatial resolution and high cadence using SDO/AIA, the Interface Region Imaging Spectrograph (IRIS) spectrograph, and the Hinode/Solar Optical Telescope (SOT) instrument. Along with spectropolarimetry provided by the Télescope Héliographique pour l’Etude du Magnétisme et des Instabilités Solaires telescope we have coverage of both optically thick emission lines and magnetic field information. AIA reveals that the two legs of the prominence are stronglymore » absorbing structures which look like they are rotating, or oscillating in the plane of the sky. The two prominence legs, which are both very bright in Ca ii (SOT), are not visible in the IRIS Mg ii slit-jaw images. This is explained by the large optical thickness of the structures in Mg ii, which leads to reversed profiles, and hence to lower integrated intensities at these locations than in the surroundings. Using lines formed at temperatures lower than 1 MK, we measure relatively low Doppler shifts on the order of ±10 km s{sup −1} in the tornado-like structure. Between the two legs we see loops in Mg ii, with material flowing from one leg to the other, as well as counterstreaming. It is difficult to interpret our data as showing two rotating, vertical structures that are unrelated to the loops. This kind of “tornado” scenario does not fit with our observations. The magnetic field in the two legs of the prominence is found to be preferentially horizontal.« less

Structure of Prominence Legs: Plasma and Magnetic Field

NASA Astrophysics Data System (ADS)

Levens, P. J.; Schmieder, B.; Labrosse, N.; López Ariste, A.

2016-02-01

We investigate the properties of a “solar tornado” observed on 2014 July 15, and aim to link the behavior of the plasma to the internal magnetic field structure of the associated prominence. We made multi-wavelength observations with high spatial resolution and high cadence using SDO/AIA, the Interface Region Imaging Spectrograph (IRIS) spectrograph, and the Hinode/Solar Optical Telescope (SOT) instrument. Along with spectropolarimetry provided by the Télescope Héliographique pour l’Etude du Magnétisme et des Instabilités Solaires telescope we have coverage of both optically thick emission lines and magnetic field information. AIA reveals that the two legs of the prominence are strongly absorbing structures which look like they are rotating, or oscillating in the plane of the sky. The two prominence legs, which are both very bright in Ca II (SOT), are not visible in the IRIS Mg II slit-jaw images. This is explained by the large optical thickness of the structures in Mg II, which leads to reversed profiles, and hence to lower integrated intensities at these locations than in the surroundings. Using lines formed at temperatures lower than 1 MK, we measure relatively low Doppler shifts on the order of ±10 km s-1 in the tornado-like structure. Between the two legs we see loops in Mg II, with material flowing from one leg to the other, as well as counterstreaming. It is difficult to interpret our data as showing two rotating, vertical structures that are unrelated to the loops. This kind of “tornado” scenario does not fit with our observations. The magnetic field in the two legs of the prominence is found to be preferentially horizontal.

Short-term observations of double-peaked Na emission from Mercury's exosphere

NASA Astrophysics Data System (ADS)

Massetti, S.; Mangano, V.; Milillo, A.; Mura, A.; Orsini, S.; Plainaki, C.

2017-04-01

We report the analysis of short-term ground-based observations of the exospheric Na emission (D1 and D2 lines) from Mercury, which was characterized by two high-latitude peaks confined near the magnetospheric cusp footprints. During a series of scheduled observations from the Télescope Héliographique pour l'Etude du Magnétisme et des Instabilités Solaires (THEMIS) telescope, achieved by scanning the whole planet, we implemented a series of extra measurements by recording the Na emission from a narrow north-south strip only, centered above the two emission peaks. Our aim was to inspect the existence of short-term variations, which were never analyzed before from ground-based observations, and their possible correlation with interplanetary magnetic field variations. Though Mercury possesses a miniature magnetosphere, characterized by fast reconnection events that develop on a timescale of few minutes, ground-based observations show that the exospheric Na emission pattern can be globally stable for a prolonged period (some days) and also exhibits fluctuations in the time range of tens of minutes.

WINDII, the wind imaging interferometer on the Upper Atmosphere Research Satellite

NASA Technical Reports Server (NTRS)

Shepherd, G. G.; Thuillier, G.; Gault, W. A.; Solheim, B. H.; Hersom, C.; Alunni, J. M.; Brun, J.-F.; Brune, S.; Charlot, P.; Cogger, L. L.

1993-01-01

The WIND imaging interferometer (WINDII) was launched on the Upper Atmosphere Research Satellite (UARS) on September 12, 1991. This joint project, sponsored by the Canadian Space Agency and the French Centre National d'Etudes Spatiales, in collaboration with NASA, has the responsibility of measuring the global wind pattern at the top of the altitude range covered by UARS. WINDII measures wind, temperature, and emission rate over the altitude range 80 to 300 km by using the visible region airglow emission from these altitudes as a target and employing optical Doppler interferometry to measure the small wavelength shifts of the narrow atomic and molecular airglow emission lines induced by the bulk velocity of the atmosphere carrying the emitting species. The instrument used is an all-glass field-widened achromatically and thermally compensated phase-stepping Michelson interferometer, along with a bare CCD detector that images the airglow limb through the interferometer. A sequence of phase-stepped images is processed to derive the wind velocity for two orthogonal view directions, yielding the vector horizontal wind. The process of data analysis, including the inversion of apparent quantities to vertical profiles, is described.

STS-93 / Columbia Flight Crew Photo Op & QA at Pad for TCDT

NASA Technical Reports Server (NTRS)

1999-01-01

The primary objective of the STS-93 mission was to deploy the Advanced X-ray Astrophysical Facility, which had been renamed the Chandra X-ray Observatory in honor of the late Indian-American Nobel Laureate Subrahmanyan Chandrasekhar. The mission was launched at 12:31 on July 23, 1999 onboard the space shuttle Columbia. The mission was led by Commander Eileen Collins. The crew was Pilot Jeff Ashby and Mission Specialists Cady Coleman, Steve Hawley and Michel Tognini from the Centre National d'Etudes Spatiales (CNES). This videotape shows a pre-flight press conference. Prior to the astronauts' arrival at the bunker area in front of the launch pad, the narrator discusses some of the training that the astronauts are scheduled to have prior to the launch, particularly the emergency egress procedures. Commander Collins introduces the crew and fields questions from the assembled press. Many questions are asked about the experiences of Commander Collins, and Mission Specialist Coleman as women in NASA. The press conference takes place outside in front of the Shuttle Columbia on the launch pad.

Contribution to the Study of Nuclear Interactions at Several Tens of Bev by Means of Cosmic Radiations (thesis); CONTRIBUTION A L'ETUDE DES INTERACTIONS NUCLEAIRES DE PLUSIEURS DIZAINES DE Gev., AU MOYEN DES RAYONS COSMIQUES (THESES)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pelletier, C.

1960-01-01

The secondaries produced by the interaction of highenergy cosmic radiation with aluminum were studied with Wilson chambers placed in a magnetic field. From 9600 photographs made, 117 interactions of charged particles with energy higher than 10 Bev in aluminum were selected. These photographs were obtained with the apparatus installed at the Observatory of the Pic du Midi de Bigorre. This apparatus is described. The quantities of motion and the emission direction of charged secondaries of each interaction were determined. The measurements and the methods of calculation are described. The results obtained on charged secondaries and unstable particles are reported. Themore » selection of the interactions which occurred with only one nucleon of the aluminum nucleus is discussed. These interactions were studied in the center-of-mass system of the interacting particles. The results obtained are compared with the predictions of the principal theoreticat models of nucleon-nucleon interactions. (trauth)« less

Unsteady Aerodynamics - Fundamentals and Applications of Aircraft Dynamics. Conference Proceedings of the Joint Symposium of the Fluid Dynamics and Flight Mechanics Panels Held in Goettingen, Federal Republic of Germany on 6-9 May 1985.

DTIC Science & Technology

1985-11-01

tourbillons daxe perpendicu-V laire A l’fcoulement principal) issu d’un profil occillant en Tamis dan;, do,, condition,, dn dorochagp dynamique. 5_10...a~rodyna- - mique sur R. A partir de cette analyse experimentale, une tentative de modelisation th~sorique des effets non *lin~ laires observes aux...cisaillement A la paroi d’un profil d’aile anim6 d’un mouvament harmonique parall~le ou parpandicu- laire A 1𔄀coulement non perturb~s", EUROMECH

Effet des Plastifiants sur la Temperature de Transition Vitreuse, Tg, du Butadiene a Terminaison Hydroxy et du Polyazoture de Glycidyle - Simulations et Experiences (Effect of the Plasticizers on the Vitreous Transition Temperature, Tg, of the Butadiene to Termination Hydroxy and the Polyazoture of Glycidyle - Simulations and Experiences)

DTIC Science & Technology

2008-09-01

diverses temperatures 26 a) HTPB pur b) HTPB-DOA (polymere et plastifiant) c) GAP pur d) Gpl pur e)Gap-Gpl Liste des tableaux Tableau 1...Composition des mailles amorphes construites 11 Tableau 2. Proprietes des polymeres et plastifiants utilises 11 Tableau 3. Comparaisons entre les Tt...obtenues experimentalement, les T% publiees dans les ecrits scientifiques et celles predites a partir des 7"gdes composes purs 19 Tableau 4. Comparaison

Oceanography in the formal and informal classroom

NASA Technical Reports Server (NTRS)

Richardson, A.; Jasnow, M.; Srinivasan, M.; Rosmorduc, V.; Blanc, F.

2002-01-01

The TOPEX/Poseidon and Jason-1 ocean altimeter missions offer the educator in the middle school or informal education venue a unique opportunity for reinforcing ocean science studies. An educational poster from NASA's Jet Propulsion Laboratory and France's Centre National d'Etudes Spatiales provide teachers and students a tool to examine topics such as the dynamics of ocean circulation, ocean research, and the oceans' role in climate.

STS-93 MS Tognini checks the BRIC experiment petri dishes on the middeck

NASA Image and Video Library

2013-11-18

STS093-350-008 (22-27 July 1999) --- Astronaut Michel Tognini, mission specialist representing France’s Centre National d’Etudes Spatiales (CNES), checks the Biological Research in Canisters (BRIC) payload petri dishes on the mid deck of the Space Shuttle Columbia. BRIC was designed to investigate the effects of space flight on small arthropod animals and plant specimens.

Canadian Mathematics Education Study Group = Groupe Canadien d'etude en didactique des matematiques. Proceedings of the Annual Meeting (St. Catharines, Ontario, Canada, May 27-31, 1989).

ERIC Educational Resources Information Center

Pereira-Mendoza, Lionel, Ed.; Quigley, Martyn, Ed.

These conference proceedings include two invited lectures, four working group reports, five topic group reports, a list of participants, and a list of previous proceedings. The invited lectures were: "Teaching Mathematical Proof: Relevance and Complexity of a Social Approach" (Nicolas Balacheff) and "Geometry Is Alive and…

Stakeholder Opinions on Suitability of Cello Etudes Created from Taksims of Tanburi Cemil Bey in Education

ERIC Educational Resources Information Center

Avci Akbel, Burcu

2017-01-01

There is a necessity for listening to and even probing into the recordings of the performers who reached the level of mastery in the performance of Turkish Classical Music, which is based on master-apprentice relationship. In this sense, the recordings of Tanburi Cemil Bey, who opened a new era for the next generations with his performances, and…

Une epreuve orale de francais en fin d'etudes de gestion. Construction et implications pedagogiques (An Oral French Exam at the End of a Marketing Program. Construction and Pedagogical Implications).

ERIC Educational Resources Information Center

Crawshaw, Robert H.

1984-01-01

An oral language test administered at the end of a four-year program combining business administration and French is described. The test consists of the formal presentation of a report including numbers, graphics, and text, a discussion of a theoretical issue, and interview. (MSE)

Canadian Journal for the Study of Adult Education = la Revue canadienne pour l'etude de l'education des adultes. 1987-1994.

ERIC Educational Resources Information Center

Canadian Journal for the Study of Adult Education, 1994

1994-01-01

These 17 issues include feature articles and perspectives on the study of adult education, as well as book reviews/recensions of works related to adult education. Some articles are written in English, and some are written in French. Among the feature articles included are the following: "The Fifties: Pivotal Decade in Canadian Adult…

Language Teaching with the Help of Multiple Methods. Collection d'"Etudes linguistiques," No. 21.

ERIC Educational Resources Information Center

Nivette, Jos, Ed.

This book presents articles on language teaching media. Among the titles are: (1) "Il Foreign Language Teaching e l'impiego degli audio-visivi" (Foreign Language Teaching and the Use of Audio Visual Methods) by D'Agostino, (2) "Le role et la nature de l'image dans l'enseignement programme de l'anglais, langue seconde" (The Role and Nature of the…

Canadian Mathematics Education Study Group = Groupe Canadian d'Etude en Didactique des Mathmatiques. Proceedings of the Annual Meeting (Burnaby, British Columbia, Canada, May 25-29, 1990).

ERIC Educational Resources Information Center

Quigley, Martyn, Ed.

These conference proceedings include two invited lectures, three working group reports, three topic group reports, two Ad Hoc group reports, a round table report, a list of participants, and a list of previous proceedings. The invited lectures were: "Values in Mathematics Education" (Ubiratan D'Ambrosio) and "Remarks on…

Adult Literacy: Policies, Programs and Practices. Lessons Learned. Final Report = Alphabetisation des adultes: politiques, programmes et pratiques. Etude bilan. Rapport final.

ERIC Educational Resources Information Center

2001

Studies and reports examining the problems associated with adult literacy and efforts to address those problems were reviewed to identify lessons for adult literacy programs in Canada and elsewhere. Low literacy levels were linked to above-average rates of personal and/or learning difficulties, low self-esteem, associated social problems, and…

Etudes diélectriques de la transition ferroélectrique induite par application d'un champ électrique dans les céramiques PbMg{1/3}Nb{2/3}O3 (PMN)

NASA Astrophysics Data System (ADS)

Chabin, M.; Malki, M.; Husson, E.; Morell, A.

1994-07-01

The evolution of the dielectric permittivity and loss factor under an external applied electric field has been studied in PbMg{1/3}Nb{2/3}O3 ceramics between 80 and 420 K. For a threshold field of 4 kV.cm^{-1}, it is possible to induce a ferroelectric transition from the average cubic phase to a macroscopically polar phase. The poling and depoling temperatures depend on the various combinations of thermal treatments and on the applied field strength. The transition between the nanopolar state and the macropolar state is discussed L'évolution de la permittivité diélectrique et du facteur de pertes diélectriques sous un champ électrique extérieur a été étudiée dans des céramiques de PbMg{1/3}Nb{2/3}O3 enre 80 et 420 K. Pour un champ de seuil de 4 kV.cm^{-1} il est possible d'induire une transition ferroélectrique de la phase cubique moyenne en une phase macroscopiquement polaire. Les températures de polarisation et de dépolarisation dépendent des différentes combinaisons de traitements thermiques et de la valeur du champ appliqué. La transition entre la phase constituée de nanodomaines polaires et la phase constituée de macrodomaines polaires est discutée.

Proceedings of the Annual Conference of the Canadian Association for the Study of Adult Education = Les actes du congres annuel de l'association canadienne pour l'etude de l'education des adultes (8th, Cornwall, Ontario, June 1-30, 1989).

ERIC Educational Resources Information Center

Bedard, Rene, Ed.

This proceedings contains 23 papers in French and the following 45 papers in English: "Arthur Lismer" (Barer-Stein); "Bootstrapping and Shoestringing to Academic Respectability" (Baskett); "Teaching by Teleconference" (Boak, Kirby); "Doing What Is Possible" (Butterwick); "Connections between Individual…

Proceedings of the Annual Conference of the Canadian Association for the Study of Adult Education/L'Association Canadienne pour L'Etude de L'Education des Adultes (17th, Ontario, Canada, May 29-31, 1998).

ERIC Educational Resources Information Center

Taylor, Maurice, Ed.

These proceedings on the theme, Adult Education Research: Shaping the Future, contain 52 papers. The papers are: "Virtual Adult Education" (W. Archer and D. Conrad); "Reversal Theory Approach to Adult Learning and Education" (M. Atleo); "Objectiver L'Action" (A. Balleux et al.); "Cultural Constructions of…

The Effects of Corona on Current Surges Induced on Conducting Lines by EMP (Electromagnetic Pulse): A Comparison of Experiment Data with Results of Analytic Corona Models

DTIC Science & Technology

1987-09-01

196. M. Schechter, A.D.A., P. 0. Box 2250 (81), Haifa, 31021, ISRAEL 197. D. Serafin, Cente d’Etudes de Gramat , 46500 Gramst, FRANCE 198. Peter Sevat...Managing Director, GERAC, B.P. 19 - 46500 Gramat FRANCE 202. Carol Smeerdon, Royal Aircraft Establishment, Flight Systems, BLdg. Q153, Farnborough

Contribution a l'etude de la nouvelle immigration libanaise au Quebec (Contribution to the Study of the New Lebanese Immigration to Quebec).

ERIC Educational Resources Information Center

Abou, Selim

This study, the result of interviews conducted in Quebec and Montreal in the spring of 1975, deals with the adaptation, integration, and acculturation of the Lebanese immigrants in Quebec since the end of World War II. This new immigration wave is contrasted with the one that took place around 1880. Generally speaking, the situation in both the…

Adult Education in a Changing Europe: A Survey of Theory and Practice. [L'Education des Adultes dans une Societe en Constante Evolution; Etude sur la Theorie et la Pratique.

ERIC Educational Resources Information Center

Hutchinson, E. M.; And Others

This course was held to review research and investigations undertaken in Europe, their significance for the practice of adult education, and the possibility of cooperative action in the future. Delegates reached conclusions calling for the general review of European adult education, bibliographic services, general and joint research, cooperation,…

Canadian Mathematics Education Study Group = Groupe Canadien d'etude en didactique des mathematiques. Proceedings of the Annual Meeting (23rd, St. Catherine's, ON, June 4-8, 1999).

ERIC Educational Resources Information Center

McLoughlin, John Grant, Ed.

This document contains the proceedings of 1999 annual meeting of the Canadian Mathematics Education Study Group (CMESG). Papers include: (1) "Mathematics Lecture I: The Impact of Technology on the Doing of Mathematics" (Jonathan Borwein); (2) "Mathematics Lecture II: The Decline and Rise of Geometry in 20th Century North America" (Walter…

Afterrise: Deep Body Temperature Following Exercise

DTIC Science & Technology

1992-03-01

Egalement, les effets de la posture et des v~tements durant la recuperation et la temperature de la salle de recuperation furent examines. Cinq hommes se...chemise a manches courtes). Les temperatures rectales et de la peau furent mesurees A chaque minute durant les exercices et la r~cup~ration affectaient...overgarment. RESUME Cette etude fut entreprise pour documenter l’augmentation continue de la temperature rectale apres exercice dans la chaleur

Canadian Mathematics Education Study Group = Groupe Canadien d'etude en didactique des mathematiques. Proceedings of the 1993 Annual Meeting (York, Ontario, Canada, May 28-June 1, 1993).

ERIC Educational Resources Information Center

Quigley, Martyn, Ed.

These proceedings contain papers presented at the 1993 annual meeting of the Canadian Mathematics Education Study Group. Papers are presented in four sections: (1) invited lectures; (2) working groups; (3) topic groups; and (4) ad hoc groups. Papers include: (1) "What is a Square Root? A Study of Geometrical Representation in Different…

STS-93 crewmembers assemble for crew inflight portrait on the middeck

NASA Image and Video Library

2013-11-18

STS093-322-017 (23-27 July 1999) --- The five STS-93 astronauts pose for the traditional inflight crew portrait on Columbia's middeck. In front are astronauts Eileen M. Collins, mission commander, and Michel Tognini, mission specialist, representing France's Centre National d'Etudes Spatiales (CNES). Behind them are (from the left) astronauts Steven A. Hawley, mission specialist; Jeffrey S. Ashby, pilot; and Catherine G. (Cady) Coleman, mission specialist.

Canadian Mathematics Education Study Group = Groupe Canadien d'etude en didactique des mathematiques. Proceedings of the 1994 Annual Meeting (Regina, Saskatchewan, Canada, June 3-7, 1994).

ERIC Educational Resources Information Center

Quigley, Martyn, Ed.

These proceedings contain papers from the 1994 annual meeting of the Canadian Mathematics Education Study Group. Papers are divided into the following sections: (1) invited lectures; (2) working groups; (3) topic groups; (4) ad hoc groups; and (5) reports on ICMI (International Committee on Mathematical Instruction) studies. Papers include: (1)…

The Pedagogical Value of Leo Brouwer's "Etudes Simples": A Perspective on Preserving an Exquisite, Yet Neglected Custom

ERIC Educational Resources Information Center

Kronenberg, Clive W.

2013-01-01

The decline in the status of the classical guitar is, for many, a cause of concern, calling for viable answers to restore its place in the expressive arts tradition. In this article, I explore a pedagogical style specifically intended for young and/or inexperienced players. It is argued that this endeavor could prospectively benefit a range of…

The abject gaze and the homosexual body: Flandrin's Figure d'Etude.

PubMed

Camille, M

1994-01-01

This article charts the history of the reception, reproduction and appropriation of a single image that has recently become a kind of "gay icon"--the Figure d'Etude in the Louvre, painted by Hippolyte Flandrin in 1835. Initially no more than a neo-classical academic exercise, the formal emptiness of this picture meant that it could be re-invested and reinscribed with new meanings and new titles at every turn. Emblematic of the anxious visibility/invisibility of the newly discovered homosexual body during a period when the gaze still had to be kept a dark secret, Flandrin's image only "came out" in its later photographic reworkings by Frederick Holland Day and Baron von Gloeden. After being reproduced for a specifically homosexual audience early this century, the popular Romantic pose of the young man curled-up in profile became a standard one, reappearing recently in the photographs of Robert Mapplethorpe. The inactive, abject and inward-turned isolation of the figure with its narcissistic self-absorption makes it, in my view, a profoundly negative stereotype of the gay gaze and the homosexual body. Flandrin's figure nonetheless appears today on gay merchandise world-wide as a sign of our separate and secluded subject positions and our community's unwillingness to radically alter older imposed and inherited classical stereotypes.

A microcosm of musical expression. I. Quantitative analysis of pianists' timing in the initial measures of Chopin's Etude in E major.

PubMed

Repp, B H

1998-08-01

Patterns of expressive timing were measured in bars 1-5 of 115 commercially recorded performances of Chopin's Etude in E major, op. 10, No. 3. These patterns were subjected to principal components analysis, which suggested at least four independent "timing strategies": (1) major ritards at the ends of melodic gestures; (2) acceleration within some of these gestures, without final ritards; (3) extreme lengthening of the initial downbeat; and (4) ritards between as well as within melodic gestures. Strategies 1 and 4 respond in different ways to the melodic-rhythmic grouping structure of the music, and strategy 3 merely represents a local emphasis. Strategy 2 is the one most difficult to rationalize; it does not seem to represent an alternative structural interpretation of the music but rather an alternative gestural shaping. Each individual pianist's timing pattern could be described as a weighted combination of these four strategies plus idiosyncratic variation. A wide variety of combinations was represented, and no two individual patterns were exactly the same. In addition, there was a wide range of basic tempi and of degrees of tempo modulation. There were no strong relationships between any of these variables and sociocultural characteristics of the artists, although some weak trends were observed.

Elaboration de revetements nanocomposites avec des proprietes superhydrophobes, semi-conductrices et photocatalytiques

NASA Astrophysics Data System (ADS)

Madidi, Fatima Zahra

Les lignes aeriennes de transport et de distribution de l'energie electrique sont souvent exposees a diverses contraintes. Parmi celles-ci, la pollution des isolateurs constitue l'un des facteurs de premiere importance dans la fiabilite du transport d'energie. En effet, la presence de pollution sur les isolateurs lorsqu'elle est humidifiee entraine la diminution de leur performance electrique en favorisant l'apparition d'arcs de contournement. De telles pannes peuvent parfois causer des impacts socioeconomiques importants. Par ailleurs, le developpement de nouveaux revetements pour ces isolateurs peut s'averer un moyen efficace pour les proteger contre l'apparition de l'arc de contournement. Les revetements superhydrophobes ont fait l'objet de nombreuses etudes au cours de ces dernieres annees. Ces surfaces sont preparees en combinant une rugosite nano-microstructuree avec une faible energie de surface. En outre, de telles surfaces ont de nombreuses applications si elles sont durables et n'ont pas d'effets nocifs sur l'environnement. L'objectif principal de la presente etude vise d'abord l'elaboration de revetements superhydrophobes, puis l'etude de leur duree de vie, leurs proprietes dielectriques et photocatalytiques. Une grande variete de materiaux a faible energie de surface peuvent etre utilises pour le developpement de ces revetements. Dans cette recherche, le caoutchouc de silicone (CS) est employe car il presente de nombreuses proprietes, notamment une forte hydrophobie, une resistance aux rayonnements ultraviolets, et une bonne tenue au feu sans degagement de produits toxiques. Toutefois, le point faible de ces materiaux est la degradation de leurs proprietes hydrophobes. Afin d'ameliorer certaines proprietes du caoutchouc de silicone, des nanoparticules seront additionnees au polymere de base. La technique d'elaboration des revetements consiste a ajouter des nanoparticules de dioxyde de titane (TiO2) au polymere de base, par des methodes ayant un potentiel d'applications industrielles. Les parametres d'elaboration ont ete optimises afin d'obtenir des revetements stables presentant des angles de contact eleves avec des gouttelettes d'eau et de faibles hysteresis. Apres avoir obtenu des surfaces superhydrophobes, des tests de stabilite ont ete effectues dans des conditions de vieillissement accelere tels que l'immersion dans des solutions aqueuses avec differents pH et conductivites ou la degradation par rayonnement UV. Les resultats obtenus ont montre que l'ajout de nanoparticules de dioxyde de titane au caoutchouc de silicone permet d'ameliorer l'hydrophobie et la stabilite de ce polymere. Les revetements superhydrophobes obtenus ont pu maintenir leur superhydrophobicite apres plusieurs jours d'immersion dans differentes solutions aqueuses. Ils presentent aussi une bonne stabilite lorsqu'ils sont exposes aux rayons UV ainsi qu'une stabilite mecanique. De plus, on a pu developper des revetements nanocomposites et microcomposites avec de bonnes proprietes dielectriques. L'etude des proprietes photocatalytiques des revetements superhydrophobes ont montre que l'adsorption des molecules reactives (polluants) sur la surface du catalyseur (TiO2) est le parametre cle de l'activite photocatalytique. L'augmentation de la concentration de TiO2 conduit a une diminution de la concentration du polluant et par consequent a un excellent rendement photocatalytique.

Bibliographie annotee de ressources complementaires. Etudes sociales: Secondaire, 7e a 12e (Annotated Bibliography of Further Resources. Social Studies: Secondary School, Grades 7-12).

ERIC Educational Resources Information Center

Soucy, Claire, Comp.; Hebert, Lorraine, Comp.

This annotated bibliography offers resources for teaching the social studies for grades 7 through 12. Subject areas include: (1) grade 7 - culture of Canada and Japan, as well as multicultural and bilingual Canada; (2) grade 8 - the geography of Canada, the United States, and the case of Brazil in South America; (3) grade 9 - economic perspectives…

Higher Education and Social Origin in France: A Statistical Study of Inequalities Since 1965 = Enseignement Superieur Et Origine Sociale En France: Etude Statistique Des Inegalites Depuis 1965

ERIC Educational Resources Information Center

Jaoul, Magali

2004-01-01

Mass education has the goal of guaranteeing the same education to all in order to moderate differences between individuals and promote a kind of "equality of opportunity." Nonetheless, it seems clear that lower-class youths do not benefit as much from their degree or university experience as do those who come from more privileged…

L'E.A.P. ou l'anglais enseigne dans les etudes superieures. Un guide pour le debutant (E.A.P. or English for Academic Purposes: A Guide for the Beginner).

ERIC Educational Resources Information Center

Roe, Peter J.

1981-01-01

Addresses those readers who are not familiar with EAP, offering an introductory discussion of its objectives and methods, in two parts. Devotes the first part to the needs that justify an EAP approach, and the second to its methodology, with particular attention to interdisciplinary, task-oriented instruction. Societe Nouvelle Didier Erudition, 40…

OSSE Observations of 3C 273

DTIC Science & Technology

1995-01-01

1991T, which was discovered on 1991 April 13 (Waagen & Knight 1991) in the spiral galaxy, NGC 4527, on the edge of the Virgo cluster . The OSSE observing...Strickman E.O. Hulburt Center for Space Research , Code 7650 Naval Research Lab, Washington DC 20375 K. McNaron-Brown George Mason University, Fairfax...VA 22030 E. Jourdain Centre d’Etude Spatiale des Rayonnements, Toulouse, France G. V. Jung Universities Space Research Association, Washington DC

Canadian Mathematics Education Study Group = Groupe Canadien d'Etude en Didactique des Mathematiques. Proceedings of the Annual Meeting (24th, Montreal, Quebec, Canada, May 26-30, 2000).

ERIC Educational Resources Information Center

Simmt, Elaine, Ed.; Davis, Brent, Ed.; McLoughlin, John Grant, Ed.

2000-01-01

This document contains the proceedings of the annual meeting of the Canadian Mathematics Education Study Group (CMESG) held at the University of Quebec in Montreal, Canada, May 26-30, 2000. The proceedings consist of two plenary lectures, five working groups, four topic sessions, new Ph.D. reports, and panel discussions. Papers include: (1)…

Managing a Job, a Family, and Studies. A Guide for Educational Institutions and the Workplace = Coordonner emploi, famille, et etudes. Un guide destine' aux institutions d'enseignement et au milieu du travail.

ERIC Educational Resources Information Center

Home, Alice; And Others

This guide, which presents the findings of a 1994 survey of nearly 500 Canadian women who fulfill family and work responsibilities while studying in social work, nursing, and adult education programs, is designed to help employers, educators, advisors, and administrators deal with the increased numbers of female students attempting to balance…

French payload specialist Patrick Baudry prepares a meal

NASA Technical Reports Server (NTRS)

1985-01-01

Payload specialist Patrick Baudry, representing the Centre National d'Etudes Spatiales of France, prepares to open a can of lobster. The bag attached to the nearby middeck locker door appears to contain several other French snacks. His food tray is also attached to the middeck lockers. Behind his head are other food trays attached to the shuttle rehydration unit. A roll of duct tape floats in space to one side of Baudry.

Le contexte du materiel pedagogique dans l'anglais de specialite. Etude sur les themes tires de l'environnement (The Context of Instructional Materials for ESP. A Study of Themes Drawn from the Environment).

ERIC Educational Resources Information Center

Williams, Ray

1981-01-01

Challenges the idea that ESP courses should be based strictly on instructional materials taken from the relevant professional context. Accordingly recommends a multidisciplinary themes approach as illustrated in the detailed description of the methods and materials used in a course offered by the University of Aston (Birmingham). Societe Nouvelle…

Foreign-Language Pedagogy: Practical Applications to Theoretical Concerns. Selected Papers from the Loyola College Conference Entitled "Bridging Theory and Practice in the Foreign-Language Classroom" (Baltimore, Maryland, October 18-20, 1991).

ERIC Educational Resources Information Center

Wieczorek, Joseph A., Ed.

1993-01-01

Papers from the conference include the following: "Activites orales et motivation dans l'etude du vocabulaire d'une langue etrangere (Oral Activities and Motivation in the Study of Vocabulary in a Foreign Language)" (M. Guisset); "Bridging High School and College Classes through the Multicultural Approach: The Case of Francophone…

A Survey of Blast Injury across the Full Landscape of Military Science (Etude d’ensemble des blessures dues aux explosions a travers le panorama complet de la science militaire)

DTIC Science & Technology

2011-04-01

Military Science (RTO-MP-HFM-207) Executive Summary Blast injury is a significant source of casualties in current NATO operations. The term “blast...toxicologique du souffle incluant les mécanismes de dose (par exemple, normes d’exposition à un tube à choc ), la description des points limites dose

Etudes sociales 30. Sujet B: Interaction entre nations. Cahier de l'eleve. Edition finale = Social Studies 30. Subject B: Interaction between Nations. Student Workbook. Final Edition.

ERIC Educational Resources Information Center

Alberta Dept. of Education, Edmonton. Curriculum Branch.

In this Alberta (Canada) student workbook, four history units are presented for study. These are: (1) Between Two Wars (1919-1936); (2) World War II; (3) The Emergence and Interaction of the Superpowers; and (4) Contemporary World Interactions. Advice is offered to students in each unit along with information about key events and issues during…

Validation of MODIS-derived bidirectional reflectivity retrieval algorithm in mid-infrared channel with field measurements.

PubMed

Tang, Bo-Hui; Wu, Hua-; Li, Zhao-Liang; Nerry, Françoise

2012-07-30

This work addressed the validation of the MODIS-derived bidirectional reflectivity retrieval algorithm in mid-infrared (MIR) channel, proposed by Tang and Li [Int. J. Remote Sens. 29, 4907 (2008)], with ground-measured data, which were collected from a field campaign that took place in June 2004 at the ONERA (Office National d'Etudes et de Recherches Aérospatiales) center of Fauga-Mauzac, on the PIRRENE (Programme Interdisciplinaire de Recherche sur la Radiométrie en Environnement Extérieur) experiment site [Opt. Express 15, 12464 (2007)]. The leaving-surface spectral radiances measured by a BOMEM (MR250 Series) Fourier transform interferometer were used to calculate the ground brightness temperatures with the combination of the inversion of the Planck function and the spectral response functions of MODIS channels 22 and 23, and then to estimate the ground brightness temperature without the contribution of the solar direct beam and the bidirectional reflectivity by using Tang and Li's proposed algorithm. On the other hand, the simultaneously measured atmospheric profiles were used to obtain the atmospheric parameters and then to calculate the ground brightness temperature without the contribution of the solar direct beam, based on the atmospheric radiative transfer equation in the MIR region. Comparison of those two kinds of brightness temperature obtained by two different methods indicated that the Root Mean Square Error (RMSE) between the brightness temperatures estimated respectively using Tang and Li's algorithm and the atmospheric radiative transfer equation is 1.94 K. In addition, comparison of the hemispherical-directional reflectances derived by Tang and Li's algorithm with those obtained from the field measurements showed that the RMSE is 0.011, which indicates that Tang and Li's algorithm is feasible to retrieve the bidirectional reflectivity in MIR channel from MODIS data.

Etude de la transmission sonore a travers un protecteur de type "coquilles" : modelisation numerique et validation experimentale

NASA Astrophysics Data System (ADS)

Boyer, Sylvain

On estime que sur les 3,7 millions des travailleurs au Quebec, plus de 500 000 sont exposes quotidiennement a des niveaux de bruits pouvant causer des lesions de l'appareil auditif. Lorsqu'il n'est pas possible de diminuer le niveau de bruit environnant, en modifiant les sources de bruits, ou en limitant la propagation du son, le port de protecteurs auditifs individualises, telles que les coquilles, demeure l'ultime solution. Bien que vue comme une solution a court terme, elle est communement employee, du fait de son caractere peu dispendieux, de sa facilite d'implantation et de son adaptabilite a la plupart des operations en environnement bruyant. Cependant les protecteurs auditifs peuvent etre a la fois inadaptes aux travailleurs et a leur environnement et inconfortables ce qui limite leur temps de port, reduisant leur protection effective. Afin de palier a ces difficultes, un projet de recherche sur la protection auditive intitule : " Developpement d'outils et de methodes pour ameliorer et mieux evaluer la protection auditive individuelle des travailleur ", a ete mis sur pied en 2010, associant l'Ecole de technologie superieure (ETS) et l'Institut de recherche Robert-Sauve en sante et en securite du travail (IRSST). S'inscrivant dans ce programme de recherche, le present travail de doctorat s'interesse specifiquement a la protection auditive au moyen de protecteurs auditifs " passifs " de type coquille, dont l'usage presente trois problematiques specifiques presentees dans les paragraphes suivants. La premiere problematique specifique concerne l'inconfort cause par exemple par la pression statique induite par la force de serrage de l'arceau, qui peut reduire le temps de port recommande pour limiter l'exposition au bruit. Il convient alors de pouvoir donner a l'utilisateur un protecteur confortable, adapte a son environnement de travail et a son activite. La seconde problematique specifique est l'evaluation de la protection reelle apportee par le protecteur. La methode des seuils auditifs REAT (Real Ear Attenuation Threshold) aussi vu comme un "golden standard" est utilise pour quantifier la reduction du bruit mais surestime generalement la performance des protecteurs. Les techniques de mesure terrains, telles que la F-MIRE (Field Measurement in Real Ear) peuvent etre a l'avenir de meilleurs outils pour evaluer l'attenuation individuelle. Si ces techniques existent pour des bouchons d'oreilles, elles doivent etre adaptees et ameliorees pour le cas des coquilles, en determinant l'emplacement optimal des capteurs acoustiques et les facteurs de compensation individuels qui lient la mesure microphonique a la mesure qui aurait ete prise au tympan. La troisieme problematique specifique est l'optimisation de l'attenuation des coquilles pour les adapter a l'individu et a son environnement de travail. En effet, le design des coquilles est generalement base sur des concepts empiriques et des methodes essais/erreurs sur des prototypes. La piste des outils predictifs a ete tres peu etudiee jusqu'a present et meriterait d'etre approfondie. L'utilisation du prototypage virtuel, permettrait a la fois d'optimiser le design avant production, d'accelerer la phase de developpement produit et d'en reduire les couts. L'objectif general de cette these est de repondre a ces differentes problematiques par le developpement d'un modele de l'attenuation sonore d'un protecteur auditif de type coquille. A cause de la complexite de la geometrie de ces protecteurs, la methode principale de modelisation retenue a priori est la methode des elements finis (FEM). Pour atteindre cet objectif general, trois objectifs specifiques ont ete etablis et sont presentes dans les trois paragraphes suivants. (Abstract shortened by ProQuest.).

Etude exploratoire de la commercialisation des nanotechnologies au Canada: L'utilisation de la fouille de donnees de contenu Web

NASA Astrophysics Data System (ADS)

Rietsch, Constant

Companies rely more every day on the Internet, sharing a lot of information to their customers but also their investors and their associates. Most companies share information such as products, services, partnerships, and research and development activities on their website. All this information is much analytical opportunities provided that we can retrieve and interpret. In this context, is the content of a website can be enough to conduct a study on innovation and commercialization? Websites are sources of information available and accessible to everyone. The majority of companies with a website, the coverage of an Internet-based study is an advantage. For our research on the commercialization of nanotechnology in Canada, we recover as many data on websites of Canadian companies listed by various sources as having activities in nanotechnology. From these data we cluster companies according to their nanotechnology field using a list of keywords from scientific papers to estimate the level of advancement of Canadian companies in nanotechnology research. Finally thanks to several indicators of innovation and marketing we describe the current state of nanotechnology in the Canadian industry.

STS-75 Flight Day 1

NASA Technical Reports Server (NTRS)

1996-01-01

On this first day of the STS-75 mission, the flight crew, Cmdr. Andrew Allen, Pilot Scott Horowitz, Payload Cmdr. Franklin Chang-Diaz, Payload Specialist Umberto Guidoni (Italy), and Mission Specialists Jeffrey Hoffman, Maurizio Cheli (ESA) and Claude Nicollier (ESA), were shown performing pre-launch and launching activities. This international space mission's primary objective is the deployment of the Tethered Satellite System Reflight (TSS-1R) to a 12 mile length from the shuttle, a variety of experiments, and the satellite retrieval. These experiments include: Research on Orbital Plasma Electrodynamics (ROPE); TSS Deployer Core Equipment and Satellite Core Equipment (DCORE/SCORE); Research on Electrodynamic Tether Effects (RETE); Magnetic Field Experiments for TSS Missions (TEMAG); Shuttle Electrodynamic Tether Systems (SETS); Shuttle Potential and Return Electron Experiment (SPREE); Tether Optical Phenomena Experiment (TOP); and Observations at the Earth's Surface of Electromagnetic Emissions by TSS (OESSE). The mission's secondary objectives were those experiments found in the United States Microgravity Payload-3 (USMP-3), which include: Advanced Automated Directional Solidification Furnace (AADSF); Material pour l'Etude des Phenomenes Interessant la Solidification sur Terre et en Orbite (MEPHISTO); Space Acceleration Measurement System (SAMS); Orbital Acceleration Research Experiment (OARE); Critical Fluid Scattering Experiment (ZENO); and Isothermal Dendritic Growth Experiment (IDGE).

Littoral Infrared Ship Self Defence Technology Studies (Autodefense cotiere infrarouge des navires etudes technologiques)

DTIC Science & Technology

2014-05-01

de simulation du Simulateur de Contre- mesures de la Menace Navale afin de pouvoir inclure des leurres et des autodirecteurs de missiles ; 4) Une...sur le littoral ; 2) La détection des petites cibles de surface sur le littoral ; 3) L’amélioration et la validation de la modélisation et du code...amélioration et une validation supplémentaire de la modélisation et du

Think-Tank: The Present and Future of University Adult Education Programs in Quebec. Proceedings = Journee d'etude: le present et l'avenior des programmes universitaires en andragogie au Quebec. Rapport (Montreal, Quebec, April 26, 1988).

ERIC Educational Resources Information Center

Simon, Pierre; Heft, Riva

These proceedings, presented in English and French, summarize a seminar on the present and future of adult education programs in Quebec. Six Quebec universities were represented. The conference was opened by Dr. Pierre Simon, who introduced the theme and rationale of the day-long workshop. Dr. Charles Bertrand welcomed the participants,…

Les sous-prefectures de Sikensi et Dabakala, Cote-d'Ivoire. (The Regions of Sikensi and Dabakala, Ivory Coast.) Method de preparation de la carte scolaire: etudes de cas 9.

ERIC Educational Resources Information Center

Hallak, J.; And Others

This volume contains the results of the first study of the problems associated with using educational television in curriculum planning in the Ivory Coast. The study was conducted in two districts of this African country, one relatively developed and situated in the southern part of the country, and the other more characteristic of the poorer…

Characterizing the Effects of Low Order Perturbations on Geodetic Satellite Precision Orbit Determination

DTIC Science & Technology

2015-08-07

Journal of Geodesy , Vol. 72, No. 6, 1998, pp. 333–342. [19] “Etalon-1, and -2,” http://ilrs.gsfc.nasa.gov/missions/satellite_missions...current_missions/g129_general.html, 2012. [24] L. Kanner and Associates, “Translation of ’Le satellite de geodesie ’Starlette’,’ Groupe de Recherches...de Geodesie Spatiale, Centre National d’Etudes Spatiales, Bretigny-sur-Orge, France, Report, 1974, 25 pp,” National Aeronautics and Space

Coupled Experimental and Theoretical Investigations of Instability, Chaos and Turbulence in an Axisymmetric Jet Flow

DTIC Science & Technology

1990-07-01

performed using two of the available methods, due respectively to Wolf et al. 8, and...FiueS1 270 Paper in progress to be submitted to: Phys. Fluids. ECOLE CENTRALE DES ARTS ET MANUFACTURES RAPPORT DE STAGE DE FIN D’ETUDES EXCITATION D’UN JET...disposition et de la souplesse dont ii a fait preuve. Je tiens dgalement & remercier tout particuliirement Patrick Reisenthel de toute 1’attention et

Polder in-flight results

NASA Astrophysics Data System (ADS)

Bermudo, F.; Lifermann, A.; Hagolle, O.; Laherrere, J.-M.; Bret-Dibat, T.

2018-04-01

This paper presents a global approach of POWER (Polarization and Directionalily of the Earths Reflectance) program: from instrument design . pre-flight and in-fligh1 calibrations till the first inflight results The POLDER sensor bas been developed by the Centre National d'Etudes Spatiales, the French space agency. It is part of the payload of the Advanced Earth Observation Satellite (ADEOS) developed by NASDA and launched m August 1996. POLDER had been acquiring data till the lost of ADEOS in June 1997.

Canadian Mathematics Education Study Group = Groupe Canadien d'Etude en Didactique des Mathematiques. Proceedings of the Annual Meeting (25th, Edmonton, Alberta, Canada, May 25-29, 2001).

ERIC Educational Resources Information Center

Simmt, Elaine, Ed.; Davis, Brent, Ed.

2001-01-01

This document contains the proceedings of the 2001 annual meeting of the Canadian Mathematics Education Study Group (CMESG) held at the University of Alberta, May 25-39, 2000. The proceedings consist of two plenary lectures, four working groups, five topic sessions, new Ph.D. reports, an AD Hoc Session, and panel discussions. Papers include: (1)…

STS-75 Flight Day 10

NASA Technical Reports Server (NTRS)

1996-01-01

On this tenth day of the STS-75 mission, the flight crew, Cmdr. Andrew Allen, Pilot Scott Horowitz, Payload Cmdr. Franklin Chang-Diaz, Payload Specialist Umberto Guidoni (Italy), and Missions Specialists Jeffrey Hoffman, Maurizio Cheli (ESA), and Claude Nicollier (ESA), are shown performing middeck and Microgravity lab experiments, including the Material pour l'Etude des Phenomenes Interessant la Solidification sur Terre et en Orbite (MEPHISTO) experiment, as well as some material burn tests. Earth views include cloud cover and horizon shots.

Etudes sociales 30. Sujet B: Interactions entre nations. Unite d'enseignement--Guide. Edition finale = Social Studies 30. Subject B: Interactions between Nations. Teaching Unit--Guide. Final Edition.

ERIC Educational Resources Information Center

Alberta Dept. of Education, Edmonton. Curriculum Branch.

In this Alberta (Canada) teacher's guide, four history units are outlined. These are: (1) Between Two Wars (1919-36); (2) World War II; (3) The Emergence and Interaction of the Superpowers; and (4) Contemporary World Interactions. At the end of each unit, questions are provided for discussion and there is a final synthesis at the end of the…

Optical Data Processing in Europe,

DTIC Science & Technology

1981-12-31

PROCESSING IN EUROPE4 _____________ 6PERFORMING ORG. REPORT NUMBER 7. AUTIKOR(eJ G . CONTRACT OR GRANT NUMBER(&) /7David/)Casasent 9. PERFORMING ORGANIZATION...Direction Des Recherches, Etudes et Techniques (DRET]). Present at this meeting were J. Graf, M. Petri and G . Marie of LEP as well as M. Constans and M...be useful in sonai , and processing studies. I visited Henri at Elf Aquitaine in Pau, Frarce. wt- w,-1. overall view of the company and a summary of

Les Interferences Semantiques Dans Les Oeuvres D'ahmadou Kourouma et De Mongo Beti: Essai D'etude Comparative [Semantic Interference in the Works of Ahmadou Kourouma and Mongo Beti: Test Comparative Study

ERIC Educational Resources Information Center

Tadoum, Jean Paul

2012-01-01

This dissertation focuses on the works of two well-known African Francophone novelists, Ahmadou Kourouma from the Ivory Coast and Mongo Beti from Cameroon. The objective of this study is to look at the influences of African oral traditions and analyze the literary transposition of semantic structures from African languages and cultures into the…

HBA1c: clinical and biological agreement for standardization of assay methods. Report by the experts of ALFEDIAM (Association de Langue Française pour lEtude du Diabète et des Maladies Métabolique) and SFBC (Société Française de Biologie Clinique).

PubMed

Gillery, P; Bordas-Fonfrède, M; Chapelle, J P; Drouin, P; Hue, G; Lévy-Marchal, C; Périer, C; Sélam, J L; Slama, G; Thivolet, C; Vialettes, B

1999-09-01

Glycohaemoglobin, and particularly haemoglobin A1c(HbA1c), assays have been used for many years to retrospectively evaluate the glycaemic control of diabetic patients. Cut-off values have been established for deciding treatment modifications. The techniques used in the laboratories however exhibit varying quality, and all of them are not yet standardized. The consequence is an under-utilization of this test, especially in non-hospital practice. In this context, working groups of Société Française de Biologie Clinique (SFBC), Association de Langue Française pour l'Etude du Diabète et des Maladies Métaboliques (ALFEDIAM) and Société Française d'Endocrinologie (SFE) have met together, in order to analyze the national status, and to propose practical recommendations for implementing a standardization process on the basis of international experiences. It is recommended to exclusively express results as HbA1c percentage, using methods standardized and certified by comparison to reference methods such as those using Diabetes Control and Complications Trial (DCCT) values. Simultaneously, contacts have been established with manufacturers, and the realisation of periodic quality control surveys was encouraged.

Competition entre supraconductivite et magnetisme au voisinage de la transition de Mott dans le conducteur organique quasi-bidimensionnel k-(BEDT-TTF)2copper[N(CN)2]bromine

NASA Astrophysics Data System (ADS)

Fournier, David

Les conducteurs organiques quasi-bidimensionnels kappa-ET2X presentent d'importantes similitudes avec les SCHT telles qu'une phase isolant de Mott, un regime de pseudogap et un etat supraconducteur. L'etude de leurs proprietes apparait donc complementaire. Parmi les interrogations persistantes concernant la physique de ces systemes, l'origine du (ou des) processus exotique d'appariement, responsable de la supraconductivite est le sujet suscitant l'interet le plus marque dans la communaute. L'hypothese d'un mecanisme lie a la proximite d'un etat antiferromagnetique est privilegiee. Une etape importante dans la resolution de cette problematique est l'identification de la symetrie du parametre d'ordre. D'apres de nombreux travaux sur les systemes fortement correles, la sonde ultrasonore, de par sa sensibilite aux excitations de quasiparticule a basse temperature, est consideree comme particulierement adaptee a l'etude de cette propriete. Cependant, son emploi necessite l'utilisation d'un compose metallique a basse temperature et completement supraconducteur. Le compose metallique organique kappa-ET 2Cu[N(CN)2]Br presente toutes les caracteristiques necessaires a l'etude de cette propriete. En effet, il est situe loin de la transition du premier ordre de Mott et est completement supraconducteur. De facon surprenante, ce systeme semble se coupler fortement avec le reseau ce qui augmente significativement la sensibilite de cette sonde aux proprietes du gaz electronique. Cependant, des difficultes techniques importantes, liees a la nature intrinseque de ce materiau, doivent etre surmontees pour proceder a des mesures suivant differentes polarisations. La presente etude a profondement modifie notre comprehension de ce systeme. En effet, ces mesures ont permis de constater que le kappa-ET2Cu[N(CN)2]Br est un compose qui est situe en bordure de la zone de coexistence entre la supraconductivite et le magnetisme, ce qui constitue un resultat totalement inattendu. De plus, la variation judicieuse du cycle thermique s'est averee etre equivalente a une modification de la pression chimique. Cette derniere est modifiee par l'intermediaire d'une relaxation structurale autour de 85 K appelee la transition de verre d'ethylenes. Cela nous a permis de suivre l'evolution de cette coexistence en s'approchant de la transition de premier ordre, et ainsi de statuer sur la competition entre la supraconductivite et le magnetisme ainsi que sur l'existence d'une separation de phase d'ordre macroscopique. De plus, nous avons observe une anisotropie similaire sur les mesures de vitesse ultrasonore entre le regime de pseudogap et la supraconductivite. Ce resultat tend a confirmer l'existence d'une physique commune entre le regime de pseudogap et l'etat supraconducteur. Le regime de pseudogap, encore meconnu a ce jour, est probablement relie a des fluctuations antiferromagnetiques, dont l'origine pourrait etre un emboitement de la surface de Fermi quasi-unidimensionnelle de ce compose, ou bien relie a la proximite de la physique de Mott. Enfin, l'analyse de la symetrie du parametre d'ordre supraconducteur, qui est probablement de type s+d, tend a demontrer que les processus de couplage interplan sont d'une importance cruciale. L'approche theorique de Hubbard purement 2D dans le plan conducteur semble donc insuffisante pour la recherche du mecanisme d'appariement.

Intelligence Effectiveness in the European Union (E.U.) in the New Security Environment

DTIC Science & Technology

2012-12-01

works. When it comes to compliance with E.U. laws, Gerda Faulkner, an Austrian scholar identifies three worlds of compliance: “a world of law...www.europarl.europa.eu/RegData/etudes/note/libe/2011/462420/IPOL- LIBE_NT(2011)462420(PAR00)_EN.pdf. 79 Gerda Falkner, Oliver Treib, Miriam Hartlapp, and Simone...http://belfercenter.ksg.harvard.edu/files/Fagersten%20theoretical%20framework.p df. Falkner, Gerda . Treib, Oliver. Hartlapp, Miriam and Leiber

Correlation of Survival Rates of Anopheles dirus A (Diptera: Culicidae) with Different Infection Densities of Plasmodium cynomolgi

DTIC Science & Technology

1986-01-01

rhesus, le premier indemne, le second infeste par Plasmodium cynomolgi. Vingt moustiques gorges de sang constituaient le groupe temoin non infest& et...60 autres moustiques infest& ont ete divises en trois groupes de 20 moustiques (groupes infest& 1, 2 et 3). On a evaI& le nombre moyen d’oocystes...port& par les moustiques en dissequant ceux du groupe 1 au septieme jour de I’etude; on a recherche la presence de sporozo’ites dans les glandes

International overview of hospital procurement.

PubMed

Ferrier, Maud; Lariviere, David; Laurent, Claire; Roque, Eric

2011-01-01

This article was written by four French hospital director students at the Ecole des Hautes Etudes en Santé Publique (EHESP-School of Public Health) from a study conducted jointly with students at the Grenoble School of Management to present an international overview of hospital procurement methods in ten countries. An analysis of these methods showed that there was a general trend towards group purchasing, with some common aims in terms of costs and performance and some differences in legislation (competition), size of the public sector and centralization or decentralization.

Proceedings of the 2004 Annual Meeting of the Canadian Mathematics Education Study Group = Actes de la Rencontre Annuelle 2004 du Groupe Canadien d'Etude en Didactique des Mathematiques (28th, Quebec City, Quebec, Canada, May 28-Jun 1, 2004)

ERIC Educational Resources Information Center

Simmt, Elaine, Ed.; Davis, Brent, Ed.

2005-01-01

This submission contains the Proceedings of the 2004 Annual Meeting of the Canadian Mathematics Education Study Group (CMESG), held at Universite Laval in Quebec City, Quebec. The CMESG is a group of mathematicians and mathematics educators who meet annually to discuss mathematics education issues at all levels of learning. The aims of the Study…

Role of Al2O3 in Sintering of Submicron Yttria-Stabilized ZrO2 Powders.

DTIC Science & Technology

1983-12-02

and dispersed by milling in a 60 : 40 alcohol : water solution, followed by pressing at 205 MPa. Significantly increased densification was obtained...the range 1100-1350-C, was investigated. The Al󈧘 was added as hydrated A1(OH)l and dispersed by milling in a 60 : 40 alcohol : water solution...124-130 (1975). 24. M. Heughebaert-Therasse, "Contribution a L’etude de L’evolution et du Frittage de la Zircone Stabilisee par Differents Oxydes , a

STS-93 Tognini and Hawley pose with the SWUIS on the middeck of Columbia

NASA Image and Video Library

2013-11-18

STS093-347-027 (23-27 July 1999) --- Astronauts Steven A. Hawley (left) and Michel Tognini, mission specialists, are pictured with the Southwest Ultraviolet Imaging System (SWUIS) on the middeck of the Space Shuttle Columbia. SWUIS was used during the mission to image planets and other solar system bodies in order to explore their atmospheres and surfaces in ultraviolet (UV) region of the spectrum, which astronomers value for diagnostic work. Tognini represents the Centre National d'Etudes Spatiales (CNES) of France.

Proceedings of the 2007 Annual Meeting of the Canadian Mathematics Education Study Group = Actes de la Rencontre Annuelle 2007 du Groupe Canadien d'Etude en Didactique des Mathematiques (31st, Fredricton, New Brunswick, Canada, Jun 8-12, 2007)

ERIC Educational Resources Information Center

Liljedahl, Peter, Ed.

2008-01-01

This submission contains the Proceedings of the 2007 Annual Meeting of the Canadian Mathematics Education Study Group (CMESG), held at the University of New Brunswick in Fredricton, New Brunswick. The CMESG is a group of mathematicians and mathematics educators who meet annually to discuss mathematics education issues at all levels of learning.…

Proceedings of the 2009 Annual Meeting of the Canadian Mathematics Education Study Group = Actes de la Rencontre Annuelle 2009 du Groupe Canadien d'Etude en Didactique des Mathematiques (33rd, Toronto, Ontario, Canada, June 5-June 9, 2009)

ERIC Educational Resources Information Center

Liljedahl, Peter, Ed.; Oesterle, Susan, Ed.; Abu-Bakare, Veda, Ed.

2010-01-01

This submission contains the Proceedings of the 2009 Annual Meeting of the Canadian Mathematics Education Study Group (CMESG), held at York University in Toronto, Ontario. The CMESG is a group of mathematicians and mathematics educators who meet annually to discuss mathematics education issues at all levels of learning. The aims of the Study Group…

Proceedings of the 2010 Annual Meeting of the Canadian Mathematics Education Study Group = Actes de la Rencontre Annuelle 2010 du Groupe Canadien d'Etude en Didactique des Mathematiques (34th, Burnaby, British Columbia, Canada, May 21-25, 2010)

ERIC Educational Resources Information Center

Liljedahl, Peter, Ed.; Oesterle, Susan, Ed.; Allan, Darien, Ed.

2011-01-01

This submission contains the Proceedings of the 2010 Annual Meeting of the Canadian Mathematics Education Study Group (CMESG), held at Simon Fraser University in Burnaby, British Columbia. The CMESG is a group of mathematicians and mathematics educators who meet annually to discuss mathematics education issues at all levels of learning. The aims…

T2L2 on JASON-2: First Evaluation of the Flying Model

DTIC Science & Technology

2007-01-01

Para, J.-M. Torre R&D Metrology CNRS/GEMINI Observatoire de la Côte d’Azur Caussol, France E-mail: philippe.guillemot@cnes.fr Abstract...Laser Link” experiment T2L2 [1], under development at OCA (Observatoire de la Côte d’Azur) and CNES (Centre National d’Etudes Spatiales), France, will be...Experimental Astronomy, 7, 191-207. [2] P. Fridelance and C. Veillet, 1995, “Operation and data analysis in the LASSO experiment,” Metrologia

Etude par spectrométrie infrarouge et Raman de la pyrimidone-2 et de son chlorhydrate (chlorure d'oxo-2 pyrimidinium)

NASA Astrophysics Data System (ADS)

Picquenard, Eric; Lautié, Alain

The i.r. and Raman spectra of crystalline 2-pyrimidone, its hydrochloride and corresponding N-deuterated derivatives have been investigated between 4000 and 200 cm -. Aqueous solutions were also examined. An assignment for all intramolecular fundamentals is given. Effects of the protonation on the C=O group and on the ring are discussed as well as strength and characteristics of the hydrogen bonds NH … O and NH … Cl -.

Proceedings of the 2002 Annual Meeting of the Canadian Mathematics Education Study Group = Actes de la Rencontre Annuelle 2002 du Groupe Canadien d'Etude en Didactique des Mathematiques (26th, Kingston, Ontario, Canada, May 24-28, 2002)

ERIC Educational Resources Information Center

Simmt, Elaine, Ed.; Davis, Brent, Ed.

2003-01-01

This submission contains the Proceedings of the 2002 Annual Meeting of the Canadian Mathematics Education Study Group (CMESG), held at Queen's University in Kingston, Ontario. The CMESG is a group of mathematicians and mathematics educators who meet annually to discuss mathematics education issues at all levels of learning. The aims of the Study…

Non-Lethal Weapons Effectiveness Assessment Development and Verification Study (Etude d’evaluation, de developpement et de verification de l’efficacite des armes non letales)

DTIC Science & Technology

2009-10-01

will guarantee a solid base for the future. The content of this publication has been reproduced directly from material supplied by RTO or the...intensity threat involving a local population wanting to break into the camp to steal material and food supplies ; and • A higher intensity threat...combatant evacuation opeations, distribute emergency supplies , and evacuate/ relocate refugees and displaced persons. Specified NLW-relevant tasks are

Proceedings of the 2005 Annual Meeting of the Canadian Mathematics Education Study Group = Actes de la Rencontre Annuelle 2005 du Groupe Canadien d'Etude en Didactique des Mathematiques (29th, Ottawa, Ontario, Canada, May 27-31, 2005)

ERIC Educational Resources Information Center

Liljedahl, Peter, Ed.

2006-01-01

This submission contains the Proceedings of the 2005 Annual Meeting of the Canadian Mathematics Education Study Group (CMESG), held at the University of Ottawa in Ottawa, Ontario. The CMESG is a group of mathematicians and mathematics educators who meet annually to discuss mathematics education issues at all levels of learning. The aims of the…

Proceedings of the 2008 Annual Meeting of the Canadian Mathematics Education Study Group = Actes de la Rencontre Annuelle 2008 du Groupe Canadien d'Etude en Didactique des Mathematiques (32nd, Sherbrooke, Quebec, Canada, May 23-27, 2008)

ERIC Educational Resources Information Center

Liljedahl, Peter, Ed.; Oesterle, Susan, Ed.; Berneche, Christian, Ed.

2009-01-01

This submission contains the Proceedings of the 2008 Annual Meeting of the Canadian Mathematics Education Study Group (CMESG), held at the Universite de Sherbrooke in Sherbrooke, Quebec. The CMESG is a group of mathematicians and mathematics educators who meet annually to discuss mathematics education issues at all levels of learning. The aims of…

NASA Cryogenic Propellant Systems Technology Development and Potential Opportunities for Discussion

NASA Technical Reports Server (NTRS)

Meyer, Michael L.

2015-01-01

Members of the eCryo Team are traveling to France to meet with CNES (Centre National d'Etudes Spatiales) on the benchmarking of CFM (Cryogenic Fluids Management) analytical models the week of January 26th, 2015. Mike Meyer is representing the Agency and eCryo Project and will conduct a conversation to explore future work. This slide package (28 charts and 3 movies) requires approval via a 1676. ISS data in this chart set has been copied from public websites.

L'Education et l'information juridiques dans un contexte bilingue. Etude exploratrice sur la comprehension populaire des lois (Legal Education and Information in a Bilingual Context. Exploratory Study on the Popular Understanding of Laws).

ERIC Educational Resources Information Center

Ribordy, Francois-Xavier; And Others

A study investigated the readability of current laws for Canadian francophones and anglophones. The 63 subjects were asked to read a variety of brief legal texts available in parallel styles in both languages and to answer questions about the texts' content. Subjects were also surveyed about their preference for a formal or vulgarized style of…

Etude Comparative des Systemes de Reperage de l'Information Bibliographique en Mode Dialogue. Rapports de Recherche, No. 13 (Comparative Study of Systems for the Online Retrieval of Bibliographic Information. Research Report No. 13).

ERIC Educational Resources Information Center

Perusse, Lyse

This study, which was conducted at the University of Quebec over a period of six months, focuses on four systems for online information retrieval that are available to users at the university and provide access to some of the same databases: BRS (Bibliographic Retrieval Services Inc.), CAN/OLE (Canadian On-Line Inquiry), Lockheed DIALOG, and…

Pressure Suppresses Serotonin Release by Guinea Pig Striatal Synaptosomes

DTIC Science & Technology

1988-01-01

neurological syndrome. Brit J Pharmacol 1982; 76:447-452. 5. Wardley-Smith B, Meldrum BS. Effect of excitatory amino acid antagonists on !he high pressure...Res 1974; 1:,-28. *14. IBichard AR, Little HIJ. Drugs that increase Y-aminobutyric acid tr.ansmission prm ict PF..atnst * I the high pressure...Effects of high pressure of heliox on the striatal 5-HIAA and ascorbic acid rates in the rat. Cent Etud Rech Bio-Physiol Rep 84-08. 1984:35. 7

Some Implications of Linguistic Theory for Applied Linguistics. Collection d'"Etudes linguistiques," No. 19. Papers from the Neuchatel Colloquium in Applied Linguistics in collaboration with AIMAV, AILA, CILA, and the University of Neuchatel (3rd, May 30-June 1, 1974).

ERIC Educational Resources Information Center

Corder, S. P., Ed.; Roulet, E., Ed.

Papers that address implications of linguistic theory for applied linguistics are presented. In "Some Semantic Properties of Some Conjunctions," W. Abraham is concerned with the function of "but" and its translation equivalents in German and other languages. In "Is It Possible and Necessary to Write Text Grammars?," T. P. Krzeszowski examines the…

Proceedings of the 2015 Annual Meeting of the Canadian Mathematics Education Study Group = Actes De La Rencontre Annuelle 2015 Du Groupe Canadien D'etude en Didactique Des Mathematiques (39th, Moncton, New Brunswick, Canada, June 5-9, 2015)

ERIC Educational Resources Information Center

Oesterle, Susan, Ed.; Allan, Darien, Ed.

2015-01-01

This submission contains the Proceedings of the 2015 Annual Meeting of the Canadian Mathematics Education Study Group (CMESG), held at the Université de Moncton in Moncton, New Brunswick. The CMESG is a group of mathematicians and mathematics educators who meet annually to discuss mathematics education issues at all levels of learning. The aims of…

Proceedings of the 2003 Annual Meeting of the Canadian Mathematics Education Study Group = Actes de la Rencontre Annuelle 2003 du Groupe Canadien d'Etude en Didactique des Mathematiques (27th, Wolfville, Nova Scotia, Canada, May 30-June 3, 2003)

ERIC Educational Resources Information Center

Simmt, Elaine, Ed.; Davis, Brent, Ed.

2004-01-01

This submission contains the Proceedings of the 2003 Annual Meeting of the Canadian Mathematics Education Study Group (CMESG), held at Acadia University in Wolfville, Nova Scotia. The CMESG is a group of mathematicians and mathematics educators who meet annually to discuss mathematics education issues at all levels of learning. The aims of the…

Advances in Guidance and Control Systems.

DTIC Science & Technology

1983-01-01

contrble optimal. de techniques de synth~se et de m~thodes conceptuelles ont 616 r~alis~s depuis le dernier symposium consacri A ce domaine en 1973. L ...PILOTAGE DES AlIONS A GRAMD MAflONWnABILITS par Oiner L .* MERCIER Office National d’Etudes et de Recherches A~rospatiales (OaRA) 92320 Chitillon...par le fait que, dons le domaine de manauvre envisag;6, le mod~le dynamique eat fortement nonliniaire, variable l ~e long du domaine de vol, et sujet i

The Training of Modern Language Teachers in Various Countries. Collection d'"Etudes linguistiques," No. 20. Selected papers from the Association Internationale pour la Recherche et la Diffusion des Methodes Audio-Visuelles et Structuro-Globales Seminar (5th, August 27-September 1, 1973).

ERIC Educational Resources Information Center

Nivette, Jos, Ed.

Selected papers that address theoretical and practical training of the modern language teacher and language teaching experiments in various countries are presented. Some of the articles included are the following: "Les problemes de la formation linguistique et pedagogique des professeurs de francais en Afrique Subsaharienne" (The…

Survey of Hyperspectral and Multispectral Imaging Technologies (Etude sur les technologies d’imagerie hyperspectrale et multispectrale)

DTIC Science & Technology

2007-05-01

but relatively low acoustic figure of merit (the ability to couple acoustic wave to the crystal). In the infrared region TeO2 crystal (0.35 – 5.0 µm...filter. More in particular, it is based on a Lyot filter, which is a sandwich of birefringent liquid crystal, glass , quartz placed between two...variable retardance element in the sandwich composed of quartz, glass , polarizers and liquid crystal itself. To achieve the desired wavelength

Rotary-Balance Testing for Aircraft Dynamics (Les Essais sur Balance Rotative pour l’Etude de la Dynamique du Vol de l’Avion)

DTIC Science & Technology

1990-01-01

critical examination of the rotary-balance techniques used in the AGARD community for the analysis of high-angle-of-attack dynamic behavior of aircraft. It...aircraft. It was felt that sudi a critical examination should encompass both the experimental techniques used to obtain rotary-flow aerodynamic data and the...monitor the vibrational and critical structural characteristies of the apparatus and tunnel support system. Many of these systems are integrated directly

Proceedings of the 2006 Annual Meeting of the Canadian Mathematics Education Study Group = Actes de la Rencontre Annuelle 2006 du Groupe Canadien d'Etude en Didactique des Mathematiques (30th, Calgary, Alberta, Canada, Jun 3-7, 2006)

ERIC Educational Resources Information Center

Liljedahl, Peter, Ed.

2007-01-01

This submission contains the Proceedings of the 2006 Annual Meeting of the Canadian Mathematics Education Study Group (CMESG), held at the University of Calgary in Calgary, Alberta. The CMESG is a group of mathematicians and mathematics educators who meet annually to discuss mathematics education issues at all levels of learning. The aims of the…

Airframe/Propulsion Interference

DTIC Science & Technology

1975-03-01

elancee, en incidence, est prcsenic figure 14. L’intrados se caracterise par une divergence des lignes dc courant, et par une reducti.in ’es nombres...ale de la zone dissipative en R et A/S une fonction du nombre de Hach au recollement Mq et d’un parametre de forme Hiq caracterisant le...extralte d’une Etude expE- rimentale prEsentEe rEf. [13]. Bile se caractErise par un elancement assez important et un rapport de tronoature ft^ /\\M.t

Environmental Conditions of Surface Soils and Biomass Prevailing in the Training Area at CFB Gagetown, New Brunswick

DTIC Science & Technology

2003-09-26

sur Ia caracterisation environnementale de leurs secteurs d’entrainement majeurs afin d’ameliorer les connaissances des impacts de tous les types...et geographique. En 2001, Ia premiere phase de cette etude a consiste en la caracterisation hydrogeologique partielle dans la portion nord du...secteur d’entrainement. Cette premiere phase a implique le forage de 42 puits, afin de caracteriser la dynamique et la qualite des eaux souterraines. En

L'etude de l'apprentissage du vocabulaire en contexte par l'ecoute d'un dialogue scenarise en francais langue seconde (The Study of Vocabulary Learning in Context by Listening to a Dialogue in Scenario Form in French as a Second Language).

ERIC Educational Resources Information Center

Duquette, Lise

A study investigated the relative effectiveness of French second language vocabulary learning when presented in two contexts: video, with attention to extralinguistic factors, or audio, with focus on linguistic factors alone. Four student groups (n=137 university students) were formed from existing classes: experimental with video treatment;…

sts093-s-016

NASA Image and Video Library

1999-07-27

STS093-(S)-016 (27 July 1999) --- Members of the STS-93 crew pose in front of the Space Shuttle Columbia following the night landing on runway 33 at Kennedy Space Center's Shuttle Landing Facility. From the left are astronauts Catherine G. (Cady) Coleman and Steven A. Hawley, both mission specialists; Jeffrey S. Ashby, pilot; Eileen M. Collins, mission commander; and Michel Tognini, mission specialist representing France's Centre National d'Etudes Spatiales (CNES). Main gear touchdown occurred at 11:20:35 p.m.(EDT), July 27, 1999.

Pluriannual variability of sedimentation on mudflats in a macrotidal estuary

NASA Astrophysics Data System (ADS)

Cuvilliez, A.; Lafite, R.; Deloffre, J.; Massei, N.; Langlois, E.; Sakho, I.

2010-12-01

Antoine Cuvilliez1, Robert Lafite2, Julien Deloffre2, Nicolas Massei2, Estelle Langlois 3 and Issa Sakho2 1 Université du Havre, FRE 3102, Laboratoire d’ondes et milieux complexes, Université du Havre, 76058 Le Havre cedex, France 2 Université de Rouen, UMR 6143, Morphodynamique Continentale et Côtière, 76821 Mont Saint Aignan Cedex, France. 3 Université de Rouen, ECODIV , Etude et Compréhension de la Biodiversité, 76821 Mont Saint Aignan Cedex, France.

Etude de la formation de resonances electroniques et de leur role dans la fragmentation neutre de molecules d'interet biologique

NASA Astrophysics Data System (ADS)

Lepage, Martin

1998-12-01

Cette these est presentee a la Faculte de medecine de l'Universite de Sherbrooke en vue de l'obtention du grade de Ph.D. en Radiobiologie. Elle contient des resultats experimentaux enregistres avec un spectrometre d'electrons a haute resolution. Ces resultats portent sur la formation de resonances electroniques en phase condensee et de differents canaux pour leur decroissance. En premier lieu, nous presentons des mesures d'excitations vibrationnelles de l'oxygene dilue en matrice d'argon pour des energies des electrons incidents de 1 a 20 eV. Les resultats suggerent que le temps de vie des resonances de l'oxygene est modifie par la densite d'etats d'electrons dans la bande de conduction de l'argon. Nous presentons aussi des spectres de pertes d'energie d'electrons des molecules de tetrahydrofuranne (THF) et d'acetone. Dans les deux cas, la position en energie des pertes associees aux excitations vibrationnelles est en excellent accord avec les resultats trouves dans la litterature. Les fonctions d'excitation de ces modes revelent la presence de plusieurs nouvelles resonances electroniques. Nous comparons les resonances du THF et celles de la molecule de cyclopentane en phase gazeuse. Nous proposons une origine commune aux resonances ce qui implique qu'elles ne sont pas necessairement attribuees a l'excitation des electrons non-apparies de l'oxygene du THF. Nous proposons une nouvelle methode basee sur la spectroscopie par pertes d'energie des electrons pour detecter la production de fragments neutres qui demeurent a l'interieur d'un film mince condense a basse temperature. Cette methode se base sur la detection des excitations electroniques du produit neutre. Nous presentons des resultats de la production de CO dans un film de methanol. Le taux de production de CO en fonction de l'energie incidente des electrons est calibre en termes d'une section efficace totale de diffusion des electrons. Les resultats indiquent une augmentation lineaire du taux de production de CO en fonction de l'epaisseur du film et de la dose d'electrons incidente sur le film. Ces donnees experimentales cadrent dans un modele simple ou un electron cause la fragmentation de la molecule sans reaction avec les molecules avoisinantes. Le mecanisme propose pour la fragmentation unimoleculaire du methanol est la formation de resonances qui decroissent dans un etat electronique excite. Nous suggerons l'action combinee de la presence d'un trou dans une orbitale de coeur du methanol et de la presence de deux electrons dans la premiere orbitale vide pour expliquer la dehydrogenation complete du methanol pour des energies des electrons entre 8 et 18 eV. Pour des energies plus grandes, la fragmentation par l'intermediaire de l'ionisation de la molecule a deja ete suggeree. La methode de detection des etats electroniques offre une alternative a la detection des excitations vibrationnelles puisque les spectres de pertes d'energie des electrons sont congestionnes dans cette region d'energie pour les molecules polyatomiques.

Orbit determination support of the Ocean Topography Experiment (TOPEX)/Poseidon operational orbit

NASA Technical Reports Server (NTRS)

Schanzle, A. F.; Rovnak, J. E.; Bolvin, D. T.; Doll, C. E.

1993-01-01

The Ocean Topography Experiment (TOPEX/Poseidon) mission is designed to determine the topography of the Earth's sea surface over a 3-year period, beginning shortly after launch in July 1992. TOPEX/Poseidon is a joint venture between the United States National Aeronautics and Space Administration (NASA) and the French Centre Nationale d'Etudes Spatiales. The Jet Propulsion Laboratory is NASA's TOPEX/Poseidon project center. The Tracking and Data Relay Satellite System (TDRSS) will nominally be used to support the day-to-day orbit determination aspects of the mission. Due to its extensive experience with TDRSS tracking data, the NASA Goddard Space Flight Center (GSFC) Flight Dynamics Facility (FDF) will receive and process TDRSS observational data. To fulfill the scientific goals of the mission, it is necessary to achieve and maintain a very precise orbit. The most stringent accuracy requirements are associated with planning and evaluating orbit maneuvers, which will place the spacecraft in its mission orbit and maintain the required ground track. To determine if the FDF can meet the TOPEX/Poseidon maneuver accuracy requirements, covariance analysis was undertaken with the Orbit Determination Error Analysis System (ODEAS). The covariance analysis addressed many aspects of TOPEX/Poseidon orbit determination, including arc length, force models, and other processing options. The most recent analysis has focused on determining the size of the geopotential field necessary to meet the maneuver support requirements. Analysis was undertaken with the full 50 x 50 Goddard Earth Model (GEM) T3 field as well as smaller representations of this model.

Etude analytique et numérique de la réponse en vibration à hautes fréquences d'éprouvettes de fatigue vibratoire des métaux. Application aux aciers

NASA Astrophysics Data System (ADS)

Ben Aich, A.; El Kihel, B.; Kifani, A.; Sahban, F.

1994-07-01

In the present paper, the so-called " ultrasonic fatigue " or fatigue at very high frequency has been studied in the materials elastic behaviour case while neglecting the thermal effects that influence the mechanical fields. The determination of mechanical fields and specimen resonance length has been done both analytically and numerically. The numerical method used for this calculation is the finite element method (FEM). Martensitic steel " Soleil A2 " and austenitic steel " ICL 472 BC " have been considered in order to compare the two methods (analytical and numerical). It is shown that a perfect convergence is obtained between the two solutions. Dans le présent travail, la fatigue vibratoire a été étudiée dans le cas du comportement élastique des matériaux en négligeant les effets thermiques pouvant influencer les champs mécaniques. La détermination de ces champs et de la longueur de résonance des éprouvettes de fatigue a été faite analytiquement et numériquement. Le calcul numérique effectué se base sur la méthode des éléments finis. Dans le but d'une comparaison des solutions analytiques et numériques, deux aciers ont été considérés : un acier martensitique (Soleil A2) et un acier austénitique de type 18-10 (ICL 472 BC). Une parfaite convergence est obtenue entre les deux solutions.

Etude de la physico-chime d'un magnetoplasma de chlore pour la gravure sous-micrometrique

NASA Astrophysics Data System (ADS)

Pauna, Olivier Daniel

The aim of this thesis is to achieve a better understanding of physical and chemical phenomena occurring in a high-density plasma designed for sub-micron etching of thin films. The plasma is produced in chlorine by means of an electromagnetic surface wave and it can be confined by a uniform static magnetic field. The flexibility offered by the reactor in terms of operating conditions makes possible a parametric study of the influence of the magnetic confinement on the plasma characteristics. Thus, we have examined the plasma properties by means of several diagnostics techniques, including electrostatic probes, laser photodetachment of negative ions, ion acoustic wave propagation and optical emission spectroscopy. First, we investigated the influence of the operating conditions on the spatial properties of the plasma; this includes electric characteristics (electrons, positive and negative ions) as well as chemical characteristics (reactive neutrals). Second, we studied the impact of the reactor aspect ratio (i.e. reactor length/radius ratio) on both electrical and chemical characteristics. Together with these experimental studies, we have developed a bidimensional fluid model, by solving self-consistently the first two moments of Bolzmann equation and Poisson's equation. Using a semi-implicit scheme, it was possible to maintain a short computation time and to use this model to investigate a diffusion plasma in an electropositive gas. We were thus able to estimate the value of the diffusion coefficient in the direction perpendicular to the magnetic field. The results thus obtained are in good qualitative agreement with the diffusion coefficient proposed by Liebermann and Lichtenberg.

European Organization for Research and Treatment of Cancer and Groupe d'Etude des Lymphomes de l'Adulte very favorable and favorable, lymphocyte-predominant Hodgkin disease.

PubMed

Wilder, Richard B; Schlembach, Pamela J; Jones, Dan; Chronowski, Gregory M; Ha, Chul S; Younes, Anas; Hagemeister, Fredrick B; Barista, Ibrahim; Cabanillas, Fernando; Cox, James D

2002-03-15

Lymphocyte-predominant Hodgkin disease (LPHD) is rare and has a natural history different from that of classic Hodgkin disease. There is little information in the literature regarding the role of chemotherapy in patients with early-stage LPHD. The objective of this study was to examine recurrence free survival (RFS), overall survival (OS), and patterns of first recurrence in patients with LPHD who were treated with radiotherapy alone or with chemotherapy followed by radiotherapy. From 1963 to 1996, 48 consecutive patients ages 16-49 years (median, 28 years) with Ann Arbor Stage I (n = 30 patients) or Stage II (n = 18 patients), very favorable (VF; n = 5 patients) or favorable (F; n = 43 patients) LPHD, according to the European Organization for Research and Treatment of Cancer and Groupe d'Etude des Lymphomes de l'Adulte (EORTC-GELA) criteria, received radiotherapy alone (n = 37 patients) or received chemotherapy followed by radiotherapy (n = 11 patients). The percentages of patients with VF disease (11% vs. 9% in the radiotherapy group vs. the chemotherapy plus radiotherapy group, respectively) or F disease (89% vs. 91%, respectively) within the two treatment groups were similar (P = 1.00). A median of three cycles of chemotherapy with mechlorethamine, vincristine, procarbazine, and prednisone (MOPP) or with mitoxantrone, vincristine, vinblastine, and prednisone (NOVP) was given initially to six patients and five patients, respectively. A median total radiotherapy dose of 40 grays (Gy) given in daily fractions of 2.0 Gy was delivered to both treatment groups. The median follow-up was 9.3 years, and 98% of patients were observed for > or = 3.0 years. RFS was similar for patients who were treated with radiotherapy alone and patients who were treated with chemotherapy followed by radiotherapy (10-year survival rates: 77% and 68%, respectively; P = 0.89). The OS rate also was similar for the two groups (10-year survival rates: 90% and 100%, respectively; P = 0.43). MOPP or NOVP chemotherapy did not reduce the risk of recurrence outside of the radiotherapy fields. MOPP or NOVP chemotherapy did not improve RFS or OS significantly in patients with VF or F LPHD, although the statistical power was limited. Ongoing clinical trials will help to clarify the role of a watch-and-wait strategy or systemic therapy, including anthracycline (epirubicin or doxorubicin), bleomycin, and vinblastine-based chemotherapy or antibody-based approaches, in the treatment of these patients. Copyright 2002 American Cancer Society.

Le changement comme tradition dans la recherche et la formation a la recherche en biotechnologie et en peripherie Etude de cas en sciences de la sante, sciences naturelles et genie

NASA Astrophysics Data System (ADS)

Bourque, Claude Julie

Le champ de la recherche scientifique et de la formation a la recherche est traverse depuis quelques dizaines d'annees par plusieurs courants et discours associes au changement, mais peu de travaux empiriques permettent de comprendre ce qui change concretement. C'est la contribution originale de cette these au champ de l'education, plus specifiquement a l'etude sociologique de l'enseignement superieur ou sont concentrees les activites liees a la triade thematique du programme doctoral dans lequel elle a ete produite : recherche, formation et pratique. L'enquete-terrain a ete realisee en 2009 et 2010 aupres de 808 repondants affilies a 60 etablissements au Quebec et a produit un vaste materiau de nature mixte (donnees quantitatives et qualitatives). Un portrait de la nebuleuse biotechnologique qui touche les secteurs des sciences de la sante, des sciences naturelles et du genie a ete realise. Ce domaine concerne des dizaines de disciplines et se revele de nature transdisciplinaire, mais les pratiques n'y sont pas davantage marquees par le changement que celles d'autres domaines connexes. Les dynamiques sociales ont fait l'objet d'analyses comparatives dans quatre contextes: le choix des programmes, des objets et des methodes, le financement, la diffusion et la planification de la carriere. Les resultats indiquent que les echanges entre les agents traditionnellement situes au coeur des activites de recherche dominent ces dynamiques dans tous les contextes etudies. L'etude des representations au fondement des pratiques a revele l'existence de trois ecoles de pensee qui coexistent dans le champ scientifique: academique, pragmatique et economiste. Ces ecoles permettent de categoriser les agents en fonction des zones de fractures qui marquent leurs oppositions tout en identifiant ce qu'ils ont en commun. Les representations et les pratiques liees a la formation temoignent d'un habitus plutot homogene, alors que les contradictions semblent plus souvent ancrees dans des luttes universitaires que scientifiques, concentrees sur la negociation du capital scientifique, symbolique et economique en jeu dans la formation doctorale, dans les carrieres auxquelles elle mene, et dans les qualites du titre de Ph.D. Au final, la confusion entre des logiques opposees peut etre reduite en reinterpretant le changement comme tradition du champ scientifique. Mots-cles Sociologie, education, enseignement superieur, science et technologie, biotechnologie, formation doctorale, champ scientifique, reseaux sociaux

Etude de la Production de Paires de Leptons dans les Interactions Proton-Beryllium a 450 GEV

NASA Astrophysics Data System (ADS)

Aubry, Pierre Rene Roger

L'experience HELIOS a fait une etude precise de la production des paires e^+e^-, mu^+mu^-, mu ^+mu^-+nu, et mu^+/- e^+/- dans les interactions p-Be a 450 GeV. Le detecteur comporte un spectrometre a electrons, un spectrometre a muons, et un ensemble de calorimetres qui peuvent mesurer les photons et l'energie manquante emportee par les neutrinos. Les paires de leptons sont observees dans la region cinematique ^1: eqalign {2/m_mu 6 GeV cr E_{e}&>2.8 GeV cr.25&

Methode d'identification parametrique pour la surveillance in situ des joints a recouvrement par propagation d'ondes vibratoires

NASA Astrophysics Data System (ADS)

Francoeur, Dany

Cette these de doctorat s'inscrit dans le cadre de projets CRIAQ (Consortium de recherche et d'innovation en aerospatiale du Quebec) orientes vers le developpement d'approches embarquees pour la detection de defauts dans des structures aeronautiques. L'originalite de cette these repose sur le developpement et la validation d'une nouvelle methode de detection, quantification et localisation d'une entaille dans une structure de joint a recouvrement par la propagation d'ondes vibratoires. La premiere partie expose l'etat des connaissances sur l'identification d'un defaut dans le contexte du Structural Health Monitoring (SHM), ainsi que la modelisation de joint a recouvrements. Le chapitre 3 developpe le modele de propagation d'onde d'un joint a recouvrement endommage par une entaille pour une onde de flexion dans la plage des moyennes frequences (10-50 kHz). A cette fin, un modele de transmission de ligne (TLM) est realise pour representer un joint unidimensionnel (1D). Ce modele 1D est ensuite adapte a un joint bi-dimensionnel (2D) en faisant l'hypothese d'un front d'onde plan incident et perpendiculaire au joint. Une methode d'identification parametrique est ensuite developpee pour permettre a la fois la calibration du modele du joint a recouvrement sain, la detection puis la caracterisation de l'entaille situee sur le joint. Cette methode est couplee a un algorithme qui permet une recherche exhaustive de tout l'espace parametrique. Cette technique permet d'extraire une zone d'incertitude reliee aux parametres du modele optimal. Une etude de sensibilite est egalement realisee sur l'identification. Plusieurs resultats de mesure sur des joints a recouvrements 1D et 2D sont realisees permettant ainsi l'etude de la repetabilite des resultats et la variabilite de differents cas d'endommagement. Les resultats de cette etude demontrent d'abord que la methode de detection proposee est tres efficace et permet de suivre la progression d'endommagement. De tres bons resultats de quantification et de localisation d'entailles ont ete obtenus dans les divers joints testes (1D et 2D). Il est prevu que l'utilisation d'ondes de Lamb permettraient d'etendre la plage de validite de la methode pour de plus petits dommages. Ces travaux visent d'abord la surveillance in-situ des structures de joint a recouvrements, mais d'autres types de defauts. (comme les disbond) et. de structures complexes sont egalement envisageables. Mots cles : joint a recouvrement, surveillance in situ, localisation et caracterisation de dommages

Etudes optiques de nouveaux materiaux laser: Des orthosilicates dopes a l'ytterbium: Le yttrium (lutetium,scandium) pentoxide de silicium

NASA Astrophysics Data System (ADS)

Denoyer, Aurelie

La decouverte et l'elaboration de nouveaux materiaux laser solides suscitent beaucoup d'interet parmi la communaute scientifique. En particulier les lasers dans la gamme de frequence du micron debouchent sur beaucoup d'applications, en telecommunication, en medecine, dans le domaine militaire, pour la, decoupe des metaux (lasers de puissance), en optique non lineaire (doublage de frequence, bistabilite optique). Le plus couramment utilise actuellement est le Nd:YAG dans cette famille de laser, mais des remplacants plus performants sont toujours recherches. Les lasers a base d'Yb3+ possedent beaucoup d'avantages compares aux lasers Nd3+ du fait de leur structure electronique simple et de leur deterioration moins rapide. Parmi les matrices cristallines pouvant accueillir l'ytterbium, les orthosilicates Yb:Y 2SiO5, Yb:Lu2SiO5 et Yb:Sc2SiO 5 se positionnent tres bien, du fait de leur bonne conductivite thermique et du fort eclatement de leur champ cristallin necessaire a l'elaboration de lasers quasi-3 niveaux. De plus l'etude fine et systematique des proprietes microscopiques de nouveaux materiaux s'avere toujours tres interessante du point de vue de la recherche fondamentale, c'est ainsi que de nouveaux modeles sont concus (par exemple pour le champ cristallin) ou que de nouvelles proprietes inhabituelles sont decouvertes, menant a de nouvelles applications. Ainsi d'autres materiaux dopes a l'ytterbium sont connus pour leurs proprietes de couplage electron-phonon, de couplage magnetique, d'emission cooperative ou encore de bistabilite optique, mais ces proprietes n'ont encore jamais ete mises en evidence dans Yb:Y 2SiO5, Yb:Lu2SiO5 et Yb:Sc2SiO 5. Ainsi, cette these a pour but l'etude des proprietes optiques et des interactions microscopiques dans Yb:Y2SiO 5, Yb:Lu2SiO5 et Yb:Sc2SiO5. Nous utilisons principalement les techniques d'absorption IR et de spectroscopie Raman pour determiner les excitations du champ cristallin et les modes de vibration dans le materiau. Des mesures optiques sous champ magnetique ont egalement ete effectuees dans le but de caracteriser le comportement de ces excitations lorsqu'elles sont soumises a l'effet Zeeman. La resonance paramagnetique electronique a permis de completer cette etude de l'eclatement Zeeman suivant toutes les orientations du cristal. Enfin la fluorescence par excitation selective et la fluorescence induite par Raman FT, completent la description des niveaux d'energie et revelent l'existence d'emission cooperative de deux ions Yb3+ et de transferts d'energie. Les resultats de cette these apportent une contribution originale dans le domaine des nouveaux materiaux lasers par l'etude et la comprehension des interactions fines et des proprietes microscopiques d'un materiau en particulier. Ils debouchent a la fois sur des applications possibles dans le domaine de l'optique et des lasers, et sur la comprehension d'aspects fondamentaux. Cette these a prouve l'interet de ces matrices pour leur utilisation comme lasers solides: un fort eclatement du champ cristallin favorable a l'elaboration de laser quasi-3 niveaux, et de larges bandes d'absorption (dues a un fort couplage electron-phonon et a des raies satellites causees par une interaction d'echange entre deux ions Yb3+) qui permettent la generation d'impulsions laser ultra-courtes, l'accordabilite du laser, etc. De plus la miniaturisation des lasers est possible pour l'optique integree grace a des couches minces synthetisees par epitaxie en phase liquide dont nous avons demontre la tres bonne qualite structurale et l'ajustement possible de certains parametres. Nous avons reconstruit le tenseur g du niveau fondamental (qui donne des informations precieuses sur les fonctions d'onde), ceci dans le but d'aider les theoriciens a concevoir un modele de champ cristallin valide. Plusieurs mecanismes de transferts d'energie ont ete mis en evidence: un mecanisme de relaxation d'un site vers l'autre, un mecanisme d'emission cooperative, et un mecanisme d'excitation de l'Yb3+ par le Tm3+ (impurete presente dans le materiau). Ces transferts sont plutot nefastes pour la fabrication d'un laser mais sont interessants pour l'optique non lineaire (doublage de frequence, memoires optiques). Enfin, plusieurs elements (le couplage magnetique de paire, le couplage electron-phonon et l'emission cooperative) nous ont permis de conclure sur le caractere covalent de la matrice. Nous avons d'ailleurs demontre ici le role de la covalence dans l'emission cooperative, transition habituellement attribuee aux interactions multipolaires electriques.

Assessment of TRAC-PF1/MOD1 version 14. 3 using separate effects critical flow and blowdown experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spindler, B.; Pellissier, M.

1990-01-01

Independent assessment of the TRAC code was conducted at the Centre d'Etudes Nucleaires de Grenoble of the Commissariate a l'Energie Atomique (France) in the frame of the ICAP. This report presents the results of the assessment of TRAC-PF1/MOD1 version 14.3 using critical flow steady state tests (MOBY-DICK, SUPER-MOBY-DICK), and blowdown tests (CANON, SUPER-CANON, VERTICAL-CANON, MARVIKEN, OMEGA-TUBE, OMEGA-BUNDLE). This document, Volume 1, presents the text and tables from this assessment.

Assessment of TRAC-PF1/MOD1 Version 14. 3 using separate effects critical flow and blowdown experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spindler, B.; Pellissier, M.

1990-01-01

Independent assessment of the TRAC code was conducted at the Centre d'Etudes Nucleaires de Grenoble of the Commissariate a l'Energie Atomique (France) in the frame of the ICAP. This report presents the results of the assessment of TRAC-PF1/MOD1 version 14.3 using critical flow steady state tests (MOBY-DICK, SUPER-MOBY-DICK), and blowdown tests (CANON, SUPER-CANON, VERTICAL-CANON, MARVIKEN, OMEGA-TUBE, OMEGA-BUNDLE). This document, Volume 2, presents the experimental data and figures from the assessment.

Garde a l'enfance: Etude sur la remuneration et les conditions de travail dans le domaine de la garde a l'enfance au Canada. Rapport final (Caring for a Living: A Study on Wages and Working Conditions in Canadian Child Care. Final Report).

ERIC Educational Resources Information Center

Canadian Child Care Federation, Ottawa (Ontario).

Between November 1990 and August 1992, a study examined wages and working conditions of child care staff in both licensed group centers and family day care homes in Canada. Three instruments were developed for the study, a short telephone interview for center directors, a follow-up director's questionnaire, and a staff questionnaire. The study…

A Survey of Serious Aircraft Accidents Involving Fatigue Fracture. Volume 2. Rotary-Wing Aircraft (Etude sur des Accidents Importants d’Avions du aux Effets des Fractures de Fatigue. Volume 2. Effets sur des Helicopteres).

DTIC Science & Technology

1983-04-01

Convention on International Civil Aviation, Second Edition , March 1966. 5. WORLD AIRLINE ACCIDENT SUMMARY. Civil Aviation Authority, (Great Britain...people who either provided information, or who suggested other sources of information for the current edition of this survey. E.M.R. Alexander Civil...Waverley, New Zealand. F-28C Tail rotor drive shaft. Fatigue strength reduc- ed by softened condition & surface decarbur- isation. AISA 4130 steel. Ref: NZ

Etudes Asymptotiques en Filtrage Non Lineaire Avec Petit Bruit D’Observation (Asymptotic Studies in Nonlinear Time Filtering with Small Observation Noise)

DTIC Science & Technology

1990-09-26

Tentugal Valente, pour la maniire enthousiaste avtc laquelle il a soutenu ce projet . Je ne dois pas oublier de remercier If, Groupe de Math 6matiques...oial sur un travectie csimue d~veloppement au sein du projet MEFISTO, i. lINRIA - centre de Sophia - Antipolis. 56 Dans cette 6tude asymptotique de...Control and Information Sciences, 83, Springer 1986. 58 [Picard] Picard, J. : Nonlinear filtering and smoothing with high sig - nal-to-noise ratio

Adaptation of a Turbine Test Facility to High-Temperature Research (Adaptation d’un banc de Turbine aux Recherches pour les Hautes Temperatures,

DTIC Science & Technology

1980-12-19

Des hautes temperatures devant turbine sur turborgacteur et turbines A gaz. (High turbine inlet temperatures in turbo - jet engines and gas turbines ... turbo - jet engines .) Revue Gn(rale de Thermique, No. 166, October 1975 15 D. Arnal Etude exprimentale et thgorique de la transition de la couche J.C...r AD-AIOl 374 ROYAL AIRCRAFT ESTABLISHMENT FARNBOROUBH (ENGLAND) F/B 10/1 ADAPTATION OF A TURBINE TEST FACILITY TO HIGH-TEMPERATURE RESEA--ETC(U) DEC

Foreword

NASA Astrophysics Data System (ADS)

Brazovskii, Serguei; Dressel, Martin; Kirova, Natasha

2015-03-01

This volume presents a collection of articles based upon materials of the recent International School and Workshop on Electronic Crystals, ECRYS-2014. The series ECRYS was founded by Serguei Brazovskii and Pierre Monceau in 1993. ECRYS-2014 is the seventh in the sequence of such events, held in France every three years; the last four meetings 2005, 2008, 2011 and 2014 were hosted by the Institut d'Etudes Scientifiques of the CNRS, at Cargese, Corsica, France. Starting from 2011, ECRYS was expanded to a two-week format incorporating summer-school type tutorials of renowned scientists.

V.L.A. Observations of Solar-Active Regions. I. The Slowly Varying Component,

DTIC Science & Technology

1980-08-01

bremsstrahlung accounts for the highly polarized radiation. In this situation the magnetic energy 2 % 4 -3 density of H /(8T) 10 erg cm vastly exceeds the...equipartition value inferred from the virial theorem, for the thermal kinetic energy density in -3 the "coronal condensations" is 3N kT 5 erg cm . It...Boston: D. Reidel). Kundu, M.R., 1959a, Ann. Ap., 22, 1. Kundu, M.R., 1959b, "Etude Interferometrique des Sources d’Activite Solaire sur 3 cm de

Evaluation du programme d'etudes de francais langue seconde en immersion a la 6e annee. La comprehension orale et la production orale, 1990. Rapport Final. (Evaluation of French as a Second Language Study Program for Grade Six Immersion. Oral Comprehension and Speaking Skills, 1990. Final Report).

ERIC Educational Resources Information Center

Theberge, Raymond

An evaluation of Manitoba's French immersion programs at the levels of grades 3, 6, and 9 focused on program effectiveness in teaching listening comprehension and speech skills. The results for grade 6 are presented here. The first section describes the framework of the immersion curriculum and the listening and oral skills targeted in it. The…

The Relationship Between Non-Governmental Organizations and the Canadian Forces: A Pilot Study (La relation entre les organisations non-gouvernementales et les forces canadiennes: Une etude pilote)

DTIC Science & Technology

2010-09-01

optics, in the eyes of both the CF and NGO participants, was seen, quite literally, as a life and death issue. 3.4 Differences in Organizational...public, both local and at home in Canada. This, in turn, can affect their security and their image in the eyes of their donor, but most importantly...Canadian Forces Leaders, Davis, 2009). Cultural competence is a concept that has its origins in the sociological, anthropological and psychological

Etude des sequences de type consonne constrictive plus voyelle en francais, a l'aide de la radiocinematographie et de l'oscillographie (A Study of the Constrictive Consonant Plus Vowel Sequences in French, Using X-Ray Filming and Oscillography). Publication B-148.

ERIC Educational Resources Information Center

Rochette, Claude; Simard, Claude

A study of the phonetic combination of a constrictive consonant (specifically, [f], [v], and [r]) and a vowel in French using x-ray and oscillograph technology focused on the speed and process of articulation between the consonant and the vowel. The study considered aperture size, nasality, labiality, and accent. Articulation of a total of 407…

Aerodynamics and Acoustics of Propellers, Conference Proceedings of the Fluid Dynamics Symposium Held at Toronto, Canada on 1-4 October 1984

DTIC Science & Technology

1985-02-01

stationnaire. Le Systeme pseudo-instationnaire est constrult en rempla^ant 1 equation de 1’energie le) par la condition de rothalpie uniforme I ■ cte et...la definition de nouvelles helices permet des gains substantiels pour tout le domaine de vol et, notanment, au decollage et en montee. Nous...etudes d’un tel Systeme sont effectuees et I’essai d’une maquette dans la grande soufflerie transsonique SI de Modane est prevu en 1985. On presente

SpaceX Jason-3 Live Launch Broadcast - Part 1 of 4

NASA Image and Video Library

2016-01-17

At Space Launch Complex 4 at Vandenberg Air Force Base in California, a SpaceX Falcon 9 rocket launches the Jason-3 spacecraft into orbit for NOAA, the National Oceanic and Atmospheric Administration, and EUMETSAT, the European Organization for the Exploitation of Meteorological Satellites. Built by Thales Alenia of France, Jason-3 will measure the topography of the ocean surface for a four-agency international partnership consisting of NOAA, NASA, Centre National d’Etudes Spatiales, France’s space agency, and the European Organization for the Exploitation of Meteorological Satellites.

SpaceX Jason-3 Live Launch Broadcast - Part 4 of 4

NASA Image and Video Library

2016-01-17

At Space Launch Complex 4 at Vandenberg Air Force Base in California, a SpaceX Falcon 9 rocket launches the Jason-3 spacecraft into orbit for NOAA, the National Oceanic and Atmospheric Administration, and EUMETSAT, the European Organization for the Exploitation of Meteorological Satellites. Built by Thales Alenia of France, Jason-3 will measure the topography of the ocean surface for a four-agency international partnership consisting of NOAA, NASA, Centre National d’Etudes Spatiales, France’s space agency, and the European Organization for the Exploitation of Meteorological Satellites.

SpaceX Jason-3 Live Launch Broadcast - Part 3 of 4

NASA Image and Video Library

2016-01-17

At Space Launch Complex 4 at Vandenberg Air Force Base in California, a SpaceX Falcon 9 rocket launches the Jason-3 spacecraft into orbit for NOAA, the National Oceanic and Atmospheric Administration, and EUMETSAT, the European Organization for the Exploitation of Meteorological Satellites. Built by Thales Alenia of France, Jason-3 will measure the topography of the ocean surface for a four-agency international partnership consisting of NOAA, NASA, Centre National d’Etudes Spatiales, France’s space agency, and the European Organization for the Exploitation of Meteorological Satellites.

SpaceX Jason-3 Live Launch Broadcast - Part 2 of 4

NASA Image and Video Library

2016-01-17

At Space Launch Complex 4 at Vandenberg Air Force Base in California, a SpaceX Falcon 9 rocket launches the Jason-3 spacecraft into orbit for NOAA, the National Oceanic and Atmospheric Administration, and EUMETSAT, the European Organization for the Exploitation of Meteorological Satellites. Built by Thales Alenia of France, Jason-3 will measure the topography of the ocean surface for a four-agency international partnership consisting of NOAA, NASA, Centre National d’Etudes Spatiales, France’s space agency, and the European Organization for the Exploitation of Meteorological Satellites.

Caracterisation des proprietes dielectriques de materiaux composites a base de polyethylene terephtalate recycle =

NASA Astrophysics Data System (ADS)

Mebarki, Fouzia

Cette etude vise a etudier la possibilite d'utiliser des materiaux composites a matrice thermoplastique pour des applications electriques comme les supports des systemes d'allumage dans les moteurs d'automobile. Nous nous interessons plus particulierement aux composites a base de polyethylene terephtalate (PET) recycle. Les isolants classiques comme le PET ne peuvent pas satisfaire toutes les exigences. L'introduction des renforts comme les fibres de verre et le mica peuvent ameliorer les caracteristiques mecaniques de ces materiaux. Toutefois, cette amelioration peut etre accompagnee d'une diminution des proprietes electriques surtout que ces materiaux doivent operer sous contraintes thermiques et electriques tres severes. Afin d'estimer la duree de vie de ces isolants, des essais de vieillissement accelere ont ete effectues a une frequence de 300Hz dans une plage de temperature allant de la temperature ambiante a 140°C. L'etude a haute temperature permettra de determiner la temperature de service des materiaux candidats. Des essais de la rupture dielectrique ont ete realises sur un grand nombre d'echantillon selon la norme ASTM D-149 relative aux mesures de rigidite dielectrique des isolants solides. Ces tests ont permis de deceler les echantillons problematiques et de verifier la qualite de ces isolants solides. Les differentes connaissances acquises lors de cette analyse ont servi a predire les performances des materiaux en service et vont permettre a la compagnie Groupe Lavergne d'apporter des ameliorations au niveau des formulations existantes et par la suite developper un materiau ayant les proprietes electriques et thermiques adequates pour ce type d'application. None None None None

Problemes theoriques et methodologiques dans l'etude des langues/dialectes en contact aux niveaux macrologique et micrologique = Theoretical and Methodological Issues in the Study of Languages/Dialects in Contact at Macro- and Micro-Logical Levels of Analysis. Proceedings of the International Conference DALE (University of London)/ICRB (Laval University, Quebec)/ICSBT (Vrije Universiteit te Brussel) (London, England, May 23-26, 1985).

ERIC Educational Resources Information Center

Blanc, Michel, Ed.; Hamers, Josiane F., Ed.

Papers from an international conference on the interaction of languages and dialects in contact are presented in this volume. Papers include: "Quelques reflexions sur la variation linguistique"; "The Investigation of 'Language Continuum' and 'Diglossia': A Macrological Case Study and Theoretical Model"; "A Survey of…

Calculation of effective plutonium cross sections and check against the oscillation experiment CESAR-II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schaal, H.; Bernnat, W.

1987-10-01

For calculations of high-temperature gas-cooled reactors with low-enrichment fuel, it is important to know the plutonium cross sections accurately. Therefore, a calculational method was developed, by which the plutonium cross-section data of the ENDF/B-IV library can be examined. This method uses zero- and one-dimensional neutron transport calculations to collapse the basic data into one-group cross sections, which then can be compared with experimental values obtained from integral tests. For comparison the data from the critical experiment CESAR-II of the Centre d'Etudes Nucleaires, Cadarache, France, were utilized.

Adult Education: The Past, the Present, and the Future. Proceedings of the Annual Conference of the Canadian Association for the Study of Adult Education (14th, Montreal, Quebec, Canada, June 1-3, 1995) = L'Education des Adultes: Un Passe, Un Present, un Avenir. Les Actes du Congress Annuel, l'Association Canadienne pour l'Etude de l'Education des Adultes (14e, Montreal, Quebec, Canada, 1-3 Juin, 1995).

ERIC Educational Resources Information Center

Danis, Claudia, Ed.; Hrimech, Mohamed, Ed.

The following papers (with nine in French) are included: "Refocusing the Multicultural Discourse in Adult Education" (Acton); "University Extension and the Service University" (Archer); "Linking Cases to Course Content" (Block); "The Effects of Education on Food Security among Low Income Urban Adults"…

Study of Some Mineral Exchangers for Use in Water at High Temperature; ETUDE DE QUELQUES ECHANGEURS MINERAUX UTILISABLES DANS L'EAU A HAUTE TEMPERATURE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hure, J.; Platzer, R.; Bittel, R.

1959-10-31

The study of the use of ion exchangers at high temperatures was made with a view to the purification of water in reactors. Natural ion exchangers with mineral structures (clay of the montmorillonite type), natural mineral compounds so treated as to give them the properties of ion exchangers (activated graphite), and synthetic mineral compounds (zirconium phosphates and hydroxides and thorium hydroxide) were investigated. The preparation of the minerals is described, and the results obtained with them are discussed in detail. (J.S.R.)

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

ERIC Educational Resources Information Center

Prujiner, Alain, Ed.

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

Status of Day Care in Canada, 1984: A Review of the Major Findings of the National Day Care Study, 1984 = Situation de la garde de jour au Canada, 1984: Revue des principales conclusions tirees de l'etude nationale menee en 1984 sur la garde de jour.

ERIC Educational Resources Information Center

National Day Care Information Centre, Ottawa (Ontario).

Intended to give Canadians a general overview of the country's day care services, the study was undertaken by the Social Service Programs Branch, Health and Welfare, Canada. Begun in 1971 and updated yearly since 1973, the national survey provides an inventory of day care spaces which can be used to measure future growth in day care and to…

Status of Day Care in Canada, 1983: A Review of the Major Findings of the National Day Care Study, 1983. = Situation de la garde de jour au Canada, 1983: Revue des principales conclusions de l'etude nationale sur la garde de jour en 1983.

ERIC Educational Resources Information Center

National Day Care Information Centre, Ottawa (Ontario).

The major purpose of the Status of Day Care in Canada reports is to gather information from the provinces concerning day care spaces in order to determine the growth of day care from year to year. In addition to reporting the increase in the availability of day care services from 1973 to 1983, this report provides data on the ages of children…

Telemetre Laser a Onde Entretenue a 10.6 micrometers avec Postdetection non Lineaire: Etude d’un Systeme a un Laser (A 10.6 micrometer Amplitude Modulated Telemeter Laser with Nonlinear Postdetection: Study of a Single Laser System),

DTIC Science & Technology

1981-04-01

Courbes de variation de u et de la profondeur de modulation a en fonction de la tension appliquge V FIGURE - 4 jo NON CLASSIFIE 14 On peut donc...ET DEVELOPPEMENT RESEARCH AND DEVELOPMENT BRANCH MINISTERE DE LA DEFENSE NATIONALE UNCLASSIFIED DEA CETO AINADEFNC CANADA UNI. IMITED DISTRIBUTiIN CND...RECHERCHES POUR LA DEFENSE DEFENCE RESEARCH ESTABLISHMENT VALCARTIER Tel: (418) 844-4271 Quebec, Canada April/avril 1981 UNCLASSIFIED, /41/7z *I .. , NON

Etude par spectrometrie infrarouge et Raman de la triméthyl-4,5,6 pyrimidone-2 et de son chlorhydrate. Complexation par les halogenures de potassium

NASA Astrophysics Data System (ADS)

Lautié, Alain; Picquenard, Eric; Ratovelomanana, Nicole

The i.r. Raman spectra of crystalline 4,5,6-trimethyl 2-pyrimidone and seven deuterated derivatives have been investigated between 4000 and 180 cm -1. Aqueous and CHCl 3 solutions were also examined. An assignment for intramolecular fundamentals is given, as well as a distinction between the most characteristic of each methyl group. The methylation and protonation effects are discussed. Furthermore, a 1/1 adduct of this pyrimidone and potassium halides is observed and characterized; it contains a strong NH…X - hydrogen bond.

Passion and Politics: 99 Years of Adult Education. Proceedings of the Annual Conference of the Canadian Association for the Study of Adult Education (18th, Montreal, Canada, June 10-12, 1999) = Passion et Politique: 99 Ans d'Education des Adultes. Actes Annuel de L'Association Canadienne pour L'Etude de L'Education des Adultes (18e, Montreal, Canada, 10-12 Juin, 1999).

ERIC Educational Resources Information Center

Hrimech, Mohamed, Ed.

This document contains 35 papers and 4 symposia/poster sessions presented at a Canadian conference on the study of adult education. The following papers are among those included: "Adult Education on the Internet: New Dawn Breaking or Sky Falling?" (Archer); "'Shapeshifting': Negotiating Identity in First Nations Adult…

Rocket Motor Plume Technology (L’Etude des Jets des Moteures-Fusees)

DTIC Science & Technology

1993-06-01

observation point in a given wavelength ASSESSMENT USED IN NATO band. The contrast tends to -1 for a ideal AS M NTRU S black objet and may have a large...produits de cuivre), oxydee do for , etc combustion et dans I’atniosph~re. IF2* Les additifs anti-instabilit~ s : carbure de visible et devenir une...I, o lo.* • 20" 3a 0’ 1 so Time (smc) 4.6 Figure 10 Typical Thrust-Time, Pressure-Time Curves for a Boost Sustain Motor x 7 I, ,, ’I! .<,,.,, ON+. s

A Survey of Serious Aircraft Accidents Involving Fatigue Fracture. Volume 1. Fixed-Wing Aircraft (Etude sur des Accidents Importants d’Avions du aux Effets des Fractures de Fatigue. Volume 1. Effets sur des Avions).

DTIC Science & Technology

1983-04-01

Bureau of Standards. NTS3 National Transportation Safety Board (USA). NTSB AAR NTSB Aircraft Accident Report. NZ AAR New Zealand Aircraft Accident Report...NZ AI New Zealand Accident Investigation Bureau. 0 -5- RAN Royal Australian Navy RAAI Royal Australian Air Force RAF Royal Air Force, UK S Substantial...Ice land Iraq Ireland Jamaica (1966 -1981) Japan (1973 - Feb. 81) Kenya Lethoso Malaysia Ma law i Mal ta Mexico Netherlands New Zealand Norway

Conference Proceedings on Vortex Flow Aerodynamics Held in Scheveningen, The Netherlands on 1-4 October 1990

DTIC Science & Technology

1991-07-01

example, caracterises par l’existence d’une pointe de survitesse importante, c’est le nombre de Reynolds qui r~git It "caract~re transitionnel’" de... caracterisation d’un Ecoulement cisaillC tridimensionnel autour d’une aile en fl~che. Une precedente Etude avait Etd nen~e qui avait pour but de qualifier I...su.vant iea configi-rations Attdi4es. 4 -m CARACTERISATION DE L ECLKTEg2NT Ii eat admis. anlon [22), que i𔄀clatement tourbiiionna~re est caravteris6

sts093-s-009

NASA Image and Video Library

2009-09-23

STS93-S-009 (23 July 1999) --- The Space Shuttle Columbia lifts off from Launch Pad 39B to begin the five-day STS-93 mission. After two unsuccessful attempts earlier in the week, liftoff occurred at 12:31 a.m. (EDT), July 23, 1999. Only hours after this picture was taken, the five-member crew released the Chandra X-Ray Observatory into orbit. Onboard were astronauts Eileen M. Collins, first woman shuttle mission commander; Jeffrey S. Ashby, pilot; and Steven A. Hawley, Catherine G. Coleman and Michel Tognini, all mission specialists. Tognini represents the Centre National d'Etudes Spatiales (CNES) of France.

Synthese, etude structurale et electrochimique des materiaux d'electrode positive d'oxydes mixtes lithium cobalt nickel oxide (0 /= 1) pour les batteries rechargeables au lithium

NASA Astrophysics Data System (ADS)

Grincourt, Yves

Depuis une dizaine d'annees, on observe un interet grandissant pour les batteries rechargeables au lithium de tension superieure a 4 volts. La commercialisation de ces batteries pour l'electronique grand marche tend de plus en plus a supplanter celle des accumulateurs Ni-Cd et Ni-MH, de tension nominate 1,2 V. Ces batteries au lithium font appel a des materiaux d'electrode positive (cathode a la decharge) du type oxydes mixtes de metaux de transition LiMnO 2, LiMn2O4, LiNiO2 ou LiCoO2. Si le compose LiCoO2 est relativement aise a synthetiser, il n'en demeure pas moins que le cobalt reste un metal plus couteux compare au nickel et au manganese. La synthese de LiNiO2, quart a elle, demeure un probleme du point de vue stoechiometrique. Un defaut de lithium (5 a 10% molaire) conduira a des proprietes electrochimiques mediocres de la batterie. Dans cette etude nous nous proposons donc de preparer par voie humide et par voie seche les materiaux d'electrode positive de la famille LiCoyNi1-yO2 aver (0 ≤ y ≤ 1) et d'etudier en detail l'influence du pourcentage de nickel et de cobalt sur les proprietes electrochimiques des oxydes mixtes Li-Ni-Co. Une des caracteristiques est la morphologie plus fine des poudres de materiaux, observes par microscopie electronique a balayage (MEB). Un traitement thermique a plus basse temperature (750°C) que pour LiCoO2 (850°C) ainsi qu'un leger exces de lithium dans la preparation, ont permis d'aboutir a un materiau de stoechiometrie quasi parfaite. Neanmoins, le role de pilfer joue par 2 a 4% de moles de Ni2+ presents sur les sites lithium, permet de conserver intacte la structure hexagonale de la maille entre deux cycles consecutifs. Afin de mieux comprendre l'influence du vieillissement dune demi-pile Li/LiMeO2 (Me = Ni, Co) a temperature ambiante, des etudes electrochimiques et d'impedance spectroscopique ont ete menees en parallele. Le vieillissement de la cellule s'accompagne seulement dune chute de son potentiel due a son auto-decharge. Neanmoins, il est encore possible de la relancer en cyclage par la suite. Une baisse de la valeur de la resistance totale interfaciale et des frequences au sonnet semble indiquer une modification chimique et/ou structurale des films de passivations, pent-etre due a une transformation de ces films lors du cyclage ou a leur degradation. (Abstract shortened by UMI.)

Meddy trajectories in the Canary Basin measured during the SEMAPHORE experiment, 1993-1995

NASA Astrophysics Data System (ADS)

Richardson, Philip L.; Tychensky, Aude

1998-10-01

As part of the Structures des Echanges Mer-Atmosphere, Proprietes des Heterogeneites Oceaniques: Recherche Experimentale (SEMAPHORE) experiment, four Mediterranean water eddies (Meddies) were identified in the Canary Basin and tracked with freely drifting RAFOS floats. One large and energetic Meddy, discovered 1700 km west of Cape Saint Vincent, Portugal, set a distance and speed record as it translated another 1700 km southwestward at 3.9 cm/s during 1.5 years. This Meddy traveled 57% of the distance from Cape Saint Vincent toward the spot McDowell and Rossby [1978] found a possible Meddy north of the Dominican Republic. Two Meddies were observed to interact with the Azores Current as they passed underneath or through it. Three Meddies collided with tall seamounts, which seemed to disrupt the normal swirl velocity, perhaps fatally in two cases. One Meddy appeared to bifurcate when it collided with seamounts.

H3+: superficies de energía potencial, estados y transiciones rovibracionales

NASA Astrophysics Data System (ADS)

Aguado, M. Paniagua Y. A.

Hemos calculado varias superficies globales de energía potencial para el estado fundamental y excitados del sistema H3+ en más de ocho mil geometrías diferentes usando una base (9s 3p 1d)/[4s 3p 1d] en cada átomo de Hidrógeno y mediante un método de cálculo de interacción de configuraciones completa (FCI). Hemos ajustado las superficies a formas analíticas del tipo Aguado y Paniagua con un error promedio menor de 50 cm-1 y menor en el pozo de potencial del estado fundamental. Finalmente hemos calculado y analizado los niveles vibracionales para los dos estados electrónicos más bajos, siendo la desviación respecto de los mejores valores publicados, tanto experimentales como teóricos, de unos pocos números de onda.

Mesure et retroaction sur un qubit multi-niveaux en electrodynamique quantique en circuit non lineair

NASA Astrophysics Data System (ADS)

Boissonneault, Maxime

L'electrodynamique quantique en circuit est une architecture prometteuse pour le calcul quantique ainsi que pour etudier l'optique quantique. Dans cette architecture, on couple un ou plusieurs qubits supraconducteurs jouant le role d'atomes a un ou plusieurs resonateurs jouant le role de cavites optiques. Dans cette these, j'etudie l'interaction entre un seul qubit supraconducteur et un seul resonateur, en permettant cependant au qubit d'avoir plus de deux niveaux et au resonateur d'avoir une non-linearite Kerr. Je m'interesse particulierement a la lecture de l'etat du qubit et a son amelioration, a la retroaction du processus de mesure sur le qubit de meme qu'a l'etude des proprietes quantiques du resonateur a l'aide du qubit. J'utilise pour ce faire un modele analytique reduit que je developpe a partir de la description complete du systeme en utilisant principalement des transfprmations unitaires et une elimination adiabatique. J'utilise aussi une librairie de calcul numerique maison permettant de simuler efficacement l'evolution du systeme complet. Je compare les predictions du modele analytique reduit et les resultats de simulations numeriques a des resultats experimentaux obtenus par l'equipe de quantronique du CEASaclay. Ces resultats sont ceux d'une spectroscopie d'un qubit supraconducteur couple a un resonateur non lineaire excite. Dans un regime de faible puissance de spectroscopie le modele reduit predit correctement la position et la largeur de la raie. La position de la raie subit les decalages de Lamb et de Stark, et sa largeur est dominee par un dephasage induit par le processus de mesure. Je montre que, pour les parametres typiques de l'electrodynamique quantique en circuit, un accord quantitatif requiert un modele en reponse non lineaire du champ intra-resonateur, tel que celui developpe. Dans un regime de forte puissance de spectroscopie, des bandes laterales apparaissent et sont causees par les fluctuations quantiques du champ electromagnetique intra-resonateur autour de sa valeur d'equilibre. Ces fluctuations sont causees par la compression du champ electromagnetique due a la non-linearite du resonateur, et l'observation de leur effet via la spectroscopie d'un qubit constitue une premiere. Suite aux succes quantitatifs du modele reduit, je montre que deux regimes de parametres ameliorent marginalement la mesure dispersive d'un qubit avec un resonateur lineaire, et significativement une mesure par bifurcation avec un resonateur non lineaire. J'explique le fonctionnement d'une mesure de qubit dans un resonateur lineaire developpee par une equipe experimentale de l'Universite de Yale. Cette mesure, qui utilise les non-linearites induites par le qubit, a une haute fidelite, mais utilise une tres haute puissance et est destructrice. Dans tous ces cas, la structure multi-niveaux du qubit s'avere cruciale pour la mesure. En suggerant des facons d'ameliorer la mesure de qubits supraconducteurs, et en decrivant quantitativement la physique d'un systeme a plusieurs niveaux couple a un resonateur non lineaire excite, les resultats presentes dans cette these sont pertinents autant pour l'utilisation de l'architecture d'electrodynamique quantique en circuit pour l'informatique quantique que pour l'optique quantique. Mots-cles: electrodynamique quantique en circuit, informatique quantique, mesure, qubit supraconducteur, transmon, non-linearite Kerr

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

NASA Astrophysics Data System (ADS)

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. Il est ensuite demontre que le modele a trois bandes predit les memes resultats pour la position des structures du facteur de structure magnetique que le modele a une bande, dans la limite ou l'hybridation des orbitales des atomes d'oxygene des plans Cu-O_2 et l'amplitude de sauts vers les seconds voisins sont nulles. Il est de plus constate que l'effet de l'hybridation des orbitales des atomes d'oxygene est bien modelise par le terme de saut vers les seconds voisins. Meme si ils decrivent correctement le comportement qualitatif des maximums du facteur de structure magnetique, les modeles a trois bandes et a une bande ne permettent pas d'obtenir une position de ces structures conforme avec les mesures experimentales, si on suppose que la bande est rigide, c'est-a-dire que les parametres du Hamiltonien sont independants de la concentration de strontium. Ceci peut etre cause par la dependance des parametres du Hamiltonien sur la concentration de strontium. Finalement, les resultats sont compares avec les experiences de diffusion de neutrons et les autres theories, en particulier celles de Littlewood et al. (1993) et de Q. Si et al. (1993). La comparaison avec les resultats experimentaux pour le compose de lanthane suggere que le liquide de Fermi possede une surface de Fermi disjointe, et qu'il est situe pres d'une instabilite magnetique incommensurable.

Accuracy in the estimation of quantitative minimal area from the diversity/area curve.

PubMed

Vives, Sergi; Salicrú, Miquel

2005-05-01

The problem of representativity is fundamental in ecological studies. A qualitative minimal area that gives a good representation of species pool [C.M. Bouderesque, Methodes d'etude qualitative et quantitative du benthos (en particulier du phytobenthos), Tethys 3(1) (1971) 79] can be discerned from a quantitative minimal area which reflects the structural complexity of community [F.X. Niell, Sobre la biologia de Ascophyllum nosodum (L.) Le Jolis en Galicia, Invest. Pesq. 43 (1979) 501]. This suggests that the populational diversity can be considered as the value of the horizontal asymptote corresponding to the curve sample diversity/biomass [F.X. Niell, Les applications de l'index de Shannon a l'etude de la vegetation interdidale, Soc. Phycol. Fr. Bull. 19 (1974) 238]. In this study we develop a expression to determine minimal areas and use it to obtain certain information about the community structure based on diversity/area curve graphs. This expression is based on the functional relationship between the expected value of the diversity and the sample size used to estimate it. In order to establish the quality of the estimation process, we obtained the confidence intervals as a particularization of the functional (h-phi)-entropies proposed in [M. Salicru, M.L. Menendez, D. Morales, L. Pardo, Asymptotic distribution of (h,phi)-entropies, Commun. Stat. (Theory Methods) 22 (7) (1993) 2015]. As an example used to demonstrate the possibilities of this method, and only for illustrative purposes, data about a study on the rocky intertidal seawed populations in the Ria of Vigo (N.W. Spain) are analyzed [F.X. Niell, Estudios sobre la estructura, dinamica y produccion del Fitobentos intermareal (Facies rocosa) de la Ria de Vigo. Ph.D. Mem. University of Barcelona, Barcelona, 1979].

De l'importance des orbites periodiques: Detection et applications

NASA Astrophysics Data System (ADS)

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.

Pratique de l’analgésie péridurale auprès de 20 parturientes au Centre Hospitalier Universitaire Sylvanus Olympio de Lomé (Togo)

PubMed Central

Egbohou, Pilakimwé; Mouzou, Tabana; Sama, Hamza Doles; Tchétike, Pikabalo; Assénouwé, Sarakawabalo; Akala-Yoba, Gnimdou; Tomta, Kadjika

2017-01-01

Etude prospective et descriptive sur la pratique de l’analgésie péridurale (APD) obstétricale au CHU Sylvanus Olympio (CHU SO) de Lomé. Etude menée de février à juin 2014. Après accord des gestantes choisies au hasard et en l’absence de contre-indication à l’issue de la consultation d’anesthésie, faite au 8ème mois de la grossesse, des femmes ont été retenues pour l’étude. Sur 29 gestantes retenues, 20 (69%) ont bénéficiées de l’APD. Age moyen 30,6±6,6 ans, primigestes : 35%, multipares 50%, Obèses (BMI>30): 25%. Nombre moyen de ponctions: 1,2±0,5; reflux de sang dans le cathéter: 5%, brèche dure-mérienne : 0. Délai moyen d’installation: 8,5 ±2,2mn. Quantité moyenne de bupivacaine isobare à 0,125%: 28,8±8ml; Echelle Numérique à T10min < 3 pour toutes les parturientes. Bloc moteur: 0. Hypotension: 1cas (5%). Mode d’accouchement: voie basse: 19 (95%), césarienne: 1 (5%). Détresse respiratoire à la naissance du nouveau né: 0. Note de satisfaction: 9,8±0,5 /10. L’APD obstétricale est possible au CHU Sylvanus Olympio de Lomé. En attendant sa vulgarisation à toutes les parturientes par la disponibilité des moyens humains et matériels, la réaliser pour ses indications médicales serait un premier pas. PMID:28451033

Etude de la dynamique des porteurs dans des nanofils de silicium par spectroscopie terahertz

NASA Astrophysics Data System (ADS)

Beaudoin, Alexandre

Ce memoire presente une etude des proprietes de conduction electrique et de la dynamique temporelle des porteurs de charges dans des nanofils de silicium sondes par rayonnement terahertz. Les cas de nanofils de silicium non intentionnellement dopes et dopes type n sont compares pour differentes configurations du montage experimental. Les mesures de spectroscopie terahertz en transmission montre qu'il est possible de detecter la presence de dopants dans les nanofils via leur absorption du rayonnement terahertz (˜ 1--12 meV). Les difficultes de modelisation de la transmission d'une impulsion electromagnetique dans un systeme de nanofils sont egalement discutees. La detection differentielle, une modification au systeme de spectroscopie terahertz, est testee et ses performances sont comparees au montage de caracterisation standard. Les instructions et des recommendations pour la mise en place de ce type de mesure sont incluses. Les resultats d'une experience de pompe optique-sonde terahertz sont egalement presentes. Dans cette experience, les porteurs de charge temporairement crees suite a l'absorption de la pompe optique (lambda ˜ 800 nm) dans les nanofils (les photoporteurs) s'ajoutent aux porteurs initialement presents et augmentent done l'absorption du rayonnement terahertz. Premierement, l'anisotropie de l'absorption terahertz et de la pompe optique par les nanofils est demontree. Deuxiemement, le temps de recombinaison des photoporteurs est etudie en fonction du nombre de photoporteurs injectes. Une hypothese expliquant les comportements observes pour les nanofils non-dopes et dopes-n est presentee. Troisiemement, la photoconductivite est extraite pour les nanofils non-dopes et dopes-n sur une plage de 0.5 a 2 THz. Un lissage sur la photoconductivite permet d'estimer le nombre de dopants dans les nanofils dopes-n. Mots-cles: nanofil, silicium, terahertz, conductivite, spectroscopie, photoconductivite.

Dynamique de nanobulles et nanoplasmas generes autour de nanoparticules plasmoniques irradiees par des impulsions ultracourtes

NASA Astrophysics Data System (ADS)

Dagallier, Adrien

L'emergence des lasers a impulsion ultrabreves et des nanotechnologies a revolutionne notre perception et notre maniere d'interagir avec l'infiniment petit. Les gigantesques intensites generees par ces impulsions plus courtes que les temps de relaxation ou de diffusion du milieu irradie induisent de nombreux phenomenes non-lineaires, du doublement de frequence a l'ablation, dans des volumes de dimension caracteristique de l'ordre de la longueur d'onde du laser. En biologie et en medecine, ces phenomenes sont utilises a des fins d'imagerie multiphotonique ou pour detruire des tissus vivants. L'introduction de nanoparticules plasmoniques, qui concentrent le champ electromagnetique incident dans des regions de dimensions nanometriques, jusqu'a une fraction de la longueur d'onde, amplifie les phenomenes non-lineaires tout en offrant un controle beaucoup plus precis de la deposition d'energie, ouvrant la voie a la detection de molecules individuelles en solution et a la nanochirurgie. La nanochirurgie repose principalement sur la formation d'une bulle de vapeur a proximite d'une membrane cellulaire. Cette bulle de vapeur perce la membrane de maniere irreversible,entrainant la cellule a sa mort, ou la perturbe temporairement, ce qui permet d'envisager de faire penetrer dans la cellule des medicaments ou des brins d'ADN pour de la therapie genique. C'est principalement la taille de la bulle qui va decider de l'issue de l'irradiation laser. Il est donc necessaire de controler finement les parametres du laser et la geometrie de la nanoparticule afin d'atteindre l'objectif fixe. Le moyen le plus direct a l'heure actuelle de valider un ensemble de conditions experimentales est de realiser l'experience en laboratoire,ce qui est long et couteux. Les modeles de dynamique de bulle existants ne prennent pas en compte les parametres de l'irradiation et ajustent souvent leurs conditions initiales a partir de leurs mesures experimentales, ce qui limite la portee du modele au cas pour lequel il est ecrit. Ce memoire se propose de predire la taille maximale ainsi que la dynamique des bulles generees par des impulsions ultrabreves en fonction uniquement de la geometrie de la particule et des parametres du laser, entre autres la duree de pulse, la longueur d'onde centrale et la fluence d'irradiation.

PubMed

Valero Chávez, Francisco Javier; Luengo Pérez, Luis Miguel; Cubero Juánez, Javier

2016-09-20

Introducción: ante las nuevas implicaciones atribuidas a la vitamina D y la asociación con enfermedades tales como el cáncer, diabetes, enfermedades cardiovasculares, autoinmunes y mortalidad, no es de extrañar que se haya defendido la medición de los niveles de vitamina D en la población general. Sin embargo, no existen datos experimentales que demuestren la viabilidad y rentabilidad de la estrategia de cribado en la población y tampoco se ha comprobado la existencia de beneficios para la salud, por lo que en la actualidad solo es aconsejable la medida de 25 (OH) vitamina D en los grupos de personas de alto riesgo como indican las guías clínicas internacionales.Objetivos: analizar las peticiones de vitamina D comprobando si se adecuan a las guías clínicas.Métodos: realizamos un estudio descriptivo transversal en el Área de Salud de Badajoz (España) estudiando las peticiones de determinación de vitamina D durante 12 meses consecutivos (n = 3.907). En dicho estudio revisamos el diagnóstico de petición y la historia clínica del paciente para discriminar entre peticiones que se adecuaban a las guías clínicas y peticiones injustificadas. Por último, realizamos el estudio económico.Resultados: en nuestros resultados encontramos que casi un tercio de peticiones no se adecuaban a las guías clínicas, en patologías tales como diabetes, dislipemias e hipertensión en las que no está recomendada la medición de los niveles de vitamina D, por lo que suponía un exceso de gasto para el sistema sanitario. Gasto que se incrementa cada año, tanto es así que se ha producido un aumento en las peticiones de más del 1.000% en los últimos 6 años.Conclusiones: concluimos la necesidad de crear protocolos de petición de vitamina D que se ajusten a las guías clínicas hasta que existan más estudios experimentales sobre las nuevas implicaciones de la vitamina D y así conseguir una correcta utilización de los recursos económicos del hospital.

Comparison of multipoint linkage analyses for quantitative traits in the CEPH data: parametric LOD scores, variance components LOD scores, and Bayes factors.

PubMed

Sung, Yun Ju; Di, Yanming; Fu, Audrey Q; Rothstein, Joseph H; Sieh, Weiva; Tong, Liping; Thompson, Elizabeth A; Wijsman, Ellen M

2007-01-01

We performed multipoint linkage analyses with multiple programs and models for several gene expression traits in the Centre d'Etude du Polymorphisme Humain families. All analyses provided consistent results for both peak location and shape. Variance-components (VC) analysis gave wider peaks and Bayes factors gave fewer peaks. Among programs from the MORGAN package, lm_multiple performed better than lm_markers, resulting in less Markov-chain Monte Carlo (MCMC) variability between runs, and the program lm_twoqtl provided higher LOD scores by also including either a polygenic component or an additional quantitative trait locus.

Comparison of multipoint linkage analyses for quantitative traits in the CEPH data: parametric LOD scores, variance components LOD scores, and Bayes factors

PubMed Central

Sung, Yun Ju; Di, Yanming; Fu, Audrey Q; Rothstein, Joseph H; Sieh, Weiva; Tong, Liping; Thompson, Elizabeth A; Wijsman, Ellen M

2007-01-01

We performed multipoint linkage analyses with multiple programs and models for several gene expression traits in the Centre d'Etude du Polymorphisme Humain families. All analyses provided consistent results for both peak location and shape. Variance-components (VC) analysis gave wider peaks and Bayes factors gave fewer peaks. Among programs from the MORGAN package, lm_multiple performed better than lm_markers, resulting in less Markov-chain Monte Carlo (MCMC) variability between runs, and the program lm_twoqtl provided higher LOD scores by also including either a polygenic component or an additional quantitative trait locus. PMID:18466597

Etude Exploratoire sur l’Etat de Stress Post-Traumatique dans Deux Unites Operationnelles de l’Armee de Terre (Exploratory Study of the Condition of Post-Traumatic Stress Disorder from Two Operational Units of Ground Forces)

DTIC Science & Technology

2006-04-01

reconnues que dans leur dimension très particulière de confrontation soudaine , violente, avec l’éventualité de sa propre mort. Dans cette perspective, elles...traumatic stress disorder in Australian Vietnam veterans. J. Trauma. Stress 1999 ; 12 (4) : 625-640. [8] STRECH R.H., MARLOWE D.H., WRGHT M.K. et al ... al . Reliability and validity of a brief instrument for assessing post-traumatic stress disorder. Journal of Traumatic Stress 1993 ; 6 : 459-473. [10

Adult Education and the Contested Terrain of Public Policy. Proceedings of the Annual Conference of the Canadian Association for the Study of Adult Education (21st, Toronto, Ontario May 30-31 and June 1, 2002). = L'Education des Adultes et le Domaine Controverse des Affaires Publiques. Actes Annuel de L'Association Canadienne pour L'Etude de L'Education des Adultes (21eme, Toronto, Ontario, 30-31 Mai et 1 Juin, 2002).

ERIC Educational Resources Information Center

Mojab, Shahrzad, Ed.; McQueen, William, Ed.

This document contains the texts of 57 papers, 10 roundtables, and 7 symposia from a Canadian conference on adult education and public policy. The following are among the papers included: "Childhood, Schooling Family and Community" (Margarida Aguiar); "Voices Inside" (Irene C. Baird); "Beyond Personal Agency" (Rose…

Proceedings from the DRG Seminar on Robotics in the Battlefield (31st) Held in Paris, France on 6-8 March 1991 (Acetes du 31ieme Seminaire sur la Robotique du Champ de Bataile)

DTIC Science & Technology

1992-06-01

8217Energie.4romnique) et GIAT-Industries (Groupern.ent Indusrriei dles Armements Terrestres ) ant 6t retenus ensemble par la DAT / SEFT (Direction des...Armements Terrestres , Sections d’Erudes et Fabrications des Tilicommunications ) pour une ’Etude de concepts de robots d-~ combat". Cette t6tude de dix...d’identification des amis utiusable par los ongins terrestres . *La t6l~opdration des armes utilisera des proc~dds sp~cifiques, no reprenant qu’en p

Industrial Medicine in the Nuclear Energy Study Center at Mol.; LA MEDECINE INDUSTRIELLE DANS LE CENTRE D'ETUDE DE L'ENERGIE NUCLEAIRE DE MOL.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Faes, M.H.

1959-10-31

The aim of an industrial medical service is to maintain the health of the personnel in normal conditions and to treat personnel in the case of accidents or illnesses caused by the work. The first objective of a medical service is one of conirol, in which a thorough clinical, radiological, and laboratory examination is given to all prospective employees. This examination is described in detail. The discovery of professional illnesses is as fully described. The legal safeguards for a person accidentally exposed to radiation are discussed. (J.S.R.)

sts093-s-005

NASA Image and Video Library

2009-09-23

STS93-S-005 (23 July 1999) --- The Space Shuttle Columbia lifts off from Launch Pad 39B to begin the five-day STS-93 mission in this 70mm frame. After two unsuccessful attempts earlier in the week, liftoff occurred at 12:31 a.m. (EDT), July 23, 1999. Only hours after this picture was taken, the five-member crew released the Chandra X-Ray Observatory into orbit. Onboard were astronauts Eileen M. Collins, first woman shuttle mission commander; Jeffrey S. Ashby, pilot; and Steven A. Hawley, Catherine G. Coleman and Michel Tognini, all mission specialists. Tognini represents the Centre National d'Etudes Spatiales (CNES) of France.

STS093-S-002

NASA Image and Video Library

1998-09-01

STS093-S-002 (September 1998) --- The five astronauts assigned to fly aboard the Space Shuttle Columbia early next year for the STS-93 mission pose with a small model of their primary payload-the Advanced X-ray Astrophysics Facility (AXAF). From the left are astronauts Eileen M. Collins, mission commander; Steven A. Hawley, mission specialist; Jeffrey S. Ashby, pilot; Michel Tognini and Catherine G. Coleman, both mission specialists. Tognini represents France's Centre National d'Etudes Spatiales (CNES). The scheduled five-day mission will feature the deployment of AXAF, which will enable scientists to conduct comprehensive studies of exotic phenomena in the universe. Among bodies studied will be exploding stars, quasars and black holes.

sts093-s-007

NASA Image and Video Library

2009-09-23

STS93-S-007 (23 July 1999) --- Framed by Florida foliage in this night time scene, the Space Shuttle Columbia lifts off from Launch Pad 39B to begin the five-day STS-93 mission. After two unsuccessful attempts earlier in the week, liftoff occurred at 12:31 a.m. (EDT), July 23, 1999. Only hours after this picture was taken, the five-member crew released the Chandra X-Ray Observatory into orbit. Onboard were astronauts Eileen M. Collins, first woman shuttle commander; Jeffrey S. Ashby, pilot; and Steven A. Hawley, Catherine G. Coleman and Michel Tognini, all mission specialists. Tognini represents the Centre National d'Etudes Spatiales (CNES) of France.

Study of Behavior of Some Varieties of Belgian Potatoes Subjected to Gamma Irradiation; ETUDE DU COMPORTEMENT DE QUELQUES VARIETES BELGES DE POMMES DE TERRE SOUMISES A L'IRRADIATION GAMMA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kirchmann, R.; De Proost, M.; Demalsy, P.

1962-07-01

Different varieties of potatoes were irradiated with doses between 5000 and 20000 rads and stored at two different temperatures. Irradiation has a grent influence on the weight loss of the potatoes during storage; the degree of sprout inhibition depends on the variety of the potatoes. The glutathione content and the oxygen consumption of potatoes are influenced by irradiation. The greatest effect of irradiation on the chemical composition concerns the starch; an increase in sugar content is observed. The culinary properties of potatoes are not changed by irradiation. (auth)

Modelisation de l'erosion et des sources de pollution dans le bassin versant Iroquois/Blanchette dans un contexte de changements climatiques

NASA Astrophysics Data System (ADS)

Coulibaly, Issa

Principale source d'approvisionnement en eau potable de la municipalite d'Edmundston, le bassin versant Iroquois/Blanchette est un enjeu capital pour cette derniere, d'ou les efforts constants deployes pour assurer la preservation de la qualite de son eau. A cet effet, plusieurs etudes y ont ete menees. Les plus recentes ont identifie des menaces de pollution de diverses origines dont celles associees aux changements climatiques (e.g. Maaref 2012). Au regard des impacts des modifications climatiques annonces a l'echelle du Nouveau-Brunswick, le bassin versant Iroquois/Blanchette pourrait etre fortement affecte, et cela de diverses facons. Plusieurs scenarios d'impacts sont envisageables, notamment les risques d'inondation, d'erosion et de pollution a travers une augmentation des precipitations et du ruissellement. Face a toutes ces menaces eventuelles, l'objectif de cette etude est d'evaluer les impacts potentiels des changements climatiques sur les risques d'erosion et de pollution a l'echelle du bassin versant Iroquois/Blanchette. Pour ce faire, la version canadienne de l'equation universelle revisee des pertes en sol RUSLE-CAN et le modele hydrologique SWAT ( Soil and Water Assessment Tool) ont ete utilises pour modeliser les risques d'erosion et de pollution au niveau dans la zone d'etude. Les donnees utilisees pour realiser ce travail proviennent de sources diverses et variees (teledetections, pedologiques, topographiques, meteorologiques, etc.). Les simulations ont ete realisees en deux etapes distinctes, d'abord dans les conditions actuelles ou l'annee 2013 a ete choisie comme annee de reference, ensuite en 2025 et 2050. Les resultats obtenus montrent une tendance a la hausse de la production de sediments dans les prochaines annees. La production maximale annuelle augmente de 8,34 % et 8,08 % respectivement en 2025 et 2050 selon notre scenario le plus optimiste, et de 29,99 % en 2025 et 29,72 % en 2050 selon le scenario le plus pessimiste par rapport a celle de 2013. Pour ce qui est de la pollution, les concentrations observees (sediment, nitrate et phosphore) connaissent une evolution avec les changements climatiques. La valeur maximale de la concentration en sediments connait une baisse en 2025 et 2050 par rapport a 2013, de 11,20 mg/l en 2013, elle passe a 9,03 mg/l en 2025 puis a 6,25 en 2050. On s'attend egalement a une baisse de la valeur maximale de la concentration en nitrate au fil des annees, plus accentuee en 2025. De 4,12 mg/l en 2013, elle passe a 1,85 mg/l en 2025 puis a 2,90 en 2050. La concentration en phosphore par contre connait une augmentation dans les annees a venir par rapport a celle de 2013, elle passe de 0,056 mg/l en 2013 a 0,234 mg/l en 2025 puis a 0,144 en 2050.

Etude energetique et modelisation d'un Systeme Hybride Eolien-Diesel avec stockage d'Air Comprime (SHEDAC)

NASA Astrophysics Data System (ADS)

Martinez, Nicolas

Actuellement le Canada et plus specialement le Quebec, comptent une multitude de sites isoles dont !'electrification est assuree essentiellement par des generatrices diesel a cause, principalement, de l'eloignement du reseau central de disuibution electrique. Bien que consideree comme une source fiable et continue, 1 'utilisation des generatrices diesel devient de plus en plus problematique d'un point de vue energetique, economique et environnemental. Dans le but d'y resoudre et de proposer une methode d'approvisionnement plus performante, mains onereuse et plus respectueuse de l'environnement, l'usage des energies renouvelables est devenu indispensable. Differents travaux ont alors demontre que le couplage de ces energies avec des generauices diesel, formant des systemes hybrides, semble etre une des meilleures solutions. Parmi elles, le systeme hybride eolien-diesel avec stockage par air comprime (SHEDAC) se presente comme une configuration optimale pour 1 'electrification des sites isoles. En effet, differentes etudes ont permis de mettre en avant l'efficacite du stockage par air comprime, par rapport a d'autres technologies de stockage, en complement d'un systeme hybride eolien-diesel. Plus precisement, ce systeme se compose de sous-systemes qui sont: des eoliennes, des generatrices diesel et une chaine de compression et de stockage d'air comprime qui est ensuite utilisee pour suralimenter les generatrices. Ce processus permet ainsi de reduire Ia consommation en carburant tout en agrandissant la part d'energie renouvelable dans Ia production electrique. A ce jour, divers travaux de recherche ont pennis de demontrer I' efficacite d 'un tel systeme et de presenter une variete de configurations possibles. A travers ce memoire, un logiciel de dimensionnement energetique y est elabore dans le but d'unifom1iser !'approche energetique de cette technologie. Cet outil se veut etre une innovation dans le domaine puisqu'il est actuellement impossible de dimensionner un SHEDAC avec les outils existants. Un etat de l'art specifique associe a une validation des resultats a ete realise dans le but de proposer un logiciel fiable et performant. Dans une logique visant !'implantation d'un SHEDAC sur un site isole du Nord-du-Quebec, le logiciel developpe a ete, ensuite, utilise pour realiser une etude energetique permettant d' en degager la solution optimale a mettre en place. Enfin, a l' aide des outils et des resultats obtenus precedemment, !'elaboration de nouvelles strategies d'operation est presentee dans le but de demontrer comment le systeme pourrait etre optimise afm de repondre a differentes contraintes techniques. Le contenu de ce memoire est presente sous forme de trois articles originaux, soumis a des joumaux scientifiques avec cornite de lecture, et d'un chapitre specifique presentant les nouvelles strategies d 'operation. Ils relatent des travaux decrits dans le paragraphe precedent et permettent d'en deduire un usage concluant et pertinent du SHEDAC dans un site isole nordique.

Le transfert de connaissances entre les mathematiques et les sciences. Une etude exploratoire aupres d'eleves de 4e secondaire

NASA Astrophysics Data System (ADS)

Samson, Ghislain

2003-06-01

Au moment ou dans plusieurs pays on travaille a refondre les programmes d'etudes, tant au primaire qu'au secondaire, l'interet pour le transfert renait. Un des concepts fondamentaux en apprentissage consiste en l'habilete a reutiliser de facon consciente et efficace un acquis d'une situation a une autre situation. Cette recherche emane de preoccupations professionnelles au moment ou le chercheur etait enseignant au secondaire. Au cours de ces annees, il lui a ete possible de constater que plusieurs eleves percevaient difficilement les liens presents entre les disciplines mathematiques et scientifiques. Des travaux en psychologie cognitive et plus particulierement selon une perspective du traitement de l'information ont servi de cadre de reference pour evaluer et analyser les capacites de transfert aupres d'eleves de 4e secondaire. Ce cadre de reference permet de formuler le principal objectif qui est de mieux comprendre le processus de transfert chez des eleves en situation de resolution de problemes scientifiques. Cette these s'interesse donc au transfert en tant que phenomene important du processus d'apprentissage au sens de l'integration. La methode de recherche choisie, de nature qualitative, est principalement axee sur l'evaluation de la capacite a transferer des connaissances lors d'une epreuve et d'un entretien. Pour evaluer ce potentiel de transfert, nous avons elabore deux outils: une epreuve en mathematiques et en sciences et un guide d'entretien. Pour la passation de l'epreuve, le chercheur a pu compter sur la collaboration de 130 sujets provenant de deux ecoles. L'entretien complete la prise de donnees avec 13 sujets ayant accepte de poursuivre l'etude. Les donnees recueillies par ces instruments font ensuite l'objet d'une analyse de contenu. En premier lieu, les verbatims de l'epreuve et de l'entretien ont ete transcrits, puis codifies. La correction des reponses fournies pour les problemes resolus s'est faite a partir d'une grille d'analyse qualitative et adaptee de la litterature (Thouin, 1995). Une seconde serie d'analyses permettant de categoriser les reponses selon la typologie des connaissances declaratives, procedurales et conditionnelles complete la prise de donnees. Nos resultats indiquent que les sujets sont tres influences par des elements de surface, principalement lorsqu'il s'agit de problemes auxquels ils ne sont pas habitues. En l'absence de connaissances de base, plusieurs sujets vont tendre vers des propositions de solution "pratico-pratique" provenant de leur vecu: cela nous apparait d'importance d'un point de vue didactique et en matiere de transfert. Lors des entretiens realises un mois plus tard, les sujets ont eprouve de la difficulte a se rappeler le contenu de l'epreuve. Et lorsqu'il y avait un rappel, celui-ci etait superficiel et surtout axe sur le contenu ou le contexte d'un probleme. La plupart des sujets ne pouvait nommer que deux ou trois elements (des problemes en mathematiques, en sciences physiques, le probleme de la fenetre, le probleme du laser, etc.). Nos resultats confirment ce que plusieurs chercheurs (Julo, 1995, Jonnaert et Vander Borght, 1999; Richard et al., 1990) qui s'interessent aux questions de l'apprentissage admettent aujourd'hui: l'eleve ne travaille jamais sur la situation proposee par l'enseignant, mais bien sur la representation qu'il s'en est construite. Au plan methodologique, cette recherche est interessante par la variete des sources de collecte de donnees utilisees, par l'application d'outils methodologiques et d'analyses originaux tires de la recherche et de la pratique. Du cote theorique, il resulte de cette etude une meilleure comprehension du processus de transfert des connaissances mathematiques vers les sciences physiques. Finalement, aux plans didactique et pedagogique, cette recherche alimente la reflexion sur l'apprentissage et l'enseignement des sciences au secondaire. Elle fait ressortir que les mathematiques sont importantes dans la mobilisation de certaines connaissances scientifiques et que l'enseignant peut et devrait jouer un role pour favoriser le transfert.

Mass transport phenomena in microgravity: Preliminary results of the first MEPHISTO flight experiment

NASA Technical Reports Server (NTRS)

Favier, Jean Jacques; Garandet, J. P.; Rouzaud, A.; Camel, D.

1994-01-01

The MEPHISTO space program is the result of a cooperative effort that involves the French nuclear and space agencies (Commissariat a l'energie atomique, CEA - Centre National d'Etudes Spatiales, CNES) and the American National Aeronautics and Space Administration (NASA). The scientific studies and apparatus development were funded in the frame of the GRAMME agreement between CEA and CNES, the flight costs being taken in charge by NASA. Six flight opportunities are scheduled, with alternating French and American principal investigators. It is the purpose of this paper to briefly present MEPHISTO along with the preliminary results obtained during its first flight on USMP-1 in October 1992.

Study of the Retention of Fission Products by a Few Common Minerals. Application to the Treatment of Medium Activity Effluents; ETUDE DE LA RETENTION DES PRODUITS DE FISSION PAR QUELQUES MINERAUX USUELS. (APPLICATION AUX TRAITEMENTS D'EFFLUENTS DE MOYENNE ACTIVITE SPECIFIQUE)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Auchapt, J.M.

1962-01-01

The conditions in which Sr is fixed on calcite (the object of Geneva report P/395-USA-- 1958) are more closely studied and the work is extended to five fission products in the effluerts and to 17 common rocks and minerals. Although this fixation is not suitsble as a method of treating STE effluents (i.e., those from the effluent treatment plant at MIarcoule), the study shows that all the crystals considered are strongly contaminated by simple contact. (auth)

STS-93: Chandra Crew Arrival

NASA Technical Reports Server (NTRS)

1999-01-01

The primary objective of the STS-93 mission was to deploy the Advanced X-ray Astrophysical Facility, which had been renamed the Chandra X-ray Observatory in honor of the late Indian-American Nobel Laureate Subrahmanyan Chandrasekhar. The mission was launched at 12:31 on July 23, 1999 onboard the space shuttle Columbia. The mission was led by Commander Eileen Collins. The crew was Pilot Jeff Ashby and Mission Specialists Cady Coleman, Steve Hawley and Michel Tognini from the Centre National d'Etudes Spatiales (CNES). This videotape shows the astronauts arrival at Kennedy Space Center a week before the launch. Each of the astronauts gives brief remarks, beginning with Eileen Collins, the first woman to command a space mission.

Etude expérimentale de la lamination des stromatolithes à Rivularia haematites en climat tempéré: édification des lamines micritiques

NASA Astrophysics Data System (ADS)

Caudwell, Christiane; Lang, Jacques; Pascal, André

1997-06-01

The lamination of Rivularia haematites stromatolites (D.C.) Agardh was studied experimentally for 7 years. Micritic laminae are found to form in three stages: biological formation of dark laminae during the wet season, microsparitic calcification of these laminae in the form of clearly individualized polycrystalline aggregates and, finally, micritization of the latter by bacterial action. These three stages develop over 2 to 3 years. The occurrence of transverse, longitudinal and circular microfibrils in the outer sheath is thought to explain the nucleation and the three-dimensional structure of the microsparitic crystals of the dark laminae and of the polycrystalline aggregates.

Use of X-Ray Fluorescence in a Laboratory for the Treatment of Uranium Ores; UTILISATION DE LA FLUORESCENCE DANS UN LABORATOIRE DE TRAITEMENTS DE MINERAIS D'URANIUM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guillet, H.

1960-01-01

A brief description is given of some aspects of the experience gained over a year during which x-ray fluorescence was used at the laberatory of the present Section Autonome d'Etudes, Recherches et Applications Chimiques of the Commissariat a l'Energie Atomique. A standard is tested daily to ensure reproducibility. The observations made during the months from Dec. 1958 to May 1959 are described. In acid leaching of uranium ores, the residues are analyzed by x-ray fluorescence directly in powder form. Fixation and elution of vanadium on ion-exchange resin were also studied. (auth)

Development of black scattering coatings for space application (etude de traitements noirs diffusants pour application spatiale)

NASA Astrophysics Data System (ADS)

Mestreau-Garreau, Agnes; Pezant, Christian; Cousin, Bernard; Etcheto, Pierre; Otrio, Georges

2017-11-01

In the context of Research and Technology (R&T), studies have been performed on the coatings of vane edge in the 0.4 to 1 μm spectral range. The main purposes of the study were to improve the diffusing black coatings available on the market and to look for other diffusing black coatings. At the same time, we have also improved the machining technologies of vane edges. The characterisation (thermal tests, radiometric measurements, adhesion tests) of the most promising technologies has been carried out. The results have pointed out the stainless steel vanes with the edge obtained by polishing or by advanced grinding.

The Haiti research-based model of international public health collaboration: the GHESKIO Centers.

PubMed

Pape, Jean W; Severe, Patrice D; Fitzgerald, Daniel W; Deschamps, Marie M; Joseph, Patrice; Riviere, Cynthia; Rouzier, Vanessa; Johnson, Warren D

2014-01-01

For 3 decades, GHESKIO (the Groupe Haitien d'Etude du Sarcome de Kaposi et des Infections Opportunistes), the Haitian Ministry of Health, and Weill Cornell have pursued a tripartite mission of service, training, and translational research. The initial focus was on AIDS and tuberculosis. The mission has expanded to include the local community and now provides maternal-child health, family planning, cancer prevention and treatment, immunizations (including human papillomavirus, cholera), and primary education through vocational and microcredit programs. Outcome measures include a reduction in HIV prevalence from 6.2% to the current 2.2%, extensive tuberculosis and cholera prevention and treatment programs, and national training programs for biomedical and community health workers.

Banque de strategies d'ecoute pour un enseignement explicite de la 1re a la 7e annee. Document d'appui pour les programmes d'etudes (1998) de francais langue premiere et de francais langue seconde--immersion (Listening Strategies for Specific Instruction in Grades 1 through 7. Guide in Support of Programs Teaching French as a First Language and French as a Second Language--Immersion).

ERIC Educational Resources Information Center

Alberta Learning, Edmonton. Direction de l'education francaise.

This teacher's guide is intended for the instruction of both French as a first language and French as a second language in immersion programs. It provides a host of strategies for teaching listening skills in the classroom in Grades 1 through 7. The first section is designed to bring the teacher's awareness to the training procedure. It discusses…

Banque de strategies d'ecoute pour un enseignement explicite de la 6e a la 12e annee. Document d'appui pour les programmes d'etudes (1998) de francais langue premiere et de francais langue seconde--immersion (Listening Strategies for Specific Instruction in Grades 6 through 12. Guide in Support of Programs Teaching French as a First Language and French as a Second Language--Immersion).

ERIC Educational Resources Information Center

Alberta Learning, Edmonton. Direction de l'education francaise.

This teacher's guide is intended for the instruction of both French as a first language and French as a second language in an immersion setting. It provides a host of strategies for teaching listening skills in the classroom in Grades 6 through 12. The first section is designed to bring the teacher's awareness to the training procedure. It…

Banque de strategies de lecture pour un enseignement explicite de la 6e a la 12e annee. Document d'appui pour les programmes d'etudes (1998) de francais langue premiere et de francais langue seconde--immersion (Reading Strategies for Specific Instruction in Grades 6 through 12. Guide in Support of Programs Teaching French as a First Language and French as a Second Language--Immersion).

ERIC Educational Resources Information Center

Northwest Territories Dept. of Education, Culture and Employment, Yellowknife.

This teacher's guide is intended for the instruction of both French as a first language and French as a second language in an immersion setting. It provides a host of strategies for teaching reading skills in the classroom in Grades 6 through 12. The first section is designed to bring the teacher's awareness to the training procedure. It discusses…

Banque de strategies de lecture pour un enseignement explicite de la 1re a la 7e annee. Document d'appui pour les programmes d'etudes (1998) de francais langue premiere et de francais langue seconde--immersion (Reading Strategies for Specific Instruction in Grades 1 through 7. Guide in Support of Programs Teaching French as a First Language and French as a Second Language--Immersion).

ERIC Educational Resources Information Center

Northwest Territories Dept. of Education, Culture and Employment, Yellowknife.

This teacher's guide, intended for the instruction of both French as a first language and French as a second language in an immersion setting, provides a host of strategies for teaching reading skills in the classroom (Grades 1 through 7). Section 1 is designed to bring the teacher's awareness to the training procedure, discussing the motivation…

Banque de strategies d'ecriture pour un enseignement explicite de la 6e a la 12e annee. Document d'appui pour les programmes d'etudes de francais langue premiere et de francais langue seconde--immersion de 1998 (Writing Strategies for Specific Instruction in Grades 6 through 12. Guide in Support of Programs Teaching French as a First Language and French as a Second Language--Immersion 1998).

ERIC Educational Resources Information Center

Alberta Learning, Edmonton. Direction de l'education francaise.

This teacher's guide, intended for the instruction of both French as a first language and French as a second language in an immersion setting, provides a host of strategies for teaching writing skills in the classroom (Grades 6 through 12). Section 1 is designed to bring the teacher's awareness to the training procedure, discussing the motivation…

Banque de strategies d'ecriture pour un enseignement explicite de la 1re a la 7e annee. Document d'appui pour les programmes d'etudes de francais langue premiere et de francais langue seconde--immersion de 1998 (Writing Strategies for the Specific Instruction in Grades 1 through 7. Guide in Support of Programs Teaching French as a First Language and French as a Second Language--Immersion 1998).

ERIC Educational Resources Information Center

Alberta Learning, Edmonton. Direction de l'education francaise.

This teacher's guide, written in French, intended for the instruction of both French as a first language and French as a second language (immersion), provides a host of strategies for teaching writing skills in the classroom (grades 1 through 7). Section 1 is designed to bring the teacher's awareness to the training procedure, discussing the…

Collision Avoidance Short Course: Conjunction Assessment Risk Analysis - NASA Robotic CARA. Part I: ; Theory

NASA Technical Reports Server (NTRS)

Hejduk, M. D.; Frigm, Ryan C.

2015-01-01

Satellite conjunction assessment is perhaps the fastest growing area in space situational awareness and protection with military, civil and commercial satellite owner-operators embracing more and more sophisticated processes to avoid the avoidable - namely collisions between high value space assets and orbital debris. NASA and Centre National d'Etudes Spatiales (CNES) have collaborated to offer an introductory short course on all the major aspects of the conjunctions assessment problem. This half-day course will cover satellite conjunction dynamics and theory. Joint Space Operations Center (JsPOC) conjunction data products, major risk assessment parameters and plots, conjunction remediation decision support, and present and future challenges. This briefing represents the NASA portion of the course.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Billerud signed a contract recently with the Societe d'Etudes de la Celulose du Congo (SECC) to conduct a feasibility study for a projected eucalyptus-based pulp plant for the production of bleached marketing pulp in The People's Republic of The Congo. SECC is a consortium of financial institutions, the Congolese government and Billerud. The Congolese government has been planning for the construction of a eucalyptus-based pulp plant for a long time, and in 1978, full-scale eucalyptus plantations were started. These plantations are based on fast growing hybrid species of eucalyptus developed by the Centre Technique Forestier Tropical in the Congo andmore » are ready for harvesting after only about seven years growing time.« less

Inflammatory Responses in Brain Ischemia

PubMed Central

Kawabori, Masahito; Yenari, Midori A.

2017-01-01

Brain infarction causes tissue death by ischemia due to occlusion of the cerebral vessels and recent work has shown that post stroke inflammation contributes significantly to the development of ischemic pathology. Because secondary damage by brain inflammation may have a longer therapeutic time window compared to the rescue of primary damage following arterial occlusion, controlling inflammation would be an obvious therapeutic target. A substantial amount of experimentall progress in this area has been made in recent years. However, it is difficult to elucidate the precise mechanisms of the inflammatory responses following ischemic stroke because inflammation is a complex series of interactions between inflammatory cells and molecules, all of which could be either detrimental or beneficial. We review recent advances in neuroinflammation and the modulation of inflammatory signaling pathways in brain ischemia. Potential targets for treatment of ischemic stroke will also be covered. The roles of the immune system and brain damage versus repair will help to clarify how immune modulation may treat stroke. PMID:25666795

Modelisation des emissions de particules microniques et nanometriques en usinage

NASA Astrophysics Data System (ADS)

Khettabi, Riad

La mise en forme des pieces par usinage emet des particules, de tailles microscopiques et nanometriques, qui peuvent etre dangereuses pour la sante. Le but de ce travail est d'etudier les emissions de ces particules pour fins de prevention et reduction a la source. L'approche retenue est experimentale et theorique, aux deux echelles microscopique et macroscopique. Le travail commence par des essais permettant de determiner les influences du materiau, de l'outil et des parametres d'usinage sur les emissions de particules. E nsuite un nouveau parametre caracterisant les emissions, nomme Dust unit , est developpe et un modele predictif est propose. Ce modele est base sur une nouvelle theorie hybride qui integre les approches energetiques, tribologiques et deformation plastique, et inclut la geometrie de l'outil, les proprietes du materiau, les conditions de coupe et la segmentation des copeaux. Il ete valide au tournage sur quatre materiaux: A16061-T6, AISI1018, AISI4140 et fonte grise.

Estudio teórico del CO2. Orbitales de valencia y del ``core''

NASA Astrophysics Data System (ADS)

Olalla Gutiérrez, E.

Hemos calculado las intensidades de las transiciones E1 a los miembros de las series de Rydberg con origen en los orbitales ``no enlazantes'' del dióxido de carbono, especie de conocida relevancia atmosférica. Se han computado, asimismo, los continuos de fotoionización correspondientes a los distintos canales de ionización, representándolos como densidad espectral de fuerza de oscilador frente a la energía del fotón incidente; mostramos los resultados df/dE para la fotoionización total de esta especie en el intervalo 15-60 eV. Todos los cálculos se han llevado a cabo mediante la formulación Molecular del Método de los Orbitales de Defecto Cuántico, MQDO [1,2]. La calidad de los resultados que presentamos se ha evaluado en base a la comparación con los datos, tanto experimentales como teóricos, disponibles en la bibliografía. El acuerdo encontrado es altamente satisfactorio

Gravity model improvement using the DORIS tracking system on the SPOT 2 satellite

NASA Technical Reports Server (NTRS)

Nerem, R. S.; Lerch, F. J.; Williamson, R. G.; Klosko, S. M.; Robbins, J. W.; Patel, G. B.

1994-01-01

A high-precision radiometric satellite tracking system, Doppler Orbitography and Radio-positioning Integrated by Satellite system (DORIS), has recently been developed by the French space agency, Centre National d'Etudes Spatiales (CNES). DORIS was designed to provide tracking support for missions such as the joint United States/French TOPEX/Poseidon. As part of the flight testing process, a DORIS package was flown on the French SPOT 2 satellite. A substantial quantity of geodetic quality tracking data was obtained on SPOT 2 from an extensive international DORIS tracking network. These data were analyzed to assess their accuracy and to evaluate the gravitational modeling enhancements provided by these data in combination with the Goddard Earth Model-T3 (GEM-T3) gravitational model. These observations have noise levels of 0.4 to 0.5 mm/s, with few residual systematic effects. Although the SPOT 2 satellite experiences high atmospheric drag forces, the precision and global coverage of the DORIS tracking data have enabled more extensive orbit parameterization to mitigate these effects. As a result, the SPOT 2 orbital errors have been reduced to an estimated radial accuracy in the 10-20 cm RMS range. The addition of these data, which encompass many regions heretofore lacking in precision satellite tracking, has significantly improved GEM-T3 and allowed greatly improved orbit accuracies for Sun-synchronous satellites like SPOT 2 (such as ERS 1 and EOS). Comparison of the ensuing gravity model with other contemporary fields (GRIM-4C2, TEG2B, and OSU91A) provides a means to assess the current state of knowledge of the Earth's gravity field. Thus, the DORIS experiment on SPOT 2 has provided a strong basis for evaluating this new orbit tracking technology and has demonstrated the important contribution of the DORIS network to the success of the TOPEX/Poseidon mission.

Bistatic GPR Measurements in the Egyptian Western Desert - Measured and Simulated data

NASA Astrophysics Data System (ADS)

Ciarletti, V.; Le Gall, A.; Berthelier, J.; Ney, R.; Corbel, C.; Dolon, F.

2006-12-01

The TAPIR (Terrestrial And Planetary Investigation Radar) instrument has been designed at CETP (Centre d'etude des Environnements Terrestre et Planetaires) to explore the deep Martian subsurface (down to a few kilometers) and to detect liquid water reservoirs. TAPIR is an impulse ground penetrating radar operating at central frequencies ranging from 2 to 4 MHz operating from the surface. In November 2005, an updated version of the instrument working either in monostatic or in bi-static mode was tested in the Egyptian Western Desert. The work presented here focuses on the bi-static measurements performed on the Abou Saied plateau which shows a horizontally layered sub-surface. The electromagnetic signal was transmitted using one of the two orthogonal 70 m loaded electrical dipole antennas of the transmitting GPR. A second GPR, 50 or 100 meters apart, was dedicated to the signal reception. The received waves were characterized by a set of 5 measurements performed on the receiving GPR : the two horizontal components of the electric field and the three composants of the magnetic field. They were used to compute the direction of arrival of the incoming waves and to retrieve more accurately their propagation path and especially to discriminate between waves due to some sub-surface reflecting structure and those due to interaction with the surface clutter. A very efficient synchronization between the two radars enabled us to perform coherent additions up to 2^{31} which improves dramatically the obtained signal to noise ratio. Complementary electromagnetic measurements were conducted on the same site by the LPI (Lunar and Planetary Institute) and the SwRI (Southwest Research Institute). They provided independent information which helped the interpretation of the TAPIR data. Accurate simulations obtained by FDTD taking into account the information available are presented and used for both the interpretation of the measured data and the validation of the instrument.

Hail prevention by ground-based silver iodide generators: Results of historical and modern field projects

NASA Astrophysics Data System (ADS)

Dessens, J.; Sánchez, J. L.; Berthet, C.; Hermida, L.; Merino, A.

2016-03-01

The science of hail suppression by silver iodide (AgI) cloud seeding was developed during the second half of the 20th century in laboratory and tested in several research or operational projects using three delivery methods for the ice forming particles: ground generators, aircraft, and rockets. The randomization process for the seeding was often considered as the imperative method for a better evaluation but failed to give firm results, mostly because the projects did not last long enough considering the hazardous occurrence of severe hailfalls, and also probably due to the use of improper hail parameters. At the same time and until now, a continuous long-term research and operational field project (1952-2015) using ground generator networks has been conducted in France under the leadership of the Association Nationale d'Etude et de Lutte contre les Fléaux Atmosphériques (ANELFA), with a control initially based on annual insurance loss-to-risk ratios, then on hailpad data. More recently (2000-2009), a companion ground seeding project was developed in the north of Spain, with control mostly based on microphysical and hailpad data. The present paper, which focuses on hail suppression by ground seeding, reviews the production of the AgI nuclei, their dispersion and measurement in the atmosphere, as well as their observed or simulated effects in clouds. The paper summarizes the results of the main historical projects in Switzerland, Argentina, and North America, and finally concentrates on the current French and Spanish projects, with a review of already published results, complemented by new ones recently collected in Spain. The conclusion, at least for France and Spain, is that if ground seeding is performed starting 3 hours before the hail falls at the ground with a 10-km mesh AgI generator network located in the developing hailstorm areas, each generator burning about 9 g of AgI per hour, the hailfall energy of the most severe hail days is decreased by about 50%.

Methodologie de modelisation aerostructurelle d'une aile utilisant un logiciel de calcul aerodynamique et un logiciel de calcul par elements finis =

NASA Astrophysics Data System (ADS)

Communier, David

Lors de l'etude structurelle d'une aile d'avion, il est difficile de modeliser fidelement les forces aerodynamiques subies par l'aile de l'avion. Pour faciliter l'analyse, on repartit la portance maximale theorique de l'aile sur son longeron principal ou sur ses nervures. La repartition utilisee implique que l'aile entiere sera plus resistante que necessaire et donc que la structure ne sera pas totalement optimisee. Pour pallier ce probleme, il faudrait s'assurer d'appliquer une repartition aerodynamique de la portance sur la surface complete de l'aile. On serait donc en mesure d'obtenir une repartition des charges sur l'aile beaucoup plus fiable. Pour le realiser, nous aurons besoin de coupler les resultats d'un logiciel calculant les charges aerodynamiques de l'aile avec les resultats d'un logiciel permettant sa conception et son analyse structurelle. Dans ce projet, le logiciel utilise pour calculer les coefficients de pression sur l'aile est XFLR5 et le logiciel permettant la conception et l'analyse structurelle sera CATIA V5. Le logiciel XFLR5 permet une analyse rapide d'une aile en se basant sur l'analyse de ses profils. Ce logiciel calcule les performances des profils de la meme maniere que XFOIL et permet de choisir parmi trois methodes de calcul pour obtenir les performances de l'aile : Lifting Line Theory (LLT), Vortex Lattice Method (VLM) et 3D Panels. Dans notre methodologie, nous utilisons la methode de calcul 3D Panels dont la validite a ete testee en soufflerie pour confirmer les calculs sur XFLR5. En ce qui concerne la conception et l'analyse par des elements finis de la structure, le logiciel CATIA V5 est couramment utilise dans le domaine aerospatial. CATIA V5 permet une automatisation des etapes de conception de l'aile. Ainsi, dans ce memoire, nous allons decrire la methodologie permettant l'etude aerostructurelle d'une aile d'avion.

Le recours aux modeles dans l'enseignement de la biologie au secondaire : Conceptions d'enseignantes et d'enseignants et modes d'utilisation

NASA Astrophysics Data System (ADS)

Varlet, Madeleine

Le recours aux modeles et a la modelisation est mentionne dans la documentation scientifique comme un moyen de favoriser la mise en oeuvre de pratiques d'enseignement-apprentissage constructivistes pour pallier les difficultes d'apprentissage en sciences. L'etude prealable du rapport des enseignantes et des enseignants aux modeles et a la modelisation est alors pertinente pour comprendre leurs pratiques d'enseignement et identifier des elements dont la prise en compte dans les formations initiale et disciplinaire peut contribuer au developpement d'un enseignement constructiviste des sciences. Plusieurs recherches ont porte sur ces conceptions sans faire de distinction selon les matieres enseignees, telles la physique, la chimie ou la biologie, alors que les modeles ne sont pas forcement utilises ou compris de la meme maniere dans ces differentes disciplines. Notre recherche s'est interessee aux conceptions d'enseignantes et d'enseignants de biologie au secondaire au sujet des modeles scientifiques, de quelques formes de representations de ces modeles ainsi que de leurs modes d'utilisation en classe. Les resultats, que nous avons obtenus au moyen d'une serie d'entrevues semi-dirigees, indiquent que globalement leurs conceptions au sujet des modeles sont compatibles avec celle scientifiquement admise, mais varient quant aux formes de representations des modeles. L'examen de ces conceptions temoigne d'une connaissance limitee des modeles et variable selon la matiere enseignee. Le niveau d'etudes, la formation prealable, l'experience en enseignement et un possible cloisonnement des matieres pourraient expliquer les differentes conceptions identifiees. En outre, des difficultes temporelles, conceptuelles et techniques peuvent freiner leurs tentatives de modelisation avec les eleves. Toutefois, nos resultats accreditent l'hypothese que les conceptions des enseignantes et des enseignants eux-memes au sujet des modeles, de leurs formes de representation et de leur approche constructiviste en enseignement representent les plus grands obstacles a la construction des modeles en classe. Mots-cles : Modeles et modelisation, biologie, conceptions, modes d'utilisation, constructivisme, enseignement, secondaire.

Loess in Europe—its spatial distribution based on a European Loess Map, scale 1:2,500,000

NASA Astrophysics Data System (ADS)

Haase, D.; Fink, J.; Haase, G.; Ruske, R.; Pécsi, M.; Richter, H.; Altermann, M.; Jäger, K.-D.

2007-05-01

The paper focuses on the concept, mapping and discussion of loess distribution in Western, Central and Eastern Europe at a scale of 1:2,500,000. The research work is based on studies and data compilation primarily carried out in the 1970s and 1980s [Fink, J., Haase, G., Ruske, R., 1977. Bemerkungen zur Lößkarte von Europe 1:2,5 Mio. Petermanns Geographische Mitteilungen 2(77), 81-94; Fink, J., 1969 Les progres de l' etude de loess en Europe. Bulletin de l' Association française pour l' etude du Quarternaire 3-12. Haase, G., Ruske, R., Fink, J., 1983. Conception, preparation and some results of the Loess Map of Europe on a scale 1:2,5 Million. INQUA Newsletter 1983(1), 7-10] and completed recently by additional material and literature references. Reference is also made to recent GIS-based data processing and visualisation techniques that were utilised for the final version of the European Loess Map. The paper provides an overview of the history of the conceptualisation of the map as well as on the loess study in Europe, and than considers the cartographic data on loess sediment formation and distribution in Europe. The classification of loess and loess-like sediments and their distribution throughout Europe as reproduced in the map are discussed [Haase, G., Lieberoth, I., Ruske, R., 1970. Sedimente und Paläoböden im Lössgürtel. In: Richter, H., Haase, G., Lieberoth, I., Ruske, R. (Eds.), Periglazial-Löß-Paläolithikum om JUngpleistozän der Deutschen Demokratischen Republik; Petermanns Geographische Mitteilungen 274, 99-212]. The paper illustrates the final state of the loess distribution map of Europe at a scale of 1:2,500,000 and the digital data references on which it is based. Some applications of the map are suggested.

Evaluation de l'intergiciel de communication DDS pour son utilisation dans le domaine avionique

NASA Astrophysics Data System (ADS)

Levesque-Landry, Kevin

Les aeronefs modernes doivent combler de plus en plus de fonctionnalites afin de satisfaire les besoins de la clientele. De ce fait, les besoins en communications des systemes avioniques sont grandissants. De plus, la portabilite et la reutilisabilite des applications sont des defis d'actualite dans le domaine avionique. De ce fait, ce projet de recherche vise a faire une evaluation de la technologie d'intergiciel de service de distribution de donnees (DDS) pour son utilisation dans le domaine avionique. Cette technologie permettrait de reduire la complexite des communications et faciliter la portabilite et reutilisabilite des applications grâce a son interface standardisee. Dans ce projet de recherche, la norme DDS est tout d'abord etudiee pour cibler les fonctionnalites qui sont utiles au domaine avionique. Les differentes polices de qualite de services sont ainsi etudiees et denotent la flexibilite de la technologie DDS. Un intergiciel DDS est egalement evalue dans un environnement de laboratoire afin de mesurer l'impact de l'utilisation de cette technologie sur les performances de latence ainsi que sur l'utilisation de la bande passante. Les resultats montrent une faible augmentation de la latence moyenne lorsque l'intergiciel DDS est utilise. L'intergiciel DDS est egalement utilise dans une etude de cas avec un AFCS (automatic flight control system) afin de quantifier les effets de son utilisation sur une application avionique. Les resultats montrent que l'utilisation de l'intergiciel DDS n'empeche pas l'AFCS d'atteindre la stabilite, mais qu'elle ralentit l'atteinte de cette derniere. Finalement, une etude de cas est effectuee afin de valider que la technologie DDS peut etre utilisee pour construire des systemes redondants. Les resultats montrent que l'intergiciel DDS permet de faire de la redondance de reserve sans avoir un impact visible sur les performances du systeme redondant.

Study and Construction of Electrostatic Biprisms Useful in Corpuscular Optics; ETUDE ET REALISATION DE BIPRISMES ELECTROSTATIQUES UTILISABLES EN OPTIQUE CORPUSCULAIRE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Septier, A.

1960-03-01

In the simultaneous injection of two beams identical except in direction in an FFAG cyclotron, two beams of equal intensity and energy are needed. The two beams can be produced either by alternating the direction of a single beam by very short, rectangular, high-voltage pulses fed to a deflector, or by chopping the beam with a static apparatus. The second method was investigated because of its simplicity. The principles and properties of the electrostatic biprism are presented. Three cases are then considered: a wire stretched between two plates, a grid between two plates, and a plate between two flat conductors.more » (T.R.H.)« less

Study of the Dry Processing of Uranium Ores; ETUDE DES TRAITEMENTS DE MINERAIS D'URANIUM PAR VOIE SECHE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guillet, H.

1959-02-01

A description is given of direct fluorination of preconcentrated uranium ores in order to obtain the hexafluoride. After normal sulfuric acid treatment of the ore to eliminate silica, the uranium is precipitated by lime to obtain either impure calcium uranate of medium grade, or containing around 10% of uranium. This concentrate is dried in an inert atmosphere and then treated with a current of elementary fluorine. The uranium hexafluoride formed is condensed at the outlet of the reaction vessel and may be used either for reduction to tetrafluoride and the subsequent manufacture of uranium metal or as the initial productmore » in a diffusion plant. (auth)« less

[Prevalence of transmission of zidovudine-resistant viruses in Switzerland. l'Etude suisse de cohorte VIH].

PubMed

Yerly, S; Rakik, A; Kinloch-de-Loes, S; Erb, P; Vernazza, P; Hirschel, B; Perrin, L

1996-10-26

Zidovudine (ZDV) was the most widely used anti-HIV drug between 1987 and 1995, and, as already reported, transmission of ZDV-resistant viruses occurs. Several mutations of the reverse transcriptase gene have been identified; one of them affects the 215 codon and is associated with a high degree of resistance. We have determined, using selective PCR, the prevalence of transmission of 215 mutant isolates in 134 patients with primary HIV infection (PHI) and have identified 8 patients with 215 mutant virus between 1989 and 1995 in Switzerland. Mutant resistant viruses have been isolated from patients treated with most antiviral drugs. A systematic search for mutant viruses may provide useful information for the adaptation of treatment strategies.

Optimization of the launcher ascent trajectory leading to the global optimum without any initialization: the breakthrough of the Hamilton-Jacobi-Bellman approach

NASA Astrophysics Data System (ADS)

Bourgeois, E.; Bokanowski, O.; Zidani, H.; Désilles, A.

2018-06-01

The resolution of the launcher ascent trajectory problem by the so-called Hamilton-Jacobi-Bellman (HJB) approach, relying on the Dynamic Programming Principle, has been investigated. The method gives a global optimum and does not need any initialization procedure. Despite these advantages, this approach is seldom used because of the dicculties of computing the solution of the HJB equation for high dimension problems. The present study shows that an eccient resolution is found. An illustration of the method is proposed on a heavy class launcher, for a typical GEO (Geostationary Earth Orbit) mission. This study has been performed in the frame of the Centre National d'Etudes Spatiales (CNES) Launchers Research & Technology Program.

KSC-08pd1290

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. -- At Vandenberg Air Force Base, the OSTM/Jason-2 satellite shipping container is being moved inside the Astrotech processing facility. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1292

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. -- At Vandenberg Air Force Base, the OSTM/Jason-2 satellite shipping container has been moved inside the Astrotech processing facility. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1064

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. – The aircraft carrying the OSTM/Jason-2 spacecraft arrives at Vandenberg Air Force Base in California. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Steve Greenberg, JPL

KSC-08pd1284

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. -- At Vandenberg Air Force Base, the truck carrying the OSTM/Jason-2 satellite arrives at the Astrotech processing facility. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1291

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. -- At Vandenberg Air Force Base, the OSTM/Jason-2 satellite shipping container is being moved inside the Astrotech processing facility. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1285

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. -- At Vandenberg Air Force Base, the truck carrying the OSTM/Jason-2 satellite arrives at the Astrotech processing facility. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

STS-93 Crew Interview: Michel Tognini

NASA Technical Reports Server (NTRS)

1999-01-01

This NASA Johnson Space Center (JSC) video release presents a one-on-one interview with Mission Specialist 3, Michel Tognini (Col., French Air Force and Centre Nacional Etudes Spatiales (CNES) Astronaut). Subjects discussed include early influences that made Michel want to be a pilot and astronaut, his experience as a French military pilot and his flying history. Also discussed were French participation in building the International Space Station (ISS), the STS-93 primary mission objective, X-ray observation using the Advanced X-ray Astrophysics Facility (AXAF), and failure scenarios associated with AXAF deployment. The STS-93 mission objective was to deploy the Advanced X-ray Astrophysics Facility (AXAF), later renamed the Chandra X-Ray Observatory in honor of the late Indian-American Nobel Laureate Subrahmanyan Chandrasekhar.

Banque de strategies de production orale pour un enseignement explicite de la 1re a la 7e annee: Expose et interaction. Document d'appui pour les programmes d'etudes de francais langue premiere et de francais langue seconde--immersion de 1998 (Interactive Oral Presentation Strategies for Specific Instruction in Grades 1 through 7. Guide in Support of Programs Teaching French as a First Language and French as a Second Language--Immersion 1998).

ERIC Educational Resources Information Center

Alberta Learning, Edmonton. Direction de l'education francaise.

This teacher's guide, intended for the instruction of both French as a first language and French as a second language in an immersion setting, provides a host of strategies for teaching interactive oral presentation skills in the classroom (Grades 1 through 7). Section 1 is designed to bring the teacher's awareness to the training procedure,…

Banque de strategies de production orale pour un enseignement explicite de la 6e a la 12e annee: Expose et interaction. Document d'appui pour les programmes d'etudes de francais langue premiere et de francais langue seconde--immersion de 1998 (Interactive Oral Presentation Strategies for Specific Instruction in Grades 6 through 12. Guide in Support of Programs Teaching French as a First Language and French as a Second Language--Immersion 1998).

ERIC Educational Resources Information Center

Northwest Territories Dept. of Education, Culture and Employment, Yellowknife.

This teacher's guide, intended for the instruction of both French as a first language and French as a second language in an immersion setting, provides a host of strategies for teaching interactive oral presentation skills in the classroom (Grades 6 through 12). Section 1 is designed to bring the teacher's awareness to the training procedure,…

The Large UV/Optical/Infrared Surveyor (LUVOIR): Decadal Mission concept design update

NASA Astrophysics Data System (ADS)

Bolcar, Matthew R.; Aloezos, Steve; Bly, Vincent T.; Collins, Christine; Crooke, Julie; Dressing, Courtney D.; Fantano, Lou; Feinberg, Lee D.; France, Kevin; Gochar, Gene; Gong, Qian; Hylan, Jason E.; Jones, Andrew; Linares, Irving; Postman, Marc; Pueyo, Laurent; Roberge, Aki; Sacks, Lia; Tompkins, Steven; West, Garrett

2017-09-01

In preparation for the 2020 Astrophysics Decadal Survey, NASA has commissioned the study of four large mission concepts, including the Large Ultraviolet / Optical / Infrared (LUVOIR) Surveyor. The LUVOIR Science and Technology Definition Team (STDT) has identified a broad range of science objectives including the direct imaging and spectral characterization of habitable exoplanets around sun-like stars, the study of galaxy formation and evolution, the epoch of reionization, star and planet formation, and the remote sensing of Solar System bodies. NASA's Goddard Space Flight Center (GSFC) is providing the design and engineering support to develop executable and feasible mission concepts that are capable of the identified science objectives. We present an update on the first of two architectures being studied: a 15- meter-diameter segmented-aperture telescope with a suite of serviceable instruments operating over a range of wavelengths between 100 nm to 2.5 μm. Four instruments are being developed for this architecture: an optical / near-infrared coronagraph capable of 10-10 contrast at inner working angles as small as 2 λ/D the LUVOIR UV Multi-object Spectrograph (LUMOS), which will provide low- and medium-resolution UV (100 - 400 nm) multi-object imaging spectroscopy in addition to far-UV imaging; the High Definition Imager (HDI), a high-resolution wide-field-of-view NUV-Optical-IR imager; and a UV spectro-polarimeter being contributed by Centre National d'Etudes Spatiales (CNES). A fifth instrument, a multi-resolution optical-NIR spectrograph, is planned as part of a second architecture to be studied in late 2017.

Future U.S. ocean color missions-OCI, MODIS and HIRIS

NASA Astrophysics Data System (ADS)

Davis, C. O.

The Coastal Zone Color Scanner (CZCS) launched by the National Aeronautics and Space Administration (NASA) on the Nimbus-7 Satellite in 1978 has provided exceptionally valuable data for studies of the productivity of the ocean, fisheries, the detection of oceanic fronts and currents, and the optical properties of the ocean. NASA has been working with the scientific community, the National Oceanographic and Atmospheric Administration (NOAA), France's Centre National d'Etudes Spatiales (CNES), and industry to develop an Ocean Color Imager (OCI), a follow-on instrument which would provide the near real-time and global data necessary to fill these needs in the 1990's. The Earth Observing Satellite Company (EOSAT) is considering flying an ocean and land wide-field color instrument which would meet these needs on Landsat 6 or 7 planned for launch in 1989 and 1991, respectively. It would provide eight ocean color channels for improved atmospheric correction and in-water algorithms, global coverage and near real-time data for operational uses. In the mid 1990's NASA is planning to fly a Moderate Resolution Imaging Spectrometer (MODIS) and a High Resolution Imaging Spectrometer (HIRIS) as part of the Earth Observing System (Eos) on the Polar Platform of the Space Station. These instruments are array spectrometers which would provide full spectral resolution in the visible and infrared. This opens the possibility of separating different groups of phytoplankton, suspended sediments and other substances in the water. Also, HIRIS would have across track pointing ability which will allow high resolution rapid sampling of dynamic coastal areas and estuaries.

Space cryogenics at CEA-SBT

NASA Astrophysics Data System (ADS)

Duband, Lionel; Charles, Ivan; Duval, Jean-Marc; Ercolani, Eric; Gully, Philippe; Luchier, Nicolas; Prouve, Thomas; Thibault, Pierre

2017-11-01

The "Service des Basses Températures" (SBT) of CEA Grenoble has been involved in space cryogenics for over 20 years now. In fact a dedicated laboratory was created within SBT to carry out these developments, the "Cryocoolers and Space Cryogenics" group, which comprises about 20 persons as of today. Various cryocoolers have been developed in the past and our fields of activity focus now on four main technologies: sorption coolers, multistage pulse tubes, adiabatic demagnetization refrigerators (ADR), and cryogenic loop heat pipes. In addition work on two new concepts for ground based dilution refrigerators is also ongoing. Finally developments on various key technologies such as the heat switches, the suspension or structural systems are also carried out. These developments are mainly funded by the European Space Agency (ESA) or by the Centre National d'Etudes Spatiales (CNES). For most of these systems the common feature is the absence of any moving parts or any friction, which guarantees a very good reliability and make them very good candidates for space borne instruments requiring cryogenic temperatures. In this paper we give an overview of these developments with a particular focus on the sub Kelvin coolers. Based on the HERSCHEL heritage for which we developed the flight sorption coolers, we are now proposing an original concept featuring the association of a 300 mK sorption unit with a miniature adiabatic demagnetization refrigerator. This combination will allow to provide temperature as low as 50 mK with a system weighting less than 5 kg. This development may have direct application for the XEUS and SPICA missions.

The French Balloon Program 2013 - 2017

NASA Astrophysics Data System (ADS)

Dubourg, Vincent; Vargas, André; Raizonville, Philippe

2016-07-01

With over 50 years' experience in the field, the French Centre National d'Etudes Spatiales (CNES) goes on supporting - as designer and operator - a significant scientific ballooning program. In particular so because balloons still give a unique and valuable access to near space science. From 2008 to 2013, an important renovation effort was achieved, beginning by Zero Pressure Balloons (ZPB) systems, to comply with more stringent Safety constraints and to the growing reliability and performance requirements from scientific missions. The paper will give an overview of the CNES new capabilities and services for operational balloon activities, and their availability status. The scientific launch campaigns of the past two years will be presented. A focus will be made on the results of the Stratoscience 2015 flight campaign from Timmins, Ontario, using the NOSYCA command and control system for ZPB, qualified in flight in 2013. In particular, the PILOT telescope successfully flew during the 2015 campaign, key figures about the flight and mission will be given. An outlook of the new stratospheric long duration flight systems currently in process of developement at CNES will be given, as well as the presentation of the Stratéole 2 project, dedicated to the survey of the low stratosphere and upper troposphere in equatorial regions, with a fleet of small suprer pressure balloons (SPB). As far as tropospheric balloons are concerned, the Aeroclipper initiative will be presented, aiming at qualifying a quasi-tethered balloon, pushed by the winds close to the sea surface, for the study of cyclones. The scientific launch campaigns and the main payloads in the study for the near future will also be presented.

Polder 2 in-flight results and parasol perspectives

NASA Astrophysics Data System (ADS)

Bermudo, F.; Fougnie, B.; Bret-Dibat, T.

2017-11-01

This paper presents a global approach of the POLDER 2 mission: from instrument design, pre-flight and inflight calibrations till the first in-flight results. The POLDER 2 sensor has been developed by the Centre National d'Etudes Spatiales, the French space agency. It is part of the payload of the ADEOS II satellite developed by JAXA and launched in December 2002. POLDER 2 collected global data from April 2003, end of ADEOS II system check out phase, till the loss of the satellite on October 2003 due to a failure of the satellite power supply system. The POLDER 2 sensor is designed to collect global and repetitive observations of the solar radiation reflected by the Earth-Atmosphere system for climate research. The sensor is a wide field-of-view (2400 Km swath), low resolution (6x7 Km² at nadir) multi-spectral imaging radiometer / polarimeter. The instrument concept is based on a telecentric optics, a rotating wheel carrying 15 spectral filters and polarizers, and a bidimensionnal CCD detector array. The multidisciplinary scientific objectives of POLDER 2 lead to severe radiometric and geometrical requirements, as well as a very accurate calibration of the sensor. These requirements are achieved through a stable instrument design, exhaustive pre-flight and original in-flight calibrations. A derived model of POLDER 2 instrument will be flown on the payload of the CNES PARASOL micro satellite, the launch of which is planned end 2004. The PARASOL mission is part of the "Aqua train" i.e. the formation flying of 3 satellites following EOS-PM, so called "Aqua".

CONFERENCE NOTE: Conference on Precision Electromagnetic Measurements

NASA Astrophysics Data System (ADS)

1991-01-01

The next Conference on Precision Electromagnetic Measurements (CPEM), will be held from 9 to 12 June 1992 at the Centre des Nouvelles Industries et Technologies (CNIT), La Défense, Paris, France. This conference, which is held every two years and whose importance and high level, confirmed by thirty years' experience, are recognized throughout the world, can be considered as a forum in which scientists, metrologists and professionals will have the opportunity to present and compare their research results on fundamental constants, standards and new techniques of precision measurement in the electromagnetic domain. Topics The following topics are regarded as the most appropriate for this conference: realization of units and fundamental constants d.c. a.c. and high voltage time and frequency radio-frequency and microwaves dielectrics, antennas, fields lasers, fibre optics advanced instrumentation, cryoelectronics. There will also be a session on international cooperation. Conference Language The conference language will be English. No translation will be provided. Organizers Société des Electriciens et des Electroniciens (SEE). Bureau National de Métrologie (BNM) Sponsors Institute of Electrical and Electronics Engineers (IEEE) Instrumentation & Measurement Society Union Radio Scientifique Internationale United States National Institute of Standards and Technology Centre National d'Etudes des Télécommunications Mouvement Français pour la Qualité, Section Métrologie Comité National Français de Radioélectricité Scientifique Contact Jean Zara, CPEM 92 publicity, Bureau National de Métrologie, 22, rue Monge, 75005 Paris Tel.: (33) 1 46 34 48 16, Fax: (33) 1 46 34 48 63

Etude de l'effet du gonflement par les solvants sur les proprietes du caoutchouc butyle

NASA Astrophysics Data System (ADS)

Nohile, Cedrick

Polymers and in particular elastomers are widely used for personal protective equipment against chemical and biological hazards. Among them, butyl rubber is one of the most effective elastomers against chemicals. However, if this rubber has a very good resistance to a wide range of them, it is sensitive to non polar solvents. These solvents will easily swell the material and may dramatically affect its properties. This situation may involve a large risk for. butyl rubber protective equipment users. It is thus essential to improve the understanding of the effect of solvents on the properties of butyl rubber. The research that was carried out had two objectives: to identify the parameters controlling the resistance of butyl rubber to solvents and to study the effect of swelling on the properties of butyl rubber. The results show that the resistance of butyl rubber to solvents appears to be controlled by three main parameters: the chemical class of the solvent, its saturation vapor pressure and its molar volume. In addition, swelling affects butyl rubber mechanical properties in a permanent way. The effects can be attributed to the extraction of plasticizers by the solvent and to the degradation of the physico-chemical structure of the polymer network. This chemical degradation was linked to a phenomenon of differential swelling which seems to be controlled by the solvent flow inside the material. These results question some general beliefs within the field of protection against chemical risks. They also open new perspectives for the development of predictive tools relative to the behavior of butyl rubber in the presence of solvents

Sentinel-2: presentation of the CAL/VAL commissioning phase

NASA Astrophysics Data System (ADS)

Trémas, Thierry L.; Déchoz, Cécile; Lacherade, Sophie; Nosavan, Julien; Petrucci, Beatrice

2015-10-01

In partnership with the European Commission and in the frame of the Copernicus program, the European Space Agency (ESA) has developed the Sentinel-2 optical imaging mission devoted to the operational monitoring of land and coastal areas. The Sentinel-2 mission is based on a satellites constellation deployed in polar sun-synchronous orbits. Sentinel-2 will offer a unique combination of global coverage with a wide field of view (290km), a high revisit (5 days with two satellites), a high resolution (10m, 20m and 60m) and multi-spectral imagery (13 spectral bands in visible and shortwave infra-red domains). The first sentinel 2A has been launched on June 22nd, 2015, from Kourou, French Guyana. In this context, the Centre National d'Etudes Spatiales (CNES) supports ESA to insure the cal/val commissioning phase, for Image Quality aspects. This paper provides first, an overview of the Sentinel-2 system after the launch. Then the articles focuses on the means implemented and activated in CNES to perform the In Orbit Commissioning, the availability and performances of the different devices involved in the ground segment : the GPP in charge of producing the level 1 files, the "radiometric unit" that processes sensitivity parameters, the "geometric unit" in charge of fitting the images on a reference map, MACCS that will produce Level 2A files (computing reflectances at the Bottom of Atmosphere) and the TEC-S2 that will coordinate all the previous software and drive a database in which will be gather the incoming Level 0 files and the processed Level 1 files.

Sentinel 2: implementation of the means and methods for the CAL/VAL commissioning phase

NASA Astrophysics Data System (ADS)

Trémas, Thierry L.; Déchoz, Cécile; Lacherade, Sophie; Nosavan, Julien; Petrucci, Beatrice; Martimort, P.; Isola, Claudia

2013-10-01

In partnership with the European Commission and in the frame of the Copernicus program, the European Space Agency (ESA) is developing the Sentinel-2 optical imaging mission devoted to the operational monitoring of land and coastal areas. The Sentinel-2 mission is based on a satellites constellation deployed in polar sun-synchronous orbit. Sentinel-2 will offer a unique combination of global coverage with a wide field of view (290km), a high revisit (5 days with two satellites), a high resolution (10m, 20m and 60m) and multi-spectral imagery (13 spectral bands in visible and shortwave infra-red domains). The first satellite is planned to be launched in late 2014. In this context, the Centre National d'Etudes Spatiales (CNES) supports ESA to insure the cal/val commissioning phase. This paper provides first, an overview of the Sentinel-2 system and the image products delivered by the ground processing. Then the paper will present the ground segment, presently under preparation at CNES, and the various devices that compose it : the GPP in charge of producing the level 1 files, the "radiometric unit" that processes sensitivity parameters, the "geometric unit" in charge of fitting the images on a reference map, MACCS that will produce Level 2A files (computing reflectances at the Bottom of Atmosphere) and the TEC-S2 that will coordinate all the previous software and drive a database in which will be gather the incoming Level 0 files and the processed Level 1 files.

Artist Concept of InSight Lander on Mars

NASA Image and Video Library

2014-03-26

This artist's concept depicts the stationary NASA Mars lander known by the acronym InSight at work studying the interior of Mars. The InSight mission (for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) is scheduled to launch in March 2016 and land on Mars six months later. It will investigate processes that formed and shaped Mars and will help scientists better understand the evolution of our inner solar system's rocky planets, including Earth. InSight will deploy two instruments to the ground using a robotic arm: a seismometer (contributed by the French space agency Centre National d'Etudes Spatiales, or CNES) to measure the microscopic ground motions from distant marsquakes, providing detailed information about the interior structure of Mars; and a heat-flow probe (contributed by the German Aerospace Center, or DLR) designed to hammer itself 3 to 5 meters (about 16 feet) deep and monitor heat coming from the planet's interior. The mission will also track the lander's radio to measure wobbles in the planet's rotation that relate to the size of its core and will include a camera and a suite of environmental sensors to monitor the weather and variations in the magnetic field. Lockheed Martin Space Systems, Denver, is building the spacecraft. Note: After thorough examination, NASA managers have decided to suspend the planned March 2016 launch of the Interior Exploration using Seismic Investigations Geodesy and Heat Transport (InSight) mission. The decision follows unsuccessful attempts to repair a leak in a section of the prime instrument in the science payload. http://photojournal.jpl.nasa.gov/catalog/PIA17358

Large structures and temporal change in the Azores Front during the SEMAPHORE experiment

NASA Astrophysics Data System (ADS)

Tychensky, A.; Le Traon, P.-Y.; Hernandez, F.; Jourdan, D.

1998-10-01

The Structure des Echanges Mer-Atmosphere, Proprietes des Heterogeneites Oceaniques: Recherche Experimentale (SEMAPHORE) mesoscale experiment took place from July to November 1993 in the northern Canary Basin, where the circulation is dominated by the eastward flowing Azores Current (AC). A large data set was acquired from three hydrographic arrays (phases 1, 2, 3), current meter moorings, surface drifters drogued at 150 m, and 2000 m deep RAFOS floats. The analysis confirmed the large-scale observations previously made in this region but also provided new insights into fine-scale dynamics of the AC. The front was observed over the 6-month period. It was narrow (100 km) and mostly surface intensified (velocities reaching 40-50 cm s-1). Whereas at the beginning of the experiment (phase 1) the AC was mainly zonal with weak oscillations, large meridional meanders were observed from phase 2 until the end of the experiment. They seem to be related to the arrival of two Mediterranean eddies (Meddies), which interacted with the AC [Käse and Zenk, 1996; Tychensky and Carton, this issue]. The front had a deep dynamical signature (down to 2000 m), with a 16-18 sverdrup (Sv) volume transport (0-2000 m depth integrated). The southward recirculation branch of the AC near 22°-23°W [Klein and Siedler, 1989] corresponds to meridional transport of 5-6 Sv. Then, 4.5 Sv of these waters are recirculating westward (along 31°-32°N). Some interesting new oceanographic results were obtained by examining the RAFOS float trajectories over the abyssal plain. The circulation is similar to that observed at the surface, with mean velocities of about 1-3 cm s-1 and eddy kinetic energy <4 cm2 s-2. In agreement with the analysis of current meter data this reveals a significant barotropic component in the Azores-Madeira flow field of roughly 3-3.5 cm s-1.

Methodologie experimentale pour evaluer les caracteristiques des plateformes graphiques avioniques

NASA Astrophysics Data System (ADS)

Legault, Vincent

Within a context where the aviation industry intensifies the development of new visually appealing features and where time-to-market must be as short as possible, rapid graphics processing benchmarking in a certified avionics environment becomes an important issue. With this work we intend to demonstrate that it is possible to deploy a high-performance graphics application on an avionics platform that uses certified graphical COTS components. Moreover, we would like to bring to the avionics community a methodology which will allow developers to identify the needed elements for graphics system optimisation and provide them tools that can measure the complexity of this type of application and measure the amount of resources to properly scale a graphics system according to their needs. As far as we know, no graphics performance profiling tool dedicated to critical embedded architectures has been proposed. We thus had the idea of implementing a specialized benchmarking tool that would be an appropriate and effective solution to this problem. Our solution resides in the extraction of the key graphics specifications from an inherited application to use them afterwards in a 3D image generation application.

Realisation de composants tout-fibre passifs bases sur des fibres optiques a deux coeurs

NASA Astrophysics Data System (ADS)

Jacob Poulin, Anne C.

2002-01-01

Les composants passifs tout-optique sont des elements de choix dans les systemes de communications optiques. Cette these presente l'utilisation experimentale de fibres a deux coeurs dissimilaires pour la realisation de filtres passe-bande. Les fibres a deux coeurs ont la particularite de favoriser un couplage d'un coeur a l'autre a intervalles reguliers lorsque les coeurs sont exactement identiques. Dans le cas ou une legere difference apparait, ce couplage est rapidement reduit a zero. La premiere partie de la these montre comment, par l'emploi d'une geometrie de fibre appropriee, il est possible de compenser cette desyntonisation et de fabriquer des coupleurs 100%. Les filtres obtenus ayant toutefois une largeur de bande trop grande pour les besoins du marche des communications optiques, il est montre dans la deuxieme partie de la these comment, en alliant la technologie des reseaux de Bragg avec celle des coupleurs, il est possible de realiser des filtres operant en transmission et possedant d'excellentes caracteristiques spectrales, toujours avec ces memes fibres a deux coeurs.

Is the Newborn Individualized Developmental Care and Assessment Program (NIDCAP) effective for preterm infants with intrauterine growth restriction?

PubMed Central

Als, H; Duffy, FH; McAnulty, GB; Fischer, CB; Kosta, S; Butler, SC; Parad, RB; Blickman, JG; Zurakowski, D; Ringer, SA

2014-01-01

Objective This study investigates the effectiveness of the Newborn Individualized Developmental Care and Assessment Program (NIDCAP) on neurobehavioral and electrophysiological functioning of preterm infants with severe intrauterine growth restriction (IUGR). Study Design Thirty IUGR infants, 28 to 33 weeks gestational age, randomized to standard care (control/C = 18), or NIDCAP (experimental/E = 12), were assessed at 2 weeks corrected age (2wCA) and 9 months corrected age (9mCA) in regard to health, anthropometrics, and neurobehavior, and additionally at 2wCA in regard to electrophysiology (EEG). Result The two groups were comparable in health and anthropometrics at 2wCA and 9mCA. The E-group at 2wCA showed significantly better autonomic, motor, and self-regulation functioning, improved motility, intensity and response thresholds, and reduced EEG connectivity among several adjacent brain regions. At 9mCA, the E-group showed significantly better mental performance. Conclusion This is the first study to show NIDCAP effectiveness for IUGR preterm infants. PMID:20651694

The relation of the European Datum to a geocentric reference system

NASA Technical Reports Server (NTRS)

Marsh, J. G.; Douglas, B. C.; Klosko, S. M.

1971-01-01

Over 31,000 precision reduced optical observations of GEOS-1 and 2 in 70 two-day orbital arcs were used at Goddard Space Flight Center (GSFC) in a dynamical solution to determine center-of-mass coordinates for 15 tracking stations on the European Datum. Comparisons with the results obtained at Centre National d'Etudes Spatiales (CNES) give agreement of about 1.5 ppm for chord lengths. After considering a scale correction to the European Datum (ED) of 1950 to account for the absence of geoid heights at the time of its reduction, agreement to a few ppm between the CNES/GSFC and the ED chords is obtained. However, a small systematic difference between survey and satellite results remains for stations in southeastern France and Switzerland.

Electrodialyse inverse. Etude de l'energie electrique obtenue a partir de deux solutions de salinites differentes

NASA Astrophysics Data System (ADS)

Audinos, R.

It is possible to obtain, in the form of electric power, the energy of mixing of two solutions of different salinity by reverse electrodialysis. The laboratory electrodialyzer used was fitted in turn with two different pairs of permselective membranes, AMV-CMV and ARP-CRP. Solutions of ZnSO 4 (216/18.8, 201/34.6, 110/40.2 and 127/14.2 g/l) and of NACl (245/13 and 250/1 g/l) were used in batch recirculation. Only NACl solutions (294/1, 295/1 and 150/1 g/l) were used in continuous flow operation. Results show the influence of type of membrane, composition and concentration of solutions and type of electrode. The maximum power obtained is 400 mW/m 2.

Liftoff of Space Shuttle Columbia on mission STS-93

NASA Technical Reports Server (NTRS)

1999-01-01

The fiery launch of Space Shuttle Columbia casts ghost-like shadows on the clouds of smoke and steam surrounding it. Liftoff occurred at 12:31 a.m. EDT. STS-93 is a five-day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The crew numbers five: Commander Eileen M. Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Stephen A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a Shuttle mission. The target landing date is July 27, 1999, at 11:20 p.m. EDT.

KSC-99pp0952

NASA Image and Video Library

1999-07-23

KENNEDY SPACE CENTER, FLA. -- The fiery launch of Space Shuttle Columbia casts ghost-like shadows on the clouds of smoke and steam surrounding it. Liftoff occurred at 12:31 a.m. EDT. STS-93 is a five-day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The crew numbers five: Commander Eileen M. Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Steven A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a Shuttle mission. The target landing date is July 27, 1999, at 11:20 p.m. EDT

KSC-08pd1296

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- Inside the Astrotech processing facility at Vandenberg Air Force Base, the shipping container is removed from the OSTM/Jason-2 spacecraft. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Mark Mackley

KSC-08pd1299

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- A closeup of the OSTM/Jason-2 spacecraft after removal of the shipping container in the Astrotech processing facility at Vandenberg Air Force Base. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Mark Mackley

KSC-08pd1307

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- Inside the Astrotech processing facility at Vandenberg Air Force Base, a technician oversees the attaching of the OSTM/Jason-2 spacecraft to a tilt dolly. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Mark Mackley

KSC-08pd1066

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. – The shipping container with the OSTM/Jason-2 spacecraft inside is offloaded from the aircraft at Vandenberg Air Force Base in California. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Steve Greenberg, JPL

KSC-08pd1283

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. -- At Vandenberg Air Force Base, the truck carrying the OSTM/Jason-2 satellite is ready to transport the cargo to the Astrotech processing facility. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1298

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- Another view of the OSTM/Jason-2 spacecraft after removal of the shipping container in the Astrotech processing facility at Vandenberg Air Force Base. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Mark Mackley

KSC-08pd1308

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- Inside the Astrotech processing facility at Vandenberg Air Force Base, technicians examine the attachment of the OSTM/Jason-2 spacecraft to a tilt dolly. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Mark Mackley

KSC-08pd1065

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. – The aircraft carrying the OSTM/Jason-2 spacecraft taxis past the Astrotech processing facility at Vandenberg Air Force Base in California. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Stephen Greenberg, JPL

KSC-08pd1305

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- Inside the Astrotech processing facility at Vandenberg Air Force Base, the OSTM/Jason-2 spacecraft is lifted from its stand to be moved to a tilt dolly. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Mark Mackley

KSC-08pd1304

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- Inside the Astrotech processing facility at Vandenberg Air Force Base, technicians check the OSTM/Jason-2 spacecraft before it is moved to a tilt dolly. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Mark Mackley

KSC-08pd1297

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- Inside the Astrotech processing facility at Vandenberg Air Force Base, the OSTM/Jason-2 spacecraft is revealed after removal of the shipping container. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Mark Mackley

KSC-08pd1289

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. -- In front of the Astrotech processing facility at Vandenberg Air Force Base, the OSTM/Jason-2 satellite shipping container is on the ground, ready to be moved inside. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1295

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- Inside the Astrotech processing facility at Vandenberg Air Force Base, the shipping container is removed from the OSTM/Jason-2 spacecraft. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Mark Mackley

KSC-08pd1067

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. – The shipping container with the OSTM/Jason-2 spacecraft inside is offloaded from the aircraft at Vandenberg Air Force Base in California. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Steve Greenberg, JPL

KSC-08pd1280

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. -- The shipping container with the OSTM/Jason-2 spacecraft inside is offloaded from the aircraft at Vandenberg Air Force Base in California. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1310

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- Inside the Astrotech processing facility at Vandenberg Air Force Base, the OSTM/Jason-2 spacecraft is lifted to a vertical position on the tilt dolly. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Mark Mackley

KSC-08pd1309

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- Inside the Astrotech processing facility at Vandenberg Air Force Base, the OSTM/Jason-2 spacecraft is lifted to a near-45-degree angle on the tilt dolly. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Mark Mackley

KSC-08pd1311

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- Inside the Astrotech processing facility at Vandenberg Air Force Base, the OSTM/Jason-2 spacecraft has been lifted to a vertical position on the tilt dolly. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Mark Mackley

KSC-08pd1293

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- Inside the Astrotech processing facility at Vandenberg Air Force Base, an overhead crane is moved over the OSTM/Jason-2 spacecraft to lift off the shipping container. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Mark Mackley

KSC-08pd1288

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. -- In front of the Astrotech processing facility at Vandenberg Air Force Base, a forklift has removed the OSTM/Jason-2 satellite shipping container off the flatbed truck. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1294

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- Inside the Astrotech processing facility at Vandenberg Air Force Base, an overhead crane is attached to the OSTM/Jason-2 spacecraft shipping container to remove it. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Mark Mackley

KSC-08pd1303

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- Inside the Astrotech processing facility at Vandenberg Air Force Base, a technician (right) checks the OSTM/Jason-2 spacecraft before it is moved to a tilt dolly. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Mark Mackley

KSC-08pd1306

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- Inside the Astrotech processing facility at Vandenberg Air Force Base, the OSTM/Jason-2 spacecraft is moved to a tilt dolly. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Mark Mackley

KSC-08pd1287

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. -- In front of the Astrotech processing facility at Vandenberg Air Force Base, a forklift begins to lift the OSTM/Jason-2 satellite shipping container off the flatbed truck. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1279

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. -- The shipping container with the OSTM/Jason-2 spacecraft inside is offloaded from the aircraft at Vandenberg Air Force Base in California. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-99pp0824

NASA Image and Video Library

1999-07-16

STS-93 Mission Specialist Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES), prepares to leave the T-38 jet aircraft that brought him to KSC's Shuttle Landing Facility. He and other crew members Commander Eileen Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Steven A. Hawley (Ph.D.) and Catherine G. "Cady" Coleman (Ph.D.) are arriving for pre-launch activities. Tognini is making his inaugural Shuttle flight. The primary mission of STS-93 is the release of the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected to unlock the secrets of supernovae, quasars and black holes

KSC-99pp0823

NASA Image and Video Library

1999-07-16

STS-93 Pilot Jeffrey S. Ashby lands at Kennedy Space Center's Shuttle Landing Facility (SLF) aboard a T-38 jet aircraft. He and other crew members Commander Eileen Collins and Mission Specialists Steven A. Hawley (Ph.D.), Catherine G. "Cady" Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES), are arriving for pre-launch activities. STS-93 is Ashby's inaugural Shuttle flight. The primary mission of STS-93 is the release of the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected to unlock the secrets of supernovae, quasars and black holes

Etude des trois molecules H 2P-NH 2, ClHP-NH 2, H 2P-NHCl au moyen d'une methode de pseudopotentiels

NASA Astrophysics Data System (ADS)

Barthelat, M.; Mathis, R.; Mathis, F.

The three molecules H 2P-NH 2, ClHP-NH 2 and H 2P-NHCl have been studied by a pseudo-potential method, with a minimal basis of quality mono-zeta, with 3 d functions on the phosphorus atom. The geometry of each molecule was optimized and the phosphorus-nitrogen rotation barrier calculated. The results of the calculations confirm that the polarity of the phosphorus-nitrogen bond is P +-N -. Three weak interactions appear: a partial coordinative bond between the nitrogen doublet and a 3 d orbital of the phosphorus atom, hyperconjugation between the nitrogen doublet and the P-H bonds, and participation of the 3 d orbital of phosphorus in the P-N bond.

Etude de la texture des rubans EPR de silicium polycristallin photovoltaïque

NASA Astrophysics Data System (ADS)

Chibani, A.; Gauthier, R.; Pinard, P.; Andonov, P.

1991-09-01

EPR polysilicon ribbons are obtained from a 5N-6N purity grade silicon powder melting followed by a recrystallization step. Being assigned to the photocell manufacture, we study the texture by X-ray diffraction method to reveal the majority of the crystal orientations and prove the eventual existence of specific orientations adapted to the best photovoltaic conversion efficiencies such as (100), (110) or (111). Moreover, we tested the possibility to induce the (111) orientation with a monocrystalline seed having this orientation. It appears that the crystal growth is essentially anisotropic and that only the orientation of the grains with their (331) planes parallel to the ribbon surface may be considered as dominant after the recrystallization step; finally, the (111) starting seed has an effect only at the recrystallization onset.

Transport de paires EPR dans des structures mesoscopiques

NASA Astrophysics Data System (ADS)

Dupont, Emilie

Dans cette these, nous nous sommes particulierement interesses a la propagation de paires EPR1 delocalisees et localisees, et a l'influence d'un supraconducteur sur le transport de ces paires. Apres une introduction de cette etude, ainsi que du cadre scientifique qu'est l'informatique quantique dans lequel elle s'inscrit, nous allons dans le chapitre 1 faire un rappel sur le systeme constitue de deux points quantiques normaux entoures de deux fils supraconducteurs. Cela nous permettra d'introduire une methode de calcul qui sera reutilisee par la suite, et de trouver egalement le courant Josephson produit par ce systeme transforme en SQUID-dc par l'ajout d'une jonction auxiliaire. Le SQUID permet de mesurer l'etat de spin (singulet ou triplet), et peut etre forme a partir d'autres systemes que nous etudierons ensuite. Dans le chapitre 2, nous rappellerons l'etude detaillee d'un intricateur d'Andreev faite par un groupe de Bale. La matrice T, permettant d'obtenir le courant dans les cas ou les electrons sont separes spatialement ou non, sera etudiee en detail afin d'en faire usage au chapitre suivant. Le chapitre 3 est consacre a l'etude de l'influence du bruit sur le fonctionnement de l'intricateur d'Andreev. Ce bruit modifie la forme du courant jusqu'a aboutir a d'autres conditions de fonctionnement de l'intricateur. En effet, le bruit present sur les points quantiques peut perturber le transport des paires EPR par l'intermediaire des degres de liberte. Nous montrerons que, du fait de l'"intrication" entre la charge de la paire et le bruit, la paire est detruite pour des temps longs. Cependant, le resultat le plus important sera que le bruit perturbe plus le transport des paires delocalisees, qui implique une resonance de Breit-Wigner a deux particules. Le transport parasite n'implique pour sa part qu'une resonance de Breit-Wigner a une particule. Dans le chapitre 4, nous reviendrons au systeme constitue de deux points quantiques entoures de deux fils supraconducteurs, mais ici, les deux points quantiques seront aussi supraconducteurs. On obtiendra alors l'hamiltonien effectif de la meme maniere que precedemment ainsi que la forme du courant. Dans le cas ou la tension entre les deux fils est nulle, nous ferons une comparaison avec l'experience et nous verrons que les resultats obtenus sont plus en accord avec celle-ci si on fait l'hypothese de la presence d'un bain, qui va modeliser le bruit sur l'un des fils. Enfin, dans le dernier chapitre, nous utiliserons a la fois un qubit de charge et un qubit de spin entoures par deux fils supraconducteurs. Nous pourrons alors mesurer l'influence du supraconducteur et voir s'il est possible de creer ici des paires d'electrons intriques et d'aboutir a un pendule quantique. 1Il existe des systemes qui produisent des paires de particules ejectees simultanement dans des directions opposees et qui permettent de tester le paradoxe d' Einstein, Podolsky, Rosen. Chaque particule de la paire est dans un etat indetermine. Si on mesure les etats respectifs des deux particules, on obtient systematiquement des resultats complementaires, soit de facon aleatoire: 0-1 ou 1-0. La mecanique quantique explique que les deux particules ainsi produites constituent un seul systeme, une paire EPR.

Developpement D'un Modele Climatique Regional: Fizr Simulation des Conditions de Janvier de la Cote Ouest Nord Americaine

NASA Astrophysics Data System (ADS)

Goyette, Stephane

1995-11-01

Le sujet de cette these concerne la modelisation numerique du climat regional. L'objectif principal de l'exercice est de developper un modele climatique regional ayant les capacites de simuler des phenomenes de meso-echelle spatiale. Notre domaine d'etude se situe sur la Cote Ouest nord americaine. Ce dernier a retenu notre attention a cause de la complexite du relief et de son controle sur le climat. Les raisons qui motivent cette etude sont multiples: d'une part, nous ne pouvons pas augmenter, en pratique, la faible resolution spatiale des modeles de la circulation generale de l'atmosphere (MCG) sans augmenter a outrance les couts d'integration et, d'autre part, la gestion de l'environnement exige de plus en plus de donnees climatiques regionales determinees avec une meilleure resolution spatiale. Jusqu'alors, les MCG constituaient les modeles les plus estimes pour leurs aptitudes a simuler le climat ainsi que les changements climatiques mondiaux. Toutefois, les phenomenes climatiques de fine echelle echappent encore aux MCG a cause de leur faible resolution spatiale. De plus, les repercussions socio-economiques des modifications possibles des climats sont etroitement liees a des phenomenes imperceptibles par les MCG actuels. Afin de circonvenir certains problemes inherents a la resolution, une approche pratique vise a prendre un domaine spatial limite d'un MCG et a y imbriquer un autre modele numerique possedant, lui, un maillage de haute resolution spatiale. Ce processus d'imbrication implique alors une nouvelle simulation numerique. Cette "retro-simulation" est guidee dans le domaine restreint a partir de pieces d'informations fournies par le MCG et forcee par des mecanismes pris en charge uniquement par le modele imbrique. Ainsi, afin de raffiner la precision spatiale des previsions climatiques de grande echelle, nous developpons ici un modele numerique appele FIZR, permettant d'obtenir de l'information climatique regionale valide a la fine echelle spatiale. Cette nouvelle gamme de modeles-interpolateurs imbriques qualifies d'"intelligents" fait partie de la famille des modeles dits "pilotes". L'hypothese directrice de notre etude est fondee sur la supposition que le climat de fine echelle est souvent gouverne par des forcages provenant de la surface plutot que par des transports atmospheriques de grande echelle spatiale. La technique que nous proposons vise donc a guider FIZR par la Dynamique echantillonnee d'un MCG et de la forcer par la Physique du MCG ainsi que par un forcage orographique de meso-echelle, en chacun des noeuds de la grille fine de calculs. Afin de valider la robustesse et la justesse de notre modele climatique regional, nous avons choisi la region de la Cote Ouest du continent nord americain. Elle est notamment caracterisee par une distribution geographique des precipitations et des temperatures fortement influencee par le relief sous-jacent. Les resultats d'une simulation d'un mois de janvier avec FIZR demontrent que nous pouvons simuler des champs de precipitations et de temperatures au niveau de l'abri beaucoup plus pres des observations climatiques comparativement a ceux simules a partir d'un MCG. Ces performances sont manifestement attribuees au forcage orographique de meso-echelle de meme qu'aux caracteristiques de surface determinees a fine echelle. Un modele similaire a FIZR peut, en principe, etre implante sur l'importe quel MCG, donc, tout organisme de recherche implique en modelisation numerique mondiale de grande echelle pourra se doter d'un el outil de regionalisation.

Caracterisation thermique de modules de refroidissement pour la photovoltaique concentree

NASA Astrophysics Data System (ADS)

Collin, Louis-Michel

Pour rentabiliser la technologie des cellules solaires, une reduction du cout d'exploitation et de fabrication est necessaire. L'utilisation de materiaux photovoltaiques a un impact appreciable sur le prix final par quantite d'energie produite. Une technologie en developpement consiste a concentrer la lumiere sur les cellules solaires afin de reduire cette quantite de materiaux. Or, concentrer la lumiere augmente la temperature de la cellule et diminue ainsi son efficacite. Il faut donc assurer a la cellule un refroidissement efficace. La charge thermique a evacuer de la cellule passe au travers du recepteur, soit la composante soutenant physiquement la cellule. Le recepteur transmet le flux thermique de la cellule a un systeme de refroidissement. L'ensemble recepteur-systeme de refroidissement se nomme module de refroidissement. Habituellement, la surface du recepteur est plus grande que celle de la cellule. La chaleur se propage donc lateralement dans le recepteur au fur et a mesure qu'elle traverse le recepteur. Une telle propagation de la chaleur fournit une plus grande surface effective, reduisant la resistance thermique apparente des interfaces thermiques et du systeme de refroidissement en aval vers le module de refroidissement. Actuellement, aucune installation ni methode ne semble exister afin de caracteriser les performances thermiques des recepteurs. Ce projet traite d'une nouvelle technique de caracterisation pour definir la diffusion thermique du recepteur a l'interieur d'un module de refroidissement. Des indices de performance sont issus de resistances thermiques mesurees experimentalement sur les modules. Une plateforme de caracterisation est realisee afin de mesurer experimentalement les criteres de performance. Cette plateforme injecte un flux thermique controle sur une zone localisee de la surface superieure du recepteur. L'injection de chaleur remplace le flux thermique normalement fourni par la cellule. Un systeme de refroidissement est installe a la surface opposee du recepteur pour evacuer la chaleur injectee. Les resultats mettent egalement en evidence l'importance des interfaces thermiques et les avantages de diffuser la chaleur dans les couches metalliques avant de la conduire au travers des couches dielectriques du recepteur. Des recepteurs de multiples compositions ont ete caracterises, demontrant que les outils developpes peuvent definir la capacite de diffusion thermique. La repetabilite de la plateforme est evaluee par l'analyse de l'etendue des mesures repetees sur des echantillons selectionnes. La plateforme demontre une precision et reproductibilite de +/- 0.14 ° C/W. Ce travail fournit des outils pour la conception des recepteurs en proposant une mesure qui permet de comparer et d'evaluer l'impact thermique de ces recepteurs integres a uri module de refroidissement. Mots-cles : cellule solaire, photovoltaique, transfert de chaleur, concentration, resistances thermiques, plateforme de caracterisation, refroidissement

Les effets des interfaces sur les proprietes magnetiques et de transport des multicouches nickel/iron et cobalt/silver

NASA Astrophysics Data System (ADS)

Veres, Teodor

Cette these est consacree a l'etude de l'evolution structurale des proprietes magnetiques et de transport des multicouches Ni/Fe et nanostructures a base de Co et de l'Ag. Dans une premiere partie, essentiellement bibliographique, nous introduisons quelques concepts de base relies aux proprietes magnetiques et de transport des multicouches metalliques. Ensuite, nous presentons une breve description des methodes d'analyse des resultats. La deuxieme partie est consacree a l'etude des proprietes magnetiques et de transport des multicouches ferromagnetiques/ferromagnetiques Ni/Fe. Nous montrerons qu'une interpretation coherente de ces proprietes necessite la prise en consideration des effets des interfaces. Nous nous attacherons a mettre en evidence, a evaluer et a etudier les effets de ces interfaces ainsi que leur evolution, et ce, suite a des traitements thermiques tel que le depot a temperature elevee et l'irradiation ionique. Les analyses correlees de la structure et de la magnetoresistance nous permettront d'emettre des conclusions sur l'influence des couches tampons entre l'interface et le substrat ainsi qu'entre les couches elles-memes sur le comportement magnetique des couches F/F. La troisieme partie est consacree aux systemes a Magneto-Resistance Geante (MRG) a base de Co et Ag. Nous allons etudier l'evolution de la microstructure suite a l'irradiation avec des ions Si+ ayant une energie de 1 MeV, ainsi que les effets de ces changements sur le comportement magnetique. Cette partie debutera par l'analyse des proprietes d'une multicouche hybride, intermediaire entre les multicouches et les materiaux granulaires. Nous analyserons a l'aide des mesures de diffraction, de relaxation superparamagnetique et de magnetoresistance, les evolutions structurales produites par l'irradiation ionique. Nous etablirons des modeles qui nous aideront a interpreter les resultats pour une serie des multicouches qui couvrent un large eventail de differents comportements magnetiques et ceci en fonction de l'epaisseur de la couche magnetique de Co. Nous verrons que dans ces systemes les effets de l'irradiation ionique sont fortement influences par l'energie de surface ainsi que par l'enthalpie de formation, largement positive pour le systeme Co/Ag.

Consumption of artificially and sugar-sweetened beverages and incident type 2 diabetes in the Etude Epidemiologique aupres des femmes de la Mutuelle Generale de l'Education Nationale-European Prospective Investigation into Cancer and Nutrition cohort.

PubMed

Fagherazzi, Guy; Vilier, Alice; Saes Sartorelli, Daniela; Lajous, Martin; Balkau, Beverley; Clavel-Chapelon, Françoise

2013-03-01

It has been extensively shown, mainly in US populations, that sugar-sweetened beverages (SSBs) are associated with increased risk of type 2 diabetes (T2D), but less is known about the effects of artificially sweetened beverages (ASBs). We evaluated the association between self-reported SSB, ASB, and 100% fruit juice consumption and T2D risk over 14 y of follow-up in the French prospective Etude Epidémiologique auprès des femmes de la Mutuelle Générale de l'Education Nationale-European Prospective Investigation into Cancer and Nutrition cohort. A total of 66,118 women were followed from 1993, and 1369 incident cases of T2D were diagnosed during the follow-up. Cox regression models were used to estimate HRs and 95% CIs for T2D risk. The average consumption of sweetened beverages in consumers was 328 and 568 mL/wk for SSBs and ASBs, respectively. Compared with nonconsumers, women in the highest quartiles of SSB and ASB consumers were at increased risk of T2D with HRs (95% CIs) of 1.34 (1.05, 1.71) and 2.21 (1.56, 3.14) for women who consumed >359 and >603 mL/wk of SSBs and ASBs, respectively. Strong positive trends in T2D risk were also observed across quartiles of consumption for both types of beverage (P = 0.0088 and P < 0.0001, respectively). In sensitivity analyses, associations were partly mediated by BMI, although there was still a strong significant independent effect. No association was observed for 100% fruit juice consumption. Both SSB consumption and ASB consumption were associated with increased T2D risk. We cannot rule out that factors other than ASB consumption that we did not control for are responsible for the association with diabetes, and randomized trials are required to prove a causal link between ASB consumption and T2D.

Fabrication par injection flexible de pieces coniques pour des applications aerospatiales

NASA Astrophysics Data System (ADS)

Shebib Loiselle, Vincent

Les materiaux composites sont presents dans les tuyeres de moteurs spatiaux depuis les annees soixante. Aujourd'hui, l'avenement des tissus tridimensionnels apporte une solution innovatrice au probleme de delamination qui limitait les proprietes mecaniques de ces composites. L'utilisation de ces tissus necessite toutefois la conception de procedes de fabrication mieux adaptes. Une nouvelle methode de fabrication de pieces composites pour des applications aerospatiales a ete etudiee tout au long de ce travail. Celle-ci applique les principes de l'injection flexible (procede Polyflex) a la fabrication de pieces coniques de fortes epaisseurs. La piece de validation a fabriquer represente un modele reduit de piece de tuyere de moteur spatial. Elle est composee d'un renfort tridimensionnel en fibres de carbone et d'une resine phenolique. La reussite du projet est definie par plusieurs criteres sur la compaction et la formation de plis du renfort et sur la formation de porosites de la piece fabriquee. Un grand nombre d'etapes ont ete necessaires avant la fabrication de deux pieces de validation. Premierement, pour repondre au critere sur la compaction du renfort, la conception d'un outil de caracterisation a ete entreprise. L'etude de la compaction a ete effectuee afin d'obtenir les informations necessaires a la comprehension de la deformation d'un renfort 3D axisymetrique. Ensuite, le principe d'injection de la piece a ete defini pour ce nouveau procede. Pour en valider les concepts proposes, la permeabilite du renfort fibreux ainsi que la viscosite de la resine ont du etre caracterisees. A l'aide de ces donnees, une serie de simulations de l'ecoulement pendant l'injection de la piece ont ete realisees et une approximation du temps de remplissage calculee. Apres cette etape, la conception du moule de tuyere a ete entamee et appuyee par une simulation mecanique de la resistance aux conditions de fabrication. Egalement, plusieurs outillages necessaires pour la fabrication ont ete concus et installes au nouveau laboratoire CGD (composites grandes dimensions). En parallele, plusieurs etudes ont ete effectuees pour comprendre les phenomenes influencant la polymerisation de la resine.

Trends in incidence and early outcomes in a Black Afro-Caribbean population from 1999 to 2012: Etude Réalisée en Martinique et Centrée sur l'Incidence des Accidents Vasculaires Cérébraux II Study.

PubMed

Olindo, Stephane; Chausson, Nicolas; Mejdoubi, Mehdi; Jeannin, Severine; Rosillette, Karine; Saint-Vil, Martine; Signate, Aissatou; Edimonana-Kaptue, Mireille; Larraillet, Veronique; Cabre, Philippe; Smadja, Didier; Joux, Julien

2014-11-01

Seldom studies are available on trends in stroke incidence in blacks. We aimed to evaluate whether stroke risk prevention policies modified first-ever stroke incidence and outcomes in the black Afro-Caribbean population of Martinique. Etude Réalisée en Martinique et Centrée sur l'Incidence des Accidents Vasculaires Cérébraux (ERMANCIA) I and II are 2 sequential prospective population-based epidemiological studies. There have assessed temporal trends in first-ever stroke incidence, risk factors, pathological types, and early outcomes in the black Afro-Caribbean population of Martinique comparing two 12-month periods (1998-1999 and 2011-2012). Crude and age-standardized incidence and 30-day outcomes for stroke in the 2 study periods were compared using Poisson regression. We identified 580 and 544 first-ever strokes in the 2 studies. World age-standardized incidence rates decreased by 30.6% in overall (111 [95% confidence interval, 102-120] versus 77 [95% confidence interval, 70-84]). Rate decline was greater in women than in men (34% versus 26%) particularly in women aged 65 to 74 years (-69%) and 75 to 84 years (-43%). Frequencies of hypertension and diabetes mellitus were unchanged, whereas dyslipidemia, smoking, and atrial fibrillation significantly increased. Only ischemic stroke types showed significant rate reduction in overall and in women, incidence rate ratio (95% confidence intervals) of 0.69 (0.50-0.97) and 0.61 (0.42-0.88), respectively. The overall 30-day case-fatality ratio remained stable (19.3%/17.6%), whereas a better 30-day outcome was found (modified Rankin Score, ≤2 in 47%/37.6%; P=0.03). Over 13 years, there has been a significant decrease (30.6%) in the age-specific first-ever stroke incidence in our Afro-Carribean population. Although prevention policies seem effective, we need to focus on new risk factors limitation and on male population adherence to prevention program. © 2014 American Heart Association, Inc.

Processus de modelisation et etude des orages geomagnetiques dans les reseaux electriques: Impact sur le reseau de transport d'Hydro-Quebec

NASA Astrophysics Data System (ADS)

Abdellaoui, Amr

This research project presents a complete modelling process of the effects of GIC on Hydro-Quebec power system network for system planning studies. The advantage of the presented method is that it enables planning engineers to simulate the effects of geomagnetic disturbances on the Hydro-Quebec System under different conditions and contingencies within reasonable calculation time frame. This modelling method of GIC in electric power systems has been applied to the Hydro-Quebec System. An equivalent HQ DC model has been achieved. A numerical calculation method of DC sources from a non-uniform geoelectric field has been developed and implemented on HQ DC model. Harmonics and increased reactive power losses of saturated transformers have been defined as a function of GIC through a binary search algorithm using a chosen HQ magnetization curve. The evolution in time of each transformer saturation according to its effective GIC has been evaluated using analytical formulas. The reactive power losses of saturated transformers have been modeled in PSS/E[1] HQ network as constant reactive current loads assigned to the corresponding transformer buses. Finally, time domain simulations have been performed with PSS/E taking into account transformer saturation times. This has been achieved by integrating HQ DC model results and analytical calculations results of transformer saturation times into an EMTP load model. An interface has been used to link EMTP load model to HQ PSS/E network. Different aspects of GIC effects on the Hydro-Quebec system have been studied, including the influence of uniform and non-uniform geoelectric fields, the comparison of reactive power losses of the 735kV HQ system with those of Montreal network, the risks to voltage levels and the importance of reactive power dynamic reserve. This dissertation presents a new GIC modelling approach for power systems for planning and operations purposes. This methodology could be further enhanced, particularly, the aspect regarding the transformer saturation times. Hence more research remains to be pursued in this area.

Monte Carlo modelling of TRIGA research reactor

NASA Astrophysics Data System (ADS)

El Bakkari, B.; Nacir, B.; El Bardouni, T.; El Younoussi, C.; Merroun, O.; Htet, A.; Boulaich, Y.; Zoubair, M.; Boukhal, H.; Chakir, M.

2010-10-01

The Moroccan 2 MW TRIGA MARK II research reactor at Centre des Etudes Nucléaires de la Maâmora (CENM) achieved initial criticality on May 2, 2007. The reactor is designed to effectively implement the various fields of basic nuclear research, manpower training, and production of radioisotopes for their use in agriculture, industry, and medicine. This study deals with the neutronic analysis of the 2-MW TRIGA MARK II research reactor at CENM and validation of the results by comparisons with the experimental, operational, and available final safety analysis report (FSAR) values. The study was prepared in collaboration between the Laboratory of Radiation and Nuclear Systems (ERSN-LMR) from Faculty of Sciences of Tetuan (Morocco) and CENM. The 3-D continuous energy Monte Carlo code MCNP (version 5) was used to develop a versatile and accurate full model of the TRIGA core. The model represents in detailed all components of the core with literally no physical approximation. Continuous energy cross-section data from the more recent nuclear data evaluations (ENDF/B-VI.8, ENDF/B-VII.0, JEFF-3.1, and JENDL-3.3) as well as S( α, β) thermal neutron scattering functions distributed with the MCNP code were used. The cross-section libraries were generated by using the NJOY99 system updated to its more recent patch file "up259". The consistency and accuracy of both the Monte Carlo simulation and neutron transport physics were established by benchmarking the TRIGA experiments. Core excess reactivity, total and integral control rods worth as well as power peaking factors were used in the validation process. Results of calculations are analysed and discussed.

A mini backscatter lidar for airborne measurements in the framework of DACCIWA

NASA Astrophysics Data System (ADS)

Chazette, Patrick; Totems, Julien; Flamant, Cyrille; Shang, Xiaoxia; Denjean, Cyrielle; Meynadier, Rémi; Perrin, Thierry; Laurens, Marc

2017-04-01

During the international campaign of the European program Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA), investigating the relationship between weather, climate and air pollution in southern West Africa, a mini backscatter lidar was embedded on the French research aircraft (ATR42) of the Service des Avions Français Instrumentés pour la Recherche en Environnement (SAFIRE). This implementation was made possible thanks to the support of the Centre National d'Etude Spatial (CNES), with the aim of assessing the relative relevance of airborne or spaceborne (e.g. Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations, CALIPSO) remote sensing instruments. The lidar complemented the various in-situ observations carried out on the plane, by identifying the aerosol layers in the atmospheric column below the aircraft, and bringing strong constraints for the validation of other measurements. The field campaign took place from 27 to 16 July 2016 from Lomé, Togo. The aircraft conducted flights between 1 km and 5 km above the mean sea level (amsl), allowing the coupling of in situ and remote sensing data to assess the properties of the aerosol layers. Aerosol plumes of different origins were identified using the coupling between the lidar cross-polarized channels, satellite observations and a set of back trajectories analyses. During several flights, depolarizing aerosol layers from the northeast were observed between 2.5 and 4 km amsl, which highlight the significant contribution of dust-like particles to the aerosol load in the coastal region. Conversely, air masses originating from the east-southeast were loaded with a mixing of biomass burning and pollution aerosols. The former originated from Central Africa and the latter from human activities in and around large cities (Lomé). The flight sampling strategy and related lidar investigations will be presented and discussed.

Sentinel-2A image quality commissioning phase final results: geometric calibration and performances

NASA Astrophysics Data System (ADS)

Languille, F.; Gaudel, A.; Dechoz, C.; Greslou, D.; de Lussy, F.; Trémas, T.; Poulain, V.; Massera, S.

2016-10-01

In the frame of the Copernicus program of the European Commission, Sentinel-2 offers multispectral high-spatial-resolution optical images over global terrestrial surfaces. In cooperation with ESA, the Centre National d'Etudes Spatiales (CNES) is in charge of the image quality of the project, and so ensures the CAL/VAL commissioning phase during the months following the launch. Sentinel-2 is a constellation of 2 satellites on a polar sun-synchronous orbit with a revisit time of 5 days (with both satellites), a high field of view - 290km, 13 spectral bands in visible and shortwave infrared, and high spatial resolution - 10m, 20m and 60m. The Sentinel-2 mission offers a global coverage over terrestrial surfaces. The satellites acquire systematically terrestrial surfaces under the same viewing conditions in order to have temporal images stacks. The first satellite was launched in June 2015. Following the launch, the CAL/VAL commissioning phase is then lasting during 6 months for geometrical calibration. This paper will point on observations and results seen on Sentinel-2 images during commissioning phase. It will provide explanations about Sentinel-2 products delivered with geometric corrections. This paper will detail calibration sites, and the methods used for geometrical parameters calibration and will present linked results. The following topics will be presented: viewing frames orientation assessment, focal plane mapping for all spectral bands, results on geolocation assessment, and multispectral registration. There is a systematic images recalibration over a same reference which is a set of S2 images produced during the 6 months of CAL/VAL. This set of images will be presented as well as the geolocation performance and the multitemporal performance after refining over this ground reference.

Sentinel-2 radiometric image quality commissioning: first results

NASA Astrophysics Data System (ADS)

Lachérade, S.; Lonjou, V.; Farges, M.; Gamet, P.; Marcq, S.; Raynaud, J.-L.; Trémas, T.

2015-10-01

In partnership with the European Commission and in the frame of the Copernicus program, the European Space Agency (ESA) is developing the Sentinel-2 optical imaging mission devoted to the operational monitoring of land and coastal areas. The Sentinel-2 mission is based on a satellites constellation deployed in polar sun-synchronous orbit. Sentinel-2 offers a unique combination of global coverage with a wide field of view (290km), a high revisit (5 days with two satellites), a high spatial resolution (10m, 20m and 60m) and multi-spectral imagery (13 spectral bands in visible and shortwave infrared domains). The first satellite, Sentinel-2A, has been launched in June 2015. The Sentinel-2A Commissioning Phase starts immediately after the Launch and Early Orbit Phase and continues until the In-Orbit Commissioning Review which is planned three months after the launch. The Centre National d'Etudes Spatiales (CNES) supports ESA/ESTEC to insure the Calibration/Validation commissioning phase during the first three months in flight. This paper provides first an overview of the Sentinel-2 system and a description of the products delivered by the ground segment associated to the main radiometric specifications to achieve. Then the paper focuses on the preliminary radiometric results obtained during the in-flight commissioning phase. The radiometric methods and calibration sites used in the CNES image quality center to reach the specifications of the sensor are described. A status of the Sentinel-2A radiometric performances at the end of the first three months after the launch is presented. We will particularly address in this paper the results in term of absolute calibration, pixel to pixel relative sensitivity and MTF estimation.

GEISA-97 spectroscopic database system related information resources: current status and perspectives

NASA Astrophysics Data System (ADS)

Chursin, Alexei A.; Jacquinet-Husson, N.; Lefevre, G.; Scott, Noelle A.; Chedin, Alain

2000-01-01

This paper presents the recently developed information content diffusion facilities, e.g. the WWW-server of GEISA, MS DOS, WINDOWS-95/NT, and UNIX software packages, associated with the 1997 version of the GEISA-(Gestion et Etude des Informations Spectroscopiques Atmospheriques; word translation: Management and Study of Atmospheric Spectroscopic Information) infrared spectroscopic databank developed at LMD (Laboratoire de Meteorologie Dynamique, France). GEISA-97 individual lines file involves 42 molecules (96 isotopic species) and contains 1,346,266 entries, between 0 and 22,656 cm-1. GEISA-97 also has a catalog of cross-sections at different temperatures and pressures for species (such as chlorofluorocarbons) with complex spectra. The current version of the GEISA-97 cross- section databank contains 4,716,743 entries related to 23 molecules between 555 and 1700 cm-1.

Projection par plasma de depots de dioxyde de titane: Contribution a l'etude de leurs microstructures et proprietes electriques

NASA Astrophysics Data System (ADS)

Branland, Nadege

2002-04-01

The aim of this PhD work is, thanks to particle parameters (velocity and temperature) characterization, to try to understand the influence of plasma spray parameters on titania coating microstructures and the influence of the latter one on their electrical resistivity, for the same substrate conditions. The experimental approach has consisted in using two plasma spraying processes (Arc plasma spraying and Inductive plasma spraying) which have permitted to obtain a broad range of particle velocities and temperatures leading to coatings with specific microstructures. Despite the stoichiometry of the starting powder, all coatings obtained were grey, the oxygen loss increasing with the particle temperature. Isolating the stoichiometry influence has permitted to show that the decrease of the coatings electrical resistivity is especially due to the decrease of the number of bad interlamellar contacts.

Variations on a theme by chopin: relations between perception and production of timing in music.

PubMed

Repp, B H

1998-06-01

A note interonset interval (IOI) increment in mechanically timed music is more difficult to detect where expressive lengthening typically occurs in artistic performance. Experiment 1 showed this in an excerpt from a Chopin etude and extended the task to IOI decrement detection. A simple measure of variation in perceptual bias was derived that correlated highly with the average timing pattern of pianists' performances, more so than with acoustic surface properties of the music. Similar results, but decreasing correlations, were obtained in each of four subsequent experiments in which the music was simplified in stages. Although local psychoacoustic effects on time perception cannot be ruled out completely, the results suggest that musical structure (melodic-rhythmic grouping in particular) has temporal implications that are reflected not only in musicians' motor behavior but also in listeners' time-keeping abilities.

Special Course on Unstructured Grid Methods for Advection Dominated Flows (Les Methodes Utilisant un Maillage non Structure Pour l’Etude des Ecoulements Caracterises par l’Advection)

DTIC Science & Technology

1992-05-01

gvfl.nds. where [ý nS.VUJ denotes the jump in the F quantity • ns.VU across a triangle side S where b and i are defined by (1.11) with (in the interior of...error estimate for (1.12) recalling that i = (2.1b) u = 0o n P ,x I, max(C 2 hR(U)/ I VU I , h3/2): (2.Ic) u(.,0) u in le, ’ Theorem 1.1. There is a...8217"..< tn <"" tN -= IF be a sequence of discrete time levels, set We note that by (I. 16d) the quantity I/ = (tni, t.n+1 ), k1 = t+ I - t.n and E(h,U,f

KSC-08pd1312

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- Inside the Astrotech processing facility at Vandenberg Air Force Base, the OSTM/Jason-2 spacecraft is viewed from another angle after being lifted to a vertical position on the tilt dolly. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Mark Mackley

KSC-08pd1606

NASA Image and Video Library

2008-05-05

VANDENBERG AIR FORCE BASE, Calif. -- The Delta II second stage is transported onto Space Launch Complex 2 at Vandenberg Air Force Base in California. It will be lifted into the mobile service tower and installed on the first stage for launch of the OSTM/Jason-2 spacecraft. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched on June 20. Photo credit: NASA

KSC-08pd1080

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. – After being offloaded from the cargo plane, the shipping container holding the OSTM/Jason-2 satellite is moved away from the plane. The satellite will be taken to the Astrotech processing facility. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Steve Greenberg, JPL

KSC-08pd1615

NASA Image and Video Library

2008-05-05

VANDENBERG AIR FORCE BASE, Calif. -- On Space Launch Complex 2 at Vandenberg Air Force Base in California, the Delta II second stage is lowered inside the mobile service tower toward the first stage. The second stage will be mated to the first stage for launch of the OSTM/Jason-2 spacecraft. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched on June 20. Photo credit: NASA

KSC-08pd1082

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. – Workers prepare to move the shipping container holding the OSTM/Jason-2 satellite onto a flatbed truck at Vandenberg Air Force Base. The satellite will be transported to the Astrotech processing facility. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Steve Greenberg, JPL

KSC-08pd1610

NASA Image and Video Library

2008-05-05

VANDENBERG AIR FORCE BASE, Calif. -- Suspended vertically, the Delta II second stage is ready to be lifted into the mobile service tower on Space Launch Complex 2 at Vandenberg Air Force Base in California. The second stage will be installed on the first stage for launch of the OSTM/Jason-2 spacecraft. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched on June 20. Photo credit: NASA

KSC-08pd1282

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. -- Workers move the shipping container holding the OSTM/Jason-2 satellite on a flatbed truck at Vandenberg Air Force Base. The satellite will be transported to the Astrotech processing facility. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1327

NASA Image and Video Library

2008-04-25

VANDENBERG AIR FORCE BASE, Calif. -- On Space Launch Complex 2 at Vandenberg Air Force Base in California, workers center the Delta II first stage for the OSTM/Jason-2 spacecraft above the launcher in the umbilical tower. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1328

NASA Image and Video Library

2008-04-25

VANDENBERG AIR FORCE BASE, Calif. -- On Space Launch Complex 2 at Vandenberg Air Force Base in California, workers attach the Delta II first stage for the OSTM/Jason-2 spacecraft to the launcher in the umbilical tower. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1301

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- Inside the Astrotech processing facility at Vandenberg Air Force Base, workers attach an overhead crane to the OSTM/Jason-2 spacecraft. The spacecraft will be moved to a tilt dolly. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Mark Mackley

KSC-08pd1281

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. -- Workers prepare to move the shipping container holding the OSTM/Jason-2 satellite onto a flatbed truck at Vandenberg Air Force Base. The satellite will be transported to the Astrotech processing facility. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1614

NASA Image and Video Library

2008-05-05

VANDENBERG AIR FORCE BASE, Calif. -- On Space Launch Complex 2 at Vandenberg Air Force Base in California, the Delta II second stage is lowered inside the mobile service tower toward the first stage. The second stage will be mated to the first stage for launch of the OSTM/Jason-2 spacecraft. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched on June 20. Photo credit: NASA

KSC-08pd1286

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. -- At Vandenberg Air Force Base, workers remove the straps holding the OSTM/Jason-2 satellite shipping container on the flatbed truck. The container will be moved inside the Astrotech processing facility at right. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1084

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. – Workers adjust the shipping container holding the OSTM/Jason-2 satellite after its placement on the flatbed truck at Vandenberg Air Force Base. The satellite will be transported to the Astrotech processing facility. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Steve Greenberg, JPL

KSC-08pd1083

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. – Workers check the shipping container holding the OSTM/Jason-2 satellite after its placement on the flatbed truck at Vandenberg Air Force Base. The satellite will be transported to the Astrotech processing facility. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Steve Greenberg, JPL

KSC-08pd1300

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- Inside the Astrotech processing facility at Vandenberg Air Force Base, an overhead crane is being attached to the OSTM/Jason-2 spacecraft. The spacecraft will be moved to a tilt dolly. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Mark Mackley

KSC-08pd1086

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. – Ground support equipment associated with the OSTM/Jason-2 satellite is placed on a flatbed truck at Vandenberg Air Force Base. The equipment will accompany the satellite to the Astrotech processing facility. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Steve Greenberg, JPL

KSC-08pd1302

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- Inside the Astrotech processing facility at Vandenberg Air Force Base, technicians attach an overhead crane to the OSTM/Jason-2 spacecraft. The spacecraft will be moved to a tilt dolly. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Mark Mackley

KSC-08pd1608

NASA Image and Video Library

2008-05-05

VANDENBERG AIR FORCE BASE, Calif. -- Workers on Space Launch Complex 2 at Vandenberg Air Force Base in California maneuver the transporter with the Delta II second stage into place. It will be lifted into the mobile service tower and installed on the first stage for launch of the OSTM/Jason-2 spacecraft. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched on June 20. Photo credit: NASA

KSC-08pd1079

NASA Image and Video Library

2008-04-29

VANDENBERG AIR FORCE BASE, Calif. – After arrival of the cargo plane, the shipping container holding the OSTM/Jason-2 satellite is offloaded at Vandenberg Air Force Base. The satellite will be taken to the Astrotech processing facility. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Steve Greenberg, JPL

KSC-08pd1611

NASA Image and Video Library

2008-05-05

VANDENBERG AIR FORCE BASE, Calif. -- Workers on Space Launch Complex 2 at Vandenberg Air Force Base in California place protective covers over the engine of the Delta II second stage. It will be lifted into the mobile service tower for installation on the first stage for launch of the OSTM/Jason-2 spacecraft. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched on June 20. Photo credit: NASA

KSC-08pd1326

NASA Image and Video Library

2008-04-25

VANDENBERG AIR FORCE BASE, Calif. -- On Space Launch Complex 2 at Vandenberg Air Force Base in California, the Delta II first stage for the OSTM/Jason-2 spacecraft is moved into place above the launcher in the umbilical tower. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-99pp0861

NASA Image and Video Library

1999-07-19

The Rotating Service Structure is rolled back from Space Shuttle Columbia on Launch Pad 39-B, in preparation for launch of mission STS-93 July 20 at 12:36 a.m. EDT. The primary payload of STS-93 is the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected unlock the secrets of supernovae, quasars and black holes. The STS-93 crew numbers five: Commander Eileen M. Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Steven A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a shuttle mission

KSC-99pp0825

NASA Image and Video Library

1999-07-16

STS-93 Mission Specialist Catherine G. "Cady" Coleman (Ph.D.) shows her sense of humor upon arriving at KSC's Shuttle Landing Facility aboard a T-38 jet aircraft. She and other crew members Commander Eileen Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Steven A. Hawley (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES), are arriving for pre-launch activities. Coleman is making her second Shuttle flight. The primary mission of STS-93 is the release of the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected to unlock the secrets of supernovae, quasars and black holes

KSC-06pd0755

NASA Image and Video Library

2006-04-28

VANDENBERG AIR FORCE BASE, CALIF. - CloudSat and CALIPSO ¯ Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations ¯ thunders skyward after launch at approximately 6:02 a.m. EDT atop a Boeing Delta II rocket. The two satellites will eventually circle approximately 438 miles above Earth in a sun-synchronous polar orbit, which means they will always cross the equator at the same local time. Their technologies will enable scientists to study how clouds and aerosols form, evolve and interact. CloudSat is managed by NASA's Jet Propulsion Laboratory, in Pasadena, Calif. JPL developed the radar instrument with hardware contributions from the Canadian Space Agency. CALIPSO is collaboration between NASA and France's Centre National d'Etudes Spatiales (CNES). Langley Research Center, in Hampton, Va., is leading the CALIPSO mission and providing overall project management, systems engineering, and payload mission operations. Photo credit: Boeing/Thom Baur

KSC-99pp0626

NASA Image and Video Library

1999-06-04

STS-93 Mission Specialists Catherine Coleman (left) and Michel Tognini of France (right), representing the Centre National d'Etudes Spatiales (CNES), look over material on the mission payload behind them, the Chandra X-ray Observatory. Chandra is being mated with the Inertial Upper Stage (IUS) before testing to validate the IUS/Chandra connections and to check the orbiter avionics interfaces. Following that, an end-to-end test (ETE) will be conducted to verify the communications path to Chandra, commanding it as if it were in space. With the world's most powerful X-ray telescope, Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 22 aboard Space Shuttle Columbia, on mission STS-93

KSC-99pp0627

NASA Image and Video Library

1999-06-04

STS-93 Mission Specialists Catherine Coleman (left) and Michel Tognini of France (right), who represents the Centre National d'Etudes Spatiales (CNES), look over the controls for the Chandra X-ray Observatory. Chandra is being mated with the Inertial Upper Stage (IUS) before testing to validate the IUS/Chandra connections and to check the orbiter avionics interfaces. Following that, an end-to-end test (ETE) will be conducted to verify the communications path to Chandra, commanding it as if it were in space. With the world's most powerful X-ray telescope, Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 22 aboard Space Shuttle Columbia, on mission STS-93

Comparison of experimental proton-induced fluorescence spectra for a selection of thin high-Z samples with Geant4 Monte Carlo simulations

NASA Astrophysics Data System (ADS)

Incerti, S.; Barberet, Ph.; Dévès, G.; Michelet, C.; Francis, Z.; Ivantchenko, V.; Mantero, A.; El Bitar, Z.; Bernal, M. A.; Tran, H. N.; Karamitros, M.; Seznec, H.

2015-09-01

The general purpose Geant4 Monte Carlo simulation toolkit is able to simulate radiative and non-radiative atomic de-excitation processes such as fluorescence and Auger electron emission, occurring after interaction of incident ionising radiation with target atomic electrons. In this paper, we evaluate the Geant4 modelling capability for the simulation of fluorescence spectra induced by 1.5 MeV proton irradiation of thin high-Z foils (Fe, GdF3, Pt, Au) with potential interest for nanotechnologies and life sciences. Simulation results are compared to measurements performed at the Centre d'Etudes Nucléaires de Bordeaux-Gradignan AIFIRA nanobeam line irradiation facility in France. Simulation and experimental conditions are described and the influence of Geant4 electromagnetic physics models is discussed.

KSC-08pd1797

NASA Image and Video Library

2008-06-20

PASADENA, Calif. – A Delta II rocket carrying the Ocean Surface Topography Mission/Jason 2 satellite, is prepared for launch at Space Launch Complex 2 at Vandenberg Air Force Base, Calif. The OSTM/Jason 2 satellite will embark on a globe-circling voyage to continue charting sea level, a vital indicator of global climate change. The mission will return a vast amount of new data that will improve weather, climate and ocean forecasts. OSTM/Jason 2's expected lifetime of at least three years will extend into the next decade the continuous record of these data started in 1992 by NASA and the French space agency Centre National d'Etudes Spatiales, or CNES, with the TOPEX/Poseidon mission. The data collection was continued by the two agencies on Jason 1 in 2001. Photo credit: Carleton Bailie photograph for United Launch Alliance

Teaching and learning the geological knowledge as a part of the science education general field

NASA Astrophysics Data System (ADS)

Aguirre-Pérez, Constancio

2010-05-01

Since the early 50s of last century the Teaching of Science has undergone a process of continuous development, (Gutiérrez, 1987; Aliberas, Gutierrez and Izquierdo, 1989) to become a scientific discipline largely accepted as such by many different universities worldwide. Besides, the proliferation of publications, magazines, conferences, symposia, meetings, and so on, proves this assertion. In these publications and meetings the Teaching of Science (or Science Education in more general terms) is addressed as a new field of research, teaching and educational innovation focused on the processes of teaching and learning of the experimental sciences (all of them: Physics, Chemistry, Biology and Geology). The study of this discipline is undertaken from different pedagogical, epistemological, psychological and sociological approaches. From this general perspective we can say that over the last two decades each of the sciences has developed specific characteristics so that, today, we could speak about specific didactics for each one of them. In the case of Geology (or Geoscience) Teaching there have been significant contributions from the following fields of research: the students' prior ideas (constructivist approach), the history of geology (as a subject-specific field) and from epistemology (Pedrinaci, E. 2000). The body of geoscience knowledge has an internal logic (as happens with the other science subjects) that allows us to organize the contents to teach, selecting, arranging and establishing proper relations between them. Still geology has a central, transverse, inter-and transdisciplinary character for its relationship with the other sciences. This character makes it appear as one of the disciplines with a huge potential to combine different methodologies of teaching and learning and different learning models already tested in the research field of Physics, Chemistry or Biology Education. Moreover, the most recent term coined for it "geosciences or earth and space sciences" emphasizes still further such character receiving the contributions of physics, chemistry, biology and environmental science in a kind of scientific-technical mixture which enriches the discipline itself and constitutes a fundamental basis for the evolution of knowledge in its broadest sense (Martinez Frias et al. 2008). In this paper we propose to show some of the experiences and didactic innovations in the teaching of geology found in the scientific literature in recent years and likewise part of an author's own work on the establishment of analogies on the time variable based on Carl Sagan's cosmic calendar. With these analogies we try to approximate geologic times to the understanding of high school and first university courses students (Aguirre-Perez, C. 2008) REFERENCES ALIBERAS, J. GUTIÉRREZ, R. and IZQUIERDO, M. (1989). La Didáctica de las Ciencias: Una empresa racional. Enseñanza de las Ciencias, 7 (3), pp. 227-284. GUTIÉRREZ, R. (1987). Psicología y aprendizaje de las Ciencias. El modelo de Ausubel. Enseñanza de las Ciencias, 5 (2), pp. 118-128. MARTÍNEZ FRÍAS, J. LUNAR, R. RODRÍGUEZ-LOSADA, J.A. EFF-DARWICH, A. and MADERO JARABO, J. (2008)"La Geología en la exploración planetaria (Geology inplanetary exploration). Geo-temas 10, pp. 1621-1624. PEDRINACI, E. (2000): La Enseñanza y el aprendizaje del conocimiento geológico. Didáctica de las Ciencias Experimentales. Teoría y Práctica de la Enseñanza de las ciencias, pp. 479-503. Ed. Marfil.

Estudio ab initio del mecanismo de la reacción HSO + O3

NASA Astrophysics Data System (ADS)

Nebot Gil, I.

La reacción entre el radical HSO y el ozono ha sido ampliamente estudiada desde el punto de vista experimental debido a la importancia que tiene el radical HSO en la oxidación de los compuestos de azufre reductores y a que puede contribuir a la producción de H2SO4 [1-4]. Se realizaron diversos estudios teóricos sobre la cinética de la reacción entre el radical HSO y el ozono. La reacción del HSO con el ozono presenta tres canales diferentes : HSO + O3 &rightarrow &HSO2 + O2 &rightarrow &HS + 2 O2 &rightarrow &SO + OH + O2 La controversia existente entre los grupos experimentales sobre cuál de las tres vías es la predominante, se ha resuelto mediante un estudio teórico de todas ellas utilizando métodos ab initio. La estructura de todos los reactivos, productos, intermedios y estados de transición ha sido optimizada a nivel ab initio utilizando los métodos UMP2 /6-31G** y QCISD/6-31G**.

Consequences experimentales des effets des fluctuations du vide sur la fluorescence parametrique et la generation du second harmonique en milieu confine

NASA Astrophysics Data System (ADS)

Robichaud, Luc

Les fluctuations du vide, qui consistent en l'apparition momentanee de particules, ce qui est permit par le principe d'incertitude de Heisenberg, joue un role primordial dans les processus photoniques, en particulier les processus non-lineaires. Par la manipulation de ces fluctuations du vide a l'aide de confinement optique, on retrouve deux phenomenes particuliers : l'intensification de la fluorescence parametrique (Walker, 2008) et l'inhibition de la generation du second harmonique (Collette, 2013). Dans ce travail, on presente les resultats dans le cas classique ; c'est-a-dire sans fluctuations du vide et confinement. Par la suite, on presente les effets des fluctuations du vide et du confinement, ce qui mene aux deux effets mentionnes. Dans le cas de la fluorescence parametrique, le bruit quantique sur le champ interne et externe est calcule, le role du desaccord de phase dans le modele est expose et une generalisation tridimensionnelle est etudiee afin de generaliser la conception du modele d'un cas unidimensionnel a un cas tridimensionnel planaire. Dans le cas de la generation du second harmonique, les difficultes d'un modele purement tridimensionnel sont exposees et ensuite le cas limite planaire est etudie.

Un environnement d'apprentissage technologique pour la comprehension du concept de mesure en sciences experimentales

NASA Astrophysics Data System (ADS)

Fournier, Frederic

The learning environment created during this research/development constitutes a micro-laboratory allowing students at the secondary and collegial level to build a measurement system. This approach based on the concrete manufacture of measuring instruments showed that the student did not only acquire knowledge, but he developed a know-how in the technology of measuring systems and also a know-how and knowledge in experimental sciences. In conceptualizing and building his own measurement system, in a computer-assisted experimental environmental, the student performs a scientific investigation in which he must induce a causal relationship between the different variables at stake. He must then isolate this relationship by building a scheme for the control of the variables and model it in an algebraic and graphic form. We believe that this approach will allow the students to better understand the physical phenomena they will be measuring. The prototypes and software used to build these measuring instruments were evaluated and redesigned at the functional and didactic levels in order to offer a learning environment that respects in every way the competence approach and the integration between science and technology.

Cinética Química: el laboratorio

NASA Astrophysics Data System (ADS)

Cabañas Galán, B.

La interpretación de las transformaciones químicas que se producen en la atmósfera requiere un profundo conocimiento de la cinética, productos y mecanismos de reacción de las posibles interacciones que pueden ocurrir entre las distintas especies presentes en ella. Información cuantitativa de este tipo es un prerrequisito para la construcción de modelos numéricos adecuados que expliquen el comportamiento químico-físico de la atmósfera. Esta información se obtiene a partir de experimentos realizados en laboratorios y por tanto independiente de medidas atmosféricas, por lo que los modelos atmosféricos derivados de ellos, pueden usarse para diagnosticar y predecir adecuadamente el comportamiento atmosférico. En esta exposición se recogen las técnicas experimentales más extendidas para la obtención de datos cinéticos así como los métodos de análisis de datos más utilizados en el estudio de las distintas reacciones de interés atmosférico. Se analizan sus características generales así como su adecuación a los distintos tipos de reacciones.

Caracterisation pratique des systemes quantiques et memoires quantiques auto-correctrices 2D

NASA Astrophysics Data System (ADS)

Landon-Cardinal, Olivier

Cette these s'attaque a deux problemes majeurs de l'information quantique: - Comment caracteriser efficacement un systeme quantique? - Comment stocker de l'information quantique? Elle se divise done en deux parties distinctes reliees par des elements techniques communs. Chacune est toutefois d'un interet propre et se suffit a elle-meme. Caracterisation pratique des systemes quantiques. Le calcul quantique exige un tres grand controle des systemes quantiques composes de plusieurs particules, par exemple des atomes confines dans un piege electromagnetique ou des electrons dans un dispositif semi-conducteur. Caracteriser un tel systeme quantique consiste a obtenir de l'information sur l'etat grace a des mesures experimentales. Or, chaque mesure sur le systeme quantique le perturbe et doit done etre effectuee apres avoir reprepare le systeme de facon identique. L'information recherchee est ensuite reconstruite numeriquement a partir de l'ensemble des donnees experimentales. Les experiences effectuees jusqu'a present visaient a reconstruire l'etat quantique complet du systeme, en particulier pour demontrer la capacite de preparer des etats intriques, dans lesquels les particules presentent des correlations non-locales. Or, la procedure de tomographie utilisee actuellement n'est envisageable que pour des systemes composes d'un petit nombre de particules. Il est donc urgent de trouver des methodes de caracterisation pour les systemes de grande taille. Dans cette these, nous proposons deux approches theoriques plus ciblees afin de caracteriser un systeme quantique en n'utilisant qu'un effort experimental et numerique raisonnable. - La premiere consiste a estimer la distance entre l'etat realise en laboratoire et l'etat cible que l'experimentateur voulait preparer. Nous presentons un protocole, dit de certification, demandant moins de ressources que la tomographie et tres efficace pour plusieurs classes d'etats importantes pour l'informatique quantique. - La seconde approche, dite de tomographie variationnelle, propose de reconstruire l'etat en restreignant l'espace de recherche a une classe variationnelle plutot qu'a l'immense espace des etats possibles. Un etat variationnel etant decrit par un petit nombre de parametres, un petit nombre d'experiences peut suffire a identifier les parametres variationnels de l'etat experimental. Nous montrons que c'est le cas pour deux classes variationnelles tres utilisees, les etats a produits matriciels (MPS) et l'ansatz pour intrication multi-echelle (MERA). Memoires quantiques auto-correctrices 2D. Une memoire quantique auto-correctrice est un systeme physique preservant de l'information quantique durant une duree de temps macroscopique. Il serait done l'equivalent quantique d'un disque dur ou d'une memoire flash equipant les ordinateurs actuels. Disposer d'un tel dispositif serait d'un grand interet pour l'informatique quantique. Une memoire quantique auto-correctrice est initialisee en preparant un etat fondamental, c'est-a-dire un etat stationnaire de plus basse energie. Afin de stocker de l'information quantique, il faut plusieurs etats fondamentaux distincts, chacun correspondant a une valeur differente de la memoire. Plus precisement, l'espace fondamental doit etre degenere. Dans cette these, on s'interesse a des systemes de particules disposees sur un reseau bidimensionnel (2D), telles les pieces sur un echiquier, qui sont plus faciles a realiser que les systemes 3D. Nous identifions deux criteres pour l'auto-correction: - La memoire quantique doit etre stable face aux perturbations provenant de l'environnement, par exemple l'application d'un champ magnetique externe. Ceci nous amene a considerer les systemes topologiques 2D dont les degres de liberte sont intrinsequement robustes aux perturbations locales de l'environnement. - La memoire quantique doit etre robuste face a un environnement thermique. Il faut s'assurer que les excitations thermiques n'amenent pas deux etats fondamentaux distincts vers le meme etat excite, sinon l'information aura ete perdue. Notre resultat principal montre qu'aucun systeme topologique 2D n'est auto-correcteur: l'environnement peut changer l'etat fondamental en deplacant aleatoirement de petits paquets d'energie, un mecanisme coherent avec l'intuition que tout systeme topologique admet des excitations localisees ou quasiparticules. L'interet de ce resultat est double. D'une part, il oriente la recherche d'un systeme auto-correcteur en montrant qu'il doit soit (i) etre tridimensionnel, ce qui est difficile a realiser experimentalement, soit (ii) etre base sur des mecanismes de protection nouveaux, allant au-dela des considerations energetiques. D'autre part, ce resultat constitue un premier pas vers la demonstration formelle de l'existence de quasiparticules pour tout systeme topologique.

Study of the Disintegration Process and of the Angular Moments of the Excited Levels of Pm-147 Using Spectrographic and Angular Correlation Measurements (thesis); ETUDE DU SCHEMA DE DESINTEGRATION ET DES MOMENTS ANGULAIRES DES NIVEAUX EXCITES DU Pm 147 PAR DES MESURES DE SPECTROGRAPHIE ET DE CORRELATIONS ANGULAIRES (these)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Philis, C.

1963-07-01

The energies and relative intensities of fifteen gamma lines were determined by a direct spectrographic study. A previously unreported level at 77 plus or minus 2 kev was identified. A coincidence study confirmed the positions of the excited levels of Pm/sup 147/. The 77-kev line was laced between the 409 and 490-kev levels. Angular correlation measurements permitted the assignment of angular moments of 5/2, 7/2, and 5/2 to the 92, 409, and 532-kev levels and of 5/2 or 7/2 to the 685-kev level. The associated mixing coefficients were also obtained. (D.C.W.)

Study of Pulsed Columns with the System. Uranyl Nitrate-Nitric Acid-Water- Tributylphosphate; ETUDE DES COLONNES A PULSATIONS A L'AIDE DU SYSTEME NITRATE D'URANYLE-ACIDE NITRIQUEEAU-TRIBUTYLPHOSPHATE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Durandet, J.; Defives, D.; Choffe, B.

1959-10-31

The performsnce of a pulsed column with perforated plates was studied with the aid of a uranyl nitrate-nitric acid --water --tributyl phosphate system. The extraction of uranium from an aqueous acidic solution by an organic solvent and the extraction of uranium from organic solutions by water were the two cases investigated. The variation of the efficiency and the capacity of the pulsed column was determined as a function of the pulse amplitude and frequency, of the total flow rate, of the diameter of the holes, and of the choice of dispersed phase. The results showed that for a given amplitudemore » and total flow rate the efficiency has a maximum with an increase in frequency. (J.S.R.)« less

KSC-08pd1613

NASA Image and Video Library

2008-05-05

VANDENBERG AIR FORCE BASE, Calif. -- On Space Launch Complex 2 at Vandenberg Air Force Base in California, the Delta II second stage is lowered inside the mobile service tower toward the opening above the first stage. The second stage will be mated to the first stage for launch of the OSTM/Jason-2 spacecraft. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched on June 20. Photo credit: NASA

KSC-99pc0185

NASA Image and Video Library

1999-02-09

In the Solid Motor Assembly Building, Cape Canaveral Air Station, looking over the Inertial Upper Stage booster being readied for their mission are (left to right) STS-93 Pilot Jeffrey S. Ashby and Mission Specialists Michel Tognini, who represents the Centre National d'Etudes Spatiales (CNES), and Steven A. Hawley. On the far right is Eric Herrburger, with Boeing. Other crew members (not shown) are Commander Eileen Collins and Mission Specialist Catherine G. Coleman. STS-93, scheduled to launch July 9 aboard Space Shuttle Columbia, has the primary mission of the deployment of the Chandra X-ray Observatory. Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

KSC-99pc0187

NASA Image and Video Library

1999-02-09

In the Solid Motor Assembly Building, Cape Canaveral Air Station, STS-93 Mission Specialist Catherine G. Coleman kneels next to the Inertial Upper Stage booster being readied for the mission. Other crew members (not shown) are Commander Eileen Collins, Pilot Jeffrey S. Ashby and Mission Specialists Steven A. Hawley and Michel Tognini of France, who represents the Centre National d'Etudes Spatiales (CNES). STS-93, scheduled to launch July 9 aboard Space Shuttle Columbia, has the primary mission of the deployment of the Chandra X-ray Observatory. Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

KSC-99pc0186

NASA Image and Video Library

1999-02-09

In the Solid Motor Assembly Building, Cape Canaveral Air Station, STS-93 Pilot Jeffrey S. Ashby and Mission Specialist Steven A. Hawley look over the Inertial Upper Stage booster being readied for their mission. Other crew members (not shown) are Commander Eileen Collins and Mission Specialists Catherine G. Coleman and Michel Tognini of France, who represents the Centre National d'Etudes Spatiales (CNES). STS-93, scheduled to launch July 9 aboard Space Shuttle Columbia, has the primary mission of the deployment of the Chandra X-ray Observatory. Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

Mini 3D for shallow gas reconnaissance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vallieres, T. des; Enns, D.; Kuehn, H.

1996-12-31

The Mini 3D project was undertaken by TOTAL and ELF with the support of CEPM (Comite d`Etudes Petrolieres et Marines) to define an economical method of obtaining 3D seismic HR data for shallow gas assessment. An experimental 3D survey was carried out with classical site survey techniques in the North Sea. From these data 19 simulations, were produced to compare different acquisition geometries ranging from dual, 600 m long cables to a single receiver. Results show that short offset, low fold and very simple streamer positioning are sufficient to give a reliable 3D image of gas charged bodies. The 3Dmore » data allow a much more accurate risk delineation than 2D HR data. Moreover on financial grounds Mini-3D is comparable in cost to a classical HR 2D survey. In view of these results, such HR 3D should now be the standard for shallow gas surveying.« less

KARIN: The Ka-Band Radar Interferometer for the Proposed Surface Water and Ocean Topography (SWOT) Mission

NASA Technical Reports Server (NTRS)

Esteban-Fernandez, Daniel; Peral, Eva; McWatters, Dalia; Pollard, Brian; Rodriguez, Ernesto; Hughes, Richard

2013-01-01

Over the last two decades, several nadir profiling radar altimeters have provided our first global look at the ocean basin-scale circulation and the ocean mesoscale at wavelengths longer than 100 km. Due to sampling limitations, nadir altimetry is unable to resolve the small wavelength ocean mesoscale and sub-mesoscale that are responsible for the vertical mixing of ocean heat and gases and the dissipation of kinetic energy from large to small scales. The proposed Surface Water and Ocean Topography (SWOT) mission would be a partnership between NASA, CNES (Centre National d'Etudes Spaciales) and the Canadian Space Agency, and would have as one of its main goals the measurement of ocean topography with kilometer-scale spatial resolution and centimeter scale accuracy. In this paper, we provide an overview of all ocean error sources that would contribute to the SWOT mission.

KSC-08pd1317

NASA Image and Video Library

2008-04-25

VANDENBERG AIR FORCE BASE, Calif. -- At Vandenberg Air Force Base in California, workers on Space Launch Complex 2 prepare to raise the Delta II first stage of the OSTM/Jason-2 spacecraft. Once it is vertical, the first stage will be transferred into the mobile service tower. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1320

NASA Image and Video Library

2008-04-25

VANDENBERG AIR FORCE BASE, Calif. -- At Vandenberg Air Force Base in California, the Delta II first stage is being raised to a vertical position in front of the mobile service tower on Space Launch Complex 2. Once it is vertical, the first stage will be transferred into the tower. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1318

NASA Image and Video Library

2008-04-25

VANDENBERG AIR FORCE BASE, Calif. -- At Vandenberg Air Force Base in California, workers prepare the equipment on Space Launch Complex 2 to raise the Delta II first stage of the OSTM/Jason-2 spacecraft. Once it is vertical, the first stage will be transferred into the mobile service tower. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1340

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- On Space Launch Complex 2 at Vandenberg Air Force Base in California, the second solid rocket motor, or SRM, is moved into place alongside the Delta II first stage. The Delta II is the launch vehicle for the OSTM/Jason-2 spacecraft. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1333

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- On Space Launch Complex 2 at Vandenberg Air Force Base in California, a solid rocket motor, or SRM, is lifted alongside the mobile service tower. The SRM will be moved inside the tower and attached to the Delta II first stage, which is the launch vehicle for the OSTM/Jason-2 spacecraft. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1313

NASA Image and Video Library

2008-04-25

VANDENBERG AIR FORCE BASE, Calif. -- In pre-dawn hours at Vandenberg Air Force Base in California, the mobile service tower/umbilical tower and launcher on Space Launch Complex 2 are being prepared for the arrival of the Delta II first stage for the OSTM/Jason-2 spacecraft. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1316

NASA Image and Video Library

2008-04-25

VANDENBERG AIR FORCE BASE, Calif. -- At Vandenberg Air Force Base in California, the Delta II first stage for the OSTM/Jason-2 spacecraft arrives at the base of the mobile service tower on Space Launch Complex 2. The first stage will be raised to vertical and lifted into the tower. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1315

NASA Image and Video Library

2008-04-25

VANDENBERG AIR FORCE BASE, Calif. -- At Vandenberg Air Force Base in California, the Delta II first stage for the OSTM/Jason-2 spacecraft arrives on Space Launch Complex 2. The first stage will be raised to vertical and lifted into the mobile service tower (behind it, at left). The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1609

NASA Image and Video Library

2008-05-05

VANDENBERG AIR FORCE BASE, Calif. -- Workers on Space Launch Complex 2 at Vandenberg Air Force Base in California prepare to attach a sling crane onto the Delta II second stage. The sling will lift the second stage into the mobile service tower for installation on the first stage for launch of the OSTM/Jason-2 spacecraft. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched on June 20. Photo credit: NASA

KSC-08pd1329

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- The first solid rocket motor arrives on Space Launch Complex 2 at Vandenberg Air Force Base in California. It will be attached to the Delta II first stage inside the mobile service tower. The Delta II is the launch vehicle for the OSTM/Jason-2 spacecraft. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1325

NASA Image and Video Library

2008-04-25

VANDENBERG AIR FORCE BASE, Calif. -- On Space Launch Complex 2 at Vandenberg Air Force Base in California, the mobile service tower with the Delta II first stage moves closer to the umbilical tower/launcher at right. The Delta II is the launch vehicle for the OSTM/Jason-2 spacecraft. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1323

NASA Image and Video Library

2008-04-25

VANDENBERG AIR FORCE BASE, Calif. -- At Vandenberg Air Force Base in California, the Delta II first stage is ready to be lifted into the mobile service tower on Space Launch Complex 2. The Delta II is the launch vehicle for the OSTM/Jason-2 spacecraft. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

STS-93 Commander Eileen Collins waves to her family

NASA Technical Reports Server (NTRS)

1999-01-01

STS-93 Commander Eileen M. Collins waves to her family nearby, a last meeting before launch of mission STS-93 on July 20. Liftoff is scheduled for 12:36 a.m. EDT. The primary mission of STS-93 is the release of the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X- ray telescope and is expected to unlock the secrets of supernovae, quasars and black holes. The STS-93 crew numbers five: Commander Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Steven A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a shuttle mission.

KSC-99pp0827

NASA Image and Video Library

1999-07-16

After arrival at KSC's Shuttle Landing Facility, the STS-93 crew speak to the media about their mission. From left are Mission Specialists Michel Tognini of France, who is with the Centre National d'Etudes Spatiales (CNES), Steven A. Hawley (Ph.D.), and Catherine G. "Cady" Coleman (Ph.D.), Pilot Jeffrey S. Ashby, and Commander Eileen M. Collins. Hawley has the most Shuttle flights, this being his fifth. Collins is making her third flight (the first as a commander), Coleman is making her second flight, and Ashby and Tognini are making their first flights. The primary mission of STS-93 is the release of the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected to unlock the secrets of supernovae, quasars and black holes

KSC-99pp0863

NASA Image and Video Library

1999-07-19

Space Shuttle Columbia, sitting on its mobile launcher platform, is framed against the early morning sky after the rollback of the Rotating Service Structure on Launch Pad 39-B. Columbia waits for the launch of mission STS-93 July 20 at 12:36 a.m. EDT. The primary payload of STS-93 is the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected unlock the secrets of supernovae, quasars and black holes. The STS-93 crew numbers five: Commander Eileen M. Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Steven A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a shuttle mission

KSC-99pp0826

NASA Image and Video Library

1999-07-16

Center Director Roy D. Bridges Jr. greets STS-93 Commander Eileen M. Collins after her arrival at KSC's Shuttle Landing Facility aboard a T-38 jet aircraft (behind her). She and other crew members Pilot Jeffrey S. Ashby and Mission Specialists Steven A. Hawley (Ph.D.), Catherine G. "Cady" Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES), are arriving for pre-launch activities. Collins is the first woman to serve as mission commander. This is her third Shuttle flight. The primary mission of STS-93 is the release of the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected to unlock the secrets of supernovae, quasars and black holes

KSC-99pp0828

NASA Image and Video Library

1999-07-16

STS-93 Commander Eileen Collins poses for photographers in the early morning sun after landing at Kennedy Space Center's Shuttle Landing Facility (SLF) aboard a T-38 jet aircraft (background). She and other crew members Pilot Jeffrey S. Ashby and Mission Specialists Steven A. Hawley (Ph.D.), Catherine G. "Cady" Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES), are arriving for pre-launch activities. Collins is the first woman to serve as mission commander. This is her third Shuttle flight. The primary mission of STS-93 is the release of the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected to unlock the secrets of supernovae, quasars and black holes

KSC-99pp0822

NASA Image and Video Library

1999-07-16

STS-93 Commander Eileen Collins waves to spectators after landing at Kennedy Space Center's Shuttle Landing Facility (SLF) aboard a T-38 jet aircraft. She and other crew members Pilot Jeffrey S. Ashby and Mission Specialists Steven A. Hawley (Ph.D.), Catherine G. "Cady" Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES), are arriving for pre-launch activities. Collins is the first woman to serve as mission commander. This is her third Shuttle flight. The primary mission of STS-93 is the release of the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected to unlock the secrets of supernovae, quasars and black holes

KSC-99pp0829

NASA Image and Video Library

1999-07-16

STS-93 Commander Eileen Collins peers into the eastern early morning sky after landing at Kennedy Space Center's Shuttle Landing Facility (SLF) aboard a T-38 jet aircraft (background). She and other crew members Pilot Jeffrey S. Ashby and Mission Specialists Steven A. Hawley (Ph.D.), Catherine G. "Cady" Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES), are arriving for pre-launch activities. Collins is the first woman to serve as mission commander. This is her third Shuttle flight. The primary mission of STS-93 is the release of the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected to unlock the secrets of supernovae, quasars and black holes

KSC-99pp0862

NASA Image and Video Library

1999-07-19

Space Shuttle Columbia catches the rising sun after the rollback of the Rotating Service Structure on Launch Pad 39-B. Columbia waits for the launch of mission STS-93 July 20 at 12:36 a.m. EDT. The primary payload of STS-93 is the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected unlock the secrets of supernovae, quasars and black holes. The STS-93 crew numbers five: Commander Eileen M. Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Steven A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a shuttle mission

KSC-99pp0865

NASA Image and Video Library

1999-07-19

STS-93 Commander Eileen M. Collins waves to her family nearby, a last meeting before launch of mission STS-93 on July 20. Liftoff is scheduled for 12:36 a.m. EDT. The primary mission of STS-93 is the release of the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected to unlock the secrets of supernovae, quasars and black holes. The STS-93 crew numbers five: Commander Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Steven A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a shuttle mission

KSC-99pp0830

NASA Image and Video Library

1999-07-16

The STS-93 crew leave the Shuttle Landing Facility after answering questions for the media and posing for photographers, whose shadows stretch across the SLF. From left are Mission Specialists Michel Tognini of France, who is with the Centre National d'Etudes Spatiales (CNES) and Steven A. Hawley (Ph.D.), Commander Eileen M. Collins (waving), Mission Specialist Catherine G. "Cady" Coleman (Ph.D.), and Pilot Jeffrey S. Ashby. The crew arrived at KSC for pre-launch activities. Collins is the first woman to serve as mission commander. The primary mission of STS-93 is the release of the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected to unlock the secrets of supernovae, quasars and black holes

KSC-99pp0866

NASA Image and Video Library

1999-07-19

The STS-93 crew gathers for breakfast in the Operations and Checkout Building before suiting up for launch. Space Shuttle Columbia is due to launch Tuesday, July 20, at 12:36 a.m. EDT. Seated from left are Mission Specialists Michel Tognini, of France, who represents the Centre National d'Etudes Spatiales (CNES), and Steven A. Hawley (Ph.D.), Commander Eileen M. Collins, Pilot Jeffrey S. Ashby, and Mission Specialist Catherine G. Coleman (Ph.D.). STS-93 is a five-day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected unlock the secrets of supernovae, quasars and black holes. Collins is the first woman to serve as commander of a Shuttle mission

KSC-99pp0864

NASA Image and Video Library

1999-07-19

The rollback of the Rotating Service Structure on launch Pad 39-B reveals Space Shuttle Columbia on its mobile launcher platform, waiting for the launch of mission STS-93 on July 20 at 12:36 a.m. EDT. The primary payload of STS-93 is the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected unlock the secrets of supernovae, quasars and black holes. The STS-93 crew numbers five: Commander Eileen M. Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Steven A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a shuttle mission

Experimental and evaluated photoneutron cross sections for 197Au

NASA Astrophysics Data System (ADS)

Varlamov, V.; Ishkhanov, B.; Orlin, V.

2017-10-01

There is a serious well-known problem of noticeable disagreements between the partial photoneutron cross sections obtained in various experiments. Such data were mainly determined using quasimonoenergetic annihilation photon beams and the method of neutron multiplicity sorting at Lawrence Livermore National Laboratory (USA) and Centre d'Etudes Nucleaires of Saclay (France). The analysis of experimental cross sections employing new objective physical data reliability criteria has shown that many of those are not reliable. The IAEA Coordinated Research Project (CRP) on photonuclear data evaluation was approved. The experimental and previously evaluated cross sections of the partial photoneutron reactions (γ ,1 n ) and (γ ,2 n ) on 197Au were analyzed using the new data reliability criteria. The data evaluated using the new experimental-theoretical method noticeably differ from both experimental data and data previously evaluated using nuclear modeling codes gnash, gunf, alice-f, and others. These discrepancies needed to be resolved.

Modeling of Non-Isothermal Cryogenic Fluid Sloshing

NASA Technical Reports Server (NTRS)

Agui, Juan H.; Moder, Jeffrey P.

2015-01-01

A computational fluid dynamic model was used to simulate the thermal destratification in an upright self-pressurized cryostat approximately half-filled with liquid nitrogen and subjected to forced sinusoidal lateral shaking. A full three-dimensional computational grid was used to model the tank dynamics, fluid flow and thermodynamics using the ANSYS Fluent code. A non-inertial grid was used which required the addition of momentum and energy source terms to account for the inertial forces, energy transfer and wall reaction forces produced by the shaken tank. The kinetics-based Schrage mass transfer model provided the interfacial mass transfer due to evaporation and condensation at the sloshing interface. The dynamic behavior of the sloshing interface, its amplitude and transition to different wave modes, provided insight into the fluid process at the interface. The tank pressure evolution and temperature profiles compared relatively well with the shaken cryostat experimental test data provided by the Centre National D'Etudes Spatiales.

The Development of a Cell-Assembly for the Treatment of Irradiated Fuels on a Semi-Industrial Scale; ETUDE CONCERNANT LA REALISATION D'UN ENSEMBLE DE CELLULES DESTINEES A DES TRAITEMENTS DE COMBUSTIBLES IRRADIES A L'ECHELLE SEMI-INDUSTRIELLE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Faugeras, P.; Couture, J.; Lefort, G.

1961-01-01

The main studies and experiments involved in the development of a cell- assembly for the treatment of irradiated fuels on a semi-industrial scale are described. It must be possible to modify or transform each of these cells without interrupting the rest of the pilot. A full-scale prototype cell ( 3 x 4 x 6 m) was built with an alpha k-protection independent of the gamma - protection. It features all the main characteristics: tightness to gamma losses, dense glass lighting, and ventilation. This cell has made possible trials on transfer, remote-controls and teledismantling, as well as the development of newmore » methods of rapidly connecting hydraulic circuits. The final form is given of the cells selected for the pilot. (auth)« less

KSC-99pp0990

NASA Image and Video Library

1999-07-28

At the Skid Strip at the Cape Canaveral Air Station, Mission Specialist Michel Tognini of France, representing the Centre National d'Etudes Spatiales (CNES), and his daughter Tatinana prepare to board an aircraft for their return flight to Houston following the completion of the STS-93 Space Shuttle mission. Landing occurred on runway 33 at KSC's Shuttle Landing Facility on July 27 with main gear touchdown at 11:20:35 p.m. EDT. The mission's primary objective was to deploy the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. This was the 95th flight in the Space Shuttle program and the 26th for Columbia. The landing was the 19th consecutive Shuttle landing in Florida and the 12th night landing in Shuttle program history. On this mission, Eileen Collins became the first woman to serve as a Shuttle commander

KSC-99pp0989

NASA Image and Video Library

1999-07-28

At the Shuttle Landing Facility (from left to right), STS-93 Mission Specialist Michel Tognini of France, representing the Centre National d'Etudes Spatiales (CNES), and NASA Administrator Daniel Goldin talk with Jacques Ratie, Astronaut Director, CNES, and Serge Plattard, International Relations, CNES. Landing occurred on runway 33 with main gear touchdown at 11:20:35 p.m. EDT on July 27. The mission's primary objective was to deploy the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. This was the 95th flight in the Space Shuttle program and the 26th for Columbia. The landing was the 19th consecutive Shuttle landing in Florida and the 12th night landing in Shuttle program history. On this mission, Eileen Collins became the first woman to serve as a Shuttle commander

STS-93 Mission Specialist Tognini talks with Goldin, Ratie, and Plattard

NASA Technical Reports Server (NTRS)

1999-01-01

At the Shuttle Landing Facility (from left to right), STS-93 Mission Specialist Michel Tognini of France, representing the Centre National d'Etudes Spatiales (CNES), and NASA Administrator Daniel Goldin talk with Jacques Ratie, Astronaut Director, CNES, and Serge Plattard, International Relations, CNES. Landing occurred on runway 33 with main gear touchdown at 11:20:35 p.m. EDT on July 27. The mission's primary objective was to deploy the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. This was the 95th flight in the Space Shuttle program and the 26th for Columbia. The landing was the 19th consecutive Shuttle landing in Florida and the 12th night landing in Shuttle program history. On this mission, Eileen Collins became the first woman to serve as a Shuttle commander.

Structure of the marine atmospheric boundary layer over an oceanic thermal front: SEMAPHORE experiment

NASA Astrophysics Data System (ADS)

Kwon, B. H.; BéNech, B.; Lambert, D.; Durand, P.; Druilhet, A.; Giordani, H.; Planton, S.

1998-10-01

The Structure des Echanges Mer-Atmosphere, Proprietes des Heterogeneites Oceaniques: Recherche Experimentale (SEMAPHORE) experiment, the third phase of which took place between October 4 and November 17, 1993, was conducted over the oceanic Azores Current located in the Azores basin and mainly marked at the surface by a thermal front due to the gradient of the sea surface temperature (SST) of about 1° to 2°C per 100 km. The evolution of the marine atmospheric boundary layer (MABL) over the SST front was studied with two aircraft and a ship in different meteorological conditions. For each case, the influence of the incoming air direction with respect to the orientation of the oceanic front was taken into account. During the campaign, advanced very high resolution radiometer pictures did not show any relation between the SST field and the cloud cover. The MABL was systematically thicker on the warm side than on the cold side. The mean MABL structure described from aircraft data collected in a vertical plane crossing the oceanic front was characterized by (1) an atmospheric horizontal gradient of 1° to 2°C per 100 km in the whole depth of the mixed layer and (2) an increase of the wind intensity from the cold to the warm side when the synoptic wind blew from the cold side. The surface sensible heat (latent heat) flux always increased from the cold to the warm sector owing to the increase of the wind and of the temperature (specific humidity) difference between the surface and the air. Turbulence increased from the cold to the warm side in conjunction with the MABL thickening, but the normalized profiles presented the same structure, regardless of the position over the SST front. In agreement with the Action de Recherche Programme te Petite Echelle and Grande Echelle model, the mean temperature and momentum budgets were highly influenced by the horizontal temperature gradient. In particular, the strong ageostrophic influence in the MABL above the SST front seems linked with the secondary circulation due to the SST front.

First results of the PERSEE experiment

NASA Astrophysics Data System (ADS)

Le Duigou, J.-M.; Lozi, J.; Cassaing, F.; Houairi, K.; Sorrente, B.; Montri, J.; Jacquinod, S.; Reess, J.-M.; Pham, L.; Lhomé, E.; Buey, T.; Hénault, F.; Marcotto, A.; Girard, P.; Mauclert, N.; Barillot, M.; Coudé du Foresto, V.; Ollivier, M.

2017-11-01

Although it has been recently postponed due to high cost and risks, nulling interferometry in space remains one of the very few direct detection methods able to characterize extrasolar planets and particularly telluric ones. Within this framework, several projects such as DARWIN [1], [2], TPF-I [3], [4], FKSI [5] or PEGASE [6], [7], have been proposed in the past years. Most of them are based on a free flying concept. It allows firstly to avoid atmosphere turbulence, and secondly to distribute instrumental function over many satellites flying in close formation. In this way, a very high angular resolution can be achieved with an acceptable launch mass. But the price to pay is to very precisely position and stabilize relatively the spacecrafts, in order to achieve a deep and stable extinction of the star. Understanding and mastering all these requirements are great challenges and key issues towards the feasibility of these missions. Thus, we decided to experimentally study this question and focus on some possible simplifications of the concept. Since 2006, PERSEE (PEGASE Experiment for Research and Stabilization of Extreme Extinction) laboratory test bench is under development by a consortium composed of Centre National d'Etudes Spatiales (CNES), Institut d'Astrophysique Spatiale (IAS), Observatoire de Paris-Meudon (LESIA), Observatoire de la Côte d'Azur (OCA), Office National d'Etudes et de Recherches Aérospatiales (ONERA), and Thalès Alénia Space (TAS) [8]. It is mainly funded by CNES R&D. PERSEE couples an infrared wide band nulling interferometer with local OPD and tip/tilt control loops and a free flying Guidance Navigation and Control (GNC) simulator able to introduce realistic disturbances. Although it was designed in the framework of the PEGASE free flying space mission, PERSEE can adapt very easily to other contexts like FKSI (in space, with a 10 m long beam structure) or ALADDIN [9] (on ground, in Antarctica) because the optical designs of all those missions are very similar. After a short description of the experimental setup, we will present first the results obtained in an intermediate configuration with monochromatic light. Then we will present some preliminary results with polychromatic light. Last, we discuss some very first more general lessons we can already learn from this experiment.

SU-E-T-526: On the Linearity, Stability and Beam Energy Dependence of CdSe Quantum Dots as Scintillating Probes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Delage, M-E; Centre Hospitalier Universityde Quebec, Quebec, QC; Lecavalier, M-E

2014-06-01

Purpose: Structure and energy transfer mechanisms confer colloidal quantum dots (cQDs) interesting properties, among them their potential as scintillators. CdSe multi-shell cQDs in powder were investigated under photons irradiation. The purpose of this work is to characterize signal to dose linearity, stability with time and to quantify the dependence of their light output with beam energy. Methods: The cQDs are placed at the extremity of a non-scintillating plastic collecting fiber, with the other extremity connected to an Apogee U2000C CCD camera. The CCD camera collects the fluorescence light from irradiated cQDs from which the delivered dose is extracted. This signalmore » is corrected for Cerenkov contamination at MV energies using the chromatic technique. The detector was irradiated with two devices: Xstrahl 200 orthovoltage unit for 120, 180 and 220 kVp and a Varian Clinac iX for 6 and 23 MV. Results: Linear output response with varying dose is observed for all beam energies with R2 factors > 0,999. Reproducibility measurements were performed at 120 kVp: the same set-up was irradiated at different time intervals (one week and three months). The results showed only a small relative decrease of light output of 3,2 % after a combine deposited dose of approximately 95 Gy. CdSe nanocrystals response has been studied as a function of beam energy. The output increases with decreasing energy from 120 kVp to 6 MV and increase again for 23 MV. This behavior could be explained in part by the cQDs high-Z composition. Conclusion: The fluorescence light output of CdSe cQDs was found to be linear as a function of dose. The results suggest stability of the scintillation output of cQDs over time. The specific composition of cQDs is the main cause of the observed energy dependence. We will further look into particle beam dependence of the cQDs. Bourse d'excellence aux etudes graduees du CRC (Centre de Recherche sur le Cancer, Universite Laval) Bourse d'excellence aux etudes graduees du CRC (Centre de Recherche sur le Cancer, Universite Laval)« less

Impedance de surface dans les supraconducteurs quasi-bidimensionnels

NASA Astrophysics Data System (ADS)

Achkir, Driss Brice

Ce travail a caractere experimental et theorique vise l'etude de l'etat supraconducteur de trois familles de composes: les supraconducteurs conventionnels, les organiques et les cuprates YBCO. Pour ce faire, nous avons utilise une technique hyperfrequence, a savoir la mesure d'impedance de surface en fonction de la temperature et du champ magnetique. Dans les supraconducteurs conventionnels, nous avons mesure pour la premiere fois le pic de "coherence" dans la partie reelle de la conductivite. Bien que predit par la theorie BCS, ce pic n'avait pas ete clairement observe en raison de difficultes techniques liees a ce type d'experience. D'autre part, la theorie d'Eliashberg appliquee a la partie reelle de la conductivite du niobium nous a revele l'importance des mesures hyperfrequences pour mieux extraire la partie basse frequence de la densite spectrale alphasp2F(omega). Cette possibilite est attrayante puisque c'est precisement la region de frequences de alphasp2F(omega) ou les donnees d'effet tunnel sont imprecises. Les resultats obtenus sur la longueur de penetration dans les organiques et les cuprates ont permis de montrer que le gap presente des lignes de zeros au niveau de Fermi ou qu'il est, a tout le moins, fortement anisotrope. En effet, la dependance en temperature de la longueur de penetration dans les cristaux purs est lineaire a basse temperature et elle devient quadratique dans les cristaux dopes. Pour le cas des supraconducteurs organiques quasi-bidimensionnels (Et)sb2X, nous avons aussi observe un maximum sur la partie reelle de la conductivite qui n'a rien a voir avec un pic de coherence. Pour ces composes, nous avons effectue une des toutes premieres etudes des fluctuations supraconductrices en temperature et en champ magnetique. Nous montrons que la paraconductivite sigmasp' due aux fluctuations presente un comportement de type Aslamazov-Larkin de nature tridimensionnelle. Ces mesures sont appuyees par les resultats theoriques d'un modele Ginzburg-Landau dynamique que nous avons developpe. De plus, a partir de l'analyse des fluctuations, nous avons pu identifier le champ critique pour la transition resistive en champ et ainsi en deduire la transition de fonte du reseau de vortex dans le (Et)sb2Cu(SCN)sb2.

Etude de la Generation des Ultrasons Par Laser dans un Materiau Composite

NASA Astrophysics Data System (ADS)

Dubois, Marc

Laser generation of ultrasound is not a new subject. Many authors have proposed mathematical models of the thermoelastic process of generation of acoustic waves. However, none of those models, up to now, could take simultaneously the effects of the thermal conduction, the optical penetration, the anisotropy of the material and any time and surface profiles of the laser excitation into account. The model presented in this work takes all these parameters into consideration in the case of an infinite orthotropic plate. The mathematical approach used allows to obtain an analytical solution of the mechanical displacement field in the Laplace and two-dimensional (2-D) Fourier spaces. Numerical inverse Laplace and 2-D Fourier transformations bring the mechanical displacement field back into the normal spaces. The use of direct numerical transformations enables to consider almost any time and spatial distributions of the generation laser beam. The acoustic displacements calculated by this model have been compared to experimental displacements measured with a wide band optical detection system. The features of this system allow the quantitative measurement of the parallel and normal displacements to the surface of the sample. Hence, the calculated normal and parallel displacements have been compared to those experimentally measured at various locations on aluminum, glass and polymer samples. In all cases, the agreement between the calculated and experimentally measured displacements was good. The semi-analytical model having proved its validity, it has been used, in addition to a completely analytical one-dimensional model, to study the effects of the optical penetration and the laser pulse duration on the longitudinal acoustic wave generated. This study has established that a short enough laser pulse and a large irradiation with regard to the sample thickness allows to determine quantitatively, from the full width at half maximum of the acoustic pulse, the optical penetration depth at the wavelength of the generation laser inside the material. This semi-analytical model has also permitted to analyze the effects of the optical penetration on the directivity patterns of the longitudinal and shear waves generated by a thermoelastic source. This study has clearly shown that the optical penetration modifies significantly the longitudinal wave directivity pattern, but has only weak effects on the shear wave one. (Abstract shortened by UMI.).

L'effet Doppler et le décalage vers le rouge en mécanique rationnelle: applications et verifications experimentales.

PubMed

Loiseaus, J

1968-07-01

Shifts z and z' toward the red of the galaxy NGC 5668 for a beam of 21 cm, z measured in radioastronomy with a frequency meter and z' measured in optics with a spectrograph, not being equal, it follows that the speed of light from a galaxy c ' is not equal to that of a galaxy c which is measured on earth from stationary source. The Doppler empirical formula cannot be explained in classical mechanics since it is in contradiction with it. As for the theory of relativity c ' = c from a postulate and z' = z. If we consider the universe represented on a three-dimensional space (H), non-Euclidian, with Euclidian connection plunged in a Riemannine four-dimension space (E), a certain universal time, like that of an astronomer, can be defined and its course calculated in relation to this time: it will necessarily be confounded with the atomic clock time, but c ' not equal c and z' not equal z: the Doppler formula is not accurate. However, c ' and c as well as z' and z are so close in all the experiments carried out on earth, even when an artificial satellite is used, that the errors made in using the Doppler formula are clearly inferior to experimental errors.

Ajuste de parámetros libres en teorías de campos camaleones a partir de espectros de nubes moleculares galácticas y experimentos terrestres

NASA Astrophysics Data System (ADS)

Teppa Pannia, F. A.; Landau, S. J.

Resultados recientes, basados en el análisis de espectros moleculares de nubes galácticas a través del método del amoníaco, han arrojado nuevos límites sobre la variación del parámetro adimensional μ=m_e /m_p. Los resultados indican Δ μ/μ = (μ_{obs}-μ_{lab})/μ_{lab}= (2.2± 0.4_{est} ±0.3_{sist}) times 10 ^{-8}, en acuerdo con una variación no nula de dicha cantidad (Levshakov et al. 2010). En este trabajo, motivado por los datos astronómicos, estudiamos la solución lineal del modelo teórico fenomenológico de campo escalar camaleón, presentado por Mota y Shaw (2007), que predice variaciones en μ. Con el fin de cotejar estas predicciones con los resultados observacionales, utilizamos datos de experimentos terrestres que testean violaciones al Principio de Equivalencia para analizar el valor de los parámetros libres presentes en el modelo. El trabajo realizado muestra que la solución estudiada no se puede ajustar a los datos experimentales, sugiriendo que el modelo lineal debe ser descartado para explicar las observaciones astronómicas. FULL TEXT IN SPANISH

Cost-effectiveness of rapid syphilis screening in prenatal HIV testing programs in Haiti.

PubMed

Schackman, Bruce R; Neukermans, Christopher P; Fontain, Sandy N Nerette; Nolte, Claudine; Joseph, Patrice; Pape, Jean W; Fitzgerald, Daniel W

2007-05-01

New rapid syphilis tests permit simple and immediate diagnosis and treatment at a single clinic visit. We compared the cost-effectiveness, projected health outcomes, and annual cost of screening pregnant women using a rapid syphilis test as part of scaled-up prenatal testing to prevent mother-to-child HIV transmission in Haiti. A decision analytic model simulated health outcomes and costs separately for pregnant women in rural and urban areas. We compared syphilis syndromic surveillance (rural standard of care), rapid plasma reagin test with results and treatment at 1-wk follow-up (urban standard of care), and a new rapid test with immediate results and treatment. Test performance data were from a World Health Organization-Special Programme for Research and Training in Tropical Diseases field trial conducted at the GHESKIO Center Groupe Haitien d'Etude du Sarcome de Kaposi et des Infections Opportunistes in Port-au-Prince. Health outcomes were projected using historical data on prenatal syphilis treatment efficacy and included disability-adjusted life years (DALYs) of newborns, congenital syphilis cases, neonatal deaths, and stillbirths. Cost-effectiveness ratios are in US dollars/DALY from a societal perspective; annual costs are in US dollars from a payer perspective. Rapid testing with immediate treatment has a cost-effectiveness ratio of $6.83/DALY in rural settings and $9.95/DALY in urban settings. Results are sensitive to regional syphilis prevalence, rapid test sensitivity, and the return rate for follow-up visits. Integrating rapid syphilis testing into a scaled-up national HIV testing and prenatal care program would prevent 1,125 congenital syphilis cases and 1,223 stillbirths or neonatal deaths annually at a cost of $525,000. In Haiti, integrating a new rapid syphilis test into prenatal care and HIV testing would prevent congenital syphilis cases and stillbirths, and is cost-effective. A similar approach may be beneficial in other resource-poor countries that are scaling up prenatal HIV testing.

Prediction of TARANIS Observations of TGF's and Optical Emissions from Red Sprites

NASA Astrophysics Data System (ADS)

Nelson, M. A.

2006-12-01

TARANIS (Tool for the Analysis of Radiation from Lightning and Sprites) is a French (CNES, Centre National D'Etudes Spatiales) micro-satellite that is scheduled for launch in 2009. This will be the first satellite that will measure coincident gamma-rays and optical emissions from atmospheric discharges. These measurements will provide important clues concerning the physics of discharges that produce gamma-rays and will provide more definitive evidence of the role of conventional breakdown versus runaway breakdown than is currently available. While a variety of discharges may be associated with Transient Gamma Ray Flashes (TGF's), this study will focus on emissions expected from red sprites. Future studies will focus on other types of discharges (for example, gigantic jets or blue jets) to see whether they should produce detectable signal levels at both gamma-ray and optical frequencies. The source of terrestrial TGF's is a matter of debate at this time. Many experts in the field have interpreted the data associated with the RHESSI (Reuven Ramaty High Energy Solar Spectroscopic Imager) satellite to be indicative that the discharges associated with terrestrial gamma-rays are not associated with sprites. However, RHESSI was not designed for the purpose of collecting gamma-ray measurements from terrestrial discharges; does not possess a coincident optical measurement capability; and must average data over many events to predict a spectrum. We will present a statistical analysis of the relative efficiencies of the RHESSI and TARANIS satellite designs for the detection of TGF's associated with sprites. We will show results from a fully 2-D electromagnetic model (UNIMAX, the Unified Maxwell code) and an optical model (POEM, the Physics Based Optical Emission Model) to demonstrate the level of agreement between the simulations and the gamma-ray spectrum measurements and optical measurements (camera, photometer, and spectral measurements) for several different classes of discharges (halos, streamers, and runaway breakdown.) We will distinguish which measurements and model results are indicative of conventional breakdown and which are indicative of runaway breakdown.

Precise Estimation of Allele Frequencies of Single-Nucleotide Polymorphisms by a Quantitative SSCP Analysis of Pooled DNA

PubMed Central

Sasaki, Tomonari; Tahira, Tomoko; Suzuki, Akari; Higasa, Koichiro; Kukita, Yoji; Baba, Shingo; Hayashi, Kenshi

2001-01-01

We show that single-nucleotide polymorphisms (SNPs) of moderate to high heterozygosity (minor allele frequencies >10%) can be efficiently detected, and their allele frequencies accurately estimated, by pooling the DNA samples and applying a capillary-based SSCP analysis. In this method, alleles are separated into peaks, and their frequencies can be reliably and accurately quantified from their peak heights (SD <1.8%). We found that as many as 40% of publicly available SNPs that were analyzed by this method have widely differing allele frequency distributions among groups of different ethnicity (parents of Centre d'Etude Polymorphisme Humaine families vs. Japanese individuals). These results demonstrate the effectiveness of the present pooling method in the reevaluation of candidate SNPs that have been collected by examination of limited numbers of individuals. The method should also serve as a robust quantitative technique for studies in which a precise estimate of SNP allele frequencies is essential—for example, in linkage disequilibrium analysis. PMID:11083945

Black Hole Event Horizons and Advection-Dominated Accretion

NASA Technical Reports Server (NTRS)

McClintock, Jeffrey; Mushotzky, Richard F. (Technical Monitor)

2002-01-01

The work supported in part by this grant is part of a larger program on the detection of black hole event horizons, which is also partially supported by NASA grant GO0-1105A. This work has been carried out primarily in collaboration with Dr. M. Garcia and Prof. R. Narayan at the Harvard-Smithsonian Center for Astrophysics and with D. Barret and J. Hameury at Centre d'Etude Spoliate des Rayonnements, France. Our purpose is to confirm the existence of black-hole event horizons by comparing accreting black holes to secreting neutron stars in quiescent X-ray novae. Such a comparison is feasible because black holes and neutron stars are both present in similar environments in X-ray novae. Our second purpose is to assess the nature of accretion flows onto black holes at very low mass transfer rates. Observations of some XMM targets are still pending, whereas most of the Chandra observations have been completed. We anticipate further publications on this work in the future.

KSC-99pc0188

NASA Image and Video Library

1999-02-09

In the Solid Motor Assembly Building, Cape Canaveral Air Station, STS-93 Mission Specialist Catherine G. Coleman (left) lifts the protective covering to look at the avionics box on the Inertial Upper Stage booster. Next to her are Eric Herrburger (center), with Boeing, and crew member Mission Specialist Michel Tognini (right) of France, who represents the Centre National d'Etudes Spatiales (CNES). STS-93 is scheduled to launch July 9 aboard Space Shuttle Columbia and has the primary mission of the deployment of the Chandra X-ray Observatory. Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Other STS-93 crew members are Commander Eileen M. Collins, Pilot Jeffrey S. Ashby and Mission Specialist Steven A. Hawley

Introduction à L'Etude de la Médecine Expérimentale. Surgical revolution. Part I.

PubMed

Toledo-Pereyra, Luis H

2009-01-01

Claude Bernard (1813-1878), the most distinguished French physiologist of the 19th century, made incomparable contributions to the world of medicine of his times and even to ours. Bernard believed in scientific determinism and created the term milieu interieur as a manner to better understand experimental medicine and to present a new way of explaining the function of the living organism. Bernard dealt with innovative developments in the glycogenetic function of the liver, extrahepatic glycogenesis, the role of pancreatic juice in the digestion of fats, vasomotor nervous system discoveries, and other important physiological advances. In 1865, Bernard's most extraordinary book on the philosophy and understanding of experimental medicine appeared. This book represented Bernard's unique contribution to the progress of medical and surgical research. Because of the enormous implications of this work on the advancement of surgical research, which were subsequently applied to clinical surgical practice, we propose that this book created a surgical revolution.

Relationship between microstructure and mechanical properties of Alloy 690 tubes for steam generators

NASA Astrophysics Data System (ADS)

Diano, P.; Muggeo, A.; Van Duysen, J. C.; Guttmann, M.

1989-12-01

Alloy 690 is used to replace Alloy 600 for the fabrication of tubes for steam generators of french pressurized water nuclear reactors. In order to reduce the dispersion in tensile properties observed for the first Alloy 690 industrial tubes, and which had already been noticed for Alloy 600, a joint research programme has been carried out by Electricité de France (Département Etude des Matériaux) and Valinox Montbard. The dispersion in the tensile properties of the first industrial Alloy 690 tubes for PWR steam generators arises from two main factors: - a grain size dispersion which is in particular controlled by the carbon content and by the final heat treatment, - differences in the degree of strain hardening induced by the straightening process with rollers. An improvement of the fabrication processes which have an influence on these two factors has allowed to reduce considerably the dispersion of the tensile properties of the more recent series of tubes.

Climate impact on malaria in northern Burkina Faso.

PubMed

Tourre, Yves M; Vignolles, Cécile; Viel, Christian; Mounier, Flore

2017-11-27

The Paluclim project managed by the French Centre National d'Etudes Spatiales (CNES) found that total rainfall for a 3-month period is a confounding factor for the density of malaria vectors in the region of Nouna in the Sahel administrative territory of northern Burkina Faso. Following the models introduced in 1999 by Craig et al. and in 2003 by Tanser et al., a climate impact model for malaria risk (using different climate indices) was created. Several predictions of this risk at different temporal scales (i.e. seasonal, inter-annual and low-frequency) were assessed using this climate model. The main result of this investigation was the discovery of a significant link between malaria risk and low-frequency rainfall variability related to the Atlantic Multi-decadal Oscillation (AMO). This result is critical for the health information systems in this region. Knowledge of the AMO phases would help local authorities to organise preparedness and prevention of malaria, which is of particular importance in the climate change context.

Spectres de vibration de composés organiques des éléments de la colonne IVB—XIV. Etude physico-chimique de germa-2 azolidines, digerma-2,5 azolidines et de cyclodi- et tri-germazanes

NASA Astrophysics Data System (ADS)

Marchand, Annette; Gerval, Pierre; Rivière-Baudet, Monique; Lacrampe, Georges; Khallaayoun, Abdelhay

1985-01-01

A physicochemical study (i.r., Raman) about a series of 2-germaazolidines, 2,5-digermaazolidines and cyclodi- and tri-germazanes is presented. Infrared and Raman spectra were examined and led to the following conclusions: vibrations ν(GeN) and ν s(GeNGe) are located between 500 and 620 cm -1 and the ν a(GeNGe) mode between 750 and 900 cm -1. The influence of the dimension and the substitution of each cycle upon those vibrations is discussed. Evidence of a relation between (ν a - ν s) GeNGe and the size of the cycle is presented for cyclodi- and trigermazanes. An extension of this study to derivatives with an MXM sequence (X = N or O), (M = Si, Ge, Sn) has shown that a linear relation can be established between the characteristic frequencies of the MOM group and the corresponding angle.

Methodes de calcul des forces aerodynamiques pour les etudes des interactions aeroservoelastiques

NASA Astrophysics Data System (ADS)

Biskri, Djallel Eddine

L'aeroservoelasticite est un domaine ou interagissent la structure flexible d'un avion, l'aerodynamique et la commande de vol. De son cote, la commande du vol considere l'avion comme une structure rigide et etudie l'influence du systeme de commande sur la dynamique de vol. Dans cette these, nous avons code trois nouvelles methodes d'approximation de forces aerodynamiques: Moindres carres corriges, Etat minimal corrige et Etats combines. Dans les deux premieres methodes, les erreurs d'approximation entre les forces aerodynamiques approximees par les methodes classiques et celles obtenues par les nouvelles methodes ont les memes formes analytiques que celles des forces aerodynamiques calculees par LS ou MS. Quant a la troisieme methode, celle-ci combine les formulations des forces approximees avec les methodes standards LS et MS. Les vitesses et frequences de battement et les temps d'executions calcules par les nouvelles methodes versus ceux calcules par les methodes classiques ont ete analyses.

Etude microdosimetrique de l'influence des materiaux sur l'efficacite biologique d'une source d'iode-125

NASA Astrophysics Data System (ADS)

Taschereau, Richard

Cette these concerne les implants permanents pour la prostate. Les isotopes employes, le 103Pd et l'125I, semblent produire les memes resultats cliniques: le premier a cause d'une radiation plus efficace et le second a cause de sa demi-vie plus longue. La recherche utilise le cadre theorique de la microdosimetrie et des simulations Monte Carlo. Elle propose d'employer le spectre d'ejection dans le calcul de l'efficacite; ce changement fait passer l'efficacite relative du 103Pd de 10% a 5%. Elle montre ensuite qu'il est possible d'ameliorer l'efficacite de la radiation de 125I par l'exploitation des rayons X caracteristiques de la capsule. Une source amelioree faite de molybdene et d'yttrium est donnee en exemple. Elle procure une radiation de 5--7% plus efficace, ce qui surclasse les deux sources existantes. Les applications ne se limitent pas au traitement de la prostate; le traitement du melanome oculaire et la curietherapie endovasculaire pourraient en beneficier.

KSC-99pp0867

NASA Image and Video Library

1999-07-19

In the Operations and Checkout Building, STS-93 Mission Specialist Steven A. Hawley (Ph.D.) smiles after donning his launch and entry suit during final launch preparations. STS-93 is a five-day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected unlock the secrets of supernovae, quasars and black holes. The STS-93 crew numbers five: Commander Eileen M. Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Hawley, Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a shuttle mission. STS-93 is scheduled to lift off at 12:36 a.m. EDT July 20. The target landing date is July 24 at 11:30 p.m. EDT

KSC-99pp0871

NASA Image and Video Library

1999-07-19

In the Operations and Checkout Building, STS-93 Mission Specialist Catherine G. Coleman (Ph.D.) waves after donning her launch and entry suit during final launch preparations. STS-93 is a five-day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected unlock the secrets of supernovae, quasars and black holes. The STS-93 crew numbers five: Commander Eileen M. Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Stephen A. Hawley (Ph.D.), Coleman and Michel Tognini of France, who represents the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a shuttle mission. STS-93 is scheduled to lift off at 12:36 a.m. EDT July 20. The target landing date is July 24 at 11:30 p.m. EDT

KSC-99pp0869

NASA Image and Video Library

1999-07-19

In the Operations and Checkout Building, STS-93 Mission Specialist Michel Tognini of France, who represents the Centre National d'Etudes Spatiales (CNES), waves after donning his launch and entry suit during final launch preparations. STS-93 is a five-day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected unlock the secrets of supernovae, quasars and black holes. The STS-93 crew numbers five: Commander Eileen M. Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Stephen A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Tognini. Collins is the first woman to serve as commander of a shuttle mission. STS-93 is scheduled to lift off at 12:36 a.m. EDT July 20. The target landing date is July 24 at 11:30 p.m. EDT

KSC-99pp0868

NASA Image and Video Library

1999-07-19

In the Operations and Checkout Building, STS-93 Commander Eileen M. Collins waves while a suit tech adjusts her boot, part of the launch and entry suit, during final launch preparations. STS-93 is a five-day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected unlock the secrets of supernovae, quasars and black holes. The STS-93 crew numbers five: Commander Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Stephen A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a shuttle mission. STS-93 is scheduled to lift off at 12:36 a.m. EDT July 20. The target landing date is July 24 at 11:30 p.m. EDT

KSC-99pp0870

NASA Image and Video Library

1999-07-19

In the Operations and Checkout Building during final launch preparations, STS-93 Pilot Jeffrey S. Ashby waits after donning his launch and entry suit while a suit tech adjusts his helmet. STS-93 is a five-day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected unlock the secrets of supernovae, quasars and black holes. The STS-93 crew numbers five: Commander Eileen M. Collins, Ashby, and Mission Specialists Stephen A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a shuttle mission. STS-93 is scheduled to lift off at 12:36 a.m. EDT July 20. The target landing date is July 24 at 11:30 p.m. EDT

Study of the Radiative Recombination of Free Carriers Produced by Electron Bombardment in Cadmium Sulfide (thesis); ETUDE DE LA RECOMBINAISON RADIATIVE DES PORTEURS LIBRES PRODUITS PAR UN BOMBARDEMENT ELECTRONIQUE DANS LE SULFURE DE CADMIUM (THESES)

DOE Office of Scientific and Technical Information (OSTI.GOV)

de Gaalon, G.

1962-01-01

The structure of the blue emission at the temperature of liquid nitrogen was studied using improved apparatus. The observations were carried to the temperature of liquid He in order to deduce the mechanism of the recombination of the free carriers. Before analysis of the light emitted by CdS single crystals exposed to electron bombardment and before a description of the experimental apparatus, the interaction of electron beams with the crystal and the resultant formation of free carriers are studied theoretically. The experimental study showed that the structure of the emission situated at the absorption limit, obtained by electron bombardment, doesmore » not differ basically from that observed under uv irradiation. However, the existence at 4 deg K of radiation (not observed with uv irradiation) with wave lengths less than 4.856 A was shown. (J.S.R.)« less

KSC-99pc0182

NASA Image and Video Library

1999-02-09

In the Vertical Processing Facility (VPF), the STS-93 crew stands in front of the VPF Aft Flight Deck simulator, which is part of KSC's Cargo Integration Test Equipment. From left, they are Mission Specialist Michel Tognini of France, Commander Eileen M. Collins, Mission Specialist Steven A. Hawley, Pilot Jeffrey S. Ashby and Mission Specialist Catherine G. Coleman. Tognini represents France's space agency, the Centre National d'Etudes Spatiales (CNES). STS-93, scheduled to launch July 9 aboard Space Shuttle Columbia, has the primary mission of the deployment of the Chandra X-ray Observatory, which is undergoing testing in the VPF. Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

KSC-99pc0177

NASA Image and Video Library

1999-02-09

Members of the STS-93 crew look over the Space Shuttle Columbia's main engine in the Space Shuttle Main Engine Facility as they listen to Al Strainer, with United Space Alliance. From left, the crew members are Mission Specialist Michel Tognini of France, who represents the Centre National d'Etudes Spatiales (CNES), Pilot Jeffrey S. Ashby, Mission Specialist Steven A. Hawley, and Commander Eileen Collins. At the far right is Matt Gaetjens, with the Vehicle Integration Test Team. The fifth crew member (not shown) is Mission Specialist Catherine G. Coleman. STS-93, scheduled to launch July 9, has the primary mission of the deployment of the Chandra X-ray Observatory. Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

A global station coordinate solution based upon camera and laser data - GSFC 1973

NASA Technical Reports Server (NTRS)

Marsh, J. G.; Douglas, B. C.; Klosko, S. M.

1973-01-01

Results for the geocentric coordinates of 72 globally distributed satellite tracking stations consisting of 58 cameras and 14 lasers are presented. The observational data for this solution consists of over 65,000 optical observations and more than 350 laser passes recorded during the National Geodetic Satellite Program, the 1968 Centre National d'Etudes Spatiales/Smithsonian Astrophysical Observatory (SAO) Program, and International Satellite Geodesy Experiment Program. Dynamic methods were used. The data were analyzed with the GSFC GEM and SAO 1969 Standard Earth Gravity Models. The recent value of GM = 398600.8 cu km/sec square derived at the Jet Propulsion Laboratory (JPL) gave the best results for this combination laser/optical solution. Solutions are made with the deep space solution of JPL (LS-25 solution) including results obtained at GSFC from Mariner-9 Unified B-Band tracking. Datum transformation parameters relating North America, Europe, South America, and Australia are given, enabling the positions of some 200 other tracking stations to be placed in the geocentric system.

KSC-99pp0987

NASA Image and Video Library

1999-07-28

KENNEDY SPACE CENTER, FLA. -- The STS-93 crew pose in front of the Space Shuttle orbiter Columbia following their landing on runway 33 at the Shuttle Landing Facility. Main gear touchdown occurred at 11:20:35 p.m. EDT on July 27. From left to right, they are Mission Specialists Catherine G. Coleman (Ph.D.) and Steven A. Hawley (Ph.D.), Pilot Jeffrey S. Ashby, Commander Eileen Collins, and Mission Specialist Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). The mission's primary objective was to deploy the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. This was the 95th flight in the Space Shuttle program and the 26th for Columbia. The landing was the 19th consecutive Shuttle landing in Florida and the 12th night landing in Shuttle program history. On this mission, Collins became the first woman to serve as a Shuttle commander

KSC-99pp0986

NASA Image and Video Library

1999-07-28

KENNEDY SPACE CENTER, FLA. -- STS-93 Commander Eileen Collins poses in front of the Space Shuttle orbiter Columbia following her textbook landing on runway 33 at the Shuttle Landing Facility. Main gear touchdown occurred at 11:20:35 p.m. EDT on July 27. On this mission, Collins became the first woman to serve as a Shuttle commander. Also on board were her fellow STS-93 crew members: Pilot Jeffrey S. Ashby and Mission Specialists Steven A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). The mission's primary objective was to deploy the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. This was the 95th flight in the Space Shuttle program and the 26th for Columbia. The landing was the 19th consecutive Shuttle landing in Florida and the 12th night landing in Shuttle program history

STS-93 Mission Specialist Tognini and daughter prepare to board aircraft for return flight to Housto

NASA Technical Reports Server (NTRS)

1999-01-01

At the Skid Strip at the Cape Canaveral Air Station, Mission Specialist Michel Tognini of France, representing the Centre National d'Etudes Spatiales (CNES), and his daughter Tatinana prepare to board an aircraft for their return flight to Houston following the completion of the STS-93 Space Shuttle mission. Landing occurred on runway 33 at KSC's Shuttle Landing Facility on July 27 with main gear touchdown at 11:20:35 p.m. EDT. The mission's primary objective was to deploy the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. This was the 95th flight in the Space Shuttle program and the 26th for Columbia. The landing was the 19th consecutive Shuttle landing in Florida and the 12th night landing in Shuttle program history. On this mission, Eileen Collins became the first woman to serve as a Shuttle commander.

STS-93 Commander Collins poses in front of Columbia

NASA Technical Reports Server (NTRS)

1999-01-01

STS-93 Commander Eileen Collins poses in front of the Space Shuttle orbiter Columbia following her textbook landing on runway 33 at the Shuttle Landing Facility. Main gear touchdown occurred at 11:20:35 p.m. EDT on July 27. On this mission, Collins became the first woman to serve as a Shuttle commander. Also on board were her fellow STS-93 crew members: Pilot Jeffrey S. Ashby and Mission Specialists Stephen A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). The mission's primary objective was to deploy the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. This was the 95th flight in the Space Shuttle program and the 26th for Columbia. The landing was the 19th consecutive Shuttle landing in Florida and the 12th night landing in Shuttle program history.

The STS-93 crew pose in front of Columbia

NASA Technical Reports Server (NTRS)

1999-01-01

The STS-93 crew pose in front of the Space Shuttle orbiter Columbia following their landing on runway 33 at the Shuttle Landing Facility. Main gear touchdown occurred at 11:20:35 p.m. EDT on July 27. From left to right, they are Mission Specialists Catherine G. Coleman (Ph.D.) and Stephen A. Hawley (Ph.D.), Pilot Jeffrey S. Ashby, Commander Eileen Collins, and Mission Specialist Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). The mission's primary objective was to deploy the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. This was the 95th flight in the Space Shuttle program and the 26th for Columbia. The landing was the 19th consecutive Shuttle landing in Florida and the 12th night landing in Shuttle program history. On this mission, Collins became the first woman to serve as a Shuttle commander.

KSC-08pd1319

NASA Image and Video Library

2008-04-25

VANDENBERG AIR FORCE BASE, Calif. -- At Vandenberg Air Force Base in California, the Delta II first stage is being raised to a vertical position in front of the mobile service tower on Space Launch Complex 2. Once it is vertical, the first stage will be transferred into the tower. The Delta II is the launch vehicle for the OSTM/Jason-2 spacecraft. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1337

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. -- On Space Launch Complex 2 at Vandenberg Air Force Base in California, the second solid rocket motor, or SRM, is being raised to a vertical position. Once vertical, the SRM will be lifted into the mobile service tower and attached to the Delta II first stage inside. The Delta II is the launch vehicle for the OSTM/Jason-2 spacecraft. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

KSC-08pd1321

NASA Image and Video Library

2008-04-25

VANDENBERG AIR FORCE BASE, Calif. -- At Vandenberg Air Force Base in California, the Delta II first stage has been raised to a vertical position in front of the mobile service tower on Space Launch Complex 2. Next, the first stage will be transferred into the tower. The Delta II is the launch vehicle for the OSTM/Jason-2 spacecraft. The OSTM, or Ocean Topography Mission, on the Jason-2 satellite is a follow-on to Jason-1. It will take oceanographic studies of sea surface height into an operational mode for continued climate forecasting research and science and industrial applications. This satellite altimetry data will help determine ocean circulation, climate change and sea-level rise. OSTM is a joint effort by the National Oceanic and Atmospheric Administration, NASA, France’s Centre National d’Etudes Spatiales and the European Meteorological Satellite Organisation. OSTM/Jason-2 will be launched aboard a United Launch Alliance Delta II 7320 from Vandenberg on June 15. Photo credit: NASA/Dan Liberotti

Contribution to the Study of Phosphate Uptake (P$sup 32$) at the Level of the Thyroid, The Suprarenals, and Testicles after Administration of Epiphysis Hormone; CONTRIBUTION A L'ETUDE DE LA PHOSPHOCAPTATION (P$sup 52$) AU NIVEAU DE LA THYROIDE DES SURRENALES ET DES TESTICULES APRES ADMINISTRATION DE L'EPIPHYSE-HORMONE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Negosscou, I.; Bojinescuu, Al.; Cocou, Fl.

1959-10-31

The phosphorus uptake by several endocrine glands after the administration of epiphysis hormone was studied by a tracer technique. After ten days of daily injections of the hormone into male albino rats, the rats received an injection of P/sup 32/. The hormone was again given 6, 12, and 18 hours after the P/sup 32/ injection. Some animals were killed 8 hours after the administration of phosphorus and the rest after 24 hours. The radioactivity of the epiphysis, hypophysis, thyroid, suprarenals, testicles, and seminal vesicles was determined. The results showed a functional inhibition of the phosphorus uptake in the thyroid, suprarenals,more » testicles, and seminal vesicles. A decrease in the phosphorus uptake by the hypophysis was also observed. (J.S.R.)« less

TOPEX/POSEIDON - Mapping the ocean surface

NASA Technical Reports Server (NTRS)

Yamarone, C. A.; Rosell, S.; Farless, D. L.

1986-01-01

Global efforts are under way to model the earth as a complete planet so that weather patterns may be predicted on time scales of months and years. A major limitation in developing models of global weather is the inability to model the circulation of the oceans including the geostrophic surface currents. NASA will soon be initiating a satellite program to correct this deficiency by directly measuring these currents using the science of radar altimetry. Measurement of the ocean topography with broad, frequent coverage of all ocean basins for a long period of time will allow the derivation of the spatial and temporal behavior of surface ocean currents. The TOPEX/POSEIDON mission is a cooperative effort between NASA and the French Centre National d'Etudes Spatiales. This paper describes the goals of this research mission, the data type to be acquired, the satellite and sensors to be used to acquire the data, and the methods by which the data are to be processed and utilized.

Response functions of Fuji imaging plates to monoenergetic protons in the energy range 0.6-3.2 MeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonnet, T.; Denis-Petit, D.; Gobet, F.

2013-01-15

We have measured the responses of Fuji MS, SR, and TR imaging plates (IPs) to protons with energies ranging from 0.6 to 3.2 MeV. Monoenergetic protons were produced with the 3.5 MV AIFIRA (Applications Interdisciplinaires de Faisceaux d'Ions en Region Aquitaine) accelerator at the Centre d'Etudes Nucleaires de Bordeaux Gradignan (CENBG). The IPs were irradiated with protons backscattered off a tantalum target. We present the photo-stimulated luminescence response of the IPs together with the fading measurements for these IPs. A method is applied to allow correction of fading effects for variable proton irradiation duration. Using the IP fading corrections, amore » model of the IP response function to protons was developed. The model enables extrapolation of the IP response to protons up to proton energies of 10 MeV. Our work is finally compared to previous works conducted on Fuji TR IP response to protons.« less

KSC-08pd1798

NASA Image and Video Library

2008-06-20

PASADENA, Calif. – The NASA-French space agency Ocean Surface Topography Mission/Jason 2 satellite launched aboard a Delta II rocket from Space Launch Complex 2 at Vandenberg Air Force Base, Calif., at 12:46 a.m. PDT. Fifty-five minutes later, OSTM/Jason 2 separated from the rocket’s second stage, and then, unfurled its twin sets of solar arrays. The OSTM/Jason 2 satellite will embark on a globe-circling voyage to continue charting sea level, a vital indicator of global climate change. The mission will return a vast amount of new data that will improve weather, climate and ocean forecasts. OSTM/Jason 2's expected lifetime of at least three years will extend into the next decade the continuous record of these data started in 1992 by NASA and the French space agency Centre National d'Etudes Spatiales, or CNES, with the TOPEX/Poseidon mission. The data collection was continued by the two agencies on Jason 1 in 2001. Photo credit: Carleton Bailie photograph for United Launch Alliance

Etude de la performance des radars hautes-frequences CODAR et WERA pour la mesure des courants marins en presence partielle de glace de mer

NASA Astrophysics Data System (ADS)

Kamli, Emna

Les radars hautes-frequences (RHF) mesurent les courants marins de surface avec une portee pouvant atteindre 200 kilometres et une resolution de l'ordre du kilometre. Cette etude a pour but de caracteriser la performance des RHF, en terme de couverture spatiale, pour la mesure des courants de surface en presence partielle de glace de mer. Pour ce faire, les mesures des courants de deux radars de type CODAR sur la rive sud de l'estuaire maritime du Saint-Laurent, et d'un radar de type WERA sur la rive nord, prises pendant l'hiver 2013, ont ete utilisees. Dans un premier temps, l'aire moyenne journaliere de la zone ou les courants sont mesures par chaque radar a ete comparee a l'energie des vagues de Bragg calculee a partir des donnees brutes d'acceleration fournies par une bouee mouillee dans la zone couverte par les radars. La couverture des CODARs est dependante de la densite d'energie de Bragg, alors que la couverture du WERA y est pratiquement insensible. Un modele de fetch appele GENER a ete force par la vitesse du vent predite par le modele GEM d'Environnement Canada pour estimer la hauteur significative ainsi que la periode modale des vagues. A partir de ces parametres, la densite d'energie des vagues de Bragg a ete evaluee pendant l'hiver a l'aide du spectre theorique de Bretschneider. Ces resultats permettent d'etablir la couverture normale de chaque radar en absence de glace de mer. La concentration de glace de mer, predite par le systeme canadien operationnel de prevision glace-ocean, a ete moyennee sur les differents fetchs du vent selon la direction moyenne journaliere des vagues predites par GENER. Dans un deuxieme temps, la relation entre le ratio des couvertures journalieres obtenues pendant l'hiver 2013 et des couvertures normales de chaque radar d'une part, et la concentration moyenne journaliere de glace de mer d'autre part, a ete etablie. Le ratio des couvertures decroit avec l'augmentation de la concentration de glace de mer pour les deux types de radars, mais pour une concentration de glace de 20% la couverture du WERA est reduite de 34% alors que pour les CODARs elle est reduite de 67%. Les relations empiriques etablies entre la couverture des RHF et les parametres environnementaux (vent et glace de mer) permettront de predire la couverture que pourraient fournir des RHF installes dans d'autres regions soumises a la presence saisonniere de glace de mer.

Education relative a l'environnement (ERE): Une etude des representations sociales et des pratiques educatives d'enseignants de science et technologie du secondaire en contexte de formation continue

NASA Astrophysics Data System (ADS)

Collard-Fortin, Ugo

Le developpement des sciences/technologie a tres clairement contribue a ce que ce dernier domaine de savoirs jouisse d'une place de choix au sein de notre societe. Au-dela des progres de notre civilisation inherents a ce dernier developpement, cette croissance amena avec elle un lot d'ineluctables dommages collateraux, contribuant en corollaire a l'emergence de diverses problematiques environnementales inquietantes pour lesquelles les valeurs ainsi que le mode de fonctionnement de la societe occidentale contemporaine sont largement tributaires. C'est entre autres en reponse a cet etat de fait que la recente vague de reforme de l'Education conduisit a l'integration, dans les curricula de sciences/technologie, de contenus relavant d'education relative a l'environnement (ERE). Face au changement, les enseignants de sciences ont du s'approprier ce nouveau programme afm de l'enseigner a leurs eleves. Toutefois, l'analyse de la situation montre que les prescriptions du programme en matiere d'ERE ne se sont pas toujours traduites en de reelles actions dans la pratique. Le contexte de notre etude s'est interesse aux pratiques educatives de l'ERE ainsi qu'a la representation sociale qui en decoule. Notre recherche aborde plus specifiquement la problematique de la modification de ces derniers objets chez les enseignants de sciences et technologie du deuxieme cycle du secondaire. Pour y arriver, nous avons propose a un groupe de trois praticiens de participer a une activite, en communaute de pratique, de formation continue orientee autour de thematiques ERE. Cette recherche developpement, s'inscrivant dans un paradigme qualitatif/interpretatif, s'est appuyee sur une cueillette de donnees effectuee a partir d'entrevues semi-dirigees, d'observations en situation et d'un groupe de discussion, au debut et a la fm de la formation continue. Les donnees brutes ont ete soumises a une demarche d'analyse inductive et ont genere diverses categories etayant nos objets de recherche. Grosso modo , l'intention de cette formation continue a suivi la piste de la modification des representations sociales ainsi que des pratiques educatives en ERE. Nous avons cherche a savoir si elles se modifieraient ou non pendant la periode de recherche. Les resultats montrent que des elements de modification ont pu etre observes a posteriori, tant dans le discours que dans la pratique. On constate que les enseignants ont, soit bonifie, soit consolide leur representation et leurs pratiques a l'egard de l'ERE.