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

    NASA Astrophysics Data System (ADS)

    Lepage, Martin

    1998-12-01

    Cette these est presentee a la Faculte de medecine de l'Universite de Sherbrooke en vue de l'obtention du grade de Ph.D. en Radiobiologie. Elle contient des resultats experimentaux enregistres avec un spectrometre d'electrons a haute resolution. Ces resultats portent sur la formation de resonances electroniques en phase condensee et de differents canaux pour leur decroissance. En premier lieu, nous presentons des mesures d'excitations vibrationnelles de l'oxygene dilue en matrice d'argon pour des energies des electrons incidents de 1 a 20 eV. Les resultats suggerent que le temps de vie des resonances de l'oxygene est modifie par la densite d'etats d'electrons dans la bande de conduction de l'argon. Nous presentons aussi des spectres de pertes d'energie d'electrons des molecules de tetrahydrofuranne (THF) et d'acetone. Dans les deux cas, la position en energie des pertes associees aux excitations vibrationnelles est en excellent accord avec les resultats trouves dans la litterature. Les fonctions d'excitation de ces modes revelent la presence de plusieurs nouvelles resonances electroniques. Nous comparons les resonances du THF et celles de la molecule de cyclopentane en phase gazeuse. Nous proposons une origine commune aux resonances ce qui implique qu'elles ne sont pas necessairement attribuees a l'excitation des electrons non-apparies de l'oxygene du THF. Nous proposons une nouvelle methode basee sur la spectroscopie par pertes d'energie des electrons pour detecter la production de fragments neutres qui demeurent a l'interieur d'un film mince condense a basse temperature. Cette methode se base sur la detection des excitations electroniques du produit neutre. Nous presentons des resultats de la production de CO dans un film de methanol. Le taux de production de CO en fonction de l'energie incidente des electrons est calibre en termes d'une section efficace totale de diffusion des electrons. Les resultats indiquent une augmentation lineaire du taux de production de

  2. Operateurs et engins de calcul en virgule flottante et leur application a la simulation en temps reel sur FPGA

    NASA Astrophysics Data System (ADS)

    Ould Bachir, Tarek

    The real-time simulation of electrical networks gained a vivid industrial interest during recent years, motivated by the substantial development cost reduction that such a prototyping approach can offer. Real-time simulation allows the progressive inclusion of real hardware during its development, allowing its testing under realistic conditions. However, CPU-based simulations suffer from certain limitations such as the difficulty to reach time-steps of a few microsecond, an important challenge brought by modern power converters. Hence, industrial practitioners adopted the FPGA as a platform of choice for the implementation of calculation engines dedicated to the rapid real-time simulation of electrical networks. The reconfigurable technology broke the 5 kHz switching frequency barrier that is characteristic of CPU-based simulations. Moreover, FPGA-based real-time simulation offers many advantages, including the reduced latency of the simulation loop that is obtained thanks to a direct access to sensors and actuators. The fixed-point format is paradigmatic to FPGA-based digital signal processing. However, the format imposes a time penalty in the development process since the designer has to asses the required precision for all model variables. This fact brought an import research effort on the use of the floating-point format for the simulation of electrical networks. One of the main challenges in the use of the floating-point format are the long latencies required by the elementary arithmetic operators, particularly when an adder is used as an accumulator, an important building bloc for the implementation of integration rules such as the trapezoidal method. Hence, single-cycle floating-point accumulation forms the core of this research work. Our results help building such operators as accumulators, multiply-accumulators (MACs), and dot-product (DP) operators. These operators play a key role in the implementation of the proposed calculation engines. Therefore, this

  3. Simulation numérique d'écoulement compressible dans les joints labyrinthe

    NASA Astrophysics Data System (ADS)

    Sriti, M.; Agouzoul, M.; Ouazar, D.; Micheau, P.

    1997-05-01

    The labyrinth seals are the devices used machines which serve to restrict the leakages crossing a carter (or stator) by a rotating shaft (or rotor) and to avoid the important friction to high rotation speeds. These devices, which in addition behave as shaft bearings, can modify the dynamics characteristics of the line of the shaft in which they are integrated. The present work has been carried out with the purpose of controlling better the flows within the labyrinth seals and to determine their static (leakage-pressure) and dynamic (stiffness and damping coefficients) characteristics. It's based on the development of a global numerical model, and on the integration of the obtained correlations by 3D axisymmetric computation in this model. Les joints labyrinthe sont des dispositifs utilisés dans les machines, ils servent à limiter les fuites à la traversée d'un carter (ou stator) par un arbre tournant (ou rotor) et éviter le frottement important aux vitesses de rotation élevées. Ces dispositifs, qui de plus, se comportent comme des paliers, peuvent modifier les caractéristiques dynamiques de la ligne d'arbre dans laquelle ils sont intégrés. Le travail présenté a été effectué dans le but de mieux maîtriser les écoulements dans les joints labyrinthe et de déterminer leurs caractéristiques statiques (débit-pression) et dynamiques (coefficients de raideur et d'amortissement). Il s'appuie sur le développement d'outils numériques intégrant dans les calculs globaux des résultats de calculs locaux (3D axisymétriques).

  4. Simulations numeriques d'electrophorese de particules spheriques et de courts batons dans des systemes microfluidiques

    NASA Astrophysics Data System (ADS)

    Dube, Antoine

    This thesis consists of two articles that have been submitted to peer reviewed scientific journals. In addition, three introductory chapters precede the articles: one presenting the theory behind the work described in the articles, a second one presenting the methods used for the simulations and a third one summarising results published in literature by different research groups. The first article presents the results of the optimization of the pulse sequence during the electrophoresis of spherical particles in a gel and the presentation of two new types of pulse sequences: the correlated random telegraph signal and the dichotomous signal. Our results show that the optimal ratio of pulse durations in each direction t+/t - should be around 5, compared to a value of 2 or 3 generally used in experiments. In the second article, we explore the dynamics of rod-like DNA fragments in a 2D version of the system of Han et al. [1]. Our simulations present results that contradicts the statement made by Laachi and coworkers [2] why longer chains elude faster at high field: the "torque-assisted escape", where torque turns the DNA chains in a favourable conformation. Our results show that the torque caused by the electric field is in fact in the opposite direction to the movement near the constriction zone. Following those two articles, another chapter presents some supplementary results. The exact calculation method used for the optimization of the pulse sequences was also used to simulate a rotating field in a modified version of the system of asymmetric traps presented by Torres & Slater [3]. Our results show that separation of spheres of different sizes can be made along different directions, offering the possibility of continuous separation. In the second part of this chapter, we present the results of the separation of spherical particles in the system of Han et al. We present a new idea, the pulsed signal, and a new mode of operation with this signal.

  5. Modelisation et simulation de pyrolyse de pneus usages dans des reacteurs de laboratoire et industriel

    NASA Astrophysics Data System (ADS)

    Lanteigne, Jean-Remi

    decomposition kinetics of pyrolysables. The simulation with data obtained in industrial operation showed the robustness of the model to predict with accuracy in transient regime, tires pyrolysis, with the help of model parameters obtained at laboratory scale, namely in regards of the trigger of production, the residence time of tires (dynamic production) and the amount of oil produced (cumulative yield). It is a novel way to model pyrolysis that could be extrapolated to new waste materials. The second objective of this doctoral research was to determine the evolution of specific tires specific heat during pyrolysis and the enthalpy of pyrolysis. The origin of this objective comes from a primary contradiction. With few exceptions, it is acknowledged that organic materials pyrolysis is globally an endothermic phenomenon. At the opposite, all experiments led with laboratory apparatuses such as DSC (Differential Scanning Calorimetry) showed exothermic peaks during dynamic experiments (constant heating rate). It has been confirmed by results obtained at the industrial scale, where no sign of exothermicity has been observed. The Hess Law has also confirmed these results, that globally, pyrolysis is indeed a completely endothermic process. An accurate energy balance is required to predict mass temperature during pyrolysis, this parameter being unbindable from kinetics. An advanced investigation of char first allowed demonstrating that specific heat of solids during pyrolysis decreases with increasing temperature until the weight loss peak is reached, around 400°C, and then starts increasing again. This observation, combined with the fact that the sample loses weight during pyrolysis is considered as the major cause of the apparition of an exothermic peak in laboratory scale experiments. That is, the control system of these apparatuses generates a bias and an unavoidable overheat of the samples producing this exothermic behavior. It would thus be an artifact. On the base of new data

  6. Les biofilms bactériens : leur importance en santé animale et en santé publique

    PubMed Central

    Tremblay, Yannick D.N.; Hathroubi, Skander; Jacques, Mario

    2014-01-01

    Résumé Les biofilms bactériens sont des amas structurés de cellules bactériennes enrobés d’une matrice polymérique et attachés à une surface. Le biofilm protège les bactéries et leur permet de survivre dans des conditions environnementales hostiles. Les bactéries du biofilm peuvent résister à la réponse immunitaire de l’hôte et sont beaucoup plus résistantes aux antibiotiques et aux désinfectants que les cellules bactériennes planctoniques. La capacité de former un biofilm est maintenant reconnue comme une caractéristique propre à plusieurs microorganismes. La présence de biofilms lors d’infections demande donc de nouvelles méthodes de prévention, de diagnostic et de traitement. De même, la présence de biofilms sur des surfaces retrouvées à la ferme, à l’abattoir ou à l’usine de transformation affectera l’efficacité du protocole de désinfection. De façon surprenante, la formation de biofilms chez les bactéries pathogènes des animaux et les bactéries zoonotiques est un sujet relativement peu étudié. Ce bref compte rendu a pour objectif de sensibiliser les intervenants en santé animale à l’importance des biofilms. PMID:24688172

  7. The physiological target for LeuRS translational quality control is norvaline

    PubMed Central

    Cvetesic, Nevena; Palencia, Andrés; Halasz, Ivan; Cusack, Stephen; Gruic-Sovulj, Ita

    2014-01-01

    The fidelity of protein synthesis depends on the capacity of aminoacyl-tRNA synthetases (AARSs) to couple only cognate amino acid-tRNA pairs. If amino acid selectivity is compromised, fidelity can be ensured by an inherent AARS editing activity that hydrolyses mischarged tRNAs. Here, we show that the editing activity of Escherichia coli leucyl-tRNA synthetase (EcLeuRS) is not required to prevent incorrect isoleucine incorporation. Rather, as shown by kinetic, structural and in vivo approaches, the prime biological function of LeuRS editing is to prevent mis-incorporation of the non-standard amino acid norvaline. This conclusion follows from a reassessment of the discriminatory power of LeuRS against isoleucine and the demonstration that a LeuRS editing-deficient E. coli strain grows normally in high concentrations of isoleucine but not under oxygen deprivation conditions when norvaline accumulates to substantial levels. Thus, AARS-based translational quality control is a key feature for bacterial adaptive response to oxygen deprivation. The non-essential role for editing under normal bacterial growth has important implications for the development of resistance to antimicrobial agents targeting the LeuRS editing site. PMID:24935946

  8. Solution des systemes de controle de grandes dimensions basee sur les boucles de retroaction dans la simulation des reseaux electriques

    NASA Astrophysics Data System (ADS)

    Mugombozi, Chuma Francis

    The generation of electrical energy, as well as its transportation and consumption, requires complex control systems for the regulation of power and frequency. These control systems must take into account, among others, new energy sources such as wind energy and new technologies for interconnection by high voltage DC link. These control systems must be able to monitor and achieve such regulation in accordance with the dynamics of the energy source, faults and other events which may induce transients phenomena into the power network. Such transients conditions have to be analyzed using the most accurate and detailed hence, complex models of control system. In addition, in the feasibility study phase, the calibration or the setup of equipment as well as in the operation of the power network, one may require decision aid tools for engineers. This includes, for instance, knowledge of energy dissipated into the arresters in transient analysis. These tools use simulation programs data as inputs and may require that complex functions be solved with numerical methods. These functions are part of control system in computer simulator. Moreover, the simulation evolves in a broader context of the development of digital controller, distributed and parallel high performance computing and rapid evolutions in computer (multiprocessor) technology. In such context, a continuing improvement of the control equations solver is welcomed. Control systems are modelled using ax=b simultaneous system of equations. These equations are sometimes non-linear with feedback loops and thus require iterative Newton methods, including the formation of a Jacobian matrix and ordering as well as processing by graph theory tools. The proposed approach is based on the formulation of a reduced rank Jacobian matrix. The dimension is reduced up to the count of feedback loops. With this new approach, gains in computation speed are expected without compromising its accuracy when compared to classical full

  9. Apport de l'imagerie dans le diagnostic des sacroiliites infectieuses : à propos de 19 cas

    PubMed Central

    Abid, Hanen; Chaabouni, Salim; Frikha, Faten; Toumi, Nozha; Souissi, Basma; Lahiani, Dorra; Bahloul, Zouhir; Ben Mahfoudh, Khaireddine

    2014-01-01

    Les sacro-iliites infectieuses méritent d’être mieux connues. Leur diagnostic est souvent retardé en raison d'une symptomatologie trompeuse et des diffcultés d'exploration de l'articulation sacro-iliaque. Notre travail est basé sur une étude rétrospective portant sur les cas de SII, recueillis sur une période comprise entre 1997 et 2008 dans notre centre universitaire Sfax-Tunisie. Le diagnostic de sacro-iliite était retenu en présence d'arguments cliniques et radiologiques d'atteinte sacroiliaque. Nous rapportons dix neuf cas de sacroiliites infectieuses (10 hommes et 9 femmes), avec un âge moyen de 32 ans. L'atteinte était unilatérale dans tous les cas. Les radiographies standard faites dans tous les cas ont été suggestives dans 14 cas et normales dans les autres cas. La TDM faite dans 13 cas a montré, un abcès des parties molles dans 8 cas et un séquestre osseux dans 2 cas. L'IRM réalisée dans 8 cas, a objectivé une infiltration des parties molles dans tous les cas et un abcès dans 3 cas. Le germe a été identifié dans 9 cas (3 cas de tuberculose, 3 cas de brucellose, 2 sacro-iliites à pyogène et un cas de candidose). Cette identification était faite par biopsie dans 3 cas, hémocultures dans 2 cas, prélèvement au niveau de la porte d'entrée dans 1 cas et sérodiagnostic dans 3 cas. Pour les autres cas, l'origine pyogène a été retenue sur des arguments cliniques et biologiques. L'imagerie joue un rôle primordial dans le diagnostic précoce et l'orientation étiologique d'une sacroiliite infectieuse. PMID:25120884

  10. Fluctuations quantiques et instabilites structurales dans les conducteurs a basse dimensionalite

    NASA Astrophysics Data System (ADS)

    Dikande, Alain Moise

    Un engouement particulier s'est manifeste ces dernieres annees pour les systemes electroniques fortement correles, ce en rapport avec l'immense richesse de leurs proprietes physiques. En general, ces proprietes sont induites par la presence d'interactions entre electrons qui, combinees a la structure du reseau moleculaire, donnent parfois lieu a une tres grande variete de phases electroniques et structurales ayant des incidences directes sur les phenomenes de transport dans ces materiaux. Les systemes electroniques couples a un reseau moleculaire et designes systemes electron-phonon font partie de cette classe de materiaux qui ont recemment capte l'attention, en raison notamment de la competition entre plusieurs echelles d'energie dans un environnement caracterise par une forte anisotropie cristalline et une dynamique moleculaire assez importante. En effet, en plus des proprietes electroniques et structurales particulieres la dimensionalite de ces systemes contribue egalement a leur richesse. Ainsi, une tres forte anisotropie structurale peut rehausser de facon considerable l'importance des interactions entre electrons et entre molecules constituant le reseau au point ou la physique du systeme soit regie par de tres fortes fluctuations. Ce dernier contexte est devenu un domaine a part de la physique des systemes fortement correles, a savoir celui des les phenomenes critiques quantiques . Parmi les systemes electron-phonon, on retrouve les composes inorganique KCP et organique TTF-TCNQ decouverts durant les annees 70, et explores en profondeur a cause de leur tendance vers une instabilite du type onde de densite de charge a basse temperature. Ces composes, en general designes systemes de Peierls en reference a l'instabilite de leurs structures electroniques regie par le reseau moleculaire, ont recemment connu un regain d'interet a la lumiere des nouveaux developpements dans les techniques de caracterisation des structures electroniques ainsi que sur le plan de

  11. Le risque de détresse morale dans la pratique contemporaine des soins de santé.

    PubMed

    Austin, Wendy

    2016-05-01

    Les professionnels de la santé sont des agents moraux dont la relation fiduciaire avec le public est animée par la responsabilité et la promesse de puiser dans leurs connaissances et leurs habiletés pour aider les personnes sous leurs soins. Lorsque leur capacité à tenir cette promesse est freinée ou compromise, ils risquent de souffrir de détresse morale. Le concept de détresse morale est défini et mis en contexte dans le milieu de la santé. Les contraintes et les facteurs qui en sont à l'origine sont présentés, de même que les moyens utilisés par les professionnels de la santé et les organisations de santé pour la soulager. Un changement transformateur s'impose pour vaincre la culture du silence et maintenir un système de santé où il est possible de vivre avec sa conscience. PMID:27068874

  12. La para-osteo-arthropathie neurogene dans le syndrome de guillain barre: complication rare (à propos d'un cas et revue de la littérature)

    PubMed Central

    Abid, Hatim; El Idrissi, Mohamed; Shimi, Mohamed; El Ibrahimi, Abdelhalim; El Mrini, Abdelmajid

    2015-01-01

    Les para-ostéo-arthropathies neurogènes sont des complications classiques des affections neurologiques centrales, surtout dans les contextes traumatiques. Elles surviennent principalement au voisinage des grosses articulations. Leur physiopathologie exacte reste inconnue malgré de très nombreux travaux et cas rapportés. Il semble que leur survenue au décours d'affections neurologiques périphériques soit exceptionnelle. Nous présentons le cas d'une para-ostéo-arthropathie de hanche bilatérale compliquant un syndrome de Guillain-Barré. PMID:26161168

  13. Les Elements Legers: Diffusion dans les Enveloppes Stellaires et Implications Cosmologiques

    NASA Astrophysics Data System (ADS)

    Richer, Jacques

    1992-01-01

    Les observations des abondances des elements legers (Z <= 5) sont utilisees pour estimer la quantitie de lithium qui a ete produite lors du Big -Bang, et obtenir simultanement des contraintes sur la nature des inhomogeneites qui ont pu exister durant la nucleosynthese primordiale. Nous utilisons un modele simple capable de simuler approximativement la diffusion et la retro-diffusion des neutrons a travers la matiere inhomogene durant les premieres minutes de l'expansion de l'Univers. Nous tenons compte de la difference possible entre l'abondance primordiale de Li et les abondances observees dans les plus vieilles etoiles. Cette difference (un facteur 2, environ) est estimee en construisant des modeles evolutifs d'etoiles peu massives de Population II, incluant la sedimentation gravitationnelle du lithium et de l'helium. Ces modeles montrent egalement que les ages des vieux amas stellaires sont grandement surestimes lorsqu'ils sont determines a partir de modeles stellaires n'incluant pas l'effet de la diffusion de He. Nous calculons ensuite comment evoluent les abondances de Li et Be dans des etoiles plus massives et plus jeunes, de la pre-sequence principale ou de la ZAMS, jusqu'a l'epuisement de leur hydrogene central. Les modeles incluent la sedimentation simultanee de l'helium a travers l'enveloppe. Une approche hierarchique (evolution du coeur--evolution de l'enveloppe --tri des elements traces) est utilisee pour simuler efficacement le grand nombre d'etoiles necessaire pour la construction d'isochrones. Une attention particuliere est portee aux consequences de la sedimentation de He sur l'etendue des zones convectives, et sur la diffusion de Li et Be. Les forces radiatives agissant sur ces deux elements sont calculees en detail a partir des donnees atomiques. Les etoiles simulees correspondent approximativement aux types spectraux A, F, et AmFm. Les abondances de Li et Be observees dans les etoiles jeunes de ces types sont comparees a nos predictions dans le

  14. Caracterisation de la cohesion de l'interface AMF/polymere dans une structure deformable adaptative

    NASA Astrophysics Data System (ADS)

    Fischer-Rousseau, Charles

    Les structures déformables adaptatives (SDA) sont appelées à jouer un rôle important en aéronautique entre autres. Les alliages à mémoire de forme (AMF) sont un des candidats les plus prometteurs. Beaucoup de travail reste toutefois à faire avant que ces structures rencontrent les exigences élevées reliées à leur intégration dans un contexte aéronautique. Des travaux de recherche ont montré que la résistance à la décohésion de l’interface AMF/polymère peut être un élément limitant dans la performance des SDA. Dans ce travail, l’effet sur la résistance à la décohésion de l’interface AMF/polymère de divers traitements de surface, géométries de fil et types de polymère est évalué. La géométrie du fil est modifiée par une combinaison spécifique de laminage à froid et de recuit postdéformation qui maintient les propriétés de mémoire de forme tout en permettant de réduire l’aire de la section transversale du fil. Le traitement thermomécanique le plus prometteur est proposé. Une nouvelle méthode d’évaluation de la résistance à la décohésion est développée. Plutôt que de tester les fils en arrachement et de mesurer la force maximale, les tests en contraction sont basés sur la capacité des fils d’AMF à se contracter s’ils ont été encastrés dans un état tiré et qu’ils sont chauffés par effet Joule. L’hypothèse qu’on pose est que ces tests sont une meilleure approximation des conditions rencontrées dans une SDA, où les fils se contractent plutôt qu’ils sont arrachés par une force externe à la structure. Bien qu’une décohésion partielle ait été observée pour tous les échantillons, l’aire de la surface où il y a décohésion tait plus grande pour les échantillons avec une pré-déformation plus grande. Le front de décohésion a semblé cesser de progresser après les cycles de chauffage initiaux lorsque la vitesse de chauffage était faible. Un modèle numérique simulant la

  15. Diffusion dans les liquides

    NASA Astrophysics Data System (ADS)

    Dianoux, A. J.

    2003-09-01

    Après une brève introduction qui rappelle les concepts détaillés dans le cours de M. Bée, nous présentons un aperçu de trois de nos travaux sur l'étude de la diffusion. Tout d'abord la dynamique de l'eau, dans son état normal ou surfondu, révèle la complexité apportée par le réseau de liaisons hydrogène. Ensuite l'effet du confinement sur la dynamique de l'eau sera étudié dans le cas de la membrane Nafion. Enfin la diffusion dans les phases nématique et smectique A d'un cristal liquide permet d'obtenir la valeur du potentiel qui maintient les couches dans la phase smectique.

  16. Une formation à la recherche en médecine transfusionnelle dans le monde francophone

    PubMed Central

    Shiboski, C.; Fontanet, A.; Murphy, E.L.

    2010-01-01

    Un enseignement accéléré et francophone de formation à la recherche en médecine transfusionnelle a été récemment instauré à l’Institut Pasteur de Paris, sous la codirection de membres hospitalo-universitaires de l’université de Californie San Francisco (UCSF), du Blood Systems Research Institute (BSRI) et de l’Institut national de la transfusion sanguine (INTS). Le but est de former des professionnels de la transfusion des pays en voie de développement à mener une activité de recherche dont les résultats peuvent contribuer à un renforcement de la qualité des soins transfusionnels et de la sécurité transfusionnelle dans leur pays. Le cours enseigne les méthodes de recherche clinique et épidémiologique, et leurs applications transfusionnelles potentielles. Chaque étudiant élabore au cours du stage un protocole personnel de recherche, qu’il lui sera loisible de mettre ensuite en pratique dans le centre de transfusion ou l’hôpital où il exerce. PMID:19640755

  17. Dan Johnson the mentor

    NASA Astrophysics Data System (ADS)

    McKinley, Richard

    2003-04-01

    I first met Dan Johnson in early 1975 as I was interviewing for an engineering job with Henning von Gierke's bioengineering and bionics laboratory at Wright-Patterson Air Force Base. From the very beginning Dan was always direct and forthright. Over the ensuing next 27 years my knowledge and respect of Dan constantly grew. This presentation will review Dan's technical and personal contributions while at the laboratory at Wright-Patterson Air Force Base. He was instrumental in the development of a national noise exposure criteria with the equal-energy-rule, an accurate single number hearing protector attenuation measure based on ``C-A,'' an impulse noise exposure criteria, a longitudinal study of hearing loss in children, development of noise dosimeters, and description of hearing damage risk from nonoccupational noise exposures such as disco's, bowling alleys, lawn mowers, and school buses. Dan has had a significant effect on my career. I and the many people who knew him at the laboratory miss him greatly.

  18. Vers une resolution numerique du vent dans la couche limite atmospherique a micro-echelle avec la methode de Simulation des Grandes Echelles (LES) sous OpenFOAM

    NASA Astrophysics Data System (ADS)

    Lapointe-Theriault, David

    By using advanced mathematical modeling and modern computer resources, an improvement of numerical simulations of atmospheric flow is conceivable. Further advancement in this domain would have a positive impact on the wind energy research. In order to contribute at this effort, the present work is focused on the design of a numerical microscale solver based on the Large Eddy Simulation method with law-of-the-wall through the open-source software OpenFOAM. Neutral atmospheric conditions with slip lid or capping inversion to limit the depth of the growing boundary layer, flat terrain, incompressible flow, buoyancy by Boussinesq approximation and horizontally homogeneous turbulence are the working hypotheses. To achieve this task, a readjustment of the code is proposed. New boundary conditions for velocity and potential temperature, source term dedicated to satisfy laws-of-the-wall and modification of PISO algorithm in order to stabilize the capping inversion layer have been created, among others. Due to these additions, the new designed solver is able to perform simulations with an average behavior close to the Monin-Obukhov similarity when the High Accuracy Zone is reached. It distinguishes oneself by its capability to resolve cases in the presence of thermal stratification while conserving a strong compatibility with the official distribution of OpenFOAM. Subjected to direct comparisons with other solvers from professional organizations (notably MC2), the results obtained are quite promising. It is however recommended to pursue the refinement of the code. It is believed that an even tighter velocity-pressure-temperature coupling and a correction of the linear discretization of the differential operators from velocity field in the near-wall region would further improve the quality of the simulations.

  19. Dissolution de la matiere lignocellulosique dans les liquides ioniques

    NASA Astrophysics Data System (ADS)

    Rebiere, Jeremy

    De nos jours, avec la raréfaction des ressources fossiles, le développement de procédés entrant dans le cadre de la chimie verte s'accentue. De plus, ces procédés utilisent comme ressources, des matériaux d'origine végétale, abondants et biodégradables. Au cours de ces 20 dernières années, la littérature utilisant les liquides ioniques (LI) connait une importante croissance. Ces solvants sont de plus en plus employés dans des réactions chimiques classiques. Cependant le coût de leur synthèse en fait un solvant réactionnel cher dont l'application en tant que tel dans l'industrie ne peut être raisonnablement envisagée. Ces liquides ioniques permettent la dissolution des matériaux lignocellulosiques (lignine ou cellulose) et possèdent des propriétés physico-chimiques intéressantes. Nous savons également que la dissolution de la cellulose par des procédés d'hydrolyse classique s'effectue dans des conditions dures, dues à la structure cristalline de la cellulose, (fortes concentrations en acide) qui paraissent limitées pour une utilisation à grande échelle. Il est donc nécessaire de rechercher des méthodes moins onéreuses et plus efficaces écologiquement. S'appuyant sur des recherches démontrant que la dissolution de la cellulose dans les LI, diminue la cristallinité de la cellulose, nous allons chercher à démontrer au cours de ces travaux, la possibilité d'utiliser les LI comme moyen de prétraitement pour la dissolution de la cellulose. Nous allons nous attacher à dissoudre la cellulose, et à étudier les proportions pouvant être dissoutes. Puis nous chercherons à récupérer puis à réutiliser ces LI. Enfin nous cherchons à caractériser les modifications apportées à notre cellulose. Mots Clés liquide ionique, cellulose, cristallinité, réactivité, dissolution, régénération, non-solvant, purification, prétraitement, zone amorphe.

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

    NASA Astrophysics Data System (ADS)

    Laliberte, Francis

    2010-06-01

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

  1. Enquête entomologique dans le foyer historique de trypanosomose humaine africaine de Bendjé (Gabon)

    PubMed Central

    Kohagne Tongué, L.; Gounoue Kamkuimo, R.; Mengue M’eyi, P.; Kaba, D.; Louis, F.J.; Mimpfoundi, R.

    2011-01-01

    La situation de la maladie du sommeil est très peu connue au Gabon. De nombreux foyers historiques n’ont pas été prospectés depuis plus de 15 ans. Le foyer historique de Bendjé fournit régulièrement quelques cas, dépistés passivement, qui concernent le plus souvent des pêcheurs dont il est a priori difficile de déterminer le lieu probable de contamination du fait de leur grande mobilité au cours de leurs activités. La présence des hommes infectés dans ce foyer historique pourrait favoriser son réveil s’il existe un contact étroit entre les différents éléments potentiellement présents du cycle épidémiologique (homme, vecteur, trypanosome). Afin de vérifier l’existence éventuelle d’un risque trypanosomien dans ce foyer, nous y avons mené une enquête entomologique. Des pièges ont été posés dans des biotopes fréquentés par l’homme et laissés en place pendant quatre jours. Trois espèces de glossines (Glossina palpalis palpalis, G. pallicera newsteadi et G. caliginea) ont été capturées et deux espèces de trypanosomes (Trypanosoma vivax et T. brucei s.l.) identifiées par PCR. Ces résultats suggèrent l’existence d’un cycle de transmission animal. Le contact entre les hommes et les glossines est particulièrement étroit dans tous les types de site prospectés, à l’exception de la mangrove. PMID:22091460

  2. Contraintes residuelles et leurs impacts sur l'amorcage de fissures en fatigue de flexion dans des engrenages aeronautiques durcis superficiellement par induction

    NASA Astrophysics Data System (ADS)

    Savaria, Vincent

    The optimization of gearing for aeronautical engines depends on the development of surface hardening processes to significantly improve in-service durability. Induction heating followed by quenching is a treatment increasingly used in this field to improve the fatigue resistance of critical components such as gears. In this context, this thesis studies the impact of the induction process parameters on residual stresses and the effects of those stresses on the bending fatigue of induction hardened gears. Two existing residual stress measurement techniques, X-ray diffraction and the contour method, were adapted for induction hardened components. The residual stress measurement by X-ray diffraction technique has been significantly improved in this thesis by the consideration of the variation of the X-ray elastic constant at different locations in the hardened layer and the development of a finite element based layer removal correction method that enabled more accurate in-depth residual stress measurements in all sort of geometries. The contour method is clearly a powerful tool for residual stress mapping at the core of parts but proved to be inaccurate for near-surface measurements in the case of thin hardened layers. These methods were used to show the effects of several parameters (initial hardness, preheating, final heating, tempering) with discs and aeronautical spur gears. The results indicate that two induction treatments can sometimes produce two different residual stress distributions (amplitude, severity of gradient in the transition zone, etc.) for a similar hardened depth. The bending fatigue of those gears was studied experimentally with a single tooth bending test rig and numerically with the proposition of a fatigue model for the calculation of the bending endurance limit. The calibration of the model was based on fatigue tests results on traction and torsion specimens. Bending fatigue testing results on gears confirmed the overall accuracy of the proposed model predictions. The Crossland criterion without the gradient effect gave better predictions when compared with the experimental results for that particular case. This 3D multiaxial fatigue prediction model represents a significant improvement over previous approaches by the simultaneous consideration of the so-called gradient effect, residual stresses, surface roughness and the variation of properties caused by the surface hardening. The induction treatments used in this study improved the bending fatigue resistance of spur gears by 45 to 71 % depending on the case.

  3. Les bisphosphonates dans le traitement de l’ostéoporose

    PubMed Central

    Brown, Jacques P.; Morin, Suzanne; Leslie, William; Papaioannou, Alexandra; Cheung, Angela M.; Davison, Kenneth S.; Goltzman, David; Hanley, David Arthur; Hodsman, Anthony; Josse, Robert; Jovaisas, Algis; Juby, Angela; Kaiser, Stephanie; Karaplis, Andrew; Kendler, David; Khan, Aliya; Ngui, Daniel; Olszynski, Wojciech; Ste-Marie, Louis-Georges; Adachi, Jonathan

    2014-01-01

    Résumé Objectif Exposer l’efficacité et les risques du traitement par les bisphosphonates dans la prise en charge de l’ostéoporose et décrire les patients qui seraient de bons candidats aux congés thérapeutiques. Qualité des données Une recherche dans MEDLINE (PubMed, jusqu’au 31 décembre 2012) a permis de relever les publications pertinentes pour l’inclusion. La plupart des données probantes citées sont de niveau II (tirées d’essais non randomisés, de cohorte et d’autres essais comparatifs). Message principal L’efficacité des bisphosphonates de premier recours homologués pour la prévention des fractures a été éprouvée dans le cadre d’essais cliniques randomisés et contrôlés. Cependant, l’usage clinique répandu et prolongé des bisphosphonates a donné lieu à des rapports de manifestations indésirables rares, mais graves. L’ostéonécrose maxillaire et les fractures atypiques sous-trochantériennes ou diaphysaires du fémur seraient liées à l’emploi des bisphosphonates dans le traitement de l’ostéoporose, mais ces manifestations sont extrêmement rares et lorsqu’elles surviennent, elles sont accompagnées d’autres comorbidités ou de l’emploi concomitant de médicaments. Les congés thérapeutiques ne peuvent être envisagés que chez les patients à faible risque et dans un groupe restreint de patients dont le risque de fracture est modéré après un traitement de 3 à 5 ans. Conclusion Lorsque les bisphosphonates sont prescrits à des patients dont le risque de fracture est élevé, leur effet de prévention des fractures l’emporte de loin sur leurs torts potentiels. Chez les patients qui prennent des bisphosphonates depuis 3 à 5 ans, il faut réévaluer le besoin de poursuivre le traitement.

  4. Étude des perturbations conduites et rayonnées dans une cellule de commutation

    NASA Astrophysics Data System (ADS)

    Costa, F.; Forest, F.; Puzo, A.; Rojat, G.

    1993-12-01

    The principles used in static conversion and the rise of the performances of the new switching devices contribue to increase the level of electromagnetic noises emitted by electronic converters. We have studied the way how these perturbations are created and coupled through their environment in conducted and radiated mode by a switching cell. This one can work in hard switching, zero current or voltage switching modes. We first outline the general problems of electromagnetic pollution and their metrology in converters. Then we describe the experimental environment. We analyse the mechanisms of generation of parasitic signals in a switching cell related to the electrical constraints and its switching mode. The simulated results, issued of the analytical models obtained, are confronted with the experimental ones. Then we show a method to calculate analytically the E and H near fields. It has been confirmed by experimental results. At last, we present, in a synthetic manner, the main results obtained, relative to the switching mode and the electrical constraints, using a new characterizing method. Theses results will allow the designer to incorporate the electromagnetic considerations in the conception of a converter. Les principes de commutation employés en conversion statique, l'évolution des performances statiques et dynamiques des composants, contribuent à faire des dispositifs de conversion statique de puissants générateurs de perturbations conduites et rayonnées. Nous nous sommes attachés à étudier les mécanismes de génération et de couplage des perturbations, tant en mode conduit que rayonné dans des structures à une seule cellule de commutation et fonctionnant selon les trois principaux modes de commutation : commutation forcée, à zéro de courant (ZCS), et à zéro de tension (ZVS). Après la mise en évidence de la problématique de pollution électromagnétique dans les structures et leur métrologie, nous décrivons l'environnement exp

  5. Les protéines totales et leurs fractions dans le sérum et dans les sécrétions endométriales chez la vache atteinte d'infertilité sine materia

    PubMed Central

    Lamothe, P.; Guay, P.; Ibrahim, M.; Tremblay, A.

    1972-01-01

    Total proteins, albumine and globulins of serum and uterine secretions were evaluated in two groups of 15 normal and 15 repeat breeder cows. Cyclic significant variations of all studied parameters were observed in uterine secretions of normal cows although only total proteins showed the same pattern in repeat breeder cows where individual variations were noted to be very important. Concentrations of total proteins, albumin (P<0.05) and β globulins (P<0.01) were different between the two groups during either the estrous or the postestrous period. Concentration of proteins in uterine fluid was higher in normal breeder cows during postestrus and diestrus. PMID:4259937

  6. NPPy With Dan DeVito

    NASA Video Gallery

    The NPP mission mascot NPPy was found by the NPP Ground Project Manager Dan DeVito in a place called Svalbard, located 600 miles from the North Pole. Since then, Dan and other people on the NPP pro...

  7. Les accidents du travail dans le transport urbain en commun de la ville province de Kinshasa, République Démocratique du Congo: une étude transversale descriptive

    PubMed Central

    Wangata, Jemima; Elenge, Myriam; De Brouwer, Christophe

    2014-01-01

    Introduction Le transport en commun urbain constitue un secteur où les travailleurs sont très exposés aux accidents du travail. Cette étude visait une description épidémiologique des accidents du travail dans le secteur informel du transport en commun à Kinshasa en vue d'apporter les pistes d'amélioration de la sécurité des travailleurs dans cette activité. Méthodes Un questionnaire sur les accidents du travail, administré en Décembre 2012 a permis d'explorer les tendances significatives entre les accidents et leurs circonstances, leurs facteurs associés, leurs conséquences au sein d'une population des travailleurs (n = 472) du transport en commun à Kinshasa. Résultats Durant les 12 derniers précédant l’étude 76.5% des travailleurs ont connu au moins un accident du travail, 54,8% ont connu un arrêt d'au moins 1jour. Les accidents liés à la circulation routière étaient plus important suivis des chutes. Les facteurs ayant montré des différences significatives étaient le travail sous l'influence de l'alcool et le port des équipements de protection individuelle. Les plaies (46,3%) et les contusions (39,4%) étaient les lésions les plus courantes. Les membres supérieurs (51,3%) et inférieurs (30,7%) étaient les plus atteints. 76,6% des travailleurs ont assumé seuls leur prise en charge médicale. Conclusion L'incidence des accidents du travail dans ce secteur est très élevée. La mise en place d'une politique de prévention et gestion de différents facteurs associés ainsi qu'un système de déclaration d'accidents est nécessaire dans ce secteur. Les patrons ainsi que les politiques devraient veiller à une prise en charge médicale correcte pour des travailleurs accidentés. PMID:25667703

  8. Surpoids et obésité dans la population au-dessus de 20 ans en milieu urbain bamakois (Mali)

    PubMed Central

    Oumar Bâ, Hamidou; Menta, Ichaka; Camara, Youssouf; Sangaré, Ibrahima; Sidibé, Noumou; Doumbia, Seydou; Diarra, Mamadou Bocary

    2014-01-01

    Introduction Il est question dans notre travail d’étudier le SP et l'OB et les facteurs associés dans la population âgée de 20 ans ou plus. Méthodes Notre échantillon a été obtenu à partir d'une enquête sur les pathologies cardiovasculaires dans le District de Bamako et impliquant 2199 sujets de 5-104 ans, en sélectionnant tous les sujets âgés d'au moins 20 ans (1162). Pour chaque sujet, l'IMC, rapport taille / hanche et le tour de taille ont été déterminées. Les données ont été analysées avec SPSS 12. Résultats L’âge moyen était de 36,86 années, 61,4% étaient des femmes, 49,7% dans le secteur informel et 38,0% avaient réalisé l'enseignement primaire. Facteurs de risque cardiovasculaires étaient l'inactivité physique (72,4%), le tabagisme (12,2%) et hypertension (26,7%). La prévalence de l'obésité était de 8,8 et 14,7% respectivement sur la base de l'indice de masse et le tour de taille. Conclusion Le SP et l'OB sont à prendre en compte dans les mesures de politique sanitaire que dans la pratique quotidienne des professionnels de santé, il est peut-être plus utile d'utiliser plusieurs paramètres pour être à même de bien stratifier nos patients par rapport à leur risque. PMID:25932065

  9. Corner Office: Google's Dan Clancy

    ERIC Educational Resources Information Center

    Albanese, Andrew Richard; Oder, Norman

    2009-01-01

    This article presents an interview with Dan Clancy, engineering director for Google Book Search. In this interview, Clancy talks about the pending Google Book Search settlement, involving millions of volumes digitized from libraries, which drew a lawsuit from the Association of American Publishers and the Authors Guild. He also discusses pricing,…

  10. Les superpolynomes symetriques dans les problemes a plusieurs corps de la mecanique quantique supersymetrique

    NASA Astrophysics Data System (ADS)

    Desrosiers, Patrick

    S'inspirant de la supersymetrie, on construit dans cette these une nouvelle generalisation de la theorie des fonctions symetriques. Une theorie physique est supersymetrique si: (1) elle contient des bosons (particules de spin entier) et des fermions (particules de spin demi-entier); (2) elle reste inchangee suite a une transformation des bosons en fermions et vice versa. Les fonctions symetriques dans le superespace (superfonctions symetriques) incorporent a la fois des variables commutatives (bosoniques) et anticommutatives (fermioniques). Ces dernieres engendrent une algebre de Grassmann. Une superfonction symetrique est invariante sous l'echange simultane des variables bosoniques et fermioniques (action diagonale du groupe symetrique); elle se caracterise par une superpartition, i.e., une juxtaposition appropriee de partitions usuelles d'entiers non negatifs. On utilise deux approches dans l'elaboration de la theorie des superfonctions symetriques: l'une provient de la combinatoire et l'autre, de la physique. Suivant la premiere approche, on obtient l'extension des elements standards de la theorie des fonctions symetriques fonctions monomiales, fonctions symetriques elementaires, fonctions completement symetriques, series de puissances, fonctions generatrices et formules de Cauchy. On demontre egalement qu'il existe une extension naturelle, a un parametre, du produit scalaire combinatoire defini par l'orthogonalite des series de puissances dans le superespace. La seconde approche consiste a resoudre des problemes a N corps de la mecanique quantique supersymetrique. On etudie les extensions supersymetriques des modeles Calogero-Moser-Sutherland (CMS), lesquels decrivent l'evolution de particules dont le potentiel d'inter action est proportionnel a l'inverse du carre de la distance separant les particules. Deux modeles supersymetriques CMS sont resolus: trigonometrique (sur un cercle) et rationnel (sur une ligne) avec confinement harmonique. Leurs fonctions d

  11. Transport dans l'hélium 3 polarisé par pompage optique

    NASA Astrophysics Data System (ADS)

    Lhuillier, C.; Leduc, M.

    Optical pumping is, in the case of helium 3, a useful method for polarizing the nuclear spins of the gas. Substantial orientation rates can be now achieved using tunable infrared lasers. Large changes in the macroscopic behaviour of the helium 3 fluid occur as a consequence of the polarization of the nuclei, provided the temperature is low enough, in spite of the small nuclear magnetic moment. These effects result both from interactions and statistics and are subtle consequences of the indistinguishability of particles and of the symmetrization principle in quantum mechanics. One explains in this article the expected changes for the viscosity and the heat conduction in the gas below a few kelvins. Furthermore, one shows that the transport of spin magnetization in polarized helium 3 (3He↑) has a propagative character at low temperature, giving rise to collective oscillatory modes : the transverse spin waves. One describes a recent experiment which proved the existence of these waves and allowed measuring their quality factor. Observations and theoretical predictions are in good agreement. Le pompage optique constitue, dans le cas de l'hélium 3, une méthode commode pour polariser les spins nucléaires du gaz. Des taux d'orientation notables peuvent être maintenant réalisés grâce aux lasers accordables dans l'infrarouge. Des changements importants de comportement macroscopique du fluide d'hélium 3 se produisent sous l'effet de la polarisation des noyaux, à condition que la température soit suffisamment basse, et ceci malgré la petitesse du moment magnétique nucléaire ; il s'agit là d'effets conjugués d'interaction et de statistique, manifestations subtiles de l'indiscernabilité des particules et du principe de symétrisation en mécanique quantique. On explique dans cet article les modifications attendues pour la viscosité et la conduction de la chaleur dans le gaz en dessous de quelques kelvins. De plus, on montre que le transport de spin dans l

  12. Etude theorique des fluctuations structurales dans les composes organiques a dimensionnalite reduite

    NASA Astrophysics Data System (ADS)

    Dumoulin, Benoit

    Les systemes a dimensionnalite reduite constituent maintenant une branche entiere de la physique de la matiere condensee. Cette derniere s'est developpee rapidement au cours des dernieres annees, avec la decouverte des materiaux organiques qui presentent, justement, des proprietes physiques fortement anisotropes. Cette these presente une etude en trois parties de plusieurs composes organiques qui, bien que tres differents du point de vue de leurs compositions chimiques et de leurs proprietes physiques a haute temperature, subissent tous une instabilite structurale a tres basse temperature. De plus, dans chacun des cas, l'instabilite structurale est precedee d'un important regime fluctuatif a partir duquel les proprietes physiques changent de maniere significative. Notre etude suit un ordre chronologique inverse puisque nous nous attardons en premier lieu au cas de composes recemment decouverts: les composes de la famille des (BCPTTF)2X (X = PF6 , AsF6). Ces derniers sont des isolants magnetiques a la temperature ambiante et subissent une instabilite structurale de type spin-Peierls a une temperature appelee TSP. En particulier, nous nous interessons a l'etude des proprietes physiques de ces systemes dans le regime fluctuatif, qui precede cette instabilite. Notre etude theorique nous permet de comprendre en detail comment ces systemes s'approchent de l'instabilite struturale. Dans la seconde partie de cette these, nous etudions le regime fluctuatif (pre-transitionnel) observe experimentalement dans le compose de (TMTTF)2PF6. Ce compose organique, dont la structure s'apparente aux sels de Bechgaard, subit une instabilite de type spin-Peierls a une temperature T SP = 19K. Bien que ce compose possede la particularite d'etre un bon conducteur a la temperature ambiante, il subit une transition de type Mott-Hubbard a une temperature Trho ≈ 220K et devient alors un isolant magnetique, analogue aux composes de la famille des (BCPTTF)2X. Le regime fluctuatif precedant l

  13. Les perceptions des femmes tunisiennes selon le modèle des croyances liées à la santé et leurs pratiques relativement à l'ostéoporose

    PubMed Central

    Belgacem, Amina; Nouira, Amel; Soussi, Sonia

    2016-01-01

    Introduction L'étude a pour objectif de décrire les croyances des femmes et leurs pratiques liées à la santé et à l'ostéoporose, afin d'élaborer des interventions efficaces et ciblées pour la prévention de cette maladie dans le contexte tunisien. Méthodes Une étude descriptive transversale a été effectuée auprès de 100 femmes tunisiennes, âgées de 45 ans et plus, qui consultent au centre de santé de base d'une zone périurbaine de la région de Sousse (Tunisie). La collecte de l'information a été réalisée à l'aide de « l'échelle des croyances relatives à la santé sur l'ostéoporose» développée par Kim et ses collègues traduit en arabe et validé en Tunisie et le questionnaire de «Calcul des apports calciques quotidiens» développé par Fardellone Patrice. L'interprétation des résultants s'est basée sur le «Health Belief Model ». Résultats La perception des participantes pourrait être considérée comme au dessus de la moyenne pour la vulnérabilité de l'ostéoporose (58%), la gravité de la maladie, les avantages de la pratique de l'activité physique, les avantages de l'apport en calcium et la motivation à la santé; par contre, elle pourrait être considérée comme modérée concernant les obstacles à la prévention. Cependant, les pratiques exposant au risque de la maladie sont relativement fréquentes et ceci essentiellement en rapport avec des facteurs socio-économiques et culturels. Conclusion Les programmes de promotion doivent viser la création d'un environnement physique et social favorable à l'adoption des comportements à moindre risque et viser l'éducation ciblée de la population. PMID:27217868

  14. Faut-il préférer une technique chirurgicale dans le traitement des ruptures du tendon d'Achille?

    PubMed Central

    Hani, Redouane; Kharmaz, Mohammed; Berrada, Mohammed Saleh

    2015-01-01

    La rupture du tendon d'Achille est de plus en plus fréquente dans le monde et dans notre pays en raison du développement considérable des activités sportives, de l'accroissement de leur intensité et de l'absence de moyens de prévention. Notre travail porte sur une étude concernant 58 cas de rupture du tendon d'Achille, avec un recul moyen compris entre 5 mois et 80 mois. L’âge moyen était de 36 ans, tous les patients inclus ont tous bénéficier d'un traitement chirurgical. Le but de notre étude étant de souligner la supériorité d'une technique chirurgicale par rapport à une autre dans la prise en charge, ainsi qu'une mise au point sur les différents aspects épidémiologiques, cliniques, thérapeutiques et post-thérapeutiques de cette lésion. PMID:26161208

  15. Radiations cosmiques : danger dans l'Espace

    NASA Astrophysics Data System (ADS)

    Bonnet-Bidaud, J. M.; Dzitko, H.

    2000-06-01

    Au sol, l'atmosphere nous protege plus ou moins bien. Mais dans l'espace ou a bord des avions de ligne, l'homme est directement expose aux rayonnements cosmiques qui peuvent etre mortels. Un veritable frein a la presence humaine prolongee dans l'espace. Une menace que les agences spatiales prennent tres au serieux.

  16. Allier théorie et pratique dans la lutte contre la pandémie du Sida

    PubMed Central

    Zerbo, Roger

    2014-01-01

    Le premier cas d'infection par le VIH a été notifié en 1986 au Burkina Faso. L'ignorance qui entourait cette infection et l'absence de traitement curatif a amplifié ses conséquences sociales et économiques. La mise en œuvre des interventions communautaire est un enjeu majeur actuel qui recommande la compréhension des logiques sociales endogènes qui influencent les comportements individuels et collectifs. C'est en cela que l'implication des sciences sociales dans la lutte contre les maladies, en particulier le Sida constitue un enjeu, en termes de définition et d'identification de leur contribution. Dans notre propos, nous pouvons mettre en évidence trois niveaux de contribution des sciences sociales, notamment la sociologie, l'anthropologie, la psychologie et dans une certaine mesure le droit et l’économie, à la prévention du Sida et la prise en charge des personnes infectées par le VIH. Il faut noter que ces disciplines contribuent à la lutte contre le VIH d'une part, par des réflexions et des éléments d'analyses constructives, et d'autre part, l'aptitude des porteurs de ces disciplines est parfois sollicitée pour l'efficacité de la mise en œuvre des actions et l'organisation des systèmes de soins. PMID:25722761

  17. Nouveautes Dans la Reconstruction Cutanee: Cultures de Cellules et Substituts Dermiques et Revue de la Litterature

    PubMed Central

    Koch, N.; Erba, P.; Benathan, M.; Raffoul, W.

    2010-01-01

    Summary La prise en charge de patients souffrant de brûlures profondes et étendues reste un défi important pour les chirurgiens reconstructeurs. Ceci est d'autant plus vrai que les grands progrès réalisés dans la réanimation assurent actuellement la survie de patients brûlés sur plus de 90% de leur surface corporelle. De ce fait la reconstruction moderne a dû innover et est devenue une chirurgie complexe nécessitant un plan stratégique impliquant des matériaux et des méthodes chirurgicales multiples adaptées à chaque situation clinique. Ce type de prise en charge nécessite aussi la collaboration étroite et coordonnée de plusieurs équipes hautement spécialisées. Le taux de survie ainsi que de la qualité de vie de ces patients sont alors nettement améliorés. De même nous observons clairement que le nombre de complications secondaires telles que les rétractions et les instabilités cicatricielles ont également diminué de façon significative. Mots-clés: brûlure, greffe, culture, substitut dermique, reconstruction PMID:21991212

  18. La singularité du patient tuberculeux dans le système de santé: l'expérience du Burkina Faso

    PubMed Central

    Zerbo, Roger

    2013-01-01

    La démarche pluridisciplinaire s'impose de plus en plus dans le secteur de la santé dans le contexte africain, où les parcours thérapeutiques sont pluriels et les rapports des usagers des centres de santé sont complexes et peu satisfaisants. La compréhension des représentations de la maladie est nécessaire pour offrir des soins appropriés certes, mais l'expérience individuelle des malades représente également une source de savoir. Les données ont été collectées à travers des entretiens semi-directifs, le recueil des récits de vie et des observations participantes. Cet article rend compte d'une expérience d'implication de socio-anthropologue dans la mise en œuvre d'un programme de santé publique au Burkina Faso en vue d'une amélioration de la prise en charge des malades tuberculeux. L'analyse des données à été conduite dans une visée réflexive. Les perspectives socio-anthropologiques ont révélé que l'expérience des anciens malades tuberculeux peut être mise à profit afin d'apporter des changements dans les relations thérapeutiques et l'intégration sociale des autres malades. Cette idée à été mise en application pour tenir lieu d'une traduction des analyses anthropologiques en actes pour un changement. L'article évoque la manière dont l'approche socio-anthropologique au sein d'un programme de santé, peut mettre en évidence le potentiel des malades à être des acteurs importants dans le fonctionnement des services de soins et leur propre bien-être. Dans cette situation, la démarche théorique implique la réflexivité de l'anthropologue, mais également un regard critique sur les modes d'intervention en santé publique. PMID:24009798

  19. Developpement de mesures non destructives, par ondes ultrasonores, d'epaisseurs de fronts de solidification dans les reacteurs metallurgiques

    NASA Astrophysics Data System (ADS)

    Floquet, Jimmy

    Dans les cuves d'electrolyse d'aluminium, le milieu de reaction tres corrosif attaque les parois de la cuve, ce qui diminue leur duree de vie et augmente les couts de production. Le talus, qui se forme sous l'effet des pertes de chaleur qui maintiennent un equilibre thermique dans la cuve, sert de protection naturelle a la cuve. Son epaisseur doit etre controlee pour maximiser cet effet. Advenant la resorption non voulue de ce talus, les degats generes peuvent s'evaluer a plusieurs centaines de milliers de dollars par cuve. Aussi, l'objectif est de developper une mesure ultrasonore de l'epaisseur du talus, car elle serait non intrusive et non destructive. La precision attendue est de l'ordre du centimetre pour des mesures d'epaisseurs comprenant 2 materiaux, allant de 5 a 20 cm. Cette precision est le facteur cle permettant aux industriels de controler l'epaisseur du talus de maniere efficace (maximiser la protection des parois tout en maximisant l'efficacite energetique du procede), par l'ajout d'un flux thermique. Cependant, l'efficacite d'une mesure ultrasonore dans cet environnement hostile reste a demontrer. Les travaux preliminaires ont permis de selectionner un transducteur ultrasonore a contact ayant la capacite a resister aux conditions de mesure (hautes temperatures, materiaux non caracterises...). Differentes mesures a froid (traite par analyse temps-frequence) ont permis d'evaluer la vitesse de propagation des ondes dans le materiau de la cuve en graphite et de la cryolite, demontrant la possibilite d'extraire l'information pertinente d'epaisseur du talus in fine. Fort de cette phase de caracterisation des materiaux sur la reponse acoustique des materiaux, les travaux a venir ont ete realises sur un modele reduit de la cuve. Le montage experimental, un four evoluant a 1050 °C, instrumente d'une multitude de capteurs thermique, permettra une comparaison de la mesure intrusive LVDT a celle du transducteur, dans des conditions proches de la mesure

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

    NASA Astrophysics Data System (ADS)

    Goyette, Stephane

    1995-11-01

    Le sujet de cette these concerne la modelisation numerique du climat regional. L'objectif principal de l'exercice est de developper un modele climatique regional ayant les capacites de simuler des phenomenes de meso-echelle spatiale. Notre domaine d'etude se situe sur la Cote Ouest nord americaine. Ce dernier a retenu notre attention a cause de la complexite du relief et de son controle sur le climat. Les raisons qui motivent cette etude sont multiples: d'une part, nous ne pouvons pas augmenter, en pratique, la faible resolution spatiale des modeles de la circulation generale de l'atmosphere (MCG) sans augmenter a outrance les couts d'integration et, d'autre part, la gestion de l'environnement exige de plus en plus de donnees climatiques regionales determinees avec une meilleure resolution spatiale. Jusqu'alors, les MCG constituaient les modeles les plus estimes pour leurs aptitudes a simuler le climat ainsi que les changements climatiques mondiaux. Toutefois, les phenomenes climatiques de fine echelle echappent encore aux MCG a cause de leur faible resolution spatiale. De plus, les repercussions socio-economiques des modifications possibles des climats sont etroitement liees a des phenomenes imperceptibles par les MCG actuels. Afin de circonvenir certains problemes inherents a la resolution, une approche pratique vise a prendre un domaine spatial limite d'un MCG et a y imbriquer un autre modele numerique possedant, lui, un maillage de haute resolution spatiale. Ce processus d'imbrication implique alors une nouvelle simulation numerique. Cette "retro-simulation" est guidee dans le domaine restreint a partir de pieces d'informations fournies par le MCG et forcee par des mecanismes pris en charge uniquement par le modele imbrique. Ainsi, afin de raffiner la precision spatiale des previsions climatiques de grande echelle, nous developpons ici un modele numerique appele FIZR, permettant d'obtenir de l'information climatique regionale valide a la fine echelle spatiale

  1. Ampleur et impact des évènements indésirables graves liés aux soins: étude d'incidence dans un hôpital du Centre-Est tunisien

    PubMed Central

    Bouafia, Nabiha; Bougmiza, Iheb; Bahri, Fathi; Letaief, Mondher; Astagneau, Pascal; Njah, Mansour

    2013-01-01

    Introduction La prévention des événements indésirables représente une priorité de santé du fait de leur fréquence et de leur gravité potentielle. Ce travail a été mené afin d'avoir un diagnostic de la situation épidémiologique relative aux événements indésirables survenant dans notre hôpital. Méthodes Une étude prospective a été menée auprès de tous les patients qui ont été hospitalisés au CHU Farhat Hached - Sousse (Tunisie) sur une période d'un mois dans quatorze services de l'hôpital. La détection d'évènement indésirable grave (EIG) était basée sur les critères adoptés dans différentes études. Les tests T et Chi 2 ont été utilisés pour identifier les facteurs contribuant à l'apparition d'évènements indésirables. Résultats Au total, 162 EIG ont été identifiés pendant la période. 45% de ces évènements étaient des infections nosocomiales. Ces EIG ont eu comme conséquences un décès chez 9,2% des patients, la mise en jeu du pronostic vital de 26% des patients et la prolongation de la durée de séjour chez 61,7% d'entre eux. L'admission dans des circonstances particulières et l'exposition à des soins invasifs étaient identifiés comme des facteurs de risque potentiels EIG. Conclusion Le renforcement de la stratégie de gestion des risques sanitaires en ciblant préférentiellement le risque infectieux constitue une étape fondamentale dans l'amélioration de la sécurité des patients au sein de notre établissement de santé. PMID:24711868

  2. Place de la chirurgie dans la prise en charge des cancers du sein chez la femme au Centre Hospitalier Universitaire Yalgado Ouedraogo: à propos de 81 cas

    PubMed Central

    Zongo, Nayi; Millogo-Traore, Timonga Françoise Danielle; Bagre, Sidpawalmdé Carine; Bagué, Abdoul-Halim; Ouangre, Edgar; Zida, Maurice; Bambara, Aboubacar; Bambara, Tozoula Augustin; Traoré, Si Simon

    2015-01-01

    Etudier la place de la chirurgie dans la prise en charge des cancers du sein au centre hospitalier universitaire Yalgado Ouédraogo. Nous avons réalisé une étude prospective et descriptive sur dix (10) mois portant sur la place de la chirurgie dans le cancer du sein. Elle a eu pour cadre les services de gynécologie-obstétrique et de chirurgie viscérale et digestive du centre hospitalier universitaire Yalgado Ouédraogo. Ont été pris en compte les indications, les gestes et les résultats de la chirurgie. Nous avons colligé 81 cancers mammaires. Le délai moyen de consultation a été de 14,26 mois. Les tumeurs T3 à T4 représentaient 82,71% des cas. Trente-huit patientes (46,91%) ont été opérées. La chimiothérapie néo adjuvante a été réalisée dans 29,63% des cas. Trente-quatre patientes (41,97%) étaient opérables d'emblée. Il s'agissait de mastectomie selon Madden dans 94,74% des cas et de chirurgie de propreté dans 2 cas (5,26% des cas). Une chimiothérapie adjuvante a été réalisée chez 52,63% des patientes opérées. Des complications à type de lymphocèle ont été notées dans 23,68% des cas. Leur traitement a consisté en des ponctions évacuatrices. Les indications de la chirurgie sont limitées par le retard diagnostique corollaire de stades avancés des cancers du sein. L'absence de la radiothérapie rend délicate la pratique de la chirurgie conservatrice et la mastectomie occupe toujours une place importante. Un diagnostic précoce permettrait d'augmenter les indications chirurgicales. PMID:26848364

  3. Comparaison de deux scores pronostiques dans les hémorragies digestives hautes non variqueuses dans un centre hospitalier d'Antananarivo

    PubMed Central

    Rakotondrainibe, Aurélia; Randrianambinina, Thierry Pierre; Randriamizao, Harifetra Mamy Richard; Rasoaherinomenjanahary, Fanjandrainy; Randriamiarana, Mialimanana Joël; Samison, Luc Hervé

    2013-01-01

    Il est actuellement recommandé de stratifier les hémorragies digestives hautes, en fonction de leur risque, par des scores pronostiques. L'objectif de cette étude a été d'appliquer ces scores en vue de les comparer, dans un centre hospitalier malgache. Etude prospective sur 419 patients, sur une période entre janvier et décembre 2011, au Centre Hospitalo-Universitaire d'Antananarivo. Les scores de Rockall initial et de Blatchford ont été calculés pour chaque patient présentant une hémorragie digestive haute non variqueuse dont les dossiers été complets, avec notamment la valeur de l'urémie et de l'hémoglobine. Une comparaison de ces deux scores a été faite pour déterminer le pronostic et l’évolution de cette pathologie. 46,3% des dossiers n'avaient pas de valeur d'urémie ni de l'hémoglobine. Les 185 patients retenus, avaient une moyenne d’âge de 48,2 ± 18,2 ans et une prédominance masculine (72,4%). Le risque clinique était élevé dans 62,7% des cas, dont 59,4% ont bénéficié d'une transfusion. Une mortalité de 9,7% a été observée. Le score de Blatchford était plus prédictif du risque clinique par rapport au score de Rockall initial (AUROC = 0,82 vs 0,64; p < 0,0001), mais aussi de la nécessité d'une transfusion (AUROC = 0,79 vs 0,62; p= 0,00013). L'instauration d'un score clinico-biologique est assez limitée par faute de moyens, alors que le score de Blatchford aiderait en matière de pronostic des hémorragies digestives hautes. PMID:24839534

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

    NASA Astrophysics Data System (ADS)

    Bourque, Claude Julie

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

  5. Enjeux de fin de vie dans les cas de démence avancée

    PubMed Central

    Arcand, Marcel

    2015-01-01

    Résumé Objectif Examiner les enjeux liés à l’établissement d’objectifs des soins pour les patients atteints de démence sévère, décrire les rôles respectifs du médecin et des proches du patient dans le processus de prise de décision et suggérer des façons d’appuyer les proches qui souhaitent obtenir plus d’information sur les options thérapeutiques. Sources des données Une recherche d’articles pertinents publiés avant le 7 mars 2014 a été effectuée dans MEDLINE sur Ovid. Aucune étude de niveau I n’a été relevée; la plupart des articles fournissaient des preuves de niveaux III. Message principal Pour les patients atteints de démence avancée, la famille joue un rôle important dans la prise de décisions médicales. Les proches devraient recevoir de l’information ponctuelle sur l’évolution de la démence et les options relatives aux soins. Ils doivent comprendre qu’il pourrait être approprié d’adopter une approche de soins palliatifs, ce qui ne signifie pas que le patient est abandonné à son sort. Ils pourraient aussi souhaiter clarifier leur rôle dans le processus de prise de décision, surtout lorsqu’on envisage de mettre fin aux mesures de prolongement de vie. Conclusion Les médecins doivent voir la démence avancée comme une maladie terminale pour laquelle il existe un continuum de soins qui s’étend de l’approche de soins palliatifs avec mesures acceptables de prolongement de vie à l’approche exclusivement symptomatique. Il est primordial de clarifier les objectifs des soins et d’éduquer les proches pour éviter les interventions non souhaitées et pénibles.

  6. La stimulation magnétique transcrânienne (SMT) dans la recherche fondamentale et clinique en neuroscience

    PubMed Central

    Valero-Cabré, Antoni; Pascual-Leone, Alvaro; Coubard, Olivier A.

    2011-01-01

    Introduction Les méthodes de stimulation cérébrale non invasives telles que la Stimulation Magnétique Transcrânienne (SMT) sont largement utilisées pour établir des inférences causales sur les relations entre cerveau et comportement. Des applications cliniques basées sur la SMT ont également été développées pour traiter des affections neurologiques ou psychiatriques comme la dépression, la dystonie, la douleur, les acouphènes ou les séquelles d’accident vasculaire cérébral. État des connaissances La SMT fonctionne en induisant de manière non invasive et de manière focale des courants électriques dans des régions corticales, modulant ainsi leur niveau d’activité de façon variable suivant la fréquence, le nombre d’impulsions, les intervalles et la durée de stimulation utilisés. S’agissant du cortex moteur, on sait par exemple que les patterns d’impulsions de SMT à basse fréquence ou ceux délivrées de manière continue tendent à déprimer l’activité locale, tandis que la SMT à haute fréquence et discontinus tend à la potentialiser. Outre ses effets locaux, la SMT peut aussi avoir des effets à distance sur les régions cérébrales, véhiculés par les connections anatomiques et qui dépendent de l’efficacité et du signe de ces connexions. Perspectives Dans le domaine de la recherche fondamentale et des applications thérapeutiques, l’utilisation efficace de la SMT requiert, cependant, la compréhension approfondie de ses principes opérationnels, de ses risques, de ses potentialités et de ses limites. Dans cet article, nous présentons les principes par lesquels opèrent les méthodes de stimulation cérébrale non invasive, et en particulier la SMT. Conclusion À l’issue de sa lecture, le lecteur sera en mesure de discuter de façon critique les études scientifiques et cliniques utilisant la SMT, ainsi que de concevoir des applications SMT suivant une hypothèse a priori dans le domaine de la recherche en

  7. Dan Johnson's impact on hearing research

    NASA Astrophysics Data System (ADS)

    Shotland, Lawrence I.

    2003-04-01

    Daniel L. Johnson is well known for his many technical contributions to noise research. Throughout a long and distinguished career at Wright-Patterson Air Force Base, Dan published the results of several significant experiments, including his landmark experiments on asymptotic threshold shift and exposure to impulse noise. His work in the area of noise exposure laid much of the groundwork for a greater understanding of the physiologic response to hazardous noise, much of which has since been incorporated in national and international standards. Dan is highly regarded for his tireless work on technical and advisory committees in noise, and most recently, ototoxicity. Throughout his career, Dan has adhered to a self-imposed standard of intellectual honesty and discovery. Dan's most recent endeavor, the development of a personal noise dosimeter designed for self-monitoring by the employee, is characteristic of his creativity and energy. Perhaps less well known are his contributions over the years to the success of his younger colleagues. He has accomplished this in an unselfish and egalitarian manner, oftentimes challenging and even contradicting his own research. The focus of this talk will elaborate on these facets of Dan's professional contributions.

  8. Evaluation du niveau de connaissance des patients sur la gestion du traitement par les antis vitamines K dans le service de cardiologie de Ouagadougou

    PubMed Central

    Samadoulougou, André; Temoua Naibe, Dangwé; Mandi, Germain; Yameogo, Relwendé Aristide; Kabore, Elisé; Millogo, Georges; Yameogo, Nobila Valentin; Kologo, Jonas Koudougou; Thiam/Tall, Anna; Toguyeni, Boubacar Jean Yves; Zabsonre, Patrice

    2014-01-01

    Introduction Les antivitamines K (AVK), traitement anticoagulant oral le plus largement prescrit, posent un réel problème de santé publique du fait de leur risque iatrogène. L'objectif de cette étude était de préciser le niveau de connaissance des patients sur la gestion de leur traitement par les AVK. Méthodes Il s'est agi d'une enquête transversale descriptive réalisée au CHU-Yalgado Ouédraogo, sur une période de 03 mois : du 1er mars au 31 mai 2012. Un questionnaire a été administré aux patients bénéficiant d'un traitement AVK depuis au moins un mois. Résultats Soixante-dix patients ont été inclus dans l'étude dont 30 hommes. L'âge moyen était de 49 ans ± 16 ans. Les cardiopathies et la maladie thromboembolique veineuse justifiant l'institution du traitement AVK étaient retrouvées respectivement dans 58,6% et 41,4% des cas. Le nom de l'AVK et la raison exacte du traitement étaient connus respectivement dans 91,4% et 67,1% des cas. Plus de la moitié des patients (68,6%) savaient que les AVK rendaient le sang plus fluide. Quarante-six patients (65,7%) citaient l'INR comme examen biologique de surveillance du traitement et seulement 28 patients (40%) connaissaient les valeurs cibles. La majorité des patients ne connaissait pas les risques encourus en cas de surdosage (72,8%) et de sous-dosage (71,4%). Une automédication par anti-inflammatoire non stéroïdien était signalée par 18 patients (25,7%). Les choux (74,3%) et la laitue (62,9%), aliments à consommer avec modération, étaient les plus cités. Conclusion Les connaissances des patients sur la gestion des AVK étaient fragmentaires et insuffisantes pour assurer la sécurité et l'efficacité du traitement. La création d'un programme d'éducation thérapeutique sur les AVK s'avère alors nécessaire. PMID:25870741

  9. Conception d'un capteur intelligent pour la détection des vapeurs de styrène dans l'industrie

    NASA Astrophysics Data System (ADS)

    Agbossou, Kodjo; Agbebavi, T. James; Koffi, Demagna; Elhiri, Mohammed

    1994-10-01

    The techniques of measurement of toxic gases are nowadays based on the semiconductor type sensors. The modelling and the electronic processing of their signals can be used to improve the accuracy and the efficiency of the measurement. In this paper, an intelligent system using a semiconductor sensor has been designed for the detection of the styrene vapors. A set of the environmental parameters sensors such as the temperature, the pressure and the humidity, is added to the basic sensor and allows a precise detection of the styrene vapors in air. A microcontroller and a communication interface, that are included in the control system and in the data processing system, provide the local intelligence. The linearization routines of the differents sensors are in the memory of the microcontroller. The system made of the sensors, of the amplification circuits, of the microcontroller and of the communication network between the smart sensor and the computer is analysed. A laboratory test of the device is presented and the accuracies and efficiencies of the differents sensors are given. Les techniques fiables de quantification des gaz polluants sont aujourd'hui basées sur l'utilisation des détecteurs à récepteurs chimiques et sur des capteurs à semiconducteurs. La modélisation et le traitement numérique des signaux résultants sont importants pour une mesure efficace et précise dans un milieu donné. Dans cet article, un capteur intelligent, utilisant un détecteur de gaz type semiconducteur a été réalisé pour la détection des vapeurs de styrène. Un ensemble de détecteurs des paramètres environnementaux, tels que la température, la pression et l'humidité, ajoutés au capteur de styrène, permettent de mesurer avec un bon contrôle les vapeurs de styrène dans l'air. Le système de contrôle et de gestion local des données est constitué d'un microcontrôleur et d'une interface de communication. Le microcontrôleur contient dans sa mémoire toutes les

  10. Dan jiang kou hydropower station turbine refurbishment

    NASA Astrophysics Data System (ADS)

    Zhang, R. Y.; Nie, S. Q.; Bazin, D.; Cheng, J. H.

    2012-11-01

    Dan jiangkou hydropower station refurbished project, isan important project of Chinese refurbishment market. Tianjin Alstom Hydro Co., ltd won this contract by right of good performance and design technology,Its design took into account all the constraints linked to the existing frame. It results in a specific and highly advanced shape.The objective of this paper is to introduce the successful turbine hydraulic design, model test and mechanical design of Dan jiangkou project; and also analyze the cavitation phenomena occurred on runner band surface of Unit 4 after putting into commercial operation. These technology and feedback shall be a good reference and experience for other similar projects

  11. MSL DAN Passive Data and Interpretations

    NASA Astrophysics Data System (ADS)

    Tate, C. G.; Moersch, J.; Jun, I.; Ming, D. W.; Mitrofanov, I. G.; Litvak, M. L.; Behar, A.; Boynton, W. V.; Drake, D.; Lisov, D.; Mischna, M. A.; Hardgrove, C. J.; Milliken, R.; Sanin, A. B.; Starr, R. D.; Martín-Torres, J.; Zorzano, M. P.; Fedosov, F.; Golovin, D.; Harshman, K.; Kozyrev, A.; Malakhov, A. V.; Mokrousov, M.; Nikiforov, S.; Varenikov, A.

    2014-12-01

    In its passive mode of operation, The Mars Science Laboratory Dynamic Albedo of Neutrons experiment (DAN) detects low energy neutrons that are produced by two different sources on Mars. Neutrons are produced by the rover's Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) and by interactions of high energy galactic cosmic rays (GCR) within the atmosphere and regolith. As these neutrons propagate through the subsurface, their energies can be moderated by interactions with hydrogen nuclei. More hydrogen leads to greater moderation (thermalization) of the neutron population energies. The presence of high thermal neutron absorbing elements within the regolith also complicates the spectrum of the returning neutron population, as shown by Hardgrove et al. DAN measures the thermal and epithermal neutron populations leaking from the surface to infer the amount of water equivalent hydrogen (WEH) in the shallow regolith. Extensive modeling is performed using a Monte Carlo approach (MCNPX) to analyze DAN passive measurements at fixed locations and along rover traverse segments. DAN passive WEH estimates along Curiosity's traverse will be presented along with an analysis of trends in the data and a description of correlations between these results and the geologic characteristics of the surfaces traversed.

  12. Registration of 'Dan' winter hulless barley

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dan’ (Reg. No. CV- , PI 659066) six-rowed winter hulless barley (Hordeum vulgare L.) was developed and released by the Virginia Agricultural Experiment Station in March 2009. Dan was derived from the cross VA96-41-17 / SC872143. It was released for production in the eastern United States, as a poten...

  13. Transport quantique dans des nanostructures

    NASA Astrophysics Data System (ADS)

    Naud, C.

    2002-09-01

    Quantum transport in nanostructures This work is devoted to the design, fabrication and magnetotransport investigations of mesoscopic devices. The sample are obtain by e-beam lithography and the measurements are performed at low temperature in a dilution refrigerator in the presence of a magnetic field. We have used MBE grown AlGaAs/GaAs heterojonctions as starting material to fabricate a bipartite tiling of rhombus called mathcal{T}3 lattice. We observe for the first time large amplitude h/e oscillations in this network as compared to the one measured in square lattices of similar size. These oscillations are the signature of a recently predited localization phenomenon induced by Aharonov-Bohm interferences on this peculiar topology. For particular values of the magnetic field the propagation of the electron wave function is bounded in a small number of cells, called Aharonov-Bohm cages. More strikingly, at high magnetic field, h/2e oscillations appear whose amplitude can be much higher than the fundamental period. Their temperature dependence is similar to that of the h/e signal. These observations withdraw a simple interpretation in terms of harmonics generation. The origin of this phenomenon is still unclear and needs more investigations. The influence electrical width of the wire defining the network and so the rule of the number of channels can be studied using a gate deposited over the lattice. In particular we have measured the amplitude dependence of the h/e and h/2e signal versus the gate voltage. Ce travail est consacré à la réalisation d'échantillons mésoscopiques à partir de la lithographie électronique ainsi qu'à leur caractérisation à très basse température en magnétotransport. Nous avons pour cela exploité le gaz bidimensionnel d'électrons situé à l'interface d'une hétérojonction AlGaAs/GaAs pour réaliser un réseau de boucle d'une géométrie particulière baptisée la géométrie mathcal{T}3. Nous avons observé sur cette

  14. Perception de l'allaitement maternel et de la diversification alimentaire dans une zone urbaine congolaise

    PubMed Central

    Kanteng, Gray A Wakamb; Lubala, Toni Kasole; Mutombo, Augustin Mulangu; Mutoke, Gayllord Nkashama; Kasongo, Aubin Ndjadi; Wembonyama, Stanis Okitotsho; Luboya, Oscar Numbi

    2014-01-01

    Introduction Les habitudes d'allaitement et de diversification alimentaire sont sensiblement influencées par la perception des mères allaitantes. L'objectif de ce travail est d’évaluer la perception de ces femmes en milieu urbain à Lubumbashi (RD Congo) afin de relever les barrières à la conduite d'un allaitement optimal. Méthodes Une étude qualitative transversale a été menée, basée sur des groupes de discussion menées dans 3 centres urbains de la ville de Lubumbashi, et concernant 76 mères avec leurs nourrissons. Résultats Sur 76 mères, 52 n'ont pas pratiqué un allaitement maternel exclusif avant 6 mois. Les principales raisons évoquées sont: le bébé pleurait beaucoup (ne se rassasie pas), le bébé ne prenait pas suffisamment de poids, la production lactée insuffisante, le manque de temps, une interdiction médicale, des raisons de pudeur ou d'esthétique corporelle. Les personnes ayant conseillé le choix ou le moment de la diversification sont: la mère elle-même, un membre de la famille, un ami, le conjoint. Conclusion La promotion d'un programme de santé visant à améliorer la perception des mères sur la pratique de l'allaitement maternel et de la diversification est un axe important pour améliorer le taux d'allaitement maternel exclusif avant 6 mois. PMID:25918576

  15. Effets du Parecoxib dans la Prévention des Adhérences abdominales postopératoires: étude expérimentale randomisée chez les rats

    PubMed Central

    Arung, Willy; Tshilombo, François; Odimba, Etienne

    2015-01-01

    Introduction Bien d’études ont été menées sur les adhérences intrapéritonéales, mais aucune unanimité n'est encore acquise sur leur prévention. Le but de notre étude a été d’évaluer le potentiel effet d'un antiinflammatoire, parecoxib dans la prévention des adhérences ainsi que sur la cicatrisation chez des rats. Méthodes Dans un modèle expérimental d'adhérences postopératoires secondaires à des lésions péritonéales par brûlure, 30 rats furent randomisés en trois groupes suivant le mode d'administration de parecoxib (groupe contrôle; intrapéritonéal; intramusculaire. Résultats Le parecoxib a significativement diminué la quantité (p < .05) et la sévérité (p < .01) des adhérences postopératoires dans les deux modèles expérimentaux. Au total, 21 rats ont développé des adhérences, respectivement 9 (100%) dans le groupe A, 5 (50%) dans le groupe B et 7 (70%) dans le groupe C (p = 0.05). Du point de vue de la formation des adhérences au site du traumatisme, dix-neuf rats en ont développé: 9 (100%) dans le groupe A et 5 (50%) pour chacun de deux autres groupes B et C. Une différence significative a été constatée en comparant ces groupes deux à deux: A vs B (p < 0.05); A vs C (p < 0,05). Parecoxib n'a pas compromis la cicatrisation intestinale, ni cutanée. Conclusion Cette étude a montré que le parecoxib pouvait réduire la formation des adhérences postopératoires. La confirmation de la sécurité du parecoxib sur les anastomoses intestinales doit être investiguée au cours d'autres expérimentations. PMID:26966478

  16. Dan Marino Helping Those with Autism Spectrum Disorders | NIH MedlinePlus the Magazine

    MedlinePlus

    ... Marino Foundation. Photo: Dan Marino Foundation Former NFL star quarterback Dan Marino and his wife Claire experienced ... to succeed in life,'" says the former NFL star. "That's where the focus for The Dan Marino ...

  17. Revue systématique sur la contribution des femmes distributeurs communautaires dans la lutte contre l'onchocercose en Afrique sub-saharienne

    PubMed Central

    Vouking, Marius Zambou; Tadenfok, Carine Nouboudem; Evina, Christine Danielle; Nsangou, Moustapha; Bonono, Cécile-Renée; Yondo, David

    2014-01-01

    Le Programme Africain de lutte contre l'Onchocercose (APOC) fut lancé en 1995, comme complément au brillant programme de lutte contre l'onchocercose en Afrique de l'Ouest. En 2011, plus de 80 millions de personnes ont bénéficié de cette intervention grâce à la contribution de 268 718 Distributeurs Communautaires (DC). Ses résultats significatifs occultent le rôle des femmes DC dans cette lutte cette maladie. L'objectif de cette analyse est de déterminer la contribution des femmes DC dans le traitement de l'onchocercose sous directive communautaire en Afrique sub-saharienne, et d’évaluer leur acceptation dans ledit programme. Comme stratégie de recherche, nous avons identifié toutes les études pertinentes de Janvier 1995 à Décembre 2012. Des recherches ont été effectuées dans les bases de données suivantes: Medline, Embase (Excerpta Medica Database), CINAHL (Cumulative Index to Nursing and Allied Health Literature), LILAS (Latin American and Caribbean Literature on Health Sciences). Nous avons également consulté les sites d'APOC et de l'OMS AFRO. Deux auteurs ont indépendamment évalué la pertinence des articles potentiels à l'aide des critères d'inclusion et d'exclusion bien définis. Six (6) des 25 études ont rempli les critères d'inclusion. Une étude a montré que 81% des populations où il y avait des femmes DC ont reçu l'Ivermectine par rapport à 78% des villages où n'exerçaient pas de femmes DC. Une autre étude a montré qu'il y a eu une prise de conscience croissante dans les IDC en faveur de l'acceptation de la participation des femmes à la distribution communautaire de l'Ivermectine. De plus, 70% des membres de la communauté interrogés dans certaines zones endémiques, ont déclaré que les femmes étaient plus engagées, persuasives et plus patientes que les hommes dans la distribution de l'Ivermectine. Au terme de cette étude, les évaluations qui ont été effectuées donnent à penser que les femmes peuvent jouer

  18. Etude theorique et experimentale des evaporateurs de dioxyde de carbone operant dans des conditions de givrage

    NASA Astrophysics Data System (ADS)

    Bendaoud, Adlane Larbi

    Les evaporateurs de refrigeration sont surtout du type tube a ailettes, appeles serpentins, et fonctionnent dans l'une des conditions suivantes: seche, humide ou avec formation de givre. Il a ete demontre que la formation du givre sur la paroi exterieure de l'echangeur engendre une surconsommation energetique a cause des operations de degivrage puisque 15 a 20% seulement de la chaleur produite sert au degivrage tandis que le reste est dissipee dans l'environnement [1]. Avec l'avenement des nouveaux refrigerants, moins nocifs envers l'environnement, l'industrie du froid se trouve penalisee du fait que peu ou pas de composantes mecaniques (compresseur, pompe, echangeur...etc.) adaptees sont disponibles [3]. Il s'agit pour la communaute des frigoristes de combler ce retard technologique en redeveloppant ces composantes mecaniques afin qu'elles soient adaptees aux nouveaux refrigerants. Dans cette optique, et afin de mieux comprendre le comportement thermique des evaporateurs au CO2 fonctionnant dans des conditions seches, qu'un groupe de chercheurs du CanmetENERGIE avaient lance, en 2000, un programme de R & D. Dans le cadre de programme un outil de simulation des evaporateurs au CO2 a ete developpe et un banc d'essai contenant une boucle secondaire de refrigeration utilisant le CO2 comme refrigerant a ete construit. Comme continuite de ce travail de recherche, en 2006 ce meme groupe de recherche a lance un nouveau projet qui consiste a faire une etude theorique et experimentale des evaporateurs au CO2 operants dans des conditions de givrage. Et, c'est exactement dans le cadre de ce projet que se positionne ce travail de these. Ce travail de recherche a ete entrepris pour mieux comprendre le comportement thermique et hydrodynamique des serpentins fonctionnant dans des conditions de givrage, l'effet des circuits de refrigerant ainsi que celui des parametres geometriques et d'operation. Pour cela, un travail theorique supporte par une etude experimentale a ete effectue

  19. Processus mis en jeu dans l'evolution morpho-dynamique de Roberts Bank (Delta du Fraser): Observation et modelisation hydrodynamiques et sedimentaires

    NASA Astrophysics Data System (ADS)

    Meule, Samuel

    Roberts Bank couvre le delta intertidal entre le bras principal du fleuve Fraser et la pointe du Cap Roberts en Colombie Britannique, Canada. Sous la pression du developpement urbain et la modification du regime sedimentaire, cette plage de sable fin est soumise a une erosion significative. L'identification des forces hydrodynamiques, leur importance et leur interaction permettent de determiner les zones de transport, et donc la stabilite de Roberts Bank. Deux periodes de mesures associees a des phases de modelisation de la houle et des courants ont ete effectuees lors de ce travail. La premiere periode de mesure, entre le 29 juin et le 8 juillet 2001, a permis l'identification de processus hydrodynamiques et sedimentaires associes aux forts courants de maree presents le long de Roberts Bank. La seconde phase de mesure, entre le 1er mars et le 26 mars 2002, a permis d'etudier les processus de remise en suspension associes a la houle. Des phases de modelisation ont ete menees a partir des connaissances acquises sur le terrain, afin d'affiner la comprehension des processus sedimentaires et notamment les interactions houle - courant - sediment. Les mecanismes, mis en evidence dans cette etude, participent au faconnage de Roberts Bank, contribuent a son erosion et a la mise en place de nouvelles structures sedimentaires. Les courants de flot de maree vont initier la creation de nuages de resuspension de sediment depuis le fond. En eau peu profonde, la composante " onshore" du courant de maree induit un transport a la cote, tandis qu'en eau plus profonde une faible composante " offshore" du courant peut favoriser un transport au large le long de la pente. Les chenaux, les dunes subaquatiques et les surfaces d'erosion affleurantes fournissent une rugosite de fond suffisante a la generation de turbulence et donc de nuages de sediment en suspension. Lors de la maree de jusant, les sediments resuspendus en eau peu profonde, sont transportes vers le large a partir d

  20. 8. Wabash Ave. North. View of Loop and Dan Ryan ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Wabash Ave. North. View of Loop and Dan Ryan Line. Curve at Van Buren St. and Wabash Ave. at center. Dan Ryan line starts at center and runs south (toward bottom of picture). Photo by Jet Lowe. - Union Elevated Railroad, Union Loop, Wells, Van Buren, Lake Streets & Wabash Avenue, Chicago, Cook County, IL

  1. Detection du tore de poussieres dans les noyaux actifs de galaxies avec COMIC, la nouvelle camera infrarouge du systeme d'optique adaptative de l'ESO. (Resume de these).

    NASA Astrophysics Data System (ADS)

    Marco, O.

    1998-05-01

    L'observation a haute resolution angulaire a connu un nouvel elan avec la mise au point de systemes d'optique adaptative fonctionnant dans l'infrarouge. La camera COMIC, seconde camera dediee a ADONIS, le systeme d'optique adaptative equipant le telescope de 3.60 metres de l'ESO, permet l'observation dans le domaine spectral 3-5 microns a la limite de resolution angulaire du telescope. La caracterisation de la camera au laboratoire a Meudon et Grenoble, puis la determination de ses performances sur le site au Chili sont l'objet de la premiere partie de cette These. Une methode originale d'evaluation des magnitudes limites atteintes est proposee, qui prend en compte a chaque stade les differents facteurs de perte de detectivite entre les mesures au laboratoire et celles en conditions reelles. Cette approche pourra etre envisagee chaque fois que l'on a connaissance a priori des conditions d'observation (quantifiees en particulier par le rapport de Strehl, ou encore par une estimation du seeing). L'etude de la region centrale (~1 arcsec) des Noyaux Actifs de Galaxies necessite l'acces a la haute resolution angulaire. En particulier, la poussiere chaude emet dans le domaine 1-5 microns. L'observation des NAG avec un systeme d'optique adaptative est donc tout indiquee. La theorie d'unification des NAG prevoit la presence d'un tore moleculaire et poussiereux, responsable d'effets masquant selon l'angle de visee sous lequel on les observe, induisant des proprietes observationnelles distinctes pour des objets supposes identiques. Les observations real isees avec ADONIS & COMIC de NGC 7469 et NGC 1068 ont montre la presence d'une grande quantite de poussieres chaudes localisees a l'emplacement du tore presume, mais aussi melangees avec le gaz de la region d'emission de raies etroites. La haute resolution angulaire atteinte a permis de preciser la temperature des poussieres chaudes, leur masse, et leur distribution spatiale autour de la source centrale du NAG. Ces resultats

  2. Long-term Passive Mode Data Measured by the Dynamic Albedo of Neutrons (DAN) Instrument onboard Mars Science Laboratory (MSL) and Comparison to REMS Surface Pressure and Temperature Measurements

    NASA Astrophysics Data System (ADS)

    Jun, I.; Mitrofanov, I. G.; Litvak, M. L.; Sanin, A. B.; Martín-Torres, J.; Zorzano, M. P.; Boynton, W. V.; Fedosov, F.; Golovin, D.; Hardgrove, C. J.; Harshman, K.; Kozyrev, A.; Kuzmin, R.; Malakhov, A. V.; Mischna, M. A.; Moersch, J.; Mokrousov, M.; Nikiforov, S.; Tate, C. G.

    2014-12-01

    Since the landing in August 2012, DAN has provided a wealth of scientific data from the successful surface operation in both Active mode and Passive mode. While the main DAN science investigation so far has focused in estimating the contents of water-equivalent-hydrogen (WEH) and chlorine-equivalent-neutron-absorption in the surface, here we will provide/discuss low energy (less than about 1 keV) background neutron environment at the Martian surface as measured by DAN Passive mode operation. Passive mode measurements have been done on almost every sols with durations ranging from 1 hour to ~9 hour, covering different times of a day. Neutrons from the onboard power source Multi Mission Radioisotope Thermonuclear Generator (MMRTG) and induced by Galactic Cosmic Ray (GCR)/Solar Energetic Particles (SEP) interactions with the Martian atmosphere and the surface material contribute to the DAN passive data. An approach to separate out the respective contributions from the DAN total count rates was developed previously (Jun et al., 2013) using the data collected at Rocknest (where the rover stayed from sol 60 to sol 100). The main goal of this paper is to extend the same analysis to other locations encountered during the rover traverse especially to understand the long-term (through Sol 800, covering more than 1 Martian year) behavior of the neutron environment at the Martian surface as measured by DAN in response to variation of the free space GCR/SEP environment. Extensive Monte Carlo transport simulations using Monte Carlo N-Particle eXtended (MCNPX) have been performed to support the analysis and to aid interpretation of the DAN passive data. In addition, the DAN passive data are compared to the long-term surface temperature and pressure data (both measured and modeled) from Rover Environmental Monitoring Station (REMS) to investigate possible correlation of the DAN data with ambient environmental conditions.

  3. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2014-06-01

    Future lune ? - L'âge de la Lune - Des volcans actifs sur Vénus - Un lac dans le cratère Gusev ? - Météorites et atmosphère martiennes - L’hexagone de Saturne - Pluton - Exo-Terre - Bêta Pictoris b - Cérès et Vesta depuis Mars - Naine froide - Parallaxes par Hubble - L2 Puppis et le sort du Soleil - Supernova et lentille gravitationnelle - Champ magnétique galactique - L’objet de Sakurai - Fermi et la matière noire - Lentille naine

  4. Spectres d'absorption X dans les plasmas femtosecondes

    NASA Astrophysics Data System (ADS)

    Bastiani-Ceccotti, S.; Audebert, P.; Renaudin, P.; Chenais-Popovics, C.; Geindre, J. P.; Tzortzakis, S.; Nagels-Silvert, V.; Shepherd, R.; Matsushima, I.; Gary, S.; Girard, F.; Peyrusse, O.; Gauthier, J. C.

    2005-06-01

    Nous avons mesuré le spectre d'absorption en couche K de plasmas d'aluminium à haute densité. Deux faisceaux de la chaîne laser femtoseconde 100 TW du LULI (de durée 300 fs) ont été utilisés pour produire le plasma absorbant sur une feuille mince d'Al (830 Å ou 500 Å), et la source de radiographie sur du samarium massif. Les spectres X étaient résolus spatialement dans une direction perpendiculaire à la direction de la dispersion spectrale. Les spectres ont été mesurés pour différents retards entre la source deradiographie et le plasma d'Al. Des simulations des spectres et de l'ionisation en fonction du temps et de l'intensité, obtenues au moyen de codes hydrodynamiques et de structure atomique, montrent un bon accord avec les résultats expérimentaux.

  5. Diagnostic clinique et paraclinique des infections ostéoarticulaires digitales dans les brûlures thermiques de la main

    PubMed Central

    Zaoui, A.; Mahdhi, N.; Ben Maitigue, M.; Maaref, K.; Jemni, S.; Bouaziz, M.A.; Regaieg, H.; Dakkem, M.; Zine El Abidine, M.; Ben Fredj, M.; Khachnaoui, F.; Rejeb, N.

    2013-01-01

    Summary Les infections ostéo-articulaires digitales de la main brûlée sont particulières car longtemps méconnu. Leur diagnostic n’a pratiquement jamais été abordé dans la littérature. On distingue d’une part les ostéoarthrites survenant à la phase aiguë de la brûlure chez le patient grand brûlé, sédaté où le diagnostic est difficile en réanimation car la clinique n’est pas parlante et d’autre part les ostéoarthrites découvertes à la phase de rééducation, où douleur, tuméfaction, raideur et signes radiologiques sont nets. Le diagnostic de ces infections doit être précoce à fin de préserver la fonction de la main. PMID:24133401

  6. Diagnostic et prévalence du syndrome métabolique chez les diabétiques suivis dans un contexte de ressources limitées: cas du Burkina-Faso

    PubMed Central

    Marceline, Yaméogo Téné; Issiaka, Sombié; Gilberte, Kyélem Carole; Nadège, Rouamba; Macaire, Ouédraogo Sampawindé; Arsène, Yaméogo Aimé; Djingri, Lankoandé; Apollinaire, Sawadogo; Joseph, Drabo Youssouf

    2014-01-01

    Introduction Les conséquences du syndrome métabolique impliquent son diagnostic effectif pour une prise en charge globale des comorbidités dépistées. Objectif: Déterminer la capacité à diagnostiquer le syndrome métabolique en routine, sa prévalence chez les diabétiques, leurs connaissances et pratiques vis-à-vis du risque cardio-métabolique. Méthodes Il s'est agi d'une étude transversale auprès de 388 diabétiques au CHU de Bobo-Dioulasso. Les critères de la fédération internationale du diabète (2009) ont été utilisés. Résultats l’âge moyen était de 53,5±13,5 ans, le sex ratio de 0,7. L'obésité abdominale était présente dans 61,9% des cas; L'HTA l’était dans 56,4% des cas. La prescription du bilan lipidique a été documentée dans 55,4% des cas pour le HDL et 56,2% pour les triglycérides pour un taux de réalisation de 49,3% et 62,9%. Le taux de dépistage des critères lipidiques était de 26,8%. Un taux de HDL bas a été noté dans 46 cas (43,4%) et une hypertriglycéridémie dans 24 cas (17,6%). In fine, la prévalence du syndrome métabolique était de 48,9% (n = 190). Seuls 27,4% savaient que d'autres facteurs de risque cardiovasculaire pouvaient être associés au diabète et seulement 6,7% pratiquaient une activité physique régulière. Conclusion Malgré la faible contribution du laboratoire, le syndrome métabolique est fréquent parmi nos diabétiques. Les patients sont peu sensibilisés sur le risque vasculaire et la pratique d'une activité physique régulière reste faible. Un programme d’éducation adaptée contribuerait à un meilleur dépistage et à une prise en charge optimale des cas. PMID:25932077

  7. Canadian Thesis Abstracts: Synthèse spectrale de jeunes populations stellaires dans; l'ultraviolet lointain

    NASA Astrophysics Data System (ADS)

    Pellerin, Anne

    2005-02-01

    stellaires impliquées dans les sursauts. La synthèse des raies de l'ultraviolet lointain s'est avérée beaucoup plus précise que la synthèse à > 1200 Å en raison de la résolution spectrale exceptionnelle de FUSE et parce que les raies stellaires n'ont pas de profils saturés, même aux métallicités élevées. Les propriétés physiques globales des 24 galaxies à sursauts ont aussi été étudiées dans leur ensemble afin de mieux décrire le phénomène des sursauts de formation stellaires.

  8. Pat Thiel talks about Nobel Prize winner Dan Shechtman

    SciTech Connect

    Thiel, Pat

    2012-01-01

    Ames Laboratory senior scientist and Iowa State University Distinguished Professor of Chemistry Pat Thiel talks about her friend and colleague Dan Shechtman who received the 2011 Nobel Prize for Chemistry.

  9. 4. Historic American Buildings Survey Dan Leyrer, Photographer, July 10, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Historic American Buildings Survey Dan Leyrer, Photographer, July 10, 1963 ENTRANCE HALL & STAIRWAY with BRASS NEWEL POST - Herman-Grima House, 820 Saint Louis Street, New Orleans, Orleans Parish, LA

  10. 1. Historic American Buildings Survey Dan Leyrer, Photographer August 1963 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Historic American Buildings Survey Dan Leyrer, Photographer August 1963 PATIO AND GARCONNIERE--VIEW FROM EAST - Herman-Grima House, Garconniere & Kitchen, 820 Saint Louis Street, New Orleans, Orleans Parish, LA

  11. 2. Historic American Buildings Survey Dan Leyrer, Photographer August 1963 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Historic American Buildings Survey Dan Leyrer, Photographer August 1963 KITCHEN (SOUTHEAST ELEVATION) ATTACHED TO GARCONNIERE - Herman-Grima House, Garconniere & Kitchen, 820 Saint Louis Street, New Orleans, Orleans Parish, LA

  12. Environmental Scientist/Chemist Dan Gazda Speaks With Students

    NASA Video Gallery

    From NASA's International Space Station Mission Control Center, Environmental Scientist/Chemist Dan Gazda participates in a Digital Learning Network (DLN) event with students at from St. Peter's Pr...

  13. 1. Historic American Buildings Survey Dan Leyrer, Photographer Summer 1964 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Historic American Buildings Survey Dan Leyrer, Photographer Summer 1964 FRONT ELEVATION, OVERLOOKING BAYOU ST. JOHN - Michel-Pitot House, 1370 Moss Street (moved to 1440 Moss Street), New Orleans, Orleans Parish, LA

  14. Pat Thiel talks about Nobel Prize winner Dan Shechtman

    ScienceCinema

    Thiel, Pat

    2013-03-01

    Ames Laboratory senior scientist and Iowa State University Distinguished Professor of Chemistry Pat Thiel talks about her friend and colleague Dan Shechtman who received the 2011 Nobel Prize for Chemistry.

  15. DAN instrument for NASA`s MSL mission: fast science data processing and instrument commanding for Mars surface operations and for field tests

    NASA Astrophysics Data System (ADS)

    Vostrukhin, A.; Kozyrev, A.; Litvak, M.; Malakhov, A.; Mitrofanov, I.; Mokrousov, M.; Sanin, A.; Tretyakov, V.

    2009-04-01

    detectors (raw data) to the real science products such as estimated average content of Hydrgen content or its depth distribution along the rover trace. For the rover surface operations it is necessary to provide real time data analysis to combine DAN data with data from all another science instruments and to develop the best observation strategy for the future periods of operation activity. In our approach we use: 1) Onboard FPGA data processing for recording neutron die away curves for epthermal and thermal neutrons of post-pulse afterglow 2) Getting raw data of DAN at the Mission operation center 3) Validation of instrument parameters and operational performance 4) Fast first level science data processing (statistical analysis, background subtraction, normalization) 5) Fast deconvolution of detector counts into the Hydrogen content (including numerical simulation, comparison with the known standard models of regolith), 6) Comparison with known information obtained with another instruments 7) Development of the near-term and long-term strategy for next DAN operations onboard MSL. 8) Generation and testing commanding sequences for the next period of MSL autonomous operations All this activity shall be adjusted in the real time, so the steps 2-8 shall not exceed 2-3 hours. Before launch we plan to validate this approach trough the instrument calibrations, field tests and MSL science group activity. The first experience will be presented of fast data analysis and commanding for the field tests of DAN, which were performed in the testing facility of the Joint Institute of Nuclear Research (Russia). Also, we will discuss our plans of DAN operations for coming field tests in Antarctica.

  16. STS-108 Crew Interviews: Dan Tani

    NASA Technical Reports Server (NTRS)

    2001-01-01

    STS-108 Mission Specialist Dan Tani is seen during a prelaunch interview. He answers questions about the mission's goals and significance, explaining the meaning of 'utilization flight 1' (UF-1) as opposed to an 'assembly flight'. He gives details on the payload (Starshine Satellite, Avian Development Facility, and Rafaello Multipurpose Logistics Module (MPLM)), his role in the rendezvous, docking, and undocking of the Endeavour Orbiter to the International Space Station (ISS), how he will participate in the unloading and reloading of the MPLM, and the way in which the old and new resident crews of ISS will exchanged. Tani ends with his thoughts on the short-term and long-term future of the International Space Station.

  17. Polymorphisme de l'apolipoprotéine E dans la population du nord du Maroc: fréquence et influence sur les paramètres lipidiques

    PubMed Central

    Benyahya, Fatiha; Barakat, Amina; Ghailani, Naima; Bennani, Mohcine

    2013-01-01

    Introduction L'objectif de ce travail est de déterminer les fréquences alléliques et génotypiques des sites polymorphes situés dans le gène de l'apolipoprotéine E (apo E) ainsi que leur impact sur les paramètres cliniques et lipidiques dans un échantillon de la population du nord du Maroc cliniquement diagnostiqué ADH. Méthodes Le génotype de l'apo E a été analysé par séquençage direct chez 46 patients cliniquement diagnostiqués ADH selon les critères standards. Résultats Les fréquences des allèles epsilon 3, epsilon 2 et epsilon 4 ont été respectivement 78.3%, 2.2% et 19.6%. La fréquence de l'allèle epsilon 4 est très élevée chez la population du nord du Maroc en comparaison avec les populations des autres régions marocaines. Elle est similaire à celle rapportée dans les pays de l'Europe du nord. Les taux du cholestérol total, du cholestérol LDL ainsi que la présence des xanthomes et les maladies cardiovasculaires ne différent pas entre les génotypes de l'apoE. En revanche, les résultats ont montré une influence de l'allèle epsilon4 sur le taux des triglycérides chez les sujets obèses. Conclusion Le génotype de l'apoE ne peut expliquer le phénotype clinique et biochimique présenté par des patients du Nord du Maroc cliniquement diagnostiqués ADH. PMID:24396563

  18. Ponction biopsies rénales dans le Service de Néphrologie de Fès: indications et résultats: à propos de 522 cas

    PubMed Central

    Mbarki, Houda; Belghiti, Khadija Alaoui; Harmouch, Taoufiq; Najdi, Adil; Arrayhani, Mohamed; Sqalli, Tarik

    2016-01-01

    L'apport de la ponction biopsie rénale (PBR) dans le diagnostic, le choix thérapeutique et l’évaluation pronostique des néphropathies est considérable. Aucune étude marocaine n'a évalué la pratique et l'apport de la PBR. Notre objectif est d’étudier les indications de la PBR, déterminer la fréquence des maladies rénales identifiées par PBR dans notre région et de faire une confrontation entre les données clinico-biologiques et le diagnostic historique. Notre étude menée entre Janvier 2009 et Décembre 2012, est rétrospective. Nous avons inclus tous les patients du service de Néphrologie du CHU Hassan II de Fès ayant bénéficié d'une biopsie de reins natifs. 522 PBR ont été réalisées. Nous avons exclu 8 biopsies devant le manque de renseignements et avons donc retenu 514. L’âge moyen des patients au moment de la PBR est de 39 ±17 ans (3-82 ans). Le sex ratio est de 0,9. Le syndrome néphrotique est le diagnostic clinique le plus fréquent à tous les âges (58,2%). Les néphropathies glomérulaires représentent 94,2% des maladies rénales diagnostiquées, leur distribution varie selon l’âge des patients. La PBR a confirmé le premier diagnostic suspecté cliniquement dans 40,65% des cas, alors qu'elle a révélé un diagnostic inattendu chez 22,5% d'entre eux. Le diagnostic syndromique permet d'orienter vers la maladie rénale la plus probable et de guider les thérapeutiques urgentes en attendant les résultats de la PBR. Mais il ne peut en aucun remplacer la PBR qui reste le gold standard.

  19. Eléments traces dans le sérum des enfants malnutris et bien nourris vivants à Lubumbashi et Kawama dans un contexte d'un environnement de pollution minière

    PubMed Central

    Musimwa, Aimée Mudekereza; Kanteng, Gray Wakamb; Kitoko, Hermann Tamubango; Luboya, Oscar Numbi

    2016-01-01

    Introduction La place des éléments traces métalliques essentiels en nutrition humaine ne peut plus être ignorée. Les déficits d'apports, les carences secondaires souvent sous – estimées, et les carences iatrogènes font le lit de pathologies telles que les infections et autres. D'où leurs dosages ont une importance particulière pour en évaluer la gravité et faciliter une prise en charge précoce ou améliorer le régime alimentaire. Cette étude a eu pour objectif de déterminer le profil sanguin en éléments traces (cuivre, sélénium, zinc, fer, chrome, cobalt, etc) chez les enfants malnutris et biens nourris dans un milieu minier à Lubumbashi. Méthodes Trois cents onze cas ont été colligés, 182 malnutris et 129 biens nourris, dans une étude descriptive transversale, effectuée de juillet 2013 à décembre 2014. Pour lequel un échantillonnage exhaustif a été réalisé. Le dosage des métaux dans le sérum s'est fait à l’ ICP-OES (spectrométrie de masse à plasma gon induit) au laboratoire de l'Office Congolais de Contrôle de Lubumbashi. Résultats Les oligoéléments essentiels (cuivre, zinc, sélénium et fer) se retrouvent à des concentrations très basses chez les enfants malnutris comme chez les biens nourris. L'arsenic, le cadmium, le magnésium et le manganèse se présentent à des concentrations normales par rapport aux valeurs de références chez les enfants biens nourris. L'antimoine, le chrome, le plomb et le cobalt se retrouvent élevés chez les malnutris et biens nourris. Le nickel est normal chez les malnutris et les biens nourris. Le magnésium, manganèse se sont présentés à des taux très bas chez les enfants malnutris. Conclusion Les enfants malnutris et biens nourris présentent une malnutrition aux oligo-éléments essentiels associés aux éléments traces métalliques. Ce qui permet de supposer qu'une carence en micronutriments essentiel favorise l'absorption des métaux lourds. PMID:27583075

  20. Les scénarios globaux de changement climatique et leurs incertitudesGlobal scenarios of climate change and associated uncertainties

    NASA Astrophysics Data System (ADS)

    Le Treut, Hervé

    2003-06-01

    The changes in the atmospheric chemical composition since the beginning of the industrial era have no equivalent throughout the Quaternary. All model simulations indicate that, without a significant decrease of the greenhouse gases emissions, climate is bound to change importantly during the years and decades to come. The precise forecast of these changes is made difficult both by the characteristics of natural systems which are not entirely predictable - as well as by our present and future socio-economic choices. To cite this article: H. Le Treut, C. R. Geoscience 335 (2003).

  1. La Trypanosomose Humaine Africaine dans l’espace ivoiro-burkinabé : optimisation des stratégies de surveillance épidémiologique

    PubMed Central

    Kambiré, R.; Lingué, K.; Courtin, F.; Sidibé, I.; Kiendrébéogo, D.; N’gouan, K.E.; blé, L.; Kaba, D.; Koffi, M.; Solano, P.; Bucheton, B.; Jamonneau, V.

    2012-01-01

    L’objectif de cet article est de décrire les récentes données de surveillance médicale de la Trypanosomose Humaine Africaine (THA) au Burkina Faso et en Côte d’Ivoire afin (i) de dresser un bilan de la situation actuelle de la maladie dans ces deux pays qui entretiennent depuis plus d’un siècle des liens migratoires, économiques et épidémiologiques intimes et (ii) de définir les stratégies à mettre en place dans l’objectif d’une élimination durable. Les résultats de la surveillance active et passive ont montré que les trypanosomés dépistés au Burkina-Faso ces dernières années sont tous des cas importés provenant de Côte d’Ivoire. Cependant, la réintroduction du parasite est effective et le risque d’une reprise de la transmission existe. En Côte d’Ivoire, plusieurs foyers “historiques” toujours endémiques font craindre des phénomènes de réémergence et de propagation. Dans l’objectif d’une élimination durable de la THA dans ces deux pays, les acteurs de la lutte doivent adapter leur système de surveillance en fonction des différents contextes épidémiologiques. Les prévalences actuelles ne justifient plus, excepté des cas particuliers, l’usage systématique et très onéreux du dépistage actif par prospections médicales exhaustives. Elles tendent plutôt à privilégier des systèmes intégrés aux systèmes de santé nationaux et utiliser des méthodes permettant de cibler les zones prioritaires d’intervention à partir notamment d’un échange d’informations épidémiologiques entre les deux pays. Pour accompagner le processus d’élimination durable, les acteurs de la recherche doivent étudier le rôle respectif des réservoirs humain et animal dans le maintien de la transmission, participer au suivi sur le long terme des cas traités et des suspects sérologiques, et évaluer en termes de coût/efficacité les stratégies mises en place par les Programmes Nationaux afin de les optimiser. PMID

  2. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2007-09-01

    Anions interstellaires; S Orionis; Altaîr; Courants stellaires; Etoiles jeunes; 2MASSW J1207334-393254; Alpha Andromède; Etoiles à neutrons (1); LH54-425; AGNs invisibles; Deux supernovae; Les GRBs seon Swift; Peser les trous noirs; Formation de trous noirs; Trou noir; ondes gravitationnelles : Virgo entre dans sa phase d'exploitation scientifique; Amas de galaxies actifs; Amas de galaxies; Galaxies actives d'amas; L'univers statique: le retour; Macho; Exoplanètes; Exoplanètes habitables?; Exoplanètes habitables? (suite); Une année d'un an; Une année de 31 heures; Valse des Jupiters; Disque de HD 15115; Impact majeur; Planètes isolées; Super-Jupiter; Impact et mini-extinction; L'effet Pioneer; Toungouska; Spéléo martienne; Autres lunes dactives; Encelade; Hypérion; Pluton dépassé; Satellites d'Uranus; Titan

  3. Place du Lambeau Interosseux Posterieur dans sa Variante Aponevrotique dans le Traitement des Sequelles de Brulure de la Face Dorsale de la Main

    PubMed Central

    Achbouk, A.; Khales, A.; Oufkir, A.; Ihrai, H.

    2010-01-01

    Summary Le lambeau interosseux postérieur dans sa variante aponévrotique est un outil très intéressant dans le traitement des séquelles de brûlures de la face dorsale de la main. Les Auteurs cherchent, à travers un cas clinique et une revue de la littérature, à replacer cette variante dans l'arsenal thérapeutique. PMID:21991207

  4. Kyste hydatique du foie rompu dans la paroi abdominale et dans le muscle psoas : à propos d'une rare observation

    PubMed Central

    En-Nafaa, Issam; Moujahid, Mountassir; Alahyane, Abdelouahabe; Amil, Touria; Hanine, Ahmed; Ziadi, Tarik

    2011-01-01

    Le kyste hydatique du foie est une parasitose qui sévit à l′état endémique au maroc. La rupture dans la paroi abdominale et dans le psoas est une complication exceptionnelle. Nous rapportons un cas de kyste hydatique du foie rompu dans la paroi et dans le muscle psoas. Le diagnostic a été établi sur les données de l′échographie et surtout de la tomodensitométrie. Le patient a été opéré avec des suites simples. PMID:22187585

  5. ADFL Award for Distinguished Service in the Profession: Dan Davidson.

    ERIC Educational Resources Information Center

    Dabars, Zita D.

    1999-01-01

    Discusses the influence of Dan Davidson on the Russian language teaching profession, concentrating on the NEH-CORLAC Institutes in Russian Language and Culture and materials development projects and on Davidson's role in programs involving high schools that teach Russian, the high school exchange program, and two national contests to stimulate…

  6. Dan Poskevich demonstrates experiment for STS student involvement project

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Dan Poskevich, a college student, demonstrates an experiment he developed for the Space Transportation System (STS) student involvement project. In the aluminum box are thousands of honeybees constructing a honeycomb. Poskevich gave a brief demonstration for news media representatives in the Space Shuttle one-G trainer in JSC's mockup and integration lab.

  7. Observance thérapeutique de l’hypertension artérielle et ses facteurs dans le service de cardiologie du CHU Tokoin de Lomé

    PubMed Central

    Pio, Machihude; Baragou, Soodougoua; Afassinou, Yaovi; Pessinaba, Souleymane; Atta, Borgatia; Ehlan, Koffi; Goeh-Akue, Edem; Zoméni, Folly; Damorou, Jean-Marie

    2013-01-01

    Introduction Evaluer l’observance thérapeutique de l’HTA et de déterminer les facteurs de mauvaise observance chez les hypertendus au CHU Tokoin de Lomé. Méthodes Nous avons effectué une étude transversale descriptive sur une durée de 6 mois en consultation externe dans le service de Cardiologie du CHU-Tokoin de Lomé. L’étude a concerné 363 patients hypertendus. L’évaluation de l’observance a été effectuée avec le test d’évaluation de l’observance de Girerd. Résultats Le revenu mensuel était inférieur à 50.000 FCFA chez 49,86% patients; 85,05% des patients n’avaient aucune assurance maladie. Le coût mensuel du traitement par patient était de 10.560 FCFA soit 37,74% du SMIG au Togo. Quatre-vingt et trois virgule soixante-quinze pour cent (83,75%) de nos patients avaient eu des difficultés à observer correctement leur traitement antihypertenseur. Parmi eux 52,34% étaient mauvais observants et 31,41% avaient de minimes problèmes d’observance. Seuls 16,25% étaient de bons observants. Les facteurs de mauvaises observances étaient: le revenu mensuel faible, l’absence d’assurance maladie, le nombre de comprimés et de prises de comprimés supérieurs à 3, et la tradithérapie. Conclusion L’observance thérapeutique a été mauvaise dans notre série. Les facteurs de cette mauvaise observance sont multiples et variés mais dominés pour la plupart par la pauvreté et l’absence d’assurance maladie. PMID:23560131

  8. Transport de paires EPR dans des structures mesoscopiques

    NASA Astrophysics Data System (ADS)

    Dupont, Emilie

    Dans cette these, nous nous sommes particulierement interesses a la propagation de paires EPR1 delocalisees et localisees, et a l'influence d'un supraconducteur sur le transport de ces paires. Apres une introduction de cette etude, ainsi que du cadre scientifique qu'est l'informatique quantique dans lequel elle s'inscrit, nous allons dans le chapitre 1 faire un rappel sur le systeme constitue de deux points quantiques normaux entoures de deux fils supraconducteurs. Cela nous permettra d'introduire une methode de calcul qui sera reutilisee par la suite, et de trouver egalement le courant Josephson produit par ce systeme transforme en SQUID-dc par l'ajout d'une jonction auxiliaire. Le SQUID permet de mesurer l'etat de spin (singulet ou triplet), et peut etre forme a partir d'autres systemes que nous etudierons ensuite. Dans le chapitre 2, nous rappellerons l'etude detaillee d'un intricateur d'Andreev faite par un groupe de Bale. La matrice T, permettant d'obtenir le courant dans les cas ou les electrons sont separes spatialement ou non, sera etudiee en detail afin d'en faire usage au chapitre suivant. Le chapitre 3 est consacre a l'etude de l'influence du bruit sur le fonctionnement de l'intricateur d'Andreev. Ce bruit modifie la forme du courant jusqu'a aboutir a d'autres conditions de fonctionnement de l'intricateur. En effet, le bruit present sur les points quantiques peut perturber le transport des paires EPR par l'intermediaire des degres de liberte. Nous montrerons que, du fait de l'"intrication" entre la charge de la paire et le bruit, la paire est detruite pour des temps longs. Cependant, le resultat le plus important sera que le bruit perturbe plus le transport des paires delocalisees, qui implique une resonance de Breit-Wigner a deux particules. Le transport parasite n'implique pour sa part qu'une resonance de Breit-Wigner a une particule. Dans le chapitre 4, nous reviendrons au systeme constitue de deux points quantiques entoures de deux fils

  9. Le rôle de l’omalizumab dans le traitement de l’asthme allergique grave

    PubMed Central

    Chapman, Kenneth R; Cartier, André; Hébert, Jacques; McIvor, R Andrew; Schellenberg, R Robert

    2006-01-01

    les patients traités par l’omalizumab que chez les sujets témoins. Des analyses rétrospectives ont permis d’identifier les caractéristiques des patients les plus susceptibles de répondre au traitement par l’omalizumab. RECOMMANDATIONS : L’omalizumab pourrait être envisagé comme traitement d’appoint dans les cas atopiques d’asthme grave non maîtrisé avec des traitements classiques par des doses optimales de CSI et un traitement d’appoint approprié (p. ex. : agonistes bêta-2 à action prolongée). En général, les patients sont classés en fonction de leur recours – traitement court et fréquent ou continu et oral – aux corticostéroïdes. Il ne faut amorcer le traitement qu’après avoir consulté un spécialiste pour confirmer le diagnostic et s’assurer que le traitement classique est optimal.

  10. Transport de particules massives dans un fluide turbulent: Application a l'erosion due au sable sur les parois d'une turbine hydraulique

    NASA Astrophysics Data System (ADS)

    Bergeron, Stephen

    Le transport de particules massives par un champ turbulent est un vaste domaine de la mécanique des fluides. Il possède de nombreuses applications comme par exemple le transport de sable dans une turbine hydraulique. En raison de la dureté des grains de quartz et des grandes vitesses de collision avec les parois métalliques, un phénomène d'érosion intensif se produit. Les dommages résultants peuvent diminuer le rendement de la turbine au cours des quelques mois suivant la mise en opération. L'objectif de cette thèse est de mettre au point un outil permettant de prédire ces zones d'érosion. Ce projet de recherche en contexte industriel a été réalisé en collaboration avec la compagnie General Electric Hydro du Canada. Dans un régime hautement turbulent, il est possible d'obtenir une expression suffisamment générale en utilisant une formulation partiellement empirique: l'équation de Basset- Boussinesq-Oseen modifiée. Ce choix de modèle tient compte du niveau de précision recherché et de la méthode numérique employée afin de résoudre la phase fluide. Il permet aussi d'éliminer plusieurs ambiguïtés fréquemment rencontrées dans la littérature et implementées dans certains codes commerciaux courants. La formulation mathématique du problème est effectuée dans un espace mixte Euler-Lagrange. Les paramètres dynamiques sont relies au type de particules et à l'intensité de la turbulence. Le code numérique résultant est le plus performant développé à ce jour (août 1998). Les trajectoires de plusieurs centaines de milliers de particules peuvent être simulées et visualisées de manière interactive sur une station de travail (SGI R4K, R8K et R10K). L'utilisateur du logiciel est libre de se déplacer dans l'espace à l'aide d'un environnement similaire a un ``simulateur de vol''. Il peut ainsi analyser les détails du processus d'érosion de même que l'écoulement du fluide dans la turbine. Les zones d'érosion obtenues à l

  11. SSPX simulation model

    SciTech Connect

    Fowler, T K

    1999-09-20

    An analytical approximation to an R-L-C circuit representing SSPX is shown to reproduce the observed capacitor bank efficiency and gun optimization data. As in the SPICE code, the spheromak gun is represented by a fixed resistance chosen to balance energy transfer to the gun. A revised estimate of the magnetic decay time in SSPX Shot 1822 then brings our estimate of the gun efficiency itself in line with the observed spheromak magnetic field for this shot. Prompted by these successes, we present a turbulence-based theoretical model for the spheromak resistance that can be implemented in the SPICE code, of the form: R{sub s} = {kappa}I (1-I{sub 0}/I){sup 2} where I is the gun current, I{sub 0} = ({Lambda}{sub 0}/{mu}{sub 0}){Phi} with bias flux and Taylor eigenvalue {lambda}{sub 0}, and {kappa} is a coefficient based on the magnetic turbulence model employed in Dan Hua's spheromak simulation code. The value of {kappa} giving a good energy balance (around 0.1 m{Omega}/KA) implies substantial turbulence levels. Implementing our model in SPICE would provide a calibration for theoretical calculations of the turbulence. Our analytic approximation to the SPICE code provides guidance to optimize future performance in SSPX, the greatest benefit appearing to come from reducing or eliminating the protective resistor to increase bank efficiency. Eliminating the resistor altogether doubles the bank efficiency and the spheromak magnetic energy.

  12. Etude par Imagerie à faible Niveau dans le proche Infrarouge d'une Emission de la haute Atmosphère

    NASA Astrophysics Data System (ADS)

    Pautet, Pierre-Dominique

    2000-12-01

    Le travail effectué a eu pour but la mise en place d'un protocole d'observation et de traitement des images, ainsi que les outils appropriés, visant à l'étude d'une émission de la haute atmosphère terrestre dans le proche infrarouge. Il existe actuellement des télescopes comme le VLT (Very Large Telescope), installé au Chili, qui permettent d'observer des astres et des galaxies distants de plusieurs millions de parsecs. A cause de l'expansion de l'Univers, des objets situés aussi loin s'éloignent très rapidement de nous. Le spectre de leur émission qui nous parvient alors est décalé vers le rouge ou l'infrarouge, du fait de l'effet Doppler. Il faut donc observer ces objets dans des longueurs d'onde appropriées. Malheureusement, l'atmosphère terrestre qui nous sépare d'eux est aussi le siège de nombreuses émissions qui peuvent venir perturber les mesures. De toutes ces émissions, la principale est due au radical OH dont les raies de rotation-vibration couvrent tout le spectre entre 0,7 et 2,5 microns. Cette émission a lieu au niveau d'une couche assez fine de la haute atmosphère appelée mésopause et située à environ 85 kilomètres d'altitude. Le travail effectué a eu pour but de mettre en évidence les principales caractéristiques de cette émission qui n'est pas uniforme et constante dans le temps. Un programme d'observations dans le proche infrarouge a été élaboré. Plusieurs algorithmes de traitement d'image ont été développés. Un programme d'inversion de perspective a été mis au point pour une utilisation en temps réel sur le terrain. Les caractéristiques des images peuvent être ensuite analysées. La première partie du mémoire comporte une description des différentes émissions lumineuses que l'on peut observer la nuit lorsque l'on regarde la voûte céleste. Ces émissions peuvent avoir deux origines: astronomique ou atmosphérique. Le problème de l'absorption atmosphérique et plus précisément les conditions

  13. Analyse des transferts de chaleur et de masse transitoires dans un arena a l'aide de la methode zonale

    NASA Astrophysics Data System (ADS)

    Daoud, Ahmed

    Cette these presente les resultats d'une etude sur le mouvement de l'air et les transferts thermiques et massiques dans les arenas en regime transitoire et en 3D. Pour la partie aeraulique, il a ete question de developper un modele base sur la methode zonale qui permet de calculer les debits de l'air (dus a la ventilation et aux gradients de temperature) et de l'humidite entre les differentes zones du batiment et de determiner l'age de l'air dans chacune des zones. Pour la partie thermique, un modele de calcul du rayonnement entre les surfaces interieures du batiment qui a ete couple a TRNSYS afin de calculer sur une base annuelle les charges de chauffage et de refrigeration; ces dernieres tiennent compte des transferts radiatif et convectif, de la chaleur latente due a la condensation de l'humidite sur la glace et du surfacage. Le document presente est constitue de 7 chapitres qui peuvent etre resumes comme suit: Les chapitres 1, 2 et 3 sont consacres respectivement: a l'introduction generale, a la revue bibliographique et a la description du batiment modelise. Le chapitre 4 decrit l'approche developpee et la contribution importante qui y est apportee. Il presente l'utilisation de la methode zonale comme une alternative pratique aux methodes CFD car elle permet de realiser des simulations dynamiques sur une annee avec des temps de simulation tres courts et une precision acceptable. Il s'agit d'une approche intermediaire entre les modeles CFD et les modeles a un noeud d'air (considerant la temperature homogene dans un local). Le chapitre 5 est consacre a la methode de resolution numerique. L'outil de simulation a ete developpe en utilisant l'interface du logiciel TRNSYS: Le type 56 de ce logiciel a ete adopte comme modele energetique tandis que les autres modeles ont ete developpes et programmes en utilisant le logiciel MATLAB. Le chapitre 6 presente les resultats de simulation pour un arena sans faux plafond et avec un faux plafond et les resultats de mesures

  14. NASA Administrator Dan Goldin talks with STS-78 crew

    NASA Technical Reports Server (NTRS)

    1996-01-01

    NASA Administrator Dan Goldin (left) chats with STS-78 Mission Commander Terence 'Tom' Henricks (center) and KSC Director Jay Honeycutt underneath the orbiter Columbia. Columbia and her seven-member crew touched down on Runway 33 of KSC's Shuttle Landing Facility at 8:36 a.m. EDT, July 7, bringing to a close the longest Shuttle flight to date. STS-78, which also was the 78th Shuttle flight, lasted 16 days, 21 minutes and 47 seconds.

  15. Application de la méthode des simulations croisées à l'analyse de tendances dans la relation pluie-débit à partir du modèle GR2M : cas du bassin versant du N'zi-Bandama (Côte d'Ivoire)

    NASA Astrophysics Data System (ADS)

    Kouassi, Amani Michel; Bi, Tozan Michel N.'guessan; Kouamé, Koffi Fernand; Kouamé, Kassi Alexis; Okaingni, Jean-Claude; Biemi, Jean

    2012-05-01

    The study area is the N'zi watershed, sub-watershed of the Bandama River (Ivory Coast). The N'zi watershed is located between longitudes 3°49' and 5°22' West and latitudes 6°00' and 9°26' North and covers an area of 35,500 km2. This study aims to identify trends in the rainfall-runoff relationship by using a monthly conceptual model. The methodology has consisted on the one hand in highlighting the existence of interannual climate and hydrological variability by using the method of segmentation of Hubert, and on the other hand, in applying the crossed simulations method by using the GR2M model, over several 7-year sub-periods. The results of the application of the method of segmentation of Hubert have demonstrated the presence of a hydroclimatic variability in the N'zi watershed. The modifications of the climate and physical conditions of the flow resulted in a modification of the hydrological response of the watershed translated by a non-stationarity in the rainfall-runoff relation.

  16. JASMINE simulator

    NASA Astrophysics Data System (ADS)

    Ueda, Seiji; Yamada, Yoshiyuki; Kuwabara, Takashi; Gouda, Naoteru; Tsujimoto, Takuji; Kobayashi, Yukiyasu; Nakajima, Tadashi; Matsuhara, Hideo; Yano, Taihei; Suganuma, Masahiro; Jasmine Working Group

    2005-04-01

    We explain simulation tools in the JASMINE project (JASMINE simulator). The JASMINE project stands at the stage where its basic design will be determined in a few years. Therefore it is very important to simulate the data stream generated by astrometric fields at JASMINE in order to support investigations of error budgets, sampling strategy, data compression, data analysis, scientific performances, etc. We find that new software technologies, such as Object Oriented (OO) methodologies, are ideal tools for the simulation system of JASMINE (the JASMINE simulator). In this article, we explain the framework of the JASMINE simulator.

  17. JASMINE simulator

    NASA Astrophysics Data System (ADS)

    Yamada, Yoshiyuki; Gouda, Naoteru; Yano, Taihei; Kobayashi, Yukiyasu; Tsujimoto, Takuji; Suganuma, Masahiro; Niwa, Yoshito; Sako, Nobutada; Hatsutori, Yoichi; Tanaka, Takashi

    2006-06-01

    We explain simulation tools in JASMINE project (JASMINE simulator). The JASMINE project stands at the stage where its basic design will be determined in a few years. Then it is very important to simulate the data stream generated by astrometric fields at JASMINE in order to support investigations into error budgets, sampling strategy, data compression, data analysis, scientific performances, etc. Of course, component simulations are needed, but total simulations which include all components from observation target to satellite system are also very important. We find that new software technologies, such as Object Oriented(OO) methodologies are ideal tools for the simulation system of JASMINE(the JASMINE simulator). In this article, we explain the framework of the JASMINE simulator.

  18. Burnwire Simulator

    NASA Technical Reports Server (NTRS)

    Bummer, G. L.

    1985-01-01

    Fuse-containing device simulates pyrotechnic firing circuitry. Simulator includes housing receptacle connector at one end, and fuse at opposite end. Fuse circuit useful in any system having complex built-in wiring for current pulse applications.

  19. Network Simulation

    SciTech Connect

    Fujimoto, Richard; Perumalla, Kalyan S; Riley, George F.

    2006-01-01

    A detailed introduction to the design, implementation and use of network simulation tools is presented. The requirements and issues faced in the design of simulators for wired and wireless networks are discussed. Abstractions such as packet- and fluid-level network models are covered. Several existing simulations are given as examples, with details and rationales regarding design decisions presented. Issues regarding performance and scalability are discussed in detail, describing how one can utilize distributed simulation methods to increase the scale and performance of a simulation environment. Finally, a case study of two simulation tools is presented that have been developed using distributed simulation techniques. This text is essential to any student, researcher or network architect desiring a detailed understanding of how network simulation tools are designed, implemented, and used.

  20. 77 FR 75628 - STS Hydropower, Ltd., Dan River, Inc., and City of Danville, VA; Notice of Application for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-21

    ... Energy Regulatory Commission STS Hydropower, Ltd., Dan River, Inc., and City of Danville, VA; Notice of..., 2012, Jeoffrey L. Burtch, as Chapter 7 Bankruptcy Trustee for Dan River, Inc. and STS Hydropower, Ltd... the license for the Schoolfield Hydroelectric Project from Dan River, Inc. and STS Hydropower, Ltd....

  1. Dan Olweus: Award for Distinguished Contributions to Research in Public Policy

    ERIC Educational Resources Information Center

    American Psychologist, 2012

    2012-01-01

    Presents a short biography of the winner of the American Psychological Association's Award for Distinguished Contributions to Research in Public Policy. The 2012 winner is Dan Olweus for his rigorous scientific research on bullying among children and youth and his early and tireless attention to its public policy implications. Dan Olweus's…

  2. Etude par RMN de composés organiques contenant des chalcogènes—VIII. RMN du 13C dans la chromannone, la chromone, la coumarannone-3 et la coumarine et leurs analogues soufrés, séléniś et tellurés

    NASA Astrophysics Data System (ADS)

    Baiwir, Marcel; Llabrès, Gabriel; Christiaens, Léon; Luxen, André; Piette, Jean-Louis

    13C NMR spectra of the title compounds have been fully assigned. The results have been compared with those relative to other chalcogenated compounds, such as anisole, phenyl benzoate, benzofuran,… and their analogs. In chalcogenochromones and -coumarines, the heteroatom lone pair delocalization spreads to some extent over the heterocyclic part of the molecules, while in chalcogenochromanones and -indoxyles, it only extends to the homocycle. This electronic effect seems also to affect the heavy atom effect exhibited by Te-containing compounds.

  3. Programme experimental de developpement de competences aupres de parents quit eprouvent des difficultes a lire et a ecrire, dans des situations d'eveil au monde de l'ecrit chez leurs enfants d'age prescolaire (An Experimental Program To Develop the Competencies of Parents Who Experience Difficulties in Reading and Writing, in Unfamiliar Situations in Their Preschool Children's World of Literacy).

    ERIC Educational Resources Information Center

    Lavoie, Nathalie; Levesque, Jean-Yves

    1999-01-01

    Examined the impact of a program in Quebec to improve parents' abilities to introduce their preschoolers to the written word. Found evidence for parents' progress and gains in skills. Concluded that the program has significant potential for parental skill development. (Author/KB)

  4. MALDI-MS analysis and imaging of small molecule metabolites with 1,5-diaminonaphthalene (DAN)

    SciTech Connect

    Korte, Andrew R; Lee, Young Jin

    2014-07-08

    1,5-diaminonaphthalene (DAN) has previously been reported as an effective matrix for matrix-assisted laser desorption ionization-mass spectrometry of phospholipids. In the current work, we investigate the use of DAN as a matrix for small metabolite analysis in negative ion mode. DAN was found to provide superior ionization to the compared matrices for MW < ~400 Da; however, 9-aminoacridine (9-AA) was found to be superior for a uridine diphosphate standard (MW 566 Da). DAN was also found to provide a more representative profile of a natural phospholipid mixture than 9-AA. Finally, DAN and 9-AA were applied for imaging of metabolites directly from corn leaf sections. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  5. Blocage de Coulomb dans une boite quantique laterale contenant un faible nombre d'electrons

    NASA Astrophysics Data System (ADS)

    Gould, Charles

    Dans ce travail on utilise une nouvelle geometrie pour augmenter le controle sur le nombre d'electrons contenus dans une boite quantique laterale, et ainsi atteindre un regime de petit nombre d'electrons. Ces echantillons permettent une etude du blocage de Coulomb quand les electrons sont injectes a partir d'un gaz electronique a deux dimensions (2DEG). Les mesures a faible champ magnetique demontrent la grande flexibilite des echantillons et montrent que l'on peut faire varier le nombre d'electrons dans une boite quantique a partir de plus de 40 electrons jusqu'a un seul electron, ce qui est assez courant dans les boites quantiques verticales, mais ce qui n'avait jamais ete reussi dans une boite quantique laterale. Nos resultats montrent egalement que dans les boites quantiques laterales il est possible de determiner le spin du niveau qui participe au transport a l'aide du phenomene de blocage de spin. De plus, dans certaines circonstances il est meme possible de determiner le spin total de la boite quantique, ce qui peut avoir des applications pratiques dans des domaines tels l'informatique quantique. Les mesures dans le regime de renversement de spin a un champ magnetique plus eleve montrent l'importance des correlations electrons---electrons dans ces boites quantiques, qui menent a des depolarisations et a des structures de spins qui ont un effet sur le transport. En particulier, ces correlations menent a l'existence de niveaux excites de basse energie qui causent une dependance anormale de l'amplitude des pics de blocage de Coulomb en fonction de la temperature. Nos experiences demontrent egalement la possibilite d'utiliser ces boites quantiques comme sondes pour etudier les proprietes du bord d'un 2DEG. Une voie de recherche a etre exploree.

  6. JASMINE Simulator

    NASA Astrophysics Data System (ADS)

    Yamada, Y.; Gouda, N.; Yano, T.; Kobayashi, Y.; Suganuma, M.; Tsujimoto, T.; Sako, N.; Hatsutori, Y.; Tanaka, T.

    2006-08-01

    We explain simulation tools in JASMINE project (JASMINE simulator). The JASMINE project stands at the stage where its basic design will be determined in a few years. Then it is very important to simulate the data stream generated by astrometric fields at JASMINE in order to support investigations of error budgets, sampling strategy, data compression, data analysis, scientific performances, etc. Of course, component simulations are needed, but total simulations which include all components from observation target to satellite system are also very important. We find that new software technologies, such as Object Oriented (OO) methodologies are ideal tools for the simulation system of JASMINE (the JASMINE simulator). The simulation system should include all objects in JASMINE such as observation techniques, models of instruments and bus design, orbit, data transfer, data analysis etc. in order to resolve all issues which can be expected beforehand and make it easy to cope with some unexpected problems which might occur during the mission of JASMINE. So, the JASMINE Simulator is designed as handling events such as photons from astronomical objects, control signals for devices, disturbances for satellite attitude, by instruments such as mirrors and detectors, successively. The simulator is also applied to the technical demonstration "Nano-JASMINE". The accuracy of ordinary sensor is not enough for initial phase attitude control. Mission instruments may be a good sensor for this purpose. The problem of attitude control in initial phase is a good example of this software because the problem is closely related to both mission instruments and satellite bus systems.

  7. Dan Goldin Presentation: Pathway to the Future

    NASA Technical Reports Server (NTRS)

    1999-01-01

    for distributed collaboration, rapid synthesis and simulation tools, and life-cycle integration and validation. Mr. Goldin concludes his presentation with the following maxim "Collaborate, Integrate, Innovate or Stagnate and Evaporate." He also answers some questions after the presentation.

  8. NASA Administrator Dan Goldin greets 10-year-old VIP.

    NASA Technical Reports Server (NTRS)

    2000-01-01

    NASA Administrator Dan Goldin (left) shares a light moment during his meeting with 10-year-old Jonathan Pierce (right), who is garbed in a protective cooling suit designed by NASA. Behind Goldin is astronaut Doug Wheelock; behind Jonathan is his mother, Penny. Jonathan suffers from erythropoietic protoporphyria, a rare condition that makes his body unable to withstand ultraviolet rays. The suit allows him to be outside during the day, which would otherwise be impossible. Jonathan's trip was funded by the Make-A-Wish Foundation and included a visit to Disney World. He and his family were among a dozen VIPs at KSC to view the launch of STS-99.

  9. Quantum simulation

    NASA Astrophysics Data System (ADS)

    Georgescu, I. M.; Ashhab, S.; Nori, Franco

    2014-01-01

    Simulating quantum mechanics is known to be a difficult computational problem, especially when dealing with large systems. However, this difficulty may be overcome by using some controllable quantum system to study another less controllable or accessible quantum system, i.e., quantum simulation. Quantum simulation promises to have applications in the study of many problems in, e.g., condensed-matter physics, high-energy physics, atomic physics, quantum chemistry, and cosmology. Quantum simulation could be implemented using quantum computers, but also with simpler, analog devices that would require less control, and therefore, would be easier to construct. A number of quantum systems such as neutral atoms, ions, polar molecules, electrons in semiconductors, superconducting circuits, nuclear spins, and photons have been proposed as quantum simulators. This review outlines the main theoretical and experimental aspects of quantum simulation and emphasizes some of the challenges and promises of this fast-growing field.

  10. Le genre Tunga Jarocki, 1838 (Siphonaptera : Tungidae). I – Taxonomie, phylogénie, écologie, rôle pathogène

    PubMed Central

    Beaucournu, J.-C.; Degeilh, B.; Mergey, T.; Muñoz-Leal, S.; González-Acuña, D.

    2012-01-01

    Pour la première fois, les 12 espèces actuellement décrites dans le genre Tunga sont étudiées sur le plan de la taxonomie et de la répartition. Divers aspects de leur biologie et leur rôle pathogène sont également envisagés, et en particulier leur phylogénie, leur chorologie, leur phénologie, leur sexe-ratio et leurs dermecos. PMID:23193514

  11. Simulation Accelerator

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Under a NASA SBIR (Small Business Innovative Research) contract, (NAS5-30905), EAI Simulation Associates, Inc., developed a new digital simulation computer, Starlight(tm). With an architecture based on the analog model of computation, Starlight(tm) outperforms all other computers on a wide range of continuous system simulation. This system is used in a variety of applications, including aerospace, automotive, electric power and chemical reactors.

  12. Procedural simulation.

    PubMed

    Patel, Aalpen A; Glaiberman, Craig; Gould, Derek A

    2007-06-01

    In the past few decades, medicine has started to look at the potential use of simulators in medical education. Procedural medicine lends itself well to the use of simulators. Efforts are under way to establish national agendas to change the way medical education is approached and thereby improve patient safety. Universities, credentialing organizations, and hospitals are investing large sums of money to build and use simulation centers for undergraduate and graduate medical education. PMID:17574195

  13. Surgical Simulation

    PubMed Central

    Sutherland, Leanne M.; Middleton, Philippa F.; Anthony, Adrian; Hamdorf, Jeffrey; Cregan, Patrick; Scott, David; Maddern, Guy J.

    2006-01-01

    Objective: To evaluate the effectiveness of surgical simulation compared with other methods of surgical training. Summary Background Data: Surgical simulation (with or without computers) is attractive because it avoids the use of patients for skills practice and provides relevant technical training for trainees before they operate on humans. Methods: Studies were identified through searches of MEDLINE, EMBASE, the Cochrane Library, and other databases until April 2005. Included studies must have been randomized controlled trials (RCTs) assessing any training technique using at least some elements of surgical simulation, which reported measures of surgical task performance. Results: Thirty RCTs with 760 participants were able to be included, although the quality of the RCTs was often poor. Computer simulation generally showed better results than no training at all (and than physical trainer/model training in one RCT), but was not convincingly superior to standard training (such as surgical drills) or video simulation (particularly when assessed by operative performance). Video simulation did not show consistently better results than groups with no training at all, and there were not enough data to determine if video simulation was better than standard training or the use of models. Model simulation may have been better than standard training, and cadaver training may have been better than model training. Conclusions: While there may be compelling reasons to reduce reliance on patients, cadavers, and animals for surgical training, none of the methods of simulated training has yet been shown to be better than other forms of surgical training. PMID:16495690

  14. Simulating Science

    ERIC Educational Resources Information Center

    Markowitz, Dina; Holt, Susan

    2011-01-01

    Students use manipulative models and small-scale simulations that promote learning of complex biological concepts. The authors have developed inexpensive wet-lab simulations and manipulative models for "Diagnosing Diabetes," "A Kidney Problem?" and "A Medical Mystery." (Contains 5 figures and 3 online resources.)

  15. Simulated Experiments

    ERIC Educational Resources Information Center

    Snadden, R. B.; Runquist, O.

    1975-01-01

    Presents an experiment in which a programmable calculator is employed as a data generating system for simulated laboratory experiments. The example used as an illustration is a simulated conductimetric titration of an aqueous solution of HC1 with an aqueous solution of NaOH. (Author/EB)

  16. Neutron Background Measurements by the the MSL Dynamic Albedo of Neutrons (DAN) Instrument during the First 360 sols of the Surface Operation at Mars

    NASA Astrophysics Data System (ADS)

    Jun, I.; Mitrofanov, I. G.; litvak, M. L.; Sanin, A.; Behar, A.; Boynton, W. V.; DeFlores, L.; Golovin, D.; Hardgrove, C. J.; Harshman, K.; Kozyrev, A.; Kuzmin, R.; Malakhov, A.; Mischna, M. A.; Moersch, J.; Mokrousov, M.; Nikiforov, S.; Shvetsov, V.; Tate, C.; Vostrukhin, A.; Team, M.

    2013-12-01

    Since first commissioned on sol 3 after landing in August 2012, DAN has been operating successfully and provided a wealth of surface measurement data both in Active mode and in Passive mode operations. Active mode measurements provide a means to determine the characteristics of subsurface in terms of layering structure, content of water equivalent hydrogen (WEH), and/or content of chlorine. Passive mode measurements provide a general background level of low energy (< ~1 keV) neutrons induced by Galactic Cosmic Ray (GCR) interactions with the Martian atmosphere and the surface material and from Multi Mission Radioisotope Thermonuclear Generator (MMRTG). Passive mode measurements have been done on almost every sols with durations ranging from 1 hour to ~9 hour, covering different times of a day. Extensive numerical simulations have been carried out to aid in interpreting the DAN passive data. Both surface operation and numerical simulations show that the passive data correlate very well with the active data. It was also found that the passive data alone could provide a general trend of WEH content variation along the rover traverse. A methodology to estimate the respective contribution from each source (i.e., MMRTG neutrons and GCR-induced neutrons) for the passive data has been developed and was used to understand the neutron background environment at the Rocknest site, where the rover stayed over an extended period of time (from sol 59 to sol 100). The result shows that the MMRTG contribution to the DAN passive counts was about 60% of the total, and the GCR-induced counts were estimated to be about 40%. Details of all these observations, modeling effort, and analysis and interpretation processes will be presented in the final paper by using the passive data collected through sol 360.

  17. Motion Simulator

    NASA Technical Reports Server (NTRS)

    1993-01-01

    MOOG, Inc. supplies hydraulic actuators for the Space Shuttle. When MOOG learned NASA was interested in electric actuators for possible future use, the company designed them with assistance from Marshall Space Flight Center. They also decided to pursue the system's commercial potential. This led to partnership with InterActive Simulation, Inc. for production of cabin flight simulators for museums, expositions, etc. The resulting products, the Magic Motion Simulator 30 Series, are the first electric powered simulators. Movements are computer-guided, including free fall to heighten the sense of moving through space. A projection system provides visual effects, and the 11 speakers of a digital laser based sound system add to the realism. The electric actuators are easier to install, have lower operating costs, noise, heat and staff requirements. The U.S. Space & Rocket Center and several other organizations have purchased the simulators.

  18. JASMINE simulator

    NASA Astrophysics Data System (ADS)

    Yamada, Y.; Gouda, N.; Yano, T.; Sako, N.; Hatsutori, Y.; Tanaka, T.; Yamauchi, M.

    We explain simulation tools in JASMINE project(JASMINE simulator). The JASMINE project stands at the stage where its basic design will be determined in a few years. Then it is very important to simulate the data stream generated by astrometric fields at JASMINE in order to support investigations of error budgets, sampling strategy, data compression, data analysis, scientific performances, etc. Of course, component simulations are needed, but total simulations which include all components from observation target to satellite system are also very important. We find that new software technologies, such as Object Oriented(OO) methodologies are ideal tools for the simulation system of JASMINE(the JASMINE simulator). The simulation system should include all objects in JASMINE such as observation techniques, models of instruments and bus design, orbit, data transfer, data analysis etc. in order to resolve all issues which can be expected beforehand and make it easy to cope with some unexpected problems which might occur during the mission of JASMINE. So, the JASMINE Simulator is designed as handling events such as photons from astronomical objects, control signals for devices, disturbances for satellite attitude, by instruments such as mirrors and detectors, successively. The simulator is also applied to the technical demonstration "Nano-JASMINE". The accuracy of ordinary sensor is not enough for initial phase attitude control. Mission instruments may be a good sensor for this purpose. The problem of attitude control in initial phase is a good example of this software because the problem is closely related to both mission instruments and satellite bus systems.

  19. L'hemorragie grave du peripartum en milieu de reanimation dans un centre universitaire tunisien de niveau 3: épidémiologie et facteurs de risque de mortalité maternelle

    PubMed Central

    Nasr, Laidi Ben; Marzouk, Sofiene Ben; Kehila, Mehdi; Jabri, Hamed; Thamleoui, Saber; Maghrebi, Hayen

    2015-01-01

    L'hémorragie grave du péripartum demeure une des causes principales de mortalité maternelle. L'objectif de notre étude était de décrire le profil épidémiologique des patientes qui ont été prises en charge en milieu de réanimation suite à une hémorragie grave du péripartum et de rechercher d’éventuels facteurs de risque de mortalité. Notre étude est rétrospective descriptive et analytique. Nous avons inclus tous les cas d'hémorragie du péripartum ayant séjourné en unité de réanimation obstétricale du centre de maternité et de néonatologie de Tunis (CMNT) au cours de la période allant de janvier 2010 à Décembre 2013. Nous avons recueilli les paramètres démographiques, obstétricaux, ceux relatifs à la prise en charge chirurgicale et réanimatoire, les scores de gravité SAPS obstétrical et APACHEII, ainsi que la morbi-mortalité. Au total nous avons colligé 322 cas sur quatre ans. La répartition annuelle des patientes ainsi que les caractéristiques démographiques et obstétricales étaient comparables dans leur globalité sur les quatre années. Les pratiques thérapeutiques étaient également comparables. Le taux global de mortalité par hémorragie dans notre unité était à 4,7%, avec un taux annuel de mortalité stable. L'analyse des facteurs de risque de mortalité par hémorragie en milieu de réanimation a montré une association statistiquement significative entre la survenue du décès et les facteurs suivants: recours aux catécholamines, survenue de sepsis, œdème pulmonaire aigu, coagulation intravasculaire disséminée, insuffisance rénale aigue avec recours à l'hémodialyse, SDRA ou TRALI, atteinte neurologique grave, défaillance multiviscérale et arrêt cardiaque récupéré. PMID:26587127

  20. Etude de facteurs de risque de la transmission du VIH de la mère à l'enfant dans la stratégie « option A » à Lubumbashi, République Démocratique du Congo

    PubMed Central

    Ngwej, Dieudonné Tshikwej; Mukuku, Olivier; Mudekereza, Rachel; Karaj, Eugénie; Odimba, Etienne Bwana Fwamba; Luboya, Oscar Numbi; Kakoma, Jean-Baptiste Sakatolo; Wembonyama, Stanis Okitotshio

    2015-01-01

    Introduction L'infection à VIH chez la femme enceinte a pour principal risque la contamination du nouveau-né. L'objectif est de déterminer le taux de transmission du VIH de la mère à l'enfant (TME) dans la ville de Lubumbashi et en évaluer les facteurs de risque. Méthodes Il s'agissait d'une étude prospective transversale à visée analytique de 157 accouchées séropositives au VIH et de leurs enfants dans 12 structures sanitaires de Lubumbashi (RDCongo) du 1er octobre 2012 au 31 décembre 2013. Les paramètres sociodémographiques, cliniques et les données relatives aux activités de PTME du VIH ont été étudiés. Les statistiques usuelles ont été utilisées pour analyser les résultats. Le seuil de significativité a été fixé à une valeur de p < 0,05. Résultats Le taux de transmission verticale du VIH était de 12,7% (20/157). Il n'y avait pas d'association significative entre les caractéristiques sociodémographiques maternelles telles que l’âge, la parité, le niveau d’étude, la profession et l’état-civil et la TME (p>0,05). La transmission verticale du VIH était significativement associée aux facteurs suivants: le stade clinique 3 de l'OMS (OR=5,18 (1,5-18,1)), la présence d'infection opportuniste (OR=8,7 (2,7-27,8)), le dépistage lors de l'accouchement (OR=6,3 (1,0-39,0)) ou au cours de l'allaitement (OR=7,1 (1,1-76,7)), au taux de CD4 maternel <350/mm3 (OR=2,9 (1,1-7,7)), l'absence de thérapie antirétrovirale chez la mère (OR=19,9 (4,8-81,9)), la naissance avant terme (OR=4,7 (1,4-16,0)), la rupture prématurée de membranes (OR=45,0 (7,4-454,6)), le faible poids de naissance (OR=5,6 (1,9-16,7)), la notion de réanimation néonatale (OR=12,4 (3,8-40,1)), la non administration de la névirapine à la naissance (OR=26,4 (7,6-92,3)) et l'alimentation mixte (OR=12,6 (1,3-115,9)). Le sexe du nourrisson et le mode d'accouchement n’étaient pas non plus associés à la transmission verticale du VIH (p>0,05). Conclusion Le taux

  1. Solar Simulator

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Oriel Corporation's simulators have a high pressure xenon lamp whose reflected light is processed by an optical system to produce a uniform solar beam. Because of many different types of applications, the simulators must be adjustable to replicate many different areas of the solar radiation spectrum. Simulators are laboratory tools for such purposes as testing and calibrating solar cells, or other solar energy systems, testing dyes, paints and pigments, pharmaceuticals and cosmetic preparations, plant and animal studies, food and agriculture studies and oceanographic research.

  2. Numerical modelling of gravel unconstrained flow experiments with the DAN3D and RASH3D codes

    NASA Astrophysics Data System (ADS)

    Sauthier, Claire; Pirulli, Marina; Pisani, Gabriele; Scavia, Claudio; Labiouse, Vincent

    2015-12-01

    Landslide continuum dynamic models have improved considerably in the last years, but a consensus on the best method of calibrating the input resistance parameter values for predictive analyses has not yet emerged. In the present paper, numerical simulations of a series of laboratory experiments performed at the Laboratory for Rock Mechanics of the EPF Lausanne were undertaken with the RASH3D and DAN3D numerical codes. They aimed at analysing the possibility to use calibrated ranges of parameters (1) in a code different from that they were obtained from and (2) to simulate potential-events made of a material with the same characteristics as back-analysed past-events, but involving a different volume and propagation path. For this purpose, one of the four benchmark laboratory tests was used as past-event to calibrate the dynamic basal friction angle assuming a Coulomb-type behaviour of the sliding mass, and this back-analysed value was then used to simulate the three other experiments, assumed as potential-events. The computational findings show good correspondence with experimental results in terms of characteristics of the final deposits (i.e., runout, length and width). Furthermore, the obtained best fit values of the dynamic basal friction angle for the two codes turn out to be close to each other and within the range of values measured with pseudo-dynamic tilting tests.

  3. Transition de phase quantique de type verrouillage-deverrouillage dans les canaux lineaires coherents des phases en rayures dans les doubles puits quantiques sous champ magnetique perpendiculaire

    NASA Astrophysics Data System (ADS)

    Faribault, Alexandre

    On peut creer un gaz electronique bidimensionnel en utilisant le potentiel de confinement d'une couche mince d'un semiconducteur dans un substrat fait d'une autre semiconducteur de gap plus eleve. L'ajout d'un champ magnetique perpendiculaire au plan de confinement modifie de facon drastique les proprietes du gaz electronique. Pour des densites et des valeurs du champ magnetique adequatement choisies, on obtient un etat fondamental en onde de densite de charge. Dans un systeme compose de deux de ces gaz bidimensionnels suffisamment rapproches l'un de l'autre, on prevoit theoriquement l'existence d'un etat fondamental compose d'une onde de densite de charge dans chacun des puits et d'une serie de regions lineaires ou l'on a une delocalisation coherente des electrons entre les deux puits. Dans cette these, on etudie le comportement a temperature nulle de cet etat fondamental en rayures coherentes. L'etude numerique des modes collectifs de ces phases laisse croire qu'un deverrouillage des canaux coherents est envisageable dans ce systeme. Afin d'etudier cette possibilite, nous construisons d'abord un modele effectif de canaux quasi-unidimensionnels couples qui permettent de reproduire correctement les excitations collectives a basse energie de la phase en rayures coherentes du double puits quantique. Dans un systeme de coordonnees adequatement choisi, ces excitations peuvent etre decrites par des ondes de pseudospin. Les parametres de ce modele effectif simple peuvent etre extraits des calculs des fonctions de reponse realises dans l'approximation Hartree-Fock dependante du temps (appelee aussi Generalized Random Phase Approximation). On constate l'efficacite de ce modele a decrire la dynamique basse energie du systeme pour une certaine plage de distances inter-puits. En retirant de ce modele les contributions a l'hamiltonien provenant des couplages de type Josephson entre les canaux, on obtient alors un systeme ou les canaux sont deverrouilles. Un traitement en

  4. Wind Simulation

    Energy Science and Technology Software Center (ESTSC)

    2008-12-31

    The Software consists of a spreadsheet written in Microsoft Excel that provides an hourly simulation of a wind energy system, which includes a calculation of wind turbine output as a power-curve fit of wind speed.

  5. Mission Simulators

    NASA Video Gallery

    Students will use NASA Web-based simulators to follow sequenced directions and complete ordered tasks while learning how the shuttle is made ready for flight, how the shuttle docks with the Interna...

  6. Structure of Protein Related to DAN and Cerberus (PRDC): Insights into the Mechanism of BMP Antagonism

    PubMed Central

    Nolan, Kristof; Kattamuri, Chandramohan; Luedeke, David M.; Deng, Andy; Jagpal, Amrita; Zhang, Fuming; Linhardt, Robert; Kenny, Alan P.; Zorn, Aaron M.; Thompson, Thomas B.

    2013-01-01

    Summary The Bone Morphogenetic Proteins (BMP) are secreted ligands largely known for their functional roles in embryogenesis and tissue development. A number of structurally diverse extracellular antagonists inhibit BMP ligands to regulate signaling. The DAN family of antagonists represents the largest group of BMP inhibitors, however, little is known for how they mechanistically inhibit BMP ligands. Here, we present the structure of the DAN family member Protein Related to Dan and Cerberus (PRDC) solved by X-ray crystallography. The structure reveals an unexpected growth factor-like appearance with a novel dimerization mechanism that is formed through extensive β-strand contacts. Using site-directed mutagenesis coupled with in vitro and in vivo activity assays, we identified a BMP binding epitope on PRDC. We also determined that PRDC binds heparin with high affinity and that heparin binding to PRDC interferes with BMP antagonism. These results offer insight for how DAN family antagonists functionally inhibit BMP ligands. PMID:23850456

  7. Léiomyosarcome gastrique simulant une tumeur du hile splénique: à propos d'un cas

    PubMed Central

    Tarchouli, Mohamed; Bounaim, Ahmed; Ratbi, Moulay Brahim; Belhamidi, Mohamed Said; Bensal, Abdelhak; Aitidir, Badr; Boudhas, Adil; Ali, Abdelmounaim Ait; Sair, Khalid

    2015-01-01

    Depuis la découverte de leur phénotype particulier, les tumeurs stromales gastro-intestinales représentent les tumeurs mésenchymateuses les plus fréquentes du tractus digestif et ne sont plus confondues avec les vrais léiomyosarcomes gastriques devenant ainsi exceptionnellement rencontrés dans la pratique médicale. Nous rapportons le cas d'une jeune femme de 32 ans admise pour une masse douloureuse de l'hypochondre gauche et chez qui le bilan radiologique objectivait une volumineuse tumeur occupant le hile splénique. Une résection monobloc emportant la masse, la rate, le grand épiploon et une collerette de la paroi gastrique a été effectuée et l'examen histologique a confirmé le diagnostic d'un léiomyosarcome gastrique. Il est extrêmement important de différencier les autres tumeurs mésenchymateuses du tractus digestif des léiomyosarcomes gastriques dont l'exérèse chirurgicale complète reste, jusqu’à présent, le seul traitement à visée curative. PMID:26526400

  8. Tuberculome de Bouchut dans la tuberculose multi focale: à propos de quatre cas

    PubMed Central

    Janah, Hicham; Alami, Ahmed; Souhi, Hicham; Zegmout, Adil; Naji-Amrani, Hicham; Raoufi, Mohamed; Elouazzani, Hanane; Rhorfi, Ismail Abderrahmani; Abid, Ahmed

    2014-01-01

    La tuberculose multifocale a connu un regain de fréquence avec la pandémie du SIDA, elle s'observe encore chez des sujets non infectés par le VIH surtout dans les pays en voie de développement notamment au Maroc. Nous rapportons quatre observations de tuberculose multifocale chez trois patients immunocompétents et un patient immunodéprimé. Quatre patients ont bénéficié d'un bilan phtisiologique, biologique, sérologique(HIV), radiologique et d'angiographie à la fluorescéine pour suspicion de tuberculose multifocale. Il s'agit de trois hommes et une femme, d’âge moyen de 44 ans, trois patients sont immunocompétents et un patient séropositif. La tuberculose intéressait trois localisations chez les quatre patients: pulmonaire dans quatre cas, ophtalmique dans quatre cas, digestive dans un cas, urinaire dans un cas, cérébrale dans un cas et un cas d'atteinte de la moelle osseuse. L'atteinte ophtalmologique est représentée par des nodules choroïdiens de Bouchut dans quatre cas et un nodule papillaire de Bouchut dans un cas; aucun des ces patients ne présentait une uvéite granulomateuse. Nos malades ont reçu un traitement anti-tuberculeux d'une durée de neuf mois avec une bonne évolution clinique, biologique, radiologique et angiographique. Au Maroc, la tuberculose continue à surprendre aussi bien par son extension touchant le sujet débilité et le sujet immunocompétent, que par ses présentations diverses y compris l'atteinte oculaire qu'elle faut rechercher par un examen ophtalmologique soigneux et systématique. PMID:25478047

  9. The Dynamic Albedo of Neutrons (DAN) experiment for NASA's 2009 Mars Science Laboratory.

    PubMed

    Litvak, M L; Mitrofanov, I G; Barmakov, Yu N; Behar, A; Bitulev, A; Bobrovnitsky, Yu; Bogolubov, E P; Boynton, W V; Bragin, S I; Churin, S; Grebennikov, A S; Konovalov, A; Kozyrev, A S; Kurdumov, I G; Krylov, A; Kuznetsov, Yu P; Malakhov, A V; Mokrousov, M I; Ryzhkov, V I; Sanin, A B; Shvetsov, V N; Smirnov, G A; Sholeninov, S; Timoshenko, G N; Tomilina, T M; Tuvakin, D V; Tretyakov, V I; Troshin, V S; Uvarov, V N; Varenikov, A; Vostrukhin, A

    2008-06-01

    We present a summary of the physical principles and design of the Dynamic Albedo of Neutrons (DAN) instrument onboard NASA's 2009 Mars Science Laboratory (MSL) mission. The DAN instrument will use the method of neutron-neutron activation analysis in a space application to study the abundance and depth distribution of water in the martian subsurface along the path of the MSL rover. PMID:18598140

  10. Déterminants de la calcémie néonatale dans une maternité périphérique à Abidjan

    PubMed Central

    Konan, Diby Jean-Paul; Amon-Tanoh-Dick, Flore; Aka, Joseph; Daniel, Sess Essiagne

    2015-01-01

    Introduction Le transfert du calcium de la mère au nouveau-né est nécessaire pour la constitution de la charpente osseuse. L'hypocalcémie néonatale reste peu documentée en Afrique. En 1993, il a été observé au service de néonatologie du Centre hospitalo-universitaire de Yopougon à Abidjan une proportion d'hypocalcémie asymptomatique de 26.9%. L'objectif de ce travail était de préciser la prévalence de l'hypocalcémie néonatale dans une maternité périphérique de Yopougon et en déterminer les facteurs de risque. Méthodes Une étude transversale a été menée à la formation sanitaire de de Yopougon de février à mai 2012 auprès de 145 parturientes et leurs nouveau-nés. Les caractéristiques des mères et des nouveau-nés ont été recueillies. Les prélèvements de sang maternel et du cordon ont permis le dosage des paramètres du métabolisme phosphocalcique. Une régression linéaire multiple a été faite pour apprécier les éléments de prédilection de la calcémie néonatale. Résultats Les valeurs moyennes étaient de 2,271 mmol/l pour la calcémie, 1,169 mmol/l pour le phosphore, 0,735 mmol/l pour le magnésium et 69 g/l pour les protides totaux chez les mères. La durée moyenne du travail était de 499 minutes. L’âge gestationnel moyen était de 39 semaines. Les constantes anthropométriques et cliniques des nouveau-nés étaient normales. Les paramètres phosphocalciques étaient en moyenne normaux (calcémie = 2,52 mmol/l, phosphorémie = 1,668 mmol/l, magnesémie = 0,777 mmol/l, protidémie = 63 g/l). Six gestantes (4,1%) étaient hypocalcémiques contre 12 nouveau-nés (8,1%). La durée du travail influençait la calcémie néonatale (p = 0,02). En analyse multivariée, 34% de la variabilité de la calcémie néonatale était expliqué par la calcémie maternelle et la durée du travail. Conclusion L'hypocalcémie néonatale est rare en zone tropicale. Dans cette étude, la proportion était de 8,1%. La durée du travail

  11. Simulation speak.

    PubMed

    Fairhurst, Katherine; Strickland, Andrew; Maddern, Guy J

    2011-01-01

    The concept of using simulation to gain and improve practical skills in a safe and low-risk environment has been employed extensively in the airline industry to train pilots for many years now. The use of simulation techniques to train surgeons, however, is a new but rapidly expanding and developing area of surgical education. The introduction of simulation to surgical training curricula has inevitably led to a plethora of simulation technology entering the commercial market, as well as the introduction of new terminology used to describe both the equipment itself, and the methods used to test and validate it for use in the training of surgeons. The terminology has its basis mostly in statistical methodology, and the terms are used throughout the surgical literature, often interchangeably and with multiple meanings. In our experience, this terminology is where most confusion arises. Interpreting the literature is difficult for those not directly involved in the field. This article aims to define the statistical terms used to describe the many forms of validity testing and types of surgical simulator, and consequently to act as a reference guide for those unfamiliar with this rapidly evolving field of technology and surgical training. PMID:21821217

  12. La prise en charge à long terme de l’asthme chez les enfants inuits et des Premières nations : un outil de transfert du savoir fondé sur les lignes directrices canadiennes pour l’asthme pédiatrique, conçu pour être utilisé par les professionnels de la santé de première ligne qui travaillent dans des communautés isolées

    PubMed Central

    Kovesi, Tom; Giles, Brenda Louise; Pasterkamp, Hans

    L’asthme est un grave problème de santé pour les enfants inuits et des Premières nations. Chez les enfants de moins d’un an, il faut distinguer l’asthme de la bronchiolite virale, anormalement fréquente chez les enfants autochtones du Canada. Chez les enfants de moins de six ans, le diagnostic dépend de la présence de symptômes classiques, de l’absence de caractéristiques atypiques et de la consignation de la réponse au traitement, notamment la réponse rapide et transitoire aux bronchodilatateurs. Chez les enfants plus âgés, il faut, dans la mesure du possible, déterminer la présence d’une obstruction réversible des voies aériennes par spirométrie afin de confirmer le diagnostic, ainsi qu’évaluer et corriger les déclencheurs environnementaux. L’utilisation régulière de corticoïdes en aérosol est la principale mesure à prendre pour maintenir un bon contrôle de l’asthme chez les enfants asthmatiques. Les clients et leur famille devraient recevoir une formation sur l’asthme. Il faut réévaluer régulièrement le contrôle aux visites de suivi dans des centres de santé et rajuster le traitement à la dose la plus basse possible pour le maintien de ce contrôle.

  13. Colonoscopy simulation

    NASA Astrophysics Data System (ADS)

    Hong, Wei; Wang, Jianning; Qiu, Feng; Kaufman, Arie; Anderson, Joseph

    2007-03-01

    Effective colonoscopic screening for polyps with optical or virtual means requires adequate visualization of the entire colon surface. The purpose of this study is to investigate by simulation the degree of colon surface coverage during a routine optical colonoscopy (OC). To simulate OC, a generic wide angle and fisheye camera model is used to calibrate the fisheye lens of an Olympus endoscope with a field of view of 140 degrees. Then, the colonoscopy procedure is simulated using volume rendering fly-through along the hugging corner path in the retrograde direction. This shortest path is computed using the segmented and cleansed colon CT datasets. A large number of virtual fisheye cameras are placed along the shortest path to simulate the OC. At each camera position, a discrete volumetric ray-casting method is used to determine which triangles can be seen from the camera. Then, the percentage of the covered colon surface of the OC simulation is computed. Surface coverage at this point may serve as a rough estimate of readily visualized mucosa in a standard OC examination. We also compute the percentage of the covered colon surface for the virtual colonoscopy (VC) by placing virtual pinhole cameras on the central path of the colon and flying in only the antegrade direction as well as flying in both antegrade and retrograde directions. Our simulation study reveals that about 23% of the colon surface is missed in the standard OC examination and about 9% of the colon surface is missed in the VC examination when navigating in both directions.

  14. Simulation Software

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Various NASA Small Business Innovation Research grants from Marshall Space Flight Center, Langley Research Center and Ames Research Center were used to develop the 'kernel' of COMCO's modeling and simulation software, the PHLEX finite element code. NASA needed it to model designs of flight vehicles; one of many customized commercial applications is UNISIM, a PHLEX-based code for analyzing underground flows in oil reservoirs for Texaco, Inc. COMCO's products simulate a computational mechanics problem, estimate the solution's error and produce the optimal hp-adapted mesh for the accuracy the user chooses. The system is also used as a research or training tool in universities and in mechanical design in industrial corporations.

  15. Les fluctuations supraconductrices dans le compose praseodyme-cerium-oxyde de cuivre

    NASA Astrophysics Data System (ADS)

    Renaud, Jacques

    Ce travail etudie les fluctuations supraconductrices dans le compose supraconducteur a haute temperature critique dope aux electrons Pr2-xCe xCuO4+delta. La technique utilisee pour sonder ces fluctuations est le transport electrique DC dans le plan ab. Il s'agit, a notre connaissance, de la premiere etude de ce type dans la classe generale des supraconducteurs a haute temperature critique dopes aux electrons et, plus particulierement, dans Pr2-xCe xCuO4+delta. De plus, l'etude est effectuee pour trois regimes de dopage, soit sous-dope x = 0.135, dopage optimal x = 0.15 et surdope x = 0.17. Les echantillons etudies sont des couches minces d'epaisseur plus grande que 100 nm crues par ablation laser. Les mesures electriques DC effectuees dans ce travail sont la resistance en reponse lineaire et les courbes IV en reponse non lineaire en fonction de la temperature. La mise en oeuvre experimentale de ces mesures a necessite une grande attention au filtrage et aux effets de chauffage a haut courant. Nous montrons que, sans cette attention, les donnees experimentales sont toujours erronees dans le regime pertinent pour nos echantillons. Les resultats pour le dopage optimal x = 0.15 sont expliques de facon tres convaincante dans le cadre de fluctuations purement 2D. D'abord, le regime des fluctuations gaussiennes est tres bien decrit par le modele d'Aslamazov-Larkin en deux dimensions. Ensuite, le regime de fluctuations critiques, se trouvant a plus basse temperature que le regime gaussien, est tres bien decrit par la physique 2D de Kosterlitz-Thouless. Dans cette analyse, les deux regimes ont des temperatures critiques coherentes entre elles, ce qui semble confirmer ce scenario 2D. Une analyse des donnees dans le cadre de fluctuations 3D est exploree mais donne des conclusions incoherentes. Les resultats pour les autres dopages sont qualitativement equivalents avec le dopage optimal et permettent donc une explication purement 2D. Par contre, contrairement au dopage optimal

  16. Simulating Electrophoresis.

    ERIC Educational Resources Information Center

    Moertel, Cheryl; Frutiger, Bruce

    1996-01-01

    Describes a DNA fingerprinting simulation that uses vegetable food coloring and plastic food containers instead of DNA and expensive gel electrophoresis chambers. Allows students to decipher unknown combinations of dyes in a method similar to that used to decipher samples of DNA in DNA fingerprint techniques. (JRH)

  17. Simulated Agribusiness.

    ERIC Educational Resources Information Center

    Salisbury, Howard G., III

    "Simulated Agribusiness" is designed to provide the student with a role playing situation dealing with the complexities and problems of modern agriculture. It is a competitive game played on a hypothetical mid-latitude diversified farm in a capitalistic system. The player is faced with a series of decisions which will determine his success or…

  18. Simulating Gravity

    ERIC Educational Resources Information Center

    Pipinos, Savas

    2010-01-01

    This article describes one classroom activity in which the author simulates the Newtonian gravity, and employs the Euclidean Geometry with the use of new technologies (NT). The prerequisites for this activity were some knowledge of the formulae for a particle free fall in Physics and most certainly, a good understanding of the notion of similarity…

  19. Transitions de phase dans le oxyde de yttrium vanadium

    NASA Astrophysics Data System (ADS)

    Roberge, Benoit

    Dans le mémoire qui suit, les ordres structural, magnétiques et orbital dans le YVO3 sont étudiés avec l'aide de la diffraction des rayons X,de la spectroscopie Raman et de la technique de la cavité résonnante hyperfréquence. L'objectif premier consiste à observer l'évolution de ces ordres en fonction de la température. Le mémoire met ensuite en évidence le couplage entre les différents ordres cohabitants dans le YVO3 . Les mesures effectuées par la diffraction des rayons X permettent de mesurer le caractère polycrystallin des échantillons du YVO 3. Une comparaison de nos mesures avec des mesures de diffraction des rayons X faites sur la poudre de YVO3 indique la faible présence de maclage. Les mesures effectuées avec la technique de résonnance hyperfréquence permettent de suivre l'évolution de la constante diélectrique en fonction de la température. Les changements impliquant l'ordre orbital se manifestent de manière évidente dans la constante diélectrique à 200 K et à 77 K. La transition diélectrique détectée à 77 K est une transition de premier ordre. Un couplage entre les propriétés diélectriques et magnétiques est observable à la température de Néel à 114 K. L'effet d'un champ magnétique fixe sur la température de transition de l'ordre orbital survenant à 77 K est également remarquable. Cela indique un couplage magnétodiélectrique démontrant ainsi le caractère multiferroïque du YVO 3. Finalement, l'observation d'un mécanisme de relaxation pouvant être modélisé par le modèle d'Havriliak-Negami est observé en dessous de 77 K. En utilisant le modèle d'Arrhénius et le modèle d'Havriliak-Negami, on peut caractériser le mécanisme avec son énergie d'activation et son temps de relaxation. Les mesures effectuées en spectroscopie Raman permettent de suivre l'évolution de la structure du YVO3 en fonction de la température. Les deux changements structuraux survenant à 200 K et 77 K sont observés. Le

  20. Acceptabilité du test VIH proposé aux nourrissons dans les services pédiatriques, en Côte d'Ivoire, Significations pour la couverture du diagnostic pédiatrique

    PubMed Central

    Oga, Maxime; Brou, Hermann; Dago-Akribi, Hortense; Coffie, Patrick; Amani-Bossé, Clarisse; Ékouévi, Didier; Yapo, Vincent; Menan, Hervé; Ndondoki, Camille; Timité-Konan, M.; Leroy, Valériane

    2014-01-01

    Résumé Problème: Le dépistage VIH chez les enfants a rarement été au centre des préoccupations des chercheurs. Quand le dépistage pédiatrique a retenu l'attention, cela a été pour éclairer seulement sur les performances diagnostiques en ignorant même que le test pédiatrique comme bien d'autres peut s'accepter ou se refuser. Cet article met au cœur de son analyse les raisons qui peuvent expliquer qu'on accepte ou qu'on refuse de faire dépister son enfant. Objectif: Etudier chez les parents, les mères, les facteurs explicatifs de l'acceptabilité du test VIH des nourrissons de moins de six mois. Méthodes: Entretien semi-directif à passages répétés avec les parents de nourrissons de moins de six mois dans les formations sanitaires pour la pesée/vaccination et les consultations pédiatriques avec proposition systématique d'un test VIH pour leur nourrisson. Résultats: Nous retenons que la réalisation effective du test pédiatrique du VIH chez le nourrisson repose sur trois éléments. Primo, le personnel de santé par son discours (qui dénote de ses connaissances et perceptions même sur l'infection) orienté vers les mères influence leur acceptation ou non du test. Secundo, la mère qui par ses connaissances et perceptions même sur le VIH, dont le statut particulier, l'impression de bien-être chez elle et son enfant influence toute réalisation du test pédiatrique VIH. Tertio, l'environnement conjugal de la mère, particulièrement caractérisé par les rapports au sein du couple, sur la facilité de parler du test VIH et sa réalisation chez les deux parents ou chez la mère seulement sont autant de facteurs qui influencent la réalisation effective du dépistage du VIH chez l'enfant. Le principe préventif du VIH, et le désir de faire tester l'enfant ne suffisent pas à eux seuls pour aboutir à sa réalisation effective, selon certaines mères confrontées au refus du conjoint. A l'opposé, les autres mères refusant la r

  1. Simulating Combustion

    NASA Astrophysics Data System (ADS)

    Merker, G.; Schwarz, C.; Stiesch, G.; Otto, F.

    The content spans from simple thermodynamics of the combustion engine to complex models for the description of the air/fuel mixture, ignition, combustion and pollutant formation considering the engine periphery of petrol and diesel engines. Thus the emphasis of the book is on the simulation models and how they are applicable for the development of modern combustion engines. Computers can be used as the engineers testbench following the rules and recommendations described here.

  2. Aerodynamic simulation

    SciTech Connect

    Not Available

    1993-01-01

    In this article two integral computational fluid dynamics methods for steady-state and transient vehicle aerodynamic simulations are described using a Chevrolet Corvette ZR-1 surface panel model. In the last decade, road-vehicle aerodynamics have become an important design consideration. Originally, the design of low-drag shapes was given high priority due to worldwide fuel shortages that occurred in the mid-seventies. More recently, there has been increased interest in the role aerodynamics play in vehicle stability and passenger safety. Consequently, transient aerodynamics and the aerodynamics of vehicle in yaw have become important issues at the design stage. While there has been tremendous progress in Navier-Stokes methodology in the last few years, the physics of bluff-body aerodynamics are still very difficult to model correctly. Moreover, the computational effort to perform Navier-Stokes simulations from the geometric stage to complete flow solutions requires much computer time and impacts the design cycle time. In the short run, therefore, simpler methods must be used for such complicated problems. Here, two methods are described for the simulation of steady-state and transient vehicle aerodynamics.

  3. DAN Active Parameters and Mastcam Hydration Survey Imaging: Comparisons Across Yellowknife Bay, Gale Crater, Mars

    NASA Astrophysics Data System (ADS)

    Hardgrove, C. J.; Rice, M. S.; Moersch, J.; Mitrofanov, I. G.; Litvak, M.; Wellington, D. F.; Behar, A.; Bell, J. F.; Boynton, W. V.; DeFlores, L.; Drake, D.; Fedosov, F.; Golovin, D.; Jun, I.; Harshman, K.; Kozyrev, A.; Malakhov, A.; Milliken, R.; Kuzmin, R.; Mischna, M. A.; Mokrousov, M.; Nikiforov, S.; Sanin, A.; Tate, C.; Team, M.

    2013-12-01

    The Dynamic Albedo of Neutrons (DAN) instrument on the Mars Science Laboratory (MSL) rover Curiosity has recorded variability in neutron counts along traverses in and around Yellowknife Bay that suggest variable amounts of hydrogen (H) are present. At the locations of several DAN observations, Mastcam 'hydration survey' mosaics have been acquired with the R0 (493 nm, 551 nm and 638 nm), R5 (937 nm) and R6 (1013 nm) science filters to characterize RGB color and look for potential hydration as indicated by an absorption near 1000 nm. Whereas DAN is sensitive to H abundance down to 60cm depth, the Mastcam hydration index is sensitive to the presence of certain hydrated minerals (bound-OH and/or H2O) exposed in the upper hundreds of micrometers of the surface. Furthermore, many light-toned, Ca-sulfate-bearing features (i.e. veins and nodules within the outcrop) exposed at the surface in Yellowknife Bay have a high hydration index, consistent with a hydrated mineral such as gypsum. Other light-toned features do not have a high hydration index, suggesting they are composed of anhydrous or lower hydration state phases such as anhydrite or bassanite. The distribution of light-toned features within the outcrop at Yellowknife Bay is also highly variable within a DAN footprint. Given that there is variability in both the DAN signal and Mastcam hydration index throughout Yellowknife Bay, this work investigates whether or not increases or decreases in H seen by DAN correlate to areas of high hydration index as derived from Mastcam observations. Positive correlations of the DAN H signal and Mastcam hydration index may indicate that the observed densities of light-toned features (hydrated or dehydrated) extend to at least 60cm depth. Conversely, negative correlations could indicate that either the veins/nodules are only present at very shallow depths (a few cm), that the hydration of the phases changes with depth (e.g., gypsum at the surface and anhydrite at depth), or that there

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

    NASA Astrophysics Data System (ADS)

    Fournier, David

    Les conducteurs organiques quasi-bidimensionnels kappa-ET2X presentent d'importantes similitudes avec les SCHT telles qu'une phase isolant de Mott, un regime de pseudogap et un etat supraconducteur. L'etude de leurs proprietes apparait donc complementaire. Parmi les interrogations persistantes concernant la physique de ces systemes, l'origine du (ou des) processus exotique d'appariement, responsable de la supraconductivite est le sujet suscitant l'interet le plus marque dans la communaute. L'hypothese d'un mecanisme lie a la proximite d'un etat antiferromagnetique est privilegiee. Une etape importante dans la resolution de cette problematique est l'identification de la symetrie du parametre d'ordre. D'apres de nombreux travaux sur les systemes fortement correles, la sonde ultrasonore, de par sa sensibilite aux excitations de quasiparticule a basse temperature, est consideree comme particulierement adaptee a l'etude de cette propriete. Cependant, son emploi necessite l'utilisation d'un compose metallique a basse temperature et completement supraconducteur. Le compose metallique organique kappa-ET 2Cu[N(CN)2]Br presente toutes les caracteristiques necessaires a l'etude de cette propriete. En effet, il est situe loin de la transition du premier ordre de Mott et est completement supraconducteur. De facon surprenante, ce systeme semble se coupler fortement avec le reseau ce qui augmente significativement la sensibilite de cette sonde aux proprietes du gaz electronique. Cependant, des difficultes techniques importantes, liees a la nature intrinseque de ce materiau, doivent etre surmontees pour proceder a des mesures suivant differentes polarisations. La presente etude a profondement modifie notre comprehension de ce systeme. En effet, ces mesures ont permis de constater que le kappa-ET2Cu[N(CN)2]Br est un compose qui est situe en bordure de la zone de coexistence entre la supraconductivite et le magnetisme, ce qui constitue un resultat totalement inattendu. De plus, la

  5. Etude du faible poids de naissance associé à l’âge maternel et la parité dans une population couple mère-enfant suivi à Lubumbashi

    PubMed Central

    Luhete, Prosper Kakudji; Mukuku, Olivier; Kayamba, Prosper Kalenga Muenze

    2015-01-01

    Introduction Evaluer l'influence de l’âge maternel et de la parité sur la naissance d'un faible poids de naissance (FPN) à Lubumbashi. Méthodes Il s'agit d'une étude basée sur une analyse documentaire des dossiers médicaux des accouchées enregistrées dans les maternités des 10 hôpitaux généraux de référence (HGR) de la ville de Lubumbashi en République Démocratique du Congo entre le 1er décembre 2013 et le 31 mars 2014. Ces accouchées ont été réparties en deux groupes, en fonction du poids de naissance de leurs enfants: groupe I (femmes ayant accouché de nouveau-nés vivants dont le poids était inférieur à 2500 grammes) et groupe II (femmes ayant accouché de nouveau-nés vivants dont le poids était supérieur ou égal à 2500 grammes). Il s'agissait dans tous les cas de grossesses monofoetales âgées de 28 semaines ou plus. L’âge maternel et la parité ont été étudiés et comparés dans les deux groupes. Les données ont été analysées à l'aide des logiciels Épi info version 7.0 et SPSS version 19. Les différences étaient jugées significatives pour un seuil p < 0,05. Résultats La prévalence du FPN chez les nouveau-nés issus de ces accouchées était ainsi de 6,4% (71/1112). En analyse univariée, les femmes d’âge < 20 ans présentent un risque multiplié par 2,47 fois d'avoir un nouveau-né de FPN comparativement à celles de ≥20 ans (OR = 2,47; IC95%: 1,26-4,78) et celui pour les primipares d'avoir un enfant de FPN est 2,3 fois supérieur à celui de multipares (OR = 2,32; IC95%: 1,34-3,99). En faisant la régression logistique, nous avons observé que seule la parité est significativement corrélée au poids de naissance (OR ajusté = 2,61; IC95%: 1,43-4,74). Conclusion L’étude que nous avons menée montre que le taux de FPN diminue considérablement avec l’âge de la mère à partir de 20 ans et la multiparité. PMID:26161169

  6. Sacroiliites infectieuses dans le centre tunisien: étude rétrospective de 25 cas

    PubMed Central

    Bellazreg, Foued; Alaya, Zeineb; Hattab, Zouhour; Lasfar, Nadia Ben; Ayeche, Mohamed Laziz Ben; Bouajina, Elyes; Letaief, Amel; Hachfi, Wissem

    2016-01-01

    Les sacroiliites infectieuses sont rares mais peuvent se compliquer de séquelles fonctionnelles invalidantes. Décrire les caractéristiques cliniques et bactériologiques des sacroiliites infectieuses chez les patients suivis à Sousse, Centre Tunisien. Etude rétrospective, descriptive, des cas de sacroiliites infectieuses chez les patients hospitalisés à Sousse entre 2000 et 2015. Le diagnostic a été retenu devant des signes cliniques, d'imagerie, et microbiologiques évocateurs. Vingt-cinq patients, 10 hommes et 15 femmes, d’âge moyen 41 ans (19-78) ont été inclus. Les sacroiliites étaient dues à des bactéries pyogènes dans 14 cas (56%), brucelliennes dans 6 cas (24%), et tuberculeuses dans 5 cas (20%). La durée moyenne d’évolution était de 61, 45 et 402 jours respectivement. Les signes cliniques les plus fréquents étaient les douleurs fessières (92%) et la fièvre (88%). La radiographie standard était anormale dans 75% des cas. La TDM et l'IRM sacro-iliaques dans tous les cas. Le diagnostic a été confirmé bactériologiquement dans 24 cas (96%). La durée moyenne d'antibiothérapie était de 83 jours dans les sacroiliites à pyogènes, et de 102 jours dans les SI brucelliennes. L’évolution était favorable chez 12 patients (48%), 9 patients (36%) ont gardé une douleur sacro-iliaque séquellaire, et 4 patients (16%) sont décédés. Dans notre étude, la durée d’évolution de la sacroiliite infectieuse ne permettait pas de prédire la bactérie responsable, d'où la nécessité d'obtenir une documentation bactériologique afin de prescrire une antibiothérapie appropriée. PMID:27583067

  7. Migration pelvienne de broche guide dans la chirurgie des fractures de hanche: à propos de 3 cas

    PubMed Central

    Guèye, Mohamadou Lamine; Thiam, Ousmane; Touré, Alpha Oumar; Seck, Mamadou; Cissé, Mamadou; Kâ, Ousmane; Dieng, Madieng; Dia, Abderahmane; Touré, Cheikh Tidiane

    2015-01-01

    La migration de matériel d'ostéosynthèse est une complication bien connue du traitement chirurgical des fractures. Toutefois, la migration pelvienne de broche guide dans la chirurgie des fractures de la hanche est un incident rare et potentiellement grave. Nous rapportons 3 observations dans lesquelles on notait une migration de broche guide dans le pelvis lors d'une ostéosynthèse dela hanche de type DHS. L'indication chirurgicale était une fracture per-trochantérienne dans 2 cas et une fracture du col fémoral type 4 de Garden dans 1 cas. Une minilaparotomie permettait d'objectiver une plaie du ligament large gauche et un hématome ligamentaire dans 1 cas, tandis que dans les 2 autres cas, il n'y avait pas de lésion viscérale. L'extraction de la broche a été effectuée dans les 3 cas. Les suites opératoires ont été simples chez tous les patients. PMID:26327949

  8. Terrain Simulation

    NASA Technical Reports Server (NTRS)

    1992-01-01

    A highlight of the IMAX film, Blue Planet, is a 100-second computer- generated animation of a flight and earthquake simulation along California's San Andreas Fault. Created by the VESA group at the Jet Propulsion Laboratory, the sequence required the development of a technique to make possible terrain rendering of very large digital images. An image mosaic of California constructed from Landsat data made this possible. An advanced pyramidal terrain rendering technique was developed, significantly reducing the necessary time involved in transferring the Landsat data to film. The new technique has also enabled NASA to develop new perspective rendering technologies in order to cope with anticipated increased remote sensor data.

  9. Neuromechanical Simulation

    PubMed Central

    Edwards, Donald H.

    2010-01-01

    The importance of the interaction between the body and the brain for the control of behavior has been recognized in recent years with the advent of neuromechanics, a field in which the coupling between neural and biomechanical processes is an explicit focus. A major tool used in neuromechanics is simulation, which connects computational models of neural circuits to models of an animal's body situated in a virtual physical world. This connection closes the feedback loop that links the brain, the body, and the world through sensory stimuli, muscle contractions, and body movement. Neuromechanical simulations enable investigators to explore the dynamical relationships between the brain, the body, and the world in ways that are difficult or impossible through experiment alone. Studies in a variety of animals have permitted the analysis of extremely complex and dynamic neuromechanical systems, they have demonstrated that the nervous system functions synergistically with the mechanical properties of the body, they have examined hypotheses that are difficult to test experimentally, and they have explored the role of sensory feedback in controlling complex mechanical systems with many degrees of freedom. Each of these studies confronts a common set of questions: (i) how to abstract key features of the body, the world and the CNS in a useful model, (ii) how to ground model parameters in experimental reality, (iii) how to optimize the model and identify points of sensitivity and insensitivity, and (iv) how to share neuromechanical models for examination, testing, and extension by others. PMID:20700384

  10. Hybrid Simulator

    Energy Science and Technology Software Center (ESTSC)

    2005-10-15

    HybSim (short for Hybrid Simulator) is a flexible, easy to use screening tool that allows the user to quanti the technical and economic benefits of installing a village hybrid generating system and simulates systems with any combination of —Diesel generator sets —Photovoltaic arrays -Wind Turbines and -Battery energy storage systems Most village systems (or small population sites such as villages, remote military bases, small communities, independent or isolated buildings or centers) depend on diesel generationmore » systems for their source of energy. HybSim allows the user to determine other "sources" of energy that can greatly reduce the dollar to kilo-watt hour ratio. Supported by the DOE, Energy Storage Program, HybSim was initially developed to help analyze the benefits of energy storage systems in Alaskan villages. Soon after its development, other sources of energy were added providing the user with a greater range of analysis opportunities and providing the village with potentially added savings. In addition to village systems, HybSim has generated interest for use from military institutions in energy provisions and USAID for international village analysis.« less

  11. The local subsurface water and chlorine distributions evaluated by DAN/MSL in Curiosity observational campaigns

    NASA Astrophysics Data System (ADS)

    Litvak, Maxim; Mitrofanov, Igor; Hardgrove, Craig; Sanin, Anton; Lisov, Denis; Golovin, Dmitry; Jun, Insoo; Kozyrev, Alexander; Malakhov, Alexey; Mischna, Michael; Moersch, Jeffrey; Nikiforov, Sergey; Tate, Cristopher; Vostrukhin, Andrey

    2016-04-01

    The measurements with the Dynamic Albedo of Neutrons (DAN) instrument onboard the Mars Science Laboratory (MSL) Curiosity rover are presented and analyzed as a summary of observations acquired during several special observational campaigns at the Yellowknife Bay area (first discovery of habitability environment), at the striated units of Kimberley formation, at outcrops studied in Pahrump Hills (at the base of Mt Sharp) and in high silica area discovered in Marias Pass (Mudstone facies of the Murray formation). DAN data were analyzed to test local and global variability in the distribution of bulk hydrogen and neutron-absorbing elements, characterized as chlorine-equivalent concentration. Using multi instrument approach in the data analysis we have compared DAN estimations of subsurface H and Cl distributions with inhomogeneity of local geological context, top surface measurements of chlorine with APXS and with SAM measurements of absorbed H2O extracted from the drilled samples based on low temperature evolved gas analysis.

  12. Dynamic Albedo of Neutrons (DAN) Experiment Onboard NASA's Mars Science Laboratory

    NASA Astrophysics Data System (ADS)

    Mitrofanov, I. G.; Litvak, M. L.; Varenikov, A. B.; Barmakov, Y. N.; Behar, A.; Bobrovnitsky, Y. I.; Bogolubov, E. P.; Boynton, W. V.; Harshman, K.; Kan, E.; Kozyrev, A. S.; Kuzmin, R. O.; Malakhov, A. V.; Mokrousov, M. I.; Ponomareva, S. N.; Ryzhkov, V. I.; Sanin, A. B.; Smirnov, G. A.; Shvetsov, V. N.; Timoshenko, G. N.; Tomilina, T. M.; Tret'yakov, V. I.; Vostrukhin, A. A.

    2012-09-01

    The description of Dynamic Albedo of Neutrons (DAN) experiment is presented, as a part of the NASA's Mars Science Laboratory mission onboard the mars rover Curiosity. The instrument DAN includes Pulsing Neutron Generator (PNG) producing pulses of 14.1 MeV neutrons for irradiation of subsurface material below the rover, and Detectors and Electronics (DE) unit, which operates the instrument itself and measures the die-away time profiles of epithermal and thermal neutrons following each neutron pulse. It is shown that the DAN investigation will measure a content of hydrogen along the path of the MSL rover, and it will also provide information about a depth distribution of hydrogen at 10-20 regions selected for the detailed studies and sampling analysis.

  13. Étude de la répartition des courants de Foucault pulsés dans une configuration de contrôle non destructif

    NASA Astrophysics Data System (ADS)

    Bour, J.-C.; Zubiri, E.; Vasseur, P.; Billat, A.

    1996-01-01

    Adjusting an experimental device of control by eddy-currents in sinusoidal or pulse mode requires the optimization of a certain number of parameters. Generally, the implementation of the latter operations is long and delicate, since it is issued of many compromises. The simulation study presented in this paper can be considered as a qualitative help because it specifies the the behaviour of the different parameters implied in the adjustment of the experimental defect reserach. First, we prove the influence of the lift-off on the defect detention's sensitivity of the flat sensor we used. Next we give prominence to the fact, in practice, we cannot disregard the geometry of the sensor, as we could do in theory. This result will lead us to define a family of curves showing the evolution of the depth of penetration as a function of the pulse's duration for different coil radii. We also determine the maximal sensor's sensitivity area, with the aim of locating the defect detected in the plate with precision. Finally, we prove the dependency between the true value of the depth of penetration and the thickness of the considered metallic plate. This very important result should equally be taken under consideration in the case of a real control. La mise au point d'un dispositif expérimental de contrôle par courants de Foucault, en mode sinusoïdal ou impulsionnel, nécessite l'optimisation d'un certain nombre de paramètres. Cette optimisation est généralement longue et délicate à exécuter en pratique puisqu'elle résulte de plusieurs compromis. L'étude en simulation présentée ici peut être considéré comme une aide plutôt qualitative, puisqu'elle précise le comportement des différents paramètres impliqués dans la mise en point de la recherche expérimentale de défauts. Nous montrons dans un premier temps l'influence de la distance capteur-cible sur la sensibilité du capteur à détecter un défaut. Nous mettons ensuite en évidence le fait de la g

  14. DAnTE: a statistical tool for quantitative analysis of –omics data

    SciTech Connect

    Polpitiya, Ashoka D.; Qian, Weijun; Jaitly, Navdeep; Petyuk, Vladislav A.; Adkins, Joshua N.; Camp, David G.; Anderson, Gordon A.; Smith, Richard D.

    2008-05-03

    DAnTE (Data Analysis Tool Extension) is a statistical tool designed to address challenges unique to quantitative bottom-up, shotgun proteomics data. This tool has also been demonstrated for microarray data and can easily be extended to other high-throughput data types. DAnTE features selected normalization methods, missing value imputation algorithms, peptide to protein rollup methods, an extensive array of plotting functions, and a comprehensive ANOVA scheme that can handle unbalanced data and random effects. The Graphical User Interface (GUI) is designed to be very intuitive and user friendly.

  15. Le pompage optique naturel dans le milieu astrophysique

    NASA Astrophysics Data System (ADS)

    Pecker, J.-C.

    The title of this lecture abstracts only a part of it : the importance in astrophysics of the study of non-LTE situations has become considerable, as well in the stellar atmospheres as, still more, in the study of fortuitous coincidences as a mechanism of formation of emission line nebular spectra, or of molecular interstellar « masers ». Another part of this talk underlines the role of Kastler in his time, and describes his warm personality through his public reactions in front of the nuclear armement, of the Viet-Nam and Algerian wars, of the problems of political refugees... Kastler was a great scientist ; he was also a courageous humanist. 1976 : Les accords nucléaires du Brésil : allocution d'ouverture (19 mars). Colloque sur le sujet ci-dessus. 1976 : La promotion de la culture dans le nouvel ordre économique international, allocution à l'occasion d'une table ronde sur ce thème par l'UNESCO (23-27 juin 1976) ; « Sciences et Techniques », octobre 1976. 1979 : La bête immonde (avec J.-C. Pecker), « Le Matin », 20 mars. 1979 : Appel à nos ministres (avec J.-C. Pecker), « Le Monde », 13 décembre. 1979 : Le flou, le ténébreux, l'irrationnel (avec J.-C. Pecker), « Le Monde », 14 septembre. 1980 : Education à la paix, Préface, in : Publ. UNESCO. 1981 : Le vrai danger, « Le Monde », 6 août 1981. 1982 : Nucléaire civil et militaire, « Le Monde », 1er juin 1982. 1982 : Les scientifiques face à la perspective d'holocauste nucléaire (texte inédit). Le titre de cette communication en résume seulement une partie : l'importance prise en astrophysique par l'analyse des situations hors ETL est devenue considérable, qu'il s'agisse des atmosphères stellaires, ou plus encore, des coïncidences fortuites de la formation des spectres d'émission nébulaires, ou des « masers » moléculaires interstellaires. Une autre partie de cet exposé souligne le rôle de Kastler dans son époque, et décrit sa personnalité généreuse à travers ses r

  16. Theorie de la Levitation Radiative a L'equilibre dans les Etoiles Naines Blanches Chaudes

    NASA Astrophysics Data System (ADS)

    Chayer, Pierre

    1995-01-01

    Les resultats de nouveaux calculs detailles de levitation radiative dans des naines blanches chaudes utilisant la base de donnees atomiques TOPBASE sont presentes. Des accelerations radiatives et des abondances d'equilibre ont ete calculees pour C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, et Fe, sur des grilles de modeles d'enveloppes stellaires riches en hydrogene et riches en helium. La grille des modeles de DA a des gravites telles que log g = 7.0, 7.5, 8.0, et 8.5, et couvre les temperatures effectives pour lesquelles 100,000K >= T_ {rm eff} >= 20,000K par sauts de 2,500K. La grille des modeles de DO/DB est similaire mais se prolonge a T_{rm eff } = 130,000K. Les resultats d'abondances d'equilibre de Ni dans des DA utilisant la base de donnees de Kurucz sont aussi presentes. Nous discutons dans les moindres details de la physique incluse dans les calculs afin de fournir une bonne comprehension physique de la levitation radiative sous les conditions rencontrees dans les naines blanches. Nous discutons aussi de la forme et de la dependance en fonction de la profondeur des reservoirs des elements, crees par un equilibre entre l'acceleration radiative et la gravite locale effective dans differentes enveloppes stellaires. Nous soulignons le role important joue dans la morphologie de ces reserviors par les etats d'ionisation dominants se trouvant dans la configuration gaz noble. Nos resultats centraux sont presentes sous forme de figures montrant le comportement de l'abondance photospherique estimee pour chaque element en fonction de la temperature effective et de la gravite de surface. Nous apportons egalement des ameliorations aux calculs de levitation radiative en utilisant une approche de modeles d'atmospheres pour les etoiles riches en hydrogene. Nous mettons l'emphase, en particulier, sur le role des traces d'elements lourds qui peuvent etre presents dans le plasma. Nous utilisons une table d'opacite monochromatique detaillee calculee pour un plasma compose de H

  17. Introduction to Quantum Simulation

    NASA Technical Reports Server (NTRS)

    Williams, Colin P.

    2005-01-01

    This viewgraph presentation addresses the problem of efficiently simulating the evolution of a quantum system. The contents include: 1) Quantum Simulation; 2) Extracting Answers from Quantum Simulations; 3) Quantum Fourier Transform; 4) Eigenvalue Estimation; 5) Fermionic Simulations.

  18. Harold Goldstein (R) and Dan Leiser (L) discuss bone implant development in the the Shuttle Tile

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Harold Goldstein (R) and Dan Leiser (L) discuss bone implant development in the the Shuttle Tile Laboratory N-242. A spin-off of Ames research on both bone density in microgravity and on thermal protection foams is the bone-growth implant shown in 1993.

  19. Southwest Research Institute astronomer Dan Durda checks the alignment of the SWUIS-A Xybion digital

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Southwest Research Institute astronomer Dan Durda checks the alignment of the SWUIS-A Xybion digital camera mounted in the rear cockpit of a NASA Dryden F/A-18B before taking off on an astronomy mission to search for small vulcanoids (asteroids) that may be orbiting between the sun and the planet Mercury.

  20. An Interview with Dan Hallahan: From Clinical Researcher to Consummate Teacher Educator

    ERIC Educational Resources Information Center

    Sayeski, Kristin L.

    2014-01-01

    Kristin L. Sayeski introduces the reader to Dan Hallahan and provides a synopsis of his educational background. She reports Hallahan received his BA in psychology in 1967 and his PhD in education and psychology in 1971 from the University of Michigan, then began his career as an assistant professor in special education at the University of…

  1. L'atteinte osseuse dans le sarcome de Kaposi classique et agressif: à propos d'un cas

    PubMed Central

    Sbiyaa, Mouhcine; El Alaoui, Adil; El Bardai, Mohammed; Mezzani, Amine; Lahrach, Kamal; Marzouki, Amine; Boutayeb, Fawzi

    2016-01-01

    Le sarcome de Kaposi classique est une tumeur rare multifocale d'origine des cellules endothéliales vasculaires à caractère évolutif progressif et peu maligne. L'atteinte viscérale dans le sarcome de kaposi est parfois observée chez les patients VIH positif par contre la dissémination tumorale dans les ganglions lymphatiques viscérales dans le SK classique reste très rare. On rapporte un cas rare de sarcome de kaposi classique agressif de la main avec une évolution rapide et destructive. PMID:27347285

  2. Testing water in the soil of the Gale crater by DAN active neutron measurements onboard the Curiosity Mars Rover

    NASA Astrophysics Data System (ADS)

    Mitrofanov, Igor

    2013-04-01

    Active neutron measurements by DAN [1] are performing onboard the Curiosity Rover [2]. During active measurements, the Pulsing Neutron Generator of DAN is producing pulses of 14 MeV neutrons, which diffuse in a tested substance during a time as large as several milliseconds. Before escaping out from the martian surface, they make a large number of collisions with nuclei of the atoms of the substance encountered. This diffusion of neutrons results in a moderation of the neutron's energy, since particles lose a fraction of energy in each collision. When a substance contains atoms of hydrogen, neutrons lose about half of their energy at each collision with them. The method of neutron data deconvolution is based on the direct comparison between the measured die-away time profiles of the epithermal and thermal neutrons in the testing spot with the corresponding time profiles predicted by the numerical simulations (see [1]). For the preliminary analysis of DAN data, we used the standard composition of the soil (see [3]). The simplest model of regolith was one with the same content of hydrogen over each individual tested spot, both in length and in depth (homogeneous model). It has only one fitting parameter, the Water Equivalent Hydrogen (WEH) measured in wt% of water in the soil. It was found that data for only one measurement in the spot of Hottah agrees with this model: the WEH corresponds to about 2 wt% at this stop. The 2-layer model is the next after the homogeneous model in level of complexity: it corresponds to 2 layers with different contents of hydrogen. There are three free parameters of this model: WEH in the top layer, thickness of the top layer and WEH in the bottom layer below the top one. The content of hydrogen in the top layer was found to be practically the same at stops, the value of water in the uplayer was about 1.0 - 1.5 % WEH. The other two parameters of 2-layer model were found to vary from one testing spot to another. For the distance interval

  3. Propriétés électroniques et schémas de bandes dans les semi-conducteurs amorphes. II. Etude des phénomènes de transport

    NASA Astrophysics Data System (ADS)

    Moliton, André; Ratier, Bernard

    We present the particular study of three important electric parameters which characterize an amorphous semiconductor. The band scheme is the Mott - Davis model and the three parameters : dark conductivity, thermoelectric power and alternative conductivity are determined versus temperature : calculations are presented on the more general manner for the successive energy levels (extended states, localized states in band tails, localized states near Fermi level). The schematic representations are finally proposed : at the classical curves obtained for the conductivities, we add a peculiar scheme for the thermoelectric power : its study is of importance for determining (with its sign) the type of amorphous semiconductor. Nous présentons de façon détaillée l'étude théorique de trois importants paramètres électriques susceptibles de caractériser un semi-conducteur amorphe. Le schéma de bande retenu est celui de Mott - Davis et les trois paramètres : conductivité continue, pouvoir thermoélectrique et conductivité alternative sont déterminés en particulier en fonction de la température : nous nous sommes attachés à présenter les calculs sous leur forme la plus générale possible en faisant intervenir successivement les différents mécanismes relatifs aux différents niveaux d'énergie (énergie relative aux états délocalisés, localisés dans les queues de bande, localisés au voisinage du niveau de Fermi). Les représentations schématiques, classiques pour la conductivité continue et à un degré moindre pour la conductivité alternative, sont proposées : nous détaillons en particulier celle du pouvoir thermoélectrique S dont l'étude est en fait essentielle car le signe de S (cf. Mott) est une des seules caractérisations fiables du type de semi-conducteur amorphe étudié.

  4. Prévalence et facteurs de risque du surpoids et de l'obésité dans une population d'enfants scolarisés en milieu urbain à Sfax, Tunisie

    PubMed Central

    Regaieg, Sofien; Charfi, Nadia; Trabelsi, Lobna; Kamoun, Mahdi; Feki, Habib; Yaich, Sourour; Abid, Mohamed

    2014-01-01

    Introduction L'objectif de ce travail etait d’étudier la prévalence du surpoids et de l'obésité chez un groupe d'enfants d’âge scolaire, habitant la ville de Sfax en Tunisie, et identifier les facteurs favorisant la prise pondérale Méthodes Il s'agossait d'une enquête descriptive transversale était réalisée en 2011 sur un échantillon représentatif d’élèves recrutés dans 11 écoles primaires publiques. Des informations concernant les caractéristiques sociodémographiques, les habitudes alimentaires et le comportement sédentaire pour chaque élève ont été précisées au moyen d'un questionnaire Résultats Nous avons colligé 1529 élèves, âgés entre 9 et 12 ans et se répartissant en 787 garçons (51,14%) et 747 filles (48,86%). Selon les seuils de référence de l'IOTF, la fréquence de l'obésité était de 2,4% et celle du surpoids était de 6,3%. L'obésité était significativement associée à l'obésité parentale, un niveau socioéconomique élevé, la prise de plus de deux goûters par jour et à l'activité sédentaire. Conclusion L'identification des facteurs de risque du surpoids et de l'obésité infantile permettrait de dépister les enfants à risques afin de leur proposer des mesures de prévention adaptées. Ces mesures de prévention devraient inclure non seulement des approches individuelles, mais aussi l'environnement social et physique de l'enfant. PMID:25018807

  5. DIMENSIONS OF SIMULATION.

    ERIC Educational Resources Information Center

    CRAWFORD, MEREDITH P.

    OPEN AND CLOSED LOOP SIMULATION IS DISCUSSED FROM THE VIEWPOINT OF RESEARCH AND DEVELOPMENT IN TRAINING TECHNIQUES. AREAS DISCUSSED INCLUDE--(1) OPEN-LOOP ENVIRONMENTAL SIMULATION, (2) SIMULATION NOT INVOLVING PEOPLE, (3) ANALYSIS OF OCCUPATIONS, (4) SIMULATION FOR TRAINING, (5) REAL-SIZE SYSTEM SIMULATION, (6) TECHNIQUES OF MINIATURIZATION, AND…

  6. Apport des moyens endoscopiques dans la dilatation des sténoses caustiques de l’œsophage

    PubMed Central

    Seydou, Togo; Abdoulaye, Ouattara Moussa; xing, Li; Zi, Sanogo Zimogo; sekou, Koumaré; Wen, Yang Shang; Ibrahim, Sankare; Sekou, Toure Cheik Ahmed; Boubacar, Maiga Ibrahim; Saye, Jacque; Jerome, Dakouo Dodino; Dantoumé, Toure Ousmane; Sadio, Yena

    2016-01-01

    Introduction Toutes les sténoses symptomatiques de l’œsophage peuvent être dilatées par voie endoscopique. Nous évaluons l'apport des moyens endoscopiques dans la prise en charge de la dilatation œsophagienne pour sténose caustique de l’œsophage (SCO) au Mali. Méthodes IL s'agissait d'une étude descriptive et prospective réalisée dans le service de chirurgie thoracique à l'hôpital du Mali. Au total 46 dossiers cliniques de patients on été enregistrés et subdivisés en 4 groupes en fonction de la topographie des lésions cicatricielles. Le nombre de cas d'assistance endoscopique réalisé a été déterminé afin de comprendre l'apport des moyens endoscopiques dans le succès de la dilatation des SCO. Pour les 2 différentes méthodes de dilatation utilisées, le résultat du traitement et le coût ont comparés. Résultats La FOGD a été utilisée dans 19 cas (41.30%) de dilatation avec la bougie de Savary Guillard et dans 47.82% des cas dans la dilatation de Lerut. La vidéo-laryngoscopie a été utilisé 58.69% des cas de dilatation à la bougie de Lerut. Le passage de guide métallique et / ou de fil-guide a été réalisée dans 39.13% avec la vidéo laryngoscopie et dans 58.68% avec la FOGD. Dans la comparaison des deux méthodes, il existe une différence significative dans la survenue des complications (p=0.04075), l'anesthésie générale (p=0.02287), l'accessibilité à la méthode (p=0.04805) et la mortalité (p=0.00402). Conclusion La SCO est une pathologie grave et sous évaluée au Mali. Les moyens endoscopiques contribuent considérablement au succès de la dilatation œsophagienne pour sténose caustique dans les différentes méthodes utilisées. PMID:27200129

  7. PLATO Simulator: Realistic simulations of expected observations

    NASA Astrophysics Data System (ADS)

    Marcos-Arenal, P.; Zima, W.; De Ridder, J.; Aerts, C.; Huygen, R.; Samadi, R.; Green, J.; Piotto, G.; Salmon, S.; Catala, C.; Rauer, H.

    2015-06-01

    PLATO Simulator is an end-to-end simulation software tool designed for the performance of realistic simulations of the expected observations of the PLATO mission but easily adaptable to similar types of missions. It models and simulates photometric time-series of CCD images by including models of the CCD and its electronics, the telescope optics, the stellar field, the jitter movements of the spacecraft, and all important natural noise sources.

  8. Rôle des hyrates dans la formation de Titan et des satellites réguliers

    NASA Astrophysics Data System (ADS)

    Mousis, O.

    2001-12-01

    Cette these est dediee a l'etude de l'origine de Titan et de son atmosphere. Dans l'hypothese ou la subnebuleuse de Saturne etait geometriquement mince, le modele de disque turbulent utilise, derive des travaux de Dubrulle (1993), est moins dense que le modele de Prinn et Fegley (1981). De ce fait, les conversions de Co en CH4 et de N2 en NH3 ont ete inhibees dans la subnebuleuse, contrairement a ce qui est couramment admis pour interpreter la presence du methane dans l'atmosphere de Titan. C'est pourquoi nous avons developpe un nouveau scenario de la formation de titan, qui tient compte simultanement des contraintes resultant de la chimie de la subnebuleuse et des abondances de CH4, N2 et CH3D mesurees dans l'atmosphere du satellite. Nous faisons l'hypothese que ces gaz proviennent initialement de la vaporisation du nuage presolaire, qui s'effondra et forma le Soleil et son disque environnant. Lors du refroidissement de la nebuleuse, les volatils auraient ete pieges sous formes de clathrates d'hydrates dans les grains, puis dans les planetesimaux qu'ils formerent. Les planetesimaux hydrates a l'origine de la formation de Titan seraient alors des rescapes de l'effondrement hydsrodynamique de la feeding zone de Saturne. Ce scenario a ete applique aux subnebuleuses de Jupiter et d'Uranus, et a apporte un certain nombre de contraintes sur la formation des satellites reguliers de ces planetes. Le temps et la zone de formation des grains cometaires ont egalement ete estimes dans la nebuleuse solaire. Enfin, l'etude experimentale de la temperature de fusion du dihydrate d'ammoniac dans la gamme des hautes pressions a apporte des nouvelles donnees thermodynamiques qui permettront d'ameliorer les modeles de l'interieur de Titan.

  9. DELightcurveSimulation: Light curve simulation code

    NASA Astrophysics Data System (ADS)

    Connolly, Samuel D.

    2016-02-01

    DELightcurveSimulation simulates light curves with any given power spectral density and any probability density function, following the algorithm described in Emmanoulopoulos et al. (2013). The simulated products have exactly the same variability and statistical properties as the observed light curves. The code is a Python implementation of the Mathematica code provided by Emmanoulopoulos et al.

  10. Manifestations de la transition solide-liquide dans les agrégats

    NASA Astrophysics Data System (ADS)

    Calvo, F.

    The thermodynamics of clusters is a subject of increasing interest, both from the theoretical and experimental points of view. We present a set of theoretical and numerical methods for studying phase transitions, especially the solid-liquid transition, in atomic or molecular clusters. Several means of characterization (thermodynamical, geometrical and dynamical) are introduced, and the differences between the finite-size behaviour and the bulk behaviour are described. The phenomenon of "dynamical coexistence", which can be seen as the cluster spontaneously going back and forth between the solid and liquid states across the time, is illustrated. Its thermodynamical consequences are also emphasized. Finally, we present some typical thermodynamical phenomena due to the finite-size character, and strongly dependent on the physical chemistry of the matter at the microscopic level. We study these phenomena with Monte Carlo and molecular dynamics simulations: surface melting observed on rare gas clusters, multistage melting observed on ionic clusters, the special behaviours of molecular clusters, and the more intricate problem of free or solvated metallic clusters. La thermodynamique des agrégats est un sujet en développement croissant, tant sur le plan théorique qu'expérimental. Nous présentons un ensemble de méthodes théoriques et numériques destinées à l'étude des transitions de phase, en particulier de la transition solide-liquide, dans les agrégats atomiques et moléculaires. Divers moyens de caractérisation (thermodynamiques, géométriques et dynamiques) sont introduits, et les différences entre les comportements à taille finie et à taille macroscopique sont précisées. Le phénomène de "coexistence dynamique", qui voit l'agrégat passer spontanément de l'état solide à l'état liquide (et réciproquement) au cours du temps, est illustré, et ses conséquences thermodynamiques sont soulignées. Enfin, nous présentons un certain nombre de ph

  11. Conductivite dans le modele de Hubbard bi-dimensionnel a faible couplage

    NASA Astrophysics Data System (ADS)

    Bergeron, Dominic

    Le modele de Hubbard bi-dimensionnel (2D) est souvent considere comme le modele minimal pour les supraconducteurs a haute temperature critique a base d'oxyde de cuivre (SCHT). Sur un reseau carre, ce modele possede les phases qui sont communes a tous les SCHT, la phase antiferromagnetique, la phase supraconductrice et la phase dite du pseudogap. Il n'a pas de solution exacte, toutefois, plusieurs methodes approximatives permettent d'etudier ses proprietes de facon numerique. Les proprietes optiques et de transport sont bien connues dans les SCHT et sont donc de bonne candidates pour valider un modele theorique et aider a comprendre mieux la physique de ces materiaux. La presente these porte sur le calcul de ces proprietes pour le modele de Hubbard 2D a couplage faible ou intermediaire. La methode de calcul utilisee est l'approche auto-coherente a deux particules (ACDP), qui est non-perturbative et inclue l'effet des fluctuations de spin et de charge a toutes les longueurs d'onde. La derivation complete de l'expression de la conductivite dans l'approche ACDP est presentee. Cette expression contient ce qu'on appelle les corrections de vertex, qui tiennent compte des correlations entre quasi-particules. Pour rendre possible le calcul numerique de ces corrections, des algorithmes utilisant, entre autres, des transformees de Fourier rapides et des splines cubiques sont developpes. Les calculs sont faits pour le reseau carre avec sauts aux plus proches voisins autour du point critique antiferromagnetique. Aux dopages plus faibles que le point critique, la conductivite optique presente une bosse dans l'infrarouge moyen a basse temperature, tel qu'observe dans plusieurs SCHT. Dans la resistivite en fonction de la temperature, on trouve un comportement isolant dans le pseudogap lorsque les corrections de vertex sont negligees et metallique lorsqu'elles sont prises en compte. Pres du point critique, la resistivite est lineaire en T a basse temperature et devient

  12. Geochemistry of dissolved trace elements and heavy metals in the Dan River Drainage (China): distribution, sources, and water quality assessment.

    PubMed

    Meng, Qingpeng; Zhang, Jing; Zhang, Zhaoyu; Wu, Tairan

    2016-04-01

    Dissolved trace elements and heavy metals in the Dan River drainage basin, which is the drinking water source area of South-to-North Water Transfer Project (China), affect large numbers of people and should therefore be carefully monitored. To investigate the distribution, sources, and quality of river water, this study integrating catchment geology and multivariate statistical techniques was carried out in the Dan River drainage from 99 river water samples collected in 2013. The distribution of trace metal concentrations in the Dan River drainage was similar to that in the Danjiangkou Reservoir, indicating that the reservoir was significantly affected by the Dan River drainage. Moreover, our results suggested that As, Sb, Cd, Mn, and Ni were the major pollutants. We revealed extremely high concentrations of As and Sb in the Laoguan River, Cd in the Qingyou River, Mn, Ni, and Cd in the Yinhua River, As and Sb in the Laojun River, and Sb in the Dan River. According to the water quality index, water in the Dan River drainage was suitable for drinking; however, an exposure risk assessment model suggests that As and Sb in the Laojun and Laoguan rivers could pose a high risk to humans in terms of adverse health and potential non-carcinogenic effects. PMID:26782327

  13. LOADING SIMULATION PROGRAM C

    EPA Science Inventory

    LSPC is the Loading Simulation Program in C++, a watershed modeling system that includes streamlined Hydrologic Simulation Program Fortran (HSPF) algorithms for simulating hydrology, sediment, and general water quality on land as well as a simplified stream transport model. LSPC ...

  14. Software simulator for multiple computer simulation system

    NASA Technical Reports Server (NTRS)

    Ogrady, E. P.

    1983-01-01

    A description is given of the structure and use of a computer program that simulates the operation of a parallel processor simulation system. The program is part of an investigation to determine algorithms that are suitable for simulating continous systems on a parallel processor configuration. The simulator is designed to accurately simulate the problem-solving phase of a simulation study. Care has been taken to ensure the integrity and correctness of data exchanges and to correctly sequence periods of computation and periods of data exchange. It is pointed out that the functions performed during a problem-setup phase or a reset phase are not simulated. In particular, there is no attempt to simulate the downloading process that loads object code into the local, transfer, and mapping memories of processing elements or the memories of the run control processor and the system control processor. The main program of the simulator carries out some problem-setup functions of the system control processor in that it requests the user to enter values for simulation system parameters and problem parameters. The method by which these values are transferred to the other processors, however, is not simulated.

  15. Approximation auto-coherente a deux particules, pseudogap et supraconductivite dans le modele de Hubbard attractif

    NASA Astrophysics Data System (ADS)

    Allen, Steve

    2000-10-01

    Dans cette these nous presentons une nouvelle methode non perturbative pour le calcul des proprietes d'un systeme de fermions. Notre methode generalise l'approximation auto-coherente a deux particules proposee par Vilk et Tremblay pour le modele de Hubbard repulsif. Notre methode peut s'appliquer a l'etude du comportement pre-critique lorsque la symetrie du parametre d'ordre est suffisamment elevee. Nous appliquons la methode au probleme du pseudogap dans le modele de Hubbard attractif. Nos resultats montrent un excellent accord avec les donnees Monte Carlo pour de petits systemes. Nous observons que le regime ou apparait le pseudogap dans le poids spectral a une particule est un regime classique renormalise caracterise par une frequence caracteristique des fluctuations supraconductrices inferieure a la temperature. Une autre caracteristique est la faible densite de superfluide de cette phase demontrant que nous ne sommes pas en presence de paires preformees. Les resultats obtenus semblent montrer que la haute symetrie du parametre d'ordre et la bidimensionalite du systeme etudie elargissent le domaine de temperature pour lequel le regime pseudogap est observe. Nous argumentons que ce resultat est transposable aux supraconducteurs a haute temperature critique ou le pseudogap apparait a des' temperatures beaucoup plus grandes que la temperature critique. La forte symetrie dans ces systemes pourraient etre reliee a la theorie SO(5) de Zhang. En annexe, nous demontrons un resultat tout recent qui permettrait d'assurer l'auto-coherence entre les proprietes a une et a deux particules par l'ajout d'une dynamique au vertex irreductible. Cet ajout laisse entrevoir la possibilite d'etendre la methode au cas d'une forte interaction.

  16. La prévention des blessures dans les terrains de jeux

    PubMed Central

    Fuselli, Pamela; Yanchar, Natalie L

    2012-01-01

    RÉSUMÉ Dans un climat d’inquiétude croissante à l’égard de l’obésité juvénile et de l’inactivité, les terrains de jeux permettent aux enfants d’être actifs. Ils comportent toutefois aussi des risques, les blessures causées par des chutes étant de loin les plus courants. Les recherches démontrent la possibilité de réduire les blessures dans les terrains de jeux si on abaisse la hauteur des structures de jeu et si on utilise des surfaces molles et profondes pour amortir les chutes. L’Association canadienne de normalisation a publié des normes volontaires qu’elle a mises à jour plusieurs fois pour tenir compte de ces risques. Afin de contribuer à les réduire, les parents peuvent respecter des stratégies simples. Le présent document de principes souligne le fardeau des blessures subies dans les terrains de jeux. Il procure également aux parents et aux dispensateurs de soins des occasions de réduire l’incidence et la gravité des blessures grâce à l’éducation et à la défense d’intérêts, ainsi que de mettre en œuvre des normes de sécurité probantes et des stratégies plus sécuritaires dans les terrains de jeux locaux. Enfin, il remplace le document de principes de la Société canadienne de pédiatrie publié en 2002 sur le sujet.

  17. Franz Xaver von Zach et l'astronomie dans la France méridionale

    NASA Astrophysics Data System (ADS)

    Brosche, Peter; Débarbat, Suzanne

    Le baron Franz Xaver von Zach, né à Pest (Hongrie), a fait ses études notamment en France et en Angleterre. En 1786 le duc de Saxe-Gotha, Ernst II, lui demande de créer son observatoire de Seeberg. La même année ils se rendent dans le sud de la France, à Hyères à cette occasion, une des tours du mur d'enceinte de la ville est transformée en observatoire. En 1809, Zach et la duchesse régnante viennent près de Marseille et, lors de plusieurs voyages dans le sud de la France. Zach exécute des travaux géodésiques et astronomiques. Dans son "Journal", il mentionne les astronomes français, notamment ceux de la France méridonale auxquels il apporte son soutien. Pons devient, sur sa recommandation, astronome royal de la duchesse de Lucca, épouse du "roi d'Etrurie".

  18. Comparaison de lois de commande. Régulation numérique de courant dans l'association convertisseur-machine

    NASA Astrophysics Data System (ADS)

    Kalinowski, D.; Bergmann, C.

    1991-05-01

    This article deals with a comparison of different numerical command laws, as regards dynamical characteristics and robustness, for direct current motor control. The power converter, which uses bi-directional switches, connect directly the three-phase source to the servo-motor. Simulations, compared with experimental results, show the variations of the dynamical characteristics regarding perturbations, that is to say: model parameters are not constant, the converter is not linear, and there are numerical saturations. Cet article présente différentes stratégies de commande, sur un critère de rapidité/robustesse, pour une régulation numérique du courant dans un servo-moteur à courant continu. Le convertisseur de puissance, à la base de la structure, est constitué d'interrupteurs bidirectionnels et réalise l'alimentation directe de la charge à travers un réseau triphasé. Les simulations, confrontées aux résultats expérimentaux, montrent la très nette dépendance des caractéristiques dynamiques finales vis-à-vis des éléments perturbateurs à savoir : la variation des paramètres constituants le modèle, les non-linéarités des convertisseurs et les saturations numériques.

  19. Simulation of Storm Occurrences Using Simulated Annealing.

    NASA Astrophysics Data System (ADS)

    Lokupitiya, Ravindra S.; Borgman, Leon E.; Anderson-Sprecher, Richard

    2005-11-01

    Modeling storm occurrences has become a vital part of hurricane prediction. In this paper, a method for simulating event occurrences using a simulated annealing algorithm is described. The method is illustrated using annual counts of hurricanes and of tropical storms in the Atlantic Ocean and Gulf of Mexico. Simulations closely match distributional properties, including possible correlations, in the historical data. For hurricanes, traditionally used Poisson and negative binomial processes also predict univariate properties well, but for tropical storms parametric methods are less successful. The authors determined that simulated annealing replicates properties of both series. Simulated annealing can be designed so that simulations mimic historical distributional properties to whatever degree is desired, including occurrence of extreme events and temporal patterning.

  20. A pilot study using the Chinese herbal paste Liu-He-Dan to manage radiodermatitis associated with breast cancer radiotherapy

    PubMed Central

    Zhou, J.; Fang, L.; Xie, H.; Yao, W.X.; Zhou, X.; Xiong, Z.J.

    2015-01-01

    Background During radiotherapy for breast cancer, patients are greatly affected by pain, infection, and delayed healing of wounds caused by radiodermatitis. In the present study, we aimed to determine the efficacy of Liu-He-Dan in treating radiodermatitis. Methods In 26 breast cancer patients who experienced moist decrustation while receiving radiotherapy, 5 g Liu-He-Dan was applied externally once daily after the wound surface had been cleaned and dried. The healing time was recorded, and a Kaplan–Meier survival curve was applied to analyze the treatment course. Meanwhile, a pain assessment using the Numeric Rating Scale (nrs) recorded the pain level experienced by patients after application of the Liu-He-Dan. Results After application of Liu-He-Dan, the average healing time for the surface of the moist decrustation wounds was 14.17 ± 2.03 days (range: 5–22 days). Inflammatory seepage decreased significantly and exudation almost disappeared in 3 days. The pain trend line indicated that the average nrs score declined with treatment in all patients. The average nrs scores at days 1, 4, and 7 were 6.13, 3.62, and 2.58 respectively. After 3 days of treatment, pain was remarkably alleviated in 80.76% of patients. After treatment for 1 week, the pain remission rate was 96.15%, without any obvious adverse reactions. Conclusions Liu-He-Dan was efficacious in treating radiation skin injury with little toxicity and few side effects; the economic efficiency of the treatment was also favourable. The Liu-He-Dan was generally well tolerated by patients. In future, randomized control trials will be established for further observation of the value of Liu-He-Dan in treating radiodermatitis in breast cancer. PMID:26715882

  1. Error and efficiency of simulated tempering simulations

    PubMed Central

    Rosta, Edina; Hummer, Gerhard

    2010-01-01

    We derive simple analytical expressions for the error and computational efficiency of simulated tempering (ST) simulations. The theory applies to the important case of systems whose dynamics at long times is dominated by the slow interconversion between two metastable states. An extension to the multistate case is described. We show that the relative gain in efficiency of ST simulations over regular molecular dynamics (MD) or Monte Carlo (MC) simulations is given by the ratio of their reactive fluxes, i.e., the number of transitions between the two states summed over all ST temperatures divided by the number of transitions at the single temperature of the MD or MC simulation. This relation for the efficiency is derived for the limit in which changes in the ST temperature are fast compared to the two-state transitions. In this limit, ST is most efficient. Our expression for the maximum efficiency gain of ST simulations is essentially identical to the corresponding expression derived by us for replica exchange MD and MC simulations [E. Rosta and G. Hummer, J. Chem. Phys. 131, 165102 (2009)] on a different route. We find quantitative agreement between predicted and observed efficiency gains in a test against ST and replica exchange MC simulations of a two-dimensional Ising model. Based on the efficiency formula, we provide recommendations for the optimal choice of ST simulation parameters, in particular, the range and number of temperatures, and the frequency of attempted temperature changes. PMID:20095723

  2. Error and efficiency of simulated tempering simulations.

    PubMed

    Rosta, Edina; Hummer, Gerhard

    2010-01-21

    We derive simple analytical expressions for the error and computational efficiency of simulated tempering (ST) simulations. The theory applies to the important case of systems whose dynamics at long times is dominated by the slow interconversion between two metastable states. An extension to the multistate case is described. We show that the relative gain in efficiency of ST simulations over regular molecular dynamics (MD) or Monte Carlo (MC) simulations is given by the ratio of their reactive fluxes, i.e., the number of transitions between the two states summed over all ST temperatures divided by the number of transitions at the single temperature of the MD or MC simulation. This relation for the efficiency is derived for the limit in which changes in the ST temperature are fast compared to the two-state transitions. In this limit, ST is most efficient. Our expression for the maximum efficiency gain of ST simulations is essentially identical to the corresponding expression derived by us for replica exchange MD and MC simulations [E. Rosta and G. Hummer, J. Chem. Phys. 131, 165102 (2009)] on a different route. We find quantitative agreement between predicted and observed efficiency gains in a test against ST and replica exchange MC simulations of a two-dimensional Ising model. Based on the efficiency formula, we provide recommendations for the optimal choice of ST simulation parameters, in particular, the range and number of temperatures, and the frequency of attempted temperature changes. PMID:20095723

  3. Systems Engineering Simulator (SES) Simulator Planning Guide

    NASA Technical Reports Server (NTRS)

    McFarlane, Michael

    2011-01-01

    The simulation process, milestones and inputs are unknowns to first-time users of the SES. The Simulator Planning Guide aids in establishing expectations for both NASA and non-NASA facility customers. The potential audience for this guide includes both internal and commercial spaceflight hardware/software developers. It is intended to assist their engineering personnel in simulation planning and execution. Material covered includes a roadmap of the simulation process, roles and responsibilities of facility and user, major milestones, facility capabilities, and inputs required by the facility. Samples of deliverables, facility interfaces, and inputs necessary to define scope, cost, and schedule are included as an appendix to the guide.

  4. Manipulation coherente de qubits de spin dans une boite quantique triple

    NASA Astrophysics Data System (ADS)

    Gaudreau, Louis

    Nous presentons dans cette these une etude detaillee du moment magnetique intrinseque de l'electron, i.e. le spin electronique, incluant la manipulation quantique coherente des etats de spin de trois electrons couples. A cette fin, nous utilisons des boites quantiques laterales pour confiner les electrons. Ces nano-structures, d'une grandeur autour de 1 pm, permettent de confiner un nombre precis d'electrons de facon controlee, allant jusqu'a zero electrons. Les developpements technologiques et d'ingeniosite durant la derniere decennie ont permis de coupler trois boites quantiques, ainsi l'interaction entre plusieurs electrons confines peut etre controlee comme par exemple le couplage quantique tunnel et l'interaction d'echange entre les spins de chacun d'entre eux. A l'aide de boites quantiques couplees, il est possible de realiser des experiences dans plusieurs domaines de la physique moderne : les etats up et down du spin des electrons confines peuvent etre utilisees comme etats quantiques binaires (qubits) dans le domaine de l'informatique quantique, la non-localite quantique peut etre testee en separant spatialement deux electrons enchevetres, il est possible de creer des 'courants de spin enchevetres' utiles en spintronique, et bien d'autres. La manipulation coherente des etats de spin du systeme a trois electrons se fait de facon purement electrique grace a des pulses a haute frequence qui permettent d'augmenter le couplage entre les electrons et de faire la mesure de l'etat resultant apres la manipulation. Nous utilisons l'interaction hyperfine entre les spins des electrons et ceux des noyaux du cristal dans lequel ils resident pour creer les rotations quantiques entre les etats, notamment les etats |Q +3/2> et (D+1/2>. Les resultats obtenus indiquent un temps de coherence de l'ordre de 10 ns. Ces experiences demontrent un niveau de controle sans precedant de boites quantiques triples et pavent la voie vers des nano-structures plus sophistiquees dans

  5. Les reconstructions acétabulaires dans les prothèses totales de hanche

    PubMed Central

    Zejjari, Hassane; Louaste, Jamal; Cherrad, Taoufik; Bousbae, Hicham; Kasmaoui, Housseine; Amhajji, Larbi; Rachid, Khalid

    2015-01-01

    La chirurgie de reconstruction acétabulaire est une technique qui consiste à combler les pertes de substance osseuse siégeant au niveau du cotyle. Il s'agit d'une étude rétrospective de 15 patients (16 cotyles), sur une période de 6 ans (2006- 2012). Dans douze cas il s'agissait de prothèse totales de la hanche de première intention et dans quatre cas il s'agissait de reprise cotyloïdienne de PTH. L’évaluation clinique préopératoire et postopératoire de tous nos patients a été effectuée par le score de Postel et Merle d'Aubigné. L’évaluation des pertes de substances osseuse du cotyle a été classée selon la classification de Paprosky. L’âge moyen de nos patients au moment de l'intervention a été de 57 ans avec des extrêmes allant de 20 ans à 76 ans. La greffe osseuse a été utilisée chez 12 de nos patients. La reconstruction prothétique a été utilisée chez 8 patients (anneau de Kerboul dans six cas et anneau de Burch-Schneider dans deux cas). Recul post opératoire moyen a été de 56 mois. L’évaluation radiologique a été basée sur les clichés radiologiques du bassin de face strict ainsi que des radiographies de la hanche opérée de face prenant la totalité de la prothèse. Nos résultats cliniques et radiologiques ont été jugé bon à très bon dans la majorité des cas. Pour nous, nous optant pour le recentrage-reconstruction car c'est lui qui s'approche le plus de l'anatomie et de la biomécanique normale de la hanche. PMID:26955415

  6. Validation of Broadband Ground Motion Simulations for Japanese Crustal Earthquakes by the Recipe

    NASA Astrophysics Data System (ADS)

    Iwaki, A.; Maeda, T.; Morikawa, N.; Miyake, H.; Fujiwara, H.

    2015-12-01

    The Headquarters for Earthquake Research Promotion (HERP) of Japan has organized the broadband ground motion simulation method into a standard procedure called the "recipe" (HERP, 2009). In the recipe, the source rupture is represented by the characterized source model (Irikura and Miyake, 2011). The broadband ground motion time histories are computed by a hybrid approach: the 3-D finite-difference method (Aoi et al. 2004) and the stochastic Green's function method (Dan and Sato, 1998; Dan et al. 2000) for the long- (> 1 s) and short-period (< 1 s) components, respectively, using the 3-D velocity structure model. As the engineering significance of scenario earthquake ground motion prediction is increasing, thorough verification and validation are required for the simulation methods. This study presents the self-validation of the recipe for two MW6.6 crustal events in Japan, the 2000 Tottori and 2004 Chuetsu (Niigata) earthquakes. We first compare the simulated velocity time series with the observation. Main features of the velocity waveforms, such as the near-fault pulses and the large later phases on deep sediment sites are well reproduced by the simulations. Then we evaluate 5% damped pseudo acceleration spectra (PSA) in the framework of the SCEC Broadband Platform (BBP) validation (Dreger et al. 2015). The validation results are generally acceptable in the period range 0.1 - 10 s, whereas those in the shortest period range (0.01-0.1 s) are less satisfactory. We also evaluate the simulations with the 1-D velocity structure models used in the SCEC BBP validation exercise. Although the goodness-of-fit parameters for PSA do not significantly differ from those for the 3-D velocity structure model, noticeable differences in velocity waveforms are observed. Our results suggest the importance of 1) well-constrained 3-D velocity structure model for broadband ground motion simulations and 2) evaluation of time series of ground motion as well as response spectra.

  7. Simultaneous Measurements of Neutron Environment at Mars from Orbit (Mars Odyssey HEND) and from the Surface (MSL DAN)

    NASA Astrophysics Data System (ADS)

    Martinez Sierra, L. M.; Jun, I.; Litvak, M. L.; Sanin, A. B.; Mitrofanov, I. G.

    2015-12-01

    Currently, the high energy neutron detector (HEND) onboard Mars Odyssey and the dynamic albedo of neutrons (DAN) instrument onboard the Mars Science Laboratory rover are simultaneously measuring the neutron environment from orbit and from the surface, respectively. Naturally-occurring neutrons at Mars are produced from the interactions of galactic cosmic rays (GCR) and solar energetic particles (SEP) with the Martian atmosphere and surface material. The neutron data from these simultaneous orbital and surface measurements are a good indicator for the state of general ambient radiation environments at Mars and can be also used as a means to infer how the ambient radiation is transported through the Martian atmosphere. Both HEND and DAN are healthy, and they provide the unique data sources valuable to study these phenomena for the period since the MSL landing in August 2012. Understanding of why there is correlation or no correlation between the two measurements will provide a key clue to understand the processes of GCR/SEP propagation through the Mars atmosphere and the interaction with the Mars surface materials. More detailed comparison between the two data sets and analysis of HEND/DAN data will be presented in the final presentation. Also, the long-term trend of the HEND/DAN data will be also compared with a general space weather condition. We used only publicly available HEND/DAN data in this study, e.g., open literature and/or planetary data system (PDS).

  8. Design of interpenetrated network MWCNT/poly(1,5-DAN) on interdigital electrode: toward NO2 gas sensing.

    PubMed

    Nguyen, Dzung Tuan; Nguyen, My Thanh; Ho, Giang Truong; Nguyen, Toan Ngoc; Reisberg, S; Piro, B; Pham, M C

    2013-10-15

    In this paper, poly(1,5-diaminonaphthalene) was interpenetrated into the network made of multiwalled carbon nanotubes (MWCNT) on platinum interdigital electrode (IDE) by electro-polymerization of 1,5-diaminonaphthalene (1,5-DAN). The electro-polymerization process of 1,5-DAN on MWCNT was controlled by scanning the cyclic voltage at 50 mV s(-1) scan rate between -0.1 V and +0.95 V vs. saturated calomel electrode (SCE). The results of voltammetric responses and Raman spectroscopy represented that the films MWCNT/poly(1,5-DAN) were successfully created by this polymerization process. The films MWCNT/poly(1,5-DAN) were investigated for gas-sensing to NO2 at low concentration level. The gas-sensing results showed that the response-recovery times were long and strongly affected by thickness of the film MWCNT/poly(1,5-DAN). Nevertheless, these films represented auspicious results for gas sensors operating at room temperature. PMID:24054652

  9. DanQ: a hybrid convolutional and recurrent deep neural network for quantifying the function of DNA sequences

    PubMed Central

    Quang, Daniel; Xie, Xiaohui

    2016-01-01

    Modeling the properties and functions of DNA sequences is an important, but challenging task in the broad field of genomics. This task is particularly difficult for non-coding DNA, the vast majority of which is still poorly understood in terms of function. A powerful predictive model for the function of non-coding DNA can have enormous benefit for both basic science and translational research because over 98% of the human genome is non-coding and 93% of disease-associated variants lie in these regions. To address this need, we propose DanQ, a novel hybrid convolutional and bi-directional long short-term memory recurrent neural network framework for predicting non-coding function de novo from sequence. In the DanQ model, the convolution layer captures regulatory motifs, while the recurrent layer captures long-term dependencies between the motifs in order to learn a regulatory ‘grammar’ to improve predictions. DanQ improves considerably upon other models across several metrics. For some regulatory markers, DanQ can achieve over a 50% relative improvement in the area under the precision-recall curve metric compared to related models. We have made the source code available at the github repository http://github.com/uci-cbcl/DanQ. PMID:27084946

  10. DanQ: a hybrid convolutional and recurrent deep neural network for quantifying the function of DNA sequences.

    PubMed

    Quang, Daniel; Xie, Xiaohui

    2016-06-20

    Modeling the properties and functions of DNA sequences is an important, but challenging task in the broad field of genomics. This task is particularly difficult for non-coding DNA, the vast majority of which is still poorly understood in terms of function. A powerful predictive model for the function of non-coding DNA can have enormous benefit for both basic science and translational research because over 98% of the human genome is non-coding and 93% of disease-associated variants lie in these regions. To address this need, we propose DanQ, a novel hybrid convolutional and bi-directional long short-term memory recurrent neural network framework for predicting non-coding function de novo from sequence. In the DanQ model, the convolution layer captures regulatory motifs, while the recurrent layer captures long-term dependencies between the motifs in order to learn a regulatory 'grammar' to improve predictions. DanQ improves considerably upon other models across several metrics. For some regulatory markers, DanQ can achieve over a 50% relative improvement in the area under the precision-recall curve metric compared to related models. We have made the source code available at the github repository http://github.com/uci-cbcl/DanQ. PMID:27084946

  11. Simulation and Faculty Development.

    PubMed

    Rogers, David A; Peterson, Dawn Taylor; Ponce, Brent A; White, Marjorie Lee; Porterfield, John R

    2015-08-01

    As members of the faculty, surgeons take on a variety of roles related to the use of simulation. Surgeons will continue to interact with simulation as learners given the emerging role of simulation in continuing medical education. Surgeons who regularly teach others will also be using simulation because of its unique properties as an instructional method. Leading a simulation effort requires vision, creativity in resource management, and team leadership skills. Surgeons can use simulation to innovate in surgical patient care and in surgical education. PMID:26210966

  12. Retinal Detachment Vision Simulator

    MedlinePlus

    ... Retina Treatment Retinal Detachment Vision Simulator Retinal Detachment Vision Simulator Mar. 01, 2016 How does a detached or torn retina affect your vision? If a retinal tear is occurring, you may ...

  13. The Business Flight Simulator.

    ERIC Educational Resources Information Center

    Dwyer, P.; Simpson, D.

    1989-01-01

    The authors describe a simulation program based on a workshop approach designed for postsecondary business students. Features and benefits of the workshop technique are discussed. The authors cover practical aspects of designing and implementing simulation workshops. (CH)

  14. Grossesse dans une corne rudimentaire: difficultés diagnostiques et prise en charge thérapeutique

    PubMed Central

    Mamouni, Nisrine; Ghazal, Nabil; Erraghay, Sanaa; Bouchikhi, Chahrazed; Banani, Abdelaziz

    2016-01-01

    La survenue d'une grossesse dans une corne utérine rudimentaire est une situation obstétricale extrêmement rare et potentiellement grave, menaçant le pronostic materno-fœtal. Les auteurs rapportent cinq observations de grossesse dans une corne utérine rudimentaire, à travers lesquelles, ils relatent les difficultés sur le plan diagnostique ainsi que la prise en charge thérapeutique de cette entité pathologique, soulignant l'intérêt de l’échographie endovaginale, de l'IRM pelvienne et de la cœlioscopie dans le diagnostic précoce de ce type de malformation uterine.

  15. Distribution system simulator

    NASA Technical Reports Server (NTRS)

    Bahrami, K. A.; Kirkham, H.; Rahman, S.

    1986-01-01

    In a series of tests performed under the Department of Energy auspices, power line carrier propagation was observed to be anomalous under certain circumstances. To investigate the cause, a distribution system simulator was constructed. The simulator was a physical simulator that accurately represented the distribution system from below power frequency to above 50 kHz. Effects such as phase-to-phase coupling and skin effect were modeled. Construction details of the simulator, and experimental results from its use are presented.

  16. Microgravity Simulation Facility (MSF)

    NASA Technical Reports Server (NTRS)

    Richards, Stephanie E. (Compiler); Levine, Howard G.; Zhang, Ye

    2016-01-01

    The Microgravity Simulator Facility (MSF) at Kennedy Space Center (KSC) was established to support visiting scientists for short duration studies utilizing a variety of microgravity simulator devices that negate the directional influence of the "g" vector (providing simulated conditions of micro or partial gravity). KSC gravity simulators can be accommodated within controlled environment chambers allowing investigators to customize and monitor environmental conditions such as temperature, humidity, CO2, and light exposure.

  17. Launch Vehicle Operations Simulator

    NASA Technical Reports Server (NTRS)

    Blackledge, J. W.

    1974-01-01

    The Saturn Launch Vehicle Operations Simulator (LVOS) was developed for NASA at Kennedy Space Center. LVOS simulates the Saturn launch vehicle and its ground support equipment. The simulator was intended primarily to be used as a launch crew trainer but it is also being used for test procedure and software validation. A NASA/contractor team of engineers and programmers implemented the simulator after the Apollo XI lunar landing during the low activity periods between launches.

  18. Factorization of simulations

    SciTech Connect

    Barrett, C. L.; Mortveit, H. S.; Reidys, C. M.

    2001-01-01

    A simulation is collection of agents that, according to some schedule, are making decisions based on information about other agents in that collection. In this paper we present a class of dynamical systems called Sequential Dynamical Systems (SDS) that was developed to capture these key features of computer simulations. Here, as an example of the use of SDS, we demonstrate how one can obtain information about a simulation by a factorization into smaller simulations.

  19. Remote manipulator dynamic simulation

    NASA Technical Reports Server (NTRS)

    Wild, E. C.; Donges, P. K.; Garand, W. A.

    1972-01-01

    A simulator to generate the real time visual scenes required to perform man in the loop investigations of remote manipulator application and design concepts for the space shuttle is described. The simulated remote manipulator consists of a computed display system that uses a digital computer, the electronic scene generator, an operator's station, and associated interface hardware. A description of the capabilities of the implemented simulation is presented. The mathematical models and programs developed for the simulation are included.

  20. Denelcor HEP multiprocessor simulator

    SciTech Connect

    Dunigan, T.H.

    1986-06-01

    The structure and use of a simulator for the Denelcor HEP multiprocessor are described. The simulator provides a multitasking environment for the development of parallel programs in C or FORTRAN using a library of subroutines that simulate the parallel programming constructs available on the HEP, a shared-memory multiprocessor. The simulator also provides a trace file that can be used for debugging, performance analysis, or graphical display. 7 refs., 4 figs.

  1. Modélisation et simulation en régime stationnaire d'ateliers d'évaporation de sucreries à l'aide de l'équation d'état de Peng-Robinson

    NASA Astrophysics Data System (ADS)

    Rabi, M.; Bounahmidi, T.

    1999-03-01

    In this work the Peng-Robinson equation of state, previously adapted in our laboratory to predict physical and vapor-liquid equilibrium properties of sugar juices caracterised by the pseudo-components: sugar, amino acid ,carboxylic acid and cinders in aquesus solution, was tested in the modeling and simulation of the steady-state behaviour of multiple effect evaporation plants in sugar factory. The results of simulation has been compared to the real average measurements in the SUNABEL(Sucrerie Nationale de Betterave de Loukkos,Maroc) sugar factory, and showed that the Peng-Robinson equation of state can be used to predict, with a sufficient precision, of the steady-state behaviour of multiple effect evaporation plants in sugar factory. The originality of the model in comparison with the published others models consist in takening account of purity and natural of impurity in the juice. The simultanious modular approach is used in steady state process simulation. Dans ce travail l'équation d'état de Peng-Robinson, adaptée antérieurement dans notre laboratoire aux jus sucrés industriels en caractérisant ces derniers à l'aide de pseudo-composés sucre, acide aminé, acide carboxylique et cendre en solution dans l'eau, a ?été? testée pour la modélisation en régime stationnaire d'ateliers d'évaporation de sucreries. La confrontation des résultats de simulation à l'aide de ce modèle, avec des mesures moyennes observées sur l'atelier d'évaporation de la Sucrerie Nationale de Betterave du Loukkos (SUNABEL) Ksar El Kébir, a montré? que cette ?équation permet de prédire, avec une précision suffisante, les performances de l'atelier en régime stationnaire. L'originalité? du modèle développé, par rapport aux modèles proposés dans la littérature, réside dans la prise en compte de la pureté? et de la nature des impuretés présentes dans le jus. La simulation de l'atelier d'évaporation à l'aide de ce modèle a été menée en utilisant l

  2. Office Simulation Activities.

    ERIC Educational Resources Information Center

    North Carolina State Dept. of Community Colleges, Raleigh.

    This document consists of nineteen task simulations designed for use in developing the office skills of business education students. Each task simulation unit includes a description of the task, procedures for performing the task, and a listing of materials needed to perform the task. The task simulations included cover: (1) folding and inserting…

  3. Air Combat Simulator

    NASA Technical Reports Server (NTRS)

    1981-01-01

    By adapting COSMIC's One-on-One Adaptive Maneuvering Logic (AML) for two versus one simulation, Link Division was able to reduce software and other design/development costs. Enhancements to the AML program developed by Link for simulation of two-versus one combat, two trainees can simultaneously engage a computer driven target, thereby doubling the training utility of the simulator.

  4. NAPL: SIMULATOR DOCUMENTATION

    EPA Science Inventory

    A mathematical and numerical model is developed to simulate the transport and fate of NAPLs (Non-Aqueous Phase Liquids) in near-surface granular soils. The resulting three-dimensional, three phase simulator is called NAPL. The simulator accommodates three mobile phases: water, NA...

  5. Simulations: Selection and Development.

    ERIC Educational Resources Information Center

    Wager, Walter W.; And Others

    1992-01-01

    Examines factors affecting selection and development of computer simulations, including type of learner, simulation formats, instructional purposes, learning outcomes, fidelity, learning stages, and logistical issues. A flowchart model and set of prescriptions to help designers arrive at specifications for an instructional simulation are…

  6. Electrical Circuit Simulation Code

    Energy Science and Technology Software Center (ESTSC)

    2001-08-09

    Massively-Parallel Electrical Circuit Simulation Code. CHILESPICE is a massively-arallel distributed-memory electrical circuit simulation tool that contains many enhanced radiation, time-based, and thermal features and models. Large scale electronic circuit simulation. Shared memory, parallel processing, enhance convergence. Sandia specific device models.

  7. Test vs. simulation

    NASA Technical Reports Server (NTRS)

    Wood, Charles C.

    1991-01-01

    The following topics are presented in tabular form: (1) simulation capability assessments (no propulsion system test); (2) advanced vehicle simulation capability assessment; (3) systems tests identified events; (4) main propulsion test article (MPTA) testing evaluation; (5) Saturn 5, 1B, and 1 testing evaluation. Special vehicle simulation issues that are propulsion related are briefly addressed.

  8. Digital Simulation in Education.

    ERIC Educational Resources Information Center

    Braun, Ludwig

    Simulation as a mode of computer use in instruction has been neglected by educators. This paper briefly explores the circumstances in which simulations are useful and presents several examples of simulation programs currently being used in high-school biology, chemistry, physics, and social studies classes. One program, STERIL, which simulates…

  9. Simulation in Sport Finance

    ERIC Educational Resources Information Center

    Drayer, Joris; Rascher, Dan

    2010-01-01

    Simulations have long been used in business schools to give students experience making real-world decisions in a relatively low risk environment. The OAKLAND A'S BASEBALL BUSINESS SIMULATOR takes a traditional business simulation and applies it to the sport industry, in which sales of tangible products are replaced by sales of experiences provided…

  10. Today's Business Simulation Industry

    ERIC Educational Resources Information Center

    Summers, Gary J.

    2004-01-01

    New technologies are transforming the business simulation industry. The technologies come from research in computational fields of science, and they endow simulations with new capabilities and qualities. These capabilities and qualities include computerized behavioral simulations, online feedback and coaching, advanced interfaces, learning on…

  11. Sensor-Failure Simulator

    NASA Technical Reports Server (NTRS)

    Melcher, Kevin J.; Delaat, John C.; Merrill, Walter C.; Oberle, Lawrence G.; Sadler, Gerald G.

    1988-01-01

    Outputs of defective sensors simulated for studies of reliability of control systems. Real-time sensor-failure simulator (SFS) designed and built for use with Advance Detection, Isolation, and Accommodation (ADIA) program. Equipment consists of IBM PC/XT computer and associated analog circuitry. User defines failure scenarios to determine which sensor signals fail and method(s) used to simulate failure.

  12. Weld arc simulator

    DOEpatents

    Burr, Melvin J.

    1990-01-30

    An arc voltage simulator for an arc welder permits the welder response to a variation in arc voltage to be standardized. The simulator uses a linear potentiometer connected to the electrode to provide a simulated arc voltage at the electrode that changes as a function of electrode position.

  13. Simulation. [SITE 2001 Section].

    ERIC Educational Resources Information Center

    Seymour, Cathy R., Ed.

    This document contains three papers on simulation from the SITE (Society for Information Technology & Teacher Education) 2001 conference. "Simulations in the Learning Cycle: A Case Study Involving 'Exploring the Nardoo'" (William M. Dwyer and Valesca E. Lopez) presents a study of middle school students using a CD-based simulation program,…

  14. Conducting Effective Simulator Training.

    ERIC Educational Resources Information Center

    Gerling, Kenneth D.

    This paper describes the simulator phase of Commonwealth Edison's program for training and licensing operators of nuclear power stations. Topics covered include (1) preparing the students before starting the simulator phase; (2) the simulator schedule and the number of students that can be trained effectively in a class; (3) format and structure…

  15. Designing Simulation Systems

    ERIC Educational Resources Information Center

    Twelker, Paul A.

    1969-01-01

    "The purpose of this paper is to outline the approach to designing instructional simulation systems developed at Teaching Research. The 13 phases of simulation design will be summarized, and an effort will be made to expose the vital decision points that confront the designer as he develops simulation experiences. (Author)

  16. CAISSON: Interconnect Network Simulator

    NASA Technical Reports Server (NTRS)

    Springer, Paul L.

    2006-01-01

    Cray response to HPCS initiative. Model future petaflop computer interconnect. Parallel discrete event simulation techniques for large scale network simulation. Built on WarpIV engine. Run on laptop and Altix 3000. Can be sized up to 1000 simulated nodes per host node. Good parallel scaling characteristics. Flexible: multiple injectors, arbitration strategies, queue iterators, network topologies.

  17. Etude numerique des mecanismes d'autodiffusion dans les semiconducteurs

    NASA Astrophysics Data System (ADS)

    El-Mellouhi, Fedwa

    heterostructure interdiffusion experiments. Keywords. Nanostructure, Self-diffusion, Semiconductors, Defects, First principles calculation, Vacancy, ab-initio, Simulation, GaAs, Si.

  18. Flight Investigation of the Performance of a Two-stage Solid-propellant Nike-deacon (DAN) Meteorological Sounding Rocket

    NASA Technical Reports Server (NTRS)

    Heitkotter, Robert H

    1956-01-01

    A flight investigation of two Nike-Deacon (DAN) two-stage solid-propellant rocket vehicles indicated satisfactory performance may be expected from the DAN meteorological sounding rocket. Peak altitudes of 356,000 and 350,000 feet, respectively, were recorded for the two flight tests when both vehicles were launched from sea level at an elevation angle of 75 degrees. Performance calculations based on flight-test results show that altitudes between 358,000 feet and 487,000 feet may be attained with payloads varying between 60 pounds and 10 pounds.

  19. Simulation in Surgical Education

    PubMed Central

    de Montbrun, Sandra L.; MacRae, Helen

    2012-01-01

    The pedagogical approach to surgical training has changed significantly over the past few decades. No longer are surgical skills solely acquired through a traditional apprenticeship model of training. The acquisition of many technical and nontechnical skills is moving from the operating room to the surgical skills laboratory through the use of simulation. Many platforms exist for the learning and assessment of surgical skills. In this article, the authors provide a broad overview of some of the currently available surgical simulation modalities including bench-top models, laparoscopic simulators, simulation for new surgical technologies, and simulation for nontechnical surgical skills. PMID:23997671

  20. The vertical motion simulator

    NASA Technical Reports Server (NTRS)

    Hosein, Todd

    1988-01-01

    Today's flight simulators, such as NASA's multimillion dollar Vertical Motion Simulator (VMS), recreate an authentic aircraft environment, and reproduce the sensations of flight by mechanically generating true physical events. In addition to their application as a training tool for pilots, simulators have become essential in the design, construction, and testing of new aircraft. Simulators allow engineers to study an aircraft's flight performance and characteristics without the cost or risk of an actual test flight. Because of their practicality, simulators will become more and more important in the development and design of new, safer aircraft.

  1. Air Shower Simulations

    SciTech Connect

    Alania, Marco; Gomez, Adolfo V. Chamorro; Araya, Ignacio J.; Huerta, Humberto Martinez; Flores, Alejandra Parra; Knapp, Johannes

    2009-04-30

    Air shower simulations are a vital part of the design of air shower experiments and the analysis of their data. We describe the basic features of air showers and explain why numerical simulations are the appropriate approach to model the shower simulation. The CORSIKA program, the standard simulation program in this field, is introduced and its features, performance and limitations are discussed. The basic principles of hadronic interaction models and some gerneral simulation techniques are explained. Also a brief introduction to the installation and use of CORSIKA is given.

  2. Threat radar system simulations

    NASA Astrophysics Data System (ADS)

    Miller, L.

    The capabilities, requirements, and goals of radar emitter simulators are discussed. Simulators are used to evaluate competing receiver designs, to quantify the performance envelope of a radar system, and to model the characteristics of a transmitted signal waveform. A database of candidate threat systems is developed and, in concert with intelligence data on a given weapons system, permits upgrading simulators to new projected threat capabilities. Four currently available simulation techniques are summarized, noting the usefulness of developing modular software for fast controlled-cost upgrades of simulation capabilities.

  3. Peptide folding simulations.

    PubMed

    Gnanakaran, S; Nymeyer, Hugh; Portman, John; Sanbonmatsu, Kevin Y; García, Angel E

    2003-04-01

    Developments in the design of small peptides that mimic proteins in complexity, recent advances in nanosecond time-resolved spectroscopy methods to study peptides and the development of modern, highly parallel simulation algorithms have come together to give us a detailed picture of peptide folding dynamics. Two newly implemented simulation techniques, parallel replica dynamics and replica exchange molecular dynamics, can now describe directly from simulations the kinetics and thermodynamics of peptide formation, respectively. Given these developments, the simulation community now has the tools to verify and validate simulation protocols and models (forcefields). PMID:12727509

  4. Interpretation des donnees de flux de chaleur et de gravite dans le bouclier Canadien

    NASA Astrophysics Data System (ADS)

    Cheng, Li Zhen

    2000-10-01

    Le champ geothermique du Bouclier Canadien est caracterise par un flux moyen de 41 mW·m-2, qui suggere une production de chaleur moyenne dans la croute comprise entre 0.7 et 0.8 muW·m-3. Le flux de chaleur relativement faible favorise la stabilite du bouclier et lui a permis de resister a la deformation tectonique. Les variations du flux de chaleur a la surface sont dominees par la composition de la croute. Un flux eleve implique generalement une composition felsique et il est d'autant plus faible que la croute devient plus mafique. La production de chaleur en surface n'est pas representative de la production moyenne de la croute. Le flux de chaleur dans le Boucher Canadien ne depend donc pas de la production de chaleur en surface, mais depend de la composition principale de la croute. L'interpretation combinee des donnees geophysiques nous permet de determiner les variations de composition d'echelle crustale a partir desquelles il est possible d'etablir la structure de la croute. L'etude detaillee de l'Orogene de Trans-Hudson et de la Sous-province d'Abitibi a montre que le flux de chaleur, la gravite et la sismique lorsqu'elles sont combinees fournissent des contraintes efficaces pour determiner l'architecture crustale. En general, la croute est trop resistante pour se deformer par fluage, excepte tres localement. Le mode de deformation de la lithosphere continentale depend de la composition et du gradient geothermique. Nous montrons que la lithosphere du Bouclier Canadien demeure principalement fragile jusqu'a une profondeur de plus de 150 km. Une deformation ductile pourrait cependant etre possible localement a la base de la, croute, comme dans la ceinture de Thompson par exemple. Si l'on admet que la lithosphere peut resister a des contraintes allant jusqu'a 20 MPa (taux de deformation 3˙ < 10-15 s-1), l'epaisseur de la lithosphere est de l'ordre de 300 km pour la ceinture de Thompson et est superieure a 300 km pour la sous-province d'Abitibi. La resistance

  5. Altération des sulfures des granulats dans les chaussées

    NASA Astrophysics Data System (ADS)

    Jigorel, A.; Jauberthie, R.

    2002-07-01

    Sulfides present in hornsfeld aggregates, used in light pavanent construction in contact with humid air alter rapidly. Crystallisation of sulfates at the interface of bitumastic material and sub-base creates serious problems (intumescence and crazing) that can lead to a total reconstruction of the project (roads, sidewalks, sports areas, etc). The sulfides in the aggregates and the sulfates produced due to alteration are studied by SEM and XRD. The results show that the intensity of this phenomenon is linked to the nature and the crystallinity of the sulfides. The evolution of the sulfates formed during this alteration process is slow and complex. In new pavements (3 years) the sulfates have a pulverised appearance and consist mostly of epsomite, associated with pickeringite and halotrichite. In older pavements (20 years) the sulfates form a fibrous concretion consisting of pickeringite and small quantities of halotrichite. Les sulfures présents dans les granulats élaborés à partir de cornéen nes s'altèrent rapidement dans les chaussées légères en présence d'air humide. La cristallisation des sulfates à l'interface enrobé-couche de fondation crée des désordres si importants (intumescences, faiençage) qu'il est bien souvent nécessaire d'assurer la réfection totale des ouvrages (routes, trottoirs, plateaux sportifs...). Les sulfures des granulats et les sulfates issus du processus d'altération ont été étudiés par diffractométrie X et examen su Microscope Electronique à Balayage équipé de microanalyse X. Les résultats montrent que !intensité des désordres est liée à la nature et à la cristallinité des sulfures. Les sulfates formés évoluent su cours du processus d'altération qui est long et complexe. Dans les chaussées récentes (3 ans) ils ont un aspect pulvérulent et sont constitués d'epsomite dominante associée à de la pickeringite et à de l'halotrichite. Dans les chaussées plus anciennes (20 ans) ils forment des concr

  6. Interactions électron-électron dans les fils mésoscopiques

    NASA Astrophysics Data System (ADS)

    Pierre, F.

    Electron-electron interactions in mesoscopic wires In metallic thin films, the screening of Coulomb interactions is less efficient than in bulk metals because of electron elastic scattering from film boundaries, lattice defects, and impurities. As a consequence, at sub-kelvin temperatures, electron-electron interactions are expected to be the dominant inelastic process undergone by electrons, which determines energy exchange and limits the electronic phase coherence. We present in this book three experiments that probe inelastic collisions experienced by electrons at low temperature, in order to find out their mechanism. In the first part, we present a series of measurements of the energy distribution function of electrons in copper, gold and silver wires driven in a steady-state, out of equilibrium situation. These experiments reveal the rate at which electrons exchange energy. These results are compared in the second part with the temperature dependence of the phase coherence time of electrons tau_{φ}, which is deduced from the magnetoresistance of long wires. The phase coherence of electrons is limited by all inelastic collisions, independently of the energy exchanged. Different mechanisms to account for the energy exchange rate and dephasing times are proposed and compared with experiments. In the third part, we present measurements of the conductance of a long tunnel junction between an aluminum wire and a ground plane. The dip in the conductance at zero voltage is expected from the theory of electron-electron interactions. To compare measurements and theoretical predictions, we rephrase the microscopic theory of electron-electron interactions in terms of an electromagnetic impedance, as is done for the phenomenological theory of Coulomb blockade. Dans les couches minces métalliques, l'écrantage des interactions coulombiennes entre électrons est moins efficace que dans les métaux massifs en raison des chocs élastiques que subissent les électrons sur les

  7. Simulation verification techniques study

    NASA Technical Reports Server (NTRS)

    Schoonmaker, P. B.; Wenglinski, T. H.

    1975-01-01

    Results are summarized of the simulation verification techniques study which consisted of two tasks: to develop techniques for simulator hardware checkout and to develop techniques for simulation performance verification (validation). The hardware verification task involved definition of simulation hardware (hardware units and integrated simulator configurations), survey of current hardware self-test techniques, and definition of hardware and software techniques for checkout of simulator subsystems. The performance verification task included definition of simulation performance parameters (and critical performance parameters), definition of methods for establishing standards of performance (sources of reference data or validation), and definition of methods for validating performance. Both major tasks included definition of verification software and assessment of verification data base impact. An annotated bibliography of all documents generated during this study is provided.

  8. Perceptually Augmented Simulator Design.

    PubMed

    Edmunds, T; Pai, D K

    2012-01-01

    Training simulators have proven their worth in a variety of fields, from piloting to air-traffic control to nuclear power station monitoring. Designing surgical simulators, however, poses the challenge of creating trainers that effectively instill not only high-level understanding of the steps to be taken in a given situation, but also the low-level "muscle-memory" needed to perform delicate surgical procedures. It is often impossible to build an ideal simulator that perfectly mimics the haptic experience of a surgical procedure, but by focussing on the aspects of the experience that are perceptually salient we can build simulators that effectively instill learning. We propose a general method for the design of surgical simulators that augment the perceptually salient aspects of an interaction. Using this method, we can increase skill-transfer rates without requiring expensive improvements in the capability of the rendering hardware or the computational complexity of the simulation. In this paper, we present our decomposition-based method for surgical simulator design, and describe a user-study comparing the training effectiveness of a haptic-search-task simulator designed using our method versus an unaugmented simulator. The results show that perception-based task decomposition can be used to improve the design of surgical simulators that effectively impart skill by targeting perceptually significant aspects of the interaction. PMID:26963831

  9. Dynamique particulaire dans des lits fixes et rotatifs

    NASA Astrophysics Data System (ADS)

    Dube, Olivier

    The first part of this thesis presents an evaluation of the effect, on a bed of adsorbents, of a cyclic thermal expansion and contraction of the vessels of a RFR used for gas pre-purification using the DEM. This is the first reported study of granular flow of this kind. The accuracy of the DEM-based model was assessed using experimental values of bed porosity, analytical values of predicted wall pressure based on Janssen's theory, and experimental values of wall pressure measured during the operation of a full-scale unit. In this study, the use of DEM simulations enabled the computation of a dispersion coefficient at the interface of the adsorbents. This dispersion coefficient could be used to assess the fixed bed quality after several years of use. It must be noted that the DEM-based model developed does not consider the effect of the circulating gas and the changes in particle properties likely to occur in the course of a cycle. Nevertheless, the results obtained with the proposed model show that the DEM is a valuable tool for the investigation of such slow dynamical processes, provided a careful calibration is done. The second part of this thesis presents the optimization strategy developed to determine an optimal set of scintillation detector positions and orientations. This strategy uses a mesh adaptive direct search (MADS) optimization algorithm and the detectors resolution as an objective function. The results of this work showed that the optimal positioning found by the optimization strategy is sensitive to both the objectives of the study and the experimental conditions. It can therefore be easily applied to studies different from the one conducted in this thesis. Finally, the third part of this thesis presents the characterization of the dynamics of non-spherical particles in a rotating drum. The data collected and the observations made in the laboratory showed that non-spherical particles tend to flow with a preferred spatial orientation. This preferred

  10. Les succédanés du sucre durant la grossesse

    PubMed Central

    Pope, Eliza; Koren, Gideon; Bozzo, Pina

    2014-01-01

    Résumé Question J’ai une patiente enceinte qui consomme souvent des succédanés du sucre et elle m’a demandé si cette pratique continue pouvait nuire à sa grossesse ou à son enfant. Que devrais-je lui répondre et existe-t-il d’autres meilleurs choix durant la grossesse? Réponse Il faudrait faire plus de recherche pour déterminer plus exactement les effets de l’exposition aux succédanés du sucre in utero, mais les données disponibles ne laissent pas présager d’effets indésirables durant la grossesse. Toutefois, il est recommandé de consommer des substituts du sucre en quantités modérées et de se conformer aux doses journalières admissibles établies par les organismes de règlementation.

  11. Being Irrationally Funny as a Cognitive Psychologist: Interview With Dan Ariely.

    PubMed

    Ariely, Dan; Popescu, Beatrice

    2015-11-01

    The idea of interviewing Dan Ariely was somehow latent on my mind since I started being interested in cognitive psychology and cognitive behavior psychotherapy, but actually got more ardent ever since irrationality became a research topic for his team at Duke University. I picked him as an interviewee thinking not only at his exceptional skills as a researcher and as Kahnemann 'disciple', but mainly for his fantastic wit, true modesty and utmost interest in making people's lives easier and more comfortable, by creating awareness on a lot of topics otherwise neglected. Dan Ariely's very agreeable personality and humor would not let you think of him as a burnt casualty who, in his youth struggled to survive a personal drama, so well-documented in his paper "Painful lessons" posted on the MIT website (http://web.mit.edu/ariely/www/MIT/Papers/mypain.pdf). I think reading his paper and also this transcribed interview with him would be also comforting for people who found out about Bucharest fire incident that rocked our society and also for people who are personally related to this tragedy. PMID:27247678

  12. Simulation integration with confidence

    NASA Astrophysics Data System (ADS)

    Strelich, Tom; Stalcup, Bruce W.

    1999-07-01

    Current financial, schedule and risk constraints mandate reuse of software components when building large-scale simulations. While integration of simulation components into larger systems is a well-understood process, it is extremely difficult to do while ensuring that the results are correct. Illgen Simulation Technologies Incorporated and Litton PRC have joined forces to provide tools to integrate simulations with confidence. Illgen Simulation Technologies has developed an extensible and scaleable, n-tier, client- server, distributed software framework for integrating legacy simulations, models, tools, utilities, and databases. By utilizing the Internet, Java, and the Common Object Request Brokering Architecture as the core implementation technologies, the framework provides built-in scalability and extensibility.

  13. Parallel Atomistic Simulations

    SciTech Connect

    HEFFELFINGER,GRANT S.

    2000-01-18

    Algorithms developed to enable the use of atomistic molecular simulation methods with parallel computers are reviewed. Methods appropriate for bonded as well as non-bonded (and charged) interactions are included. While strategies for obtaining parallel molecular simulations have been developed for the full variety of atomistic simulation methods, molecular dynamics and Monte Carlo have received the most attention. Three main types of parallel molecular dynamics simulations have been developed, the replicated data decomposition, the spatial decomposition, and the force decomposition. For Monte Carlo simulations, parallel algorithms have been developed which can be divided into two categories, those which require a modified Markov chain and those which do not. Parallel algorithms developed for other simulation methods such as Gibbs ensemble Monte Carlo, grand canonical molecular dynamics, and Monte Carlo methods for protein structure determination are also reviewed and issues such as how to measure parallel efficiency, especially in the case of parallel Monte Carlo algorithms with modified Markov chains are discussed.

  14. Simulator of Road Tunnel

    NASA Astrophysics Data System (ADS)

    Danišovič, Peter; Schlosser, František; Šrámek, Juraj; Rázga, Martin

    2015-05-01

    A Tunnel Traffic & Operation Simulator is a device of the Centre of Transport Research at the University of Žilina. The Simulator allows managing technological equipment of virtual two-tube highway tunnel, which is interconnected with simulation of vehicle traffic in tunnel. Changes of the traffic-operation states and other equipment are reflecting at the simulated traffic, as well as simulations of various emergency events in traffic initiate changes in tunnel detecting and measuring devices. It is thus possible to simulate emergency states, which can be affected by various faults of technology as well as by climatic conditions. The solutions can be found in irreplaceable experiences of Slovak road tunnel operators, changes of trafficoperation states, visualizations of operator technological display screens, technological devices labelling in order to increase operational safety of road tunnels.

  15. Simulation in laparoscopic surgery.

    PubMed

    León Ferrufino, Felipe; Varas Cohen, Julián; Buckel Schaffner, Erwin; Crovari Eulufi, Fernando; Pimentel Müller, Fernando; Martínez Castillo, Jorge; Jarufe Cassis, Nicolás; Boza Wilson, Camilo

    2015-01-01

    Nowadays surgical trainees are faced with a more reduced surgical practice, due to legal limitations and work hourly constraints. Also, currently surgeons are expected to dominate more complex techniques such as laparoscopy. Simulation emerges as a complementary learning tool in laparoscopic surgery, by training in a safe, controlled and standardized environment, without jeopardizing patient' safety. Simulation' objective is that the skills acquired should be transferred to the operating room, allowing reduction of learning curves. The use of simulation has increased worldwide, becoming an important tool in different surgical residency programs and laparoscopic training courses. For several countries, the approval of these training courses are a prerequisite for the acquisition of surgeon title certifications. This article reviews the most important aspects of simulation in laparoscopic surgery, including the most used simulators and training programs, as well as the learning methodologies and the different key ways to assess learning in simulation. PMID:25039039

  16. Instrumented Architectural Simulation System

    NASA Technical Reports Server (NTRS)

    Delagi, B. A.; Saraiya, N.; Nishimura, S.; Byrd, G.

    1987-01-01

    Simulation of systems at an architectural level can offer an effective way to study critical design choices if (1) the performance of the simulator is adequate to examine designs executing significant code bodies, not just toy problems or small application fragements, (2) the details of the simulation include the critical details of the design, (3) the view of the design presented by the simulator instrumentation leads to useful insights on the problems with the design, and (4) there is enough flexibility in the simulation system so that the asking of unplanned questions is not suppressed by the weight of the mechanics involved in making changes either in the design or its measurement. A simulation system with these goals is described together with the approach to its implementation. Its application to the study of a particular class of multiprocessor hardware system architectures is illustrated.

  17. Prediction inverse d'un front de solidification dans un four de transformation a haute temperature

    NASA Astrophysics Data System (ADS)

    Marois, Marc-Andre

    Ce projet de recherche porte sur une methode numerique permettant de predire l'evolution du profil 2D de la couche solide qui recouvre l'interieur des parois de plusieurs fours de transformation a haute temperature. Un modele mathematique base sur la formulation faible de l'energie est d'abord developpe et valide. Une methode de transfert thermique inverse reposant sur ce modele est ensuite developpee afin d'obtenir une mesure rapide et continue de l'evolution du profil de cette couche solide. Vu la grande inertie thermique du systeme a l'etude, differentes strategies sont proposees afin de faciliter la mise en uvre de cette methode numerique. Finalement, cette approche inverse est confrontee aux resultats experimentaux obtenus a l'aide d'un reacteur metallurgique. Une etude preliminaire montre que les fours de transformation presentent une tres grande inertie thermique qui limite grandement l'utilisation des methodes inverses. En effet, la sensibilite de cette methode numerique repose essentiellement sur le delai temporel observe entre la variation du profil du banc et la fluctuation de la temperature a la surface externe de la paroi du four. Les resultats obtenus demontrent qu'une partie de ce delai est proportionnel a la chaleur latente de fusion lorsque le materiau a changement de phase est constitue d'un melange non eutectique. Afin de limiter l'impact de ce delai temporel, deux astuces numeriques sont proposees : reutiliser plus d'une fois les mesures de temperature et modifier le probleme thermique dans les regions pateuse et liquide. D'une part, le concept de chevauchement propose permet de reduire le temps d'acquisition des donnees entre chacune des predictions. D'autre part, l'approche virtuelle developpee permet de reduire l'inertie thermique du systeme et, par le fait meme, le delai temporel associe a la diffusion de la chaleur. Ces deux strategies ont permis de predire efficacement l'evolution 1D de l'epaisseur de la couche de gelee qui se solidifie a

  18. The Sandia Lightning Simulator.

    SciTech Connect

    Martinez, Leonard E.; Caldwell, Michele

    2005-01-01

    The Sandia Lightning Simulator at Sandia National Laboratories can provide up to 200 kA for a simulated single lightning stroke, 100 kA for a subsequent stroke, and hundreds of Amperes of continuing current. It has recently been recommissioned after a decade of inactivity and the single-stroke capability demonstrated. The simulator capabilities, basic design components, upgrades, and diagnostic capabilities are discussed in this paper.

  19. X-29 simulator

    NASA Technical Reports Server (NTRS)

    1995-01-01

    A view of the X-29 simulator taken in 1995. The pilot - fully enclosed within the simulator - sees the out-the-cockpit views on a video monitor, while the computer system changed the instrument readings according to the pilot's maneuvers and the simulated malfunctions. The X-29 was designed to test swept forward wings, a configuration with aerodynamic advantages, but which lacked practicality until the development of carbon composites.

  20. 75 FR 51292 - Before Commissioners: Ruth Y. Goldway, Chairman; Tony L. Hammond, Vice Chairman; Mark Acton; Dan...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-19

    ... From the Federal Register Online via the Government Publishing Office POSTAL REGULATORY COMMISSION Before Commissioners: Ruth Y. Goldway, Chairman; Tony L. Hammond, Vice Chairman; Mark Acton; Dan G. Blair; and Nanci E. Langley; Competitive Product Prices; Global Expedited Package Services 3...

  1. Comparison of cardioprotective effects using ramipril and DanShen for the treatment of acute myocardial infarction in rats.

    PubMed

    Ji, XinYan; Tan, Benny K-H; Zhu, Yi Chun; Linz, Wolfgang; Zhu, Yi Zhun

    2003-08-01

    In the present study, we compared cardioprotective effects of DanShen (an extract from Salvia miltiorrhiza) and the angiotensin-converting enzyme inhibitor, ramipril, in rats. With both treatment regimens, DanShen- and ramipril similar effects were observed: (1) a higher survival rate, (2) a significant reduction of infarct size, (3) significantly lower ratios of heart weight to the body weight as well as the left and right ventricular weights to body weight. DanShen showed some unique effects in the following aspects: (1) higher activities of antioxidant defense enzymes such as superoxide dismutase (SOD), catalase (CAT), glutatione perioxidase (GSH-Px) and glutathione S-transferase (GST) in the liver of rats with acute myocardial infarction (AMI), (2) lower myocardial and hepatic TBARS values; (3) augmented VEGF mRNA expressions in the non-ischemic parts of rat hearts with AMI. These results were consistent with the findings of a slight increase in myocardial capillary density and the special distribution pattern of coronary blood vessels in DanShen-treated rats. PMID:12850502

  2. Aviation Safety Simulation Model

    NASA Technical Reports Server (NTRS)

    Houser, Scott; Yackovetsky, Robert (Technical Monitor)

    2001-01-01

    The Aviation Safety Simulation Model is a software tool that enables users to configure a terrain, a flight path, and an aircraft and simulate the aircraft's flight along the path. The simulation monitors the aircraft's proximity to terrain obstructions, and reports when the aircraft violates accepted minimum distances from an obstruction. This model design facilitates future enhancements to address other flight safety issues, particularly air and runway traffic scenarios. This report shows the user how to build a simulation scenario and run it. It also explains the model's output.

  3. Helicopter simulator standards

    NASA Technical Reports Server (NTRS)

    Boothe, Edward M.

    1992-01-01

    The initial advisory circular was produced in 1984 (AC 120-XX). It was not finalized, however, because the FAR's for pilot certification did not recognize helicopter simulators and, therefore, permitted no credit for their use. That is being rectified, and, when the new rules are published, standards must be available for qualifying simulators. Because of the lack of a data base to support specification of these standards, the FAA must rely on the knowledge of experts in the simulator/training industry. A major aim of this workshop is to form a working group of these experts to produce a set of standards for helicopter training simulators.

  4. Surgical Simulation and Competency.

    PubMed

    Kim-Fine, Shunaha; Brennand, Erin A

    2016-09-01

    Simulation in surgical training is playing an increasingly important role as postgraduate medical education programs navigate an environment of increasing costs of education, increased attention on patient safety, and new duty hour restrictions. In obstetrics and gynecology, simulation has been used to teach many procedures; however, it lacks a standardized curriculum. Several different simulators exist for teaching various routes and aspects of hysterectomy. This article describes how a formal framework of increasing levels of competencies can be applied to simulation in teaching the procedure of hysterectomy. PMID:27521885

  5. Multiresolution Simulations of Photoinjectors

    SciTech Connect

    Mihalcea, D.; Bohn, C. L.; Terzic, B.

    2006-11-27

    We report a successful implementation of a three-dimensional wavelet-based solver for Poisson's equation with Dirichlet boundary conditions, optimized for use in particle-in-cell beam dynamics simulations. We explain how the new algorithm works and the advantages it brings to accelerator simulations. The solver is integrated into a full photoinjector-simulation code (Impact-T), and the code is then benchmarked by comparing its output against that of other codes (verification) and against laboratory measurements (validation). We also simulated the AES/JLab photoinjector using a suite of codes. This activity revealed certain performance limitations and their causes.

  6. Multiresolution Simulations of Photoinjectors

    NASA Astrophysics Data System (ADS)

    Mihalcea, D.; Bohn, C. L.; Terzić, B.

    2006-11-01

    We report a successful implementation of a three-dimensional wavelet-based solver for Poisson's equation with Dirichlet boundary conditions, optimized for use in particle-in-cell beam dynamics simulations. We explain how the new algorithm works and the advantages it brings to accelerator simulations. The solver is integrated into a full photoinjector-simulation code (Impact-T), and the code is then benchmarked by comparing its output against that of other codes (verification) and against laboratory measurements (validation). We also simulated the AES/JLab photoinjector using a suite of codes. This activity revealed certain performance limitations and their causes.

  7. Hémophilie: état des lieux dans un service de pédiatrie dans la région de l'oriental du Maroc

    PubMed Central

    Benajiba, Noufissa; Boussaadni, Yousra EL; Aljabri, Mohammed; Bentata, Yassamine; Amrani, Rim; Rkain, Maria

    2014-01-01

    Pour les pays en voie de développement, l'hémophilie continue d’être une maladie de conséquence médicale et sociale désastreuse. Le but de ce travail est d'analyser le suivi d'une cohorte de patients hémophiles. Patients et méthodes: étude prospective étalée sur deux années et menée au centre référent d'hémophilie dans la région de l'orient du Maroc. Ont été inclus tous les patients présentant une hémophilie confirmée et âgé de moins de 18 ans. Résultats: sur 16 hémophiles, Quinze patients présentait une hémophilie A, l’âge moyen des patients était de 6,18 ans, la forme sévère, représentait 20,7%, la forme modérée: 33,3% et la forme mineure: 40%. Les circonstances de découverte étaient post circoncisionnelle chez 53,3% des patients, 20,7% post traumatique, 20% à l’âge de la marche; la durée d’évolution variait entre 2 mois et 10 ans. L'hémarthrose a été décrite au niveau des genoux, coudes et chevilles, avec une moyenne allant de 2 à 5 fois par an; l'arthropathie a été remarquée dans 33,3%. Le bilan immunologique a révélé des facteurs circulant inhibant chez deux patients. Le traitement était à base d'antalgiques, de plasma frais congelé. L'administration de facteurs VIII recombinés a été instaurée chez 40,6% des patients (plus de 90% des formes modérées et graves), grâce au programme national de prise en charge des hémophiles. Le décès était noté dans un seul cas lié à une hémorragie cérébrale. Conclusion: Nous insistons sur l'intérêt du programme national de prise en charge des hémophiles dernièrement instauré qui pourrait améliorer les conditions de vie de ces enfants. PMID:25404986

  8. Morbimortalité périnatale dans les grossesses gémellaires dans une maternité marocaine de niveau 3

    PubMed Central

    Boubkraoui, Mohamed El-Mahdi; Aguenaou, Hassan; Mrabet, Mustapha; Barkat, Amina

    2016-01-01

    Introduction Les grossesses gémellaires sont associées à un risque de morbimortalité périnatale plus élevé que les grossesses simples. Le but de cette étude était d’évaluer la morbimortalité périnatale dans les grossesses gémellaires dans une maternité marocaine de niveau 3. Méthodes Il s'agit d'une étude transversale comparative de la morbimortalité périnatale des nouveau-nés issus de grossesses gémellaires versus grossesses simples ayant accouché à la maternité Souissi de Rabat du 1 janvier au 28 février 2014. Résultats Il y a eu 3297 naissances issues de 65 grossesses gémellaires et 3167 grossesses simples. Les grossesses gémellaires étaient associées à des taux plus élevés de prééclampsie et d’éclampsie (P = 0,046), de HELLP syndrome (P= 0,030), de rupture prématurée des membranes (P < 0,001), de présentation dystocique (P < 0,001), de prématurité (P < 0,001), d'hypotrophie chez les nouveau-nés à terme (P < 0,001), de détresse respiratoire néonatale (P < 0,001), de malformations congénitales (P = 0,015), d'hospitalisation en période néonatale (P = 0,001) et de mortalité périnatale (P = 0,001) par rapport aux grossesses simples. Les jumeaux monochoriaux présentaient des taux plus élevés d'hypotrophie en cas de grossesse menée à terme (P = 0,016) et de mortalité périnatale (P = 0,017) par rapport aux jumeaux bichoriaux. Conclusion Les grossesses gémellaires étaient à risque plus élevé de morbimortalité périnatale par rapport aux grossesses simples en exposant notamment à la prématurité. Les grossesses gémellaires monochoriales étaient plus à risque en exposant notamment à l'hypotrophie chez les nouveau-nés à terme. PMID:27217903

  9. Assessment of trace element impacts on agricultural use of water from the Dan River following the Eden coal ash release.

    PubMed

    Hesterberg, Dean; Polizzotto, Matthew L; Crozier, Carl; Austin, Robert E

    2016-04-01

    Catastrophic events require rapid, scientifically sound decision making to mitigate impacts on human welfare and the environment. The objective of this study was to analyze potential impacts of coal ash-derived trace elements on agriculture following a 35,000-tonne release of coal ash into the Dan River at the Duke Energy Steam Station in Eden, North Carolina. We performed scenario calculations to assess the potential for excessive trace element loading to soils via irrigation and flooding with Dan River water, uptake of trace elements by crops, and livestock consumption of trace elements via drinking water. Concentrations of 13 trace elements measured in Dan River water samples within 4 km of the release site declined sharply after the release and were equivalent within 5 d to measurements taken upriver. Mass-balance calculations based on estimates of soil trace-element concentrations and the nominal river water concentrations indicated that irrigation or flooding with 25 cm of Dan River water would increase soil concentrations of all trace elements by less than 0.5%. Calculations of potential increases of trace elements in corn grain and silage, fescue, and tobacco leaves suggested that As, Cr, Se, Sr, and V were elements of most concern. Concentrations of trace elements measured in river water following the ash release never exceeded adopted standards for livestock drinking water. Based on our analyses, we present guidelines for safe usage of Dan River water to diminish negative impacts of trace elements on soils and crop production. In general, the approach we describe here may serve as a basis for rapid assessment of environmental and agricultural risks associated with any similar types of releases that arise in the future. PMID:26033746

  10. The effects of dan-shen root on cardiomyogenic differentiation of human placenta-derived mesenchymal stem cells

    SciTech Connect

    Li, Kun; Li, Shi-zheng; Zhang, Yun-li; Wang, Xue-zhe

    2011-11-11

    Highlights: Black-Right-Pointing-Pointer Conditional medium and dan-shen root were used for cardiomyogenic differentiation. Black-Right-Pointing-Pointer They all could induce hPDMSCs to differentiate into cardiomyocytes. Black-Right-Pointing-Pointer The induction effect of the latter was slightly higher compared to that of the former. Black-Right-Pointing-Pointer Dan-shen root could be a good inducer for cardiomyogenic differentiation. -- Abstract: The aim of this study was to search for a good inducer agent using for cardiomyogenic differentiation of stem cells. Human placenta-derived mesenchymal stem cells (hPDMSCs) were isolated and incubated in enriched medium. Fourth passaged cells were treated with 10 mg/L dan-shen root for 20 days. Morphologic characteristics were analyzed by confocal and electron microscopy. Expression of {alpha}-sarcomeric actin was analyzed by immunohistochemistry. Expression of cardiac troponin-I (TnI) was analyzed by immunohistofluorescence. Atrial natriuretic factor (ANF) and beta-myocin heavy chain ({beta}-MHC) were detected by reverse transcriptase polymerase chain reaction (RT-PCR). hPDMSCs treated with dan-shen root gradually formed a stick-like morphology and connected with adjoining cells. On the 20th day, most of the induced cells stained positive with {alpha}-sarcomeric actin and TnI antibody. ANF and {beta}-MHC were also detected in the induced cells. Approximately 80% of the cells were successfully transdifferentiated into cardiomyocytes. In conclusion, dan-shen root is a good inducer agent used for cardiomyogenic differentiation of hPDMSCs.

  11. Damselfly Network Simulator

    Energy Science and Technology Software Center (ESTSC)

    2014-04-01

    Damselfly is a model-based parallel network simulator. It can simulate communication patterns of High Performance Computing applications on different network topologies. It outputs steady-state network traffic for a communication pattern, which can help in studying network congestion and its impact on performance.

  12. Assessment in Simulations

    ERIC Educational Resources Information Center

    Raymond, Chad; Usherwood, Simon

    2013-01-01

    Simulations are employed widely as teaching tools in political science, yet evidence of their pedagogical effectiveness, in comparison to other methods of instruction, is mixed. The assessment of learning outcomes is often a secondary concern in simulation design, and the qualitative and quantitative methods used to evaluate outcomes are…

  13. Simulating Laboratory Procedures.

    ERIC Educational Resources Information Center

    Baker, J. E.; And Others

    1986-01-01

    Describes the use of computer assisted instruction in a medical microbiology course. Presents examples of how computer assisted instruction can present case histories in which the laboratory procedures are simulated. Discusses an authoring system used to prepare computer simulations and provides one example of a case history dealing with fractured…

  14. Radiation detector spectrum simulator

    DOEpatents

    Wolf, Michael A.; Crowell, John M.

    1987-01-01

    A small battery operated nuclear spectrum simulator having a noise source nerates pulses with a Gaussian distribution of amplitudes. A switched dc bias circuit cooperating therewith generates several nominal amplitudes of such pulses and a spectral distribution of pulses that closely simulates the spectrum produced by a radiation source such as Americium 241.

  15. Radiation detector spectrum simulator

    DOEpatents

    Wolf, M.A.; Crowell, J.M.

    1985-04-09

    A small battery operated nuclear spectrum simulator having a noise source generates pulses with a Gaussian distribution of amplitudes. A switched dc bias circuit cooperating therewith to generate several nominal amplitudes of such pulses and a spectral distribution of pulses that closely simulates the spectrum produced by a radiation source such as Americium 241.

  16. Simulating is Stimulating

    ERIC Educational Resources Information Center

    Christy, Raymond M.

    1975-01-01

    Describes an unusual learning experience available to eighth-grade students in Louisiana through exposure to a World War II B-25 simulator. The flight simulator is used to motivate students in the science area, develop an awareness of flight problems and challenges and provide exposure to the electronics career field. (BR)

  17. Numerical Aerodynamic Simulation

    NASA Technical Reports Server (NTRS)

    1989-01-01

    An overview of historical and current numerical aerodynamic simulation (NAS) is given. The capabilities and goals of the Numerical Aerodynamic Simulation Facility are outlined. Emphasis is given to numerical flow visualization and its applications to structural analysis of aircraft and spacecraft bodies. The uses of NAS in computational chemistry, engine design, and galactic evolution are mentioned.

  18. Beamstrahlung simulation and diagnostics

    SciTech Connect

    Ziemann, V.

    1991-06-01

    A simulation code that models the mutual deflection and the emission of beamstrahlung of two ultra-relativistic electron and positron bunches is described. The simulations are used to determine transverse beam sizes from observed beamstrahlung fluxes. 8 refs., 3 figs.

  19. Computerized Clinical Simulations.

    ERIC Educational Resources Information Center

    Reinecker, Lynn

    1985-01-01

    Describes technique involved in designing a clinical simulation problem for the allied health field of respiratory therapy; discusses the structure, content, and scoring categories of the simulation; and provides a sample program which illustrates a programming technique in BASIC, including a program listing and a sample flowchart. (MBR)

  20. Electric-car simulation

    NASA Technical Reports Server (NTRS)

    Chapman, C. P.; Slusser, R. A.

    1980-01-01

    PARAMET, interactive simulation program for parametric studies of electric vehicles, guides user through simulation by menu and series of prompts for input parameters. Program considers aerodynamic drag, rolling resistance, linear and rotational acceleration, and road gradient as forces acting on vehicle.

  1. Beyond Iconic Simulation

    ERIC Educational Resources Information Center

    Dormans, Joris

    2011-01-01

    Realism remains a prominent topic in game design and industry research; yet, a strong academic case can be made that games are anything, but realistic. This article frames realism in games in semiotic terms as iconic simulation and argues that games can gain expressiveness when they move beyond the current focus on iconic simulation. In parallel…

  2. Improving WEPP snow simulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Snow simulation is essential to reliable prediction of runoff and erosion, particularly in high-latitude areas in the northern tier of states and forested watersheds at high elevations. The Water Erosion Prediction Project (WEPP) model is one of a few including a component for winter hydrology simul...

  3. VCSEL Applications and Simulation

    NASA Technical Reports Server (NTRS)

    Cheung, Samson; Goorjian, Peter; Ning, Cun-Zheng; Li, Jian-Zhong

    2000-01-01

    This viewgraph presentation gives an overview of Vertical Cavity Surface Emitting Laser (VCSEL) simulation and its applications. Details are given on the optical interconnection in information technology of VCSEL, the formulation of the simulation, its numeric algorithm, and the computational results.

  4. Breathing-metabolic simulator

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G.; Hendricks, C. M.; Morison, W. B.

    1972-01-01

    Breathing-metabolic simulator was developed to be used for evaluation of life support equipment. Apparatus simulates human breathing rate and controls temperature and humidity of exhaled air as well as its chemical composition. All functions are designed to correspond to various degrees of human response.

  5. Modeling and simulation

    SciTech Connect

    Hanham, R.; Vogt, W.G.; Mickle, M.H.

    1986-01-01

    This book presents the papers given at a conference on computerized simulation. Topics considered at the conference included expert systems, modeling in electric power systems, power systems operating strategies, energy analysis, a linear programming approach to optimum load shedding in transmission systems, econometrics, simulation in natural gas engineering, solar energy studies, artificial intelligence, vision systems, hydrology, multiprocessors, and flow models.

  6. Political Simulations Using Excel

    ERIC Educational Resources Information Center

    Jackson, Steven F.

    2013-01-01

    Simulations have received considerable attention as a tool to promote problem-solving skills, intense involvement, and high-order thinking among students. Whether semester-long exercises or a single-class session, simulations are often used in areas of conflict studies, diplomatic studies, trade disputes, electoral processes, and policy and legal…

  7. Simulating Price-Taking

    ERIC Educational Resources Information Center

    Engelhardt, Lucas M.

    2015-01-01

    In this article, the author presents a price-takers' market simulation geared toward principles-level students. This simulation demonstrates that price-taking behavior is a natural result of the conditions that create perfect competition. In trials, there is a significant degree of price convergence in just three or four rounds. Students find this…

  8. Prototyping distributed simulation networks

    NASA Technical Reports Server (NTRS)

    Doubleday, Dennis L.

    1990-01-01

    Durra is a declarative language designed to support application-level programming. The use of Durra is illustrated to describe a simple distributed application: a simulation of a collection of networked vehicle simulators. It is shown how the language is used to describe the application, its components and structure, and how the runtime executive provides for the execution of the application.

  9. Radio Channel Simulator (RCSM)

    Energy Science and Technology Software Center (ESTSC)

    2007-01-31

    This is a simulation package for making site specific predictions of radio signal strength. The software computes received power at discrete grid points as a function of the transmitter location and propagation environment. It is intended for use with wireless network simulation packages and to support wireless network deployments.

  10. Simulation: An Overview.

    ERIC Educational Resources Information Center

    Twelker, Paul A.

    Simulation may be defined as (1) a technique of modeling (physically, iconically, verbally, or mathematically) some aspects of a real or proposed system, process, or environment or (2) the model (physical, iconic, verbal, or mathematical) of some aspects of a real or proposed system, process, or environment. Simulation may be used to generate…

  11. Contrail Modeling and Simulation

    NASA Astrophysics Data System (ADS)

    Paoli, Roberto; Shariff, Karim

    2016-01-01

    There is large uncertainty in the radiative forcing induced by aircraft contrails, particularly after they transform to cirrus. It has recently become possible to simulate contrail evolution for long periods after their formation. We review the main physical processes and simulation efforts in the four phases of contrail evolution, namely the jet, vortex, vortex dissipation, and diffusion phases. Recommendations for further work are given.

  12. Learning Through Simulation Games.

    ERIC Educational Resources Information Center

    Gillispie, Philip H.

    A broad overview of the educational applications of simulation games is provided. The first section of the book offers an introduction to the major concepts of such games and develops the idea that it is relatively easy for individuals to design and use their own simulation games. The remainder of the book serves as a teacher's guide for…

  13. Reality versus Simulation

    ERIC Educational Resources Information Center

    Srinivasan, Srilekha; Perez, Lance C.; Palmer, Robert D.; Brooks, David W.; Wilson, Kathleen; Fowler, David

    2006-01-01

    A systematic study of the implementation of simulation hardware (TIMS) replacing software (MATLAB) was undertaken for advanced undergraduate and early graduate courses in electrical engineering. One outcome of the qualitative component of the study was remarkable: most students interviewed (4/4 and 6/9) perceived the software simulations as…

  14. Parallel simulation today

    NASA Technical Reports Server (NTRS)

    Nicol, David; Fujimoto, Richard

    1992-01-01

    This paper surveys topics that presently define the state of the art in parallel simulation. Included in the tutorial are discussions on new protocols, mathematical performance analysis, time parallelism, hardware support for parallel simulation, load balancing algorithms, and dynamic memory management for optimistic synchronization.

  15. Multicore Education through Simulation

    ERIC Educational Resources Information Center

    Ozturk, O.

    2011-01-01

    A project-oriented course for advanced undergraduate and graduate students is described for simulating multiple processor cores. Simics, a free simulator for academia, was utilized to enable students to explore computer architecture, operating systems, and hardware/software cosimulation. Motivation for including this course in the curriculum is…

  16. Simulating Ordinal Data

    ERIC Educational Resources Information Center

    Ferrari, Pier Alda; Barbiero, Alessandro

    2012-01-01

    The increasing use of ordinal variables in different fields has led to the introduction of new statistical methods for their analysis. The performance of these methods needs to be investigated under a number of experimental conditions. Procedures to simulate from ordinal variables are then required. In this article, we deal with simulation from…

  17. Trick Simulation Environment 07

    NASA Technical Reports Server (NTRS)

    Lin, Alexander S.; Penn, John M.

    2012-01-01

    The Trick Simulation Environment is a generic simulation toolkit used for constructing and running simulations. This release includes a Monte Carlo analysis simulation framework and a data analysis package. It produces all auto documentation in XML. Also, the software is capable of inserting a malfunction at any point during the simulation. Trick 07 adds variable server output options and error messaging and is capable of using and manipulating wide characters for international support. Wide character strings are available as a fundamental type for variables processed by Trick. A Trick Monte Carlo simulation uses a statistically generated, or predetermined, set of inputs to iteratively drive the simulation. Also, there is a framework in place for optimization and solution finding where developers may iteratively modify the inputs per run based on some analysis of the outputs. The data analysis package is capable of reading data from external simulation packages such as MATLAB and Octave, as well as the common comma-separated values (CSV) format used by Excel, without the use of external converters. The file formats for MATLAB and Octave were obtained from their documentation sets, and Trick maintains generic file readers for each format. XML tags store the fields in the Trick header comments. For header files, XML tags for structures and enumerations, and the members within are stored in the auto documentation. For source code files, XML tags for each function and the calling arguments are stored in the auto documentation. When a simulation is built, a top level XML file, which includes all of the header and source code XML auto documentation files, is created in the simulation directory. Trick 07 provides an XML to TeX converter. The converter reads in header and source code XML documentation files and converts the data to TeX labels and tables suitable for inclusion in TeX documents. A malfunction insertion capability allows users to override the value of any

  18. Rainfall simulation in education

    NASA Astrophysics Data System (ADS)

    Peters, Piet; Baartman, Jantiene; Gooren, Harm; Keesstra, Saskia

    2016-04-01

    Rainfall simulation has become an important method for the assessment of soil erosion and soil hydrological processes. For students, rainfall simulation offers an year-round, attractive and active way of experiencing water erosion, while not being dependent on (outdoors) weather conditions. Moreover, using rainfall simulation devices, they can play around with different conditions, including rainfall duration, intensity, soil type, soil cover, soil and water conservation measures, etc. and evaluate their effect on erosion and sediment transport. Rainfall simulators differ in design and scale. At Wageningen University, both BSc and MSc student of the curriculum 'International Land and Water Management' work with different types of rainfall simulation devices in three courses: - A mini rainfall simulator (0.0625m2) is used in the BSc level course 'Introduction to Land Degradation and Remediation'. Groups of students take the mini rainfall simulator with them to a nearby field location and test it for different soil types, varying from clay to more sandy, slope angles and vegetation or litter cover. The groups decide among themselves which factors they want to test and they compare their results and discuss advantage and disadvantage of the mini-rainfall simulator. - A medium sized rainfall simulator (0.238 m2) is used in the MSc level course 'Sustainable Land and Water Management', which is a field practical in Eastern Spain. In this course, a group of students has to develop their own research project and design their field measurement campaign using the transportable rainfall simulator. - Wageningen University has its own large rainfall simulation laboratory, in which a 15 m2 rainfall simulation facility is available for research. In the BSc level course 'Land and Water Engineering' Student groups will build slopes in the rainfall simulator in specially prepared containers. Aim is to experience the behaviour of different soil types or slope angles when (heavy) rain

  19. Cryogenic process simulation

    SciTech Connect

    Panek, J.; Johnson, S.

    1994-01-01

    Combining accurate fluid property databases with a commercial equation-solving software package running on a desktop computer allows simulation of cryogenic processes without extensive computer programming. Computer simulation can be a powerful tool for process development or optimization. Most engineering simulations to date have required extensive programming skills in languages such as Fortran, Pascal, etc. Authors of simulation code have also usually been responsible for choosing and writing the particular solution algorithm. This paper describes a method of simulating cryogenic processes with a commercial software package on a desktop personal computer that does not require these traditional programming tasks. Applications include modeling of cryogenic refrigerators, heat exchangers, vapor-cooled power leads, vapor pressure thermometers, and various other engineering problems.

  20. Hardware Accelerated Simulated Radiography

    SciTech Connect

    Laney, D; Callahan, S; Max, N; Silva, C; Langer, S; Frank, R

    2005-04-12

    We present the application of hardware accelerated volume rendering algorithms to the simulation of radiographs as an aid to scientists designing experiments, validating simulation codes, and understanding experimental data. The techniques presented take advantage of 32 bit floating point texture capabilities to obtain validated solutions to the radiative transport equation for X-rays. An unsorted hexahedron projection algorithm is presented for curvilinear hexahedra that produces simulated radiographs in the absorption-only regime. A sorted tetrahedral projection algorithm is presented that simulates radiographs of emissive materials. We apply the tetrahedral projection algorithm to the simulation of experimental diagnostics for inertial confinement fusion experiments on a laser at the University of Rochester. We show that the hardware accelerated solution is faster than the current technique used by scientists.

  1. 2007 simulation education summit.

    PubMed

    Huang, Yue Ming; Pliego, Jose F; Henrichs, Bernadette; Bowyer, Mark W; Siddall, Viva J; McGaghie, William C; Raemer, Daniel B

    2008-01-01

    The Society for Simulation in Healthcare convened the second Simulation Education Summit meeting in October 2007 in Chicago, Illinois. The purpose of the Summit was to bring together leaders of public, private, and government organizations, associations, and agencies involved in healthcare education for a focused discussion of standards for simulation-based applications. Sixty-eight participants representing 36 organizations discussed in structured small and large groups the criteria needed for various training and assessment applications using simulation. Although consensus was reached for many topics, there were also areas that required further thought and dialogue. This article is a summary of the results of these discussions along with a preliminary draft of a guideline for simulation-based education. PMID:19088663

  2. Simulation in spinal diseases.

    PubMed

    Aso Escario, José; Martínez Quiñones, José Vicente; Aso Vizán, Alberto; Arregui Calvo, Ricardo; Bernal Lafuente, Marta; Alcázar Crevillén, Andrés

    2014-01-01

    Simulation is frequent in spinal disease, resulting in problems for specialists like Orthopedic Surgeons, Neurosurgeons, Reumathologists, etc. Simulation requires demonstration of the intentional production of false or exaggerated symptoms following an external incentive. The clinician has difficulties in demonstrating these criteria, resulting in misdiagnosis of simulation or misinterpretation of the normal patient as a simulator, with the possibility of iatrogenic distress and litigation. We review simulation-related problems in spine, proposing a terminological, as well as a diagnostic strategy including clinical and complementary diagnosis, as a way to avoid misinterpretation and minimize the iatrogenic distress and liability Based on the clinical-Forensic author's expertise, the literature is analyzed and the terminology readdressed to develop new terms (inconsistences, incongruences, discrepancies and contradictions). Clinical semiology and complementary test are adapted to the new scenario. Diagnostic strategy relies on anamnesis, clinical and complementary tests, adapting them to a uniform terminology with clear meaning of signs and symptoms. PMID:24913963

  3. Transport et bruit quantique dans les fils mésoscopiques

    NASA Astrophysics Data System (ADS)

    Torrès, J.

    2002-01-01

    Un conducteur quantique est bien caractérisé par sa conductance donnée par la formule de Landauer. Mais le bruit contient davantage d'informations que la conductance : il mesure les fluctuations temporelles du courant autour de sa valeur moyenne. De plus, le signe des corrélations de bruit est lié à la statistique des porteurs de charge. Dans une jonction entre un métal normal et un supraconducteur, le bruit présente une singularité à la fréquence Josephson, signature de la charge 2e des paires de Cooper impliquées dans le transport. Lorsque la tension appliquée est supérieure au gap du supraconducteur, la courbe du bruit exhibe des singularités à plusieurs fréquences auxquelles on peut associer un processus de réflexion ou de transmission. L'analogue fermionique de l'expérience d'Hanbury-Brown et Twiss avec un supraconducteur permet d'observer à la fois des corrélations positives et négatives dans un même système. Maintenir une différence de potentiel entre les deux extrémités d'un fil crée une situation relevant de la thermodynamique hors de l'équilibre. Formellement, on peut se ramener à un calcul à l'équilibre et écrire une théorie des perturbations grâce à la méthode de Keldysh. La théorie des liquides de Luttinger décrit les systèmes unidimensionnels d'électrons en interaction. Le hamiltonien peut se mettre sous forme quadratique grâce à la bosonisation. D'autre part, un liquide de Luttinger chiral constitue un bon modèle des états de bord de l'effet Hall quantique fractionnaire. Grâce au formalisme de Keldysh, on peut retrouver une formule de type Schottky et identifier la charge des quasiparticules de Laughlin.

  4. First results from the CheMin, DAN and SAM instruments on Mars Science Laboratory

    NASA Astrophysics Data System (ADS)

    Blake, D. F.; Mahaffy, P. R.; Mitrofanov, I.

    2012-12-01

    One of the principal goals of the Mars Science Laboratory rover Curiosity is to identify and characterize the early habitable environments of Mars, as recorded in the stratified rocks and soil of Gale crater. The suite of instruments aboard Curiosity will make measurements useful for determining the presence and lateral/vertical distribution of hydrated phases, the mineralogy and "preservation potential" of sediments and rocks, and the identity and isotopic composition of organic and other carbon containing molecules, should such be present. Three of Curiosity's instruments, DAN ("Dynamic Albedo of Neutrons," a soil hydrogen detector), CheMin ("Chemistry and Mineralogy," a mineralogy instrument) and SAM ("Surface Analysis at Mars," an organic molecule and isotopic analysis instrument) are uniquely suited to this purpose. DAN consists of a pulsed neutron generator and neutron detector that will measure the hydrogen content (i.e., hydrated phases, water ice) in the upper meter of the soil. Both passive and active measurements will be obtained, resulting in a meter-scale resolution transect map of near-surface hydrogen along the path of the rover. These measurements will provide context for the mineralogical and organic measurements of drilled and scooped samples analyzed by CheMin and SAM. CheMin, a powder X-ray Diffraction (pXRD) instrument, will determine the mineralogy of scooped soils and powders obtained from drilled rocks. Hydrated minerals will be identified, along with whole-rock mineralogy for characterizing the environment of formation and preservation potential for organic molecules. SAM consists of a sample handling system, a gas chromatograph, a mass spectrometer, and a tunable laser spectrometer. SAM will accept the same powdered rock and soil samples as CheMin, and will measure and identify organic carbon in these samples as well as evolved inorganic gases such as CO2, CH4, and H2O. Isotopic composition of noble gases and several light elements are

  5. Profil de l'infection urinaire nosocomiale dans un service de nephrology

    PubMed Central

    Lazrak, Mohamed Amine; El Bardai, Ghita; Jaafour, Soumia; Kabbali, Nadia; Arrayhani, Mohamed; Houssaini, Tarik Sqalli

    2014-01-01

    L'infection urinaire est l'infection nosocomiale la plus fréquente. Elle constitue un véritable problème de santé publique par la surmortalité et le surcoût qu'elle entraîne. L'objectif de notre étude est de déterminer l'incidence et le profil des IU nosocomiales dans un service de Néphrologie. Etude rétrospective sur dossier de tous les patients hospitalisés dans notre service durant l'année 2011, ayant bénéficié d'un examen cytobactériologique des urines. Ont été exclus, tous les patients admis avec une IU connue ou active. 325 dossiers ont été retenus. L'incidence de l'IU nosocomiale était de l'ordre de 16,9%. La durée moyenne d'hospitalisation était de 14,1±10,15 jours. 30% de nos patients ont été transférés du service des urgences. 80% des IU nosocomiales étaient compliquées. Le germe responsable était E.Coli dans 2/3 des cas dont 14,5% était à E.Coli sécrétrice de bétalactamases à spectre étendu. L’évolution après traitement était favorable chez 90,7%. En analyse multivariée, les facteurs de risque pour contracter une IU nosocomiale étaient le sexe féminin; le sondage urinaire et l'antécédent d'IU à répétition. Nos résultats rejoignent ceux de la littérature concernant les facteurs de risque liés à la survenue de l'IU nosocomiale, la fréquence des infections à entérobactéries, et l’émergence de souches résistantes. Une Surveillance microbiologique et une évaluation de la résistance aux antibiotiques constituent une ligne de défense pour faire face à l'accentuation de nouvelles souches bactériennes de plus en plus résistantes aux antibiotiques rendant les options thérapeutiques très limitées. PMID:25667721

  6. Interactive reservoir simulation

    SciTech Connect

    Regtien, J.M.M. Por, G.J.A.; Stiphout, M.T. van; Vlugt, F.F. van der

    1995-12-31

    Shell`s new Modular Reservoir Simulator (MoReS) has been equipped with a comprehensive and versatile user interface called FrontEnd. Apart from providing a user-friendly environment for interactive reservoir simulation, FrontEnd serves a software platform for other dynamic simulation and reservoir-engineering applications. It offers to all supported applications a common user interface, enables the re-use of code and reduces overall maintenance and support costs associated with the embedded applications. Because of its features, FrontEnd facilitates the transfer of research results in the form of operational software to end users. When coupled with MoReS, FrontEnd can be used for pre- and post-processing and interactive simulation. The pre-processing options allow data to be inputted by means of various OSF/Motif widgets containing a spreadsheet, text editors, dialogues and graphical input. The display of the input data as well as the post-processing of all simulation results is made possible by a variety of user-defined plot of tabular (e.g. timestep summary) and array (simulation grid) data. During a simulation user-defined plots can be displayed and edited, allowing a close inspection of the results as they are being calculated. FrontEnd has been equipped with a powerful input command language, which gives the batch user as much flexibility and control over the input as the interactive user.

  7. Simulation in neurology.

    PubMed

    Micieli, Giuseppe; Cavallini, Anna; Santalucia, Paola; Gensini, Gianfranco

    2015-10-01

    Simulation is a frontier for disseminating knowledge in almost all the fields of medicine and it is attracting growing interest because it offers a means of developing new teaching and training models, as well as of verifying what has been learned in a critical setting that simulates clinical practice. The role of simulation in neurology, until now limited by the obvious physical limitations of the dummies used to train students and learners, is now increasing since, today, it allows anamnestic data to be related to the instrumental evidence necessary for diagnosis and therapeutic decision-making, i.e., to the findings of neurophysiological investigations (EEG, carotid and vertebral echography and transcranial Doppler, for example) and neuroradiological investigations (CT, MRI imaging), as well as vital parameter monitoring (ECG, saturimetry, blood pressure, respiratory frequency, etc.). Simulation, by providing learners with opportunities to discuss, with experts, different profiles of biological parameters (both during the simulation itself and in the subsequent debriefing session), is becoming an increasingly important tool for training those involved in evaluation of critical neurological patients (stroke, Guillan Barrè syndrome, myasthenia, status epilepticus, headache, vertigo, confusional status, etc.) and complex cases. In this SIMMED (Italian Society for Simulation in Medicine) position paper, the applications (present and, possibly, future) of simulation in neurology are reported. PMID:25926070

  8. Fusion processor simulation (FPSim)

    NASA Astrophysics Data System (ADS)

    Barnell, Mark D.; Wynne, Douglas G.; Rahn, Brian J.

    1998-07-01

    The Fusion Processor Simulation (FPSim) is being developed by Rome Laboratory to support the Discrimination Interceptor Technology (DITP) and Advanced Sensor Technology (ASTP) Programs of the Ballistic Missile Defense Organization. The purpose of the FPSim is to serve as a test bed and evaluation tool for establishing the feasibility of achieving threat engagement timelines. The FPSim supports the integration, evaluation, and demonstration of different strategies, system concepts, and Acquisition Tracking & Pointing (ATP) subsystems and components. The environment comprises a simulation capability within which users can integrate and test their application software models, algorithms and databases. The FPSim must evolve as algorithm developments mature to support independent evaluation of contractor designs and the integration of a number of fusion processor subsystem technologies. To accomplish this, the simulation contains validated modules, databases, and simulations. It possesses standardized engagement scenarios, architectures and subsystem interfaces, and provides a hardware and software framework which is flexible to support growth, reconfigurration, and simulation component modification and insertion. Key user interaction features include: (1) Visualization of platform status through displays of the surveillance scene as seen by imaging sensors. (2) User-selectable data analysis and graphics display during the simulation execution as well as during post-simulation analysis. (3) Automated, graphical tools to permit the user to reconfigure the FPSim, i.e., 'Plug and Play' various model/software modules. The FPSim is capable of hosting and executing user's software algorithms of image processing, signal processing, subsystems, and functions for evaluation purposes.

  9. Ballistic skin simulant.

    PubMed

    Jussila, Jorma; Leppäniemi, Ari; Paronen, Mikael; Kulomäki, Erkki

    2005-05-28

    Hydrogels prepared from water solutions containing 10-20 mass% gelatine are generally accepted muscle tissue simulants in terminal ballistic research. They, however, do not have a surface layer which simulates the effect of human skin. The purpose of this research was to find a suitable skin simulant for enhancing the testing fidelity and the credibility of the results with gelatine-based materials when assessing the injury potential of not only high energy bullets, but also especially that of non-penetrating "less lethal" kinetic impact ammunition and relatively low energy ricochet fragments. A skin simulant also permits the simulation and assessment of exit wounds. The mechanical and ballistic properties of human skin and target simulant were established on the basis of results found in the literature. Some errors in these were found. The corrected values are included in this paper for comparison. The target values of the mechanical properties of the skin simulant were the following: threshold velocity v(th)=94+/-4 m/s, tensile strength 18+/-2 N/mm2 and elongation at break 65+/-5%. A selection of synthetic and natural materials was evaluated as skin simulants by analysing their mechanical and ballistic properties. The results were compared to literature values obtained with human cadavers. The tests showed that the best skin simulant of the ones evaluated was semi-finished chrome tanned upholstery "crust" cowhide of 0.9-1.1 mm nominal thickness. Its threshold velocity was 90.7 m/s, tensile strength 20.89+/-4.11 MPa and elongation at break 61+/-9%. These values are the same as the average values of human skin. Of the synthetic materials evaluated, 1mm thick natural rubber can be used on impact side as a threshold velocity filter with some reservations although its theoretical threshold velocity is only 82.9 m/s. PMID:15837009

  10. Bruit thermique et effets quantiques dans une cavité optique de grande finesse

    NASA Astrophysics Data System (ADS)

    Caniard, T.; Briant, T.; Heidmann, A.; Pinard, M.

    2006-10-01

    Nous nous intéressons aux bruits dans les mesures optiques de très grande sensibilité et aux limites associées. Une des limitations fondamentales des mesures interférométriques, telles que les détections d'ondes gravitationnelles, est liée aux fluctuations de la pression de radiation exercée par la lumière sur les miroirs. Celle-ci induit des corrélations quantiques entre la position des miroirs et les fluctuations de la lumière. L'observation de ces effets quantiques ouvrirait de nombreuses perspectives: étude de la limite quantique standard, production d'états comprimés, réalisation d'une mesure quantique non destructive ldots

  11. [Story life CHENG Dan-an's, works and his achievements on acupuncture and moxibustion science].

    PubMed

    Lu, Xiang; Cai, Yue

    2011-05-01

    Mr. CHENG Dan-an, who devoted himself to the renaissance of the course of modern Chinese acupuncture, the establishment of acupuncture education unit, correspondence education, acupuncture personnel fostering and publication of periodicals on acupuncture, has great contribution to the academic exchanges and popularization of acupuncture. Mr. CHENG has completed over 10 articles and more than 20 works and translations. According to him, mechanism on meridians, collaterals, acupoints and acupuncture techniques were explored with the promotion on application of "Shen" and "qi" in clinic. Pulse and tongue diagnosis as well as acupuncture treatment were supplemented into Shanghanlun (Treatise on Febrile Diseases). And great importance was attached on the scientific validity and practicability. His professional ethics and dedication are worth to be learned by all medical workers nowadays. His acupuncture theories and academic achievements still inspire us today, which are also taken as the origin for the innovation and development of modern acupuncture science. PMID:21692305

  12. Simulation of a microgrid

    NASA Astrophysics Data System (ADS)

    Dulǎu, Lucian Ioan

    2015-12-01

    This paper describes the simulation of a microgrid system with storage technologies. The microgrid comprises 6 distributed generators (DGs), 3 loads and a 150 kW storage unit. The installed capacity of the generators is 1100 kW, while the total load demand is 900 kW. The simulation is performed by using a SCADA software, considering the power generation costs, the loads demand and the system's power losses. The generators access the system in order of their power generation cost. The simulation is performed for the entire day.

  13. Simulation in hospitals.

    PubMed

    Proctor, T

    1996-01-01

    Health care costs continue to rise because increased demand for services and limited budgets put pressure on resources, however efficiently they may be used. Proposes discrete event simulation as an effective tool in the search for more efficient health care systems. Looks at the application of a desktop computer simulation package to model part of a hospital subsystem. The simulation package shows how efficiency might be improved by moderating available resources and times taken to complete tasks. Maintains that the principles expounded here are applicable to many different aspects of health care management. PMID:10161783

  14. Vortex breakdown simulation

    NASA Technical Reports Server (NTRS)

    Nakamura, Y.; Leonard, A.; Spalart, P. R.

    1985-01-01

    A vortex breakdown was simulated by the vortex filament method, and detailed figures are presented based on the results. Deformations of the vortex filaments showed clear and large swelling at a particular axial station which implied the presence of a recirculation bubble at that station. The tendency for two breakdowns to occur experimentally was confirmed by the simulation, and the jet flow inside the bubble was well simulated. The particle paths spiralled with expansion, and the streamlines took spiral forms at the breakdown with expansion.

  15. XMASS MC simulation

    NASA Astrophysics Data System (ADS)

    Abe, K.

    2016-02-01

    XMASS is a single phase liquid xenon (LXe) detector, designed for a program of physics targets. As a first step in the program, the XMASS-I detector started operation with 832 kg of LXe in the sensitive volume from Sep. 2010. GEANT4 tools are used for the detector simulation to understand the detector response and background. In the simulation detailed structure and processes are required to reproduce background such as detector surface events and Cherenkov events. We present details of the geometry and processes used in the XMASS simulation in this paper.

  16. Structural mechanics simulations

    NASA Technical Reports Server (NTRS)

    Biffle, Johnny H.

    1992-01-01

    Sandia National Laboratory has a very broad structural capability. Work has been performed in support of reentry vehicles, nuclear reactor safety, weapons systems and components, nuclear waste transport, strategic petroleum reserve, nuclear waste storage, wind and solar energy, drilling technology, and submarine programs. The analysis environment contains both commercial and internally developed software. Included are mesh generation capabilities, structural simulation codes, and visual codes for examining simulation results. To effectively simulate a wide variety of physical phenomena, a large number of constitutive models have been developed.

  17. Breathing metabolic simulator.

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G., Jr.; Hendricks, C. M.; Morison, W. B.

    1971-01-01

    Description of a device for simulation of the human breathing and metabolic parameters required for the evaluation of respiratory diagnostic, monitoring, support and resuscitation equipment. The remotely controlled device allows wide variations in breathing rate and depth, breath velocity contour, oxygen uptake and carbon dioxide release to simulate conditions from sleep to hard work, with respiration exchange ratios ranging from hypoventilation to hyperventilation. It also reduces the cost of prolonged testing when simulation chambers with human subjects require three shifts of crews and standby physicians. Several block diagrams of the device and subsystems are given.

  18. Global Feedback Simulator

    SciTech Connect

    Carlos Serrano, Lawrence Doolittle

    2015-10-29

    GFS is a simulation engine that is used for the characterization of Accelerator performance parameters based on the machine layout, configuration and noise sources. It combines extensively tested Feedback models with a longitudinal phase space tracking simulator along with the interaction between the two via beam-based feedback using a computationally efficient simulation engine. The models include beam instrumentation, considerations on loop delays for in both the R and beam-based feedback loops, as well as the ability to inject noise (both correlated and uncorrelated) at different points of the machine including a full characterization of the electron gun performance parameters.

  19. Solar Sail Spaceflight Simulation

    NASA Technical Reports Server (NTRS)

    Lisano, Michael; Evans, James; Ellis, Jordan; Schimmels, John; Roberts, Timothy; Rios-Reyes, Leonel; Scheeres, Daniel; Bladt, Jeff; Lawrence, Dale; Piggott, Scott

    2007-01-01

    The Solar Sail Spaceflight Simulation Software (S5) toolkit provides solar-sail designers with an integrated environment for designing optimal solar-sail trajectories, and then studying the attitude dynamics/control, navigation, and trajectory control/correction of sails during realistic mission simulations. Unique features include a high-fidelity solar radiation pressure model suitable for arbitrarily-shaped solar sails, a solar-sail trajectory optimizer, capability to develop solar-sail navigation filter simulations, solar-sail attitude control models, and solar-sail high-fidelity force models.

  20. Computer-simulated phacoemulsification

    NASA Astrophysics Data System (ADS)

    Laurell, Carl-Gustaf; Nordh, Leif; Skarman, Eva; Andersson, Mats; Nordqvist, Per

    2001-06-01

    Phacoemulsification makes the cataract operation easier for the patient but involves a demanding technique for the surgeon. It is therefore important to increase the quality of surgical training in order to shorten the learning period for the beginner. This should diminish the risks of the patient. We are developing a computer-based simulator for training of phacoemulsification. The simulator is built on a platform that can be used as a basis for several different training simulators. A prototype has been made that has been partly tested by experienced surgeons.

  1. Global Feedback Simulator

    Energy Science and Technology Software Center (ESTSC)

    2015-10-29

    GFS is a simulation engine that is used for the characterization of Accelerator performance parameters based on the machine layout, configuration and noise sources. It combines extensively tested Feedback models with a longitudinal phase space tracking simulator along with the interaction between the two via beam-based feedback using a computationally efficient simulation engine. The models include beam instrumentation, considerations on loop delays for in both the R and beam-based feedback loops, as well as themore » ability to inject noise (both correlated and uncorrelated) at different points of the machine including a full characterization of the electron gun performance parameters.« less

  2. Lagrangian Simulation of Combustion

    SciTech Connect

    Ahmed F. Ghoniem

    2008-05-01

    A Lagrangian approach for the simulation of reactive flows has been developed during the course of this project, and has been applied to a number of significant and challenging problems including the transverse jet simulations. An efficient strategy for parallel domain decomposition has also been developed to enable the implementation of the approach on massively parallel architecture. Since 2005, we focused our efforts on the development of a semi-Lagrangian treatment of diffusion, and fast and accurate Lagrangian simulation tools for multiphysics problems including combustion.

  3. Curiethérapie dans le traitement palliatif du cancer de l’œsophage

    PubMed Central

    Toulba, Ahmedou; Bakkali, Hanae; Boutayeb, Salwa; Kebdani, Tayeb; Ahid, Samir; Benjaafar, Noureddine

    2015-01-01

    Les patients atteints du cancer de l’œsophage ont souvent une maladie localement avancée, la dysphagie est le symptôme majeur chez la plupart de ces patients, plusieurs modalités thérapeutiques ont été utilisées pour améliorer cette dysphagie. Le but de ce travail est d’étudier l'efficacité et la tolérance de la curiethérapie haut débit de dose (HDR) endo-luminale dans le traitement palliatif des cancers de l’œsophage inopérable. Sur une période de 15 ans, l’étude a inclus les patients atteints de cancer de l’œsophage inopérable et/ou métastatique avec une dysphagie, sans extension à l'hypopharynx ou a la trachée et qui ont bénéficié d'une curiethérapie HDR avec ou sans radiothérapie externe à visée palliative. Au total 46 patients ont été inclus dans l’étude, 58,7% étaient des hommes, 42,2% avaient une dysphagie grade 2 et 37,8% étaient aphagiques, 78,6% des patients étaient performance satus PS 2, l'amaigrissement à été trouvé chez 81,4%, la localisation de la tumeur était surtout au niveau du tiers moyen et inférieur dans 97,8%, la hauteur médiane de la tumeur était de 7 cm (5,5-9), le carcinome épidermoïde était le type histologique le plus fréquent chez 31 patients (70,5%). Après un médiane de suivi de 5 mois, l'amélioration de la dysphagie a été retrouvée chez 76% des malades (p1]. L′incidence la plus élevée est observée dans certains pays notamment en Asie et en Afrique, et l′incidence dans les pays développés occidentaux est en augmentation [2]. Selon le registre du cancer de Rabat 2006-2008, le cancer de l’œsophage est rare et constitue 1,5% de tous les cancers chez l'homme [3]. Le taux de survie globale à 5 ans est de 8%, avec 80% des décès liés à l’évolution locale de la maladie [4]. Pour la minorité des patients avec une maladie localisée, le traitement par radiochimiothérapie concomitante avec ou sans chirurgie permet une amélioration de la survie [5]. Plus de 50

  4. Research through simulation. [simulators and research applications at Langley

    NASA Technical Reports Server (NTRS)

    Copeland, J. L. (Compiler)

    1982-01-01

    The design of the computer operating system at Langley Research Center allows for concurrent support of time-critical simulations and background analytical computing on the same machine. Signal path interconnections between computing hardware and flight simulation hardware is provided to allow up to six simulation programs to be in operation at one time. Capabilities and research applications are discussed for the: (1) differential maneuvering simulator; (2) visual motion simulator; (3) terminal configured vehicle simulator; (4) general aviation aircraft simulator; (5) general purpose fixed based simulator; (6) transport simulator; (7) digital fly by wire simulator; (8) general purpose fighter simulator; and (9) the roll-up cockpit. The visual landing display system and graphics display system are described and their simulator support applications are listed.

  5. Binary synchronous simulator

    NASA Technical Reports Server (NTRS)

    Rogers, J. R., III

    1980-01-01

    Flexible simulator for trouble-shooting data transmission system uses binary synchronous communications protocol to produce error-free transmission of data between two points. Protocol may be used to replace display generator or be directly fed to display generator.

  6. Observing System Simulation Experiments

    NASA Technical Reports Server (NTRS)

    Prive, Nikki

    2015-01-01

    This presentation gives an overview of Observing System Simulation Experiments (OSSEs). The components of an OSSE are described, along with discussion of the process for validating, calibrating, and performing experiments. a.

  7. Rocket engine numerical simulation

    NASA Technical Reports Server (NTRS)

    Davidian, Ken

    1993-01-01

    The topics are presented in view graph form and include the following: a definition of the rocket engine numerical simulator (RENS); objectives; justification; approach; potential applications; potential users; RENS work flowchart; RENS prototype; and conclusions.

  8. Electromechanical simulations of dislocations

    NASA Astrophysics Data System (ADS)

    Skiba, Oxana; Gracie, Robert; Potapenko, Stanislav

    2013-04-01

    Improving the reliability of micro-electronic devices depends in part on developing a more in-depth understanding of dislocations because dislocations are barriers to charge carriers. To this end, the quasi-static simulation of discrete dislocations dynamics in materials under mechanical and electrical loads is presented. The simulations are based on the extended finite element method, where dislocations are modelled as internal discontinuities. The strong and weak forms of the boundary value problem for the coupled system are presented. The computation of the Peach-Koehler force using the J-integral is discussed. Examples to illustrate the accuracy of the simulations are presented. The motion of the network of the dislocations under different electrical and mechanical loads is simulated. It was shown that even in weak piezoelectric materials the effect of the electric field on plastic behaviour is significant.

  9. Dynamic Power Grid Simulation

    Energy Science and Technology Software Center (ESTSC)

    2015-09-14

    GridDyn is a part of power grid simulation toolkit. The code is designed using modern object oriented C++ methods utilizing C++11 and recent Boost libraries to ensure compatibility with multiple operating systems and environments.

  10. Breathing metabolic simulator

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G.; Hendricks, C. M.; Morison, W. B.

    1972-01-01

    The development of a breathing metabolic simulator (BMS) is reported. This BMS simulates all of the breathing and metabolic parameters required for complete evaluation and test of life support and resuscitation equipment. It is also useful for calibrating and validating mechanical and gaseous pulmonary function test procedures. Breathing rate, breathing depth, breath velocity contour, oxygen uptake, and carbon dioxide release are all variable over wide ranges simulating conditions from sleep to hard work with respiratory exchange ratios covering the range from hypoventilation. In addition, all of these parameters are remotely controllable to facilitate use of the device in hostile or remote environments. The exhaled breath is also maintained at body temperature and a high humidity. The simulation is accurate to the extent of having a variable functional residual capacity independent of other parameters.

  11. Television Quiz Show Simulation

    ERIC Educational Resources Information Center

    Hill, Jonnie Lynn

    2007-01-01

    This article explores the simulation of four television quiz shows for students in China studying English as a foreign language (EFL). It discusses the adaptation and implementation of television quiz shows and how the students reacted to them.

  12. Fundamentals of plasma simulation

    SciTech Connect

    Forslund, D.W.

    1985-01-01

    With the increasing size and speed of modern computers, the incredibly complex nonlinear properties of plasmas in the laboratory and in space are being successfully explored in increasing depth. Of particular importance have been numerical simulation techniques involving finite size particles on a discrete mesh. After discussing the importance of this means of understanding a variety of nonlinear plasma phenomena, we describe the basic elements of particle-in-cell simulation and their limitations and advantages. The differencing techniques, stability and accuracy issues, data management and optimization issues are discussed by means of a simple example of a particle-in-cell code. Recent advances in simulation methods allowing large space and time scales to be treated with minimal sacrifice in physics are reviewed. Various examples of nonlinear processes successfully studied by plasma simulation will be given.

  13. Electronic Falling Body Simulator

    ERIC Educational Resources Information Center

    Goodman, John M.

    1975-01-01

    Describes an analog electronic simulator for the motion of an object projected horizontally in a vertical acceleration field. The device features adjustable values for the horizontal speeds and "gravity." Trajectories are displayed on an oscilloscope. (Author/CP)

  14. Simulation of Gravitational Microlensing

    NASA Video Gallery

    This simulation shows the 22-year journey of a star moving through space and passing directly in front of a more distant background star. All stars drift through space. Occasionally, a star lines u...

  15. Chemical Transformation Simulator

    EPA Science Inventory

    The Chemical Transformation Simulator (CTS) is a web-based, high-throughput screening tool that automates the calculation and collection of physicochemical properties for an organic chemical of interest and its predicted products resulting from transformations in environmental sy...

  16. Compressible Astrophysics Simulation Code

    Energy Science and Technology Software Center (ESTSC)

    2007-07-18

    This is an astrophysics simulation code involving a radiation diffusion module developed at LLNL coupled to compressible hydrodynamics and adaptive mesh infrastructure developed at LBNL. One intended application is to neutrino diffusion in core collapse supernovae.

  17. Color Blindness Simulations

    MedlinePlus

    ... many disables? The fastest growing segment? Myths of disability The Law The Rules Accessibility Resources Page Updates, additions Contact Us For assistance contact your NOAA Line Office Section 508 Coordinator Color blindness Simulations Normal Color Vision Deuteranopia Color blindness marked ...

  18. TGF simulation movie

    NASA Video Gallery

    A TGF produces gamma rays (magenta) as well as high-energy electrons (yellow) and positrons (green). This simulation tracks a TGF and its particle beams from their origin altitude of 9.3 miles (15 ...

  19. Xyce parallel electronic simulator.

    SciTech Connect

    Keiter, Eric Richard; Mei, Ting; Russo, Thomas V.; Rankin, Eric Lamont; Schiek, Richard Louis; Thornquist, Heidi K.; Fixel, Deborah A.; Coffey, Todd Stirling; Pawlowski, Roger Patrick; Santarelli, Keith R.

    2010-05-01

    This document is a reference guide to the Xyce Parallel Electronic Simulator, and is a companion document to the Xyce Users' Guide. The focus of this document is (to the extent possible) exhaustively list device parameters, solver options, parser options, and other usage details of Xyce. This document is not intended to be a tutorial. Users who are new to circuit simulation are better served by the Xyce Users' Guide.

  20. Generic Distributed Simulation Architecture

    SciTech Connect

    Booker, C.P.

    1999-05-14

    A Generic Distributed Simulation Architecture is described that allows a simulation to be automatically distributed over a heterogeneous network of computers and executed with very little human direction. A prototype Framework is presented that implements the elements of the Architecture and demonstrates the feasibility of the concepts. It provides a basis for a future, improved Framework that will support legacy models. Because the Framework is implemented in Java, it may be installed on almost any modern computer system.

  1. Water hammer simulator

    SciTech Connect

    Sinha, S.K.; Madia, J.; Dixon, S.

    1995-11-01

    The Consolidated Edison Company of New York, Inc. (Con Edison) has constructed a first-of-a-kind water hammer events simulator for use at its training center. The Learning Center, Con Edison`s central training facility, intends to use the simulator as an educational tool to demonstrate the various mechanisms of the water hammer phenomenon to power plant designers, engineers and operators. The water hammer phenomenon has been studied extensively for the past 15 years for the nuclear industry. However, the acknowledge of the various water hammer mechanisms and the measures to prevent or mitigate water hammer have not been widely disseminated among the operators of fossil-fueled power plants. Con Edison personnel who operate the various generation stations and the New York City steam distribution systems are expected to benefit from the new simulator. Knowledge gained from interacting with the simulator will be very important in helping the Con Edison prevent, mitigate, or accommodate water hammer at its facilities. The water hammer simulator was fabricated in Con Edison`s central machine shop. Details of the design and construction of the simulator were finalized in consultation with Creare, Inc., an engineering research firm, located in Hanover, New Hampshire. The simulator seeks to recreate the essential features of water hammer in steam mines following the buildup of cold (subcooled) water by condensation and steam-water interaction. This paper describes the fabrication, design, testing, and operation of the Con Edison water hammer simulator. A discussion of how Con Edison plans to use the facility at The Learning Center is included.

  2. Accelerator simulation using computers

    SciTech Connect

    Lee, M.; Zambre, Y.; Corbett, W.

    1992-01-01

    Every accelerator or storage ring system consists of a charged particle beam propagating through a beam line. Although a number of computer programs exits that simulate the propagation of a beam in a given beam line, only a few provide the capabilities for designing, commissioning and operating the beam line. This paper shows how a multi-track'' simulation and analysis code can be used for these applications.

  3. Accelerator simulation using computers

    SciTech Connect

    Lee, M.; Zambre, Y.; Corbett, W.

    1992-01-01

    Every accelerator or storage ring system consists of a charged particle beam propagating through a beam line. Although a number of computer programs exits that simulate the propagation of a beam in a given beam line, only a few provide the capabilities for designing, commissioning and operating the beam line. This paper shows how a ``multi-track`` simulation and analysis code can be used for these applications.

  4. Theory Modeling and Simulation

    SciTech Connect

    Shlachter, Jack

    2012-08-23

    Los Alamos has a long history in theory, modeling and simulation. We focus on multidisciplinary teams that tackle complex problems. Theory, modeling and simulation are tools to solve problems just like an NMR spectrometer, a gas chromatograph or an electron microscope. Problems should be used to define the theoretical tools needed and not the other way around. Best results occur when theory and experiments are working together in a team.

  5. Geothermal reservoir simulation

    NASA Technical Reports Server (NTRS)

    Mercer, J. W., Jr.; Faust, C.; Pinder, G. F.

    1974-01-01

    The prediction of long-term geothermal reservoir performance and the environmental impact of exploiting this resource are two important problems associated with the utilization of geothermal energy for power production. Our research effort addresses these problems through numerical simulation. Computer codes based on the solution of partial-differential equations using finite-element techniques are being prepared to simulate multiphase energy transport, energy transport in fractured porous reservoirs, well bore phenomena, and subsidence.

  6. Multiplex data bus simulator

    SciTech Connect

    Garbo, D.L.

    1983-01-01

    A multiplex data-bus simulator for analyzing multiprocessor designs is presented. The simulator was designed to be user-friendly, thus allowing a multiprocessor designer to enter various configuration inputs in a concise and orderly fashion through the use of menus. The designer is also provided a method of visualizing a message traffic flow through the use of graphical representation of events. 3 references.

  7. Simulating Underwater Leader Growth

    NASA Astrophysics Data System (ADS)

    Culver, Lee

    2005-11-01

    Dielectric breakdown in water is always preceded by the growth of leaders. The structure and growth of these leaders have been previously simulated with fractals; however, present mathematical models are rife with undesired parameters. We eliminate many of these parameters with a physical model that describes a leader as a protonic mobility wave. Graphical-simulation results will be presented and compared with photographic data.

  8. The OLYMPUS Experiment Simulation

    NASA Astrophysics Data System (ADS)

    Schmidt, Axel

    2013-04-01

    The OLYMPUS Experiment aims to measure the ratio of electron-proton to positron-proton elastic scattering cross-sections to better than 1% systematic uncertainty. Achieving this goal requires a precise understanding of a wide range of systematic effects, such as the radiative corrections internal to the reaction, the varying acceptance of the detector aparatus, and efficiency of the tracking algorithms. A detailed Geant4 simulation of the OLYMPUS experiment has been developed to study these effects, and using the Monte Carlo method, properly account for their convolution. Radiative corrections are applied by the event generator, whose events are propagated through the simulation. Simulated detector signals are produced with identical format to the raw OLYMPUS data, so that simulated data can be processed using the same analysis software. The simulation, therefore, serves as a benchmark for comparison with the final OLYMPUS results. A discussion of the radiative corrections procedure and an overview of the simulation will be presented. This work is supported by DOE Grant DE-FG02-94ER40818.

  9. Ultrasound simulation in bone.

    PubMed

    Kaufman, Jonathan J; Luo, Gangming; Siffert, Robert S

    2008-01-01

    The manner in which ultrasound interacts with bone is of key interest in therapy and diagnosis alike. These may include applications directly to bone, as, for example, in treatment to accelerate the healing of bone fractures and in assessment of bone density in osteoporosis, or indirectly in diagnostic imaging of soft tissue with interest in assessing exposure levels to nearby bone. Because of the lack of analytic solutions to virtually every "practical problem" encountered clinically, ultrasound simulation has become a widely used technique for evaluating ultrasound interactions in bone. This paper provides an overview of the use of ultrasound simulation in bone. A brief description of the mathematical model used to characterize ultrasound propagation in bone is first provided. A number of simulation examples are then presented that explain how simulation may be utilized in a variety of practical configurations. The focus of this paper in terms of examples presented is on diagnostic applications in bone, and, in particular, for assessment of osteoporosis. However, the use of simulation in other areas of interest can easily be extrapolated from the examples presented. In conclusion, this paper describes the use of ultrasound simulation in bone and demonstrates the power of computational methods for ultrasound research in general and tissue and bone applications in particular. PMID:18599409

  10. Mission Simulation Toolkit

    NASA Technical Reports Server (NTRS)

    Pisaich, Gregory; Flueckiger, Lorenzo; Neukom, Christian; Wagner, Mike; Buchanan, Eric; Plice, Laura

    2007-01-01

    The Mission Simulation Toolkit (MST) is a flexible software system for autonomy research. It was developed as part of the Mission Simulation Facility (MSF) project that was started in 2001 to facilitate the development of autonomous planetary robotic missions. Autonomy is a key enabling factor for robotic exploration. There has been a large gap between autonomy software (at the research level), and software that is ready for insertion into near-term space missions. The MST bridges this gap by providing a simulation framework and a suite of tools for supporting research and maturation of autonomy. MST uses a distributed framework based on the High Level Architecture (HLA) standard. A key feature of the MST framework is the ability to plug in new models to replace existing ones with the same services. This enables significant simulation flexibility, particularly the mixing and control of fidelity level. In addition, the MST provides automatic code generation from robot interfaces defined with the Unified Modeling Language (UML), methods for maintaining synchronization across distributed simulation systems, XML-based robot description, and an environment server. Finally, the MSF supports a number of third-party products including dynamic models and terrain databases. Although the communication objects and some of the simulation components that are provided with this toolkit are specifically designed for terrestrial surface rovers, the MST can be applied to any other domain, such as aerial, aquatic, or space.

  11. Converting DYNAMO simulations to Powersim Studio simulations

    SciTech Connect

    Walker, La Tonya Nicole; Malczynski, Leonard A.

    2014-02-01

    DYNAMO is a computer program for building and running 'continuous' simulation models. It was developed by the Industrial Dynamics Group at the Massachusetts Institute of Technology for simulating dynamic feedback models of business, economic, and social systems. The history of the system dynamics method since 1957 includes many classic models built in DYANMO. It was not until the late 1980s that software was built to take advantage of the rise of personal computers and graphical user interfaces that DYNAMO was supplanted. There is much learning and insight to be gained from examining the DYANMO models and their accompanying research papers. We believe that it is a worthwhile exercise to convert DYNAMO models to more recent software packages. We have made an attempt to make it easier to turn these models into a more current system dynamics software language, Powersim © Studio produced by Powersim AS2 of Bergen, Norway. This guide shows how to convert DYNAMO syntax into Studio syntax.

  12. Photons uniques indiscernables à partir d'une boîte quantique unique dans un cristal photonique

    NASA Astrophysics Data System (ADS)

    Laurent, S.; Varoutsis, S.; Le Gratiet, L.; Lemaître, A.; Sagnes, I.; Raineri, F.; Levenson, A.; Robert-Philip, I.; Abram, I.

    2006-10-01

    Nous avons développé et caractérisé une source de photons uniques basée sur l'émission spontanée d'une boîte quantique unique insérée dans une cavité à bande interdite photonique bidimensionnelle. Ce système nous a d'abord permis de produire des photons uniques, puis des photons uniques indiscernables avec une indiscernabilité supérieure à 70%. L'observation de l'indiscernabilité des photons, impossible sans un raccourcissement important de la durée de vie, met en évidence un effet Purcell supérieur à 25 dans ce système.

  13. Modélisation des charges d'espace dans les isolants solides par une analyse spectrale

    NASA Astrophysics Data System (ADS)

    Haas, V.; Scouarnec, Ch.; Franceschi, J. L.

    1998-01-01

    A mathematical method based on spectral algebra is developped for the thermal modulation method. These methods permit to measure the space charge distribution in solid insulators. The modelling presented permits to evaluate the performances and the limitations of the measurement method. Une linéarisation par l'algèbre spectrale a été développée dans une méthode de modulation thermique pour mesurer la distribution des charges électriques dans les isolants solides. La modélisation présentée permet d'évaluer les performances et les limites tant numériques que physiques de la méthode de mesure.

  14. EMU Suit Performance Simulation

    NASA Technical Reports Server (NTRS)

    Cowley, Matthew S.; Benson, Elizabeth; Harvill, Lauren; Rajulu, Sudhakar

    2014-01-01

    Introduction: Designing a planetary suit is very complex and often requires difficult trade-offs between performance, cost, mass, and system complexity. To verify that new suit designs meet requirements, full prototypes must be built and tested with human subjects. However, numerous design iterations will occur before the hardware meets those requirements. Traditional draw-prototype-test paradigms for research and development are prohibitively expensive with today's shrinking Government budgets. Personnel at NASA are developing modern simulation techniques that focus on a human-centric design paradigm. These new techniques make use of virtual prototype simulations and fully adjustable physical prototypes of suit hardware. This is extremely advantageous and enables comprehensive design down-selections to be made early in the design process. Objectives: The primary objective was to test modern simulation techniques for evaluating the human performance component of two EMU suit concepts, pivoted and planar style hard upper torso (HUT). Methods: This project simulated variations in EVA suit shoulder joint design and subject anthropometry and then measured the differences in shoulder mobility caused by the modifications. These estimations were compared to human-in-the-loop test data gathered during past suited testing using four subjects (two large males, two small females). Results: Results demonstrated that EVA suit modeling and simulation are feasible design tools for evaluating and optimizing suit design based on simulated performance. The suit simulation model was found to be advantageous in its ability to visually represent complex motions and volumetric reach zones in three dimensions, giving designers a faster and deeper comprehension of suit component performance vs. human performance. Suit models were able to discern differing movement capabilities between EMU HUT configurations, generic suit fit concerns, and specific suit fit concerns for crewmembers based

  15. Etude des phenomenes de penetration des especes chimiques dans les revetements cathodiques des cuves d'electrolyse de l'aluminium

    NASA Astrophysics Data System (ADS)

    Brisson, Pierre-Yves

    Cette these decrit l'etude effectuee sur les phenomenes d'insertion du sodium et de penetration du bain electrolytique dans les revetements cathodiques des cuves d'electrolyse de l'aluminium. L'etude fut effectuee a l'aide d'un montage permettant d'effectuer l'electrolyse en laboratoire. Trois types de revetement cathodiques furent etudies : des blocs semi-graphitique, des blocs graphitiques et des blocs graphitises. L'insertion du sodium dans les trois differents types de blocs fut etudiee a l'aide de la spectrometrie des photoelectrons X (XPS). L'analyse a permis de mettre en evidence deux formes de sodium dans l'anthracite et la phase liante des materiaux semi-graphitiques et graphitiques, indiquant qu'une fraction du sodium se retrouve sous forme adsorbee dans les micropores des materiaux alors que l'autre fraction est inseree dans la structure cristalline du carbone. Dans les phases graphitiques (materiaux graphitises et graphitiques), seuls les micropores sont occupes par le sodium Ce resultat explique la tendance observee selon laquelle l'ajout de graphite dans les blocs permet d'abaisser le gonflement sodique. Les mecanismes de penetration du bain dans le reseau poreux des materiaux furent etudies en microscopie electronique et en diffraction des rayons X sur des echantillons apres differents temps d'electrolyses et en variant l'atmosphere (soit sous argon ou sous azote). Ces analyses ont permis d'identifier le mecanisme conduisant a la mouillabilite du bain sur le carbone en fonction de l'atmosphere entourant l'electrolyse. Ainsi, sous azote, la formation de NaCN dans les pores des materiaux par reactions entre le sodium et l'azote permet une mouillabilite accrue du bain alors qu'en absence d'azote (sous argon), le carbure d'aluminium, formes a la surface des pores, joue un role similaire. Dans ce dernier cas, la penetration du bain est moins rapide etant donnee la necessite de toujours amener des especes contenant de l'aluminium en tete du front de

  16. Danning tablets attenuates α-naphthylisothiocyanate-induced cholestasis by modulating the expression of transporters and metabolic enzymes

    PubMed Central

    2014-01-01

    Background The Danning tablets (DNts) is commonly prescribed in China as a cholagogic formula. Our previous studies showed that DNts exerted the protective effect on α-naphthylisothiocyanate (ANIT)-induced liver injury with cholestasis in a dose-dependent mannar. However, the detailed molecular mechanisms of DNts against ANIT-induced cholestasis are still not fully explored. Methods Danning tablet (3 g/kg body weight/day) was administered orally to experimental rats for seven days before they were treated with ANIT (60 mg/kg daily via gastrogavage) which caused cholestasis. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total bilirubin (T-Bil), direct bilirubin (D-Bil) and total bile acid (TBA) were measured to evaluate the protective effect of Danning tablet at 12, 24 and 48h after ANIT treatment. Meanwhile, total bilirubin or total bile acid in the bile, urine and liver were also measured at 48h after ANIT treatment. Furthermore, the hepatic or renal mRNA and protein levels of metabolic enzymes and transports were investigated to elucidate the protective mechanisms of Danning tablet against ANIT-induced cholestasis. Results In this study, we found that DNts significantly attenuated translocation of multidrug resistance-associated protein 2 (Mrp2) from the canalicular membrane into an intracellular and up-regulated the hepatic mRNA and protein expressions of metabolic enzymes including cytochrome P450 2b1(Cyp2b1) and uridine diphosphate-5¢- glucuronosyltransferase (Ugt1a1)) and transporters including bile salt export pump (Bsep) and multidrug resistance protein 2 (Mdr2)) as well as renal organic solute transporter beta (Ostβ), accompanied by further increase in urinary and biliary excretion of bile acid and bilirubin. Conclusions DNts might promote bile acid and bilirubin elimination by regulating the expressions of hepatic and renal transporters as well as hepatic metabolic enzymes. PMID:25033983

  17. Monitoring of microenvironmental changes in the major and minor grooves of DNA by dan-modified oligonucleotides.

    PubMed

    Kimura, Takumi; Kawai, Kiyohiko; Majima, Tetsuro

    2005-12-22

    [graph: see text] We describe the synthesis of new environmentally sensitive fluorescence probes to elucidate DNA structures. DNA oligonucleotides containing fluorophore dan (6-(dimethylamino)-2-acylnaphthalene)-modified dC or dG were able to monitor the microenvironmental changes in both the major and minor grooves of DNA with a B- to A-DNA conformational transition and RNA hybridization. PMID:16354077

  18. Ion Beam Simulator

    Energy Science and Technology Software Center (ESTSC)

    2005-11-08

    IBSimu(Ion Beam Simulator) is a computer program for making two and three dimensional ion optical simulations. The program can solve electrostatic field in a rectangular mesh using Poisson equation using Finite Difference method (FDM). The mesh can consist of a coarse and a fine part so that the calculation accuracy can be increased in critical areas of the geometry, while most of the calculation is done quickly using the coarse mesh. IBSimu can launch ionmore » beam trajectories into the simulation from an injection surface or fomo plasma. Ion beam space charge of time independent simulations can be taken in account using Viasov iteration. Plasma is calculated by compensating space charge with electrons having Boltzmann energy distribution. The simulation software can also be used to calculate time dependent cases if the space charge is not calculated. Software includes diagnostic tools for plotting the geometry, electric field, space charge map, ion beam trajectories, emittance data and beam profiles.« less

  19. DSN Array Simulator

    NASA Technical Reports Server (NTRS)

    Tikidjian, Raffi; Mackey, Ryan

    2008-01-01

    The DSN Array Simulator (wherein 'DSN' signifies NASA's Deep Space Network) is an updated version of software previously denoted the DSN Receive Array Technology Assessment Simulation. This software (see figure) is used for computational modeling of a proposed DSN facility comprising user-defined arrays of antennas and transmitting and receiving equipment for microwave communication with spacecraft on interplanetary missions. The simulation includes variations in spacecraft tracked and communication demand changes for up to several decades of future operation. Such modeling is performed to estimate facility performance, evaluate requirements that govern facility design, and evaluate proposed improvements in hardware and/or software. The updated version of this software affords enhanced capability for characterizing facility performance against user-defined mission sets. The software includes a Monte Carlo simulation component that enables rapid generation of key mission-set metrics (e.g., numbers of links, data rates, and date volumes), and statistical distributions thereof as functions of time. The updated version also offers expanded capability for mixed-asset network modeling--for example, for running scenarios that involve user-definable mixtures of antennas having different diameters (in contradistinction to a fixed number of antennas having the same fixed diameter). The improved version also affords greater simulation fidelity, sufficient for validation by comparison with actual DSN operations and analytically predictable performance metrics.

  20. Computer Modeling and Simulation

    SciTech Connect

    Pronskikh, V. S.

    2014-05-09

    Verification and validation of computer codes and models used in simulation are two aspects of the scientific practice of high importance and have recently been discussed by philosophers of science. While verification is predominantly associated with the correctness of the way a model is represented by a computer code or algorithm, validation more often refers to model’s relation to the real world and its intended use. It has been argued that because complex simulations are generally not transparent to a practitioner, the Duhem problem can arise for verification and validation due to their entanglement; such an entanglement makes it impossible to distinguish whether a coding error or model’s general inadequacy to its target should be blamed in the case of the model failure. I argue that in order to disentangle verification and validation, a clear distinction between computer modeling (construction of mathematical computer models of elementary processes) and simulation (construction of models of composite objects and processes by means of numerical experimenting with them) needs to be made. Holding on to that distinction, I propose to relate verification (based on theoretical strategies such as inferences) to modeling and validation, which shares the common epistemology with experimentation, to simulation. To explain reasons of their intermittent entanglement I propose a weberian ideal-typical model of modeling and simulation as roles in practice. I suggest an approach to alleviate the Duhem problem for verification and validation generally applicable in practice and based on differences in epistemic strategies and scopes

  1. Multilevel turbulence simulations

    SciTech Connect

    Tziperman, E.

    1994-12-31

    The authors propose a novel method for the simulation of turbulent flows, that is motivated by and based on the Multigrid (MG) formalism. The method, called Multilevel Turbulence Simulations (MTS), is potentially more efficient and more accurate than LES. In many physical problems one is interested in the effects of the small scales on the larger ones, or in a typical realization of the flow, and not in the detailed time history of each small scale feature. MTS takes advantage of the fact that the detailed simulation of small scales is not needed at all times, in order to make the calculation significantly more efficient, while accurately accounting for the effects of the small scales on the larger scale of interest. In MTS, models of several resolutions are used to represent the turbulent flow. The model equations in each coarse level incorporate a closure term roughly corresponding to the tau correction in the MG formalism that accounts for the effects of the unresolvable scales on that grid. The finer resolution grids are used only a small portion of the simulation time in order to evaluate the closure terms for the coarser grids, while the coarse resolution grids are then used to accurately and efficiently calculate the evolution of the larger scales. The methods efficiency relative to direct simulations is of the order of the ratio of required integration time to the smallest eddies turnover time, potentially resulting in orders of magnitude improvement for a large class of turbulence problems.

  2. Range Process Simulation Tool

    NASA Technical Reports Server (NTRS)

    Phillips, Dave; Haas, William; Barth, Tim; Benjamin, Perakath; Graul, Michael; Bagatourova, Olga

    2005-01-01

    Range Process Simulation Tool (RPST) is a computer program that assists managers in rapidly predicting and quantitatively assessing the operational effects of proposed technological additions to, and/or upgrades of, complex facilities and engineering systems such as the Eastern Test Range. Originally designed for application to space transportation systems, RPST is also suitable for assessing effects of proposed changes in industrial facilities and large organizations. RPST follows a model-based approach that includes finite-capacity schedule analysis and discrete-event process simulation. A component-based, scalable, open architecture makes RPST easily and rapidly tailorable for diverse applications. Specific RPST functions include: (1) definition of analysis objectives and performance metrics; (2) selection of process templates from a processtemplate library; (3) configuration of process models for detailed simulation and schedule analysis; (4) design of operations- analysis experiments; (5) schedule and simulation-based process analysis; and (6) optimization of performance by use of genetic algorithms and simulated annealing. The main benefits afforded by RPST are provision of information that can be used to reduce costs of operation and maintenance, and the capability for affordable, accurate, and reliable prediction and exploration of the consequences of many alternative proposed decisions.

  3. Inflight IFR procedures simulator

    NASA Technical Reports Server (NTRS)

    Parker, L. C. (Inventor)

    1984-01-01

    An inflight IFR procedures simulator for generating signals and commands to conventional instruments provided in an airplane is described. The simulator includes a signal synthesizer which generates predetermined simulated signals corresponding to signals normally received from remote sources upon being activated. A computer is connected to the signal synthesizer and causes the signal synthesizer to produce simulated signals responsive to programs fed into the computer. A switching network is connected to the signal synthesizer, the antenna of the aircraft, and navigational instruments and communication devices for selectively connecting instruments and devices to the synthesizer and disconnecting the antenna from the navigational instruments and communication device. Pressure transducers are connected to the altimeter and speed indicator for supplying electrical signals to the computer indicating the altitude and speed of the aircraft. A compass is connected for supply electrical signals for the computer indicating the heading of the airplane. The computer upon receiving signals from the pressure transducer and compass, computes the signals that are fed to the signal synthesizer which, in turn, generates simulated navigational signals.

  4. Étude du bruit quantique dans les microlasers à semi-conducteurs à cavité verticale (VCSELs)

    NASA Astrophysics Data System (ADS)

    Maurin, I.; Hermier, J.-P.; Bramati, A.; Ducci, S.; Giacobino, E.; Kolobov, M.; Zelaquett Khoury, A.

    2002-06-01

    Nous étudions le bruit quantique dans les microlasers semi-conducteurs à cavité verticale. Ils émettent des faisceaux avec plusieurs modes transverses de polarisations variées. Lorsqu'un seul mode transverse, polarisé linéairement oscille, nous démontrons théoriquement et expérimentalement l'importance de l'émission dans la direction de polarisation orthogonale pour la caractérisation du bruit d'intensité. En régime multimode transverse, les anticorrélations sont importantes entre modes transverses, certains échantillons produisent des faisceaux au bruit d'intensité comprimé. Pour les échantillons présentant un excès de bruit, l'injection optique permet d'obtenir un bruit comprimé. Nous étudions également la structure spatiale du bruit d'intensité dans le plan transverse.

  5. Un exemple de transfert de technologie dans le domaine des polymères conducteurs : le projet ``HYRA"

    NASA Astrophysics Data System (ADS)

    Parneix, J. P.; Miane, J. L.; Colin, T.; Ruffie, G.; Mege, J.

    1998-06-01

    The HYRA project is a response to the restructuration of local companies : these are purveyors of high technology military and spatial especially in the radars business. Furthermore, the development of mobile communications needs devices and materials in the millimeter range (from 20 to 100Ghz). The aim of the HYRA project is the development of materials with specific properties - particularly conducting materials - in the millimeter wave range. The results obtained on thermoplastic/conducting polymer composites are presented. Le projet HYRA répond à des préoccupations régionales liées à des restructurations industrielles : les industries régionales fournissant les marchés militaires et spatiaux disposent de techniques très performantes mais coûteuses, en particulier dans le domaine des radars. Par ailleurs le développement des communications mobiles a besoin de dispositifs et de matériaux dans tout le domaine millimétrique (de 20 à 100 Ghz). Le projet HYRA a pour but le développement de matériaux à propriétés spécifiques - en particulier conducteurs - dans ce domaine de fréquence. Les résultats obtenus sur des composites thermoplastiques/polymères conducteurs sont présentés.

  6. Le syndrome de Vogt-Koyanagi Harada dans sa forme purement oculaire: à propos d'un cas

    PubMed Central

    Louaya, Shamil; Bennouk, Youssef; Kriet, Mohamed; Oubaaz, Abdelbarre

    2014-01-01

    Le syndrome de Vogt-Koyanagi-Harada (VKH) est une affection systémique rare, sévère mettant en jeu le pronostic visuel malgré les traitements agressifs, caractérisée par l'association de plusieurs symptômes: oculaires, méningés, auditifs et cutanés secondaire à une auto-immunisation où le mélanocyte serait la cellule cible. Nous rapportons un nouveau cas rare où l'atteinte oculaire est isolée. La sévérité de l'uvéite réside dans la fréquence des récidives, dans la cortico-résistance et dans la forte incidence des complications qui conditionnent le pronostic et expliquent les acuités visuelles finales médiocres. La prise en charge doit être précoce afin d'essayer d'améliorer le pronostic visuel. PMID:25667692

  7. Détermination des paramètres bioécologiques et entomologiques d’Anopheles gambiae sl dans la transmission du paludisme à Bandundu-ville, République Démocratique de Congo

    PubMed Central

    Matubi, Emery Metelo; Bukaka, Eric; Luemba, Trésor Bakambana; Situakibanza, Hyppolite; Sangaré, Ibrahim; Mesia, Gauthier; Ngoyi, Dieudonné Mumba; Maniania, Nguya Kalemba; Akikwa, Charles Ngandote; Kanza, Jean Pierre Basilua; Tamfum, Jean-Jacques Muyembe; sudi, Jonas Nagahuedi Bongo

    2015-01-01

    Introduction La présente étude a été menée à Bandundu-ville (RDC) en vue d'identifier les paramètres écologiques et entomologiques modulant la transmission du paludisme ainsi que leur tendance saisonnière dans cette agglomération. Méthodes Cette étude a été réalisée dans la période du 1er juin au 31 décembre 2011. Des prospections des gîtes larvaires d'anophèles avec récolte ont été réalisées, les paramètres physiques, physico-chimiques et environnementaux déterminés. La densité larvaire a été estimée selon une échelle de classes de densité, inspirée de la méthode de Carron pour chaque type de gîtes. Quarante-huit maisons ont été sélectionnées et prospectées pour la récolte des moustiques par pulvérisation intradomicilaire. L'identification des moustiques a été faite sur base des critères morphologiques de Gilles et Demeillon. L'Indice sporozoïtique (Is) a été déterminé par le test ELISA CSP de Plasmodium falciparum à l'Institut National de Recherche Biomédicale selon le protocole de Robert Wirtz. Les autres paramètres entomologiques comme la densité, le taux d'agressivité, le taux d'inoculation entomologique (TIE) ainsi que l'indice de stabilité ont été déterminés selon le protocole de l'OMS. La régression linéaire a été réalisée au seuil de signification de 0,05 pour identifier les déterminants de la densité larvaire. Résultats Cent-sept gîtes larvaires ont été identifiés et caractérisés en 5 types (digues et puits d'eau, collections d'eau maraîchère et concasseurs moellons, marais Régie de distribution d'eau, marais le long des rivières et ruisseaux et flaques d'eau de pluies). La densité larvaire moyenne a été de 117,4±64,1. Quatre mille cinq cents quatre-vingt-huit moustiques ont été capturés et identifiés, parmi lesquels 1.258 Anopheles gambiae sl avec une densité de 8,86, un taux d'agressivité de 1,55 piqûre par homme par nuit, l'Is de 5,6%, un TIE de 0,085 piq

  8. Simulator verification techniques study. Integrated simulator self test system concepts

    NASA Technical Reports Server (NTRS)

    Montoya, G.; Wenglinski, T. H.

    1974-01-01

    Software and hardware requirements for implementing hardware self tests are presented in support of the development of training and procedures development simulators for the space shuttle program. Self test techniques for simulation hardware and the validation of simulation performance are stipulated. The requirements of an integrated simulator self system are analyzed. Readiness tests, fault isolation tests, and incipient fault detection tests are covered.

  9. The Brian Simulator

    PubMed Central

    Goodman, Dan F. M.; Brette, Romain

    2009-01-01

    “Brian” is a simulator for spiking neural networks (http://www.briansimulator.org). The focus is on making the writing of simulation code as quick and easy as possible for the user, and on flexibility: new and non-standard models are no more difficult to define than standard ones. This allows scientists to spend more time on the details of their models, and less on their implementation. Neuron models are defined by writing differential equations in standard mathematical notation, facilitating scientific communication. Brian is written in the Python programming language, and uses vector-based computation to allow for efficient simulations. It is particularly useful for neuroscientific modelling at the systems level, and for teaching computational neuroscience. PMID:20011141

  10. VAWT stochastic wind simulator

    SciTech Connect

    Strickland, J.H.

    1987-04-01

    A stochastic wind simulation for VAWTs (VSTOC) has been developed which yields turbulent wind-velocity fluctuations for rotationally sampled points. This allows three-component wind-velocity fluctuations to be simulated at specified nodal points on the wind-turbine rotor. A first-order convection scheme is used which accounts for the decrease in streamwise velocity as the flow passes through the wind-turbine rotor. The VSTOC simulation is independent of the particular analytical technique used to predict the aerodynamic and performance characteristics of the turbine. The VSTOC subroutine may be used simply as a subroutine in a particular VAWT prediction code or it may be used as a subroutine in an independent processor. The independent processor is used to interact with a version of the VAWT prediction code which is segmented into deterministic and stochastic modules. Using VSTOC in this fashion is very efficient with regard to decreasing computer time for the overall calculation process.

  11. Computer simulation of earthquakes

    NASA Technical Reports Server (NTRS)

    Cohen, S. C.

    1977-01-01

    In a computer simulation study of earthquakes a seismically active strike slip fault is represented by coupled mechanical blocks which are driven by a moving plate and which slide on a friction surface. Elastic forces and time independent friction are used to generate main shock events, while viscoelastic forces and time dependent friction add aftershock features. The study reveals that the size, length, and time and place of event occurrence are strongly influenced by the magnitude and degree of homogeneity in the elastic, viscous, and friction parameters of the fault region. For example, periodically reoccurring similar events are observed in simulations with near-homogeneous parameters along the fault, whereas seismic gaps are a common feature of simulations employing large variations in the fault parameters. The study also reveals correlations between strain energy release and fault length and average displacement and between main shock and aftershock displacements.

  12. Simulated workplace neutron fields

    NASA Astrophysics Data System (ADS)

    Lacoste, V.; Taylor, G.; Röttger, S.

    2011-12-01

    The use of simulated workplace neutron fields, which aim at replicating radiation fields at practical workplaces, is an alternative solution for the calibration of neutron dosemeters. They offer more appropriate calibration coefficients when the mean fluence-to-dose equivalent conversion coefficients of the simulated and practical fields are comparable. Intensive Monte Carlo modelling work has become quite indispensable for the design and/or the characterization of the produced mixed neutron/photon fields, and the use of Bonner sphere systems and proton recoil spectrometers is also mandatory for a reliable experimental determination of the neutron fluence energy distribution over the whole energy range. The establishment of a calibration capability with a simulated workplace neutron field is not an easy task; to date only few facilities are available as standard calibration fields.

  13. Simulating solar MHD

    NASA Astrophysics Data System (ADS)

    Schüssler, M.

    1999-05-01

    Two aspects of solar MHD are discussed in relation to the work of the MHD simulation group at KIS. Photospheric magneto-convection, the nonlinear interaction of magnetic field and convection in a strongly stratified, radiating fluid, is a key process of general astrophysical relevance. Comprehensive numerical simulations including radiative transfer have significantly improved our understanding of the processes and have become an important tool for the interpretation of observational data. Examples of field intensification in the solar photosphere ('convective collapse') are shown. The second line of research is concerned with the dynamics of flux tubes in the convection zone, which has far-reaching implications for our understanding of the solar dynamo. Simulations indicate that the field strength in the region where the flux is stored before erupting to form sunspot groups is of the order of 105 G, an order of magnitude larger than previous estimates based on equipartition with the kinetic energy of convective flows.

  14. Simulation of Mission Phases

    NASA Technical Reports Server (NTRS)

    Carlstrom, Nicholas Mercury

    2016-01-01

    This position with the Simulation and Graphics Branch (ER7) at Johnson Space Center (JSC) provided an introduction to vehicle hardware, mission planning, and simulation design. ER7 supports engineering analysis and flight crew training by providing high-fidelity, real-time graphical simulations in the Systems Engineering Simulator (SES) lab. The primary project assigned by NASA mentor and SES lab manager, Meghan Daley, was to develop a graphical simulation of the rendezvous, proximity operations, and docking (RPOD) phases of flight. The simulation is to include a generic crew/cargo transportation vehicle and a target object in low-Earth orbit (LEO). Various capsule, winged, and lifting body vehicles as well as historical RPOD methods were evaluated during the project analysis phase. JSC core mission to support the International Space Station (ISS), Commercial Crew Program (CCP), and Human Space Flight (HSF) influenced the project specifications. The simulation is characterized as a 30 meter +V Bar and/or -R Bar approach to the target object's docking station. The ISS was selected as the target object and the international Low Impact Docking System (iLIDS) was selected as the docking mechanism. The location of the target object's docking station corresponds with the RPOD methods identified. The simulation design focuses on Guidance, Navigation, and Control (GNC) system architecture models with station keeping and telemetry data processing capabilities. The optical and inertial sensors, reaction control system thrusters, and the docking mechanism selected were based on CCP vehicle manufacturer's current and proposed technologies. A significant amount of independent study and tutorial completion was required for this project. Multiple primary source materials were accessed using the NASA Technical Report Server (NTRS) and reference textbooks were borrowed from the JSC Main Library and International Space Station Library. The Trick Simulation Environment and User

  15. Liquid filtration simulation

    SciTech Connect

    Corey, I.; Bergman, W.

    1996-06-01

    We have a developed a computer code that simulates 3-D filtration of suspended particles in fluids in realistic filter structures. This code, being the most advanced filtration simulation package developed to date, provides LLNL and DOE with new capabilities to address problems in cleaning liquid wastes, medical fluid cleaning, and recycling liquids. The code is an integrated system of commercially available and LLNL-developed software; the most critical are the computational fluid dynamics (CFD) solver and the particle transport program. For the CFD solver, we used a commercial package based on Navier-Stokes equations and a LLNL-developed package based on Boltzman-lattice gas equations. For the particle transport program, we developed a cod based on the 3-D Langevin equation of motion and the DLVO theory of electrical interactions. A number of additional supporting packages were purchased or developed to integrate the simulation tasks and to provide visualization output.

  16. Simulating Contact Binaries

    NASA Astrophysics Data System (ADS)

    Kadam, Kundan; Clayton, Geoffrey C.; Frank, Juhan; Tohline, Joel E.; Staff, Jan E.; Motl, Patrick M.; Marcello, Dominic

    2014-06-01

    About one in every 150 stars is a contact binary system of WUMa type and it was thought for a long time that such a binary would naturally proceed towards merger, forming a single star. In September 2008 such a merger was observed in the eruption of a “red nova", V1309 Sco. We are developing a hydrodynamics simulation for contact binaries using Self Consistent Field (SCF) techniques, so that their formation, structural, and merger properties could be studied. This model can also be used to probe the stability criteria such as the large-scale equatorial circulations and the minimum mass ratio. We also plan to generate light curves from the simulation data in order to compare with the observed case of V1309 Sco. A comparison between observations and simulations will help us better understand the nova-like phenomena of stellar mergers.

  17. Vehicle track loading simulation

    NASA Astrophysics Data System (ADS)

    Chalupa, Milan; Severa, Libor; Vlach, Radek

    2011-12-01

    The paper describes possible design of the vehicle track computational model and basic testing procedure of the track dynamic loading simulation. The proposed approach leads to an improvement of track vehicle course stability. The computational model is built for MSC. ADAMS, AVT computational simulating system. Model, which is intended for MSC computational system, is built from two basic parts. The first one is represented by geometrical part, while the second one by contact computational part of the model. The aim of the simulating calculation consist in determination of change influence of specific vehicle track constructive parameters on changes of examined qualities of the vehicle track link and changes of track vehicle course stability. The work quantifies the influence of changes of track preloading values on the demanded torque changes of driving sprocket. Further research possibilities and potential are also presented.

  18. Flight code validation simulator

    SciTech Connect

    Sims, B.A.

    1995-08-01

    An End-To-End Simulation capability for software development and validation of missile flight software on the actual embedded computer has been developed utilizing a 486 PC, i860 DSP coprocessor, embedded flight computer and custom dual port memory interface hardware. This system allows real-time interrupt driven embedded flight software development and checkout. The flight software runs in a Sandia Digital Airborne Computer (SANDAC) and reads and writes actual hardware sensor locations in which IMU (Inertial Measurements Unit) data resides. The simulator provides six degree of freedom real-time dynamic simulation, accurate real-time discrete sensor data and acts on commands and discretes from the flight computer. This system was utilized in the development and validation of the successful premier flight of the Digital Miniature Attitude Reference System (DMARS) in January 1995 at the White Sands Missile Range on a two stage attitude controlled sounding rocket.

  19. [Simulation of mental illness].

    PubMed

    Mastronardi, Vincenzo; Del Casale, Antonio

    2012-01-01

    The DSM-IV-TR defines the simulation an "intentional production of physical or psychological symptoms false or grossly exaggerated, motivated by external incentives". The first point to consider is that it has a near zero prevalence in the general population, occurring almost exclusively in people imprisoned, treated in Forensic Psychiatric Hospital, in individuals subjected to trial, or in personalities seen as deviated from a criminological point of view. Both the criteria to set diagnoses of simulation, previously examined by Foreal and Kaufman since 1943, and the relative suspicion indicators, not separated by 'reasons of simulated behavior, are taken into account. The work also addresses several other meanings of self injurious actions appointed by Bachler, as well as the associationist/mechanistic theories of the classical dynamic model and the differential diagnosis with other conditions of Psychiatric Interest and concludes with the topic of "Premeditation". PMID:23023120

  20. FASTBUS simulation tools

    SciTech Connect

    Dean, T.D. ); Haney, M.J. )

    1992-08-01

    In this paper a generalized model of a FASTBUS master is presented. The model is used with simulation tools to aid in the specification, design, and production of FASTBUS slave modules. The model provides a mechanism to interact with the electrical schematics and software models to predict performance. The model is written in the IEEE std 1076-1987 hardware description language VHDL. A model of the ATC logic is also presented. VHDL was chosen to provide portability to various platforms and simulation tools. The models, in conjunction with most commercially available simulators, will perform all of the transactions specified in IEEE std 960-1989. The models may be used to study the behavior of electrical schematics and other software models and detect violations of the FASTBUS protocol. For example, a hardware design of a slave module could be studied, protocol violations detected and corrected before committing money to prototype development.

  1. Robot graphic simulation testbed

    NASA Technical Reports Server (NTRS)

    Cook, George E.; Sztipanovits, Janos; Biegl, Csaba; Karsai, Gabor; Springfield, James F.

    1991-01-01

    The objective of this research was twofold. First, the basic capabilities of ROBOSIM (graphical simulation system) were improved and extended by taking advantage of advanced graphic workstation technology and artificial intelligence programming techniques. Second, the scope of the graphic simulation testbed was extended to include general problems of Space Station automation. Hardware support for 3-D graphics and high processing performance make high resolution solid modeling, collision detection, and simulation of structural dynamics computationally feasible. The Space Station is a complex system with many interacting subsystems. Design and testing of automation concepts demand modeling of the affected processes, their interactions, and that of the proposed control systems. The automation testbed was designed to facilitate studies in Space Station automation concepts.

  2. Constructive Engineering of Simulations

    NASA Technical Reports Server (NTRS)

    Snyder, Daniel R.; Barsness, Brendan

    2011-01-01

    Joint experimentation that investigates sensor optimization, re-tasking and management has far reaching implications for Department of Defense, Interagency and multinational partners. An adaption of traditional human in the loop (HITL) Modeling and Simulation (M&S) was one approach used to generate the findings necessary to derive and support these implications. Here an entity-based simulation was re-engineered to run on USJFCOM's High Performance Computer (HPC). The HPC was used to support the vast number of constructive runs necessary to produce statistically significant data in a timely manner. Then from the resulting sensitivity analysis, event designers blended the necessary visualization and decision making components into a synthetic environment for the HITL simulations trials. These trials focused on areas where human decision making had the greatest impact on the sensor investigations. Thus, this paper discusses how re-engineering existing M&S for constructive applications can positively influence the design of an associated HITL experiment.

  3. A generic multibody simulation

    NASA Technical Reports Server (NTRS)

    Hopping, K. A.; Kohn, W.

    1986-01-01

    Described is a dynamic simulation package which can be configured for orbital test scenarios involving multiple bodies. The rotational and translational state integration methods are selectable for each individual body and may be changed during a run if necessary. Characteristics of the bodies are determined by assigning components consisting of mass properties, forces, and moments, which are the outputs of user-defined environmental models. Generic model implementation is facilitated by a transformation processor which performs coordinate frame inversions. Transformations are defined in the initialization file as part of the simulation configuration. The simulation package includes an initialization processor, which consists of a command line preprocessor, a general purpose grammar, and a syntax scanner. These permit specifications of the bodies, their interrelationships, and their initial states in a format that is not dependent on a particular test scenario.

  4. Collisionless galaxy simulations

    NASA Technical Reports Server (NTRS)

    Hohl, F.; Zang, T. A.; Miller, J. B.

    1979-01-01

    Three-dimensional fully self-consistent computer models were used to determine the evolution of galaxies consisting of 100 000 simulation stars. Comparison of two-dimensional simulations with three-dimensional simulations showed only a very slight stabilizing effect due to the additional degree of freedom. The addition of a fully self-consistent, nonrotating, exponential core/halo component resulted in considerable stabilization. A second series of computer experiments was performed to determine the collapse and relaxation of initially spherical, uniform density and uniform velocity dispersion stellar systems. The evolution of the system was followed for various amounts of angular momentum in solid body rotation. For initally low values of the angular momentum satisfying the Ostriker-Peebles stability criterion, the systems quickly relax to an axisymmetric shape and resemble elliptical galaxies in appearance. For larger values of the initial angular momentum bars develop and the systems undergo a much more drastic evolution.

  5. Background illumination simulator

    SciTech Connect

    Towry, E.R.

    1992-05-12

    This patent describes a testing apparatus for testing and evaluating the performance of laser seeking warheads for missiles, under simulated weather conditions. It comprises support means for supporting a warhead seeker; laser means for generating a laser beam and for directing a laser beam towards the seeker; a diffusion screen interposed between the seeker support means and the laser means for diffusing the laser beam; a collimating lens interposed between the diffusion screen and the seeker support means for collimating the diffused laser beam and for directing the collimated laser beam onto a warhead seeker, supported in the seeker support; background illuminator means for illuminating the seeker support and a seeker disposed therein, supported for movement into and out of an operating position between the diffusion means and the collimating lens for providing background lighting in simulation of weather lighting conditions; and control means for controlling the intensity of the light provided by the illuminator means to simulate various weather conditions.

  6. Whipple bumper shield simulations

    SciTech Connect

    Hertel, E.S.; Chhabildas, L.C. ); Hill, S.A. . George C. Marshall Space Flight Center)

    1991-01-01

    The Whipple bumper is a space shield designed to protect a space station from the most hazardous orbital space debris environment. A series of numerical simulations has been performed using the multi-dimensional hydrodynamics code CTH to estimate the effectiveness of the thin Whipple bumper design. These simulations are performed for impact velocities of {approximately}10 km/s which are now accessible by experiments using the Sandia hypervelocity launcher facility. For a {approximately}10 km/s impact by a 0.7 gm aluminum flier plate, the experimental results indicate that the debris cloud resulting upon impact of the bumper shield by the flier plate, completely penetrates the sub-structure. The CTH simulations also predict complete penetration by the subsequent debris cloud. 5 refs., 4 figs., 2 tabs.

  7. Simple Electric Vehicle Simulation

    Energy Science and Technology Software Center (ESTSC)

    1993-07-29

    SIMPLEV2.0 is an electric vehicle simulation code which can be used with any IBM compatible personal computer. This general purpose simulation program is useful for performing parametric studies of electric and series hybrid electric vehicle performance on user input driving cycles.. The program is run interactively and guides the user through all of the necessary inputs. Driveline components and the traction battery are described and defined by ASCII files which may be customized by themore » user. Scaling of these components is also possible. Detailed simulation results are plotted on the PC monitor and may also be printed on a printer attached to the PC.« less

  8. Real time digital propulsion system simulation for manned flight simulators

    NASA Technical Reports Server (NTRS)

    Mihaloew, J. R.; Hart, C. E.

    1978-01-01

    A real time digital simulation of a STOL propulsion system was developed which generates significant dynamics and internal variables needed to evaluate system performance and aircraft interactions using manned flight simulators. The simulation ran at a real-to-execution time ratio of 8.8. The model was used in a piloted NASA flight simulator program to evaluate the simulation technique and the propulsion system digital control. The simulation is described and results shown. Limited results of the flight simulation program are also presented.

  9. Simulation verification techniques study. Subsystem simulation validation techniques

    NASA Technical Reports Server (NTRS)

    Duncan, L. M.; Reddell, J. P.; Schoonmaker, P. B.

    1974-01-01

    Techniques for validation of software modules which simulate spacecraft onboard systems are discussed. An overview of the simulation software hierarchy for a shuttle mission simulator is provided. A set of guidelines for the identification of subsystem/module performance parameters and critical performance parameters are presented. Various sources of reference data to serve as standards of performance for simulation validation are identified. Environment, crew station, vehicle configuration, and vehicle dynamics simulation software are briefly discussed from the point of view of their interfaces with subsystem simulation modules. A detailed presentation of results in the area of vehicle subsystems simulation modules is included. A list of references, conclusions and recommendations are also given.

  10. Probabilistic Fatigue: Computational Simulation

    NASA Technical Reports Server (NTRS)

    Chamis, Christos C.

    2002-01-01

    Fatigue is a primary consideration in the design of aerospace structures for long term durability and reliability. There are several types of fatigue that must be considered in the design. These include low cycle, high cycle, combined for different cyclic loading conditions - for example, mechanical, thermal, erosion, etc. The traditional approach to evaluate fatigue has been to conduct many tests in the various service-environment conditions that the component will be subjected to in a specific design. This approach is reasonable and robust for that specific design. However, it is time consuming, costly and needs to be repeated for designs in different operating conditions in general. Recent research has demonstrated that fatigue of structural components/structures can be evaluated by computational simulation based on a novel paradigm. Main features in this novel paradigm are progressive telescoping scale mechanics, progressive scale substructuring and progressive structural fracture, encompassed with probabilistic simulation. These generic features of this approach are to probabilistically telescope scale local material point damage all the way up to the structural component and to probabilistically scale decompose structural loads and boundary conditions all the way down to material point. Additional features include a multifactor interaction model that probabilistically describes material properties evolution, any changes due to various cyclic load and other mutually interacting effects. The objective of the proposed paper is to describe this novel paradigm of computational simulation and present typical fatigue results for structural components. Additionally, advantages, versatility and inclusiveness of computational simulation versus testing are discussed. Guidelines for complementing simulated results with strategic testing are outlined. Typical results are shown for computational simulation of fatigue in metallic composite structures to demonstrate the

  11. CAPS Simulation Environment Development

    NASA Technical Reports Server (NTRS)

    Murphy, Douglas G.; Hoffman, James A.

    2005-01-01

    The final design for an effective Comet/Asteroid Protection System (CAPS) will likely come after a number of competing designs have been simulated and evaluated. Because of the large number of design parameters involved in a system capable of detecting an object, accurately determining its orbit, and diverting the impact threat, a comprehensive simulation environment will be an extremely valuable tool for the CAPS designers. A successful simulation/design tool will aid the user in identifying the critical parameters in the system and eventually allow for automatic optimization of the design once the relationships of the key parameters are understood. A CAPS configuration will consist of space-based detectors whose purpose is to scan the celestial sphere in search of objects likely to make a close approach to Earth and to determine with the greatest possible accuracy the orbits of those objects. Other components of a CAPS configuration may include systems for modifying the orbits of approaching objects, either for the purpose of preventing a collision or for positioning the object into an orbit where it can be studied or used as a mineral resource. The Synergistic Engineering Environment (SEE) is a space-systems design, evaluation, and visualization software tool being leveraged to simulate these aspects of the CAPS study. The long-term goal of the SEE is to provide capabilities to allow the user to build and compare various CAPS designs by running end-to-end simulations that encompass the scanning phase, the orbit determination phase, and the orbit modification phase of a given scenario. Herein, a brief description of the expected simulation phases is provided, the current status and available features of the SEE software system is reported, and examples are shown of how the system is used to build and evaluate a CAPS detection design. Conclusions and the roadmap for future development of the SEE are also presented.

  12. LSST Operations Simulator

    NASA Astrophysics Data System (ADS)

    Cook, K. H.; Delgado, F.; Miller, M.; Saha, A.; Allsman, R.; Pinto, P.; Gee, P. A.

    2005-12-01

    We have developed an operations simulator for LSST and used it to explore design and operations parameter space for this large etendue telescope and its ten year survey mission. The design is modular, with separate science programs coded in separate modules. There is a sophisticated telescope module with all motions parametrized for ease of testing different telescope capabilities, e.g. effect of acceleration capabilities of various motors on science output. Sky brightness is calculated as a function of moon phase and separation. A sophisticated exposure time calculator has been developed for LSST which is being incorporated into the simulator to allow specification of S/N requirements. All important parameters for the telescope, the site and the science programs are easily accessible in configuration files. Seeing and cloud data from the three candidate LSST sites are used for our simulations. The simulator has two broad categories of science proposals: sky coverage and transient events. Sky coverage proposals base their observing priorities on a required number of observations for each field in a particular filter with specified conditions (maximum seeing, sky brightness, etc) and one is used for a weak lensing investigation. Transient proposals are highly configurable. A transient proposal can require sequential, multiple exposures in various filters with a specified sequence of filters, and require a particular cadence for multiple revisits to complete an observation sequence. Each science proposal ranks potential observations based upon the internal logic of that proposal. We present the results of a variety of mixed science program observing simulations, showing how varied programs can be carried out simultaneously, with many observations serving multiple science goals. The simulator has shown that LSST can carry out its multiple missions under a variety of conditions. KHC's work was performed under the auspices of the US DOE, NNSA by the Univ. of California

  13. Hydrogen and chlorine abundances in the Kimberley formation of Gale crater measured by the DAN instrument on board the Mars Science Laboratory Curiosity rover

    NASA Astrophysics Data System (ADS)

    Litvak, M. L.; Mitrofanov, I. G.; Hardgrove, C.; Stack, K. M.; Sanin, A. B.; Lisov, D.; Boynton, W. V.; Fedosov, F.; Golovin, D.; Harshman, K.; Jun, I.; Kozyrev, A. S.; Kuzmin, R. O.; Malakhov, A.; Milliken, R.; Mischna, M.; Moersch, J.; Mokrousov, M.; Nikiforov, S.; Starr, R.; Tate, C.; Tret'yakov, V. I.; Vostrukhin, A.

    2016-05-01

    The Dynamic Albedo of Neutron (DAN) instrument on board the Mars Science Laboratory Curiosity rover acquired a series of measurements as part of an observational campaign of the Kimberley area in Gale crater. These observations were planned to assess the variability of bulk hydrogen and neutron-absorbing elements, characterized as chlorine-equivalent concentration, in the geologic members of the Kimberley formation and in surface materials exposed throughout the area. During the traverse of the Kimberley area, Curiosity drove primarily over the "Smooth Hummocky" unit, a unit composed primarily of sand and loose rocks, with occasional stops at bedrock of the Kimberley formation. During the Kimberley campaign, DAN detected ranges of water equivalent hydrogen (WEH) and chlorine-equivalent concentrations of 1.5-2.5 wt % and 0.6-2 wt %, respectively. Results show that as the traverse progressed, DAN observed an overall decrease in both WEH and chlorine-equivalent concentration measured over the sand and loose rocks of the Smooth Hummocky unit. DAN measurements of WEH and chlorine-equivalent concentrations in the well-exposed sedimentary bedrock of the Kimberley formation show fluctuations with stratigraphic position. The Kimberley campaign also provided an opportunity to compare measurements from DAN with those from the Sample Analysis at Mars (SAM) and the Alpha-Particle X-ray Spectrometer (APXS) instruments. DAN measurements obtained near the Windjana drill location show a WEH concentration of ~1.5 wt %, consistent with the concentration of low-temperature absorbed water measured by SAM for the Windjana drill sample. A comparison between DAN chlorine-equivalent concentrations measured throughout the Kimberley area and APXS observations of corresponding local surface targets and drill fines shows general agreement between the two instruments.

  14. Mesoscopic simulations of Nitromethane

    NASA Astrophysics Data System (ADS)

    Maillet, Jean-Bernard; Bourasseau, Emeric; Desbiens, Nicolas; Stoltz, Gabriel

    2011-06-01

    We present recent developments of the Dissipative Particle Model that allow simulating the physico-chemical behavior of a molecular material at the mesoscale level. Several ingredients have been added to the previous model (see JB Maillet, L. Soulard and G. Stoltz, Europhys. Lett., 78, 68001 (2007)), in particular concerning the intermolecular force field and the contributions of the internal degrees of freedom. Multiple steps chemistry is handled through the use of additional degrees of freedom. This model is applied to micron scale simulations of nitromethane, both at equilibrium and under shock conditions.

  15. Financing a Simulation Center.

    PubMed

    Tsuda, Shawn; Mohsin, Adnan; Jones, Daniel

    2015-08-01

    As simulation-based training has become established within medical and health professional disciplines, skills training laboratories have become a standard in surgery training programs. In 2008, the American College of Surgeons and Association of Program Directors in Surgery developed a simulation-based surgical skills curriculum; the Residency Review Committee for Surgery of the Accreditation Council for Graduate Medical Education mandated access to skills laboratories for all surgery programs. Establishing a surgical skills laboratory and adapting the training curriculum requires a significant amount of resources. This article discusses the financial aspects of establishing a training center, from funding opportunities to budgeting considerations. PMID:26210971

  16. Wellbore simulation - case studies

    SciTech Connect

    Freeston, Derek; Gunn, Calum

    1993-01-28

    The use of a wellbore simulator, WELLSIM, to characterise the effects of multi-feed inflow on wellbore pressure-temperature characteristics, and diameter changes to a well on the deliverability curve, is discussed. Matching analyses are performed with the simulator on a well which has a number of two-phase and liquid infeeds, and it is demonstrated that good matches to both pressure and temperature profiles can be achieved. The significance of the reservoir/feed response curve for a steam well is illustrated, and the optimisation of wellbore diameter is shown to be related to whether the discharge is wellbore or reservoir controlled.

  17. Visual simulation of radiographs

    SciTech Connect

    Laguna, G.

    1985-01-18

    A method for computer simulation of radiographs has been added to the LLNL version of the solid modeler TIPS-1 (Technical Information Processing System-1). This new tool will enable an engineer to compare an actual radiograph of a solid to its computer-generated counterpart. The appearance of discrepancies between the two can be an indication of flaws in the solid object. Simulated radiographs can also be used to preview the placement of x-ray sources to focus on areas of concern before actual radiographs are made.

  18. Emotional Intelligence and Simulation.

    PubMed

    McKinley, Sophia K; Phitayakorn, Roy

    2015-08-01

    Emotional intelligence (EI) is an established concept in the business literature with evidence that it is an important factor in determining career achievement. There is increasing interest in the role that EI has in medical training, but it is still a nascent field. This article reviews the EI literature most relevant to surgical training and proposes that simulation offers many benefits to the development of EI. Although there are many unanswered questions, it is expected that future research will demonstrate the effectiveness of using simulation to develop EI within surgery. PMID:26210976

  19. Terascale Optimal PDE Simulations

    SciTech Connect

    David Keyes

    2009-07-28

    The Terascale Optimal PDE Solvers (TOPS) Integrated Software Infrastructure Center (ISIC) was created to develop and implement algorithms and support scientific investigations performed by DOE-sponsored researchers. These simulations often involve the solution of partial differential equations (PDEs) on terascale computers. The TOPS Center researched, developed and deployed an integrated toolkit of open-source, optimal complexity solvers for the nonlinear partial differential equations that arise in many DOE application areas, including fusion, accelerator design, global climate change and reactive chemistry. The algorithms created as part of this project were also designed to reduce current computational bottlenecks by orders of magnitude on terascale computers, enabling scientific simulation on a scale heretofore impossible.

  20. Tether Dynamics Simulation

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The proceedings of the conference are presented. The objective was to provide a forum for the discussion of the structure and status of existing computer programs which are used to simulate the dynamics of a variety of tether applications in space. A major topic was different simulation models and the process of validating them. Guidance on future work in these areas was obtained from a panel discussion; the panel was composed of resource and technical managers and dynamic analysts in the tether field. The conclusions of this panel are also presented.

  1. Faster simulation plots

    NASA Technical Reports Server (NTRS)

    Fowell, Richard A.

    1989-01-01

    Most simulation plots are heavily oversampled. Ignoring unnecessary data points dramatically reduces plot time with imperceptible effect on quality. The technique is suited to most plot devices. The departments laser printer's speed was tripled for large simulation plots by data thinning. This reduced printer delays without the expense of a faster laser printer. Surpisingly, it saved computer time as well. All plot data are now thinned, including PostScript and terminal plots. The problem, solution, and conclusions are described. The thinning algorithm is described and performance studies are presented. To obtain FORTRAN 77 or C source listings, mail a SASE to the author.

  2. Dynamic load simulator

    NASA Technical Reports Server (NTRS)

    Joncas, K. P.

    1972-01-01

    Concepts and techniques for identifying and simulating both the steady state and dynamic characteristics of electrical loads for use during integrated system test and evaluation are discussed. The investigations showed that it is feasible to design and develop interrogation and simulation equipment to perform the desired functions. During the evaluation, actual spacecraft loads were interrogated by stimulating the loads with their normal input voltage and measuring the resultant voltage and current time histories. Elements of the circuits were optimized by an iterative process of selecting element values and comparing the time-domain response of the model with those obtained from the real equipment during interrogation.

  3. Logic Simulator Program

    NASA Technical Reports Server (NTRS)

    Agarwal, R. K.

    1983-01-01

    The source code for the SPICE 2 program was deblocked in order to isolate and compile the subroutine in an effort to provide a software simulation of discrete and combinatorial electronic components. Incompatibilities between the UNIVAC 1180 FORTRAN and the Sigma V CP-V FORTRAN 4 were resolved. The SPICE 2 model is to be used to determine gate and fan-out delays, logic state conditions, and signal race conditions for transistor array elements and circuit logic to be patterned in the (SPI) 7101 CMOS silicon gate semicustom array. The simulator is to be operable from the CP-V time sharing terminals.

  4. Apport de la biopsie radioguidée dans le diagnostic histopathologique des tumeurs de l'enfant: expérience de l'Hôpital d'Enfant de Rabat

    PubMed Central

    El Ochi, Mohamed Réda; Bellarbi, Salma; Rouas, Lamiae; Lamalmi, Najat; Malihy, Abderrahmane; Alhamany, Zaitouna; Cherradi, Nadia

    2015-01-01

    La biopsie radioguidée constitue une alternative à la biopsie chirurgicale invasive et à la cytologie pour le diagnostic des tumeurs pédiatriques. L'intérêt de notre étude est d’évaluer la valeur diagnostique des biopsies radioguidées examinées au laboratoire d'anatomopathologie de l'hôpital d'Enfants de Rabat (HER). L’étude a porté sur 78 biopsies radioguidées recueillies dans notre laboratoire entre janvier 2008 et décembre 2011. l’âge moyen des patients était de 5 ans et 10 mois avec une prédominance masculine (65,4%). La tumeur était abdominale dans 80% des cas, thoracique dans 15% cas, thoracique et abdominale dans 2,5% et sacrée dans 1,2%. Les biopsies étaient écho-guidées dans 90% des cas et scannoguidées dans 10% des cas. Le diagnostic histopathologique était posé dans 89% des cas. L'immuno-histochimie a été indiquée dans 35% des cas. Les diagnostics les plus fréquents étaient: tumeurs neuroblastiques (42 cas), lymphomes non hodgkiniens (10 cas), rhabdomyosarcomes (6 cas), autres (sarcome d'Ewing, néphroblastomes, tumeur myofibroblastique inflammatoire, maladies de Hodgkin, leucémie aiguë, hépatoblastome et ostéosarcome). Dans notre série, la biopsie radioguidée a permis un diagnostic histopathologique certain dans 89% des cas. Elle nécessite une étroite collaboration entre clinicien, radiologue et anatomopathologiste pour discuter son indication, afin de diminuer le nombre de biopsies peu ou non représentatives. PMID:26587165

  5. The Boltysh crater record of rapid vegetation change during the Dan-C2 hyperthermal event.

    NASA Astrophysics Data System (ADS)

    Jolley, D. W.; Daly, R.; Gilmour, I.; Gilmour, M.; Kelley, S. P.

    2012-04-01

    Analysis of a cored borehole drilled through the sedimentary fill of the 24km wide Boltysh meteorite crater, Ukraine has yielded a unique, high resolution record spanning <1my of Early Paleocene terrestrial environmental change. While the oldest crater fill sediments preserve a record of the K/Pg boundary, overlying sediments preserve a record through the earliest Danian Dan-C2 hyperthermal event. This event is preserved in ~220m of lacustrine organic mudrocks and shows close similarities to the carbon isotope records of the Toarcian and PETM CIE's. At Boltysh, the rapid sedimentation rate and lack of bioturbation in the crater fill lacustrine deposits preserve uniquely high resolution pollen, spore and algae records. These records reflect environmental change from the K/Pg1 to the post Dan-C2 Danian. Leading into the CIE, warm temperate gymnosperm - angiosperm - fern communities are replaced by precipitation limited (winterwet) plant communities within the negative CIE. Winterwet plant communities dominate the negative CIE, but are replaced within the isotope recovery stage by warm temperate floras. These in turn give way to cooler temperate floras in the post positive CIE section of the uppermost crater fill. The distribution of temperate taxa about the negative CIE represents the broadest scale of oscillatory variation in the palynofloras. Shorter frequency oscillations are evident from diversity and botanical group distributions reflecting changes in moisture availability over several thousand years. Detailed analysis of variability within one of these oscillations records plant community cyclicity across the inception of the negative CIE. This short term cyclicity provides evidence that the replacement of warm termperate by winterwet floras occurred in a stepwise manner at the negative CIE suggesting cumulative atmospheric forcing. At <1mm scale, lamination within the negative CIE showed no obvious lithological or colour differences, and are not seasonal

  6. Lake evolution during the Early Danian Dan-C2 hyperthermal, Boltysh impact crater, Ukraine

    NASA Astrophysics Data System (ADS)

    Ebinghaus, Alena; Jolley, David W.

    2016-04-01

    Lacustrine facies record complex relationships between lake evolution and environmental conditions and provide proxies for climate changes. However, lacustrine successions formed during past hyperthermals as recorded from negative carbon isotope excursions (CIEs) are of limited availability and thus less well understood. Here, we present a complete lacustrine record of the Early Danian Dan-C2 hyperthermal at c. 65.2 Ma from a core drilled in the K-Pg Boltysh impact crater, Ukraine. This borehole allows a detailed facies analysis and reconstruction of lake evolution and associated plant ecosystem in correspondence with rapid climate change. The Boltysh borehole reveals a c. 400 m thick siliciclastic and organic-rich succession overlying impact melt-breccia dated at 65.17 ± 0.64 Ma. Based on detailed core logging, 8 distinctive facies associations are identified, including 1) littoral mudstones, 2) siliciclastic shoreline deposits, 3) siliciclastic littoral to sublittoral deposits, 4) mudstone laminites, 5) organic-rich mudstones, and deposits of 6) coarse-grained, 7) fine-grained density currents, and 8) debris flows. Based on the occurrence of these facies associations 3 major phases of lake evolution are distinguished: 1) an initial pre-CIE rising clastic-dominated lake phase characterised by the presence of coarse-grained density and debris flow deposits, 2) an organic-rich fluctuating shallow lake phase during the main phase of the CIE, characterised by alternating packages of the mudstone laminites and organic-rich mudstones; and 3) a rising clastic-dominated lake during and post-CIE recovery phase, which shows a high presence of siliciclastic shoreline and littoral to sublittoral deposits. This study provides a full record of lacustrine response to climate change during the Dan-C2 hyperthermal, and subsequently allows us to infer lake formation and environmental conditions at different stages during climate warming. The high resolution sedimentary record

  7. Milankovitch Forcing in Equatorial, Late Triassic Pangea: (Deep River; Dan River, and Richmond Basins, Southeastern USA)

    NASA Astrophysics Data System (ADS)

    Olsen, P. E.; Kent, D. V.; Letourneau, P. M.

    2003-12-01

    The Milankovitch character of lake level fluctuations in the tropics of central Pangea has been well established since the pioneering work of Van Houten in the 1960's (1) that laid the foundation for quantitative analysis of core and outcrops in the 1990's (2,3). In the region from about 3° to 10° N latitude giant rift lakes fluctuated to the classic Milankovitch frequencies of precessional forcing of ~20, 96, 128, and 404 ky, as well as the less well known 1.75 and 3.5 m.y. cycles. The latter are the Triassic values for the periods of g4-g3 of eccentricity related precessional forcing and the secular resonance, theta (2(g4- g3) - (s4-s3)), of precessional and obliquity related forcing. We attribute the forcing of lake depth largely to modulation of the strength of tropical convergence. Late Triassic rifts located from 0° to 3° N latitude show similar patterns, except with a strong tendency towards a doubling of the climatic precessional frequency and a lack of evaporites as previously reported from the Dan River basin (4,5,6). Here we report on new analyses of coal-bearing cores and drill holes from the Deep River, Dan River, and Richmond basin of older Late Triassic lacustrine strata that reinforce this pattern but show that the doubling of the precessional frequency is not ubiquitous at the equator and also show that very strong climatic transitions appear related to the 1.75 and 3.5 m.y. cycles juxtaposing coals and caliches in vertical sequence and sometimes coinciding with major faunal and floral transitions. (1) Van Houten FB. 1964. Kansas Geol. Surv. Bull. 169:497. (2) Olsen PE & Kent DV. 1996. Palaeogeo. Palaeoclim. Palaeoecol. 122:1-26. (3) Olsen PE & Kent DV. 1999. Phil. Trans. Roy. Soc. Lond. (A) 357:1761-1787. (4) Olsen PE & Kent DV.1996. Eos, Trans., AGU 77(46), Suppl.:301. (5) Olsen PE. 1997. Ann. Rev. Earth Planet. Sci. 25:337-401. (6) Olsen PE & Kent DV. 2000. in Bachmann G. and Lerche I. (eds.), Epicontinental Triassic, Vol. 3, Zent. Geol

  8. L'observance thérapeutique dans les dermatoses chroniques: à propos de 200 cas

    PubMed Central

    Amraoui, Nissrine; Gallouj, Salim; Berraho, Mohamed Amine; Najjari, Chakib; Mernissi, Fatima zohra

    2015-01-01

    Introduction L'observance thérapeutique est la capacité à prendre correctement son traitement, tel qu'il est prescrit par le médecin. Elle est peu étudiée en dermatologie. Méthodes Le but de notre étude est d’évaluer l'observance chez les patients suivis au service de dermatologie du Centre Hospitalier Universitaire Hassan II de Fès pour une dermatose chronique et de rechercher les facteurs liés à une mauvaise observance à travers une étude incluant 200 patients suivis depuis au moins 6 mois. L’évaluation de l'observance s'est faite essentiellement à l'aide d'un entretien et les facteurs liés à l'observance ont été recherchés par un questionnaire. Résultats 68% de nos patients étaient observant, la mauvaise observance était associée à un niveau socio économique et d’étude bas, à une vie solitaire, à une durée de suivi longue, aux effets secondaires et au coût élevé des traitements, à l'absence d'efficacité, à une faible visibilité des lésions, à une ordonnance complexe, à une explication faible de la maladie, et à des difficultés d'accès à la consultation. Le taux d'observance retrouvé dans notre étude est un taux satisfaisant selon les données de la littérature, notre étude a confirmée certaines facteurs connues et a mis le point sur d'autres facteurs peu étudiés tel un traitement traditionnel associé, la part de chaque forme de traitement dans le respect de l'ordonnance, les dermatoses les plus touchées par les difficulté d'observance a savoir les dermatoses bulleuses et le psoriasis, et l'intérêt du pharmacien. Conclusion Cette analyse de la fréquence de ce phénomène et des facteurs essentiels qui l'influencent permet de cibler la prise en charge à travers une personnalisation de l'entretien médical, une adaptation du suivi au contexte de nos patients et à la nature de notre institution de santé. PMID:26848363

  9. Heat simulation via Scilab programming

    NASA Astrophysics Data System (ADS)

    Hasan, Mohammad Khatim; Sulaiman, Jumat; Karim, Samsul Arifin Abdul

    2014-07-01

    This paper discussed the used of an open source sofware called Scilab to develop a heat simulator. In this paper, heat equation was used to simulate heat behavior in an object. The simulator was developed using finite difference method. Numerical experiment output show that Scilab can produce a good heat behavior simulation with marvellous visual output with only developing simple computer code.

  10. Simulating neural systems with Xyce.

    SciTech Connect

    Schiek, Richard Louis; Thornquist, Heidi K.; Mei, Ting; Warrender, Christina E.; Aimone, James Bradley; Teeter, Corinne; Duda, Alex M.

    2012-12-01

    Sandia's parallel circuit simulator, Xyce, can address large scale neuron simulations in a new way extending the range within which one can perform high-fidelity, multi-compartment neuron simulations. This report documents the implementation of neuron devices in Xyce, their use in simulation and analysis of neuron systems.

  11. Simulation in International Relations Education.

    ERIC Educational Resources Information Center

    Starkey, Brigid A.; Blake, Elizabeth L.

    2001-01-01

    Discusses the educational implications of simulations in international relations. Highlights include the development of international relations simulations; the role of technology; the International Communication and Negotiation Simulations (ICONS) project at the University of Maryland; evolving information technology; and simulating real-world…

  12. Trajectory constraints in qualitative simulation

    SciTech Connect

    Brajnik, G.; Clancy, D.J.

    1996-12-31

    We present a method for specifying temporal constraints on trajectories of dynamical systems and enforcing them during qualitative simulation. This capability can be used to focus a simulation, simulate non-autonomous and piecewise-continuous systems, reason about boundary condition problems and incorporate observations into the simulation. The method has been implemented in TeQSIM, a qualitative simulator that combines the expressive power of qualitative differential equations with temporal logic. It interleaves temporal logic model checking with the simulation to constrain and refine the resulting predicted behaviors and to inject discontinuous changes into the simulation.

  13. Simulations of laser thrombolysis

    SciTech Connect

    Chapyak, E.J.; Godwin, R.P.

    1999-03-01

    The authors have shown that bubble expansion and collapse near the interface between two materials with modest property differences produces jet-like interpenetration of the two materials. The bubble dynamics at a water-viscous fluid interface is compared with that at the interface of water with a weak elastic-plastic material. The authors find that, despite rather similar behavior during bubble growth and the initial portion of bubble collapse, the terminal jetting behavior is quite different, even in direction. The elastic-plastic properties chosen realistically represent real and surrogate thrombus. Simulations using the elastic-plastic model quantitatively agree with laboratory thrombolysis mass removal experiments. In the earlier simulations of laboratory experiments, walls have been remote so as to not effect the dynamics. Here the authors present two-dimensional simulations of thrombolysis with water over elastic-plastic surrogate thrombus in a geometry representative of the clinical situation. The calculations include thin cylindrical elastic walls with properties and dimensions appropriate for arteries. The presence of these artery walls does not substantially change the interface jetting predicted in unconfined simulations.

  14. Satellite Hyperspectral Imaging Simulation

    NASA Technical Reports Server (NTRS)

    Zanoni, Vicki; Stanley, Tom; Blonski, Slawomir; Cao, Changyong; Gasser, Jerry; Ryan, Robert

    1999-01-01

    Simulation of generic pushbroom satellite hyperspectral sensors have been performed to evaluate the potential performance and validation techniques for satellite systems such as COIS(NEMO), Warfighter-1(OrbView-4) and Hyperion(EO-1). The simulations start with a generation of synthetic scenes from material maps of studied terrain. Scene-reflected radiance is corrected for atmospheric effects and convolved with sensor spectral response using MODTRAN 4 radiance and transmissions calculations. Scene images are further convolved with point spread functions derived from Optical Transfer Functions (OTF's) of the sensor system. Photon noise and etectorr/electronics noise are added to the simulated images, which are also finally quantized to the sensor bit resolution. Studied scenes include bridges and straight roads used for evaluation of sensor spatial resolution, as well as fields of minerals, vegetation and manmade materials used for evaluation of sensor radiometric response and sensitivity. The scenes are simulated with various seasons and weather conditions. Signal-to-noise ratios and expected performance are estimated for typical satellite system specifications and are discussed for all the scenes.

  15. Numerical Propulsion System Simulation

    NASA Technical Reports Server (NTRS)

    Naiman, Cynthia

    2006-01-01

    The NASA Glenn Research Center, in partnership with the aerospace industry, other government agencies, and academia, is leading the effort to develop an advanced multidisciplinary analysis environment for aerospace propulsion systems called the Numerical Propulsion System Simulation (NPSS). NPSS is a framework for performing analysis of complex systems. The initial development of NPSS focused on the analysis and design of airbreathing aircraft engines, but the resulting NPSS framework may be applied to any system, for example: aerospace, rockets, hypersonics, power and propulsion, fuel cells, ground based power, and even human system modeling. NPSS provides increased flexibility for the user, which reduces the total development time and cost. It is currently being extended to support the NASA Aeronautics Research Mission Directorate Fundamental Aeronautics Program and the Advanced Virtual Engine Test Cell (AVETeC). NPSS focuses on the integration of multiple disciplines such as aerodynamics, structure, and heat transfer with numerical zooming on component codes. Zooming is the coupling of analyses at various levels of detail. NPSS development includes capabilities to facilitate collaborative engineering. The NPSS will provide improved tools to develop custom components and to use capability for zooming to higher fidelity codes, coupling to multidiscipline codes, transmitting secure data, and distributing simulations across different platforms. These powerful capabilities extend NPSS from a zero-dimensional simulation tool to a multi-fidelity, multidiscipline system-level simulation tool for the full development life cycle.

  16. FASTBUS simulation tools

    SciTech Connect

    Dean, T.D. ); Haney, M.J. )

    1991-10-01

    A generalized model of a FASTBUS master is presented. The model is used with simulation tools to aid in the specification, design, and production of FASTBUS slave modules. The model provides a mechanism to interact with the electrical schematics and software models to predict performance. The model is written in the IEEE std 1076-1987 hardware description language VHDL. A model of the ATC logic is also presented. VHDL was chosen to provide portability to various platforms and simulation tools. The models, in conjunction with most commercially available simulators, will perform all of the transactions specified in IEEE std 960-1989. The models may be used to study the behavior of electrical schematics and other software models and detect violations of the FASTBUS protocol. For example, a hardware design of a slave module could be studied, protocol violations detected and corrected before committing money to prototype development. The master model accepts a stream of high level commands from an ASCII file to initiate FASTBUS transactions. The high level command language is based on the FASTBUS standard routines listed in IEEE std 1177-1989. Using this standard-based command language to direct the model of the master, hardware engineers can simulate FASTBUS transactions in the language used by physicists and programmers to operate FASTBUS systems. 15 refs., 6 figs.

  17. Human Simulated Diving Experiments.

    ERIC Educational Resources Information Center

    Bruce, David S.; Speck, Dexter F.

    1979-01-01

    This report details several simulated divinq experiments on the human. These are suitable for undergraduate or graduate laboratories in human or environmental physiology. The experiment demonstrates that a diving reflex is precipitated by both facial cooling and apnea. (Author/RE)

  18. GSFC Venus atmosphere simulator

    NASA Technical Reports Server (NTRS)

    Cridlin, M. S.; Munford, J. A.

    1974-01-01

    The design and preliminary testing of a Venus Atmosphere Simulation System are described. The system was designed for testing a quadrupole mass spectrometer proposed for the Pioneer-Venus Experiment. The system is capable of providing programmed temperature cycles up to 550 C, and manually controlled pressure up to 100 atmospheres.

  19. Computer simulation of earthquakes

    NASA Technical Reports Server (NTRS)

    Cohen, S. C.

    1976-01-01

    Two computer simulation models of earthquakes were studied for the dependence of the pattern of events on the model assumptions and input parameters. Both models represent the seismically active region by mechanical blocks which are connected to one another and to a driving plate. The blocks slide on a friction surface. In the first model elastic forces were employed and time independent friction to simulate main shock events. The size, length, and time and place of event occurrence were influenced strongly by the magnitude and degree of homogeniety in the elastic and friction parameters of the fault region. Periodically reoccurring similar events were frequently observed in simulations with near homogeneous parameters along the fault, whereas, seismic gaps were a common feature of simulations employing large variations in the fault parameters. The second model incorporated viscoelastic forces and time-dependent friction to account for aftershock sequences. The periods between aftershock events increased with time and the aftershock region was confined to that which moved in the main event.

  20. Data Systems Dynamic Simulator

    NASA Technical Reports Server (NTRS)

    Rouff, Christopher; Clark, Melana; Davenport, Bill; Message, Philip

    1993-01-01

    The Data System Dynamic Simulator (DSDS) is a discrete event simulation tool. It was developed for NASA for the specific purpose of evaluating candidate architectures for data systems of the Space Station era. DSDS provides three methods for meeting this requirement. First, the user has access to a library of standard pre-programmed elements. These elements represent tailorable components of NASA data systems and can be connected in any logical manner. Secondly, DSDS supports the development of additional elements. This allows the more sophisticated DSDS user the option of extending the standard element set. Thirdly, DSDS supports the use of data streams simulation. Data streams is the name given to a technique that ignores packet boundaries, but is sensitive to rate changes. Because rate changes are rare compared to packet arrivals in a typical NASA data system, data stream simulations require a fraction of the CPU run time. Additionally, the data stream technique is considerably more accurate than another commonly-used optimization technique.

  1. General Data Simulation Program.

    ERIC Educational Resources Information Center

    Burns, Edward

    Described is a computer program written in FORTRAN IV which offers considerable flexibility in generating simulated data pertinent to education and educational psychology. The user is allowed to specify the number of samples, data sets, and variables, together with the population means, standard deviations and intercorrelations. In addition the…

  2. Simulating solar MHD

    NASA Astrophysics Data System (ADS)

    Schüssler, M.

    1999-05-01

    Two aspects of solar MHD are discussed in relation to the work of the MHD simulation group at KIS. Photospheric magneto-convection, the nonlinear interaction of magnetic field and convection in a strongly stratified, radiating fluid, is a key process of general astrophysical relevance. Comprehensive numerical simulations including radiative transfer have significantly improved our understanding of the processes and have become an important tool for the interpretation of observational data. Examples of field intensification in the solar photosphere ('convective collapse') are shown. The second line of research is concerned with the dynamics of flux tubes in the convection zone, which has far-reaching implications for our understanding of the solar dynamo. Simulations indicate that the field strength in the region where the flux is stored before erupting to form sunspot groups is of the order of 105 G, an order of magnitude larger than previous estimates based on equipartition with the kinetic energy of convective flows.Key words. Solar physics · astrophysics and astronomy (photosphere and chromosphere; stellar interiors and dynamo theory; numerical simulation studies).

  3. Computer Simulation of Mutagenesis.

    ERIC Educational Resources Information Center

    North, J. C.; Dent, M. T.

    1978-01-01

    A FORTRAN program is described which simulates point-substitution mutations in the DNA strands of typical organisms. Its objective is to help students to understand the significance and structure of the genetic code, and the mechanisms and effect of mutagenesis. (Author/BB)

  4. Solar-Array Simulator

    NASA Technical Reports Server (NTRS)

    Wright, M. C.

    1982-01-01

    A convenient solar-array simulator has been built for testing systems powered by solar cells. Built for evaluating power extension package in Space Shuttle, the circuit produces the V/I curves of photocell sources; even duplicating transient behavior under partial illumination associated with morning and evening penumbra.

  5. Primary: A Simulation Game.

    ERIC Educational Resources Information Center

    Shelly, Ann

    A game designed to introduce elementary and middle school students to the primary election process and its operational elements through simulation and role playing activities is presented in this document. A hypothetical town of Notae which has been controlled by one political party for years without resulting change is described. Issues in the…

  6. GLOBECORP: Simulation versus Tradition.

    ERIC Educational Resources Information Center

    Spelman, Mary Dean

    2002-01-01

    Describes an empirical study conducted at the University of Central Oklahoma that investigated the differences in learning outcomes between English as a second language composition courses taught with two different methods, one based on a simulation called GLOBECORP and one on traditional instruction. Discusses progress measured by mandated…

  7. AGRICULTURAL SIMULATION MODEL (AGSIM)

    EPA Science Inventory

    AGSIM is a large-scale econometric simulation model of regional crop and national livestock production in the United States. The model was initially developed to analyze the aggregate economic impacts of a wide variety issues facing agriculture, such as technological change, pest...

  8. Juno Mission Simulation

    NASA Technical Reports Server (NTRS)

    Lee, Meemong; Weidner, Richard J.

    2008-01-01

    The Juno spacecraft is planned to launch in August of 2012 and would arrive at Jupiter four years later. The spacecraft would spend more than one year orbiting the planet and investigating the existence of an ice-rock core; determining the amount of global water and ammonia present in the atmosphere, studying convection and deep- wind profiles in the atmosphere; investigating the origin of the Jovian magnetic field, and exploring the polar magnetosphere. Juno mission management is responsible for mission and navigation design, mission operation planning, and ground-data-system development. In order to ensure successful mission management from initial checkout to final de-orbit, it is critical to share a common vision of the entire mission operation phases with the rest of the project teams. Two major challenges are 1) how to develop a shared vision that can be appreciated by all of the project teams of diverse disciplines and expertise, and 2) how to continuously evolve a shared vision as the project lifecycle progresses from formulation phase to operation phase. The Juno mission simulation team addresses these challenges by developing agile and progressive mission models, operation simulations, and real-time visualization products. This paper presents mission simulation visualization network (MSVN) technology that has enabled a comprehensive mission simulation suite (MSVN-Juno) for the Juno project.

  9. Simulated breath waveform control

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G.; Hendricks, C. M.; Morison, W. B.

    1972-01-01

    Subsystem was developed which provides twelve waveform controls to breath drive mechanism. Twelve position, magnetically actuated rotary switch is connected to one end of crankshaft drive, such that it makes one complete revolution for each simulated breath. Connections with common wired point are included in modifications made to standard motor speed controller.

  10. Quantitative Simulation Games

    NASA Astrophysics Data System (ADS)

    Černý, Pavol; Henzinger, Thomas A.; Radhakrishna, Arjun

    While a boolean notion of correctness is given by a preorder on systems and properties, a quantitative notion of correctness is defined by a distance function on systems and properties, where the distance between a system and a property provides a measure of "fit" or "desirability." In this article, we explore several ways how the simulation preorder can be generalized to a distance function. This is done by equipping the classical simulation game between a system and a property with quantitative objectives. In particular, for systems that satisfy a property, a quantitative simulation game can measure the "robustness" of the satisfaction, that is, how much the system can deviate from its nominal behavior while still satisfying the property. For systems that violate a property, a quantitative simulation game can measure the "seriousness" of the violation, that is, how much the property has to be modified so that it is satisfied by the system. These distances can be computed in polynomial time, since the computation reduces to the value problem in limit average games with constant weights. Finally, we demonstrate how the robustness distance can be used to measure how many transmission errors are tolerated by error correcting codes.

  11. Teaching Conflict Resolution Simulations.

    ERIC Educational Resources Information Center

    Hare, Mark A.

    The use of simulation in teaching conflict can be an effective way to promote student involvement. The role of the classroom teacher is to deal with actual student conflict while facilitating the development of communication skills which will aid in the resolustion of conflict. This paper suggests one classroom model which utilizes a combination…

  12. Parallel Dislocation Simulator

    Energy Science and Technology Software Center (ESTSC)

    2006-10-30

    ParaDiS is software capable of simulating the motion, evolution, and interaction of dislocation networks in single crystals using massively parallel computer architectures. The software is capable of outputting the stress-strain response of a single crystal whose plastic deformation is controlled by the dislocation processes.

  13. Introduction. Biomolecular simulation

    PubMed Central

    Mulholland, Adrian J.

    2008-01-01

    ‘Everything that living things do can be understood in terms of the jigglings and wigglings of atoms’ as Richard Feynman provocatively stated nearly 50 years ago. But how can we ‘see’ this wiggling and jiggling and understand how it drives biology? Increasingly, computer simulations of biological macromolecules are helping to meet this challenge. PMID:18826912

  14. Explosives simulants: Preliminary report

    SciTech Connect

    Moody, G.L.; Pruneda, C.O.; Simpson, R.L.

    1992-03-04

    Two TNT high explosives simulants have been developed. Small scale testing has shown them to be insensitive to: impact, spark, friction, temperature, and shock. The materials have been scaled to 0.5 kg quantities and samples given to the Protective Services Department for field evaluation using explosives detecting canines.

  15. Simulation in medical education.

    PubMed

    Khan, Kamran; Pattison, Tim; Sherwood, Morgan

    2011-01-01

    Studies in cognitive psychology inform us that the recall of information and its application are best when it is taught and rehearsed in environments similar to workplace. The healthcare professions are heavily task- and performance-based where non-technical skills, decision making and clinical reasoning are important alongside integrity, empathy and compassion. Most of these attributes are difficult to teach and assess in the traditional classrooms. Enhanced patient safety on one hand has to be the ultimate outcome of any medical curriculum while on the other hand, it itself can be potentially compromised in an apprenticeship-based model of medical education. A range of simulation techniques are very well placed to be used alongside clinical placements. These can be employed to enhance learning of healthcare professionals in safe environments, without compromising the patient safety, while maintaining a high degree of realism. This article builds an argument for the use of simulation techniques to enhance patient safety and points the readers to the AMEE Guide No. 50 on simulation, which is written as a practical manual on building a simulation programme in healthcare education. PMID:21182376

  16. Bolometer Simulation Using SPICE

    NASA Technical Reports Server (NTRS)

    Jones, Hollis H.; Aslam, Shahid; Lakew, Brook

    2004-01-01

    A general model is presented that assimilates the thermal and electrical properties of the bolometer - this block model demonstrates the Electro-Thermal Feedback (ETF) effect on the bolometers performance. This methodology is used to construct a SPICE model that by way of analogy combines the thermal and electrical phenomena into one simulation session. The resulting circuit diagram is presented and discussed.

  17. A Simulated Journey

    ERIC Educational Resources Information Center

    Yoder, Lisa

    2006-01-01

    Students learn best when they interact with new information on a personal level. It is a challenge for teachers to tightly align student experiences with the standards assessed on high-stakes tests. To achieve this goal in social studies, the author has turned increasingly to simulations where students find such activities engaging, and their…

  18. Simulation of phase structures

    SciTech Connect

    Lawson, J.

    1995-04-20

    This memo outlines a procedure developed by the author to extract information from phase measurements and produce a simulated phase structure for use in modeling optical systems, including characteristic optics for the Beamlet and NIF laser systems. The report includes an IDL program listing.

  19. Student Simulated Election.

    ERIC Educational Resources Information Center

    Institute for Political/Legal Education, Sewell, NJ.

    Guidelines for a school-wide simulated election on the state, county, or local level to be conducted by high school social studies or political science classes are provided. The objective is to prepare students for observation of and participation in a real political campaign in the community. Details for the election, establishing political…

  20. Battery Particle Simulation

    SciTech Connect

    2014-09-15

    Two simulations show the differences between a battery being drained at a slower rate, over a full hour, versus a faster rate, only six minutes (a tenth of an hour). In both cases battery particles go from being fully charged (green) to fully drained (red), but there are significant differences in the patterns of discharge based on the rate.

  1. Enabling immersive simulation.

    SciTech Connect

    McCoy, Josh; Mateas, Michael; Hart, Derek H.; Whetzel, Jonathan; Basilico, Justin Derrick; Glickman, Matthew R.; Abbott, Robert G.

    2009-02-01

    The object of the 'Enabling Immersive Simulation for Complex Systems Analysis and Training' LDRD has been to research, design, and engineer a capability to develop simulations which (1) provide a rich, immersive interface for participation by real humans (exploiting existing high-performance game-engine technology wherever possible), and (2) can leverage Sandia's substantial investment in high-fidelity physical and cognitive models implemented in the Umbra simulation framework. We report here on these efforts. First, we describe the integration of Sandia's Umbra modular simulation framework with the open-source Delta3D game engine. Next, we report on Umbra's integration with Sandia's Cognitive Foundry, specifically to provide for learning behaviors for 'virtual teammates' directly from observed human behavior. Finally, we describe the integration of Delta3D with the ABL behavior engine, and report on research into establishing the theoretical framework that will be required to make use of tools like ABL to scale up to increasingly rich and realistic virtual characters.

  2. Simulation Insights Using "R"

    ERIC Educational Resources Information Center

    Kostadinov, Boyan

    2013-01-01

    This article attempts to introduce the reader to computational thinking and solving problems involving randomness. The main technique being employed is the Monte Carlo method, using the freely available software "R for Statistical Computing." The author illustrates the computer simulation approach by focusing on several problems of…

  3. Simulation of geothermal subsidence

    SciTech Connect

    Miller, I.; Dershowitz, W.; Jones, K.; Myer, L.; Roman, K.; Schauer, M.

    1980-03-01

    The results of an assessment of existing mathematical models for subsidence simulation and prediction are summarized. The following subjects are discussed: the prediction process, physical processes of geothermal subsidence, computational models for reservoir flow, computational models for deformation, proficiency assessment, and real and idealized case studies. (MHR)

  4. Ion trap simulation tools.

    SciTech Connect

    Hamlet, Benjamin Roger

    2009-02-01

    Ion traps present a potential architecture for future quantum computers. These computers are of interest due to their increased power over classical computers stemming from the superposition of states and the resulting capability to simultaneously perform many computations. This paper describes a software application used to prepare and visualize simulations of trapping and maneuvering ions in ion traps.

  5. Evaluation Training: Simulation Exercises.

    ERIC Educational Resources Information Center

    Smith, Carl B.; Farr, Roger

    The preparation of this simulation material package is guided by the concept of an evaluator as a decision-maker, based on the definition of evaluation as a continuous assessment concerned with answering decision-making questions. The continuous concept of evaluation is based on the model created by Egon Guba and Daniel Stufflebeam, named by its…

  6. A Turing Machine Simulator.

    ERIC Educational Resources Information Center

    Navarro, Aaron B.

    1981-01-01

    Presents a program in Level II BASIC for a TRS-80 computer that simulates a Turing machine and discusses the nature of the device. The program is run interactively and is designed to be used as an educational tool by computer science or mathematics students studying computational or automata theory. (MP)

  7. Mars Surface Simulations

    NASA Astrophysics Data System (ADS)

    Nørnberg, Per; Merrison, Jonathan P.; Gunnlaugsson, Haraldur P.

    2010-05-01

    Laboratory simulations of the Martian surface are of importance to broaden scientific understanding of the physical processes, but also in order to develop the technology necessary for exploration of the planet. The Mars Simulation Laboratory at Aarhus University [1] has been involved in such simulations for around ten years and has developed several experimental facilities for carrying out science or instrument testing under conditions similar to those at the Martian surface, specifically low pressure, low temperature and importantly recreating the wind flow environment and dust suspension (reproducing the Martian dusty aerosol) using Mars analogue material [2]. The science involved in this simulation work has covered a broad spectrum including, erosion induced mineralogy/chemistry, particulate electrification, magnetic properties of Martian dust, biological survival, UV induced chemistry/mineralogy (using a solar simulator), adhesion/cohesion processes and the wind driven transport of dust and sand [3,4]. With regard to technology the wind tunnel facilities have been used in the development of the latest wind and dust sensing instrumentation [5,6]. With support from the European Space Agency (ESA) and Danish national funding an advanced Mars simulation facility has recently been constructed (2009). This wind tunnel facility has a cross section of 2 x 1 m and a length of 8 m, a temperature range down to below -120C, wind speeds in excess of 20m/s, and automated dust control. With a range of (specialised) sensing instrumentation it provides the opportunity to perform a new generation of scientific experiments and allow testing and technology development in the most realistic and rigorous environment. As well as being available for the space agencies, this facility will be open to all potential scientific collaborators. Also European planetary scientists may benefit from support through the EU Europlanet FP7 networking programme. For more information on access

  8. The LSST operations simulator

    NASA Astrophysics Data System (ADS)

    Delgado, Francisco; Saha, Abhijit; Chandrasekharan, Srinivasan; Cook, Kem; Petry, Catherine; Ridgway, Stephen

    2014-08-01

    The Operations Simulator for the Large Synoptic Survey Telescope (LSST; http://www.lsst.org) allows the planning of LSST observations that obey explicit science driven observing specifications, patterns, schema, and priorities, while optimizing against the constraints placed by design-specific opto-mechanical system performance of the telescope facility, site specific conditions as well as additional scheduled and unscheduled downtime. It has a detailed model to simulate the external conditions with real weather history data from the site, a fully parameterized kinematic model for the internal conditions of the telescope, camera and dome, and serves as a prototype for an automatic scheduler for the real time survey operations with LSST. The Simulator is a critical tool that has been key since very early in the project, to help validate the design parameters of the observatory against the science requirements and the goals from specific science programs. A simulation run records the characteristics of all observations (e.g., epoch, sky position, seeing, sky brightness) in a MySQL database, which can be queried for any desired purpose. Derivative information digests of the observing history are made with an analysis package called Simulation Survey Tools for Analysis and Reporting (SSTAR). Merit functions and metrics have been designed to examine how suitable a specific simulation run is for several different science applications. Software to efficiently compare the efficacy of different survey strategies for a wide variety of science applications using such a growing set of metrics is under development. A recent restructuring of the code allows us to a) use "look-ahead" strategies that avoid cadence sequences that cannot be completed due to observing constraints; and b) examine alternate optimization strategies, so that the most efficient scheduling algorithm(s) can be identified and used: even few-percent efficiency gains will create substantive scientific

  9. Hardware Fault Simulator for Microprocessors

    NASA Technical Reports Server (NTRS)

    Hess, L. M.; Timoc, C. C.

    1983-01-01

    Breadboarded circuit is faster and more thorough than software simulator. Elementary fault simulator for AND gate uses three gates and shaft register to simulate stuck-at-one or stuck-at-zero conditions at inputs and output. Experimental results showed hardware fault simulator for microprocessor gave faster results than software simulator, by two orders of magnitude, with one test being applied every 4 microseconds.

  10. Estimation of water distribution at Gale crater based on the joint analysis of DAN/MSL and HEND/Odyssey data.

    NASA Astrophysics Data System (ADS)

    Litvak, Maxim; Mitrofanov, Igor; Behar, Alberto; Boynton, William; Fedosov, Fedor; Golovin, Dmitry; Jun, Insoo; Lisov, Denis; Malakhov, Alexey; Milliken, Ralph; Mischna, Michael; Moersch, Jeffrey; Mokrousov, Maxim; Nikiforov, Sergey; Sanin, Anton; Tate, Chris; Varenikov, Alexey; Vostrukhin, Andrey; Harshman, Karl

    2013-04-01

    The observations made by the Dynamic Albedo of Neutrons (DAN) experiment onboard the MSL rover Curiosity have been analyzed to search for variability of the neutron flux along a traverse of the rover. The results of such an analysis have been used to compare surface measurements with measurements performed during the Mars Odyssey orbital mission with the neutron spectrometer HEND flying around Mars more than 10 years. DAN instrument consists of pulse neutron generator (DAN/PNG) and neutron detectors of epithermal and thermal neutrons (DAN/DE). In active mode of measurements DAN/PNG emits very short (~2 microseconds) pulses of high energy neutrons (14MeV) which penetrate to a subsurface under the rover, losing their energy down to the epithermal and thermal range. This process strongly depends on the soil composition; especially it is sensitive to the depth distribution of Hydrogen (which could exist in the soil in the hydrated minerals). The moderated neutrons can escape from the soil and be detected by DAN/DE within hundreds of microseconds after the pulse. It is recorded as a time profile of die away curve and its shape brings to us information about the subsurface structure and hydrogen abundance. In passive mode DAN/PNG is off and DAN/DE is measuring natural neutron background produced by Galactic Cosmic Rays (GCRs) and induced neutron background from Radioisotope Thermoelectric Generator (RTG) installed onboard MSL rover (as a main power supply system). Variations of this background along MSL traverse also could be used for a monitoring of the average content of water. HEND instrument is a neutron spectrometer measuring Martian neutron flux in a wide energy range starting from 0.4eV up to 15 MeV. It is installed onboard Mars Odyssey mission as a part of Gamma Ray Spectrometer (GRS) suite. During last 11 years it provides global mapping of neutron flux from martian surface to derive distribution of water/water ice in Martian subsurface. In our investigation we

  11. Drosophila CtBP regulates proliferation and differentiation of eye precursors and complexes with Eyeless, Dachshund, Dan and Danr during eye and antennal development

    PubMed Central

    Hoang, Chinh Q.; Burnett, Micheal E.; Curtiss, Jennifer

    2010-01-01

    Specification factors regulate cell fate in part by interacting with transcriptional co-regulators like CtBP to regulate gene expression. Here, we demonstrate that CtBP forms a complex or complexes with the Drosophila melanogaster Pax6 homolog Eyeless (Ey), and with Distal antenna (Dan), Distal antenna related (Danr) and Dachshund to promote eye and antennal specification. Phenotypic analysis together with molecular data indicates that CtBP interacts with Ey to prevent overproliferation of eye precursors. In contrast CtBP,dan,danr triple mutant adult eyes have significantly fewer ommatidia than CtBP single or dan,danr double mutants, suggesting that the CtBP/Dan/Danr complex functions to recruit ommatidia from the eye precursor pool. Further, CtBP single and to a greater extent CtBP,dan,danr triple mutants affect the establishment and maintenance of the R8 precursor, which is the founding ommatidial cells. Thus, CtBP interacts with different eye specification factors to regulate gene expression appropriate for proliferative versus differentiative stages of eye development. PMID:20730908

  12. Sur la nature des absorbeurs dans l'interpretation transactionnelle de la mecanique quantique

    NASA Astrophysics Data System (ADS)

    Boisvert, Jean-Sebastien

    L'interpretation transactionnelle de la mecanique quantique est l'une des plus recentes propositions de description des phenomenes du microcosme. En accord avec les predictions de la mecanique quantique standard, l'interpretation transactionnelle propose une alternative a celle de Copenhague. Son principal avantage est qu'elle permet de visualiser les mecanismes sous-jacents a l'echange d'energie, de quantite de mouvement ou d'autres quantites quantiques entre un emetteur et un absorbeur. Ces echanges sont le resultat, a l'instar de la theorie de l'absorbeur de Wheeler et Feynman, de l'utilisation autant d'ondes avancees que retardees. Bien que l'interpretation transactionnelle n'ait pas attire la plus grande attention scientifique, plusieurs critiques lui ont ete adressees. Dans les annees 1990, differentes experiences a mesure sans interaction ont ete concues. Depuis, il a ete avance que la version originale de l'interpretation transactionnelle pouvait difficilement rendre compte de ce type d'experience et meme qu'elle n'est pas compatible avec le concept d'univers quadridimensionnel. La recherche de ce memoire par article consiste a montrer que lorsque l'on utilise systematiquement l'interpretation transactionnelle en considerant la configuration totale des absorbeurs (incluant l'absorbeur universel), il n'est pas necessaire de faire appel a une hierarchie de transactions comme certains l'ont propose.

  13. Amplification paramétrique de polaritons dans des microcavités semi-conductrices

    NASA Astrophysics Data System (ADS)

    Baas, A.; Karr, J.-P.; Courty, J.-M.; Giacobino, E.

    2002-06-01

    Nous étudions l'émission non linéaire de microcavités serai-conductrices en régime de couplage fort. Des expériences en régime d'excitation continue et résonante ont été récemment interprétées par un modèle de mélange paramétrique à quatre ondes de polaritons[1]. Nous avons retrouvé cette émission non linéaire dans une configuration nouvelle. Nous avons mis en évidence pour la première fois la dépendance en phase de l'émission, preuve de la cohérence du processus d'amplification. De plus, certaines quadratures du champ réfléchi ont des fluctuations réduites en dessous du bruit thermique, et proches de la limite quantique standardé[2

  14. Gongjin-Dan Enhances Hippocampal Memory in a Mouse Model of Scopolamine-Induced Amnesia.

    PubMed

    Lee, Jin-Seok; Hong, Sung-Shin; Kim, Hyeong-Geug; Lee, Hye-Won; Kim, Won-Yong; Lee, Sam-Keun; Son, Chang-Gue

    2016-01-01

    We evaluated the neuropharmacological effects of Gongjin-Dan (GJD) on the memory impairment caused by scopolamine injection. BALB/c mice were orally treated with GJD (100, 200, or 400 mg/kg, daily) or tacrine (THA, 10 mg/kg) for 10 days, and scopolamine (2 mg/kg) was injected intraperitoneally. The radial arm maze and passive avoidance tests were performed to evaluate the animal's learning and memory. Scopolamine increased the task completing time, the number of total errors (reference and working memory error) in the radial arm maze task, and the latency time in the passive avoidance test, which were significantly ameliorated by treatment with GJD. The GJD treatment also attenuated the scopolamine-induced hyperactivation of acetylcholinesterase activity, and suppression of the expression of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF) and their receptors in the hippocampus. These effects of GJD were supported by both the doublecortin (DCX)-positive staining and Nissl staining, which were used to measure hippocampal neurogenesis and atrophy, respectively. These findings strongly suggest that GJD exerts a potent anti-amnesic effect, and its underlying mechanism might involve the modulation of cholinergic activity. PMID:27483466

  15. Gongjin-Dan Enhances Hippocampal Memory in a Mouse Model of Scopolamine-Induced Amnesia

    PubMed Central

    Lee, Jin-Seok; Hong, Sung-Shin; Kim, Hyeong-Geug; Lee, Hye-Won; Kim, Won-Yong; Lee, Sam-Keun; Son, Chang-Gue

    2016-01-01

    We evaluated the neuropharmacological effects of Gongjin-Dan (GJD) on the memory impairment caused by scopolamine injection. BALB/c mice were orally treated with GJD (100, 200, or 400 mg/kg, daily) or tacrine (THA, 10 mg/kg) for 10 days, and scopolamine (2 mg/kg) was injected intraperitoneally. The radial arm maze and passive avoidance tests were performed to evaluate the animal’s learning and memory. Scopolamine increased the task completing time, the number of total errors (reference and working memory error) in the radial arm maze task, and the latency time in the passive avoidance test, which were significantly ameliorated by treatment with GJD. The GJD treatment also attenuated the scopolamine-induced hyperactivation of acetylcholinesterase activity, and suppression of the expression of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF) and their receptors in the hippocampus. These effects of GJD were supported by both the doublecortin (DCX)-positive staining and Nissl staining, which were used to measure hippocampal neurogenesis and atrophy, respectively. These findings strongly suggest that GJD exerts a potent anti-amnesic effect, and its underlying mechanism might involve the modulation of cholinergic activity. PMID:27483466

  16. Identification and expression analysis of BMP signaling inhibitors genes of the DAN family in amphioxus.

    PubMed

    Le Petillon, Yann; Oulion, Silvan; Escande, Marie-Line; Escriva, Hector; Bertrand, Stephanie

    2013-12-01

    Bone morphogenetic proteins (BMPs) are members of the Transforming Growth Factor-β (TGF-β) family implicated in many developmental processes in metazoans such as embryo axes specification. Their wide variety of actions is in part controlled by inhibitors that impede the interaction of BMPs with their specific receptors. Here, we focused our attention on the Differential screening-selected gene Aberrative in Neuroblastoma (DAN) family of inhibitors. Although they are well-characterized in vertebrates, few data are available for this family in other metazoan species. In order to understand the evolution of potential developmental roles of these inhibitors in chordates, we identified the members of this family in the cephalochordate amphioxus, and characterized their expression patterns during embryonic development. Our data suggest that the function of Cerberus/Dand5 subfamily genes is conserved among chordates, whereas Gremlin1/2 and NBL1 subfamily genes seem to have acquired divergent expression patterns in each chordate lineage. On the other hand, the expression of Gremlin in the amphioxus neural plate border during early neurulation strengthens the hypothesis of a conserved neural plate border gene network in chordates. PMID:23872339

  17. Molecular Simulations in Astrobiology

    NASA Technical Reports Server (NTRS)

    Pohorille, Andrew; Wilson, Michael A.; Schweighofer, Karl; Chipot, Christophe; New, Michael H.

    2000-01-01

    One of the main goals of astrobiology is to understand the origin of cellular life. The most direct approach to this problem is to construct laboratory models of protocells. Such efforts, currently underway in the NASA Astrobiology Program, are accompanied by computational studies aimed at explaining self-organization of simple molecules into ordered structures that are capable of performing protocellular functions. Many of these functions, such as importing nutrients, capturing energy and responding to changes in the environment, are carried out by proteins bound to membranes. We use computer simulations to address the following questions about these proteins: (1) How do small proteins self-organize into ordered structures at water-membrane interfaces and insert into membranes? (2) How do peptides form membrane-spanning structures (e.g. channels)? (3) By what mechanisms do such structures perform their functions? The simulations are performed using the molecular dynamics method. In this method, Newton's equations of motion for each atom in the system are solved iteratively. At each time step, the forces exerted on each atom by the remaining atoms are evaluated by dividing them into two parts. Short-range forces are calculated in real space while long-range forces are evaluated in reciprocal space, using a particle-mesh algorithm which is of order O(NInN). With a time step of 2 femtoseconds, problems occurring on multi-nanosecond time scales (10(exp 6)-10(exp 8) time steps) are accessible. To address a broader range of problems, simulations need to be extended by three orders of magnitude, which requires algorithmic improvements and codes scalable to a large number of processors. Work in this direction is in progress. Two series of simulations are discussed. In one series, it is shown that nonpolar peptides, disordered in water, translocate to the nonpolar interior of the membrane and fold into helical structures (see Figure). Once in the membrane, the peptides

  18. Plasma Simulation Using Gyrokinetic-Gyrofluid Hybrid Models

    SciTech Connect

    Scott Parker

    2009-04-09

    We are developing kinetic ion models for the simulation of extended MHD phenomena. The model they have developed uses full Lorentz force ions, and either drift-kinetic or gyro-kinetic electrons. Quasi-neutrality is assumed and the displacement current is neglected. They are also studying alpha particle driven Toroidal Alfven Eigenmodes (TAE) in the GEM gyrokinetic code [Chen 07]. The basic kinetic ion MHD model was recently reported in an invited talk given by Dan Barnes at the 2007 American Physical Society - Division of Plasma Physics (APS-DPP) and it has been published [Jones 04, Barnes 08]. The model uses an Ohm's law that includes the Hall term, pressure term and the electron inertia [Jones 04]. These results focused on the ion physics and assumed an isothermal electron closure. It is found in conventional gyrokinetic turbulence simulations that the timestep cannot be made much greater than the ion cyclotron period. However, the kinetic ion MHD model has the compressional mode, which further limits the timestep. They have developed an implicit scheme to avoid this timestep constraint. They have also added drift kinetic electrons. This model has been benchmarked linearly. Waves investigated where shear and compressional Alfven, whisterl, ion acoustic, and drift waves, including the kinetic damping rates. This work is ongoing and was first reported at the 2008 Sherwood Fusion Theory Conference [Chen 08] and they are working on a publication. They have also formulated an integrated gyrokinetic electron model, which is of interest for studying electron gradient instabilities and weak guide-field magnetic reconnection.

  19. NASA Lunar Regolith Simulant Program

    NASA Technical Reports Server (NTRS)

    Edmunson, J.; Betts, W.; Rickman, D.; McLemore, C.; Fikes, J.; Stoeser, D.; Wilson, S.; Schrader, C.

    2010-01-01

    Lunar regolith simulant production is absolutely critical to returning man to the Moon. Regolith simulant is used to test hardware exposed to the lunar surface environment, simulate health risks to astronauts, practice in situ resource utilization (ISRU) techniques, and evaluate dust mitigation strategies. Lunar regolith simulant design, production process, and management is a cooperative venture between members of the NASA Marshall Space Flight Center (MSFC) and the U.S. Geological Survey (USGS). The MSFC simulant team is a satellite of the Dust group based at Glenn Research Center. The goals of the cooperative group are to (1) reproduce characteristics of lunar regolith using simulants, (2) produce simulants as cheaply as possible, (3) produce simulants in the amount needed, and (4) produce simulants to meet users? schedules.

  20. Obstetric ultrasound simulation.

    PubMed

    Nitsche, Joshua F; Brost, Brian C

    2013-06-01

    Obstetric ultrasound is becoming an increasingly important part of the practice of maternal-fetal medicine. Thus, it is important to develop rigorous and effective training curricula for obstetrics and gynecology residents and maternal-fetal medicine fellows. Traditionally, this training has come almost entirely from exposure to ultrasound in the clinical setting. However, with the increased complexity of modern ultrasound and advent of duty-hour restrictions, a purely clinical training model is no longer viable. With the advent of high-fidelity obstetric ultrasound simulators, a significant amount of training can occur in a non-clinical setting which allows learners to obtain significant skill prior to their first patient ultrasound encounter and obtain proficiency in a shorter period of time. In this manuscript we discuss the available obstetric ultrasound simulators and ways to construct a comprehensive ultrasound training curricula to meet the increasing demands of modern maternal-fetal medicine. PMID:23721777

  1. Simulators for Safer Shipping

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Each year one ship out of every five afloat collides with another vessel, rams a dock, or runs a ground. CAORF (Computer Aided Operations Research Facility), designed and built by Sperry Rand Corporation, incorporates technology developed in a wide variety of aerospace simulation and technical training programs. CAORF can be set up to duplicate the exact handling qualities of any vessel under various conditions of wind, tide and current. Currently a dozen different ships can be "plugged in." Bridge instrumentation is typical of modern shipboard equipment including radar, internal and external c.ommunications and new collision avoidance systems. From repetitive operation of simulated ships, MarAd is building a valuable data base for improving marine safety.

  2. PEBBLES Mechanics Simulation Speedup

    SciTech Connect

    Joshua J. Cogliati; Abderrafi M. Ougouag

    2010-05-01

    Pebble bed reactors contain large numbers of spherical fuel elements arranged randomly. Determining the motion and location of these fuel elements is required for calculating certain parameters of pebble bed reactor operation. These simulations involve hundreds of thousands of pebbles and involve determining the entire core motion as pebbles are recirculated. Single processor algorithms for this are insufficient since they would take decades to centuries of wall-clock time. This paper describes the process of parallelizing and speeding up the PEBBLES pebble mechanics simulation code. Both shared memory programming with the Open Multi-Processing API and distributed memory programming with the Message Passing Interface API are used in simultaneously in this process. A new shared memory lock-less linear time collision detection algorithm is described. This method allows faster detection of pebbles in contact than generic methods. These combine to make full recirculations on AVR sized reactors possible in months of wall clock time.

  3. The Simulation Intranet Architecture

    SciTech Connect

    Holmes, V.P.; Linebarger, J.M.; Miller, D.J.; Vandewart, R.L.

    1998-12-02

    The Simdarion Infranet (S1) is a term which is being used to dcscribc one element of a multidisciplinary distributed and distance computing initiative known as DisCom2 at Sandia National Laboratory (http ct al. 1998). The Simulation Intranet is an architecture for satisfying Sandia's long term goal of providing an end- to-end set of scrviccs for high fidelity full physics simu- lations in a high performance, distributed, and distance computing environment. The Intranet Architecture group was formed to apply current distributed object technologies to this problcm. For the hardware architec- tures and software models involved with the current simulation process, a CORBA-based architecture is best suited to meet Sandia's needs. This paper presents the initial desi-a and implementation of this Intranct based on a three-tier Network Computing Architecture(NCA). The major parts of the architecture include: the Web Cli- ent, the Business Objects, and Data Persistence.

  4. Electromagnetic particle simulation codes

    NASA Technical Reports Server (NTRS)

    Pritchett, P. L.

    1985-01-01

    Electromagnetic particle simulations solve the full set of Maxwell's equations. They thus include the effects of self-consistent electric and magnetic fields, magnetic induction, and electromagnetic radiation. The algorithms for an electromagnetic code which works directly with the electric and magnetic fields are described. The fields and current are separated into transverse and longitudinal components. The transverse E and B fields are integrated in time using a leapfrog scheme applied to the Fourier components. The particle pushing is performed via the relativistic Lorentz force equation for the particle momentum. As an example, simulation results are presented for the electron cyclotron maser instability which illustrate the importance of relativistic effects on the wave-particle resonance condition and on wave dispersion.

  5. Flexible spacecraft simulator

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Verification of control algorithms for flexible spacecraft can be done only through simulation and test; these are necessary to understand control/structure interaction (C/SI) sufficiently to design robust controllers for future spacecraft. The objective persued is to develop a low-cost facility which simulates the fundamental problem of C/SI; and to provide accessibility for designs so that experience can be gained in applying various multivariable control design methods to an actual structure. A test facility is being constructed with test elements that provide 3 rigid body and 6 flexible modes, all in the horizontal plane, with frequencies below 2.5 Hz. The control force actuator are on/off air jets with sensing by optical displacement sensors. Loop closure is provided by a digital computer with control algorithms designed using the IAC and MATRIX-X.

  6. Deep depth undex simulator

    SciTech Connect

    Higginbotham, R. R.; Malakhoff, A.

    1985-01-29

    A deep depth underwater simulator is illustrated for determining the dual effects of nuclear type underwater explosion shockwaves and hydrostatic pressures on a test vessel while simulating, hydrostatically, that the test vessel is located at deep depths. The test vessel is positioned within a specially designed pressure vessel followed by pressurizing a fluid contained between the test and pressure vessels. The pressure vessel, with the test vessel suspended therein, is then placed in a body of water at a relatively shallow depth, and an explosive charge is detonated at a predetermined distance from the pressure vessel. The resulting shockwave is transmitted through the pressure vessel wall so that the shockwave impinging on the test vessel is representative of nuclear type explosive shockwaves transmitted to an underwater structure at great depths.

  7. Simulation of robot manipulators

    SciTech Connect

    Kress, R.L.; Babcock, S.M.; Bills, K.C.; Kwon, D.S.; Schoenwald, D.A.

    1995-03-01

    This paper describes Oak Ridge National Laboratory`s development of an environment for the simulation of robotic manipulators. Simulation includes the modeling of kinematics, dynamics, sensors, actuators, control systems, operators, and environments. Models will be used for manipulator design, proposal evaluation, control system design and analysis, graphical preview of proposed motions, safety system development, and training. Of particular interest is the development of models for robotic manipulators having at least one flexible link. As a first application, models have been developed for the Pacific Northwest Laboratories` Flexible Beam Testbed which is a one-Degree-Of-Freedom, flexible arm with a hydraulic base actuator. Initial results show good agreement between model and experiment.

  8. Electromagnetic Gyrokinetic Simulations

    SciTech Connect

    Wan, W

    2003-11-19

    A new electromagnetic kinetic electron {delta} particle simulation model has been demonstrated to work well at large values of plasma {beta} times the ion-to-electron mass ratio. The simulation is three-dimensional using toroidal flux-tube geometry and includes electron-ion collisions. The model shows accurate shear Alfven wave damping and microtearing physics. Zonal flows with kinetic electrons are found to be turbulent with the spectrum peaking at zero and having a width in the frequency range of the driving turbulence. This is in contrast with adiabatic electron cases where the zonal flows are near stationary, even though the linear behavior of the zonal flow is not significantly affected by kinetic electrons. zonal fields are found to be very weak, consistent with theoretical predictions for {beta} below the kinetic ballooning limit. Detailed spectral analysis of the turbulence data is presented in the various limits.

  9. Real-Time Simulation

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Coryphaeus Software, founded in 1989 by former NASA electronic engineer Steve Lakowske, creates real-time 3D software. Designer's Workbench, the company flagship product, is a modeling and simulation tool for the development of both static and dynamic 3D databases. Other products soon followed. Activation, specifically designed for game developers, allows developers to play and test the 3D games before they commit to a target platform. Game publishers can shorten development time and prove the "playability" of the title, maximizing their chances of introducing a smash hit. Another product, EasyT, lets users create massive, realistic representation of Earth terrains that can be viewed and traversed in real time. Finally, EasyScene software control the actions among interactive objects within a virtual world. Coryphaeus products are used on Silican Graphics workstation and supercomputers to simulate real-world performance in synthetic environments. Customers include aerospace, aviation, architectural and engineering firms, game developers, and the entertainment industry.

  10. Plateau Rayleigh instability simulation.

    PubMed

    Mead-Hunter, Ryan; King, Andrew J C; Mullins, Benjamin J

    2012-05-01

    The well-known phenomena of Plateau-Rayleigh instability has been simulated using computational fluid dynamics (CFD). The breakup of a liquid film into an array of droplets on a cylindrical element was simulated using a volume-of-fluid (VOF) solver and compared to experimental observations and existing theory. It is demonstrated that the VOF method can correctly predict the breakup of thins films into an array of either axisymmetric droplets or clam-shell droplets, depending on the surface energy. The existence of unrealistically large films is precluded. Droplet spacing was found to show reasonable agreement with theory. Droplet motion and displacement under fluid flow was also examined and compared to that in previous studies. It was found that the presence of air flow around the droplet does not influence the stable film thickness; however, it reduces the time required for droplet formation. Novel relationships for droplet displacement were derived from the results. PMID:22512475

  11. Simulation of Hyperspectral Images

    NASA Technical Reports Server (NTRS)

    Richsmeier, Steven C.; Singer-Berk, Alexander; Bernstein, Lawrence S.

    2004-01-01

    A software package generates simulated hyperspectral imagery for use in validating algorithms that generate estimates of Earth-surface spectral reflectance from hyperspectral images acquired by airborne and spaceborne instruments. This software is based on a direct simulation Monte Carlo approach for modeling three-dimensional atmospheric radiative transport, as well as reflections from surfaces characterized by spatially inhomogeneous bidirectional reflectance distribution functions. In this approach, "ground truth" is accurately known through input specification of surface and atmospheric properties, and it is practical to consider wide variations of these properties. The software can treat both land and ocean surfaces, as well as the effects of finite clouds with surface shadowing. The spectral/spatial data cubes computed by use of this software can serve both as a substitute for, and a supplement to, field validation data.

  12. Simulated Craters on Venus

    NASA Technical Reports Server (NTRS)

    Zahnle, Kevin; Cuzzi, Jeffrey N. (Technical Monitor)

    1995-01-01

    The thick atmosphere of Venus prevents all but the largest impactors from cratering the surface. The number of small craters on Venus provides an interesting, and statistically significant test of models for the disruption and deceleration of impacting bodies. Here we compare Monte Carlo simulated crater distributions to the observed crater distribution on Venus. The simulation assumes: (1) a power law mass distribution for impactors of the form N(sub cum) alpha m (exp-b) where b=0.8; (2) isotropic incidence angles; (3) velocity at the top of the atmosphere of 20 kilometers per second (more realistic velocity distributions are also considered); (4) Schmidt-Housen crater scaling, modified such that only the normal component of the impact velocity contributes to cratering, and using crater slumping as parameterized (5) and modern populations (60% carbonaceous, 40% stone, 3% iron) and fluxes of asteroids. We use our previously developed model for the disruption and deceleration of large bodies striking thick planetary atmospheres to calculate the impact velocity at the surface as a function of impactor mass, incident velocity, and incident angle. We use a drag coefficient c(sub d) =1; other parameters are as described in Chyba et al. We set a low velocity cutoff of 500 meters per second on crater-forming impacts. Venus's craters are nicely matched by the simulated craters produced by 700 million years of striking asteroids. Shown for comparison are the simulated craters produced by incident comets over the same period, where for comets we have assumed b=0.7 and a flux at 10(exp 14) g 30% that of asteroids. Systematic uncertainties in crater scaling and crater slumping may make the surface age uncertain by a factor of two.

  13. Advanced Wellbore Thermal Simulator

    Energy Science and Technology Software Center (ESTSC)

    1992-03-04

    GEOTEMP2, which is based on the earlier GEOTEMP program, is a wellbore thermal simulator designed for geothermal well drilling and production applications. The code treats natural and forced convection and conduction within the wellbore and heat conduction within the surrounding rock matrix. A variety of well operations can be modeled including injection, production, forward and reverse circulation with gas or liquid, gas or liquid drilling, and two-phase steam injection and production. Well completion with severalmore » different casing sizes and cement intervals can be modeled. The code allows variables, such as flow rate, to change with time enabling a realistic treatment of well operations. Provision is made in the flow equations to allow the flow areas of the tubing to vary with depth in the wellbore. Multiple liquids can exist in GEOTEMP2 simulations. Liquid interfaces are tracked through the tubing and annulus as one liquid displaces another. GEOTEMP2, however, does not attempt to simulate displacement of liquids with a gas or two-phase steam or vice versa. This means that it is not possible to simulate an operation where the type of drilling fluid changes, e.g. mud going to air. GEOTEMP2 was designed primarily for use in predicting the behavior of geothermal wells, but it is flexible enough to handle many typical drilling, production, and injection problems in the oil industry as well. However, GEOTEMP2 does not allow the modeling of gas-filled annuli in production or injection problems. In gas or mist drilling, no radiation losses are included in the energy balance. No attempt is made to model flow in the formation. Average execution time is 50 CP seconds on a CDC CYBER170. This edition of GEOTEMP2 is designated as Version 2.0 by the contributors.« less

  14. Radiation in Particle Simulations

    SciTech Connect

    More, R; Graziani, F; Glosli, J; Surh, M

    2010-11-19

    Hot dense radiative (HDR) plasmas common to Inertial Confinement Fusion (ICF) and stellar interiors have high temperature (a few hundred eV to tens of keV), high density (tens to hundreds of g/cc) and high pressure (hundreds of megabars to thousands of gigabars). Typically, such plasmas undergo collisional, radiative, atomic and possibly thermonuclear processes. In order to describe HDR plasmas, computational physicists in ICF and astrophysics use atomic-scale microphysical models implemented in various simulation codes. Experimental validation of the models used to describe HDR plasmas are difficult to perform. Direct Numerical Simulation (DNS) of the many-body interactions of plasmas is a promising approach to model validation but, previous work either relies on the collisionless approximation or ignores radiation. We present four methods that attempt a new numerical simulation technique to address a currently unsolved problem: the extension of molecular dynamics to collisional plasmas including emission and absorption of radiation. The first method applies the Lienard-Weichert solution of Maxwell's equations for a classical particle whose motion is assumed to be known. The second method expands the electromagnetic field in normal modes (planewaves in a box with periodic boundary-conditions) and solves the equation for wave amplitudes coupled to the particle motion. The third method is a hybrid molecular dynamics/Monte Carlo (MD/MC) method which calculates radiation emitted or absorbed by electron-ion pairs during close collisions. The fourth method is a generalization of the third method to include small clusters of particles emitting radiation during close encounters: one electron simultaneously hitting two ions, two electrons simultaneously hitting one ion, etc. This approach is inspired by the virial expansion method of equilibrium statistical mechanics. Using a combination of these methods we believe it is possible to do atomic-scale particle simulations of

  15. Software thermal imager simulator

    NASA Astrophysics Data System (ADS)

    Le Noc, Loic; Pancrati, Ovidiu; Doucet, Michel; Dufour, Denis; Debaque, Benoit; Turbide, Simon; Berthiaume, Francois; Saint-Laurent, Louis; Marchese, Linda; Bolduc, Martin; Bergeron, Alain

    2014-10-01

    A software application, SIST, has been developed for the simulation of the video at the output of a thermal imager. The approach offers a more suitable representation than current identification (ID) range predictors do: the end user can evaluate the adequacy of a virtual camera as if he was using it in real operating conditions. In particular, the ambiguity in the interpretation of ID range is cancelled. The application also allows for a cost-efficient determination of the optimal design of an imager and of its subsystems without over- or under-specification: the performances are known early in the development cycle, for targets, scene and environmental conditions of interest. The simulated image is also a powerful method for testing processing algorithms. Finally, the display, which can be a severe system limitation, is also fully considered in the system by the use of real hardware components. The application consists in Matlabtm routines that simulate the effect of the subsystems atmosphere, optical lens, detector, and image processing algorithms. Calls to MODTRAN® for the atmosphere modeling and to Zemax for the optical modeling have been implemented. The realism of the simulation depends on the adequacy of the input scene for the application and on the accuracy of the subsystem parameters. For high accuracy results, measured imager characteristics such as noise can be used with SIST instead of less accurate models. The ID ranges of potential imagers were assessed for various targets, backgrounds and atmospheric conditions. The optimal specifications for an optical design were determined by varying the Seidel aberration coefficients to find the worst MTF that still respects the desired ID range.

  16. Numerical simulations in combustion

    NASA Technical Reports Server (NTRS)

    Chung, T. J.

    1989-01-01

    This paper reviews numerical simulations in reacting flows in general and combustion phenomena in particular. It is shown that use of implicit schemes and/or adaptive mesh strategies can improve convergence, stability, and accuracy of the solution. Difficulties increase as turbulence and multidimensions are considered, particularly when finite-rate chemistry governs the given combustion problem. Particular attention is given to the areas of solid-propellant combustion dynamics, turbulent diffusion flames, and spray droplet vaporization.

  17. Simulation on quantum authentication

    NASA Astrophysics Data System (ADS)

    Dobšíček, M.

    2007-03-01

    This paper divides into two main parts. The first one discusses authentication of quantum messages. The protocol proposed in [1] for one qubit message-length case is especially considered. The protocol uses a shared EPR pair as a secret key. In the second part, it is shown how such a protocol can be simulated using the Quantum-Octave package. Quantum-Octave is a set of functions for a Matlab-like numerical environment allowing calculations with general density matrices.

  18. Simulations: The dark side

    NASA Astrophysics Data System (ADS)

    Frenkel, D.

    2013-01-01

    This paper discusses the Monte Carlo and Molecular Dynamics methods. Both methods are, in principle, simple. However, simple does not mean risk-free. In the literature, many of the pitfalls in the field are mentioned, but usually as a footnote --and these footnotes are scattered over many papers. The present paper focuses on the "dark side" of simulation: it is one big footnote. I should stress that "dark", in this context, has no negative moral implication. It just means: under-exposed.

  19. Satellite Hyperspectral Imaging Simulation

    NASA Technical Reports Server (NTRS)

    Zanoni, Vicki; Stanley, Tom; Blonski, Slawomir; Cao, Changyong; Gasser, Jerry; Ryan, Robert; Zanoni, Vicki; Stanley, Tom

    1999-01-01

    Simulations of generic pushbroom satellite hyperspetral sensors have been performed to evaluate the potential performance and validation techniques for satellite systems such as COIS (NEMO), Warfighter-1 (OrbView-4), and Hyperion (EO-1). The simulaitons start with a generation of synthetic scenes form material maps of studied terrain. Scene-reflected radiance is corrected for atmospheric effects and convolved with sensor spectral response uwing MODTRAN 4 radiance and transmission calculations. Scene images are further convolved with point spread functions derived from Optical Transfer Functions (OTF's) of the sensor system. Photon noise and detector/electronics noise are added to the simulated images, which are also finally quantized to the sensor bit resolution. Studied scenes include bridges and straight roads used for evaluation of sensor spatial resolution, as well as fields of minerals, vegetation, and manmade materials used for evaluation of sensor radiometric response and sensitivity. The scenes are simulated with various seasons and weather conditions. Signal-to-noise ratos and expected performance are estimated for typica satellite system specifications and are discussed for all the scenes.

  20. Training by simulation

    SciTech Connect

    Angelini, E.

    1984-12-01

    Effective training by simulation is a matter of 1. accurate definition of the training need, 2. selecting the right hardware/software package to do the job cost effectively, 3. careful, methodical building of the training program and 4. an appropriate setting, such as a well-equipped training center. Several points seem clear: 1. ''Computer shock'' or computer phobia -- that is, fear of the simulator, can be a factor with some of the older operators. But it quickly disappears once they're into the program, and learn the versatility and the exciting dynamics of simulators. 2. Operator training is becoming more sophisticated throughout the HPI. Among other things, operators should get out into the plant to learn more about how their actions in the control room impact the plant. Operators are becoming more ''big picture'' oriented. 3. When inexperienced training instructors are used, they should attend a good ''train the trainer'' course emphasizing platform skills and instructional technology. 4. Operators need as much ''hands on'' experience with the plant's actual operating equipment as possible. The cognitive ''linkage'' between that equipment and what they see on the CRT is vitally important.

  1. Terminal Descent Sensor Simulation

    NASA Technical Reports Server (NTRS)

    Chen, Curtis W.

    2009-01-01

    Sulcata software simulates the operation of the Mars Science Laboratory (MSL) radar terminal descent sensor (TDS). The program models TDS radar antennas, RF hardware, and digital processing, as well as the physics of scattering from a coherent ground surface. This application is specific to this sensor and is flexible enough to handle end-to-end design validation. Sulcata is a high-fidelity simulation and is used for performance evaluation, anomaly resolution, and design validation. Within the trajectory frame, almost all internal vectors are represented in whatever coordinate system is used to represent platform position. The trajectory frame must be planet-fixed. The platform body frame is specified relative to arbitrary reference points relative to the platform (spacecraft or test vehicle). Its rotation is a function of time from the trajectory coordinate system specified via dynamics input (file for open loop, callback for closed loop). Orientation of the frame relative to the body is arbitrary, but constant over time. The TDS frame must have a constant rotation and translation from the platform body frame specified at run time. The DEM frame has an arbitrary, but time-constant, rotation and translation with respect to the simulation frame specified at run time. It has the same orientation as sigma0 frame, but is possibly translated. Surface sigma0 has the same arbitrary rotation and translation as DEM frame.

  2. LSST optical beam simulator

    NASA Astrophysics Data System (ADS)

    Tyson, J. A.; Sasian, J.; Gilmore, K.; Bradshaw, A.; Claver, C.; Klint, M.; Muller, G.; Poczulp, G.; Resseguie, E.

    2014-07-01

    We describe a camera beam simulator for the LSST which is capable of illuminating a 60mm field at f/1.2 with realistic astronomical scenes, enabling studies of CCD astrometric and photometric performance. The goal is to fully simulate LSST observing, in order to characterize charge transport and other features in the thick fully-depleted CCDs and to probe low level systematics under realistic conditions. The automated system simulates the centrally obscured LSST beam and sky scenes, including the spectral shape of the night sky. The doubly telecentric design uses a nearly unit magnification design consisting of a spherical mirror, three BK7 lenses, and one beam-splitter window. To achieve the relatively large field the beam-splitter window is used twice. The motivation for this LSST beam test facility was driven by the need to fully characterize a new generation of thick fully-depleted CCDs, and assess their suitability for the broad range of science which is planned for LSST. Due to the fast beam illumination and the thick silicon design [each pixel is 10 microns wide and over 100 microns deep] at long wavelengths there can be effects of photon transport and charge transport in the high purity silicon. The focal surface covers a field more than sufficient for a 40×40mm LSST CCD. Delivered optical quality meets design goals, with 50% energy within a 5 micron circle. The tests of CCD performance are briefly described.

  3. Exploration Supply Chain Simulation

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Exploration Supply Chain Simulation project was chartered by the NASA Exploration Systems Mission Directorate to develop a software tool, with proper data, to quantitatively analyze supply chains for future program planning. This tool is a discrete-event simulation that uses the basic supply chain concepts of planning, sourcing, making, delivering, and returning. This supply chain perspective is combined with other discrete or continuous simulation factors. Discrete resource events (such as launch or delivery reviews) are represented as organizational functional units. Continuous resources (such as civil service or contractor program functions) are defined as enabling functional units. Concepts of fixed and variable costs are included in the model to allow the discrete events to interact with cost calculations. The definition file is intrinsic to the model, but a blank start can be initiated at any time. The current definition file is an Orion Ares I crew launch vehicle. Parameters stretch from Kennedy Space Center across and into other program entities (Michaud Assembly Facility, Aliant Techsystems, Stennis Space Center, Johnson Space Center, etc.) though these will only gain detail as the file continues to evolve. The Orion Ares I file definition in the tool continues to evolve, and analysis from this tool is expected in 2008. This is the first application of such business-driven modeling to a NASA/government-- aerospace contractor endeavor.

  4. Gyrokinetic particle simulation model

    SciTech Connect

    Lee, W.W.

    1986-07-01

    A new type of particle simulation model based on the gyrophase-averaged Vlasov and Poisson equations is presented. The reduced system, in which particle gyrations are removed from the equations of motion while the finite Larmor radius effects are still preserved, is most suitable for studying low frequency microinstabilities in magnetized plasmas. It is feasible to simulate an elongated system (L/sub parallel/ >> L/sub perpendicular/) with a three-dimensional grid using the present model without resorting to the usual mode expansion technique, since there is essentially no restriction on the size of ..delta..x/sub parallel/ in a gyrokinetic plasma. The new approach also enables us to further separate the time and spatial scales of the simulation from those associated with global transport through the use of multiple spatial scale expansion. Thus, the model can be a very efficient tool for studying anomalous transport problems related to steady-state drift-wave turbulence in magnetic confinement devices. It can also be applied to other areas of plasma physics.

  5. Simulating "Mars on Earth"

    NASA Technical Reports Server (NTRS)

    Clancey, William J.; Clancy, Daniel (Technical Monitor)

    2002-01-01

    By now, everyone who's heard of the Haughton-Mars Project knows that we travel to Devon Island to learn how people will live and work on Mars. But how do we learn about Mars operations from what happens in the Arctic? We must document our experience--traverses, life in the hab, instrument deployment, communications, and so on. Then we must analyze and formally model what happens. In short, while most scientists are studying the crater, other scientists must be studying the expedition itself. That's what I have done in the past four field seasons. I study field science, both as it naturally occurs at Haughton (unconstrained by a "Mars Sam") and as a constrained experiment using the Flashline Mars Arctic Research Station. During the second week of July 2001, I lived and worked in the hab as part of the Phase 2 crew of six. Besides participating in all activities, I took many photographs and time lapse video. The result of my work will be a computer simulation of how we lived and worked in the hab. It won't be a model of particular people or even my own phase per se, but a pastiche that demonstrates (a proof of concept) that we have appropriate tools for simulating the layout of the hab and daily routines followed by the group and individual scientists. Activities-how people spend their time-are the focus of my observations for building such a simulation model.

  6. Space robot simulator vehicle

    NASA Technical Reports Server (NTRS)

    Cannon, R. H., Jr.; Alexander, H.

    1985-01-01

    A Space Robot Simulator Vehicle (SRSV) was constructed to model a free-flying robot capable of doing construction, manipulation and repair work in space. The SRSV is intended as a test bed for development of dynamic and static control methods for space robots. The vehicle is built around a two-foot-diameter air-cushion vehicle that carries batteries, power supplies, gas tanks, computer, reaction jets and radio equipment. It is fitted with one or two two-link manipulators, which may be of many possible designs, including flexible-link versions. Both the vehicle body and its first arm are nearly complete. Inverse dynamic control of the robot's manipulator has been successfully simulated using equations generated by the dynamic simulation package SDEXACT. In this mode, the position of the manipulator tip is controlled not by fixing the vehicle base through thruster operation, but by controlling the manipulator joint torques to achieve the desired tip motion, while allowing for the free motion of the vehicle base. One of the primary goals is to minimize use of the thrusters in favor of intelligent control of the manipulator. Ways to reduce the computational burden of control are described.

  7. Simulation and CRM.

    PubMed

    Ostergaard, Doris; Dieckmann, Peter; Lippert, Anne

    2011-06-01

    Patients are harmed as a result of incidents. Both poor interdisciplinary communication and teamwork are contributing factors to such events. The principles of crisis resource management are meant to help prevent and manage difficulties and reflect both, the social-team-oriented and cognitive-individual-oriented aspects of human factors. This article explores the importance of human factors training for safe care of patients and the role of simulation. Based on the available literature, the need to integrate this type of training to increase awareness of the importance of human factors and to change attitudes appears obvious. A combination of different training methods appears to be useful. Simulation-based training appears to be favourable, although the number of studies demonstrating the impact of training is limited. It is important to develop training programmes for individual teams, based on the knowledge of challenges and deficiencies, and to monitor behavioural change. Several methods, including patient safety data, interviews, observational studies and simulations, can be used to specify learning objectives. The training should be established for the real team(s). Furthermore, leaders need to implement training in the organisation and establish databases to monitor the impact on patient outcome. PMID:21550548

  8. Large scale traffic simulations

    SciTech Connect

    Nagel, K.; Barrett, C.L.; Rickert, M.

    1997-04-01

    Large scale microscopic (i.e. vehicle-based) traffic simulations pose high demands on computational speed in at least two application areas: (i) real-time traffic forecasting, and (ii) long-term planning applications (where repeated {open_quotes}looping{close_quotes} between the microsimulation and the simulated planning of individual person`s behavior is necessary). As a rough number, a real-time simulation of an area such as Los Angeles (ca. 1 million travellers) will need a computational speed of much higher than 1 million {open_quotes}particle{close_quotes} (= vehicle) updates per second. This paper reviews how this problem is approached in different projects and how these approaches are dependent both on the specific questions and on the prospective user community. The approaches reach from highly parallel and vectorizable, single-bit implementations on parallel supercomputers for Statistical Physics questions, via more realistic implementations on coupled workstations, to more complicated driving dynamics implemented again on parallel supercomputers. 45 refs., 9 figs., 1 tab.

  9. SATCOM constellation power simulation

    SciTech Connect

    Capulli, J.; Badke, B.; Davis, G.

    1995-12-31

    Three basic variables directly impact the power and energy generated by the SATCOM satellite constellation and its individual Space Vehicles (SVs). They are (1) telecommunications traffic patterns, (2) network resource management controllables, and (3) system hardware and software performance. This power simulation has verified the robustness of the telecommunications architecture. It has validated the onboard resource allocation process from an SV and network level power and energy perspective. The analyses have led to development of operational procedures that prevent SV node outages, and maximize network telecommunication traffic capacity. The program objective is to optimize overall system operation, availability and quality of service. Achieving this goal requires a thorough understanding of the Electrical Power Subsystem and its interfaces. The EPS simulation model analyzes network level performance by evaluating requirement compliance in the expected operating environments. Specifically, the simulation tool evaluates different design approaches and network operational strategies from a power and energy perspective. As a result, optimal load management solutions will be implemented both on-board the SV and via ground station directed resource allocation strategies.

  10. The Indra Simulation Database

    NASA Astrophysics Data System (ADS)

    Falck, Bridget; Budavari, T.; Cole, S.; Crankshaw, D.; Dobos, L.; Lemson, G.; Neyrinck, M.; Szalay, A.; Wang, J.

    2011-05-01

    We present the Indra suite of cosmological N-body simulations and the design of its companion database. Indra consists of 512 different instances of a 1 Gpc/h-sided box, each with 100 million dark matter particles and the same input cosmology, enabling a characterization of very large-scale modes of the matter power spectrum with galaxy-scale mass resolution and an excellent handle on cosmic variance. Each simulation outputs 64 snapshots, giving over 100 TB of data for the full set of simulations, all of which will be loaded into a SQL database. We discuss the database design for the particle data, consisting of the positions and velocities of each particle; the FOF halos, with links to the particle data so that halo properties can be calculated within the database; and the density field on a power-of-two grid, which can be easily linked to each particle's Peano-Hilbert index. Initial performance tests and example queries will be given. The authors are grateful for support from the Gordon and Betty Moore and the W.M. Keck Foundations.

  11. Simulating rotational grazing management.

    PubMed

    Cros, M J; Duru, M; Garcia, F; Martin-Clouaire, R

    2001-09-01

    Dairy systems predominantly based on rotational grazing are notoriously hard to manage. In order to ensure profitability, this type of production requires quite good organisation, planning, and operating capability on the part of the farmer. A simulation-based decision support system, called SEPATOU, has been developed for this purpose. At the core of the decision support approach lies an explicit and rigorous modelling of the management strategy that underlies a dairy farmer's decision-making behaviour (real or hypothetical). The SEPATOU system is a discrete-event simulator that reproduces the day-to-day dynamics of the farmer's decision process and the response of the controlled biophysical system for which models of grass growth, animal consumption, and milk production are used. SEPATOU provides the means to evaluate and compare tentative strategies by simulating their application throughout the production season under different hypothetical weather conditions. The relative worth of a strategy can be assessed by analysing the effects on the biophysical system and their variability across the representative range of possible conditions that is considered. The activities to be managed concern the type and amount of conserved feed, where to fertilise and how much, the choice of fields to harvest, and most importantly, which field to graze next. Typically, SEPATOU is designed to be used by extension services and farming system scientists. It is implemented in C++ and is currently undergoing a validation process with the intended users. PMID:11697661

  12. Simulated Ionian Column Densities

    NASA Astrophysics Data System (ADS)

    Walker, Andrew C.; Goldstein, D. B.; Varghese, P. L.; Trafton, L. M.; Moore, C. H.

    2010-10-01

    The sublimation atmosphere of Io is modeled using the direct simulation Monte Carlo (DSMC) method. These three-dimensional simulations improve upon previous work by implementing a more accurate two-component surface temperature model. This surface temperature model solves the one-dimensional heat conduction equation with depth for every 1° by 1° surface element. It also includes the following physics: Jovian eclipse, reflected sunlight from Jupiter, latent heat of sublimation/condensation, hot spots, endogenic heating, and independent thermal inertias and albedos for the frost and non-frost surfaces. These simulations model only the dominant dayside atmospheric species, SO2. The non-equilibrium rotational and vibrational energy states of SO2 are treated as well as photo-emission from those states. Plasma heating of the atmosphere by high energy ions and electrons from the Jovian plasma torus is also modeled via a plasma energy flux. Resulting column densities are compared to recent observations in an attempt to constrain the thermal parameters for the frost and non-frost surfaces.

  13. Astronaut John Young in Command Module Simulator during Apollo Simulation

    NASA Technical Reports Server (NTRS)

    1968-01-01

    Astronaut John W. Young, command module pilot, inside the Command Module Simulator in bldg 5 during an Apollo Simulation. Astronauts Thomas P. Stafford, commander and Eugene A. Cernan, lunar module pilot are out of the view.

  14. Analysis of material entrainment with an unmanned aerial vehicle (UAV) and simulation of the debris-flow event at the Sattelbach torrent - Austria, 2013.

    NASA Astrophysics Data System (ADS)

    Scheidl, Christian; Schraml, Klaus; Moser, Markus; Hübl, Johannes

    2014-05-01

    In summer 2013, a disastrous debris-flow destroyed several houses and infrastructure facilities on the fan of the Sattelbach catchment located in the district of St. Johann im Pongau, Salzburg (Austria). Fortunately, no damage to persons could be registered. The debris flow was triggered by shallow landslides within the upper catchment, mobilizing in total approximately 4,000 m3 of debris. However, the volume of the debris-flow event at the fan was documented with 12,000 m3, whereas a maximum discharge of 380 m3/s was estimated near the fan apex. Witnesses reported only one big wave passing the fan area, which seems to be out of character for a typical Alpine debris-flow event showing such high discharge. For the later, one would suppose multiple smaller waves. Due to the fact of evolving material entrainment resulted in one big wave, the debris-flow event at the Sattelbach catchment was chosen as case study to analyze mass bulking. For this reason, an unmanned aerial vehicle (UAV) was used to establish a digital terrain model (DTM) of the whole reach after the event. This terrain model was then compared to a LiDAR DTM, showing the topographical situation before the event. Based on the analyzed mass bulking along the whole reach, numerical simulations were performed using the DAN3D (Dynamic Analysis of Landslides in Three Dimensions) code. The DAN3D model allows selection between different rheologies as well as the implementation of entrainment. The study will show the applicability of UAV's in small and steep catchments and will test DAN 3D a debris-flow simulation tool with an implemented mass-bulking model.

  15. L'Apport de la Greffe de Peau Totale dans le Traitement des Sequelles des Brulures de la Main: a Propos de 14 Cas

    PubMed Central

    Ettalbi, S.; Ibnouzahir, M.; Rachid, M.; Bahaichar, N.; Boukind, H.

    2007-01-01

    Summary La main est fréquemment exposée aux brûlures, ce qui entraîne des séquelles cutanées. A partir d'une série de 14 patients suivis dans notre service sur une année, nous avons essayé d'établir la simplicité, l'efficacité et le rôle de la greffe de peau totale dans le traitement de ces séquelles (les organes nobles ne sont pas mis à nu). La greffe de peau totale associée à une rééducation efficace permet aux patients de reprendre la mobilité des mains dans les brefs délais. PMID:21991094

  16. GRMHD and GRPIC Simulations

    NASA Technical Reports Server (NTRS)

    Nishikawa, K.-I.; Mizuno, Y.; Watson, M.; Fuerst, S.; Wu, K.; Hardee, P.; Fishman, G. J.

    2007-01-01

    We have developed a new three-dimensional general relativistic magnetohydrodynamic (GRMHD) code by using a conservative, high-resolution shock-capturing scheme. The numerical fluxes are calculated using the HLL approximate Riemann solver scheme. The flux-interpolated constrained transport scheme is used to maintain a divergence-free magnetic field. We have performed various 1-dimensional test problems in both special and general relativity by using several reconstruction methods and found that the new 3D GRMHD code shows substantial improvements over our previous code. The simulation results show the jet formations from a geometrically thin accretion disk near a nonrotating and a rotating black hole. We will discuss the jet properties depended on the rotation of a black hole and the magnetic field configuration including issues for future research. A General Relativistic Particle-in-Cell Code (GRPIC) has been developed using the Kerr-Schild metric. The code includes kinetic effects, and is in accordance with GRMHD code. Since the gravitational force acting on particles is extreme near black holes, there are some difficulties in numerically describing these processes. The preliminary code consists of an accretion disk and free-falling corona. Results indicate that particles are ejected from the black hole. These results are consistent with other GRMHD simulations. The GRPIC simulation results will be presented, along with some remarks and future improvements. The emission is calculated from relativistic flows in black hole systems using a fully general relativistic radiative transfer formulation, with flow structures obtained by GRMHD simulations considering thermal free-free emission and thermal synchrotron emission. Bright filament-like features protrude (visually) from the accretion disk surface, which are enhancements of synchrotron emission where the magnetic field roughly aligns with the line-of-sight in the co-moving frame. The features move back and forth as

  17. Molecular Simulations in Astrobiology

    NASA Technical Reports Server (NTRS)

    Pohorille, Andrew; Wilson, Michael A.; Schweighofer, Karl; Chipot, Christophe; New, Michael H.; Vincenzi, Donald L. (Technical Monitor)

    2001-01-01

    One of the main goals of astrobiology is to understand the origin of cellular life. In the absence of any record of the earliest ancestors of contemporary cells, protocells, the most direct way to test our understanding of their characteristics is to construct laboratory models of protocells. Such efforts, currently underway in the NASA Astrobiology Program, are accompanied by computational studies aimed at explaining self-organization of simple molecules into ordered structures and developing designs of molecules that are capable of performing protocellular functions. Many of these functions, such as importing nutrients, capturing and storing energy, and responding to changes in the environment, are carried out by proteins bound to membranes. We use computer simulations to address the following, questions about these proteins: (1) How do small proteins (peptides) organize themselves into ordered structures at water-membrane interfaces and insert into membranes? (2) How do peptides aggregate to form membrane-spannin(y structures (e.g., channels)? (3) By what mechanisms do such aggregates perform their functions? The simulations are performed using the molecular dynamics (MD) method. In this method, Newton's equations of motion for each atom in the system are solved iteratively. At each time step, the forces exerted on each atom by the remaining atoms are evaluated by dividing them into two parts. Short-range forces are calculated directly in real space while long-range forces are evaluated in reciprocal space, usually using a particle-mesh algorithm which is of order O(NlnN). Currently, a time step of 2 femtoseconds is typically used, thereby making studies of problems occurring on multi-nanosecond time scales (10(exp 6) - 10(exp 8) time steps) accessible. To address a broader range of problems, simulations need to be extended by three orders of magnitude. Such an extension requires both algorithmic improvements and codes scalable to a large number of parallel

  18. Simulation Framework for Teaching in Modeling and Simulation Areas

    ERIC Educational Resources Information Center

    De Giusti, Marisa Raquel; Lira, Ariel Jorge; Villarreal, Gonzalo Lujan

    2008-01-01

    Simulation is the process of executing a model that describes a system with enough detail; this model has its entities, an internal state, some input and output variables and a list of processes bound to these variables. Teaching a simulation language such as general purpose simulation system (GPSS) is always a challenge, because of the way it…

  19. A Nonlinear Propulsion System Simulation Technique for Piloted Simulators

    NASA Technical Reports Server (NTRS)

    Mihaloew, J. R.

    1981-01-01

    In the past, propulsion system simulations used in flight simulators have been extremely simple. This resulted in a loss of simulation realism since significant engine and aircraft interactions were neglected and important internal engine parameters were not computed. More detailed propulsion system simulators are needed to permit evaluations of modern aircraft propulsion systems in a simulated flight environment. A real time digital simulation technique has been developed which provides the capabilities needed to evaluate propulsion system performance and aircraft system interaction on manned flight simulators. A parameter correlation technique is used with real and pseudo dynamics in a stable integration convergence loop. The technique has been applied to a multivariable propulsion system for use in a piloted NASA flight simulator program. Cycle time is 2.0 ms on a Univac 1110 computer and 5.7 ms on the simulator computer, a Xerox Sigma 8. The model is stable and accurate with time steps up to 50 ms. The program evaluated the simulation technique and the propulsion system digital control. The simulation technique and model used in that program are described and results from the simulation are presented.

  20. Baisse du HDL-cholestérol indicateur du stress oxydatif dans le diabète de type 2

    PubMed Central

    Kabamba, Arsène Tshikongo; Bakari, Salvius Amuri; Longanga, Albert Otshudi; Lukumwena, Zet Kalala

    2014-01-01

    L'hypercholestérolémie est étroitement liée au stress oxydatif. Lorsqu'il y a trop de cholestérol qui circule dans le sang, il n'est pas utilisé en totalité par les cellules et il risque de s'accumuler dans les vaisseaux sanguins. Cela peut entrainer la formation des plaques d'athérosclérose qui gênent la circulation sanguine et provoquent des accidents cardiovasculaires. Le stress oxydatif apparait très tôt dans l'histoire des complications du diabète de type 2, et est lié à l'oxydation du glucose mais aussi à la peroxydation lipidique. Le cholestérol-HDL est un marqueur important du stress oxydatif par sa capacité à faciliter la métabolisation du cholestérol, sa baisse est souvent considérée comme la source de beaucoup d'inquiétudes. L'objectif est l’évaluation de la variation du taux de cholestérol-HDL, marqueur du stress oxydatif, chez les patients diabétiques de type 2 dans la population congolaise. Nous avons inclus dans cette étude prospective des cas témoins des patients diabétiques de type 2 reconnus et diagnostiqués, et des témoins non diabétiques appariés selon l’âge et le sexe. Parallèlement au bilan biologique classique, une analyse d'un des facteurs de risque du stress oxydatif a été réalisée: baisse de HDL-Cholestérol. L’âge moyen des 30 patients diabétiques (47,77±10,78 ans) était comparable à celui des 30 témoins (48,83±10,73 ans). Une baisse significative du cholestérol-HDL dans le sang était observée chez 100% des diabétiques et 50% des témoins (p=0,0000). L'augmentation du HDL cholestérol permet d’éliminer le mauvais cholestérol en excès en nettoyant les tissus et en ramenant le cholestérol vers le foie. Lors du diabète de type 2 on constate une baisse sanguine sensible du taux de HDL-cholestérol, qui est signe indicateur du stress oxydatif. PMID:25767660

  1. La place de la thoracoscopie dans la prise en charge des pathologies thoraciques: à propos de 104 cas

    PubMed Central

    Lakranbi, Marwane; Rabiou, Sani; Ghalimi, Jamal; Issoufou, Ibrahim; Ouadnouni, Yassine; Smahi, Mohamed

    2015-01-01

    Introduction La thoracoscopie est l'exploration endoscopique de la cavité pleurale, des organes avoisinants (diaphragme, péricarde, médiastin) et du poumon. Le but de ce travail se veut d'abord didactique; décrivant la thoracoscopie, ses techniques ainsi que sa place dans la prise en charge de la pathologie thoracique (indications et perspectives thérapeutiques) et informatif en rapportant l'expérience de notre équipe. Méthodes Il s'agit d'une étude rétrospective intéressant 104 thoracoscopies à visée diagnostique et/ou thérapeutique réalisées au service de chirurgie thoracique du Centre Hospitalier Universitaire Hassan II de Fès, sur une période de 04 ans (Août 2008-décembre 2012). Nous avons exclu de notre étude les cas ayant bénéficié d'une médiastinoscopie ainsi que les cas ayant bénéficié d'une thoracoscopie dans le cadre des traumatismes fermés du thorax ou des plaies thoraciques. Résultats L’ âge moyen des patients est de 47 ans, avec des extrêmes allant de 18 à 80 ans, et une légère prédominance masculine à 54%. La thoracoscopie est d'ordre pleural chez 86 patients, pulmonaire chez 10 patients et médiastinale chez 8 patients. La thoracoscopie avait une indication à visée diagnostique chez 87 cas et thérapeutique chez 52 patients (talcage dans 45 cas, décortication pleuropulmonaire dans 2 cas, résection de kystepleuro-péricardique dans 2 cas, cure de pneumothorax dans 2 cas et une fenêtre péricardique). L’évolution post opératoire etait marquée par une amélioration clinico-radiologique chez 40 malades, 11 ont présenté une amélioration clinique seule, 6 ont présenté une persistance ou une récidive de l’épanchement. Conclusion La thoracoscopie représente un réel gain en matière de diagnostic de certaines pathologies intra-thoraciques. Son intérêt thérapeutique limité doit être éventuellement étendu grâce à la chirurgie thoracique vidéo assistée, qui est une technique récente fiable

  2. Real time flight simulation methodology

    NASA Technical Reports Server (NTRS)

    Parrish, E. A.; Cook, G.; Mcvey, E. S.

    1977-01-01

    Substitutional methods for digitization, input signal-dependent integrator approximations, and digital autopilot design were developed. The software framework of a simulator design package is described. Included are subroutines for iterative designs of simulation models and a rudimentary graphics package.

  3. Simulator for heterogeneous dataflow architectures

    NASA Technical Reports Server (NTRS)

    Malekpour, Mahyar R.

    1993-01-01

    A new simulator is developed to simulate the execution of an algorithm graph in accordance with the Algorithm to Architecture Mapping Model (ATAMM) rules. ATAMM is a Petri Net model which describes the periodic execution of large-grained, data-independent dataflow graphs and which provides predictable steady state time-optimized performance. This simulator extends the ATAMM simulation capability from a heterogenous set of resources, or functional units, to a more general heterogenous architecture. Simulation test cases show that the simulator accurately executes the ATAMM rules for both a heterogenous architecture and a homogenous architecture, which is the special case for only one processor type. The simulator forms one tool in an ATAMM Integrated Environment which contains other tools for graph entry, graph modification for performance optimization, and playback of simulations for analysis.

  4. Computer Simulation in Chemical Kinetics

    ERIC Educational Resources Information Center

    Anderson, Jay Martin

    1976-01-01

    Discusses the use of the System Dynamics technique in simulating a chemical reaction for kinetic analysis. Also discusses the use of simulation modelling in biology, ecology, and the social sciences, where experimentation may be impractical or impossible. (MLH)

  5. Bioaccumulation and Aquatic System Simulator

    EPA Science Inventory

    BASS (Bioaccumulation and Aquatic )System Simulator) is a Fortran 95 simulation program that predicts the population and bioaccumulation dynamics of age-structured fish assemblages that are exposed to hydrophobic organic pollutants and class B and bord...

  6. Simulating relativistic binaries with Whisky

    NASA Astrophysics Data System (ADS)

    Baiotti, L.

    We report about our first tests and results in simulating the last phase of the coalescence and the merger of binary relativistic stars. The simulations were performed using our code Whisky and mesh refinement through the Carpet driver.

  7. Simultaneous analysis of eight bioactive compounds in Danning tablet by HPLC-ESI-MS and HPLC-UV.

    PubMed

    Liu, Runhui; Zhang, Jiye; Liang, Mingjin; Zhang, Weidong; Yan, Shikai; Lin, Min

    2007-02-19

    A high performance liquid chromatography (HPLC) coupled with electrospray tandem mass spectrometry (ESI-MS) and ultraviolet detector (UV) has been developed for the simultaneous analysis of eight bioactive compounds in Danning tablet (including hyperin, hesperidin, resveratrol, nobiletin, curcumine, emodin, chrysophanol, and physcion), a widely used prescription of traditional Chinese medicine (TCM). The chromatographic separation was performed on a ZORBAX Extend C(18) analytical column by gradient elution with acetonitrile and formate buffer (containing 0.05% formic acid, adjusted with triethylamine to pH 5.0) at a flow rate of 0.8 ml/min. The eight compounds in Danning tablet were identified and their MS(n) fractions were elucidated by using HPLC-ESI-MS, and the contents of these compounds were determined by using HPLC-UV method. The standard calibration curves were linear between 5.0 and 100 microg/ml for hyperin, 10-200 microg/ml for hesperidin, 1.0-150 microg/ml for resveratrol, 2.0-120 microg/ml for nobiletin, 2.0-225 microg/ml for curcumine, 20-300 microg/ml for emodin, 2.0-200 microg/ml for chrysophanol, and 20-250 microg/ml for physcion with regression coefficient r(2)>0.9995. The intra-day and inter-day precisions of this method were evaluated with the R.S.D. values less than 0.7% and 1.3%, respectively. The recoveries of the eight investigated compounds were ranged from 99.3% to 100.2% with R.S.D. values less than 1.5%. This method was successfully used to determine the 8 target compounds in 10 batches of Danning tablet. PMID:17079108

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

    NASA Astrophysics Data System (ADS)

    Le Boeuf, David

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

  9. Etude experimentale des excitations topologiques de l'effet Hall quantique a nu = 1 dans les heterostructures semiconductrices a double puits quantique

    NASA Astrophysics Data System (ADS)

    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

  10. Look-ahead Dynamic Simulation

    Energy Science and Technology Software Center (ESTSC)

    2015-10-20

    Look-ahead dynamic simulation software system incorporates the high performance parallel computing technologies, significantly reduces the solution time for each transient simulation case, and brings the dynamic simulation analysis into on-line applications to enable more transparency for better reliability and asset utilization. It takes the snapshot of the current power grid status, functions in parallel computing the system dynamic simulation, and outputs the transient response of the power system in real time.

  11. Simulating A Factory Via Software

    NASA Technical Reports Server (NTRS)

    Schroer, Bernard J.; Zhang, Shou X.; Tseng, Fan T.

    1990-01-01

    Software system generates simulation program from user's responses to questions. AMPS/PC system is simulation software tool designed to aid user in defining specifications of manufacturing environment and then automatically writing code for target simulation language, GPSS/PC. Domain of problems AMPS/PC simulates is that of manufacturing assembly lines with subassembly lines and manufacturing cells. Written in Turbo Pascal Version 4.

  12. Redesigned Human Metabolic Simulator

    NASA Technical Reports Server (NTRS)

    Duffield, Bruce; Jeng, Frank; Lange, Kevin

    2008-01-01

    A design has been formulated for a proposed improved version of an apparatus that simulates atmospheric effects of human respiration by introducing controlled amounts of carbon dioxide, water vapor, and heat into the air. Denoted a human metabolic simulator (HMS), the apparatus is used for testing life-support equipment when human test subjects are not available. The prior version of the HMS, to be replaced, was designed to simulate the respiratory effects of as many as four persons. It exploits the catalytic combustion of methyl acetate, for which the respiratory quotient (the molar ratio of carbon dioxide produced to oxygen consumed) is very close to the human respiratory quotient of about 0.86. The design of the improved HMS provides for simulation of the respiratory effects of as many as eight persons at various levels of activity. The design would also increase safety by eliminating the use of combustion. The improved HMS (see figure) would include a computer that would exert overall control. The computer would calculate the required amounts of oxygen removal, carbon dioxide addition, water addition, and heat addition by use of empirical equations for metabolic profiles of respiration and heat. A blower would circulate air between the HMS and a chamber containing a life-support system to be tested. With the help of feedback from a mass flowmeter, the blower speed would be adjusted to regulate the rate of flow according to the number of persons to be simulated and to a temperature-regulation requirement (the air temperature would indirectly depend on the rate of flow, among other parameters). Oxygen would be removed from the circulating air by means of a commercially available molecular sieve configured as an oxygen concentrator. Oxygen, argon, and trace amounts of nitrogen would pass through a bed in the molecular sieve while carbon dioxide, the majority of nitrogen, and other trace gases would be trapped by the bed and subsequently returned to the chamber. If

  13. Charges convectées par écoulements laminaires et turbulents dans des tubes de section rectangulaire

    NASA Astrophysics Data System (ADS)

    Touchard, G.; Dominguez, G.; Madani, K.

    1991-07-01

    This study relates the phenomenon of streaming currents by flow in a pipe of rectangular cross section. We compute at first the velocity profile in the case of a laminar flow. Then with the assumption of a weak space charge density an analytical solution for the space charge density profile in such pipe and for that kind of flow is also obtained. Thus we give the expression of the space charge density convected by a laminar flow. In the case of a turbulent flow the space charge convected is computed in the case of two parallel walls. At least, the experimental conditions and the confrontation between experiments and theoretical predictions are presented. Dans cette étude, nous analysons le phénomène de transport de charges électriques par convection dans un tube de section rectangulaire. Il nous faut tout d'abord définir le champ des vitesses hydrodynamiques. Dans le cas laminaire, une solution analytique peut être obtenue, aussi bien pour la vitesse que pour la densité volumique de charge en faisant l'hypothèse des faibles densités. A partir de ces résultats, nous calculons alors la densité volumique de charge transportée par un écoulement laminaire. Dans le cas d'un écoulement turbulent, la complexité du phénomène aussi bien hydrodynamique que d'électrisation, nous oblige à nous ramener au cas monodimensionnel de deux plans parallèles. Une expression de la vitesse moyenne axiale et de la vitesse fluctuante transversale est proposée ainsi qu'une modélisation de la nouvelle répartition de la charge. Les courants d'écoulement en turbulent peuvent alors être calculés. Nous présentons ensuite les conditions expérimentales ainsi qu'une confrontation entre les expériences réalisées en écoulement laminaire et turbulent avec les prévisions théoriques.

  14. Dermatomyosite du sujet âgé: étude de 4 observations dans le sud tunisien

    PubMed Central

    Frikha, Faten; Snoussi, Mouna; Salah, Raida Ben; Saidi, Noura; Kaddour, Neila; Bahloul, Zouhir

    2012-01-01

    La dermatomyosite (DM) touche essentiellement l’adolescent et l’adulte jeune, elle est très rare chez le sujet âgé, le plus souvent associée à des complications iatrogènes et à une pathologie cancéreuse. Nous avons étudié les caractéristiques de la DM du sujet âgé à travers une étude rétrospective dans laquelle nous avons comparé 4 patients âgés de plus de 65 ans au début de la myosite avec 40 sujets jeunes. PMID:23308331

  15. Réactions chimiques et courant de transport dans la phase Bi2223

    NASA Astrophysics Data System (ADS)

    Duperray, G.; Legat, D.; Savary, H.

    1994-11-01

    To get high transport capacities in magnetic field with Ag sheathed conductors, the Bi2223 phase must be free of residual phases, well-crystallized, the lamellas being parallel with the current lines and very dense. In a research context on multifilamentary conductor, a preliminary study has been done on bulk material (1 × 4 × 40 mm^3 bars) to optimize the frabrication parameters of the multifilamentary tapes. A lot of samples, corresponding to the different operating conditions have been electrically characterized and analyzed by EDS so as to get some correlations between microstructure and superconducting performances : determination, concentration and repartition of residual phases, crystallinity, orientation and compacity of the Bi2223 phase. We also examined the interactions between the " refractory phases ", (Ca, Sr)2CuO3 ; (Ca, Sr) CuO2, ; CuO and the liquid phase, Bi2212 enriched with Bi and Sr + (Ca, Sr)2PbO4 which promote the recombination into pure and well recristallized Bi2223 phase. Maximum transport current capacities at 77 K-O T were 11 A/mm^2 for a commercial powder and 17 A/mm^2 (47 A) for a laboratory type powder, the values being around 50 A/mm^2 for the corresponding multifilamentary conductors. Pour qu'un fil supraconducteur gainé d'argent présente une capacité de transport de courant élevée ainsi qu'une bonne tenue sous champ, il faut que la phase Bi2223 soit exempte de phases résiduelles, soit bien cristallisée en feuillets orientés dans le sens de passage du courant et soit compacte. Dans le contexte d'une recherche sur les conducteurs multifilamentaires, nous avons mené une étude préliminaire sur matériau massif (barrettes de 1 × 4 × 40 mm^3) afin de déterminer les conditions physicochimiques optimales de fabrication de brins multifilamentaires. Un grand nombre d'échantillons, correspondant à différentes conditions opératoires et caractérisés électriquement, ont été analysés par EDS de façon à corréler les

  16. Apport de l'orientation clinique dans le diagnostic des hypertensions arterielles endocriniennes

    PubMed Central

    El Aziz, Siham; Chadli, Asma; Louda, Fatima; El Ghomari, Hassan; Farouqi, Ahmed

    2014-01-01

    L'hypertension artérielle d'origine endocrinienne représente une cause curable d'hypertension artérielle (HTA), ce qui en justifie le dépistage. Une orientation clinique est souhaitable afin de prescrire les bilans adéquats, notamment dans les pays en voie de développement. L'objectif de notre étude est décrire les aspects cliniques des patients ayant une HTA endocrinienne diagnostiquée au CHU de Casablanca. Méthodes: Il s'agit d'une étude descriptive rétrospective de 2004 à 2011, incluant tout patient ayant une HTA endocrinienne (en dehors des dysthyroïdies) admis en Endocrinologie. Les données concernant les facteurs cliniques, paracliniques et thérapeutiques ont été colligées. Au cours de la période étudiée, 53 cas d'HTA endocrinienne ont été admis, avec une age moyen au diagnostic de 39,3 ans et un sex-ratio F/H de 3,9. Trente patients (56.6%) ont un age ont un âge inférieur à 40 ans. On ne retrouve pas d'hérédité tensionelle chez 88.7% des patients. Les étiologies sont le Syndrome de cushing (41.5%), le phéochromocytome (32%), les adénomes somatotropes (15%) et les hyperaldostéronismes primaire (7.5%). L'HTA est essentiellement de grade un ou deux (69.8%), avec un retentissement cardio-vasculaire chez 11 patients (20.7%). Les patients ayant un SC avaient tous des signes cutanés spécifiques. Il s'agissait de sujets jeunes avec plusieurs facteurs de risque cardiovasculaire. Nous avons retrouvé un amaigrissement chez 37.5% des patients ayant un phéochromocytome avec un indice de masse corporel moyen de 20 kg/m2. L'HTA était permanente dans 5 cas de phéochromocytomes. Il n'existait pas d'hypokaliémie chez 50% des patients ayant un hyperaldostéronisme. Les signes cliniques des patients ayant une acromégalie étaient francs, avec un age moyen plus élevé de 50 ans. Nous avons noté une régression de l'HTA chez 59% de ces patients après guérison de l'endocrinopathie en cause. Plusieurs signes cliniques peuvent nous

  17. Evaluation de la tenue du partogramme dans une maternité universitaire

    PubMed Central

    Limam, Manel; Zedini, Chekib; El Ghardallou, Meriem; Mellouli, Menel; Bougmiza, Iheb; Sahli, Jihène; Khairi, Hédi; Mtiraoui, Ali; Ajmi, Thouraya Nabli

    2015-01-01

    Introduction La mortalité maternelle est un problème majeur de santé mondiale. Une grande proportion de ces décès serait évitable par des soins adéquats, une aide à l'accouchement, la disponibilité des soins d'urgence et l'utilisation des outils d'aide à la décision tels que le partogramme. L'objectif était d’évaluer l’écart entre ce qui est censé être fait et ce qui est fait réellement pour les différents paramètres situés dans le partogramme au sein d'une maternité de 3ème niveau et élaborer des recommandations pour la mise en place d'un plan d'action. Méthodes Il s'agit d'une étude descriptive rétrospective par audit clinique, effectuée sur un échantillon de 400 dossiers obstétricaux des parturientes ayant accouchées dans la maternité du CHU Farhat Hached durant l'année 2011. Le référentiel utilisé est celui réalisé par l'Agence Nationale d'Accréditation et d'Evaluation en Santé en l'an 2000, concernant la qualité de la tenue du partogramme. Résultats La majorité des critères d’évaluation portant sur la présentation du partogramme était conforme. Deux critères concernant la variété de la présentation et le rythme cardiaque fœtal étaient non conformes parmi ceux portant sur la surveillance du fœtus. Plusieurs critères en rapport avec la surveillance de la mère étaient non conformes. Aucun des critères portant sur les traitements administrés et les marqueurs d’évènements n'est conforme. Les critères portant sur la naissance et la surveillance immédiate qui étaient non conformes sont: le début des efforts expulsifs, le mode d'accouchement, l’état du périnée, la délivrance et la révision utérine. Conclusion La véritable démarche de l'audit clinique se doit d'aller au-delà du recueil et de l'analyse des données, le but final étant l'amélioration des pratiques. PMID:26516400

  18. DAN measures water in the soil of the Gale crater: new results from Curiosity

    NASA Astrophysics Data System (ADS)

    Mitrofanov, Igor; Litvak, Maxim; Sanin, Anton; Starr, Richard; Lisov, Denis; Kuzmin, Ruslan; Behar, Alberto; Boynton, William; Hardgrove, Craig; Harshman, Karl; Jun, Ionsoo; Miliken, Ralf; Mischna, Michael; Moersch, Jeffry; Tate, Criss

    2014-05-01

    The Gale crater was selected as the landing site for NASA's rover Curiosity (1). Since the landing in the August 2012, the neutron active instrument DAN (2) is performing active testing measurements of ground water and chlorine content along the traverse of the rover. The best model for the water content in the subsurface was found to be the 2-layer one, with the traverse-averaged contents of water in the top and bottom layers 1.51±0.42 wt% and 2.97±1.16 wt%, respectively. The traverse-average thickness of the top layer is about 18.5±8.0 cm, and the traverse-average content of chlorine is about 1.14±0.25 wt%. The uncertainties of the values above represent the physical dispersion of measurements along the traverse, while the uncertainties of individual measurements are much smaller for each tested spot. These values are not consistent with the predictions for the ground water and chlorine in the Gale, which were based on the orbital measurements by GRS suite onboard Mars Odyssey (3). The average content of water around Gale, provided it is depth independent, was found to be about 5 wt%. More accurate estimations based on 2-layer model provide even much more water in the subsurface. The content of chlorine was determined from the orbit, about 0.5 wt%. The difference between water content estimations based on the orbital and surface data are larger than the statistical uncertainty, and one cannot explain the difference by different depth of neutron sensing by DAN and GRS. Therefore, one should consider the physical reason for depletion of ground water and enhancement of chlorine in Gale in comparison with the content in the soil of the surrounding area. The Gale was not the natural site of soil hydratation, the soil around the crater has the water at higher content. During the epoch of wet Mars, the transport of soil by creeks and rivers into the Gale lake was probably associated with some selection process, which predominantly supply particles with larger sizes

  19. Binaural room simulation

    NASA Technical Reports Server (NTRS)

    Lehnert, H.; Blauert, Jens; Pompetzki, W.

    1991-01-01

    In every-day listening the auditory event perceived by a listener is determined not only by the sound signal that a sound emits but also by a variety of environmental parameters. These parameters are the position, orientation and directional characteristics of the sound source, the listener's position and orientation, the geometrical and acoustical properties of surfaces which affect the sound field and the sound propagation properties of the surrounding fluid. A complete set of these parameters can be called an Acoustic Environment. If the auditory event perceived by a listener is manipulated in such a way that the listener is shifted acoustically into a different acoustic environment without moving himself physically, a Virtual Acoustic Environment has been created. Here, we deal with a special technique to set up nearly arbitrary Virtual Acoustic Environments, the Binaural Room Simulation. The purpose of the Binaural Room Simulation is to compute the binaural impulse response related to a virtual acoustic environment taking into account all parameters mentioned above. One possible way to describe a Virtual Acoustic Environment is the concept of the virtual sound sources. Each of the virtual sources emits a certain signal which is correlated but not necessarily identical with the signal emitted by the direct sound source. If source and receiver are non moving, the acoustic environment becomes a linear time-invariant system. Then, the Binaural Impulse Response from the source to a listener' s eardrums contains all relevant auditory information related to the Virtual Acoustic Environment. Listening into the simulated environment can easily be achieved by convolving the Binaural Impulse Response with dry signals and representing the results via headphones.

  20. LSST operation simulator implementation

    NASA Astrophysics Data System (ADS)

    Delgado, Francisco; Cook, Kem; Miller, Michelle; Allsman, Robyn; Pierfederici, Francesco

    2006-06-01

    We have developed an operation simulator for the Large Synoptic Survey Telescope (LSST) that is an implementation in Python language using the SimPy extension, with a modular and object-oriented design. The main components include a telescope model, a sky model, a weather database for 3 sites, a scheduler and multiple observing proposals. All the proposals derive from a parent class which is fully configurable through about 75 parameters to implement a specific science survey. These parameters control the target selection region, the composition of the sequence of observations for each field, the timing restrictions and filter selection criteria of each observation, the lunation handling, seeing limits, etc. The current implemented proposals include Weak Lensing, Near Earth Asteroids, Supernova and Kuiper Belt Objects. The telescope model computes the slew time delay from the current position to any given target position, using a complete kinematic model for the mount, dome and rotator, as well as optics alignment corrections. The model is fully configurable through about 50 parameters. The scheduler module combines the information received from the proposals and the telescope model for selecting the best target at each moment, promoting targets that fulfill multiple surveys and storing all the simulator activities in a MySQL database for further analysis of the run. This scheduler is also configurable; for example, balancing the weight of the slew time delay in selecting the next field to observe. This simulator has been very useful in clarifying some of the technical and scientific capabilities of the LSST design, and gives a good baseline for a future observation scheduler.