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  1. Valorisation et Recyclage des Déchets Plastiques dans le Béton

    Directory of Open Access Journals (Sweden)

    Benimam Samir

    2014-04-01

    Full Text Available La valorisation des déchets dans le génie civil est un secteur important dans la mesure où les produits que l’on souhaite obtenir ne sont pas soumis à des critères de qualité trop rigoureux. Le recyclage des déchets touche deux impacts très importants à savoir l’impact et l’impact économique. Donc plusieurs pays du monde, différents déchets sont utilisé dans le domaine de la construction et spécialement dans le ciment ou béton comme poudre, fibres ou agrégats. Ce travail s’intéresse à la valorisation d’un déchet qui est nuisible pour l’environnement vu son caractère encombrant et inesthétique il s’agit du déchet plastique. Trois types de déchets plastiques sont ajoutés dans le béton (sous forme de grains et fibres (ondulées et rectilignes. Les propriétés à l’état frais (maniabilité, air occlus et densité et à l’état durci (résistance à la compression, à la traction, retrait et absorption d’eau des différents bétons réalisés sont analysées et comparés par rapport leurs témoins respectifs. D’après les résultats expérimentaux on peut conclure que le renforcement de la matrice cimentaire avec des fibres plastiques ondulées montrent une nette amélioration de la résistance à la traction du béton ainsi qu’une diminution remarquable de sa capacité d’absorption de l’eau lorsqu’on utilise des grains plastiques.

  2. Doing for Learning? Enseignement des arts plastiques et littératie, des apports réciproques

    Directory of Open Access Journals (Sweden)

    Fabre Sylvain

    2015-01-01

    Full Text Available l'enseignement des arts plastiques (AP en France apporte une contribution spécifique au développement de la littératie des élèves. En effet, si les arts du visuel mettent au défi les possibilités du langage, en ce qui concerne l'expression et l'analyse, ils permettent en retour d'en explorer les différentes dimensions. Trois ordres de bénéfice peuvent être dégagés : a en tant que réalisations de projet, les arts développent l'usage d'outils scripturaires aidant à leur conduite, comme les fiches-projets ou les story-boards. b Les arts permettent de faire l'expérience de la construction des notions, ainsi que de leur valeur d'outillage de la perception et de l'action (notion de proportion par exemple. c Enfin nous faisons l'hypothèse que les arts plastiques favorisent le développement de ce que Vygotski nomme le « langage intérieur »  par des situations permettant l'expérience des processus visuels et gestuels de l'action Ces trois ordres de bénéfice sont complémentaires : ils approfondissent la compréhension de la littératie en même temps qu'ils aident à clarifier les enjeux didactiques de la discipline.

  3. Modèle élasto-plastique à écrouissage microstructural : Application à la mise en forme des tôles métalliques

    OpenAIRE

    Haddag, Badis; BALAN, Tudor; ABED-MERAIM, Farid

    2007-01-01

    Ce travail consiste à étudier par simulation le phénomène du retour élastique dans le procédé d’emboutissage des tôles métalliques. Un modèle phénoménologique d’élasto-plasticité, incluant deux modèles d’écrouissage combiné, a été implanté dans le code d’éléments finis ABAQUS/Standard, via la routine UMAT, suivant un schéma d’intégration implicite. Des simulations de tests rhéologiques, à trajet direct et séquentiels, ont été réalisées pour montrer la capacité de chaque modèle à reproduire le...

  4. Propagation de fissure en mode mixte dans un milieu élasto-plastique avec prise en compte des contraintes résiduelles

    OpenAIRE

    Ma, Shixiang

    2005-01-01

    La bifurcation et la propagation de fissure dans un matériau élasto-plastique sous chargement en mode mixte avec la présence de contraintes résiduelles sont etudiées numériquement et expérimentalement. En combinant les essais expérimentaux et les simulations numériques, nous développons une procédure pour prévoir, sous conditions statiques, le début de propagation, le type de rupture, et le trajet de fissuration dans un matériau ductile. De nombreux essais expérimentaux sont effectués sur les...

  5. Fuites dans les filetages des tubages : influence de la température et du passage dans le domaine plastique Leakage Through Tubular Connections: Influence of Temperature and of Partial Overstressing Unto the Plastic State

    Directory of Open Access Journals (Sweden)

    Bes De Berg F.

    2006-11-01

    Full Text Available Après un rappel des conditions et des résultats du frettage purement mécanique des raccords filetés coniques, puis de l'influence d'une pression intérieure de fluide sur la réaction entre filetage mâle et manchon, l'étude montre que l'existence d'un gradient thermique élevé entre l'intérieur et l'extérieur du raccord bloqué entraîne une variation de la pression de contact dans le filetage (suivant approximativement une loi deltaPbar = 0,5 deltaT(°C qui peut favoriser une fuite. On voit aussi qu'en régime thermique établi (pseudoéquilibre les différences de température entre intérieur et extérieur du raccord sont trop faibles pour avoir quelque influence sur la pression de frettage. Les conséquences d'un accroissement des contraintes entraînant le passage de l'acier du raccord dans le domaine plastique ont été ensuite analysées, dans la perspective d'un critère suivant lequel le cylindre entre en déformation plastique, lorsque la contrainte de cisaillement maximum devient égale à la limite élastique du matériau du raccord. Examinant deux situations bien typées (dont on peut déduire toute situation intermédiaire, soit pression intérieure ou pression extérieure agissant seule, les auteurs montrent que la relaxation lente des contraintes qui avaient amené le matériau dans le domaine plastique, laissent subsister des contraintes résiduelles mobilisables dans un nouveau processus de sollicitation du raccord, pour en accroître d'autant la résistance dans le domaine élastique (à la limite duquel apparaît en principe la pression de fuite. Sous réserve d'un contrôle expérimental, cette démarche pourrait être appliquée en vue d'accroître la pression d'interférence dans les filetages, et d'augmenter les pressions de fuite, ce qui peut prendre une importance particulière dans le cas des tubes les plus épais de chaque dimension nominale, dont la résistance à l'éclatement des corps est toujours sup

  6. TEXTURE ET ANISOTROPIE PLASTIQUE D'ALLIAGES AI-Li

    OpenAIRE

    MIZERA, Jaroslaw

    1993-01-01

    Le rôle spécifique des éléments d'alliage Li, Zr et Cu dans les alliages A1Li est déterminé en termes de leur influence sur l'évolution de la texture pendant un laminage et de leur incidence sur l'anisotropie plastique. Trois alliages modèles (Al-2,3% Li; Al-2,3% Li-0,1% Zr; Al-2,3%-1,2% Cu-0,1% Zr) sont lamines à chaud et à froid jusqu'à une réduction d'épaisseur de 92%. L'évolution de la texture et l'anisotropie des propriétés mécaniques de ces alliages sont caractérisées systématiquement a...

  7. Exploitation des mesures en ligne pour la maîtrise des capacités de filtration sur les bioréacteurs à membranes

    OpenAIRE

    Delrue, F.; Husson, A.; Vedrenne, J.; Racault, Y.

    2009-01-01

    Les bioréacteurs à membranes sont des procédés en pleine expansion dans le domaine du traitement des eaux usées d'origine domestique. Leurs avantages sur les procédés conventionnels par boues activées sont nombreux (capacité épuratoire, compacité, flexibilité, etc ) et concernant leurs contraintes, la maîtrise des capacités de filtration reste le principal souci des exploitants. Deux installations réelles de bioréacteurs à membranes ont été suivies pendant plusieurs mois. Les moyennes journal...

  8. Planification des opérations de cross-docking : prise en compte des incertitudes opérationelles et de la capacité des ressources internes

    OpenAIRE

    Ladier, Anne-Laure

    2014-01-01

    Dans une plateforme de cross-docking, les produits sont déchargés descamions entrants, triés puis directement rechargés dans les camions sortants– chaque produit passe moins de 24 heures sur la plateforme.L’analyse des écarts entre la littérature et les observations réalisées sur leterrain permet de dégager deux axes de recherche : la prise en compte desincertitudes opérationnelles d’une part, et de la capacité des ressourceshumaines de la plateforme d’autre part.Le problème de planification ...

  9. Les innovations de produits dans la chimie du végétal comme substituts aux plastiques

    OpenAIRE

    Manon JUBIEN

    2015-01-01

    La chimie du végétal se définit par l'utilisation de ressources renouvelables au lieu des ressources pétrolières. La chimie du végétal présente une dimension environnementale et est porteuse d'innovations dans les différents domaines de l'industrie chimique. Le polyacide lactique est l'innovation de produit la plus mature et la plus répandue sous diverses applications dans la plasturgie. Cependant, la substituabilité des plastiques pétrosourcés usuels par le polyacide lactique doit être évalu...

  10. Fuites dans les filetages des tubages : influence de la température et du passage dans le domaine plastique Leakage Through Tubular Connections: Influence of Temperature and of Partial Overstressing Unto the Plastic State

    OpenAIRE

    Bes De Berg F.; Retail P.

    2006-01-01

    Après un rappel des conditions et des résultats du frettage purement mécanique des raccords filetés coniques, puis de l'influence d'une pression intérieure de fluide sur la réaction entre filetage mâle et manchon, l'étude montre que l'existence d'un gradient thermique élevé entre l'intérieur et l'extérieur du raccord bloqué entraîne une variation de la pression de contact dans le filetage (suivant approximativement une loi deltaPbar = 0,5 deltaT(°C) qui peut favoriser une fuite. On voit aussi...

  11. Ethylene : composants dynamiques pour la mise en øeuvre d'IHM plastiques en informatique ambiante

    OpenAIRE

    Balme, Lionel; Coutaz, Joëlle

    2009-01-01

    L'informatique ambiante impose de nouvelles contraintes sur la manière de construire les interfaces Homme- Machine (IHM). Traditionnellement centralisée sur un unique dispositif, l'IHM doit maintenant être distribuable de manière opportuniste sur un ensemble dynamique de dispositifs hétérogènes. Ces nouvelles IHM, dites plastiques, sont abordées dans cet article sous l'angle du génie logiciel (GL). Ce sont des logiciels répartis, dynamiquement adaptables, capables de s'affranchir de l'hétérog...

  12. Comment développer des capacités cognitives et métacognitives ?

    OpenAIRE

    Leclercq, Dieudonné; Noel, Bernadette

    2011-01-01

    Les sous-titres de cette section sont : -Quelles capacités cognitives développer ? Comment les exercer et les évaluer ? Quelles capacités métacognitives développer ? Métacognition et degrés de certitude. Métacognition et portfolio. Métacognition et prise de notes.

  13. Effet de taille sur la capacité portante des fondations superficielles

    OpenAIRE

    Garnier, J.

    2003-01-01

    Il y a plus d'un demi siècle que les premières preuves expérimentales de l'effet de la taille sur la portance des fondations ont été apportées et des données nouvelles sont régulièrement produites. De nombreuses théories ont été avancées pour rendre compte de cet effet. Elles sont présentées et comparées dans cet article et des conclusions sont tirées tant pour la prévision de la portance des fondations que pour la conduite d'essais sur ouvrages en semi-grandeur ou sur modèles réduits. Siz...

  14. Simulation par dynamique moléculaire de la déformation élastique et plastique de polyéthylènes semi-cristallins

    OpenAIRE

    Monasse, Bernard; Queyroy, Séverine; Lhost, Olivier

    2007-01-01

    La déformation plastique d'un polyéthylène semi-cristallin est simulée par dynamique moléculaire. Les molécules sont décrites avec tous les atomes pour pouvoir décrire les phases cristalline et amorphe. Dans ce modèle, deux molécules de haute masse molaire participent à la formation de ces deux phases amorphe, avec des conditions triplement périodiques. C'est un des premiers modèles physiquement couplés qui inclus les propriétés d'organisation moléculaire connus. Une traction est appliquée pe...

  15. Étude de l'influence des défauts de soudage sur le comportement plastique et la durée de vie en fatigue de soudures par friction-malaxage d'un alliage Al-Cu-Li

    OpenAIRE

    Le Jolu, Thomas

    2011-01-01

    Dans un but de réduction de poids des avions, un alliage Al-Cu-Li (2198-T8) assemblé par friction-malaxage est envisagé par les avionneurs pour des applications de type fuselage et intrados de l'aile. L'objectif de cette étude est de déterminer le comportement en fatigue des soudures par friction-malaxage et l'influence de certains défauts de soudage pour une durée de vie de l'ordre de 105 cycles. Pour cela le matériau de base, des soudures réalisées pleine tôle (sans défaut), des soudures co...

  16. Produire de la capacité de gestion de crise internationale: le cas de l'OTAN au cours des années 2000

    OpenAIRE

    Wasinski, Christophe

    2009-01-01

    Cette analyse soulève la question de savoir comment l’OTAN parvient à créer sa capacité de gestion de crise. Plus précisément, elle s’intéresse, dans une optique sociologique constructiviste à ceux qui, en parlant au nom de l’OTAN, parviennent à fonder et diffuser la représentation de l’organisation en tant qu’entité capable de résoudre des crises internationales (comme en Afghanistan de nos jours). Le questionnement ne porte donc pas sur la mise en place d’une capacité matérielle de gestion ...

  17. Capacites de morphogenese in vitro de divers clones de lavandes et lavandins : observations preliminaires sur la valeur agronomique des vitroplants

    OpenAIRE

    Chambon, C; Poupet, A; D. Beck; Bettachini, B.; Touche, J

    1992-01-01

    Nous avons comparé les aptitudes morphogénétiques de clones commerciaux de lavandins (Abrial, Grosso, Super) et de lavandes (aspic et Maillette) cultivés in vitro. Des milieux de culture adaptés au développement des apex méristématiques, à la multiplication et à l’enracinement des pousses feuillées de clones de lavandin et de la lavande aspic ont été définis. Des exigences spécifiques des clones sont toutefois apparues, en particulier vis-à-vis des régulateurs de croissance. En revanche, il n...

  18. Elaboration of an Elasto-Plastic Model for High Porosity Chalks. Application to the Compaction of Petroleum Reservoirs Elaboration d'un modèle de comportement élasto-plastique pour les craies très poreuses. Application à la compaction des réservoirs pétroliers

    Directory of Open Access Journals (Sweden)

    Shahrour I.

    2006-11-01

    Full Text Available This paper presents a study of the compaction of petroleum reservoirs applied to very porous carbonate rocks such as chalk. In production estimates made in reservoir engineering, the processing of the mechanical problem is often greatly simplified. Good modelling of how materials behave gives special consideration to the influence of mechanical deformations on fluid recovery. After an analysis of the mechanical behaviour of very porous chalks, an elastoplastic behaviour model is derived so as to reproduce the principal experimental observations. This behaviour model can then be used to perform local simulations of the mechanical behaviour of a reservoir under- going depletion and thus to demonstrate the importance of the stress path and the initial stress state on the deformation of materials and hence on the recovery rate. Dans les applications pétrolières, les études de la compaction des roches réservoirs interviennent dans l'estimation des quantités de fluide récupérables et de la subsidence induite par la déplétion du champ de production. Dans la première partie du travail, nous montrons qu'à partir de l'équation linéarisée de la conservation de la masse de fluide, il est possible d'exprimer un taux de récupération distinguant les contributions respectives du fluide et de la roche. En ingénierie de réservoirs, l'hypothèse d'un chemin de contrainte prépondérant dans le milieu de production permet d'exprimer la contribution de la déformation de la roche au moyen de la compressibilité volumique des pores selon ce chemin. Le taux de récupération obtenu est alors dépendant du chemin de contrainte. Lorsque le chemin de contrainte dans le réservoir n'est pas homogène, il est alors nécessaire de connaître la loi de comportement mécanique du matériau étudié. Dans le cas des carbonates très poreux, nous désirons montrer l'influence liée au choix du chemin de contrainte sur les estimations obtenues par une m

  19. Determination of the exchange capacity of soils using radio-strontium; Determination de la capacite d'echange des sols au moyen du radio-strontium

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-07-01

    In order to improve the technique and in particular to reduce the time required for measuring the exchange capacity of soils, the authors have developed a rapid measurement method based on the use of radio-active tracers. The element chosen for showing the occurrence of exchangeable bases is radio-strontium; it can displace the ions Ca{sup ++}, Mg{sup ++}, Na{sup ++}, K{sup +} from the soil. The use of a de-sorbent, barium chloride, makes it possible to recover the strontium fixed. A comparison of the results obtained using the two methods appears to be very satisfactory. The conventional method requires from 1 1/2 to 2 days - the radio-strontium method requires only 3 hours with the possibility also of carrying out large series of measurements. (authors) [French] Pour ameliorer la technique et surtout reduire le temps de manipulation que necessite la mesure de la capacite d'echange des sols, les auteurs ont mis au point une methode de mesure rapide qui fait appel aux traceurs radioactifs. C'est le radio-strontium qui a ete choisi pour la mise en evidence des bases echangeables. Il permet de deplacer les ions Ca{sup ++}, Mg{sup ++}, Na{sup ++}, K{sup +} du sol. Un desorbant, le chlorure de baryum, permet de recuperer la quantite du strontium fixe. La comparaison des resultats obtenus par les deux methodes semble tres satisfaisante. La methode classique necessite 1 jour et demi a 2 jours - la methode radiostrontium exige seulement 3 heures avec la possibilite de grandes series. (auteurs)

  20. Une etude sur la superiorite des bles hybrides au niveau des capacites de remplissage du grain : resultats d'une experimentation multilocale

    OpenAIRE

    Oury, F.X.; Brabant, P; Pluchard, P; Berard, P.; Rousset, M

    1993-01-01

    Une expérimentation multilocale nous a permis de comparer 29 hybrides de blé tendre d’hiver avec leurs parents, dans des conditions environnementales variées. Ce matériel a été évalué dans des dispositifs en blocs complets randomisés, la parcelle élémentaire ayant au moins 6 m2. Dans les 3 lieux, il y a un hétérosis par rapport au parent supérieur pour la matière sèche aérienne à la récolte. Cette production de biomasse plus importante est associée à un hétérosis pour le rendement en grains, ...

  1. Linguistique textuelle et poésie plastique : quelques enjeux épistémologiques et méthodologiques

    Directory of Open Access Journals (Sweden)

    Chol Isabelle

    2012-07-01

    Full Text Available L'article a pour objectif de montrer comment certaines productions poétiques, depuis le Coup de dés de Mallarmé faisant de l'espacement un élément de composition du texte écrit, interrogent la textualité dans son processus de construction et ses limites. Il s'agira alors de réfléchir sur les possibilités d'une linguistique de l'écrit qui permette d'envisager les processus de textualisation dont la mise en scène dans certaines productions est aussi une mise en question, ainsi que les processus de stylisation qu'ils engagent. Le projet d'une réflexion concernant les outils d'analyse et la démarche interprétative susceptibles de rendre compte des productions poétiques spatialisées s'inscrit actuellement dans le cadre d'un programme ANR (ANR LEC, resp. I. Chol en cours. L'article proposé vise donc simplement à poser quelques jalons pour cette réflexion rendue nécessaire par un corpus d'oeuvres qui échappent aux classifications. Un corpus qui va du début du XXe siècle à nos jours permettra ainsi d'affronter un certain nombre d'outils d'analyse et de concepts à la pratique, et d'émettre quelques propositions, notamment par rapport au concept d' "objet-texte", par rapport à la notion de "syntaxe" et à l'énonciation. Il s'agira aussi de montrer que l'écart que manifestent ses productions avec l'organisation sémantico-syntaxique que la norme communicationnelle suppose ne saurait se résoudre dans le constat d'un double appartenance sémiotique (linguistique et plastique. La dimension linguistique doit elle-même être réévaluée, en partie du moins, par l'élargissement ou l'ajout de certains concepts aptes à rendre compte de l'ensemble des processus de textualisation et de stylisation, incluant notamment le blanc typographique. Un dernier point qui sera alors aussi abordé est celui de l'apparition de nouvelles normes supposant une nouvelle éthique du langage.

  2. Study of human mesenchymal stem cells plasticity into radiation injured tissues in a N.O.D./S.C.I.D. mouse model: therapeutic approach of the multiple organ dysfunction; Etude de la capacite plastique des Cellules Souches Mesenchymateuses humaines (CSM) apres irradiation du tissu receveur: approche therapeutique de l'atteinte multiorgane radio-induite

    Energy Technology Data Exchange (ETDEWEB)

    Francois, S

    2006-01-15

    The therapeutic potential of bone marrow-derived human mesenchymal stem cells (h.M.S.C.) has recently been brought into the spotlight of many fields of research. One possible application of the approach is the repair of injured tissues arising from side effects of radiation treatments and accidents. The first challenge in cell therapy is to assess the quality of the cell and the ability to retain their differentiation potential during the expansion process. Efficient delivery to the sites of intended action is also necessary. We addressed both questions using h.M.S.C. cultured and then infused to Non Obese Diabetes/Severe Combined Immunodeficiency (N.O.D./S.C.I.D.) mice submitted to total body irradiation. Further, we tested the impact of additional local irradiation superimposed to total body irradiation (T.B.I.), as a model of accidental irradiation. Our results showed that the h.M.S.C. used for transplant have been expanded without significant loss in their differentiation capacities. After transplantation into adult unconditioned mice, h.M.S.C. not only migrate in bone marrow but also into other tissues. Total body irradiation increased h.M.S.C. implantation in bone marrow and muscle and further led to engraftment in brain, heart, and liver. Local irradiation, in addition to T.B.I., increased both specific homing of injected cells to the injured tissues and to other tissues outside the local irradiation field. M.S.C. may participate to restoration of intestinal homeostasis 3 days post abdominal irradiation. This study suggests that using the potential of h.M.S.C. to home to various organs in response to tissue injuries could be a promising strategy to repair the radiation induced damages. (author)

  3. Séverisation de l'essai de capacité de charge des lubrifiants sur machine a engrenages FZG Obtaining Greater Severity for the Load-Carrying Capacity Test for Lubricants with the Fzg Gear Machine

    OpenAIRE

    Ayel J.; Kraus Y.; Michel J. P.

    2006-01-01

    La machine à engrenages FZG reste l'appareil de laboratoire le plus utilisé pour l'évaluation de la capacité de charge des lubrifiants pour engrenages et transmissions. Mais, les différentes méthodes normalisées actuellement utilisées ne sont pas assez sévères pour bien discriminer les huiles extrême-pression actuelles en ce qui concerne leur capacité de charge. L'institut Français du Pétrole a développé une méthode beaucoup plus sévère, tout en restant aussi répétable que les méthodes classi...

  4. Have We Overestimated Saline Aquifer CO2 Storage Capacities? Avons-nous surestimé les capacités de stockage de CO2 des aquifères salins ?

    Directory of Open Access Journals (Sweden)

    Thibeau S.

    2011-03-01

    this approach, it is applied to the Utsira aquifer in the North Sea. In Sections 3 and 4, we discuss possible effects that may lead to higher or lower CO2 storage efficiencies. Water production appears to be an attractive strategy in order to address regional scale pressure build up and, consequently, to increase the storage capacity. Following these quantitative applications, we recommend to evaluate the CO2 storage capacities of an aquifer, during a screening study for ranking purposes, using a pressure and compressibility formula rather than a volumetric approach, in order to avoid large overestimation of the aquifer storage capacity. Further studies are naturally required to validate the storage capacities at a qualification stage. Au cours d’opérations à grande échelle de stockage géologique de CO2 dans des aquifères salins, la pression des fluides dans les formations va augmenter, mais devra rester sous des limites définies par des contraintes d’intégrité des sites de stockage. La hausse de pression est la conséquence de deux effets distincts. Premièrement, la pression augmente localement autour des injecteurs de CO2 pour permettre l’injection du CO2 dans les nappes. Cet effet peut être contrôlé en ajoutant des injecteurs de CO2. Deuxièmement, la pression va augmenter à une échelle régionale, soit parce que l’aquifère est fermée, soit parce que le flux d’eau s’échappant de la zone pressurisée ne compense pas volumétriquement le CO2 injecté. Ce second effet ne peut pas être maîtrisé en augmentant le nombre d’injecteurs. Dans la première section du papier, nous discutons sur des évaluations mondiales ou régionales de capacités de stockage du CO2 en aquifère, tant du point de vue de la quantité que de l’efficacité de stockage. Ces capacités sont principalement basées sur une approche volumétrique : la capacité de stockage est la somme des volumes de CO2 pouvant être stockés par différents processus de pi

  5. Contribution à l'analyse des capacités musculaires des membres supérieurs et inférieurs lors de l'actionnement de commandes automobiles. Application au frein à main

    OpenAIRE

    NUMA,J

    2009-01-01

    Mon stage de Master s'est déroulé au Laboratoire de Biomécanique des Chocs (LBMC) de l'Institut National de la Recherche sur les Transports et leur Sécurité (INRETS). Les principaux axes de recherche du LBMC concernent l'amélioration des connaissances biomécaniques sur la structure et le comportement du corps humain en interaction avec son environnement, afin de développer et d'exploiter des outils notamment pour l'évaluation et l'amélioration de la protection des usagers des transpor...

  6. La capacité d'adaptation des enfants et adolescents ayant un parent souffrant d'un trouble de l'humeur: travail de Bachelor

    OpenAIRE

    Héritier, Brinda; Jacovino, Claudia; Miguelez, Vanessa; Rosa, Lindsay; Coulon, Delphine

    2014-01-01

    Contexte : Au niveau mondial, l’augmentation épidémiologique des troubles de l’humeur impose aux sociétés la nécessité d’une prise de conscience des politiques de santé publique. Les enfants ayant un parent atteint d’un trouble de l’humeur sont des sujets fragiles et parfois oubliés des services de santé. Question de recherche : Cette recherche s’inscrit dans la problématique de santé mentale actuelle. L’objectif de cette revue de la littérature est de comprendre comment les enfants et les ad...

  7. Capacitive Extensometer

    Science.gov (United States)

    Perusek, Gail P. (Inventor)

    2003-01-01

    The present invention provides for measurements of the principal strain magnitudes and directions, and maximum shear strain that occurs in a porous specimen, such as plastic, ceramic or porous metal, when it is loaded (or subjected to a load). In one embodiment the invention includes a capacitive delta extensometer arranged with six sensors in a three piece configuration, with each sensor of each pair spaced apart from each other by a predetermined angle, such as 120 degrees.

  8. Action de I'AlA sur la teneur en azote total et protéinique des graines de céréales cultivées à different niveau de la capacité capillaire en eau

    Directory of Open Access Journals (Sweden)

    Wiesław Nowakowski

    2015-06-01

    Full Text Available L'action de I'AIA sur la teneur en azote total et en azote protéinique des graines du Triticum vulgare, d'Hordeum vulgare et d'Avena sativa cultivés a 30%, 60% et 90% de la capacité capillaire en eau du sable a tété étudiée au cours de trois ans (1969, 1970, 1971. La teneur en g-protéines totales liée au rendement des graines de céréales examinees a été plus élevée dans les conditions de sécheresse (30% de la capacite capillaire en eau à la suite d'un traitement auxinique. La teneur (% en azote total et proteinique ne semble pas etre tellement modifiee dans les graines de cereales à la suite d'un traitement auxinique.

  9. L’impact des insectes parasites des graines sur les capacités de régénération naturelle des peuplements de cèdre de l’Atlas et de sapin pectiné en Languedoc-Roussillon

    OpenAIRE

    Candau, Jean-Noël; Boivin, Thomas; Chalon, Alain

    2009-01-01

    La régénération naturelle des peuplements forestiers est soumise à diverses contraintes environnementales, parmi lesquelles, les insectes ravageurs des cônes et des graines jouent un rôle majeur. Depuis 2004, une étude a été menée sur des cédraies et sapinières de la région Languedoc-Roussillon. Les résultats montrent que ces insectes peuvent causer des pertes importantes de graines et, localement, l’impact peut être important. Certaines mesures sanitaires et le maintien du suivi des populati...

  10. False capacitance of supercapacitors

    OpenAIRE

    Ragoisha, G. A.; Aniskevich, Y. M.

    2016-01-01

    Capacitance measurements from cyclic voltammetry, galvanostatic chronopotentiometry and calculation of capacitance from imaginary part of impedance are widely used in investigations of supercapacitors. The methods assume the supercapacitor is a capacitor, while real objects correspond to different equivalent electric circuits and show various contributions of non-capacitive currents to the current which is used for calculation of capacitance. Specific capacitances which are presented in F g-1...

  11. Assemblage mécanique : stratégies d'optimisation des procédés et d'identification des comportements mécaniques des matériaux

    OpenAIRE

    Roux, Émile

    2011-01-01

    Ce travail de thèse porte sur la mise en place d'une méthodologie d'optimisation des procédés d'assemblage, ainsi que sur l'identification de paramètres de lois de comportement et d'endommagement pour la modélisation des assemblages par déformation plastique. La première partie du travail est axée sur la création d'une plateforme d'optimisation et d'analyse inverse permettant d'exploiter des calculs par éléments finis. Dans le cadre du développement de cette plateforme, un algorithme d'optimi...

  12. Des « univers de consolation ». Note sur la sociologie des écrivains amateurs

    Directory of Open Access Journals (Sweden)

    Valérie Stiénon

    2008-09-01

    Full Text Available Du sport aux sciences exactes et aux jeux, de la cuisine aux arts plastiques, l’« amateurisme » est d’une redoutable polyvalence. De même qu’il existe des amateurs parmi les musiciens et les peintres, il s’en trouve également chez les écrivains. L’amateurisme n’a d’ailleurs pas fini d’être récupéré comme objet d’étude de la sociologie, en particulier depuis le développement de la sociologie des loisirs qui a contribué, dans les années 1970, notamment sous l’impulsion de l’étude pionnière de R...

  13. Compatibilité électromagnétiques CEM des systèmes - Matériaux et procédés susceptibles de réduire leurs perturbations électromagnétiques

    OpenAIRE

    Heddebaut, M.; Klingler, M.

    2001-01-01

    Les développements dans le domaine de l'électronique, de l'électrotechnique et de l'informatique industrielle se sont accompagnés de nombreux problèmes de perturbations électromagnétiques. Les faibles niveaux de tension sous lesquels fonctionnent les circuits électroniques, la multiplicité des émissions hertziennes, la coexistence de courants forts et faibles dans un même système, la compacité des installations et le recours aux matériaux composites et plastiques sont les causes principales d...

  14. Mesoscopic Capacitance Oscillations

    OpenAIRE

    Buttiker, Markus; Nigg, Simon

    2006-01-01

    We examine oscillations as a function of Fermi energy in the capacitance of a mesoscopic cavity connected via a single quantum channel to a metallic contact and capacitively coupled to a back gate. The oscillations depend on the distribution of single levels in the cavity, the interaction strength and the transmission probability through the quantum channel. We use a Hartree-Fock approach to exclude self-interaction. The sample specific capacitance oscillations are in marked contrast to the c...

  15. Variable Synthetic Capacitance

    Science.gov (United States)

    Kleinberg, L. L.

    1986-01-01

    Feedback amplifier circuit synthesizes electronically variable capacitance. Variable Synthetic Capacitor is amplifier circuit with follower/feedback configuration. Effective input capacitance depends on input set current. If synthetic capacitor is connected across resonant element of oscillator, oscillator frequency controlled via input set current. Circuit especially suitable for fine frequency adjustments of piezoelectric-crystal or inductor/capacitor resonant oscillators.

  16. Apport des expériences de mécaniques des roches à la géologie structurale des bassins sédimentaires Contribution of Rock-Mechanics Experiments to the Stuctural Geology of Sedimentary Basins

    Directory of Open Access Journals (Sweden)

    Poulet M.

    2006-11-01

    Full Text Available Dans le but de préciser le domaine d'application des expériences de Mécanique des Roches à la Géologie Structurale, l'auteur définit d'abord les ordres de grandeur des différents facteurs qui contrôlent, dans la nature, les relations contrainte déformation : contraintes mises en leu, vitesse de déformation, température, anisotropie des roches. Sont ensuite passés en revue les résultats des essais de laboratoire de type uniaxial (conditions de surface puis de type triaxial (conditions de fond en distinguant dans chaque cas la nature des contraintes intervenant : tension, compression, cisaillement. Le comportement des roches dans les essais en compression permet de les classer en trois catégories : les roches dites élastiques (roches sédimentaires compactes, métamorphiques et cristallines, les roches dites élastoplastiques possédant une certaine porosité (grés, calcaires, les roches dites plastiques (sel, gypse. Sur chaque type ainsi défini les expériences de laboratoire permettent d'étudier l'influence des paramètres suivants : la pression de confinement qui augmente avec la profondeur et permet une déformation permanente importante des roches élasto-plastiques, la pression des fluides qui les rend au contraire plus fragiles, la température dont l'influence est prédominante pour les roches plastiques, le temps qui seul permet des déformations continues importantes sous de faibles contraintes, l'anisotropie liée soit au dépôt (stratification, soit aux déformations antérieures. Bien que les caractéristiques mécaniques mesurées en laboratoire ne soient pas transposables directement dans la nature, les résultats des essais fournissent au géologue une clef pour l'interprétation qualitative de nombreuses observations à petite et grande échelle : relations socle-couverture sédimentaire, conditions de rejeu des accidents anciens, formation des plis, répartition et nature de la tracturation. In on attempt ta

  17. System for Measuring Capacitance

    Science.gov (United States)

    McNichol, Randal S. (Inventor)

    2001-01-01

    A system has been developed for detecting the level of a liquid in a tank wherein a capacitor positioned in the tank has spaced plates which are positioned such that the dielectric between the plates will be either air or the liquid, depending on the depth of the liquid in the tank. An oscillator supplies a sine wave current to the capacitor and a coaxial cable connects the capacitor to a measuring circuit outside the tank. If the cable is very long or the capacitance to be measured is low, the capacitance inherent in the coaxial cable will prevent an accurate reading. To avoid this problem, an inductor is connected across the cable to form with the capacitance of the cable a parallel resonant circuit. The impedance of the parallel resonant circuit is infinite, so that attenuation of the measurement signal by the stray cable capacitance is avoided.

  18. Capacitance pressure sensor

    Science.gov (United States)

    Eaton, William P.; Staple, Bevan D.; Smith, James H.

    2000-01-01

    A microelectromechanical (MEM) capacitance pressure sensor integrated with electronic circuitry on a common substrate and a method for forming such a device are disclosed. The MEM capacitance pressure sensor includes a capacitance pressure sensor formed at least partially in a cavity etched below the surface of a silicon substrate and adjacent circuitry (CMOS, BiCMOS, or bipolar circuitry) formed on the substrate. By forming the capacitance pressure sensor in the cavity, the substrate can be planarized (e.g. by chemical-mechanical polishing) so that a standard set of integrated circuit processing steps can be used to form the electronic circuitry (e.g. using an aluminum or aluminum-alloy interconnect metallization).

  19. Capacitive chemical sensor

    Science.gov (United States)

    Manginell, Ronald P; Moorman, Matthew W; Wheeler, David R

    2014-05-27

    A microfabricated capacitive chemical sensor can be used as an autonomous chemical sensor or as an analyte-sensitive chemical preconcentrator in a larger microanalytical system. The capacitive chemical sensor detects changes in sensing film dielectric properties, such as the dielectric constant, conductivity, or dimensionality. These changes result from the interaction of a target analyte with the sensing film. This capability provides a low-power, self-heating chemical sensor suitable for remote and unattended sensing applications. The capacitive chemical sensor also enables a smart, analyte-sensitive chemical preconcentrator. After sorption of the sample by the sensing film, the film can be rapidly heated to release the sample for further analysis. Therefore, the capacitive chemical sensor can optimize the sample collection time prior to release to enable the rapid and accurate analysis of analytes by a microanalytical system.

  20. Induced Charge Capacitive Deionization

    OpenAIRE

    Rubin, S.; Suss, M. E.; Biesheuvel, P. M.; Bercovici, M.

    2016-01-01

    We demonstrate the phenomenon of induced-charge capacitive deionization (ICCDI) that occurs around a porous and conducting particle immersed in an electrolyte, under the action of an external electrostatic field. The external electric field induces an electric dipole in the porous particle, leading to capacitive charging of its volume by both cations and anions at opposite poles. This regime is characterized both by a large RC charging time and a small electrochemical charge relaxation time, ...

  1. Nonlinear Quantum Capacitance

    OpenAIRE

    Wang, B; Zhao, X; Guo, H; Wang, J.

    1999-01-01

    We analyze the nonlinear voltage dependence of electrochemical capacitance for nanoscale conductors. This voltage dependence is due to the finite density of states of the conductors. Within Hartree theory we derive an exact expression for the electrochemical capacitance–voltage curve for a parallel plate system. The result suggests a quantum scanning capacitance microscopy at the nanoscale: by inverting the capacitance–voltage expression one is able to deduce the local spectral function of th...

  2. Quantum capacitance: a microscopic derivation

    OpenAIRE

    Mukherjee, Sreemoyee; MANNINEN, M; Deo, P. Singha

    2010-01-01

    We start from microscopic approach to many body physics and show the analytical steps and approximations required to arrive at the concept of quantum capacitance. These approximations are valid only in the semi-classical limit and the quantum capacitance in that case is determined by Lindhard function. The effective capacitance is the geometrical capacitance and the quantum capacitance in series, and this too is established starting from a microscopic theory.

  3. Rupture sismique des fondations par perte de capacit\\'e portante: Le cas des semelles circulaires

    OpenAIRE

    Chatzigogos, Charisis; Pecker, Alain; Salençon, J.

    2008-01-01

    Within the context of earthquake-resistant design of shallow foundations, the present study is concerned with the determination of the seismic bearing capacity of a circular footing resting on the surface of a heterogene-ous purely cohesive semi-infinite soil layer. In the first part of the paper, a database, containing case histories of civil engineering structures that sustained a foundation seismic bearing capacity failure, is briefly pre-sented, aiming at a better understanding of the stu...

  4. Rupture sismique des fondations par perte de capacit\\'e portante: Le cas des semelles circulaires

    CERN Document Server

    Chatzigogos, Charisis; Salençon, J

    2008-01-01

    Within the context of earthquake-resistant design of shallow foundations, the present study is concerned with the determination of the seismic bearing capacity of a circular footing resting on the surface of a heterogene-ous purely cohesive semi-infinite soil layer. In the first part of the paper, a database, containing case histories of civil engineering structures that sustained a foundation seismic bearing capacity failure, is briefly pre-sented, aiming at a better understanding of the studied phenomenon and offering a number of case studies useful for validation of theoretical computations. In the second part of the paper, the aforementioned problem is addressed using the kinematic approach of the Yield Design theory, thus establishing optimal upper bounds for the ultimate seismic loads supported by the soil-footing system. The results lead to the establishment of some very simple guidelines that extend the existing formulae for the seismic bearing capacity contained in the European norms (proposed for st...

  5. Pyramide des âges et gestion des ressources humaines

    OpenAIRE

    Godelier, Eric

    2007-01-01

    L'utilisation de la pyramide des âges dans les discours des directeurs de ressources humaines s'est développée au cours des années 1980. Elle renvoie au choix d'un critère de sélection de salariés jugés en sureffectif. Derrière l'âge et ses représentations, c'est bien la question de la capacité des salariés à s'adapter au changement de l'entreprise qui est posée. En définitive, il s'agit de savoir s'il existe des conditions démographiques au changement organisationnel.

  6. Etude des non-linéarités de permittivité de diélectriques utilisés en microélectronique. Application aux capacités MIM.

    OpenAIRE

    Bécu, Stéphane

    2006-01-01

    In order to fabricate ICs with more and more functions it is necessary to develop newelectronic devices. METAL-INSULATOR-METAL (MIM) capacitors integrated in the ICsinterconnections are some of these new devices. ICs down-scaling imposes to reduce MIMcapacitors dimensions and to increase surfacic capacitance. For that using dielectrics withhigher dielectric constant than SiO2 is necessary. Metallic oxides such as Al2O3, Ta2O5and HfO2 are good candidates as dielectrics of MIM capacitors. Never...

  7. Membrane capacitive deionization

    NARCIS (Netherlands)

    Biesheuvel, P.M.; Wal, van der A.

    2010-01-01

    Membrane capacitive deionization (MCDI) is an ion-removal process based on applying an electrical potential difference across an aqueous solution which flows in between oppositely placed porous electrodes, in front of which ion-exchange membranes are positioned. Due to the applied potential, ions ar

  8. Steerable Capacitive Proximity Sensor

    Science.gov (United States)

    Jenstrom, Del T.; Mcconnell, Robert L.

    1994-01-01

    Steerable capacitive proximity sensor of "capaciflector" type based partly on sensing units described in GSC-13377 and GSC-13475. Position of maximum sensitivity adjusted without moving sensor. Voltage of each driven shield adjusted separately to concentrate sensing electric field more toward one side or other.

  9. Digital capacitance measuring system

    Science.gov (United States)

    1973-01-01

    The hardware phase of a digital capacitance measuring system is presented with the major emphasis placed on the electrical design and operation. Test results are included of the three units fabricated. The system's interface is applicable to existing requirements for the space shuttle vehicle.

  10. RECHERCHES Distribution anormale des apolipoprotéines CIII et diminution de la capacité d’efflux de cholestérol du plasma de sujets normolipidémiques présentant une maladie coronarienne précoce

    Directory of Open Access Journals (Sweden)

    Delplanque Bernadette

    2002-07-01

    étaboliquement à une mauvaise épuration postprandiale de particules « remnants », qui sont connues pour être très athérogènes (voir encadré. Enfin, à l’inverse, le transport reverse du cholestérol (RCT des cellules périphériques vers le foie représente une étape critique dans l’épuration du cholestérol et dans la protection vis-à-vis des phénomènes d’athérosclérose. Les HDL sont essentielles dans ce processus, tant pour leur capacité d’efflux de cholestérol cellulaire que pour leur rôle dans le transport en retour du cholestérol vers le foie en vue de son élimination [8-10]. Nous rapportons ici les résultats d’une étude comparant, la distribution des apoCIII plasmatiques et la capacité d’efflux de cholestérol à jeun chez des sujets normolipidémiques présentant ou non une maladie coronarienne.

  11. Plasticité des Interfaces par Perception de l'Interaction Homme-Machine : illustration en oculométrie

    OpenAIRE

    Jambon, Francis; Chappellet, Kévin; Calvary, Gaëlle

    2013-01-01

    Aujourd'hui, les efforts en plasticité des IHM ont principalement porté sur les méthodes de conception. Or, l'utilisation en ligne d'informations sur les perceptions de l'utilisateur est une source d'informations intéressantes pour la plasticité : elle permettrait une adaptation à la volée de l'IHM pour mieux l'ajuster à l'humain. Pour montrer la pertinence et la faisabilité de l'approche, nous avons réalisé un démonstrateur d'une IHM plastique s'adaptant, en ligne, en fonction des interactio...

  12. Junction temp erature measurement of light-emitting dio des using temp erature-dep endent capacitance%利用温变电容特性测量发光二极管结温的研究∗

    Institute of Scientific and Technical Information of China (English)

    招瑜; 魏爱香; 刘俊

    2015-01-01

    结区的温度,简称结温,是发光二极管(LED)的重要参数之一,它对LED 器件的出光效率、光色、器件可靠性和寿命均有很大影响,准确测量LED器件的结温对制备LED芯片、器件封装和应用有着重要的意义。本文利用反向偏压下的LED的势垒电容随温度变化的特性,提出了一种LED结温测量的新方法。论文首先测量和分析了LED在室温下反向偏压时的电容-电压(C-V )曲线和不同反向偏压下的电容-温度(C-T )曲线,结果表明,在合适的偏压下, LED的电容随温度的增大而显著增加,并呈现良好的线性关系。在LED工作中监测其电容的变化,并与C-T曲线进行对比,实现了LED结温的测量,其测量结果和传统的正向电压法的结果相对比,两者符合较好。最后,利用上述方法测量了LED 在恒流和恒压条件下的结温的实时变化过程。较传统的结温测量方法,本方法的优点在于只须要一次定标测量,且可实现LED在任意电压和电流下的结温测量。%Junction temperature, as one of the most important properties of light-emitting diodes (LEDs), has great impact on LEDs’ power efficiency, luminosity, reliability, life-time, and so on. Precise measurement of junction temperature for LED device is quite important in the research of chip’s fabrication, device packaging and related applications. In this paper, we propose a new approach to measure the junction temperature of LEDs by using temperature-dependent capacitance. The capacitance of white LEDs at room temperature is measured and found to be decreased first and then increased with an increasing reverse bias. Equivalent model using vertical and horizontal capacitances connected in parallel is proposed to qualitatively explain the variation of capacitance under different reverse bias. Result obtained from the model fitting agrees well with the experimental result. The capacitance-temperature (C

  13. Induced Charge Capacitive Deionization

    CERN Document Server

    Rubin, S; Biesheuvel, P M; Bercovici, M

    2016-01-01

    We demonstrate the phenomenon of induced-charge capacitive deionization (ICCDI) that occurs around a porous and conducting particle immersed in an electrolyte, under the action of an external electrostatic field. The external electric field induces an electric dipole in the porous particle, leading to capacitive charging of its volume by both cations and anions at opposite poles. This regime is characterized both by a large RC charging time and a small electrochemical charge relaxation time, which leads to rapid and significant deionization of ionic species from a volume which is on the scale of the particle. We show by theory and experiment that the transient response around a cylindrical particle results in spatially non-uniform charging and non-steady growth of depletion regions which emerge around the particle's poles. Potentially, ICCDI can be useful in applications where fast concentration changes of ionic species are required over large volumes.

  14. Molecular Aspects of Capacitation

    OpenAIRE

    Gulfidan Zulfikaroglu; Hulya Ozgur; Sait Polaturkey

    2010-01-01

    Male and female gamets are derived from the primordial germ cells, which migrate from the wall of the yolk sac toward the developing gonads. Following a series of mitotic divisions these cells increase in number at the gonads. The primordial germ cells differentiate into spermatogonia and take the form of mature spermatozoa after spermotogensis and spermotogenesis at puberty. Capacitation is the reaction, which includes all of the molecular and physiological events of mature sperm to gain the...

  15. Capacitance of graphene nanoribbons

    OpenAIRE

    Shylau, A. A.; Klos, J. W.; Zozoulenko, I. V.

    2009-01-01

    We present an analytical theory for the gate electrostatics and the classical and quantum capacitance of the graphene nanoribbons (GNRs) and compare it with the exact self-consistent numerical calculations based on the tight-binding p-orbital Hamiltonian within the Hartree approximation. We demonstrate that the analytical theory is in a good qualitative (and in some aspects quantitative) agreement with the exact calculations. There are however some important discrepancies. In order to underst...

  16. Electrical capacitance clearanceometer

    Science.gov (United States)

    Hester, Norbert J. (Inventor); Hornbeck, Charles E. (Inventor); Young, Joseph C. (Inventor)

    1992-01-01

    A hot gas turbine engine capacitive probe clearanceometer is employed to measure the clearance gap or distance between blade tips on a rotor wheel and its confining casing under operating conditions. A braze sealed tip of the probe carries a capacitor electrode which is electrically connected to an electrical inductor within the probe which is inserted into a turbine casing to position its electrode at the inner surface of the casing. Electrical power is supplied through a voltage controlled variable frequency oscillator having a tuned circuit in which the probe is a component. The oscillator signal is modulated by a change in electrical capacitance between the probe electrode and a passing blade tip surface while an automatic feedback correction circuit corrects oscillator signal drift. A change in distance between a blade tip and the probe electrode is a change in capacitance therebetween which frequency modulates the oscillator signal. The modulated oscillator signal which is then processed through a phase detector and related circuitry to provide an electrical signal is proportional to the clearance gap.

  17. Lutte contre la pauvreté et capacité d’action des femmes dans la longue durée : une discussion autour du concept d’encastrement

    Directory of Open Access Journals (Sweden)

    Karen Bähr Caballero

    2008-12-01

    Full Text Available A partir des années 1990, une nouvelle version du discours dominant sur le développement fait état de la nécessité de réguler certains aspects du marché et de créer des institutions pour soulager l’impact social de la mise en opération de l’économie de marché. Cette évolution pourrait être interprétée comme un scénario d’inclusion et de ré-encastrement de l’économie, dans la mesure où la construction des activités économiques reconnaît désormais l’existence de conditions sociales et institutionnelles comme étant nécessaires à son fonctionnement. Sommes-nous devant un contre-mouvement visant à contrôler l’expansion du modèle néo-libéral et à ré-encastrer l’économie dans le social ? Dans cet article, nous proposons d’explorer les notions d’encastrement-étayage et d’encastrement-insertion, afin d’éclairer le débat sur le " retour de l’État " et ce, dans le cadre d’une étude de cas sur les femmes paysannes comme actrices du développement au Honduras.From the 90’s on, a new version of the dominant discourse on development mentions the need to regulate certain aspects of the market and to create institutions to alleviate the social impacts of the market economy. This evolution could be interpreted as a scenario for inclusion and reembedding the economy, inasmuch as the construction of economic activities now recognizes the existence of social and institutional conditions as essential to its functioning. Are we in the presence of a counter-movement aiming at controlling the expansion of the neo-liberal model and reembedding the economy in the social? In this article, we propose to explore the notions of embeddedness in its various views (amongst which insertion, in order to contribute to the debate on the « return of the State », in the context of a study on women of Honduras as actors of development.

  18. Capacitance of circular patch resonator

    International Nuclear Information System (INIS)

    In this paper the capacitance of the circular microstrip patch resonator is computed. It is shown that the electrostatic problem can be formulated as a system of dual integral equations, and the most interesting techniques of solutions of these systems are reviewed. Some useful approximated formulas for the capacitance are derived and plots of the capacitance are finally given in a wide range of dielectric constants

  19. Capacitance of circular patch resonator

    Energy Technology Data Exchange (ETDEWEB)

    Miano, G.; Verolino, L. [Dip. di Ingegneria Elettrica, Ist. Nazionale di Fisica Nucleare, Naples (Italy); Panariello, G. [Dip. di Ingegneria Elettronica, Naples (Italy); Vaccaro, V.G. [Ist. Nazionale di Fisica Nucleare, Naples (Italy). Dipt. di Scienze Fisiche

    1995-11-01

    In this paper the capacitance of the circular microstrip patch resonator is computed. It is shown that the electrostatic problem can be formulated as a system of dual integral equations, and the most interesting techniques of solutions of these systems are reviewed. Some useful approximated formulas for the capacitance are derived and plots of the capacitance are finally given in a wide range of dielectric constants.

  20. Des interactions biologiques à l’écologie des perturbations

    OpenAIRE

    Ganteaume, A.

    2014-01-01

    / Ce mémoire d'HDR présente mes activités de recherche depuis mon doctorat jusqu’à aujourd’hui. Elles couvrent plusieurs thématiques, toutes dans le domaine de l’écologie, tant au niveau terrestre que marin, dans le domaine animal ou végétal. Elles illustrent parfaitement ma capacité d’adaptation à travailler sur des sujets totalement différents, dans des environnements géographiques différents. Mes activités dans ces différents domaines sont présentées successivement...

  1. Improved Capacitive Liquid Sensor

    Science.gov (United States)

    Waldman, Francis A.

    1992-01-01

    Improved capacitive sensor used to detect presence and/or measure thickness of layer of liquid. Electrical impedance or admittance of sensor measured at prescribed frequency, and thickness of liquid inferred from predetermined theoretical or experimental relationship between impedance and thickness. Sensor is basically a three-terminal device. Features interdigitated driving and sensing electrodes and peripheral coplanar ground electrode that reduces parasitic effects. Patent-pending because first to utilize ground plane as "shunting" electrode. System less expensive than infrared, microwave, or refractive-index systems. Sensor successfully evaluated in commercial production plants to characterize emulsions, slurries, and solutions.

  2. Programmable electronic synthesized capacitance

    Science.gov (United States)

    Kleinberg, Leonard L. (Inventor)

    1987-01-01

    A predetermined and variable synthesized capacitance which may be incorporated into the resonant portion of an electronic oscillator for the purpose of tuning the oscillator comprises a programmable operational amplifier circuit. The operational amplifier circuit has its output connected to its inverting input, in a follower configuration, by a network which is low impedance at the operational frequency of the circuit. The output of the operational amplifier is also connected to the noninverting input by a capacitor. The noninverting input appears as a synthesized capacitance which may be varied with a variation in gain-bandwidth product of the operational amplifier circuit. The gain-bandwidth product may, in turn, be varied with a variation in input set current with a digital to analog converter whose output is varied with a command word. The output impedance of the circuit may also be varied by the output set current. This circuit may provide very small ranges in oscillator frequency with relatively large control voltages unaffected by noise.

  3. A novel capacitive micro-accelerometer with grid strip capacitances and sensing gap alterable capacitances

    Institute of Scientific and Technical Information of China (English)

    Dong Linxi; Chen Jindan; Yan Haixia; Huo Weihong; Li Yongjie; Sun Lingling

    2009-01-01

    The comb capacitances fabricated by deep reactive ion etching (RIE) process have high aspect ratio which is usually smaller than 30 : 1 for the complicated process factors, and the combs are usually not parallel due to the well-known micro-loading effect and other process factors, which restricts the increase of the seismic mass by increasing the thickness of comb to reduce the thermal mechanical noise and the decrease of the gap of the comb capacitances for increasing the sensitive capacitance to reduce the electrical noise. Aiming at the disadvantage of the deep RIE, a novel capacitive micro-accelerometer with grid strip capacitances and sensing gap alterable capacitances is developed. One part of sensing of inertial signal of the micro-accelerometer is by the grid strip capacitances whose overlapping area is variable and which do not have the non-parallel plate's effect caused by the deep RIE process. Another part is by the sensing gap alterable capacitances whose gap between combs can be reduced by the actuators. The designed initial gap of the alterable comb capacitances is relatively large to depress the effect of the maximum aspect ratio (30 : 1) of deep RIE process. The initial gap of the capacitance of the actuator is smaller than the one of the comb capacitances. The difference between the two gaps is the initial gap of the sensitive capacitor. The designed structure depresses greatly the requirement of deep RIE process. The effects of non-parallel combs on the accelerometer are also analyzed. The characteristics of the micro-accelerometer are discussed by field emission microscopy (FEM) tool ANSYS. The tested devices based on slide-film damping effect are fabricated, and the tested quality factor is 514, which shows that grid strip capacitance design can partly improve the resolution and also prove the feasibility of the designed silicon-glass anodically bonding process.

  4. Optimal pricing of capacitated networks

    NARCIS (Netherlands)

    Grigoriev, Alexander; Loon, van Joyce; Sitters, René; Uetz, Marc

    2009-01-01

    We address the algorithmic complexity of a profit maximization problem in capacitated, undirected networks. We are asked to price a set of $m$ capacitated network links to serve a set of $n$ potential customers. Each customer is interested in purchasing a network connection that is specified by a si

  5. Libération des acides gras par autolyse enzymatique des triglycérides des graines oléoprotéagineuses

    Directory of Open Access Journals (Sweden)

    Alibert Gilbert

    2001-01-01

    Full Text Available Les acides gras produits par hydrolyse chimique des lipides des plantes sont des matériaux de base pour l’industrie des biocarburants, des lubrifiants, des plastiques, des détergents et également des adjuvants de préparations commerciales d’herbicides. Cependant les procédés actuels de production des acides gras sont hautement polluants et coûteux en énergie. Dans ce travail nous développons un nouveau procédé de production des acides gras mettant en œuvre des plantes génétiquement modifiées. Nous avons introduit dans le tabac, retenu comme plante modèle, une construction génétique comprenant un gène de lipase (de la levure Geotrichum candidum sous le contrôle d’un promoteur graine spécifique (promoteur AtEm1 d’Arabidopsis thaliana. Ce promoteur devrait permettre l’expression du gène de lipase au niveau de l’axe embryonnaire tandis que les lipides s’accumulent dans les corps lipidiques des cotylédons. Dans ces conditions, les lipides de la graine devraient être séparés de la lipase par une compartimentation tissulaire et ne pas interférer. Après broyage des graines on peut penser que la mise en contact des lipides et de la lipase conduira à la libération d’acides gras. Plusieurs transformants ont été produits par transfert de gène à l’aide d’Agrobacterium tumefaciens, quelques-uns d’entre eux exprimant, comme attendu, la lipase dans leurs graines. Trois clones (2, 19 et 43 présentent une activité lipase significative et ont été retenus pour des études complémentaires. Cependant l’activité enzymatique observée est faible et certains clones présentent un défaut de compartimentation entre l’enzyme et les lipides se traduisant par la production d’acides gras dans la graine intacte. Lorsque les graines du clone 43 sont broyées dans un tampon, des acides gras sont produits dans le milieu réactionnel, validant le procédé imaginé. De nouvelles constructions réalisées, soit

  6. Efficiency of Capacitively Loaded Converters

    DEFF Research Database (Denmark)

    Andersen, Thomas; Huang, Lina; Andersen, Michael A. E.;

    2012-01-01

    introduced as a definition of efficiency. The calculated and measured efficiency curves for charging DEAP actuator, polypropylene film capacitor and X7R MLCC are provided and compared. The attention has to be paid for the voltage dependent capacitive load, like X7R MLCC, when evaluating the charging......This paper explores the characteristic of capacitance versus voltage for dielectric electro active polymer (DEAP) actuator, 2kV polypropylene film capacitor as well as 3kV X7R multi layer ceramic capacitor (MLCC) at the beginning. An energy efficiency for capacitively loaded converters is...... polypropylene film capacitor can be the equivalent capacitive load. Because of the voltage dependent characteristic, X7R MLCC cannot be used to replace the DEAP actuator. However, this type of capacitor can be used to substitute the capacitive actuator with voltage dependent property at the development phase....

  7. Incorporation des principes de la chimie verte dans la synthèse de semi-conducteurs organiques

    OpenAIRE

    Faurie, Alexandre

    2015-01-01

    Les travaux réalisés aux cours de cette thèse ont pour but de proposer une alternative verte à la synthèse de nouveaux systèmes conjugués linéaires pour des applications en électronique plastique. La première partie sera consacrée à l’élaboration de systèmes conjugués de type D-A par une combinaison de réactions vertes : substitution nucléophile aromatique et condensation de Knoevenagel réalisées,respectivement, dans l’eau et l’éthanol. De plus, une nouvelle méthodologie sera explorée pour re...

  8. Analyse des besoins des usagers

    OpenAIRE

    KHOUDOUR,L; LANGLAIS,A; Charpentier, C.; MOTTE,C; PIAN,C

    2002-01-01

    Il s'agit d'étendre la surveillance vidéo de l'enceinte du métro vers l'intérieur des rames. Les images captées constituent des prises de vue des événements qui se déroulent à l'intérieur des véhicules afin notamment d'améliorer la sécurité des usagers transportes. Il est possible de mémoriser les images des quelques instants précédant un incident usager, d'analyser ces images en temps différé et de mieux appréhender en temps réel le comportement des usagers face à des événements ou des consi...

  9. Capacitive Position Sensor For Accelerometer

    Science.gov (United States)

    Vanzandt, Thomas R.; Kaiser, William J.; Kenny, Thomas W.

    1995-01-01

    Capacitive position sensor measures displacement of proof mass in prototype accelerometer described in "Single-Crystal Springs for Accelerometers" (NPO-18795). Sensor is ultrasensitive, miniature device operating at ultra-high frequency and described in more detail in "Ultra-High-Frequency Capacitive Displacement Sensor," (NPO-18675). Advances in design and fabrication of prototype accelerometer also applicable to magnetometers and other sensors in which sensed quantities measured in terms of deflections of small springs.

  10. Intérêts de l'utilisation d'un pansement liquide vétérinaire sur des plaies d'ovariectomie : étude clinique sur 100 chattes

    OpenAIRE

    Papillon, Amandine

    2011-01-01

    Les pansements liquides sont utilisés depuis des années en médecine humaine pour diverses utilisations (dermatologie, chirurgie plastique, ophtalmologie, ...). La médecine vétérinaire n'utilise pas encore au quotidien ce type de produit. Il existe une formulation adaptée à l’usage vétérinaire. Dans cette étude prospective, il a été testé son utilisation sur 100 chattes pour protéger les plaies d’ovariectomie. Les animaux sont rentrés chez eux sans collerette. Au retrait des points, il a été d...

  11. The concept of chemical capacitance, A critique.

    OpenAIRE

    Trissl, H. W.

    1981-01-01

    The concept of chemical capacitance as introduced by Hong and Mauzerall (Proc. Natl. Acad. Sci. U.S.A. 1974. 71:1564) is critically reexamined. This novel capacitance was introduced to explain the time-course of flash-induced photocurrents observed in lipid bilayer membranes containing porphyrins. According to Hong and Mauzerall, the chemical capacitance results from a combination of three fundamental capacitances: the geometric membrane capacitance and the two interfacial double layer capaci...

  12. Adsorption de PCB par des phases HDL organomodifiées

    OpenAIRE

    Dumas, Edith; Laforest, Valérie; De Roy, Marie-Elisabeth; Forano, Claude; Bourgois, Jacques

    2012-01-01

    Les PCB sont des polluants persistants pour lesquels il faut encore chercher des solutions permettant de les retirer des sédiments. Le lavage par des tensioactifs offre de bons rendements de nettoyage. Il faut ensuite traiter les eaux du lessivage. Les Hydroxydes Doubles Lamellaires (HDL) ont montré des capacités intéressantes pour l'adsorption de polluants. L'insertion de tensioactifs lors de la synthèse de ces matériaux permet d'intercaler des polluants hydrophobes entre les feuillets bruci...

  13. ADONIS : adoption des nouvelles informations spatialisées

    OpenAIRE

    Roche, Stéphane

    2013-01-01

    Note portant sur l’auteur PROBLÉMATIQUE ET OBJECTIFS INITIAUX La problématique de recherche initiale est centrée sur l’analyse des modes de participation publique en matière d’aménagement urbain et des formes d’appropriation sociale des TIC/TIG (Technologies de l’Information Géographique). La question des relations de cause à effet entre capacité différenciée d’appropriation des TIC/TIG et niveau de participation des citoyens est posée. Les effets de ces phénomènes dans le domaine des pratiqu...

  14. Borehole Breakout. Bibliographic Synthesis L'ovalisation des trous de forages. Synthèse bibliographique

    Directory of Open Access Journals (Sweden)

    Gauer P.

    2006-11-01

    Full Text Available Natural borehole breakout (borehole cross-section elongation due to the fracturing and spalling of well walls has been used in recent years to determine the direction of stress in the Earth's crust. Its performances and scope of application are compared to those of other methods used in boreholes. An initial selection of information obtained by different logging tools appeared necessary to prevent any contamination of measurements by phenomena independent of deformation under stress. The principal parameters governing the amplitude and frequency of the phenomenon are reviewed. The outlook for the future of the method are examined, including the recent development of research on borehole breakout by the plastic deformation of the surrounding formations. L'ovalisation naturelle des trous de forages par fracturation et écaillage des parois du puits est utilisée, depuis quelques années, pour déterminer la direction des contraintes dans la croûte. Ses performances et son champ d'application sont comparés à ceux des autres méthodes utilisées dans les forages. Une sélection initiale de l'information fournie par les différents outils diagraphiques apparaît nécessaire, pour éviter toutes contaminations des mesures par des phénomènes indépendants de la déformation sous contraintes. Les principaux paramètres contrôlant l'ampleur et la fréquence du phénomène sont passés en revue. Enfin, les perspectives concernant l'avenir de la méthode, et parmi celles-ci le développement récent de l'étude de l'ovalisation par la déformation plastique de l'encaissant, sont examinées.

  15. Matériau plastique composite sous la forme de granulats issus de matières protéiques végétales et son procédé de fabrication

    OpenAIRE

    Humbert, Julien; Makoumbou, Urbain; Rigal, Luc; Chelle, René; Rouilly, Antoine; Geneau Sbartai, Celine

    2010-01-01

    La présente invention concerne un procédé de préparation d'agrogranulats plastiques composites stables et calibrés comprenant les étapes suivantes: - introduire un sel de sulfites en solution dans un dispositif d'extrusion préalablement chargé en matière protéique végétale et en eau de telle sorte que la proportion de sulfite SO soit comprise entre 1 et 10 grammes pour 100 grammes de protéines, - ajuster la quantité d'eau de manière à obtenir un mélange comprenant 10 à 40 % en eau, - porter l...

  16. L'accessibilité des réseaux de transport en commun en Europe : état des lieux des pratiques de référence

    OpenAIRE

    Thomas, Rachel; Rémy, Nicolas; Léothaud, Isabelle

    2007-01-01

    L'Europe vieillit. Selon un rapport de la Conférence Européenne des Ministres des Transports, la proportion du nombre des personnes âgées de plus de 65 ans augmentera d'environ 40 % dans les trente prochaines années, dans les pays membres (CEMT, 2002). Or en vieillissant, la population subit un certain nombre d'altérations de ses capacités fonctionnelles ou sensorielles, et multiplie l'expérience des situations de handicap. Pour faire face à cette évolution, les pays européens adoptent des me...

  17. INFLUENCE DES CONDITIONS D'ENCASTREMENT SUR LES CARACTÉRISTIQUES D'UN CAPTEUR UTILISÉ EN TÉLÉHONIE

    OpenAIRE

    Zoghdani, A.; BRISSAUD, M; Grange, G.

    1992-01-01

    La réalisation de microphones et d'écouteurs fait, actuellement, de plus en plus appel aux matériaux céramiques piézoélectriques. L'élément moteur, généralement constitué d'un diaphragme métallique en laiton sur lequel est collé un disque céramique mince piézoélectrique est enfermé dans un boîtier en matière plastique qui assure le maintien du diaphragme et une insertion simple dans le combiné. Du fait de l'élasticité du boîtier le diaphragme n'est pas rigidement bridé. Il s'ensuit des modifi...

  18. Improving capacitance/damping ratio in a capacitive MEMS transducer

    International Nuclear Information System (INIS)

    Damping forces play an important role in capacitive MEMS (microelectromechanical systems) behavior, and typical damper design (parallel-plates) cannot address the design conflict between increase in electrical capacitance and damping reduction. Squeeze-film damping in in-plane parallel-plate MEMS is discussed here and a novel damper geometry for gap-varying parallel-plates is introduced and used to increase the capacitance/damping ratio. The new geometry is compared with a typical parallel-plate design for an silicon-on-insulator process (25 µm thick) and experimental data shows an approximate 25% to 50% reduction for the damping coefficient in structures with 500 µm long dampers (for a gap variation between 0.75 and 3.75 µm), in agreement with computational fluid dynamics simulations, without significantly affecting the capacitance value (∼4% reduction). Preliminary simulations to study the role of the different geometric parameters involved in the improved geometry are also performed and reveal that the channel width is the most critical value for effective damping reduction. (paper)

  19. Driven shielding capacitive proximity sensor

    Science.gov (United States)

    Vranish, John M. (Inventor); McConnell, Robert L. (Inventor)

    2000-01-01

    A capacitive proximity sensing element, backed by a reflector driven at the same voltage as and in phase with the sensor, is used to reflect the field lines away from a grounded robot arm towards an intruding object, thus dramatically increasing the sensor's range and sensitivity.

  20. Water desalination via capacitive deionization

    NARCIS (Netherlands)

    Suss, M.E.; Porada, S.; Sun, X.; Biesheuvel, P.M.; Yoon, J.; Presser, V.

    2015-01-01

    Capacitive deionization (CDI) is an emerging technology for the facile removal of charged ionic species from aqueous solutions, and is currently being widely explored for water desalination applications. The technology is based on ion electrosorption at the surface of a pair of electrically charg

  1. Voltage Dependence of Supercapacitor Capacitance

    Directory of Open Access Journals (Sweden)

    Szewczyk Arkadiusz

    2016-09-01

    Full Text Available Electronic Double-Layer Capacitors (EDLC, called Supercapacitors (SC, are electronic devices that are capable to store a relatively high amount of energy in a small volume comparing to other types of capacitors. They are composed of an activated carbon layer and electrolyte solution. The charge is stored on electrodes, forming the Helmholtz layer, and in electrolyte. The capacitance of supercapacitor is voltage- dependent. We propose an experimental method, based on monitoring of charging and discharging a supercapacitor, which enables to evaluate the charge in an SC structure as well as the Capacitance-Voltage (C-V dependence. The measurement setup, method and experimental results of charging/discharging commercially available supercapacitors in various voltage and current conditions are presented. The total charge stored in an SC structure is proportional to the square of voltage at SC electrodes while the charge on electrodes increases linearly with the voltage on SC electrodes. The Helmholtz capacitance increases linearly with the voltage bias while a sublinear increase of total capacitance was found. The voltage on SC increases after the discharge of electrodes due to diffusion of charges from the electrolyte to the electrodes. We have found that the recovery voltage value is linearly proportional to the initial bias voltage value.

  2. Capacitive Proximity Sensor Has Longer Range

    Science.gov (United States)

    Vranish, John M.

    1992-01-01

    Capacitive proximity sensor on robot arm detects nearby object via capacitive effect of object on frequency of oscillator. Sensing element part of oscillator circuit operating at about 20 kHz. Total capacitance between sensing element and ground constitutes tuning capacitance of oscillator. Sensor circuit includes shield driven by replica of alternating voltage applied to sensing element. Driven shield concentrates sensing electrostatic field in exterior region to enhance sensitivity to object. Sensitivity and dynamic range has corresponding 12-to-1 improvement.

  3. Active Targets For Capacitive Proximity Sensors

    Science.gov (United States)

    Jenstrom, Del T.; Mcconnell, Robert L.

    1994-01-01

    Lightweight, low-power active targets devised for use with improved capacitive proximity sensors described in "Capacitive Proximity Sensor Has Longer Range" (GSC-13377), and "Capacitive Proximity Sensors With Additional Driven Shields" (GSC-13475). Active targets are short-distance electrostatic beacons; they generate known alternating electro-static fields used for alignment and/or to measure distances.

  4. Chimie des processus biologiques : une introduction

    OpenAIRE

    Corvol, Pierre; Fontecave, Marc

    2013-01-01

    La vie dépend de la capacité des organismes vivants à utiliser efficacement le potentiel chimique de leur environnement : le soleil, pour l’énergie, et un certain nombre de molécules accumulées à la surface de la terre (eau, oxygène, dioxyde de carbone, azote, etc.). Pour en tirer parti, il faut les activer, et cela nécessite des modifications électroniques profondes que seuls les ions métalliques permettent. Les métalloenzymes qui réalisent ces activations sont véritablement extraordinaires,...

  5. Effects of stray capacitance to ground in bipolar water impedance measurements based on capacitive electrodes

    OpenAIRE

    Pallàs Areny, Ramon; Aliau Bonet, Carles

    2015-01-01

    Liquid impedance measurements based on capacitive (or contactless) electrodes Overcome electrode polarization problems but are affected by stray capacitance from the material being measured to ground, the same as measurements with direct-contact electrodes. This study shows that the effects of that capacitance depend on the impedance being measured and for bipolar impedance measurements they increase when the ratio between that stray capacitance and lectrode capacitance increases.

  6. Full-bridge capacitive extensometer

    Science.gov (United States)

    Peters, Randall D.

    1993-08-01

    Capacitive transducers have proven to be very effective sensors of small displacements, because of inherent stability and noninvasive high resolution. The most versatile ones have been those of a differential type, in which two elements are altered in opposite directions in response to change of the system parameter being monitored. Oftentimes, this differential pair has been incorporated into a bridge circuit, which is a useful means for employing synchronous detection to improve signal to noise ratios. Unlike previous differential capacitive dilatometers which used only two active capacitors, the present sensor is a full-bridge type, which is well suited to measuring low-level thermal expansions. This analog sensor is capable of 0.1 μm resolution anywhere within a range of several centimeters, with a linearity of 0.1%. Its user friendly output can be put on a strip chart recorder or directed to a computer for sophisticated data analysis.

  7. Water desalination via capacitive deionization

    OpenAIRE

    Suss, M. E.; Porada, S.; Sun, X.; Biesheuvel, P. M.; Yoon, J.; Presser, V.

    2015-01-01

    Capacitive deionization (CDI) is an emerging technology for the facile removal of charged ionic species from aqueous solutions, and is currently being widely explored for water desalination applications. The technology is based on ion electrosorption at the surface of a pair of electrically charged electrodes, commonly composed of highly porous carbon materials. The CDI community has grown exponentially over the past decade, driving tremendous advances via new cell architectures and system de...

  8. Capacitive de-ionization electrode

    Energy Technology Data Exchange (ETDEWEB)

    Daily, III, William D.

    2013-03-19

    An electrode "cell" for use in a capacitive deionization (CDI) reactor consists of the electrode support structure, a non-reactive conductive material, the electrode accompaniment or substrate and a flow through screen/separator. These "layers" are repeated and the electrodes are sealed together with gaskets between two end plates to create stacked sets of alternating anode and cathode electrodes in the CDI reactor.

  9. Capacitively-Heated Fluidized Bed

    Science.gov (United States)

    Mchale, E. J.

    1982-01-01

    Fluidized-bed chamber in which particles in bed are capacitively heated produces high yields of polycrystalline silicon for semiconductor devices. Deposition of unrecoverable silicon on chamber wall is reduced, and amount of recoverable silicon depositing on seed particles in bed is increased. Particles also have a size and density suitable for direct handling without consolidation, unlike silicon dust produced in heated-wall chambers.

  10. Caractérisation électrique des interfaces métal-semiconducteur

    OpenAIRE

    Barret, C.; Lu, G.N.; Neffati, T.

    1987-01-01

    Nous présentons un panorama des caractérisations électriques des interfaces métal-semiconducteur. Nous montrons que la nécessité d'effectuer des mesures de barrière précises implique une amélioration des interprétations des anomalies des caractéristiques I-V et C-V des diodes réelles. D'autre part, l'étude des états d'interface par Spectroscopie de Capacité Schottky met en évidence l'existence d'états bien localisés énergétiquement mais à profondeur de pénétration significative dans le semico...

  11. An approach to evaluate capacitance, capacitive reactance and resistance of pivoted pads of a thrust bearing

    Science.gov (United States)

    Prashad, Har

    1992-07-01

    A theoretical approach is developed for determining the capacitance and active resistance between the interacting surfaces of pivoted pads and thrust collar, under different conditions of operation. It is shown that resistance and capacitive reactance of a thrust bearing decrease with the number of pads times the values of these parameters for an individual pad, and that capacitance increases with the number of pads times the capacitance of an individual pad. The analysis presented has a potential to diagnose the behavior of pivoted pad thrust bearings with the angle of tilt and the ratio of film thickness at the leading to trailing edge, by determining the variation of capacitance, resistance, and capacitive reactance.

  12. De l'appropriation des connaissances vers l'acquisition des compétences

    OpenAIRE

    Castillo, Oswaldo; Matta, Nada; Ermine, Jean-Louis

    2004-01-01

    La gestion explicite des savoirs et savoir-faire occupe une place de plus en plus importante dans les organisations. La construction de mémoires d'entreprise dans un but de préservation et de partage est devenu une pratique assez courante. Cependant, on oublie trop souvent que l'efficacité de ces activités est étroitement liée aux capacités d'appropriation et d'apprentissage des acteurs de l'organisation. C'est à travers cet apprentissage que de nouvelles compétences peuvent être acquises. Da...

  13. Capacitance enhancement via electrode patterning.

    Science.gov (United States)

    Ho, Tuan A; Striolo, Alberto

    2013-11-28

    The necessity of increasing the energy density in electric double layer capacitors to meet current demand is fueling fundamental and applied research alike. We report here molecular dynamics simulation results for aqueous electrolytes near model electrodes. Particular focus is on the effect of electrode patterning on the structure of interfacial electrolytes, and on the potential drop between the solid electrodes and the bulk electrolytes. The latter is estimated by numerically integrating the Poisson equation using the charge densities due to water and ions accumulated near the interface as input. We considered uniform and patterned electrodes, both positively and negatively charged. The uniformly charged electrodes are modeled as graphite. The patterned ones are obtained by removing carbon atoms from the top-most graphene layer, yielding nanoscopic squares and stripes patterns. For simplicity, the patterned electrodes are effectively simulated as insulators (the charge remains localized on the top-most layer of carbon atoms). Our simulations show that the patterns alter the structure of water and the accumulation of ions at the liquid-solid interfaces. Using aqueous NaCl solutions, we found that while the capacitance calculated for three positively charged electrodes did not change much, that calculated for the negatively charged electrodes significantly increased upon patterning. We find that both water structure and orientation, as well as ion accumulation affect the capacitance. As electrode patterning affects differently water structure and ion accumulation, it might be possible to observe ion-specific effects. These results could be useful for advancing our understanding of electric double layer capacitors, capacitive desalination processes, as well as of fundamental interfacial electrolytes properties. PMID:24289370

  14. Dual Cryogenic Capacitive Density Sensor

    Science.gov (United States)

    Youngquist, Robert; Mata, Carlos; Vokrot, Peter; Cox, Robert

    2009-01-01

    A dual cryogenic capacitive density sensor has been developed. The device contains capacitive sensors that monitor two-phase cryogenic flow density to within 1% accuracy, which, if temperature were known, could be used to determine the ratio of liquid to gas in the line. Two of these density sensors, located a known distance apart, comprise the sensor, providing some information on the velocity of the flow. This sensor was constructed as a proposed mass flowmeter with high data acquisition rates. Without moving parts, this device is capable of detecting the density change within a two-phase cryogenic flow more than 100 times a second. Detection is enabled by a series of two sets of five parallel plates with stainless steel, cryogenically rated tubing. The parallel plates form the two capacitive sensors, which are measured by electrically isolated digital electronics. These capacitors monitor the dielectric of the flow essentially the density of the flow and can be used to determine (along with temperature) the ratio of cryogenic liquid to gas. Combining this information with the velocity of the flow can, with care, be used to approximate the total two-phase mass flow. The sensor can be operated at moderately high pressures and can be lowered into a cryogenic bath. The electronics have been substantially improved over the older sensors, incorporating a better microprocessor, elaborate ground loop protection and noise limiting circuitry, and reduced temperature sensitivity. At the time of this writing, this design has been bench tested at room temperature, but actual cryogenic tests are pending

  15. Nucleotide Capacitance Calculation for DNA Sequencing

    OpenAIRE

    Lu, Jun-Qiang; Zhang, X.-G.

    2008-01-01

    Using a first-principles linear response theory, the capacitance of the DNA nucleotides, adenine, cytosine, guanine, and thymine, are calculated. The difference in the capacitance between the nucleotides is studied with respect to conformational distortion. The result suggests that although an alternate current capacitance measurement of a single-stranded DNA chain threaded through a nanogap electrode may not be sufficient to be used as a standalone method for rapid DNA sequencing, the capaci...

  16. Electrical Capacitance Volume Tomography: Design and Applications

    OpenAIRE

    Warsito Warsito; Liang-Shih Fan; Qussai Marashdeh; Fei Wang

    2010-01-01

    This article reports recent advances and progress in the field of electrical capacitance volume tomography (ECVT). ECVT, developed from the two-dimensional electrical capacitance tomography (ECT), is a promising non-intrusive imaging technology that can provide real-time three-dimensional images of the sensing domain. Images are reconstructed from capacitance measurements acquired by electrodes placed on the outside boundary of the testing vessel. In this article, a review of progress on capa...

  17. Electrochemical capacitance of a leaky nanocapacitor

    OpenAIRE

    Zhao, X; Guo, H; Wang, J.

    1999-01-01

    We report a detailed theoretical investigation on electrochemical capacitance of a nanoscale capacitor where there is a DC coupling between the two conductors. For this ``leaky'' quantum capacitor, we have derived general analytic expressions of the linear and second order nonlinear electrochemical capacitance within a first principles quantum theory in the discrete potential approximation. Linear and nonlinear capacitance coefficients are also derived in a self-consistent manner without the ...

  18. Flexible PVDF ferroelectric capacitive temperature sensor

    KAUST Repository

    Khan, Naveed

    2015-08-02

    In this paper, a capacitive temperature sensor based on polyvinylidene fluoride (PVDF) capacitor is explored. The PVDF capacitor is characterized below its Curie temperature. The capacitance of the PVDF capacitor changes vs temperature with a sensitivity of 16pF/°C. The linearity measurement of the capacitance-temperature relation shows less than 0.7°C error from a best fit straight line. An LC oscillator based temperature sensor is demonstrated based on this capacitor.

  19. Detection of Telomerase Activity Using Capacitance Measurements

    Science.gov (United States)

    Kang, Bong Keun; Lee, Ri Mi; Choi, Ahmi; Jung, Hyo-Il; Yoo, Kyung-Hwa

    2007-03-01

    Telomerase activity has been found in about 85% cancer cells, while no activity observed in normal cells, so that telomerase has been proposed as a marker for cancer detection. Here, we describe electrical detection of telomerase activity using capacitance measurements. We have investigated the length dependence of capacitance on DNA solutions and found that the capacitance of DNA solutions were dependent on the DNA length. In addition, upon adding telomerase into the solution of telomeric substrate primer, the capacitance was observed to change as a function of time due to the telomeric elongation. These results suggest that this novel nanosensor may be used for rapid detection of telomerase activity.

  20. ÉTUDE DU TRAITEMENT DES SILOXANES PAR ADSORPTION SUR MATÉRIAUX POREUX : APPLICATION AU TRAITEMENT DES BIOGAZ

    OpenAIRE

    Ricaurte Ortega, Deyanira

    2009-01-01

    Étude du traitement des siloxanes par adsorption sur matériaux poreux : application au traitement des biogaz Les biogaz sont des mélanges à forte teneur en méthane utilisés dans la production de chaleur ou d'électricité. Ils contiennent des quantités plus ou moins importantes de siloxanes qui sont interdits pour de nombreuses utilisations du biogaz. La possibilité d'élimination des siloxanes par adsorption est étudiée. Une étude en réacteurs statiques permet d'évaluer les capacités d'adsorpti...

  1. Module Eleven: Capacitance; Basic Electricity and Electronics Individualized Learning System.

    Science.gov (United States)

    Bureau of Naval Personnel, Washington, DC.

    In this module the student will learn about another circuit quantity, capacitance, and discover the effects of this component on circuit current, voltage, and power. The module is divided into seven lessons: the capacitor, theory of capacitance, total capacitance, RC (resistive-capacitive circuit) time constant, capacitive reactance, phase and…

  2. Capacitance Measurement with a Sigma Delta Converter for 3D Electrical Capacitance Tomography

    Science.gov (United States)

    Nurge, Mark

    2005-01-01

    This paper will explore suitability of a newly available capacitance to digital converter for use in a 3D Electrical Capacitance Tomography system. A switch design is presented along with circuitry needed to extend the range of the capacitance to digital converter. Results are then discussed for a 15+ hour drift and noise test.

  3. Ultrahigh Temperature Capacitive Pressure Sensor

    Science.gov (United States)

    Harsh, Kevin

    2014-01-01

    Robust, miniaturized sensing systems are needed to improve performance, increase efficiency, and track system health status and failure modes of advanced propulsion systems. Because microsensors must operate in extremely harsh environments, there are many technical challenges involved in developing reliable systems. In addition to high temperatures and pressures, sensing systems are exposed to oxidation, corrosion, thermal shock, fatigue, fouling, and abrasive wear. In these harsh conditions, sensors must be able to withstand high flow rates, vibration, jet fuel, and exhaust. In order for existing and future aeropropulsion turbine engines to improve safety and reduce cost and emissions while controlling engine instabilities, more accurate and complete sensor information is necessary. High-temperature (300 to 1,350 C) capacitive pressure sensors are of particular interest due to their high measurement bandwidth and inherent suitability for wireless readout schemes. The objective of this project is to develop a capacitive pressure sensor based on silicon carbon nitride (SiCN), a new class of high-temperature ceramic materials, which possesses excellent mechanical and electric properties at temperatures up to 1,600 C.

  4. Comportement rhéologique des systèmes mixtes biopolymères / protéines

    Science.gov (United States)

    Rebiha, M.; Moulai-Mostefa, N.; Sadok, A. Hadj; Sabri, N.

    2005-05-01

    Dans ce travail, on s'est intéressé à l'étude des effets du caséinate de sodium et du xanthane sur les propriétés rhéologiques des solutions aqueuses, préparées suivant un plan d'expériences. Les caractéristiques mécaniques obtenues sont traduites par les coefficients du modèle rhéologique de Casson, en l'occurrence la contrainte seuil, τ 0, et la viscosité plastique, η _c. Ainsi, à l'issue de la modélisation en surface de réponses, il apparaît une interaction répulsive à l'échelle structurale entre le caséinate de sodium et le xanthane, traduite par un abaissement considérable de τ 0. Cet baissement de la rigidité peut conduire à une séparation de phases, phénomène conditionné par la viscosité limite de Casson,η _c.

  5. The Pyramidal Capacitated Vehicle Routing Problem

    DEFF Research Database (Denmark)

    Lysgaard, Jens

    This paper introduces the Pyramidal Capacitated Vehicle Routing Problem (PCVRP) as a restricted version of the Capacitated Vehicle Routing Problem (CVRP). In the PCVRP each route is required to be pyramidal in a sense generalized from the Pyramidal Traveling Salesman Problem (PTSP). A pyramidal...

  6. Dissecting graphene capacitance in electrochemical cell

    International Nuclear Information System (INIS)

    Quantum capacitance of graphene plays a significant role for graphene's applications in electrochemical devices and sensors, while the determination of these basic characters of Dirac point, Fermi energy, quantum capacitance, etc is still a subject of considerable debate in both experiments and simulations. Here, we report joint first-principles/continuum calculations (JFPCCs) on a monolayer graphene electrode immersed in an electrolyte coupled with a reference electrode under an applied potential. The JFPCCs gave the Fermi level, charge density on graphene, Dirac point energy, electrostatic potential, electric double layer etc as a function of the applied potential with respect to the reference electrode. These results revealed the strongly coupled relationship between Fermi level change and Dirac point shift in electrochemical cell. The total capacitance of the electrochemical cell was dissected into the quantum capacitance of the graphene electrode and the capacitance of the electric double layer. Furthermore, simple and analytic formulas were proposed for the three capacitances, which predicted, in sufficient accuracy, the behavior of capacitance versus potential. These findings deepen the understanding of quantum capacitance of graphene, which will stimulate novel experimental and theoretical studies and boost the applications of graphene in electrochemical and energy areas

  7. Quantum capacitance of the monolayer graphene

    OpenAIRE

    Cheremisin, M. V.

    2012-01-01

    The quantum capacitance of the monolayer graphene for arbitrary carrier density, magnetic field and temperature is found. The density dependence of the quantum capacitance is analyzed for magnetic field(temperature) is fixed(varied) and vice versa. The theory is compared with the experimental data.

  8. Capacitance densitometer for flow regime identification

    Science.gov (United States)

    Shipp, Jr., Roy L.

    1978-01-01

    This invention relates to a capacitance densitometer for determining the flow regime of a two-phase flow system. A two-element capacitance densitometer is used in conjunction with a conventional single-beam gamma densitometer to unambiguously identify the prevailing flow regime and the average density of a flowing fluid.

  9. Capacitance-coupled wiper increases potentiometer life

    Science.gov (United States)

    Dimeff, J.

    1968-01-01

    Capacitively-coupled wiper reduces the friction between the sliding contact and the potentiometer element in conventional potentiometers. A small preamplifier employed close to the wiper reduces errors caused by output cable capacitance. The device is friction free with resultant low wear and has high speed and high resolution.

  10. The pyramidal capacitated vehicle routing problem

    DEFF Research Database (Denmark)

    Lysgaard, Jens

    2010-01-01

    This paper introduces the pyramidal capacitated vehicle routing problem (PCVRP) as a restricted version of the capacitated vehicle routing problem (CVRP). In the PCVRP each route is required to be pyramidal in a sense generalized from the pyramidal traveling salesman problem (PTSP). A pyramidal...

  11. Energy-Efficient Capacitive-Sensor Interfaces

    OpenAIRE

    Z. Tan

    2013-01-01

    This thesis describes the theory, design and realization of energy-efficient capacitive-sensor interfaces that are dedicated to energy-constrained applications. The goal of this work is to explore energy-efficient capacitive-sensor interface design techniques both at the system and the circuit level.

  12. Energy-Efficient Capacitive-Sensor Interfaces

    NARCIS (Netherlands)

    Tan, Z.

    2013-01-01

    This thesis describes the theory, design and realization of energy-efficient capacitive-sensor interfaces that are dedicated to energy-constrained applications. The goal of this work is to explore energy-efficient capacitive-sensor interface design techniques both at the system and the circuit level

  13. Transferts d'eau et des ions potassium et nitrate dans un sol à capacité d'échange anionique sous un couvert redistributeur de la pluie ; étude expérimentale et modélisation dans une bananeraie fertilisée sur un andosol

    OpenAIRE

    Sansoulet, Julie

    2007-01-01

    La compréhension des transferts d’eau et d’ions dans la zone non saturée d’un andosol sous bananeraie est complexe car gouvernée par des mécanismes hydrodynamiques et chimiques intervenant à des échelles spatiales différentes. D’une part, le bananier intercepte la pluie incidente et la concentre plus de 20 fois le long de son pseudo-tronc (stemflow). D’autre part, les engrais solubles épandus manuellement et intensivement à proximité du pseudo-tronc sont exposés à ce stemflow, qui les entraîn...

  14. Conductivity Effect on the Capacitance Measurement of a Parallel-Plate Capacitive Sensor System

    Directory of Open Access Journals (Sweden)

    Peyman Azimi

    2011-01-01

    Full Text Available In this article design and operation of a parallel-plate capacitive sensor based on the dielectric capacitance and conductance change of the gap medium is reported. The designed system was used to determine characteristics of different water liquids as a result of the capacitance variations. The air gap capacitance is measured and then by filling the gap with a liquid the capacitance is monitored for different liquids. Proposed sensor is used for the distilled, tap, boiled, and salt water measurements and the capacitance results are compared. A big difference about 45.5 :F in capacitance values for the salt and distilled water shows a high sensitivity, which can be used to recognize different water liquids. The experimental results are promising for water liquids and verify the successful operation of such a device as a liquid sensor, a useful method for checking the electrical quality of the water that is required for different applications.

  15. L’actrice, du cinéma aux arts plastiques et au roman : genre et représentation

    OpenAIRE

    Casagrande, Thibaut

    2014-01-01

    Cet article analyse les représentations des actrices de cinéma dans les romans et les arts visuels. Il remet en question la façon dont cette figure (être humain et construction cinématographique) est représentée en dehors du monde auquel elle appartient, c’est-à-dire en dehors du cinéma et de la culture populaire. Plus précisément, cet article aborde le statut particulier du sexe en tant qu’enjeu essentiel dans ces œuvres, du sexe de ces récits et de ces images et du sexe de ceux qui les crée...

  16. Les réformes hospitalières au début des années 1980 : une bifurcation du système hospitalier ? Politisation de l'action publique et capacités réformatrices limitées

    OpenAIRE

    Gay, Renaud

    2011-01-01

    La crise économique et l'alternance politique de 1981 constituent-elles un moment de grande incertitude propice à l'adoption de réformes structurelles du secteur hospitalier ? Autrement dit, une bifurcation du système hospitalier peut-elle être observée dans les années 1980 ? Ou bien l'action des réformateurs est-elle entravée par des obstacles institutionnels et politiques ? Nous avançons deux hypothèses. L'alternance politique de 1981 constitue une fenêtre d'opportunité pour un programme ré...

  17. Rupture sismique des fondations par perte de capacité portante: Le cas des semelles circulaires

    OpenAIRE

    Chatzigogos, Charisis; Pecker, Alain; Salençon, J.

    2007-01-01

    International audience Within the context of earthquake-resistant design of shallow foundations, the present study is concerned with the determination of the seismic bearing capacity of a circular footing resting on the surface of a heterogene-ous purely cohesive semi-infinite soil layer. In the first part of the paper, a database, containing case histories of civil engineering structures that sustained a foundation seismic bearing capacity failure, is briefly pre-sented, aiming at a bette...

  18. Des guides et des cartes

    OpenAIRE

    Mathieu, Patricia; Maryvonne LE BERRE; Jean-Marc ROCHE

    1987-01-01

    Consultés pour leurs références régionales ou locales, les guides touristiques donnent aussi une vision globale de la France qui est rarement perçue par l'utilisateur. Différents types de représentations cartographiques ont été choisis pour montrer, à partir d'informations simples, découpage en «régions» touristiques, étoilement des sites et des espaces touristiques, cette image de la France.

  19. Des guides et des cartes

    Directory of Open Access Journals (Sweden)

    Patricia MATHIEU

    1987-12-01

    Full Text Available Consultés pour leurs références régionales ou locales, les guides touristiques donnent aussi une vision globale de la France qui est rarement perçue par l'utilisateur. Différents types de représentations cartographiques ont été choisis pour montrer, à partir d'informations simples, découpage en «régions» touristiques, étoilement des sites et des espaces touristiques, cette image de la France.

  20. Etude préliminaire de l'influence des disponibilités alimentaires et des activités humaines sur l’utilisation spatiale de l’habitat par les chimpanzés et les bonobos1

    OpenAIRE

    Narat, Victor; Cibot, Marie; Bokika Ngawolo, Jean Christophe; Dumez, Richard; Krief, Sabrina

    2012-01-01

    L’étude des interactions existant entre les populations locales, l’environnement et les grands singes est indispensable pour une meilleure compréhension des capacités d'adaptation des grands singes aux perturbations de l’habitat et pour l’évaluation des menaces spécifiques au contexte local. De telles études peuvent contribuer à améliorer l’efficacité et la durabilité des actions de conservation ainsi que le développement des populations locales. Cette étude préliminaire compare l’influence d...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1969-07-01

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

  2. La reconstruction des édifices religieux en Basse-Normandie après la Seconde Guerre mondiale

    Directory of Open Access Journals (Sweden)

    Alain Nafilyan

    2012-04-01

    Full Text Available L’étude entreprise aux fins de protection au titre des monuments historiques a permis d’établir une synthèse globale relative à la reconstruction des édifices religieux en la replaçant dans son contexte local historique et économique. L’analyse typologique a mis en lumière un grand éclatement formel offrant diversité et tâtonnement architectural, très caractéristiques des hésitations stylistiques dans l’architecture des années 1950. L’art du vitrail trouva une place privilégiée au travers d’une recherche toujours plus plastique et subtile autour de la diffusion de la lumière. La conclusion tentera d’apporter sous forme de synthèse une contribution à une légitime interrogation : peut-on parler d’un « style » de la reconstruction ?The study begun for the purposes of legal protection in conformance with ancient memorials allowed to establish synthetic material global relative to the reconstruction of the religious buildings by replacing it in its historic and economic local context. The typological analysis revealed a big formal explosion offering very characteristic, architectural variety and experimentation of the stylistic hesitances in the architecture of the 1950s. The art of stained-glass window making found a privileged position through research always more plastic around the lighting of the church. The conclusion will try to bring in the form of synthesis a contribution to a legitimate interrogation: can we speak about a « style » of the reconstruction?

  3. « Mais où sont les neiges d’antan ? ». Questionnement des auteurs italiens et français aux XVIe et XVIIe siècles devant la rareté des traces des premières femmes écrivains

    OpenAIRE

    Anne Debrosse

    2011-01-01

    Pendant la Querelle des Femmes en Italie et en France (XVIe-XVIIe s.), la controverse portait souvent sur la capacité des femmes dans les domaines réputés masculins. La rareté des textes des autrices antiques en était l’un des ressorts. Pour les ennemis des femmes, elle traduisait leur incapacité intrinsèque à bien écrire. Pour leurs « champions », elle était le fruit de la méchanceté des hommes ou, curieusement, de la supériorité des femmes, argumentations que nous analysons dans notre artic...

  4. Perspectives de production et de commercialisation des prunes et des pruneaux au Maroc à l’horizon 2025

    Directory of Open Access Journals (Sweden)

    Issam Eddine Sellika

    2015-10-01

    Full Text Available La filière de production de prunes et pruneaux au Maroc a connu un développement important du fait de coûts de production relativement faibles comparativement à d’autres rosacées. Cet article propose une réflexion globale sur la situation actuelle de la production et commercialisation des prunes et pruneaux au niveau des exploitations agricoles, et leur possible évolution future. Il présente les principales caractéristiques actuelles de la filière, les principaux facteurs d’évolution et deux scénarios à l’horizon 2025. La filière connait déjà des tensions fortes sur les prix au champ, avec des différences importantes liées à la qualité des productions. Trois facteurs de changement ont été identifiés : 1 l’augmentation des coûts de production ; 2 l’augmentation des surfaces plantées induite par le Plan Maroc Vert ; 3 la baisse des prix de vente. Un premier scénario tendanciel prévoit une faible augmentation des superficies, mais une différenciation forte entre les exploitations en fonction de leurs capacités à maitriser les coûts de production, à produire des prunes de qualité, et à prendre des marges en aval en investissant dans la transformation des prunes et la commercialisation des pruneaux. Cette filière restera ainsi rentable pour certaines exploitations tandis que d’autres opteront pour l’arrachage. Un second scénario prévoit des actions publiques pour promouvoir l’export et améliorer la rentabilité sur le marché intérieur, par une baisse des coûts de production, une augmentation de la qualité des prunes et une organisation collective de la transformation des prunes et la commercialisation des pruneaux. Ces activités, menées dans le cadre de coopératives pour les exploitations de petite taille, permettraient à ces exploitations de maintenir voire d’améliorer la rentabilité de cette production.

  5. Des tuiles, des toits et des couleurs

    OpenAIRE

    Bonnot, Thierry

    2007-01-01

    La Bourgogne est une des régions françaises dont l’image de marque est le plus imprégnée par la notion de tradition. Elle est présentée comme un terroir où il fait bon vivre, où la gastronomie demeure à travers les siècles une valeur de base, où les paysages sont majestueux et où la gloire passée est sans cesse rappelée par de somptueux monuments. Parmi quelques emblèmes, l’hôtel-Dieu de Beaune et ses toitures de tuiles colorées sont très souvent mobilisés pour représenter ces valeurs « tradi...

  6. Infrared natural gas for painting: pre-gelation, drying, polymerization of paints on metals and plastics; Infrarouge gaz naturel en peinture: pregelification, sechage, polymerisation des peintures sur metaux et plastiques

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-06-01

    This document provides information on the advantages of the infrared natural gas, illustrated by six examples in the industrial painting sector. The infrared natural gas and Gaz de France, a better efficiency for the radiation and the convection and the sector actors are also presented. (A.L.B.)

  7. Les polymères issus du végétal : matériaux à propriétés spécifiques pour des applications ciblées en industrie plastique

    Directory of Open Access Journals (Sweden)

    Dubois P.

    2006-01-01

    Full Text Available Features of plant-based polymers with special applications in plastic fi eld. The new interest of plastic fi eld with renewable resources results from a global environmental respect awareness and the fossil depletion problem. In these perspectives, vegetable raw materials mainly polymers show attractive properties with great interests in plastic industry such as biodegradability, biocompatibility, selective permeability or variability in physico-mechanical properties. These properties have targeted applications in various fi elds specifi cally packaging, agricultural, textile, pharmaceutical, electronic or medical domains. This paper describes the different raw materials from plants and their valuable properties in relation with potential applications

  8. Utilisation de la PCR-RFLP sur de l'ADN chloro-plastique pour l'étude des relations phylogénétiques au sein du genre Phaseolus

    Directory of Open Access Journals (Sweden)

    Baudoin JP.

    1998-01-01

    Full Text Available Phylogenetic relationships among 74 accessions belonging to six species of Phaseolus are investigated using variation in chloroplast DNA assessed according to a PCR-RFLP protocol. Three fragments of chloroplast DNA are amplified using universal primers, and then digested with 10 restriction enzymes. Thirty-six haplotypes are identified on the basis of the polymorphism in fragment number and size. Three main phylogenetic groups, strongly supported through bootstrap analysis, are identified: (1 accessions from Phaseolus lunatus and Phaseolus xolocotzii; (2 accessions from Phaseolus glabellus; (3 accessions from Phaseolus vulgaris, Phaseolus polyanthus and Phaseolus coccineus. Within the third group, accessions of Phaseolus coccineus are scattered along the phylogenetic tree, which provides some evidence that coccineus accessions are paraphyletic with respect to Phaseolus vulgaris and Phaseolus polyanthus. An analysis of molecular variance applied on four species show that they are significantly differentiated with 79% of molecular variance among species and 21% within species. The results agree with previous investigations on chloroplast DNA variation in the genus Phaseolus, and suggest that PCRRFLP methods, which are technically less labour-intensive than previous methods, are of great value for phylogenetic investigations at the generic level.

  9. Capacitive Cells for Dielectric Constant Measurement

    Science.gov (United States)

    Aguilar, Horacio Munguía; Maldonado, Rigoberto Franco

    2015-01-01

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

  10. Complementary surface charge for enhanced capacitive deionization

    NARCIS (Netherlands)

    Gao, X.; Porada, S.; Omosebi, A.; Liu, K.L.; Biesheuvel, P.M.; Landon, J.

    2016-01-01

    Commercially available activated carbon cloth electrodes are treated using nitric acid and ethylenediamine solutions, resulting in chemical surface charge enhanced carbon electrodes for capacitive deionization (CDI) applications. Surface charge enhanced electrodes are then configured in a CDI cel

  11. Experimental determination of dielectric barrier discharge capacitance.

    Science.gov (United States)

    Pipa, A V; Hoder, T; Koskulics, J; Schmidt, M; Brandenburg, R

    2012-07-01

    The determination of electrical parameters (such as instantaneous power, transferred charge, and gas gap voltage) in dielectric barrier discharge (DBD) reactors relies on estimates of key capacitance values. In the classic large-scale sinusoidal-voltage driven DBD, also known as silent or ozonizer discharge, capacitance values can be determined from charge-voltage (Q-V) plot, also called Lissajous figure. For miniature laboratory reactors driven by fast pulsed voltage waveforms with sub-microsecond rise time, the capacitance of the dielectric barriers cannot be evaluated from a single Q-V plot because of the limited applicability of the classical theory. Theoretical determination can be problematic due to electrode edge effects, especially in the case of asymmetrical electrodes. The lack of reliable capacitance estimates leads to a "capacitance bottleneck" that obstructs the determination of other DBD electrical parameters in fast-pulsed reactors. It is suggested to obtain capacitance of dielectric barriers from a plot of the maximal charge versus maximal voltage amplitude (Q(max) - V(max) plot) in a manner analogous to the classical approach. The method is examined using measurements of current and voltage waveforms of a coaxial DBD reactor in argon at 100 mbar driven by square voltage pulses with a rise time of 20 ns and with different voltage amplitudes up to 10 kV. Additionally, the applicability of the method has been shown for the data reported in literature measured at 1 bar of nitrogen-oxygen gas mixtures and xenon. PMID:22852728

  12. Direction des ressources humaines et competitivite

    OpenAIRE

    Calderón Hernández, Gregorio

    2011-01-01

    La Direction des Ressources Humaines (DRH) est une capacité organisationnelle classée parmi les actifs intangibles et comme telle elle peut se transformer en un appui important dans la construction d'avantage compétitif constant pour l'entreprise. L'étude présente a pour but d'établir jusqu'à quel point la DRH se constitue comme un support de l'entreprise colombienne pour atteindre cet avantage compétitif. La base empirique qui a été prise pour rédiger l'article est une information pro...

  13. Chimie des processus biologiques : une introduction

    OpenAIRE

    Fontecave, Marc

    2013-01-01

    La vie dépend de la capacité des organismes vivants à utiliser efficacement le potentiel chimique de leur environnement : le soleil, pour l’énergie, et un certain nombre de molécules accumulées à la surface de la Terre (eau, oxygène, dioxyde de carbone, azote, etc.). Pour en tirer parti, il faut les activer, et cela nécessite des modifications électroniques profondes que seuls les ions métalliques permettent. Les métallo-enzymes qui réalisent ces activations sont véritablement extraordinaires...

  14. Reconstruction des identités professionnelles autour de la multi-fonctionnalité de l'agriculture. L'exemple des Coteaux du Lyonnais.

    OpenAIRE

    Dufour, Annie; Bernard, Cécile; Angelucci, Marie Alix

    2007-01-01

    La reconnaissance de la multifonctionnalité de l'agriculture implique une remise en question du métier d'agriculteur, car elle modifie les finalités de la production ainsi que la nature des liens entre les agriculteurs et la société. L'article propose une analyse sociologique de la multifonctionnalité, au travers des représentations du métier. L'hypothèse est que la construction de la multifonctionnalité est liée à la capacité des groupes à transformer leur système de normes. Les auteu...

  15. Capacitance of Graphene Bilayer as a Which-Layer Probe

    OpenAIRE

    Young, Andrea F.; Levitov, Leonid S.

    2011-01-01

    The unique capabilities of capacitance measurements in bilayer graphene enable probing of layer-specific properties that are normally out of reach in transport measurements. Furthermore, capacitance measurements in the top-gate and penetration field geometries are sensitive to different physical quantities: the penetration field capacitance probes the two layers equally, whereas the top gate capacitance preferentially samples the near layer, resulting in the "near-layer capacitance enhancemen...

  16. Nanoscale capacitance: A classical charge-dipole approximation

    OpenAIRE

    Jun-Qiang Lu; Jonathan Gonzalez; Carlos Sierra; Yang Li

    2013-01-01

    Modeling nanoscale capacitance presents particular challenge because of dynamic contribution from electrodes, which can usually be neglected in modeling macroscopic capacitance and nanoscale conductance. We present a model to calculate capacitances of nano-gap configurations and define effective capacitances of nanoscale structures. The model is implemented by using a classical atomic charge-dipole approximation and applied to calculate capacitance of a carbon nanotube nano-gap and effective ...

  17. Conception de fonctions spécialisées dans un système de calcul formel : L'exemple des suites en Terminale S sous MAPLE

    OpenAIRE

    Gelis, Jean-Michel; Lenne, Dominique

    1997-01-01

    Depuis quelques années, des systèmes de calcul formel relativement simples d'emploi sont disponibles sur des matériels utilisables en éducation. Ces systèmes offrent des capacités importantes en matière de calcul et de représentation graphique et deviennent progressivement des instruments indispensables en mathématiques. Leur intégration dans l'enseignement pose cependant bien des questions et fait l'objet de recherches et d'expérimentations.Les systèmes actuels, s'ils sont généralement fiabl...

  18. Vulnérabilité des sols méditerranéens aux incendies récurrents et restauration de leurs qualités chimiques et microbiologiques par des apports de composts

    OpenAIRE

    Guénon, René

    2010-01-01

    A partir de la fin des années 1960, la fermeture des milieux consécutive à la déprise agricole a favorisé la recrudescence des grands feux, et au plan local, a augmenté la fréquence des incendies. Les objectifs de la thèse étaient d'évaluer les effets des incendies récurrents sur la capacité de résilience des propriétés microbiennes des sols, d'identifier les principaux facteurs impliqués dans la résilience microbienne et d'évaluer l'efficacité d'apports de composts pour favoriser la restaura...

  19. L’implication des acteurs dans l’implantation de projets d’amélioration des situations de travail en ergonomie participative : des constats différenciés dans deux usines

    OpenAIRE

    Montreuil, Sylvie; Marier, Micheline; Bellemare, Marie; Prévost, Johanne; Allard, Denis

    2014-01-01

    Une intervention en ergonomie participative a été conduite pendant deux ans dans deux usines d’une grande entreprise de production de métal. Son objectif visait la prévention des troubles musculo-squelettiques en misant sur la capacité des acteurs des milieux à procéder à l’analyse et à la transformation des situations de travail estimées à risque. Les résultats présentés dans cet article sont focalisés sur les processus de l’intervention et des projets de transformation. Ils démontrent que l...

  20. Les infections à Pseudomonas aeruginosa au service des maladies infectieuses du CHU YO, Burkina Faso: à propos deux cas

    OpenAIRE

    Mamoudou, Savadogo; Lassina, Dao; Fla, Koueta

    2015-01-01

    Nous rapportons deux cas d'infection à Pseudomonas aeruginosa: un cas de méningite et un cas d'infection urinaire. Les auteurs rappellent qu’à côté des étiologies classiques des méningites et des infections urinaires, des germes résistants comme Pseudomonas aeruginosa peuvent être responsables d'infections à localisation méningées et urinaires et dont il faut connaître pour une bonne prise en charge. Le traitement de ces infections requiert un antibiogramme au regard de la grande capacité de ...

  1. Les infections à Pseudomonas aeruginosa au service des maladies infectieuses du CHU YO, Burkina Faso: à propos deux cas

    Science.gov (United States)

    Mamoudou, Savadogo; Lassina, Dao; Fla, Koueta

    2015-01-01

    Nous rapportons deux cas d'infection à Pseudomonas aeruginosa: un cas de méningite et un cas d'infection urinaire. Les auteurs rappellent qu’à côté des étiologies classiques des méningites et des infections urinaires, des germes résistants comme Pseudomonas aeruginosa peuvent être responsables d'infections à localisation méningées et urinaires et dont il faut connaître pour une bonne prise en charge. Le traitement de ces infections requiert un antibiogramme au regard de la grande capacité de résistance de Pseudomonas aeruginosa en milieu hospitalier. La limitation des gestes invasifs et l'application rigoureuse des mesures de prévention des infections en milieu hospitalier contribueront à lutter efficacement contre ces infections en milieu de soins. PMID:26491521

  2. Carbon flow electrodes for continuous operation of capacitive deionization and capacitive mixing energy generation

    NARCIS (Netherlands)

    Porada, S.; Hamelers, H.V.M.; Bryjak, M.; Presser, V.; Biesheuvel, P.M.; Weingarth, D.

    2014-01-01

    Capacitive technologies, such as capacitive deionization and energy harvesting based on mixing energy (“capmix” and “CO2 energy”), are characterized by intermittent operation: phases of ion electrosorption from the water are followed by system regeneration. From a system application point of view, c

  3. Dislocations and radiation damage in {alpha}-uranium; Dislocations et effets des radiations dans l'uranium {alpha}

    Energy Technology Data Exchange (ETDEWEB)

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

    1968-07-01

    Dislocations in {alpha}-uranium were studied by electron microscopy. Electropolishing of thin foils was performed at low temperature (-110 deg. C) to prevent oxidation. Burgers vectors of twins dislocations are defined. Interactions between slip and twinning are studied from both experimental and theoretical point of view. Samples irradiated at several burn-up were examined. In order to explain our micrographic results, and also all information gathered in literature about radiation damage in {alpha}-uranium, a coherent model is propound for the fission particles effects. We analyse the influences of parameters: temperature, dislocation density, impurity content. The number of point defects created by one initial fission is determined for pure and annealed metal. The importance of the self-anneal which occurs immediately in each displacement spike, and the anneal due to a new fission on the damage resulting from a previous fission, are estimated. The focussing distance in [100] direction is found to be about 1000 Angstrom, at 4 deg. K. (author) [French] Ce travail est une etude par microscopie electronique des dislocations induites dans l'uranium {alpha}, soit par deformation plastique, soit par irradiation. Une methode de preparation des lames minces a basse temperature (-110 deg. C) a ete mise au point. Les vecteurs de Burgers des diverses dislocations de macles de ce metal ont ete definis. Les interactions glissements- maclages sont etudiees experimentalement et theoriquement. Des echantillons irradies a divers taux de combustion ont ete examines. Pour expliquer nos resultats micrographiques, et aussi l'ensemble des informations recueillies dans la litterature concernant l'endommagement par irradiation de l'uranium-{alpha}, nous proposons un modele coherent de l'effet des fragments de fission dans ce metal. L'influence des parametres: temperature, densite de dislocations, impuretes est analysee. Le nombre de defauts ponctuels crees

  4. La conception des règles des marchés de l’électricité ouverts à la concurrence

    OpenAIRE

    Bouttes, Jean-Paul; Trochet, Jean-Michel

    2006-01-01

    Les investissements jouent un rôle capital dans les performances économiques et environnementales du secteur électrique, dans la production comme dans les réseaux. L’ouverture des marchés réalisée au cours des années 1990 a conduit à laisser de côté cet objectif pour trois raisons : (1) l’ouverture des marchés a le plus souvent été réalisée dans des contextes de capacités de production bondantes, d’où un déplacement des préoccupations vers l’efficacité de court terme du secteur ; (2) le rempl...

  5. Ion channels, phosphorylation and mammalian sperm capacitation

    Institute of Scientific and Technical Information of China (English)

    Pablo E Visconti; Dario Krapf; José Luis de la Vega-Beltrán; Juan José Acevedo; Alberto Darszon

    2011-01-01

    Sexually reproducing animals require an orchestrated communication between spermatozoa and the egg to generate a new individual. Capacitation, a maturational complex phenomenon that occurs in the female reproductive tract, renders spermatozoa capable of binding and fusing with the oocyte, and it is a requirement for mammalian fertilization. Capacitation encompasses plasma membrane reorganization, ion permeability regulation, cholesterol loss and changes in the phosphorylation state of many proteins. Novel tools to study sperm ion channels, image intracellular ionic changes and proteins with better spatial and temporal resolution, are unraveling how modifications in sperm ion transport and phosphorylation states lead to capacitation. Recent evidence indicates that two parallel pathways regulate phosphorylation events leading to capacitation, one of them requiring activation of protein kinase A and the second one involving inactivation of ser/thr phosphatases. This review examines the involvement of ion transporters and phosphorylation signaling processes needed for spermatozoa to achieve capacitation. Understanding the molecular mechanisms leading to fertilization is central for societies to deal with rising male infertility rates, to develop safe male gamete-based contraceptives and to preserve biodiversity through better assisted fertilization strategies.

  6. Effets d'irradiation et comportement des produits de fission dans la zircone et le spinelle

    OpenAIRE

    Gentils, Aurélie

    2003-01-01

    Certains oxydes sous forme cristalline, plus particulièrement la zircone (ZrO2) et le spinelle (MgAl2O4), sont des matrices potentielles pour la transmutation du plutonium et des actinides mineurs. Ce travail concerne l'étude des propriétés physico-chimiques de ces matrices, avec un accent particulier sur leur comportement vis-à-vis de l'irradiation et leur capacité à confiner les produits de fission. Les irradiations à basse énergie et l'incorporation d'analogues stables de produits de fissi...

  7. Capacitance measurement of magnetic specific heat

    Science.gov (United States)

    King, A. R.; Belanger, D. P.; Nordblad, P.; Jaccarino, V.

    1984-03-01

    A new technique-low frequency capacitance (C) measurement-has been used to study the critical behavior of both isotropic and anisotropic antiferromagnets. We find that dC/dT is accurately proportional to the known magnetic specific heat Cm of FeF2. This indicates that both dɛ/dT and dl/dT scale with Cm. For cubic KNiF3, the critical exponent (Cm=At-α) has been found to be α=-0.151±.004 and A/A'=1.56±0.03. The experiments measured the capacitance of disk-shaped samples with a three-terminal capacitance technique. A ratio transformer bridge was employed, yielding a resolution in ΔC/C of about 10-8. The quality of the results is comparable to the best obtainable from conventional Cm and birefringence measurements.

  8. Carbon nanofiber supercapacitors with large areal capacitances

    KAUST Repository

    McDonough, James R.

    2009-01-01

    We develop supercapacitor (SC) devices with large per-area capacitances by utilizing three-dimensional (3D) porous substrates. Carbon nanofibers (CNFs) functioning as active SC electrodes are grown on 3D nickel foam. The 3D porous substrates facilitate a mass loading of active electrodes and per-area capacitance as large as 60 mg/ cm2 and 1.2 F/ cm2, respectively. We optimize SC performance by developing an annealing-free CNF growth process that minimizes undesirable nickel carbide formation. Superior per-area capacitances described here suggest that 3D porous substrates are useful in various energy storage devices in which per-area performance is critical. © 2009 American Institute of Physics.

  9. Signal processing electronics for a capacitive microsensor

    Science.gov (United States)

    Amendola, Gilles; Lu, Guo N.

    2000-04-01

    An interface circuit in a 0.8-micrometers CMOS process for the on- chip integration of a capacitive micro-sensor used as a microphone is presented. In order to circumvent 1/f noise contributions and to improve the signal/noise ratio, a synchronous modulation-demodulation technique has been applied. For the implementation of this technique, we have studied and designed several functional block, such as modulator with signal conversion, low-noise amplifier, demodulator, etc. To deal with problems related to dispersion of intrinsic capacitance of the sensor, a feedback compensating solution is suggested. The designed circuit has a sensibility of 1200 V/pF, with a minimum detectable capacitance variation of 2 10-6 pF.

  10. A high performance, variable capacitance accelerometer

    Science.gov (United States)

    Wilner, L. Bruce

    1988-12-01

    A variable capacitance acceleration sensor is described. Manufactured using silicon microfabrication techniques, the sensor uses a midplane, flat plate suspension, gas damping, and overrange stops. The sensor is assembled from three silicon wafers, using anodic bonds to inlays of borosilicate glass. Typical sensor properties are 7-pF active capacitance, 3-pF tare capacitance, a response of 0.05 pF/G, a resonance frequency of 3.4 kHz, and damping 0.7 critical. It is concluded that this sensor, with appropriate electronics, forms an accelerometer with an order-of-magnitude greater sensitivity-bandwidth product than a comparable piezoresistive acclerometer, and with extraordinary shock resistance.

  11. Analyse de stabilité des évolutions quasi-statiques de systèmes standard dissipatifs

    OpenAIRE

    ABED-MERAIM, Farid; Nguyen, Quoc Son

    2007-01-01

    Cette étude est consacrée à la stabilité de la réponse quasi-statique de systèmes standard dissipatifs (visco-élastiques, visco-plastiques ou élasto-plastiques). Dans le cas de solides visqueux (visco-élastiques ou visco-plastiques), pour lesquels la réponse à une sollicitation est en partie différée dans le temps, l’absence d’équilibre nous suggère naturellement d’étudier la stabilité de leurs évolutions quasi-statiques. Dans le cas de solides élasto-plastiques, cette approche est motivée pa...

  12. Highly sensitive micromachined capacitive pressure sensor with reduced hysteresis and low parasitic capacitance

    DEFF Research Database (Denmark)

    Pedersen, Thomas; Fragiacomo, Giulio; Hansen, Ole;

    2009-01-01

    This paper describes the design and fabrication of a capacitive pressure sensor that has a large capacitance signal and a high sensitivity of 76 pF/bar in touch mode operation. Due to the large signal, problems with parasitic capacitances are avoided and hence it is possible to integrate the sensor...... with a discrete components electronics circuit for signal conditioning. Using an AC bridge electronics circuit a resolution of 8 mV/mbar is achieved. The large signal is obtained due to a novel membrane structure utilizing closely packed hexagonal elements. The sensor is fabricated in a process based...

  13. Development of a 3D capacitive gyroscope with reduced parasitic capacitance

    Science.gov (United States)

    Walther, A.; Desloges, B.; Lejuste, C.; Coster, B.; Audebert, P.; Willemin, J.

    2013-02-01

    We present the development of a technological platform dedicated to 3D capacitive inertial sensors. The proof of concept will be made on a 3D gyroscope. The mobile structure is made within a 30 µm thick Si top layer of a SOI substrate, while poly-Si deposited on top of a sacrificial PSG layer serves as suspended top electrodes and connection wires. This technology enables us to maintain low parasitic capacitance, which is of paramount significance for capacitive detection. After packaging and association with an analogue electronic board, functionality of the sensor is demonstrated.

  14. Development of a 3D capacitive gyroscope with reduced parasitic capacitance

    International Nuclear Information System (INIS)

    We present the development of a technological platform dedicated to 3D capacitive inertial sensors. The proof of concept will be made on a 3D gyroscope. The mobile structure is made within a 30 µm thick Si top layer of a SOI substrate, while poly-Si deposited on top of a sacrificial PSG layer serves as suspended top electrodes and connection wires. This technology enables us to maintain low parasitic capacitance, which is of paramount significance for capacitive detection. After packaging and association with an analogue electronic board, functionality of the sensor is demonstrated. (paper)

  15. Quantum capacitance of the armchair-edge graphene nanoribbon

    Indian Academy of Sciences (India)

    Ling-Feng Mao

    2013-08-01

    The quantum capacitance, an important parameter in the design of nanoscale devices, is derived for armchair-edge single-layer graphene nanoribbon with semiconducting property. The quantum capacitance oscillations are found and these capacitance oscillations originate from the lateral quantum confinement in graphene nanoribbon. Detailed studies of the capacitance oscillations demonstrate that the local channel electrostatic potential at the capacitance peak, the height and the number of the capacitance peak strongly depend on the width, especially a few nanometres, of the armchair-edge graphene nanoribbon. It implies that the capacitance oscillations observed in the experiments can be utilized to measure the width of graphene nanoribbon. The results also show that the capacitance oscillations are not seen when the width is larger than 30 nm.

  16. Analysis of mutual capacitance and inductance of printed circuit

    OpenAIRE

    Ivanov, V. G.

    2014-01-01

    The article analyzes the mutual capacitance and inductance of printed circuit and introduces an evaluation technique for conductor-to-conductor capacitance under electrical connections tracing, the technique based on a multi-layer channel model.

  17. Observation of Quantum Capacitance of individual single walled carbon nanotubes

    OpenAIRE

    Dai, Junfeng; Li, Jun; Zeng, Hualing; Cui, Xiaodong

    2008-01-01

    We report a measurement on quantum capacitance of individual semiconducting and small band gap SWNTs. The observed quantum capacitance is remarkably smaller than that originating from density of states and it implies a strong electron correlation in SWNTs.

  18. Fabrication of capacitively-shunted superconducting qubits

    Science.gov (United States)

    Yoder, Jonilyn L.; Gudmundsen, Theodore J.; Bolkhovsky, Vladimir; Welander, Paul B.; Gustavsson, Simon; Hover, David; Kerman, Andrew J.; Sears, Adam P.; Oliver, William D.

    2014-03-01

    Improvements in superconducting qubit coherence times and reproducibility have been demonstrated using capacitive shunting. In this study, we present methods for the preparation of both capacitively-shunted charge qubits (transmons) and capacitively-shunted flux qubits. Hybrid fabrication techniques were employed to combine high-quality-factor aluminum capacitive shunts with shadow-evaporated Josephson junctions, and the Josephson junctions were prepared using suspended-bridge germanium masks. We also will describe process testing results that were acquired to assess wafer-to-wafer reproducibility of our fabrication protocols. This research was funded in part by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA); and by the Assistant Secretary of Defense for Research and Engineering under Air Force Contract number FA8721-05-C-0002. All statements of fact, opinion or conclusions contained herein are those of the authors and should not be construed as representing the official views or policies of IARPA, the ODNI, or the U.S. Government.

  19. Teaching of Inductive and Capacitive Reactance.

    Science.gov (United States)

    MacInnes, I.; Jeffrey, W. S.

    1983-01-01

    Discusses how understanding mechanical systems and their graphic representation can be of value when teaching inductive and capacitive reactance, in particular, the response of inductors and capacitors to an alternating potential difference. Suggests that mechanical systems be taught, not just before introducing reactance but earlier in the…

  20. Thermodynamic cycle analysis for capacitive deionization

    NARCIS (Netherlands)

    Biesheuvel, P.M.

    2009-01-01

    Capacitive deionization (CDI) is an ion removal technology based on temporarily storing ions in the polarization layers of two oppositely positioned electrodes. Here we present a thermodynamic model for the minimum work required for ion separation in the fully reversible case by describing the ionic

  1. Capacitive Proximity Sensors With Additional Driven Shields

    Science.gov (United States)

    Mcconnell, Robert L.

    1993-01-01

    Improved capacitive proximity sensors constructed by incorporating one or more additional driven shield(s). Sensitivity and range of sensor altered by adjusting driving signal(s) applied to shield(s). Includes sensing electrode and driven isolating shield that correspond to sensing electrode and driven shield.

  2. Phase-Discriminating Capacitive Sensor System

    Science.gov (United States)

    Vranish, John M.; Rahim, Wadi

    1993-01-01

    Crosstalk eliminated by maintaining voltages on all electrodes at same amplitude, phase, and frequency. Each output feedback-derived control voltage, change of which indicates proximity-induced change in capacitance of associated sensing electrode. Sensors placed close together, enabling imaging of sort. Images and/or output voltages used to guide robots in proximity to various objects.

  3. Capacitive Displacement Sensor With Frequency Readout

    Science.gov (United States)

    Fritsch, Klaus

    1989-01-01

    Simple displacement-measuring circuit senses capacitance between two parallel conducting plates and produces output signal, with frequency proportional to distance between plates. Principle of circuit provides advantages over other methods because of frequency-encoded output and high linearity. Used to measure displacements.

  4. Negative capacitance in multidomain ferroelectric superlattices

    Science.gov (United States)

    Zubko, Pavlo; Wojdeł, Jacek C.; Hadjimichael, Marios; Fernandez-Pena, Stéphanie; Sené, Anaïs; Luk’Yanchuk, Igor; Triscone, Jean-Marc; Íñiguez, Jorge

    2016-06-01

    The stability of spontaneous electrical polarization in ferroelectrics is fundamental to many of their current applications, which range from the simple electric cigarette lighter to non-volatile random access memories. Research on nanoscale ferroelectrics reveals that their behaviour is profoundly different from that in bulk ferroelectrics, which could lead to new phenomena with potential for future devices. As ferroelectrics become thinner, maintaining a stable polarization becomes increasingly challenging. On the other hand, intentionally destabilizing this polarization can cause the effective electric permittivity of a ferroelectric to become negative, enabling it to behave as a negative capacitance when integrated in a heterostructure. Negative capacitance has been proposed as a way of overcoming fundamental limitations on the power consumption of field-effect transistors. However, experimental demonstrations of this phenomenon remain contentious. The prevalent interpretations based on homogeneous polarization models are difficult to reconcile with the expected strong tendency for domain formation, but the effect of domains on negative capacitance has received little attention. Here we report negative capacitance in a model system of multidomain ferroelectric–dielectric superlattices across a wide range of temperatures, in both the ferroelectric and paraelectric phases. Using a phenomenological model, we show that domain-wall motion not only gives rise to negative permittivity, but can also enhance, rather than limit, its temperature range. Our first-principles-based atomistic simulations provide detailed microscopic insight into the origin of this phenomenon, identifying the dominant contribution of near-interface layers and paving the way for its future exploitation.

  5. Site Specific Evaluation of Multisensor Capacitance Probes

    Science.gov (United States)

    Multisensor capacitance probes (MCPs) are widely used for measuring soil water content (SWC) at the field scale. Although manufacturers supply a generic MCP calibration, many researchers recognize that MCPs should be calibrated for specific field conditions. MCPs measurements are typically associa...

  6. Capacitors and Resistance-Capacitance Networks.

    Science.gov (United States)

    Balabanian, Norman; Root, Augustin A.

    This programed textbook was developed under a contract with the United States Office of Education as Number 5 in a series of materials for use in an electrical engineering sequence. It is divided into three parts--(1) capacitors, (2) voltage-current relationships, and (3) simple resistance-capacitance networks. (DH)

  7. Inside-out electrical capacitance tomography

    DEFF Research Database (Denmark)

    Kjærsgaard-Rasmussen, Jimmy; Meyer, Knud Erik

    2011-01-01

    In this work we demonstrate the construction of an ‘inside-out’ sensor geometry for electrical capacitance tomography (ECT). The inside-out geometry has the electrodes placed around a tube, as usual, but measuring ‘outwards’. The flow between the electrodes and an outer tube is reconstructed; all...

  8. [Experience in developing and using capacitive electrodes].

    Science.gov (United States)

    Grishanovich, A P; Iarmolinskiĭ, V I

    1984-01-01

    A capacitive-type electrode using titanium or tantalum oxide obtained through anodizing is described. Incorporated in the electrode is a source for a buffer amplifier. A shielding cap is used as an indifferent electrode. High performance allows using the electrodes for ECG, EEG, and other signal recording in clinical practice and researches. PMID:6708763

  9. Study of deformation mechanisms of zinc bicrystals by thermal cycling (1963); Etude des mecanismes de deformation par cyclage thermique de bicristaux de zinc (1963)

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-06-15

    transitoire pour des deformations de l'ordre de 10{sup -4} a 10{sup -3} quand le cristal est plastiquement 'dur'. L'etude micrographique montre que la migration du joint accompagne le cisaillement intergranulaire et que le cyclage produit une forte polygonisation dans les grains, confirmant le fait que le joint exerce toujours des contraintes et qu'il se produit un fluage dans le volume des grains. La discussion des resultats montre que le fluage primaire du grain 'dur' d'un bicristal rend la deformation par cyclage irreversible et permet un allongement a chaque cycle si ce grain possede un coefficient de dilatation plus faible que l'autre. (auteur)

  10. Anisotropic magneto-capacitance in ferromagnetic-plate capacitors

    OpenAIRE

    Haigh, J. A.; Ciccarelli, C; Betz, A. C.; Irvine, A; Novák, V.; Jungwirth, T.; Wunderlich, J.

    2015-01-01

    The capacitance of a parallel plate capacitor can depend on applied magnetic field. Previous studies have identified capacitance changes induced via classical Lorentz force or spin-dependent Zeeman effects. Here we measure a magnetization direction dependent capacitance in parallel-plate capacitors where one plate is a ferromagnetic semiconductor, gallium manganese arsenide. This anisotropic magneto-capacitance is due to the anisotropy in the density of states dependent on the magnetization t...

  11. Membrane capacitance techniques to monitor granule exocytosis in neutrophils.

    OpenAIRE

    Lollike, K; Lindau, M

    1999-01-01

    Cell membranes behave like electrical capacitors and changes in cell capacitance therefore reflect changes in the cell area. Monitoring capacitance can thus be used to study dynamic cellular phenomenon involving rapid changes in cell surface, such as exo- and/or endocytosis. In this review focus is on the use of capacitance techniques to study exocytosis in human neutrophils. We compare the whole-cell and the cell-attached capacitance techniques, and we review the complete literature dealing ...

  12. Negative Quantum Capacitance of Carbon Nanotube Field-Effect Transistors

    OpenAIRE

    Latessa, L.; Pecchia, A.; Di Carlo, A.; P. Lugli

    2004-01-01

    Atomistic density functional theory (DFT) calculations of the capacitance between a metallic cylindric gate and a carbon nanotube (CNT) are reported. Results stressing the predominant effect of quantum capacitance in limiting or even enhancing screening properties of the CNT are shown. Other contributions to the quantum capacitance beyond the electronic density of state (DOS) are pointed out. Negative values of the quantum capacitance are obtained for low-density systems, which correspondingl...

  13. MOS Capacitance-Voltage Characteristics:V.Methods to Enhance the Trapping Capacitance

    Institute of Scientific and Technical Information of China (English)

    揭斌斌; 薩支唐

    2012-01-01

    Low-frequency and High-frequency Capacitance-Voltage (C-V) curves of Silicon Metal-Oxide-Semiconductor Capacitors,showing electron and hole trapping at shallow-level dopant and deep-level generationrecombination-trapping impurities,are presented to illustrate the enhancement of the giant trapping capacitances by physical means via device and circuit designs,in contrast to chemical means via impurity characteristics previously reported.Enhancement is realized by masking the electron or/and hole storage capacitances to make the trapping capacitances dominant at the terminals.Device and materials properties used in the computed CV curves are selected to illustrate experimental realizations for fundamental trapping parameter characterizations and for electrical and optical signal processing applications.

  14. Electric field theory and the fallacy of void capacitance

    OpenAIRE

    McAllister, Iain Wilson

    1991-01-01

    The concept of the capacitance of a gaseous void is discussed as applied to electrical insulation science. The most pertinent aspect of the capacitance definition is that of reference to a single-valued potential difference between surfaces. This implies that these surfaces must be surfaces of equipotential. With this essential characteristics the validity of void capacitance is examined

  15. Quels dispositifs d'appui pour la promotion des petites entreprises agroalimentaires des savanes d'Afrique Centrale ?

    OpenAIRE

    Cerdan, Claire; Kaméni, Anselme; Kénikou Mounkama, Christine; Ndjouenkeu, Robert

    2003-01-01

    Les années 1990 ont vu une certaine réhabilitation du rôle des petites entreprises dans le développement local. Dans le cas du secteur agroalimentaire africain, il a été reconnu que la capacité d'innovation et d'adaptation des petites entreprises, en grande partie informelles, a contribué à éviter le scénario souvent prédit d'importations alimentaires, tout en stimulant la valorisation des productions agricoles locales. Les services d'appui sont longtemps restés limités et constitués par les ...

  16. La résilience des Turkana

    Directory of Open Access Journals (Sweden)

    Clémence Cantoni

    2010-07-01

    Full Text Available Cet article analyse les stratégies d’adaptation de pasteurs turkana du district d’Isiolo (Nord Kenya, face aux chocs, politiques comme climatiques, subis. Cette analyse passe par un détour historique, la société turkana s’étant de longue date organisée autour de sa capacité à affronter de tels aléas. Elle passe aussi par une réflexion, plus conceptuelle sur la portée de la notion de résilience, perçue tant dans sa dimension collective qu’au niveau des familles de pasteurs elles-mêmes. Elle passe enfin par la mise en évidence des limites des stratégies mises en œuvre, conduisant à la disparition du pastoralisme tant comme moyen de production (ou l'inverse (décapitalisation que comme mode de vie (dilution des liens sociaux, et tenant à la non durabilité des activités alternatives, tels le charbonnage et le maraîchage.This article focuses on the adaptive strategies of Turkana pastoralists in Isiolo District (Kenya, coping with political and climate shocks. This analysis involves a historical detour, Turkana society having long been organized around its ability to deal with such risks. It also leads to the concept of resilience, either in its collective dimension or at the level of pastoralist families themselves. It finally brings out the limits of those strategies, leading to the regression of pastoralism as a livelihood (decapitalization and as a lifestyle (dilution of social ties, and to the non sustainability of alternative activities, such as charcoal burning and market gardening.

  17. Strukturmerkmale des chinesischen Kapitalismus

    OpenAIRE

    Brink, Tobias ten

    2010-01-01

    Für ein Verständnis der chinesischen Wirtschaft ist es hilfreich, das theoretische Instrumentarium der Kapitalismusforschung nutzbar zu machen. Es ermöglicht eine fundierte Charakterisierung des chinesischen Systems als einer eigentümlichen Spielart des Kapitalismus – eines marktliberalen, wettbewerbsgetriebenen Staatskapitalismus. Zu den Eigentümlichkeiten des chinesischen Kapitalismus gehören ein dynamischer Staatsdirigismus, eine besondere Form des Wettbewerbs und der privat-öffentlichen U...

  18. 77 FR 58175 - Resale Royalty Right

    Science.gov (United States)

    2012-09-19

    ...], Societe des Auteurs dans les Arts Graphiques et Plastiques, available at http://www.adagp.fr/ENG/Liste...], Societe des Auteurs dans les Arts Graphiques et Plastiques, available at http://www.adagp.fr/ENG/Liste... Copyright Office Resale Royalty Right AGENCY: Copyright Office, Library of Congress. ACTION: Notice...

  19. Civili, langue des Baloango

    DEFF Research Database (Denmark)

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

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

  20. Remittances | Transferts des migrants

    OpenAIRE

    2012-01-01

    Major Recipients of Remittances (in Million USD, 2008) Principaux pays bénéficiaires des transferts des migrants (en millions USD, 2008) ­ Migrants’ Remittances per Capita (in USD, 2008) Transferts des migrants par habitant (en USD, 2008) Source: World Bank, migration and remittances data.

  1. Méthodologie de dimensionnement d’un moteur électrique pour véhicules hybrides : optimisation conjointe des composants et de la gestion d’énergie

    OpenAIRE

    Reinbold, Vincent

    2014-01-01

    Depuis l'essor des ordinateurs et des capacités de calcul, la conception des composants du génie électrique repose largement sur des simulations informatiques et sur des calculs numériques. Dans les systèmes complexes, où de nombreux composants interagissent pour le bon fonctionnement du système, le dimensionnement optimal du composant dépend nécessairement de son environnement systémique. La conception de celui-ci est fortement liée au fonctionnement du système global. La conception intégré ...

  2. Méthodologie de dimensionnement d'un moteur électrique pour véhicules hybrides. Optimisation conjointe des composants et de la gestion d'énergie

    OpenAIRE

    Reinbold, Vincent

    2015-01-01

    Depuis l'essor des ordinateurs et des capacités de calcul, la conception des composants du génie électrique repose largement sur des simulations informatiques et sur des calculs numériques. Dans les systèmes complexes, où de nombreux composants interagissent pour le bon fonctionnement du système, le dimensionnement optimal du composant dépend nécessairement de son environnement systémique. La conception de celui-ci est fortement liée au fonctionnement du système global. La conception intégré ...

  3. Hydraulic Fracturing At Sedimentary Basin Scale Fracturation hydraulique à l'échelle des bassins sédimentaires

    Directory of Open Access Journals (Sweden)

    Schneider F.

    2006-12-01

    domain and then may initiate some fracturing. In other cases, the sediment changes its loading path but stay at the elastoplastic yield surface. In this case the theoretical considerations are not valid anymore and fracture criteria should be defined in the plastic domain. Fracturation hydraulique à l'échelle des bassins sédimentaires Fracturation hydraulique à l'échelle des bassins sédimentaires Le calcul du tenseur des contraintes est déterminant pour pouvoir simuler la fracturation hydraulique à l'échelle des bassins sédimentaires. Ce calcul n'est généralement pas abordé dans les modèles de bassins en raison de la complexité du problème. Pour pouvoir estimer le tenseur des contraintes, nous sommes alors amenés à formuler les hypothèses suivantes: - une des contraintes principales est verticale et égale, en module, au poids des terrains sus-jacents ; - la contrainte horizontale se déduit de la contrainte verticale à partir d'un coefficient de report K0 qui est une fonction de la profondeur et du contexte géodynamique. La consolidation est supposée être le résultat à la fois de la compaction mécanique et de la compaction chimique. La compaction mécanique est principalement due au réarrangement mécanique des grains pendant l'enfouissement. Elle peut se simuler, à l'échelle macroscopique, par une rhéologie élasto-plastique. La compaction chimique est le résultat des mécanismes de pression-dissolution. Elle peut être simulée, à l'échelle macroscopique, par une rhéologie viscoplastique. La surface de charge est complètement définie par l'union de la surface de consolidation avec les différentes limites de rupture. Cette surface de charge est alors définie par six surfaces élémentaires qui représentent la compaction verticale, la compaction horizontale, la rupture verticale en traction, la rupture horizontale en traction, la rupture subverticale en cisaillement, et la rupture subhorizontale en cisaillement. En raison du

  4. Aide à la conception de Système d'Information Collaboratif , support de l'interopérabilité des entreprises

    OpenAIRE

    TOUZI, Jihed

    2007-01-01

    Dans un contexte de collaboration industrielle ou inter-organisationnelle, la qualité de l'intégration des différents partenaires dépend grandement de la capacité de leurs systèmes d'information (SI) à interagir efficacement. C'est pourquoi nous proposons dans ce manuscrit d'aborder cette problématique selon l'angle de l'interopérabilité des systèmes d'information. Dans notre approche, l'interopérabilité des SI des partenaires s'appuie conceptuellement sur deux caractéristiques : (i) la facul...

  5. Liste des contributeurs

    OpenAIRE

    2014-01-01

    Abouhani Abdelghani, Inau, Rabat. Blili Leïla, Université de La Manouba, Faculté des lettres, des arts et des humanités, La Manouba. Boubrik Rahal, Ihcc, Aix-en-Provence. Boujarra Hussein, Université de Tunis, Faculté des sciences humaines et sociales, Tunis/Diraset. Études maghrébines. Cattedra Raffaele, Université de Montpellier III. Catusse Myriam, Cnrs-Iremam, Aix-en-Provence. Cheraï Ahmed, École nationale d’administration, Rabat. Ettayeb Mahmoud, Université de Tunis, Faculté des sciences...

  6. Layer resolved capacitive probing of graphene bilayers

    Science.gov (United States)

    Zibrov, Alexander; Parmentier, François; Li, Jia; Wang, Lei; Hunt, Benjamin; Dean, Cory; Hone, James; Taniguchi, Takashi; Watanabe, Kenji; Young, Andrea

    Compared to single layer graphene, graphene bilayers have an additional ``which-layer'' degree of freedom that can be controlled by an external electric field in a dual-gated device geometry. We describe capacitance measurements capable of directly probing this degree of freedom. By performing top gate, bottom gate, and penetration field capacitance measurements, we directly extract layer polarization of both Bernal and twisted bilayers. We will present measurements of hBN encapsulated bilayers at both zero and high magnetic field, focusing on the physics of the highly degenerate zero-energy Landau level in the high magnetic field limit where spin, valley, and layer degeneracy are all lifted by electronic interactions.

  7. A simple and reproducible capacitive electrode.

    Science.gov (United States)

    Spinelli, Enrique; Guerrero, Federico; García, Pablo; Haberman, Marcelo

    2016-03-01

    Capacitive Electrodes (CE) allow the acquisition of biopotentials through a dielectric layer, without the use of electrolytes, just by placing them on skin or clothing, but demands front-ends with ultra-high input impedances. This must be achieved while providing a path for bias currents, calling for ultra-high value resistors and special components and construction techniques. A simple CE that uses bootstrap techniques to avoid ultra-high value components and special materials is proposed. When electrodes are placed on the skin; that is, with coupling capacitances CS of around 100 pF, they present a noise level of 3.3 µVRMS in a 0.5-100 Hz bandwidth, which is appropriate for electrocardiography (ECG) measurements. Construction details of the CE and the complete circuit, including a fast recovery feature, are presented. PMID:26792172

  8. Development of a capacitive bioimpedance measurement system

    OpenAIRE

    Gómez Abad, Daniel

    2009-01-01

    Bioelectrical impedance spectroscopy (BIS) is a well-established and non-invasive method to determine and monitor body composition. Commercially available bioelectrical impedance systems use coated hydrogel-aluminium electrodes, where the hydrogel acts as an adhesive and as an electrolytic medium. The gel/adhesive is physiologically inert over short periods. However, when used over longer periods, hydrogel-aluminium electrodes present limitations, which capacitive electrodes ma...

  9. Performance relations in Capacitive Deionization systems

    OpenAIRE

    Limpt, van, C.

    2010-01-01

    Capacitive Deionization (CDI) is a relatively new deionization technology based on the temporary storage of ions on an electrically charged surface. By directing a flow between two oppositely charged surfaces, negatively charged ions will adsorb onto the positively charged surface, and positively charged ions will adsorb onto the negatively charged surface. To optimize CDI design for various applications, performance relations in CDI systems have to be understood. CDI performance is determine...

  10. Ultra-High-Frequency Capacitive Displacement Sensor

    Science.gov (United States)

    Vanzandt, Thomas R.; Kenny, Thomas W.; Kaiser, William J.

    1994-01-01

    Improved class of compact, high-resolution capacitive displacement sensors operates at excitation frequency of 915 MHz and measures about 7.5 by 4 by 2 centimeters. Contains commercially available 915-MHz oscillator and transmission-line resonator. Resonator contains stripline inductor in addition to variable capacitor. Ultrahigh excitation frequency offers advantages of resolution and frequency response. Not deleteriously affected by mechanical overdriving, or contact between electrodes.

  11. Capacitive Sensors And Targets Would Measure Alignments

    Science.gov (United States)

    Jenstrom, Del T.

    1994-01-01

    Multiple capacitive sensors and active targets used to measure distance between, and relative orientation of, two objects. Sensed target signals processed and used by control systems to align objects to be joined. Shapes, sizes, and layouts of sensors and targets optimized for specific application. Particular layout of targets and sensors enables determination of relative position and orientation of two objects in all six degrees of freedom.

  12. The fringe capacitance formula of microstructures

    International Nuclear Information System (INIS)

    This paper presents a fringe capacitance formula of microstructures. The formula is derived by curve fitting on ANSYS simulation results. Compared with the ANSYS and experimental results, the deviation is within ±2%. The application to determine the pull-in voltage of an electrostatic micro-beam is demonstrated, which agrees very well with the experimental data. The formula presented is very accurate, yields explicit physical meanings and is applicable to common dimension ranges for MEMS devices. (paper)

  13. Effect of astaxanthin on human sperm capacitation.

    Science.gov (United States)

    Donà, Gabriella; Kožuh, Ivana; Brunati, Anna Maria; Andrisani, Alessandra; Ambrosini, Guido; Bonanni, Guglielmo; Ragazzi, Eugenio; Armanini, Decio; Clari, Giulio; Bordin, Luciana

    2013-06-01

    In order to be able to fertilize oocytes, human sperm must undergo a series of morphological and structural alterations, known as capacitation. It has been shown that the production of endogenous sperm reactive oxygen species (ROS) plays a key role in causing cells to undergo a massive acrosome reaction (AR). Astaxanthin (Asta), a photo-protective red pigment belonging to the carotenoid family, is recognized as having anti-oxidant, anti-cancer, anti-diabetic and anti-inflammatory properties and is present in many dietary supplements. This study evaluates the effect of Asta in a capacitating buffer which induces low ROS production and low percentages of acrosome-reacted cells (ARC). Sperm cells were incubated in the presence or absence of increasing concentrations of Asta or diamide (Diam) and analyzed for their ROS production, Tyr-phosphorylation (Tyr-P) pattern and percentages of ARC and non-viable cells (NVC). Results show that Asta ameliorated both sperm head Tyr-P and ARC values without affecting the ROS generation curve, whereas Diam succeeded in enhancing the Tyr-P level but only of the flagellum without increasing ARC values. It is suggested that Asta can be inserted in the membrane and therefore create capacitation-like membrane alteration which allow Tyr-P of the head. Once this has occurred, AR can take place and involves a higher numbers of cells. PMID:23736766

  14. Effect of Astaxanthin on Human Sperm Capacitation

    Directory of Open Access Journals (Sweden)

    Luciana Bordin

    2013-06-01

    Full Text Available In order to be able to fertilize oocytes, human sperm must undergo a series of morphological and structural alterations, known as capacitation. It has been shown that the production of endogenous sperm reactive oxygen species (ROS plays a key role in causing cells to undergo a massive acrosome reaction (AR. Astaxanthin (Asta, a photo-protective red pigment belonging to the carotenoid family, is recognized as having anti-oxidant, anti-cancer, anti-diabetic and anti-inflammatory properties and is present in many dietary supplements. This study evaluates the effect of Asta in a capacitating buffer which induces low ROS production and low percentages of acrosome-reacted cells (ARC. Sperm cells were incubated in the presence or absence of increasing concentrations of Asta or diamide (Diam and analyzed for their ROS production, Tyr-phosphorylation (Tyr-P pattern and percentages of ARC and non-viable cells (NVC. Results show that Asta ameliorated both sperm head Tyr-P and ARC values without affecting the ROS generation curve, whereas Diam succeeded in enhancing the Tyr-P level but only of the flagellum without increasing ARC values. It is suggested that Asta can be inserted in the membrane and therefore create capacitation-like membrane alteration which allow Tyr-P of the head. Once this has occurred, AR can take place and involves a higher numbers of cells.

  15. Capacitive Structures for Gas and Biological Sensing

    KAUST Repository

    Sapsanis, Christos

    2015-04-01

    The semiconductor industry was benefited by the advances in technology in the last decades. This fact has an impact on the sensors field, where the simple transducer was evolved into smart miniaturized multi-functional microsystems. However, commercially available gas and biological sensors are mostly bulky, expensive, and power-hungry, which act as obstacles to mass use. The aim of this work is gas and biological sensing using capacitive structures. Capacitive sensors were selected due to its design simplicity, low fabrication cost, and no DC power consumption. In the first part, the dominant structure among interdigitated electrodes (IDEs), fractal curves (Peano and Hilbert) and Archimedean spiral was investigated from capacitance density perspective. The investigation consists of geometrical formula calculations, COMSOL Multiphysics simulations and cleanroom fabrication of the capacitors on a silicon substrate. Moreover, low-cost fabrication on flexible plastic PET substrate was conducted outside cleanroom with rapid prototyping using a maskless laser etching. The second part contains the humidity, Volatile Organic compounds (VOCs) and Ammonia sensing of polymers, Polyimide and Nafion, and metal-organic framework (MOF), Cu(bdc)2.xH2O using IDEs and tested in an automated gas setup for experiment control and data extraction. The last part includes the biological sensing of C - reactive protein (CRP) quantification, which is considered as a biomarker of being prone to cardiac diseases and Bovine serum albumin (BSA) protein quantification, which is used as a reference for quantifying unknown proteins.

  16. Multi-Channel Capacitive Sensor Arrays.

    Science.gov (United States)

    Wang, Bingnan; Long, Jiang; Teo, Koon Hoo

    2016-01-01

    In this paper, multi-channel capacitive sensor arrays based on microstrip band-stop filters are studied. The sensor arrays can be used to detect the proximity of objects at different positions and directions. Each capacitive sensing structure in the array is connected to an inductive element to form resonance at different frequencies. The resonances are designed to be isolated in the frequency spectrum, such that the change in one channel does not affect resonances at other channels. The inductive element associated with each capacitive sensor can be surface-mounted inductors, integrated microstrip inductors or metamaterial-inspired structures. We show that by using metamaterial split-ring structures coupled to a microstrip line, the quality factor of each resonance can be greatly improved compared to conventional surface-mounted or microstrip meander inductors. With such a microstrip-coupled split-ring design, more sensing elements can be integrated in the same frequency spectrum, and the sensitivity can be greatly improved. PMID:26821023

  17. Distributed Capacitive Sensor for Sample Mass Measurement

    Science.gov (United States)

    Toda, Risaku; McKinney, Colin; Jackson, Shannon P.; Mojarradi, Mohammad; Manohara, Harish; Trebi-Ollennu, Ashitey

    2011-01-01

    Previous robotic sample return missions lacked in situ sample verification/ quantity measurement instruments. Therefore, the outcome of the mission remained unclear until spacecraft return. In situ sample verification systems such as this Distributed Capacitive (DisC) sensor would enable an unmanned spacecraft system to re-attempt the sample acquisition procedures until the capture of desired sample quantity is positively confirmed, thereby maximizing the prospect for scientific reward. The DisC device contains a 10-cm-diameter pressure-sensitive elastic membrane placed at the bottom of a sample canister. The membrane deforms under the weight of accumulating planetary sample. The membrane is positioned in close proximity to an opposing rigid substrate with a narrow gap. The deformation of the membrane makes the gap narrower, resulting in increased capacitance between the two parallel plates (elastic membrane and rigid substrate). C-V conversion circuits on a nearby PCB (printed circuit board) provide capacitance readout via LVDS (low-voltage differential signaling) interface. The capacitance method was chosen over other potential approaches such as the piezoelectric method because of its inherent temperature stability advantage. A reference capacitor and temperature sensor are embedded in the system to compensate for temperature effects. The pressure-sensitive membranes are aluminum 6061, stainless steel (SUS) 403, and metal-coated polyimide plates. The thicknesses of these membranes range from 250 to 500 m. The rigid substrate is made with a 1- to 2-mm-thick wafer of one of the following materials depending on the application requirements glass, silicon, polyimide, PCB substrate. The glass substrate is fabricated by a microelectromechanical systems (MEMS) fabrication approach. Several concentric electrode patterns are printed on the substrate. The initial gap between the two plates, 100 m, is defined by a silicon spacer ring that is anodically bonded to the glass

  18. Contributions à l'étude du complexe absorbant des sols acides à charges mixtes : application aux andosols du Velay

    OpenAIRE

    Espiau, P.

    1987-01-01

    En prenant comme modèle les andosols à charges mixtes du Velay, l'auteur s'intéresse, dans le contexte naturel, à la détermination des charges négatives et des cations échangeables qui les saturent. Ainsi, il discute les problèmes posés par les membres de l'égalité qui assure l'électroneutralité dans les sols (somme des cations échangeables = capacité d'échange cationique effective)

  19. Appropriation des Tic et performance des entreprises

    OpenAIRE

    Lethiais, Virginie; Smati, Wided

    2009-01-01

    L'utilisation des TIC (Technologies de l'information et de la Communication) se développe dans les entreprises pour assurer des tâches de plus en plus nombreuses : la communication, la recherche d'informations, la commercialisation des produits et services, le travail en groupe, la gestion de l'entreprise, la prospection, etc. Les équipements en TIC ainsi que l'usage qui en est fait diffèrent d'une entreprise à une autre selon de nombreux critères. L'objet de ce quatre pages est de déterminer...

  20. Celle des riches et celle des pauvres

    OpenAIRE

    Roussel, Bernard; Woldeyes, Feleke

    2013-01-01

    Les graines de la fausse cardamome kororima, Aframomum corrorima (Braun) Jansen, maniguette endémique d’Éthiopie, constituent une épice indispensable, emblématique du pays tout entier, aux usages multiples et quasi quotidiens. Plante spontanée des sous-bois des forêts humides du Kafa, c’est aussi une plante cultivée dans les jardins de diverses régions de l’Éthiopie méridionale.Cet article, à partir de l’analyse de la production et des filières de commercialisation de la kororima, se propose ...

  1. Évaluation de la qualité des comportements des agents en simulation : application à un simulateur de conduite en environnement virtuel

    OpenAIRE

    DARTY, Kevin

    2015-01-01

    Cette thèse se situe dans le contexte de la Simulation Multi-Agents et s'intéresse à l'évaluation de la capacité des agents à reproduire individuellement des comportements humains. Les comportements que nous considérons sont dits 'de haut niveau', par opposition aux comportements moteurs ou réflexes. Cette problématique se retrouve dans de nombreux domaines avec la Réalité Virtuelle, les Agents Conversationnels Animés, les agents d'un simulateur immersif, les jeux. L'approche dominante pour é...

  2. Évaluation de la qualité des comportements des agents en simulation : application à un simulateur de conduite en environnement virtuel

    OpenAIRE

    Darty, Kévin

    2015-01-01

    Cette thèse se situe dans le contexte de la Simulation Multi-Agent et s'intéresse à l'évaluation de la capacité des agents à reproduire individuellement des comportements humains. Les comportements que nous considérons sont dits "de haut niveau", par opposition aux comportements moteurs ou réflexes. Cette problématique se retrouve dans de nombreux domaines avec la Réalité Virtuelle, les Agents Conversationnels Animés, les agents d'un simulateur immersif, les jeux. L'approche dominante pour év...

  3. Improved capacitance sensor with variable operating frequency for scanning capacitance microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Joonhyung [PSIA Corporation, Induspia 5F, Sang-Daewon-Dong 517-13, Sungnam 462-120 (Korea, Republic of); Kim, Joonhui [PSIA Corporation, Induspia 5F, Sang-Daewon-Dong 517-13, Sungnam 462-120 (Korea, Republic of); Jeong, Jong-Hwa [PSIA Corporation, Induspia 5F, Sang-Daewon-Dong 517-13, Sungnam 462-120 (Korea, Republic of); Lee, Euy-Kyu [Department of Physics, Myongji University, Yongin, Kyunggido 449-728 (Korea, Republic of); Seok Kim, Yong [PSIA Corporation, Induspia 5F, Sang-Daewon-Dong 517-13, Sungnam 462-120 (Korea, Republic of); Kang, Chi Jung [Department of Physics, Myongji University, Yongin, Kyunggido 449-728 (Korea, Republic of); Park, Sang-il [PSIA Corporation, Induspia 5F, Sang-Daewon-Dong 517-13, Sungnam 462-120 (Korea, Republic of)]. E-mail: park@psia.co.kr

    2005-11-15

    Scanning capacitance microscopy (SCM) has been gaining attention for its capability to measure local electrical properties in doping profile, oxide thickness, trapped charges and charge dynamics. In many cases, stray capacitance produced by different samples and measurement conditions affects the resonance frequency of a capacitance sensor. The applications of conventional SCM are critically limited by the fixed operating frequency and lack of tunability in its SCM sensor. In order to widen SCM application to various samples, we have developed a novel SCM sensor with variable operating frequency. By performing variable frequency sweep over the band of 160 MHz, the SCM sensor is tuned to select the best and optimized resonance frequency and quality factor for each sample measurement. The fundamental advantage of the new variable frequency SCM sensor was demonstrated in the SCM imaging of silicon oxide nano-crystals. Typical sensitivity of the variable frequency SCM sensor was found to be 10{sup -19} F/V.

  4. Improved capacitance sensor with variable operating frequency for scanning capacitance microscopy

    International Nuclear Information System (INIS)

    Scanning capacitance microscopy (SCM) has been gaining attention for its capability to measure local electrical properties in doping profile, oxide thickness, trapped charges and charge dynamics. In many cases, stray capacitance produced by different samples and measurement conditions affects the resonance frequency of a capacitance sensor. The applications of conventional SCM are critically limited by the fixed operating frequency and lack of tunability in its SCM sensor. In order to widen SCM application to various samples, we have developed a novel SCM sensor with variable operating frequency. By performing variable frequency sweep over the band of 160 MHz, the SCM sensor is tuned to select the best and optimized resonance frequency and quality factor for each sample measurement. The fundamental advantage of the new variable frequency SCM sensor was demonstrated in the SCM imaging of silicon oxide nano-crystals. Typical sensitivity of the variable frequency SCM sensor was found to be 10-19 F/V

  5. Modelisations des effets de surface sur les jets horizontaux subsoniques d'hydrogene et de methane

    Science.gov (United States)

    Gomez, Luis Fernando

    Le developpement des codes et de normes bases sur une methodologie scientifique requiert la capacite de predire l'etendue inflammable de deversements gazeux d'hydrogene sous differentes conditions. Des etudes anterieures ont deja etabli des modeles bases sur les lois de conservation de la mecanique des fluides basees sur des correlations experimentales qui permettent de predire la decroissance de la concentration et de la vitesse d'un gaz le long de l'axe d'un jet libre vertical. Cette etude s'interesse aux effets de proximite a une surface horizontale parallele sur un jet turbulent. Nous nous interessons a son impact sur l'etendue du champ de la concentration et sur l'enveloppe inflammable en particulier. Cette etude est comparative : l'hydrogene est compare au methane. Ceci permet de degager l'influence des effets de difference de la densite sur le comportement du jet, et de comparer le comportement de l'hydrogene aux correlations experimentales, qui ont ete essentiellement etablies pour le methane. Un modele decrivant l'evolution spatio-temporelle du champ de concentration du gaz dilue est propose, base sur la mecanique des fluides computationnelle. Cette approche permet de varier systematiquement les conditions aux frontieres (proximite du jet a la surface, par exemple) et de connaitre en detail les proprietes de l'ecoulement. Le modele est implemente dans le code de simulations par volumes finis de FLUENT. Les resultats des simulations sont compares avec les lois de similitudes decoulant de la theorie des jets d'ecoulements turbulents libres ainsi qu'avec les resultats experimentaux disponibles. L'effet de la difference des masses molaires des constituantes du jet et des constituantes du milieu de dispersion est egalement etudie dans le contexte du comportement d'echelle de la region developpee du jet.

  6. Image reconstruction for field-focusing capacitance imaging

    International Nuclear Information System (INIS)

    For online monitoring of multi-phase flows of non-conductive materials, a field-focusing capacitance imaging system has been developed. With a field focusing capacitance sensor, a tomographic image based on capacitance measurements is used directly to map the material distribution. However, it is difficult to achieve a required accuracy for measurement of void fraction from the capacitance image, because of the soft-field effect of the capacitance sensor. In this paper, the forward and inverse problems with a field-focusing capacitance sensor are described. Simulation and experimental results show that deconvolution-based algorithms can reduce the blurring artefact and can reconstruct an image close to the original distribution

  7. Numerical analysis of capacitive pressure micro-sensors

    Institute of Scientific and Technical Information of China (English)

    WANG Xiaomin; LI Mingxuan; WANG Chenghao

    2005-01-01

    Pseudo-spectral method is used to numerically model the diaphragm deflection of capacitive pressure micro-sensor under uniform load. The relationship between the capacitance of the micro-sensor and the load is then analyzed after the description of the computational principle. For normal mode micro-sensor, the tensile force on the diaphragm can be ignored and thereby the capacitance increases linearly with the load increase only when the load is so small that the resultant deflection is less than the diaphragm thickness. The linear relationship between the capacitance and the load turns to be nonlinear thereafter and the capacitance rises dramatically with the constant increase of the load. For touch mode micro-sensor, an algorithm to determine the touch radius of the diaphragm and substrate is presented and the curve of capacitance versus load is shown on the numerical results laying a theoretical foundation for micro-sensor design.

  8. CMOS MEMS capacitive absolute pressure sensor

    International Nuclear Information System (INIS)

    This paper presents the design, fabrication and characterization of a capacitive pressure sensor using a commercial 0.18 µm CMOS (complementary metal–oxide–semiconductor) process and postprocess. The pressure sensor is capacitive and the structure is formed by an Al top electrode enclosed in a suspended SiO2 membrane, which acts as a movable electrode against a bottom or stationary Al electrode fixed on the SiO2 substrate. Both the movable and fixed electrodes form a variable parallel plate capacitor, whose capacitance varies with the applied pressure on the surface. In order to release the membranes the CMOS layers need to be applied postprocess and this mainly consists of four steps: (1) deposition and patterning of PECVD (plasma-enhanced chemical vapor deposition) oxide to protect CMOS pads and to open the pressure sensor top surface, (2) etching of the sacrificial layer to release the suspended membrane, (3) deposition of PECVD oxide to seal the etching holes and creating vacuum inside the gap, and finally (4) etching of the passivation oxide to open the pads and allow electrical connections. This sensor design and fabrication is suitable to obey the design rules of a CMOS foundry and since it only uses low-temperature processes, it allows monolithic integration with other types of CMOS compatible sensors and IC (integrated circuit) interface on a single chip. Experimental results showed that the pressure sensor has a highly linear sensitivity of 0.14 fF kPa−1 in the pressure range of 0–300 kPa. (paper)

  9. Les nouvelles typologies architecturales des équipements hôteliers en france*1

    OpenAIRE

    Vilan, Teresa Cristina

    2013-01-01

    Note portant sur l’auteur OBJET ET PROBLÉMATIQUE Les chaînes hôtelières sont aujourd’hui très présentes en France. Statistiquement, l’hôtellerie reste l’affaire des petits propriétaires familiaux, qui possèdent 42 % des chambres en 1998, part qui passe à 57 % au début 2001 et même 61 % si l’on y ajoute les indépendants franchisés. Toutefois, avec une plus grande capacité d’hébergement par hôtel et des stratégies de développement performantes, le nombre de chambres appartenant à des chaînes in...

  10. Evolution des Geistes

    OpenAIRE

    Roth, Gerhard

    2004-01-01

    Evolution des Geistes Vortrag am 9. Februar 2003 im Rahmen der Reihe "Evolution – Entstehung der Erde bis zur Entfaltung des Geistes" des Zoologischen Museums Nach traditioneller Auffassung besitzt nur der Mensch Geist und Bewusstsein, und hierin besteht seine Einzigartigkeit. Aus Sicht der Hirnforschung und der Verhaltensbiologie haben sich jedoch während der tierischen Evolution Geist und Bewusstsein über viele Stufen entwickelt. Eine Reihe nichtmenschlicher Tiere, vor allem Säugetiere und ...

  11. Probing Quantum Capacitance in a 3D Topological Insulator

    OpenAIRE

    Kozlov, D. A.; Bauer, Dominik; Ziegler, Johannes; Fischer, Ralf, 1965-; Savchenko, M. L.; Kvon, Z.D.; Mikhailov, N. N.; Dvoretsky, S. A.; Weiss, Dieter

    2016-01-01

    We measure the quantum capacitance and probe thus directly the electronic density of states of the high mobility, Dirac type of two-dimensional electron system, which forms on the surface of strained HgTe. Here we show that observed magneto-capacitance oscillations probe, in contrast to magnetotransport, primarily the top surface. Capacitance measurements constitute thus a powerful tool to probe only one topological surface and to reconstruct its Landau level spectrum for different positions ...

  12. Accurate sizing of supercapacitors storage system considering its capacitance variation.

    OpenAIRE

    Trieste, Sony; Bourguet, Salvy; Olivier, Jean-Christophe; Loron, Luc; Le Claire, Jean-Claude

    2011-01-01

    This paper highlights the energy errors made for the design of supercapacitors used as a main energy source. First of all, the paper presents the two definitions of capacitance of a capacitance-voltage dependent material. The number of supercapacitors is important for the application purchasing cost. That is why the paper introduces an analytical model and an electrical model along with an identification method for the capacitance variation. This variation is presented and compared to the man...

  13. Carrier Statistics and Quantum Capacitance Models of Graphene Nanoscroll

    Directory of Open Access Journals (Sweden)

    M. Khaledian

    2014-01-01

    schematic perfect scroll-like Archimedes spiral. The DOS model was derived at first, while it was later applied to compute the carrier concentration and quantum capacitance model. Furthermore, the carrier concentration and quantum capacitance were modeled for both degenerate and nondegenerate regimes, along with examining the effect of structural parameters and chirality number on the density of state and carrier concentration. Latterly, the temperature effect on the quantum capacitance was studied too.

  14. Nonlinear dynamics of capacitive charging and desalination by porous electrodes

    OpenAIRE

    Biesheuvel, P. M.; Bazant, M.Z.

    2010-01-01

    The rapid and efficient exchange of ions between porous electrodes and aqueous solutions is important in many applications, such as electrical energy storage by super-capacitors, water desalination and purification by capacitive deionization (or desalination), and capacitive extraction of renewable energy from a salinity difference. Here, we present a unified mean-field theory for capacitive charging and desalination by ideally polarizable porous electrodes (without Faradaic reactions or spec...

  15. Capacitive position measurement for high-precision space inertial sensor

    Institute of Scientific and Technical Information of China (English)

    Yan-zheng BAI; Ze-bing ZHOU; Hai-bo TU; Shu-chao WU; Lin CAI; LI LIU; Jun LUO

    2009-01-01

    Low noise position measurement is fundamental for space inertial sensors, and at present the capacitive position sensor is widely employed for space inertial sensors. The design for the possible suppression of the front-end electric noises for a capacitive sensor is presented. A prototype capacitive sensor with 2x 10-6pF/Hzi/2 at frequency above 0.04 Hz is achieved and further improvements are discussed.

  16. DEVELOPMENT OF ADAPTED CAPACITANCE MANOMETER FOR  THERMOSPHERIC APPLICATIONS

    OpenAIRE

    Orr, Cameron Scott

    2016-01-01

    An adapted capacitance manometer is a sensor composed of one fixed plate and one movable plate that is able to make accurate pressure measurements in a low pressure environment. Using detection circuitry, a change in capacitance between the two plates can be measured and correlated to a differential pressure. First, a high sensitivity manometer is produced that exhibits a measurable change in capacitance when experiencing a pressure differential in a low pressure space environment. Second,...

  17. Static and Motional Feedthrough Capacitance of Flexural Microresonator

    OpenAIRE

    Wen-Teng Chang

    2011-01-01

    The present paper evaluates the static and motional feedthrough capacitance of a silicon carbide-based flexural-mode microelectromechanical system resonator. The static feedthrough capacitance was measured by a network analyzer under atmospheric pressure. The motional feedthrough was obtained by introducing various values into the modeling circuit in order to fit the Bode plots measured under reduced pressure. The static feedthrough capacitance was 0.02 pF, whereas the motional feedthrough ca...

  18. Anatomie et identification des bois

    OpenAIRE

    Jourez, Benoît

    2010-01-01

    Anatomie des bois Structure anatomique des résineux et des feuillus Structure de la membrane cellulaire structure submicroscopique Anatomie du bois des essences feuillues tropicales Caractères anatomiques servant à l'identification des essences Reconnaissance microscopique du bois des essences résineuses et feuillues Duramen et duraminisation Formations anormales ( bois de compression et bois de tension) Chimie du bois Composition générale Cellulose, hé...

  19. Capacitive tool standoff sensor for dismantlement tasks

    International Nuclear Information System (INIS)

    A capacitive sensing technology has been applied to develop a Standoff Sensor System for control of robotically deployed tools utilized in Decontamination and Dismantlement (D and D) activities. The system combines four individual sensor elements to provide non-contact, multiple degree-of-freedom control of tools at distances up to five inches from a surface. The Standoff Sensor has been successfully integrated to a metal cutting router and a pyrometer, and utilized for real-time control of each of these tools. Experiments demonstrate that the system can locate stationary surfaces with a repeatability of 0.034 millimeters

  20. Capacitive tool standoff sensor for dismantlement tasks

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, D.J.; Weber, T.M. [Sandia National Labs., Albuquerque, NM (United States); Liu, J.C. [Univ. of Illinois, Urbana, IL (United States)

    1996-12-31

    A capacitive sensing technology has been applied to develop a Standoff Sensor System for control of robotically deployed tools utilized in Decontamination and Dismantlement (D and D) activities. The system combines four individual sensor elements to provide non-contact, multiple degree-of-freedom control of tools at distances up to five inches from a surface. The Standoff Sensor has been successfully integrated to a metal cutting router and a pyrometer, and utilized for real-time control of each of these tools. Experiments demonstrate that the system can locate stationary surfaces with a repeatability of 0.034 millimeters.

  1. 3-D capacitance density imaging system

    Science.gov (United States)

    Fasching, G.E.

    1988-03-18

    A three-dimensional capacitance density imaging of a gasified bed or the like in a containment vessel is achieved using a plurality of electrodes provided circumferentially about the bed in levels and along the bed in channels. The electrodes are individually and selectively excited electrically at each level to produce a plurality of current flux field patterns generated in the bed at each level. The current flux field patterns are suitably sensed and a density pattern of the bed at each level determined. By combining the determined density patterns at each level, a three-dimensional density image of the bed is achieved. 7 figs.

  2. Combinatorial Algorithms for Capacitated Network Design

    OpenAIRE

    Hajiaghayi, MohammadTaghi; Khandekar, Rohit; Kortsarz, Guy; Nutov, Zeev

    2011-01-01

    We focus on designing combinatorial algorithms for the Capacitated Network Design problem (Cap-SNDP). The Cap-SNDP is the problem of satisfying connectivity requirements when edges have costs and hard capacities. We begin by showing that the Group Steiner tree problem (GST) is a special case of Cap-SNDP even when there is connectivity requirement between only one source-sink pair. This implies the first poly-logarithmic lower bound for the Cap-SNDP. We next provide combinatorial algorithms fo...

  3. Groupement des faits

    OpenAIRE

    Langlois, Charles-Victor; Seignobos, Charles

    2014-01-01

    I. La première nécessité qui s’impose à l’historien mis en présence du chaos des faits historiques, c’est de limiter son champ de recherches. Dans l’océan de l’histoire universelle quels faits choisira-t-il pour les recueillir ? – Puis, dans la masse des faits ainsi choisis, il lui faudra distinguer des groupes et faire des sections. – Enfin dans chacune de ces sections il aura à ranger les faits un à un. Ainsi toute construction historique doit commencer par trouver un principe pour trier, e...

  4. Quantum capacitance of graphene in contact with metal

    International Nuclear Information System (INIS)

    We report a versatile computation method to quantitatively determine the quantum capacitance of graphene when it is in contact with metal. Our results bridge the longstanding gap between the theoretically predicted and experimentally measured quantum capacitance of graphene. Contrary to popular assumptions, the presence of charged impurities or structural distortions of graphene are not the only sources of the asymmetric capacitance with respect to the polarity of the bias potential and the higher-than-expected capacitance at the Dirac point. They also originate from the field-induced electronic interactions between graphene and metal. We also provide an improved model representation of a metal–graphene junction

  5. Quantum capacitance of graphene in contact with metal

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Jin Hyun, E-mail: jin.chang@mail.utoronto.ca; Dawson, Francis [The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King' s College Road, Toronto, Ontario M5S 3G4 (Canada); Huzayyin, Ahmed [The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King' s College Road, Toronto, Ontario M5S 3G4 (Canada); Electrical Power and Machines Department, Cairo University, Giza 12316 (Egypt); Lian, Keryn [Department of Materials Science and Engineering, University of Toronto, 184 College Street, Toronto M5S 1A1 (Canada)

    2015-11-09

    We report a versatile computation method to quantitatively determine the quantum capacitance of graphene when it is in contact with metal. Our results bridge the longstanding gap between the theoretically predicted and experimentally measured quantum capacitance of graphene. Contrary to popular assumptions, the presence of charged impurities or structural distortions of graphene are not the only sources of the asymmetric capacitance with respect to the polarity of the bias potential and the higher-than-expected capacitance at the Dirac point. They also originate from the field-induced electronic interactions between graphene and metal. We also provide an improved model representation of a metal–graphene junction.

  6. Calibration of capacitive hydrostatic leveling sensors of NSRL

    International Nuclear Information System (INIS)

    The principle of capacitive hydrostatic leveling sensors was presented. Simulations of sensors with two kinds of materials (metal and distilled water) as target electrode in the situations of calibration and work were carried out by Ansoft Maxwell software. Different values of capacitances in different situations were compared and analyzed. Then some experiments were done with independently developed prototype of capacitive hydrostatic leveling sensors to verify the above simulations. In the situations of calibration and work, the same property (conductivity and dielectric constant) material as target electrode should be chosen for capacitive hydrostatic leveling sensors. Otherwise, there is an error of sensors after calibration, and the main factor is conductivity. (authors)

  7. Variable-capacitance tachometer eliminates troublesome magnetic fields

    Science.gov (United States)

    1966-01-01

    Dual variable-capacitance tachometer measures angular speed and sense of rotation without magnetic components. Thus it eliminates magnetic flux interference with associated instrumentation in an electromechanical system.

  8. Void fraction measurement with capacitance meter

    International Nuclear Information System (INIS)

    The void fraction in an air-water system has been measured using the capacitance meter. Various flow regimes including bubbly, slug, churn, annular and drop-annular flow have been investigated. The superficial air and water velocity have been varied in the range of 0.145 less than or equal to j /SUB f/ less than or equal to 3.62 ft/sec and 0.183 less than or equal to j /SUB g/ less than or equal to 63.7 ft/sec respectively and the void fraction has been varied from 0.04 to 0.94. The capacitance meter is calibrated by both quick closing valve method and theoretical calculation based on drift-flux model. The sensitivity of void fraction measurement on sensor shape has been investigated with sensors of different width. Using the conventional theoretical curves of void fraction vs. relative susceptance, the results show that the sensor width has strong effect on void fraction measurement especially annular flow regime. The results also show that significant discrepancy exists between the theoretical curve and the experimental results. The reason for this discrepancy has been identified due to two dimensional edge effect of the circular sensor. A 2-D model has been developed taking into account of both sensor width and flow regime which gives good prediction of the experimental results

  9. THERMAL DRIFT CHARACTERISTICS OF CAPACITIVE PRESSURE SENSORS

    Directory of Open Access Journals (Sweden)

    ABDELAZIZ BEDDIAF

    2016-03-01

    Full Text Available The capacitive pressure sensors based on silicon are characterized by their very high sensitivities and their low power consumption. Nevertheless, their thermal behavior remains more or less unpredictable because they can indicate very high thermal coefficients. The study of the thermal behavior of these sensors is essential to define the parameters that cause the output characteristics drift. In this study, we modeled the thermal behavior of this sensors, using Finite Element Analysis (FEA made in COMSOL. The model solved by COMSOL environment takes into account the entire sensor and thermal effects due to the temperature considering the materials’ properties, the geometric shape and also the heat transfer mechanisms. By COMSOL we determine how the temperature affects the sensor during the manufacturing process. For that end, we calculated the thermal drift of capacitance at rest, the thermal coefficients and we compared them with experimental results to validate our model. Further, we studied the thermal drift of sensor characteristics both at rest and under constant and uniform pressure. Further, our study put emphasis on the geometric influence parameters on these characteristics to optimize the sensor performance. Finally, this study allows us to predict the sensor behavior against temperature and to minimize this effect by optimizing the geometrical parameters.

  10. Proportional microvolume capacitive liquid level sensor array.

    Science.gov (United States)

    Seliskar, D; Waterbury, R; Kearney, R

    2005-01-01

    A sensor array has been developed for use with laboratory automation to permit closed-loop control of liquid levels in a multiwell microplate geometry. We extended a simple electrical model for non-contact capacitance-based fluid sensors to describe a fluid-level dependency. The new model shows that a charge-transfer based capacitance transducer, employing a liquid-specific calibration, can be used to obtain an output signal that varies linearly with the liquid level. The calibration also compensates for liquid-to-liquid conductivity and permittivity differences. A prototype 3×3 sensor array was built and tested using NaCl and ethanol solutions to simulate the range of conductivity and permittivity typical in biological and chemical research. Calibrated output signals were linear with liquid volume for all tested solutions (R2>0.92). Measurement error averaged 1.3 % (2.0 μl) with a standard deviation of 6.0% (9.0 μl). These results demonstrate the feasibility of developing a microvolume sensor array in essentially any M×N microplate geometry. PMID:17281955

  11. A capacitive electrode with fast recovery feature

    International Nuclear Information System (INIS)

    Capacitive electrodes (CEs) allow for acquiring biopotentials without galvanic contact, avoiding skin preparation and the use of electrolytic gel. The signal quality provided by present CEs is similar to that of standard wet electrodes, but they are more sensitive to electrostatic charge interference and motion artifacts, mainly when biopotentials are picked up through clothing and coupling capacitances are reduced to tens of picofarads. When artifacts are large enough to saturate the preamplifier, several seconds (up to tens) are needed to recover a proper baseline level, and during this period biopotential signals are irremediably lost. To reduce this problem, a CE that includes a fast-recovery (FR) circuit is proposed. It works directly on the coupling capacitor, recovering the amplifier from saturation while preserving ultra-high input impedance, as a CE requires. A prototype was built and tested acquiring ECG signals. Several experimental data are presented, which show that the proposed circuit significantly reduces record segment losses due to amplifier saturation when working in real environments. (paper)

  12. Étapes clé du devenir des aliments dans le tube digestif

    OpenAIRE

    Fioramonti, Jean

    2014-01-01

    La capacité du tube digestif à digérer les aliments et absorber les nutriments est considérable. Plusieurs caractéristiques de la physiologie digestive visent à optimiser le contact de l'aliment avec les enzymes et favoriser l'absorption des nutriments. L'estomac joue un rôle primordial dans la digestion en ne laissant passer à travers le pylore que des particules de petite taille et en régulant l'évacuation de son contenu de façon à obtenir une digestion optimale dans l'intestin grêle. Les c...

  13. Pouvoir des séries télévisées

    OpenAIRE

    Esquenazi, Jean-Pierre

    2014-01-01

    L’auteur s’interroge sur la notion de pouvoir des séries télévisées. Il rejette la conception d’un pouvoir industriel tout puissant dupant les téléspectateurs. Le pouvoir des séries tient plutôt à la capacité du texte fictionnel à maintenir ses publics dans l’état d’immersion fictionnelle : le lecteur de fiction vit alors entre deux mondes, l’univers fictionnel et son monde réel. La notion d’univers fictionnel se réfère à sa capacité à s’enrichir grâce aux propositions contenues dans le texte...

  14. Gestion des risques

    CERN Document Server

    Louisot, Jean-Paul

    2009-01-01

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

  15. Freins et leviers à la diversification des cultures : étude au niveau des exploitations agricoles et des filières

    Directory of Open Access Journals (Sweden)

    Meynard Jean-Marc

    2013-07-01

    Full Text Available La diversification des cultures est souvent présentée comme un levier d’action pour accroître la durabilité des systèmes de production agricoles. Bien raisonnée, elle favorise en effet une réduction de l’usage d’intrants extérieurs à l’exploitation – pesticides, engrais, eau – et des nuisances environnementales associées à leur utilisation excessive. À l’inverse, la simplification des systèmes de culture engagée depuis plus de 40 ans s’est accompagnée d’un recours croissant aux intrants. Cependant, malgré son intérêt pour les systèmes de production en termes de durabilité écologique mais aussi économique (répartition des risques, et son inscription dans divers plans et dispositifs incitatifs, la diversification des cultures progresse peu. Les ministères en charge de l’agriculture et de l’environnement ont donc commandé à l’INRA une étude visant à identifier les freins à la diversification des cultures en France et les leviers mobilisables, par les pouvoirs publics notamment, pour la favoriser. L’hypothèse de travail est que ces freins relèvent du fonctionnement global du système agro-industriel, et de la capacité de développement de filières valorisant les cultures de diversification. L’étude a examiné un certain nombre de cas représentatifs de la diversité des filières et notamment de leurs modes d’organisation, qui déterminent la coordination et l’engagement des acteurs économiques impliqués dans le développement d’une culture de diversification.

  16. Des Chiffres et des Lettres : distraction, variations, habitudes

    OpenAIRE

    Barbara Laborde

    2011-01-01

    Cet article envisage une des émissions les plus anciennes du Paysage Audiovisuel Français : Des Chiffres et des Lettres. La sérialité que l’émission met en œuvre au cours de son histoire est faite de variations qui témoignent à la fois des évolutions des techniques audiovisuelles, des logiques de programmations, des attentes spectatorielles. Ce jeu télévisé, toujours le même et pourtant toujours différent, permet à la fois la reconnaissance immédiate et la perception d'un changement, double a...

  17. Capacitance tuning of nanoscale split-ring resonators

    DEFF Research Database (Denmark)

    Jeppesen, Claus; Mortensen, Asger; Kristensen, Anders

    2009-01-01

    We investigate the capacitance tuning of nanoscale split-ring resonators. Based on a simple inductor-capacitor circuit model, we derive an expression, where the inductance is proportional to the area while the capacitance reflects the aspect ratio of the slit. The resonance frequency may thus be...

  18. Improved circuit for measuring capacitive and inductive reactances

    Science.gov (United States)

    Dalins, I.; Mc Carty, V.

    1967-01-01

    Amplifier circuit measures very small changes of capacitive or inductive reactance, such as produced by a variable capacitance or a variable inductance displacement transducer. The circuit employs reactance-sensing oscillators in which field effect transistors serve as the active elements.

  19. Nonlinear dynamics of capacitive charging and desalination by porous electrodes

    NARCIS (Netherlands)

    Biesheuvel, P.M.; Bazant, M.Z.

    2010-01-01

    The rapid and efficient exchange of ions between porous electrodes and aqueous solutions is important in many applications, such as electrical energy storage by supercapacitors, water desalination and purification by capacitive deionization, and capacitive extraction of renewable energy from a salin

  20. Electric field theory and the fallacy of void capacitance

    DEFF Research Database (Denmark)

    McAllister, Iain Wilson

    1991-01-01

    The concept of the capacitance of a gaseous void is discussed as applied to electrical insulation science. The most pertinent aspect of the capacitance definition is that of reference to a single-valued potential difference between surfaces. This implies that these surfaces must be surfaces...

  1. Polycrystalline VO2 film characterization by quantum capacitance measurement

    International Nuclear Information System (INIS)

    Capacitance measurement is performed using a home-built bridge on quasi two-dimensional vanadium dioxide films grown on silicon-dioxide/p-doped silicon substrates. Correlated effects appearing in the quantum capacitance are obtained as a function of temperature at low frequencies. The thermodynamic density of states reveals the opening band gap in the insulating monoclinic phase

  2. Traveling mirror compressor delay line with nonconstant capacitance

    OpenAIRE

    Bellan, P. M.

    1981-01-01

    The scaling relations for a traveling mirror magnetic compressor [P.M. Bellan, Phys. Rev. Lett. 43, 858 (1979)] having nonconstant capacitance are derived. Varying capacitance (rather than inductance) makes possible a lower impedance device, and hence, higher field levels or faster compression times.

  3. Large Capacitance Measurement by Multiple Uses of MBL Charge Sensor

    Science.gov (United States)

    Lee, Jung Sook; Chae, Min; Kim, Jung Bog

    2010-01-01

    A recent article by Morse described interesting electrostatics experiments using an MBL charge sensor. In this application, the charge sensor has a large capacitance compared to the charged test object, so nearly all charges can be transferred to the sensor capacitor from the capacitor to be measured. However, the typical capacitance of commercial…

  4. Gouvernance et étude de l'impact du changement des processus métiers sur les architectures orientées services : une approche dirigée par les modèles

    OpenAIRE

    Dahman, Karim

    2012-01-01

    La plupart des entreprises évoluent dans des marchés concurrentiels en adaptant rapidement leurs processus métiers. Leur performance dépend de leur capacité à utiliser des techniques d'amélioration continue de leur organisation par la mise au point de Systèmes Informatiques (SI) durables pour l'automatisation des processus. En ce sens, les architectures orientées services (Service Oriented Architectures) ont permis le développement de SI flexibles avec un style d'architecture prédominant de c...

  5. Nonlinear Dynamics of Capacitive Charging and Desalination by Porous Electrodes

    CERN Document Server

    Biesheuvel, P M

    2009-01-01

    The rapid and efficient exchange of ions between porous electrodes and aqueous solutions is important in many applications, such as electrical energy storage by super-capacitors, water desalination and purification by capacitive deionization (or desalination), and capacitive extraction of renewable energy from a salinity difference. Here, we present a unified mean-field theory for capacitive charging and desalination by ideally polarizable porous electrodes (without Faradaic reactions or specific adsorption of ions) in the limit of thin double layers (compared to typical pore dimensions). We illustrate the theory in the case of a dilute, symmetric, binary electrolyte using the Gouy-Chapman-Stern (GCS) model of the double layer, for which simple formulae are available for salt adsorption and capacitive charging of the diffuse part of the double layer. We solve the full GCS mean-field theory numerically for realistic parameters in capacitive deionization, and we derive reduced models for two limiting regimes wi...

  6. Study of CMOS integrated signal processing circuit in capacitive sensors

    Institute of Scientific and Technical Information of China (English)

    CAO Yi-jiang; YU Xiang; WANG Lei

    2007-01-01

    A CMOS integrated signal processing circuit based on capacitance resonance principle whose structure is simple in capacitive sensors is designed. The waveform of output voltage is improved by choosing bootstrap reference current mirror with initiate circuit, CMOS analogy switch and positive feedback of double-stage inverter in the circuit. Output voltage of this circuit is a symmetric square wave signal. The variation of sensitive capacitance, which is part of the capacitive sensors, can be denoted by the change of output voltage's frequency. The whole circuit is designed with 1.5 μm P-well CMOS process and simulated by PSpice software.Output frequency varies from 261.05 kHz to 47.93 kHz if capacitance varies in the range of 1PF~15PF. And the variation of frequency can be easily detected using counter or SCU.

  7. Electrostatic capacitance and Faraday cage behavior of carbon nanotube forests

    International Nuclear Information System (INIS)

    Understanding of the electrostatic properties of carbon nanotube (CNT) forests is essential to enable their integration in microelectronic and micromechanical devices. In this study, we sought to understand how the hierarchical geometry and morphology of CNT forests determines their capacitance. First, we find that at small gaps, solid micropillars have greater capacitance, yet at larger gaps the capacitance of the CNT forests is greater. The surface area of the CNT forest accessible to the electrostatic field was extracted by analysis of the measured capacitance, and, by relating the capacitance to the average density of CNTs in the forest, we find that the penetration depth of the electrostatic field is on the order of several microns. Therefore, CNT forests can behave as a miniature Faraday cage. The unique electrostatic properties of CNT forests could therefore enable their use as long-range proximity sensors and as shielding elements for miniature electronic devices

  8. Fund allocation using capacitated vehicle routing problem

    Science.gov (United States)

    Mamat, Nur Jumaadzan Zaleha; Jaaman, Saiful Hafizah; Ahmad, Rokiah Rozita; Darus, Maslina

    2014-09-01

    In investment fund allocation, it is unwise for an investor to distribute his fund into several assets simultaneously due to economic reasons. One solution is to allocate the fund into a particular asset at a time in a sequence that will either maximize returns or minimize risks depending on the investor's objective. The vehicle routing problem (VRP) provides an avenue to this issue. VRP answers the question on how to efficiently use the available fleet of vehicles to meet a given service demand, subjected to a set of operational requirements. This paper proposes an idea of using capacitated vehicle routing problem (CVRP) to optimize investment fund allocation by employing data of selected stocks in the FTSE Bursa Malaysia. Results suggest that CRVP can be applied to solve the issue of investment fund allocation and increase the investor's profit.

  9. Further capacitive imaging experiments using modified probes

    Science.gov (United States)

    Yin, Xiaokang; Li, Zhen; Yan, An; Li, Wei; Chen, Guoming; Hutchins, David A.

    2016-02-01

    In recent years, capacitive imaging (CI) is growing in popularity within the NDE communities, as it has the potential to test materials and structures for defects that are not easily tested by other techniques. In previous work, The CI technique has been successfully used on a various types of materials, including concrete, glass/carbon fibre composite, steel, etc. In such CI experiments, the probes are normally with symmetric or concentric electrodes etched onto PCBs. In addition to these conventional coplanar PCB probes, modified geometries can be made and they can lead to different applications. A brief overview of these modified probes, including high resolution surface imaging probe, combined CI/eddy current probe, and CI probe using an oscilloscope probe as the sensing electrode, is presented in this work. The potential applications brought by these probes are also discussed.

  10. A capacitive bioelectrode for recording electrophysiological signals

    International Nuclear Information System (INIS)

    In this paper we describe a gel-free sensor with on-board electrode design, which capacitive couples to the skin to detect the electrical activity in the body. The integrated sensor is manufactured on a standard printed circuit board within 2.2 cm diameter enclosure that can operate through fabric or other insulation. The electrode includes amplification (60db gain) and passive band pass filtering (0.5 to 100 Hz). Active shielding surrounding the sensor plate is used to reduce noise pickup. The input referred noise, measured over the electrode bandwidth is 4 μV rms at 0.2 mm sensor distance, and 16 μV rms at 1.2 mm distance trough two cotton cloths. The bioelectrodes were coupled to the scalp trough hair for EEG signals (with 80 db gain), and coupled to the chest through clothing for ECG signals. The recorded signals show well performance of the designed bielectrode. (Author)

  11. Phase discriminating capacitive array sensor system

    Science.gov (United States)

    Vranish, John M. (Inventor); Rahim, Wadi (Inventor)

    1993-01-01

    A phase discriminating capacitive sensor array system which provides multiple sensor elements which are maintained at a phase and amplitude based on a frequency reference provided by a single frequency stabilized oscillator. Sensor signals provided by the multiple sensor elements are controlled by multiple phase control units, which correspond to the multiple sensor elements, to adjust the sensor signals from the multiple sensor elements based on the frequency reference. The adjustment made to the sensor signals is indicated by output signals which indicate the proximity of the object. The output signals may also indicate the closing speed of the object based on the rate of change of the adjustment made, and the edges of the object based on a sudden decrease in the adjustment made.

  12. Capacitance multiplier and filter synthesizing network

    Science.gov (United States)

    Kline, A. J. (Inventor)

    1974-01-01

    A circuit using a differential amplifier multiplies the capacitance of a discrete interating capacitor by (r sub 1 + R sub 2)/R sub 2, where R sub 1 and R sub 2 are values of discrete resistor coupling an input signal e sub 1 of the amplifier inputs. The output e sub 0 of the amplifier is fed back and added to the signal coupled by the resistor R sub 2 to the amplifier through a resistor of value R sub 1. A discrete resistor R sub x may be connected in series for a lag filter, and a discrete resistor may be connected in series with the capacitor for a lead-lag filter. Voltage dividing resistors R sub a and R sub b may be included in the feedback circuit of the amplifier output e sub o to independently adjust the circuit gain e sub i/e sub o.

  13. MOS Capacitance-Voltage Characteristics Ⅲ.Trapping Capacitance from 2-Charge-State Impurities

    Institute of Scientific and Technical Information of China (English)

    Jie Binbin; Sah Chihtang

    2011-01-01

    Low-frequency and high-frequency capacitance-voltage curves of Metal-Oxide-Semiconductor Capacitors are presented to illustrate giant electron and hole trapping capacitances at many simultaneously present two-charge-state and one-trapped-carrier,or one-energy-level impurity species.Models described include a donor electron trap and an acceptor hole trap,both donors,both acceptors,both shallow energy levels,both deep,one shallow and one deep,and the identical donor and acceptor.Device and material parameters are selected to simulate chemically and physically realizable capacitors for fundamental trapping parameter characterizations and for electrical and optical signal processing applications.

  14. The hysteresis-free negative capacitance field effect transistors using non-linear poly capacitance

    Science.gov (United States)

    Fan, S.-T.; Yan, J.-Y.; Lai, D.-C.; Liu, C. W.

    2016-08-01

    A gate structure design for negative capacitance field effect transistors (NCFETs) is proposed. The hysteresis loop in current-voltage performances is eliminated by the nonlinear C-V dependence of polysilicon in the gate dielectrics. Design considerations and optimizations to achieve the low SS and hysteresis-free transfer were elaborated. The effects of gate-to-source/drain overlap, channel length scaling, interface trap states and temperature impact on SS are also investigated.

  15. Droit des organisations internationales

    CERN Document Server

    Sorel, Jean-Marc; Ndior, Valère

    2013-01-01

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

  16. Photonique des Morphos

    CERN Document Server

    Berthier, Serge

    2010-01-01

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

  17. Les savoirs des autres

    OpenAIRE

    Bromberger, Christian

    2007-01-01

    En ethnologie, comme dans bien d'autres domaines scientifiques, le renouvellement des problématiques est souvent venu des confins territoriaux, de points marginaux de rencontre entre disciplines voisines. Chacun de ces rendez-vous marque une étape importante dans l'histoire de la démarche ethnologique ; le dialogue qui s'est noué avec la technologie, la linguistique et la sémiologie, les sciences naturelles, la médecine... a permis non seulement une extension du champ et un affinement des mét...

  18. Des femmes au tribunal

    OpenAIRE

    Le Pape, Marc

    2010-01-01

    Les archives judiciaires constituent une source essentielle pour les études des sociabilités africaines en situation coloniale. Cet article prend appui sur l’analyse des procès tenus, entre 1923 et 1939, au tribunal du premier degré d’Abidjan, il vise à décrire les argumentations contradictoires par lesquelles femmes et hommes expliquent leurs différends dans l’espace du prétoire. Les registres issus des « juridictions indigènes » permettent également d’apprécier sur quels repères se fondent ...

  19. Liste des auteurs

    OpenAIRE

    2014-01-01

    Abdoul Razack Adjibi-Oualiou, agronome forestierdirection des Forêts et des Ressources naturellesBP 393, Cotonou, république du Béninmailto: Aristide Cossi Adomou, botanisteuniversité d’Abomey-Calavi, faculté des Sciences et Techniques département de Biologie végétaleHerbier national du Bénin, 01 BP 4521, Cotonou, république du Béninmailto: Pierre Onodjè Agbani, botaniste systématicien, écologuelaboratoire d'Écologie appliquée, Cotonou, république du B...

  20. Les effluents vinicoles : problématique du traitement et premier bilan sur la conception et le fonctionnement des procédés biologiques

    OpenAIRE

    Racault, Y.; Stricker, A.E.; Vedrenne, J.

    2002-01-01

    Une large gamme de procédés de traitement est désormais applicable aux effluents vinicoles et une méthodologie propre à ce type d'effluents est nécessaire pour choisir la solution la plus adaptée en fonction des contraintes (caractéristiques des rejets, qualité requise pour les eaux traitées, environnement, capacités de stockage in situ...). Les spécificités de fonctionnement des traitements biologiques appliqués aux effluents vinicoles sont rappelées ainsi que les performances possibles. Une...

  1. A review of reconstruction techniques for capacitance tomography

    Science.gov (United States)

    Isaksen, Øyvind

    1996-03-01

    Capacitance tomography has been used to image several processes, such as liquid/gas pipe flow, oil/water/gas gravity separation, pneumatic conveying, fluidized beds and flame combustion. The nature of the capacitance sensors is such that reconstruction algorithms well developed for medical tomography are not applicable. The main problem is that the relationship between the measured quantity (capacitance) and the parameter of interest (distribution of the dielectric constant) is nonlinear. Furthermore, it is impossible to establish an explicit expression which relates the dielectric constant distribution to the measured capacitance. Also it should be pointed out that the number of measurements in capacitance tomography is small (typically less than 100) compared to medical tomography. For these reasons the first tested algorithm in capacitance tomography was based on the crude back projection algorithm. This algorithm has over the years been enhanced for use with a capacitance tomograph. In addition other techniques, such as various iterative methods, algorithms based on artificial neural networks and `look-up' tables have been developed and tested. This paper outlines the working principles for the different techniques and presents the main results.

  2. Hydraulic Resistance and Capacitance in the Soil—Plant System

    Institute of Scientific and Technical Information of China (English)

    SHAOMING-AN; L.P.SIMMONDS

    1991-01-01

    In this paper,the hydraulic resistances and capacitances were evaluated.based on the development of non-linear model of water flow in the soil-plant system and the simulating experiment work.The results show that the mean hydraulic resistance in the soil-plant system is 6.79×109 MPa·S·m-3;the mean hydraulic capacitance in the system is 5.2×10-7m3·MPa-1.In the components of hydraulic capacitance in the system,the capacitance in soil (81.8×10-6m3·MPa-1)is the biggest and its variability with soil water potential is extremely strong,the capacitance in plant (5.3×10-7m3·MPa-1) is much smaller than that in soil,and the capacitance in shoots (15.5×10-7m3·MPa-1) is bigger than that in roots (8.4×10-7m3·MPa-1).An interesting result is that the capacitance in plant is almost equivalent to that in the soil-plant system.

  3. La prévention des blessures non intentionnelles chez les enfants et adolescents autochtones au Canada

    Science.gov (United States)

    Banerji, Anna

    2012-01-01

    RÉSUMÉ Les blessures non intentionnelles sont la principale cause de décès chez les enfants et adolescents autochtones canadiens, à un taux de trois à quatre fois la moyenne nationale. Non seulement les décès et les blessures invalidantes dévastent les familles et les communautés, mais elles font également d’énormes ravages sur les ressources de santé. L’absence de statistiques, de surveillance continue ou de programmes de prévention des blessures à l’égard des enfants et adolescents autochtones exacerbe les coûts en matière de main-d’œuvre et de santé. Les communautés autochtones sont hétérogènes sur le plan culturel, qu’il s’agisse de l’accès aux ressources ou même des risques et des types de blessures. Pourtant, en général, ces communautés sont beaucoup plus susceptibles d’être pauvres, d’habiter dans un logement insalubre et d’éprouver de la difficulté à accéder aux soins de santé, des facteurs qui accroissent le risque et les conséquences des blessures. Il existe un besoin urgent de surveillance des blessures, de recherche, de renforcement des capacités, de diffusion des connaissances et de programmes de prévention des blessures qui sont axés sur les populations autochtones. Pour prévenir les blessures de manière efficace, il faut adopter des démarches multidisciplinaires, coopératives et durables, fondées sur des pratiques exemplaires, tout en étant spécifiques et sensibles sur le plan culturel et linguistique.

  4. Architecture des contemplatifs

    OpenAIRE

    2005-01-01

    Architecture des contemplatifs. — Il serait nécessaire de comprendre un jour, et probablement ce jour est-il proche, ce qui manque avant tout à nos grandes villes : des lieux de silence, spacieux et forts étendus, destinés à la méditation, pourvus de hautes et de longues galeries pour les intempéries ou le trop ardent soleil, où ne pénètre nulle rumeur de voitures ni de crieurs, et où une bienséance plus subtile interdirait même au prêtre l’oraison à voix haute : des édifices et des jardins q...

  5. Dental Encounter System (DES)

    Data.gov (United States)

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

  6. Diethylstilbestrol (DES) and Cancer

    Science.gov (United States)

    ... been recommended that DES daughters have a yearly Pap test and pelvic exam to check for abnormal ... thorough examination may include the following: Pelvic examination Pap test and colposcopy —A routine cervical Pap test ...

  7. La descente des certitudes

    Directory of Open Access Journals (Sweden)

    Frédéric Lesemann

    2010-12-01

    Full Text Available Je rédige ce texte de discussion de la thèse de l’ouvrage de Robert Castel, La Montée des incertitudes, à Montréal, en août 2010. Ces précisions initiales ont pour but de situer d’où je parle : un pays nord-américain francophone où les travaux et la personne de Robert Castel sont connus et très appréciés dans le domaine des sciences sociales, et à un moment où la crise économique découlant des crises financières internationales des deux dernières années amène les gouvernements québécois et ca...

  8. Chimie des processus biologiques

    OpenAIRE

    Fontecave, Marc

    2010-01-01

    La chimie du vivant : enzymes et métalloenzymes, des biocatalyseurs fascinants La catalyse enzymatique, ce pouvoir que possèdent certaines protéines d’accélérer de façon extraordinaire et d’orienter avec une précision fascinante les réactions chimiques de la cellule, reste, encore aujourd’hui, l’un des grands mystères des systèmes vivants. Les réactions dont il est question vont de la simple hydrolyse de liaisons peptidiques à des processus poly-électroniques d’une très grande complexité, com...

  9. Organisation et pilotage des services sur le trajet des urgences

    OpenAIRE

    Wang, Tao

    2008-01-01

    L'exigence des soins à apporter aux patients accueillis aux urgences combinée au contexte économique impose aux établissements hospitaliers, surtout aux SAU, des décisions rapides ainsi que l'optimisation de l'emploi des ressources matérielles et humaines pour maintenir la fluidité des patients sans pour autant compromettre la qualité de soins. Nous proposons à travers ce mémoire de thèse des solutions appropriées aux services d'urgence permettant d'améliorer la prise en charge des urgences d...

  10. Verification of overlap and fringing capacitance models for MOSFETs

    Science.gov (United States)

    Wakita, Naoki; Shigyo, Naoyuki

    2000-06-01

    Parasitic capacitance and resistance limit the VLSI device performance. Hence, a circuit model is needed to treat these effects correctly. This article focuses on the circuit models for the overlap capacitance ( Cgd,overlap) and the fringing capacitance ( Cgd,fringe) of MOSFETs. Comparisons between the models and the device simulations are carried out for verification of the models. Also, a limitation of Cgd,fringe model for a future device miniaturization is found based on SIA Road Map. We propose a modified Cgd,fringe model. The effectiveness of the modified model is demonstrated using two circuits.

  11. Nanoporous activated carbon cloth for capacitive deionization of aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Han-Jun [Department of Materials Science, Hanseo University, Seosan, 352-820 (Korea, Republic of); Lee, Jong-Ho [Department of Chemistry, Hanseo University, Seosan, 352-820 (Korea, Republic of); Ahn, Hong-Joo [Korea Atomic Energy Research Institute, Daejeon, 305-600 (Korea, Republic of); Jeong, Yongsoo [Korea Institute of Machinery and Materials, Changwon, 641-010 (Korea, Republic of); Kim, Young-Jig [Department of Metallurgical Engineering, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of); Chi, Choong-Soo [School of Advanced Materials Engineering, Kookmin University, Seoul, 136-702 (Korea, Republic of)]. E-mail: cschi@kookmin.ac.kr

    2006-09-25

    Activated nanostructured-carbon cloths with a high ratio of surface area to volume are used as electrode for capacitive deionization. The electrochemical properties on capacitive deionization for NaCl solution have been investigated to improve efficiency of capacitive deionization properties from aqueous solution, employing chemical surface-modification by etching in alkaline and acidic solution. The removal efficiency of inorganic salts of activated carbon cloths by chemical modification significantly increased. Specially the carbon cloth surface modified in HNO{sub 3} showed an effect of improvement in the CDI efficiency due to not only ion adsorption by an electric double layer, but also electron transfer by Faradaic reaction.

  12. Bloch inductance in small-capacitance Josephson junctions

    OpenAIRE

    Zorin, A. B.

    2005-01-01

    We show that the electrical impedance of a small-capacitance Josephson junction includes besides the capacitive term $-i/\\omega C_B$ also an inductive term $i\\omega L_B$. Similar to the known Bloch capacitance $C_B(q)$, the Bloch inductance $L_B(q)$ also depends periodically on the quasicharge $q$, and its maximum value achieved at $q=e (\\textrm{mod} 2e)$ always exceeds the value of the Josephson inductance of this junction $L_J(\\phi)$ at fixed $\\phi=0$. The effect of the Bloch inductance on ...

  13. Bloch Inductance in Small-Capacitance Josephson Junctions

    International Nuclear Information System (INIS)

    We show that the electrical impedance of a small-capacitance Josephson junction also includes, in addition to the capacitive term -i/ωCB, an inductive term iωLB. Similar to the known Bloch capacitance CB(q), the Bloch inductance LB(q) also depends periodically on the quasicharge, q, and its maximum value achieved at q=e(mod 2e) always exceeds the value of the Josephson inductance of this junction LJ(φ) at fixed φ=0. The effect of the Bloch inductance on the dynamics of a single junction and a one-dimensional array is described

  14. Flexible transparent iontronic film for interfacial capacitive pressure sensing.

    Science.gov (United States)

    Nie, Baoqing; Li, Ruya; Cao, Jennifer; Brandt, James D; Pan, Tingrui

    2015-10-21

    A flexible, transparent iontronic film is introduced as a thin-film capacitive sensing material for emerging wearable and health-monitoring applications. Utilizing the capacitive interface at the ionic-electronic contact, the iontronic film sensor offers a large unit-area capacitance (of 5.4 μF cm(-2) ) and an ultrahigh sensitivity (of 3.1 nF kPa(-1) ), which is a thousand times greater than that of traditional solid-state counterparts. PMID:26333011

  15. Human body capacitance: static or dynamic concept? [ESD

    DEFF Research Database (Denmark)

    Jonassen, Niels M

    1998-01-01

    A standing human body insulated from ground by footwear and/or floor covering is in principle an insulated conductor and has, as such, a capacitance, i.e. the ability to store a charge and possibly discharge the stored energy in a spark discharge. In the human body, the human body capacitance (HBC...... method leads to higher values when a substantial part of the flux extends itself through badly defined stray fields. Since the concept of human body capacitance is normally used in a static (electric) context, it is suggested that the HBC be determined by a static method. No theoretical explanation of...

  16. Correcting For Capacitance In Tests Of Solar Cells

    Science.gov (United States)

    Mueller, Robert L.

    1995-01-01

    Modified procedure for testing solar photovoltaic cells and modified software for processing test data provide corrections for effects of cell capacitance. Procedure and software needed because (a) some photovoltaic devices (for example, silicon solar cells with back-surface field region) store minority charge carriers in cell junction and thus exhibit significant capacitance, (b) capacitance affects current-vs.-voltage (I-V) measurements made when transient load connected to cell, and (c) transient load used in unmodified version of test procedure. Corrected I-V curve obtained in test of solar cell according to modified procedure approximates true cell voltage vs. cell current more closely.

  17. Electrochemical Capacitance DNA Sensing at Hairpin-Modified Au Electrodes

    OpenAIRE

    Joel Rivera-Gandía; Maria del Mar Maldonado; Yarimar De La Torre-Meléndez; Edwin O. Ortiz-Quiles; Vargas-Barbosa, Nella M.; Cabrera, Carlos R.

    2011-01-01

    An interfacial capacitance measurement electrochemical technique has been used for the sensing of self-assembled DNA hairpin probes (M. tuberculosis and B. anthracis) attached to Au electrodes. The double-layer capacitance (Cdl) was determined with electrochemical perturbations from 0.2 V to 0.5 V versus Ag/AgCl at a Au/M. tuberculosis DNA hairpin probe at surface coverage Au electrodes. The capacitance study was done at pH 7, which was necessary to maintain the M. tuberculosis and B. anthrac...

  18. Developing capacitive equipment on-line monitoring intelligence software

    Science.gov (United States)

    Zhang, Weicong; Yang, Lichun

    2011-12-01

    In order to improve the safety and reliability of capacitive equipment developed online monitoring system of capacitive equipment dielectric loss. Introduce the structure and function of the software, based on the B/S skeleton, uses the modular design, improve the readability and scalability. Detail the design of communication module, parameter setting module, data acquisition and processing module, the user management module, database systems, etc. The entire process is given. By testing the monitoring software work is stable, reliable, long-term continuous and effective monitoring capacitive equipment various insulation data, can satisfy the requirements on site application.

  19. Low Power/Low Voltage Interface Circuitry for Capacitive Sensors

    DEFF Research Database (Denmark)

    Furst, Claus Efdmann

    This thesis focuses mainly on low power/low voltage interface circuits, implemented in CMOS, for capacitive sensors. A brief discussion of demands and possibilities for analog signal processing in the future is presented. Techniques for low power design is presented. This is done by analyzing power...... low power consumption. It is shown that the Sigma-Delta modulator is advantageous when embedded in a feedback loop with a mechanical sensor. Here a micro mechanical capacitive microphone. Feedback and detection circuitry for a capacitive microphone is presented. Practical implementations of low power...

  20. Touch mode micromachined capacitive pressure sensor with signal conditioning electronics

    DEFF Research Database (Denmark)

    Fragiacomo, Giulio; Eriksen, Gert F.; Christensen, Carsten;

    2010-01-01

    In the last decades, pressure sensors have been one of the greatest successes of the MEMS industry. Many companies are using them in a variety of applications from the automotive to the environmental field. Currently piezoresistive pressure sensors are the most developed, and a well established...... technology to design and fabricate these sensors has been implemented. Capacitive pressure sensing, on the other hand, is still an open and really promising field. Results Capacitive microsensors were designed and fabricated (Fig. 1) and an analytical model for touch mode regime, which fitted accurately the...... is therefore to develop new technologies based on capacitive sensing to be able to fulfil future requirements in this field....

  1. Die Raumfahrtpolitik des Bundesforschungsministeriums

    OpenAIRE

    Weyer, Johannes

    2005-01-01

    Der vorliegende Beitrag befasst sich mit der Raumfahrtpolitik des Bundesforschungsministeriums. Zunächst wird auf die Raketenforschung der Nachkriegszeit 1945-1955 eingegangen. Im Anschluss wird der Aufbau einer forschungspolitischen Identität des Bundes auf dem Wege über die Weltraumforschung (1955-1969) nachgezeichnet. Im vierten Kapitel werden die Probleme und Herausforderungen der Raumfahrtpolitik (1969-1982) beleuchtet. Danach widmet sich der Autor der bemannten Raumfahrt und dem Aufbruc...

  2. The institutional dimension of capacity reinforcement; La dimension institutionelle du concept de renforcement des capacites

    Energy Technology Data Exchange (ETDEWEB)

    Girod, J.

    1998-01-01

    The concept of capacity reinforcement, the acceptance of the demands of market economy and economic liberalism in African countries was discussed. In the view of this author, the institutionalization of capacity reinforcement requires acknowledgement of two concurrent fundamental principles. The first requirement is to make the need to acquire information and to increase the internal competence in a large variety of subjects a matter of national priority. The second is to define the internal structures necessary to realize the required objectives under the most realistic conditions.

  3. La revolution des savants

    CERN Document Server

    Chavanne, A

    1989-01-01

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

  4. Boosting the agricultural production capabilities of Indian rural communities in the micro region of South Ahuachapán (El Salvador, in order to improve food safety and raise income for the local population Renforcement des capacités de production agricole des communautés rurales indiennes dans la micro région du Sud Ahuachapán (République du Salvador pour améliorer la sécurité alimentaire et augmenter les revenus pour la population locale Aumento de las capacidades de producción agrícola de las comunidades rurales indígenas en la microrregión del sur de Ahuachapán (El Salvador, para mejorar la seguridad alimentaria y aumentar los ingresos para la población local

    Directory of Open Access Journals (Sweden)

    J-M. Fouillade

    2011-11-01

    in the community, far exceeded its original objectives.Régulièrement touché par les ouragans et évoluant dans un contexte démocratique récent suite à une violente période de guerre civile, le Salvador souffre comme beaucoup de pays latino-américains d’une forte inégalité dans la répartition des richesses nationales et près de la moitié de la population se trouve en dessous du seuil de pauvreté. C’est dans ce contexte que le Secours populaire français intervient en 2002 au nord-ouest du pays dans la région caféière d’Ahuachapán-Sud, région classée en zone de développement prioritaire par les autorités gouvernementales. Il s’agit d’un projet mené en partenariat avec l’ONG locale FUNDESYRAM cofinancé par l’Union européenne et développé sur neuf ans, visant à améliorer la sécurité alimentaire et l’économie familiale des populations en situation d’extrême pauvreté. Cela, à travers une logique de solidarité interfamiliale et la promotion de techniques respectueuses de l’environnement. L’implication du partenaire et des bénéficiaires aboutit au renforcement des associations communales (ADESCO ainsi que la création d’une association de producteurs (AGROCESA afin de mieux encadrer, gérer et appuyer les projets de développement social et économique. Ce qui a garanti le succès du programme et permet de renforcer les capacités d’autogestion et le développement autonome et solidaire des communautés bénéficiaires. Ce projet qui a permis, entre autre, d’éradiquer la dénutrition infantile en assurant la sécurité alimentaire des familles ainsi que de renforcer le rôle des femmes au sein de la communauté, a largement dépassé les objectifs fixés au départ.Regularmente afectado por los huracanes y tras un largo periodo de una violenta guerra civil, El Salvador conoce actualmente un contexto político democrático. Sin embargo, el país sufre, como muchos otros Estados latino-americanos, de un

  5. Simulation et gestion des risques en planification distribuée de chaînes logistiques : application au secteur de l'électronique et des télécommunications

    OpenAIRE

    Mahmoudi, Jaouher

    2006-01-01

    Dans un contexte économique et industriel changeant rapidement, cette thèse présente une approche d’aide à la coopération pour la planification distribuée des capacités au sein d’une chaîne logistique. Nous proposons un outil de simulation permettant l’évaluation de comportements de planification des partenaires plus ou moins coopératifs, pour différents scénarios de comportement du marché. En se basant sur les théories de la décision et des jeux, nous introduisons ensuite une évaluation des ...

  6. Numerical and experimental study of the influence of the operational parameters on the formation mechanisms of oxides of nitrogen during the combustion of mixtures of cellulosic and plastic materials; Etude experimentale et numerique de l'influence des parametres operatoires sur les mecanismes de formation des oxydes d'azote lors de la combustion de melanges de materiaux cellulosiques et plastiques

    Energy Technology Data Exchange (ETDEWEB)

    Andzi Barhe, T.

    2004-10-15

    The current thesis was performed within a collaboration between the Laboratoire de Combustion et de Detonique (LCD of the University of Poitiers) and the Laboratoire de Physique et de Chimie d'Environnement (LPCE) of the University of Ouagadougou. It was financed by Agency for Environment and Energy Management (ADEME). The principle object of this study is the optimisation of the combustion process during the incineration of waste. This optimisation is aimed at the reduction of the polluting emissions, principally CO and NO, during the incineration of cellulosic and plastic materials. It involves the analysis of the influence of the operational parameters on the polluting emissions and the control of reaction mechanisms of formation and reduction of these pollutants during the combustion process. Consequently, the study was performed in two parts: an experimental part and a numerical part. The experimental part was realised using a fixed bed counterflow reactor. This setup simulates the combustion within an industrial waste incinerator. The reactor allows the combustion of a vertical layer of waste mixture (wood, cardboard, PET, polyamide) to be followed. Three model mixtures representative of the makeup of household waste were studied in order to determine the influence of the composition of the waste on the emission of pollutants (CO and NO). The obtained results show that this parameter has a practically negligible influence within the tested parameter range. Consequently the formation of pollutants depends on the operating parameters - the equivalence ratio and the temperature. A numerical study of the influence of these parameters in order to show their impact on the mechanisms of pollutant formation and to determine the chemical mechanisms involved in the formation of oxides of nitrogen. The numerical study was performed with software developed at the LCD. This programme based on a detailed chemical model coupled to a simple physical model. It uses the calculation code CHEMKIN. It permits the simulation of combustion process within the gaseous zone of the fixed bed reactor. The programme is initialized with the results of the analysis of the pyrolysis which had previously been performed at the LCD on the materials which make up the model waste mixture. The pyrolysis products identified during this study are: HCN, NH{sub 3}, NO, NO{sub 2}, CO and light hydrocarbons. The results show that the simulation enables the determination of reactional mechanisms of the formation and reduction of oxides of nitrogen in the three combustion regimes identified during the experimental study. For each of the three regimes, a study of the impact of the combustion parameters on the yield of NO was performed. It can be seen that the response to the parameters is itself heavily dependent on the combustion regime. (author)

  7. Etude de la structure des flammes diphasiques dans les brûleurs aéronautiques

    OpenAIRE

    Hannebique, Gregory

    2013-01-01

    La régulation des polluants a mené à la création de nouveaux systèmes de combustion. Le carburant étant stocké sous forme liquide, sa transformation jusqu’à sa combustion est complexe. La capacité de la Simulation aux grandes échelles à simuler des écoulements turbulents réactifs a été montrée sur des cas académiques comme sur des configurations industrielles, tout en prenant en compte les phénomènes multiphysiques intervenant dans ces configurations, mais les études sur la structure de flamm...

  8. Au risque de rester "dedans" : Le double travail ajustement des usagers de drogues incarcérés

    OpenAIRE

    Fernandez, Fabrice

    2008-01-01

    L'articulation de l'expérience carcérale et de l'expérience toxicomaniaque est indissociable des types de double ajustement à la prison et à la réalité extérieure (la bifurcation, la coordination, la confrontation et la conjonction ). Selon la participation ou le refus des détenus à la logique carcérale, et leur capacité ou non à maintenir des liens avec le monde extérieur, les modes de consommation de drogues vont prendre des formes différenciées. Si l'expérience carcérale peut permettre de ...

  9. Développement d'un module de traitement des signaux de rupture à partir du superviseur CASC

    OpenAIRE

    D'ORLANDO, Angélina; LABORATOIRE CENTRAL DES PONTS ET CHAUSSEES - LCPC; INSTITUT UNIVERSITAIRE TECHNOLOGIQUE DE SAINT NAZAIRE

    2009-01-01

    Le Laboratoire des Ponts et Chaussées a une longue expérience dans la surveillance acoustique des câbles d'ouvrages d'art. Celle-ci a conduit à la conception d'un système de surveillance, le superviseur CASC, opérationnel depuis 1974, la dernière version étant équipée d'une capacité WiFi associée à une numérisation complète des formes d'onde détectées. Le but de ce stage est alors de développer un module additionnel, adaptable au superviseur, qui permettra l'analyse des signaux à partir de no...

  10. La place du traitement dans la gestion des excédents structurels d'effluents d'élevage

    OpenAIRE

    Gitton, C.; Hurvois, Y.

    1999-01-01

    Le défi qui doit être relevé aujourd'hui est la restauration d'un lien entre le sol et les élevages hors-sol qui consomment massivement des aliments produits en dehors de l'exploitation. Il faut pour cela tenir compte de la capacité épuratoire des sols et des cultures. Les régions qui ont fortement développé les élevages hors-sol sont aujourd'hui en situation d'excédent structurel lié aux élevages. Le recours au traitement des effluents d'élevage doit souvent compléter d'autres mesures de rés...

  11. Characterization of electrical and mechanical activities of rabbit uterus associated with the presence of capacitated and non-capacitated spermatozoa

    OpenAIRE

    J.F. Lazcano-Reyes; Montiel, J.L.; Medrano, A.

    2013-01-01

    To investigate the effects capacitated spermatozoa may exert upon motility of the rabbit uterus, both contractility and electrical activity (frequency and intensity) were measured in 3 distinctive uterine segments of anaesthetized does: horn (UH), uterotubal junction (UTJ) and tube (UT) after 1) natural mating, 2) infusion of either seminal plasma or PBS, 3) infusion of either capacitated or non-capacitated spermatozoa. Basal values were: 17.1, 15.7, 16.4 g (contractility, P>0.05); 3.5, 3.5, ...

  12. Mechano-capacitive properties of polarized membranes.

    Science.gov (United States)

    Mosgaard, Lars D; Zecchi, Karis A; Heimburg, Thomas

    2015-10-28

    Biological membranes are capacitors that can be charged by applying a field across the membrane. The charges on the capacitor exert a force on the membrane that leads to electrostriction, i.e. a thinning of the membrane. Since the force is quadratic in voltage, negative and positive voltage have an identical influence on the physics of symmetric membranes. However, this is not the case for a membrane with an asymmetry leading to a permanent electric polarization. Positive and negative voltages of identical magnitude lead to different properties. Such an asymmetry can originate from a lipid composition that is different on the two monolayers of the membrane, or from membrane curvature. The latter effect is called 'flexoelectricity'. As a consequence of permanent polarization, the membrane capacitor is discharged at a voltage different from zero. This leads to interesting electrical phenomena such as outward or inward rectification of membrane permeability. Here, we introduce a generalized theoretical framework, that treats capacitance, polarization, flexoelectricity, piezoelectricity and thermoelectricity in the same language. We show applications to electrostriction, membrane permeability and piezoelectricity and thermoelectricity close to melting transitions, where such effects are especially pronounced. PMID:26324950

  13. Thermodynamic cycle analysis for capacitive deionization.

    Science.gov (United States)

    Biesheuvel, P M

    2009-04-01

    Capacitive deionization (CDI) is an ion removal technology based on temporarily storing ions in the polarization layers of two oppositely positioned electrodes. Here we present a thermodynamic model for the minimum work required for ion separation in the fully reversible case by describing the ionic solution as an ideal gas of pointlike particles. The work input is fully utilized to decrease the entropy of the outflowing streams compared to that of the inflow. Based on the Gouy-Chapman-Stern (GCS) model for planar diffuse polarization layers-with and without including additional ion volume constraints in the diffuse part of the double layer-we analyze the electric work input during charging and the work output during discharging, for a reversible charging-discharging cycle. We present a graphical thermodynamic cycle analysis for the reversible net work input during one full cycle of batchwise operation of CDI based on the charge-voltage relations for different ionic strengths. For the GCS model, an analytical solution is derived for the charge efficiency Lambda, which is the number of salt molecules removed per electron transferred from one electrode to the other. Only in the high voltage limit and for an infinite Stern layer capacity does Lambda approach unity. PMID:19167009

  14. Energy recovery in membrane capacitive deionization.

    Science.gov (United States)

    Długołęcki, Piotr; van der Wal, Albert

    2013-05-01

    Membrane capacitive deionization (MCDI) is a water desalination technology based on applying a cell voltage between two oppositely placed porous carbon electrodes. In front of each electrode, an ion-exchange membrane is positioned, and between them, a spacer is situated, which transports the water to be desalinated. In this work, we demonstrate for the first time that up to 83% of the energy used for charging the electrodes during desalination can be recovered in the regeneration step. This can be achieved by charging and discharging the electrodes in a controlled manner by using constant current conditions. By implementing energy recovery as an integral part of the MCDI operation, the overall energy consumption can be as low as 0.26 (kW·h)/m(3) of produced water to reduce the salinity by 10 mM, which means that MCDI is more energy efficient for treatment of brackish water than reverse osmosis. Nevertheless, the measured energy consumption is much higher than the thermodynamically calculated values for desalinating the water, and therefore, a further improvement in thermodynamic efficiency will be needed in the future. PMID:23477563

  15. Complementary surface charge for enhanced capacitive deionization.

    Science.gov (United States)

    Gao, X; Porada, S; Omosebi, A; Liu, K-L; Biesheuvel, P M; Landon, J

    2016-04-01

    Commercially available activated carbon cloth electrodes are treated using nitric acid and ethylenediamine solutions, resulting in chemical surface charge enhanced carbon electrodes for capacitive deionization (CDI) applications. Surface charge enhanced electrodes are then configured in a CDI cell to examine their salt removal at a fixed charging voltage and both reduced and opposite polarity discharge voltages, and subsequently compared to the salt removal of untreated electrodes. Substantially improved salt removal due to chemical surface charge and the use of a discharge voltage of opposite sign to the charging voltage is clearly demonstrated in these CDI cycling tests, an observation which for the first time validates both enhanced CDI and extended-voltage CDI effects predicted by the Donnan model [Biesheuvel et al., Colloids Interf. Sci. Comm., 10.1016/j.colcom.2015.12.001 (2016)]. Our experimental and theoretical results demonstrate that the use of carbon electrodes with optimized chemical surface charge can extend the CDI working voltage window through discharge voltages of opposite sign to the charging voltage, which can significantly enhance the salt adsorption capacity of CDI electrodes. Thus, in addition to carbon pore size distribution, chemical surface charge in carbon micropores is considered foundational for salt removal in CDI cells. PMID:26878361

  16. Capacitance Probe Resonator for Multichannel Electrometer

    Science.gov (United States)

    Blaes, Brent R.; Schaefer, Rembrandt T> Glaser, Robert J.

    2012-01-01

    A multichannel electrometer voltmeter has been developed that employs a mechanical resonator with voltage-sensing capacitance-probe electrodes that enable high-impedance, high-voltage, radiation-hardened measurement of an Internal Electrostatic Discharge Monitor (IESDM) sensor. The IESDM is new sensor technology targeted for integration into a Space Environmental Monitor (SEM) subsystem used for the characterization and monitoring of deep dielectric charging on spacecraft. The resonator solution relies on a non-contact, voltage-sensing, sinusoidal-varying capacitor to achieve input impedances as high as 10 petaohms as determined by the resonator materials, geometries, cleanliness, and construction. The resonator is designed with one dominant mechanical degree of freedom, so it resonates as a simple harmonic oscillator and because of the linearity of the variable sense capacitor to displacement, generates a pure sinusoidal current signal for a fixed input voltage under measurement. This enables the use of an idealized phase-lock sensing scheme for optimal signal detection in the presence of noise.

  17. Acoustic lens for capacitive micromachined ultrasonic transducers

    International Nuclear Information System (INIS)

    Capacitive micromachined ultrasonic transducers (CMUTs) have great potential to compete with traditional piezoelectric transducers in therapeutic ultrasound applications. In this paper we have designed, fabricated and developed an acoustic lens formed on the CMUT to mechanically focus ultrasound. The acoustic lens was designed based on the paraxial theory and made of silicone rubber for acoustic impedance matching and encapsulation. The CMUT was fabricated based on the local oxidation of silicon (LOCOS) and fusion-bonding. The fabricated CMUT was verified to behave like an electromechanical resonator in air and exhibited wideband response with a center frequency of 2.2 MHz in immersion. The fabrication for the acoustic lens contained two consecutive mold castings and directly formed on the surface of the CMUT. Applied with ac burst input voltages at the center frequency, the CMUT with the acoustic lens generated an output pressure of 1.89 MPa (peak-to-peak) at the focal point with an effective focal gain of 3.43 in immersion. Compared to the same CMUT without a lens, the CMUT with the acoustic lens demonstrated the ability to successfully focus ultrasound and provided a viable solution to the miniaturization of the multi-modality forward-looking endoscopes without electrical focusing. (paper)

  18. Locating Depots for Capacitated Vehicle Routing

    CERN Document Server

    Goertz, Inge Li

    2011-01-01

    We study a location-routing problem in the context of capacitated vehicle routing. The input is a set of demand locations in a metric space and a fleet of k vehicles each of capacity Q. The objective is to locate k depots, one for each vehicle, and compute routes for the vehicles so that all demands are satisfied and the total cost is minimized. Our main result is a constant-factor approximation algorithm for this problem. To achieve this result, we reduce to the k-median-forest problem, which generalizes both k-median and minimum spanning tree, and which might be of independent interest. We give a (3+c)-approximation algorithm for k-median-forest, which leads to a (12+c)-approximation algorithm for the above location-routing problem, for any constant c>0. The algorithm for k-median-forest is just t-swap local search, and we prove that it has locality gap 3+2/t; this generalizes the corresponding result known for k-median. Finally we consider the "non-uniform" k-median-forest problem which has different cost ...

  19. Combinatorial Algorithms for Capacitated Network Design

    CERN Document Server

    Hajiaghayi, MohammadTaghi; Kortsarz, Guy; Nutov, Zeev

    2011-01-01

    We focus on designing combinatorial algorithms for the Capacitated Network Design problem (Cap-SNDP). The Cap-SNDP is the problem of satisfying connectivity requirements when edges have costs and hard capacities. We begin by showing that the Group Steiner tree problem (GST) is a special case of Cap-SNDP even when there is connectivity requirement between only one source-sink pair. This implies the first poly-logarithmic lower bound for the Cap-SNDP. We next provide combinatorial algorithms for several special cases of this problem. The Cap-SNDP is equivalent to its special case when every edge has either zero cost or infinite capacity. We consider a special case, called Connected Cap-SNDP, where all infinite-capacity edges in the solution are required to form a connected component containing the sinks. This problem is motivated by its similarity to the Connected Facility Location problem [G+01,SW04]. We solve this problem by reducing it to Submodular tree cover problem, which is a common generalization of Con...

  20. Design Considerations in Capacitively Coupled Plasmas

    Science.gov (United States)

    Song, Sang-Heon; Ventzek, Peter; Ranjan, Alok

    2015-11-01

    Microelectronics industry has driven transistor feature size scaling from 10-6 m to 10-9 m during the past 50 years, which is often referred to as Moore's law. It cannot be overstated that today's information technology would not have been so successful without plasma material processing. One of the major plasma sources for the microelectronics fabrication is capacitively coupled plasmas (CCPs). The CCP reactor has been intensively studied and developed for the deposition and etching of different films on the silicon wafer. As the feature size gets to around 10 nm, the requirement for the process uniformity is less than 1-2 nm across the wafer (300 mm). In order to achieve the desired uniformity, the hardware design should be as precise as possible before the fine tuning of process condition is applied to make it even better. In doing this procedure, the computer simulation can save a significant amount of resources such as time and money which are critical in the semiconductor business. In this presentation, we compare plasma properties using a 2-dimensional plasma hydrodynamics model for different kinds of design factors that can affect the plasma uniformity. The parameters studied in this presentation include chamber accessing port, pumping port, focus ring around wafer substrate, and the geometry of electrodes of CCP.

  1. Instabilities in a capacitively coupled oxygen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Küllig, C., E-mail: kuellig@physik.uni-greifswald.de; Wegner, Th., E-mail: physics@thwegner.com; Meichsner, J., E-mail: meichsner@physik.uni-greifswald.de [Institute of Physics, University of Greifswald, Felix-Hausdorff-Str. 6, 17489 Greifswald (Germany)

    2015-04-15

    Periodic fluctuations in the frequency range from 0.3 to 3 kHz were experimentally investigated in capacitively coupled radio frequency (13.56 MHz) oxygen plasma. The Gaussian beam microwave interferometry directly provides the line integrated electron density fluctuations. A system of two Langmuir probes measured the floating potential spatially (axial, radial) and temporally resolved. Hence, the floating potential fluctuation development is mapped within the discharge volume and provides a kind of discharge breathing and no wave propagation. Finally, it was measured the optical emission pattern of atomic oxygen during the fluctuation as well as the RF phase resolved optical emission intensity at selected phase position of the fluctuation by an intensified charge-coupled device camera. The deduced excitation rate pattern reveals the RF sheath dynamics and electron heating mechanisms, which is changing between low and high electronegativity during a fluctuation cycle. A perturbation calculation was taken into account using a global model with 15 elementary collision processes in the balance equations for the charged plasma species (O{sub 2}{sup +}, e, O{sup −}, O{sub 2}{sup −}) and a harmonic perturbation. The calculated frequencies agree with the experimentally observed frequencies. Whereby, the electron attachment/detachment processes are important for the generation of this instability.

  2. An ultra-small capacitance Josephson junction

    International Nuclear Information System (INIS)

    We consider a voltage biased ultra-small capacitance Josephson junction, with the coupling to the external source containing both resistive and inductive elements. In addition we include a phenomenological coupling to an external heat bath. Our goal is to extend and generalize previous studies of current biased ultra-small junctions. Charging effects, due to the presence of discrete charge carriers in the junction, play a crucial role. In particular we find an infinite resistance branch in the I-V characteristic for a d.c. bias, and resistive steps in the I-V curve when the external bias contains an additional a.c. component. These effects are reminiscent of the 'Coulomb blockade' and the inverse Shapiro steps, respectively, predicted earlier in the context of current biased circuits. As a response to an a.c. voltage bias we also predict spikes of the voltage across the junction and a noisy background, when this voltage is plotted as a function of either the external d.c. biasing voltage or the external frequency. Our analysis shows that various circuitry components may qualitatively affect the response of the junction to an external bias. (authors)

  3. Spatial resolution in electrical capacitance tomography

    CERN Document Server

    Lucas, Jérôme; Oussar, Yacine; Holé, Stéphane

    2015-01-01

    Electrical Capacitance Tomography (ECT) is an imaging technique providing the distribution of permittivity in a medium by the mean of electrodes. As for any imaging systems, the reachable spatial resolution is a key parameter. In this paper the spatial resolution of ECT sensors is analyzed in terms of the accuracy of an object position and of the ability to distinguish between two close objects. Cylindrical geometry sensors are particularly studied and the example of a square geometry sensor is used to show how to study any other geometries. In cylindrical geometries, it is shown that a 50% gap between electrodes is a good compromise and that increasing the number of electrodes improves the spatial resolution near the electrodes but decreases the spatial resolution in the center. The best spatial resolution at the center of the sensor is obtained with 3 or 4 electrodes. In the square geometry studied, it is shown that a better distribution of the spatial resolution is obtained when there are electrodes in the...

  4. On some uses of the recording op fission fragments occurring in insulators; Sur quelques utilisations de l'enregistrement des fragments de fission dans les isolants

    Energy Technology Data Exchange (ETDEWEB)

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

    1965-07-01

    The passage of fission fragments is manifested in insulators by the formation of damage lines which can easily be observed by transparence using the electron microscope after a suitable chemical attack. Since the recording efficiency is 100 per cent for mica and plastics this phenomenon has a certain number of applications. After briefly recalling the interaction processes between charged particles and matter, and giving a quantitative study of the relationships connecting the various parameters, the author considers here some of these applications: - thermal neutron dosimetry: it is possible to measure integrated fluxes of between lO{sup 3} and 10{sup 21} n/cm{sup 2}, according to the method used; - fast neutron dosimetry: by using fission fragment threshold sources it is easy to measure biological type doses of about 1 rem: - dosage of very low fissile impurity concentrations: atomic concentrations of about 10{sup -9}; can be measured; this limit has never been attained by conventional methods; - study of fissile elements occurring in atmospheric dusts. Results are then briefly given of an automated counting test for traces effected by measuring the electrical resistivity, of the irradiated membrane. Finally are given the advantages and disadvantages of these solid detectors, especially with respect to nuclear emulsions whose uses are approximately identical. (author) [French] Le passage des fragments de fission se materialise dans les isolants par des lignes de dommages que l'on peut facilement observer par transparence au microscope optique apres une attaque chimique appropriee. L'efficacite d'enregistrement etant de 100 pour cent dans le mica et les plastiques, ce phenomene peut avoir un certain nombre d'applications. Apres un bref rappel des processus d'interaction entre particules chargees et matiere, et une etude quantitative des relations unissant les differents parametres, on etudie ici quelques-unes de ces applications

  5. Agroforesterie, des arbres et des cultures

    OpenAIRE

    dupraz, Christian; Liagre, Fabien

    2008-01-01

    Des arbres dans nos parcelles cultivées ? Pourquoi pas ! Depuis un siècle, ils ont été systématiquement retirés des parcelles agricoles. Pourtant, de plus en plus, on étudie leur valeur ajoutée en matière : de sols et pour les différentes productions végétales, de biodiversité, de protection de l'environnement, de qualité de l'eau (bilan hydrique). Les auteurs, dans une première partie, exposent les données pour comprendre le fonctionnement d'une parcelle agroforestière. Ils donnent, dans une...

  6. Rachid Santaki, Des chiffres et des litres

    OpenAIRE

    Harzoune, Mustapha

    2013-01-01

    Avec Des chiffres et des litres, Rachid Santaki signe un roman qui s’inscrit dans la pure tradition du néo-polar. Nous sommes en 1998, la Coupe du monde de football mobilise l’attention du pays. Hachim, un jeune de Saint-Denis intelligent et sensible, doué pour les études souhaite faire carrière dans le journalisme mais s’embarque dans une galère qui n’est pas faite pour lui : le deal de shit. Il faut savoir pourtant rester à sa place, ne pas jouer les gros durs quand on a une “gueule de prem...

  7. Design of Excitation Capacitance for Self-Excited Induction Generator

    Directory of Open Access Journals (Sweden)

    Swati Devabhaktuni

    2011-12-01

    Full Text Available This paper presents simple and accurate approach to compute the minimum value of capacitance required for initiating the voltage build-up in a three-phase selfexcited induction generator. Based on the steady-state equivalent circuit model different numerical methods for solving frequency are known from previous literature, which are of 6th order polynomial. In this paper the order of the polynomial is reduced to the 4thorder frequency with a new, simple and direct method is developed to find the capacitance requirement. Critical values of the impedance and speed, below which the machine fails to self excite irrespective of the capacitance used, are found to exist. Closed form solutions for capacitance are derived for no-load and RL loads. Experimental results obtained on a 3.5kW induction machine confirm the feasibility and accuracy of the proposed method.

  8. Segmented Capacitance Sensor with Partially Released Inactive Segments

    Directory of Open Access Journals (Sweden)

    Lev Jakub

    2015-09-01

    Full Text Available Material throughput measurement is important for many applications, for example yield maps creation or control of mass flow in stationary lines. Quite perspective can be the capacitive throughput method. Segmented capacitance sensor (SCS is discussed in this paper. SCS is a compromise between simple capacitive throughput sensors and electrical capacitance tomography sensors. The SCS variant with partially released inactive segments is presented. The mathematical model of SCS was created and verified by measurements. A good correspondence between measured and computed values was found and it can be stated that the proposed mathematical model was verified. During measurement the voltage values on the inactive segments were monitored as well. On the basis of the measurement there was found that these values are significantly influenced by material distribution.

  9. Fringe Capacitance of a Parallel-Plate Capacitor.

    Science.gov (United States)

    Hale, D. P.

    1978-01-01

    Describes an experiment designed to measure the forces between charged parallel plates, and determines the relationship among the effective electrode area, the measured capacitance values, and the electrode spacing of a parallel plate capacitor. (GA)

  10. Composite metal-oxide device has voltage sensitive capacitance

    Science.gov (United States)

    Mattauch, R. J.; Viola, T. J., Jr.

    1970-01-01

    Device with step function variation of the capacitance is useful for voltage-controlled oscillator circuits and as a voltage-sensitive switch. Simplicity of construction makes the device suitable for large-scale integration, microelectronic circuits.

  11. Enhancement of the carbon electrode capacitance by brominated hydroquinones

    Science.gov (United States)

    Gastol, Dominika; Walkowiak, Jedrzej; Fic, Krzysztof; Frackowiak, Elzbieta

    2016-09-01

    This paper presents supercapacitors utilizing new redox-active electrolytes with bromine species. Two sources of Br specimen were investigated, i.e. dibromodihydroxybenzene dissolved in KOH and potassium bromide dissolved in KOH with hydroxybenzene additive. KOH-activated carbon, exhibiting a well-developed porosity, was incorporated as an electrode material. The tested systems revealed a capacitance enhancement explained by Br- and partial BrO3- redox activity. The optimisation of the electrolyte concentration resulted in a capacitance value of 314 F g-1 achieved at 1.1 V voltage range. Good cyclability performance (11% capacitance loss) combined with a high capacitance value (244 F g-1) were obtained for the system operating in 0.2 mol L- 1 C6H4Br2O2 in 2 mol L-1 KOH electrolytic solution.

  12. Integration of Capacitive Micromachined Ultrasound Transducers to Microfluidic Devices

    KAUST Repository

    Viržonis, Darius

    2013-10-22

    The design and manufacturing flexibility of capacitive micromachined ultrasound transducers (CMUT) makes them attractive option for integration with microfluidic devices both for sensing and fluid manipulation. CMUT concept is introduced here by presentin

  13. Des fourmis pour le problème d'ordonnancement de voitures

    OpenAIRE

    Solnon, Christine

    2006-01-01

    Le problème d'ordonnancement de voitures consiste à séquencer des voitures sur une chaine de montage en satisfaisant des contraintes liées à la capacité des différents ateliers de montage positionnés le long de la chaine. On décrit dans cet article un algorithme à base de fourmis pour résoudre ce problème, et on propose deux structures phéromonales complémentaires pour cet algorithme : la première vise à apprendre les bonnes sous séquences de voitures ; la seconde vise à apprendre les voiture...

  14. Promotion des ventes, psychologie de l'achat et comportement de consommation

    OpenAIRE

    Chandon, Pierre

    1997-01-01

    La promotion des ventes a connu un développement considérable au cours des vingt dernières années à tel point que les sommes investies dans les opérations promotionnelles représentent aujourd'hui le double de celles investies dans la publicité. Pourtant, le bienfondé des politiques promotionnelles mises en place par les entreprises est profondément remis en cause. Bien qu'on leur reconnaisse une efficacité réelle sur le court terme, on s'interroge sur leur capacité réelle à augmenter les vent...

  15. Capacitive Sensors for Measuring Masses of Cryogenic Fluids

    Science.gov (United States)

    Nurge, Mark; Youngquist, Robert

    2003-01-01

    An effort is under way to develop capacitive sensors for measuring the masses of cryogenic fluids in tanks. These sensors are intended to function in both microgravitational and normal gravitational settings, and should not be confused with level sensors, including capacitive ones. A sensor of this type is conceptually simple in the sense that (1) it includes only one capacitor and (2) if properly designed, its single capacitance reading should be readily convertible to a close approximation of the mass of the cryogenic fluid in the tank. Consider a pair of electrically insulated electrodes used as a simple capacitive sensor. In general, the capacitance is proportional to the permittivity of the dielectric medium (in this case, a cryogenic fluid) between the electrodes. The success of design and operation of a sensor of the present type depends on the accuracy of the assumption that to a close approximation, the permittivity of the cryogenic fluid varies linearly with the density of the fluid. Data on liquid nitrogen, liquid oxygen, and liquid hydrogen, reported by the National Institute of Standards and Technology, indicate that the permittivities and densities of these fluids are, indeed, linearly related to within a few tenths of a percent over the pressure and temperature regions of interest. Hence, ignoring geometric effects for the moment, the capacitance between two electrodes immersed in the fluid should vary linearly with the density, and, hence, with the mass of the fluid. Of course, it is necessary to take account of the tank geometry. Because most cryogenic tanks do not have uniform cross sections, the readings of level sensors, including capacitive ones, are not linearly correlated with the masses of fluids in the tanks. In a sensor of the present type, the capacitor electrodes are shaped so that at a given height, the capacitance per unit height is approximately proportional to the cross-sectional area of the tank in the horizontal plane at that

  16. Probing Quantum Capacitance in a 3D Topological Insulator

    Science.gov (United States)

    Kozlov, D. A.; Bauer, D.; Ziegler, J.; Fischer, R.; Savchenko, M. L.; Kvon, Z. D.; Mikhailov, N. N.; Dvoretsky, S. A.; Weiss, D.

    2016-04-01

    We measure the quantum capacitance and probe thus directly the electronic density of states of the high mobility, Dirac type two-dimensional electron system, which forms on the surface of strained HgTe. Here we show that observed magnetocapacitance oscillations probe—in contrast to magnetotransport—primarily the top surface. Capacitance measurements constitute thus a powerful tool to probe only one topological surface and to reconstruct its Landau level spectrum for different positions of the Fermi energy.

  17. Direct measurement of specific membrane capacitance in neurons.

    OpenAIRE

    Gentet, L.J.; Stuart, G J; Clements, J D

    2000-01-01

    The specific membrane capacitance (C(m)) of a neuron influences synaptic efficacy and determines the speed with which electrical signals propagate along dendrites and unmyelinated axons. The value of this important parameter remains controversial. In this study, C(m) was estimated for the somatic membrane of cortical pyramidal neurons, spinal cord neurons, and hippocampal neurons. A nucleated patch was pulled and a voltage-clamp step was applied. The exponential decay of the capacitative char...

  18. Quantum inductance and negative electrochemical capacitance at finite frequency

    OpenAIRE

    Wang, J.; Wang, B. G.; Guo, H

    2007-01-01

    We report on theoretical investigations of frequency dependent quantum capacitance. It is found that at finite frequency a quantum capacitor can be characterized by a classical RLC circuit with three parameters: a static electrochemical capacitance, a charge relaxation resistance, and a quantum inductance. The quantum inductance is proportional to the characteristic time scale of electron dynamics and due to its existence, the time dependent current can accumulate a phase delay and becomes la...

  19. Simultaneous capacitance and amperometric measurements of exocytosis: a comparison.

    OpenAIRE

    Oberhauser, A F; Robinson, I M; Fernandez, J. M.

    1996-01-01

    We measured the exocytotic response induced by flash photolysis of caged compounds in isolated mast cells and chromaffin cells. Vesicle fusion was measured by monitoring the cell membrane capacitance. The release of vesicular contents was followed by amperometry. In response to a GTP gamma S stimulus we found that the time integral of the amperometric current could be superimposed on the capacitance trace. This shows that the integrated amperometric signal provides an alternative method of me...

  20. Graphene-based quantum capacitance wireless vapor sensors

    OpenAIRE

    Deen, David A.; Olson, Eric J.; Ebrish, Mona A.; Koester, Steven J.

    2013-01-01

    A wireless vapor sensor based upon the quantum capacitance effect in graphene is demonstrated. The sensor consists of a metal-oxide-graphene variable capacitor (varactor) coupled to an inductor, creating a resonant oscillator circuit. The resonant frequency is found to shift in proportion to water vapor concentration for relative humidity (RH) values ranging from 1% to 97% with a linear frequency shift of 5.7 +- 0.3 kHz / RH%. The capacitance values extracted from the wireless measurements ag...

  1. A Review of High Voltage Drive Amplifiers for Capacitive Actuators

    DEFF Research Database (Denmark)

    Huang, Lina; Zhang, Zhe; Andersen, Michael A. E.

    2012-01-01

    This paper gives an overview of the high voltage amplifiers, which are used to drive capacitive actuators. The amplifiers for both piezoelectric and DEAP (dielectric electroactive polymer) actuator are discussed. The suitable topologies for driving capacitive actuators are illustrated in detail......, including linear as well as switched mode amplifiers. In the past much attention has been paid on the driver for piezoelectric actuator. As DEAP is a type of new material, there is not much literature reference for it....

  2. Capacitance extraction from complex 3D interconnect structures

    Energy Technology Data Exchange (ETDEWEB)

    Cartwright, D.; Csanak, G.; George, D.; Walker, R.; Kuprat, A. [Los Alamos National Lab., NM (United States). Theoretical Div.; Dengi, A.; Grobman, W. [Motorola, Austin, TX (United States)

    1999-06-01

    A new tool has been developed for calculating the capacitance matrix for complex 3D interconnect structures involving multiple layers of irregularly shaped interconnect, imbedded in different dielectric materials. This method utilizes a new 3D adaptive unstructured grid capability, and a linear finite element algorithm. The capacitance is determined from the minimum in the total system energy as the nodes are varied to minimize the error in the electric field in the dielectric(s).

  3. Probing Quantum Capacitance in a 3D Topological Insulator.

    Science.gov (United States)

    Kozlov, D A; Bauer, D; Ziegler, J; Fischer, R; Savchenko, M L; Kvon, Z D; Mikhailov, N N; Dvoretsky, S A; Weiss, D

    2016-04-22

    We measure the quantum capacitance and probe thus directly the electronic density of states of the high mobility, Dirac type two-dimensional electron system, which forms on the surface of strained HgTe. Here we show that observed magnetocapacitance oscillations probe-in contrast to magnetotransport-primarily the top surface. Capacitance measurements constitute thus a powerful tool to probe only one topological surface and to reconstruct its Landau level spectrum for different positions of the Fermi energy. PMID:27152818

  4. New Type Multielectrode Capacitance Sensor for Liquid Level

    International Nuclear Information System (INIS)

    This paper introduces the design of a new type multielectrode capacitance sensor for liquid level. The system regards electric field sensor MC33794 as the core and applies microcontroller MC9S12DJ128 to realize intelligent liquid level monitoring system, which overcomes the disadvantages of the traditional capacitance sensor, improves on the anti-jamming ability and the measurement precision and simplifies the system structure. Finally, the paper sums up the design of the system

  5. Capacitive Coupling in Double-Circuit Transmission Lines

    Directory of Open Access Journals (Sweden)

    Zdenka Benesova

    2004-01-01

    Full Text Available The paper describes an algorithm for calculation of capacitances and charges on conductors in systems with earth wires and in double-circuit overhead lines with respect to phase arrangement. A balanced voltage system is considered. A suitable transposition of individual conductors enables to reduce the electric and magnetic fields in vicinity of overhead lines and to limit the inductive and capacitive linkage. The procedure is illustrated on examples the results of which lead to particular recommendations for designers.

  6. Current Progress of Capacitive Deionization for Removal of Pollutant Ions

    Science.gov (United States)

    Gaikwad, Mahendra S.; Balomajumder, Chandrajit

    2016-08-01

    A mini review of a recently developing water purification technology capacitive deionization (CDI) applied for removal of pollutant ions is provided. The current progress of CDI for removal of different pollutant ions such as arsenic, fluoride, boron, phosphate, lithium, copper, cadmium, ferric, and nitrate ions is presented. This paper aims at motivating new research opportunities in capacitive deionization technology for removal of pollutant ions from polluted water.

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

    Science.gov (United States)

    Fathy El Dessouky, Naglaa

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

  8. Switchless charge-discharge circuit for electrical capacitance tomography

    International Nuclear Information System (INIS)

    The main factor limiting the performance of electrical capacitance tomography (ECT) is an extremely low value of inter-electrode capacitances. The charge-discharge circuit is a well suited circuit for a small capacitance measurement due to its immunity to noise and stray capacitance, although it has a problem associated with a charge injected by the analogue switches, which results in a dc offset. This paper presents a new diode-based circuit for capacitance measurement in which a charge transfer method is realized without switches. The circuit was built and tested in one channel configuration with 16 multiplexed electrodes. The performance of the elaborated circuit and a comparison with a classic charge-discharge circuit are presented. The elaborated circuit can be used for sensors with inter-electrode capacitances not lower than 10 fF. The presented approach allows us to obtain a similar performance to the classic charge-discharge circuit, but has a simplified design. A lack of the need to synchronize the analogue switches in the transmitter and the receiver part of this circuit could be a desirable feature in the design of measurement systems integrated with electrodes. (paper)

  9. Diversité des carrières des chèvres laitières et pratiques d’alimentation et de reproduction : approche par modélisation

    OpenAIRE

    Puillet, Laurence; Martin, Olivier; Sauvant, Daniel; Tichit, Muriel

    2008-01-01

    La capacité du troupeau à répondre au projet de production de l’éleveur en dépit de perturbations est un élément essentiel de la performance du troupeau. Elle demande d’analyser la diversité des carrières de femelles pour évaluer l’effet des pratiques sur la capacité de résistance du troupeau aux perturbations. Cependant à ce jour peu d’études ont analysé le rôle de cette diversité. Cette analyse nécessite le développement d’un modèle simulant les stratégies d’alimentation et de reproduction ...

  10. L'effet du statut social sur la flexibilité alimentaire des singes magots (Macaca sylvanus)

    OpenAIRE

    Orient Pérez, Ester; Amezcua Valmala, Nerea; Guillén Salazar, Federico; Colmenares, Fernando

    2015-01-01

    Parmi les animaux, les primates se caractérisent par leur flexibilité comportementale, connue comme la capacité à s'adapter à de nouvelles conditions ou à des conditions très variables à travers de nouveaux comportements. Cette caractéristique définit particulièrement le comportement du macaque de Barbarie. Traditionnellement, la plupart des études réalisées chez cette espèce ont eu comme objectif principal l'étude de la variabilité de son régime alimentaire dans leur aire de répartition natu...

  11. Comment améliorer la prise en compte des agriculteurs dans la gouvernance foncière territoriale ?

    OpenAIRE

    Alavoine Mornas, F.; Léger, C.

    2012-01-01

    Symposium PSDR 3 "les chemins du développement rural", Clermont-Ferrand, FRA, 19-/06/2012 - 21/06/2012 National audience La nécessité de préserver les espaces agricoles des zones périurbaines est aujourd'hui largement affirmée dans le discours public. Dans le contexte actuel de territorialisation de l'action publique, les décideurs des différents échelons territoriaux sont interpellés dans leur capacité à assurer la préservation de ces espaces dont les enjeux se cristallisent souvent au...

  12. A QUALITATIVE ANALYSIS OF BIOMASS FLOW SENSING BEHAVIOR USING CAPACITIVE TECHNIQUE

    OpenAIRE

    Rumana Tasnim; Sheroz Khan; Musse Mohamud; Atika Arshad

    2016-01-01

    Flowsensing technology from today’s application perspective has gained significant research interest over the past few years. Among the existing sensing techniques, electrostatic and capacitive sensing techniques have proven promising although cable capacitance and stray capacitance cause inaccuracy while measuring very small capacitances. The existing measurement circuit model is complicated and has flawed electrode arrangement. By sensing very small capacitive variation, the developed capac...

  13. Histoire intellectuelle des droits humains

    OpenAIRE

    Zuber, Valentine

    2014-01-01

    Sous le titre générique « Histoire intellectuelle des droits humains », le séminaire de l’année 2012-2013 a été tout spécialement consacré aux origines spécifiquement religieuses des grands textes des droits de l’homme contemporains.

  14. An Analytical Model for Fringing Capacitance in Double gate Hetero Tunnel FET and Analysis of effect of Traps and Oxide charges on Fringing Capacitance

    Directory of Open Access Journals (Sweden)

    Brinda Bhowmick

    2012-03-01

    Full Text Available In this paper fringe capacitance of double hetero gate Tunnel FET has been studied. The physical modelfor fringe capacitance is derived considering source gate overlap and gate drain non overlap. Inerface trap charge and oxide charges are also introduced under positive bias stress and hot carrier stress and their effect on fringe capacitance is also studied. The fringe capacitance is significant speed limiter in Double gate technology. The model is tested by comparing with simulation results obtained from Sentauras TCADsimulations.

  15. An Analytical Model for Fringing Capacitance in Double gate Hetero Tunnel FET and Analysis of effect of Traps and Oxide charges on Fringing Capacitance

    OpenAIRE

    Brinda Bhowmick; Srimanta Baishya

    2012-01-01

    In this paper fringe capacitance of double hetero gate Tunnel FET has been studied. The physical model for fringe capacitance is derived considering source gate overlap and gate drain non overlap. Inerface trap charge and oxide charges are also introduced under positive bias stress and hot carrier stress and their effect on fringe capacitance is also studied. The fringe capacitance is significant speed limiter in Double gate technology. The model is tested by comparing with simulation results...

  16. Le statut vitaminique des individus et des populations…

    Directory of Open Access Journals (Sweden)

    Icart Jean-Claude

    2000-05-01

    Full Text Available Comme le souligne un récent rapport du Haut comité de santé publique, le statut vitaminique des individus et des populations demeure une question d’actualité. Si les études ne révèlent plus de signes évocateurs de carence, au plus des problèmes de déficiences pour certains groupes à risque, des interrogations, demeurent malgré le contexte d’abondance, concernant la couverture des besoins, laquelle pourrait s’avérer inférieure aux valeurs considérées comme satisfaisantes.

  17. Table des documents

    OpenAIRE

    2015-01-01

    Tableaux Sommes octroyées en don par le roi à la ville de Poitiers (1418-1429) 56 Sommes octroyées en don par le roi à la ville de Tours (1421-1422) 56 Sommes octroyées en don par le roi à la ville de Tours (1422-1432) pour le payement des délégations communales 57 Répartition chronologique des ambassades urbaines de Tours et Poitiers vers le roi (1438-1461) 76 Les groupes d'opinions à Bourges le 26 avril 1474 93 Rapport des octrois royaux à la ville de Bourges entre 1487 et 1535 (en moyennes...

  18. Table des figures

    OpenAIRE

    2015-01-01

    Figure n° 1 : Nombre de traités sur la culture des arbres fruitiers publiés en français à l’époque moderne 30 Figure n° 2 : Un exemple de plagiat, la vraie fausse nouvelle instruction pour la culture des figuiers 33 Figure n° 3 : Nombre d’espèces fruitières sélectionnées dans les traités horticoles parisiens (xviie-xviiie siècles) 65 Figure n° 4 : Nombre d’espèces fruitières proposées à la vente dans les catalogues des pépiniéristes parisiens (xviiie-début xixe s.) 65 Figure n° 5 : Les ustens...

  19. Table des illustrations

    OpenAIRE

    2015-01-01

    Intégrer les Tsiganes Hongrie, 1970 (photo DR) 34 Discuter entretient la fraternité. (photo M. Stewart) 35 La veille du mariage (photo M. Stewart) 36 Le « salon » (photo M. Stewart) 37 Les activités économiques des Tsiganes sont conçues comme des jeux. (photo M. Stewart) 39 Lev cheval (photo I. Nemeth) 41 Le cortège d’un mariage (photo M. Stewart) 43 Avant le mariage (photo M. Stewart) 43 C’est par le chant (photo M. Stewart) 45 Des « frères » boivent en harmonie (photo M. Stewart) 46 Les che...

  20. Les lueurs des sables

    CERN Multimedia

    Les lueurs des sables

    2013-01-01

    Two CERN ladies are getting ready for the “Trophée Roses des Sables” rally adventure: Julie and Laetitia are finalizing the last details before setting off on Monday 7th October 2013. Julie from EN-MEF group and Laetitia from DGS-SEE group, met at the CERN Rugby club. This year, they are participating in the 100 % female rally which will take place in Morocco from 10 to 20 October. They will be carrying along 100 kg of humanitarian donation for children such as some clothes, books and medical material. Do not hesitate to show your support at their farewell party to be held on Monday 7 October, from 4 to 6 pm in front of the St Genis-Pouilly Mairie (city Hall). Follow their exciting adventure on the blog leslueursdessables.trophee-roses-des-sables.org and on their association’s Facebook page Les Lueurs des Sables.

  1. La fin des certitudes ?

    OpenAIRE

    Renard, Philippe

    2008-01-01

    2006 fut l’année anniversaire des 150 ans de la naissance de l’hydrogéologie quantitative. La théorie des variables régionalisées, ou géostatistique, est beaucoup plus jeune mais a eu un impact majeur. Aujourd’hui, tout étudiant manie avec brio le krigeage que ce soit pour cartographier une contamination, un champ de transmissivité, ou le toit d’une nappe. Mais la géostatistique n’est pas seulement cela. Son intérêt majeur réside non pas dans l’interpolation des paramètres mais dans la possib...

  2. Geschichte des SIN

    CERN Document Server

    Pritzker, Andreas

    2013-01-01

    Dieses Buch erzählt die Geschichte des Schweizerischen Instituts für Nuklearforschung (SIN). Das Institut wurde 1968 gegründet und ging 1988 ins Paul Scherrer Institut (PSI) über. Die Gründung des SIN erfolgte in einer Zeit, als die Physik weitherum als Schlüsseldisziplin für die technologische und gesellschaftliche Entwicklung galt. Der Schritt war für ein kleines Land wie die Schweiz ungewöhnliche und zeugte von Mut und Weitsicht. Ungewöhnlich waren der Folge die Leistungen des SIN im weltweiten Vergleich sowie sein Einfluss auf die schweizerische, teils auf die internationale Wissenschaftspolitik.

  3. Chimie des processus biologiques

    OpenAIRE

    Fontecave, Marc

    2016-01-01

    Enseignement Cours : Du CO2 aux carburants, un renversement salutaire Le développement des nouvelles technologies de l’énergie pour l’exploitation des énergies renouvelables, comme l’énergie solaire ou l’énergie éolienne diluées et intermittentes, nécessite celui des procédés de stockage de l’énergie. Une façon de stocker ces énergies est de les transformer en énergie chimique. L’exemple le plus classique est l’électrolyse de l’eau en hydrogène, ce dernier pouvant être en effet ensuite utilis...

  4. Des millets aux nations

    OpenAIRE

    Pitsos, Nicolas

    2012-01-01

    L’auteur de ce roman construit son intrigue sur l’histoire de plusieurs familles d’une part au moment de l’effondrement d’un monde, celui des millets de l’Empire ottoman fondé sur le principe de l’identification des individus en fonction de leurs croyances religieuses et, d’autre part, lors de la mise en place d’une nouvelle organisation politique, celle des États-nations obsédés par l’idée de la définition de l’individu sur la base de critères nationaux. L'exemple narratif dominant est celui...

  5. La foi des charbonniers

    OpenAIRE

    Desbois, Evelyne; Jeanneau, Yves; Mattéi, Bruno

    2014-01-01

    Entre 1945 et 1947, deux années lourdes d'effets historiques et sociaux : la corporation minière atteint son apogée et commence son déclin. Trois regards croisés, complémentaires, portés sur un même objet, cette bataille du charbon dont on ne sait plus grand-chose, même du côté des terrils du Nord. Face au trou noir laissé dans les mémoires par cet épisode productiviste - amnésie collective remarquable - cette recherche soulève des questions iconoclastes, convoque des témoins, acteurs ou spe...

  6. Les archives des bagnes

    Directory of Open Access Journals (Sweden)

    Archives Nationales d’Outre-Mer

    2008-01-01

    Full Text Available Les établissements pénitentiaires coloniaux étaient administrés par le ministère de la Marine et des Colonies, puis par le ministère des Colonies (1881, en liaison avec les ministères de la Justice et de l’Intérieur. Les archives ont par conséquent été versées aux Archives nationales d’outre-mer avec le fonds du ministère des Colonies.Le fonds représente environ 760 ml (5358 articles. Il concerne presque exclusivement les bagnes de Guyane et de Nouvelle-Calédonie et couvre la période 1852-1...

  7. Extracellular signal-regulated kinases modulate capacitation of human spermatozoa.

    Science.gov (United States)

    Luconi, M; Barni, T; Vannelli, G B; Krausz, C; Marra, F; Benedetti, P A; Evangelista, V; Francavilla, S; Properzi, G; Forti, G; Baldi, E

    1998-06-01

    Recent evidence indicates the presence of p21 Ras and of a protein with characteristics similar to mitogen-activated protein kinases (MAPKs), also known as extracellular signal-regulated kinases (ERKs), in mammalian spermatozoa, suggesting the occurrence of the Ras/ERK cascade in these cells. In the present study we investigated the subcellular localization of ERKs and their biological functions in human spermatozoa. Immunohistochemistry, immunofluorescence, confocal microscopy, and immunoelectron microscopy demonstrated localization of ERKs in the postacrosomal region of spermatozoa. After stimulation of acrosome reaction with the calcium ionophore A23187 and progesterone, ERKs were mostly localized at the level of the equatorial region, indicating redistribution of these proteins in acrosome-reacted spermatozoa. Two proteins of 42 and 44 kDa that are tyrosine phosphorylated in a time-dependent manner during in vitro capacitation were identified as p42 (ERK-2) and p44 (ERK-1) by means of specific antibodies. The increase in tyrosine phosphorylation of these proteins during capacitation was accompanied by increased kinase activity, as determined by the ability of ERK-1 and ERK-2 to phosphorylate the substrate myelin basic protein. The role of this activity in the occurrence of sperm capacitation was also investigated by using PD098059, an inhibitor of the MAPK cascade. The presence of this compound during in vitro capacitation inhibits ERK activation and significantly reduces the ability of spermatozoa to undergo the acrosome reaction in response to progesterone. Since only capacitated spermatozoa are able to respond to progesterone, these data strongly indicate that ERKs are involved in the regulation of capacitation. In summary, our data demonstrate the presence of functional ERKs in human spermatozoa and indicate that these enzymes are involved in activation of these cells during capacitation, providing new insight in clarifying the molecular mechanisms and the

  8. Study on capacitance evolving mechanism of polypyrrole during prolonged cycling.

    Science.gov (United States)

    Wang, JingPing; Xu, Youlong; Wang, Jie; Zhu, Jianbo; Bai, Yang; Xiong, Lilong

    2014-02-01

    A simple model on the evolution mechanism of PPy capacitance during prolonged cycling offers a reasonably description on the rapid increase and decay of PPy capacitance in 1 M 1-ethyl-3-methylimidazolium tetrafluoroborate/propylene carbonate (EtMeImBF4/PC). The capacitance of PPy films reached a very high specific capacitance of 420 F·g(-1) after 15 cycles when they worked in 1 M MeEt3ImBF4/PC. However, the capacitance rapidly decreased to 5% after only 400 cycles. The electronic conductivity and protonation level on the nitrogen site of PPy films rapidly decreased with the increase of cyclic number. The salt of EtMeImBF4 was monitored in PPy matrix by FTIR spectra after 400 cycles. The EQCM results indicated that a lot of 1-ethyl-3-methylimidazolium cations (EtMeIm(+)) were inserted during reduction process and retained in PPy matrix. The detained EtMeIm(+) cations bonded with doped p-toluenesulfonate anions (PTS(-)) in PPy matrix or BF4(-) anions from electrolyte and formed salts. Small amount of salts in PPy matrix can open more channels of ion insertion and resulted in a very high capacitance after 15 cycles. The continuous combination of detained EtMeIm(+) cations with doping anions of PTS(-) resulted in the rapid decrease of PPy protonation level on the nitrogen site and formation of compensate semiconductor state in PPy matrix. This should be responsible for the rapid decay of PPy conductivity and capacitance. The continuous accumulation of salts resulted in the great increase of PPy internal resistance. PMID:24428582

  9. Bildwerke des Meisters HW

    OpenAIRE

    Schellenberger, Simona

    2007-01-01

    Etwa 20 skulpturale Arbeiten des frühen 16. Jahrhunderts werden auf der Basis stilkritischer Untersuchungen dem so genannten Meister HW zugeschrieben. Die Bildwerke gruppieren sich um drei mit den Buchstaben HW monogrammierte und datierte Bildwerke: die Figur der Hl. Helena von der Hl.-Kreuz-Kapelle des Rathauses in Halle/Saale (1501/1502), das Altarretabel in der Bornaer Marienkirche (1511) und die Schöne Tür von der Franziskanerklosterkirche in Annaberg (1512). Neben zwei Arbeiten in Goslar...

  10. Fokale Therapie des Prostatakarzinoms

    Directory of Open Access Journals (Sweden)

    Roosen A

    2013-01-01

    Full Text Available Die EAU bezeichnet die fokale Therapie des Prostatakarzinoms als die therapeutische Option mit dem größten Zukunftspotenzial, auch wenn es sich dabei derzeit nicht um ein Standardverfahren handelt. Sie vermag bei Patienten mit einem niedrigmalignen, fokal begrenzten Prostatakarzinom die Lücke zu schließen zwischen potenzieller Übertherapie durch die radikalen Standardverfahren und der onkologischen Unsicherheit einer ,,Active surveillance“. Dieser Überblick gibt den derzeitigen Kenntnisstand bei der fokalen Therapie des Prostatakarzinoms wieder.

  11. Classification des rongeurs

    OpenAIRE

    Mignon, Jacques; Hardouin, Jacques

    2003-01-01

    Les lecteurs du Bulletin BEDIM semblent parfois avoir des difficultés avec la classification scientifique des animaux connus comme "rongeurs" dans le langage courant. Vu les querelles existant encore aujourd'hui dans la mise en place de cette classification, nous ne nous en étonnerons guère. La brève synthèse qui suit concerne les animaux faisant ou susceptibles de faire partie du mini-élevage. The note aims at providing the main characteristics of the principal families of rodents relevan...

  12. Figures mythiques des mondes musulmans

    OpenAIRE

    Aigle, Denise; Arnaud, Jean-Luc; Bacqué-Grammont, Jean-Louis; Balaÿ, Christophe; Bohas, Georges; Claudot-Hawad, Hélène; Copeaux, Etienne; Deheuvels, Luc-Willy; Démians d'Archimbaud, Gabrielle; Denoix, Sylvie; DeWeese, Devin; Farès-Drappeau, Saba; Forbes Manz, Beatrice; Frank, Allen J.; Guichard, Pierre

    2004-01-01

    En rapportant des récits extraordinaires mettant en scène des ancêtres fondateurs, l'historiographie islamique remplit une fonction mythique. Dans la mémoire des peuples, l'histoire est dominée par une longue succession de figures glorieuses comme Iskandar, l'Alexandre le Grand des musulmans, le Prophète et ses Compagnons, Saladin, Baybars, Gengis Khan, Tamerlan qui fondent, défendent et rénovent au fil des siècles une tradition immémoriale. Ces grands ancêtres sont pris pour modèles, se char...

  13. Dans la Trajectoire des Choses

    OpenAIRE

    Coupaye, Ludovic; Douny, Laurence

    2010-01-01

    Dans la trajectoire des choses. Comparaison des approches francophones et anglophones contemporaines en anthropologie des techniques. Dans cette introduction, les auteurs exposent les approches francophones et anglophones de l’étude des techniques et suggèrent que ces deux traditions ont traité d’enjeux comparables. Ils les resituent dans l’histoire des Sciences humaines et analysent leur place dans le champ anthropologique. Ils retracent les débats et les échanges qui les ont enrichies, part...

  14. Effets des digues filtrantes sur la productivité des pâturages naturels en région sahélienne du Burkina Faso

    Directory of Open Access Journals (Sweden)

    Kiema, A.

    2007-01-01

    Full Text Available Effects of Straining Dams on the Productivity of Natural Pastures in the Sahelian Region of Burkina Faso. Des systèmes de cultures améliorés de niébé ont été introduits dans des exploitations mixtes agriculture-élevage de la zone semi-aride au Burkina Faso et ensuite évalués dans des modèles de programmation linéaire. Les résultats ont montré que les variétés améliorées de niébé associées aux céréales permettent d'accroître la production agricole et le disponible fourrager, et de dégager des revenus pour acheter des compléments de vivriers. L'application de ces systèmes sur les terres de cultures peut varier entre 38% et 64% dans la partie sahélienne. Ils permettent aux agriculteurs de doubler la production de mil et de produire en plus annuellement 353 kg de niébé. Ces systèmes peuvent être promus dans la zone semi-aride du pays sans politique de soutien à la production. Par contre les soles améliorées de cultures pures de niébé ne sont pas profitables en raison des pertes liées au risque climatique, et aussi des coûts de production élevés par rapport aux capacités financières des exploitants. Elles permettent toutefois d'accroître le disponible fourrager à la ferme. Des stratégies de diminution des coûts de production des systèmes améliorés auront un impact considérable sur la sécurité alimentaire et sur le revenu.

  15. Application des techniques de contrôle des écoulements au pilotage des projectiles : Contrôle fluidique d'un projectile gyrostabilisé de 155 mm par effet Coanda

    OpenAIRE

    Zeidler, M

    2015-01-01

    Afin d'améliorer les performances des systèmes d'armes, les industriels de l'armement envisagent la mise en service de projectiles intégrant une capacité de correction de trajectoires. Le principal objectif consiste à proposer de nouveaux dispositifs de correction permettant de réduire l'erreur de dispersion de l'engin. Dans le cadre de projectiles aérostabilisés, le contrôle de leurs trajectoires est assuré à l'aide de surfaces portantes, technologie éprouvée depuis de nombreuses décennies. ...

  16. Radioactive versus capacitance techniques for measuring soil water

    International Nuclear Information System (INIS)

    A field study was conducted to compared a capacitance probe and a neutron probe for use in measuring the soil water changes and the absolute values of soil water. The study was conducted using three plots each receiving different amounts of water by a surface drip irrigation system. The 50 mm PVC access tubes were installed using a machine to auger the holes. One hole was dug using a 50 mm bulk density probe and the remaining two holes were dug using a 54 mm soil sampling tube. The two probes were calibrated to this site. The capacitance probe measured both absorption and desorption of the soil water in the semi-dry site as well as the neutron probe. The capacitance probe gave slightly higher soil water values in the semi-dry plot than the neutron probe. However, both instruments tracked the changes reasonably well. In the wet site, both probes underpredicted the actual water content, but still tracked the changes. In the dry site, which had a poorly install access tube, the capacitance probe did not accurately predict the water content or changes, while the neutron probe did. The capacitance technique will provide acceptable soil water measurements if the access tube is properly installed and appropriate calibration used. (author). 4 refs, 4 figs, 1 tab

  17. Nonlinear dynamics of capacitive charging and desalination by porous electrodes.

    Science.gov (United States)

    Biesheuvel, P M; Bazant, M Z

    2010-03-01

    The rapid and efficient exchange of ions between porous electrodes and aqueous solutions is important in many applications, such as electrical energy storage by supercapacitors, water desalination and purification by capacitive deionization, and capacitive extraction of renewable energy from a salinity difference. Here, we present a unified mean-field theory for capacitive charging and desalination by ideally polarizable porous electrodes (without Faradaic reactions or specific adsorption of ions) valid in the limit of thin double layers (compared to typical pore dimensions). We illustrate the theory for the case of a dilute, symmetric, binary electrolyte using the Gouy-Chapman-Stern (GCS) model of the double layer, for which simple formulae are available for salt adsorption and capacitive charging of the diffuse part of the double layer. We solve the full GCS mean-field theory numerically for realistic parameters in capacitive deionization, and we derive reduced models for two limiting regimes with different time scales: (i) in the "supercapacitor regime" of small voltages and/or early times, the porous electrode acts like a transmission line, governed by a linear diffusion equation for the electrostatic potential, scaled to the RC time of a single pore, and (ii) in the "desalination regime" of large voltages and long times, the porous electrode slowly absorbs counterions, governed by coupled, nonlinear diffusion equations for the pore-averaged potential and salt concentration. PMID:20365735

  18. Capacitance-Based Frequency Adjustment of Micro Piezoelectric Vibration Generator

    Directory of Open Access Journals (Sweden)

    Xinhua Mao

    2014-01-01

    Full Text Available Micro piezoelectric vibration generator has a wide application in the field of microelectronics. Its natural frequency is unchanged after being manufactured. However, resonance cannot occur when the natural frequencies of a piezoelectric generator and the source of vibration frequency are not consistent. Output voltage of the piezoelectric generator will sharply decline. It cannot normally supply power for electronic devices. In order to make the natural frequency of the generator approach the frequency of vibration source, the capacitance FM technology is adopted in this paper. Different capacitance FM schemes are designed by different locations of the adjustment layer. The corresponding capacitance FM models have been established. Characteristic and effect of the capacitance FM have been simulated by the FM model. Experimental results show that the natural frequency of the generator could vary from 46.5 Hz to 42.4 Hz when the bypass capacitance value increases from 0 nF to 30 nF. The natural frequency of a piezoelectric vibration generator could be continuously adjusted by this method.

  19. Low-Temperature Scanning Capacitance Probe for Imaging Electron Motion

    International Nuclear Information System (INIS)

    Novel techniques to probe electronic properties at the nanoscale can shed light on the physics of nanoscale devices. In particular, studying the scattering of electrons from edges and apertures at the nanoscale and imaging the electron profile in a quantum dot, have been of interest [1]. In this paper, we present the design and implementation of a cooled scanning capacitance probe that operates at liquid He temperatures to image electron waves in nanodevices. The conducting tip of a scanned probe microscope is held above the nanoscale structure, and an applied sample-to-tip voltage creates an image charge that is measured by a cooled charge amplifier [2] adjacent to the tip. The circuit is based on a low-capacitance, high- electron-mobility transistor (Fujitsu FHX35X). The input is a capacitance bridge formed by a low capacitance pinched-off HEMT transistor and tip-sample capacitance. We have achieved low noise level (0.13 e/VHz) and high spatial resolution (100 nm) for this technique, which promises to be a useful tool to study electronic behavior in nanoscale devices

  20. Logarithmic derivative method and system for capacitance measurement

    Science.gov (United States)

    Wu, Yichun; Wang, Lingzhi; Cai, Yuanfeng; Wu, Cunqiao

    2015-08-01

    A novel method based on logarithmic derivative is introduced to analyze multi-lifetime decay. As the discharge voltage signal of a RC circuit is a special kind of multi-lifetime exponential decay, the logarithmic derivative method can be used to measure single capacitance and multiple capacitances. With the logarithmic derivative method, a log(t) curve strongly peaked at precisely log(τ) is obtained, where the lifetime τ equals to RC. In a measurement system, if the resistance R is known, then the capacitance under test can be calculated. A logarithmic derivative curve fitting method is also presented, which has better anti-noise capability than the method that simply finds the maximum data on the peak. The curve fitting method can also be used for multiple capacitors measurement. To measure small capacitances, a large enough time window of the measuring instrument is required. Based on a field programmable gate array and a high speed analog-to-digital converter, a measurement system is developed. This system can provide the 16-bit resolution with sampling rate up to 250 MHz, which has a large enough time window for measuring lifetime shorter than 10-8 s. To reduce the amount of data needed to be stored and the noise due to the derivative treatment of transient data, the interpolation and noise-filter algorithms are employed. Experiments indicate that the logarithmic derivative method and system are suitable for the measurement of capacitances discharge and other exponential decay processes.

  1. Development and application of a real-time capacitive sensor.

    Science.gov (United States)

    Wongkittisuksa, Booncharoen; Limsakul, Chusak; Kanatharana, Proespichaya; Limbut, Warakorn; Asawatreratanakul, Punnee; Dawan, Supaporn; Loyprasert, Suchera; Thavarungkul, Panote

    2011-01-15

    A real-time capacitive sensor based on a potentiostatic step method was developed. It can display in real-time the evoked current waveform, capacitance and the electrical resistance of elements serially connected to the insulation layer on the electrode as a function of time as well as the ohmic resistance of the insulation layer. These features enable the user to observe the association and dissociation of the affinity binding pairs and to evaluate the insulating property of the electrode surface during measurement. The system allows the setting of potential pulse height, pulse interval, gain, filter, and sampling frequency, enabling the system to be more flexible. The performance of the system was firstly evaluated with equivalent circuits. Under suitable parameter settings it provided good accuracy of both the capacitance and resistance. Using the affinity binding pair of human serum albumin (HSA) and anti human serum albumin (anti-HSA) the measured capacitance change was used for the direct detection of HSA. The developed system provided the same sensitivity as the commercially available potentiostat (P>0.05). The proposed system was then applied to analyse HSA in real urine samples and the results agreed well with the immunoturbidimetric assay (P>0.05). The proposed system can be applied for capacitance measurement to directly detect other target analytes using different affinity binding pairs. Other applications such as kinetics analysis of the interaction between affinity bindings, thickness analysis, and the study of the insulation property of the modified layer are also promising. PMID:21087852

  2. REPRISE DES COURS - Yoga

    CERN Document Server

    Club de Yoga

    2015-01-01

    REPRISE DES COURS – Venez nombreux ! Yoga, Sophrologie, Tai Chi La liste des cours pour le semestre allant du 1er septembre 2015 au 31 janvier 2016 est disponible sur notre site web : http://club-yoga.web.cern.ch Lieu Les cours ont lieu dans la salle des clubs, à l’entresol du restaurant No 2, Bât. 504 (dans la salle no 3 pour la Sophrologie). Prix des cours Le prix pour le semestre (environ 18 leçons) est fixé à 220 CHF plus 10 CHF d’adhésion annuelle au Club. Couple : 200 CHF par personne. 2 cours par semaine : 400 CHF. Inscriptions Les inscriptions aux cours seront prises directement auprès du professeur, lors de la 1ère séance. Avant de s’inscrire pour le semestre, il est possible d’essayer une séance gratuitement. Informations : http://club-yoga.web.cern.ch ----------------------------------------- cern.ch/club-yoga/

  3. Vom Ort des Philosophierens

    Directory of Open Access Journals (Sweden)

    Damir Barbaric

    2002-12-01

    Full Text Available Im Aufsatz wird versucht, den ursprünglichen Sinn der Platonischen Bestimmung vom Staunen als Anfang der Philosophie zu ermitteln, und zwar durch eine kritischen Abhebung von ihrer Umdeutung bei Aristoteles, und dann insbesondere in der Stoa wie auch bei Spinoza und Hegel. Dabei wird auf die frühgriechische Erfahrung vom Staunen als _______ aufmerksam gemacht, wo es vor allem die Grundstimmung des Dabeiseins des Göttlichen und der menschlichen Teilnahme am Göttlichen bedeutet. Dem entspricht die bei Platon stark hervorgehobene Rolle des “Pathetischen” am Staunen, das in der nachkommenden Tradition grundsätzlich verlorengegangen ist. Für Platon entspringt das Staunen einem nie zu überwindenden Zustand der wesentlichen philosophischen “Weglosigkeit” (_____, welche schon bei Aristoteles nur noch im Sinne eines unbedingt zu verlassenden Ausgangspunkts der methodisch sicher fortfahrenden philosophischen Wissenschaft verstanden wird. Durch ein Zurückgreifen auf die Diotimas Lehre im Dialog Symposion wird dementgegen die Sokratisch-Platonische “Weglosigkeit” als der einzig angemessene “Ort” des echten Philosophierens bestimmt, welchen es, als das “Zwischen” für das Weltspiel der Unsterblichen und Sterblichen, um jeden Preis zu bewahren und offen zu halten gilt.

  4. La physique des infinis

    CERN Document Server

    Bernardeau, Francis

    2013-01-01

    Écrire l'histoire de l'Univers, tel est l'objectif commun des physiciens des particules et des astrophysiciens. Pour y parvenir, deux approches s'épaulent : la voie de l'infiniment petit, que l'on emprunte via de gigantesques accélérateurs de particules, et celle de l'infiniment grand, dont le laboratoire est l'Univers. Un Univers qui est bien loin d'avoir livré tous ses secrets. On connaît à peine 4,8 % de la matière qui le constitue, le reste étant composé de matière noire (25,8 %) et d'énergie noire (69,4 %), toutes deux de nature inconnue. Et si la récente découverte du boson de Higgs valide le Modèle standard de la physique des particules, celui-ci est toujours incomplet et doit être étendu à ou dépassé. Est-on arrivé au bout du jeu de poupées russes de la matière ? Quelles sont les particules manquantes ? Faut-il revoir les lois fondamentales ? Quels instruments faut-il mettre en œuvre pour accéder à cette « nouvelle physique » ? Comment parler de Super Big Science aux citoye...

  5. CHAINE DES ROTISSEUR @ HILTON

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The annual gala dinner of Chaine des Rotisseurs was hosted by Hilton Beijing. The “Ballet Dinner” - a great creation for both art and fine dining lovers was taken place in varies places within the hotel, including hotel lobby, 3rd floor and lobby lounge.

  6. A Rain Gauge System using a Capacitance Sensor

    Directory of Open Access Journals (Sweden)

    Worawat Sa-Ngiamvibool

    2013-08-01

    Full Text Available This paper proposes a rain gauge system using a coaxial capacitance sensor. The proposed system consists of a high-pass filter, a coaxial capacitance sensor, SMS module, a microcontroller and a smartphone. The sensor capacitance is proportional to the rainfall levels. It is converted into voltage signal. The corresponding voltage signal is sent to the microcontroller for converting the signal levels to the rainfall levels in millimetres. The microcontroller sends the rainfall levels to the SMS module that then sends the rainfall level data to show on the display screen of the smartphone. The experimentalresults showed that the proposed prototype can provide the correct data compared to the traditional system.

  7. A microcontroller-based interface circuit for lossy capacitive sensors

    International Nuclear Information System (INIS)

    This paper introduces and analyses a low-cost microcontroller-based interface circuit for lossy capacitive sensors, i.e. sensors whose parasitic conductance (Gx) is not negligible. Such a circuit relies on a previous circuit also proposed by the authors, in which the sensor is directly connected to a microcontroller without using either a signal conditioner or an analogue-to-digital converter in the signal path. The novel circuit uses the same hardware, but it performs an additional measurement and executes a new calibration technique. As a result, the sensitivity of the circuit to Gx decreases significantly (a factor higher than ten), but not completely due to the input capacitances of the port pins of the microcontroller. Experimental results show a relative error in the capacitance measurement below 1% for Gx x) shows the effectiveness of the circuit

  8. New low-cost MEMS capacitive pressure sensor concept

    Science.gov (United States)

    Wang, Yun; Cheung, Kin P.; Sheng, Kuang; Pai, Chien-Shing

    2005-01-01

    Capacitive pressure sensors based on surface or bulk MEMS technology have many attributes that make them highly desirable for many applications. The biggest technical challenge of capacitive pressure sensor technology is the creation of a reference cavity. It dictates the packaging approach and therefore the cost of the sensor. In this paper we introduce a new design of capacitive pressure sensor that takes advantage of a novel new wafer level packaging technology - A thin-film sealing technology that allows independent pressure control from high vacuum to high pressure. The new technology seals the vacuum cavity formed by standard surface micro machining technology by a brief melting of a metal layer using a pulsed laser. The ability to form reference vacuum cavity without the need for fusing or bonding with another structure allows the design to be simplified, leading to low cost and high yield.

  9. Class D audio amplifiers for high voltage capacitive transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis

    implications of driving the non-linear transducer of the DEAP. 2-level modulated high voltage amplifiers driving the capacitive load of the DEAP transducer are addressed in chapter 4. An amplifier with fourth order output filter and full-state self-oscillating hysteresis based control loop is proposed...... on a silicone film. As a consequence a capacitive transducer emerges, which can be shaped into the loudspeaker membrane itself, rolled up into a transducer driving a membrane or being part of an active suspension system for the membrane. In order to document the full potential of the DEAP transducer, suitable....... Due to the similarities between the electrostatic loudspeaker and the DEAP transducer, the state-of-the-art has a special focus on amplifiers for electrostatic loudspeakers. Amplifiers for other type of capacitive transducers like piezoelectric ones are also considered. Finally the current state...

  10. Capacitive Micromachined Ultrasonic Transducers (CMUTs for Underwater Imaging Applications

    Directory of Open Access Journals (Sweden)

    Jinlong Song

    2015-09-01

    Full Text Available A capacitive micromachined ultrasonic transducer structure for use in underwater imaging is designed, fabricated and tested in this paper. In this structure, a silicon dioxide insulation layer is inserted between the top electrodes and the vibration membrane to prevent ohmic contact. The capacitance-voltage (C-V characteristic curve shows that the transducer offers suitable levels of hysteresis and repeatability performance. The −6 dB center frequency is 540 kHz and the transducer has a bandwidth of 840 kHz for a relative bandwidth of 155%. Underwater pressure of 143.43 Pa is achieved 1 m away from the capacitive micromachined ultrasonic transducer under 20  excitation. Two-dimensional underwater ultrasonic imaging, which is able to prove that a rectangular object is present underwater, is achieved. The results presented here indicate that our work will be highly beneficial for the establishment of an underwater ultrasonic imaging system.

  11. Effect of surfactants on capacitance properties of carbon electrodes

    International Nuclear Information System (INIS)

    Effect of surfactants present in alkaline solutions on the capacitance of carbon electrodes has been studied. Different types of surfactants, i.e., sodium and lithium dodecyl sulphate as anionic surfactants, tetrapropylammonium bromide and iodide as cationic surfactants and polymer of polyethylene glycol and p-t-octylophenol (commercially called Triton® X-100) as non-ionic one have been selected for this target. Concentration of these electrolyte additives was 0.005 mol L−1. Decreasing the surface tension in the electrode/electrolyte interface allows better penetration of electrolyte into the pores. However, surfactants played a different role depending on the electrode polarity. Detailed analysis of capacitance versus current load, frequency dependence as well as self-discharge, cyclability and behaviour in wider voltage range proved especially a profitable effect of Triton® X-100 on capacitor operating in alkaline solution. Influence of surfactant concentration on capacitance properties was also investigated.

  12. Intrinsic Low Hysteresis Touch Mode Capacitive Pressure Sensor

    DEFF Research Database (Denmark)

    Fragiacomo, Giulio; Pedersen, Thomas; Hansen, Ole;

    2011-01-01

    Hysteresis has always been one of the main concerns when fabricating touch mode capacitive pressure sensors (TMCPS). This phenomenon can be fought at two different levels: during fabrication or after fabrication with the aid of a dedicated signal conditioning circuit. We will describe a...... microfabrication step that can be introduced in order to reduce drastically the hysteresis of this type of sensors without compromising their sensitivity. Medium-high range (0 to 10 bar absolute pressure) TMCPS with a capacitive signal span of over 100pF and less than 1 % hysteresis in the entire pressure range...... have been obtained. Temperature characterization was performed and showed a decrease in capacitance as the temperature increases. The maximum output variation, relative to room temperature, has been found to be 0.15 %/°C at 80 °C, while an almost constant variation of 0.044 %/°C is achieved if working...

  13. Capacitive measurement of mercury column heights in capillaries.

    Science.gov (United States)

    Frey, Sarah; Richert, Ranko

    2010-03-01

    The detection of changes in volume, e.g., in expansivity or aging measurements, are often translated into mercury column height within a glass capillary. We propose a capacitive technique for measuring the meniscus position using a cylindrical capacitor with mercury as the inner electrode, the capillary material as the dielectric, and a metal coat covering the outside surface of the capillary as the second electrode. The measured capacitance changes linearly with meniscus height, as long as the top mercury level remains within the range of the outer electrode. With the demonstrated noise level of 48 nm for our preliminary setup, meniscus height changes beyond 100 nm can be observed via the capacitance. PMID:20370203

  14. Wavelet approach to artifact noise removal from Capacitive coupled Electrocardiograph.

    Science.gov (United States)

    Lee, Seung Min; Kim, Ko Keun; Park, Kwang Suk

    2008-01-01

    Capacitive coupled Electrocardiography (ECG) is introduced as non-invasive measurement technology for ubiquitous health care and appliance are spread out widely. Although it has many merits, however, capacitive coupled ECG is very weak for motion artifacts for its non-skin-contact property. There are many studies for artifact problems which treats all artifact signals below 0.8Hz. In our capacitive coupled ECG measurement system, artifacts exist not only below 0.8Hz but also over than 10Hz. Therefore, artifact noise removal algorithm using wavelet method is tested to reject artifact-wandered signal from measured signals. It is observed that using power calculation each decimation step, artifact-wandered signal is removed as low frequency artifacts as high frequency artifacts. Although some original ECG signal is removed with artifact signal, we could level the signal quality for long term measure which shows the best quality ECG signals as we can get. PMID:19163323

  15. On Machine Capacitance Dimensional and Surface Profile Measurement System

    Science.gov (United States)

    Resnick, Ralph

    1993-01-01

    A program was awarded under the Air Force Machine Tool Sensor Improvements Program Research and Development Announcement to develop and demonstrate the use of a Capacitance Sensor System including Capacitive Non-Contact Analog Probe and a Capacitive Array Dimensional Measurement System to check the dimensions of complex shapes and contours on a machine tool or in an automated inspection cell. The manufacturing of complex shapes and contours and the subsequent verification of those manufactured shapes is fundamental and widespread throughout industry. The critical profile of a gear tooth; the overall shape of a graphite EDM electrode; the contour of a turbine blade in a jet engine; and countless other components in varied applications possess complex shapes that require detailed and complex inspection procedures. Current inspection methods for complex shapes and contours are expensive, time-consuming, and labor intensive.

  16. Quantum Capacitance Modifies Interionic Interactions in Semiconducting Nanopores

    CERN Document Server

    Lee, Alpha A; Goriely, Alain

    2016-01-01

    Nanopores made with low dimensional semiconducting materials, such as carbon nanotubes and graphene slit pores, are used in supercapacitors. In theories and simulations of their operation, it is often assumed that such pores screen ion-ion interactions like metallic pores, i.e. that screening leads to an exponential decay of the interaction potential with ion separation. By introducing a quantum capacitance that accounts for the density of states in the material, we show that ion-ion interactions in carbon nanotubes and graphene slit pores actually decay algebraically with ion separation. This result suggests a new avenue of capacitance optimization based on tuning the electronic structure of a pore: a marked enhancement in capacitance might be achieved by developing nanopores made with metallic materials or bulk semimetallic materials.

  17. A Wearable Capacitive Sensor for Monitoring Human Respiratory Rate

    Science.gov (United States)

    Kundu, Subrata Kumar; Kumagai, Shinya; Sasaki, Minoru

    2013-04-01

    Realizing an untethered, low-cost, and comfortably wearable respiratory rate sensor for long-term breathing monitoring application still remains a challenge. In this paper, a conductive-textile-based wearable respiratory rate sensing technique based on the capacitive sensing approach is proposed. The sensing unit consists of two conductive textile electrodes that can be easily fabricated, laminated, and integrated in garments. Respiration cycle is detected by measuring the capacitance of two electrodes placed on the inner anterior and posterior sides of a T-shirt at either the abdomen or chest position. A convenient wearable respiratory sensor setup with a capacitance-to-voltage converter has been devised. Respiratory rate as well as breathing mode can be accurately identified using the designed sensor. The sensor output provides significant information on respiratory flow. The effectiveness of the proposed system for different breathing patterns has been evaluated by experiments.

  18. Superconducting flux qubit capacitively coupled to an LC resonator

    International Nuclear Information System (INIS)

    We study the system where a superconducting flux qubit is capacitively coupled to an LC resonator. In three devices with different coupling capacitance, the magnitude of the dispersive shift is enhanced by the third level of the qubit and quantitatively agrees with the theory. We show by numerical calculation that the capacitive coupling plays an essential role for the enhancement in the dispersive shift. We investigate the coherence properties in two of these devices, which are in the strong-dispersive regime, and show that the qubit energy relaxation is currently not limited by the coupling. We also observe the discrete ac-Stark effect, a hallmark of the strong-dispersive regime, in accordance with the theory. (paper)

  19. High Voltage Bi-directional Flyback Converter for Capacitive Actuator

    DEFF Research Database (Denmark)

    Thummala, Prasanth; Zhang, Zhe; Andersen, Michael A. E.

    2013-01-01

    in a number of applications. In this paper, the discharging energy efficiency definition is introduced. The proposed converter has been experimentally tested with the film capacitive load and the DEAP actuator, and the experimental results are shown together with the efficiency measurements.......This paper presents a high voltage DC-DC converter topology for bi-directional energy transfer between a low voltage DC source and a high voltage capacitive load. The topology is a bi-directional flyback converter with variable switching frequency control during the charge mode, and constant...... switching frequency control during the discharge mode. The converter is capable of charging the capacitive load from 24 V DC source to 2.5 kV, and discharges it to 0 V. The flyback converter has been analyzed in detail during both charge and discharge modes, by considering all the parasitic elements in the...

  20. Perception des émotions non verbales dans la musique, les voix et les visages chez les adultes implantés cochléaires présentant une surdité évolutive

    OpenAIRE

    Ambert-Dahan, Emmanuèle

    2014-01-01

    Le bénéfice de l’implant cochléaire pour la compréhension de la parole en milieu calme, et même dans certains cas pour des situations auditives complexes telles que les environnements bruyants ou l’écoute de la musique est aujourd’hui connu. Si la compréhension de la parole est nécessaire à la communication, la perception des informations non verbales transmises par la voix de même que des expressions faciales est fondamentale pour interpréter le message d’un interlocuteur. Les capacités de p...

  1. Nickel Oxide/Carbon Nanotubes Nanocomposite for Electrochemical Capacitance

    Institute of Scientific and Technical Information of China (English)

    Kui LIANG; Kayhyeok AN; Younghee LEE

    2005-01-01

    A nanocomposite of nickel oxide/carbon nanotubes was prepared through a simple chemical precipitation followed by thermal annealing. The electrochemical capacitance of this electrode material was studied. When the mass fraction of CNTs (carbon nanotubes) in NiO/CNT composites increases, the electrical resistivity of nanocomposites decreases and becomes similar to that of pure CNTs when it reaches 30%. The specific surface area of composites increases with increasing CNT mass fraction and the specific capacitance reaches 160 F/g under 10 mA/g discharge current density at CNT mass fraction of 10%.

  2. Scanning Capacitance Microscopy in the Quantum Hall Regime

    OpenAIRE

    Suddards, Matthew Edmund

    2007-01-01

    This thesis discusses the development of a novel scanning capacitance microscope (SCM) that enables the investigation of the local capacitance and conductivity of surfaces and near-surface nanostructures at cryogenic temperatures and high magnetic fields. Simultaneous atomic force microscopy (AFM) and SCM measurements can be made at a temperature of 1.5K and a magnetic field of 12T. The AFM/SCM sensor is based on a quartz-tuning fork with an etched metal tip. SCM measurements are made us...

  3. Analysis of Capacitive Parasitism in PWM Inverter-Fed Motor

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The effects of parasitic capacitance in induction motor system are unnoticed when it is fed from the AC line. but they are obvious when supplied directly from a PWM inverter. Consequently. many parasitic problems occur, such as motor-to-earth leakage current, bearing current, incoming line current distortion and uneven distribution of electrical stresses along the winding. On the ba sis of the uniform transmission line principle, a complete equivalent circuit of the PWM inverter-fed motor system is presented, based on which all the capacitive parasitic problems mentioned above are analyzed and simulated by means of PSPICE. All the results are consistent with the existing ones.

  4. Optimizing the Materials Response in Humidity Capacitive Sensors

    OpenAIRE

    Elham Noroozi Afshar; Hossein Golnabi; Nima E. Gorji

    2015-01-01

    The number of humidity outputs on the cap of a cylindrical capacitance sensor is optimized by designing three different probes with direct and indirect windows. The time interval is measured within which 30-70 % humidity can influence the dielectric constant and conductivity of the capacitance when exposed to a range of relative humidity. It is then compared with a simple set-up including a simplified equivalent circuit. The direct probes had four and double outputs on the window of the cylin...

  5. Characterisation of a highly symmetrical miniature capacitive triaxial accelerometer

    OpenAIRE

    Lotters, J.C.; Olthuis, W.; Veltink, P.H.; Bergveld, P.

    1997-01-01

    A highly symmetrical cubic capacitive triaxial accelerometer for biomedical applications has been designed, realised and tested. The sensors are available in two outer dimensions, namely 2×2×2 and 5×5×5 mm3. The devices are mounted on a standard IC package for easy testing. Features of the sensor are a highly symmetrical cubic structure, capacitive coupling of the high frequency input voltage to the seismic mass and the use of the polymers polydimethylsiloxane (PDMS) as spring material betwee...

  6. Flexible Capacitive Electrodes for Minimizing Motion Artifacts in Ambulatory Electrocardiograms

    Directory of Open Access Journals (Sweden)

    Jeong Su Lee

    2014-08-01

    Full Text Available This study proposes the use of flexible capacitive electrodes for reducing motion artifacts in a wearable electrocardiogram (ECG device. The capacitive electrodes have conductive foam on their surface, a shield, an optimal input bias resistor, and guarding feedback. The electrodes are integrated in a chest belt, and the acquired signals are transmitted wirelessly for ambulatory heart rate monitoring. We experimentally validated the electrode performance with subjects standing and walking on a treadmill at speeds of up to 7 km/h. The results confirmed the highly accurate heart rate detection capacity of the developed system and its feasibility for daily-life ECG monitoring.

  7. Capacitive Touch User Interface and Implementation with Virtual Refrigerator

    Directory of Open Access Journals (Sweden)

    MIT Academy of Engineering Global Technology and Engineering centre, Whirlpool of India

    2014-05-01

    Full Text Available The proposed User Interface incorporates 14 Touch keys, including slider and wheeler functionality using self capacitance technology, 24 side throw LED with intensity controlled Fade-IN, Fade-OUT effects, Buzzer chime, Voltage regulator circuit, and communication circuitry for the control board. The major advantage that this User Interface is that the entire assembly is less than 10mm thick including PCB, components, light guide and graphics sticker. In this project the mentioned capacitive touch user Interface is interfaced with a Lab view system simulating a virtual refrigerator capable of responding to the commands from the User Interface.

  8. Double-driven shield capacitive type proximity sensor

    Science.gov (United States)

    Vranish, John M. (Inventor)

    1993-01-01

    A capacity type proximity sensor comprised of a capacitance type sensor, a capacitance type reference, and two independent and mutually opposing driven shields respectively adjacent to the sensor and reference and which are coupled in an electrical bridge circuit configuration and driven by a single frequency crystal controlled oscillator is presented. The bridge circuit additionally includes a pair of fixed electrical impedance elements which form adjacent arms of the bridge and which comprise either a pair of precision resistances or capacitors. Detection of bridge unbalance provides an indication of the mutual proximity between an object and the sensor. Drift compensation is also utilized to improve performance and thus increase sensor range and sensitivity.

  9. [Impact of sperm capacitation on various populations of human spermatozoa].

    Science.gov (United States)

    Villanueva Díaz, C; Suárez Juárez, M; Díaz, M A; Ayala Ruiz, A

    1989-02-01

    With the purpose of evaluating the impact of spermatic capacitation on different spermatozooa populations, 49 samples of semen, before and after in vitro spermatic capacitation with Ham F-10 medium, were studied; motility of cells was evaluated according to WHO criteria. There was diminution of percentage of immobile cells, 27.8 to 20.0, as well as increase in population of cells with more mobility, 28.6% to 39.1%. Both difference were statistically significant (p = less than 0.05 and p = less than 0.005, respectively). These data suggest that spermatic capacitacion activates "in cascade" all groups of gametes. PMID:2486981

  10. Development of Image Reconstruction Algorithms in electrical Capacitance Tomography

    International Nuclear Information System (INIS)

    The Electrical Capacitance Tomography (ECT) has not obtained a good development in order to be used at industrial level. That is due first to difficulties in the measurement of very little capacitances (in the range of femto farads) and second to the problem of reconstruction on- line of the images. This problem is due also to the small numbers of electrodes (maximum 16), that made the usual algorithms of reconstruction has many errors. In this work it is described a new purely geometrical method that could be used for this purpose. (Author) 4 refs

  11. Differential capacitance probe for process control involving aqueous dielectric fluids

    Science.gov (United States)

    Svoboda, John M.; Morrison, John L.

    2002-10-08

    A differential capacitance probe device for process control involving aqueous dielectric fluids is disclosed. The device contains a pair of matched capacitor probes configured in parallel, one immersed in a sealed container of reference fluid, and the other immersed in the process fluid. The sealed container holding the reference fluid is also immersed in the process fluid, hence both probes are operated at the same temperature. Signal conditioning measures the difference in capacitance between the reference probe and the process probe. The resulting signal is a control error signal that can be used to control the process.

  12. A low-noise/low-power preamplifier for capacitive microphones

    OpenAIRE

    Fürst, Claus Erdmann

    1996-01-01

    A design for a microphone preamplifier for application in hearing aids is presented. The amplifier operates at a supply of 1-1.5 V, the current drain is 40 μA. The maximum sound level allowed is more than 120 dB SPL (Sound Pressure Level), with a typical noise level of 25 dB(A) SPL (A-weighted). The amplifier is optimized for a capacitive microphone with a capacitance of 1.2 pF. The amplifier is fully integrated in a 0.7 μm n-well CMOS technology. Design details concerning noise performance a...

  13. Quantum capacitance in monolayers of silicene and related buckled materials

    Science.gov (United States)

    Nawaz, S.; Tahir, M.

    2016-02-01

    Silicene and related buckled materials are distinct from both the conventional two dimensional electron gas and the famous graphene due to strong spin orbit coupling and the buckled structure. These materials have potential to overcome limitations encountered for graphene, in particular the zero band gap and weak spin orbit coupling. We present a theoretical realization of quantum capacitance which has advantages over the scattering problems of traditional transport measurements. We derive and discuss quantum capacitance as a function of the Fermi energy and temperature taking into account electron-hole puddles through a Gaussian broadening distribution. Our predicted results are very exciting and pave the way for future spintronic and valleytronic devices.

  14. A low-noise/low-power preamplifier for capacitive microphones

    DEFF Research Database (Denmark)

    Fürst, Claus Erdmann

    1996-01-01

    A design for a microphone preamplifier for application in hearing aids is presented. The amplifier operates at a supply of 1-1.5 V, the current drain is 40 μA. The maximum sound level allowed is more than 120 dB SPL (Sound Pressure Level), with a typical noise level of 25 dB(A) SPL (A-weighted). ......-weighted). The amplifier is optimized for a capacitive microphone with a capacitance of 1.2 pF. The amplifier is fully integrated in a 0.7 μm n-well CMOS technology. Design details concerning noise performance are analytically described...

  15. Des Chiffres et des Lettres : distraction, variations, habitudes

    Directory of Open Access Journals (Sweden)

    Barbara Laborde

    2011-04-01

    Full Text Available Cet article envisage une des émissions les plus anciennes du Paysage Audiovisuel Français : Des Chiffres et des Lettres. La sérialité que l’émission met en œuvre au cours de son histoire est faite de variations qui témoignent à la fois des évolutions des techniques audiovisuelles, des logiques de programmations, des attentes spectatorielles. Ce jeu télévisé, toujours le même et pourtant toujours différent, permet à la fois la reconnaissance immédiate et la perception d'un changement, double adresse qui explique sans doute sa longévité et fait de ce programme un parangon de la sérialité télévisuelle.This article considers one of the oldest programs in the French media landscape: « Des Chiffres et des Lettres ». Seriality that implements the program in its history is made changes that reflect both the evolution of audiovisual techniques, of logic programming and expectations spectatorial. This TV show, always the same and yet still different, allows both the immediate recognition and perception of a change which probably explains its longevity and made this program a paragon of seriality in television.

  16. Biodégradation des herbicides en sols tempérés - Contrôle des communautés bactériennes dégradantes par la bioturbation du sol

    OpenAIRE

    Monard, Cécile

    2008-01-01

    L'intensification de l'agriculture s'est accompagnée d'une utilisation importante de pesticides qui a généré une pollution généralisée des sols et des eaux, problème environnemental majeur et actuel. Sous la pression de sélection liée à l'usage régulier de pesticides (molécules xénobiotiques) des bactéries du sol se sont adaptées à ces molécules et ont acquis la capacité de les utiliser comme source nutritive et donc de les dégrader. La biodégradation constitue un service écologique majeur fo...

  17. Le territoire des tarifs

    OpenAIRE

    2014-01-01

    Société pour la défense du commerce et de l’industrie de Marseille, Rapport présenté à la séance de la Chambre syndicale du 15 novembre 1921, par M. Camille Dufay, Marseille, 1922, p. 164-168. … D’une façon générale, commerçants et industriels se plaignent de l’élévation des tarifs, qui, en fait, excède souvent exagérément la majoration légale de 140 %, et de la suppression de certaines facilités qu’ils estiment indispensables à l’essor des affaires. Ils demandent, entre autres réformes, le r...

  18. La barricade des femmes

    OpenAIRE

    Dalotel, Alain

    2016-01-01

    L’histoire de la Commune est riche en eaux-fortes. L’une d’elles nous prend littéralement à la gorge : en pleine agonie du pouvoir révolutionnaire, 120 femmes se retranchent, fusil en main, derrière une barricade, aux pieds de Montmartre, pour s’opposer à l’armée de l’Ordre. Elles sont exterminées. Cet épisode de la guerre civile de 1871 s’est imposé à la mémoire, indiscutablement. Des barricades, lors de cette bataille tragique, on en a compté par centaines. Pourquoi pas une « barricade des ...

  19. Paiements pour services environnementaux et vulnérabilité des populations locales dans les pays du Sud – Études de cas costaricien et congolais

    OpenAIRE

    Froger, Géraldine; Maizière, Pierre Alexandre; Legrand, Thomas

    2016-01-01

    À l’aide de l’économie écologique institutionnaliste combinée à l’approche des « moyens de subsistance durables » (MSD) (sustainable livelihoods approach), cet article analyse la capacité des dispositifs de paiements pour services environnementaux (PSE) à réduire la vulnérabilité à la pauvreté des populations locales en comparant deux terrains d’étude : le Costa-Rica (CR) et la République Démocratique du Congo (RDC). Le programme de PSE permet globalement de réduire la vulnérabilité des popul...

  20. Contribution à l'étude juridique des risques psychosociaux au travail. Aspects de droit national, de droit comparé, d'interdisciplinarité

    OpenAIRE

    Lerouge, Loïc

    2014-01-01

    Les « risques psychosociaux au travail » (RPS) présentent des caractères qui les rendent difficiles à saisir en droit. Dans le même temps, ils désignent une réalité de la dégradation des conditions de travail d’aujourd’hui en lien avec l’évolution des organisations du travail et des contraintes économiques que le droit ne peut ignorer. Les recherches menées sur les RPS onttenté d’analyser la manière dont la science juridique s’est emparée du sujet, l’étendue et la relativité de ses capacités ...

  1. Analyse a posteriori d’une université paysanne au Brésil : quels éléments pour l’insertion territoriale des acteurs ?

    OpenAIRE

    Coudel, Emilie; Rey-Valette, Hélène; Tonneau, Jean-Philippe; Chia, Eduardo

    2008-01-01

    Alors que la participation d'acteurs aux politiques publiques devient l'objet de nombreuses études, l'accent est souvent mis sur la légitimité des acteurs, le type de structure de concertation, et les rapports sociaux en jeu (Bacqué et al., 2005) mais la capacité des acteurs à participer à ces processus est moins souvent abordée, alors qu'il s'agit d'un aspect fondamental de la gouvernance (Rey-Valette, 2006). Le Brésil, en décidant de développer des forums de développement durable dans des t...

  2. Evaluation de la Contamination des Dispositifs Médicaux (Cathéters et Sondes)à l'hôpital de Ain_Témouchentj

    OpenAIRE

    Boudelal, KHEIRA

    2015-01-01

    Dans le présent travail, 53 prélèvements ont été réalisé (43 cathéters et 10 sondes urinaires) 29/53ont presenté des cultures positives: 17 cultures sont des Gram positives et 14 cultures sont des Gram négatifs. L'antibiogramrne de certaines souches identifiées vis-à-vis d' une gamme d'antibiotiques a confirmé la multirésistance des souches de Staphylococcus aureus. La capacité de certaines baeteries à former un biofiim a été étudiée par deux méthodes: la Méthode de Plaque de C...

  3. Conductance mesophyllienne pour le CO2 et caractéristiques morphologiques des feuilles sous stress hydrique pendant la repousse de Quercus ilex L.

    OpenAIRE

    Fleck, Isabel; Peña-Rojas, Karen; Aranda, Xavier

    2010-01-01

    * Quercus ilex L., l'espèce dominante dans les forêts méditerranéennes qui a une grande capacité de rejets après des perturbations, est menacée par l'augmentation prévue de la fréquence des incendies et de la sécheresse associées au changement climatique.* Le but de cette étude était de déterminer, chez cette espèce, la contribution des limitations de la photosynthèse, en particulier de la conductance du mésophylle (gmes) au cours de la repousse et sous sécheresse estivale.* Les feuilles des ...

  4. Zur Biographie des Thomas Finck

    OpenAIRE

    Graf, Klaus

    2009-01-01

    Aus der Überlieferung der Werke des Mönchs Thomas Finck ergeben sich die Jahre 1489 und 1507 als Eckdaten seiner derzeit bekannten Lebenszeugnisse. Nach Ausweis des Cgm 6940 beendete Thomas Finck, der sich als Bruder des Benediktinerordens bezeichnet, am 8. Juli 1489 im Benediktinerkloster Elchingen die Übertragung der pseudothomasischen Schrift 'De beatitudine'. Der nur in der Karlsruher Handschrift St. Georgen 84 (möglicherweise ein Konzeptautograph) überlieferten Vorrede und Datierung sein...

  5. A silicon MEMS structure for characterization of femto-farad-level capacitive sensors with lock-in architecture

    OpenAIRE

    Wei, J; Chen, Z.L.; Liu, Z. W.; Sarro, P. M.

    2010-01-01

    This paper presents a silicon MEMS capacitive structure to investigate a test methodology for fF-level capacitive sensors’ measurement. The device mimics a capacitive sensor with a changing intermediate layer between the electrodes. A single mask bulk micromachining process is used to fabricate the device, which has a nominal capacitance of 1.2 fF. A high performance measurement setup based on lock-in principle is developed to detect the capacitance variation. The maximum capacitance variatio...

  6. RF-MEMS capacitive switches with high reliability

    Science.gov (United States)

    Goldsmith, Charles L.; Auciello, Orlando H.; Carlisle, John A.; Sampath, Suresh; Sumant, Anirudha V.; Carpick, Robert W.; Hwang, James; Mancini, Derrick C.; Gudeman, Chris

    2013-09-03

    A reliable long life RF-MEMS capacitive switch is provided with a dielectric layer comprising a "fast discharge diamond dielectric layer" and enabling rapid switch recovery, dielectric layer charging and discharging that is efficient and effective to enable RF-MEMS switch operation to greater than or equal to 100 billion cycles.

  7. Topology Optimization of Stressed Capacitive RF MEMS Switches

    DEFF Research Database (Denmark)

    Philippine, Mandy A.; Sigmund, Ole; Rebeiz, Gabriel M.;

    2013-01-01

    Geometry design can improve a capacitive radio-frequency microelectromechanical system switch's reliability by reducing the impacts of intrinsic biaxial stresses and stress gradients on the switch's membrane. Intrinsic biaxial stresses cause stress stiffening, whereas stress gradients cause out-o...

  8. A Multifunction Low-Power Preamplifier for MEMS Capacitive Microphones

    DEFF Research Database (Denmark)

    Jawed, Syed Arsalan; Nielsen, Jannik Hammel; Gottardi, Massimo;

    2009-01-01

    A multi-function two-stage chopper-stabilized preamplifier (PAMP) for MEMS capacitive microphones (MCM) is presented. The PAMP integrates digitally controllable gain, high-pass filtering and offset control, adding flexibility to the front-end readout of MCMs. The first stage of the PAMP consists of...

  9. Multilevel inverter based class D audio amplifier for capacitive transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    The reduced semiconductor voltage stress makes the multilevel inverters especially interesting, when driving capacitive transducers for audio applications. A ± 300 V flying capacitor class D audio amplifier driving a 100 nF load in the midrange region of 0.1-3.5 kHz with Total Harmonic Distortion...

  10. Optimization of salt adsorption rate in membrane capacitive deionization

    NARCIS (Netherlands)

    Zhao, R.; Satpradit, O.A.; Rijnaarts, H.; Biesheuvel, P.M.; Wal, van der A.

    2013-01-01

    Membrane capacitive deionization (MCDI) is a water desalination technique based on applying a cell voltage between two oppositely placed porous electrodes sandwiching a spacer channel that transports the water to be desalinated. In MCDI, ion-exchange membranes are positioned in front of each porous

  11. FPGA Based Low Power ROM Design Using Capacitance Scaling

    DEFF Research Database (Denmark)

    Bansal, Meenakshi; Bansal, Neha; Saini, Rishita;

    2015-01-01

    An ideal capacitor will not dissipate any power, but a real capacitor wil l have some power dissipation. In this work, we are going to design capacitance scaling based low power ROM design. In order to test the compatibility of this ROM design with latest i7 Processor, we are operating this ROM...

  12. Capacitive technology for energy extraction from chemical potential differences

    NARCIS (Netherlands)

    Bastos Sales, B.

    2013-01-01

    This thesis introduces the principle of Capacitive energy extraction based on Donnan Potential (CDP) to exploit salinity gradients. It also shows the fundamental characterization and improvements of CDP. An alternative application of this technology aimed at thermal gradients was tested.  

  13. Effect of parasitic capacitance on dc SQUID performance

    International Nuclear Information System (INIS)

    This paper reports on the effect of parasitic capacitance Cp on dc SQUID characteristics and noise performance studied using a test structure consisting of 11 identical SQUID washers with Nb films of various widths covering the slit. The measured IV characteristics are in good agreement with simulations based on a simple lumped circuit model

  14. An integrated energy-efficient capacitive sensor digital interface circuit

    KAUST Repository

    Omran, Hesham

    2014-06-19

    In this paper, we propose an energy-efficient 13-bit capacitive sensor interface circuit. The proposed design fully relies on successive approximation algorithm, which eliminates the need for oversampling and digital decimation filtering, and thus low-power consumption is achieved. The proposed architecture employs a charge amplifier stage to acheive parasitic insensitive operation and fine absolute resolution. Moreover, the output code is not affected by offset voltages or charge injection. The successive approximation algorithm is implemented in the capacitance-domain using a coarse-fine programmable capacitor array, which allows digitizing wide capacitance range in compact area. Analysis for the maximum achievable resolution due to mismatch is provided. The proposed design is insensitive to any reference voltage or current which translates to low temperature sensitivity. The operation of a prototype fabricated in a standard CMOS technology is experimentally verified using both on-chip and off-chip capacitive sensors. Compared to similar prior work, the fabricated prototype achieves and excellent energy efficiency of 34 pJ/step.

  15. High bandwidth on-chip capacitive tuning of microtoroid resonators.

    Science.gov (United States)

    Baker, Christopher G; Bekker, Christiaan; McAuslan, David L; Sheridan, Eoin; Bowen, Warwick P

    2016-09-01

    We report on the design, fabrication and characterization of silica microtoroid based cavity opto-electromechanical systems (COEMS). Electrodes patterned onto the microtoroid resonators allow for rapid capacitive tuning of the optical whispering gallery mode resonances while maintaining their ultrahigh quality factor, enabling applications such as efficient radio to optical frequency conversion, optical routing and switching applications. PMID:27607646

  16. A High-Precision Capacitive Sensor System for Displacement Measurements

    NARCIS (Netherlands)

    Yang, R.

    2015-01-01

    This thesis presents the theory, design and qualification of a precision capacitive sensor system for displacement measurement that require high resolution, high precision and simultaneously, low power consumption. The challenge to achieve the required performance has been taken care at both mechani

  17. Reconfigurable Prototyping Microfluidic Platform for DEP Manipulation and Capacitive Sensing.

    Science.gov (United States)

    Miled, Amine; Auclair, Benoit; Srasra, Anis; Sawan, Mohamad

    2015-04-01

    In this paper, we present a new rapid prototyping platform dedicated to dielectrophoretic microfluidic manipulation and capacitive cell sensing. The proposed platform offers a reconfigurable design including 4 independently programmable output channels to be distributed across 64 electrodes. Although its range of frequency covers up to 3.4 MHz, signal amplitude accuracy ( +/-10%) was demonstrated for frequencies up to 1 MHz and channel-to-channel phase shift setting was stable up to 1.5 MHz. A test of maximum resistive load showed a 10% attenuation of a 12 V peak-to-peak signal with a 22 Ω load. The platform has an advanced capacitive sensor to measure capacitance variation between in-channel electrodes with a sampling frequency up to 5 kH z. Experimental data of capacitive sensor showed a sensitivity of 100 fF. The sensor can be extended to 4 parallel measurements with lower frequency. We also present a new assembly technique for reusable microfluidic chip based on anisotropic adhesive conductive film, epoxy and PDMS. The proposed platform provides a wide range of control signals depending on the type of manipulation as sine, rectangular or square wave. The frequency range is extendible up to 3.4 MHz, in addition to a programmable phase shift circuit with a minimum phase step of 3.6(°) for each signal. PMID:25879968

  18. Capacitive pressure sensor in post-processing on LTCC substrates

    NARCIS (Netherlands)

    Meijerink, M.G.H.; Nieuwkoop, E.; Veninga, E.P.; Meuwissen, M.H.H.; Tijdink, M.W.W.J.

    2005-01-01

    A capacitive pressure sensor was realized by means of a post-processing step on a low temperature co-fired ceramics (LTCC) substrate. The new sensor fabrication technology allows for integration of the sensor with interface circuitry and possibly also wireless transmission circuits on LTCC substrate

  19. Capacitive sensor probe to assess frying oil degradation

    Directory of Open Access Journals (Sweden)

    Alfadhl Yahya Khaled

    2015-09-01

    Full Text Available The repeated usage of frying oil has been proven hazardous due to the degradation process by chemical reactions that lead to changes in the quality of the oil. Currently, the degree of frying oil degradation is indicated by the percentage of its total polar compounds (TPC. In this study, a capacitive sensor was designed to assess frying oil degradation at several heating time intervals by measuring changes on its electrical capacitance. The sensor was designed using interdigitated electrode structure. A total of 30 samples of 130 ml palm oil were heated at 180 °C up to 30 h. For each one hour interval, one sample was moved out from the laboratory oven. The electrical capacitance, total polar compound (TPC and viscosity of the samples were measured for analysis. Preliminary results demonstrated significant correlation between oil electrical capacitance with TPC and viscosity with R2 ranged from 0.83 to 0.90. The designed sensor has good potential for simple and inexpensive way of determining frying oil quality.

  20. Correlated Coulomb drag in capacitively coupled quantum-dot structures

    DEFF Research Database (Denmark)

    Kaasbjerg, Kristen; Jauho, Antti-Pekka

    2016-01-01

    We study theoretically Coulomb drag in capacitively coupled quantum dots (CQDs) -- a biasdriven dot coupled to an unbiased dot where transport is due to Coulomb mediated energy transfer drag. To this end, we introduce a master-equation approach which accounts for higher-order tunneling (cotunneli...

  1. A Low-Cost Universal Integrated Interface for Capacitive Sensors

    NARCIS (Netherlands)

    Heidary, A.

    2010-01-01

    This thesis reports the results of research on features, options and limitations of low-cost, high-performance, universal integrated interface for capacitive sensors. It concerns development-driven research, where the objectives of the research focus upon possible realization and application of the

  2. MEMS Very Low Capacitive Pressure Sensor Based on CMOS Process

    International Nuclear Information System (INIS)

    The CMOS standard process with advantage of simplicity in term of design and fabrication process compatibility has triggered the invention of MEMS very low capacitive pressure sensor, (MEMS-VLCPS). In this paper the development of the whole structure of MEMS-VLCPS that involves the design simulation, fabrication and testing is described. The novelty of this work lies in the design and fabrication process itself. A new technique in fabricating thin sensor membrane of VLCPS using seal-off techniques is also presented. The physical structure of the membrane consists of parallel plate. The top plate acts as the flexible electrode membrane and the bottom plate acts as the counter electrode membrane. Both plates are separated by absolute air gap with fixed end at both sides. As a result, it was found that the etch-opening holes of 0.8 μm and seal-off thickness of 4000 Angstrom gave the optimum sealing surface. The percentage of relative capacitance change is extracted from the reference capacitance measurement. Air gap thickness of 0.3 μm gives the highest percentage of PRCC showing that smaller air gap thickness provides a larger change in capacitance value. (author)

  3. Mesoporous carbon microspheres with high capacitive performances for supercapacitors

    International Nuclear Information System (INIS)

    Highlights: • Small mesopores-enriched porous carbon microspheres were easily synthesized. • Small mesopores offer high ion-accessible surface area and facilitated ion diffusion. • The porous carbon exhibited a high specific capacitance and a good power property. - Abstract: Novel small-mesopores-enriched porous carbon microspheres have been synthesized from carbonaceous polysaccharide microspheres, by using the associated lithium acetate treating and heat treating strategies. X-ray diffraction, scanning electron microscope, transmission electron microscopy and nitrogen adsorption-desorption techniques have been employed to investigate the as-prepared samples. The analysis results indicate that the porous carbon microspheres has a high specific surface area of 1163 m2 g−1 and a satisfactory small mesoporous texture (2∼5 nm), with the mean pore size of 3.24 nm and the pore volume ratio of 2∼5 nm pores up to 92%. The capacitive performances of the samples in 6 mol L−1 KOH aqueous electrolyte, have been tested by cyclic voltammetry, electrochemical impedance spectroscopy and charge-discharge techniques. A specific capacitance of 171.5 F/g is obtained for the porous carbon microspheres via charge-discharge at a current density of 1000 mA/g. It also displayed a very high cycle stability of 97.8%, compared with the initial capacitance, after 1000 cycles at the high current density of 1000 mA/g

  4. High bandwidth on-chip capacitive tuning of microtoroid resonators

    CERN Document Server

    Baker, Christopher G; McAuslan, David L; Sheridan, Eoin; Bowen, Warwick P

    2016-01-01

    We report on the design, fabrication and characterization of silica microtoroid based cavity opto-electromechanical systems (COEMS). Electrodes patterned onto the microtoroid resonators allow for rapid capacitive tuning of the optical whispering gallery mode resonances while maintaining their ultrahigh quality factor, enabling applications such as efficient radio to optical frequency conversion, optical routing and switching applications.

  5. Miniature electrometer preamplifier effectively compensates for input capacitance

    Science.gov (United States)

    Burrous, C. N.; Deboo, G. J.

    1966-01-01

    Negative capacitance preamplifier using a dual MOS /Metal Oxide Silicon/ transistor in conjunction with bipolar transistors is used with intracellular microelectrodes in recording bioelectric potentials. Applications would include use as a pickup plate video amplifier in storage tube tests and for pH and ionization chamber measurements.

  6. Energy consumption and constant current operation in membrane capacitive deionization

    NARCIS (Netherlands)

    Zhao, R.; Biesheuvel, P.M.; Wal, van der A.F.

    2012-01-01

    Membrane capacitive deionization (MCDI) is a water desalination technology based on applying a cell voltage between two oppositely placed porous electrodes sandwiching a spacer channel that transports the water to be desalinated. In the salt removal step, ions are adsorbed at the carbon–water interf

  7. Stray capacitances in the watt balance operation: electrostatic forces

    DEFF Research Database (Denmark)

    Quagliotti, Danilo; Mana, G.

    2014-01-01

    In a watt balance, stray capacitances exist between the coil and the magnet. Since the electric current flowing in the coil creates a difference in electric potentials between the coil and magnet, their electrostatic interactions must be taken into account. This paper reports the results of a...

  8. A Micro Dynamically Tuned Gyroscope with Adjustable Static Capacitance

    Directory of Open Access Journals (Sweden)

    Lun Kong

    2013-02-01

    Full Text Available This paper presents a novel micro dynamically tuned gyroscope (MDTG with adjustable static capacitance. First, the principle of MDTG is theoretically analyzed. Next, some simulations under the optimized structure parameters are given as a reference for the mask design of the rotor wafer and electrode plates. As two key components, the process flows of the rotor wafer and electrode plates are described in detail. All the scanning electron microscopy (SEM photos show that the fabrication process is effective and optimized. Then, an assembly model is designed for the static capacitance adjustable MDTG, whose static capacitance can be changed by rotating the lower electrode plate support and substituting gasket rings of different thicknesses. Thus, the scale factor is easily changeable. Afterwards, the digitalized closed-loop measurement circuit is simulated. The discrete correction and decoupling modules are designed to make the closed-loop stable and cross-coupling effect small. The dual axis closed-loop system bandwidths can reach more than 60 Hz and the dual axis scale factors are completely symmetrical. All the simulation results demonstrate the proposed fabrication of the MDTG can meet the application requirements. Finally, the paper presents the test results of static and dynamic capacitance values which are consistent with the simulation values.

  9. Capacitive deionization on-chip; desalination of small volume samples

    NARCIS (Netherlands)

    Roelofs, S.H.; Rooijen, van M.; Kim, B.; Han, J.; Berg, van den A.; Odijk, M.

    2014-01-01

    This abstract demonstrates, for the first time, capacitive deionization (CDI) inside a chip measured using impedance spectroscopy [1]. CDI is a promising technique for the pre-treatment of extremely small volume protein samples (nL range) before analysis by mass spectroscopy [2]. The results include

  10. Probing 2D black phosphorus by quantum capacitance measurements.

    Science.gov (United States)

    Kuiri, Manabendra; Kumar, Chandan; Chakraborty, Biswanath; Gupta, Satyendra N; Naik, Mit H; Jain, Manish; Sood, A K; Das, Anindya

    2015-12-01

    Two-dimensional materials and their heterostructures have emerged as a new class of materials, not only for fundamental physics but also for electronic and optoelectronic applications. Black phosphorus (BP) is a relatively new addition to this class of materials. Its strong in-plane anisotropy makes BP a unique material for making conceptually new types of electronic devices. However, the global density of states (DOS) of BP in device geometry has not been measured experimentally. Here, we report the quantum capacitance measurements together with the conductance measurements on an hBN-protected few-layer BP (∼six layers) in a dual-gated field effect transistor (FET) geometry. The measured DOS from our quantum capacitance is compared with density functional theory (DFT). Our results reveal that the transport gap for quantum capacitance is smaller than that in conductance measurements due to the presence of localized states near the band edge. The presence of localized states is confirmed by the variable range hopping seen in our temperature dependence conductivity. A large asymmetry is observed between the electron and hole side. This asymmetric nature is attributed to the anisotropic band dispersion of BP. Our measurements establish the uniqueness of quantum capacitance in probing the localized states near the band edge, hitherto not seen in conductance measurements. PMID:26559656

  11. Resistance identification and rational process design in Capacitive Deionization

    NARCIS (Netherlands)

    Dijkstra, J.E.; Zhao, R.; Biesheuvel, P.M.; Wal, van der A.

    2016-01-01

    Capacitive Deionization (CDI) is an electrochemical method for water desalination employing porous carbon electrodes. To enhance the performance of CDI, identification of electronic and ionic resistances in the CDI cell is important. In this work, we outline a method to identify these resistances. W

  12. Quantum superposition of charge states on capacitively coupled superconducting islands

    NARCIS (Netherlands)

    Heij, C.P.; Dixon, D.C.; Wal, C.H. van der; Hadley, P.; Mooij, J.E.

    2003-01-01

    We investigate the ground state properties of a system containing two superconducting islands coupled capacitively by a wire. The ground state is a macroscopic superposition of charge states, even though the islands cannot exchange charge carriers. The ground state of the system is probed by measuri

  13. Des Ogle's old stump

    International Nuclear Information System (INIS)

    On 17 October 1997 Sylvia Bryan of RD4 Kaitaia wrote to 'Dear Somebody-Everybody' at the Anthropology Department, University of Auckland, urging further examination of an adzed stump found by Des Ogle during planting out of the Te Aupouri forest. The authors have since sought out relevant information and present it here for the interests of our readers. (author). 7 refs., 1 fig

  14. Ontologie des Kunstwerks

    OpenAIRE

    Hubig, Christoph

    1984-01-01

    Die Ontologie beansprucht, die Wissenschaft vom Sein der Dinge oder - nimmt man die Zeitkomponente hinzu - der Ereignisse zu sein. Als eine solche philosophische Disziplin grenzt sie sich einerseits ab von den Einzelwissenschaften, die das Dasein der Dinge zu erfassen suchen, also die Dinge in ihrer jeweiligen uns zugänglichen Tatsächlichkeit; andererseits ist die Ontologie jedoch auch nicht eine Wissenschaft vom Wesen der Dinge: Wesensbestimmungen nämlich sind Bestimmungen des Seins als Geda...

  15. Plus que des engrais

    OpenAIRE

    Fuchs, Jacques G.

    2008-01-01

    COMPOSTS ET RÉSIDUS DE MÉTHANISATION Compte tenu de l'augmentation du prix des engrais minéraux, il se manifeste un intérêt croissant pour les composts et les résidus de méthanisation. En plus de leur effet nutritif, ces produits de substitution stimulent l'activité biologique dans le sol et peuvent exercer une action favorable sur le pH.

  16. A la recherche des hybrides

    OpenAIRE

    DUPONT, Ariane

    2013-01-01

    Mon programme de recherche se développe autour de deux axes : 1/ l’analyse de la demande de transport des voyageurs et de ses impacts environnementaux pour permettre la définition et l’évaluation des politiques de transport durable, et 2/ une analyse des méthodes et des outils économétriques, notamment ceux définis et développés par Ragnar Frisch. Ces deux champs semblent si disjoints que l’on pourrait croire à une schizophrénie développée suite à un basculement de parcou...

  17. Dictionnaire des risques psychosociaux

    CERN Document Server

    Zawieja, Philippe

    2014-01-01

    Stress, suicide, harcèlement, épuisement professionnel, workaholism... Au-delà de la souffrance qu'elles désignent, ces notions souvent récentes constituent une approche inédite, et demandent à mieux être comprises, dans leur ensemble et isolément. C'est tout l'enjeu de ce dictionnaire, pionnier en son genre. Le lecteur y trouvera représentés, avec les 314 entrées (rédigées par 251 contributeurs) qui le composent, tous les champs disciplinaires s'intéressant à la souffrance au travail : psychologie du travail et des organisations, psychologie sociale et psychosociologie, psychanalyse, psychopathologie et psychiatrie, ergonomie, sociologie du travail et des organisations, médecine du travail, droit du travail et de la sécurité sociale, sciences de gestion, philosophie... Y sont détaillés les principaux concepts, notions, approches, méthodes, théories, outils, études, etc., ayant cours dans l'étude des risques psychosociaux, mais aussi certaines professions emblématiques (infirmières,...

  18. Méthode d'évaluation semi-quantitative des caséinophosphopeptides dans le fromage

    OpenAIRE

    Dupas, Coralie; Adt, Isabelle; Cottaz, Amandine; Boutrou, Rachel; Mollé, Daniel; Jardin, Julien; Jouvet, Thierry; Degraeve, Pascal

    2009-01-01

    Les caséinophosphopeptides (CPP) sont des fragments phosphorylés de caséine présents dans les produits laitiers qui possèdent la capacité de se lier au calcium. S'il existe différentes méthodes pour les extraire à partir de fromage, aucune ne permet cependant leur évaluation quantitative. La méthode proposée ici pour l'évaluation semi-quantitative des CPPs a été adaptée à partir de travaux publiés précédemment par une autre équipe ; elle a été appliquée au Beaufort. Après extraction des pepti...

  19. Étude multi-échelles des courbes de désaturation capillaire par tomographie RX

    OpenAIRE

    Oughanem, Rezki

    2013-01-01

    L'injection de tensioactifs est une méthode très appliquée dans le domaine de la récupération améliorée des hydrocarbures. Cependant, son efficacité repose sur la capacité de ces agents chimiques à mobiliser l'huile résiduelle en diminuant la tension interfaciale entre l'huile et l'eau. Des modèles à l'échelle du réservoir calculent l'efficacité de la récupération d'huile résiduelle par injection de solutions contenant des tensioactifs. Les mécanismes physiques pris en compte dans les modélis...

  20. Deep-Hole Inner Diameter Measuring System Based on Non-contact Capacitance Sensor

    Institute of Scientific and Technical Information of China (English)

    于永新; 张恒; 王宗超; 常以哲

    2010-01-01

    A precise aperture measuring system of small deep holes with capacitance sensors is presented. Based on the working principle of non-contact capacitance sensors, influence of the edge effect of gauge head is studied, and one capacitance sensor for measuring the aperture of the small blind holes or through holes is introduced. The system is composed of one positioning device, one aperture measuring capacitance sensor, one measuring circuit, and software. This system employs visual CCD and two-dimensional mic...

  1. Characterization and Modeling of Subfemtofarad Nanowire Capacitance Using the CBCM Technique

    OpenAIRE

    Zhao, Hui; Kim, Raseong; Paul, Abhijeet; Luisier, Mathieu; Klimeck, Gerhard; Ma, Fa-Jun; Rustagi, Subhash; Ganesh S. Samudra; Singh, Navab; Lo, Guo-Qiang; Kwong, Dim-Lee

    2009-01-01

    The experimental characterization of gate capacitance in nanoscale devices is challenging. We report an application of the charge-based capacitance measurement (CBCM) technique to measure the gate capacitance of a single-channel nanowire transistor. The measurement results are validated by 3-D electrostatic computations for parasitic estimation and 2-D self-consistent sp(3)s*d5 tight-binding computations for intrinsic gate capacitance calculations. The device simulation domains were construct...

  2. Characterization and Modeling of Subfemotofarad Nanowire Capacitance Using the CBCM Technique

    OpenAIRE

    Zhao, Hui; Kim, Raseong; Paul, Abhijeet; Luisier, Mathieu; Klimeck, Gerhard; Ma, Fa-Jun; Rustagi, Subhash C.; Ganesh S. Samudra; Singh, Navab; Lo, Guo-Qiang; Kwong, Dim-Lee

    2009-01-01

    The experimental characterization of gate capacitance in nanoscale devices is challenging. We report an application of the charge-based capacitance measurement (CBCM) technique to measure the gate capacitance of a single-channel nanowire transistor. The measurement results are validated by 3-D electrostatic computations for parasitic estimation and 2-D self-consistent sp3s∗d5 tight-binding computations for intrinsic gate capacitance calculations. The device simulation domains were constructed...

  3. On the capacitance of crystalline silicon solar cells in steady state

    OpenAIRE

    BARRO, FABE IDRISSA; SANE, Moustapha; ZOUMA, BERNARD

    2015-01-01

    In this work, an analytical approach is presented for modeling the capacitance of crystalline silicon solar cells. Based on a one-dimensional modeling of the cell, the excess minority carrier density, the photovoltage, and the capacitance are calculated. The motivation of this work are two-fold: to show base doping density and illumination effects on the capacitance of silicon solar cells, and to propose a determination technique for both dark capacitance and base doping density f...

  4. Theory of volumetric capacitance of an electric double-layer supercapacitor

    OpenAIRE

    Skinner, Brian; Chen, Tianran; Loth, M. S.; Shklovskii, B. I.

    2011-01-01

    Electric double layer supercapacitors are a fast-rising class of high-power energy storage devices based on porous electrodes immersed in a concentrated electrolyte or ionic liquid. As of yet there is no microscopic theory to describe their surprisingly large capacitance per unit volume (volumetric capacitance) of ~ 100 F/cm^3, nor is there a good understanding of the fundamental limits on volumetric capacitance. In this paper we present a non-mean-field theory of the volumetric capacitance o...

  5. Electrode Polarization in Glassy Electrolytes: Large Interfacial Capacitance Values and Indication for Pseudocapacitive Charge Storage

    OpenAIRE

    Mariappan, C. R.; Heins, T. P.; Roling, B.

    2009-01-01

    We study the electrode polarization behaviour of different Na-Ca-phosphosilicate glasses by measuring the differential capacitance between blocking Pt electrodes. At low applied dc bias voltages, we detect a linear capacitance regime with interfacial capacitance values considerably larger than expected from double layer theories and also considerably larger than found for ionic liquids with similar ion concentrations. With increasing bias voltages, the differential capacitance of interfacial ...

  6. Corrections to the Capacitance between Two Electrodes Due to the Presence of Quantum Confined System

    OpenAIRE

    Macucci, M.; K. Hess

    1998-01-01

    We have studied the capacitance between two parallel plates enclosing a quantum confined system and its dependence on the applied voltage. The concepts of capacitance and differential capacitance are discussed together with their applicability to systems characterized by single.electron tunneling. We determine the tunneling thresholds by means of a formalism based on the minimization of the system free energy and we retrieve, as a special case, Luryi's quantum capacitance formula. We apply ou...

  7. An Annular Mechanical Temperature Compensation Structure for Gas-Sealed Capacitive Pressure Sensor

    OpenAIRE

    Kohei Higuchi; Yonggang Jiang; Kazusuke Maenaka; Hidekuni Takao; Xiuchun Hao

    2012-01-01

    A novel gas-sealed capacitive pressure sensor with a temperature compensation structure is reported. The pressure sensor is sealed by Au-Au diffusion bonding under a nitrogen ambient with a pressure of 100 kPa and integrated with a platinum resistor-based temperature sensor for human activity monitoring applications. The capacitance-pressure and capacitance-temperature characteristics of the gas-sealed capacitive pressure sensor without temperature compensation structure are calculated. It is...

  8. Molecular dynamics simulation study on capacitive nano-accelerometers based on telescoping carbon nanotubes

    International Nuclear Information System (INIS)

    We investigated the characteristics of a capacitive nano-accelerometer based on a telescoping carbon nanotube by means of classical molecular dynamics simulations. The position of the telescoping nanotube was controlled by an externally applied force, and feedback sensing was based on the capacitance change. The capacitance variations, which were almost linearly proportional to the applied acceleration, were monitored within an error tolerance

  9. Simplified Capacitance Monitoring for the Determination of Campylobacter spp. Growth Rates

    Science.gov (United States)

    Capacitance monitoring is commonly used as an efficient means to measure growth curves of bacterial pathogens. However, the use of capacitance monitoring with Campylobacter spp. was previously determined difficult due to the complexity of the required media. We investigated capacitance monitoring ...

  10. Die Klassifizierung des Blutdrucks

    Directory of Open Access Journals (Sweden)

    Skrabal F

    2004-01-01

    Full Text Available Während der systolische Blutdruck in der Bevölkerung mit zunehmendem Lebensalter in jedem Dezennium weiter ansteigt, beginnt der diastolische Blutdruck ab dem 50. Lebensjahr für jede systolische Blutdruckstratifizierung als Ausdruck einer zunehmenden Gefäßschädigung wieder zu sinken. Deswegen muß der Blutdruck ausschließlich nach dem systolischen Blutdruck klassifiziert werden. Die Häufigkeitsverteilung des systolischen und diastolischen Blutdrucks innerhalb der Bevölkerung entspricht einer Gauss'schen Glockenkurve. Jede Unterteilung in normotensiv und hypertensiv entspricht deshalb einer völlig willkürlichen Dichotomisierung. Je niedriger der Blutdruck, desto geringer die mechanische Belastung der Blutgefäße und desto geringer auch die mechanisch induzierten Gefäßschäden. Das war der Grund für die zuletzt vom "7th JNC on Prevention, Detection and Treatment of Hypertension" des NIH, USA, vorgenommene Klassifizierung des Blutdrucks in normal (kleiner als 120 mmHg systolisch, prähypertensiv (120-140 mmHg und Hypertonie-Stadium I (140-160 mmHg systolisch und Hypertonie-Stadium II ( 160 mmHg systolisch. Damit muß leider die nahezu gesamte gesunde österreichische Bevölkerung, die nach bisheriger Klassifikation noch keinen Hochdruck aufweist, als prähypertensiv klassifiziert werden. Ein wirklicher Informationsgewinn (der ja mit der Klassifikation bezweckt wird ist meiner Meinung nach damit nicht mehr gegeben. Die Österreichische Hochdruckliga schlägt eine zusätzliche Klassifikation des Blutdrucks nach dem „Pressure Load“ vor, welches aus einer statistisch aussagekräftigen Zahl von Selbstmessungen leicht zu errechnen ist. Jedes Pressure Load von mehr als 20 % (mehr als 20 % der selbst gemessenen Blutdruckwerte 135/85 mmHg entspricht einer Hypertonie, die je nach Höhe der Blutdruckwerte entweder mit Änderungen des Lebensstils oder mit antihypertensiver Medikation zu bekämpfen ist.

  11. « Mais où sont les neiges d’antan ? ». Questionnement des auteurs italiens et français aux XVIe et XVIIe siècles devant la rareté des traces des premières femmes écrivains

    Directory of Open Access Journals (Sweden)

    Anne Debrosse

    2011-07-01

    Full Text Available Pendant la Querelle des Femmes en Italie et en France (XVIe-XVIIe s., la controverse portait souvent sur la capacité des femmes dans les domaines réputés masculins. La rareté des textes des autrices antiques en était l’un des ressorts. Pour les ennemis des femmes, elle traduisait leur incapacité intrinsèque à bien écrire. Pour leurs « champions », elle était le fruit de la méchanceté des hommes ou, curieusement, de la supériorité des femmes, argumentations que nous analysons dans notre article.During the Querelle des Femmes in 16th and 17th centuries in France and Italy, one of the major topics was often women’s ability to perform fields marked as masculine. As few texts remaine from Ancient women writers, women’s ennemies took it for granted that they basically couldn’t become great writers. For their “champions”, on the contrary, it underlined men’s meanness or, curiously, women’s superiority. This paper analyses these two different types of gender-centered explanations.Durante la Querella de las mujeres en los siglos XVI y XVII en Francia y en Italia, la controversia versaba sobre la capacidad de las mujeres en ámbitos considerados como masculinos. La escasez de textos de autoras antiguas era uno de los argumentos. Para los enemigos de las mujeres, traducía su incapacidad para escribir bien. Para sus defensores, era el resultado de la mezquindad de los hombres o, curiosamente, de la superioridad de las mujeres, argumentos que analizamos en nuestro artículo.

  12. Le tarif d’achat photovoltaïque comme outil d’innovation territoriale : l’exemple des Fermes de Figeac

    OpenAIRE

    Cointe, Béatrice

    2016-01-01

    Entre 2008 et 2012, la coopérative des Fermes de Figeac a installé un parc photovoltaïque mutualisé dispersé sur une centaine de toitures. Ce projet visait à capter l’opportunité des tarifs d’achat lorsqu’ils étaient à leur plus haut niveau, mais également à la mutualiser et à la territorialiser. Pour analyser la constitution d’une capacité entrepreneuriale et financière adaptée au tarif, mais capable de le transformer, cet article se penche sur l’articulation entre investissement, mutualisat...

  13. Etude experimentale des excitations topologiques de l'effet Hall quantique a nu = 1 dans les heterostructures semiconductrices a double puits quantique

    Science.gov (United States)

    Charlebois, Serge

    De nombreux travaux theoriques et experimentaux ont ete publies sur les excitations topologiques de gaz electroniques bidimensionnels (GE2D), appellees skyrmions, dans le regime de l'effet Hall quantique a remplissage unitaire. On attend des excitations semblables appellees bimerons dans les systemes formes de deux GE2D couples. Contrairement au cas des GE2D simples, aucune experience n'a, a notre connaissance, presente la mesure d'une propriete specifique aux bimerons. Nous presentons dans cette these des travaux experimentaux ayant pour objectif l'etude d'excitations topologiques dans les heterostructures a double puits quantique. Une manifestation attendue (les bimerons est la presence d'une anisotropie dans la conductivite a travers une constriction. Nous avons concu un dispositif original a point de contact a trois grilles non-coplanaires. Ce dispositif a trois grilles a la particularite de permettre la creation d'une constriction etroite dans le double GE2D tout en permettant l'equilibrage de la densite electronique entre les deux puits dans l'etroit canal de conduction. Nous avons fabrique ce dispositif de taille submicronique par electrolithographie sur des heterostructures a double puits. Les dispositifs ainsi fabriques ont ete etudies a basse temperature (0.3K) et ont montre un fonctionnement conforme aux attentes. Les travaux n'ont pas permis de mettre en evidence une anisotropie de transport revelatrice de l'existence de bimerons. Cette these est a notre connaissance la premiere etude experimentale visant la realisation de l'experience d'anisotropie de transport et est ainsi une contribution significative a l'avancement des connaissances dans ce domaine. Les travaux theoriques que nous presentons ont permis de montrer l'effet des excitations topologiques sur la capacite grille-GE2D du systeme. Ces travaux ouvrent la voie de la detection des bimerons par l'intermediaire de la mesure de la capacite grille-GE2D ou encore de la susceptibilite electrique du

  14. Rôle des régulateurs post-transcriptionnels Pumilio 1 et Pumilio 2 dans les cellules souches hématopoïétiques murines

    OpenAIRE

    Michelet, Fabio

    2013-01-01

    Les propriétés centrales des cellules souches sont la pluripotence et la capacité d'auto-renouvellement. Les cellules souches hématopoïétiques (CSHs) sont dotées de ces caractéristiques qui leur permettent de générer toutes les cellules du compartiment hématopoïétique, tout en maintenant en parallèle leur compartiment. Nous menons des approches visant à amplifier ex vivo les CSHs en les activant par HOXB4 exogène (CSHs humaines) ou via la signalisation Notch/DLL-4 (CSHs murines). Or deux anal...

  15. Des insectes et des hommes (Nord du Cameroun)

    OpenAIRE

    Seignobos, Christian

    2015-01-01

    Cet article est le prolongement de celui publié par le JATBA 38 de 1996 : « Les Mofu et leurs insectes », de C. Seignobos, J.-Ph. Deguine et P.H. Aberlenc. Il répond à une interrogation : la focalisation de la société mofu sur son entomofaune se retrouve-t-elle chez ses voisines des monts Mandara ? Et qu’en est-il du regard sur les insectes des populations des plaines ?Le biais des insectes dans l’étude des sociétés est toujours révélateur de leur histoire et de leur organisation sociale et p...

  16. Comprehensive characterization of interface and oxide states in metal/oxide/semiconductor capacitors by pulsed mode capacitance and differential isothermal capacitance spectroscopy

    OpenAIRE

    Muret, Pierre

    2014-01-01

    In metal/insulator/semi-conductor structures, capacitance-voltage characteristics and capacitance or voltage transients can be measured in different conditions, which are described and implemented. Each method contains information about charges which are accommodated, captured or emitted by energy levels or bands at interface and inside the oxide. Pulsed capacitance measurements and differential isothermal procedures are analysed and performed. Calibration of the energy scale from the interfa...

  17. Capacités de récupération d'une population de gorilles de plaine de l'Ouest (Gorilla gorilla gorilla) suite à un effondrement démographique engendré par une épidémie à virus Ebola

    OpenAIRE

    Genton, Céline

    2012-01-01

    Cette étude se place dans le contexte des maladies infectieuses émergentes maintenant reconnues comme une menace majeure de la biodiversité. Engendrant un taux de mortalité atteignant 95 %, les épidémies à virus Ebola ayant affecté les populations de gorilles de plaine de l'Ouest (Gorilla gorilla gorilla) conduisirent à la classification de ce taxon comme " En danger critique d'extinction ". Cette étude s'intéresse aux capacités de récupération de ses populations. Grâce à des données uniques ...

  18. Pas seulement des «lemmings». Les relations entre les organisations et leur environnement dans le néo-institutionnalisme sociologique

    OpenAIRE

    Bernard Leca

    2006-01-01

    (VF)Développé pour expliquer l’isomorphisme interorganisationnel, le néo-institutionnalisme sociologique insiste initialement sur l’influence de l’environnement social et culturel sur les organisations, prenant peu en compte leur capacité d’action stratégique. Des évolutions récentes et moins connues de ce courant réintroduisent au cœur du néo-institutionnalisme les capacités stratégiques des agents et notamment leurs aptitudes à modifier les «règles du jeu» qui régissent l’environnement, pro...

  19. An Analytical Model for Fringing Capacitance in Double gate Hetero Tunnel FET and Analysis of effect of Traps and Oxide charges on Fringing Capacitance

    Directory of Open Access Journals (Sweden)

    Brinda Bhowmick

    2012-02-01

    Full Text Available In this paper fringe capacitance of double hetero gate Tunnel FET has been studied. The physical model for fringe capacitance is derived considering source gate overlap and gate drain non overlap. Inerface trap charge and oxide charges are also introduced under positive bias stress and hot carrier stress and their effect on fringe capacitance is also studied. The fringe capacitance is significant speed limiter in Double gate technology. The model is tested by comparing with simulation results obtained from Sentauras TCAD simulations.

  20. Digitalisierung des Kulturellen Erbes (Europas)

    OpenAIRE

    Gruber, Marion

    2011-01-01

    Gruber, M. R. (2011, 13 December). Digitalisierung des Kulturellen Erbes (Europas). Guest lecture at the IPMZ - Institute of Mass Communication and Media Research, Devision Media Change & Innovation, University of Zurich, Switzerland. (http://www.slideshare.net/em3rg3/digitalisierung-des-kulturellen-erbes-europa)

  1. Digitalisierung des Kulturellen Erbes (Europas)

    NARCIS (Netherlands)

    Gruber, Marion

    2011-01-01

    Gruber, M. R. (2011, 13 December). Digitalisierung des Kulturellen Erbes (Europas). Guest lecture at the IPMZ - Institute of Mass Communication and Media Research, Devision Media Change & Innovation, University of Zurich, Switzerland. (http://www.slideshare.net/em3rg3/digitalisierung-des-kulturelle

  2. MEMS Capacitive Pressure Sensors: A Review on Recent Development and Prospective

    Directory of Open Access Journals (Sweden)

    Eswaran P

    2013-06-01

    Full Text Available Recently MEMS Capacitive Pressure Sensor gains more advantage over micromachined piezoresistive pressure sensor due to high sensitivity, low power consumption, free from temperature effects, IC compatibility, etc,. The spectrum of capacitive pressure sensor application is increasing, hence it is essential to review the path of technological development and further prospective of micromachinedcapacitive pressure sensor. This paper focuses on the review of various types of capacitive pressure sensor principle, MEMS materials used in fabrication, procedures adopted in microfabrication for silicon and polymer material diaphragm, bonding and packaging techniques used. Selected result on capacitive sensitivity, effect of temperature on capacitive sensitivity was also presented. Finally, the development of smart sensor was discussed.

  3. Study of materials for the design of MEMS capacitive pressure sensor

    Science.gov (United States)

    Jindal, Sumit Kumar; Raghuwanshi, Sanjeev Kumar

    2016-04-01

    Highly sensitive MEMS capacitive pressure sensor is nowadays used for many different applications such as aerospace, automobile, Bio-MEMS etc. This paper deals with study and comparison of different types of materials that can be used in design of MEMS capacitive pressure sensor. Initially principle and design of basic MEMS capacitive pressure sensor is explained. In the next section the properties of different materials is elaborated. The centre deflection of the diaphragm is calculated using COMSOL Multiphysics and Capacitance is calculated using MATLAB simulation. From the capacitance calculated sensitivity of the materials can be interpreted. The analysis is carried out for a pressure range of 0 to 0.1 MPa.

  4. Mécanique des fluides

    CERN Document Server

    Cengel, Y A

    2016-01-01

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

  5. Liste des auteurs

    OpenAIRE

    2015-01-01

    Yves Tanguy, Université de Nantes, France Jacques Verger, Université Paris Sorbonne, Paris, France Jéremy duQuesnay Adams, Dept of History, SMU, USA Étienne Wolff, Université de Paris X­Nanterre, France Claire Nouvet, Emory University, USA François Lejeune, Université de Nantes, France Wim Verbaal, Université de Gand, Belgique Thomas N. Bisson, Harvard University, USA Jean Jolivet, École Pratique des Hautes Études, Paris, France Guy Lobrichon, Collège de France, France Constant J. Mews, Sc...

  6. Table des tableaux

    OpenAIRE

    2013-01-01

    1. Ordonnances à caractère financier adoptées sous Charles VIII 22 2. Personnel de la Chambre en 1492 85 3. Personnel de la Chambre en 1498 86 4. Personnel de la Chambre en 1514 86 5. Personnel de la Chambre en 1515 87 6. Personnel de la Chambre en 1524 88 7. Personnel de la Chambre en 1540 89 8. Personnel de la Chambre en 1547 90 9. Revenu de la Bretagne 108 10. Prélèvement directs 109 11. Parties ordinaires prélevées sur le revenu de Bretagne en 1535 110 12. Revenants-bons des recettes ordi...

  7. Manifeste des digital humanities

    OpenAIRE

    2012-01-01

    Introduction au manifeste L’utilisation de l’informatique en sciences humaines et sociales est pratiquée depuis maintenant plus de quarante ans. Plusieurs voies ont été explorées au cours de cette déjà assez longue histoire. La plus récente, qui prend le nom de digital humanities, désigne une intégration intense et à plu­sieurs niveaux des technologies numériques dans tous les processus de recherche, depuis la collecte de données jusqu’à la publication. Dans ce nouveau contexte d’un travail n...

  8. Liste des figures

    OpenAIRE

    2013-01-01

    Illustrations dans le texte Villes italiennes 1. Plan de Naples en 1560. Source : Bibliothèque nationale de France, cliché BNF …………………… 8 2. Plan du nouveau tracé des rioni de Rome (1744). Source : Bernardino Bernardini, Descrizione del nuovo ripartimento de’ Rioni di Roma fatto pet ordine di N.S. Papa Benedetto XIV. Con la Notizia di quanto in essi si contiene, Rome, per Generoso Salomone, 1744, p. 225. Bibliothèque nationale de France, cliché BNF ……. 26 3. Détail du plan du quartiere de S. ...

  9. Des ignames au riz

    OpenAIRE

    Ivanoff, Jacques

    2003-01-01

    L'igname a toujours été une nourriture importante pour les populations littorales et nomades du monde insulindien. Cependant, avec l'installation du héros civilisateur Gaman le Malais chez le peuple de la reine Sibian, le riz va devenir la composante essentielle des repas moken. En intégrant Gaman en son sein, la société moken va devoir répondre au double défi posé par la menace de la riziculture et de l'islam. En donnant femme à Gaman, en adoptant le nomadisme pour échapper à l'islam ...

  10. Universos (Des) conocidos

    OpenAIRE

    Gutiérrez Vásquez, Martín Kanek

    2014-01-01

    Universos (Des) conocidos es un proyecto de creación plástica. Tiene como objetivo la construcción de imágenes poéticas sobre el universo, las estrellas y nuestra relación como humanos con ellas. El proceso consintió en conformar durante 2 años un archivo de objetos recolectados de la calle, para después construir esculturas que fueron quemadas en un acto ritual. Al final se presentó los restos quemados de las esculturas, a la par se presentaban videos del registro junto con 4 afiches q...

  11. Der Preis des Reiches

    OpenAIRE

    Wilker, Julia

    2015-01-01

    Wie schon die meisten hellenistischen Könige zeichneten sich auch die römischen Klientelherrscher in der Zeit des frühen Prinzipat durch Stitungen und Spenden an Städte, Gemeinden und Heiligtümer außerhalb ihrer eigenen Herrschatsgebiete aus. Jedoch zeigt eine genauere Analyse der Stitungsempfänger, der Verteilung und Art ihrer Gaben, dass es bei der euergetischen Praxis der Klientelherrscher nicht um eine einfach Imitation oder Fortsetzung überlebter monarchischer Traditionen ging, sond...

  12. Chauffage solaire des gaz

    OpenAIRE

    Genneviève, F.; Olalde, G.; Daguenet, M.

    1980-01-01

    Les auteurs calculent numériquement les répartitions de température d'un gaz circulant en convection forcée à travers une cavité poreuse soumise à un rayonnement solaire concentré. Ils étudient l'influence des divers paramètres du système et comparent ses performances énergétiques à celles obtenues par le dispositif étudié par G. Olalde, M. Daguenet et J. L. Peube.

  13. Bibliographie des expositions

    Directory of Open Access Journals (Sweden)

    Eléonore Fournié

    2009-09-01

    Full Text Available Autun, 1985Le Livre au siècle des Rolin, sous la dir. de Marie-Josette Perrat, Autun, Bibliothèque municipale, 8 juin-28 septembre 1985. Baltimore, 2002The Book of Kings: Art, War and the Morgan Library's Medieval Picture Bible, Baltimore, Walter Art Museum, 27 octobre-29 décembre 2002, Baltimore, Third Millennium Publishing, 2002. Bruxelles, 1937Les manuscrits à miniatures, du viiie siècle à 1350, Bruxelles, Bibliothèque royale de Belgique, 1937. Bruxelles, 1940La Bibliothèque de Marguerite ...

  14. Nanoscale capacitance imaging with attofarad resolution using ac current sensing atomic force microscopy

    International Nuclear Information System (INIS)

    Nanoscale capacitance imaging with attofarad resolution (∼1 aF) of a nano-structured oxide thin film, using ac current sensing atomic force microscopy, is reported. Capacitance images are shown to follow the topographic profile of the oxide closely, with nanometre vertical resolution. A comparison between experimental data and theoretical models shows that the capacitance variations observed in the measurements can be mainly associated with the capacitance probed by the tip apex and not with positional changes of stray capacitance contributions. Capacitance versus distance measurements further support this conclusion. The application of this technique to the characterization of samples with non-voltage-dependent capacitance, such as very thin dielectric films, self-assembled monolayers and biological membranes, can provide new insight into the dielectric properties at the nanoscale

  15. A system for measuring thermal activation energy levels in silicon by thermally stimulated capacitance

    Science.gov (United States)

    Cockrum, R. H.

    1982-01-01

    One method being used to determine energy level(s) and electrical activity of impurities in silicon is described. The method is called capacitance transient spectroscopy (CTS). It can be classified into three basic categories: the thermally stimulated capacitance method, the voltage-stimulated capacitance method, and the light-stimulated capacitance method; the first two categories are discussed. From the total change in capacitance and the time constant of the capacitance response, emission rates, energy levels, and trap concentrations can be determined. A major advantage of using CTS is its ability to detect the presence of electrically active impurities that are invisible to other techniques, such as Zeeman effect atomic absorption, and the ability to detect more than one electrically active impurity in a sample. Examples of detection of majority and minority carrier traps from gold donor and acceptor centers in silicon using the capacitance transient spectrometer are given to illustrate the method and its sensitivity.

  16. Composition change and capacitance properties of ruthenium oxide thin film

    Institute of Scientific and Technical Information of China (English)

    刘泓; 甘卫平; 刘仲武; 郑峰

    2015-01-01

    RuO2·nH2O film was deposited on tantalum foils by electrodeposition and heat treatment using RuCl3·3H2O as precursor. Surface morphology, composition change and cyclic voltammetry from precursor to amorphous and crystalline RuO2·nH2O films were studied by X-ray diffractometer, Fourier transformation infrared spectrometer, differential thermal analyzer, scanning electron microscope and electrochemical analyzer, respectively. The results show that the precursor was transformed gradually from amorphous to crystalline phase with temperature. When heat treated at 300 °C for 2 h, RuO2·nH2O electrode surface gains mass of 2.5 mg/cm2 with specific capacitance of 782 F/g. Besides, it is found that the specific capacitance of the film decreased by roughly 20%with voltage scan rate increasing from 5 to 250 mV/s.

  17. Numerical model for RF capacitive regional deep hyperthermia

    International Nuclear Information System (INIS)

    Full text: Regional hyperthermia is widely used as an adjuvant therapy for advanced pelvic tumors. Heat delivery to deep seated tumors, however, is much challenging: since regional hyperthermia techniques apply energy in an unfocused manner, energy is delivered to both tumor and normal tissues. Under such conditions, selective heating of tumor is only possible when heat dissipation by blood flow in normal tissues is much greater than in tumor tissue. In the RF (8 and 13.56 MHz) capacitive heating devices the patient is placed between two electrodes connected to a power generator. In the case of circular electrodes, a diameter of more than 1.5 times the space between both electrodes is needed to achieve deep uniform heating inside the human body. To smoothly attach the electrodes to the body surface, the metal plates of the electrodes are covered with flexible water pads, in which temperature-controlled water (5-10 oC) flows, so that excessive heating of the skin and subcutaneous fat can be reduced. Nevertheless, the overheating of fat layers remains one of the main disadvantages of RF capacitive heating and clinical experience suggests that this technique is not appropriate for patients with fat layers thicker than approximately 1.5-2 cm. Another considerable limitation of capacitive heating is that the distribution of current flow and power density in an electrically inhomogeneous body can lead to undesirable hot spots in normal tissues. Besides the deep SAR distribution is mainly influenced by the shielding effect of the pelvic bone that causes insufficient energy deposition in the central area with the tumor. Today it is clear that the evaluation of a capacitive hyperthermia device with an homogeneous agar phantom leads to overly optimistic results. Hence the use of numerical models to simulate the propagation and power deposition of electromagnetic waves and the temperature distribution in an anatomic patient model is fundamental for systematic research and

  18. Microbial desalination cell with capacitive adsorption for ion migration control.

    Science.gov (United States)

    Forrestal, Casey; Xu, Pei; Jenkins, Peter E; Ren, Zhiyong

    2012-09-01

    A new microbial desalination cell with capacitive adsorption capability (cMDC) was developed to solve the ion migration problem facing current MDC systems. Traditional MDCs remove salts by transferring ions to the anode and cathode chambers, which may prohibit wastewater beneficial reuse due to increased salinity. The cMDC uses adsorptive activated carbon cloth (ACC) as the electrodes and utilizes the formed capacitive double layers for electrochemical ion adsorption. The cMDC removed an average of 69.4% of the salt from the desalination chamber through electrode adsorption during one batch cycle, and it did not add salts to the anode or cathode chamber. It was estimated that 61-82.2mg of total dissolved solids (TDS) was adsorbed to 1g of ACC electrode. The cMDC provides a new approach for salt management, organic removal, and energy production. Further studies will be conducted to optimize reactor configuration and achieve in situ electrode regeneration. PMID:22784594

  19. A High Temperature Capacitive Humidity Sensor Based on Mesoporous Silica

    Directory of Open Access Journals (Sweden)

    Michael Tiemann

    2011-03-01

    Full Text Available Capacitive sensors are the most commonly used devices for the detection of humidity because they are inexpensive and the detection mechanism is very specific for humidity. However, especially for industrial processes, there is a lack of dielectrics that are stable at high temperature (>200 °C and under harsh conditions. We present a capacitive sensor based on mesoporous silica as the dielectric in a simple sensor design based on pressed silica pellets. Investigation of the structural stability of the porous silica under simulated operating conditions as well as the influence of the pellet production will be shown. Impedance measurements demonstrate the utility of the sensor at both low (90 °C and high (up to 210 °C operating temperatures.

  20. Capacitance Variation of Electrolyte-Gated Bilayer Graphene Based Transistors

    Directory of Open Access Journals (Sweden)

    Hediyeh Karimi

    2013-01-01

    Full Text Available Quantum capacitance of electrolyte-gated bilayer graphene field-effect transistors is investigated in this paper. Bilayer graphene has received huge attention due to the fact that an energy gap could be opened by chemical doping or by applying external perpendicular electric field. So, this extraordinary property can be exploited to use bilayer graphene as a channel in electrolyte-gated field-effect transistors. The quantum capacitance of bi-layer graphene with an equivalent circuit is presented, and also based on the analytical model a numerical solution is reported. We begin by modeling the DOS, followed by carrier concentration as a function V in degenerate and nondegenerate regimes. To further confirm this viewpoint, the presented analytical model is compared with experimental data, and acceptable agreement is reported.

  1. Cable Capacitance Attack against the KLJN Secure Key Exchange

    Directory of Open Access Journals (Sweden)

    Hsien-Pu Chen

    2015-10-01

    Full Text Available The security of the Kirchhoff-law-Johnson-(like-noise (KLJN key exchange system is based on the fluctuation-dissipation theorem of classical statistical physics. Similarly to quantum key distribution, in practical situations, due to the non-idealities of the building elements, there is a small information leak, which can be mitigated by privacy amplification or other techniques so that unconditional (information-theoretic security is preserved. In this paper, the industrial cable and circuit simulator LTSPICE is used to validate the information leak due to one of the non-idealities in KLJN, the parasitic (cable capacitance. Simulation results show that privacy amplification and/or capacitor killer (capacitance compensation arrangements can effectively eliminate the leak.

  2. Studies in the capacitance properties of diaminoalkane-intercalated graphene

    International Nuclear Information System (INIS)

    A series of diaminoalkane-intercalated graphenes (DIGs) are successfully synthesized by intercalating graphite oxide with diaminoalkanes, followed by a reduction process using hydrazine as a reductant at room temperature. The as-prepared intercalated graphite oxides (DIGOs) and their reduced products are characterized using a variety of approaches such as X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy and elemental analysis. Electrochemical tests show that the specific capacitances of DIGOs and DIGs decrease with the increase of the interlayer distance, and that the DIGs possess larger capacitance than DIGOs after hydrazine reduction. The ion diffusion in the DIGOs/DIGs follows pseudo-second-order kinetics and is dominated mainly by their pore sizes

  3. Integrated vertical parallel-plate capacitive humidity sensor

    International Nuclear Information System (INIS)

    A high sensitivity capacitive chemical vapor sensing topology, a vertical parallel-plate sensor, was successfully integrated with CMOS testing electronics. The sensor was fabricated by etching a sacrificial aluminum layer in the CMOS stack and filling the resulting cavity with polyimide. The measured humidity response is a 0.31% change in capacitance per percent relative humidity. The temperature sensitivity of the sensor, an important specification for a sensor exposed to a variety of environmental conditions, is 0.19% °C−1. The rising and falling response time constants for a change in relative humidity are 70 and 85 s, respectively. The minimum detectable signal is 0.06 fF, corresponding to a limit of detection of 0.0023% relative humidity

  4. High resolution capacitance detection circuit for rotor micro-gyroscope

    Directory of Open Access Journals (Sweden)

    Ming-Yuan Ren

    2014-03-01

    Full Text Available Conventional methods for rotor position detection of micro-gyroscopes include common exciting electrodes (single frequency and common sensing electrodes (frequency multiplex, but they have encountered some problems. So we present a high resolution and low noise pick-off circuit for micro-gyroscopes which utilizes the time multiplex method. The detecting circuit adopts a continuous-time current sensing circuit for capacitance measurement, and its noise analysis of the charge amplifier is introduced. The equivalent output noise power spectral density of phase-sensitive demodulation is 120 nV/Hz1/2. Tests revealed that the whole circuitry has a relative capacitance resolution of 1 × 10−8.

  5. Capacitance Probe for Fluid Flow and Volume Measurements

    Science.gov (United States)

    Arndt, G. Dickey (Inventor); Nguyen, Thanh X. (Inventor); Carl, James R. (Inventor)

    1997-01-01

    Method and apparatus for making measurements on fluids are disclosed, including the use of a capacitive probe for measuring the flow volume of a material within a flow stream. The capacitance probe has at least two elongate electrodes and, in a specific embodiment of the invention, has three parallel elongate electrodes with the center electrode being an extension of the center conductor of a co-axial cable. A conductance probe is also provided to provide more accurate flow volume data in response to conductivity of the material within the flow stream. A preferred embodiment of the present invention provides for a gas flow stream through a micro-gravity environment that allows for monitoring a flow volume of a fluid sample, such as a urine sample, that is entrained within the gas flow stream.

  6. Concentration Fluctuations and Capacitive Response in Dense Ionic Solutions

    CERN Document Server

    Uralcan, Betul; Debenedetti, Pablo G; Limmer, David T

    2016-01-01

    We use molecular dynamics simulations in a constant potential ensemble to study the effects of solution composition on the electrochemical response of a double layer capacitor. We find that the capacitance first increases with ion concentration following its expected ideal solution behavior but decreases upon approaching a pure ionic liquid. The non-monotonic behavior of the capacitance as a function of ion concentration results from the competition between the independent motion of solvated ions in the dilute regime and solvation fluctuations in the concentrated regime. When charge fluctuations induced by correlated ion-solvent fluctuations are large relative to those induced by the pure ionic liquid, such non-monotonic behavior is expected to be generic.

  7. Capacitated Vehicle Routing with Non-Uniform Speeds

    CERN Document Server

    Gortz, Inge Li; Nagarajan, Viswanath; Ravi, R

    2010-01-01

    The capacitated vehicle routing problem (CVRP) involves distributing (identical) items from a depot to a set of demand locations, using a single capacitated vehicle. We study a generalization of this problem to the setting of multiple vehicles having non-uniform speeds (that we call Heterogenous CVRP), and present a constant-factor approximation algorithm. The technical heart of our result lies in achieving a constant approximation to the following TSP variant (called Heterogenous TSP). Given a metric denoting distances between vertices, a depot r containing k vehicles with possibly different speeds, the goal is to find a tour for each vehicle (starting and ending at r), so that every vertex is covered in some tour and the maximum completion time is minimized. This problem is precisely Heterogenous CVRP when vehicles are uncapacitated. The presence of non-uniform speeds introduces difficulties for employing standard tour-splitting techniques. In order to get a better understanding of this technique in our con...

  8. LE COLMATAGE MINÉRAL DU LIT DES COURS D’EAU : REVUE BIBLIOGRAPHIQUE DES MÉCANISMES ET DES CONSÉQUENCES SUR LES HABITATS ET LES PEUPLEMENTS DE MACROINVERTÉBRÉS.

    Directory of Open Access Journals (Sweden)

    GAYRAUD S.

    2002-04-01

    Full Text Available Le développement des activités humaines a conduit dans de nombreuses régions à une augmentation du transfert de sédiments fins vers les cours d’eau, multipliant les phénomènes de colmatage. Le colmatage fait référence au dépôt de sédiments organiques ou minéraux et à leur infiltration dans le benthos et l’hyporhéos. Dans cet article de synthèse, le colmatage par les sédiments minéraux est présenté du point de vue de ses mécanismes et de sa variabilité spatio-temporelle dans un schéma d’organisation global du cours d’eau. Le colmatage entraîne une modification des habitats benthique et interstitiel, ainsi que des échanges d’eau et de matières entre la surface et l’hyporhéos. Il affecte la structure du peuplement d’invertébrés en modifiant la structure et la stabilité du substrat, la disponibilité des ressources trophiques et de l’oxygène, ainsi que de la pression de prédation. Les conséquences à court terme sont une augmentation de la dérive et une réduction de l’abondance totale des organismes. Sur le long terme le colmatage affecte la survie, le développement et la croissance des invertébrés ainsi que la biomasse et la productivité du peuplement. Les espèces sensibles adaptées aux substrats grossiers disparaissent au profit des espèces adaptées aux sédiments fins. Les conséquences sur la faune hyporhéique sont peu connues mais l’importance de l’hyporhéos dans le fonctionnement du cours d’eau suggère que son altération pourrait avoir des conséquences importantes en terme de capacité de résilience du peuplement face aux perturbations.

  9. A High-Precision Capacitive Sensor System for Displacement Measurements

    OpenAIRE

    Yang, R.

    2015-01-01

    This thesis presents the theory, design and qualification of a precision capacitive sensor system for displacement measurement that require high resolution, high precision and simultaneously, low power consumption. The challenge to achieve the required performance has been taken care at both mechanical domain (sensor head) and electronic domain (interface circuit). To overcome the design challenges, several precision techniques and new concepts have been proposed both at system level and circ...

  10. Advances in Modern Capacitive ECG Systems for Continuous Cardiovascular Monitoring

    OpenAIRE

    A. Schommartz; Eilebrecht, B.; Wartzek, T.; Walter, M.; Leonhardt, S

    2011-01-01

    The technique of capacitive electrocardiography (cECG) is very promising in a flexible manner. Already integrated into several everyday objects, the single lead cECG system has shown that easy-to-use measurements of electrocardiograms are possible without difficult preparation of the patients. Multi-channel cECG systems enable the extraction of ECG signals even in the presence of coupled interferences, due to the additional redundant information. Thus, this paper presents challenges for elect...

  11. Enhanced Capacitive Characteristics of Activated Carbon by Secondary Activation

    Institute of Scientific and Technical Information of China (English)

    YANG Hui; LU Tian-hong; Yoshio Masaki

    2004-01-01

    The effect of the improvement of commercial activated carbon(AC) on its specific capacitance and high rate capability of double layer(dl) charging/discharging process has been studied. The improvement of AC was carried out via a secondary activation under steam in the presence of catalyst NiCl2, and the suitable condition was found to be a heat treatment at about 875 ℃ for 1 h. Under those conditions, the discharge specific capacitance of the improved AC increases up to 53.67 F/g, showing an increase of about 25% as compared with that of as-received AC. The good rectangular-shaped voltammograms and A.C. impedance spectra prove that the high rate capability of the capacitor made of the improved AC is enhanced significantly. The capacitance resistance(RC) time constant of the capacitor containing the improved AC is 1.74 s, which is much lower than that of the one containing as-received AC(an RC value of 4. 73 s). It is noted that both kinds of AC samples show a similar specific surface area and pore size distribution, but some changes have taken place in the carbon surface groups, especially a decrease in the concentration of surface carbonyl groups after the improvement, which have been verified by means of X-photoelectron spectroscopy. Accordingly, it is suggested that the decrease in the concentration of surface carbonyl groups for the improved AC is beneficial to the organic electrolyte ion penetrating into the pores, thus leading to the increase in both the specific capacitance and high rate capability of the supercapacitor.

  12. High volumetric capacitance near insulator-metal percolation transition

    OpenAIRE

    Efros, A. L.

    2011-01-01

    A new type of a capacitor with a very high volumetric capacitance is proposed. It is based upon the known phenomenon of a sharp increase of the dielectric constant of the metal-insulator composite in the vicinity of the percolation threshold, but still on the insulator side. The optimization suggests that the metallic particles should be of nanoscale and that the distance between planar electrodes should be somewhat larger than the correlation length of the percolation theory and 10 to 20 tim...

  13. Computation of Capacitance for MEMS Comb-Drive Structures

    Institute of Scientific and Technical Information of China (English)

    LI Ming-hui; GAO Shi-qiao; LIU Hai-peng; LIANG Xin-jian

    2009-01-01

    According to the characteristics of comb-drive structures,the electrical potential field is analyzed;the model based on corner capacitor is presented and solved with the capacitance characteristic formula of nonlinear capacitor.Compared with the results of finite element method simulation,the model based on corner capacitor is more accurate than the models based on infinite parallel plate capacitor and parallel plate capacitor with edge effects,

  14. Capacitive Extensometer Particularly Suited for Measuring in Vivo Bone Strain

    Science.gov (United States)

    Perusek, Gail P. (Inventor)

    2000-01-01

    The present invention provides for in vivo measurements of the principal strain magnitudes and directions, and maximum shear strain that occurs in a material, such as human bone, when it is loaded (or subjected to a load). In one embodiment the invention includes a capacitive delta extensometer arranged with six sensors in a three piece configuration, with each sensor of each pair spaced apart from each other by 120 degrees.

  15. Capacitance-based damage detection sensing for aerospace structural composites

    Science.gov (United States)

    Bahrami, P.; Yamamoto, N.; Chen, Y.; Manohara, H.

    2014-04-01

    Damage detection technology needs improvement for aerospace engineering application because detection within complex composite structures is difficult yet critical to avoid catastrophic failure. Damage detection is challenging in aerospace structures because not all the damage detection technology can cover the various defect types (delamination, fiber fracture, matrix crack etc.), or conditions (visibility, crack length size, etc.). These defect states are expected to become even more complex with future introduction of novel composites including nano-/microparticle reinforcement. Currently, non-destructive evaluation (NDE) methods with X-ray, ultrasound, or eddy current have good resolutions (analysis currently requires excessive wiring and complex signal analysis. Here, we present a capacitance sensor-based, structural defect detection technology with improved sensing capability. Thin dielectric polymer layer is integrated as part of the structure; the defect in the structure directly alters the sensing layer's capacitance, allowing full-coverage sensing capability independent of defect size, orientation or location. In this work, capacitance-based sensing capability was experimentally demonstrated with a 2D sensing layer consisting of a dielectric layer sandwiched by electrodes. These sensing layers were applied on substrate surfaces. Surface indentation damage (~1mm diameter) and its location were detected through measured capacitance changes: 1 to 250 % depending on the substrates. The damage detection sensors are light weight, and they can be conformably coated and can be part of the composite structure. Therefore it is suitable for aerospace structures such as cryogenic tanks and rocket fairings for example. The sensors can also be operating in space and harsh environment such as high temperature and vacuum.

  16. Encapsulation of Capacitive Micromachined Ultrasonic Transducers Using Viscoelastic Polymer

    OpenAIRE

    Lin, Der-Song; Zhuang, Xuefeng; Wong, Serena H.; Kupnik, Mario; Khuri-Yakub, Butrus Thomas

    2010-01-01

    The packaging of a medical imaging or therapeutic ultrasound transducer should provide protective insulation while maintaining high performance. For a capacitive micromachined ultrasonic transducer (CMUT), an ideal encapsulation coating would therefore require a limited and predictable change on the static operation point and the dynamic performance, while insulating the high dc and dc actuation voltages from the environment. To fulfill these requirements, viscoelastic materials, such as poly...

  17. Discontinuity of capacitance at the onset of surface superconductivity

    Czech Academy of Sciences Publication Activity Database

    Morawetz, K.; Lipavský, Pavel; Mareš, Jiří J.

    2009-01-01

    Roč. 11, č. 2 (2009), 023032/1-023032/8. ISSN 1367-2630 R&D Projects: GA AV ČR IAA1010404; GA ČR(CZ) GA202/06/0040; GA AV ČR IAA100100712 Institutional research plan: CEZ:AV0Z10100521 Keywords : capacitance * surface supraconductivity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.312, year: 2009

  18. Kelvin probe’s stray capacitance and noise simulation

    OpenAIRE

    Danyluk, S.; Dubanevich, A. V.; O. K. Gusev; A. I. Svistun; Tyavlovsky, A. K.; K. L. Tyavlovsky; R. I. Vorobey; A. L. Zharin

    2014-01-01

    Stray capacitance effects and their influence on Kelvin probe’s performance are studied using mathematical and computer simulation. Presence of metal surface, even grounded, in vicinity of vibrating Kelvin probe produces the additional stray signal of complex harmonic character. Mean value and amplitude of this stray signal depends mostly on the ratio of stray and measurement vibrating capacitors gaps d1/d0. The developed model can be used for theoretical analysis of Kelvin probe configuratio...

  19. Effect of electrode thickness variation on operation of capacitive deionization

    OpenAIRE

    Porada, S.; Bryjak, M.; Wal, van der, A.C.; Biesheuvel, P. M.

    2012-01-01

    In capacitive deionization (CDI) water is desalinated by applying an electrical field between two porous electrodes placed on either side of a spacer channel that transports the aqueous solution. In this work we investigate the equilibrium salt adsorption and the dynamic development of the effluent salt concentration in time, both as function of spacer and electrode thicknesses. The electrode thickness will be varied in a symmetric manner (doubling both electrodes) and in an asymmetric manner...

  20. Novel nitrogen doped graphene sponge with ultrahigh capacitive deionization performance

    OpenAIRE

    Xu, Xingtao; Sun, Zhuo; Chua, Daniel H. C.; Pan, Likun

    2015-01-01

    As water shortage has become a serious global problem, capacitive deionization (CDI) with high energy efficiency and low cost, is considered as a promising desalination technique to solve this problem. To date, CDI electrodes are mainly made up of porous carbon materials. However, the electrosorption performance obtained by now still cannot meet the demand of practical application. Therefore, a rationally designed structure of electrode materials has been an urgent need for CDI application. H...