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Sample records for produto num projeto

  1. Using the Global Arrays Toolkit to Reimplement NumPy for Distributed Computation

    SciTech Connect

    Daily, Jeffrey A.; Lewis, Robert R.

    2011-09-01

    Global Arrays (GA) is a software system from Pacific Northwest National Laboratory that enables an efficient, portable, and parallel shared memory programming interface to manipulate distributed defense arrays. Using a combination of GA and NumPy, we have reimplemented NumPy as a distributed drop-in replacement called Global Arrays in NumPy (GAiN). Scalability studies will be presented showing the utility of developing serial NumPy codes which can later run on more capable clusters or supercomputers.

  2. Yeast Num1p associates with the mother cell cortex during S/G2 phase and affects microtubular functions

    PubMed Central

    1995-01-01

    The NUM1 gene is involved in the control of nuclear migration in Saccharomyces cerevisiae. The content of NUM1 mRNA fluctuates during the cell cycle, reaching a maximum at S/G2 phase, and the translation product Num1p associates with the cortex of mother cells mainly during S, G2, and mitosis, as seen by indirect immunofluorescence. The nuclear spindle in NUM1-deficient large-budded cells often fails to align along the mother/bud axis, while abnormally elongated astral microtubules emanate from both spindle pole bodies. A num1 null mutation confers temperature sensitivity to the cold-sensitive alpha-tubulin mutant tub1- 1, and shows synthetic lethality with the beta-tubulin mutant alleles tub2-402, tub2-403, tub2-404, and tub2-405. Deletion mapping has defined three functionally important Num1p regions: a potential EF hand Ca2+ binding site, a cluster of potential phosphorylation sites and a pleckstrin homology domain. The latter domain appears to be involved in targeting Num1p to the mother cell cortex. Our data suggest that the periodically expressed NUM1 gene product controls nuclear migration by affecting astral microtubule functions. PMID:7490278

  3. Review and Application of ASME NOG-1 and ASME NUM-1-2000

    NASA Technical Reports Server (NTRS)

    Lytle, Bradford P.; Delgado, H. (Technical Monitor)

    2002-01-01

    The intent of the workshop is to review the application of the ASME Nuclear Crane Standards ASME NOG-1 and ASME NUM-1-2000. The ASME Nuclear Crane standards provide a basis for purchasing overhead handling equipment with enhanced safety features, based upon accepted engineering principles, and including performance and environmental parameters specific to nuclear facilities.

  4. Complete Genome Sequence of Aggregatibacter actinomycetemcomitans Serotype g Strain NUM4039 (JCM 30399)

    PubMed Central

    Saito, Masanori; Hirasawa, Masaaki; Kuwahara, Noriko; Okada, Tamami; Umezawa, Koji; Kobayashi, Taira; Okamoto, Masaaki; Naito, Mariko; Hirasawa, Masatomo

    2016-01-01

    Aggregatibacter actinomycetemcomitans is considered to be a major etiological agent of aggressive periodontitis and includes serotype a to g strains. We herein report the first complete genome sequence of A. actinomycetemcomitans serotype g strain NUM4039. The genome is 2,382,853 bp in length with a G+C content of 44.34%. PMID:26988057

  5. Learning to Improve E-mail Classification with numéro interactive

    NASA Astrophysics Data System (ADS)

    Jones, Dean M.

    This paper describes some of the ways in which we use artificial intelligence technologies in numéro interactive, a Customer Interaction Management system. In particular, we focus on the classification of e-mail messages into one of multiple business categories. We describe different features that are extracted from e-mail messages to help in this classification, and the improvement in the overall classification accuracy that results from the use of each kind of feature.

  6. The dynein cortical anchor Num1 activates dynein motility by relieving Pac1/LIS1-mediated inhibition.

    PubMed

    Lammers, Lindsay G; Markus, Steven M

    2015-10-26

    Cortically anchored dynein orients the spindle through interactions with astral microtubules. In budding yeast, dynein is offloaded to Num1 receptors from microtubule plus ends. Rather than walking toward minus ends, dynein remains associated with plus ends due in part to its association with Pac1/LIS1, an inhibitor of dynein motility. The mechanism by which dynein is switched from "off" at the plus ends to "on" at the cell cortex remains unknown. Here, we show that overexpression of the coiled-coil domain of Num1 specifically depletes dynein-dynactin-Pac1/LIS1 complexes from microtubule plus ends and reduces dynein-Pac1/LIS1 colocalization. Depletion of dynein from plus ends requires its microtubule-binding domain, suggesting that motility is required. An enhanced Pac1/LIS1 affinity mutant of dynein or overexpression of Pac1/LIS1 rescues dynein plus end depletion. Live-cell imaging reveals minus end-directed dynein-dynactin motility along microtubules upon overexpression of the coiled-coil domain of Num1, an event that is not observed in wild-type cells. Our findings indicate that dynein activity is directly switched "on" by Num1, which induces Pac1/LIS1 removal. PMID:26483554

  7. The dynein cortical anchor Num1 activates dynein motility by relieving Pac1/LIS1-mediated inhibition

    PubMed Central

    Lammers, Lindsay G.

    2015-01-01

    Cortically anchored dynein orients the spindle through interactions with astral microtubules. In budding yeast, dynein is offloaded to Num1 receptors from microtubule plus ends. Rather than walking toward minus ends, dynein remains associated with plus ends due in part to its association with Pac1/LIS1, an inhibitor of dynein motility. The mechanism by which dynein is switched from “off” at the plus ends to “on” at the cell cortex remains unknown. Here, we show that overexpression of the coiled-coil domain of Num1 specifically depletes dynein–dynactin–Pac1/LIS1 complexes from microtubule plus ends and reduces dynein-Pac1/LIS1 colocalization. Depletion of dynein from plus ends requires its microtubule-binding domain, suggesting that motility is required. An enhanced Pac1/LIS1 affinity mutant of dynein or overexpression of Pac1/LIS1 rescues dynein plus end depletion. Live-cell imaging reveals minus end–directed dynein–dynactin motility along microtubules upon overexpression of the coiled-coil domain of Num1, an event that is not observed in wild-type cells. Our findings indicate that dynein activity is directly switched “on” by Num1, which induces Pac1/LIS1 removal. PMID:26483554

  8. Analysis and Visualization of Multi-Scale Astrophysical Simulations using Python and NumPy

    SciTech Connect

    Turk, M.; /KIPAC, Menlo Park

    2008-09-30

    The study the origins of cosmic structure requires large-scale computer simulations beginning with well-constrained, observationally-determined, initial conditions. We use Adaptive Mesh Refinement to conduct multi-resolution simulations spanning twelve orders of magnitude in spatial dimensions and over twenty orders of magnitude in density. These simulations must be analyzed and visualized in a manner that is fast, accurate, and reproducible. I present 'yt,' a cross-platform analysis toolkit written in Python. 'yt' consists of a data-management layer for transporting and tracking simulation outputs, a plotting layer, a parallel analysis layer for handling mesh-based and particle-based data, as well as several interfaces. I demonstrate how the origins of cosmic structure--from the scale of clusters of galaxies down to the formation of individual stars--can be analyzed and visualized using a NumPy-based toolkit. Additionally, I discuss efforts to port this analysis code to other adaptive mesh refinement data formats, enabling direct comparison of data between research groups using different methods to simulate the same objects.

  9. 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).

  10. "Projeto Rios" (Rivers Project) a methodology of classroom of the future (northern Portugal)

    NASA Astrophysics Data System (ADS)

    Almeida, Ana

    2013-04-01

    The rivers and the surrounding land drained by them are very important wildlife habitats. The water itself provides the environment for plants and animals, while the banks and nearby land support creatures such as otters, water lizards, dragonflies and a variety of water-loving plants. Using a different teaching strategy, on the latest three years, students of the eighth grade of the EB 2.3 Agrela school have been implementing the project "Nós e o Leça" (We and the river Leça). This initiative is part of a nationwide project in Portugal, the "Projeto Rios", which is a tool that aims the adoption and monitoring of a 500 meter river section, promoting society's awareness for the problems and the need of protection and recovery of the riparian systems. These students adopted a section of the Leça River, which is the one that is passing nearby our school. Throughout the mentioned school years, the children made field trips for characterization, knowledge and observation of some happenings on the section adopted, with the aid of a complete kit of materials (galoshes, loupes, tweezers, trays, fishnets, tape measure, tape of pH...). Token fields for identifications of plants and animals and specific data sheets/questionnaires, were also used and fulfilled. While in the river, it is done the collection of macro invertebrates to conclude about the water quality of the section under study. Youth also detect disturbances in the balance of the riverine ecosystem, either naturally occurring or of human origin. Aiming the sustained development and the citizenship education, the students performed a final action for improvement, which consisted in the uprooting of an invasive plant, in this case "the herb-of-fortune" and also gathering the "trash" founded along the adopted stretch of the river. Back to the classroom, we selected photographs and the collected data is treated and discussed to produce information (summaries, reports, tables, charts,...) which will be published

  11. Projeto do sistema anti-ressonante da fiação dos transdutores para o detector Mario Schenberg

    NASA Astrophysics Data System (ADS)

    Vieira, S. J.., Jr.; Melo, J. L.

    2003-08-01

    O detector de ondas gravitacionais Mario Schenberg está sendo projetado e construído pelo grupo Gráviton. Sua construção está ocorrendo no Laboratório de Estado Sólido e Baixas Temperaturas (LESBT) da Universidade de São Paulo, na cidade de São Paulo. Esse detector possui uma massa ressonante esférica de cobre-alumínio, com 65 cm de diâmetro, pesando aproximadamente 1150 Kg, suspensa por um sistema de isolamento vibracional, que se encontra em fase de testes preliminares. A real eficácia desse sistema, entretanto, só poderá ser comprovada quando o detector estiver aparelhado com, pelo menos, um transdutor eletromecânico de altíssima sensibilidade acoplado à massa ressonante. Neste momento, não só este sistema de isolamento vibracional será posto em teste, como o do projeto da fiação que transporta os sinais de microondas até os transdutores e destes para a pré-amplificação. Apesar dessa fiação ter sido projetada para não apresentar nenhum contato com a superfície esférica da antena, de maneira a não haver nenhuma transmissão de ruído vibracional do laboratório para esta, deve-se minimizar o ruído microfônico produzido nessa fiação por oscilações mecânicas, uma vez que ela não utiliza nenhum sistema de isolamento vibracional. Com o intuito de resolver este problema, projetamos uma estrutura, formada por pequenos cilindros conectados por barras, a qual não terá nenhuma ressonância mecânica na faixa de freqüências de interesse para detecção (3000 - 3400 Hz). Desta forma, as vibrações nessa faixa não serão amplificadas. O projeto foi feito usando iterativamente, de maneira a otimizar os resultados obtidos, o programa de elementos finitos Msc/Nastran. Através de simulações feitas neste programa, determinamos os parâmetros geométricos ideais a serem utilizados, os quais proporcionam a maior região espectral de interesse livre de ressonâncias.

  12. Projeto observatórios virtuais: educação através de telescópios robóticos

    NASA Astrophysics Data System (ADS)

    Santana, P. H. S.; Shida, R. Y.

    2003-08-01

    O principal objetivo do projeto Observatórios Virtuais é o ensino na área de ciências através de atividades práticas desenvolvidas em colaboração entre instituições de pesquisa em astronomia e escolas de ensino médio e fundamental. Este ano deverá ser concluída a implantação do programa piloto de estudos, pesquisas e observação astronômica direta, com utilização em tempo real de telescópios robóticos, que assim funcionarão como "observatórios virtuais". O objetivo pedagógico das atividades práticas baseadas nas imagens atronômicas é desenvolver as habilidades e competências dos alunos no uso do método científico. Para isso, serão realizados projetos interdisciplinares, a partir de observações astronômicas, já que a astronomia é uma área interdisciplinar por excelência. Essas atividades terão níveis diferenciados de complexidade, que podem ser adequados aos vários graus do ensino e realidades regionais. Será dada ênfase ao desenvolvimento e aplicação em São Paulo, onde atua a equipe do IAG/USP. Como resultados apresentados no presente trabalho, temos a criação de um software em português para o processamento de imagens obtidas através de CCDs e a elaboração de material para as atividades educacionais relacionadas.

  13. 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.

  14. Projeto educação em ciências com observatórios virtuais: a participação da Escola Moppe no período 2000-2003

    NASA Astrophysics Data System (ADS)

    Wuensche, C. A.; Gavioli, E.; Oliveira, A. L. P. R. S.; da Silva, C.; Cardoso, H. P.; Estácio, S.

    2003-08-01

    O projeto Educação em Ciências com Observatórios Virtuais foi concebido pelo Instituto Astronômico e Geofísico da USP, agregando diversas instituições de ensino e pesquisa no país para desenvolver competências diversas na educação fundamental, média e superior utilizando a astronomia como ferramenta multidisciplinar. Este trabalho descreve a participação da MOPPE, escola-piloto do INPE no projeto, no período de 2000-2003. Serão apresentadas 1) a criação de um clube de ciências (1999 a 2001) cujo tema foi a colonização de Marte e 2) a ementa de astronomia trabalhada com as 7a. e 8a. séries do ensino fundamental. A proposta do projeto Colonizando Marte foi estudar diversos aspectos de uma missão interplanetária e construir experiementos que permitissem quantificar esses aspectos. Os resultados obtidos incluiram apresentações nas SBPC Jovem em 2000 e 2001. Discutiremos também as ementas de astronomia trabalhadas desde 2001 e o envolvimento dos alunos com atividades ligadas a astronomia, fora da aula de ciências. A inclusão de astronomia no currículo das últimas séries motivou a participação de mais alunos culminando com a conquista de duas medalhas para alunos da 7a. série na Olimpiada Brasileira de Astronomia em 2002. Houve também um aumento no número de participantes na OBA 2003 e nos projetos de astronomia mais elaborados nas Feira de Ciências de 2001 e 2002. Destacamos em 2003 a inclusão da MOPPE no projeto TIE - Telescopes in Education - da NASA, que utiliza o telescópio do Observatório de Mount Wilson (EUA) para observações remotas em projetos pedagógicos para o ensino de astronomia.

  15. On the tradeoffs of programming language choice for numerical modelling in geoscience. A case study comparing modern Fortran, C++/Blitz++ and Python/NumPy.

    NASA Astrophysics Data System (ADS)

    Jarecka, D.; Arabas, S.; Fijalkowski, M.; Gaynor, A.

    2012-04-01

    The language of choice for numerical modelling in geoscience has long been Fortran. A choice of a particular language and coding paradigm comes with different set of tradeoffs such as that between performance, ease of use (and ease of abuse), code clarity, maintainability and reusability, availability of open source compilers, debugging tools, adequate external libraries and parallelisation mechanisms. The availability of trained personnel and the scale and activeness of the developer community is of importance as well. We present a short comparison study aimed at identification and quantification of these tradeoffs for a particular example of an object oriented implementation of a parallel 2D-advection-equation solver in Python/NumPy, C++/Blitz++ and modern Fortran. The main angles of comparison will be complexity of implementation, performance of various compilers or interpreters and characterisation of the "added value" gained by a particular choice of the language. The choice of the numerical problem is dictated by the aim to make the comparison useful and meaningful to geoscientists. Python is chosen as a language that traditionally is associated with ease of use, elegant syntax but limited performance. C++ is chosen for its traditional association with high performance but even higher complexity and syntax obscurity. Fortran is included in the comparison for its widespread use in geoscience often attributed to its performance. We confront the validity of these traditional views. We point out how the usability of a particular language in geoscience depends on the characteristics of the language itself and the availability of pre-existing software libraries (e.g. NumPy, SciPy, PyNGL, PyNIO, MPI4Py for Python and Blitz++, Boost.Units, Boost.MPI for C++). Having in mind the limited complexity of the considered numerical problem, we present a tentative comparison of performance of the three implementations with different open source compilers including CPython and

  16. Formation et Evolution des Structures dans le Milieu interstellaire. Une Approche théorique, numérique et observationnelle

    NASA Astrophysics Data System (ADS)

    Hennebelle, Patrick

    2000-11-01

    Le milieu interstellaire, au sein duquel se forme les étoiles,présente d'importants contrastes de densités. Ces structures se forment sous l'action couplée de processus magnétohydrodynamiques, thermiques et chimiques. La première partie de cette thèse est un travail théorique et numérique sur la condensation induite dynamiquement de gaz chaud et diffus en une phase froide et condensée. Nous montrons, tout d'aborddans le cas hydrodynamique, puis MHD, comment, dans un milieu thermiquement bistable, une fluctuation de vitesse typiquement transonique conduit, si elle est d'amplitude suffisante et dure un temps assez long, à la formationd'une structure stable. L'influence de divers paramètres -amplitude et échelle spatiale caractéristique de la perturbation, pression initiale, configuration du champ magnétique- sur la condensationest étudiée numériquement et analytiquement. Des spectres synthétiques sont calculés et qualitativement comparés aux spectres observationnels. La seconde partie de la thèse porte sur l'étudeobservationnelle des phases les plus condensées du milieu interstellaire détectées en absorption sur le fond infrarouge galactique par le satellite ISO. Nous effectuons tout d'abordune extraction systématique de ces objets à partir d'une analyse multi-échelle des données ISOGAL.L'étude du rapport des contrastes à 7 et 15 um permet de mesurer le rapport de l'extinction interstellaire, peu connue dans cette région du spectre, à ces deux longueurs d'onde. Des estimations d'opacité de quelques objets sont égalementdéduites des données en infrarouge. Des observations complémentaires spectroscopiques et bolométriques dans le domaineradio ont été effectuées et permettent une analyse plus détaillée des paramètres physico-chimiques de ces nuages.

  17. Um Projeto de Intervenção nos Espaços de Exposições do Planetário do Parque do Ibirapuera

    NASA Astrophysics Data System (ADS)

    Elias, D. S.; Amaral, L. H.; de Araújo, C. F., Jr.; Matsuura, O. T.; Voelzke, M. R.

    2005-08-01

    Cada vez mais a humanidade, em sua imensa maioria, está alheia às próprias conquistas. A insatisfação com esta realidade tem levado muitos pesquisadores, instituições, empresas e governos a procurar formas alternativas de acompanhar e transmitir todo este acervo científico cultural à sociedade, buscando a melhoria da qualidade da divulgação científica e contribuindo para o processo de cultura e alfabetização científica. Não há tempo nem espaço nos limitados planos curriculares do ensino médio e mesmo nos programas de ensino que propiciem a cultura científica e o acompanhamento do vertiginoso progresso científico e tecnológico atual. Neste sentido, a educação formal escolar precisa ser complementada ou acrescida de uma educação informal, extra-escolar, que possa oferecer à sociedade o que a escola não pode oferecer. A interação do público com museus, feiras de ciências, planetários, exposições científicas e/ou culturais é de grande importância para a aquisição e difusão de conhecimentos relacionados ao mundo científico. Reconhecidamente como um modelo de alfabetização científica esses ambientes promovem uma interação social capaz de propiciar de forma efetiva uma melhor relação ensino-aprendizagem com o público. Partindo desta realidade a Universidade Cruzeiro do Sul e a Escola Municipal de Astronomia (EMA) vêm desenvolvendo um projeto de intervenção no espaço em torno do Planetário do Parque do Ibirapuera com o objetivo de se implantar um ambiente de aprendizagem motivador e desafiador que promova a popularização de conteúdos relacionados à astronomia, astrofísica e cosmologia. Busca-se, também, a aproximação e interação do público com exposições que estão sendo implementadas no planetário. Considerando que se trata de um projeto de mestrado em fase inicial o objetivo do presente trabalho é apresentar a concepção básica e os critérios que estão sendo utilizados do ponto de vista pedag

  18. Object-oriented numerics with FOSS: comparing PyPy & NumPy, GCC/Clang & Bitz++ and Gfortran

    NASA Astrophysics Data System (ADS)

    Jarecka, Dorota; Arabas, Sylwester; Fijalkowski, Maciej; Jaruga, Anna; Del Vento, Davide

    2013-04-01

    Employment of object-oriented programming (OOP) techniques may help to improve code readability, and hence its auditability and maintainability - both being arguably crucial for scientific software. OOP offers, in particular, the possibility to reproduce in the program code the mathematical "blackboard abstractions" used in the literature. There exist a number of free and open-source tools allowing to obtain this goal without sacrificing performance. An OOP implementation of the MPDATA advection algorithm used as a core of weather, ocean and climate modelling systems will serve as an example for briefly highlighting some relevant recent FOSS developments including: - NumPy support in the PyPy just-in-time compiler of Python. - the Blitz++ library coupled with the C++11 support in GCC and Clang; - support for OOP constructs from Fortran 2003/2008 in GFortran; A brief overview of other performance-related packages for Python like Numba and Cython will be also given. This poster will describe and extends key findings presented in http://arxiv.org/abs/1301.1334

  19. Filtrage actif des harmoniques en courant et en tension des reseaux électriques : modélisation, simulation numérique et expérimentation

    NASA Astrophysics Data System (ADS)

    Lott, C.; Lapierre, O.; Pouliquen, H.; Saadate, S.

    1997-12-01

    calcul des puissances active et réactive instantanées donne des résultats satisfaisants. Des simulations numériques ont été réalisées. Enfin une maquette expérimentale de 100kVA a été réalisée et testée sur un site industriel. Les essais de la maquette ont montré de bonnes performances du filtre actif à thyristor GTO. Le filtrage en tension d'un jeu de barres perturbé par un convertisseur de 5MVA connecté sur un réseau amont a également été réalisé et étudié dans cet article.

  20. Élaboration et validation d'un modèle numérique reflétant le comportement mécanique du fémur sous chargement statique de compression

    NASA Astrophysics Data System (ADS)

    Jacquet, E.; Garbuio, P.; Pernin, J. N.

    2002-12-01

    Pour tenter d'améliorer les techniques d'ostéosynthèse, afin de réduire les fractures du fémur, apparaît la nécessité de développer un modèle géométrique et numérique capable de caractériser le comportement mécanique du fémur humain. La présente étude propose des résultats expérimentaux issus de tests de compression sur fémurs frais équipés de jauges d'extensomètre. Le modèle géométrique est introduit dans un code de calculs par éléments finis pour représenter le champ des déformations à la surface de l'os. On montre la cohérence du modèle au plan qualitatif et des améliorations pouvant être apportées à ce modèle sont discutées.

  1. Analyse numérique du problème de déplacement du noyau fondu en soudage par points de tôles à différentes épaisseurs

    NASA Astrophysics Data System (ADS)

    Benkedda, Y.; Tahar Chaouch, K.; Ibrir, B.

    2005-05-01

    Le soudage par résistance par points est une technique d'assemblage très répandue, en particulier dans l'industrie automobile, parce qu'elle est rapide, fiable et bon marché. Pour cela, la réalisation d'un point de soudure de qualité reste encore une préoccupation de l'industrie, surtout lorsqu'il s'agit de souder des tôles à différentes épaisseurs. Les premiers modèles mathématiques et expérimentaux qui couvrent ces différents aspects, sont principalement dirigés vers les modèles de transfert de chaleur ou vers les phénomènes de surfaces (modèles de surfaces) ; ces derniers, sont un problème d'importance, puisqu'ils interviennent chaque fois qu'un transfert de chaleur s'effectue entre deux solides accolés. Les physiciens ont étudie expérimentalement la réponse de la région de contact de deux solides aux pulsations de courant. Ils ont montré que le contact possède une résistance de resserrement due aux aspérités de surface, et que la température moyenne à l'interface des deux solides sous un chargement uniforme produit un adoucissement local lequel fait augmenter la région de contact. Le but de ce travail est consacré à l'analyse de l'influence des épaisseurs de tôles sur la position du noyau fondu. Expérimentalement, il a été montré que lorsque le rapport des épaisseurs est compris entre 1/1 et 1/10, le noyau fondu se déplace vers la pièce la plus épaisse. Ce phénomène peut s'expliquer à partir d'une étude thermique. Nous proposons donc, de résoudre le problème de transfert thermique transitoire associé au processus de soudage par points moyennant une méthode numérique. Ce modèle est capable de prédire l'évolution du noyau fondu en fonction des paramètres du procédé à savoir l'intensité de soudage et temps de soudage, ainsi que la répartition thermique en chaque point de l'assemblage.

  2. Calcul numérique accéléré de mesures de performance sur les modèles Markoviens appliqués aux systèmes informatiques et de télécommunications

    NASA Astrophysics Data System (ADS)

    Ghaddar, A.; Sinno, N.

    2005-05-01

    La complexité du phénomène de files d'attente dans les systèmes informatiques et télécommunications nécessite leur simulation par des modèles Markoviens pour les mesures de performance, mesure des délais d'attente au niveau des routeurs pour le modèle informatique et l'étude de la gestion des appels téléphoniques pour le modèle des circuits téléphoniques. L'optimisation des méthodes numériques de résolution des équations relatives à ces deux modèles va permettre d' ídentifier les critères de convergence rapide vers les états stationnaires correspondant à ces mesures.

  3. Efficient Memory Access with NumPy Global Arrays using Local Memory Access

    SciTech Connect

    Daily, Jeffrey A.; Berghofer, Dan C.

    2013-08-03

    This paper discusses the work completed working with Global Arrays of data on distributed multi-computer systems and improving their performance. The tasks completed were done at Pacific Northwest National Laboratory in the Science Undergrad Laboratory Internship program in the summer of 2013 for the Data Intensive Computing Group in the Fundamental and Computational Sciences DIrectorate. This work was done on the Global Arrays Toolkit developed by this group. This toolkit is an interface for programmers to more easily create arrays of data on networks of computers. This is useful because scientific computation is often done on large amounts of data sometimes so large that individual computers cannot hold all of it. This data is held in array form and can best be processed on supercomputers which often consist of a network of individual computers doing their computation in parallel. One major challenge for this sort of programming is that operations on arrays on multiple computers is very complex and an interface is needed so that these arrays seem like they are on a single computer. This is what global arrays does. The work done here is to use more efficient operations on that data that requires less copying of data to be completed. This saves a lot of time because copying data on many different computers is time intensive. The way this challenge was solved is when data to be operated on with binary operations are on the same computer, they are not copied when they are accessed. When they are on separate computers, only one set is copied when accessed. This saves time because of less copying done although more data access operations were done.

  4. Commande numérique d'axe avec compensation du couple résistant

    NASA Astrophysics Data System (ADS)

    Reis Costa, J. C.; Fadel, M.; de Fomel, B.

    1991-03-01

    A PWM fed synchronous motor drive with high performances is achieved by utilization of a state space control with load torque compensation. With a simple model, a state space load torque observer is studied and implemented. This control law, applied to a synchronous motor, results in a low sensitive position control system. La réalisation d'un variateur de position de haute performance, constitué d'une machine synchrone associée à un onduleur de tension MLI, peut s'obtenir en utilisant des techniques d'état associées à la compensation du couple résistant. Nous avons, dans ce travail, développé un observateur dynamique de couple, élaboré à partir d'un modèle simple assurant une bonne évaluation de la charge entrainée. L'utilisation d'un tel dispositif, nous permet d'obtenir un servomoteur synchrone doué de caractéristiques indépendantes de la charge.

  5. Projeto Vida no Vale: universal access to water and sanitation in the North East of Minas Gerais (Brazil)

    NASA Astrophysics Data System (ADS)

    Kauark-Leite, L.; Vinçon-Leite, B.; Deroubaix, J. F.; Loireau, A.; Silveira, D.; Haddad, E.

    2008-08-01

    In the rural areas of the developing countries, the access to water supply and sanitation services is still largely inadequate. Poor governance of the water sector is frequently singled out as a cause and reforms are required. Studies analyzing the great diversity of restructuring efforts currently being undertaken in the water sector have not succeeded in determining the most appropriate institutional and economic framework for such reforms. Moreover they underline the lack of documentation on actual projects and call for concrete models and tools for improving water and sanitation services (WSS) and for adapting water utility practice to real conditions. In this context, the Vida no Vale (Life in the Valley) project is aimed at bringing universal access to WSS for all inhabitants of both urban and rural areas, in the north-eastern area of the Brazilian State of Minas Gerais. The project takes sustainable development as its guiding principle, and relies on the joint implementation of an innovative technical design, a governance model involving public participation and subsidiarity, and an economic structure combining financial viability and social equity. Designed at a consistent geographical and hydrological scale, it includes the creation of a regional subsidiary of the existing state water company as a keystone element. The institutional organisation also relies on the creation of a public board consisting of the 92 municipalities of the project region and of the State of Minas Gerais. This board will be in charge of the system's governance. This paper presents the first step of the project (2006), consisting of a feasibility study and the implementation of 9 pilot sub-projects. During the feasibility study, the supply, demand and capacity to pay for water services were defined, existing infrastructure appraised, the necessary amount of investment assessed and an innovative operational model and a sustainable management system, including civil society participation, defined. The main features of the Vida no Vale project have been tested in 9 pilot sub-projects, and implemented in municipalities chosen for their low Human Development Index and for the lack of WSS, in both urban and rural areas. A second phase corresponding to the project's final implementation will run from 2007 to 2011. The Vida no Vale project design resulted in a logical and extensive framework which could be used for developing similar WSS projects in other poor, rural regions, its adaptiveness being a key feature for taking into account the specific, local conditions.

  6. Projeto Vida no Vale: universal access to water and sanitation in the North East of Minas Gerais (Brazil)

    NASA Astrophysics Data System (ADS)

    Kauark-Leite, L.; Vinçon-Leite, B.; Deroubaix, J. F.; Loireau, A.; Silveira, D.; Haddad, E.

    2007-08-01

    In the rural areas of the developing countries, the access to water supply and sanitation services is still largely inadequate. Poor governance of the water sector is frequently singled out as a cause and reforms are required. Studies analyzing the great diversity of restructuring efforts currently being undertaken in the water sector have not succeeded in determining the most appropriate institutional and economic framework for such reforms. Moreover they underline the lack of documentation on actual projects and call for concrete models and tools for improving water and sanitation services (WSS) and for adapting water utility practice to real conditions. In this context, the Vida no Vale (Life in the Valley) project is aimed at bringing universal access to WSS for all inhabitants of both urban and rural areas, in the north-eastern area of the Brazilian State of Minas Gerais. The project takes sustainable development as its guiding principle, and relies on the joint implementation of an innovative technical design, a governance model involving public participation and subsidiarity, and an economic structure combining financial viability and social equity. Designed at a consistent geographical and hydrological scale, it includes the creation of a regional subsidiary of the existing state water company as a keystone element. The institutional organisation also relies on the creation of a public board consisting of the 92 municipalities of the project region and of the State of Minas Gerais. This board will be in charge of the system's governance. The paper will present the first step of the project (2006), consisting of a feasibility study and the implementation of 9 pilot sub-projects. During the feasibility study, the supply, demand and capacity to pay for water services were defined, existing infrastructure appraised, the necessary amount of investment assessed and an innovative operational model and a sustainable management system, including civil society participation, defined. The main features of the Vida no Vale project have been tested in 9 pilot sub-projects, and implemented in municipalities chosen for their low Human Development Index and for the lack of WSS, in both urban and rural areas. A second phase corresponding to the project's final implementation will run from 2007 to 2011. The ongoing successful accomplishment of the Vida no Vale project would make it an exemplary and replicable model for other poor regions.

  7. An Institutional Approach to First-Year Adjustment: The "Projeto FEUP" Case Study of a Portuguese University

    ERIC Educational Resources Information Center

    Mouraz, Ana; Sousa, Armando

    2016-01-01

    This article intends to debate the institutional modes of first-year adjustment to higher education. Specifically, the aim is to analyze and consider the need to include social and academic integration activities in the curricular programs. The presented contributions are based on the investigations over the case study course that was studied…

  8. Informacion Bibliografica: Ano 3, Num. 9, Enero-Febrero, 1972 (Bibliographic Information: Volume 3, Number 9, January-February 1972).

    ERIC Educational Resources Information Center

    Martinez Martinez, Antonio L., Ed.

    This bulletin contains several articles on various topics concerning information science. The first article is a report on the November 1971 Seminar on Documentation and Pedagogical Information in Latin America held in Panama. The second article, entitled "Informatica," provides a discussion of information science by three Soviet writers;…

  9. Simulation numérique en électronique de puissance. Méthode dela topologie variable

    NASA Astrophysics Data System (ADS)

    Matt, D.; Prieur, F.; Glaize, C.

    1994-01-01

    This paper presents an original development of a most efficient model for representing switches in power electronics simulation. This model, quite simple after all, considers semiconductor components as perfect interruptors, leading to a variable topology analysis of the studied circuit. This circuit then becomes purely passive, the way of connecting passive components among themselves depending on the sermiconductors' states for each configuration. This concept, though it is not new, is rarely used, due to complications it induces for the construction of equations. The approach we presents aims to automatically eliminate this problem and make the most of the interests of the model. New possibilities are offered for perfecting efficient programs of power electronics simulation. L'article présente une méthode de mise en équation automatique des circuits de l'électronique de puissance basée sur le concept de la topologie variable. Cette méthode, dont les principes ont fait l'objet de nombreuses publications dans les années 70 [1-4], utilise un modèle de semi-conducteur parfait se comportant comme un simple interrupteur. La topologie du circuit évolue au gré des commutations des semi-conducteurs et est de ce fait "variable". Malgré ses nombreux avantages, cette méthode n'a jamais connu le succès mérité en raison des nombreuses difficultés liées à l'élimination des semi-conducteurs du circuit. L'article présenté propose une méthodologie de mise en équation entièrement automatique s'appuyant sur une analyse topologique des circuits. Elle permet de s'affranchir de bon nombre des difficultés inhérentes au concept. Cette méthodologie appliquée à un simulateur de convertisseurs statiques donne actuellement de très bons résultats avec un avantage appréciable tant dans la rapidité de calcul que dans la précision et fiabilité des résultats obtenus. L'analyse topologique du circuit effectuée permet de plus la détection automatique des défauts d'association de sources/charges.

  10. Historia Oral, Experiencias de Aprendizagem e Enraizamento Sociocultural--Um Projeto em Curso (Oral History, Learning Experiences, and Sociocultural Setting--A Project in Process).

    ERIC Educational Resources Information Center

    Vidigal, Luis

    1995-01-01

    Examines education and childhood in Portugal. Uses oral history methods in an educational context, exploring oral statements pedagogically. Considers these statements especially suitable to maintaining aspects of collective memory and social identity, reinforcing students' national and regional identities. Suggests this is very important in…

  11. Telescópio de pequeno porte como suporte ao ensino em cidades com intensa poluição luminosa II

    NASA Astrophysics Data System (ADS)

    Pereira, P. C. R.; Santos-Júnior, J. M.; Cruz, W. S.

    2003-08-01

    Para a maioria dos estudantes, sua passagem pelo ensino formal fundamental envolve a transmissão de fatos que devem ser guardados para um exame, a habilidade para lembrar fórmulas e, eventualmente, a repetição de experimentos que devem produzir resultados exigidos pelo professor. O resultado deste modelo de ensino, ao longo dos anos, é conhecido por todos: desconhecimento e descontentamento, por parte dos estudantes, de temas relativos ao papel e aos processos da ciência. Acreditamos que a Astronomia, pelo seu caráter observacional, é uma das áreas do conhecimento que pode contribuir neste cenário. A Fundação Planetário da Cidade do Rio de Janeiro possui um telescópio Meade LX-200 (25cm) que, juntamente com as câmeras CCD ST-7E e ST8E, tem sido utilizado em projetos voltados aos estudantes do ensino médio desde o ano 2000. Tais projetos envolvem a condução de um projeto de pesquisa observacional num nível apropriado, e possibilitam o contato com técnicas e novas tecnologias: computador, software para manipulação de dados e gráficos, programas de tratamento e redução de dados, uso de equipamentos óptico-eletrônicos (telescópio e CCD), bem como o processo de aquisição de conhecimento. Dentro da proposta dos anos anteriores, priorizamos projetos de uma noite, ou seja, procuramos trabalhar com fenômenos que apresentem variabilidade com intervalo de recorrência relativamente curto. Em todos os casos, optamos pela fotometria diferencial, que tem se mostrado bastante eficiente para o céu luminoso como o da cidade do Rio de Janeiro. Neste painel, apresentamos alguns dos projetos desenvolvidos no último ano, com 25 estudantes. Apresentamos os resultados da observação da variável pulsante AI Vel (V = 6,6) e da variável cataclísmica FO Aqr (V = 13,5), e do monitoramento do trânsito da lua de Júpiter, Europa, ocorrido em 30 de abril de 2003. As curvas de luz produzidas para as primeiras estão concordantes com as da literatura, assim

  12. Análise da aplicação e dos resultados do modelo OPM3® para a área da saúde

    PubMed Central

    Augusto dos Santos, Luis; de Fátima Marin, Heimar

    2015-01-01

    Esta pesquisa procurou analisar se um modelo de questionário criado por uma comunidade internacional de gerenciamento de projetos e se é aplicavél a organizações voltadas a área de saúde. O modelo OPM3® (Organizational Project Management Maturity Model) foi criado para que organizações de qualquer área ou porte pudessem identificar a presença, ou ausência, de boas práticas de gerenciamento. O objetivo da aplicação desse modelo é avaliar sempre a organização e não o entrevistado. No presente artigo, são apresentados os resultados da aplicação desse modelo em uma organização que possuía produtos e serviços de tecnologia da informação aplicados à área de saúde. Este estudo verificou que o modelo é aplicável de forma rápida e que a organização analisada possuía um número expressivo de boas práticas. PMID:26924862

  13. Evolution of the passive and active microwave signatures of a large sea ice feature during its 2<num>1num>2-year drift through the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Gohin, Francis; Cavanié, Alain; Ezraty, Robert

    1998-04-01

    Although estimation of the total ice concentration from special sensor microwave imagers (SSM/I) has proven to be successful, none of the various algorithms developed to discriminate new and older ice provide satisfying results. While the strong contrast between the emissivity of sea ice and that of open water can be utilized to provide reliable estimators of the total ice concentration, passive microwave characteristics of second-year and multiyear ice may locally evolve in different ways, even during the cold season. Scatterometers, as the active microwave instrument in wind mode (AMI-wind) on board the European Remote Sensing Satellites (ERS), provide backscatter data which have a higher sensitivity to the surface topography of ice and a better stability in time, at a resolution compatible with the SSM/I measurements. Here we present the evolutions of the microwave properties of an ice feature appearing along the shores of Novosibirskiye Ostrova (New Siberian Islands) at the end of July 1992 as the ice ages during its 3-year drift toward the Fram Strait. The track of this well-defined ice surface is easily followed on the maps of the backscatter coefficient provided by the AMI-wind during the cold season. In summer, because of melting, the ice undergoes critical changes which alter its microwave signatures and hamper automatic tracking. Moreover, on approaching the Fram Strait the resolution of the scatterometer is not sufficient to capture the complex and rapid transformations of the ice cover. To compensate for this, buoy data obtained from the International Arctic Buoy Program are used, alone during summers or together with satellite data, to build basin-wide ice displacement fields. These displacement fields, successively applied to each pixel of the ice feature selected, provide a series of Lagrangian observations. During the drift, which ends in May 1995, the active and passive signatures evolve coherently, except for the cold season 1992-1993 when unrealistic multiyear ice concentrations are deduced from the brightness temperatures, which, at that time, are much less stable than the backscatter coefficient over the ice surface tracked, identified as second-year ice.

  14. Looking Back and Ahead: 20 Years of Technologies for Language Learning

    ERIC Educational Resources Information Center

    Godwin-Jones, Robert

    2016-01-01

    Over the last 20 years Robert Godwin-Jones has written 48 columns on "Emerging Technologies"; an additional six columns have been written by guest columnists. Several topics have been re-examined in regular intervals of approximately five years, namely digital literacy (Vol. 4, Num. 2; Vol. 10, Num. 2; Vol. 14, Num. 3; Vol. 19, Num. 3)…

  15. Estudo da utilizacao da biomassa florestal como fonte de produtos quimicos e energia atraves de processos quimicos e biotechnologicos (Utilization of forest biomass for chemicals and energy by chemical and biotechnological processes). Master's thesis

    SciTech Connect

    de Miranda, I.M.S.S.

    1989-04-01

    The chemical composition and the non-structural carbohydrate composition were determined for 1-year-old Eucalyptus globulus Labill trees, grown in an experimental plantation with different nutrient and water supplies (C-trees, where no treatment was made and IL-trees, which received a nutrient supply and irrigation). Leaf carbohydrates were determined for the same conditions. Pulping experiments were made using kraft cooks of eucalyptus wood. The results of the pretreatments are complemented with scanning electron microscopy observations. Average wood composition was: ash 1.6%, total extractives 5.2%, Klason lignin 21.0%, soluble lignin 3.1% (% of o.d. weight). The results did not show statistical significant differences between the two growth conditions. The average wood carbohydrate composition was: glucose 2.7%, frutose 4.1% sucrose 1.3% and starch 0.5%. The average carbohydrate composition of leaves was: glucose 1.0%, frutose 1.7%, sucrose 0.1% and starch 4.1%. The average yield for the kraft wood delinification was 49%. The saccharification of pretreated eucalyptus chips with a steam-explosion pretreatment was: For H2SO4 impregnation 26.6% and for H2O impregnation 44.2%.

  16. Usina de ciências: um espaço pedagógico para aprendizagens múltiplas

    NASA Astrophysics Data System (ADS)

    Martin, V. A. F.; Poppe, P. C. R.; Orrico, A. C. P.; Pereira, M. G.

    2003-08-01

    Entendemos que o Ensino de Astronomia é especialmente apropriado para motivar os alunos e aprofundar conteúdos em diversas áreas do conhecimento, pois envolve temas ligados à Física, Matemática, Química, Computação, Tratamento de Imagens e Instrumentação de Alta Precisão, além daqueles pertinentes as áreas de Geografia, História e Antropologia. Contudo, apesar do caráter interdisciplinar que esta ciência possui, a realidade atual é que a maioria dos professores em sala de aula não foram devidamente capacitados, durante o período de formação acadêmica, para ministrar conteúdos de Astronomia nos atuais Ensinos Fundamental e Médio. Neste trabalho, discutiremos de maneira ampla, num primeiro momento, a realidade do atual ensino de ciências praticado no Estado da Bahia, apontando por dependência administrativa, o crescimento e a redução do número de escolas, da taxa de analfabetismo por faixa etária, da escolarização, do atendimento, da aprovação, reprovação e abandono, de equipamentos e laboratórios e o grau de formação dos nossos atuais professores em pleno exercício de atividade docente. Num segundo momento, discutiremos o papel do Observatório Astronômico Antares/UEFS dentro desse contexto, ou seja, suas ações implementadas ao longo dos últimos anos e em particular, o recente projeto de extensão Ensino e Difusão de Astronomia, financiado pela Fundação Vitae, que procura traduzir no lúdico, no brincar de ciências, um espaço pedagógico para aprendizagens múltiplas. Neste, o papel do professor multiplicador associado ao laboratório de kits didáticos, de fácil construção e manipulação (alguns dos quais serão mostrados), perfazem os principais veículos para o desenvolvimento de conhecimentos, atitudes, habilidades e valores que preparam os nossos alunos para a carreira técnico-científica e para sua participação crítica e criativa na Sociedade.

  17. Présentations de différentes régulations numériques de courant par la méthode de l'échantillonneur équivalent

    NASA Astrophysics Data System (ADS)

    Bergmann, C.

    1991-03-01

    In this paper, we are showing how to take into account the non linear characteristics in the power converter described by states equations. This model gives the dynamical response of the set converter/machine around a steady state which value is obtained by a classical study (for example, a slide average method on the sampling period). To illustrate the utility of this tool, we are choosing two didactic examples. In a first part, we describe a set of static DC converter and DC motor. In a second part, we present a multivariable system deduced from the synchronous servomotor by the same method including the difficulties of the control in the real time. Nous montrons comment prendre en compte les non-linéarités des convertisseurs de puissance décrits par des équations d'état. Le modèle donne les performances dynamiques autour d'un point de fonctionnement qui est obtenu par une méthode plus classique comme par exemple " la moyenne glissante ". Pour illustrer la mise en ceuvre de ce modèle, nous avons choisi deux exemples didactiques. Dans une première partie, nous traitons un système monovariable, une association Hacheur moteur à courant continu. Dans une deuxième partie, nous présentons un système multivariable, illustré par une machine synchrone autopilotée associée à un onduleur. Le modèle inclut les difficultés dues au calcul " temps réel ".

  18. Métallurgie fondamentale et métallurgie numérique : l'héritage de Jacques Friedel dans la théorie de la plasticité des métaux et alliages

    NASA Astrophysics Data System (ADS)

    Bréchet, Yves

    2016-03-01

    Jacques Friedel's contribution to the theory of plasticity is described, as well as the more recent developments it inspired. It involves the microscopic properties of dislocations as well as macroscopic effects. The evolution of fundamental metallurgy toward numerical metallurgy is discussed, and Friedel's point of view on numerical methods is analyzed.

  19. Prevailing Lexical-Stylistic Features in Emirati Language Learners' Digital Discourse (Caractéristiques lexicales stylistiques dominantes dans le discours numérique des apprenants en langue émirienne)

    ERIC Educational Resources Information Center

    Grigoryan, Tsoghik

    2015-01-01

    Today's language classroom is undergoing an irreversible hyperbole and one of the most powerful drivers of this transformation is ICT. Digital classroom not only exposes the learners to grammatical language of linguistics, but rather the everyday life of the language in use (Thurlow & Mroczek, 2011). The aim of this study was to explore the…

  20. Differentiation inducing factor-1 (DIF-1) induces gene and protein expression of the Dictyostelium nuclear calmodulin-binding protein nucleomorphin.

    PubMed

    O'Day, Danton H; Poloz, Yekaterina; Myre, Michael A

    2009-02-01

    The nucleomorphin gene numA1 from Dictyostelium codes for a multi-domain, calmodulin binding protein that regulates nuclear number. To gain insight into the regulation of numA, we assessed the effects of the stalk cell differentiation inducing factor-1 (DIF-1), an extracellular signalling molecule, on the expression of numA1 RNA and protein. For comparison, the extracellular signalling molecules cAMP (mediates chemotaxis, prestalk and prespore differentiation) and ammonia (NH(3)/NH(4)(+); antagonizes DIF) were also studied. Starvation, which is a signal for multicellular development, results in a greater than 80% decrease in numA1 mRNA expression within 4 h. Treatment with ammonium chloride led to a greater than 90% inhibition of numA1 RNA expression within 2 h. In contrast, the addition of DIF-1 completely blocked the decrease in numA1 gene expression caused by starvation. Treatment of vegetative cells with cAMP led to decreases in numA1 RNA expression that were equivalent to those seen with starvation. Western blotting after various morphogen treatments showed that the maintenance of vegetative levels of numA1 RNA by DIF-1 in starved cells was reflected in significantly increased numA1 protein levels. Treatment with cAMP and/or ammonia led to decreased protein expression and each of these morphogens suppressed the stimulatory effects of DIF-1. Protein expression levels of CBP4a, a calcium-dependent binding partner of numA1, were regulated in the same manner as numA1 suggesting this potential co-regulation may be related to their functional relationship. NumA1 is the first calmodulin binding protein shown to be regulated by developmental morphogens in Dictyostelium being upregulated by DIF-1 and down-regulated by cAMP and ammonia. PMID:19000924

  1. Evaluation de la qualité de modèles numériques de terrain dérivés par interférométrieEvaluación de la calidad de modelos digitales de elevación derivados por interferometría

    NASA Astrophysics Data System (ADS)

    Gens, Rüdiger

    One of the most important uses of SAR interferometry is in the generation of digital elevation models (DEMs). However, a standard procedure for quality estimation of DEMs does not exist. This paper proposes a method of quality estimation using an adapted Monte Carlo simulation, which has the advantage that it could be used in areas where appropriate reference DEMs are not available. This paper also addresses interferometric processing, with special emphasis on the influence of the input parameters. Practical implementation of the proposed technique is shown on a data set from Lower Saxony in Germany. The error map generated, which is a measure of the quality of the DEM, is also presented. For further analysis of the critical aspects of quality, a reference DEM has also been used.

  2. Automatic Parallelization of Numerical Python Applications using the Global Arrays Toolkit

    SciTech Connect

    Daily, Jeffrey A.; Lewis, Robert R.

    2011-11-30

    Global Arrays is a software system from Pacific Northwest National Laboratory that enables an efficient, portable, and parallel shared-memory programming interface to manipulate distributed dense arrays. The NumPy module is the de facto standard for numerical calculation in the Python programming language, a language whose use is growing rapidly in the scientific and engineering communities. NumPy provides a powerful N-dimensional array class as well as other scientific computing capabilities. However, like the majority of the core Python modules, NumPy is inherently serial. Using a combination of Global Arrays and NumPy, we have reimplemented NumPy as a distributed drop-in replacement called Global Arrays in NumPy (GAiN). Serial NumPy applications can become parallel, scalable GAiN applications with only minor source code changes. Scalability studies of several different GAiN applications will be presented showing the utility of developing serial NumPy codes which can later run on more capable clusters or supercomputers.

  3. Sequoia Messaging Rate Benchmark

    SciTech Connect

    Friedley, Andrew

    2008-01-22

    The purpose of this benchmark is to measure the maximal message rate of a single compute node. The first num_cores ranks are expected to reside on the 'core' compute node for which message rate is being tested. After that, the next num_nbors ranks are neighbors for the first core rank, the next set of num_nbors ranks are neighbors for the second core rank, and so on. For example, testing an 8-core node (num_cores = 8) with 4 neighbors (num_nbors = 4) requires 8 + 8 * 4 - 40 ranks. The first 8 of those 40 ranks are expected to be on the 'core' node being benchmarked, while the rest of the ranks are on separate nodes.

  4. Sequoia Messaging Rate Benchmark

    Energy Science and Technology Software Center (ESTSC)

    2008-01-22

    The purpose of this benchmark is to measure the maximal message rate of a single compute node. The first num_cores ranks are expected to reside on the 'core' compute node for which message rate is being tested. After that, the next num_nbors ranks are neighbors for the first core rank, the next set of num_nbors ranks are neighbors for the second core rank, and so on. For example, testing an 8-core node (num_cores = 8)more » with 4 neighbors (num_nbors = 4) requires 8 + 8 * 4 - 40 ranks. The first 8 of those 40 ranks are expected to be on the 'core' node being benchmarked, while the rest of the ranks are on separate nodes.« less

  5. A Influência da Escola e da Mídia na Obtenção dos Conhecimentos Astronômicos

    NASA Astrophysics Data System (ADS)

    da Cunha, W. S.; Voelzke, M. R.; Amaral, L. H.

    2006-08-01

    O universo em que vivemos possui segredos jamais imaginados pelo homem, fruto da pequena proporção que ocupamos diante de um cosmos infinito. A astronomia funciona como um instrumento que sacia a sede humana em desvendar esses segredos, estudando as galáxias, quasares, pulsares além da existência de todos os elementos que preenchem o espaço cósmico, o vácuo, não mais vazio como se pensou em outros tempos. A mídia explora esse campo de forma mística e também científica. A difusão adequada e dentro dos padrões educacionais vigentes, de conceitos astronômicos, se faz necessária, devido sua presença nos conteúdos escolares, centros de ciência e na mídia, de modo geral. A reforma do Currículo Básico da Escola Pública da maioria dos Estados brasileiros introduziu conceitos astronômicos desde a pré-escola até o Ensino Médio. Num estudo realizado com 1.032 alunos do Ensino Médio de seis escolas estaduais, revelou-se através da aplicação de um questionário que abordava conheciment os básicos em astronomia, como estes foram adquiridos e qual era a infra-estrutura oferecida pela escola: para 66,2% dos entrevistados o professor já fez alguma apresentação a respeito de astronomia. O presente estudo revelou também que 44,5% dos alunos entrevistados adquiriram seus conhecimentos astronômicos na escola, 28,1% através da televisão e 27,4% afirmaram que seus conhecimentos foram obtidos através de outros tipos de mídia (internet, filmes e revistas). Embora o estudo revele claramente que há certo equilíbrio na forma em que os alunos obtiveram seus conhecimentos astronômicos, a mídia ainda explora e muitas vezes desperta o interesse pela astronomia com assuntos que não fazem parte de nosso cotidiano como, por exemplo, o homem na Lua, os projetos espaciais e a primeira viagem de um astronauta brasileiro no espaço. Porém, em certos casos, a mídia pode promover conhecimentos incompletos ou mesmo equivocados sobre os conceitos que envolvam

  6. Carotenoids, chemistry, sources and physiology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter for the Enclyclopedia of Human Nutrition (3rd edition) summarizes the structure, chemical and physiological mechanisms, dietary sources, and metabolism of carotenoids. Carotenoids are a family of phytonutrients which have antioxidant properties under most physiological conditions. Num...

  7. QUALITY ASSESSMENT OF CONFOCAL MICROSCOPY SLIDE-BASED SYSTEMS: INSTABLITY

    EPA Science Inventory

    Background: All slide-based fluorescence cytometry detections systems basically include an excitation light source, intermediate optics, and a detection device (CCD or PMT). Occasionally, this equipment becomes unstable, generating unreliable and inferior data. Methods: A num...

  8. RimabotulinumtoxinB Injection

    MedlinePlus

    (rim a bott' you lye num bee)RimabotulinumtoxinB injection may spread from the area of injection and ... Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

  9. Dictyostelium nucleomorphin is a member of the BRCT-domain family of cell cycle checkpoint proteins.

    PubMed

    Myre, Michael A; O'Day, Danton H

    2004-11-18

    A search of the Dictyostelium genome project database (http://dictybase.org/db/cgi-bin/blast.pl) with nucleomorphin, a protein that regulates the nuclear number, predicted it to be encoded by a larger gene containing a putative breast cancer carboxy-terminus domain (BRCT). Using RT-PCR, Northern and Western blotting we have identified a differentially expressed, 2318 bp cDNA encoding a protein isoform of Dictyostelium NumA with an apparent molecular weight of 70 kDa that we have called NumB. It contains a single amino-terminal BRCT-domain spanning residues 125-201. Starvation of shaking cultures reduces NumA expression by approximately 88+/-5.6%, whereas NumB expression increases approximately 35+/-3.5% from vegetative levels. NumC, a third isoform that is also expressed during development but not growth, remains to be characterized. These findings suggest NumB may be a member of the BRCT-domain containing cell cycle checkpoint proteins. PMID:15535983

  10. Social Transformation and "Popular Schooling" in Brazil.

    ERIC Educational Resources Information Center

    Rossatto, Cesar Augusto

    2001-01-01

    Describes three school programs designed to provide alternative schooling for Brazilian street children and illiterate adult students with the basic skills to survive in their world. Directly or indirectly embedded in Freirean principles, the three programs are: (1) Sao Paulo Interdisciplinary School Reform; (2) Projeto Axe: Schooling for Street…

  11. Astronomia para/com crianças carentes em Limeira

    NASA Astrophysics Data System (ADS)

    Bretones, P. S.; Oliveira, V. C.

    2003-08-01

    Em 2001, o Instituto Superior de Ciências Aplicadas (ISCA Faculdades de Limeira) iniciou um projeto pelo qual o Observatório do Morro Azul empreendeu uma parceria com o Centro de Promoção Social Municipal (CEPROSOM), instituição mantida pela Prefeitura Municipal de Limeira para atender crianças e adolescentes carentes. O CEPROSOM contava com dois projetos: Projeto Centro de Convivência Infantil (CCI) e Programa Criança e Adolescente (PCA), que atendiam crianças e adolescentes em Centros Comunitários de diversas áreas da cidade. Esses projetos têm como prioridades estabelecer atividades prazerosas para as crianças no sentido de retirá-las das ruas. Assim sendo, as crianças passaram a ter mais um tipo de atividade - as visitas ao observatório. Este painel descreve as várias fases do projeto, que envolveu: reuniões de planejamento, curso de Astronomia para as orientadoras dos CCIs e PCAs, atividades relacionadas a visitas das crianças ao Observatório, proposta de construção de gnômons e relógios de Sol nos diversos Centros Comunitários de Limeira e divulgação do projeto na imprensa. O painel inclui discussões sobre a aprendizagem de crianças carentes, relatos que mostram a postura das orientadoras sobre a pertinência do ensino de Astronomia, relatos do monitor que fez o atendimento no Observatório e o que o número de crianças atendidas representou para as atividades da instituição desde o início de suas atividades e, em particular, em 2001. Os resultados são baseados na análise de relatos das orientadoras e do monitor do Observatório, registros de visitas e matérias da imprensa local. Conclui com uma avaliação do que tal projeto representou para as Instituições participantes. Para o Observatório, em particular, foi feita uma análise com relação às outras modalidades de atendimentos que envolvem alunos de escolas e público em geral. Também é abordada a questão do compromisso social do Observatório na educação do

  12. The impact of RNA-seq aligners on gene expression estimation

    PubMed Central

    Yang, Cheng; Wu, Po-Yen; Tong, Li; Phan, John H.; Wang, May D.

    2016-01-01

    While numerous RNA-seq data analysis pipelines are available, research has shown that the choice of pipeline influences the results of differentially expressed gene detection and gene expression estimation. Gene expression estimation is a key step in RNA-seq data analysis, since the accuracy of gene expression estimates profoundly affects the subsequent analysis. Generally, gene expression estimation involves sequence alignment and quantification, and accurate gene expression estimation requires accurate alignment. However, the impact of aligners on gene expression estimation remains unclear. We address this need by constructing nine pipelines consisting of nine spliced aligners and one quantifier. We then use simulated data to investigate the impact of aligners on gene expression estimation. To evaluate alignment, we introduce three alignment performance metrics, (1) the percentage of reads aligned, (2) the percentage of reads aligned with zero mismatch (ZeroMismatchPercentage), and (3) the percentage of reads aligned with at most one mismatch (ZeroOneMismatchPercentage). We then evaluate the impact of alignment performance on gene expression estimation using three metrics, (1) gene detection accuracy, (2) the number of genes falsely quantified (FalseExpNum), and (3) the number of genes with falsely estimated fold changes (FalseFcNum). We found that among various pipelines, FalseExpNum and FalseFcNum are correlated. Moreover, FalseExpNum is linearly correlated with the percentage of reads aligned and ZeroMismatchPercentage, and FalseFcNum is linearly correlated with ZeroMismatchPercentage. Because of this correlation, the percentage of reads aligned and ZeroMismatchPercentage may be used to assess the performance of gene expression estimation for all RNA-seq datasets.

  13. On the Achievable Efficiency-Fairness Tradeoff in Utility-Optimal MAC Protocols

    NASA Astrophysics Data System (ADS)

    Lee, Jang-Won; Chiang, Mung; Calderbank, A. Robert

    We use the network utility maximization (NUM) framework to create an efficient and fair medium access control (MAC) protocol for wireless networks. By adjusting the parameters in the utility objective functions of NUM problems, we control the tradeoff between efficiency and fairness of radio resource allocation through a rigorous and systematic design. In this paper, we propose a scheduling-based MAC protocol. Since it provides an upper-bound on the achievable performance, it establishes the optimality benchmarks for comparison with other algorithms in related work.

  14. Dictyostelium calcium-binding protein 4a interacts with nucleomorphin, a BRCT-domain protein that regulates nuclear number.

    PubMed

    Myre, Michael A; O'Day, Danton H

    2004-09-17

    Nucleomorphin from Dictyostelium discoideum is a nuclear calmodulin-binding protein that is a member of the BRCT-domain containing cell cycle checkpoint proteins. Two differentially expressed isoforms, NumA and NumB, share an extensive acidic domain (DEED) that when deleted produces highly multinucleated cells. We performed a yeast two-hybrid screen of a Dictyostelium cDNA library using NumA as bait. Here we show that nucleomorphin interacts with calcium-binding protein 4a (CBP4a) in a Ca(2+)-dependent manner. Further deletion analysis suggests this interaction requires residues found within the DEED domain. NumA and CBP4a mRNAs are expressed at the same stages of development. CBP4a belongs to a large family of Dictyostelium CBPs, for which no cellular or developmental functions had previously been determined. Since the interaction of CBP4a with nucleomorphin requires the DEED domain, this suggests that CBP4a may respond to Ca(2+)-signalling through modulating factors that might function in concert to regulate nuclear number. PMID:15325281

  15. Sodium tetraborate decahydrate (borax) treatment reduces hydrogen sulfide emissions and correlates with a decrease in the sulfate reducing bacteria population of stored swine manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The emission of odorous and toxic gases from stored livestock manure is well documented, and poses a serious health risk to farmers and livestock. Hydrogen sulfide emissions have been sharply rising with more intensive livestock production and are of particular concern due to its acute toxicity. Num...

  16. V2.1.4 L2AS Detailed Release Description September 27, 2001

    Atmospheric Science Data Center

    2013-03-14

    ... Report NumAcceptSubr as number of subregions of good quality, instead of number of subregions actually used in final retrieval. ... het. surface retrieval algorithm over areas of 100% dark water. Modify algorithm for selecting a default aerosol model to use in ...

  17. Selection and adaptation to high plant density in the Iowa Stiff Stalk synthetic maize (Zea mays L.) population: II. Plant morphology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The plant density at which Zea mays L. hybrids achieve maximum grain yield has increased throughout the hybrid era while grain yield on a per plant basis has increased little. Changes in plant characteristics including flag leaf angle, anthesis-silking interval (ASI), plant height, tassel branch num...

  18. The impact of supervisor-subordinate relationships on nurses' ability to solve workplace problems: implications for their commitment to the organization.

    PubMed

    Brunetto, Yvonne; Farr-Wharton, Rodney; Shacklock, Kate

    2011-01-01

    This chapter uses the structural and relational dimension of social capital theory (SCT) as a lens for examining the impact of the supervisor-subordinate relationship on nurses' perceptions of the usefulness of their workplace networks, sociability, and affective commitment. A survey was used to collect data from 1,064 Australian nurses. The findings suggest that nurses rely on very small workplace networks (typically only one other person) with which they have strong ties. Further, in over half of the cases, the supervisor (the Nurse Unit Manager (NUM)) holds the centric position. Moreover, for those nurses who did not include the NUM in their workplace network, their position appears even worse. For example, the usual reason given by nurses for not including the NUM was that the NUM was unavailable. This is a concern for health-care management because the past two decades have delivered many changes to the nursing profession, including a reduction in the number of nursing positions and subsequent higher workloads. The consequences suggest that without effective workplace networks, nurses are working under conditions where solving problems is more difficult. PMID:21887947

  19. METHOD OF IMPROVING THE CARRIER PRECIPITATION OF PLUTONIUM

    DOEpatents

    Kamack, H.J.; Balthis, J.H.

    1958-12-01

    Plutonium values can be recovered from acidic solutlons by adding lead nitrate, hydrogen fluoride, lantha num nitrate, and sulfurlc acid to the solution to form a carrler preclpitate. The lead sulfate formed improves the separatlon characteristics of the lanthanum fluoride carrier precipitate,

  20. GENE EXPRESSION IN HEAD HAIR FOLLICLES PLUCKED FROM MEN AND WOMEN

    EPA Science Inventory

    Characterizing gene expression in hair follicles can help to elucidate the hair growth cycle by delineating the genes and pathways involved in follicular growth and degeneration. The objectives of this study were to determine whether intact RNA could be extracted from a small num...

  1. GENETIC ENGINEERING AND THE DEVELOPMENT OF NEW POLLUTION CONTROL TECHNOLOGIES

    EPA Science Inventory

    This report relates genetic engineering and biological waste treatment, so that opportunities for its improvement can be identified and evaluated. It describes the state of development of gene manipulation and natural limits to biodegradation as of early 1983. It identifies a num...

  2. CosmicPy: Interactive cosmology computations

    NASA Astrophysics Data System (ADS)

    Lanusse, Francois; Rassat, Anais; Starck, Jean-Luc

    2016-01-01

    CosmicPy performs simple and interactive cosmology computations for forecasting cosmological parameters constraints; it computes tomographic and 3D Spherical Fourier-Bessel power spectra as well as Fisher matrices for galaxy clustering. Written in Python, it relies on a fast C++ implementation of Fourier-Bessel related computations, and requires NumPy, SciPy, and Matplotlib.

  3. Changes in the use of young bulls

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Availability of genomic information since 2008 has increased accuracy of genetic evaluations for young bulls in Holstein (HO), Jersey (JE), and Brown Swiss (BS). As a result, AI organizations have been aggressively promoting young bulls and producers have been using young bulls more extensively. Num...

  4. POLYBROMINATED DIPHENYL ETHERS (PBDES) IN AMERICAN MOTHERS' MILK

    EPA Science Inventory

    No previous reports exist on polybrominated diphenyl ether (PBDE) congeners in individual American mothers' milk. This report on PBDEs is an extension of our previous studies on concentrations of dioxins, dibenzofurans, PCBs, and other chlorinated organics in human milk in a num...

  5. Determiner Phrase and Definiteness in Old High German

    ERIC Educational Resources Information Center

    Kraiss, Andrew M.

    2011-01-01

    This study investigates the status of nominal functional categories in the Old High German (OHG) "Isidor" and "Tatian" translations and Otfrid's "Evangelienbuch" and the structure of the extended nominal group, including the Noun Phrase (NP) and the functional phrases Determiner Phrase (DP), Case Phrase (KP) and Number Phrase (NumP), which govern…

  6. THEONA—a numerical-analytical theory of motion of artificial satellites of celestial bodies

    NASA Astrophysics Data System (ADS)

    Golikov, A. R.

    2012-11-01

    Basic principles of operation of the numerical-analytical theory THEONA (THéorie Numérique-Analytique) are presented, as well as force models taken into account and special functions used. Possibilities of applying the THEONA in problems of ballistic and navigation support are discussed. The accuracy of predicting the motion of the Earth's satellites is estimated for various classes of orbits.

  7. Cellular Stress Response to Engineered Nanoparticles: Effect of Size, Surface Coating, and Cellular Uptake

    EPA Science Inventory

    CELLULAR STRESS RESPONSE TO ENGINEERED NANOPARTICLES: EFFECT OF SIZE, SURFACE COATING, AND CELLULAR UPTAKE RY Prasad 1, JK McGee2, MG Killius1 D Ackerman2, CF Blackman2 DM DeMarini2 , SO Simmons2 1 Student Services Contractor, US EPA, RTP, NC 2 US EPA, RTP, NC The num...

  8. Photocopy of drawing located at National Archives, San Bruno, California ...

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

    Photocopy of drawing located at National Archives, San Bruno, California (Navy # NUM), showing 680-A-9. Machine shop expansion joint and details; 1938. - Mare Island Naval Shipyard, Machine Shop, California Avenue, southwest corner of California Avenue & Thirteenth Street, Vallejo, Solano County, CA

  9. Does reduced peri-pubertal nutrient intake influence the ovarian reserve in beef heifers?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reducing nutrient intake in beef heifers after weaning decreases production costs; however, the impact of reduced nutrient intake on the ovarian reserve has not been investigated in this species. In rodent models, caloric restriction increased the number of primordial follicles and decreased the num...

  10. Comment on: "Bachmann, R. W., M. V. Hoyer, and D. E. Canfield. 2013. The extent that natural lakes in the United States of America have been changed by cultural eutrophication. Limnology and Oceanography 58:945-950."

    EPA Science Inventory

    In a recent paper, Bachmann et al. (2013) conclude, based on paleolimnological reconstructions, that lakes in the conterminous U.S. have undergone very little cultural eutrophication. They go on to suggest that their results invalidate the efforts of the U.S. EPA to establish num...

  11. Preparation for the introduction of a new yellow starthistle biological control agent into California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yellow starthistle populations were monitored at six locations in California. At each location, two sites were selected with the intention of using one as a future release site and one as a control site. Permanent transects were established and data were collected on plant density, plant size, num...

  12. Variable Number of Tandem Repeat Markers in the Genome Sequence of Mycosphaerella Fijiensis, the Causal Agent of Black Leaf Streak Disease of Banana (Musa spp.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mycosphaerella fijiensis, the causal agent of banana leaf streak disease (commonly known as black Sigatoka), is the most devastating pathogen attacking bananas (Musa spp). Recently the whole genome sequence of M. fijiensis became available. This sequence was screened for the presence of Variable Num...

  13. Learning Scientific Programming with Python

    NASA Astrophysics Data System (ADS)

    Hill, Christian

    2016-02-01

    1. Introduction; 2. The core Python language I; 3. Interlude: simple plotting with pylab; 4. The core Python language II; 5. IPython and IPython notebook; 6. NumPy; 7. Matplotlib; 8. SciPy; 9. General scientific programming; Appendix A; Solutions; Index.

  14. Passage rates in poultry digestion using stable isotope markers and INAA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A method has been developed for the study of passage rates and mean residence times (MRT) of test rations through the gastrointestinal tracts of layer hens. The use of rare earth elements as stable indigestible markers monitored by neutron activation analysis has been previously demonstrated in num...

  15. BIOCONCENTRATION OF A HEXACHLOROBIPHENYL IN GREAT LAKES PLANKTONIC ALGAE

    EPA Science Inventory

    The bioconcentration of 2,4,5,2',4',5'-hexachlorobiphenyl (HCB) was examined in the Great Lakes algae Fragilaria crotonensis, Ankistrodesmus falcatus, and Microcystis sp. The bioconcentration factors varied from species to species, whether they were expressed in terms of cell num...

  16. EVALUATION OF OZONE EXPOSURE INDICES IN EXPOSURE-RESPONSE MODELING (JOURNAL VERSION)

    EPA Science Inventory

    In exposure-response modeling, a major concern is the numerical definition of exposure in relating crop loss to O3, yet few indices have been considered. The paper addresses research in which plant growth was regressed for soybean, wheat, cotton, corn, and sorghum against 613 num...

  17. THE TOXICOLOGY OF COMPLEX MIXTURES OF DISINFECTION BY-PRODUCTS

    EPA Science Inventory

    Chemical disinfection of water is a major public health advance that has decreased dramatically water-borne disease. Chemical disinfectants react with naturally occurring organic and inorganic matter in water to produce a wide variety of disinfection byproducts (DBPs). DBP num...

  18. Relationship between sensory and chemical attributes of Vidalia onions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavor in fresh onions is dominated by sulfur containing volatiles that are released once tissues are disrupted and the S-alk(en)yl-L-cysteine sulfoxide (ACSOs) are hydrolyzed by the enzyme alliinase. Four intensities of flavor levels of Vidalia onions were induced by cultivating sweet (Num 1006) an...

  19. Amplifying youth voices in the developing world.

    PubMed

    Fotenos, Saori; Rohatgi, Deepti

    2007-01-01

    Low-literacy youth in the slums of Brazil have been historically unequipped to share their ideas on how to improve their lives, because outside of the spoken word, it is difficult for them to express their thoughts persuasively. The Amplifying Voices afterschool video program piloted at Projeto Uerê in Rio de Janeiro shows that youth can leverage technological tools to voice their perspectives on social issues relevant to themselves and their communities. PMID:18271053

  20. An N-terminal nuclear localization sequence but not the calmodulin-binding domain mediates nuclear localization of nucleomorphin, a protein that regulates nuclear number in Dictyostelium.

    PubMed

    Myre, Michael A; O'Day, Danton H

    2005-06-24

    Nucleomorphin is a novel nuclear calmodulin (CaM)-binding protein (CaMBP) containing an extensive DEED (glu/asp repeat) domain that regulates nuclear number. GFP-constructs of the 38 kDa NumA1 isoform localize as intranuclear patches adjacent to the inner nuclear membrane. The translocation of CaMBPs into nuclei has previously been shown by others to be mediated by both classic nuclear localization sequences (NLSs) and CaM-binding domains (CaMBDs). Here we show that NumA1 possesses a CaMBD (171EDVSRFIKGKLLQKQQKIYKDLERF195) containing both calcium-dependent-binding motifs and an IQ-like motif for calcium-independent binding. GFP-constructs containing only NumA1 residues 1-129, lacking the DEED and CaMBDs, still localized as patches at the internal periphery of nuclei thus ruling out a direct role for the CaMBD in nuclear import. These constructs contained the amino acid residues 48KKSYQDPEIIAHSRPRK64 that include both a putative bipartite and classical NLS. GFP-bipartite NLS constructs localized uniformly within nuclei but not as patches. As with previous work, removal of the DEED domain resulted in highly multinucleate cells. However as shown here, multinuclearity only occurred when the NLS was present allowing the protein to enter nuclei. Site-directed mutation analysis in which the NLS was changed to 48EF49 abolished the stability of the GFP fusion at the protein but not RNA level preventing subcellular analyses. Cells transfected with the 48EF49 construct exhibited slowed growth when compared to parental AX3 cells and other GFP-NumA1 deletion mutants. In addition to identifying an NLS that is sufficient for nuclear translocation of nucleomorphin and ruling out CaM-binding in this event, this work shows that the nuclear localization of NumA1 is crucial to its ability to regulate nuclear number in Dictyostelium. PMID:15896312

  1. NASA Astrophysics Data System (ADS)

    Brunini, A.

    Se presenta una revisión de los conocimientos actuales sobre el proceso de acreción del sistema solar exterior. En base a nuevas y más realistas simulaciones numéricas, se analiza el impacto que tuvo dicho proceso en otras regiones del sistema solar tales como la nube de Oort, el cinturón de Kuiper y el sistema solar interior. Se presentan entonces, las principales limitaciones de los modelos numéricos actuales, los principales puntos aún oscuros en el problema, y algunos de los posibles caminos a seguir para mejorar nuestro conocimiento en el tema. Se discute a continuación la posible utilidad de este tipo de estudios para el diseño de estrategias de búsqueda de otros sistemas planetarios.

  2. Estabilidad de los modelos de Heggie y Ramamani

    NASA Astrophysics Data System (ADS)

    Muzzio, J. C.; Vergne, M. M.; Wachlin, F. C.; Carpintero, D. D.

    Los modelos de Heggie y Ramamani de satélites galácticos en órbitas circulares se basan en una teoría aproximada, por lo que es importante verificar su estabilidad mediante simulaciones numéricas. En esta forma, hemos logrado mostrar que son estables sobre intervalos de tiempo mucho mayores que los que lograron los propios autores de los modelos. Por otra parte, dado que hemos mostrado que el caos es significativo en estos modelos, son un sistema ideal para investigar si, pese a ello, se mantienen estacionarios. Nuestras simulaciones numéricas muestran que, pese al caos, la estacionariedad se mantiene sobre intervalos de centenares de tiempos de cruce del sistema, mucho mayores que los tiempos de Liapunov característicos de sus movimientos caóticos.

  3. LORENE: Spectral methods differential equations solver

    NASA Astrophysics Data System (ADS)

    Gourgoulhon, Eric; Grandclément, Philippe; Marck, Jean-Alain; Novak, Jérôme; Taniguchi, Keisuke

    2016-08-01

    LORENE (Langage Objet pour la RElativité NumériquE) solves various problems arising in numerical relativity, and more generally in computational astrophysics. It is a set of C++ classes and provides tools to solve partial differential equations by means of multi-domain spectral methods. LORENE classes implement basic structures such as arrays and matrices, but also abstract mathematical objects, such as tensors, and astrophysical objects, such as stars and black holes.

  4. PyXel: A Python Package for Astronomical X-ray Data Modeling

    NASA Astrophysics Data System (ADS)

    Ogrean, Georgiana

    2016-06-01

    PyXel is an new Python package for modeling astronomical X-ray imaging data. It is built on NumPy, SciPy, matplotlib, and Astropy, and distributed under an open-source license. The package aims to provide a common set of image analysis tools for astronomers working with extended X-ray sources. I will present an overview of its existing and planned features, and analysis examples based on public Chandra data.

  5. Eulerian and Lagrangian statistics in fully developed rotating turbulent flows.

    NASA Astrophysics Data System (ADS)

    Biferale, Luca; Bonaccorso, Fabio; Mazzitelli, Irene; Lanotte, Alessandra; Perlekar, Prasad; Musacchio, Stefano; Hinsberg, Michel; Toschi, Federico

    2015-11-01

    We present results concerning both Eulerian and Lagrangian statistics for turbulent under rotation at small and large Rossby numbers. Concerning the Eulerian statistics we discuss the effects of the presence of strong coherent large-scale vortical structures on the small-scale statistics. Concerning Lagrangian properties, we discuss the effects of preferential sampling at changing the inertial properties of the particles also due to the centrifugal and Coriolis forces. Supported by the ERC AdG NewTURB num. 339032.

  6. DEZ ANOS DE EXPERIÊNCIA DO COMITÊ DE ÉTICA EM PESQUISA DA SECRETARIA DE SAÚDE DO DISTRITO FEDERAL, BRASIL

    PubMed Central

    Novaes, Maria Rita C. G.; Guilhem, Dirce; Lolas, Fernando

    2009-01-01

    O objetivo deste artigo é relatar a experiência do Comitê de Ética em Pesquisa da Secretaria de Estado de Saúde do Distrito Federal (CEP/SES/DF) Brasil, durante o período de 10 anos a partir de sua fundação. Trata-se de uma avaliação descritiva e documental, na modalidade estudo de caso, utilizando-se a totalidade de projetos protocolados no CEP/SES/DF (N° 052/08) nesse período. As pendências mais freqüentes dos projetos foram: termo de consentimento livre e esclarecido (30%), folha de rosto (25%), metodologia (20%), curriculum vitae (12%), planilha de orçamento (9%), outros (4%). O relato das atividades do CEP/SES/DF no período de 10 anos revelou, através de sua produtividade, a legitimidade do processo de análise ética dos protocolos visando à proteção dos participantes da pesquisa. PMID:19888441

  7. Willingness to participate in HIV vaccine trials among a sample of men who have sex with men, with and without a history of commercial sex, Rio de Janeiro, Brazil.

    PubMed

    de Souza, C T; Lowndes, C M; Szwarcwald, C Landman; Sutmöller, F; Bastos, F I

    2003-08-01

    The study objective was to assess willingness of men who have sex with men (MSM) enrolled in a vaccine preparedness study ('Projeto Rio') to participate in phase III anti-HIV/AIDS vaccine trials. Overall, 57% of Projeto Rio participants stated they would participate in a putative vaccine trial. MSM who reported commercial sex work were significantly (p < 0.05) more likely to engage in risky behaviours than others. In bivariate analysis, commercial sex workers (CSWs) were significantly (p < 0.05) more likely than non-commercial sex workers (NCSWs) to be willing to participate in vaccine trials (62.6% versus 51.4%). Among those willing, CSWs reported significantly more often (p < 0.05) (50.5%) than NCSWs (38.0%) that they would enroll to protect themselves from HIV. In multivariate analyses, variables associated with willingness to participate (WTP) were lower educational level, positive serology for syphilis, and 'engagement, under the influence of alcohol, in risky sexual practices that would normally be avoided', but not commercial sex work. The potential enrollment in vaccine trials of MSM CWSs, as well as participants of low socio-economic status and high risk, seems thus to be possible. PMID:14509868

  8. Methodologie de conception numerique d'un ventilateur helico-centrifuge basee sur l'emploi du calcul meridien

    NASA Astrophysics Data System (ADS)

    Lallier-Daniels, Dominic

    La conception de ventilateurs est souvent basée sur une méthodologie « essais/erreurs » d'amélioration de géométries existantes ainsi que sur l'expérience de design et les résultats expérimentaux cumulés par les entreprises. Cependant, cette méthodologie peut se révéler coûteuse en cas d'échec; même en cas de succès, des améliorations significatives en performance sont souvent difficiles, voire impossibles à obtenir. Le projet présent propose le développement et la validation d'une méthodologie de conception basée sur l'emploi du calcul méridien pour la conception préliminaire de turbomachines hélico-centrifuges (ou flux-mixte) et l'utilisation du calcul numérique d'écoulement fluides (CFD) pour la conception détaillée. La méthode de calcul méridien à la base du processus de conception proposé est d'abord présentée. Dans un premier temps, le cadre théorique est développé. Le calcul méridien demeurant fondamentalement un processus itératif, le processus de calcul est également présenté, incluant les méthodes numériques de calcul employée pour la résolution des équations fondamentales. Une validation du code méridien écrit dans le cadre du projet de maîtrise face à un algorithme de calcul méridien développé par l'auteur de la méthode ainsi qu'à des résultats de simulation numérique sur un code commercial est également réalisée. La méthodologie de conception de turbomachines développée dans le cadre de l'étude est ensuite présentée sous la forme d'une étude de cas pour un ventilateur hélico-centrifuge basé sur des spécifications fournies par le partenaire industriel Venmar. La méthodologie se divise en trois étapes: le calcul méridien est employé pour le pré-dimensionnement, suivi de simulations 2D de grilles d'aubes pour la conception détaillée des pales et finalement d'une analyse numérique 3D pour la validation et l'optimisation fine de la géométrie. Les résultats de calcul m

  9. Nucleomorphin. A novel, acidic, nuclear calmodulin-binding protein from dictyostelium that regulates nuclear number.

    PubMed

    Myre, Michael A; O'Day, Danton H

    2002-05-31

    Probing of Dictyostelium discoideum cell extracts after SDS-PAGE using (35)S-recombinant calmodulin (CaM) as a probe has revealed approximately three-dozen Ca(2+)-dependent calmodulin binding proteins. Here, we report the molecular cloning, expression, and subcellular localization of a gene encoding a novel calmodulin-binding protein (CaMBP); we have called nucleomorphin, from D. discoideum. A lambdaZAP cDNA expression library of cells from multicellular development was screened using a recombinant calmodulin probe ((35)S-VU1-CaM). The open reading frame of 1119 nucleotides encodes a polypeptide of 340 amino acids with a calculated molecular mass of 38.7 kDa and is constitutively expressed throughout the Dictyostelium life cycle. Nucleomorphin contains a highly acidic glutamic/aspartic acid inverted repeat (DEED) with significant similarity to the conserved nucleoplasmin domain and a putative transmembrane domain in the carboxyl-terminal region. Southern blotting reveals that nucleomorphin exists as a single copy gene. Using gel overlay assays and CaM-agarose we show that bacterially expressed nucleomorphin binds to bovine CaM in a Ca(2+)-dependent manner. Amino-terminal fusion to the green fluorescence protein (GFP) showed that GFP-NumA localized to the nucleus as distinct arc-like patterns similar to heterochromatin regions. GFP-NumA lacking the acidic DEED repeat still showed arc-like accumulations at the nuclear periphery, but the number of nuclei in these cells was increased markedly compared with control cells. Cells expressing GFP-NumA lacking the transmembrane domain localized to the nuclear periphery but did not affect nuclear number or gross morphology. Nucleomorphin is the first nuclear CaMBP to be identified in Dictyostelium. Furthermore, these data present the first identification of a member of the nucleoplasmin family as a calmodulin-binding protein and suggest nucleomorphin has a role in nuclear structure in Dictyostelium. PMID:11919178

  10. The Early Days of Computer Aided Newspaper Production Systems

    NASA Astrophysics Data System (ADS)

    Enlund, Nils; Andersin, Hans E.

    During the years 1970-1973, the Laboratory of Information Processing Science at the Helsinki Uni versity of Technology carried out the Computer Graph ics Pro ject (CGP). The activities foc us ed on the problems of producing news paper text, ad vert isements, and com plete pages using inter act ive computer graphics. The project and its commercial spin-off, Typlan, as well as the BUNPAPS continuation project 1973-1975, cre ated a num ber of innovative, pioneering solutions for computer aided news pap er production, laying the found at ion for the digitalization of media production.

  11. Reaction-diffusion in the NEURON simulator

    PubMed Central

    McDougal, Robert A.; Hines, Michael L.; Lytton, William W.

    2013-01-01

    In order to support research on the role of cell biological principles (genomics, proteomics, signaling cascades and reaction dynamics) on the dynamics of neuronal response in health and disease, NEURON's Reaction-Diffusion (rxd) module in Python provides specification and simulation for these dynamics, coupled with the electrophysiological dynamics of the cell membrane. Arithmetic operations on species and parameters are overloaded, allowing arbitrary reaction formulas to be specified using Python syntax. These expressions are then transparently compiled into bytecode that uses NumPy for fast vectorized calculations. At each time step, rxd combines NEURON's integrators with SciPy's sparse linear algebra library. PMID:24298253

  12. Role of Bioindicators In Earthquake Modelling

    NASA Astrophysics Data System (ADS)

    Zelinsky, I. P.; Melkonyan, D. V.; Astrova, N. G.

    On the basis of experimental researches of influence of sound waves on bacteria- indicators a model of earthquake is constructed. It is revealed that the growth of num- ber of bacteria depends on frequency of a sound wave, influencing on the bacterium, (the less frequency of a sound wave, the faster takes place a growth). It is shown, that at absorption of energy of a sound wave by bacterium occurs growth of concentration of isopotential lines of biodynamic field in a bacterium. This process leads to the bac- terium braking and heating. By structure of deformation of lines of a biodynamic field it is possible to predict various geodynamic processes including earthquakes.

  13. Reaction-diffusion in the NEURON simulator.

    PubMed

    McDougal, Robert A; Hines, Michael L; Lytton, William W

    2013-01-01

    In order to support research on the role of cell biological principles (genomics, proteomics, signaling cascades and reaction dynamics) on the dynamics of neuronal response in health and disease, NEURON's Reaction-Diffusion (rxd) module in Python provides specification and simulation for these dynamics, coupled with the electrophysiological dynamics of the cell membrane. Arithmetic operations on species and parameters are overloaded, allowing arbitrary reaction formulas to be specified using Python syntax. These expressions are then transparently compiled into bytecode that uses NumPy for fast vectorized calculations. At each time step, rxd combines NEURON's integrators with SciPy's sparse linear algebra library. PMID:24298253

  14. Ureka: A Distribution of Python and IRAF Software for Astronomy

    NASA Astrophysics Data System (ADS)

    Hirst, P.; Slocum, C.; Turner, J.; Sienkiewicz, M.; Greenfield, P.; Hogan, E.; Simpson, M.; Labrie, K.

    2014-05-01

    As astronomical data processing expands from our historical platforms into modern Python applications, users are faced with installing and maintaining large numbers of heterogeneous dependencies. A handful of scientific Python distributions make installing key packages easy, but don't cater for specific needs such as integration with IRAF. We have therefore recently released a beta version of a new astronomical software distribution for Linux and OSX, known as Ureka. Ureka is based around STScI Python and dependencies, notably Python, NumPy, IRAF, SciPy, AstroPy, Matplotlib and Tk. It also contains data reduction packages for Gemini, HST, JWST and other observatories, alongside various complementary tools.

  15. Raízes pós-mitológicas da Astronomia Clássica

    NASA Astrophysics Data System (ADS)

    di Bartolo, L.; Villas da Rocha, J. F.

    2004-02-01

    Apresentamos como a invenção de um modelo astronômico e cosmológico fundado em causas naturais foi um processo gestado num ambiente cultural específico, o do advento do pensamento pós-mitológico, que tem como sua raiz mais funda a trajetória particular da Grécia Antiga, com ênfase na resolução de uma grave crise social e a evolução do mundo clássico para o contexto espiritual de um império universal.

  16. Formación y evolución de planetas gigantes

    NASA Astrophysics Data System (ADS)

    Benvenuto, O. G.; Brunini, A.

    Presentamos el estado actual del trabajo que estamos realizando en el estudio de la formación de planetas gigantes. Detallamos los algoritmos numéricos necesarios para realizar este tipo de cálculo. Presentamos algunos resultados de la formación de objetos con masas de hasta una docena de veces la del planeta Júpiter, resaltando las principales caracteríticas. Finalmente detallamos los problemas que pensamos abordar en un futuro cercano en este tema de investigación.

  17. K2SC: K2 Systematics Correction

    NASA Astrophysics Data System (ADS)

    Aigrain, Suzanne; Parviainen, Hannu; Pope, Benjamin

    2016-05-01

    K2SC (K2 Systematics Correction) models instrumental systematics and astrophysical variability in light curves from the K2 mission. It enables the user to remove both position-dependent systematics and time-dependent variability (e.g., for transit searches) or to remove systematics while preserving variability (for variability studies). K2SC automatically computes estimates of the period, amplitude and evolution timescale of the variability for periodic variables and can be run on ASCII and FITS light curve files. Written in Python, this pipeline requires NumPy, SciPy, MPI4Py, Astropy (ascl:1304.002), and George (ascl:1511.015).

  18. PyVO: Python access to the Virtual Observatory

    NASA Astrophysics Data System (ADS)

    Graham, Matthew; Plante, Ray; Tody, Doug; Fitzpatrick, Mike

    2014-02-01

    PyVO provides access to remote data and services of the Virtual observatory (VO) using Python. It allows archive searches for data of a particular type or related to a particular topic and query submissions to obtain data to a particular archive to download selected data products. PyVO supports querying the VAO registry; simple data access services (DAL) to access images (SIA), source catalog records (Cone Search), spectra (SSA), and spectral line emission/absorption data (SLAP); and object name resolution (for converting names of objects in the sky into positions). PyVO requires both AstroPy and NumPy.

  19. Fatigue strength of high-temperature alloys under conditions of cyclic temperature variation. Communication 1: Experimental procedure and results

    NASA Astrophysics Data System (ADS)

    Troshchenko, V. T.; Gryaznov, B. A.; Yamshanov, Yu. B.

    1994-03-01

    Determination of the serviceability of the material of gas-turbine engine blades, one of the most loaded elements of the engine, critical for the reliability of the turbine, is discussed. The NUM-3 setup, intended for studying fatigue strength of high-temperature alloys under conditions simulating service ones, is briefly described. The results of the investigation into the fatigue of alloys EP962 and EI698 under isothermal conditions and complex thermal-mechanical loading are presented. The analysis of the findings revealed a number of regularities in the effect of thermal cycling and resulting varying thermal stresses on the fatigue strength of the materials studied.

  20. Quantitative Sensory Testing of the Effect of Desensitizing Treatment After Dental Bleaching.

    PubMed

    Rahal, Vanessa; Gallinari, Marjorie O; Perdigão, Jorge; Cintra, Luciano T A; dos Santos, Paulo H; Briso, André L F

    2015-12-01

    The aim of this study was to quantify tooth sensitivity during bleaching and after a desensitizing treatment. Sensitivity was measured with a new device, TSA-II, which uses thermal stimuli for Quantitative Sensory Testing (QST). Ten patients underwent bleaching treatment using Whiteness HP Maxx (FGM Produtos Odontológicos Ltda) containing 35% hydrogen peroxide. After the bleaching session, the teeth were cleaned with air/water spray and the product Desensibilize KF 2% (FGM Produtos Odontológicos Ltda) was applied to the upper left teeth. Saline solution at room temperature was applied in the upper right teeth. QST was performed before bleaching, immediately after bleaching, and immediately after desensitizing treatment. In order to standardize tooth analysis, a 100% ethylene copolymer and vinyl acetate tray with circular perforations was used during measurements. Analysis of variance and the Student's t-test were used (a=0.05). Mean temperatures (SD) of cold sensation threshold for the upper right quadrant were: BB-13.898 (4.81), AB- 19.241 (3.68), AD-20.646 (3.72) and for the upper left quadrant they were: BB-14.102 (3.22), AB-19.646 (4.82), AD- 13.835 (3.63). Dental bleaching with highly concentrated peroxides changed dental cold sensation thresholds, but the topical desensitizer changed the immediate cold sensation thresholds produced by the cold stimulus. PMID:27095628

  1. Auditory target detection in reverberation

    NASA Astrophysics Data System (ADS)

    Zurek, Patrick M.; Freyman, Richard L.; Balakrishnan, Uma

    2004-04-01

    Measurements and theoretical predictions of auditory target detection in simulated reverberant conditions are reported. The target signals were pulsed <num>1num>3-octave bands of noise and the masker signal was a continuous wideband noise. Target and masker signals were passed through a software simulation of a reverberant room with a rigid sphere modeling a listener's head. The location of the target was fixed while the location of the masker was varied in the simulated room. Degree of reverberation was controlled by varying the uniform acoustic absorption of the simulated room's surfaces. The resulting target and masker signals were presented to the listeners over headphones in monaural-left, monaural-right, or binaural listening modes. Changes in detection performance in the monaural listening modes were largely predictable from the changes in target-to-masker ratio in the target band, but with a few dB of extra masking in reverberation. Binaural detection performance was generally well predicted by applying Durlach's [in Foundations of Modern Auditory Theory (Academic, New York, 1972)] equalization-cancellation theory to the direct-plus-reverberant ear signals. Predictions in all cases were based on a statistical description of room acoustics and on acoustic diffraction by a sphere. The success of these detection models in the present well-controlled reverberant conditions suggests that they can be used to incorporate listening mode and source location as factors in speech-intelligibility predictions.

  2. Differential Toll-Like Receptor Recognition and Induction of Cytokine Profile by Bifidobacterium breve and Lactobacillus Strains of Probiotics ▿

    PubMed Central

    Plantinga, Theo S.; van Maren, Wendy W. C.; van Bergenhenegouwen, Jeroen; Hameetman, Marjolijn; Nierkens, Stefan; Jacobs, Cor; de Jong, Dirk J.; Joosten, Leo A. B.; van't Land, Belinda; Garssen, Johan; Adema, Gosse J.; Netea, Mihai G.

    2011-01-01

    The use of probiotics as a food supplement has gained tremendous interest in the last few years as beneficial effects were reported in gut homeostasis and nutrient absorption but also in immunocompromised patients, supporting protection from colonization or infection with pathogenic bacteria or fungi. As a treatment approach for inflammatory bowel diseases, a suitable probiotic strain would ideally be one with a low immunogenic potential. Insight into the immunogenicities and types of T-cell responses induced by potentially probiotic strains allows a more rational selection of a particular strain. In the present study, the bacterial strains Bifidobacterium breve (NumRes 204), Lactobacillus rhamnosus (NumRes1), and Lactobacillus casei (DN-114 001) were compared concerning their capacity to induce inflammatory responses in terms of cytokine production by human and mouse primary immune cells. It was demonstrated that the B. breve strain induced lower levels of the proinflammatory cytokine gamma interferon (IFN-γ) than the tested L. rhamnosus and L. casei strains. Both B. breve and lactobacilli induced cytokines in a Toll-like receptor 9 (TLR9)-dependent manner, while the lower inflammatory profile of B. breve was due to inhibitory effects of TLR2. No role for TLR4, NOD2, and C-type lectin receptors was apparent. In conclusion, TLR signaling is involved in the differentiation of inflammatory responses between probiotic strains used as food supplements. PMID:21288993

  3. Optimal rate allocation in cluster-tree WSNs.

    PubMed

    Morell, Antoni; Vicario, Jose Lopez; Vilajosana, Xavier; Vilajosana, Ignasi; Seco-Granados, Gonzalo

    2011-01-01

    In this paper, we propose a solution to the problem of guaranteed time slot allocation in cluster-tree WSNs. Our design uses the so-called Network Utility Maximization (NUM) approach as far as we aim to provide a fair distribution of the available resources. From the point of view of implementation, we extend here the authors' proposed Coupled-Decompositions Method (CDM) in order to compute the NUM problem inside the cluster tree topology and we prove the optimality of this new extended version of the method. As a result, we obtain a distributed solution that reduces the total amount of signalling information in the network up to a factor of 500 with respect to the classical techniques, that is, primal and dual decomposition. This is possible because the CDM finds the optimal solution with a small number of iterations. Furthermore, when we compare our solution to the standard-proposed First Come First Serve (FCFS) policy, we realize that FCFS becomes pretty unfair as the traffic load in the network increases and thus, a fair allocation of resources can be considered whenever the price to pay in terms of signalling and computational complexity is controlled. PMID:22163812

  4. Streptococcus oriloxodontae sp. nov., isolated from the oral cavities of elephants.

    PubMed

    Shinozaki-Kuwahara, Noriko; Saito, Masanori; Hirasawa, Masatomo; Takada, Kazuko

    2014-11-01

    Two strains were isolated from oral cavity samples of healthy elephants. The isolates were Gram-positive, catalase-negative, coccus-shaped organisms that were tentatively identified as a streptococcal species based on the results of biochemical tests. Comparative 16S rRNA gene sequence analysis suggested classification of these organisms in the genus Streptococcus with Streptococcus criceti ATCC 19642(T) and Streptococcus orisuis NUM 1001(T) as their closest phylogenetic neighbours with 98.2 and 96.9% gene sequence similarity, respectively. When multi-locus sequence analysis using four housekeeping genes, groEL, rpoB, gyrB and sodA, was carried out, similarity of concatenated sequences of the four housekeeping genes from the new isolates and Streptococcus mutans was 89.7%. DNA-DNA hybridization experiments suggested that the new isolates were distinct from S. criceti and other species of the genus Streptococcus. On the basis of genotypic and phenotypic differences, it is proposed that the novel isolates are classified in the genus Streptococcus as representatives of Streptococcus oriloxodontae sp. nov. The type strain of S. oriloxodontae is NUM 2101(T) ( =JCM 19285(T) =DSM 27377(T)). PMID:25139416

  5. Difusión de Arnold en un modelo simple

    NASA Astrophysics Data System (ADS)

    Cincotta, P. M.; Nuñez, J. A.; Miloni, O.

    Investigadores como Merritt, Valluri, Pfenniger o Contopoulos (por citar los más relevantes) consideran seriamente la hipótesis que la difusión de Arnold juega un rol importante en la evolución dinámica de los sistemas estelares y planetarios. Sin embargo no existe ninguna evidencia. El mayor problema para investigar fenómenos como éste es que uno debe estudiar numéricamente sistemas multidimensionales (más de dos grados de libertad) y visualizar de alguna manera el espacio de fases (más de cuatro dimensiones). Más complicado aún es el caso de difusión de Arnold, donde deben considerarse tiempos de movimiento extremadamente largos y tratar con parámetros exponencialmente pequeños. El propósito de este trabajo es estudiar, en un modelo simple 3D, la existencia o no de difusión de Arnold mediante experimentos numéricos y estimaciones analíticas. Siguiendo los trabajos de Cincotta (2000) y Cincotta, Nuñez y Simo (2000), aquí se pretende ``visualizar" la difusión y, a la vez, determinar la escala de tiempo en la que ésta se podría manifestar. Este trabajo es el escalón inicial para luego abordar este problema en modelos.

  6. MDAnalysis: a toolkit for the analysis of molecular dynamics simulations.

    PubMed

    Michaud-Agrawal, Naveen; Denning, Elizabeth J; Woolf, Thomas B; Beckstein, Oliver

    2011-07-30

    MDAnalysis is an object-oriented library for structural and temporal analysis of molecular dynamics (MD) simulation trajectories and individual protein structures. It is written in the Python language with some performance-critical code in C. It uses the powerful NumPy package to expose trajectory data as fast and efficient NumPy arrays. It has been tested on systems of millions of particles. Many common file formats of simulation packages including CHARMM, Gromacs, Amber, and NAMD and the Protein Data Bank format can be read and written. Atoms can be selected with a syntax similar to CHARMM's powerful selection commands. MDAnalysis enables both novice and experienced programmers to rapidly write their own analytical tools and access data stored in trajectories in an easily accessible manner that facilitates interactive explorative analysis. MDAnalysis has been tested on and works for most Unix-based platforms such as Linux and Mac OS X. It is freely available under the GNU General Public License from http://mdanalysis.googlecode.com. PMID:21500218

  7. Simulaciones hidrodinámicas de flujos complejos

    NASA Astrophysics Data System (ADS)

    María Ibáñez Cabanell, José

    Son muchos los escenarios astrofísicos en que los procesos hidrodinámicos juegan un papel clave. En la complejidad que encierra la descripción de dichos procesos destaca el de la correcta simulación de flujos complejos donde la presencia de ondas de choque fuertes que, eventualmente, interaccionan entre ellas o también la presencia de inestabilidades (Kelvin-Helmholtz, Rayleigh-Taylor, etc.) suponen un verdadero desafío numérico. Los códigos hidrodinámicos basados en la solución de un problema de valores iniciales discontinuo (problema de Riemann) son, en la actualidad, los más robustos en el campo de la dinámica de fluidos computacional. En esta charla se dará un resumen de los fundamentos de dichas técnicas numéricas (esquemas de alta resolución de captura de choques) y se ilustrará su potencialidad mostrando una amplia gama de resultados en diferentes aplicaciones astrofísicas.

  8. La historia orbital de Deimos y la oblicuidad de Marte

    NASA Astrophysics Data System (ADS)

    Brunini, A.; Yokoyama, T.

    Recientemente, se ha demostrado mediante extensas integraciones numéricas, que la rotación de Marte pasó repetidamente por estados caóticos de movimiento, debido al pasaje por zonas de resonancia spin - órbita. En dichas circunstancias, la oblicuidad marciana pudo haber sufrido grandes excursiones de varias decenas de grados. Las consecuencias de dichas variaciones son de extrema importancia en el contexto de la búsqueda de manifestaciones de vida fósil en dicho planeta. El estudio de la dinámica orbital del satélite más exterior de Marte, Deimos, nos ha permitido comprobar, en el marco de las distintas teorías sobre su orígen, que la oblicuidad de Marte dificilmente pudo haber sufrido variaciones que la aparten más de 10o respecto de actual valor. Este resultado parece ser mucho más robusto que las simulaciones numéricas de Touma y Wisdom asi como las de Laskar y Robutel, lo que permite poner cotas más severas a la evolución paleoclimática de Marte.

  9. ASME Nuclear Crane Standards for Enhanced Crane Safety and Increased Profit

    NASA Astrophysics Data System (ADS)

    Parkhurst, Stephen N.

    2000-01-01

    The ASME NOG-1 standard, 'Rules for Construction of Overhead and Gantry Cranes', covers top running cranes for nuclear facilities; with the ASME NUM-1 standard, 'Rules for Construction of Cranes, Monorails, and Hoists', covering the single girder, underhung, wall and jib cranes, as well as the monorails and hoists. These two ASME nuclear crane standards provide criteria for designing, inspecting and testing overhead handling equipment with enhanced safety to meet the 'defense-in-depth' approach of the United States Nuclear Regulatory Commission (USNRC) documents NUREG 0554 and NUREG 0612. In addition to providing designs for enhanced safety, the ASME nuclear crane standards provide a basis for purchasing overhead handling equipment with standard safety features, based upon accepted engineering principles, and including performance and environmental parameters specific to nuclear facilities. The ASME NOG-1 and ASME NUM-1 standards not only provide enhanced safety for handling a critical load, but also increase profit by minimizing the possibility of load drops, by reducing cumbersome operating restrictions, and by providing the foundation for a sound licensing position. The ASME nuclear crane standards can also increase profit by providing the designs and information to help ensure that the right standard equipment is purchased. Additionally, the ASME nuclear crane standards can increase profit by providing designs and information to help address current issues, such as the qualification of nuclear plant cranes for making 'planned engineered lifts' for steam generator replacement and decommissioning.

  10. MDAnalysis: A Toolkit for the Analysis of Molecular Dynamics Simulations

    PubMed Central

    Michaud-Agrawal, Naveen; Denning, Elizabeth J.; Woolf, Thomas B.; Beckstein, Oliver

    2011-01-01

    MDAnalysis is an object-oriented library for structural and temporal analysis of molecular dynamics (MD) simulation trajectories and individual protein structures. It is written in the Python language with some performance-critical code in C. It uses the powerful NumPy package to expose trajectory data as fast and efficient NumPy arrays. It has been tested on systems of millions of particles. Many common file formats of simulation packages including CHARMM, Gromacs, Amber, and NAMD and the Protein Data Bank format can be read and written. Atoms can be selected with a syntax similar to CHARMM’s powerful selection commands. MDAnalysis enables both novice and experienced programmers to rapidly write their own analytical tools and access data stored in trajectories in an easily accessible manner that facilitates interactive explorative analysis. MDAnalysis has been tested on and works for most Unix-based platforms such as Linux and Mac OS X. It is freely available under the GNU Public License from http://mdanalysis.googlecode.com. PMID:21500218

  11. Adapted G-mode Clustering Method applied to Asteroid Taxonomy

    NASA Astrophysics Data System (ADS)

    Hasselmann, Pedro H.; Carvano, Jorge M.; Lazzaro, D.

    2013-11-01

    The original G-mode was a clustering method developed by A. I. Gavrishin in the late 60's for geochemical classification of rocks, but was also applied to asteroid photometry, cosmic rays, lunar sample and planetary science spectroscopy data. In this work, we used an adapted version to classify the asteroid photometry from SDSS Moving Objects Catalog. The method works by identifying normal distributions in a multidimensional space of variables. The identification starts by locating a set of points with smallest mutual distance in the sample, which is a problem when data is not planar. Here we present a modified version of the G-mode algorithm, which was previously written in FORTRAN 77, in Python 2.7 and using NumPy, SciPy and Matplotlib packages. The NumPy was used for array and matrix manipulation and Matplotlib for plot control. The Scipy had a import role in speeding up G-mode, Scipy.spatial.distance.mahalanobis was chosen as distance estimator and Numpy.histogramdd was applied to find the initial seeds from which clusters are going to evolve. Scipy was also used to quickly produce dendrograms showing the distances among clusters. Finally, results for Asteroids Taxonomy and tests for different sample sizes and implementations are presented.

  12. Cohort Profile update: The 1993 Pelotas (Brazil) Birth Cohort follow-up visits in adolescence

    PubMed Central

    Gonçalves, Helen; Assunção, Maria CF; Wehrmeister, Fernando C; Oliveira, Isabel O; Barros, Fernando C; Victora, Cesar G; Hallal, Pedro C; Menezes, Ana MB

    2014-01-01

    In this paper we update the profile of the 1993 Pelotas (Brazil) Birth Cohort Study, with emphasis on a shift of priority from maternal and child health research topics to four main categories of outcome variables, collected throughout adolescence: (i) mental health; (ii) body composition; (iii) risk factors for non-communicable diseases (NCDs); (iv) human capital. We were able to trace 81.3% (n = 4106) of the original cohort at 18 years of age. For the first time, the 18-years visit took place entirely on the university premises, in a clinic equipped with state-of-the-art equipment for the assessment of body composition. We welcome requests for data analyses from outside scientists. For more information, refer to our website (http://www.epidemio-ufpel.org.projetos_de_pesquisas/estudos/coorte_1993) or e-mail the corresponding author. PMID:24729426

  13. Flood forecasting for Tucurui Hydroelectrical Plant, Brazil

    SciTech Connect

    Solomon, S.I.; Basso, E.; Osorio, C.; Melo de Moraes, H.; Serrano, A.

    1986-04-01

    The construction of the Tucurui Hydroelectric Plant on the Tocantins River basin in Brazil requires flood forecasting to ensure the safety of the cofferdam. The latter has been initially designed for a flood with a return frequency of one in 25 years. Lack of adequate forecasting facilities during the earlier stages of construction has resulted in significant damages and construction delays. Statistical forecasting models were developed by Projeto de Hidrologia y Climatologie da Amazonia (PHCA) for the purpose of preventing further damage at the site. The application of these models during the 1980 flood season, when the highest flood on record occurred at the Tucurui site, proved of great assistance in preventing the flooding of the cofferdam. In conjunction with the development of these models a number of data collection platforms using data transmission through the GOES system were installed to provide the data required for forecasting.

  14. [Programa de saúde: a case of book censorship during the Brazilian military dictatorship].

    PubMed

    Reimão, Sandra

    2013-11-30

    Some documents produced by the government during the Brazilian military dictatorship have been made available for reference, including censors' reports on television and radio programs, plays, films, songs, advertisements and printed matter. Of the 500 or so reports on books, there is one that vetoes Programa de saúde: projetos e temas de higiene e saúde, an educational work that proposed actions to help students understand their sanitary conditions and acquire knowledge about health and health-promoting habits in this area. The argument for vetoing it was that the information could fall into the hands of poorly trained teachers, who could distort its content, causing serious damage to Brazilian youth. In this report we see evidence of the obscurantist, elitist posture adopted by the Department of Censorship of Public Entertainment, which aimed to restrict the circulation of information and curb debate. PMID:24346208

  15. Mapping of land use and geomorphology in the APAPORE project area by LANDSAT satellite data, volume 1

    NASA Technical Reports Server (NTRS)

    Parada, N. D. J. (Principal Investigator); Dossantos, A. P.; Kux, H. J.; Sausen, T. M.; Bueno, A. M. T. R.; Desouza, L. F.; Nunes, J. S. D.

    1982-01-01

    The results of a land use and geomorphological mapping of the so-called Projeto APAPORE area, at Mato Grosso do Sul State are presented. The study was carried out using multispectral scanner (MSS) and return beam vidicon LANDSAT images (channels 5 and 7 for the MSS) at the scale of 1:250,000 from 1980 through visual interpretation. The results indicate that pastureland is the most widespead class and that the agricultural areas re concentrated in the north of the area under study. The area covered with cerradao (arboreous savanna type) has a great areal extention, thus permitting the advance of the agricultural frontier. The geomorphological mapping can be useful to regional planning of future land use within the studied area.

  16. Contaminant concentrations, biochemical and hematological biomarkers in blood of West Indian manatees Trichechus manatus from Brazil.

    PubMed

    Anzolin, D G; Sarkis, J E S; Diaz, E; Soares, D G; Serrano, I L; Borges, J C G; Souto, A S; Taniguchi, S; Montone, R C; Bainy, A C D; Carvalho, P S M

    2012-07-01

    The West Indian manatee Trichechus manatus is threatened with extinction in Brazil, and this study focused on nondestructive blood samples analyzed for metals, polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs), as well as biochemical and hematological biomarkers. Studied manatees were kept at Projeto Peixe-Boi headquarters in Pernambuco State, and at two natural areas in estuaries where they are released to the wild. Manatees kept at the natural estuary in Paraiba State have blood concentrations of Al, Pb, Cd, Sn that are 11, 7, 8 and 23 times greater, respectively, than the concentrations found in blood of animals from the same species in Florida, USA. An inhibition of butyrylcholinesterase in manatees kept at the two reintroduction sites in Alagoas and Paraiba States indicated possible exposure of the animals to cholinesterase inhibitor insecticides. PCBs and OCPs were not detected. Results from this study will help delineate conservation efforts in the region. PMID:22626623

  17. Condiciones Físicas en Nebulosas Gaseosas

    NASA Astrophysics Data System (ADS)

    Luridiana, V.

    1999-03-01

    El presente trabajo se ha enfocado a determinar y entender las condiciones físicas en una variedad de objetos nebulares, prestando particular atención al problema de la determinación de las abundancias químicas. Para este fin, hemos utilizado métodos analíticos en algunos casos, y modelos numéricos de fotoionización en otros. El objetivo general del trabajo es proveer de una visión amplia de las herramientas teórico-observacionales que se utilizan para la determinación de la estructura de temperatura y densidad de las regiones fotoionizadas, poniendo en evidencia posibles fuentes de errores sistemáticos y sus consecuencias para la determinación de las abundancias químicas, y proponiendo métodos para corregirlos. Los resultados principales de este trabajo est´n listados a continuación: a) Se discute el problema de la discrepancia entre T(C III) y T(O III) en las nebulosas planetarias, y se muestra como tal discrepancia implica probablemente la presencia de fluctuaciones de temperatura. Debido a que la temperatura de O++ es muy afectada por fluctuaciones de temperatura, se recomienda usar la temperatura de C++ para determinar la abundancia de carbono. b) Presentamos dos nuevos métodos para determinar la temperatura electrónica en nebulosas planetarias, basados en la medición de las intensidades de las líneas de He I. Las temperaturas que se obtienen a partir de estos métodos son menores que aquellas que se obtienen a partir de las líneas de [O III], implicando la presencia de fluctuaciones espaciales de temperatura. Despreciando las fluctuaciones de temperatura, se obtienen valores sesgados de las abundancias químicas. Determinamos las abundancias en las nebulosas planetarias de tipo I de algunos de los elementos más importantes, tomando en cuenta las fluctuaciones de temperatura. c) Presentamos modelos numéricos de las dos regiones H II extragalácticas gigantes NGC 2363 y NGC 5461. Con el modelaje numérico, pretendemos acotar las car

  18. A constitutive-relationship model for film flow on rough fracture surfaces

    NASA Astrophysics Data System (ADS)

    Liu, H. H.

    Film flow on fracture surfaces may be an important mechanism for fast flow in unsaturated fractured rocks. Incorporating this mechanism into a numerical model requires knowledge of constitutive relationships for film flow. Based on fractal concepts and a conceptual argument of Tokunaga et al. that water films could be treated as analogues to water in unsaturated porous media, a simple constitutive-relationship model has been developed. The validity of the model is supported by excellent agreements between calculation results and experimental observations for two different fracture surfaces. L'écoulement en film sur les surfaces de fracture peut être un mécanisme important pour l'écoulement rapide dans les roches fracturées non saturées. L'incorporation de ce mécanisme dans un modèle numérique nécessite la connaissance des relations fondamentales pour l'écoulement en film. Basé sur des concepts fractals et sur un argument conceptuel de Tokunaga et al. selon lequel des films d'eau peuvent être considérés comme des analogues de l'eau en milieu poreux non saturé, un modèle simple des relations fondamentales a été développé. La validité de ce modèle est confirmée grâce à une excellente concordance entre les résultats du calcul et les observations expérimentales pour deux surfaces différentes de fractures. El flujo pelicular en la superficie de las fracturas puede ser un mecanismo importante para el flujo rápido en rocas fracturadas no saturadas. Incorporarlo en un modelo numérico requiere conocer las relaciones constitutivas del flujo pelicular. Se ha desarrollado un modelo de una relación constitutiva sencilla partiendo de conceptos fractales y de un argumento conceptual de Tokunaga et al., según el cual las películas de agua pueden ser tratadas como análogos del agua en medios porosos no saturados. La validez del modelo es corroborada por los excelentes ajustes entre los resultados numéricos y las observaciones experimentales en dos

  19. Le syndrome de la pince aorto-mésentérique chez l'enfant: à propos d'un cas primitive

    PubMed Central

    Fall, Mbaye; Bâ, Papa Abdoulaye; Touré, Fodé Baba; Mbaye, Pape Alassane; Ngom, Gabriel

    2014-01-01

    Le syndrome de la pince aorto-mésentérique résulte de la compression du troisième duodénum entre l'artère mésentérique supérieure et l'aorte. Elle détermine un tableau d'occlusion intestinale haute aiguë ou chronique. Nous faisons une revue de la littérature à partir d'un cas de syndrome de la pince aorto-mésentérique. Il s'agit d'un nourrisson de 16 mois suivi pour des vomissements alimentaires évoluant depuis l’âge de 03 mois et rebelles au traitement médical. Il s'agit de vomissements postprandiaux tardifs d'apparition intermittente, améliorés par la position de décubitus ventral. Le bilan radiologique composé d'une radiographie de l'abdomen sans préparation, d'un transit oeso-gastroduodénal (TOGD) et d'un angioscanner a permis d'aboutir au diagnostic d'obstruction extrinsèque et incomplète du 3ème duodénum par la pince aorto-mésentérique. Une dérivation interne par duodéno-jéjunostomie sur anse en oméga a permis de contourner l'obstacle vasculaire avec des suites simples. Le TOGD de contrôle du 9ème jour postopératoire a montré une bonne perméabilité de l'anastomose duodéno-jéjunale. Les vomissements ont disparu et on note un gain pondéral de 2 kg en 3 mois. Les vomissements chroniques chez le nourrisson sont d’étiologies variées. L'obstacle siégeant au 3ème duodénum est le plus souvent dû à une pince aorto-mésentérique. Malheureusement ce diagnostic est rarement porté surtout en Afrique probablement du fait de l'insuffisance des moyens diagnostiques en particulier dans les zones reculées. Le traitement peut être fait par les moyens chirurgicaux ou nutritionnels. PMID:25767670

  20. Teaching and Popularization of Astronomy in Latin America by the Liada Perspective. (Spanish Title: Enseñanza y Divulgación de la Astronomía en la América Latina en la Perspectiva de la Liada.) Ensino e Divulgação da Astronomia na América Latina na Perspectiva da Liada

    NASA Astrophysics Data System (ADS)

    Bretones, Paulo Sergio

    2008-12-01

    disponibilizados en la página de la Sección, faz-se una análisis y discusión sobre la importancia de tales relatos para finalidades educacionales. Es presentada una Hoja de reporte elaborado como sugestión para presentación de relatos por parte de individuos y instituciones ben como discutida la importancia de la sistematización de experiencias visando mayor visibilidad y cambio de informaciones en el área. Concluí con una evaluación de los proyectos, su potencial y limitaciones, ben como sugestiones de proyectos futuros visando mayor interacción entre los países de la América Latina y tornando disponible la Sección para esta finalidad.

    Esse trabalho visa divulgar e analisar as atividades da Seção de Ensino e Divulgação de Astronomia (SEDA) da Liga Iberoamericana de Astronomia (LIADA). Após um histórico da LIADA, são apresentados os diversos projetos da Seção que conta com a colaboração de coordenadores locais na maioria dos países da América Latina. São apresentados os projetos que visam chamar a atenção do público em geral, estudantes e professores para a observação do céu e posterior envio de relatos para colocação na página da Seção na Internet. Mais especificamente são analisados os projetos e relatos relacionados aos eclipses ocorridos desde o ano 2000. Utilizando-se os arquivos disponibilizados na página da Seção, faz-se uma análise e discussão sobre a importância de tais relatos para finalidades educacionais. É apresentado um formulário elaborado como sugestão para apresentação de relatos por parte de indivíduos e instituições bem como discutida a importância da sistematização de experiências visando maior visibilidade e troca de informações na área. Conclui com uma avaliação dos projetos, seu potencial e limitações, bem como sugestões de projetos futuros visando maior interação entre os países da América Latina e tornando disponível a Seção para esta finalidade.

  1. Predicting the Effects of Sugar-Sweetened Beverage Taxes on Food and Beverage Demand in a Large Demand System.

    PubMed

    Zhen, Chen; Finkelstein, Eric A; Nonnemaker, James; Karns, Shawn; Todd, Jessica E

    2014-01-01

    A censored Exact Affine Stone Index incomplete demand system is estimated for 23 packaged foods and beverages and a numéraire good. Instrumental variables are used to control for endogenous prices. A half-cent per ounce increase in sugar-sweetened beverage prices is predicted to reduce total calories from the 23 foods and beverages but increase sodium and fat intakes as a result of product substitution. The predicted decline in calories is larger for low-income households than for high-income households, although welfare loss is also higher for low-income households. Neglecting price endogeneity or estimating a conditional demand model significantly overestimates the calorie reduction. PMID:24839299

  2. Radiation Scanning Methods for Ship-to-Rail Intermodal Cargo Containers

    SciTech Connect

    Reichmuth, Barbara A.; Stansbury, Paul S.; Taira, Randal Y.; Sanquist, Thomas F.; Collins, Robert

    2009-05-11

    The Department of Homeland Security’s (DHS) Domestic Nuclear Detection Office (DNDO) runs the Rail Test Center (RTC) at the Port of Tacoma (POT). The RTC affords DNDO with the opportunity to test radiological and nuclear threat detection systems associated with the unique on-dock rail environment while in an operational seaport. DNDO selected the Pacific Northwest National Laboratory (PNNL) to manage the RTC. The RTC is conducting various evaluation studies to assess scanning opportunities in terms of their affects on the num-ber of container moves required and the affect that the scanning opportunity has on the time it takes to move a container through the on-dock transfer process from ship to rail. The velocity and the number of container moves are directly associated with incremental costs to the terminal operators; increases in either of these parameters help in-form the potential for incremental costs that would result from the implementation of the opportunity.

  3. 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.

  4. Numerical analysis of natural convection for non-Newtonian fluid conveying nanoparticles between two vertical parallel plates

    NASA Astrophysics Data System (ADS)

    Sahebi, S. A. R.; Pourziaei, H.; Feizi, A. R.; Taheri, M. H.; Rostamiyan, Y.; Ganji, D. D.

    2015-12-01

    In this paper, natural convection of non-Newtonian bio-nanofluids flow between two vertical flat plates is investigated numerically. Sodium Alginate (SA) and Sodium Carboxymethyl Cellulose (SCMC) are considered as the base non-Newtonian fluid, and nanoparticles such as Titania ( TiO2 and Alumina ( Al2O3 were added to them. The effective thermal conductivity and viscosity of nanofluids are calculated through Maxwell-Garnetts (MG) and Brinkman models, respectively. A fourth-order Runge-Kutta numerical method (NUM) and three Weighted Residual Methods (WRMs), Collocation (CM), Galerkin (GM) and Least-Square Method (LSM) and Finite-Element Method (FEM), are used to solve the present problem. The influence of some physical parameters such as nanofluid volume friction on non-dimensional velocity and temperature profiles are discussed. The results show that SCMC- TiO2 has higher velocity and temperature values than other nanofluid structures.

  5. Predicting the Effects of Sugar-Sweetened Beverage Taxes on Food and Beverage Demand in a Large Demand System

    PubMed Central

    Zhen, Chen; Finkelstein, Eric A.; Nonnemaker, James; Karns, Shawn; Todd, Jessica E.

    2013-01-01

    A censored Exact Affine Stone Index incomplete demand system is estimated for 23 packaged foods and beverages and a numéraire good. Instrumental variables are used to control for endogenous prices. A half-cent per ounce increase in sugar-sweetened beverage prices is predicted to reduce total calories from the 23 foods and beverages but increase sodium and fat intakes as a result of product substitution. The predicted decline in calories is larger for low-income households than for high-income households, although welfare loss is also higher for low-income households. Neglecting price endogeneity or estimating a conditional demand model significantly overestimates the calorie reduction. PMID:24839299

  6. SkData: data sets and algorithm evaluation protocols in Python

    NASA Astrophysics Data System (ADS)

    Bergstra, James; Pinto, Nicolas; Cox, David D.

    2015-01-01

    Machine learning benchmark data sets come in all shapes and sizes, whereas classification algorithms assume sanitized input, such as (x, y) pairs with vector-valued input x and integer class label y. Researchers and practitioners know all too well how tedious it can be to get from the URL of a new data set to a NumPy ndarray suitable for e.g. pandas or sklearn. The SkData library handles that work for a growing number of benchmark data sets (small and large) so that one-off in-house scripts for downloading and parsing data sets can be replaced with library code that is reliable, community-tested, and documented. The SkData library also introduces an open-ended formalization of training and testing protocols that facilitates direct comparison with published research. This paper describes the usage and architecture of the SkData library.

  7. New version of hex-ecs, the B-spline implementation of exterior complex scaling method for solution of electron-hydrogen scattering

    NASA Astrophysics Data System (ADS)

    Benda, Jakub; Houfek, Karel

    2016-07-01

    We provide an updated version of the program hex-ecs originally presented in Comput. Phys. Commun. 185 (2014) 2903-2912. The original version used an iterative method preconditioned by the incomplete LU factorization (ILU), which-though very stable and predictable-requires a large amount of working memory. In the new version we implemented a "separated electrons" (or "Kronecker product approximation", KPA) preconditioner as suggested by Bar-On et al., Appl. Num. Math. 33 (2000) 95-104. This preconditioner has much lower memory requirements, though in return it requires more iterations to reach converged results. By careful choice between ILU and KPA preconditioners one is able to extend the computational feasibility to larger calculations. Secondly, we added the option to run the KPA preconditioner on an OpenCL device (e.g. GPU). GPUs have generally better memory access times, which speeds up particularly the sparse matrix multiplication.

  8. Resonancias en la región trans-neptuniana

    NASA Astrophysics Data System (ADS)

    Gallardo, T.; Ferraz-Mello, S.

    La expansión de la órbita del planeta Neptuno en la etapa de acreción del Sistema Solar exterior (Fernández e Ip 1984, 1996) parece ser un mecanismo eficiente para la captura de planetesimales en las resonancias exteriores con Neptuno (Malhotra 1995). Por otro lado, los estudios dinámicos realizados por varios autores indican que las resonancias son regiones de evolución estable, en contraste con el comportamiento caótico del resto de la región trans-neptuniana. Por estas razones, y si bien los datos observacionales son todavía muy limitados, se supone que los objetos descubiertos se encuentran en alguna de esas resonancias. En esta comunicación presentamos un estudio analítico y numérico de las principales resonancias exteriores con Neptuno.

  9. Comportamiento dinámico de asteroides en la resonancia 2:1

    NASA Astrophysics Data System (ADS)

    López García, F.; Brunini, A.

    El propósito de este trabajo es mostrar los resultados obtenidos del estudio del movimiento de asteroides cercanos a la conmensurabilidad 2:1 con el movimiento medio de Júpiter, analizando el comportamiento de órbitas de asteroides reales y ficticios. Se analizan los tiempos de Lyapunov obtenidos a partir de la integración de las ecuaciones del movimiento. Se han estudiado la órbitas utilizando el modelo de cinco cuerpos y se han considerado los casos planar y espacial. Las simulaciones numéricas se realizaron utilizando integradores simpléticos y el intervalo de tiempo de integración fue de T = 107 años.

  10. Improving the trust algorithm of information in semantic web

    NASA Astrophysics Data System (ADS)

    Wan, Zong-bao; Min, Jiang

    2012-01-01

    With the rapid development of computer networks, especially with the introduction of the Semantic Web perspective, the problem of trust computation in the network has become an important research part of current computer system theoretical. In this paper, according the information properties of the Semantic Web and interact between nodes, the definition semantic trust as content trust of information and the node trust between the nodes of two parts. By Calculate the content of the trust of information and the trust between nodes, then get the final credibility num of information in semantic web. In this paper , we are improve the computation algorithm of the node trust .Finally, stimulations and analyses show that the improved algorithm can effectively improve the trust of information more accurately.

  11. Improving the trust algorithm of information in semantic web

    NASA Astrophysics Data System (ADS)

    Wan, Zong-Bao; Min, Jiang

    2011-12-01

    With the rapid development of computer networks, especially with the introduction of the Semantic Web perspective, the problem of trust computation in the network has become an important research part of current computer system theoretical. In this paper, according the information properties of the Semantic Web and interact between nodes, the definition semantic trust as content trust of information and the node trust between the nodes of two parts. By Calculate the content of the trust of information and the trust between nodes, then get the final credibility num of information in semantic web. In this paper , we are improve the computation algorithm of the node trust .Finally, stimulations and analyses show that the improved algorithm can effectively improve the trust of information more accurately.

  12. Local Existence of Weak Solutions to Kinetic Models of Granular Media

    NASA Astrophysics Data System (ADS)

    Agueh, Martial

    2016-08-01

    We prove in any dimension {d ≥q 1} a local in time existence of weak solutions to the Cauchy problem for the kinetic equation of granular media, partial_t f+v\\cdot nabla_x f = {div}_v[f(nabla W *_v f)] when the initial data are nonnegative, integrable and bounded functions with compact support in velocity, and the interaction potential {W} is a {C^2({{R}}^d)} radially symmetric convex function. Our proof is constructive and relies on a splitting argument in position and velocity, where the spatially homogeneous equation is interpreted as the gradient flow of a convex interaction energy with respect to the quadratic Wasserstein distance. Our result generalizes the local existence result obtained by Benedetto et al. (RAIRO Modél Math Anal Numér 31(5):615-641, 1997) on the one-dimensional model of this equation for a cubic power-law interaction potential.

  13. Détection et exaltation de la luminescence de molécules biologiques individuelles en solution

    NASA Astrophysics Data System (ADS)

    Etienne, E.; Lenne, P. F.; Rigneault, H.

    2002-06-01

    La Spectroscopie de Corrélation de Fluorescence (FCS) est une technique d'analyse statistique des fluctuations de luminescence produites par des molécules fluorescentes diffusant librement dans un volume de collection de quelque μm^3. Une limitation fondamentale de la technique provient de l'ouverture numérique limitée des systèmes optiques conventionnels qui ne collectent qu'une faible partie des photons émis. Nous présentons des résultats relatifs à l'augmentation du nombre de photons collectés en utilisant le concept du contrôle de l'émission spontanée par des structures photoniques de type miroir diélectrique.

  14. Combustión turbulenta de materia nuclear en materia extraña

    NASA Astrophysics Data System (ADS)

    Vucetich, H.

    La simulación numérica de supernovas tipo II muestra que los mecanismos físicos convencionales no son suficientes como para producir la explosión. La detonación de materia nuclear en materia extraña es un mecanismo físico capaz de proveer la energía faltante en las simulaciones. En esta comunicación se muestra que la turbulencia en el corazón compacto de una supernova, después del primer choque, es capaz de transformar una combustión lenta en una detonación. Se concluye que, si la materia extraña existe, todas las ``estrellas de neutrones'' son, en realidad, ``estrellas extrañas''.

  15. Radiative Influences On The Dynamical Structure of Cirrus Clouds

    NASA Astrophysics Data System (ADS)

    Dobbie, S.; Jonas, P. R.

    The results of a study will be presented which investigates the role of radiative and la- tent heating processes on the dynamical and microphysical evolution of cirrus clouds. The UK Met. Office's LES model run in 2D is used as the cloud resolving model for this work. Results will be shown pertaining to the effects that solar and IR radiation have on cloud stability, morphology, microphysics, time evolution, and cloud lifetime. In an attempt to generalize the results beyond the model calculations, stability num- bers will be presented that help to assess the influence that these diabatic processes have on the cloud stability. Recent work will also be shown pertaining to full 3D model simulations and a study showing a comparison of results from the LES double moment microphysics scheme to observations.

  16. Extragalactic radio sources

    NASA Technical Reports Server (NTRS)

    Sturrock, P. A.

    1984-01-01

    The standard model for extragalactic variable radio sources comprises an isotropically expanding plasmoid with frozen magnetic flux and an electron distribution which evolves adiabatically. This model leads to the following relaton between the peak luminosity L (sub nu, m) and the relevant frequency nu(sub m) which are functions of time: L(sub nu,m) is proportional to nu(sub m)(n) where N = (7n + 5)/(4n + 5). In this expression, n is the spectral index in the optically thin part of the spectrum, where L (sub nu) is proportional to nu (-n). For n in the range 0.5 to 1.5, the standard model yields N in the range 1.2 to 1.4. By contrast, analysis of observational data yields estimates of N in a small range about the mean value 0.4, in clear contradiction with the standard model.

  17. Captura de galaxias enanas en cúmulos de galaxias

    NASA Astrophysics Data System (ADS)

    Bassino, L. P.; Muzzio, J. C.; Pérez, J.

    Se investiga el proceso de captura de galaxias enanas por parte de galaxias gigantes, en presencia de un campo externo causado por materia distribuída y otras galaxias pertenecientes al cúmulo en que se produce el fenómeno. Se trabaja mediante simulaciones numéricas, generando condiciones iniciales típicas de cúmulos de galaxias y representando, con un espectro de masas, a las galaxias más masivas y, como partículas de prueba, a las enanas. Se sigue la evolución del sistema empleando un código de integración de N-cuerpos y se analizan los resultados para determinar las capturas de galaxias enanas.

  18. PyTrilinos: Recent Advances in the Python Interface to Trilinos

    SciTech Connect

    Spotz, William F.

    2012-01-01

    PyTrilinos is a set of Python interfaces to compiled Trilinos packages. This collection supports serial and parallel dense linear algebra, serial and parallel sparse linear algebra, direct and iterative linear solution techniques, algebraic and multilevel preconditioners, nonlinear solvers and continuation algorithms, eigensolvers and partitioning algorithms. Also included are a variety of related utility functions and classes, including distributed I/O, coloring algorithms and matrix generation. PyTrilinos vector objects are compatible with the popular NumPy Python package. As a Python front end to compiled libraries, PyTrilinos takes advantage of the flexibility and ease of use of Python, and the efficiency of the underlying C++, C and Fortran numerical kernels. This paper covers recent, previously unpublished advances in the PyTrilinos package.

  19. Sintetizadores de síntesis digital directa

    NASA Astrophysics Data System (ADS)

    Olalde, J. C.; Perilli, D.; Larrarte, J. J.

    Se describen las características e implementación de sintetizadores de alta resolución en frecuencia, <= 2 mHz, tiempos de conmutación rápidos, submicrosegundo, con posibilidad de control de fase basados en la técnica de síntesis digital directa. La implementación se realiza a partir del circuito integrado AD7008, que incluye un oscilador controlado numéricamente y un conversor analógico digital, y en el trabajo se dan pautas para la especificación de los filtros de reconstrucción. El instrumento implementado posee un módulo basado en un microcontrolador INTEL 8752 el cual provee la posibilidad de monitoreo, indicación visual y control en forma local a partir de un teclado; y remoto a partir de un ``host" con interfases RS232 y RS 485.

  20. Network Properties of the Ensemble of RNA Structures

    PubMed Central

    Clote, Peter; Bayegan, Amir

    2015-01-01

    We describe the first dynamic programming algorithm that computes the expected degree for the network, or graph G = (V, E) of all secondary structures of a given RNA sequence a = a1, …, an. Here, the nodes V correspond to all secondary structures of a, while an edge exists between nodes s, t if the secondary structure t can be obtained from s by adding, removing or shifting a base pair. Since secondary structure kinetics programs implement the Gillespie algorithm, which simulates a random walk on the network of secondary structures, the expected network degree may provide a better understanding of kinetics of RNA folding when allowing defect diffusion, helix zippering, and related conformation transformations. We determine the correlation between expected network degree, contact order, conformational entropy, and expected number of native contacts for a benchmarking dataset of RNAs. Source code is available at http://bioinformatics.bc.edu/clotelab/RNAexpNumNbors. PMID:26488894

  1. High performance Python for direct numerical simulations of turbulent flows

    NASA Astrophysics Data System (ADS)

    Mortensen, Mikael; Langtangen, Hans Petter

    2016-06-01

    Direct Numerical Simulations (DNS) of the Navier Stokes equations is an invaluable research tool in fluid dynamics. Still, there are few publicly available research codes and, due to the heavy number crunching implied, available codes are usually written in low-level languages such as C/C++ or Fortran. In this paper we describe a pure scientific Python pseudo-spectral DNS code that nearly matches the performance of C++ for thousands of processors and billions of unknowns. We also describe a version optimized through Cython, that is found to match the speed of C++. The solvers are written from scratch in Python, both the mesh, the MPI domain decomposition, and the temporal integrators. The solvers have been verified and benchmarked on the Shaheen supercomputer at the KAUST supercomputing laboratory, and we are able to show very good scaling up to several thousand cores. A very important part of the implementation is the mesh decomposition (we implement both slab and pencil decompositions) and 3D parallel Fast Fourier Transforms (FFT). The mesh decomposition and FFT routines have been implemented in Python using serial FFT routines (either NumPy, pyFFTW or any other serial FFT module), NumPy array manipulations and with MPI communications handled by MPI for Python (mpi4py). We show how we are able to execute a 3D parallel FFT in Python for a slab mesh decomposition using 4 lines of compact Python code, for which the parallel performance on Shaheen is found to be slightly better than similar routines provided through the FFTW library. For a pencil mesh decomposition 7 lines of code is required to execute a transform.

  2. Methodes non perturbatives en mecanique quantique et en theorie des champs quantiques

    NASA Astrophysics Data System (ADS)

    Jirari, Hamza

    2001-10-01

    Nous construisons un hamiltonien effectif à partir de l'intégrale de chemin via la méthode Monte-Carlo. Cet hamiltonien décrit les phénomènes physiques dans le domaine de basse énergie. Nous déterminons le spectre d'énergie et les fonctions d'ondes de plusieurs systèmes quantiques. Les résultats obtenus montrent que cette nouvelle approche Monte-Carlo hamiltonienne fonctionne. En mécanique quantique, nous suggérons une expression analytique de l'intégrale de chemin en introduisant une action quantique avec des paramètres renormalisés. Nous présentons des résultats numériques pour quelques potentiels locaux. Cette action quantique offre la possibilité de comparer l'évolution classique et quantique et permet de quantifier les instantons classiques et éventuellement le chaos classique. Nous investiguons la QCD sur un réseau bidimensionnel en utilisant une version améliorée des fermions de Wilson. Nous montrons que la théorie améliorée conduit à une réduction significative des erreurs dues à la valeur finie du pas du réseau. Nous calculons le condensat chiral et la masse de l'état lié quark-antiquark. Nous aboutissons à une bonne concordance entre nos résultats numériques et les résultats analytiques du modèle dans le continu.

  3. ANÁLISE DA INSERÇÃO DOS TEMAS DE HUMANIDADES E ÉTICA, COM METODOLOGIA DE APRENDIZAGEM BASEADA EM PROBLEMAS, EM CURRICULO MÉDICO INTEGRADO EM ESCOLA PÚBLICA NO DISTRITO FEDERAL, BRASIL

    PubMed Central

    Novaes, Maria Rita Carvalho Garbi; Novaes, Luiz Carlos Garcez; Guilhem, Dirce; Lolas, Fernando; Silveira, Carla; Guiotti, Murilo

    2009-01-01

    Objetivo Realizar uma análise da inserção da ética e humanidades no currículo do Curso de Medicina da Escola Superior em Ciências da Saúde - ESCS, escola pública do Distrito Federal, Brasil, de forma a contribuir com o processo de gestão curricular. Metodologia O Estudo é de coorte e documental. Foram pesquisados 37 termos relacionados à ética e 36 referentes à humanização nos objetivos educacionais e conteúdo dos módulos temáticos, habilidades e atitudes e interação ensino-serviço-comunidade, de 1a a 4a série e no programa do internato no currículo (ano 2006) e no projeto pedagógico do Curso de Medicina (2001). Resultados Maior inserção da humanização, ética e bioética na 1a e 2a série, quando comparado à inserção na 3a e 4a série e no internato, (IC95%-α=0,034, pvalue=0,007). Unidade de habilidades e atitudes: freqüência das 3 temáticas no currículo da 1a a 4a séries (IC95%-α=0,026, pvalue=0,013). Quando comparada a inserção entre o internato e as quatro primeiras séries, observa-se que nestas a inserção da temática humanização é superior (IC95%-α=0,042, pvalue=0,029). Conclusão O currículo desenvolvido no ano de 2006 na ESCS apresentou correlação com o projeto pedagógico do curso e contemplou a temática de forma abrangente, em todas as séries e internato. PMID:20396594

  4. Determinação da massa de júpiter a partir das órbitas de seus satélites: um experimento didático

    NASA Astrophysics Data System (ADS)

    Schlickmann, M. S.; Saito, R. K.; Becker, D. A.; Rezende, M. F., Jr.; Cid Fernandes, R.

    2003-08-01

    Este trabalho apresenta o roteiro piloto de uma prática observacional em astronomia, junto com os primeiros resultados obtidos nesta fase de implementacão. O projeto, que será executado em duas etapas, visa introduzir noções de Astronomia a alunos do Ensino Médio e iniciantes nos cursos de Física. O experimento consiste em medir as órbitas dos satélites Galileanos e, a partir da análise dos dados coletados, verificar a validade da Lei das órbitas de Kepler, determinando a massa do planeta Júpiter. Em uma primeira etapa, as observações serão feitas utilizando um telescópio Meade LX200 10" e câmera CCD para obter uma seqüência de imagens do planeta, que possibilitará medir o movimento de seus satélites. A segunda etapa terá início a partir do funcionamento do telescópio em modo robótico, com a possibilidade de observações via internet por instituições de ensino. Para o desenvolvimento deste experimento foram inicialmente coletadas várias imagens de Júpiter obtidas com os instrumentos citados acima. Estas imagens serviram como base para confecção dos roteiros para a experiência no nível médio e superior. Os roteiros serão inicialmente apresentados em uma home-page. Nela também se buscará uma contextualização histórica da experiência bem como o estabelecimento de relações com professores e alunos, propostas metodológicas e a disponibilização dos programas computacionais necessários para a utilização "on-line" pelos usuários. O projeto conta com apoio da Fundação VITAE.

  5. Desenvolvimento das câmeras de raios-X duros do satélite MIRAX

    NASA Astrophysics Data System (ADS)

    Braga, J.; Rothschild, R.; Staubert, R.; Heise, J.; Remillard, R.; D'Amico, F.; Jablonski, F.; Mejía, J.; Carvalho, H.; Heindl, B.; Matteson, J.; Kendziorra, E.; Wilms, J.; in't Zand, J.; Kuulkers, E.

    2003-08-01

    O MIRAX (Monitor e Imageador de RAios-X) é um projeto de desenvolvimento de um pequeno satélite astronômico de raios-X (~200 kg, ~240 W). A estratégia básica da missão será observar continuamente (~9 meses por ano) a região central (~1000 graus2) do plano Galáctico e realizar estudos espectroscópicos de banda larga (2-200 keV) e alta sensibilidade de um grande conjunto de fontes através de imagens com resolução de ~6'. Isso proporcionará uma cobertura inédita do "espaço de descobertas" através da detecção, localização, identificação e estudo detalhado de fenômenos imprevisíveis, tais como transientes fracos de raios-X, novas rápidas de raios-X e bursts de raios gama, assim como o estudo de fontes com emissão persistente. Neste trabalho apresentamos o projeto das duas câmeras de raios-X duros (CXDs) do MIRAX, que irão operar na faixa de 10 a 200 keV. Cada CXD consistirá de um plano de detectores CZT (Cd0,9Zn0,1Te) de 0,5 mm de resolução espacial e 370 cm2 de área total, e de uma máscara codificada com elementos quadrados de 1,3 mm de lado e 0,5 cm de espessura. A máscara terá dimensões de 315 cm ´ 275 cm e será montada a 700 cm de distância dos detectores. Com essa configuração as CXDs terão 6' de resolução angular e, quando colocadas a um ângulo de 29° entre si, as duas câmeras propiciam um campo totalmente codificado de 39° ´ 6°12' e um campo total de 76° ´ 44°. Serão apresentadas simulações de observações da região do plano Galáctico com o conjunto formado pelas duas CXDs.

  6. Respostas religiosas à aids no Brasil: impressões de pesquisa acerca da Pastoral de DST/Aids da Igreja Católica1

    PubMed Central

    Seffner, Fernando; Silva, Cristiane Gonçalves Meireles da; Maksud, Ívia; Garcia, Jonathan; Rios, Luís Felipe; Natividade, Marcelo; Borges, Priscila Rodrigues; Parker, Richard; Terto, Veriano

    2009-01-01

    O texto encontra-se estruturado em quatro partes. Na primeira delas, apresentamos um conjunto de considerações e informações acerca da situação da aids no Brasil, das relações entre religião, sexualidade, aids e estado laico, bem como uma descrição mais clara do Projeto Respostas Religiosas ao HIV/Aids no Brasil, do qual este texto apresenta algumas impressões de pesquisa preliminares. A seguir, dedicamos um item a apresentação da Pastoral de DST/Aids, sua história, estrutura e objetivos. No item seguinte problematizamos diversas questões em particular no âmbito das relações Estado e Igreja, relações entre agentes de pastoral e hierarquia da Igreja, e questões ligadas mais diretamente à sexualidade e aids, todas referenciadas ao trabalho da Pastoral de DST/Aids. Ao final, apresentamos a bibliografia e fontes consultadas. PMID:20442806

  7. Respostas religiosas à aids no Brasil: impressões de pesquisa1

    PubMed Central

    Seffner, Fernando; da Silva, Cristiane Gonçalves Meireles; Maksud, Ívia; Garcia, Jonathan; Rios, Luís Felipe; Natividade, Marcelo; Borges, Priscila Rodrigues; Parker, Richard; Terto, Veriano

    2009-01-01

    Resumo O texto encontra-se estruturado em quatro partes. Na primeira delas, apresentamos um conjunto de considerações e informações acerca da situação da aids no Brasil, das relações entre religião, sexualidade, aids e estado laico, bem como uma descrição mais clara do Projeto Respostas Religiosas ao HIV/Aids no Brasil, do qual este texto apresenta algumas impressões de pesquisa preliminares. A seguir, dedicamos um item a apresentação da Pastoral de DST/Aids, sua história, estrutura e objetivos. No item seguinte problematizamos diversas questões em particular no âmbito das relações Estado e Igreja, relações entre agentes de pastoral e hierarquia da Igreja, e questões ligadas mais diretamente à sexualidade e aids, todas referenciadas ao trabalho da Pastoral de DST/Aids. Ao final, apresentamos a bibliografia e fontes consultadas. PMID:20428503

  8. A correlação índice espectral vs. luminosidade em QSOs e suas implicações

    NASA Astrophysics Data System (ADS)

    Garcia-Rissmann, A.

    2003-08-01

    Estudos de variabilidade de núcleos ativos já demonstraram ser comum o fato de seu contínuo óptico/UV tornar-se mais "duro" à medida que a luminosidade aumenta. Essa tendência ocorre tanto de forma individual quanto global, e pode ter implicações importantes (1) para estudos fotométricos de variabilidade conduzidos numa banda fixa no referencial do observador, comparando objetos a diferentes redshifts, e (2) no cálculo da correção K, com consequente impacto na determinação de massas de buracos negros e bojos de galáxias hospedeiras (através da relação de Magorrian). Confirmo aqui as correlações positivas entre o índice espectral e a luminosidade óptica, utilizando dados espectroscópicos de 11 QSOs monitorados no Brasil e no Chile, durante ~2 anos. O estudo é complementado com parâmetros extraídos de espectros e de dados fotométricos públicos de quasares. Destaco ainda as diferenças observadas em tais correlações para objetos do tipo radio-loud e radio-quiet. Este projeto é financiado pelo I. Milênio/CNPq.

  9. Rad53 homologue forkhead-associated kinase A (FhkA) and Ca2+-binding protein 4a (CBP4a) are nucleolar proteins that differentially redistribute during mitosis in Dictyostelium

    PubMed Central

    2013-01-01

    Background During mitosis most nucleolar proteins redistribute to other locales providing an opportunity to study the relationship between nucleolar protein localization and function. Dictyostelium is a model organism for the study of several fundamental biological processes and human diseases but only two nucleolar proteins have been studied during mitosis: NumA1 and Snf12. Both of them are linked to the cell cycle. To acquire a better understanding of nucleolar protein localization and dynamics in Dictyostelium we studied the nucleolar localization of two additional proteins during mitosis: Snf12-linked forkhead-associated kinase A (FhkA), which is involved in the cell cycle, and Ca2+-binding protein 4a (CBP4a), which is a binding partner of NumA1. Methods Polyclonal antibodies were produced in-house. Cells were fixed and probed with either anti-FhkA or anti-CBP4a in order to determine cellular localization during interphase and throughout the stages of mitosis. Colocalization with DAPI nuclear stain allowed us to determine the location of the nucleus and nucleolus while colocalization with anti-α-tubulin allowed us to determine the cell cycle stage. Results Here we verify two novel nucleolar proteins, Rad53 homologue FhkA which localized around the edge of the nucleolus and CBP4a which was detected throughout the entire nucleolus. Treatment with the Ca2+ chelator BAPTA (5 mM) showed that the nucleolar localization of CBP4a is Ca2+-dependent. In response to actinomycin D (0.05 mg/mL) CBP4a disappeared from the nucleolus while FhkA protruded from the nucleus, eventually pinching off as cytoplasmic circles. FhkA and CBP4a redistributed differently during mitosis. FhkA redistributed throughout the entire cell and at the nuclear envelope region from prometaphase through telophase. In contrast, during prometaphase CBP4a relocated to many large, discrete “CBP4a islands” throughout the nucleoplasm. Two larger “CBP4a islands” were also detected specifically

  10. GMES: A Python package for solving Maxwell’s equations using the FDTD method

    NASA Astrophysics Data System (ADS)

    Chun, Kyungwon; Kim, Huioon; Kim, Hyounggyu; Jung, Kil Su; Chung, Youngjoo

    2013-04-01

    This paper describes GMES, a free Python package for solving Maxwell’s equations using the finite-difference time-domain (FDTD) method. The design of GMES follows the object-oriented programming (OOP) approach and adopts a unique design strategy where the voxels in the computational domain are grouped and then updated according to its material type. This piecewise updating scheme ensures that GMES can adopt OOP without losing its simple structure and time-stepping speed. The users can easily add various material types, sources, and boundary conditions into their code using the Python programming language. The key design features, along with the supported material types, excitation sources, boundary conditions and parallel calculations employed in GMES are also described in detail. Catalog identifier: AEOK_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEOK_v1_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: GNU General Public License v3.0 No. of lines in distributed program, including test data, etc.: 17700 No. of bytes in distributed program, including test data, etc.: 89878 Distribution format: tar.gz Programming language: C++, Python. Computer: Any computer with a Unix-like system with a C++ compiler, and a Python interpreter; developed on 2.53 GHz Intel CoreTM i3. Operating system: Any Unix-like system; developed under Ubuntu 12.04 LTS 64 bit. Has the code been vectorized or parallelized?: Yes. Parallelized with MPI directives (optional). RAM: Problem dependent (a simulation with real valued electromagnetic field uses roughly 0.18 KB per Yee cell.) Classification: 10. External routines: SWIG [1], Cython [2], NumPy [3], SciPy [4], matplotlib [5], MPI for Python [6] Nature of problem: Classical electrodynamics Solution method: Finite-difference time-domain (FDTD) method Additional comments: This article describes version 0.9.5. The most recent version can be downloaded at the GMES

  11. Scattering and coupling effects of electromagnetic waves in 3D networks of spheres

    NASA Astrophysics Data System (ADS)

    Defos Du Rau, M.; Pessan, F.; Ruffie, G.; Vignéras-Lefebvre, V.; Parneix, J. P.

    1998-01-01

    In this paper, the problem of electromagnetic scattering from a 3D system of spheres is considered and an iterative solution that accounts for multiple scattering is proposed. The Mie formalism used for a single sphere is extended to account for multiple scattered fields between several particles. The translational addition theorems for spherical wave functions are used to express the electromagnetic field scattered by a sphere S_i in terms of an incident field for a sphere S_k in a spherical coordinates system attached to the sphere S_k. In this work, the numerical convergence of the method is discussed and associated computational times are given. Numerical computations including Radar Cross Section (RCS) and radiation patterns for various 3D configurations are presented. Some of them are compared with free-space measurements made in the 8 to 100 GHz frequency band using vectorial network analyzers. 11.55.-m S-matrix theory; analytic structure of amplitudes Cet article étudie la diffusion des ondes électromagnétiques par des réseaux tridimensionnels de sphères et propose une méthode itérative pour prendre en compte les effets de multidiffusion. Le formalisme de Mie utilisé dans le cas d'une sphère est étendu pour calculer les champs "multidiffusés" entre plusieurs particules. Les théorèmes d'addition et de translation des fonctions d'onde sphériques sont utilisés pour exprimer le champ diffusé par une sphère S_i comme étant incident sur une sphère S_k, dans un système de coordonnées sphériques lié au centre de S_k. La convergence numérique de la méthode est discutée et des temps de calcul sont donnés. Des résultats numériques tels que des Surfaces Équivalentes Radar (SER) et des diagrammes de rayonnement pour différentes configurations tridimensionnelles sont montrés. Certains d'entre eux sont comparés à des mesures en espace libre faites à l'aide d'analyseurs de réseaux vectoriels dans la bande de fréquence 8{-}100 GHz.

  12. Etude theorique du jet de plasma supersonique a courant continu

    NASA Astrophysics Data System (ADS)

    Jodoin, Bertrand

    La déposition par plasma supersonique à courant continu permet d'obtenir une qualité de dépôt supérieure au jet subsonique. Un modèle numérique a été développé dans le but de mieux comprendre les mécanismes de transfert à l'intérieur de la tuyère et d'estimer l'influence des paramètres d'opération de la torche sur le jet à la sortie de la tuyère. Les équations d'Euler, auxquelles sont ajoutées l'effet Joule, la conduction et les pertes par rayonnement sont résolues à l'aide de la méthode de Jameson. Un schéma centré est utilisé pour résoudre les champs électriques. La sous-couche cathodique en déséquilibre thermodynamique est modélisée à l'aide du modèle simple de Morrow et Lowke. Quelques détails sur les aspects numériques facilitant la convergence du système sont donnés. Le modèle est validé pour un écoulement compressible classique et pour un jet de plasma supersonique à l'aide de résultats de la littérature. Les champs à l'intérieur de la tuyère sont analysés afin de déterminer l'influence de l'hydrogène, de l'intensité du courant et de la géométrie de la tuyère sur les caractéristiques de l'écoulement.

  13. Modélisation du bruit des jets turbulents libres et subsoniques à température ambiante

    NASA Astrophysics Data System (ADS)

    Béchara, W.; Lafon, P.; Candel, S. M.

    1993-03-01

    Based on the theoretical model of Goldstein for a round free jet, we establish analytical expressions (G_a model) for the noise radiation from a turbulent jet, depending on the local statistical properties of the flow. These characteristics are calculated by solving the Reynolds average Navier-Stokes equations with a numerical code based on a K - \\varepsilon turbulence closure model. A comparison between the numerical results and the experimental data for a simple jet and two coaxial jets shows that this model correctly predicts the evolution of the acoustic radiation. The G_a model developed in the case of axisymmetric turbulence superimposed over a mean flow is found to be more suitable than the Ribner model associated to an isotropic turbulence. A comparison between differents models issued from Lighthill theory, shows that the G_a model yields the best directivity of the acoustic intensity at high jet exit velocities. À partir du modèle théorique proposé initialement par Goldstein pour un jet libre turbulent circulaire, on établit des expressions analytiques (modèle G_a) permettant le calcul du bruit émis à partir des grandeurs statistiques locales du jet turbulent. Ces grandeurs sont estimées par résolution des équations de Navier-Stokes moyennées à l'aide d'un code numérique de turbulence utilisant un modèle de fermeture de type K - \\varepsilon. La comparaison entre les résultats numériques obtenus et les données expérimentales, pour un jet simple et deux jets coaxiaux, montre que ce modèle estime correctement l'évolution des grandeurs acoustiques étudiées. Les calculs indiquent que le modèle G_a développé pour une turbulence axisymétrique convectée par un écoulement moyen est mieux adapté que celui de Ribner associé à une turbulence isotrope. De plus, une comparaison entre différents modèles basés sur la théorie de Lighthill indique que le modèle G_a donne la meilleure directivité de l'intensité acoustique aux

  14. Étude descriptive du processus d’évaluation et de documentation de la douleur postopératoire dans un hôpital universitaire

    PubMed Central

    Bergeron, Dave A; Leduc, Geneviève; Marchand, Serge; Bourgault, Patricia

    2011-01-01

    Plusieurs études démontrent que les patients reçoivent souvent un traitement insatisfaisant de la douleur en contexte postopératoire. Le but de la présente étude descriptive était d’examiner et d’analyser diverses données ayant trait au soulagement de 40 patients après une intervention chirurgicale non urgente. Les patients ont rempli un journal de douleur afin d’évaluer le niveau d’intensité et de désagrément engendré par la douleur durant les trois premières journées postopératoires. Une analyse du dossier a permis de vérifier la documentation de l’évaluation de la douleur par le personnel infirmier. Les résultats indiquent que la douleur en contexte postopératoire est peu et inadéquatement évaluée et peu documentée par le personnel infirmier. Lorsque la douleur est évaluée selon une échelle numérique, les infirmières ont tendance à la sous-évaluer en comparaison avec l’évaluation notée par les patients. Pour la première journée postopératoire, l’intensité moyenne de la douleur documentée par les infirmières est de 1,57 (±0,23) sur une échelle numérique de 0 à 10, alors que l’intensité moyenne documentée par les patients est de 3,82 (±0,41). Cette étude fait ainsi ressortir qu’il n’y a pas de corrélation significative entre l’intensité de la douleur documentée par l’infirmière et celle notée par le patient, ce qui peut expliquer en partie un soulagement non optimal. PMID:21499582

  15. Dynamic seismic moment tensor creation for the Antelope Environmental Monitoring System

    NASA Astrophysics Data System (ADS)

    Newman, R. L.; Reyes, J. C.; van den Hazel, G.; Vernon, F. L.

    2011-12-01

    The native creation and display of seismic moment tensors, including the 'beachball' representation of the double-couple mechanism, have been missing in the popular BRTT Antelope Environmental Monitoring System that is used for seismic network and event monitoring. The seismic moment tensor inversion software package written by Dreger (2003) and updated by Minson & Dreger (2008) has been rewritten using a combination of the Python interface to Antelope (Lindquist et al., 2008) and various native Python packages, including NumPy, MatPlotLib and ObsPy (Beyreuther et al., 2010). The new moment tensor application ('dbmoment') uses the community standard Center for Seismic Studies (CSS) 3.0 schema, and can augment any real time earthquake monitoring system that uses the schema for post-event creation of moment tensor solutions. Rewriting the original code base from a combination of configuration scripts, Numerical Recipes for C, Seismic Analysis Code (SAC), the Fortran FKRPROG package (Saikia, 1994), and various intermediary files in ASCII and binary formats greatly simplifies installation, upgrading, and deployment of the software. All configuration files have been converted and condensed into BRTT parameter files and CSS schema extensions. The code has been added to the Github hosted open-source contributed code repository for the Antelope Environmental Monitoring System.

  16. Cloud-Based Computational Tools for Earth Science Applications

    NASA Astrophysics Data System (ADS)

    Arendt, A. A.; Fatland, R.; Howe, B.

    2015-12-01

    Earth scientists are increasingly required to think across disciplines and utilize a wide range of datasets in order to solve complex environmental challenges. Although significant progress has been made in distributing data, researchers must still invest heavily in developing computational tools to accommodate their specific domain. Here we document our development of lightweight computational data systems aimed at enabling rapid data distribution, analytics and problem solving tools for Earth science applications. Our goal is for these systems to be easily deployable, scalable and flexible to accommodate new research directions. As an example we describe "Ice2Ocean", a software system aimed at predicting runoff from snow and ice in the Gulf of Alaska region. Our backend components include relational database software to handle tabular and vector datasets, Python tools (NumPy, pandas and xray) for rapid querying of gridded climate data, and an energy and mass balance hydrological simulation model (SnowModel). These components are hosted in a cloud environment for direct access across research teams, and can also be accessed via API web services using a REST interface. This API is a vital component of our system architecture, as it enables quick integration of our analytical tools across disciplines, and can be accessed by any existing data distribution centers. We will showcase several data integration and visualization examples to illustrate how our system has expanded our ability to conduct cross-disciplinary research.

  17. The Global Atmospheric Angular Momentum Under Varying Thermal and Orographic Forcing, Simulated In A Simple Gcm

    NASA Astrophysics Data System (ADS)

    Stenzel, O.; von Storch, J.

    This work investigates the impacts of various large-scale thermal and orographic forc- ing on the global AAM. The investigation is based on numerical experiments with a simple GCM, PUMA (Portable University Model of the Atmosphere). The non-linear hydrodynamics of the atmosphere are represented in PUMA in the same way as in a standard GCM, but the latitude-dependent radiative forcing is strongly simplified and expressed as a Newtonian cooling. By modifying the restoration temperature field, the large-scale thermal forcing of the atmosphere can be easily controlled. A series of numerical experiments are carried out using different restoration tempera- ture fields and orographies. The restoration temperature fields are zonally symmetric and have different meridional gradients. It is found that the global AAM increases with increasing meridional gradient in the thermal forcing. The increase in the AAM is characterized by a change in circulation regime in the mid- and high-latitudes: The structure of the transients changes from a zonal wavenumber six to three, and the num- ber of cells in the meridional circulation reduces from three to two with a diminishing polar cell.

  18. Geological Mapping Uses Landsat 4-5TM Satellite Data in Manlai Soum of Omnogovi Aimag

    NASA Astrophysics Data System (ADS)

    Norovsuren, B.

    2014-12-01

    Author: Bayanmonkh N1, Undram.G1, Tsolmon.R2, Ariunzul.Ya1, Bayartungalag B31 Environmental Research Information and Study Center 2NUM-ITC-UNESCO Space Science and Remote Sensing International Laboratory, National University of Mongolia 3Geology and Hydrology School, Korea University KEY WORDS: geology, mineral resources, fracture, structure, lithologyABSTRACTGeologic map is the most important map for mining when it does exploration job. In Mongolia geological map completed by Russian geologists which is done by earlier technology. Those maps doesn't satisfy for present requirements. Thus we want to study improve geological map which includes fracture, structural map and lithology use Landsat TM4-5 satellite data. If we can produce a geological map from satellite data with more specification then geologist can explain or read mineralogy very easily. We searched all methodology and researches of every single element of geological mapping. Then we used 3 different remote sensing methodologies to produce structural and lithology and fracture map based on geographic information system's softwares. There can be found a visible lithology border improvement and understandable structural map and we found fracture of the Russian geological map has a lot of distortion. The result of research geologist can read mineralogy elements very easy and discovered 3 unfound important elements from satellite image.

  19. Computer simulation of MHD blood conveying gold nanoparticles as a third grade non-Newtonian nanofluid in a hollow porous vessel.

    PubMed

    Hatami, M; Hatami, J; Ganji, D D

    2014-02-01

    In this paper, heat transfer and flow analysis for a non-Newtonian third grade nanofluid flow in porous medium of a hollow vessel in presence of magnetic field are simulated analytically and numerically. Blood is considered as the base third grade non-Newtonian fluid and gold (Au) as nanoparticles are added to it. The viscosity of nanofluid is considered a function of temperature as Vogel's model. Least Square Method (LSM), Galerkin method (GM) and fourth-order Runge-Kutta numerical method (NUM) are used to solve the present problem. The influences of the some physical parameters such as Brownian motion and thermophoresis parameters on non-dimensional velocity and temperature profiles are considered. The results show that increasing the thermophoresis parameter (N(t)) caused an increase in temperature values in whole domain and an increase in nanoparticles concentration just near the inner wall of vessel. Furthermore by increasing the MHD parameter, velocity profiles decreased due to magnetic field effect. PMID:24286727

  20. Hydroelastic behaviour of a structure exposed to an underwater explosion

    PubMed Central

    Colicchio, G.; Greco, M.; Brocchini, M.; Faltinsen, O. M.

    2015-01-01

    The hydroelastic interaction between an underwater explosion and an elastic plate is investigated num- erically through a domain-decomposition strategy. The three-dimensional features of the problem require a large computational effort, which is reduced through a weak coupling between a one-dimensional radial blast solver, which resolves the blast evolution far from the boundaries, and a three-dimensional compressible flow solver used where the interactions between the compression wave and the boundaries take place and the flow becomes three-dimensional. The three-dimensional flow solver at the boundaries is directly coupled with a modal structural solver that models the response of the solid boundaries like elastic plates. This enables one to simulate the fluid–structure interaction as a strong coupling, in order to capture hydroelastic effects. The method has been applied to the experimental case of Hung et al. (2005 Int. J. Impact Eng. 31, 151–168 (doi:10.1016/j.ijimpeng.2003.10.039)) with explosion and structure sufficiently far from other boundaries and successfully validated in terms of the evolution of the acceleration induced on the plate. It was also used to investigate the interaction of an underwater explosion with the bottom of a close-by ship modelled as an orthotropic plate. In the application, the acoustic phase of the fluid–structure interaction is examined, highlighting the need of the fluid–structure coupling to capture correctly the possible inception of cavitation. PMID:25512585

  1. Construction of a physics minimal formalism using the collision symbols: systematical condensing of the resulting laws

    NASA Astrophysics Data System (ADS)

    Rioux, Ch.

    1998-01-01

    In this article, a formalism of physics is built by using only algebric combinations of symbols which represent collisions between bodies. The connection with reality is made by measures of time. The formalism is brought down to that of Dirac's matrices in a constant curvature space (De Sitter space). As a result it becomes possible to condense most of the physical basic laws, that are moreover written in a unified symbolism. The general application of this formalism will be the numerical treatment of physical problems. L'article bâtit un formalisme de la physique ne mettant en œuvre que les combinaisons algébriques de symboles représentatifs des chocs entre objets; le raccord au réel s'effectue par l'intermédiaire des mesures de temps. Le formalisme se ramène à celui d'une algèbre des matrices de DIRAC dans un espace à courbure constante (espace de De Sitter). Il en résulte la possibilité potentielle de condenser la plupart des lois physiques de base, écrites de surcroît dans un symbolisme unifié. L'application générale de ce formalisme est le traitement numérique des problèmes de physique.

  2. Cinética Química: el laboratorio

    NASA Astrophysics Data System (ADS)

    Cabañas Galán, B.

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

  3. PyKrige: Development of a Kriging Toolkit for Python

    NASA Astrophysics Data System (ADS)

    Murphy, B. S.

    2014-12-01

    While Python continues to grow in popularity as a convenient and powerful means of data manipulation and analysis, the language still lacks a package that provides easy access to commonly utilized geostatistical routines. PyKrige is a new contribution that attempts to create a Python library that can be used for basic geostatistical tasks, such as creating water level maps using Ordinary and Universal Kriging. While written in pure Python, the code makes extensive use of NumPy in order to enable fast processing. Supported drift terms for Universal Kriging currently include a regional linear drift (such as would be used to simulate an overall groundwater gradient, as discussed in Tonkin and Larson, Groundwater, 2002), a point-logarithmic drift (such as would be used to simulate wells, as discussed in Tonkin and Larson, Groundwater, 2002), and an external digital elevation model drift (such as would be used to simulate a topographically controlled groundwater surface, as discussed in Desbarats et al., Journal of Hydrology, 2002). The package is intended primarily for kriging of two-dimensional data, but limited support for three-dimensional kriging is currently under development. Though similar tools already exist for other commonly utilized scientific languages, such as R and MATLAB, PyKrige is intended to ease data processing by providing further functionality in Python that can be implemented in a single analysis pipeline. The code will be made available on GitHub.

  4. A Novel Method of Automatic Plant Species Identification Using Sparse Representation of Leaf Tooth Features

    PubMed Central

    Jin, Taisong; Hou, Xueliang; Li, Pifan; Zhou, Feifei

    2015-01-01

    Automatic species identification has many advantages over traditional species identification. Currently, most plant automatic identification methods focus on the features of leaf shape, venation and texture, which are promising for the identification of some plant species. However, leaf tooth, a feature commonly used in traditional species identification, is ignored. In this paper, a novel automatic species identification method using sparse representation of leaf tooth features is proposed. In this method, image corners are detected first, and the abnormal image corner is removed by the PauTa criteria. Next, the top and bottom leaf tooth edges are discriminated to effectively correspond to the extracted image corners; then, four leaf tooth features (Leaf-num, Leaf-rate, Leaf-sharpness and Leaf-obliqueness) are extracted and concatenated into a feature vector. Finally, a sparse representation-based classifier is used to identify a plant species sample. Tests on a real-world leaf image dataset show that our proposed method is feasible for species identification. PMID:26440281

  5. Using open-source programs to create a web-based portal for hydrologic information

    NASA Astrophysics Data System (ADS)

    Kim, H.

    2013-12-01

    Some hydrologic data sets, such as basin climatology, precipitation, and terrestrial water storage, are not easily obtainable and distributable due to their size and complexity. We present a Hydrologic Information Portal (HIP) that has been implemented at the University of California for Hydrologic Modeling (UCCHM) and that has been organized around the large river basins of North America. This portal can be easily accessed through a modern web browser that enables easy access and visualization of such hydrologic data sets. Some of the main features of our HIP include a set of data visualization features so that users can search, retrieve, analyze, integrate, organize, and map data within large river basins. Recent information technologies such as Google Maps, Tornado (Python asynchronous web server), NumPy/SciPy (Scientific Library for Python) and d3.js (Visualization library for JavaScript) were incorporated into the HIP to create ease in navigating large data sets. With such open source libraries, HIP can give public users a way to combine and explore various data sets by generating multiple chart types (Line, Bar, Pie, Scatter plot) directly from the Google Maps viewport. Every rendered object such as a basin shape on the viewport is clickable, and this is the first step to access the visualization of data sets.

  6. OWL site survey: first seeing measurement with ADIMM

    NASA Astrophysics Data System (ADS)

    Benkhaldoun, Zouhair; Abahamid, Abdelouahed; El Azhari, Youssef; Siher, El Arbi

    2004-10-01

    The ESO OWL site survey plan includes the analysis of the astronomical quality of the Atlas mountains in Morocco. In this paper we are presenting the first long time measurement of optical turbulence at Oukaimeden site. For this work we built an instrument called ADIMM for an Automated Differencial Image Motion Monitor, and we use it to the measure the optical turbulence at the Oukaimeden Site. We are describing the instrument and reporting the first results obtained after six month of working on this project. The results of night-time seeing measurements carried out during the period from Jun 14 up to October 01 2003 are presented. The median and mean values of the seeing for the entire period of observations are respectively 0.75" and 0.84". This work was organized in the framework of contract Num.69651/ODG/02/9005/GWI between the European Southern Observatory (ESO) and Astrophysics and Physics of High Energy Laboratory of the Faculty of Sciences, Cadi Ayyad University (LPHEA).

  7. SunPy—Python for solar physics

    NASA Astrophysics Data System (ADS)

    SunPy Community; Mumford, Stuart J.; Christe, Steven; Pérez-Suárez, David; Ireland, Jack; Shih, Albert Y.; Inglis, Andrew R.; Liedtke, Simon; Hewett, Russell J.; Mayer, Florian; Hughitt, Keith; Freij, Nabil; Meszaros, Tomas; Bennett, Samuel M.; Malocha, Michael; Evans, John; Agrawal, Ankit; Leonard, Andrew J.; Robitaille, Thomas P.; Mampaey, Benjamin; Campos-Rozo, Jose Iván; Kirk, Michael S.

    2015-01-01

    This paper presents SunPy (version 0.5), a community-developed Python package for solar physics. Python, a free, cross-platform, general-purpose, high-level programming language, has seen widespread adoption among the scientific community, resulting in the availability of a large number of software packages, from numerical computation (NumPy, SciPy) and machine learning (scikit-learn) to visualization and plotting (matplotlib). SunPy is a data-analysis environment specializing in providing the software necessary to analyse solar and heliospheric data in Python. SunPy is open-source software (BSD licence) and has an open and transparent development workflow that anyone can contribute to. SunPy provides access to solar data through integration with the Virtual Solar Observatory (VSO), the Heliophysics Event Knowledgebase (HEK), and the HELiophysics Integrated Observatory (HELIO) webservices. It currently supports image data from major solar missions (e.g., SDO, SOHO, STEREO, and IRIS), time-series data from missions such as GOES, SDO/EVE, and PROBA2/LYRA, and radio spectra from e-Callisto and STEREO/SWAVES. We describe SunPy's functionality, provide examples of solar data analysis in SunPy, and show how Python-based solar data-analysis can leverage the many existing tools already available in Python. We discuss the future goals of the project and encourage interested users to become involved in the planning and development of SunPy.

  8. SunPy - Python for Solar Physics, Version 0.4

    NASA Astrophysics Data System (ADS)

    Christe, Steven; Mumford, Stuart; Perez-Suarez, David; Ireland, Jack; Shih, Albert Y.; Inglis, Andrew; Liedtke, Simon; Hewett, Russel

    2014-06-01

    We presents version 0.4 of SunPy, a community-developed Python package for solar physics. Python, a free, cross-platform, general-purpose, high-level programming language, has seen widespread adoption among the scientific community, resulting in the availability of a large number of software packages, from numerical computation NumPy, SciPy and machine learning (scikit-learn) to visualisation and plotting (matplotlib).SunPy is a data-analysis environment specialising in providing the software necessary to analyse solar and heliospheric datasets in Python. SunPy is open-source software (BSD licence) and has an open and transparent development workflow that anyone can contribute to. SunPy provides access to solar data through integration with the Virtual Solar Observatory (VSO), the Heliophysics Event Knowledgebase (HEK), and the HELiophysics Integrated Observatory (HELIO) webservices. It currently supports image data from major solar missions (e.g., SDO, SOHO, STEREO, and IRIS), time-series data from missions such as GOES, SDO/EVE, and PROBA2/LYRA, and radio spectra from e-Callisto and STEREO/SWAVES. We describe SunPy's functionality, provide examples of solar data analysis in SunPy, and show how Python-based solar data-analysis can leverage the many existing tools already available in Python. We discuss the future goals of the project and encourage interested users to become involved in the planning and development of SunPy.

  9. SunPy: Solar Physics in Python

    NASA Astrophysics Data System (ADS)

    Ryan, Daniel; Christe, Steven; Mumford, Stuart; Perez Suarez, David; Ireland, Jack; Shih, Albert Y.; Inglis, Andrew; Liedtke, Simon; Hewett, Russel

    2015-04-01

    SunPy is a community-developed open-source software library for solar physics. It is written in Python, a free, cross-platform, general-purpose, high-level programming language which is being increasingly adopted throughout the scientific community as well as further afield. This has resulted in a wide array of software packages useful for scientific computing, from numerical computation (NumPy, SciPy, etc.), to machine learning (scifitlearn), to visualization and plotting (matplotlib). SunPy aims to provide required specialised software for analysing solar and heliospheric datasets in Python. The current version is 0.5 with 0.6 expected to be released later this year. SunPy provides solar data access through integration with the Virtual Solar Observatory (VSO), the Heliophysics Event Knowledgebase (HEK), and the HELiophysics Integrated Observatory (HELIO) webservices. It supports common data types from major solar missions such as images (SDO/AIA, STEREO, PROBA2/SWAP etc.), time series (GOES/XRS, SDO/EVE, PROBA2/LYRA), and radio spectra (e-Callisto, STEREO/WAVES). SunPy’s code base is publicly available through github.com and can be contributed to by anyone. In this poster we demonstrate SunPy’s functionality and future goals of the project. We also encourage interested users to become involved in further developing SunPy.

  10. LAPS Grid generation and adaptation

    NASA Astrophysics Data System (ADS)

    Pagliantini, Cecilia; Delzanno, Gia Luca; Guo, Zehua; Srinivasan, Bhuvana; Tang, Xianzhu; Chacon, Luis

    2011-10-01

    LAPS uses a common-data framework in which a general purpose grid generation and adaptation package in toroidal and simply connected domains is implemented. The initial focus is on implementing the Winslow/Laplace-Beltrami method for generating non-overlapping block structured grids. This is to be followed by a grid adaptation scheme based on Monge-Kantorovich optimal transport method [Delzanno et al., J. Comput. Phys,227 (2008), 9841-9864], that equidistributes application-specified error. As an initial set of applications, we will lay out grids for an axisymmetric mirror, a field reversed configuration, and an entire poloidal cross section of a tokamak plasma reconstructed from a CMOD experimental shot. These grids will then be used for computing the plasma equilibrium and transport in accompanying presentations. A key issue for Monge-Kantorovich grid optimization is the choice of error or monitor function for equi-distribution. We will compare the Operator Recovery Error Source Detector (ORESD) [Lapenta, Int. J. Num. Meth. Eng,59 (2004) 2065-2087], the Tau method and a strategy based on the grid coarsening [Zhang et al., AIAA J,39 (2001) 1706-1715] to find an ``optimal'' grid. Work supported by DOE OFES.

  11. Hydroelastic behaviour of a structure exposed to an underwater explosion.

    PubMed

    Colicchio, G; Greco, M; Brocchini, M; Faltinsen, O M

    2015-01-28

    The hydroelastic interaction between an underwater explosion and an elastic plate is investigated num- erically through a domain-decomposition strategy. The three-dimensional features of the problem require a large computational effort, which is reduced through a weak coupling between a one-dimensional radial blast solver, which resolves the blast evolution far from the boundaries, and a three-dimensional compressible flow solver used where the interactions between the compression wave and the boundaries take place and the flow becomes three-dimensional. The three-dimensional flow solver at the boundaries is directly coupled with a modal structural solver that models the response of the solid boundaries like elastic plates. This enables one to simulate the fluid-structure interaction as a strong coupling, in order to capture hydroelastic effects. The method has been applied to the experimental case of Hung et al. (2005 Int. J. Impact Eng. 31, 151-168 (doi:10.1016/j.ijimpeng.2003.10.039)) with explosion and structure sufficiently far from other boundaries and successfully validated in terms of the evolution of the acceleration induced on the plate. It was also used to investigate the interaction of an underwater explosion with the bottom of a close-by ship modelled as an orthotropic plate. In the application, the acoustic phase of the fluid-structure interaction is examined, highlighting the need of the fluid-structure coupling to capture correctly the possible inception of cavitation. PMID:25512585

  12. A Distributed Python HPC Framework: ODIN, PyTrilinos, & Seamless

    SciTech Connect

    Grant, Robert

    2015-11-23

    Under this grant, three significant software packages were developed or improved, all with the goal of improving the ease-of-use of HPC libraries. The first component is a Python package, named DistArray (originally named Odin), that provides a high-level interface to distributed array computing. This interface is based on the popular and widely used NumPy package and is integrated with the IPython project for enhanced interactive parallel distributed computing. The second Python package is the Distributed Array Protocol (DAP) that enables separate distributed array libraries to share arrays efficiently without copying or sending messages. If a distributed array library supports the DAP, it is then automatically able to communicate with any other library that also supports the protocol. This protocol allows DistArray to communicate with the Trilinos library via PyTrilinos, which was also enhanced during this project. A third package, PyTrilinos, was extended to support distributed structured arrays (in addition to the unstructured arrays of its original design), allow more flexible distributed arrays (i.e., the restriction to double precision data was lifted), and implement the DAP. DAP support includes both exporting the protocol so that external packages can use distributed Trilinos data structures, and importing the protocol so that PyTrilinos can work with distributed data from external packages.

  13. Porphyrin Based neuton capture agents for cancer therapy

    DOEpatents

    Vicente, Maria Da; Shetty, Shankar Jayaram; Jaquinod, Laurent; Smith, Kevin M.

    2006-06-27

    The invention describes the synthesis of a panel of novel carbon-carbon linked carboranyl-containing 5,10,15,20-tetraphenylporphyrins bearing 25–44% boron by weight. In certain embodiments, a phenyl porphyrin compound has a carboranyl group attached to the phenyl group by a carbon-carbon linkage, wherein the phenyl group corresponds to the following formula num="00001">embedded image
    where R7 through R11 are hydrogen, a carboranyl group, or are selected from the group consisting of hydroxyl, NMe3+, PMePh2+, PO(OH)2, SO3H, COOH, and NH2. In this embodiment, the carboranyl group is attached to the phenyl group by a carbon-carbon linkage, either one or two of R7 through R11 are other than hydrogen; and the phenyl porphyrin compound contains at least one phenyl group having at least one of said carboranyl groups.

  14. Indicators for the evaluation of the quality of education and career development in the hard science: a case report

    NASA Astrophysics Data System (ADS)

    Arany-Prado, L. I.

    2003-08-01

    We report the results of the self-evaluation of the Astronomy Bachelor Course of the Observatório do Valongo (OV), Universidade Federal do Rio de Janeiro (UFRJ). We have created, heuristically, data indicators capable of quantifying the impact of curriculum and institutional improvements on the student's background and career development in the last 30 years. It is remarkable that the institution in study: i) has undergone appreciable recent development; ii) has its graduation course as a long term investment and an essentially complete database on past professors and students; iii) is inserted in a young scientific Society (Sociedade Astronômica Brasileira - SAB), which has shown marked recent maturation and a large rate of growth. This enabled us to diagnose the evolution of the institution and its suitability to the different requirements of the astronomical career. We show that, in the hard science field, the increase of the number of graduated students and the decrease of the time spent as an undergraduate student are not sufficient, or even adequate, to evaluate the efficiency of education in science (Arany-Prado, L., 2003, Revista Brasileira de Ensino de Física, vol. 25, no. 1, 105-115; http://sbf.if.usp.br/rbef/Vol25/Num1).

  15. Spatiotemporal Modeling for Assessing Complementarity of Renewable Energy Sources in Distributed Energy Systems

    NASA Astrophysics Data System (ADS)

    Ramirez Camargo, L.; Zink, R.; Dorner, W.

    2015-07-01

    Spatial assessments of the potential of renewable energy sources (RES) have become a valuable information basis for policy and decision-making. These studies, however, do not explicitly consider the variability in time of RES such as solar energy or wind. Until now, the focus is usually given to economic profitability based on yearly balances, which do not allow a comprehensive examination of RES-technologies complementarity. Incrementing temporal resolution of energy output estimation will permit to plan the aggregation of a diverse pool of RES plants i.e., to conceive a system as a virtual power plant (VPP). This paper presents a spatiotemporal analysis methodology to estimate RES potential of municipalities. The methodology relies on a combination of open source geographic information systems (GIS) processing tools and the in-memory array processing environment of Python and NumPy. Beyond the typical identification of suitable locations to build power plants, it is possible to define which of them are the best for a balanced local energy supply. A case study of a municipality, using spatial data with one square meter resolution and one hour temporal resolution, shows strong complementarity of photovoltaic and wind power. Furthermore, it is shown that a detailed deployment strategy of potential suitable locations for RES, calculated with modest computational requirements, can support municipalities to develop VPPs and improve security of supply.

  16. The ultrastructure and genetic traits of plants under the condition of hypobaric and hypoxia

    NASA Astrophysics Data System (ADS)

    Guo, Shuangsheng; Tang, Yongkang; Wang, Shulei; Cheng, Quanyong; Zhao, Qi

    This study analyzed the cellular, sub-cellular and molecular levels, particle composition and volume changes of Indian lettuce under the conditions of hypobaric and hypoxia. Firstly, in the hypobaric and hypoxia conditions, two kinds of sample showed a decrease in the num-ber of cells, the increase in volume and the deflation in nuclear size. Secondly, Significant changes of the chloroplast ultrastructure have taken place in the two conditions. Thirdly, in the hypoxia condition, the chloroplast grana lamellae fractured and aggregated, which caused the chloroplasts to enlarge, their lamellae to reduce,become vaguer and finally to disintegrate. Fourthly, the volume change and aggregation of the chloroplasts induced mitochondria to ap-proach the chloroplasts. Fifthly, cytoskeleton immunofluorescence positioning results showed that the microtubules had decreased in number, shortened in length and gathered in the vicinity of the nucleus. In addition, total leaf DNA-sequence alignment found no rbcl gene mutation in the extreme conditions. Keywords: Chloroplast Ultrastructure Cytoskeleton rbcl gene Indian lettuce

  17. Le dimensionnement des actionneurs électriques : un problème de programmation non linéaire

    NASA Astrophysics Data System (ADS)

    Kone, A. D.; Nogarede, B.; Lajoie Mazenc, M.

    1993-02-01

    In this paper, a generic design methodology of electric actuators is proposed. This methodology is based on the direct interpretation of the design problem as an optimization problem. After having formalized the design process, the authors specify the numerical solution methods suited to the obtained formulation. The process is finally validated in the particular case of the design of a slotless permanent magnet structure. Dans cet article, une méthodologie générique de dimensionnement des actionneurs électriques est proposée. Cette méthodologie est basée sur l'interprétation directe du problème de dimensionnement en tant que problème d'optimisation. Après avoir procédé à la formalisation du problème, les auteurs précisent les méthodes numériques de résolution adaptées à la formulation obtenue. La procédure est enfin validée dans le cas particulier du dimensionnement d'une structure à aimants permanents sans encoche.

  18. [Not Available].

    PubMed

    Ettalbi, S; Ibnouzahir, M; Droussi, H; Wahbi, S; Bahaichar, N; Boukind, E H

    2009-06-30

    La brûlure est un accident qui reste toujours très fréquent au Maroc, ce qui fait d'elle un problème de la santé publique. Les brûlures, quand elles sont graves ou profondes, entraînent de façon quasi inéluctable des séquelles fonctionnelles et esthétiques. A travers deux observations de deux enfants présentant des séquelles de brûlures graves, ayant retenti péjorativement sur leurs scolarités, on a essayé de mettre en évidence quelques facteurs incriminés dans cette tragédie (feu, petites bouteilles de gaz et le manque d'infrastructure, du personnel médical et paramédical, du matériel ainsi que de la prévention) comme étant une grande cause dans la survenue de ces séquelles. Le but de notre travail est d'énumérer ces différents facteurs intriqués, ainsi que de proposer quelques solutions, tout en insistant sur la prévention. PMID:21991156

  19. Threshold modeling of extreme spatial rainfall

    NASA Astrophysics Data System (ADS)

    Thibaud, E.; Davison, A.

    2013-12-01

    Complex events such as sustained extreme precipitation have major effects on human populations and environmental sustainability, and there is a growing interest in modeling them realistically. For risk assessment based on spatial quantities such as the total amount of rainfall falling over a region, it is necessary to properly model the dependence among extremes over that region, based on data from perhaps only a few sites within it. We propose an approach to spatial modeling of extreme rainfall, based on max-stable processes fitted using partial duration series and a censored threshold likelihood function. The resulting models are coherent with classical extreme-value theory and allow the consistent treatment of spatial dependence of rainfall using ideas related to those of classical geostatistics. The method can be used to produce simulations needed for hydrological models, and in particular for the generation of spatially heterogeneous extreme rainfall fields over catchments. We illustrate the ideas through data from the Val Ferret watershed in the Swiss Alps, based on daily cumulative rainfall totals recorded at 24 stations for four summers, augmented by a longer series from nearby. References: Davison, A. C., Huser, R., Thibaud, E. (2013). Geostatistics of Dependent and Asymptotically Independent Extremes, Mathematical Geosciences, vol. 45, num. 5, p. 511-529, 2013, doi:10.1007/s11004-013-9469-y Thibaud, E., Mutzner, R., Davison A. C. (2013, to appear). Threshold modeling of extreme spatial rainfall, Water Resources Research, doi:10.1002/wrcr.20329

  20. Infarctus du myocarde révélateur d'une thrombocytémie essentielle chez un sujet jeune noir africain: à propos d'une observation

    PubMed Central

    Yaméogo, Nobila Valentin; Kagambèga, Larissa Justine; Yaméogo, Aimé Arsène; Kologo, Koudougou Jonas; Millogo, Georges Rosario Christian; Toguyéni, Boubacar Jean Yves; Samadoulougou, André Koudnoaga; Zabsonré, Patrice

    2014-01-01

    La thrombocytémie essentielle est un syndrome myéloprolifératif qui se complique rarement d'infarctus du myocarde. Nous rapportons l'observation d'un patient de 23 ans, sans facteurs de risque cardio-vasculaire connus, aux antécédents de thrombose veineuse cérébrale à l’âge de 20 ans, admis dans le service de cardiologie pour un syndrome douloureux thoracique. L'examen physique était pauvre. L'ECG, la troponinémie et la coronarographie ont conclu à un infarctus du myocarde par obstruction distale de l'IVA. La numération formule sanguine objectivait une importante thrombocytose isolée à 1.197.000/mm3. La recherche de la mutation V617F de JAK2 était positive. Il n'y avait pas de thrombophilie. L’évolution était favorable sous héparine de bas poids moléculaire, antiagrégant plaquettaire, hydroxyurée et hydratation alcaline abondante. PMID:25574323

  1. On the divergence-free condition in Godunov-type schemes for ideal magnetohydrodynamics: the upwind constrained transport method

    NASA Astrophysics Data System (ADS)

    Londrillo, P.; del Zanna, L.

    2004-03-01

    We present a general framework to design Godunov-type schemes for multidimensional ideal magnetohydrodynamic (MHD) systems, having the divergence-free relation and the related properties of the magnetic field B as built-in conditions. Our approach mostly relies on the constrained transport (CT) discretization technique for the magnetic field components, originally developed for the linear induction equation, which assures [∇.B]num=0 and its preservation in time to within machine accuracy in a finite-volume setting. We show that the CT formalism, when fully exploited, can be used as a general guideline to design the reconstruction procedures of the B vector field, to adapt standard upwind procedures for the momentum and energy equations, avoiding the onset of numerical monopoles of O(1) size, and to formulate approximate Riemann solvers for the induction equation. This general framework will be named here upwind constrained transport (UCT). To demonstrate the versatility of our method, we apply it to a variety of schemes, which are finally validated numerically and compared: a novel implementation for the MHD case of the second-order Roe-type positive scheme by Liu and Lax [J. Comput. Fluid Dyn. 5 (1996) 133], and both the second- and third-order versions of a central-type MHD scheme presented by Londrillo and Del Zanna [Astrophys. J. 530 (2000) 508], where the basic UCT strategies have been first outlined.

  2. Xray: N-dimensional, labeled arrays for analyzing physical datasets in Python

    NASA Astrophysics Data System (ADS)

    Hoyer, S.

    2015-12-01

    Efficient analysis of geophysical datasets requires tools that both preserve and utilize metadata, and that transparently scale to process large datas. Xray is such a tool, in the form of an open source Python library for analyzing the labeled, multi-dimensional array (tensor) datasets that are ubiquitous in the Earth sciences. Xray's approach pairs Python data structures based on the data model of the netCDF file format with the proven design and user interface of pandas, the popular Python data analysis library for labeled tabular data. On top of the NumPy array, xray adds labeled dimensions (e.g., "time") and coordinate values (e.g., "2015-04-10"), which it uses to enable a host of operations powered by these labels: selection, aggregation, alignment, broadcasting, split-apply-combine, interoperability with pandas and serialization to netCDF/HDF5. Many of these operations are enabled by xray's tight integration with pandas. Finally, to allow for easy parallelism and to enable its labeled data operations to scale to datasets that does not fit into memory, xray integrates with the parallel processing library dask.

  3. A role for Mfb1p in region-specific anchorage of high-functioning mitochondria and lifespan in Saccharomyces cerevisiae

    PubMed Central

    Pernice, Wolfgang M.; Vevea, Jason D.; Pon, Liza A.

    2016-01-01

    Previous studies indicate that replicative lifespan in daughter cells of Sacchraromyces cerevisiae depends on the preferential inheritance of young, high-functioning mitochondria. We report here that mitochondria are functionally segregated even within single mother cells in S. cerevisiae. A high-functioning population of mitochondria accumulates at the tip of the mother cell distal to the bud. We find that the mitochondrial F-box protein (Mfb1p) localizes to mitochondria in the mother tip and is required for mitochondrial anchorage at that site, independent of the previously identified anchorage protein Num1p. Deletion of MFB1 results in loss of the mother-tip-localized mitochondrial population, defects in mitochondrial function and premature replicative ageing. Inhibiting mitochondrial inheritance to buds, by deletion of MMR1, in mfb1Δ cells restores mitochondrial distribution, promotes mitochondrial function and extends replicative lifespan. Our results identify a mechanism that retains a reservoir of high-functioning mitochondria in mother cells and thereby preserves maternal reproductive capacity. PMID:26839174

  4. A numerical investigation of blood damage in the hinge area of bileaflet mechanical heart valves

    NASA Astrophysics Data System (ADS)

    Yun, Min; Wu, Jingshu; Simon, Helene; Sotiropoulos, Fotis; Aidun, Cyrus; Yoganathan, Ajit

    2010-11-01

    Studies have shown that high shear stress and large recirculation regions have a strong impact on thromboembolic complications in Bileaflet mechanical heart valves (BMHV). This study quantitatively compares the hinge flow field and blood damage of the 23mm St. Jude Medical (SJM) regent with different hinge gap widths and the 23mm CarboMedics (CM) valves. The lattice-Boltzmann method with external boundary force (LBM-EBF) [Wu and Aidun, Int. J Num. Methods Fluids, 62, 7, 2009] was implemented to simulate the flow and capture the dynamics and the surface shear stress of the platelets with realistic geometry. The velocity boundary conditions for the small-scale hinge flow are obtained from previous 3D large-scale computational fluid dynamics (CFD) simulations [Simon et al, Annals of Biomedical Engineering, 38, 3, 2009]. The flow patterns of three hinges that were studied were similar during diastole. However, velocity magnitudes and shear stresses at the hinge gap were different, which may explain the higher blood damage index (BDI) value for the CM valve and lower BDI value for the SJM valve with a larger gap width. The multiscale computational method used to quantitatively measure the BDI during a full cardiac cycle will be discussed.

  5. Le syndrome de la pince aorto-mésentérique: rare, mais pensez-y

    PubMed Central

    Tidjane, Anisse; Tabeti, Benali; Benmaarouf, Noureddine; Boudjenan, Nabil; Bouziane, Chaouky; Kessai, Nadia

    2014-01-01

    Le syndrome de la pince aorto-mésentérique «SPAM » ou syndrome de Wilkie, est une obstruction duodénale secondaire à une pince anatomiquement acquise qui résulte de la compression du troisième duodénum par l'artère mésentérique supérieure « AMS » en avant, et l'aorte en arrière suite à la disparition du tissu graisseux périvasculaire. Les états de dénutrition avancés en sont souvent la cause, et le SPAM se manifeste cliniquement par des vomissements, des plénitudes et des douleurs post prandiales. Le traitement est médical, mais en cas d’échec la chirurgie s'impose. Nous rapportons un cas de SPAM survenu chez un patient âgé de 78 ans présentant une broncho-pneumopathiechronique obstructive, une démence sénile et une anorexie, consultant pour vomissements répétés remontant à plus d'une semaine. PMID:25018797

  6. Fiabilité des structures mécaniques adaptatives: effet de la panne des actionneurs ou des capteurs sur la stabilité

    NASA Astrophysics Data System (ADS)

    Fall, H.; Charon, W.; Kouta, R.

    2002-12-01

    Ces dernières décennies, des activités significatives dans le monde étaient dirigées autour du contrôle actif. Le but de ces recherches était essentiellement d'améliorer les performances, la fiabilité et la sécurité des systèmes. Notamment dans le cas des structures soumises à des vibrations aléatoires. D'importants travaux ont été consacré à l'utilisation des “matériaux intelligents” comme capteurs et actionneurs. Cette article propose l'analyse de la fiabilité des systèmes mécaniques en étudiant les pannes des actionneurs ou des capteurs. L'effet de ces pannes sur la stabilité et la performance du système y est démontré. Les méthodologies de conception y sont rappelées. Des exemples numériques sont fournis à travers le contrôle d'un panneau sous chargement dynamique pour illustrer la méthode proposée.

  7. The Clawpack Community of Codes

    NASA Astrophysics Data System (ADS)

    Mandli, K. T.; LeVeque, R. J.; Ketcheson, D.; Ahmadia, A. J.

    2014-12-01

    Clawpack, the Conservation Laws Package, has long been one of the standards for solving hyperbolic conservation laws but over the years has extended well beyond this role. Today a community of open-source codes have been developed that address a multitude of different needs including non-conservative balance laws, high-order accurate methods, and parallelism while remaining extensible and easy to use, largely by the judicious use of Python and the original Fortran codes that it wraps. This talk will present some of the recent developments in projects under the Clawpack umbrella, notably the GeoClaw and PyClaw projects. GeoClaw was originally developed as a tool for simulating tsunamis using adaptive mesh refinement but has since encompassed a large number of other geophysically relevant flows including storm surge and debris-flows. PyClaw originated as a Python version of the original Clawpack algorithms but has since been both a testing ground for new algorithmic advances in the Clawpack framework but also an easily extensible framework for solving hyperbolic balance laws. Some of these extensions include the addition of WENO high-order methods, massively parallel capabilities, and adaptive mesh refinement technologies, made possible largely by the flexibility of the Python language and community libraries such as NumPy and PETSc. Because of the tight integration with Python tecnologies, both packages have benefited also from the focus on reproducibility in the Python community, notably IPython notebooks.

  8. Estimation of Biomass and Carbon Stocks in Rubber Plantation Using Thaichote Satellite Imagery

    NASA Astrophysics Data System (ADS)

    Charoenjit, Kitsanai; Zuddas, Pierpaolo; Allemand, Pascal

    2014-05-01

    This goal of study is to improve model for estimate biomass and carbon stocks of rubber plantation (clone RRIM 600) in sub-basin of mae num prasae, East Thailand with total area is 232 Km2. We mapped 2011 of the biomass and carbon stocks with the used of integrated Thaichote satellite imagery and field data. In order to tree girth prediction and tree density population, we applied the objected based image analysis (OBIA) which include image mining and modeling by linear multiple regression, then estimate biomass and carbon stocks in rubber plantation. The image mining includes spectral, vegetation, textural and mask information for modeling construction. We found an parameters of the Global Environmental Monitoring Index (GEMI) and texture of homogeneity, dissimilarity, contrast and variance were accepted relationship of tree girt prediction with R2 0.865. The total amount of biomass and carbon stocks in study area is 2,227 Kt and 991.5 KtC respectively. For summary of study area, the annual sequestered in 2011 is 121.3 tCO2 from the atmosphere and the rubber plantation at mature age stage (25 years) had highest capacity of sequestered at 33.53 tCO2 ha-1 yr-1.

  9. Insight into the dynamics of granular column collapse using Discrete Element Methods and laboratory experiments

    NASA Astrophysics Data System (ADS)

    Martin, Hugo; Mangeney, Anne; Farin, Maxime; Richard, Patrick

    2016-04-01

    The mechanical behavior of granular flows is still an open issue. In particular, quantitative agreement between the detailed dynamics of the flow and laboratory experiments is necessary to better constrain the performance and limits of the models. We propose here to compare quantitatively the flow profiles and the force during granular column collapse simulated using Discrete Element Models and laboratory experiments. These small scale experiments are performed with dry granular material released initially from a cylinder on a sloping plane. The flow profiles and the acoustic signal generated by the granular impacts and stresses on the plane are recorded systematically [Farin et al., 2015]. These experiments are simulated using the Discrete Element Method Modys [Richard et al., 2000]. We show that the effect of the removing gate should be taken into account in the model in order to quantatively reproduce the flow dynamics. Furthermore we compare the simulated and observed acoustic signals that are generated by the fluctuating stresses exerted by the grains on the substrate in different frequency bands. [1] P. Richard et Luc Oger. 2000 Etude de la géométrie de milieux granulaires modèles tridimensionnels par simulation numérique. [2] Farin, M., Mangeney, A., Toussaint, R., De Rosny, J., Shapiro, N., Dewez, T., Hibert, C., Mathon, C., Sedan, O., Berger. 2015, Characterization of rockfalls from seismic signal: insights from laboratory experiments

  10. APASVO: A free software tool for automatic P-phase picking and event detection in seismic traces

    NASA Astrophysics Data System (ADS)

    Romero, José Emilio; Titos, Manuel; Bueno, Ángel; Álvarez, Isaac; García, Luz; Torre, Ángel de la; Benítez, M.a. Carmen

    2016-05-01

    The accurate estimation of the arrival time of seismic waves or picking is a problem of major interest in seismic research given its relevance in many seismological applications, such as earthquake source location and active seismic tomography. In the last decades, several automatic picking methods have been proposed with the ultimate goal of implementing picking algorithms whose results are comparable to those obtained by manual picking. In order to facilitate the use of these automated methods in the analysis of seismic traces, this paper presents a new free, open source, software graphical tool, named APASVO, which allows picking tasks in an easy and user-friendly way. The tool also provides event detection functionality, where a relatively imprecise estimation of the onset time is sufficient. The application implements the STA-LTA detection algorithm and the AMPA picking algorithm. An autoregressive AIC-based picking method can also be applied. Besides, this graphical tool is complemented with two additional command line tools, an event picking tool and a synthetic earthquake generator. APASVO is a multiplatform tool that works on Windows, Linux and OS X. The application can process data in a large variety of file formats. It is implemented in Python and relies on well-known scientific computing packages such as ObsPy, NumPy, SciPy and Matplotlib.

  11. Performance Characterization of KAPAO, a Low-Cost Natural Guide Star Adaptive Optics Instrument

    NASA Astrophysics Data System (ADS)

    Long, Joseph; Choi, P. I.; Severson, S. A.; Littleton, E.; Badham, K.; Bolger, D.; Guerrero, C.; Ortega, F.; Wong, J.; Baranec, C.; Riddle, R. L.

    2014-01-01

    We present a software overview of KAPAO, an adaptive optics system designed for the Pomona College 1-meter telescope at Table Mountain Observatory. The instrument is currently in the commissioning phase and data presented here are from both in-lab and on-sky observations. In an effort to maximize on-sky performance, we have developed a suite of instrument-specific data analysis tools. This suite of tools aids in the alignment of the instrument's optics, and the optimization of on-sky performance. The analysis suite visualizes and extends the telemetry output by the Robo-AO control software. This includes visualization of deformable mirror and wavefront sensor telemetry and a Zernike decomposition of the residual wavefront error. We complement this with analysis tools for the science camera data. We model a synthetic PSF for the Table Mountain telescope to calibrate our Strehl measurements, and process image data cubes to track instrument performance over the course of an observation. By coupling WFS telemetry with science camera data we can use image sharpening techniques to account for non-common-path wavefront errors and improve image performance. Python packages for scientific computing, such as NumPy and Matplotlib, are employed to complement existing IDL code. A primary goal of this suite of software is to support the remote use of the system by a broad range of users that includes faculty and undergraduate students from the consortium of member campuses.

  12. Wyrm: A Brain-Computer Interface Toolbox in Python.

    PubMed

    Venthur, Bastian; Dähne, Sven; Höhne, Johannes; Heller, Hendrik; Blankertz, Benjamin

    2015-10-01

    In the last years Python has gained more and more traction in the scientific community. Projects like NumPy, SciPy, and Matplotlib have created a strong foundation for scientific computing in Python and machine learning packages like scikit-learn or packages for data analysis like Pandas are building on top of it. In this paper we present Wyrm ( https://github.com/bbci/wyrm ), an open source BCI toolbox in Python. Wyrm is applicable to a broad range of neuroscientific problems. It can be used as a toolbox for analysis and visualization of neurophysiological data and in real-time settings, like an online BCI application. In order to prevent software defects, Wyrm makes extensive use of unit testing. We will explain the key aspects of Wyrm's software architecture and design decisions for its data structure, and demonstrate and validate the use of our toolbox by presenting our approach to the classification tasks of two different data sets from the BCI Competition III. Furthermore, we will give a brief analysis of the data sets using our toolbox, and demonstrate how we implemented an online experiment using Wyrm. With Wyrm we add the final piece to our ongoing effort to provide a complete, free and open source BCI system in Python. PMID:26001643

  13. Weather forecasting with open source software

    NASA Astrophysics Data System (ADS)

    Rautenhaus, Marc; Dörnbrack, Andreas

    2013-04-01

    To forecast the weather situation during aircraft-based atmospheric field campaigns, we employ a tool chain of existing and self-developed open source software tools and open standards. Of particular value are the Python programming language with its extension libraries NumPy, SciPy, PyQt4, Matplotlib and the basemap toolkit, the NetCDF standard with the Climate and Forecast (CF) Metadata conventions, and the Open Geospatial Consortium Web Map Service standard. These open source libraries and open standards helped to implement the "Mission Support System", a Web Map Service based tool to support weather forecasting and flight planning during field campaigns. The tool has been implemented in Python and has also been released as open source (Rautenhaus et al., Geosci. Model Dev., 5, 55-71, 2012). In this presentation we discuss the usage of free and open source software for weather forecasting in the context of research flight planning, and highlight how the field campaign work benefits from using open source tools and open standards.

  14. A parallelized Python based Multi-Point Thomson Scattering analysis in NSTX-U

    NASA Astrophysics Data System (ADS)

    Miller, Jared; Diallo, Ahmed; Leblanc, Benoit

    2014-10-01

    Multi-Point Thomson Scattering (MPTS) is a reliable and accurate method of finding the temperature, density, and pressure of a magnetically confined plasma. Nd:YAG (1064 nm) lasers are fired into the plasma with a frequency of 60 Hz, and the light is Doppler shifted by Thomson scattering. Polychromators on the midplane of the tokamak pick up the light at various radii/scattering angles, and the avalanche photodiode's voltages are added to an MDSplus tree for later analysis. This project ports and optimizes the prior serial IDL MPTS code into a well-documented Python package that runs in parallel. Since there are 30 polychromators in the current NSTX setup (12 more will be added when NSTX-U is completed), using parallelism offers vast savings in performance. NumPy and SciPy further accelerate numerical calculations and matrix operations, Matplotlib and PyQt make an intuitive GUI with plots of the output, and Multiprocessing parallelizes the computationally intensive calculations. The Python package was designed with portability and flexibility in mind so it can be adapted for use in any polychromator-based MPTS system.

  15. Evolución de planetas gigantes y posibilidades de su detección directa

    NASA Astrophysics Data System (ADS)

    Brunini, A.; Benvenuto, O. G.

    Desde la reciente detección de planetas gigantes orbitando estrellas cercanas de tipo solar por medio de efecto Doppler, uno de los principales problemas, en cuanto al estudio de los sistemas planetarios extrasolares, se refiere a la posibilidad de obtener evidencia directa de su existencia. Esto parece ser factible gracias a que en un futuro cercano entrarán en operación algunos telescopios especialmente adecuados a estos propósitos. Por tal motivo, hemos comenzado desde hace un tiempo un esfuerzo en cuanto al estudio de la evolución planetaria. A tales efectos hemos adaptado el código de evolución estelar de nuestro Observatorio al caso planetario. Las principales diferencias entre el caso estelar y el planetario se encuentran en la ecuación de estado. A tales fines hemos incluído la reciente ecuación de estado de Saumon, Chabrier y Van Horn, las opacidades radiativas de Guillot et al., procesos de quema de Deuterio, etc. También se ha considerado la posible existencia de fases de hielo y roca en el interior planetario. Por el momento hemos despreciado los efectos de la rotación planetaria. Con este código hemos computado la evolución de planetas con masas desde 10 hasta 0.3 masas de Júpiter. Utilizando nuestros resultados numéricos discutimos la detectabilidad de estos objetos en condiciones realistas.

  16. El origen de las galaxias en modelos jerárquicos de formación de la estructura

    NASA Astrophysics Data System (ADS)

    Navarro, J. F.

    En esta charla presentaré una revisión de los modelos corrientes de formación de galaxias. En particular, haré énfasis en el origen de la gran variedad de morfologías galácticas y de las correlaciones entre las propiedades estructurales de discos y esferoides, todo dentro del contexto cosmológico jerárquico provisto por teorías como la de materia oscura fría. En este tipo de teorías las correlaciones observadas entre la luminosidad, velocidad de rotación, momento angular, y tamaño de galaxias son el resultado de la falta de escalas naturales en el proceso de formación de los halos de materia oscura que dichas galaxias habitan. Simulaciones numéricas que incorporan efectos gravitacionales, hidrodinámicos y de formación estelar ilustran estas ideas y demuestran las dificultades que aquejan a modelos donde tanto discos como esferoides son el resultado final de una secuencia de fusiones de sistemas protogalácticos.

  17. Multi Spectral Pushbroom Imaging Radiometer (MPIR) for remote sensing cloud studies

    SciTech Connect

    Phipps, G.S.; Grotbeck, C.L.

    1995-10-01

    A Multi Spectral Pushbroom Imaging Radiometer (MPIR) has been developed as are relatively inexpensive ({approximately}$IM/copy), well-calibrated,imaging radiometer for aircraft studies of cloud properties. The instrument is designed to fly on an Unmanned Aerospace Vehicle (UAV) platform at altitudes from the surface up to 20 km. MPIR is being developed to support the Unmanned Aerospace Vehicle portion of the Department of Energy`s Atmospheric Radiation Measurements program (ARM/UAV). Radiation-cloud interactions are the dominant uncertainty in the current General Circulation Models used for atmospheric climate studies. Reduction of this uncertainty is a top scientific priority of the US Global Change Research Program and the ARM program. While the DOE`s ARM program measures a num-ber of parameters from the ground-based Clouds and Radiation Testbed sites, it was recognized from the outset that other key parameters are best measured by sustained airborne data taking. These measurements are critical in our understanding of global change issues as well as for improved atmospheric and near space weather forecasting applications.

  18. GAiN: Distributed Array Computation with Python

    SciTech Connect

    Daily, Jeffrey A.

    2009-05-01

    Scientific computing makes use of very large, multidimensional numerical arrays - typically, gigabytes to terabytes in size - much larger than can fit on even the largest single compute node. Such arrays must be distributed across a "cluster" of nodes. Global Arrays is a cluster-based software system from Battelle Pacific Northwest National Laboratory that enables an efficient, portable, and parallel shared-memory programming interface to manipulate these arrays. Written in and for the C and FORTRAN programming languages, it takes advantage of high-performance cluster interconnections to allow any node in the cluster to access data on any other node very rapidly. The "numpy" module is the de facto standard for numerical calculation in the Python programming language, a language whose use is growing rapidly in the scientific and engineering communities. numpy provides a powerful N-dimensional array class as well as other scientific computing capabilities. However, like the majority of the core Python modules, numpy is inherently serial. Our system, GAiN (Global Arrays in NumPy), is a parallel extension to Python that accesses Global Arrays through numpy. This allows parallel processing and/or larger problem sizes to be harnessed almost transparently within new or existing numpy programs.

  19. NASA Astrophysics Data System (ADS)

    Sampath, S.; Wayne, S. F.

    1994-09-01

    Thermally sprayed molybdenum coatings are used in a variety of industrial applications, such as auto-motive piston rings, aeroturbine engines, and paper and plastics processing machinery. Molybdenum ex-hibits excellent scuffing resistance under sliding contact conditions. However, plasma-sprayed molybde-num coatings are relatively soft and require dispersion strengthening (e.g., Mo2C) or addition of a second phase (e.g., NiCrBSi) to improve hardness, wear resistance, and thus coating performance. In this study, Mo-Mo2C composite powders were plasma sprayed onto mild steel substrates. Considerable decarburi-zation was observed during air plasma spraying—a beneficial condition because carbon acts as a sacrifi-cial getter for the oxygen, thereby reducing the oxide content in the coating. Finer powders showed a greater degree of decarburization due to the increased surface area; however, the starting carbide con-tent in the powder exerted very little influence on the extent of decarburization. The friction properties of Mo-Mo2C coatings were significantly improved compared to those of pure molybdenum under con-tinuous sliding contact conditions. It also was found that the abrasion resistance of the coatings improved with increasing carbide addition.

  20. pyXSIM: Synthetic X-ray observations generator

    NASA Astrophysics Data System (ADS)

    ZuHone, John A., Hallman, Eric. J.

    2016-08-01

    pyXSIM simulates X-ray observations from astrophysical sources. X-rays probe the high-energy universe, from hot galaxy clusters to compact objects such as neutron stars and black holes and many interesting sources in between. pyXSIM generates synthetic X-ray observations of these sources from a wide variety of models, whether from grid-based simulation codes such as FLASH (ascl:1010.082), Enzo (ascl:1010.072), and Athena (ascl:1010.014), to particle-based codes such as Gadget (ascl:0003.001) and AREPO, and even from datasets that have been created “by hand”, such as from NumPy arrays. pyXSIM can also manipulate the synthetic observations it produces in various ways and export the simulated X-ray events to other software packages to simulate the end products of specific X-ray observatories. pyXSIM is an implementation of the PHOX (ascl:1112.004) algorithm and was initially the photon_simulator analysis module in yt (ascl:1011.022); it is dependent on yt.

  1. An Architectural Concept for Intrusion Tolerance in Air Traffic Networks

    NASA Technical Reports Server (NTRS)

    Maddalon, Jeffrey M.; Miner, Paul S.

    2003-01-01

    The goal of an intrusion tolerant network is to continue to provide predictable and reliable communication in the presence of a limited num ber of compromised network components. The behavior of a compromised network component ranges from a node that no longer responds to a nod e that is under the control of a malicious entity that is actively tr ying to cause other nodes to fail. Most current data communication ne tworks do not include support for tolerating unconstrained misbehavio r of components in the network. However, the fault tolerance communit y has developed protocols that provide both predictable and reliable communication in the presence of the worst possible behavior of a limited number of nodes in the system. One may view a malicious entity in a communication network as a node that has failed and is behaving in an arbitrary manner. NASA/Langley Research Center has developed one such fault-tolerant computing platform called SPIDER (Scalable Proces sor-Independent Design for Electromagnetic Resilience). The protocols and interconnection mechanisms of SPIDER may be adapted to large-sca le, distributed communication networks such as would be required for future Air Traffic Management systems. The predictability and reliabi lity guarantees provided by the SPIDER protocols have been formally v erified. This analysis can be readily adapted to similar network stru ctures.

  2. GIS-based hydrogeological databases and groundwater modelling

    NASA Astrophysics Data System (ADS)

    Gogu, Radu Constantin; Carabin, Guy; Hallet, Vincent; Peters, Valerie; Dassargues, Alain

    2001-12-01

    'applications qui ont été développées permet dès maintenant de prochaines avancées. L'intérêt grandit pour le potentiel d'intégration de la technologie des SIG et les modèles de simulation des nappes. Un outil de couplage a été créé entre le schéma de base de données spatiales et l'interface GMS (GroundWater Modelling System, système de modélisation de nappe) du modèle numérique de nappe. Suivant les requêtes en fonction du temps et de l'espace, les données hydrogéologiques stockées dans la base de données peuvent être aisément utilisées dans différents modèles numériques de nappes. Resumen. La fiabilidad y validez de los análisis de aguas subterráneas dependen enormemente de la disponibilidad de muchos datos de alta calidad. Integrarlos en una estructura consistente y lógica mediante un entorno informático sirve para asegurar su validez y disponibilidad, y rrepresenta una herramienta muy potente para ulteriores estudios hidrogeológicos. Se ha diseñado en la región de Valonia (Bélgica) una base de datos hidrogeológica basada en un sistema de información geográfica (GIS), con el que se dispone de útiles para elaborar análisis de vulnerabilidad y modelos hidregeológicos. Se ha utilizado datos de cinco cuencas fluviales, elegidas por sus características hidrogeológicas contrastadas, así como un conjunto de aplicaciones desarrolladas con vistas al futuro. El interés por el potencial que ofrece la integración de la tecnología GIS y los modelos de simulación de aguas subterráneas está en auge. Se ha desarrollado un "emulador" que integra el esquema espacial de la base de datos y la interfaz GMS (GroundWater Modelling System) de modelación numérica de aguas subterráneas. A partir de búsquedas temporales y espaciales, los datos hidrogeológicos almacenados en la base de datos pueden ser utilizados fácilmente en modelos numéricos diferentes de aguas subterráneas.

  3. Uma Comparação entre Técnicas de Propagação de Erros em Astrofísica: Monte Carlo x Bootstrap

    NASA Astrophysics Data System (ADS)

    Zabot, Alexandre; Baptista, Raymundo

    2005-07-01

    Neste trabalho é feito um estudo comparativo entre dois algoritmos numéricos usados para propagação de erros em dados experimentais. Um deles é conhecido por Método de Monte carlo e o outro por Método de Bootstrap. Recentemente, Dhullon & Watson argüiram que a aplicação do método de Monte Carlo introduz ruído nos dados, e propuseram então a utilização do Bootstrap como alternativa capaz de produzir resultados superiores. O objetivo deste trabalho é testar a validade dessa afirmação. As duas técnicas foram aplicadas a três problemas diferentes: o ajsute de modelos de emissão LTE simples e atmosfera estelar a espectros estelares observados e o ajuste de curvas de luz de eclipses de Variáveis Cataclísmicas para a detemrinação da distribuição radial de brilho dos seus discos de acréscimo. Os métodos foram testados quanto à sua robusteza, ou seja, a capacidade de prover resultados coerentes enre si. Além disso, as soluções dos métodos foram comparadas. Os resultados indicam que não existe evidência de superioridade de um métodos em relação ao outro.

  4. Modèle de comportement dynamique d'un matériau en présence de l'endommagement par cisaillement adiabatique

    NASA Astrophysics Data System (ADS)

    Longère, P.; Dragon, A.; Trumel, H.; de Resseguier, T.; Deprince, X.; Petitpas, E.

    2002-12-01

    L'objectif industriel du travail dans lequel s'inscrit ce papier est la simulation numérique de la réponse de structures à l'impact. Or, pour un grand nombre de matériaux métalliques à haute résistance soumis à des sollicitations à grande vitesse, le cisaillement adiabatique constitue un processus endommageant conduisant souvent à la ruine par macrofissuration. Nous présentons ici un modèle continu qui, construit sur des bases thermodynamiques, rend compte du comportement thermo-élasto/viscoplastique du matériau sain et de l'anisotropie mécanique (dégradation directionnelle des modules élastiques et viscoplastiques induite par la présence des bandes de cisaillement adiabatique dans le matériau endommagé. Dans notre démarche de modélisation qui tend à refléter les constats expérimentaux, la population de bandes est représentée par une variable tensorielle d'endommagement au sein d'un matériau homogène équivalent. Le modèle est formulé dans le cadre des transformations finies élasto-plastiques avec prise en compte de l'anisotropie induite. Sa particularisation au cas des petites perturbations est illustrée pour certains processus homogènes.

  5. Study of the Local Horizon. (Spanish Title: Estudio del Horizonte Local.) Estudo do Horizonte Local

    NASA Astrophysics Data System (ADS)

    Ros, Rosa M.

    2009-12-01

    The study of the horizon is fundamental to easy the first observations of the students at any education center. A simple model, to be developed in each center, allows to easy the study and comprehension of the rudiments of astronomy. The constructed model is presented in turn as a simple equatorial clock, other models (horizontal and vertical) may be constructed starting from it. El estudio del horizonte es fundamental para poder facilitar las primeras observaciones de los alumnos en un centro educativo. Un simple modelo, que debe realizarse para cada centro, nos permite facilitar el estudio y la comprensión de los primeros rudimentos astronómicos. El modelo construido se presenta a su vez como un sencillo modelo de reloj ecuatorial y a partir de él se pueden construir otros modelos (horizontal y vertical). O estudo do horizonte é fundamental para facilitar as primeiras observações dos alunos num centro educativo. Um modelo simples, que deve ser feito para cada centro, permite facilitar o estudo e a compreensão dos primeiros rudimentos astronômicos. O modelo construído apresenta-se, por sua vez, como um modelo simples de relógio equatorial e a partir dele pode-se construir outros modelos (horizontal e vertical)

  6. Advanced Python Scripting Using Sherpa

    NASA Astrophysics Data System (ADS)

    Refsdal, R.; Doe, S.; Nguyen, D.; Siemiginowska, A.; Burke, D.; Evans, J.; Evans, I.

    2011-07-01

    Sherpa is a general purpose modeling and fitting application written in Python. The dynamism of Python allows Sherpa to be a powerful and extensible software package ready for the modern challenges of data analysis. Primarily developed for the Chandra Interactive Analysis of Observations (CIAO) package, it provides a flexible environment for resolving spectral and image properties, analyzing time series, and modeling generic types of data. Complex model expressions are supported using Sherpa's general purpose definition syntax. Sherpa's parameterized data modeling is achieved using robust optimization methods implementing the forward fitting technique. Sherpa includes functions to calculate goodness-of-fit and parameter confidence limits. CPU intensive routines are written in C++/FORTRAN. But since all other data structures are contained in Python modules, users can easily add their own data structures, models, statistics or optimization methods to Sherpa. We will introduce a scripted example that highlights Sherpa's ability to estimate energy and photon flux errors using simulations. The draws from these simulations, accessible as NumPy ndarrays, can be sampled from uni-variate and multi-variate normal distributions and can be binned and visualized with simple high level functions. We will demonstrate how Sherpa can be extended with user-defined model and statistic classes written in Python. Sherpa's open design even allows users to incorporate prior statistics derived from the source model.

  7. Aspect Epidemiologique des Sequelles de Brulures a Marrakech, Maroc, a Travers Deux Observations

    PubMed Central

    Ettalbi, S.; Ibnouzahir, M.; Droussi, H.; Wahbi, S.; Bahaichar, N.; Boukind, E.H.

    2009-01-01

    Summary La brûlure est un accident qui reste toujours très fréquent au Maroc, ce qui fait d'elle un problème de la santé publique. Les brûlures, quand elles sont graves ou profondes, entraînent de façon quasi inéluctable des séquelles fonctionnelles et esthétiques. A travers deux observations de deux enfants présentant des séquelles de brûlures graves, ayant retenti péjorativement sur leurs scolarités, on a essayé de mettre en évidence quelques facteurs incriminés dans cette tragédie (feu, petites bouteilles de gaz et le manque d'infrastructure, du personnel médical et paramédical, du matériel ainsi que de la prévention) comme étant une grande cause dans la survenue de ces séquelles. Le but de notre travail est d'énumérer ces différents facteurs intriqués, ainsi que de proposer quelques solutions, tout en insistant sur la prévention. PMID:21991156

  8. Hardware-accelerated interactive data visualization for neuroscience in Python

    PubMed Central

    Rossant, Cyrille; Harris, Kenneth D.

    2013-01-01

    Large datasets are becoming more and more common in science, particularly in neuroscience where experimental techniques are rapidly evolving. Obtaining interpretable results from raw data can sometimes be done automatically; however, there are numerous situations where there is a need, at all processing stages, to visualize the data in an interactive way. This enables the scientist to gain intuition, discover unexpected patterns, and find guidance about subsequent analysis steps. Existing visualization tools mostly focus on static publication-quality figures and do not support interactive visualization of large datasets. While working on Python software for visualization of neurophysiological data, we developed techniques to leverage the computational power of modern graphics cards for high-performance interactive data visualization. We were able to achieve very high performance despite the interpreted and dynamic nature of Python, by using state-of-the-art, fast libraries such as NumPy, PyOpenGL, and PyTables. We present applications of these methods to visualization of neurophysiological data. We believe our tools will be useful in a broad range of domains, in neuroscience and beyond, where there is an increasing need for scalable and fast interactive visualization. PMID:24391582

  9. Aspheric mirror measurement based on fringe reflection

    NASA Astrophysics Data System (ADS)

    Su, Xianyu; Tang, Yan; Liu, Yuankun; Zhang, Qican; Xiang, Liqun

    2009-05-01

    The aspheric mirror can correct aberrations and improve imaging quality of optical system . M oreover using such mirror can reduce the num ber of optical elem ents in an optical system and further reduce the weight and size of the system . In order to improve the accuracy of aspheric mirror fabrication, there are many methods used to m easure aspheric mirror. Am ong these methods, the most popular one is interferom etry which can m easure the surface with very high accuracy. However, interferom etry commonly requires com plicated and expensive assistant optics, and its m easurem ent range is limited. In order to measure aspheric mirror conveniently and effectively, we further evolve the well know n approaches of 'Phase M easuring Deflectom ety'(PM D) to measure such surface. In this study, we present a novel m ethod based on fringe reflection to m easure aspheric m irror. In the m easurem ent process, the screen and the cam era are m oved along the mirror optical axis, respectively. Using the phase information of the recording fringe patterns, for each cam era pixel, we can calculate the slope and coordinate of its corresponding point on the surface to be tested. By integrating, the absolute height of the tested surface can be reconstructed. Com pared with traditional PM D, this m ethod can m easure the absolute height of an aspheric m irror unam biguously and doesn't need com plex calibration.

  10. General and Specific Abilities as Predictors of School Achievement.

    PubMed

    Gustafsson, J E; Balke, G

    1993-10-01

    The purpose of this study is to investigate the relations between aptitude variables and school achievement using a model of ability which allows simultaneous identification of general and specific abilities. A battery of 16 aptitude tests was administered in the 6th grade and course grades were collected in 17 different subject matter areas in the 9th grade (N = 866). For the aptitude tests a confirmatory factor model is fitted with a general factor (G) along with nine orthogonal, residual factors. Some of the residual factors are quite broad (Crystallized intelligence, Gc(1), and General visualization G(1)), but most are narrow factors identified by pairs of tests (e.g., V(1), Ms(1), Num Ach(1), Vz(1), S, and Cs(1)). A model is fitted to the 17 course grades as well. The model includes a general school achievement factor (GENACH) and domain specific achievement factors in areas such as science-mathematics (SCIENCE), social science (SOCSCI(1)), language (LANG(1)) and spatial-practical performance (SPATPR(1)). Relating the latent criterion variables to the latent aptitude variables it is found that some 40% of the variance in GENACH may be accounted for by G and Gc(1). However, larger proportions of variance are accounted for in the domain specific achievement factors and different aptitude factors are important in different domains. It is conclu~ded that differentiation among at least a limited number of broad abilities may be worthwhile. PMID:26801141

  11. Astronomy in High School: Using a Mini-Planetarium to Understand Details of the Apparent Movement of Stars. (Spanish Title: Astronomía en la Escuela Secundaria: Comprendiendo los Detalles del Movimiento Aparente de Las Estrellas con un Miniplanetario.) Astronomia no Ensino Médio: Compreendendo Detalhes do Movimento Aparente das Estrelas com um Miniplanetário

    NASA Astrophysics Data System (ADS)

    dos Santos Leão, Demetrius

    2013-07-01

    en la comprensión de estas cuestiones y demostraron un gran interés por esta metodología. O objetivo deste artigo é apresentar parte dos resultados obtidos com a intervenção feita como projeto da dissertação de mestrado do autor, que consistiu no desenvolvimento de um conjunto de aulas de Astronomia, com alunos do 1º Ano do Ensino Médio de uma escola da rede privada do Distrito Federal (Brasília, Brasil), empregando como recurso principal um material didático chamado miniplanetário (MP). Utilizando como pressuposto teórico norteador dessas aulas as ideias de contextualização e dialogicidade de Paulo Freire, foi proposta aos estudantes a montagem e utilização desse recurso em uma sessão de planetário. Durante o projeto, enfatizaram-se assuntos como a trajetória aparente das estrelas para o céu de Brasília, a localização dos pontos cardeais a partir da constelação do Cruzeiro do Sul, as cores das estrelas e as estrelas vistas de uma determinada localidade. Apurou-se que os alunos apresentaram melhoria na compreensão desses assuntos, bem como demonstraram expressiva empolgação com essa metodologia desenvolvida.

  12. Ondas de choque em jatos de quasares e objetos BL Lacertae

    NASA Astrophysics Data System (ADS)

    Melo, F. E.; Botti, L. C. L.

    2003-08-01

    Este trabalho é parte de um projeto que vem sendo realizado há dois anos no CRAAM, cujos objetivos principais são analisar e aplicar um modelo generalizado de ondas de choque em jatos relativísticos de plasma, presentes em quasares e objetos BL Lacertae, para explicar a variabilidade observada nestes objetos. O método consiste em uma decomposição de curvas de luz em séries de explosões similares, em várias freqüências, baseando-se em uma evolução espectro-temporal média das explosões. A partir da evolução média, um ajuste de cada explosão é feito com base em equações empíricas, modificando-se apenas parâmetros específicos de cada explosão. Inicialmente o modelo foi aplicado ajustando-se as curvas de luz a explosões delineadas por uma evolução do choque em três estágios, segundo a predominância do processo de emissão: síncrotron, Compton e adiabático. Entretanto, nesta nova fase de projeto, visando uma parametrização mais concisa, uma otimização do algoritmo de ajuste e uma convergência mais rápida, a formulação para cada evento foi assumida com uma evolução em apenas dois estágios: subida e descida. Isto possibilitou uma ótima delineação das curvas de luz das fontes OV236, OJ287, 3C273 e BL Lac, entre 1980 e 2000, nas freqüências 4.8, 8.0, 14.5 e 22 GHz, utilizando-se dados do Observatório da Universidade de Michigan, do Observatório do Itapetinga (Atibaia SP) e do Observatório Metsähovi. Como conclusões importantes, verificou-se que: os parâmetros ajustados descrevem o comportamento do jato; os valores do índice que descreve a expansão do jato sugerem que o mesmo se expande de uma forma não-cônica; o campo magnético é turbulento atrás da frente de choque; e as peculiaridades das explosões são devidas à influência de grandezas tais como o coeficiente da distribuição espectral de energia dos elétrons, a intensidade de campo magnético e o fator de feixe Doppler, no início do choque.

  13. Astronomy at School: Measurements of the Earth-Moon Distance. (Spanish Title: Astronomía en la Escuela: Medición de la Distancia Tierra-Luna.) Astronomia na Escola: Medida da Distância Terra-Lua

    NASA Astrophysics Data System (ADS)

    Paolantonio, Santiago; Pintado, Olga I.

    2006-12-01

    The aim of this project is to approach High School students to Science. We propose to measure the Earth-Moon distance using the parallax. The observation and measurements techniques and all the calculations needed are described in this paper. The results obtained in a test experience realized during 2003 are presented. This test shows that this is a feasible project and also shows which things needed to be improved. Se plantea la propuesta de un proyecto educativo dirigido al Nivel Medio de enseñanza, consistente en la determinación de la distancia Tierra - Luna por paralaje. Se describen las técnicas de observación, mediciones y cálculos. Se proporcionan a continuación los resultados obtenidos en la experiencia piloto realizada en el 2003, la que permitió comprobar la factibilidad de llevar a cabo la propuesta, así como perfeccionar los diferentes aspectos involucrados en la misma. Propomos neste trabalho um projeto educativo dirigido ao Ensino Médio que consiste na determinação da distância Terra-Lua pelo efeito da paralaxe. As técnicas de observação, medidas e cálculos auxiliares são descritos, e os resultados obtidos numa experiência-teste realizada no ano de 2003 apresentados. Este último teste permitiu comprovar a viabilidade de execução da proposta e aperfeiçoar diversos aspectos da mesma.

  14. Ventos em supergigantes B[e] das nuvens de Magalhães e da Galáxia

    NASA Astrophysics Data System (ADS)

    de Araújo, F. X.; Pilling, D. A.; Pereira, C. B.; Fernandes, M. B.

    2003-08-01

    As Supergigantes B[e] apresentam as seguintes características: (i) alta luminosidade; (ii) espectro típico de estrelas de tipo B; (iii) linhas permitidas e proibidas em emissão de metais de baixa ionização, especialmente FeII; (iv) linhas de Balmer, e por vêzes também dos ions HeI e FeII, com perfis tipo P Cygni indicativos de altas taxas de perda de massa. Atualmente estamos desenvolvendo um projeto que visa comparar as propriedades fisicas (principalmente e v¥) dos ventos destes objetos nas Nuvens de Magalhães e na Galaxia. O objetivo é estudar a influência da metalicidade. No presente painel apresentamos uma determinação das velocidades terminais de 11 estrelas, sendo 4 na GNM (Hen S111, 66, R126 e Hen S93), 4 na PNM (Hen S18, S23, S65 e R4) e 3 na Galaxia (CPD-529243, MWC 300 e GG Car). Nossos dados são espectros de alta resolução obtidos no telescópio 1.52m do ESO com o espectrógrafo FEROS. Para determinar as velocidades terminais usamos as linhas Hd e HeI 3888 Å cujas componentes em absorção costumam estar livres de "blends" e estruturas. Nossos resultados sugerem que as velocidades de expansão na GNM são maiores (ainda que apenas ligeiramente) do que aquelas da PNM, como esperado. No entanto, os objetos da Galaxia não parecem seguir a mesma tendência.

  15. Observações no âmbito dos "additional programs" do satélite COROT

    NASA Astrophysics Data System (ADS)

    Janot Pacheco, E.

    2003-08-01

    O satélite Fraco-europeu COROT fará fotometria de altissima precisão (pretende-se atingir uma parte em um milhão), grande campo (3x3 graus) e por longos períodos, de duas regiões pré-determinadas do céu, com 10 graus de raio. Suas finalidades básicas serão estudos em sismologia estelar e a procura de exoplanetas. A comunidade astronômica brasileira participará dessa missão espacial, com direitos iguais aos dos parceiros europeus. Isso se deve a que o satélite utilizará a estação de recepção de dados de Natal (INPE), 5 a 6 brasileiros participarão das equipes de software e cientistas do país atuarão na fase de pré-lançamento. Apresentamos nesta comunicação sugestões para a preparação de propostas de observações com COROT, no âmbito dos Programas Adicionais, que contemplam outros projetos que não de sismologia ou exoplanetas. As últimas definições técnicas e decisões tomadas na 4th Corot Week de junho último serão igualmente apresentadas, em particular quanto às regiões de observação escolhidas e quanto aos procedimentos a seguir para se propor observações.

  16. Brazilian Eratosthenes Project

    NASA Astrophysics Data System (ADS)

    Langhi, R.; Vilaça, J.

    2014-10-01

    The objective of Brazilian Eratosthenes Project is the development and application of teaching training actions according the ``docent autonomy" concept to basic Astronomy Education. Argentina coordinates the project in South America, but Brazil works in this project since 2010 with the theme ``Projeto Eratóstenes Brasil" in the homepage: http://sites.google.com/site/projetoerato. Two schools measure a sticks shadow and communicate their results. After, they calculate an average radius of Earth. The stick (gnomon) should stay in vertical position in the leveled ground. Since 2010, the project received hundreds of Brazilian schools with different experiments that were constructed with autonomy, because our site doesn't show some itinerary pre-ready to elaborate the experiments. To collect data for our research, we will use interviews via Skype with the teachers. These data are useful to researches about Science Education area and the Teaching Formation. Teaching professional practice could change and we see modifications in the teachers work, what depends of their realities and context. This project intents to respect the docent autonomy. This autonomy to responsible modifications during continued formation is called ``activist formative model" according Langhi & Nardi (Educação em Astronomia: repensando a formação de professores. São Paulo: Escrituras Editora, 2012). This project discusses about researches in Astronomy Education - still extreme rare in Brazil, when we compare with other areas in Science Education. We believe that actions like this could motivate the students to learn more Astronomy. Furthermore, this national action can be a rich source of data to investigations about teaching formation and scientific divulgation.

  17. Development of Educational Resources to Include the Teaching of Astronomy in the First Years of the Basic Education. (Spanish Title: Desarrollo de Recursos Pedagógicos Para Incluir la Enseñanza de la Astronomía en los Primeros Años de la Educación Básica.) Desenvolvimento de Recursos Pedagógicos Para Inserir o Ensino de Astronomia nas Séries Iniciais do Ensino Fundamental

    NASA Astrophysics Data System (ADS)

    da Silva Morett, Samara; de Oliveira Souza, Marcelo

    2010-07-01

    ía y la vida cotidiana de los estudiantes. La inclusión de la astronomía en la escuela primaria es una manera de demostrar a los estudiantes cómo este campo está presente de forma activa en su vida cotidiana. Las clases que participan en el proyecto participaron en un estudio con el objetivo de proporcionar información a los conocimientos previos que tenían sobre los temas de la astronomía que se examinaron durante el proyecto. Con los experimentos realizados, y la ayuda de las nuevas tecnologías, conceptos astronómicos fueron presentados a los estudiantes de 4to y 5to año de la educación básica de una escuela municipal de Campos dos Goytacazes (RJ). Después de las presentaciones nuevos datos fueran colectados y se han llevado a cabo con el fin de verificar el nivel de aprendizaje alcanzado y se observó que el método utilizado fue una herramienta importante para ayudar al proceso de enseñanza y aprendizaje. El proyecto logró resultados satisfactorios. Neste trabalho será apresentado o desenvolvimento de recursos pedagógicos para a apresentação de conceitos de astronomia nas séries iniciais do ensino fundamental. Este material é composto por apresentações realizadas com o uso de novos recursos tecnológicos, pela fabricação de experimentos e a discussão de curiosidades relativas a esta área de conhecimento. Os experimentos foram construídos com material de baixo custo com o objetivo de permitir que os alunos envolvidos pudessem refazê-los em outras ocasiões. O material apresentado busca enfatizar a relação entre a astronomia e o cotidiano dos alunos. A inclusão da astronomia no ensino fundamental e uma forma de demonstrar aoestudante como esta área está presente de forma ativa em seu cotidiano. As turmas envolvidas no projeto participaram de uma pesquisa com o objetivo de obter dados relativos ao conhecimento prévio que possuíam sobre os tópicos de astronomia que foram considerados no decorrer do projeto. Com os experimentos

  18. Essays on Eclipses, Transits and Occultations as Teaching Tools in the Introductory Astronomy College Course. (Spanish Title: Ensayos sobre Eclipses, Tránsitos y Ocultaciones Como Herramientas de Enseñanza en el Curso Universitario Introductorio a la Astronomía.) Ensaios sobre Eclipses, Trânsitos e Ocultações Como Ferramentas de Ensino em um Curso Universitário Introdutório de Astromomia

    NASA Astrophysics Data System (ADS)

    Dcruz, Noella L.

    2014-07-01

    estudiantes que escribieran dos ensayos cortos de tres que se proponían. Los ensayos contenían partes descriptivas y conceptuales. Los mismos estaban destinados a servir como herramientas de enseñanza. 62% de los 106 ensayos de 55 estudiantes obtuvo grados A, B o C. 21% de los 47 encuestados que respondieron al cuestionario posterior consideró que los ensayos aumentaron su interés por la astronomía. 49% de los encuestados consideró que los ensayos no eran educacionalmente útiles y que no deben ser propuestos de nuevo. Las respuestas escritas más comunes a nuestra encuesta indicaran que los estudiantes necesitan más orientación y una mejor preparación en la redacción de ensayos exitosos. Dado que los estudiantes encontraron las piezas conceptuales de los ensayos difíciles, en el futuro vamos a ofrecer actividades pertinentes antes de los plazos de redacción para ayudar a los estudiantes a crear ensayos de mayor calidad. Nós ocasionalmente incluímos projetos em nosso curso universitário introdutório centrado no aluno para permitir aos estudantes que pertencem às carreiras não científicas explorar alguns conceitos astronômicos em mais detalhes do que o normal. Tais projetos também enfatizam eventos astronômicos em curso ou futuros. Esperamos que os alunos se sintam mais interessados na astronomia através de projetos ligados a eventos astronômicos. No termo de Primavera de 2012 (EUA), propomos ensaios curtos focados em eclipses, trânsitos e ocultações para promover o raro trânsito de Vênus que ocorreu no dia 5 de junho de 2012. Pedimos aos alunos que escrevessem dois ensaios curtos dentre três que foram propostos. Os ensaios continham partes descritivas e conceituais. Eles foram feitos para servir como ferramentas de ensino. 62% de 106 ensaios de 55 alunos ganhou graus A, B ou C. 21% dos 47 entrevistados que responderam ao levantamento posterior sentiu que os ensaios aumentaram seu interesse na astronomia. 49% dos inquiridos consideraram que os

  19. Bromazepam determination in human plasma by high-performance liquid chromatography coupled to tandem mass spectrometry: a highly sensitive and specific tool for bioequivalence studies.

    PubMed

    Laurito, Tiago L; Mendes, Gustavo D; Santagada, Vincenzo; Caliendo, Giuseppe; de Moraes, Maria Elisabete A; De Nucci, Gilberto

    2004-02-01

    A rapid, sensitive and specific method to quantify bromazepam in human plasma using diazepam as the internal standard (IS) is described. The analyte and the IS were extracted from plasma by liquid-liquid extraction using diethyl ether-hexane (80 : 20, v/v). The extracts were analyzed by high-performance liquid chromatography (HPLC) coupled to electrospray tandem mass spectrometry (MS/MS). Chromatography was performed isocratically on a Genesis C(18) analytical column (100 x 2.1 mm i.d., film thickness 4 microm). The method had a chromatographic run time of 5.0 min and a linear calibration curve over the range 5.0-150 ng ml(-1) (r(2) > 0.9952). The limit of quantification was 5 ng ml(-1). This HPLC/MS/MS procedure was used to assess the bioequivalence of two bromazepam 6 mg tablet formulations (bromazepam from Medley SA Indústria Farmacêutica as the test formulation and Lexotan from Produtos Roche Químico e Farmacêutico SA as the reference formulation). A single 6 mg dose of each formulation was administered to 24 healthy volunteers (12 males and 12 females). The study was conducted using an open, randomized, two-period crossover design with a 3 week washout interval. Since the 90% CI for C(max), AUC(last), AUC(0-240 h) (linear) and AUC((0- infinity )) ratios were all inside the 80-125% interval proposed by the US Food and Drug Administration, it was concluded that the bromazepam formulation from Medley is bioequivalent to the Lexotan formulation for both the rate and the extent of absorption. PMID:14991686

  20. Embedded Analytical Solutions Improve Accuracy in Convolution-Based Particle Tracking Models using Python

    NASA Astrophysics Data System (ADS)

    Starn, J. J.

    2013-12-01

    Particle tracking often is used to generate particle-age distributions that are used as impulse-response functions in convolution. A typical application is to produce groundwater solute breakthrough curves (BTC) at endpoint receptors such as pumping wells or streams. The commonly used semi-analytical particle-tracking algorithm based on the assumption of linear velocity gradients between opposing cell faces is computationally very fast when used in combination with finite-difference models. However, large gradients near pumping wells in regional-scale groundwater-flow models often are not well represented because of cell-size limitations. This leads to inaccurate velocity fields, especially at weak sinks. Accurate analytical solutions for velocity near a pumping well are available, and various boundary conditions can be imposed using image-well theory. Python can be used to embed these solutions into existing semi-analytical particle-tracking codes, thereby maintaining the integrity and quality-assurance of the existing code. Python (and associated scientific computational packages NumPy, SciPy, and Matplotlib) is an effective tool because of its wide ranging capability. Python text processing allows complex and database-like manipulation of model input and output files, including binary and HDF5 files. High-level functions in the language include ODE solvers to solve first-order particle-location ODEs, Gaussian kernel density estimation to compute smooth particle-age distributions, and convolution. The highly vectorized nature of NumPy arrays and functions minimizes the need for computationally expensive loops. A modular Python code base has been developed to compute BTCs using embedded analytical solutions at pumping wells based on an existing well-documented finite-difference groundwater-flow simulation code (MODFLOW) and a semi-analytical particle-tracking code (MODPATH). The Python code base is tested by comparing BTCs with highly discretized synthetic steady

  1. 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

  2. Linear electronic transport in dense plasmas. II. Finite degeneracy contributions

    NASA Astrophysics Data System (ADS)

    Léger, D.; Deutsch, C.

    1991-06-01

    exactes pour les corrections mentionnées sont dérivées jusqu'à l'odre α2. Leur traduction numérique est finalement appliquée au cas des mélanges binaires proton-helium complètement ionisés, d'intérêt Astrophysique. Le lien entre le présent formalisme, et notamment ses implications numériques, et d'autres résultats antérieurs, fait aussi l'objet d'un examen attentif.

  3. Comparative analysis of several sediment transport formulations applied to dam-break flows over erodible beds

    NASA Astrophysics Data System (ADS)

    Cea, Luis; Bladé, Ernest; Corestein, Georgina; Fraga, Ignacio; Espinal, Marc; Puertas, Jerónimo

    2014-05-01

    studied. The first one is the benchmark case presented in Soares-Frazao et al. (2012), and consists in an instanteneous dam-break flow over a sand bed. The second one corresponds to the experimental studies performed at the Engineering Faculty of the UNAM (Fuentes-Mariles et al. (2010)) and consists in the erosion of a volcanic sand dike by an overtopping flow. In both cases experimental measurements of water depth and bed evolution are available to evaluate the performance of different sediment transport formulations. A sensitivity analysis to the physical properties of the bed material (grain density and size) is also presented for each formulation, in order to analyse to which degree the properties of the bed material need to be defined in the numerical model. References Bladé, E., Cea, L., Corestein, G., Escolano, E., Puertas, J., Vázquez-Cendón, M.E., Dolz, J., Coll, A. (2014). Iber: herramienta de simulación numérica del flujo en ríos. Revista Internacional de Métodos Numéricos para Cálculo y Diseño en Ingeniería, Vol.30(1), pp.1-10 Fuentes-Mariles, Ó. A., Cruz-Gerón, J. A., Rivera-Díaz, C., Luna-Cruz, F., and González-Prado, J. (2010). "Caracterización Experimental de Ruptura de Diques." XXIV Congreso Latinoamericano de Hidráulica Soares-Frazão et al. (2012). Dambreak flows over mobile beds: experiments and benchmark tests for numerical models. Journal of Hydraulic Research, Vol.50(4), pp.364-375

  4. Contribution à l'Etude des Disques Planétaires et Protoplanétaires Perturbés

    NASA Astrophysics Data System (ADS)

    Charnoz, Sébastien

    2000-11-01

    Nous avons étudié plusieurs aspects dynamiques et photométriques des disques planétaires et protoplanétaires perturbés. Dans la première partie, à l'aide de modèles numériques simples, nous avons étudié l'eacute;volution thermodynamique d'un disque protoplanétaire composé de planétésimaux subissant des collisions physiques inélastiques, au voisinage d'un embryon de planète géante (~ 15 masses terrestres). Dès l'apparition de l'embryon planétaire, un transfert de chaleur se met en place dans le disque, augmentant fortement les vitesses relatives dans ce dernier, sur une région s'étendant sur plusieurs unités astronomiques. L'évolution de ce mécanisme transitoire a été étudiée sur des temps longs (un million d'années) et pour une vaste gamme demasses du perturbateur. C'est un mécanisme générique qui pourrait avoir profondément affecté le processus de formation des planètes, aussi bien telluriques que géantes. Les conséquences sur la formation de la Ceinture d'Astéroïdes sont discutées, ainsi que l'effet possible de la fragmentation des planétésimaux, qui n'a pu être prise en compte dans le modèle numérique. La deuxième partie de cette thèse est une étude photométrique de l'anneau F de Saturne, qui est perturbé par ses deux satellites gardiens. En étudiant un ensemble de plus de 300 images prises au télescope CFH, nous avons mis en évidence la présence de structures étendues, dont l'origine est toujours mal connue. En combinant nos données et celles du télescope spatial, nous avons établi avec précision une nouvelle orbite de l'anneau F, à 140060+/-60 km, soit plus faible de 150 km par rapport à celle déterminée en 1980-81. Cecipourrait être le signe qu'une important restructuration radiale de l'anneau F a dû avoir lieu entre 1980 et 1995.

  5. TRANSPLANTATION EN MASSE DES ORGANES ABDOMINAUX

    PubMed Central

    STARZL, T.

    2010-01-01

    Les transplantations multi-organes, comprenant les blocs foie-duodénum-pancréas, foie-estomac-duodénum-pancréas, et foie-intestin sont réalisées avec un succés croissant Ces techniques et leurs combinaisons variées de transplantation monobloc ne sont pas de pratique courante. Les techniques de prélévement, de conservation et de soins post-opératoires sont décrites pour la transplantation multi-organes compléte ainsi que pour les variantes incomplétes. Le probléme particulier à ce type de transplantation est celui de la transplantation intestinale, c’est-à-dire la transplantation d’un organe à composante lymphoréticulaire complexe ce qui peut provoquer un syndrome greffon contre hôte. Par erreur de conception, et un peu par esprit de systéme, les efforts par le passé étaient dirigés sur la modification et la destruction des systémes lymphoréticulaires grâce au traitement préalable du donneur ou des organes transplantés, par médicaments, radiation ou autres moyens. Actuellement, I’idée directrice est de garder intacte les systémes lymphoréticulaires qui deviennent alors le site d’une circulation à double sens aprés transplantation. Avec la puissante immunodépression que fournit le FK 506, les cellules lymphoréticulaires du donneur peuvent circuler chez le receveur sans créer de syndrome du greffon contre hôte clinique et les cellules de la greffe s’assimilent à celles du receveur (chimérisme local) sans provoquer de rejet. Même si I’on évite le rejet ou le syndrome greffon contre hôte, il existe, à côté de ces entités, des relations métaboliques entre les organes greffés ainsi qu’entre les organes greffés et les viscéres du receveur laissés en place, qui peuvent influencer I’avenir soit des organes greffés, soit des organes laissés en place. Parmi les échanges métaboliques les mieux connus actuellement, il y a les facteurs splanchniques hépatotrophes endogénes, dont I’insuline est la mieux

  6. Temporal evolution of a Current Sheet with Initial Finite Perturbations by Three-dimensional MHD Simulations

    NASA Astrophysics Data System (ADS)

    Yokoyama, Takaaki

    Temporal evolution of a current sheet with initial perturbations is studied by using the threedimensional resistive magnetohydrodynamic (MHD) simulations. The magnetic reconnection is considered to be the main engine of the energy rele ase in solar flares. The structure of the diffusion region is, however, not stil l understood under the circumstances with enormously large magnetic Reynolds num ber as the solar corona. In particular, the relationship between the flare's macroscopic physics and the microscopic ones are unclear. It is generally believed that the MHD turbulence s hould play a role in the intermediate scale. The initial current sheet is in an approximately hydromagnetic equilibrium with anti-parallel magnetic field in the y-direction. We imposed a finite-amplitude perturbations (=50ee what happens. Special attention is paid upon the evolution of a three-dimens ional structure in the direction along the initial electric current (z-direction ). Our preliminary results are as follows: (1) In the early phase of the evolut ion, high wavenumber modes in the z-direction are excited and grow. (2) Many "X "-type neutral points (lines) are generated along the magnetic neutral line (pla ne) in the current sheet. When they evolve into the non-linear phase, three-dime nsional structures in the z-direction also evolve. The spatial scale in the z-di rection seems to be almost comparable with that in the xy-plane. (3) The energy release rate is reduced in case of 3D simulations compared with 2D ones probably because of the reduction of the inflow cross sections by the formation of pattc hy structures in the current sheet.

  7. La estructura dinámica del cinturón de Kuiper interior y la formación de Urano y Neptuno

    NASA Astrophysics Data System (ADS)

    Melita, M. D.; Brunini, A.

    De acuerdo a los más recientes estudios sobre la formación de Urano y Neptuno, éstos podrían haber sufrido una importante migración radial hacia el exterior, debido al intercambio de momento angular con los planetesimales presentes en esa región durante las últimas etapas de la formación del Sistema Solar. Esta migración radial habría tenido importantes consecuencias sobre la presente estructura dinámica del cinturón cometario de Kuiper. Tal como lo reflejan las observaciones, la mayoría de los cuerpos observados en el cinturón de Kuiper se encuentran en resonancia de movimientos medios exteriores con Neptuno, hecho que también se refleja en la presente órbita de Plutón. En el presente trabajo se estudia tanto numérica como analíticamente la influencia de la variación de las masas de Urano y Neptuno durante el proceso de migración sobre las probabilidades de captura en algunas de las resonancias exteriores de Neptuno. Se estudia también la influencia de encuentros gravitacionales mutuos sobre la estabilidad de las órbitas resonantes. Este estudio ofrece argumentos de plausibilidad para explicar por qué ninguno de los objetos descubiertos en el cinturón de Kuiper se encontraría en la resonancia 2:1.

  8. Mining industry enters a new era of AIDS prevention. Eye witness: South Africa.

    PubMed

    Heywood, M

    1996-06-01

    Miners in South Africa are now more at risk of contracting human immunodeficiency virus (HIV) than of being in a mining accident. Some epidemiologists predict that the mines could be experiencing 12,000-40,000 deaths related to acquired immunodeficiency syndrome (AIDS) by 2010. In 1986, HIV infection among mineworkers was 1/3500. Gencor medical personnel now estimate that 20% of the company's employees are HIV-positive and that 30 workers are dying of AIDS each month. In August 1995, the Chamber of Mines, the World Bank, and the World Health Organization (WHO) held a seminar to discuss the potential impact of the epidemic; it was followed by a workshop, "Research Needs and Priorities for the Management of HIV/AIDS Transmission in the Mining Industry," which was organized by the Epidemiology Unit in Johannesburg. Although the seminar invited no people with HIV, mineworkers, or government representatives, the workshop did; however, no representatives of the National Union of Mineworkers (NUM), or the Chamber of Mines, came. In spite of this, a new, holistic approach to HIV-prevention is emerging in the mining sector. A decade of education has not changed risk behaviors, so more emphasis will be placed on outreach programs to the communities, including the prostitutes, with which the miners interact, and on treatment of sexually transmitted diseases (STDs). The mining sector is in a unique position to fight HIV because it already has an extensive medical infrastructure with the capacity to treat STDs effectively, a unionized workforce to provide a pool of peer educators, and recruitment agencies to extend HIV-prevention into rural areas. Obstacles to effective HIV/AIDS education include discrimination (Workers are tested for HIV without consent, and dismissed, if found to be positive, regardless of union agreements.); a psychological factor that is related to underground work and produces recklessness; poor living conditions; and illiteracy. Many myths remain about

  9. Aster Global dem Version 3, and New Aster Water Body Dataset

    NASA Astrophysics Data System (ADS)

    Abrams, M.

    2016-06-01

    In 2016, the US/Japan ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) project released Version 3 of the Global DEM (GDEM). This 30 m DEM covers the earth's surface from 82N to 82S, and improves on two earlier versions by correcting some artefacts and filling in areas of missing DEMs by the acquisition of additional data. The GDEM was produced by stereocorrelation of 2 million ASTER scenes and operation on a pixel-by-pixel basis: cloud screening; stacking data from overlapping scenes; removing outlier values, and averaging elevation values. As previously, the GDEM is packaged in ~ 23,000 1 x 1 degree tiles. Each tile has a DEM file, and a NUM file reporting the number of scenes used for each pixel, and identifying the source for fill-in data (where persistent clouds prevented computation of an elevation value). An additional data set was concurrently produced and released: the ASTER Water Body Dataset (AWBD). This is a 30 m raster product, which encodes every pixel as either lake, river, or ocean; thus providing a global inland and shore-line water body mask. Water was identified through spectral analysis algorithms and manual editing. This product was evaluated against the Shuttle Water Body Dataset (SWBD), and the Landsat-based Global Inland Water (GIW) product. The SWBD only covers the earth between about 60 degrees north and south, so it is not a global product. The GIW only delineates inland water bodies, and does not deal with ocean coastlines. All products are at 30 m postings.

  10. ObsPy: A Python Toolbox for Seismology - Recent Developments and Applications

    NASA Astrophysics Data System (ADS)

    Megies, T.; Krischer, L.; Barsch, R.; Sales de Andrade, E.; Beyreuther, M.

    2014-12-01

    ObsPy (http://www.obspy.org) is a community-driven, open-source project dedicated to building a bridge for seismology into the scientific Python ecosystem. It offersa) read and write support for essentially all commonly used waveform, station, and event metadata file formats with a unified interface,b) a comprehensive signal processing toolbox tuned to the needs of seismologists,c) integrated access to all large data centers, web services and databases, andd) convenient wrappers to legacy codes like libtau and evalresp.Python, currently the most popular language for teaching introductory computer science courses at top-ranked U.S. departments, is a full-blown programming language with the flexibility of an interactive scripting language. Its extensive standard library and large variety of freely available high quality scientific modules cover most needs in developing scientific processing workflows. Together with packages like NumPy, SciPy, Matplotlib, IPython, Pandas, lxml, and PyQt, ObsPy enables the construction of complete workflows in Python. These vary from reading locally stored data or requesting data from one or more different data centers through to signal analysis and data processing and on to visualizations in GUI and web applications, output of modified/derived data and the creation of publication-quality figures.ObsPy enjoys a large world-wide rate of adoption in the community. Applications successfully using it include time-dependent and rotational seismology, big data processing, event relocations, and synthetic studies about attenuation kernels and full-waveform inversions to name a few examples. All functionality is extensively documented and the ObsPy tutorial and gallery give a good impression of the wide range of possible use cases.We will present the basic features of ObsPy, new developments and applications, and a roadmap for the near future and discuss the sustainability of our open-source development model.

  11. DVS-SOFTWARE: An Effective Tool for Applying Highly Parallelized Hardware To Computational Geophysics

    NASA Astrophysics Data System (ADS)

    Herrera, I.; Herrera, G. S.

    2015-12-01

    Most geophysical systems are macroscopic physical systems. The behavior prediction of such systems is carried out by means of computational models whose basic models are partial differential equations (PDEs) [1]. Due to the enormous size of the discretized version of such PDEs it is necessary to apply highly parallelized super-computers. For them, at present, the most efficient software is based on non-overlapping domain decomposition methods (DDM). However, a limiting feature of the present state-of-the-art techniques is due to the kind of discretizations used in them. Recently, I. Herrera and co-workers using 'non-overlapping discretizations' have produced the DVS-Software which overcomes this limitation [2]. The DVS-software can be applied to a great variety of geophysical problems and achieves very high parallel efficiencies (90%, or so [3]). It is therefore very suitable for effectively applying the most advanced parallel supercomputers available at present. In a parallel talk, in this AGU Fall Meeting, Graciela Herrera Z. will present how this software is being applied to advance MOD-FLOW. Key Words: Parallel Software for Geophysics, High Performance Computing, HPC, Parallel Computing, Domain Decomposition Methods (DDM)REFERENCES [1]. Herrera Ismael and George F. Pinder, Mathematical Modelling in Science and Engineering: An axiomatic approach", John Wiley, 243p., 2012. [2]. Herrera, I., de la Cruz L.M. and Rosas-Medina A. "Non Overlapping Discretization Methods for Partial, Differential Equations". NUMER METH PART D E, 30: 1427-1454, 2014, DOI 10.1002/num 21852. (Open source) [3]. Herrera, I., & Contreras Iván "An Innovative Tool for Effectively Applying Highly Parallelized Software To Problems of Elasticity". Geofísica Internacional, 2015 (In press)

  12. ObsPy: A Python Toolbox for Seismology and Seismological Observatories

    NASA Astrophysics Data System (ADS)

    Krischer, Lion; Megies, Tobias; Barsch, Robert; Beyreuther, Moritz; Wassermann, Joachim

    2013-04-01

    Python combines the power of a full-blown programming language with the flexibility and accessibility of an interactive scripting language. Its extensive standard library and large variety of freely available high quality scientific modules cover most needs in developing scientific processing workflows. ObsPy extends Python's capabilities to fit the specific needs that arise when working with seismological data. It a) comes with a continuously growing signal processing toolbox that covers most tasks common in seismological analysis, b) provides read and write support for many common waveform, station and event metadata formats and c) enables access to various data centers, webservices and databases to retrieve waveform data and station/event metadata. In combination with mature and free Python packages like NumPy, SciPy, Matplotlib, IPython and PyQt, ObsPy makes it possible to develop complete workflows in Python, ranging from reading locally stored data or requesting data from one or more different data centers via signal analysis and data processing to visualization in GUI and web applications, output of modified/derived data and the creation of publication-quality figures. All functionality is extensively documented and the ObsPy Tutorial and Gallery give a good impression of the wide range of possible use cases. ObsPy is tested and running on Linux, OS X and Windows and comes with installation routines for these systems. ObsPy is developed in a test-driven approach and is available under the GPL/LGPLv3 open source licences. Users are welcome to request help, report bugs, propose enhancements or contribute code via either the user mailing list or the project page on GitHub.

  13. Discriminação de núcleos primários no Observatório Auger

    NASA Astrophysics Data System (ADS)

    Tiba, A. K. O.; Medina Tanco, G. A.; Sciutto, S. J.

    2003-08-01

    A identidade das partículas, com energias E > 10EeV, que geram chuveiros atmosféricos extensivos (CAE) na atmosfera terrestre é um incógnita. Existem diferenças sutis, mas apreciáveis entre chuveiros gerados por fótons e por núcleos, como temos demonstrado em trabalho recente. Porém entre os núcleos, as diferenças são tão sutis, que a baixa estatística e incertezas experimentais têm limitado fortemente sua diferenciação até o presente. Tal discriminação precede qualquer aplicação astrofísica mas sofisticada de raios cósmicos de ultra-alta energia. Apresentamos aqui os resultados do desenvolvimento de novos métodos de diagnóstico para a análise de CAEs com aplicação específica ao Experimento Pierre Auger. Redes neurais, combinadas com simulações numéricas detalhadas de CAEs e dos dois tipos diferentes de detectores (Cherenkov em água e de fluorescência atmosférica) presentes no experimento são empregados na análise. Mostraremos a capacidade dos métodos de diagnóstico desenvolvidos, para a discriminação de diversas distribuições hipotéticas de massa-anergia.

  14. MEG and EEG data analysis with MNE-Python

    PubMed Central

    Gramfort, Alexandre; Luessi, Martin; Larson, Eric; Engemann, Denis A.; Strohmeier, Daniel; Brodbeck, Christian; Goj, Roman; Jas, Mainak; Brooks, Teon; Parkkonen, Lauri; Hämäläinen, Matti

    2013-01-01

    Magnetoencephalography and electroencephalography (M/EEG) measure the weak electromagnetic signals generated by neuronal activity in the brain. Using these signals to characterize and locate neural activation in the brain is a challenge that requires expertise in physics, signal processing, statistics, and numerical methods. As part of the MNE software suite, MNE-Python is an open-source software package that addresses this challenge by providing state-of-the-art algorithms implemented in Python that cover multiple methods of data preprocessing, source localization, statistical analysis, and estimation of functional connectivity between distributed brain regions. All algorithms and utility functions are implemented in a consistent manner with well-documented interfaces, enabling users to create M/EEG data analysis pipelines by writing Python scripts. Moreover, MNE-Python is tightly integrated with the core Python libraries for scientific comptutation (NumPy, SciPy) and visualization (matplotlib and Mayavi), as well as the greater neuroimaging ecosystem in Python via the Nibabel package. The code is provided under the new BSD license allowing code reuse, even in commercial products. Although MNE-Python has only been under heavy development for a couple of years, it has rapidly evolved with expanded analysis capabilities and pedagogical tutorials because multiple labs have collaborated during code development to help share best practices. MNE-Python also gives easy access to preprocessed datasets, helping users to get started quickly and facilitating reproducibility of methods by other researchers. Full documentation, including dozens of examples, is available at http://martinos.org/mne. PMID:24431986

  15. Curcumin Inhibits The Adverse Effects of Sodium Arsenite in Mouse Epididymal Sperm

    PubMed Central

    Momeni, Hamid Reza; Eskandari, Najmeh

    2016-01-01

    Background The aim of this study was to investigate the effects of curcumin on epididy- mal sperm parameters in adult male Navel Medical Research Institute (NMRI) mice ex- posed to sodium arsenite. Materials and Methods In this experimental study, we divided the animals into four groups: control, sodium arsenite (5 mg/kg), curcumin (100 mg/kg) and curcumin+sodium arsenite. Exposures were performed by intraperitoneal injections for a 5-week period. After the exposure period, we recorded the animals’ body and left testes weights. The left caudal epididymis was used to count the sperm number and analyze motility, viability, morphological abnormalities, acrosome reaction, DNA integrity, and histone-protamine replacement in the spermatozoa. One-way analysis of variance (ANOVA) followed by the Tukey’s test was used to assess the statistical significance of the data with SPSS 16.0. P<0.05 was considered significant. Results Mice exposed to sodium arsenite showed a significant decrease in the num- ber, motility, viability, normal sperm morphology and acrosome integrity of spermato- zoa compared to the control group. In the curcumin+sodium arsenite group, curcumin significantly reversed these adverse effects to the point where they approximated the control. In addition, the application of curcumin alone had no significant difference in these parameters compared to the control and curcumin+sodium arsenite groups. However, we observed no significant differences in the body and the testis weight as well as the DNA integrity and histone-protamine replacement in the spermatozoa of the four groups. Conclusion Curcumin compensated for the toxic effects of sodium arsenite on a number of sperm parameters in adult mice. PMID:27441059

  16. On sopro do magnetar

    NASA Astrophysics Data System (ADS)

    Allen, M. P.; Horvath, J. E.

    2003-08-01

    Magnetares sao estrelas de nêutrons com campos magnéticos acima do limiar quântico de 4,4´1013 G. Por causa desse intenso campo magnético, que exige período de rotação inicial da ordem de 1 ms, o torque eletromagnético é capaz de injetar 2´1052 erg, em menos de um dia, no Remanescente de Supernova (RSN) formado por ocasião da formação do magnetar. A energia injetada acelera a expansão do RSN, de modo que estimativas de idade do RSN feitas sem considerar a injeção de energia superestimarão a idade verdadeira. Além do cenário usual de formação de magnetares em colapsos gravitacionais de estrelas massivas, estudamos a possibilidade de formação dos mesmos através do Colapso Induzido por Acresção em anãs brancas. Estudamos, através de simulação numérica unidimensional, com diversas massas ejetadas e diversas densidades de meio interestelar local, as associações propostas entre candidatos a magnetar e RSNs, incluindo a injeção de energia. Concluímos que aproximadamente metade delas podem ser verdadeiras, e determinamos a faixa de velocidades e idades possíveis de cada associação. As incertezas observacionais a respeito do tamanho e densidade do meio interestelar local limitam a acurácia da análise.

  17. Steam tables for pure water as an ActiveX component in Visual Basic 6.0

    NASA Astrophysics Data System (ADS)

    Verma, Mahendra P.

    2003-11-01

    The IAPWS-95 formulation for the thermodynamic properties of pure water was implemented as an ActiveX component ( SteamTables) in Visual Basic 6.0. For input parameters as temperature ( T=190-2000 K) and pressure ( P=3.23×10 -8-10,000 MPa) the program SteamTables calculates the following properties: volume ( V), density ( D), compressibility factor ( Z0), internal energy ( U), enthalpy ( H), Gibbs free energy ( G), Helmholtz free energy ( A), entropy ( S), heat capacity at constant pressure ( Cp), heat capacity at constant volume ( Cv), coefficient of thermal expansion ( CTE), isothermal compressibility ( Ziso), velocity of sound ( VelS), partial derivative of P with T at constant V (d Pd T), partial derivative of T with V at constant P (d Td V), partial derivative of V with P at constant T (d Vd P), Joule-Thomson coefficient ( JTC), isothermal throttling coefficient ( IJTC), viscosity ( Vis), thermal conductivity ( ThrmCond), surface tension ( SurfTen), Prandtl number ( PrdNum) and dielectric constant ( DielCons) for the liquid and vapor phases of pure water. It also calculates T as a function of P (or P as a function of T) along the sublimation, saturation and critical isochor curves, depending on the values of P (or T). The SteamTables can be incorporated in a program in any computer language, which supports object link embedding (OLE) in the Windows environment. An application of SteamTables is illustrated in a program in Visual Basic 6.0 to tabulate the values of the thermodynamic properties of water and vapor. Similarly, four functions, Temperature(Press), Pressure(Temp), State(Temp, Press) and WtrStmTbls(Temp, Press, Nphs, Nprop), where Temp, Press, Nphs and Nprop are temperature, pressure, phase number and property number, respectively, are written in Visual Basic for Applications (VBA) to use the SteamTables in a workbook in MS-Excel.

  18. A Bama Minipig Model of Laryngopharyngeal Reflux and the Change of Laryngopharyngeal Mucosal Ultrastructure

    PubMed Central

    Feng, Guijian; Zhang, Zhenyu; Diao, Chunyan; Jiang, Jun; Zheng, Shuying; Liu, Yulan

    2015-01-01

    Background/Aims To establish an animal model of laryngopharyngeal reflux (LPR) and study the effect of LPR on the laryngopharyngeal mucosal ultrastructure. Methods Ten Bama minipigs were randomly divided into control group and stent group. Every pig underwent endoscope, and baseline pH was monitored for 4 hours at laryngopharynx and distal esophagus, then specimens from laryngopharyngeal mucosa were biopsied. For the control group, these procedures were repeated on the 14th day. In the stent group, a custom-designed esophageal stent suit was implanted into esophagus, laryngopharyngeal and distal esophageal pH monitoring lasted for 2 hours, then stent suit was removed 3 days later. At last, the same procedures were done as the control group on the 14th day. Specimens were observed under transmission electron microscope to measure the intercellular space and desmosome number. Results In the control group, there was no laryngopharyngeal reflux on the first day and 14th day. Before the stent was implanted, there was also no laryngopharyngeal reflux in the stent group. In both 2 hours and 14 days after stent implantation, the num -ber of reflux, reflux time, and percentage time of pH < 4.0 were significantly increased (P < 0.05) in the stent group. There was no difference in intercellular space and desmosomes in the control group between baseline and 14th day. In the stent group, intercellular space of laryngopharyngeal mucosa was significantly increased (0.37 μm vs 0.96 μm, P = 0.008), and the number of desmosomes was significantly decreased (20.25 vs 9.5, P = 0.003). Conclusions A Bama minipig model of LPR was established by implanting a custom-designed stent suit. LPR might destroy the laryngophar yngeal mucosal barrier. PMID:25843072

  19. Combination of Vandetanib, Radiotherapy, and Irinotecan in the LoVo Human Colorectal Cancer Xenograft Model

    SciTech Connect

    Wachsberger, Phyllis; Burd, Randy; Ryan, Anderson; Daskalakis, Constantine; Dicker, Adam P.

    2009-11-01

    Purpose: The tumor growth kinetics of the human LoVo colorectal xenograft model was assessed in response to vandetanib, an orally available receptor tyrosine kinase inhibitor, radiotherapy (RT), or irinotecan (CPT-11), as single therapies and in combination. Methods and Materials: LoVo cells were injected subcutaneously into the right hind limb (5x10{sup 6} cells in 100muL phosphate-buffered saline) of athymic NCR NUM mice and tumors were grown to a volume of 200-300 mm{sup 3} before treatment. Vandetanib was administered at 50 mg/kg daily orally for 14 days starting on Day 1. RT was given as three fractions (3x3 Gy) on Days 1, 2, and 3. CPT-11 was given at 15 mg/kg intraperitoneally on Days 1 and 3. Tumor volumes were measured on a daily basis and calculated by measuring tumor diameters with digital calipers in two orthogonal dimensions. Results: All three single treatments (vandetanib, CPT-11, and radiation) significantly slowed LoVo colorectal tumor growth. Vandetanib significantly increased the antitumor effects of CPT-11 and radiation when given in combination with either of these treatments. These treatment combinations resulted in a slow tumor growth rate during the 2 weeks of vandetanib administration. The triple combination of vandetanib, CPT-11, and radiation produced the most marked improvement in response as observed by measurable shrinkage of tumors during the first week of treatment. Conclusions: The tumor growth delay kinetics observed in this study of the LoVo colorectal model suggest concurrent and sustained post-sequencing of vandetanib with cytotoxic therapy may be beneficial in tumors of this type.

  20. Dynamique sub-picoseconde de l'interaction laser de puissance agrégats de gaz rare: emission intense de rayons X et production d'ions multichargés

    NASA Astrophysics Data System (ADS)

    Prigent, C.; Adoui, L.; Dreuil, S.; Gauthier, J. C.; Gobert, O.; Lamour, E.; Meynadier, P.; Normand, D.; Perdrix, M.; Rozet, J.-P.; Vernhet, D.

    2003-06-01

    Lors de campagnes d'expériences réalisées sur le Laser Ultra Court Accordable du CEA/Saclay, nous avons étudié le rayonnement X, tant qualitativement (spectroscopie et énergie moyenne des photons) que quantitativement (taux absolus et lois d'évolution), émis lors de l'interaction d'un jet effusif d'agrégats de gaz rare (Ar, Kr, Xe comprenant entre 10^4 et 10^6 atome/agrégat) avec un laser femtoseconde de puissance (éclairement jusqu'à quelques 10^{17} W/cm^2). Les résultats présentés dans ce manuscrit sont uniquement dédiés aux agrégats d'Ar pour lesquels nous avons observé un rayonnement X issu d'ions fortement multichargés (jusqu'à l'Ar^{16+}) présentant des lacunes en couches K. La technique de spectroscopie X utilisée a permis de déterminer pour la première fois des taux absolus ainsi que les lois d'évolution de l'émission X en fonction de l'ensemble des paramètres gouvernant l'interaction (intensité, polarisation, longueur d'onde et durée du pulse laser aussi bien que taille, densité et numéro atomique des agrégats).

  1. MEG and EEG data analysis with MNE-Python.

    PubMed

    Gramfort, Alexandre; Luessi, Martin; Larson, Eric; Engemann, Denis A; Strohmeier, Daniel; Brodbeck, Christian; Goj, Roman; Jas, Mainak; Brooks, Teon; Parkkonen, Lauri; Hämäläinen, Matti

    2013-12-26

    Magnetoencephalography and electroencephalography (M/EEG) measure the weak electromagnetic signals generated by neuronal activity in the brain. Using these signals to characterize and locate neural activation in the brain is a challenge that requires expertise in physics, signal processing, statistics, and numerical methods. As part of the MNE software suite, MNE-Python is an open-source software package that addresses this challenge by providing state-of-the-art algorithms implemented in Python that cover multiple methods of data preprocessing, source localization, statistical analysis, and estimation of functional connectivity between distributed brain regions. All algorithms and utility functions are implemented in a consistent manner with well-documented interfaces, enabling users to create M/EEG data analysis pipelines by writing Python scripts. Moreover, MNE-Python is tightly integrated with the core Python libraries for scientific comptutation (NumPy, SciPy) and visualization (matplotlib and Mayavi), as well as the greater neuroimaging ecosystem in Python via the Nibabel package. The code is provided under the new BSD license allowing code reuse, even in commercial products. Although MNE-Python has only been under heavy development for a couple of years, it has rapidly evolved with expanded analysis capabilities and pedagogical tutorials because multiple labs have collaborated during code development to help share best practices. MNE-Python also gives easy access to preprocessed datasets, helping users to get started quickly and facilitating reproducibility of methods by other researchers. Full documentation, including dozens of examples, is available at http://martinos.org/mne. PMID:24431986

  2. Thrombasthénie de Glanzmann: à propos de 11 cas

    PubMed Central

    Mukendi, Jean-Louis Ntumba; Benkirane, Souad; Masrar, Azlarab

    2015-01-01

    Introduction La thrombasthénie de Glanzmann est une pathologie hémorragique héréditaire rare due à une déficience ou un dysfonctionnement du complexe glycoprotéique IIb/IIIa de la membrane plaquettaire. Le but de notre étude est de décrire les caractéristiques démographiques, cliniques et biologiques d'une série de patients atteints de thrombasthénie de Glanzmann. Méthodes C'est une étude portant sur tous les patients atteints de thrombasthénie de Glanzmann diagnostiqués au Laboratoire Central d'Hématologie du Centre Hospitalier Ibn Sina de Rabat au Maroc pendant la période allant du 1er mars 2011 au 31 mars 2013, soit 25 mois. Après avoir recueilli les données épidémiologiques et cliniques de nos patients, nous avons réalisé une étude biologique comportant une numération plaquettaire et une agrégométrie. Résultats 11 patients ont présenté des profils agrégométriques compatibles à une TG. La majorité de ces malades étaient issus de mariages consanguins (54,5%) et originaires de régions situées dans le nord du Maroc. Le syndrome hémorragique s'est révélé principalement cutanéo-muqueux, avec une prédominance des gingivorragies (72,7%), des épistaxis (63,6%) et des ecchymoses (45,5%). Conclusion Nos résultats ont montré que la thrombasthénie de Glanzmann est une pathologie relativement fréquente au Maroc. PMID:26587119

  3. Perfis de temperatura eletrônica em regiões HII

    NASA Astrophysics Data System (ADS)

    Copetti, M. V. F.

    2003-08-01

    As flutuações de temperatura eletrônica em regiões HII, inicialmente propostas para explicar as discrepâncias entre os valores de temperatura obtidos por diferentes métodos, têm sido apontadas como a causa mais provável das enormes diferenças encontradas entre as abundâncias químicas medidas através de linhas excitadas colisionalmente e de linhas de recombinação. Recentemente têm sido reportadas tentativas de detecção e quantificação diretas das flutuações de temperatura eletrônica através de medidas ponto a ponto, obtidas por meio de espectroscopia de fenda longa, das razões de linhas [OIII]l4263/l5007 e [NII]l5755/l6584, principais sensores de temperatura. Neste trabalho, utilizamos o código numérico de fotoionização Cloudy para avaliar a confiabilidade desse procedimento. Concluímos que, para valores de densidade eletrônica e de temperatura efetiva da estrela ionizante típicos das regiões HII, os perfis superficiais de temperatura obtidos via medidas do sensor [OIII]l4263/l5007 são bons traçadores dos gradientes internos de temperatura eletrônica. Já os perfis de temperatura eletrônica medidos por meio da razão [NII]l5755/l6584 não reproduzem os gradientes verdadeiros de temperatura.

  4. An Interactive Web-Based Analysis Framework for Remote Sensing Cloud Computing

    NASA Astrophysics Data System (ADS)

    Wang, X. Z.; Zhang, H. M.; Zhao, J. H.; Lin, Q. H.; Zhou, Y. C.; Li, J. H.

    2015-07-01

    Spatiotemporal data, especially remote sensing data, are widely used in ecological, geographical, agriculture, and military research and applications. With the development of remote sensing technology, more and more remote sensing data are accumulated and stored in the cloud. An effective way for cloud users to access and analyse these massive spatiotemporal data in the web clients becomes an urgent issue. In this paper, we proposed a new scalable, interactive and web-based cloud computing solution for massive remote sensing data analysis. We build a spatiotemporal analysis platform to provide the end-user with a safe and convenient way to access massive remote sensing data stored in the cloud. The lightweight cloud storage system used to store public data and users' private data is constructed based on open source distributed file system. In it, massive remote sensing data are stored as public data, while the intermediate and input data are stored as private data. The elastic, scalable, and flexible cloud computing environment is built using Docker, which is a technology of open-source lightweight cloud computing container in the Linux operating system. In the Docker container, open-source software such as IPython, NumPy, GDAL, and Grass GIS etc., are deployed. Users can write scripts in the IPython Notebook web page through the web browser to process data, and the scripts will be submitted to IPython kernel to be executed. By comparing the performance of remote sensing data analysis tasks executed in Docker container, KVM virtual machines and physical machines respectively, we can conclude that the cloud computing environment built by Docker makes the greatest use of the host system resources, and can handle more concurrent spatial-temporal computing tasks. Docker technology provides resource isolation mechanism in aspects of IO, CPU, and memory etc., which offers security guarantee when processing remote sensing data in the IPython Notebook. Users can write

  5. Beam Halo Measurements at UMER and the JLAB FEL Using an Adaptive Masking Method

    SciTech Connect

    Zhang, H D; Fiorito, R B; Kishek, R A; O' Shea, P G; Shkvarunets, A G; Benson, S V; Douglas, D; Wilson, F G

    2011-03-01

    Beam halo is a chal­leng­ing issue for in­tense beams since it can cause beam loss, emit­tance growth, nu­cle­ar ac­ti­va­tion and sec­ondary elec­tron emis­sion. Be­cause of the po­ten­tial­ly low num­ber of par­ti­cles in the halo com­pared with beam core, tra­di­tion­al imag­ing meth­ods may not have suf­fi­cient con­trast to de­tect faint halos. We have de­vel­oped a high dy­nam­ic range, adap­tive mask­ing method to mea­sure halo using a dig­i­tal mi­cro-mir­ror array de­vice and demon­strat­ed its ef­fec­tive­ness ex­per­i­men­tal­ly on the Uni­ver­si­ty of Mary­land Elec­tron Ring (UMER). We also re­port on sim­i­lar ex­per­i­ments cur­rent­ly in progress at the Jef­fer­son Lab Free Elec­tron Laser (FEL) using this method.

  6. Numerical Calculation of the Drag Force Acting on an Insoluble Particle Moving in Front of a Solidifying Interface

    NASA Technical Reports Server (NTRS)

    Catalina, Adrian V.; Stefanescu, Doru M.; Sen, Subhayu

    2000-01-01

    The distribution of insoluble particles in a metal casting depends primarily on the interaction of the particles with the solid/liquid interface (SLI) during the solidification process. Whether a particle will be engulfed or continuously pushed by SLI is essentially determined by the balance of forces acting on the particle. An important component of this force balance is the drag force generated by the particle motion in front of the SLI. Previously developed mathematical models for particle/SLI interaction made use of steady-state solutions of this force provided by the lubrication theory. However, our numerical model based on the SLI tracking approach shows that not only the steady-state approach is inappropriate to model the interaction process but also that even at steady-state the theoretical solution underestimates the drag force. A regression analysis of steady-state numerical solutions for cylindrical particles moving normal to a flat SLI gave a relationship of the form F(sub d) (exp num) = (square root of 3) pi eta V(sub p)((R(sub p) / d) (exp 10 gamma/3)) as compared to the theoretical solution F(sub d) (exp theor) = 3 X (square root of 2) pi eta V(sub p)((R(sub p) / d) (exp 3/2)) where F(sub d) is the drag force, eta is the dynamic viscosity of the fluid, V(sub p) is the particle velocity, R(sub p) is the particle radius, gamma is Euler's constant (gamma is approximately equal to 0.577), and d is the width of the gap between the particle and the SLI. Model validation as well as the influence of the interface shape on the value of F(sub d) will also be discussed.

  7. Spatial Pattern of Land Use Change and Its Driving Force in Jiangsu Province

    PubMed Central

    Du, Xindong; Jin, Xiaobin; Yang, Xilian; Yang, Xuhong; Zhou, Yinkang

    2014-01-01

    Scientific interpretation of the mechanism of land use change is important for government planning and management activities. This study analyzes the land use change in Jiangsu Province using three land use maps of 2000, 2005 and 2008. The study results show that there was a significant change in land use. The change was mainly characterized by a continuous built-up land expansion primarily at the expense of cropland loss, and the trend became increasingly rapid. There was an obvious regional difference, as most of the cropland loss or built-up land expansion took place in southern Jiangsu, where the rate of built-up land expansion was faster than in central and northern Jiangsu. Meanwhile, the spatial pattern changed remarkably; in general, the number of patches (NumP) showed a declining trend, and the mean patch size (MPS) and patch size standard deviation (PSSD) displayed increase trends. Furthermore, the relative importance of selected driven factors was identified by principal component analysis (PCA) and general linear model (GLM). The results showed that not only the relative importance of a specific driving factor may vary, but the driven factors may as well. The most important driven factor changed from urban population (UP), secondary gross domestic product (SGDP) and gross domestic product (GDP) during 2000–2005 to resident population (RP), population density (POD) and UP during 2005–2008, and the deviance explained (DE) decreased from 91.60% to 81.04%. Policies also had significant impacts on land use change, which can be divided into direct and indirect impacts. Development policies usually had indirect impacts, particularly economic development policies, which promote the economic development to cause land use change, while land management policies had direct impacts. We suggest that the government should think comprehensively and cautiously when proposing a new development strategy or plan. PMID:24646864

  8. Hybrid K-Rb Spin Exchange Optical Pumping Cells for the Polarization of ^3He

    NASA Astrophysics Data System (ADS)

    Couture, Alex; Daniels, Tim; Arnold, Charles; Clegg, Tom

    2006-11-01

    We are transitioning from polarizing ^3He using optical pumping cells charged with pure Rb to using a mixture of Rb and K, lean in Rb. The reason for this is the spin exchange efficiency between K and ^3He is an order of magnitude greater than that of Rb and ^3He. Also the spin exchange cross section between Rb and K is very large, which leads to a very fast rate of polarization transfer from Rb to K. Thus by optically pumping using a standard 795 nm Rb laser on a hybrid K-Rb cell, we can obtain significant improvements in spin-up time as well as improvements in overall polarization.[1] We produce hybrid pumping cells at TUNL using a filling station consisting of an oven and a turbo pumping station to bake out and pump away any impurities in the cells. The alkali metals are introduced into the pumping cells from a Y-shaped manifold with a separate retort for each alkali. We are able to determine the ratio of K to Rb in the vapor using white light absorption spectroscopy. Light from a halogen light bulb is incident upon the heated cell and enters a spectrometer beyond. We examine the relative sizes of the D1 and D2 absorption lines for the two alkali metals. We will have data comparing hybrid cells to pure Rb cells, GE-180 cells to Pyrex, and are working to obtain comparative performance data for spectrally unnarrowed and narrowed lasers. Our latest results will be reported. [1] E. Babcock, et al. (2003) Phys. Rev. Letter Vol. 91, Num.12, 123003

  9. Fast prototyping of wavelet spatio-temporal RS fusion with Raingauge time series with GDAL and Python-DWT

    NASA Astrophysics Data System (ADS)

    Chemin, Yann

    2013-04-01

    Availability of rainfall time-series is limited in many parts of the World, and the continuity of such records is variable. This research endeavors to extend actual daily rainfall observations to ungauged areas using vegetation response as witnessed by remote sensing data and taking into account rainfall event histograms as well as cumulative total daily rainfall, over a period of 11 years. Open Source code development permitted to gain on several aspects. The first one pertains to space, Python and its numerical part (NumPy) are scientifically concise, as a bonus to be expressive. The second is the availability of the Discrete Wavelet Transform (DWT) in Python already, which permitted to reduce the Wavelet Transform to a small set of instructions, clarifying and simplifying the understanding of the code once it reaches the Public Domain. GDAL interface permitted to load satellite imagery and write fused rainfall time-series in spatio-temporal dimensions. Other scientific tool from Numerical Python were also used in the process of developing the algorithm (scipy.stats.stats and scipy.interpolate.griddata). Due to the large amount of days (4019) and the kilometer based resolution of the vegetation RS data, it takes about a week for the code to resolve the fusion problem. An attempt at using an multicore interpolation implementation in Python (hpgl) which unfortunately was not an active project anymore, though certainly deserving interest. Results show that rainfall events histograms can be reconstructed, and that total cumulative rainfall is estimated with 85% accuracy, using a surrounding network of rain gauges at 30-50 km of distance from the point of study. This research can strengthen various types of research and applications such as ungauged basins research, regional climate modeling, agricultural insurance systems, etc. Further development aims at porting the code to distributed computing.

  10. Volcanic Event Recurrence Rate Model (VERRM): Incorporating Radiometric Ages, Volcanic Stratigraphy and Paleomagnetic Data into a Monte Carlo Simulation to Estimate Uncertainty in Recurrence Rate through Time

    NASA Astrophysics Data System (ADS)

    Wilson, J. A.; Richardson, J. A.

    2015-12-01

    Traditional methods used to calculate recurrence rate of volcanism, such as linear regression, maximum likelihood and Weibull-Poisson distributions, are effective at estimating recurrence rate and confidence level, but these methods are unable to estimate uncertainty in recurrence rate through time. We propose a new model for estimating recurrence rate and uncertainty, Volcanic Event Recurrence Rate Model. VERRM is an algorithm that incorporates radiometric ages, volcanic stratigraphy and paleomagnetic data into a Monte Carlo simulation, generating acceptable ages for each event. Each model run is used to calculate recurrence rate using a moving average window. These rates are binned into discrete time intervals and plotted using the 5th, 50th and 95th percentiles. We present recurrence rates from Cima Volcanic Field (CA), Yucca Mountain (NV) and Arsia Mons (Mars). Results from Cima Volcanic Field illustrate how several K-Ar ages with large uncertainties obscure three well documented volcanic episodes. Yucca Mountain results are similar to published rates and illustrate the use of using the same radiometric age for multiple events in a spatially defined cluster. Arsia Mons results show a clear waxing/waning of volcanism through time. VERRM output may be used for a spatio-temporal model or to plot uncertainty in quantifiable parameters such as eruption volume or geochemistry. Alternatively, the algorithm may be reworked to constrain geomagnetic chrons. VERRM is implemented in Python 2.7 and takes advantage of NumPy, SciPy and matplotlib libraries for optimization and quality plotting presentation. A typical Monte Carlo simulation of 40 volcanic events takes a few minutes to couple hours to complete, depending on the bin size used to assign ages.

  11. Role of MoAND1-mediated nuclear positioning in morphogenesis and pathogenicity in the rice blast fungus, Magnaporthe oryzae.

    PubMed

    Jeon, Junhyun; Rho, Heekyoung; Kim, Seongbeom; Kim, Kyoung Su; Lee, Yong-Hwan

    2014-08-01

    To cause disease on host plants, many phytopathogenic fungi undergo morphological transitions including development of reproductive structures as well as specialized infection structures called appressoria. Such morphological transitions display distinct nuclear dynamics. Here we report the developmental requirement of MoAND1-mediated nuclear positioning for pathogenesis of the rice blast fungus, Magnaporthe oryzae. The MoAND1 gene encodes a protein that shows high similarity to Num1 in Saccharomyces cerevisiae and ApsA in Aspergillus nidulans, both of which are cell cortex proteins involved in nuclear migration and positioning. Targeted deletion of MoAND1 did not affect radial growth of the fungus but impaired nuclear distribution along the hyphae, which is reminiscent of ApsA mutant. In contrast to the wild-type, which produces three to five spores in a sympodial manner on the conidiophore, only a single spore was borne on the conidiophore of ΔMoand1, resulting in ∼65% decrease in conidia production, compared to the wild-type. The mutant conidia displayed abnormalities in septation pattern and nuclear distribution, which were correlated with their inability to germinate. Spores of the mutant that did germinate were capable of differentiating appressoria but were defective in the execution of programmed nuclear migration and positioning during development. Furthermore, mutant appressoria were not fully functional, leading to delay in penetration of host plants. However, the ability of ΔMoand1 to grow inside host tissues was comparable to that of the wild-type. All these defects greatly decreased the virulence of the mutant. Taken together, our data suggest that there is a stringent but incomplete developmental requirement for proper migration and positioning of fungal nuclei mediated by MoAND1 during asexual reproduction and pre-penetration phase of fungal pathogenesis. PMID:24875422

  12. Mapeamento do fenômeno de pulsações não-radiais no DHR

    NASA Astrophysics Data System (ADS)

    Waelkens, A. H.; Janot Pacheco, E.

    2003-08-01

    Neste trabalho de IC, pretende-se estabelecer um mapa das características do fenômeno das pulsações não-radiais (PNR) no diagrama HR (DHR). Trata-se de oscilações que não mantém a homotecia radial. O fenômeno foi inicialmente descoberto no Sol nos anos 60 e hoje é detectado num grande número de objetos. Sua grande importância reside em que as pulsações descrevem a física da cavidade em que se propagam. As PNR são classificadas basicamente por suas frequências, amplitudes e certos números quânticos associados. Com o objetivo de descrever a variação desses parâmetros no DHR, procedeu-se a um extenso levantamento bibliográfico (artigos de revistas e outras fontes) cobrindo o tema. Compôs-se assim uma tabela, que será apresentada nesta comunicação, contendo os parâmetros físicos das estrelas (T, L, logg, M) e suas características de PNR, deduzidas a partir de observações fotométricas e/ou espectroscópicas. No momento, completamos os dados sobre as Anãs Brancas e Beta Cep. Apresentaremos no trabalho diagramas L-T com os últimos resultados obtidos, eventualmente com uma terceira dimensão que descreva características pulsacionais.

  13. ObsPy: A Python Toolbox for Seismology

    NASA Astrophysics Data System (ADS)

    Wassermann, J. M.; Krischer, L.; Megies, T.; Barsch, R.; Beyreuther, M.

    2013-12-01

    Python combines the power of a full-blown programming language with the flexibility and accessibility of an interactive scripting language. Its extensive standard library and large variety of freely available high quality scientific modules cover most needs in developing scientific processing workflows. ObsPy is a community-driven, open-source project extending Python's capabilities to fit the specific needs that arise when working with seismological data. It a) comes with a continuously growing signal processing toolbox that covers most tasks common in seismological analysis, b) provides read and write support for many common waveform, station and event metadata formats and c) enables access to various data centers, webservices and databases to retrieve waveform data and station/event metadata. In combination with mature and free Python packages like NumPy, SciPy, Matplotlib, IPython, Pandas, lxml, and PyQt, ObsPy makes it possible to develop complete workflows in Python, ranging from reading locally stored data or requesting data from one or more different data centers via signal analysis and data processing to visualization in GUI and web applications, output of modified/derived data and the creation of publication-quality figures. All functionality is extensively documented and the ObsPy Tutorial and Gallery give a good impression of the wide range of possible use cases. ObsPy is tested and running on Linux, OS X and Windows and comes with installation routines for these systems. ObsPy is developed in a test-driven approach and is available under the LGPLv3 open source licence. Users are welcome to request help, report bugs, propose enhancements or contribute code via either the user mailing list or the project page on GitHub.

  14. PynPoint code for exoplanet imaging

    NASA Astrophysics Data System (ADS)

    Amara, A.; Quanz, S. P.; Akeret, J.

    2015-04-01

    We announce the public release of PynPoint, a Python package that we have developed for analysing exoplanet data taken with the angular differential imaging observing technique. In particular, PynPoint is designed to model the point spread function of the central star and to subtract its flux contribution to reveal nearby faint companion planets. The current version of the package does this correction by using a principal component analysis method to build a basis set for modelling the point spread function of the observations. We demonstrate the performance of the package by reanalysing publicly available data on the exoplanet β Pictoris b, which consists of close to 24,000 individual image frames. We show that PynPoint is able to analyse this typical data in roughly 1.5 min on a Mac Pro, when the number of images is reduced by co-adding in sets of 5. The main computational work, the calculation of the Singular-Value-Decomposition, parallelises well as a result of a reliance on the SciPy and NumPy packages. For this calculation the peak memory load is 6 GB, which can be run comfortably on most workstations. A simpler calculation, by co-adding over 50, takes 3 s with a peak memory usage of 600 MB. This can be performed easily on a laptop. In developing the package we have modularised the code so that we will be able to extend functionality in future releases, through the inclusion of more modules, without it affecting the users application programming interface. We distribute the PynPoint package under GPLv3 licence through the central PyPI server, and the documentation is available online (http://pynpoint.ethz.ch).

  15. Only pick the right grains: Modelling the bias due to subjective grain-size interval selection for chronometric and fingerprinting approaches.

    NASA Astrophysics Data System (ADS)

    Dietze, Michael; Fuchs, Margret; Kreutzer, Sebastian

    2016-04-01

    Many modern approaches of radiometric dating or geochemical fingerprinting rely on sampling sedimentary deposits. A key assumption of most concepts is that the extracted grain-size fraction of the sampled sediment adequately represents the actual process to be dated or the source area to be fingerprinted. However, these assumptions are not always well constrained. Rather, they have to align with arbitrary, method-determined size intervals, such as "coarse grain" or "fine grain" with partly even different definitions. Such arbitrary intervals violate principal process-based concepts of sediment transport and can thus introduce significant bias to the analysis outcome (i.e., a deviation of the measured from the true value). We present a flexible numerical framework (numOlum) for the statistical programming language R that allows quantifying the bias due to any given analysis size interval for different types of sediment deposits. This framework is applied to synthetic samples from the realms of luminescence dating and geochemical fingerprinting, i.e. a virtual reworked loess section. We show independent validation data from artificially dosed and subsequently mixed grain-size proportions and we present a statistical approach (end-member modelling analysis, EMMA) that allows accounting for the effect of measuring the compound dosimetric history or geochemical composition of a sample. EMMA separates polymodal grain-size distributions into the underlying transport process-related distributions and their contribution to each sample. These underlying distributions can then be used to adjust grain-size preparation intervals to minimise the incorporation of "undesired" grain-size fractions.

  16. Splitting based finite volume schemes for ideal MHD equations

    NASA Astrophysics Data System (ADS)

    Fuchs, F. G.; Mishra, S.; Risebro, N. H.

    2009-02-01

    We design finite volume schemes for the equations of ideal magnetohydrodynamics (MHD) and based on splitting these equations into a fluid part and a magnetic induction part. The fluid part leads to an extended Euler system with magnetic forces as source terms. This set of equations are approximated by suitable two- and three-wave HLL solvers. The magnetic part is modeled by the magnetic induction equations which are approximated using stable upwind schemes devised in a recent paper [F. Fuchs, K.H. Karlsen, S. Mishra, N.H. Risebro, Stable upwind schemes for the Magnetic Induction equation. Math. Model. Num. Anal., Available on conservation laws preprint server, submitted for publication, URL: ]. These two sets of schemes can be combined either component by component, or by using an operator splitting procedure to obtain a finite volume scheme for the MHD equations. The resulting schemes are simple to design and implement. These schemes are compared with existing HLL type and Roe type schemes for MHD equations in a series of numerical experiments. These tests reveal that the proposed schemes are robust and have a greater numerical resolution than HLL type solvers, particularly in several space dimensions. In fact, the numerical resolution is comparable to that of the Roe scheme on most test problems with the computational cost being at the level of a HLL type solver. Furthermore, the schemes are remarkably stable even at very fine mesh resolutions and handle the divergence constraint efficiently with low divergence errors.

  17. Determination of HF artificial ionospheric turbulence characteristics using comparison of calculated plasma wave decay rates with the measured see decay rates

    NASA Astrophysics Data System (ADS)

    Grach, Savely; Bareev, Denis; Gavrilenko, Vladimir; Sergeev, Evgeny

    Damping rates of plasma waves with ω ˜ ωuh (ω is the plasma wave frequency, ωuh is the upper hybrid frequency) were calculated for frequencies close to and distant from the double resonance where ωuh ˜ nωce (ωce is the electron cyclotron frequency, n=4,5 are the gyroharmonic num-bers). The calculations were performed numerically on the base of full plasma wave dispersion relation not restricted by both the 'long wave limit' and 'short wave limit', i.e. a fulfillment of the inequalities |∆| |k |vTe and |∆| |k |vTe was not required. Here ∆ = ω - nωce , vTe = (Te /me )1/2 is the electron thermal velocity and k is the projection of the wave vector onto the magnetic field direction. It is shown that the plasma wave damping rates do not differ noticeably from ones calculated under the long wave and short wave limits. The results obtained are compared with the data of the relaxation of the stimulated electromagnetic emission (SEE) after the pump wave turn off, which demonstrate an essential decrease of the relaxation time near 4th electron gyroharmonic, so far as the SEE relaxation is attributed to the damping of plasma waves responsible for the SEE generation. The comparison allows to determine characteristics of plasma waves mostly contributing to the SEE generation, such as wave numbers and the angles between the wave vectors and geomagnetic field, and the altitude region of the SEE source. The dependence of the decay rate on ∆ can be applied also to interpretation of the SEE spectral shape at different pump frequencies near gyroharmonics. The work is supported by RFBR grants 10-02-00642, 09-02-01150 and Federal Special-purpose Program "Scientific and pedagogical personnel of innovative Russia".

  18. Numerical tools to validate stationary points of SO(8)-gauged N=8D=4 supergravity

    NASA Astrophysics Data System (ADS)

    Fischbacher, Thomas

    2012-03-01

    Until recently, the preferred strategy to identify stationary points in the scalar potential of SO(8)-gauged N=8 supergravity in D=4 has been to consider truncations of the potential to sub-manifolds of E/SU(8) that are invariant under some postulated residual gauge group G⊂SO(8). As powerful alternative strategies have been shown to exist that allow one to go far beyond what this method can achieve — and in particular have produced numerous solutions that break the SO(8) gauge group to no continuous residual symmetry — independent verification of results becomes a problem due to both the complexity of the scalar potential and the large number of new solutions. This article introduces a conceptually simple self-contained piece of computer code that allows independent numerical validation of claims on the locations of newly discovered stationary points. Program summaryProgram title: e7-vacua Catalogue identifier: AELB_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AELB_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 4447 No. of bytes in distributed program, including test data, etc.: 281 689 Distribution format: tar.gz Programming language: Python Computer: Any Operating system: Unix/Linux RAM: 1 Giga-byte Classification: 1.5, 11.1 External routines: Scientific Python (SciPy) ( http://www.scipy.org/), NumPy ( http://numpy.scipy.org) Nature of problem: This code allows numerical validation of claims about the existence of critical points in the scalar potential of four-dimensional SO(8)-gauged N=8 supergravity. Solution method: Tensor algebra. Running time: Full analysis of a solution (including scalar mass matrices): about 15 minutes. Otherwise, about 1-2 minutes.

  19. An Object-Based Workflow Developed to Extract Aquaculture Ponds from Airborne LIDAR Data: a Test Case in Central Visayas, Philippines

    NASA Astrophysics Data System (ADS)

    Loberternos, R. A.; Porpetcho, W. P.; Graciosa, J. C. A.; Violanda, R. R.; Diola, A. G.; Dy, D. T.; Otadoy, R. E. S.

    2016-06-01

    Traditional remote sensing approach for mapping aquaculture ponds typically involves the use of aerial photography and high resolution images. The current study demonstrates the use of object-based image processing and analyses of LiDAR-data-generated derivative images with 1-meter resolution, namely: CHM (canopy height model) layer, DSM (digital surface model) layer, DTM (digital terrain model) layer, Hillshade layer, Intensity layer, NumRet (number of returns) layer, and Slope layer. A Canny edge detection algorithm was also performed on the Hillshade layer in order to create a new image (Canny layer) with more defined edges. These derivative images were then used as input layers to perform a multi-resolution segmentation algorithm best fit to delineate the aquaculture ponds. In order to extract the aquaculture pond feature, three major classes were identified for classification, including land, vegetation and water. Classification was first performed by using assign class algorithm to classify Flat Surfaces to segments with mean Slope values of 10 or lower. Out of these Flat Surfaces, assign class algorithm was then performed to determine Water feature by using a threshold value of 63.5. The segments identified as Water were then merged together to form larger bodies of water which comprises the aquaculture ponds. The present study shows that LiDAR data coupled with object-based classification can be an effective approach for mapping coastal aquaculture ponds. The workflow currently presented can be used as a model to map other areas in the Philippines where aquaculture ponds exist.

  20. Identification d'une loi thermo-élasto-viscoplastique en vue de la modélisation du laminage à chaud du cuivre

    NASA Astrophysics Data System (ADS)

    Moureaux, P.; Moto Mpong, S.; Remy, M.; Bouffioux, C.; Lecomte-Beckers, J.; Habraken, A. M.

    2002-12-01

    la mise au point d'un modèle de simulation de la dernière passe du laminage à chaud du cuivre ne présente à priori pas de problème du point de vue numérique pour un code d'éléments finis non linéaire. La collecte d'informations précises tant sur le procédé industriel que sur le comportement du matériau est par contre une opération non triviale. Cet article présente les diverses méthodes expérimentales mises en œuvre pour caractériser le matériau : essais de compression à chaud, mesures d'analyse thermique différentielle, essais de dilatométrie et de diffusivité. Les méthodes permettant d'identifier les paramètres de la loi élasto-visco-plastique de type Norton-Hoff à partir des essais sont présentées et une analyse bibliographique investigue le problème de la détermination du module de Young à haute température. Tant les hypothèses supplémentaires relatives au procédé et nécessaires au modèle que les résultats finaux sont résumés.

  1. A Community Python Library for Solar Physics (SunPy)

    NASA Astrophysics Data System (ADS)

    Christe, Steven; Shih, A. Y.; Ireland, J.; Perez-Suarez, D.; Mumford, S.; Hughitt, V. K.; Hewett, R.; Mayer, F.; SunPy Dev Team

    2013-07-01

    Python, a free, cross platform, general purpose, high-level programming language, has seen widespread adoption among the scientific community resulting in the availability of a large range of software, from numerical computation (NumPy, SciPy) and machine learning to spectral analysis and visualization (Matplotlib). SunPy is a data analysis toolkit specializing in providing the software necessary to analyze solar and heliospheric datasets in Python. It aims to provide a free and open-source alternative to the IDL-based SolarSoft (SSW) solar data analysis environment. We present the latest release of SunPy (0.3). This release includes a major refactor of the main SunPy code to improve ease of use for the user as well as a more consistent interface. SunPy provides downloading capability through integration with the Virtual Solar Observatory (VSO) and the the Heliophysics Event Knowledgebase (HEK). It can open image fits files from major solar missions (SDO/AIA, SOHO/EIT, SOHO/LASCO, STEREO) into WCS-aware maps. SunPy provides advanced time-series tools for data from mission such as GOES, SDO/EVE, and Proba2/LYRA as well as support for radio spectra (e.g. e-Callisto). We present examples of solar data analysis in SunPy, and show how Python-based solar data-analysis can leverage the many existing data analysis tools already available in Python. We discuss the future goals of the project and encourage interested users to become involved in the planning and development of SunPy.

  2. Towards Year 2009, a 25 000 person rehearsal

    NASA Astrophysics Data System (ADS)

    Fierro Gossman, Julieta; Espinosa, M.

    2008-05-01

    In this presentations we will talk about the way we planned and achieved successfully a 25 000 people observation in Mexico City downtown taking advantage of a lunar eclipse. We shall guide people so they think about their own activities. We shall mention the way we planned the event, carried out found raising and advertisement. We shall describe the way we handled people mainly during the observations with one hundred telescopes and parallel activities. These included: a public lecture enhanced with dance and hands-on demonstrations, workshops for children, workshops on the night sky, talking to an astronomer, how to handle a telescope and a picture exhibit as well as music till midnight. We shall also mentioned written materials for that particular event and for Year 2009, some of which were specially crafted for teachers. Hector Dominguez y Julieta Fierro Galileo y el telescopio, 400 anios de ciencia Uribe y Ferrari Editores, 2007 ISBN 970 756 238-2 Hector Dominguez y Julieta Fierro, Galileo para Maestros I Correo del Maestro, Núm. 133, p. 15-26, Anios 12, Junio 2007. Hector Dominguez y Julieta Fierro, Galileo para Maestros II Correo del Maestro, Núm. 134, p. 17-26, Anio 12, 2007. Hector Dominguez y Julieta Fierro, Galileo para Maestros III Correo del Maestro, Num. 135, p. 10-18, Anio 12, 2007. Hector Dominguez y Julieta Fierro Experimentos sobre la caida de los cuerpos El Correo del Maestro, anio 12 Numero 142, p. 5-18, 2008. Mariana Espinosa, Julieta Fierro y Silvia Torres Fiesta de estrellas El Correo del Maestro, aceptado para su publicacion.

  3. A digital photogrammetric workstation on the WEB

    NASA Astrophysics Data System (ADS)

    Drap, P.; Grussenmeyer, P.

    The main features of a WEB-based tool for digital architectural photogrammetry called Architectural Photogrammetry Network Tool for Education and Research (ARPENTEUR) are presented. The aim of this project is to propose a photogrammetric software package made freely available on the Internet as an applet through a simple browser ( http://www.arpenteur.net). All the photogrammetric adjustment and image processing classes are written in Java™. The use of large applets in photogrammetry has not been very advanced until now but rate transfers and compatibility levels of Internet browsers will increase in the near future. Users can set up their own projects by transferring their images, camera, and control information on the ARPENTEUR servers from any place in the world connected on the Internet. Various examples of small format architectural photogrammetry projects are also accessible via WWW and can be used for teaching. This software is an extension of the Traitement d'Images et Photogrammétrie Numérique (TIPHON) software developed at ENSAIS-LERGEC. The photogrammetric model is currently computed by the traditional steps of inner, relative and absolute orientations. The measurements in the images can be performed manually or by image correlation. The measured points, lines, and geometrical primitives are recorded in text files and visualised inside a standard WEB browser. The plotting module is especially dedicated to architectural surveys and based on a formalisation of architectural and geometrical knowledge. The latest developments of the Java programming language and object-oriented systems are used in ARPENTEUR, both in the photogrammetric and in the architectural part, and ensure a high level of compatibility with any hardware platform supporting a WEB browser.

  4. Les liquéfacteurs d'hélium en France

    NASA Astrophysics Data System (ADS)

    Gianèse, P.; Maréchal, J. C.

    1991-02-01

    This article is a synopsis of a meeting held at the begining of 1990 between the managers of the principal helium liquefaction installations in France. The mains types of helium liquefiers encountered are described and then the French installations are listed and detailed. The problems encountered in different parts of the installations (liquefier, recovery system, purifying, ...) during the last few years are discussed. In a final section about the economics of liquefaction, the cost of liquefying helium and nitrogen is compared with the cost of purchasing these liquids commercially. Cet article constitue la synthèse d'une réunion tenue début 1990 qui regroupait les principaux responsables français des centres de liquéfaction d'hélium. L'article décrit successivement les principaux types de liquéfacteurs rencontrés puis recense les installations françaises en fournissant leurs principales caractéristiques. Il énumère ensuite les problèmes survenus avec les différents éléments d'une installation (liquéfacteur, circuit de récupération, épurateur, ...). L'article s'achève par un volet économique fournissant les coûts moyens actuels soit pour l'achat, soit pour la liquéfaction sur place de l'hélium et de l'azote liquide. Une comparaison entre les deux solutions est effectuée.

  5. PLATINO, a nine-year follow-up study of COPD in the city of São Paulo, Brazil: the problem of underdiagnosis*

    PubMed Central

    Moreira, Graciane Laender; Manzano, Beatriz Martins; Gazzotti, Mariana Rodrigues; Nascimento, Oliver Augusto; Perez-Padilla, Rogelio; Menezes, Ana Maria Baptista; Jardim, José Roberto

    2014-01-01

    OBJECTIVE: To determine the underdiagnosis rate in new COPD cases at the end of a nine-year follow-up period-in the study designated "Projeto Latino-Americano de Investigação em Obstrução Pulmonar" (PLATINO, Latin-American Pulmonary Obstruction Investigation Project)-and compare that with the underdiagnosis rate during the initial phase of the study, as well as to identify the clinical features exhibited by the subjects who were not diagnosed until the end of the follow-up phase. METHODS: The study population comprised the 1,000 residents of the city of São Paulo, Brazil, who took part in the PLATINO study. Of those, 613 participated in the follow-up phase, during which the subjects were assessed with the same instruments and equipment employed in the initial phase of the study. We used the chi-square test or the independent sample t-test to analyze the underdiagnosis rate and to identify the characteristics of the subjects who were not diagnosed until the end of the follow-up phase. RESULTS: The underdiagnosis rate for new COPD cases at the end of the nine-year follow-up period was 70.0%. The underdiagnosis rate during the follow-up phase was 17.5% lower than that reported for the initial phase of the study. The subjects who were not diagnosed until the end of the follow-up phase presented with fewer respiratory symptoms, better pulmonary function, and less severe disease than did those previously diagnosed with COPD. CONCLUSIONS: The underdiagnosis rate for new COPD cases was lower in the follow-up phase of the study than in the initial phase. The subjects who were not diagnosed until the end of the follow-up phase of the PLATINO study presented with the same clinical profile as did those who were not diagnosed in the initial phase. These findings underscore the need for spirometry in order to confirm the diagnosis of COPD and provide early intervention. PMID:24626267

  6. Determinação de regiões de órbitas diretas estáveis ao redor da Lua

    NASA Astrophysics Data System (ADS)

    de Melo, C. F.; Winter, O. C.; Vieira Neto, E.

    2003-08-01

    Neste Trabalho estamos investigando regiões do sistema Terra-Lua que contêm órbitas diretas estáveis ao redor da Lua visando a utilização destas órbitas em futuras missões de veículos espaciais como alternativas de trajetórias com baixo custo de manutenção. Adotando-se o problema restrito de três corpos, Terra-Lua-partícula, a localização e a extensão destas regiões de estabilidade foram investigadas numericamente considerando como estável toda órbita que permanece ao redor a Lua por, no mínimo, 1000 dias com energia de dois corpos da partícula em relação à Lua negativa. A estabilidade de tais regiões está associada a duas famílias de órbitas periódicas simples H1 e H2 e a órbitas quase-periódicas associadas a elas. Uma vez identificadas as regiões de estabilidade passamos a analisá-las introduzindo, paulatinamente, outras interações relevantes ao sistema como as perturbações do Sol (via problema restrito de quatro corpos), das marés, da pressão de radiação e do achatamento terrestre. Os resultados encontrados até o momento mostram que a perturbação do Sol é a única que reduz significativamente o tamanho das regiões de estabilidade. Também estamos investigando o comportamento de tais regiões quando características intrínsecas do sistema como as excentricidades das órbitas da Terra e da Lua e a inclinação da órbita Lua são consideradas. Com este estudo estamos reunindo informações que nos permitirão compreender a evolução das regiões de estabilidade no sistema Terra-Lua, bem como estabelecer parâmetros adequados para a utilização das trajetórias estáveis em futuras missões espaciais. Agradecimentos: Este projeto conta com o apoio do CNPq, da Capes e da Fapesp.

  7. Estimativa de imagens solares soho através de redes neurais artificiais

    NASA Astrophysics Data System (ADS)

    Andrade, M. C.; Fernandes, F. C. R.; Cecatto, J. R.; Rios Neto, A.; Rosa, R. R.; Sawant, H. S.

    2003-08-01

    A Rede Neural Artificial (RNA), no âmbito da teoria computacional, constitui uma teoria emergente que, por possuir habilidade em aprender a partir de dados de entrada, encontra diferentes aplicações em diferentes áreas. Um exemplo é a utilização de RNA na caracterização de padrões associados à dinâmica de processos espaço-temporais relacionados a fenômenos físicos não-lineares. Para obter informações sobre o comportamento destes fenômenos físicos utiliza-se, em diversos casos, seqüências de imagens digitalizadas, onde a caracterização de alguns fenômenos espaço-temporais é o procedimento mais viável para descrever a dinâmica das regiões ativas do Sol. Com base em imagens observadas por telescópios a bordo de satélites, estudos de previsão de eventos solares podem ser programados, permitindo prever possíveis efeitos posteriores nas regiões mais próximas da Terra (tempestades geomagnéticas e irregularidades ionosféricas). Neste trabalho avaliamos o desempenho da RNA para estimar padrões espaço-temporais, ou seja, imagens solares em ultravioleta, obtidas através do telescópio a bordo do satélite SOHO. Os resultados mostraram que as RNA conseguem generalizar os padrões de maneira satisfatória sem perder de forma significativa os principais aspectos da configuração global da atmosfera solar, comprovando a eficácia da RNA como ferramenta para esse tipo de aplicação. Portanto, este trabalho comprova a viabilidade de uso desta ferramenta em projetos voltados ao estudo do comportamento solar, em trabalhos do grupo de Física do Meio Interplanetário (FMI) na DAS e em programas desenvolvidos pelo Núcleo de Simulação e Análise de Sistemas Complexos (NUSASC) do Laboratório Associado de Computação e Matemática Aplicada (LAC) do INPE.

  8. Ensino de gravitação clássica no nível médio: uma proposta de abordagem e resultados preliminares

    NASA Astrophysics Data System (ADS)

    Medeiros, G. C. M.; Jafelice, L. C.

    2003-08-01

    O ensino de gravitação clássica é comumente realizado de maneira formal e descontextualizado da experiência com a força-peso e da história do tema. Fustigados por anos de experiência de ensino no assunto, nem sempre com bons resultados, propomos uma abordagem ancorada nos eixos: a) contextualização histórica; e b) reconhecimento do peso como a força de atração gravitacional. O primeiro eixo integra o tema no desenvolvimento cultural do ser humano, praticando a interdisciplinaridade. O segundo eixo embasa construtivamente a abordagem, levando o aluno a realizar experiências e a vivenciar o reconhecimento de uma força universal. A abordagem foi construída através das etapas: 1) análise crítica do tema em livros didáticos; 2) elaboração de um curso para professores das várias disciplinas do ensino médio, identificando conexões para a prática da interdisciplinaridade; 3) elaboração de material didático; e 4) avaliação da eficácia da abordagem. No trabalho discutimos em detalhe as quatro etapas. Como resultados, adiantamos que: tabulamos a abordagem de gravitação nos livros didáticos, ainda muito tradicional e carecedora de atividades criativas que poderiam melhor explorar esse assunto; mapeamos, junto aos professores, padrões de conceitos espontâneos e erros associados ao tema; e, no curso, adaptamos e testamos a eficiência de materiais instrucionais existentes e criamos outros novos (e.g., para trabalhar excentricidades das órbitas planetárias), além disto elaboramos roteiros e figuras para tratamentos qualitativo e quantitativo da lei da gravitação universal. As avaliações feitas pelos professores foram muito animadoras. O espaço da presente reunião será aproveitado para socializar a proposta e os resultados obtidos e para submeter o projeto à análise crítica. (PPGECNM/UFRN; PRONEX/FINEP; NUPA/USP; Temáticos/FAPESP)

  9. Ensino e divulgação de astronomia no Planetário de Campinas

    NASA Astrophysics Data System (ADS)

    Faria, R. P.

    2003-08-01

    Projeto desenvolvido em 1981 por professores da Unicamp, sob a coordenação do Prof. Dr. Carlos Alfredo Argüello propunha a instalação de um Planetário em Campinas. Convênio firmado em 1982 entre a Unicamp, a Prefeitura de Campinas, a Funcamp e a Academia de Ciências do Estado de São Paulo, possibilitou a aquisição de um planetário Zeiss ZKP2, através do MEC, e em 28 de outubro de 1987 foi inaugurado o Planetário de Campinas. Desde então várias atividades de ensino e divulgação da Astronomia foram desenvolvidas regularmente. A verificação dos registros das atividades realizadas mostra um alto índice de atendimento, considerada a capacidade das instalações (sala de projeção para 60 pessoas, auditório com 45 poltronas e hall de exposições). As atividades dirigidas ao público, estudantes e professores, atenderam cerca de 400.000 participantes nos quase 16 anos de sua existência. Além de sessões públicas e escolares, com duração de 1 hora, são oferecidas às escolas vários outros tipos de atividades, com duração de 2,5 horas. Abordam diversos temas e são dirigidas a diferentes níveis de escolaridade. Cursos para o público e para professores, palestras, exposições e eventos especiais completam o quadro de atividades regulares. Mesmo enfrentando quase sempre dificuldades financeiras e administrativas verifica-se que o Planetário de Campinas realizou um trabalho quantitativamente e qualitativamente satisfatório, prestando bom serviços à comunidade de Campinas e de outras cidades de São Paulo e outros Estados. Isso é também atestado pela grande procura de reservas para suas atividades.

  10. Uma análise do fenômeno “alternância de línguas” na fala de bilíngues intermodais (Libras e Português)

    PubMed Central

    de Sousa, Aline Nunes; de Quadros, Ronice Müller

    2013-01-01

    Um interessante fenômeno lingüístico presente nas interações das pessoas bilíngues é a alternância de línguas. Neste trabalho, estamos investigando a alternância entre a língua portuguesa oral e a língua de sinais brasileira – Libras, numa mesma cadeia enunciativa, com o objetivo de identificar e analisar o uso dessa alternância na fala de uma criança e de um adulto (ambos ouvintes, filhos de pais surdos), interagindo em uma situação de bilinguismo intermodal, com interlocutores surdos e ouvintes. A alternância de línguas, nesse caso, ocorre quando se para de falar em português e se alterna para sinalizar. O presente trabalho se caracteriza como um estudo inicial, com análise qualitativa de dados. Fazem parte do nosso corpus nove sessões de interações em Libras e em português oral, gravadas em vídeo, que fazem parte do Projeto Desenvolvimento Bilíngue Bimodal da UFSC. Os dados revelam que as características da alternância de línguas pelo adulto e pela criança parecem ter semelhanças e diferenças. O sujeito adulto parece ter feito um uso da alternância mais preocupado com o curso da interação. A criança, por sua vez, não parece tê-la usado com propósitos pragmáticos específicos. Quanto à extensão das alternâncias, pode-se perceber que tanto a criança quanto o adulto utilizaram enunciados maiores do que uma única palavra isolada. O papel dos interlocutores parece ter sido decisivo nas interações aqui investigadas – especialmente nas do adulto, já que a criança ainda está em processo de tomada de consciência do papel do interlocutor na interação. PMID:24379831

  11. Verification of concentration time formulae accuracy in Southern Brazil

    NASA Astrophysics Data System (ADS)

    Freitas Ferreira, Pedro; Allasia, Daniel; Herbstrith Froemming, Gabriel; Ribeiro Fontoura, Jessica; Tassi, Rutineia

    2016-04-01

    The time of concentration (TC) of an urban catchment is a fundamental watershed parameter used to compute the peak discharge and/or in the hydrological simulation of sewer systems. In the lack of hydrological data for its estimative, several empirical formulae are used, however, almost none of them have been verified in Brazil leading to large uncertainties in the correct value. In this light, were tested several formulae such as the proposed by Kirpich (and a modifications of this equation proposed by the National Transport Bureau of Brazil (DNIT)), U.S. Corps. Of Engineers, Pasini, Dooge , Johnstone , Ventura and Ven T Chow as they are used in Brazil. The verification was accomplished against measured data in 5 sub-basins situated in the Dilúvio basin, a semi urbanized watershed that contains the most developed area of the city of Porto Alegre. All the rainfall stations were active in the period from late 1970's until early 1980's due to the existence of Projeto Dilúvio but today, however, only two of them are still in operation. Porto Alegre is the capital and largest city in the Brazilian southernmost state of Rio Grande do Sul with a population of approximately 1.6 million inhabitants, the tenth most populous city in the country and the centre of Brazil's fourth largest metropolitan area, with almost 4,5 million inhabitants (IBGE, 2010). The city is situated in a humid subtropical climate with high and regular precipitation throughout the year. Most summer rainfall occurs during thunderstorms and an occasional tropical storm, hurricane or cyclone. The results showed an error of around 70% for half of the formulas, with a tendency to underestimate TC values. Among the tested methods, Johnstone had the best overall result, with an average error of 25%, well far from the second, Dooge, with 43% of average error. The best results were obtained in only one basin, Dilúvio, the largest one, with an area of 25km², with an error of just 3% for Modified Kirpich, and

  12. Significant variance in genetic diversity among populations of Schistosoma haematobium detected using microsatellite DNA loci from a genome-wide database

    PubMed Central

    2013-01-01

    Background Urogenital schistosomiasis caused by Schistosoma haematobium is widely distributed across Africa and is increasingly being targeted for control. Genome sequences and population genetic parameters can give insight into the potential for population- or species-level drug resistance. Microsatellite DNA loci are genetic markers in wide use by Schistosoma researchers, but there are few primers available for S. haematobium. Methods We sequenced 1,058,114 random DNA fragments from clonal cercariae collected from a snail infected with a single Schistosoma haematobium miracidium. We assembled and aligned the S. haematobium sequences to the genomes of S. mansoni and S. japonicum, identifying microsatellite DNA loci across all three species and designing primers to amplify the loci in S. haematobium. To validate our primers, we screened 32 randomly selected primer pairs with population samples of S. haematobium. Results We designed >13,790 primer pairs to amplify unique microsatellite loci in S. haematobium, (available at http://www.cebio.org/projetos/schistosoma-haematobium-genome). The three Schistosoma genomes contained similar overall frequencies of microsatellites, but the frequency and length distributions of specific motifs differed among species. We identified 15 primer pairs that amplified consistently and were easily scored. We genotyped these 15 loci in S. haematobium individuals from six locations: Zanzibar had the highest levels of diversity; Malawi, Mauritius, Nigeria, and Senegal were nearly as diverse; but the sample from South Africa was much less diverse. Conclusions About half of the primers in the database of Schistosoma haematobium microsatellite DNA loci should yield amplifiable and easily scored polymorphic markers, thus providing thousands of potential markers. Sequence conservation among S. haematobium, S. japonicum, and S. mansoni is relatively high, thus it should now be possible to identify markers that are universal among Schistosoma

  13. Identificação de variáveis cataclísmicas eruptivas na direção do bojo galáctico e Nuvens de Magalhães usando dados do OGLE

    NASA Astrophysics Data System (ADS)

    Cieslinski, D.; Diaz, M. P.; Mennickent, R.; Pietrzyski, G.

    2003-08-01

    Na década de 90 iniciaram-se vários programas para a pesquisa de matéria escura na Galáxia usando o efeito de microlentes gravitacionais. Entre os projetos mais bem conhecidos podemos mencionar o OGLE (Optical Gravitational Lensing Experiment) e o MACHO (MAssive Compact Halo Objects). A estratégia usada por eles consiste em fazer fotometria de banda larga (normalmente B, R e I) de um grande número de estrelas (dezenas de milhões) tão freqüentemente quanto possí vel e por longos perí odos de tempo (anos). Uma tal sistemática de observação, além de descobrir inúmeras lentes gravitacionais, é também muito apropriada para a descoberta de estrelas variáveis. De fato, inúmeras novas variáveis de vários tipos foram descobertas como subproduto. Exemplos podem ser encontrados nos endereços http://bulge.princeton.edu/~ogle/ e http://wwwmacho.mcmaster.ca/. As variáveis cataclí smicas eruptivas (novas clássicas, novas recorrentes e novas anãs) são objetos que apresentam variabilidade de grande amplitude com escalas de tempo de dias a centenas de dias e, por esta razão, devem ter sido detectadas em grande número nestes "surveys". Para testar esta possibilidade nós procuramos nos dados do OGLE por tais sistemas e o presente trabalho mostra os resultados desta pesquisa. Os objetos foram selecionados entre as variáveis detectadas usando a amplitude de variação de brilho como critério principal. Este critério forneceu 13756 objetos, sendo 2169 na direção da Grande Nuvem de Magalhães, 1162 na direção da Pequena Nuvem de Magalhães e o restante na direção do Bojo Galáctico. A análise foi feita inspecionando-se visualmente cada curva de luz por erupções com as características acima mencionadas. Os resultados obtidos podem ser sumarizados como: descoberta de duas novas clássicas e 33 novas anãs. Além disso, pode-se mencionar a identificação de candidatas a outros tipos de variáveis como: estrelas simbióticas, RV Tauri, R Coronae

  14. Memória fonológica em crianças bilíngues bimodais e crianças com implante coclear

    PubMed Central

    de Quadros, Ronice Müller; Cruz, Carina Rebello; Pizzio, Aline Lemos

    2014-01-01

    RESUMO Este estudo comparou o desempenho de crianças bilíngues bimodais ouvintes (filhas de pais surdos) e crianças surdas usuárias de implante coclear (filhas de pais surdos e de pais ouvintes), com diferentes contextos de acesso à Língua Brasileira de Sinais (Libras), em tarefas que envolvem memória fonologica. Os testes utilizados foram: Teste de Pseudopalavras (Santos e Bueno, 2003) e Teste de Pseudosinais (desenvolvido pelos pesquisadores responsáveis pelo Projeto ‘Desenvolvimento Bilíngue Bimoda’). Além disso, foram incluídos dois grupos de controle, formados por crianças surdas (usuarias de Libras), e adultos bilíngues bimodais ouvintes. Na análise dos resultados, em relação ao desempenho entre os dois grupos testados foi constatado que o grupo de crianças bilíngues bimodais ouvintes apresentou desempenho superior, nos dois testes. No entanto, ao ser analisado o desempenho da criança surda usuaria de implante coclear, filha de pais surdos, que possui acesso irrestrito à Libras e comparado com o das crianças surdas usuárias de implante coclear, que possuem acesso restrito à Libras, foi constatado que o seu desempenho foi semelhante ao do grupo de crianças bilíngues bimodais ouvintes. As crianças surdas usuárias de implante coclear com acesso restrito à Libras e, portanto, com acesso maior ao Português apresentaram escores mais baixos nas tarefas, principalmente do teste em Português. Os resultados sugerem que as crianças surdas usuárias de implante coclear em processo de aquisição da línguagem podem se beneficiar com o acesso irrestrito à Libras, atingindo inclusive desempenho semelhante a de crianças bilíngues bimodais ouvintes. PMID:25110473

  15. Development of Educational Resources to Include the Teaching of Astronomy in the First Years of the Basic Education. (Spanish Title: Desarrollo de Recursos Pedagógicos Para Incluir la Enseñanza de la Astronomía en los Primeros Años de la Educación Básica.) Desenvolvimento de Recursos Pedagógicos Para Inserir o Ensino de Astronomia nas Séries Iniciais do Ensino Fundamental

    NASA Astrophysics Data System (ADS)

    da Silva Morett, Samara; de Oliveira Souza, Marcelo

    2010-07-01

    ía y la vida cotidiana de los estudiantes. La inclusión de la astronomía en la escuela primaria es una manera de demostrar a los estudiantes cómo este campo está presente de forma activa en su vida cotidiana. Las clases que participan en el proyecto participaron en un estudio con el objetivo de proporcionar información a los conocimientos previos que tenían sobre los temas de la astronomía que se examinaron durante el proyecto. Con los experimentos realizados, y la ayuda de las nuevas tecnologías, conceptos astronómicos fueron presentados a los estudiantes de 4to y 5to año de la educación básica de una escuela municipal de Campos dos Goytacazes (RJ). Después de las presentaciones nuevos datos fueran colectados y se han llevado a cabo con el fin de verificar el nivel de aprendizaje alcanzado y se observó que el método utilizado fue una herramienta importante para ayudar al proceso de enseñanza y aprendizaje. El proyecto logró resultados satisfactorios. Neste trabalho será apresentado o desenvolvimento de recursos pedagógicos para a apresentação de conceitos de astronomia nas séries iniciais do ensino fundamental. Este material é composto por apresentações realizadas com o uso de novos recursos tecnológicos, pela fabricação de experimentos e a discussão de curiosidades relativas a esta área de conhecimento. Os experimentos foram construídos com material de baixo custo com o objetivo de permitir que os alunos envolvidos pudessem refazê-los em outras ocasiões. O material apresentado busca enfatizar a relação entre a astronomia e o cotidiano dos alunos. A inclusão da astronomia no ensino fundamental e uma forma de demonstrar aoestudante como esta área está presente de forma ativa em seu cotidiano. As turmas envolvidas no projeto participaram de uma pesquisa com o objetivo de obter dados relativos ao conhecimento prévio que possuíam sobre os tópicos de astronomia que foram considerados no decorrer do projeto. Com os experimentos

  16. Ensino de astronomia e óptica: é possível fazê-lo de forma contextualizada no nível médio?

    NASA Astrophysics Data System (ADS)

    Sobrinho, A. A.; Jafelice, L. C.

    2003-08-01

    Discutimos nossa participação em um curso de treinamento para professores de diversas disciplinas do ensino médio. Nossa preocupação básica foi desenvolver instrumentos educacionais adequados para levar à sala de aula, nesse nível de ensino, de forma contextualizada, questionamentos freqüentes dos alunos sobre astronomia e sua relação com tecnologia e sociedade. Encaminhamos questões como: a evolução da astronomia, suas relações com outros ramos do conhecimento humano e conseqüentes aplicações; avanços na tecnologia dos instrumentos ópticos versus a importância da observação do céu a olho nu; a relação entre olho humano, luneta e telescópio; e desenvolvimento da tecnologia espacial e sua influência em nosso cotidiano. Objetivamos com isto fazer um resgate histórico e pedagógico das aplicações e observações do céu no cenário escolar, destacando a relação entre eventos astronômicos, olho humano, instrumentos mediadores e suas contextualizações históricas e sociais. Produtos desta abordagem foram o desenvolvimento e a adaptação de práticas e materiais instrucionais diversos (e.g., "espelhos" de isopor e "raios luminosos" de bolinhas de gude; montagens envolvendo velas, lasers, lentes e espelhos; desmonte e análise de peças de um telescópio; etc.). Além disto, como outro resultado deste trabalho, elaboramos textos sobre história da astronomia e da óptica para atividades em classe. Com estas ações visamos facilitar a concretização de conceitos físicos envolvidos, exemplificar um ensino contextualizado e interdisciplinar motivado por temas astronômicos e favorecer que práticas e discussões feitas com os treinandos possam ser transpostas para a sala de aula. A reação dos professores às práticas propostas foi bastante positiva. Todos esses aspectos são discutidos em detalhe neste trabalho. (PPGECNM/UFRN; PRONEX/FINEP; NUPA/USP; Temáticos/FAPESP)

  17. Cometa Hyakutake (C/1996 B2): análise do gás e características físicas das partículas de poeira

    NASA Astrophysics Data System (ADS)

    Sanzovo, G. C.; de Almeida, A. A.; Boczko, R.

    2003-08-01

    A completa caracterização e compreensão do núcleo de um cometa novo é de fundamental importância para a elucidação dos processos físicos e químicos atuantes na época da formação do Sistema Solar. O Cometa Hyakutake, conjuntamente com o Cometa Hale-Bopp representam os objetos mais brilhantes que visitaram o Sistema Solar Interno nos últimos 20 anos. Neste Trabalho, nós aplicamos o Método Semi-Empírico das Magnitudes Visuais (MSEMV) à aproximadamente 4000 dados observacionais que correlacionam a magnitude visual absoluta com a distância heliocêntrica para o Cometa Hyakutake nas fases pré- e pós-periélicas. Como produto da aplicação desse método, conseguimos caracterizar dimensionalmente seu núcleo e área ativa efetiva. As taxas de produção dos radicais CN, C2 e C3, obtidos a partir de dados disponíveis na literatura, revelam que, além de muito brilhante, o Hyakutake é um cometa "normal" no sentido de Cochran (1986). Desse modo, deduzimos as taxas de perdas de água (em moléculas/s) a partir da análise de sua magnitude visual aparente, e as convertemos em taxas de perdas de gás (em g/s), despreendido pelo nucleo cometário. Com o auxílio do modelo fotométrico clássico da poeira, realizamos uma análise sistemática e uniforme dessa componente cometária, a partir dos fluxos observacionais no contínuo, para os comprimentos de onda 365,0 e 484,5 nm, assumindo que esses fluxos são o resultado da radiação solar espalhada por grãos de partículas micrométricos presentes na coma. Com isso, pudemos obter as taxas de produção (em g/s), cores (relativas à cor neutra solar), e as dimensões efetivas médias das partículas de poeira, bem como as razões poeira-gás.

  18. Abundância química de simbióticas na direção do bojo galáctico

    NASA Astrophysics Data System (ADS)

    Luna, G. J. M.; Costa, R. D. D.

    2003-08-01

    O estudo da distribuição de metalicidades de gigantes K no Bojo indica um largo intervalo com valores entre 0.1 a 10 vezes o valor solar. As razões elementais Ca/Fe, Si/Fe, Mg/Fe são típicas de estrelas do halo, apontando para um processo rápido de enriquecimento, via estrelas masssivas (SN's tipo II). No entanto, este cenário não combina com os resultados derivados de nebulosas planetárias do bojo tais como os de Ratag et al. (1992, A&A,255,270), Cuisinier et al.(2000, A&A,353, 543), Escudero e Costa (2001, A&A,380, 300),que obtêm abundâncias análogas às do disco. Neste cenário, o estudo de estrelas simbióticas possibilita uma abordagem particularmente apropriada para o problema das abundâncias químicas de estrelas de massa intermediária em estágios avançados da evoluçao estelar. Apresentamos aqui os resultados da determinacão das abundâncias do grupo do CNO numa extensa amostra de simbióticas do bojo. Aliás, com a disponibilidade de espectros no visível determinamos também abundâncias de Ar, Ne, S e He, fundamentais para analisar os processos de enriquecimento químico ocorridos ao longo da evolução estelar, bem como a evolução química do meio interestelar. Com os espectros UV do satelite IUE obtivemos abundâncias de C, necessárias no estudo da evolução dos sistemas. As relaçoes C/N-O/N mostram que o material nebular é produto do vento da componente gigante e não dos eventos de nova que às vezes acontecem nestes sistemas, como foi mostrado por Nussbaumer et al (1988,A&A,198,179). As abundâncias de Ar, S, Ne e O são compativeis com resultados de fontes no disco e bojo, seguindo o gradiente proposto por muitos autores na literatura a partir de diferentes objetos como cefeidas, nebulosas planetárias e anãs G. (CAPES,FAPESP,CNPq)

  19. Observação do abrilhantamento de limbo solar e de estruturas filamentares em 48 ghz utilizando a técnica de regularização adaptativa

    NASA Astrophysics Data System (ADS)

    Machado, W. R. S.; Mascarenhas, N.; Costa, J. E. R.; Silva, A. V. R.

    2003-08-01

    O radiotelescópio do Itapetinga tem sido utilizado em campanhas de observações de explosões solares gerando um grande número de mapas diários em 48 GHz como sub-produto destas observações. A resolução espacial do telescópio de 14m do Itapetinga nesta freqüência é de aproximadamente dois minutos de arco. Estruturas de interesse para análise da atmosfera solar quiescente tais como os filamentos e o anel de abrilhantamento do limbo são de dimensão angular moderada da ordem ou ligeiramente menores que a resolução do telescópio. É conhecido que a convolução da função de espalhamento do telescópio, PSF (padrão de ganho do feixe) borra as estruturas de dimensão angular abaixo do HPBW (largura a meia potência do feixe) e portanto é comum a busca por técnicas de restauração que eliminem pelo menos em parte este borramento. Estudamos a restauração destas radioimagens usando a técnica de regularização adaptativa e os resultados ressaltam estas estruturas espaciais de pequeno contraste. O algoritmo da regularização adaptativa faz uso de k imagens, chamadas protótipos, obtidas através da variação de parâmetros de um filtro de regularização. Para controle da qualidade da restauração utilizamos uma imagem de alta resolução espacial obtida na linha H-a e a PSF do Itapetinga para borrá-la. Pequenos desvios, entre a PSF utilizada para o borramento e a PSF utilizada na restauração, produziram alguns desvios notáveis na imagem restaurada porém a adição de ruído nas simulações de restauração foram mais influentes no cálculo da rugosidade da imagem e portanto mais limitante para a restauração. Apresentamos como nosso primeiro resultado uma imagem em 48 GHz com a presença clara do abrilhantamento de limbo que não estava evidente na imagem original e traços de estruturas filamentares, porém ainda sem grande evidência.

  20. Ability of immunodiagnostic tests to differentiate between dogs naturally infected with Leishmania infantum and Leishmune(®)-vaccinated dogs.

    PubMed

    Ribeiro, R A N; Teixeira-Neto, R G; Belo, V S; Ferreira, E C; Schallig, H D F H; Silva, E S

    2015-06-01

    Visceral leishmaniasis (VL) is a serious chronic disease with a lethality rate of up to 10% in humans. In urban areas of Brazil, dogs are the main reservoirs of the etiological agent (Leishmania infantum) of VL, and the Brazilian Ministry of Health recommends the euthanasia of animals that are seropositive in both the immunochromatographic dual path platform rapid test (DPP(®); Bio-Manguinhos) and the enzyme-linked immunosorbent assay (ELISA) with an L. major-like antigen (Bio-Manguinhos). Vaccination is an additional tool in the control of canine VL, but the use of Leishmune(®) (Zoetis Indústria de Produtos Veterinários, São Paulo, SP, Brazil), which contains the fucose mannose ligand (FML) isolated from L. donovani, is not currently recommended by the Brazilian Ministry of Health because vaccinated animals may exhibit positive serology and there are reservations regarding the efficacy of the vaccine. The aims of the present study were: (i) to verify the abilities of the fast agglutination screening test (FAST), the direct agglutination test (DAT), the indirect fluorescent-antibody test (IFAT), the DPP rapid test, and ELISA tests with L. major-like and FML antigens to differentiate between L. infantum-infected and Leishmune(®)-vaccinated dogs, and (ii) to analyze the sensitivities and specificities of the different methods. The reactivities to these tests of Leishmune(®)-vaccinated dogs (n = 71), asymptomatic (n = 20) and symptomatic (n = 20) naturally infected dogs, and unvaccinated healthy control dogs (n = 5) were compared. None of the Leishmune(®)-vaccinated dogs tested seropositive in FAST and DAT, although one dog was reactive to DPP and four dogs to ELISA/L. major-like and IFAT tests. While 69 (97%) of vaccinated dogs reacted to ELISA/FML, only one was seropositive in both ELISA/L. major-like and IFAT tests. Individually, all immunodiagnostic tests presented high specificities and positive likelihood ratios (LR+), and high specificity values were

  1. Farmyard Manure and Fertilizer Effects on Seed Potato (Solanum tuberosum L.) Yield in Green House Production

    NASA Astrophysics Data System (ADS)

    László, M.

    2009-04-01

    ção máximas, principalmente em solos mais ácidos e pobres em matéria orgânico. A adubação fosfatada é muito importante no crescimento inicial da planta e, além de aumentar a produção de tuberculos em peso e números, aumenta também a quantidade e qualidade do amido neles contidos e reduz perdas durante o armazenamento dos mesmos. A quantidade de fósforo a aplicar dependerá da análise do solo considerando- se principalmente o nível de P existente e a textura do solo. Solos de textura média e arenosa necessitam maior conteúdo de fósforo do que os de textura argilosa para serem considerandos solos de baixo, médio ou alto teor de fósfato. Efeito da potássica Embora seja o elemento mais absorbido pela batateira, nem sempre há resposta positiva da aduba potássica sobre o rendimento da cultura. Provavelmente isto esteja relacionado com níveis elevados deste elemento no solo (Kurnik et all. 2001.). Entretanto, em solos com médios e baixos teores de potássio, aumentos significativos são conseguidos. Por isto, as recomendações de adubação com potássio, nas diversas regiões do mundo, variam de 50-300 kg ha-1 de K2O. Resultados de trabalhos em brasiléiros têm demonstrado que a aduba potássica pode ser substituída pela aplicação de 150 m3 ha-1 de vinhaça de cana de açúcar. Ao elevar- se a dose de fertilização potássica deverá haver precaução para que a adubação magnesiana seja suficiente. O K além de aumentar a produção, em solos deficientes, aumenta também o tamanho dos tubérculos produzidos, e a proporção de tubérculos grandes. Deficiência no suprimento de potássio á planta pode acarretar produção de tubérculos com elevada susceptibilidade aos danos mecánicos pós-colheita. Os tubérculos injuriados enegrecem facilmente e este enegrecimento é inversamente proporcional á quantidade de potássio nos tuberculos. Ademais, quando fritos dão origem a um produto escuro, de baixa valor comercial. Manejo de aduba

  2. Water-gas dynamics and coastal land subsidence over Chioggia Mare field, northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Teatini, Pietro; Baú, Domenico; Gambolati, Giuseppe

    2000-09-01

    menace potentielle pour la ville de Venise, à 25 km au nord-ouest du centre de Chioggia Mare. Afin d'évaluer le risque de subsidence du sol provoquée par les prélèvements de gaz, un modèle numérique a été développé pour prévoir la compaction des formations réservoirs de gaz en même temps que celle de l'aquifère latéral et sous-jacent, par effet de drainance, sur une période de 13 ans de production, suivie de 12 ans, et pour prévoir le transfert de la compaction profonde jusqu'à la surface du sol. Afin de prendre en compte l'incertitude sur un petit nombre de paramètres hydromécaniques importants, plusieurs scénarios ont été simulés et les prévisions les plus pessimistes ont été obtenues. Les résultats de la modélisation montrent qu'on doit s'attendre, au cours des 25 ans, au plus à une subsidence du sol de 1 cm à Chioggia, tandis que Venise ne subira aucun effet. Si la baisse de l'aquifère est compensée par une injection d'eau, la subsidence du sol s'arrêtera à 5 km au large et la zone côtière de Chioggia subira un effet de 0,6 à 0,7 cm. Resumen. Recientemente, la compañía nacional italiana del petróleo, ENI-Agip, ha enviado al Ministerio de Medio Ambiente de Italia (Comité VIA) un gran programa de desarrollo de 15 campos de gas en el norte del Mar Adriático para la evaluación de su impacto medioambiental. Una de las reservas principales de gas se halla en el mar de Chioggia, a unos 10 km mar adentro de la costa veneciana, a una profundidad de entre 1.000 y 1.400 m. Se espera que la producción en este campo produzca un impacto en la estabilidad de la línea de costa, y que suponga una amenaza potencial para la ciudad de Venecia, situada a 25 km al noroeste de la explotación. Se desarrolló un modelo numérico para evaluar el riesgo de subsidencia debido a la extracción de gas a lo largo de los 13 años de producción y del período post-productivo de 12 años. Sus predicciones indican que se causará la compactación tanto

  3. Effet de l'interaction coulombienne sur la localisation d'Anderson dans le gaz bidimensionnel d'électrons

    NASA Astrophysics Data System (ADS)

    Fleury, G.

    2010-09-01

    Nous étudions l’effet des interactions coulombiennes sur la localisation d’Anderson dans le gaz bidimensionnel d’électrons désordonné. L’objectif est de statuer sur la question de l’existence de métaux à deux dimensions. En l’absence d’interaction, la théorie d’échelle de la localisation prédit qu’un désordre infinitésimal suffit à localiser la fonction d’onde électronique et donc à rendre le système isolant à température nulle (Abrahams et al., 1979). Dans certaines limites extrêmes, les interactions peuvent être prises en compte et l’on aboutit également à un état isolant. Cependant, aucune théorie analytique ne permet de traiter le régime quantique non-perturbatif où désordre et interaction sont intermédiaires. Expérimentalement, il est possible de l’explorer dans des échantillons de haute mobilité et basse densité. Depuis 1994, des comportements métalliques inexpliqués y ont été observés (Kravchenko et al., 1994). Nous avons mis au point une méthode numérique permettant d’étudier le problème couplé de la localisation d’Anderson en présence d’interaction. Cette méthode mêle Monte Carlo quantique à température nulle et théorie d’échelle pour la conductance de Thouless. Nous trouvons que la théorie d’échelle de la localisation est préservée en présence d’interaction et donc que le gaz bidimensionnel, même corrélé, est isolant à température nulle. Nos résultats montrent de plus que les interactions délocalisent le gaz bidimensionnel et que cet effet de délocalisation est accru en présence de dégénérescence de vallées. Ils nous permettent de proposer un mécanisme simple rendant compte des principales caractéristiques des comportements métalliques observés expérimentalement.

  4. Les astronomes européens auscultent les cieux avec le plus grand télescope du monde

    NASA Astrophysics Data System (ADS)

    Malbet, F.

    2008-09-01

    À l'heure des projets de télescopes extrêmement grands, l'Europe a déjà une longueur d'avance. Le télescope européen (VLT), en mode interférométrique avec l'instrument AMBER devient le plus grand télescope jamais utilisé dans le domaine optique aussi bien en surface de miroir (plus de 150 m2) qúen finesse de résolution qui atteint celle d'un télescope de 130 m de diamètre. Le journal professionnel Astronomy & Astrophysics a publié en 2007 un numéro spécial qui rapporte les premiers résultats obtenus avec l'instrument AMBER (Astronomical MultiBEam Recombiner) par le très grand télescope européen. Ces articles couvrent pratiquement tous les stades de l'évolution stellaire depuis la formation des étoiles et des planètes jusqu'a l'observation de l'explosion de type nova dans un système stellaire évolué. Ces résultats inédits ont été obtenus en utilisant simultanément 3 des 4 télescopes du VLT basés à l'Observatoire européen austral du mont Paranal au Chili. L'instrument AMBER équipant le VLTI (mode interférométrique du VLT) permet dâatteindre une résolution angulaire inégalée de l'ordre du millième de seconde d'angle autorisant l'observation des astres dans différentes longueurs d'onde, dans l'infrarouge proche. Les astronomes obtiennent donc des observations avec une finesse 13 fois plus importante que celle d'un télescope seul. Il devient alors possible de sonder les régions de formation de planètes, d'observer les vents des étoiles en rotation très rapide, d'étudier les différents types de matières éjectées par une étoile massive, de séparer les deux composantes d'une étoile double serrée et de voir en direct l'évolution d'une nova quelques jours seulement après son explosion.

  5. Limit analysis of multi-layered plates. Part I: The homogenized Love-Kirchhoff model

    NASA Astrophysics Data System (ADS)

    Dallot, Julien; Sab, Karam

    The purpose of this paper is to determine Gphom, the overall homogenized Love-Kirchhoff strength domain of a rigid perfectly plastic multi-layered plate, and to study the relationship between the 3D and the homogenized Love-Kirchhoff plate limit analysis problems. In the Love-Kirchhoff model, the generalized stresses are the in-plane (membrane) and the out-of-plane (flexural) stress field resultants. The homogenization method proposed by Bourgeois [1997. Modélisation numérique des panneaux structuraux légers. Ph.D. Thesis, University Aix-Marseille] and Sab [2003. Yield design of thin periodic plates by a homogenization technique and an application to masonry wall. C. R. Méc. 331, 641-646] for in-plane periodic rigid perfectly plastic plates is justified using the asymptotic expansion method. For laminated plates, an explicit parametric representation of the yield surface ∂Gphom is given thanks to the π-function (the plastic dissipation power density function) that describes the local strength domain at each point of the plate. This representation also provides a localization method for the determination of the 3D stress components corresponding to every generalized stress belonging to ∂Gphom. For a laminated plate described with a yield function of the form F(x3,σ)=σu(x3)F^(σ), where σu is a positive even function of the out-of-plane coordinate x3 and F^ is a convex function of the local stress σ, two effective constants and a normalization procedure are introduced. A symmetric sandwich plate consisting of two Von-Mises materials ( σu=σ1u in the skins and σu=σ2u in the core) is studied. It is found that, for small enough contrast ratios ( r=σ1u/σ2u≤5), the normalized strength domain G^phom is close to the one corresponding to a homogeneous Von-Mises plate [Ilyushin, A.-A., 1956. Plasticité. Eyrolles, Paris].

  6. Dynamic aerofracture or hydrofracture of dense granular packing: pressure and viscosity control of the fracture patterns

    NASA Astrophysics Data System (ADS)

    Niebling, Michael J.; Toussaint, Renaud; Flekkøy, Eirik G.; Jørgen Måløy, Knut

    2013-04-01

    øy and K.J. Måløy, Dynamic aerofracture of dense granular packings, Phys. Rev. E 86, 061315 (2012). [4] Niebling, M., R. Toussaint, E.G. Flekkøy and K.J. Måløy, Estudios numéricos de Aerofractures en medios poros / Numerical Studies of Aerofractures in Porous Media, Revista Cubana de Fisica, 29, 1E, 1E66, 2012.

  7. Uma grade de perfis teóricos para estrelas massivas em transição

    NASA Astrophysics Data System (ADS)

    Nascimento, C. M. P.; Machado, M. A.

    2003-08-01

    Na XXVIII Reunião Anual da Sociedade Astronômica Brasileira (2002) apresentamos uma grade de perfis calculados de acordo com os pontos da trajetória evolutiva de metalicidade solar, Z = 0.02 e taxa de perda de massa () padrão, para estrelas com massa inicial de 25, 40, 60, 85 e 120 massas solares. Estes perfis foram calculados com o auxílio de um código numérico adequado para descrever os ventos de objetos massivos, supondo simetria esférica, estacionaridade e homogeneidade. No presente trabalho, apresentamos a complementação da grade com os perfis teóricos relativos às trajetórias de Z = 0.02 com taxa de perda de massa dobrada em relação a padrão (2´), e de metalicidade Z = 0.008. Para cada ponto das três trajetórias obtemos os perfis teóricos de Ha, Hb, Hg e Hd, e como esperado eles se apresentam em pura emissão, pura absorção ou em P-Cygni. Para valores de taxa de perda de massa muito baixos (~10-7) não há formação de linhas, o que é visto nos primeiros pontos em todas as trajetórias. Em geral, para um mesmo ponto a componente de emissão diminui e a absorção aumenta de Ha para Hd. É verificado que as trajetórias com Z = 0.02 e padrão possuem menos circuitos (loops) do que as com metalicidade Z = 0.02 e 2´ padrão, e seus perfis são, em geral, menos intensos. Em relação a trajetória de Z = 0.008, verifica-se menos circuitos e maior variação em luminosidade, e seus perfis mostram-se em, algumas trajetórias, mais intensos. Verificamos também que, pontos distintos em uma mesma trajetória, apresentam perfis diferentes para valores similares de luminosidade e temperatura efetiva. Sendo assim, uma grade de perfis teóricos parece ser útil para fornecer uma informação preliminar sobre o estágio evolutivo de uma estrela massiva.

  8. Precessão do jato de 3C120: simulações hidrodinâmicas 3D

    NASA Astrophysics Data System (ADS)

    Caproni, A.; de Gouveia dal Pino, E. M.; Abraham, Z.; Raga, A. C.

    2003-08-01

    Observações com técnicas de interferometria com longa linha de base têm mostrado a existência de um jato relativístico com componentes superluminais na região central de 3C 120. Estas componentes são ejetadas em distintas direções no plano do céu e com diferentes velocidades aparentes. Estas características foram interpretadas em trabalhos anteriores como efeitos da precessão do jato relativístico. Neste trabalho, realizamos simulações tri-dimensionais do jato de 3C 120 utilizando os parâmetros de precessão determinados em trabalhos anteriores e variando as características iniciais do jato e meio ambiente, tais como densidade numérica e temperatura. Todas as simulações foram feitas com o código hidrodinâmico YGUAZÚ-A, assumindo-se um jato adiabático descrito por uma equação de estado relativística. Pelo fato de estarmos utilizando um código hidrodinâmico, nós assumimos que a intensidade do campo magnético e a distribuição de partículas, necessários para se calcular a emissão sincrotron, são proporcionais à pressão hidrodinâmica. Comparação entre dois cenários distintos, nos quais o material do jato é ejetado com velocidade constante (jato contínuo) e com velocidade modulada por um padrão sinusoidal no tempo (jato intermitente), é apresentada e discutida. Para jatos que apresentam fenômenos de precessão e intermitência, com amplitude de variação na velocidade de injeção maior que dez por cento da velocidade média de injeção, a hipótese balística, controlada pela intermitencia, é mais provável. Por outro lado, para jatos com precessão mas sem intermitência (ou com amplitude de variabilidade em velocidade mais baixa que no caso anterior), o efeito da precessão na morfologia do jato não é desprezível. Portanto, de um modo geral, ambos efeitos (precessão e movimentos balísticos) devem estar concorrendo para afetar a morfologia dos jatos superluminais.

  9. The Ophidia Stack: Toward Large Scale, Big Data Analytics Experiments for Climate Change

    NASA Astrophysics Data System (ADS)

    Fiore, S.; Williams, D. N.; D'Anca, A.; Nassisi, P.; Aloisio, G.

    2015-12-01

    The Ophidia project is a research effort on big data analytics facing scientific data analysis challenges in multiple domains (e.g. climate change). It provides a "datacube-oriented" framework responsible for atomically processing and manipulating scientific datasets, by providing a common way to run distributive tasks on large set of data fragments (chunks). Ophidia provides declarative, server-side, and parallel data analysis, jointly with an internal storage model able to efficiently deal with multidimensional data and a hierarchical data organization to manage large data volumes. The project relies on a strong background on high performance database management and On-Line Analytical Processing (OLAP) systems to manage large scientific datasets. The Ophidia analytics platform provides several data operators to manipulate datacubes (about 50), and array-based primitives (more than 100) to perform data analysis on large scientific data arrays. To address interoperability, Ophidia provides multiple server interfaces (e.g. OGC-WPS). From a client standpoint, a Python interface enables the exploitation of the framework into Python-based eco-systems/applications (e.g. IPython) and the straightforward adoption of a strong set of related libraries (e.g. SciPy, NumPy). The talk will highlight a key feature of the Ophidia framework stack: the "Analytics Workflow Management System" (AWfMS). The Ophidia AWfMS coordinates, orchestrates, optimises and monitors the execution of multiple scientific data analytics and visualization tasks, thus supporting "complex analytics experiments". Some real use cases related to the CMIP5 experiment will be discussed. In particular, with regard to the "Climate models intercomparison data analysis" case study proposed in the EU H2020 INDIGO-DataCloud project, workflows related to (i) anomalies, (ii) trend, and (iii) climate change signal analysis will be presented. Such workflows will be distributed across multiple sites - according to the

  10. Détermination quotidienne, en tous les points d'une région, de l'évolution de l'éclairement solaire utilisable à partir d'images de meteosat

    NASA Astrophysics Data System (ADS)

    Ben Jemaa, A.; Delorme, C.

    1992-05-01

    Our methodology Gistel gives, for each pixel of each numerical image of the visible channel from meteosat, the global irradiance on the ground. It is described here. It has been applied in Tunisia to archived B2 images and in France to Wefax images regularly received at Carpentras. Results are compared with measured daily and hourly irradiations from several stations. The ability to reproduce the evolution of the available solar radiation during several days is analysed. The accuracy about irradiances of our methodology is, indeed, lower than of this one of pyranometers. But if 6 or 8 Wefax images are daily processed, it is possible to get useful data about the distribution of radiation versus time and space. These data disseminated with a short delay allow users to check the daily performances of their solar energy systems. The stored data will be useful to systems designers. La méthodologie Gistel fournit pour chaque pixel de chaque image numérique du canal visible du satellite géostationnaire meteosat l'éclairement global au sol. Elle est brièvement décrite ici. Elle a été appliquée, d'une part en Tunisie à des images archivées B2 et d'autre part en France à des images Wefax reçues régulièrement à Carpentras. Les résultats obtenus sont comparés aux mesures d'irradiations journalières et horaires des stations actinométriques. La reproductibilité de l'évolution du rayonnement disponible au cours de quelques journées est analysée et discutée. La précision des éclairements fournis est, certes, inférieure à celle d'un pyranomètre mais appliquée quotidiennement à 6 ou 8 images Wefax par jour Gistel peut donner des informations utiles sur l'évolution du flux solaire dans l'espace et le temps. Ces informations, transmises en temps peu différé, permettent aux utilisateurs de vérifier les performances de leurs systèmes énergétiques solaires, non équipés de pyranomètres. Les informations stockées pourront servir aux concepteurs de

  11. PyR@TE. Renormalization group equations for general gauge theories

    NASA Astrophysics Data System (ADS)

    Lyonnet, F.; Schienbein, I.; Staub, F.; Wingerter, A.

    2014-03-01

    : Personal computer. Operating system: Tested on Fedora 15, MacOS 10 and 11, Ubuntu 12. Classification: 11.1. External routines: SymPy, PyYAML, NumPy, IPython, SciPy Nature of problem: Deriving the renormalization group equations for a general quantum field theory. Solution method: Group theory, tensor algebra Running time: Tens of seconds per model (one-loop), tens of minutes (two-loop)

  12. Soft x-ray holography and microscopy of biological cells

    NASA Astrophysics Data System (ADS)

    Chen, Jianwen; Gao, Hongyi; Xie, Honglan; Li, Ruxin; Xu, Zhizhan

    2003-10-01

    Some experimental results on soft X-ray microscopy and holography imaging of biological specimens are presented in the paper. As we know, due to diffraction effects, there exists a resolution limit determined by wavelength λ and numerical aperture NA in conventional optical microscopy. In order to improve resolution, the num erical aperture should be made as large as possible and the wavelength as short as possible. Owing to the shorter wavelength, X-rays provide the potential of higher resolution in X-ray microscopy, holography image and allow for exam ination the interior structures of thicker specimens. In the experiments, we used synchrotron radiation source in Hefei as light source. Soft X-rays come from a bending magnet in 800 M eV electron storage ring with characteristic wavelength of 2.4 nm. The continuous X-ray spectrums are monochromatized by a zone-plate and a pinhole with 300 m diameter. The experimental set-up is typical contact microscopic system, its main advantage is simplicity and no special optical element is needed. The specimens used in the experiments of microscopic imaging are the colibacillus, the gingko vascular hundle and the fritillaries ovary karyon. The specimen for holographic imaging is the spider filam ents. The basic structures of plant cells such as the cell walls, the cytoplasm and the karyon especially the joint structures between the cells are observed clearly. An experimental study on a thick biological specimen that is a whole sporule w ith the thickness of about 30 μm is performed. In the holographic experiments, the experimental setup is typical Gabor in-line holography. The specimen is placed in line with X-ray source, which provides both the reference w aves and specimen illum ination. The specimen is some spider filament, which adhere to a Si3N4 film. The recording medium is PM M A, which is placed at recording distance of about 400 μm from the specimen. The hologram s were reconstructed by digital method with 300 nm

  13. Gas Phase Model of Surface Reactions for N{2} Afterglows

    NASA Astrophysics Data System (ADS)

    Marković, V. Lj.; Petrović, Z. Lj.; Pejović, M. M.

    1996-07-01

    The adequacy of the homogeneous gas phase model as a representation of the surface losses of diffusing active particles in gas phase is studied. As an example the recent data obtained for the surface recombination coefficients are reanalyzed. The data were obtained by the application of the breakdown delay times which consists of the measurements of the breakdown delay times t_d as a function of the afterglow period tau. It was found that for the conditions of our experiment, the diffusion should not be neglected as the final results are significantly different when obtained by approximate gas phase representation and by exact numerical solution to the diffusion equation. While application of the gas phase effective coefficients to represent surface losses gives an error in the value of the recombination coefficient, it reproduces correctly other characteristics such as order of the process which can be obtained from simple fits to the experimental data. Dans cet article, nous étudions la validité du modèle approximatif représentant les pertes superficielles des particules actives qui diffusent de la phase gazeuse comme pertes dans la phase homogène du gaz. Les données actuelles du coefficient de recombination en surface sont utilisées par cette vérification . Les données experimentales sont obtenues en utilisant la technique qui consiste en la mesure du temps de retard du début de la décharge en fonction de la période de relaxation. Nous avons trouvé que, pour nos conditions expérimentales, la diffusion ne peut être négligée. Aussi, les résultats finals sont considérablement différents quand ils sont obtenus en utilisant le modèle approximatif par comparaison aves les résultats obtenus par la solution numérique exacte de l'équation de la diffusion. L'application des coefficients effectifs dans la phase gaseuse pour la présentation des pertes superficielles donne, pour les coefficients de la recombinaison, des valeurs qui diffèrent en

  14. Pricing A Raindrop: A Case Study For The Upper-zambezi

    NASA Astrophysics Data System (ADS)

    Houba, H.; Keyzer, M.

    A successful economic valuation of water flows and stored water in aquifers re- quires the interdisciplinary collaboration of hydrology and economics. A common difficulty in this context is that a process-based representation of the underlying pro- cesses necessarily causes the model specification to depart from basic postulates of micro-economic theory. Consequently, regular valuation procedures do not apply, and current practice has become either to discard the irregularities in the hydrological process or to restrict the valuation procedure to impact assessments for a limited num- ber of scenario simulations. In this contribution, relying on capital theory, we first describe a technique that enables us to effectuate a comprehensive valuation despite the non-standard features and, then, apply this technique to an existing hydrological process-based model developed by experts in this matter. The technique consists of formulating a suitable mathematical optimization program such that Lagrange multi- pliers can be computed. Such multipliers represent both the marginal returns of vari- ations of inflows (precipitation) and the adjustments in structural characteristics of the physical process. By imbedding this program in suitable optimization software it can be solved numerically without having to calculate analytical expressions for the derivatives. The multipliers automatically take into account the intertemporal and spatial effects of variations in inflow throughout the system, including all effects of upstream variations of inflows in both upstream and downstream in situ values. Appli- cation of this technique only requires that existing hydrological models are translated into suitable optimization software. In this contribution the results of such an exercise are presented, where the optimization package is GAMS. The hydrological model ap- plied, called Aqua, was recently developed at IHE, Delft, for the Upper-Zambezi river basin. The applied technique is very

  15. OREGANO_VE: a new parallelised 3D solver for the general (non-)linear Maxwell visco-elastic problem: validation and application to the calculation of surface deformation in the earthquake cycle

    NASA Astrophysics Data System (ADS)

    Yamasaki, Tadashi; Houseman, Gregory; Hamling, Ian; Postek, Elek

    2010-05-01

    We have developed a new parallelized 3-D numerical code, OREGANO_VE, for the solution of the general visco-elastic problem in a rectangular block domain. The mechanical equilibrium equation is solved using the finite element method for a (non-)linear Maxwell visco-elastic rheology. Time-dependent displacement and/or traction boundary conditions can be applied. Matrix assembly is based on a tetrahedral element defined by 4 vertex nodes and 6 nodes located at the midpoints of the edges, and within which displacement is described by a quadratic interpolation function. For evaluating viscoelastic relaxation, an explicit time-stepping algorithm (Zienkiewicz and Cormeau, Int. J. Num. Meth. Eng., 8, 821-845, 1974) is employed. We test the accurate implementation of the OREGANO_VE by comparing numerical and analytic (or semi-analytic half-space) solutions to different problems in a range of applications: (1) equilibration of stress in a constant density layer after gravity is switched on at t = 0 tests the implementation of spatially variable viscosity and non-Newtonian viscosity; (2) displacement of the welded interface between two blocks of differing viscosity tests the implementation of viscosity discontinuities, (3) displacement of the upper surface of a layer under applied normal load tests the implementation of time-dependent surface tractions (4) visco-elastic response to dyke intrusion (compared with the solution in a half-space) tests the implementation of all aspects. In each case, the accuracy of the code is validated subject to use of a sufficiently small time step, providing assurance that the OREGANO_VE code can be applied to a range of visco-elastic relaxation processes in three dimensions, including post-seismic deformation and post-glacial uplift. The OREGANO_VE code includes a capability for representation of prescribed fault slip on an internal fault. The surface displacement associated with large earthquakes can be detected by some geodetic observations

  16. Chania multitudinisentens gen. nov., sp. nov., an N-acyl-homoserine-lactone-producing bacterium in the family Enterobacteriaceae isolated from landfill site soil.

    PubMed

    Ee, Robson; Madhaiyan, Munusamy; Ji, Lianghui; Lim, Yan-Lue; Nor, Nuruddin Muhammad; Tee, Kok-Keng; Chen, Jian-Woon; Yin, Wai-Fong

    2016-06-01

    Phylogenetic and taxonomic characterization was performed for bacterium RB-25T, which was isolated from a soil sample collected in a former municipal landfill site in Puchong, Malaysia. Growth occurred at 20-37 °C at pH 5-8 but not in the presence of 9 % (w/v) NaCl or higher. The principal fatty acids were C16:0, C18:1ω7c and summed feature 3 (C16:1ω7c and/or iso-C15:0 2-OH). Ubiquinone-8 was the only isoprenoid quinone detected. Polar lipid analysis revealed the presence of phospholipid, phosphoaminolipid, phosphatidylethanolamine, phosphatidylglycerol and one unidentified aminolipid. DNA G+C content was 50.9 mol% phylogenetic analysis based on 16S rRNA gene sequence showed that strain RB-25T formed a distinct lineage within the family Enterobacteriaceae of the class Gammaproteobacteria. It exhibited a low level of 16S rRNA gene sequence similarity with its phylogenetic neighbours Pantoea rwandensis LMG 26275T (96.6 %), Rahnella aquatilis CIP 78.65T (96.5 %), Pectobacterium betavasculorum ATCC 43762T (96.4 %), Pantoea rodasii LMG 26273T (96.3 %), Gibbsiella dentisursi NUM 1720T (96.3 %) and Serratia glossinae C1T (96.2 %). Multilocus sequence analyses based on fusA, pyrG, rplB, rpoB and sucA sequences showed a clear distinction of strain RB-25T from the most closely related genera. Isolate RB-25T could also be distinguished from members of these genera by a combination of the DNA G+C content, respiratory quinone system, fatty acid profile, polar lipid composition and other phenotypic features. Strain RB-25T represents a novel species of a new genus, for which the name Chaniamultitudinisentens gen. nov., sp. nov. is proposed. The type strain is RB-25T (=DSM 28811T=LMG 28304T). PMID:26978486

  17. ObsPy: A Python toolbox for Seismology, a Data Center Perspective

    NASA Astrophysics Data System (ADS)

    Beyreuther, Moritz; Barsch, Robert; Krischer, Lion; Megies, Tobias; Behr, Yannik; Wassermann, Joachim

    2010-05-01

    ObsPy: A Python toolbox for seismology (http://www.obspy.org) aims at filling the gap between interactive analysis and automatic data acquistion systems. Automatic batch analysis of continuous data streams or feeding a so far unknown formatted data stream into an acquistion system are two possible applications. Python provides a platform independent, free and open source interpreter language including a large collection of scientific open-source modules thus allowing rapid development of prototype code. ObsPy extends Python by providing the seismologist with basic seismological routines, e.g. MiniSEED, SAC, GSE2 read and write support, various pickers, filters, instrument correction... The data itself is stored in numpy.ndarrays allowing powerful numerical array-programming modules like NumPy (http://numpy.scipy.org) or SciPy (http://scipy.org) to be used. Also SeisComP3 has a Python API which makes use of the previous mentioned modules, thus making it easy to extend SeisComP3 with the help of the ObsPy library. Especially for data centers the ObsPy ArcLink and XSEED modules are of special interest. The ArcLink module makes it possible to easily automatically access the data via ArcLink or for testing the servers functionality. The XSEED module allows to convert data from dataless SEED to XML-SEED and back. The XML-SEED format is very verbose and easy extensible for internal purposes. For "public" distribution the resulting extended XML-SEED can always be converted back to the standard exchange format dataless SEED (loosing the additionally fields). An application of ObsPy is running on the Azores. Here, seismic data are continuous recorded with National Instruments digitizers which are writing data in an binary format every 10s. ObsPy is used to feed the data in EarthWorm and SeisComP3 by decoding the binary format every 30s and appending the new data to a MiniSEED file. The MiniSEED file is continuously scanned by the mseed_scan module of the seedlink server and

  18. Parasitose intestinale simulant une appendicite à l’échographie: à propos de deux cas

    PubMed Central

    Gabrielle, Andrianah Emmylou Prisca; Hasina, Rajaonarison NyOny Narindra Lova; Ravelonarivo, RandrianantenainaFarlahy; Ahmad, Ahmad

    2015-01-01

    L'objectif de ce travail est d'apporter un diagnostic différentiel d'appendicite à l’échographie sur la région de la fosse iliaque droite, destiné notamment aux échographistes mal entrainés ou débutant. Nous rapportons deux cas de parasitoses intestinales découvertes au niveau de la fosse iliaque droite simulant une appendicite. Le premier cas concernait une femme de 45 ans, sans antécédent particulier, référée pour échographie abdominale suite à une douleur de la fosse iliaque droite, apyrétique, sans trouble de transit. L'examen échographique par voie sus-pubienne de la fosse iliaque droite (FID) objectivait une structure arrondie à paroi épaisse, de 8 mm de diamètre en coupe transversale et tubulée à extrémité borgne en coupe longitudinale, à contenu hétérogène hypoéchogène en coupe longitudinale et une sensibilité de cette zone au passage de la sonde. La biologie présentait une hyperéosinophilie et à l'examen des selles par recherche de kyste, amibe et oeufs parasitaires, on décelait des oeufs parasitaires. Le deuxième cas était un garçon de 15 ans, sans antécédent particulier. Son échographie était indiquée suite à une douleur abdominale aigue fébrile. Les images échographiques sur la FID montraient une structure arrondie de 7 mm de diamètre et à paroi épaisse hyperéchogène en coupe transversale et en coupe longitudinale, elle était tubulée borgne, immobile et sensible au passage de la sonde. La numération formule sanguine rapportait une hyperleucocytose à prédominance polynucléaire. Au total, la parasitose intestinale peut mimer un aspect échographique d'une appendicite, que tout échographiste notamment les débutants et peu expérimentésdoit éliminer. PMID:26587169

  19. Embracing Open Software Development in Solar Physics

    NASA Astrophysics Data System (ADS)

    Hughitt, V. K.; Ireland, J.; Christe, S.; Mueller, D.

    2012-12-01

    We discuss two ongoing software projects in solar physics that have adopted best practices of the open source software community. The first, the Helioviewer Project, is a powerful data visualization tool which includes online and Java interfaces inspired by Google Maps (tm). This effort allows users to find solar features and events of interest, and download the corresponding data. Having found data of interest, the user now has to analyze it. The dominant solar data analysis platform is an open-source library called SolarSoft (SSW). Although SSW itself is open-source, the programming language used is IDL, a proprietary language with licensing costs that are prohibative for many institutions and individuals. SSW is composed of a collection of related scripts written by missions and individuals for solar data processing and analysis, without any consistent data structures or common interfaces. Further, at the time when SSW was initially developed, many of the best software development processes of today (mirrored and distributed version control, unit testing, continuous integration, etc.) were not standard, and have not since been adopted. The challenges inherent in developing SolarSoft led to a second software project known as SunPy. SunPy is an open-source Python-based library which seeks to create a unified solar data analysis environment including a number of core datatypes such as Maps, Lightcurves, and Spectra which have consistent interfaces and behaviors. By taking advantage of the large and sophisticated body of scientific software already available in Python (e.g. SciPy, NumPy, Matplotlib), and by adopting many of the best practices refined in open-source software development, SunPy has been able to develop at a very rapid pace while still ensuring a high level of reliability. The Helioviewer Project and SunPy represent two pioneering technologies in solar physics - simple yet flexible data visualization and a powerful, new data analysis environment. We

  20. Using Python for scientific computing: Efficient and flexible evaluation of the statistical characteristics of functions with multivariate random inputs

    NASA Astrophysics Data System (ADS)

    Chudoba, R.; Sadílek, V.; Rypl, R.; Vořechovský, M.

    2013-02-01

    This paper examines the feasibility of high-level Python based utilities for numerically intensive applications via an example of a multidimensional integration for the evaluation of the statistical characteristics of a random variable. We discuss the approaches to the implementation of mathematically formulated incremental expressions using high-level scripting code and low-level compiled code. Due to the dynamic typing of the Python language, components of the algorithm can be easily coded in a generic way as algorithmic templates. Using the Enthought Development Suite they can be effectively assembled into a flexible computational framework that can be configured to execute the code for arbitrary combinations of integration schemes and versions of instantiated code. The paper describes the development cycle using a simple running example involving averaging of a random two-parametric function that includes discontinuity. This example is also used to compare the performance of the available algorithmic and executional features. The implemented package including further examples and the results of performance studies have been made available via the free repository [1] and CPCP library. Program summaryProgram title: spirrid Catalogue identifier: AENL_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AENL_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Special licence provided by the author No. of lines in distributed program, including test data, etc.: 10722 No. of bytes in distributed program, including test data, etc.: 157099 Distribution format: tar.gz Programming language: Python and C. Computer: PC. Operating system: LINUX, UNIX, Windows. Classification: 4.13, 6.2. External routines: NumPy (http://numpy.scipy.org/), SciPy (http://www.scipy.com) Nature of problem: Evaluation of the statistical moments of a function of random variables. Solution method: Direct multidimensional

  1. EBSD observations of dynamic recrystallization mechanisms in ice.

    NASA Astrophysics Data System (ADS)

    Montagnat, Maurine; Chauve, Thomas; Barou, Fabrice; Beausir, Benoît; Fressengeas, Claude; Tommasi, Andrea

    2014-05-01

    direction. Within our condition range, the grain boundary migration highly dominates the DRX mechanisms and induces strongly serrated grain boundaries. This is to be associated with a highly heterogeneous state of stress and strain that is not "homogenised" by DRX mechanisms. Indeed, higher resolution observations (5 microns) reveal highly distorted areas close to grain boundaries and triple junctions. T. H. Jacka and M. Maccagnan (1984). Ice crystallographic and strain rate changes with strain in compression and extension. Cold Reg. Sci. Technol. Vol. 8 pp 269-286 D. S. Russell-Head and C. J. L. Wilson (2001). Automated fabric analyser system for quartz and ice. J. Glaciol. Vol. 24 Num 90 pp 117-130

  2. Espectroscopia de candidatos a remanescentes de aglomerados abertos

    NASA Astrophysics Data System (ADS)

    Pavani, D. B.; Bica, E.; Ahumada, A. V.; Clariá, J. J.

    2003-08-01

    A pesquisa sobre remanescentes de aglomerados abertos tem despertado grande interesse. Seguindo esta tendência encontramos estudos teóricos e observacionais. Os primeiros baseiam-se em simulações numéricas buscando determinar fração de binárias e distâncias galatocêntricas, tempo de vida e conteúdo estelar. Estes estão relacionados à função inicial de massa e densidade de estrelas, ou seja, se ricos ou pobremente povoados, compactos ou esparsos. No caso observacional procuram-se identificar os remanescentes considerando-se que trazem estas assinaturas de seus percursores. No presente estudo empregamos espectroscopia para analisar oito concentrações pobremente povoadas, previamente classificadas como aglomerados abertos, sendo sete compactas e uma esparsa. As observações foram obtidas através do telescópio de 2,15 m do CASLEO em San Juan, Argentina, em turnos entre 2001 e 2003. Utilizamos uma câmara CCD contendo um chip Tektronics de 1024X1024 pixeis aliado a um espectrógrafo REOSC. O domínio espectral vai de 3700 a 7000 Å. As reduções foram realizadas no Observatório Astronômico de Córdoba (Argentina) usando pacotes IRAF padrões. Determinamos idades, avermelhamentos e tipos espectrais através de comparações com biblioteca de estrelas e de aglomerados. Em alguns casos nossos espectros estavam dominados por estrelas individuais às quais determinamos seus tipos espectrais. Aos oito objetos adicionamos mais cinco da literatura recente analisados via espectro ou diagrama cor-magnitude. O histograma resultante contém idades típicas entre 0.5 e 3 Ganos. Considerando que predominantemente estes objetos encontram-se na vizinhança solar e, portanto, não cruzaram muitas vezes o plano Galático esperamos que a diferença no tempo necessário para dissolução destes prováveis remanescentes seja em função de diferentes massas iniciais.

  3. Simulação de ejeções de massa coronal

    NASA Astrophysics Data System (ADS)

    Corsini, M. A.; Silva, A. V. R.

    2003-08-01

    Ejeções de massa coronal (EMC) são bolhas gigantes de gás permeadas por campos magnéticos que são ejetadas do Sol durante um período de várias horas. Caso estas ejeções atinjam a Terra, geralmente, causam uma série de distúrbios às comunicações de longa distância e navegação, além de danos a satélites e transformadores. Portanto, é desejável que sejamos capazes de prever quando estas ejeções atingirão a Terra. Para tanto, é necessário um bom entendimento dos mecanismos causadores das ejeções e, principalmente, de como se dá a propagação das EMC e sua interação com o vento solar que permeia o meio interplanetário. Nesse sentido foi desenvolvido um programa computacional para resolver as equações MHD (Magneto-Hidro-Dinâmica) que regem a evolução das EMC. Primeiramente foram estabelecidas as condições necessárias para descrever o vento solar, no estado estacionário, que permeia todo o meio interplanetário. Num primeiro momento, resolveu-se o sistema de equações para o caso do vento isotérmico, conhecida como a solução de Parker, a fim de testarmos o modelo. Então, foi considerado o caso do vento solar com temperatura variável no meio interplanetário. Este resultado foi utilizado como a base de nosso sistema em seu instante inicial. Posteriormente foram feitas as considerações necessárias para descrever a propagação da Ejeção de Massa Coronal. As EMC foram simuladas como um aumento de densidade e temperatura local na coroa solar. A órbita e a posição da Terra foram incluídas no sistema. Os dados gerados possibilitaram uma análise da evolução da EMC pelo meio interplanetário até encontrar-se com a Terra. Os perfis de densidade e temperatura a 1 Unidade Astronômica são comparados com os dados de satélites reportados na literatura.

  4. Sobre a largura da última superfície de espalhamento

    NASA Astrophysics Data System (ADS)

    Nobre, M. A. S.; Pires, N.; Lima, J. A. S.

    2003-08-01

    De acordo com o modelo do "Big-Bang", no universo primordial a matéria estava em equilíbrio térmico com a radiação. Com a expansão a temperatura da radiação cai. Quando a temperatura chega em torno dos 4.000K, os espalhamentos diminuem, começando a recombinação dos prótons e elétrons em Hidrogênio neutro (era conhecida como da recombinação). Ao final da recombinação, os fótons se propagam livremente sofrendo, em princípio, somente os efeitos do "redshift" cosmológico. Esses fótons nos alcançam hoje como a radiação cósmica de fundo (RCF), e parecem vir de uma superfície esférica ao nosso redor, tal que o raio dela é a distância que ele viajou desde seu último espalhamento na época da recombinação. Naturalmente, esse processo não ocorreu abruptamente, implicando na existência de uma largura no espaço dos "redshifts" que deve depender do modelo cosmológico específico e dos processos físicos considerados. Neste trabalho analisamos os efeitos de diferentes modelos - a saber, aqueles com decaimento do vácuo L(t), criação de matéria, quintessência e gás de Chaplygin - sobre a última superfície de espalhamento da RCF, em particular sua largura e a função visibilidade, que determina a probabilidade de um fóton ter tido seu último espalhamento num "redshift" z. No caso particular dos modelos com decaimento do vácuo, existe uma forte dependência da função visibilidade com L(t). Tais efeitos poderão ser testados através da análise dos resultados de experimentos mais precisos que estão atualmente em andamento, como por exemplo, o WMAP.

  5. Electromagnetic Gauge Study of Laser-Induced Shock Waves in Aluminium Alloys

    NASA Astrophysics Data System (ADS)

    Peyre, P.; Fabbro, R.

    1995-12-01

    The laser-shock behaviour of three industrial aluminum alloys has been analyzed with an Electromagnetic Gauge Method (EMV) for measuring the velocity of the back free surface of thin foils submitted to plane laser irradiation. Surface pressure, shock decay in depth and Hugoniot Elastic Limits (HEL) of the materials were investigated with increasing thicknesses of foils to be shocked. First, surface peak pressures values as a function of laser power density gave a good agreement with conventional piezoelectric quartz measurements. Therefore, comparison of experimental results with computer simulations, using a 1D hydrodynamic Lagrangian finite difference code, were also in good accordance. Lastly, HEL values were compared with static and dynamic compressive tests in order to estimate the effects of a very large range of strain rates (10^{-3} s^{-1} to 10^6 s^{-1}) on the mechanical properties of the alloys. Cet article fait la synthèse d'une étude récente sur la caractérisation du comportement sous choc-laser de trois alliages d'aluminium largement utilisés dans l'industrie à travers la méthode dite de la jauge électromagnétique. Cette méthode permet de mesurer les vitesses matérielles induites en face arrière de plaques d'épaisseurs variables par un impact laser. La mise en vitesse de plaques nous a permis, premièrement, de vérifier la validité des pressions d'impact superficielles obtenues en les comparant avec des résultats antérieurs obtenus par des mesures sur capteurs quartz. Sur des plaques d'épaisseurs croissantes, nous avons caractérisé l'atténuation des ondes de choc en profondeur dans les alliages étudiés et mesuré les limites d'élasticité sous choc (pressions d'Hugoniot) des alliages. Les résultats ont été comparés avec succès à des simulations numériques grâce à un code de calcul monodimensionnel Lagrangien. Enfin, les valeurs des pressions d'Hugoniot mesurées ont permis de tracer l'évolution des contraintes d

  6. A stochastic immersed boundary method for fluid-structure dynamics at microscopic length scales

    SciTech Connect

    Atzberger, Paul J. . E-mail: atzberg@math.ucsb.edu; Kramer, Peter R.; Peskin, Charles S.

    2007-06-10

    In modeling many biological systems, it is important to take into account flexible structures which interact with a fluid. At the length scale of cells and cell organelles, thermal fluctuations of the aqueous environment become significant. In this work, it is shown how the immersed boundary method of [C.S. Peskin, The immersed boundary method, Acta Num. 11 (2002) 1-39.] for modeling flexible structures immersed in a fluid can be extended to include thermal fluctuations. A stochastic numerical method is proposed which deals with stiffness in the system of equations by handling systematically the statistical contributions of the fastest dynamics of the fluid and immersed structures over long time steps. An important feature of the numerical method is that time steps can be taken in which the degrees of freedom of the fluid are completely underresolved, partially resolved, or fully resolved while retaining a good level of accuracy. Error estimates in each of these regimes are given for the method. A number of theoretical and numerical checks are furthermore performed to assess its physical fidelity. For a conservative force, the method is found to simulate particles with the correct Boltzmann equilibrium statistics. It is shown in three dimensions that the diffusion of immersed particles simulated with the method has the correct scaling in the physical parameters. The method is also shown to reproduce a well-known hydrodynamic effect of a Brownian particle in which the velocity autocorrelation function exhibits an algebraic ({tau} {sup -3/2}) decay for long times [B.J. Alder, T.E. Wainwright, Decay of the Velocity Autocorrelation Function, Phys. Rev. A 1(1) (1970) 18-21]. A few preliminary results are presented for more complex systems which demonstrate some potential application areas of the method. Specifically, we present simulations of osmotic effects of molecular dimers, worm-like chain polymer knots, and a basic model of a molecular motor immersed in fluid

  7. Evolución Dinámica de Cúmulos Estelares Abiertos

    NASA Astrophysics Data System (ADS)

    de La Fuente Marcos, R.

    Las estrellas que observamos no se formaron aisladamente, sino que lo hicieron en grupos o cúmulos. Estos sistemas estelares recibenel nombre de cúmulos estelares abiertos o galácticos cuando están constituidos por estrellas de la Población I. Los cúmulos abiertos se localizan preferentemente en el plano galáctico, y en muchos de ellos está teniendo lugar aún una activa formación estelar. El propósito principal de esta tesis doctoral es el estudio de la evolución dinámica de estos sistemas estelares por medio de simulaciones numéricas y de la comparación de sus resultados con datos observacionales. Con este fin se analizan los efectos que, sobre la dinámica de los cúmulos, ejercen varios fenómenos de interés astrofísico tales como el campo gravitatorio galáctico, la pérdida de masa causada por la evolución estelar y la presencia de binarias primordiales. En este trabajo se presentan los resultados de más de un centenar de modelos de cúmulos, con poblaciones comprendidas en el intervalo [100, 10.000] estrellas, calculados con NBODY5, un programa estándar en el campo de la Dinámica Estelar Experimental. De los mismos se deduce que el mecanismo principal que rige la dinámica de los cúmulos abiertos es la evolución estelar de su distribución de masas, encontrándose un comportamiento diferencial fuertemente dependiente de la población inicial del cúmulo. Los mecanismos responsables de la desintegración de los cúmulos abiertos son analizados en detalle, proponiéndose un modelo analítico que ajusta razonablemente los resultados de las simulaciones. Además, y con el fin de explicar el elevado número de sistemas múltiples observados en cúmulos abiertos, se estudian los efectos que, sobre los mismos, ejerce la presencia de una cierta fracción de binarias primordiales. El papel de las binarias tambiín depende de la riqueza del cúmulo y sus efectos se interrelacionan con aquellos debidos a la evolución estelar. Por último, se

  8. Étude et modélisation des mécanismes complexes en conception assistée par ordinateur

    NASA Astrophysics Data System (ADS)

    Satori, K.; El Kihel, B.

    1997-11-01

    The conception of the mechanical systems becomes very automated in the setting of the Mechanical Computer Aided Design (M.C.A.D.). Actually the geometric modelisation involves Computer Aided Design (C.A.D.). Particularly, the numerical analysis is the origin of Finite Element Methods (F.E.M.). These two techniques give a real image of calculation results; this is due to the discretization methods (stress concentration, loads assignation, ...). The aim of this work is to study the gear box with parallel shafts (reducer of speeds), it includes two steps of reductions. The kinematic chain is constituted by shafts, gears with right denture and bearings (ball and cylindrical), who achieve the link with the box. The mean problem is to quantify the dynamic and vibratory behaviour in order to qualify the conception of gear box. La conception des systèmes mécaniques devient très automatisée dans le cadre de la Conception Mécanique Assistée par Ordinateur (C.M.A.O.). La modélisation géométrique est effectuée de plus en plus avec l'aide des logiciels de Dessin Assisté par Ordinateur (D.A.O.). La modélisation des structures et la simulation numérique s'effectuent généralement par la Méthode des Éléments Finis (M.E.F.). Le couplage de ces deux techniques permet de donner une image concrète et réaliste des résultats de calcul issus des méthodes de discrétisation (concentration des contraintes, répartition des charges, etc.). L'application qu'on présente concerne une boîte de vitesse à arbres parallèle, comporte deux étages de réductions (réducteur de vitesse). La chaîne cinématique est constituée d'arbres d'engrenages à dentures droites et de paliers à roulements à billes et à rouleaux qui réalisent la liaison avec le carter. Le problème posé dans cette application consiste à quantifier le comportement dynamique et vibratoire afin de qualifier la conception du réducteur.

  9. Land subsidence caused by groundwater exploitation in Suzhou City, China

    NASA Astrophysics Data System (ADS)

    Chen, Chongxi; Pei, Shunping; Jiao, Jiu Jimmy

    2002-09-01

    in pumping rates on the basis of the spatial distribution of the thick mud layer could significantly reduce the ground settlement. Résumé. La ville de Suzhou, située dans la basse vallée du fleuve Yangtsé dans le sud-est de la province de Jiangsu, est l'une des rares villes de Chine qui souffrent cruellement de tassements du sol. Un projet de recherche a été mené pour étudier ce problème. Des études géologiques et hydrogéologiques montrent qu'il existe un système aquifère multicouche constitué de trois niveaux distincts de limons non consolidés d'origine marine et lagunaire. Un examen des historiques des prélèvements d'eau souterraine, des niveaux de nappe et des tassements de sol montrent que la subsidence du sol est associée à des prélèvements continuellement croissants d'eau souterraine dans l'aquifère captif profond. On pense que le compactage des couches limoneuses non consolidées, en particulier de la troisième couche qui est épaisse et proche du principal aquifère pompé, contribue aux tassements du sol. Un modèle numérique aux différences finies en trois dimensions, représentant l'aquifère multicouche, a été réalisé pour étudier les tassements du sol en réponse aux prélèvements d'eau souterraine. Les paramètres de l'aquifère ont été estimés par calibration du modèle au moyen à la fois des niveaux piézométriques et des tassements du sol. Les résultats de la simulation s'ajustent convenablement aux résultats observés, ce qui indique que le modèle numérique peut reproduire les processus dynamiques aussi bien des écoulements souterrains que de compactage du sol. La conductivité hydraulique de la troisième couche de limon non consolidé au voisinage du centre du tassement de sol a été réduit de plus de 30% au cours des 14 dernières années. La dégradation progressive de la conductivité hydraulique du limon peut avoir un effet significatif néfaste sur la pérennité de la ressource en eau souterraine

  10. A software to digital image processing to be used in the voxel phantom development.

    PubMed

    Vieira, J W; Lima, F R A

    2009-01-01

    Anthropomorphic models used in computational dosimetry, also denominated phantoms, are based on digital images recorded from scanning of real people by Computed Tomography (CT) or Magnetic Resonance Imaging (MRI). The voxel phantom construction requests computational processing for transformations of image formats, to compact two-dimensional (2-D) images forming of three-dimensional (3-D) matrices, image sampling and quantization, image enhancement, restoration and segmentation, among others. Hardly the researcher of computational dosimetry will find all these available abilities in single software, and almost always this difficulty presents as a result the decrease of the rhythm of his researches or the use, sometimes inadequate, of alternative tools. The need to integrate the several tasks mentioned above to obtain an image that can be used in an exposure computational model motivated the development of the Digital Image Processing (DIP) software, mainly to solve particular problems in Dissertations and Thesis developed by members of the Grupo de Pesquisa em Dosimetria Numérica (GDN/CNPq). Because of this particular objective, the software uses the Portuguese idiom in their implementations and interfaces. This paper presents the second version of the DIP, whose main changes are the more formal organization on menus and menu items, and menu for digital image segmentation. Currently, the DIP contains the menus Fundamentos, Visualizações, Domínio Espacial, Domínio de Frequências, Segmentações and Estudos. Each menu contains items and sub-items with functionalities that, usually, request an image as input and produce an image or an attribute in the output. The DIP reads edits and writes binary files containing the 3-D matrix corresponding to a stack of axial images from a given geometry that can be a human body or other volume of interest. It also can read any type of computational image and to make conversions. When the task involves only an output image

  11. Estudio de la formación de galaxias espirales en un modelo de agregación jerárquica

    NASA Astrophysics Data System (ADS)

    Tissera, P.; Saiz, A.; Dominguez-Tenreiro, R.

    El estudio de formación de galaxias espirales ha llevado al desarrollo de numerosos modelos teóricos (e.g. White & Rees 1978). En la actualidad, el modelo más aceptado predice la formación de una galaxia espiral a partir del colapso disipativo del gas en el pozo de potencial de un halo oscuro, conservando su momento angular específco (Fall & Efstathiou 1980). En los últimos años, ha sido posible realizar simulaciones numéricas hidrodinámicas, las cuales describen la evolución conjunta de la materia oscura y los bariones. Estos experimentos han señalado la dificultad de formar estructuras discoidales con propiedades consistentes con las observaciones, en modelos de agregación jerárquica. El problema principal se origina en la pérdida catastrófica de momento angular de la componente disipativa, durante el proceso de ensamblaje de los objetos, a través de la fusión de subestructura (Navarro & Steinmetz 1997). Estos experimentos no incluían procesos de formación estelar. En este trabajo, se expondrán resultados de simulaciones hidrodinámicas cosmológicas, incluyendo formación estelar (Tissera et al 1997), donde ha sido posible reproducir objetos discoidales con contrapartida observacional. El elemento fundamental ha sido la formación de bulbos estelares, los cuales han evitado la pérdida catastrófica de momento angular de los bariones. Se encontró que los discos exponenciales puramente gaseosos son altamente inestables y suceptibles de generar barras, responsables de la pérdida de momento angular y la caída violenta del gas hacia la región central. Estas inestabilidades son fácilmente inducidas durante interacciones y fusiones con objetos vecinos (Barnes & Hernquist 1996). Un bulbo estelar (o un objeto masivo y compacto) estabiliza el disco ante perturbaciones externas, asegurándole un potencial simétrico (Sellwood & Moore 1998, Van der Bosch 1998). En este caso, el gas en el disco no pierde completamente su momento angular intr

  12. Evidence for nucleolar subcompartments in Dictyostelium

    SciTech Connect

    Catalano, Andrew; O’Day, Danton H.

    2015-01-24

    Highlights: • Two nucleolar subcompartments (NoSC1, NoSC2) were found in Dictyostelium. • Specific nucleolar proteins localize to different nucleolar subcompartments. • Specific proteins exit NoSC1 and NoSC2 differently upon Actinomycin D treatment. • KRKR appears to function as an NoSC2 nucleolar subcompartment localization signal. - Abstract: The nucleolus is a multifunctional nuclear compartment usually consisting of two to three subcompartments which represent stages of ribosomal biogenesis. It is linked to several human diseases including viral infections, cancer, and neurodegeneration. Dictyostelium is a model eukaryote for the study of fundamental biological processes as well as several human diseases however comparatively little is known about its nucleolus. Unlike most nucleoli it does not possess visible subcompartments at the ultrastructural level. Several recently identified nucleolar proteins in Dictyostelium leave the nucleolus after treatment with the rDNA transcription inhibitor actinomycin-D (AM-D). Different proteins exit in different ways, suggesting that previously unidentified nucleolar subcompartments may exist. The identification of nucleolar subcompartments would help to better understand the nucleolus in this model eukaryote. Here, we show that Dictyostelium nucleolar proteins nucleomorphin isoform NumA1 and Bud31 localize throughout the entire nucleolus while calcium-binding protein 4a localizes to only a portion, representing nucleolar subcompartment 1 (NoSC1). SWI/SNF complex member Snf12 localizes to a smaller area within NoSC1 representing a second nucleolar subcompartment, NoSC2. The nuclear/nucleolar localization signal KRKR from Snf12 localized GFP to NoSC2, and thus also appears to function as a nucleolar subcompartment localization signal. FhkA localizes to the nucleolar periphery displaying a similar pattern to that of Hsp32. Similarities between the redistribution patterns of Dictyostelium nucleolar proteins during

  13. An Integrated Information System for Supporting Quality Management Tasks

    NASA Astrophysics Data System (ADS)

    Beyer, N.; Helmreich, W.

    2004-08-01

    In a competitive environment, well defined processes become the strategic advantage of a company. Hence, targeted Quality Management ensures efficiency, trans- parency and, ultimately, customer satisfaction. In the particular context of a Space Test Centre, a num- ber of specific Quality Management standards have to be applied. According to the revision of ISO 9001 dur- ing 2000, and due to the adaptation of ECSS-Q20-07, process orientation and data analysis are key tasks for ensuring and evaluating the efficiency of a company's processes. In line with these requirements, an integrated management system for accessing the necessary infor- mation to support Quality Management and other proc- esses has been established. Some of its test-related fea- tures are presented here. Easy access to the integrated management system from any work place at IABG's Space Test Centre is ensured by means of an intranet portal. It comprises a full set of quality-related process descriptions, information on test facilities, emergency procedures, and other relevant in- formation. The portal's web interface provides direct access to a couple of external applications. Moreover, easy updating of all information and low cost mainte- nance are features of this integrated information system. The timely and transparent management of non- conformances is covered by a dedicated NCR database which incorporates full documentation capability, elec- tronic signature and e-mail notification of concerned staff. A search interface allows for queries across all documented non-conformances. Furthermore, print ver- sions can be generated at any stage in the process, e.g. for distribution to customers. Feedback on customer satisfaction is sought through a web-based questionnaire. The process is initiated by the responsible test manager through submission of an e- mail that contains a hyperlink to a secure website, ask- ing the customer to complete the brief online form, which is directly fed to a database

  14. Rotação do jato em DG tau próximo à região de sua formação: análise comparativa das velocidades radiais simuladas e observadas

    NASA Astrophysics Data System (ADS)

    Cerqueira, A. H.; de Gouveia dal Pino, E. M.

    2003-08-01

    Os modelos magneto-centrífugos utilizados para explicar a formação dos jatos Herbig-Haro assumem a presença de um disco de acresção em rotação kepleriana na base de lançamento do jato. Neste cenário, o jato transmite a informação da rotação do disco para regiões distantes da fonte central, além da superfície de Alfvén, na região de colimação inicial do jato. Recentemente, Bacciotti et al. (2002, ApJ, 537, L49) obtiveram pela primeira vez uma evidência observacional de rotação em um jato HH, o jato em DG Tau, em regiões próximas da fonte central, compatível (qualitativa e quantitativamente) com o esperado a partir dos modelos magneto-centrífugos para a produção e colimação inicial de jatos HH. No presente trabalho, apresentamos mapas de velocidade radial, obtidos através de simulações numéricas tri-dimensionais SPH, para um jato com características semelhantes ao jato em DG Tau, objetivando uma comparação com os mapas de velocidade radiais obtidos por Bacciotti et al.. Nossos resultados, embora preliminares, indicam que a inclusão de efeitos como a precessão, evidenciada em DG Tau (Dougados et al. 2000, A&A, 357, L61) devem ser levadas em consideração na análise da presença de rotação não só em DG Tau mas em qualquer sistema, com o uso das velocidades radias observadas. A ausência de um grau elevado de simetria axial (quebrada, por exemplo, pela precessão do eixo do jato; ou pela presença de uma superfície interna de trabalho, ou seja, um bow shock interno), implica também em uma maior complexidade nos mapas, com conseqüências relevantes para suas interpretações.

  15. i-PI: A Python interface for ab initio path integral molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Ceriotti, Michele; More, Joshua; Manolopoulos, David E.

    2014-03-01

    Recent developments in path integral methodology have significantly reduced the computational expense of including quantum mechanical effects in the nuclear motion in ab initio molecular dynamics simulations. However, the implementation of these developments requires a considerable programming effort, which has hindered their adoption. Here we describe i-PI, an interface written in Python that has been designed to minimise the effort required to bring state-of-the-art path integral techniques to an electronic structure program. While it is best suited to first principles calculations and path integral molecular dynamics, i-PI can also be used to perform classical molecular dynamics simulations, and can just as easily be interfaced with an empirical forcefield code. To give just one example of the many potential applications of the interface, we use it in conjunction with the CP2K electronic structure package to showcase the importance of nuclear quantum effects in high-pressure water. Catalogue identifier: AERN_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AERN_v1_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: GNU General Public License, version 3 No. of lines in distributed program, including test data, etc.: 138626 No. of bytes in distributed program, including test data, etc.: 3128618 Distribution format: tar.gz Programming language: Python. Computer: Multiple architectures. Operating system: Linux, Mac OSX, Windows. RAM: Less than 256 Mb Classification: 7.7. External routines: NumPy Nature of problem: Bringing the latest developments in the modelling of nuclear quantum effects with path integral molecular dynamics to ab initio electronic structure programs with minimal implementational effort. Solution method: State-of-the-art path integral molecular dynamics techniques are implemented in a Python interface. Any electronic structure code can be patched to receive the atomic

  16. SpacePy - a Python-based library of tools for the space sciences

    SciTech Connect

    Morley, Steven K; Welling, Daniel T; Koller, Josef; Larsen, Brian A; Henderson, Michael G

    2010-01-01

    Space science deals with the bodies within the solar system and the interplanetary medium; the primary focus is on atmospheres and above - at Earth the short timescale variation in the the geomagnetic field, the Van Allen radiation belts and the deposition of energy into the upper atmosphere are key areas of investigation. SpacePy is a package for Python, targeted at the space sciences, that aims to make basic data analysis, modeling and visualization easier. It builds on the capabilities of the well-known NumPy and MatPlotLib packages. Publication quality output direct from analyses is emphasized. The SpacePy project seeks to promote accurate and open research standards by providing an open environment for code development. In the space physics community there has long been a significant reliance on proprietary languages that restrict free transfer of data and reproducibility of results. By providing a comprehensive, open-source library of widely used analysis and visualization tools in a free, modern and intuitive language, we hope that this reliance will be diminished. SpacePy includes implementations of widely used empirical models, statistical techniques used frequently in space science (e.g. superposed epoch analysis), and interfaces to advanced tools such as electron drift shell calculations for radiation belt studies. SpacePy also provides analysis and visualization tools for components of the Space Weather Modeling Framework - currently this only includes the BATS-R-US 3-D magnetohydrodynamic model and the RAM ring current model - including streamline tracing in vector fields. Further development is currently underway. External libraries, which include well-known magnetic field models, high-precision time conversions and coordinate transformations are wrapped for access from Python using SWIG and f2py. The rest of the tools have been implemented directly in Python. The provision of open-source tools to perform common tasks will provide openness in the

  17. Grain Boundary Wetting In The Stressed Rock Salt

    NASA Astrophysics Data System (ADS)

    Traskine, V.; Skvortsova, Z.; Barrallier, L.

    Safety assessment of underground salt-based waste disposal sites requires a detailed study of transport mechanisms in the salt around waste containers. Grain boundaries in dense polycrystalline aggregates are known to act as the main mass transfer path, provided that they form an interconnected network. A two-step model has been pro- posed (V.Traskine et al., Colloids and Surfaces A, 2000) allowing firstly to assess the grain boundary wetting (GBW) probability from the solid-liquid to solid-solid inter- face free energy ratio and from the scatter of the latter parameter among individual GBs, and then to estimate the percolation threshold for GBW (critical GBW proba- bility at which fluid inclusions would become interconnected in a polycrystal of any size). This approach, in spite of being simplified (the only driving force for GBW is assumed to be the minimization of interfacial energy), accounts well enough for a dra- matic change in physical and mechanical properties due to GBW observed in various solid-liquid couples. In this paper, we extend the above outlined model taking into account the role of mechanical stresses which are, reportedly, of a great importance in GBW. Experimental study has been made on disks of coarse-grained pore-free syn- thetic NaCl of a diameter of 18 mm and a thickness of 2 to 3 mm, immersed into the brine and submitted to the Brazilian test at increasing applied loads. The overall num- ber of wetted boundaries increases with rising load from about 30% for unstressed salt up to 60 to 70% for a load of 15 N. As it is known, the Brazilian test provides various combinations of shear and normal (mainly compressive) stress components. The anal- ysis of stress state on individual boundaries shows that the shear components enhance the GBW irrespectively to compressive components over practically the whole range of stress states studied. All the boundaries are wetted for shear stresses > 0.7 MPa or tensile stresses > 0.3 MPa. The compressive

  18. QuTiP 2: A Python framework for the dynamics of open quantum systems

    NASA Astrophysics Data System (ADS)

    Johansson, J. R.; Nation, P. D.; Nori, Franco

    2013-04-01

    We present version 2 of QuTiP, the Quantum Toolbox in Python. Compared to the preceding version [J.R. Johansson, P.D. Nation, F. Nori, Comput. Phys. Commun. 183 (2012) 1760.], we have introduced numerous new features, enhanced performance, and made changes in the Application Programming Interface (API) for improved functionality and consistency within the package, as well as increased compatibility with existing conventions used in other scientific software packages for Python. The most significant new features include efficient solvers for arbitrary time-dependent Hamiltonians and collapse operators, support for the Floquet formalism, and new solvers for Bloch-Redfield and Floquet-Markov master equations. Here we introduce these new features, demonstrate their use, and give a summary of the important backward-incompatible API changes introduced in this version. Catalog identifier: AEMB_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEMB_v2_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: GNU General Public License, version 3 No. of lines in distributed program, including test data, etc.: 33625 No. of bytes in distributed program, including test data, etc.: 410064 Distribution format: tar.gz Programming language: Python. Computer: i386, x86-64. Operating system: Linux, Mac OSX. RAM: 2+ Gigabytes Classification: 7. External routines: NumPy, SciPy, Matplotlib, Cython Catalog identifier of previous version: AEMB_v1_0 Journal reference of previous version: Comput. Phys. Comm. 183 (2012) 1760 Does the new version supercede the previous version?: Yes Nature of problem: Dynamics of open quantum systems Solution method: Numerical solutions to Lindblad, Floquet-Markov, and Bloch-Redfield master equations, as well as the Monte Carlo wave function method. Reasons for new version: Compared to the preceding version we have introduced numerous new features, enhanced performance, and made changes in

  19. CosmoTransitions: Computing cosmological phase transition temperatures and bubble profiles with multiple fields

    NASA Astrophysics Data System (ADS)

    Wainwright, Carroll L.

    2012-09-01

    I present a numerical package (CosmoTransitions) for analyzing finite-temperature cosmological phase transitions driven by single or multiple scalar fields. The package analyzes the different vacua of a theory to determine their critical temperatures (where the vacuum energy levels are degenerate), their supercooling temperatures, and the bubble wall profiles which separate the phases and describe their tunneling dynamics. I introduce a new method of path deformation to find the profiles of both thin- and thick-walled bubbles. CosmoTransitions is freely available for public use.Program summaryProgram Title: CosmoTransitionsCatalogue identifier: AEML_v1_0Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEML_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 8775No. of bytes in distributed program, including test data, etc.: 621096Distribution format: tar.gzProgramming language: Python.Computer: Developed on a 2009 MacBook Pro. No computer-specific optimization was performed.Operating system: Designed and tested on Mac OS X 10.6.8. Compatible with any OS with Python installed.RAM: Approximately 50 MB, mostly for loading plotting packages.Classification: 1.9, 11.1.External routines: SciPy, NumPy, matplotLibNature of problem: I describe a program to analyze early-Universe finite-temperature phase transitions with multiple scalar fields. The goal is to analyze the phase structure of an input theory, determine the amount of supercooling at each phase transition, and find the bubble-wall profiles of the nucleated bubbles that drive the transitions.Solution method: To find the bubble-wall profile, the program assumes that tunneling happens along a fixed path in field space. This reduces the equations of motion to one dimension, which can then be solved using the overshoot

  20. Propriedades de estruturas temporais rápidas submilimétricas durante uma grande explosão solar

    NASA Astrophysics Data System (ADS)

    Raulin, J.-P.; Kaufmann, P.; Gimenez de Castro, C. G.; Pacini, A. A.; Makhmutov, V.; Levato, H.; Rovira, M.

    2003-08-01

    Apresentamos novas propriedades de variações rápidas da emissão submilimétrica durante uma das maiores explosões solares do ciclo solar 23. Os dados analisados neste estudo foram obtidos com o Telescópio Solar Submilimétrico (SST), que observa o Sol em 212 GHz e 405 GHz, e comparados com emissões em Raios-X duros e Raios-gama (fótons de energia > 10 MeV), que foram obtidas pelo experimento GRS do Yohkoh. Aplicamos diferentes metodologias para detectar e caracterizar, ao longo do evento, os pulsos submilimétricos (duração de 50-300 ms) detectados acima de uma componente mais lenta (alguns minutos). Os resultados mostram que durante a fase impulsiva, num instante próximo ao tempo do máximo do evento, houve um aumento da ocorrência de maiores e de mais rápidas estruturas temporais. Também identificamos uma boa correlação com as emissões em raios-X e raios-gama (até a faixa de energia 10-100 MeV), indicando que os pulsos rápidos submilimétricos refletiram injeções primárias de energia durante o evento.O espectro do fluxo desses pulsos é crescente com a freqüência entre 212 and 405 GHz, na maioria dos casos, ao contrário do observado para a componente gradual. As posições calculadas para as estruturas rápidas são discretas, compactas e localizadas em toda a área da região ativa, o que é previsto nos modelos de explosões solares decorrentes de instabilidades múltiplas em diferentes pequenas regiões. Por outro lado, a posição calculada para a componente lenta é estável durante a fase impulsiva. Assim, a comparação entre as características do espectro de fluxo e da localização da emissão, para os pulsos rápidos e para a componente gradual, sugere que as respectivas emissões são de natureza diferente.

  1. Prevendo a atividade solar através de redes neurais nebulosas

    NASA Astrophysics Data System (ADS)

    Martin, V. A. F.; Poppe, P. C. R.

    2003-08-01

    Atualmente, a integração de redes neurais com técnicas da Matemática Nebulosa (Fuzzy Sets), tem sido usada robustamente para fazer previsões em vários sistemas físicos. Este trabalho representa uma continuidade da contribuição apresentada anteriormente durante a XXVIIa Reunião Anual da SAB, onde exploramos a aplicação de redes neurais para previsões futuras de séries temporais. Para este, enfatizamos o uso da técnica ANFIS (Adaptative Neuro-Fuzzy Inference System), que consiste em uma rede do tipo back-propagation, onde os dados são processados em uma camada intermediária, tendo numa camada de saída, os dados numéricos. Para que a previsão seja feita com sucesso utilizando-se técnicas matemáticas adequadas, é fundamental a existência de uma série razoavelmente longa de modo que a dinâmica contida nesta possa ser melhor extraída pela rede neural. Nesse sentido, foram utilizados novamente os dados históricos das manchas do Sol (1818-2002) afim de verificar o comportamento futuro da atividade solar (Ciclos de Schawbe) a partir da técnica descrita acima. Previsões realizadas para o ciclo anterior (n.22, máximo de 158,5 em julho de 1989), bem como para o atual (n.23, máximo de 153 em setembro de 2000), apontam valores bastante coerentes com os publicados na literatura, levando em consideração, respectivamente, as barras de erros associadas: 166+/-18 e 160+/-14. Para o próximo ciclo de Schawbe (2006-2017), nossa previsão aponta o valor de 172+/-23 como máximo para o primeiro semestre de 2011 (Abril +/- 3 meses). A ANFIS acompanha de maneira satisfatória o movimento das séries estudadas durante o treinamento e durante a verificação (menor dispersão das funções de pertinência), com erro absoluto inferior a 20 por cento.

  2. Profil clinique et bactériologique des infections néonatales bactériennes à l'Hôpital Laquintinie de Douala, Cameroun

    PubMed Central

    Kemeze, Sandrine; Moudze, Béatrice; Chiabi, Andreas; Eposse, Charlotte; Kaya, Alexis; Mbangue, Madeleine; Guifo, Odette; Kago, Innocent

    2016-01-01

    Introduction L'Organisation Mondiale de la Santé a estimé la survenue globale de décès néonatal à 2,8 millions en 2015, dont 47,6% étaient dues aux infections. Ces infections peuvent survenir chez un nouveau-né de 0 à un mois de vie, pouvant aller jusqu’à 3 mois. Méthodes C'est une étude prospective allant du 1er mars au 30 juin 2015 au Service de néonatologie de l'Hôpital Laquintinie de Douala. Etaient inclus tout nouveau-né symptomatique avec ou sans critère anamnestique et tout nouveau-né asymptomatique, présentant au moins un risque infectieux et ayant au moins une culture positive ou une anomalie de la numération formule sanguine ou une protéine C réactive positive. Résultats Des 310 nouveau-nés admis, 300 ont été retenus pour infection néonatale, soit une incidence de 96,8%. Nous avons réalisé 104 cultures dont 25 positives, soit une incidence de l'infection néonatale confirmée de 24%. Les facteurs associés à l'infection étaient la prématurité inexpliquée <35 semaines d'aménorrhée(45,1%) et la réanimation néonatale (34,8%). La fièvre (56%) et les troubles neurologiques (48,8%) étaient les manifestations cliniques les plus fréquentes. Les Gram négatifs étaient les germes les plus fréquents (56%). L'imipenème (95%) et l'amikacine (66,7%) étaient les antibiotiques les plusefficaces. L’évolution était favorable dans 66,4% des cas et le taux de décès était de 33,6%. Conclusion Cette étude révèle une forte prévalence de l'infection dans cet hôpital. L’écologie bactérienne est dominée par les Gram négatifs, on note une importante résistance aux antibiotiques usuels et une mortalité assez élevée. PMID:27222688

  3. New high-order, semi-implicit Hybridized Discontinuous Galerkin - Spectral Element Method (HDG-SEM) for simulation of complex wave propagation involving coupling between seismic, hydro-acoustic and infrasonic waves: numerical analysis and case studies.

    NASA Astrophysics Data System (ADS)

    Terrana, S.; Vilotte, J. P.; Guillot, L.

    2015-12-01

    continuous Galerkin methods for second order elliptic problems, SIAM J. Num. Anal., 47, 2, 1319-1365, 2009.[2] Nguyen, N., Peraire, J., Cockburn, B., High-order implicit hybridizable discontinuous Galerkin methods for acoustics and elastodynamics, J. Comp. Physics, 230, 10, 3695-3718, 2011.

  4. Estimation of the depth to the fresh-water/salt-water interface from vertical head gradients in wells in coastal and island aquifers

    NASA Astrophysics Data System (ADS)

    Izuka, Scot K.; Gingerich, Stephen B.

    gradients verticaux de charge à partir des mesures de niveau piézométrique faites en cours de foration d'un puits incomplet; le gradient est alors utilisé pour estimer la profondeur de l'interface. L'application de cette méthode à un système eau douce - eau salée simulé numériquement montre que la méthode est la plus précise lorsque le gradient est mesuré dans un puits pénétrant profondément dans l'aquifère. Même en utilisant un puits peu profond, la méthode estime la position de l'interface avec plus de précision que ne le fait la relation de Ghyben-Herzberg lorsqu'il existe un gradient vertical de charge bien marqué. L'application de la méthode à des données de terrain montre que la foration, les méthodes de mesure de niveau et les hétérogénéités au sein de l'aquifère peuvent être la cause de difficultés, mais que les effets de ces difficultés peuvent être réduits. Resumen Para la estimación de la productividad de pozos en acuíferos costeros y en islas es necesaria una estimación precisa de la profundidad de la interfaz teórica entre agua dulce y agua salada. La relación de Ghyben-Herzberg, usada habitualmente para estimar la profundidad de la interfaz, puede subestimar o sobrestimar el espesor de agua dulce, al asumir la ausencia de flujos y gradientes verticales. La estimación de la profundidad de la interfaz debe considerar tanto estos gradientes verticales, como la posible anisotropía del acuífero. En este artículo se presenta un método para calcular los gradientes verticales de niveles a partir de las medidas obtenidas durante la perforación de un pozo parcialmente penetrante para, a partir de este gradiente, estimar la profundidad de la interfaz. La aplicación del método a un sistema de agua dulce/agua salada simulado numéricamente muestra que el método es más preciso cuando el gradiente se mide en un pozo profundo. Incluso en el caso de un pozo superficial, el método permite una estimación más precisa de la

  5. Characterization of III-V materials by optical interferometry

    NASA Astrophysics Data System (ADS)

    Montgomery, P. C.; Vabre, P.; Montaner, D.; Fillard, J. P.

    1993-09-01

    microscopie interférentielle numérique est une nouvelle méthode de mesure qui a une résolution latérale micronique et une résolution verticale nanométrique. Ceci est utile pour l'analyse tri-dimensionnelle des défauts de surface et de la forme des composants dans beaucoup d'applications sur les matériaux massifs et épitaxiés. Dans cet article nous démontrons comment certains défauts peuvent être analysés sur les matériaux et les composants III-V avec deux méthodes interférométriques différentes. La microscopie à saut de phase est mieux adaptée, avec sa résolution de 1 nm et sa meilleure précision, à la mesure des petits défauts de moins de λ/2 en hauteur, ou des surfaces avec des pentes douces et continues, jusqu'à une altitude de 1 ou 2 μm. Ceci est illustré par les études du polissage de plaquettes d'InP, des défauts sur une couche épitaxiée de GaAs sur InP et des boîtes quantiques sur GaAs. Pour mesurer les motifs, les mésas et les sillons qui ont des marches de plus que λ/2, la microscopie à glissement de franges est le meilleur choix. La résolution verticale est un peu moins bonne que celle de la PSM (4 nm) mais la dynamique verticale est plus grande (15 μm). Ceci est démontré par les mesures d'un sillon gravé dans une structure laser/détecteur sur une couche quaternaire sur InP et d'un MESFET sur GaAs. En comparaison avec la microscopie électronique et les méthodes de champ proche, la microscopie interférentielle numérique a les avantages de la facilité d'utilisation et de la rapidité. Elle est également capable de résoudre certains problèmes difficiles ou insolubles avec les autres techniques, comme par exemple le profil des sillons étroits, ou la mesure des reliefs enterrés sous une couche transparente. Les inconvénients sont la résolution latérale qui est limitée au pouvoir résolutif de l'objectif et l'introduction d'erreurs liées aux variations des propriétés optiques de l'échantillon qui doivent être

  6. Climate change impacts on groundwater resources: modelled deficits in a chalky aquifer, Geer basin, Belgium

    NASA Astrophysics Data System (ADS)

    Brouyère, Serge; Carabin, Guy; Dassargues, Alain

    An integrated hydrological model (MOHISE) was developed in order to study the impact of climate change on the hydrological cycle in representative water basins in Belgium. This model considers most hydrological processes in a physically consistent way, more particularly groundwater flows which are modelled using a spatially distributed, finite-element approach. Thanks to this accurate numerical tool, after detailed calibration and validation, quantitative interpretations can be drawn from the groundwater model results. Considering IPCC climate change scenarios, the integrated approach was applied to evaluate the impact of climate change on the water cycle in the Geer basin in Belgium. The groundwater model is described in detail, and results are discussed in terms of climate change impact on the evolution of groundwater levels and groundwater reserves. From the modelling application on the Geer basin, it appears that, on a pluri-annual basis, most tested scenarios predict a decrease in groundwater levels and reserves in relation to variations in climatic conditions. However, for this aquifer, the tested scenarios show no enhancement of the seasonal changes in groundwater levels. Un modèle hydrologique intégré (MOHISE) a été développé afin d'étudier l'impact du changement climatique sur le cycle hydrologique de bassins versants représentatifs de Belgique. Ce modèle prend en compte tous les processus hydrologiques d'une manière physiquement consistante, plus particulièrement les écoulements souterrains qui sont modélisés par une approche spatialement distribuée aux éléments finis. Grâce à cet outil numérique précis, après une calibration et une validation détaillées, des interprétations quantitatives peuvent être réalisées à partir des résultats du modèle de nappe. Considérant des scénarios de changements climatiques de l'IPCC, l'approche intégrée a été appliquée pour évaluer l'impact du changement climatique sur le cycle de l

  7. 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

  8. Assessment of hydraulic properties of sedimentary and volcanic aquifer systems under arid conditions in the Republic of Djibouti (Horn of Africa)

    NASA Astrophysics Data System (ADS)

    Jalludin, Mohamed; Razack, Moumtaz

    déduire la transmissivité. Concernant les aquifères volcaniques, la transmissivité a également été estimée à l'aide d'une relation empirique reliant la transmissivité et le débit spécifique corrigé des pertes de charge anormales. La transmissivité pour chaque aquifère couvre jusqu'à quatre ordres de grandeur, montrant la forte hétérogénéité de ces milieux. Pour les roches volcaniques, on observe que la transmissivité est d'autant meilleure que la roche est plus jeune. Leur transmissivité a ainsi diminué durant les temps géologiques. La compréhension des propriétés hydrauliques de ces aquifères complexes est à présent bien meilleure, ce qui permet d'envisager une gestion optimale de leurs ressources à l'aide de modèles numériques. La República de Yibuti (23.000 km2, 500.000 habitantes) está situada en el Cuerno de África, donde se han formado diversas unidades volcánicas-basaltos y riolitas-y rocas sedimentarias desde la expansión de los continentes acaecida al inicio de la deriva continental (hace 30 millones de años). La precipitación media anual es inferior a 150 mm. Las rocas volcánicas y sedimentarias, con dimensión inferior a 2.000 km2, constituyen acuíferos locales. Los basaltos estratificados forman un acuífero regional que se extiende a más de 9.000 km2. La multitud de datos existente ha sido almacenada desde los años 1960 en una base de datos. La transmisividad de estos acuíferos ha sido determinada mediante datos de ensayos de bombeo y una relación empírica que usa la capacidad específica corregida con las pérdidas turbulentas en el pozo. La transmisividad de estos acuíferos se comporta como una variable lognormal, hecho importante para los trabajos previstos de modelación con métodos estadísticos. La transmisividad de cada acuífero puede variar hasta en cuatro órdenes de magnitud, manifestando su gran heterogeneidad. Para los materiales volcánicos, la transmisividad es mayor cuanto más joven es

  9. Dinámica y crecimiento de los granos de polvo en la nebulosa protoplanetaria

    NASA Astrophysics Data System (ADS)

    de La Fuente Marcos, Carlos

    2001-06-01

    corriente no circulares perturba significativamente el movimiento de las partículas alrededor del Sol e incrementa su vida media en la Nebulosa. El flujo medio del gas se modela de forma simple, analizándose la dinámica y el crecimiento de las partículas mediante simulaciones numéricas. Al incrementarse la vida media y la densidad superficial de las partículas sólidas, los mecanismos de confinamiento derivados de la presencia de vórtices y ondas espirales actuan sobre el material sólido de la Nebulosa (mediante agregación colisional o inestabilidades gravitacionales) de manera mucho más eficiente que la previamente considerada. Esto ofrece nuevas posibilidades para la formación de planetesimales y núcleos de planetas gigantes, y puede explicar la formación rápida de planetas extrasolares gigantes. Además, esta Tesis analiza la respuesta de las partículas, en un disco protoplanetario con un radio de 100 UA en torno a una estrella de tipo solar, al campo gravitatorio derivado de la presencia de dos estrellas compañeras ligadas en una órbita relativamente elongada (300-1600 UA). Para llevar a cabo este análisis, se han realizado una serie de simulaciones numéricas de configuraciones jerárquicas coplanares utilizando un programa FORTRAN que integra directamente las ecuaciones del movimiento con el objeto de modelar la presencia de las fuerzas gravitacionales y viscosas. El disco protoplanetario masivo se encuentra en torno a una de las componentes de la binaria. La evolución temporal del subdisco de polvo depende directamente de la naturaleza (directa o retrógrada) de la revolución relativa de la compañera estelar, y de la temperatura y la masa del disco circunestelar.

  10. Land subsidence caused by groundwater exploitation in Suzhou City, China

    NASA Astrophysics Data System (ADS)

    Chen, Chongxi; Pei, Shunping; Jiao, Jiu Jimmy

    2002-09-01

    in pumping rates on the basis of the spatial distribution of the thick mud layer could significantly reduce the ground settlement. Résumé. La ville de Suzhou, située dans la basse vallée du fleuve Yangtsé dans le sud-est de la province de Jiangsu, est l'une des rares villes de Chine qui souffrent cruellement de tassements du sol. Un projet de recherche a été mené pour étudier ce problème. Des études géologiques et hydrogéologiques montrent qu'il existe un système aquifère multicouche constitué de trois niveaux distincts de limons non consolidés d'origine marine et lagunaire. Un examen des historiques des prélèvements d'eau souterraine, des niveaux de nappe et des tassements de sol montrent que la subsidence du sol est associée à des prélèvements continuellement croissants d'eau souterraine dans l'aquifère captif profond. On pense que le compactage des couches limoneuses non consolidées, en particulier de la troisième couche qui est épaisse et proche du principal aquifère pompé, contribue aux tassements du sol. Un modèle numérique aux différences finies en trois dimensions, représentant l'aquifère multicouche, a été réalisé pour étudier les tassements du sol en réponse aux prélèvements d'eau souterraine. Les paramètres de l'aquifère ont été estimés par calibration du modèle au moyen à la fois des niveaux piézométriques et des tassements du sol. Les résultats de la simulation s'ajustent convenablement aux résultats observés, ce qui indique que le modèle numérique peut reproduire les processus dynamiques aussi bien des écoulements souterrains que de compactage du sol. La conductivité hydraulique de la troisième couche de limon non consolidé au voisinage du centre du tassement de sol a été réduit de plus de 30% au cours des 14 dernières années. La dégradation progressive de la conductivité hydraulique du limon peut avoir un effet significatif néfaste sur la pérennité de la ressource en eau souterraine

  11. Etude thermo-aeraulique d'une piscine interieure

    NASA Astrophysics Data System (ADS)

    Guerfala, Nasreddine

    Les grands espaces fermés (amphithéâtres, supermarchés, gymnases et piscines) jouent un rôle essentiel dans l'économie et la société canadienne mais n'assurent pas nécessairement le confort thermique et la bonne qualité de l'air intérieur. En outre, leur consommation énergétique demeure très élevée. Plus spécifiquement, les piscines intérieures présentent certaines particularités telles qu'une humidité relative élevée, une température contrôlée de l'eau et une condensation possible sur les parois ce qui rend la tâche d'assurer le confort des baigneurs encore plus difficile. Rares sont les études réalisées pour ce type de bâtiment malgré l'existence de pistes d'optimisation de la consommation énergétique et l'amélioration de la qualité d'air intérieur. Dans cette optique, ce mémoire présente une étude thermo-aéraulique réalisée sur la piscine intérieure de l'Université Bishop's (Sherbrooke, Canada). La simulation numérique a été effectuée en utilisant le logiciel TRNSYS. L'approche adoptée pour la modélisation est la méthode zonale qui découpe l'espace de travail étudié en plusieurs zones fictives tout en calculant les caractéristiques thermo-aérauliques (température, pression, nombre de changement d'air par heure). D'autre part, une validation expérimentale en situations réelles est mise en œuvre au sein de cette piscine moyennant un dispositif expérimental spécifique. Ce dernier a été conçu spécialement pour s'adapter aux caractéristiques du milieu (hauteur du bâtiment, présence de l'eau et forte humidité) afin de mesurer la température, la pression et la vitesse de l'air dans plusieurs endroits significatifs de la piscine. Cette étude développe un outil de calcul capable de prédire les températures de différentes zones thermiques et des surfaces de l'enveloppe du bâtiment d'une part et de calculer le débit massique de l'air entre les zones ainsi que le nombre de changement d'air par

  12. Water-gas dynamics and coastal land subsidence over Chioggia Mare field, northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Teatini, Pietro; Baú, Domenico; Gambolati, Giuseppe

    2000-09-01

    menace potentielle pour la ville de Venise, à 25 km au nord-ouest du centre de Chioggia Mare. Afin d'évaluer le risque de subsidence du sol provoquée par les prélèvements de gaz, un modèle numérique a été développé pour prévoir la compaction des formations réservoirs de gaz en même temps que celle de l'aquifère latéral et sous-jacent, par effet de drainance, sur une période de 13 ans de production, suivie de 12 ans, et pour prévoir le transfert de la compaction profonde jusqu'à la surface du sol. Afin de prendre en compte l'incertitude sur un petit nombre de paramètres hydromécaniques importants, plusieurs scénarios ont été simulés et les prévisions les plus pessimistes ont été obtenues. Les résultats de la modélisation montrent qu'on doit s'attendre, au cours des 25 ans, au plus à une subsidence du sol de 1 cm à Chioggia, tandis que Venise ne subira aucun effet. Si la baisse de l'aquifère est compensée par une injection d'eau, la subsidence du sol s'arrêtera à 5 km au large et la zone côtière de Chioggia subira un effet de 0,6 à 0,7 cm. Resumen. Recientemente, la compañía nacional italiana del petróleo, ENI-Agip, ha enviado al Ministerio de Medio Ambiente de Italia (Comité VIA) un gran programa de desarrollo de 15 campos de gas en el norte del Mar Adriático para la evaluación de su impacto medioambiental. Una de las reservas principales de gas se halla en el mar de Chioggia, a unos 10 km mar adentro de la costa veneciana, a una profundidad de entre 1.000 y 1.400 m. Se espera que la producción en este campo produzca un impacto en la estabilidad de la línea de costa, y que suponga una amenaza potencial para la ciudad de Venecia, situada a 25 km al noroeste de la explotación. Se desarrolló un modelo numérico para evaluar el riesgo de subsidencia debido a la extracción de gas a lo largo de los 13 años de producción y del período post-productivo de 12 años. Sus predicciones indican que se causará la compactación tanto

  13. Applicability and methodology of determining sustainable yield in groundwater systems

    NASA Astrophysics Data System (ADS)

    Kalf, Frans R. P.; Woolley, Donald R.

    2005-03-01

    facteurs excessif qui se rejoignent dans la définition, et qui ne sont pas toujours quantifiables (5) il y a souvent confusion entre le débit durable et optimal et le débit spécifique durable (6) dans de nombreux environnements arides et semi-arides, les systèmes d'eau souterraine ne peuvent être sensiblement développés selon une politique de développement durable particulière où les contraintes écologiques sont appliquées. La dérivation du débit spécifique en utilisant le principe de la conservation des masses mène à l'expression de développement durable de bassin-versant, développement « minier » (mining) partiel (non durable), et développement minier total de l'exploitation (non durable) qui peut être déterminé en utilisant des méthodes numériques de modélisation, sélectionnées en fonction de contraintes appliquées. Dans certains cas il faut reconnaître que la ressource en eau souterraine n'est pas renouvelable et que sont utilisation ne peut donc pas être durable. Dans ces cas ses destinées seraient la meilleure utilisation équitable. Existe actualmente necesidad de revisar la definición y metodología para determinar lo que significa producción sostenible. Las razones son: (1) los conceptos y definiciones actuales son ambiguos y sin base física de modo que no pueden usarse para aplicación cuantitativa, (2) existe necesidad de eliminar interpretaciones variables y mal interpretaciones y aportar bases sanas para aplicación, (3) la noción de que todos los sistemas de aguas subterráneas son o pueden ser sostenibles no esvalida, (4) frecuentemente existen un numero excesivo de factores ligados a la definición de producción sostenible los cuales no son fácil de cuantificar, (5) frecuentemente existe confusión entre la producción optima de un establecimiento y la producción sostenible de unacuenca, (6) en muchos ambientes áridos a semi-áridos los sistemas de aguas subterráneas no pueden desarrollarse sensiblemente en base a

  14. Distribution of stable isotopes in arid storms . II. A double-component model of kinematic wave flow and transport

    NASA Astrophysics Data System (ADS)

    Yakirevich, Alexander; Dody, Avraham; Adar, Eilon M.; Borisov, Viacheslav; Geyh, Mebus

    A new mathematical method based on a double-component model of kinematic wave flow and approach assesses the dynamic isotopic distribution in arid rain storms and runoff. This model describes the transport and δ18O evolution of rainfall to overland flow and runoff in an arid rocky watershed with uniformly distributed shallow depression storage. The problem was solved numerically. The model was calibrated using a set of temporal discharge and δ18O distribution data for rainfall and runoff collected on a small rocky watershed at the Sede Boker Experimental Site, Israel. Simulation of a reliable result with respect to observation was obtained after parameter adjustment by trial and error. Sensitivity analysis and model application were performed. The model is sensitive to changes in parameters characterizing the depression storage zones. The model reflects the effect of the isotopic memory in the water within the depression storage between sequential rain spells. The use of the double-component model of kinematic wave flow and transport provides an appropriate qualitative and quantitative fitting between computed and observed δ18O distribution in runoff. RésuméUne nouvelle méthode mathématique basée sur un modèle à double composante d'écoulement et de transport par une onde cinématique a été développée pour évaluer la distribution dynamique en isotopes dans les précipitations et dans l'écoulement en région aride. Ce modèle décrit le transport et les variations des δ18O de la pluie vers le ruissellement et l'écoulement de surface dans un bassin aride rocheux où le stockage se fait dans des dépressions peu profondes uniformément réparties. Le problème a été résolu numériquement. Le modèle a été calibré au moyen d'une chronique de débits et d'une distribution des δ18O dans la pluie et dans l'écoulement de surface sur un petit bassin versant rocheux du site expérimental de Sede Boker (Israël). La simulation d'un résultat cr

  15. Forms of Appropriation of Tools for the Astronomy Education in Continuous Training of Teachers. (Spanish Title: Formas de Apropriación de Herramientas Para la Enseñanza de la Astronomía en la Formación Docente Continua.) Formas de Apropriação de Instrumentos Para o Ensino de Astronomia na Formação Continuada de Professores

    NASA Astrophysics Data System (ADS)

    Marques Soares, Leonardo; Sousa Nascimento, Silvania

    2012-07-01

    siete relatos. O objetivo principal desse artigo é apresentar algumas reflexões sobre a maneira como um grupo de professores se apropriaram dos instrumentos do KIT PARA O ENSINO DE ASTRONOMIA (KITPEA). Os sujeitos dessa pesquisa participaram do curso de especialização em ensino de astronomia oferecido pelo Projeto de Formação Continuada (Foco) no Centro de Ensino de Ciências e Matemática (CECIMIG) da Faculdade de Educação da Universidade Federal de Minas Gerais (FaE/UFMG). Coletamos as informações por meio de um questionário e de uma entrevista, aplicados a esses professores. Estruturamos a análise dessas informações com a ajuda da Teoria da Atividade e da Teoria da Ação Mediada. Interpretamos as falas dos professores usando como dispositivo analítico os elementos constituintes do sistema de atividade e os conceitos de apropriação e domínio. Dentre os 11 sujeitos que participaram da pesquisa, foi possível identificar a apropriação dos instrumentos em 7 narrativas.

  16. Observações das explosões cósmicas de raios gama GRB021004 e GRB021211 com o satélite HETE

    NASA Astrophysics Data System (ADS)

    Braga, J.; Ricker, G.; Hurley, K.; Lamb, D.; Grew, G.; et al.

    2003-08-01

    O High Energy Transient Explorer (HETE) é o primeiro satélite inteiramente dedicado ao estudo das explosões cósmicas de raios gama (ECRGs). Lançado em 9 de outubro de 2000, o HETE possui instrumentação capaz de observar as ECRGs desde o UV até raios gama e localizá-las com precisão de ~ 1-10 minutos de arco. As localizações das ECRGs detectadas são disseminadas rapidamente (em alguns segundos) pela Internet através de uma rede de estações de recepção ao longo do equador. A participação brasileira nesse projeto se dá através da montagem e operação de uma estação de recepção em Natal, RN, e da participação na equipe científica da missão. Neste trabalho são apresentados resultados da observação pelo HETE de duas ECRGs: GRB 021004 e GRB 021211. A GRB021004 foi detectada em raios gama pelo HETE em 4 de outubro de 2002 e localizada em raios-X em apenas 48 s, quando a emissão de raios gama ainda estava se processando. A explosão, relativamente brilhante e longa, durou aproximadamente 100 s. Um transiente óptico de magnitude 15 foi detectado no local da explosão nove minutos após o evento, e observações realizadas após 7 horas determinaram um desvio para o vermelho de absorção de 1,6. O GRB021004 foi o burst mais bem observado até o momento e suas observações em vários comprimentos de onda têm sido fundamentais para o aprimoramento dos modelos de ECRGs. O GRB21211, um burst brilhante e rico em raios-X, foi detectado em 11 de dezembro de 2002 e localizado em raios-X em 22 s após o início do evento. A duração do burst foi de 2,3 s em altas energias (85 a 400 keV) e de 8,5 s em baixas energias (2 a 10 keV). Caso essa explosão não tivesse sido rapidamente localizada pelo HETE, ela teria sido classificada como "opticamente escura", já que o transiente óptico decaiu rapidamente de R < 14 a R»19 dentro dos primeiros 20 minutos e já estava mais fraco do que R»23 depois de 24 horas da ocorrência do burst. Ser

  17. Sky Observation with the Use of the Software Stellarium for Teaching Astronomy in Classes of Youth and Adult Education. (Spanish Title: Observación del Cielo con la Utilización del Software Stellarium en Las Clases de Educación de Jóvenes y Adultos.) Observação do Céu Aliada À Utilização do Software Stellarium no Ensino de Astronomia em Turmas de Educação de Jovens e Adultos (EJA)

    NASA Astrophysics Data System (ADS)

    Oliveira Bernardes, Adriana

    2010-12-01

    en las ciencias, o sea, elaborar y desarrollar un plan de alfabetización científica. Se describe en detalle este plan, las actividades realizadas y los resultados obtenidos hasta el presente. O objetivo do presente artigo é apresentar um projeto desenvolvido através de parceria entre o Clube de Astronomia de Itaocara Marcos Pontes (CAIMP) e o Colégio Estadual Jaime Queiroz de Souza, ambos localizados na cidade de Itaocara, no Noroeste Fluminense, no sentido de divulgar junto às turmas de EJA (Ensino de Jovens e Adultos) a disciplina Astronomia. Conhecendo o caráter interdisciplinar da Astronomia, desenvolvemos este trabalho para motivar o aprendizado de Ciências junto a alunos de EJA do Ensino Médio que cursam as disciplinas Química, Física e Biologia. Inicialmente, realizamos na escola pesquisa sobre o conhecimento prévio de Astronomia da turma de EJA, observando que é escasso o conhecimento de conceitos básicos do tema, muitos dos quais deveriam ser assimilados através do conteúdo da disciplina Física. Com esses dados, foi possível elaborar várias atividades que possibilitassem um maior envolvimento dos estudantes com a Ciência, realizando dentro da escola um trabalho de alfabetização científica, cujas atividades serão apresentadas neste artigo.

  18. Analysis of Service-learning activities adopted in health courses of Federal University of Bahia.

    PubMed

    Baldoino, Aline Silva; Veras, Renata Meira

    2016-06-01

    is study aimed to raise and discuss the data about the integration of health courses teaching and service activities o ered at the Federal University of Bahia (UFBA), pre- senting scenarios practices and major di culties existing in the relationship between the university and the services of health. is was a qualitative study of descriptive explo- ratory character, using a questionnaire as a research tool applied to the coordinators of selected health courses. e selection was by reading the political pedagogical project, the following courses were selected: nursing, physical therapy, speech therapy, medicine, nu- trition, dentistry and public health. e results indicated eight types of teaching-service integration activities, 57 scenarios of practice and the main di culties. It was concluded that these courses are sticking to changes in academic training in health, in view of the large number of basic health units in the teaching service process. us, it emphasizes that the UFBA includes activities in health care that enable the integration-education in the higher education process, although there are some di culties in this relationship indicated by the coordinators. Esse estudo teve como objetivo levantar e discutir os dados acerca das atividades de integração ensino-serviço de cursos de saúde oferecidos na Universidade Federal da Bahia (UFBA), apresentando os cenários de práticas e as principais di culdades existentes na relação entre a uni- versidadeeosserviçosdesaúde.Tratou-sedeumapesquisaqualitativa,decaráterdescritivoexploratório,utilizando-seumquestionáriocomo instrumento de investigação aplicado aos coordenadores dos cursos de saúde selecionados. A seleção foi mediante a leitura do projeto político pedagógico, sendo selecionados os seguintes cursos: enfermagem, sioterapia, fonoaudiologia, medicina, nutrição, odontologia e saúde coletiva. Os resultados indicaram 8 tipos de atividades de integração ensino-serviço, 57 cenários de pr

  19. Mathematical modeling of the "plant community -soil-like substrate -gas exchange with the human" closed ecosystem

    NASA Astrophysics Data System (ADS)

    Barkhatov, Yuri; Gubanov, Vladimir; Tikhomirov, Alexander A.; Degermendzhy, Andrey G.

    A mathematical model of the "plant community -soil-like substrate -gas exchange with the human" experimental biological life support system (BLSS) has been constructed to predict its functioning and estimate feasibility of controlling it. The mathematical model consists of three compartments -two `phytotron' models (with wheat and radish) and the `mycotron' model (for mushrooms). The following components are included in the model: edible mushrooms (mushroom fruit bodies and mycelium); wheat; radish; straw (processed by mycelium); dead organic matter in the phytotron (separately for the wheat unit and for the radish unit); worms; worms' coprolites; vermicompost used as a soil-like substrate (SLS); bacterial microflora; min-eral nitrogen, phosphorus and iron; products of the system intended for humans (wheat grains, radish roots and mushroom fruit bodies); oxygen and carbon dioxide. Under continuous gas exchange, the mass exchange between the compartments occurs at the harvesting time. The conveyor character of the closed ecosystem functioning has been taken into account -the num-ber of culture age groups can be regulated (in experiments -4 and 8 age groups). The conveyor cycle duration can be regulated as well. The module is designed for the food and gas exchange requirements of 1/30 of a virtually present human. Aim of model analysis is determination of investigation direction in real experimental BLSS. The model allows doing dynamic calcu-lations of closure coefficient based on the main elements taken into account in the model and evaluating all dynamic components of the system under different conditions and modes of its operation, especially under the conditions that can hardly be created experimentally. One of the sustainability conditions can be long-duration functioning of the system under the light-ing that is far from the optimum. The mathematical model of the system can demonstrate variants of its sustainable functioning or ruin under various critical

  20. Préface

    NASA Astrophysics Data System (ADS)

    Mazière, D.

    2002-04-01

    -sept d'entre elles sont développées dans cet ouvrage. On pourra consulter avec profit le numéro 44 des Clefs CEA "Nouvelles Technologies de l'énergie" en complément du présent ouvrage.

  1. 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

  2. Percepção Astronômica de Alunos do Ensino Médio da Rede Estadual de São Paulo

    NASA Astrophysics Data System (ADS)

    de Oliveira, E. F.; Voelzke, M. R.; Amaral, L. H.

    2005-08-01

    Embora a astronomia seja uma das ciências mais antigas da humanidade e muitos dos conceitos astronômicos serem populares, principalmente nesta época de alta globalização do conhecimento por intermédio de eficientes meios de comunicação e de obtenção da informação, notadamente através da internet, observa-se que uma parcela significativa dos estudantes encontra-se à margem dessas informações. O presente trabalho visa analisar o nível de conhecimento básico dos alunos de Ensino Médio da rede estadual da cidade de Suzano quanto aos fenômenos astronômicos que os rodeiam, tais como a sucessão dos dias e das estações do ano, além de questioná-los sobre fatos genéricos tais como: quais são os astros que se encontram mais próximos do planeta Terra, o que vem a ser o Sol, o Big Bang, um ano-luz, uma estrela cadente, a estrela de Bélem e o que ocasionou a extinção dos dinossauros. Para tanto foi elaborado um formulário constando de questões de múltipla escolha, o qual foi aplicado no primeiro colegial noturno da Escola Estadual Batista Renzi. Num espaço amostral de 34 alunos constatou-se que apenas 29,4% compreendiam a sucessão dos dias da semana, que apenas 20,6% explicaram corretamente as estações do ano, que apenas 20,6% tinham idéia de quais são os objetos celestes mais próximos da Terra, em contraposição 67,6% sabiam classificar corretamente o Sol como estrela, 55,9% relacionavam o Big Bang à origem do universo, apenas 20,6% identificavam um ano-luz como unidade de distância, 32,4% reconheciam uma estrela cadente como meteoro, 41,2% consideravam a estrela de Belém como um cometa e 50,0% explicaram corretamente a extinção dos dinossauros. A presente análise será expandida para as demais classes de primeiro colegial, não somente do período noturno, mas também do diurno da Escola Estadual Batista Renzi, bem como o formulário será devidamente ampliado. Já nesta primeira fase nota-se claramente o pequeno discernimento

  3. Correction partielle des Effets de la Turbulence atmosphérique en Interférométrie optique: Traitement des Données et Développement d'Optiques adaptatives pour l'Interféromètre GI2T

    NASA Astrophysics Data System (ADS)

    Vérinaud, Christophe

    2000-11-01

    Dans le domaine de la haute résolution angulaire en astronomie, les techniques de l'interférométrie optique et de l'optique adaptative sont en plein essor. La principale limitation de l'interférométrie est laturbulence atmosphérique qui entraîne des pertes de cohérence importantes, préjudiciables à la sensibilité et à la précision des mesures. L'optique adaptative appliquée à l'interférométrie va permettre un gain en sensibilité considérable. Le but de cette thèse est l'étude de l'influence de l'optique adaptative sur les mesures interférométriques et son application au Grand Interféromètre à DeuxTélescopes (GI2T) situé sur le Mont Calern dans le sud de la France. Deux problèmes principaux sont étudiés de manière théorique par des développements analytiques et des simulations numériques: le premier est le contrôle en temps réel de la variation des différences de marche optique, encore appelée piston différentiel, induite par l'optique adaptative ; le deuxième problème important est la calibration des mesures de contraste des franges dans le cas de la correction partielle. Je limite mon étude au cas d'un interféromètre multi-modes en courtes poses, mode de fonctionnement principal du GI2T également prévu sur le Very Large Telescope Interferometer installé au Cerro Paranal au Chili. Je développe une méthode de calibration des pertes de cohérence spatio-temporelles connaissant la fonction de structure des fronts d'onde corrigés. Je montre en particulier qu'il est possible d'estimer fréquence par fréquence la densité spectrale des images en courtes poses, méthode très utile pour augmenter la couverture du plan des fréquences spatiales dans l'observation d'objets étendus. La dernière partie de ce mémoire est consacrée au développements instrumentaux auxquels j'ai participé. J'ai développé un banc de qualification du système d'optique adaptative à courbure destiné au GI2T et j'ai étudié l

  4. Diurnal cycling of urban aerosols under different weather regimes

    NASA Astrophysics Data System (ADS)

    Gregorič, Asta; Drinovec, Luka; Močnik, Griša; Remškar, Maja; Vaupotič, Janja; Stanič, Samo

    2016-04-01

    A one month measurement campaign was performed in summer 2014 in Ljubljana, the capital of Slovenia (population 280,000), aiming to study temporal and spatial distribution of urban aerosols and the mixing state of primary and secondary aerosols. Two background locations were chosen for this purpose, the first one in the city center (urban background - KIS) and the second one in the suburban background (Brezovica). Simultaneous measurements of black carbon (BC) and particle number size distribution of submicron aerosols (PM1) were conducted at both locations. In the summer season emission from traffic related sources is expected to be the main local contribution to BC concentration. Concentrations of aerosol species and gaseous pollutants within the planetary boundary layer are controlled by the balance between emission sources of primary aerosols and gases, production of secondary aerosols, chemical reactions of precursor gases under solar radiation and the rate of dilution by mixing within the planetary boundary layer (PBL) as well as with tropospheric air. Only local emission sources contribute to BC concentration during the stable PBL with low mixing layer height, whereas during the time of fully mixed PBL, regionally transported BC and other aerosols can contribute to the surface measurements. The study describes the diurnal behaviour of the submicron aerosol at the urban and suburban background location under different weather regimes. Particles in three size modes - nucleation (< 25 nm, NUM), Aitken (25 - 90 nm, AIM) and accumulation mode (90 - 800 nm, ACM), as well as BC mass concentration were evaluated separately for sunny, cloudy and rainy days, taking into account modelled values of PBL height. Higher particle number and black carbon concentrations were observed at the urban background (KIS) than at the suburban background location (Brezovica). Significant diurnal pattern of total particle concentration and black carbon concentration was observed at both

  5. 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

  6. Undrained heating and anomalous pore-fluid pressurization of a hardened cement paste

    NASA Astrophysics Data System (ADS)

    Ghabezloo, S.; Sulem, J.; Saint-Marc, J.

    2009-04-01

    cement paste are also measured in the heating tests. The measured value of the thermal pressurization coefficient is found equal to 0.6MPa/°C and the test results unexpectedly show that it does not change with temperature between 20°C and 55°C. In most geomaterials, as shown experimentally by Ghabezloo and Sulem (2008), the temperature dependency of the thermal expansion of the pore fluid results in temperature dependency of the thermal pressurization coefficient. The observed anomalous thermal pressurization phenomenon is attributed to the anomalous thermal behaviour of cement paste pore fluid. The anomalous thermal behaviour of cement pore fluid is back analysed from the results of the undrained heating test and it is shown that the thermal expansion of the cement paste pore fluid is higher than the one of pure bulk water and is much less sensitive to temperature changes. This anomalous thermal behaviour is due to the confinement of the pore fluid in the very small pores of the microstructure of the cement paste, and also to the presence of dissolved ions in the pore fluid. References: 1.Sulem J., Lazar P., Vardoulakis I. (2007) Thermo-Poro-Mechanical Properties of Clayey Gouge and Application to Rapid Fault Shearing, Int. J. Num. Anal. Meth. Geomechanics, 31(3), 523-540 2.Ghabezloo S., Sulem J. (2008) Stress dependent thermal pressurization of a fluid-saturated rock. Rock Mechanics and Rock Engineering, in press, DOI 10.1007/s00603-008-0165-z. 3.Ghabezloo S., Sulem J., Saint-Marc, J. (2009) The effect of undrained heating on a fluid-saturated hardened cement paste. Cement and Concrete Research, 39(1), 54-64. 4.Ghabezloo S., Sulem J. (2009) Evaluation of the undrained thermo-poro-elastic parameters in a conventional triaxial cell: the effect of the dead volume of the drainage system. Submitted to Int J Rock Mech Min Sci.

  7. Seasonality in cholera dynamics : a rainfall-driven model explains the wide range of patterns of an infectious disease in endemic areas

    NASA Astrophysics Data System (ADS)

    Baracchini, Theo; Pascual, Mercedes; King, Aaron A.; Bouma, Menno J.; Bertuzzo, Enrico; Rinaldo, Andrea

    2015-04-01

    to determine whether the seasonality is uni- or bimodal, as well as whether it is pre-, post-, or in-phase with the monsoon te{akanda_2009}. We present evidence that the environmental reservoir is responsible for the persistence of the disease, and therefore its endemicity. Given the interplay between the seasonality of cholera and the environment, a deeper understanding of the underlying mechanisms could allow for the better management and planning of public health policies with respect to climate. We provide an interpretation of those dynamics and discuss their implications. In terms of disease prevention and mitigation strategies this is of paramount importance today, as changes in the population dynamics of infectious diseases are expected in response to fast anthropogenic climate change. M. Pascual, M. J. Bouma, and A. P. Dobson, "Cholera and climate: revisiting the quantitative evidence", Microbes and infections, 2002. A. A. King, E. L. Ionides, M. Pascual, M. J. Bouma, "Inapparent infections and cholera dynamics", Nature, 2008. E. Bertuzzo, L. Mari, L. Righetto, M. Gatto and R. Casagrandi et al., "Hydroclimatology of dual-peak annual cholera incidence: Insights from a spatially explicit model", Geophysical Research Letters, vol. 39, num. 5, p. -, 2012. M. Emch, C. Feldacker, M. S. Islam, and M. Ali, "Seasonality of cholera from 1974 to 2005: a review of global patterns", International Journal of Health Geographics, 2008. E. L. Ionides, A. Bhadra, Y. Atchade, A. A. King, "Iterated filtering", Annals of Statistics, 2011. A. S. Akanda, A. S. Jutla, S. Islam, "Dual peak cholera transmission in Bangal Delta: A hydroclimatological explanation", Geophysical Reseach Letters, 2009.

  8. Balancing The Books - A Statistical Theory of Mass Balances

    NASA Astrophysics Data System (ADS)

    O'Kane, J. P.

    budget. We can now make definite statements about any observed value of e, which are log- ically consistent with the law of conservation of mass, the measurement/sampling procedure, and the data reduction. When the observed value of e lies outside its the- oretical distribution, we reject the hypothesis that this could have occurred only by chance. It is much more likely that systematic errors are present and we may reject the attempted budget. If the observed value of e lies within its distribution, we have no grounds for rejecting the hypothesis or the budget. However, by increasing the num- ber of measurements, we can reduce Var(e'), refining the discrimination of the test. All 1 other types of mass budget lack this logical and objective conclusion. Measurements at fixed points in time or space, only allow subjective judgements to be made about the closing error. 2

  9. Identification of thermal properties distribution in building wall using infrared thermography

    NASA Astrophysics Data System (ADS)

    Brouns, Jordan; Dumoulin, Jean

    2016-04-01

    [1] L. Ibos, J-P. Monchau, V. Feuillet, Y. Candau, A comparative study of in-situ measurement methods of a building wall thermal resistance using infrared thermography, in Proc. SPIE 9534, Twelfth International Conference on Quality Control by Artificial Vision 2015, 95341I (April 30, 2015); doi:10.1117/12.2185126 [2] Nassiopoulos, A., Bourquin, F., On-site building walls characterization, Numerical Heat Transfer, Part A : Applications, 63(3) :179 :200, 2013 [3] J. Brouns, Développement d'outils numériques pour l'audit énergétique des bâtiments, PhD thesis, Université Paris-Est, SIE, 2014 [4] J.-L. Lions, Contrôle optimal de systèmes gouvernés par des équations aux dérivées partielles. Book, Dunod editor, 1968.

  10. Determining the Shape of the Orbit of Mars in the High School. (Spanish Title: Determinación de la Forma de la Órbita de Marte en la Escuela Secundaria.) Determinando a Forma da Órbita de Marte no Ensino Médio

    NASA Astrophysics Data System (ADS)

    Dutra, Carlos Maximiliano; Rossini Goulart, Andressa

    2014-12-01

    obtivemos em um trabalho de duas horas de duração o traçado da órbita de Marte com resultados numéricos médios que reproduzem com erro inferior a 14% os parâmetros orbitais de referência da órbita de Marte.

  11. GIAnT - Generic InSAR Analysis Toolbox

    NASA Astrophysics Data System (ADS)

    Agram, P.; Jolivet, R.; Riel, B. V.; Simons, M.; Doin, M.; Lasserre, C.; Hetland, E. A.

    2012-12-01

    noise covariance models through the processing chain for robust estimation of uncertainties in the deformation estimates. We will demonstrate the ease of use of our framework with results ranging from regional scale analysis around Long Valley, CA and Parkfield, CA to continental scale analysis in Western South America. We will also present preliminary results from a new time-series approach that simultaneously estimates deformation over the complete spatial domain at all time epochs on a distributed computing platform. GIAnT has been developed entirely using open source tools and uses Python as the underlying platform. We build on the extensive numerical (NumPy) and scientific (SciPy) computing Python libraries to develop an object-oriented, flexible and modular framework for time-series InSAR applications. The toolbox is currently configured to work with outputs from ROI-PAC, ISCE and DORIS, but can easily be extended to support products from other SAR/InSAR processors. The toolbox libraries include support for hierarchical data format (HDF5) memory mapped files, parallel processing with Python's multi-processing module and support for many convex optimization solvers like CSDP, CVXOPT etc. An extensive set of routines to deal with ASCII and XML files has also been included for controlling the processing parameters.

  12. Analysis of the seasonal and interannual evolution of Jakobshavn Isbrae from 2010-2013 using high spatial/temporal resolution DEM and velocity data

    NASA Astrophysics Data System (ADS)

    Shean, D. E.; Joughin, I. R.; Smith, B. E.; Moratto, Z. M.; Alexandrov, O.; Floricioiu, D.; Morin, P. J.; Porter, C. C.; Beyer, R. A.; Fong, T.

    2013-12-01

    Greenland's large marine-terminating outlet glaciers have displayed marked retreat, speedup, and thinning in recent decades. Jakobshavn Isbrae, one of Greenland's largest outlet glaciers, has retreated ~15 km, accelerated ~150%, and thinned ~200 m since the early 1990s. Here, we present the first comprehensive analysis of high spatial (~2-5 m/px) and temporal (daily-monthly) resolution elevation and velocity data for Jakobshavn from 7/2010 to 7/2013. We have developed an automated processing pipeline using open-source software (Ames Stereo Pipeline, GDAL/OGR, NumPy/SciPy, etc.) to produce orthoimage, digital elevation model (DEM), and surface velocity products from DigitalGlobe WorldView-1/2 stereo imagery (~0.5 m/px, ~17 km swath width). Our timeseries consists of 35 WV DEMs (~2-4 m/px) covering the lower trunks of the main+north branches and fjord, but also extending >110 km inland. We supplement this record with 7 TanDEM-X DEMs (~5 m/px, ~35 km swath width) between 6/2011-9/2012. Elevation data from IceBridge ATM/LVIS, ICESat GLAS, and GPS campaigns provide absolute control data over fixed surfaces (i.e., exposed bedrock). Observed WV DEM offsets are consistent with DigitalGlobe's published value of 5.0 m CE90/LE90 horizontal/vertical accuracy. After DEM co-registration, we observe sub-meter horizontal and vertical absolute accuracy. Velocity data are derived from TerraSAR-X data with 11 day repeat interval. Supplemental velocity data are derived through correlation of high-resolution WV DEM/image data. The contemporaneous DEM and velocity data provide full 3D displacement vectors for each time interval, allowing for the analysis of both Eulerian and Lagrangian elevation change. The lower trunk of Jakobshavn displays significant seasonal velocity variations, with recent rates of ~8 km/yr during winter to >17 km/yr during summer. DEM data show corresponding elevation changes of -30 to -45 m in summer and +15 to +20 m in winter, corresponding to integrated volumes

  13. Populações estelares do bojo galáctico

    NASA Astrophysics Data System (ADS)

    Escudero, A. V.; Costa, R. D. D.; Maciel, W. J.

    2003-08-01

    Os estudos mais recentes do bojo galáctico têm enfocado essencialmente as abundâncias químicas de elementos pesados, como o ferro, obtidos a partir das estrelas nas regiões centrais da galáxia. Elementos leves, como hélio, nitrogênio, oxigênio e argônio ainda são pouco estudados nestas regiões, devido à difícil determinação de suas abundâncias a partir de estrelas. Nestas condições as nebulosas planetárias desempenham um importante papel, pois permitem a determinação de abundâncias destes elementos usando técnicas de espectroscopia nebular. Neste trabalho, reportamos a análise das abundâncias químicas de uma nova amostra de nebulosas planetárias do bojo, bem como os resultados preliminares de um código numérico destinado a modelar a evolução química desta região. Usamos como vínculos observacionais os resultados obtidos das nebulosas planetárias, bem como de abundâncias estelares da região do bojo, obtidas da literatura. A partir deste modelo da evolução química e dos vínculos observacionais foi possível fazer um diagnóstico mais preciso das populações que constituem o bojo galáctico. O estudo destas populações que compõem a região central de nossa galáxia é de extrema importância para o maior entendimento da evolução química e dinâmica da galáxia como um todo. Por isto, verificamos a importância dos modelos de formação simples e mista utilizados para explicar características da população da região central da galáxia. Algumas destas características são: uma grande dispersão nos valores das abundâncias químicas e um grande espalhamento nas correlações entre as abundâcias de nitrogênio e oxigênio. Estas peculiaridades são dificilmente reproduzidas por modelos de formação simples, e portanto são importantes indícios da validade dos modelos de formação mista, tais como um rápido colapso do bojo seguido de uma evolução secular. (FAPESP, CNPq)

  14. Mesoscopics of ultrasound and seismic waves: application to passive imaging

    NASA Astrophysics Data System (ADS)

    Larose, É.

    2006-05-01

    ondes, qui démontre l'aspect mésoscopique de leur propagation, est une limitation majeure pour les techniques d'imagerie conventionelles (imagerie médicale, sismique réflexion ou réfraction, tomographie...). La deuxième partie du document (Chaps. 3 5) est consacrée à une application de cette physique mésoscopique : le principe de l'imagerie passive. En effectuant la corrélation temporelle d'enregistrement de bruit ambiant ou d'ondes diffuses, il est possible de reconstruire la réponse impulsionnelle du milieu entre deux capteurs passifs comme si l'on avait placé une source en lieu et place d'un des capteurs. Cela offre la possibilité de faire de l'acoustique ou de la sismologie sans source. Plusieurs aspects sont présentés dans ce manuscrit : des aspects théoriques et numériques (Chaps. 3, 4), ensuite des aspects expérimentaux avec des applications (Chap. 5) à l'échelle des ultrasons (tomographie passive d'un milieu stratifié), et des applications à l'échelle de la sismologie (imagerie du sous-sol de la Californie, et même de la Lune).

  15. Qual o Papel da Escola e da Mídia na Obtenção dos Conhecimentos Astronômicos?

    NASA Astrophysics Data System (ADS)

    da Cunha, W. S.; Voelzke, M. R.; Amaral, L. H.

    2007-08-01

    É amplamente reconhecido que as pessoas em geral têm grande fascínio e interesse pela Astronomia. Por outro lado, o conteúdo dessa área incluído no ensino formal está longe de ser abrangente e suficiente para suprir a demanda. Esse interesse permite aperfeiçoar a divulgação e o ensino não formal de Astronomia através da mídia aliando a adequação do conteúdo à expectativa das pessoas. A reforma do Currículo Básico da Escola Pública da maioria dos Estados brasileiros tem introduzido Astronomia desde a pré-escola até o Ensino Médio. Num estudo realizado com 1180 alunos do Ensino Médio de seis escolas estaduais, revelou-se através da aplicação de um formulário contendo questões que abordavam conhecimentos básicos em Astronomia, como foram adquiridos tais conhecimentos e à infra-estrutura da escola. Para 66,1% dos entrevistados o professor já fez alguma apresentação a respeito de Astronomia. O presente estudo revelou também que 54,4% dos alunos entrevistados adquiriram seus conhecimentos astronômicos na escola, 18,4% através da televisão e 27,1% afirmaram que seus conhecimentos foram obtidos através de outros tipos de mídia (internet, livros didáticos, filmes e revistas). Embora o estudo revele claramente que há certo equilíbrio no meio em que os alunos obtiveram seus conhecimentos astronômicos, a mídia busca não somente sua difusão, mas a disponibilização desse conhecimento de maneira correta, que às vezes, não é atingido, apresentando conceitos sem fundamentação e incorretos. Por outro lado, no dia-a-dia escolar, é comum encontrar professores que vêm para as aulas com concepções prévias, que podem diferir substancialmente das idéias a serem ensinadas, dificultando o aprendizado de futuros conceitos científicos. Uma avaliação criteriosa, avaliando as dificuldades dos professores em determinar o sentido correto dos conceitos e observando a metodologia que utilizam no ensino, poderá proporcionar uma melhor

  16. Aspects cliniques et biologiques des anémies pédiatriques dans un hôpital de District urbain au Cameroun

    PubMed Central

    Koum, Danièle Kedy; Tsakeu, Eveline Ngouadjeu Dongho; Sack, Françoise Ngo; Ngalagou, Pierre Tchienrg Moueleu; Kamanyi, Albert; Mandengue, Samuel Honoré

    2013-01-01

    Introduction L'anémie est un problème de santé publique prédominant chez les enfants et les femmes en âge de procréer. L'objectif de cette étude était de caractériser et de déterminer sa prévalence chez les enfants âgés de 6 mois à 14 ans hospitalisés à l'hôpital de District de Bonassama à Douala-Cameroun. Méthodes Il s'agissait d'une étude descriptive transversale qui s'est déroulée de février à mars 2012 avec une collecte rétrospective des données de janvier 2009 à mars 2012. Etaient inclus, les patients de 6 mois à 14 ans hospitalisés, quel que soit leur motif de consultation et leur diagnostic, et ayant réalisé au moins une numération formule sanguine (NFS). Les patients transfusés moins de 120 jours avant la NFS étaient exclus. L’âge, le sexe, les motifs de consultation, les signes cliniques, les diagnostics et les résultats de la NFS étaient enregistrés. L'anémie était définie selon les critères de l'OMS. La recherche étiologique était guidée par les signes cliniques et les examens complémentaires. Résultats La prévalence de l'anémie était de 88,5%. Le sex-ratio garçon/fille était de 1,3. La fièvre était le premier motif de consultation. L'anémie modérée prédominait (62,7%). Le taux moyen d'hémoglobine chez les patients anémiques était de 8,6 ± 1,7 g/dl (2,3- 11,4). L'anémie microcytaire hypochrome dominait (48,5%). Le paludisme était la principale pathologie (46,3%). Le taux de mortalité des patients anémiques était de 5,9%. Conclusion La prévalence de l'anémie était élevée avec une prédominance des formes hypochromes microcytaires. La principale étiologie était le paludisme. PMID:24772220

  17. AlphaSpectrum ASPECT analysis code for background correction & peak integration

    Energy Science and Technology Software Center (ESTSC)

    2005-04-13

    The ASPECT code provides a means for rapid analysis of energy-resolved spectra obtained by multi-channel pulse-height analysis (MCA) during (or after) counting of alpha-emissions from a filter air sample (or other suitably prepared sample) utilizing a solid-state detector, or other detector having sufficient energy resolution indiviual radioisotope peaks indentified in a spectrum are fitted using a peak shape algorithm by non-linear least-square fitting procedures that minimize Chi-square differences between the data and a fitted peakmore » function. The code accomplishes the identification of all significant peaks present in the spectrum with automatic recalibration to the 7.68 Po-214 alpha peak from the Radon-222 decay chain, the subtraction of all radon progeny interference overlaps with lower energy peaks in the energy range of Pu-238, Am-241, Pu-239, and U-234/Th-232, and the integration of the counts in any peak identified for these transuranic radionuclides. The output is therefore in the form of isotope specific net transuranic CPM, DPM or concentration, available in near real-time during air sampling. In this "copyright" version, the assumption is made that the alpha spectra to be analyzed have been stored by unique name in sequential form: "FileName(i)", where "FileName" can be any name and i is the index number of the file saved (e.g., i = 1,2, ..., n). this format is one automatically generated by the alpha Environmental Continuous Air Monitor (ECAM), developed by Los Alamos National Laboratory, and manufactured by Canberra Industries, a Laboratory Industrial Partner for this technology. It is assumed in this version of the code that the alpha spectrum data are stored in a 256 channel spectrum, although a larger num ber of channels could be easily accommodated by small code changes. The ECAM data output format is RADNET compliant (an inidustry standard developed at Los Alamos), and include, in addition to a 256-channel alpha spectrum, data on the

  18. ogs6 - a new concept for porous-fractured media simulations

    NASA Astrophysics Data System (ADS)

    Naumov, Dmitri; Bilke, Lars; Fischer, Thomas; Rink, Karsten; Wang, Wenqing; Watanabe, Norihiro; Kolditz, Olaf

    2015-04-01

    OpenGeoSys (OGS) is a scientific open-source initiative for numerical simulation of thermo-hydro-mechanical/chemical (THMC) processes in porous and fractured media, continuously developed since the mid-eighties. The basic concept is to provide a flexible numerical framework for solving coupled multi-field problems. OGS is targeting mainly on applications in environmental geoscience, e.g. in the fields of contaminant hydrology, water resources management, waste deposits, or geothermal energy systems, but it has also been successfully applied to new topics in energy storage recently. OGS is actively participating several international benchmarking initiatives, e.g. DECOVALEX (waste management), CO2BENCH (CO2 storage and sequestration), SeSBENCH (reactive transport processes) and HM-Intercomp (coupled hydrosystems). Despite the broad applicability of OGS in geo-, hydro- and energy-sciences, several shortcomings became obvious concerning the computational efficiency as well as the code structure became too sophisticated for further efficient development. OGS-5 was designed for object-oriented FEM applications. However, in many multi-field problems a certain flexibility of tailored numerical schemes is essential. Therefore, a new concept was designed to overcome existing bottlenecks. The paradigms for ogs6 are: - Flexibility of numerical schemes (FEM#FVM#FDM), - Computational efficiency (PetaScale ready), - Developer- and user-friendly. ogs6 has a module-oriented architecture based on thematic libraries (e.g. MeshLib, NumLib) on the large scale and uses object-oriented approach for the small scale interfaces. Usage of a linear algebra library (Eigen3) for the mathematical operations together with the ISO C++11 standard increases the expressiveness of the code and makes it more developer-friendly. The new C++ standard also makes the template meta-programming technique code used for compile-time optimizations more compact. We have transitioned the main code development to

  19. Evaluation of different processing strategies of Continuous GPS (CGPS) observations for landslide monitoring

    NASA Astrophysics Data System (ADS)

    Ferhat, Gilbert; Malet, Jean-Philippe; Ulrich, Patrice

    2015-04-01

    techniques, and because sophisticated a posteriori data processing techniques are required to process long observation sessions, model errors introduced by variations of the satellite constellation and multi-path effects. The objectives of this work are to evaluate the performance of PPP (Precise Point Positioning) and DD (Double Difference) processing techniques on observations acquired at the landslides since 2010. The PPP approach is a positioning method used to calculate precise positions using a single receiver from un-differenced phase measurements, precise clocks and precise satellite orbits. The PPP method is different from the DD positioning method which eliminate most errors using one or more reference stations with known positions. Position time series of several GPS located on landslides are computed with the NRCan (Natural Resource Canada) PPP software, the GINS (Géodésie par Intégrations Numériques Simultanées) PPP software and the GAMIT/GLOBK DD software. Evaluation of the results are discussed.

  20. KAO observations of SN1987A

    NASA Astrophysics Data System (ADS)

    Wooden, Diane H.

    Explosion calculations of SN1987A generate pictures of Rayleigh-Taylor fingers of radioactive Ni-56 (Ni-56 yields Co-56 yields Fe-56) which are boosted to velocities of several thousand km/s. From the KAO observations of the mid-IR iron lines, a picture of the iron in the ejecta emerges which is consistent with the 'frothy iron fingers' having expanded to fill about 50% of the metal-rich volume of the ejecta (num less than or equal to 2500 km/s). The ratio of the nickel line intensities I(Ni I7.5 micron)/I(Ni II6.6 microns) yields a high ionization fraction of xNi greater than or equal to 0.9 in the volume associated with the iron-group elements at day 415, before dust condenses in the ejecta. From the KAO observations of the dust's thermal emission (2 microns to 100 microns), it is deduced that when the grains condense, their infrared radiation is trapped, their apparent opacity is gray, and they have a surface area filling factor of about 50%. The dust emission from SN1987A is featureless: no 9.7 micron silicate feature, nor PAH features, nor dust emission features of any kind are seen at any time. The total dust opacity increases with time even though the surface area filling factor and the dust/gas ratio remain constant. This suggests that the dust forms along coherent structures which can maintain their radial line-of-sight opacities, i.e., along fat fingers. The coincidence of the filling factor of the dust and the filling factor of the iron strongly suggests that the dust condenses within the iron, and therefore the dust is iron-rich. It only takes approximately 10-4 solar mass of dust for the ejecta to be optically thick out to approximately 100 microns; a lower limit of 4 x 10-4 solar mass of condensed grains exists in the metal-rich volume, but much more dust could be present. The episode of dust formation started at about 539 days and proceeded rapidly, so that by 600 days 45% of the bolometric luminosity was being emitted in the IR; by 775 days, 86% of

  1. A Massive Parallel Variational Multiscale FEM Scheme Applied to Nonhydrostatic Atmospheric Dynamics

    NASA Astrophysics Data System (ADS)

    Vazquez, Mariano; Marras, Simone; Moragues, Margarida; Jorba, Oriol; Houzeaux, Guillaume; Aubry, Romain

    2010-05-01

    evolution from a smooth initial cold disturbance as in Straka et al. [3]. (2) The warm raising anomaly of initial smooth distribution (i.e. Wicker and Skamarock [4]; Ahmad and Lindeman [5]) run on a structured grid of quadrilaterals first, and on a fully unstructured next; and (3) the interaction of a small cold anomaly falling and a raising warm bubble raising (Robert [6]). Problems in a stably stratified environment are also described and compared with (1) the hydrostatic and non-hydrostatic, linear and non linear mountain wave problems for flows over different sets of topographic features. The definitions and results of Smith [7], Bonaventura [8], Mayr and Gohm [9], and Schär [10] are taken as reference. The parallel performances of the algorithm were tested for the solution of the fully compressible Navier-Stokes equations in a three dimensional boundary layer problem. The scalability in the strong sense was measured for runs on 1, 1000, 2000, and 5000 processors, exploiting a combination of message passing interface (MPI) with automatic domain partition, and threads using OpenMP. Keywords: Numerical Weather Prediction, Computational Fluid Dynamics, Low Mach, Compressible Flows, High Performance Computing References [1] T.J. Hughes (1995), "Multiscale phenomena: Green's functions, the Dirichlet-to-Neumann formulation, subgrid scale models, bubbles and the origins of stabilized methods" Comp. Methods Appl. Mech. and Eng. 127, 387-401 [2] G. Houzeaux and M. Vázquez and R. Aubry (2009), "A Parallel Incompressible Navier-Stokes Solver for Large Scale Supercomputers" J. Comput. Phys., In press [3] J. Straka and R. Wilhelmson and L. Wicker and J. Anderson and K. Droegemeier (1993), "Numerical solution of a nonlinear density current: a benchmark solution and comparisons" Int. J. Num. Meth. in Fluids 17, 1-22 [4] L. Wicker and W. Skamarock (1998), "A time-splitting scheme for the elastic equations incorporating second-order Runge-Kutta time differencing" Mon. Weather Rev. 126

  2. High-order Hybridized Discontinuous Galerkin (HDG) method for wave propagation simulation in complex geophysical media (elastic, acoustic and hydro-acoustic); an unifying framework to couple continuous Spectral Element and Discontinuous Galerkin Methods

    NASA Astrophysics Data System (ADS)

    Terrana, Sebastien; Vilotte, Jean-Pierre; Guillot, Laurent; Mariotti, Christian

    2015-04-01

    assessed against classical SEMs and DGMs through two-dimensional geophysical examples, as well as the coupling between hybridized SEMs and DGMs in the same computational domain. Finally on-going extension of this HDG method for three-dimensional wave propagation phenomena will be outlined in conclusion. References: Chaljub, E., Komatitsch, D., Vilotte, J.-P., Capdeville, Y., Valette, B., Festa, G., Spectral Element analysis in seismology, Advances in Geophysics, 48, 365-419, 2006. Cockburn, B., Gopalakrishnan, J., Lazarov, R., Unified hybridization of discontinuous Galerkin, mixed and continuous Galerkin methods for second order elliptic problems, SIAM J. Num. Anal., 47, 2, 1319-1365, 2009. Dumbser, M. and M. Käser, An abitrary high-order discontinuous Galerkin method for elastic waves on unstructured meshes II : the three-dimensional isotropic case, Geophys. J. Int., 167 (1), 319-336, 2006. Etienne, V., Chaljub, E., Virieux, J., Glinsky N., A hp-adaptative Discontinuous Galerkin finite element method for 3-D elastic wave modelling, Geophys. J. Int., 183, 941-962, 2010. Komatitsch, D. and J.-P. Vilotte, The Spectral Element Method : An efficient tool to simulate the seismic response of 2-D and 3-D geological structures, Bull. Seism. Soc. Am., 88, 368-392, 1998. Nguyen, N., Peraire, J., Cockburn, B., High-order implicit hybridizable discontinuous Galerkin methods for acoustics and elastodynamics, J. Comp. Physics, 230, 10, 3695-3718, 2011. Wilcox, L., Stadler, G., Burstede, C., Ghattas, O., A high-order discontinuous Galerkin method for wave propagation through coupled elastic-acoustic media, J. Comp. Phys., 229, 9379-9386, 2010.

  3. Variational fine-grained data assimilation schemes for atmospheric chemistry transport and transformation models

    NASA Astrophysics Data System (ADS)

    Penenko, Alexey; Penenko, Vladimir; Tsvetova, Elena

    2015-04-01

    out of two models each having its own assimilation scheme. In integrated schemes data assimilation is carried out with respect to the split model as a whole. First approach is more efficient from computational point of view, for in some important cases it can be implemented without iterations [2]. Its shortcoming is that control functions in different part of the model are adjusted independently thus having less evident physical sense. With the aid of numerical experiments we compare the two approaches. Work has been partially supported by COST Action ES1004 STSM Grants #16817 and #21654, RFBR 14-01-31482 mol a and 14-01-00125, Programmes # 4 Presidium RAS and # 3 MSD RAS, integration projects SB RAS #8 and #35. References: [1] V. V. Penenko Variational methods of data assimilation and inverse problems for studying the atmosphere, ocean, and environment Num. Anal. and Appl., 2009 V 2 No 4, 341-351. [2] A.V. Penenko and V.V. Penenko. Direct data assimilation method for convection-diffusion models based on splitting scheme. Computational technologies, 19(4):69-83, 2014.

  4. On a class of Newton-like methods for solving nonlinear equations

    NASA Astrophysics Data System (ADS)

    Argyros, Ioannis K.

    2009-06-01

    We provide a semilocal convergence analysis for a certain class of Newton-like methods considered also in [I.K. Argyros, A unifying local-semilocal convergence analysis and applications for two-point Newton-like methods in Banach space, J. Math. Anal. Appl. 298 (2004) 374-397; I.K. Argyros, Computational theory of iterative methods, in: C.K. Chui, L. Wuytack (Eds.), Series: Studies in Computational Mathematics, vol. 15, Elsevier Publ. Co, New York, USA, 2007; J.E. Dennis, Toward a unified convergence theory for Newton-like methods, in: L.B. Rall (Ed.), Nonlinear Functional Analysis and Applications, Academic Press, New York, 1971], in order to approximate a locally unique solution of an equation in a Banach space. Using a combination of Lipschitz and center-Lipschitz conditions, instead of only Lipschitz conditions [F.A. Potra, Sharp error bounds for a class of Newton-like methods, Libertas Math. 5 (1985) 71-84], we provide an analysis with the following advantages over the work in [F.A. Potra, Sharp error bounds for a class of Newton-like methods, Libertas Math. 5 (1985) 71-84] which improved the works in [W.E. Bosarge, P.L. Falb, A multipoint method of third order, J. Optimiz. Theory Appl. 4 (1969) 156-166; W.E. Bosarge, P.L. Falb, Infinite dimensional multipoint methods and the solution of two point boundary value problems, Numer. Math. 14 (1970) 264-286; J.E. Dennis, On the Kantorovich hypothesis for Newton's method, SIAM J. Numer. Anal. 6 (3) (1969) 493-507; J.E. Dennis, Toward a unified convergence theory for Newton-like methods, in: L.B. Rall (Ed.), Nonlinear Functional Analysis and Applications, Academic Press, New York, 1971; H.J. Kornstaedt, Ein allgemeiner Konvergenzstaz fü r verschä rfte Newton-Verfahrem, in: ISNM, vol. 28, Birkhaü ser Verlag, Basel and Stuttgart, 1975, pp. 53-69; P. Laasonen, Ein überquadratisch konvergenter iterativer algorithmus, Ann. Acad. Sci. Fenn. Ser I 450 (1969) 1-10; F.A. Potra, On a modified secant method, L'analyse num

  5. Datação do disco galáctico pela nucleocosmocronologia do [Th/Eu

    NASA Astrophysics Data System (ADS)

    del Peloso, E. F.; da Silva, L.; Arany-Prado, L. I.

    2003-08-01

    A nucleocosmocronologia emprega abundâncias de nuclídeos radioativos na datação de escalas de tempo astrofísicas. O 232Th é um nuclídeo radioativo com meia-vida de 14 Gano, enquanto que os dois isótopos mais abundantes do Eu são estáveis. O decaimento radioativo do Th modifica as razões de abundâncias [Th/Eu], fornecendo assim um meio de sondar a escala de formação das populações estelares. O objetivo deste trabalho é averiguar a possibilidade de estimar uma idade para o disco Galáctico através da nucleocosmocronologia do [Th/Eu] e investigar o nível de incerteza associado a esta estimativa. Para tanto, foi selecionada uma amostra de 20 estrelas anãs ou subgigantes de tipos espectrais F5 a G9, com -1,00 £ [Fe/H] £ +0,30 e idade(Gano) £ 13. As abundâncias de Th e Eu foram obtidas por síntese espectral das linhas localizadas em 4019,1 Å e 4129,7 Å, respectivamente. Uma comparação destas abundâncias com outros resultados da literatura demonstra que nossos valores apresentam dispersão 2 a 3 vezes menor que qualquer trabalho anterior. Os parâmetros atmosféricos e abundâncias dos elementos que contaminam as regiões espectrais destas linhas foram determinados por nós, de maneira totalmente autoconsistente, através de análise espectral detalhada diferencial em relação ao Sol. As idades estelares individuais foram determinadas através de curvas isócronas teóricas no diagrama HR. Foi realizada, então, uma análise cronológica dos gráficos [Th/Eu] vs. [Fe/H] e [Th/Eu] vs. idade. Os dados estelares foram comparados a curvas calculadas para 3 idades do disco Galáctico - 9, 12, 15 Gano - e foi estudada a sensibilidade à idade assumida no cálculo do ajuste destas curvas aos dados. Estas curvas foram calculadas com base num modelo analítico de evolução química da Galáxia que leva em consideração a formação de refugos, que são compostos pelos remanescentes da evolução estelar, pelos resíduos da formação de estrelas de

  6. Walking to Olympus: An EVA Chronology

    NASA Technical Reports Server (NTRS)

    Portree, David S. F.; Trevino, Robert C.

    1997-01-01

    display the large num- ber of flights in which EVA played a role. This approach also makes apparent significant EVA gaps, for example, the U.S. gap between 1985 and 1991 following the Challenger accident. This NASA History Monograph is an edited extract from an extensive EVA Chronology and Reference Book being produced by the EVA Project Office, NASA Johnson Space Center, Houston, Texas. The larger work will be published as part of the NASA Formal Series in 1998. The authors gratefully acknowledge the assistance rendered by Max Ary, Ashot Bakunts, Gert-Jan Bartelds, Frank Cepollina, Andrew Chaikin, Phillip Clark, Richard Fullerton, Steven Glenn, Linda Godwin, Jennifer Green, Greg Harris, Clifford Hess, Jeffrey Hoffman, David Homan, Steven Hopkins, Nicholas Johnson, Eric Jones, Neville Kidger, Joseph Kosmo, Alexei Lebedev, Mark Lee, James LeBlanc, Dmitri Leshchenskii, Jerry Linenger, Igor Lissov, James McBarron, Clay McCullough, Joseph McMann, Story Musgrave, Dennis Newkirk, James Oberg, Joel Powell, Lee Saegesser, Andy Salmon, Glen Swanson, Joseph Tatarewicz, Kathy Thornton, Chris Vandenberg, Charles Vick, Bert Vis, David Woods, Mike Wright, John Young, and Keith Zimmerman. Special thanks to Laurie Buchanan, John Charles, Janet Kovacevich, Joseph Loftus, Sue McDonald, Martha Munies, Colleen Rapp, and Jerry Ross. Any errors remain the responsibility of the authors.

  7. Numerical Calculation of the Drag Force Acting on a Solid Particle Pushed by a Solid/Liquid Interface

    NASA Technical Reports Server (NTRS)

    Catalina, Adrian V.; Stefanescu, Doru M.; Sen, Subhayu

    2000-01-01

    The distribution of insoluble particles in a metal casting depends primarily on the interaction of the particles with the solid/liquid interface (SLI) during the solidification process. The balance of the forces acting on the particle essentially determines whether a particle will be engulfed or pushed by the SLI. An important component of this force balance is the drag force generated by the particle motion in front of the SLI. Previously developed mathematical models for particle/SLI interaction made use of steady-state solutions of this force provided by the lubrication theory. However, our numerical model based on the SLI tracking approach shows that the steady-state approach is inappropriate to model the interaction process and that at steady-state the theoretical solution underestimates the drag force. It was found that regression analysis of steady-state numerical solutions for cylindrical particles moving normal to a flat SLI gives a relationship of the form: Abstract The distribution of insoluble particles in a metal casting depends primarily on the interaction of the particles with the solid/liquid interface (SLI) during the solidification process. The balance of the forces acting on the particle essentially determines whether a particle will be engulfed or pushed by the SLI. An important component of this force balance is the drag force generated by the particle motion in front of the SLI. Previously developed mathematical models for particle/SLI interaction made use of steady-state solutions of this force provided by the lubrication theory. However, our numerical model based on the SLI tracking approach shows that the steady-state approach is inappropriate to model the interaction process and that at steady-state the theoretical solution underestimates the drag force. It was found that regression analysis of steady-state numerical solutions for cylindrical particles moving normal to a flat SLI gives a relationship of the form: F(sub D, sup num) =sqoare

  8. Estimated Rock Abundance and Thermophysical Parameters in Oppenheimer Crater on the Moon

    NASA Astrophysics Data System (ADS)

    Bauch, Karin E.; Hiesinger, Harald; Ivanov, Mikhail; van der Bogert, Carolyn H.; Pasckert, Jan-Hendrik; Weinauer, Julia

    2016-04-01

    anisothermal surfaces and, thus, the abundance of rocks within a field of view [e.g., 6, 9, 10]. The thermal maps show low temperatures, thus low thermal inertia and low rock abundances on the flat floor of Oppenheimer. Dark mantle deposits have similar thermal signatures as the floor. Higher rock abundances and thermal inertias are associated with the graben structures close to the rim of Oppenheimer and the floors of Oppenheimer-U and -H. We found that the highest values correlate with fresh craters in the northern part of Oppenheimer. High-resolution NAC images confirm the presence of boulders on the surface. References: [1] Petro, N.E., Pieters, C. M. (2004), JGR 109, E6. [2] Hiesinger, H. et al. (2012), LPSC XLIII, #2863. [3] Ivanov, M. et al. (2015), LPSC IIIX, #1070. [4] Paige, D. et al. (2010), Spac. Sci. Rev. 150, Num 1-4, p125-160. [5] Bauch, K.E. et al. (2014), PSS 101, 27-36. [6] Bauch, K.E. at al. (2013), EGU2013-8053. [7] Urquhart, M.L. and Jakosky, B.M. (1997), JGR 102, 10,959-10,969. [8] Mellon, M.T. et al. (2000), Icarus 148, 437-455. [9] Christensen, P.R. (1986), Icarus 68, 217-238. [10] Bandfield, J.L. et al. (2011), JGR 108, E12, 8086.

  9. Analyzing rasters, vectors and time series using new Python interfaces in GRASS GIS 7

    NASA Astrophysics Data System (ADS)

    Petras, Vaclav; Petrasova, Anna; Chemin, Yann; Zambelli, Pietro; Landa, Martin; Gebbert, Sören; Neteler, Markus; Löwe, Peter

    2015-04-01

    helps researchers to ensure the robustness of the algorithm, correctness of the results in edge cases as well as the detection of changes in results due to new development. For all modules GRASS GIS automatically creates standardized command line and graphical user interfaces and documentation. Finally, we will show how GRASS GIS can be used together with powerful Python tools such as the NumPy package and the IPython Notebook. References: Gebbert, S., Pebesma, E., 2014. A temporal GIS for field based environmental modeling. Environmental Modelling & Software 53, 1-12. Neteler, M., Bowman, M.H., Landa, M. and Metz, M., 2012. GRASS GIS: a multi-purpose Open Source GIS. Environmental Modelling & Software 31: 124-130. Petras, V., Gebbert, S., 2014. Testing framework for GRASS GIS: ensuring reproducibility of scientific geospatial computing. Poster presented at: AGU Fall Meeting, December 15-19, 2014, San Francisco, USA. Zambelli, P., Gebbert, S., Ciolli, M., 2013. Pygrass: An Object Oriented Python Application Programming Interface (API) for Geographic Resources Analysis Support System (GRASS) Geographic Information System (GIS). ISPRS International Journal of Geo-Information 2, 201-219.

  10. Evolução rotacional de corpos reacumulados

    NASA Astrophysics Data System (ADS)

    Penteado, P.; Lazzaro, D.; Roig, F.; Duffard, R.; Kodama, T.

    2003-08-01

    Asteróides reacumulados (rubble-piles) são corpos formados por um conjunto de fragmentos agregados primariamente pela sua gravidade. A importância do estudo de corpos reacumulados para a compreensão da evolução do Cinturão de Asteróides tem sido bastante evidenciada, não apenas pela constatação de que estes devem corresponder a uma grande parcela da população de asteróides, mas também por recentes estudos da estrutura e evolução colisional deste tipo de asteróide. A evolução rotacional de corpos reacumulados e a formação de famílias têm sido estudadas pelo nosso grupo, com base no modelo de elipsóides interagentes. Este modelo foi desenvolvido recentemente pelo grupo, e baseia-se na integração numérica das equações de movimento para translação e rotação de corpos formados por um conjunto de elipsóides que interagem entre si pela sua gravidade, força de contato e dissipação de energia por atrito. Considerar a rotação de cada fragmento é a principal diferenciação do nosso modelo em relação aos que têm sido desenvolvidos recentemente. Apresentamos aqui os resultados obtidos para a evolução da rotação de populações de corpos reacumulados. Estes foram submetidos a séries de colisões com projéteis de altas velocidades (5Km/s, típicas do Cinturão atual), distribuídos em uma lei de potências de tamanhos. Estes resultados são comparados com os de Harris (1979), um dos poucos trabalhos analíticos existentes para evolução rotacional de asteróides. O principal resultado obtido por Harris foi a distribuição final de velocidades de rotação como uma lei de potências para corpos pequenos, passando de forma bem definida para rotação constante para os grandes. Nas nossas simulações observamos que as distribuições de velocidades de rotação resultantes tendem a leis de potência, com a inclinação evoluindo no decorrer de colisões subsequentes.

  11. Recommendations for the establishment of the seismic code of Haiti

    NASA Astrophysics Data System (ADS)

    Pierristal, G.; Benito, B.; Cervera, J.; Belizaire, D.

    2013-05-01

    propose the more suitable classification for Haiti. Finally, we have proposed a methodology for the forces estimation providing the values of the relevant coefficients. References: EN 1998-1:2004 (E): Eurocode 8, Design of structures for earthquake resistance, Part 1(General Rules, seismic actions and rules for buildings), 2004. -MTPTC, (2011). Règles de calcul intérimaires pour les bâtiments en Haïti, Ministère des Travaux Publics, Transports et Communications, Février 2011, Haïti. -NBCC 2005: National Building Code of Canada, vol1, National Research Council of Canada 2005. -NCSE-02: Norma de construcción sismorresistente de España. BOE num.244, Viernes 11 Octubre 2002. -NEHRP, 2009. Recommended Provisions for Seismic Regulations for new Buildings and Other Structures, FEMA P-750, February, Part 1 (Provisions) and Part 2 (Commentary). -R-001 (2011): Reglamento para el análisis y diseño sísmico de estructuras de República Dominicana. Decreto No. 201-11. Ministerio de Obras Públicas y Comunicaciones.

  12. Sea Surface Salinity signatures of tropical instability waves: New evidences from SMOS

    NASA Astrophysics Data System (ADS)

    Yin, Xiaobin; Boutin, Jacqueline; Reverdin, Gilles; Lee, Tong; Martin, Nicolas

    2014-05-01

    The European Space Agency's (ESA) Soil Moisture and Ocean Salinity (SMOS) mission, launched in November 2009, has been providing global maps of sea surface salinity (SSS) since 2010. SSS measurements from the SMOS satellite during June 2010 and December 2012 provide an unprecedented space-borne observation of the salinity structure of tropical instability waves (TIWs) including strong La Niña conditions during recent years. We use SMOS level 3 SSS maps averaged over 100 x 100 km2 with a 10-day running window and sampled daily over a 0.25 x 0.25° grid generated at Laboratoire d'Océanographie et du Climat: Expérimentation et Approches Numériques (http://catds.ifremer.fr/Products/Available-products-from-CEC-OS/Locean-v2013) [Boutin et al., 2013; Yin et al., 2012]. We also analyze daily SST from the Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA) produced on an operational basis at the UK Met Office using optimal interpolation [Donlon et al., 2011]. From a time-longitude section in the eastern Pacific ocean, westward propagations of SSS and SST anomalies along 2° N became apparent west of 90° W during June 2010 - March 2011 and June 2011 - March 2012, coincident with negative indexes in the NINO3 and NINO3.4 regions. The 33-day SSS anomaly and SST anomaly appeared together approximately in the same time and regions. The 17-day SSS anomaly is less clear than the 17-day SST anomaly. The SSS anomaly has approximate amplitude of 0.5 practical salinity scale (pss) and the SST anomaly has approximate amplitude of 2 ° C. Then, we focus on analysis of SSS and SST anomalies during June to December 2010. During this period the tropical Pacific was characterized by a strong La Niña, providing favorable conditions for the occurrence of TIWs. The high anomalies and meridional gradients of both SSS and SST appear north of the equator west of 100° W. Near 100W, they straddle the equator where South Pacific water and eastern edge upwelling water with high

  13. Calibração do sistema imageador do telescópio MASCO

    NASA Astrophysics Data System (ADS)

    Mejía, J.; D'Amico, F.; Villela, T.; Braga, J.

    2003-08-01

    O MASCO (MÁScara COdificada) é um telescópio imageador de raios-X e gama atualmente configurado para operar na faixa de 50 a 600 keV com uma resolução angular de 14 minutos de arco num campo de visada total circular de 23,5° de diâmetro. O MASCO está totalmente operacional e deverá ser lançado em um balão estratosférico no segundo semestre de 2003 para realizar observações durante ~20 horas a ~40 km de altitude. O telescópio utiliza uma máscara codificada de padrão uniformemente redundante modificado (MURA) de dimensões 19 ´ 19. Esse padrão pertence a uma subclasse de MURAs que apresenta anti-simetria de 90° e conseqüentemente permite a utilização da técnica de subtração de variações sistemáticas de ruído de fundo através de utilização da configuração anti-máscara, obtida com uma simples rotação da máscara. Neste trabalho apresentamos resultados de calibrações em laboratório que tiveram como objetivo testar o sistema imageador. Imagens de fontes radioativas foram obtidas com o telescópio em configuração de vôo, com a máscara girando. Serão discutidos os resultados desses testes e as técnicas desenvolvidas para eliminar ambigüidades de posição de fontes, otimização da relação sinal-ruído e observação de fontes fora do campo totalmente codificado. O sistema de máscara/antimáscara mostrou-se capaz de aumentar a relação sinal-ruído de ~60% para fontes intensas (100 s). Com a máscara girando, a técnica de reconstrução de imagens desenvolvida identificou a posição exata da fonte e não introduziu perda de sensibilidade. Imagens de uma fonte colocada a 8,3° - fora do campo totalmente codificado do telescópio -, mostraram uma diminuição de ~40% na relação sinal/ruído em relação ao centro do campo de visada, o que se deve à codificação incompleta pela máscara e à absorção parcial do fluxo pelos detectores de blindagem.

  14. High resolution numerical simulation (WRF V3) of an extreme rainy event over the Guadeloupe archipelago: Case of 3-5 january 2011.

    NASA Astrophysics Data System (ADS)

    Bernard, Didier C.; Cécé, Raphaël; Dorville, Jean-François

    2013-04-01

    spatio-temporal distribution of simulated rainfall could help to design the prevention and evacuation plan, particularly for the flooding areas. The meteorological variable fields simulated are evaluated by comparison with observed data of meteorological weather stations (French Met. Office) available in the area. Brévignon, C., 2003: Atlas climatique: l'environnement atmosphérique de la Guadeloupe, de Saint-Barthélémy et Saint-martin. Météo-France, Service Régional de Guadeloupe, 92 pp. Cécé, R., T. Plocoste, C. D'Alexis, D. Bernard and J.-F. Dorville, 2012: Modélisation numérique à l'échelle locale des situations météorologiques observées au cours de la transition saison sèche - saison humide à l'aide de WRF ARW V3 : cas de l'archipel de la Guadeloupe. AMA 2012, Toulouse. Skamarock, W. C., J. B. Klemp, J. Dudhia, D. O. Gill, D. M. Barker, M. G. Duda, X.-Y. Huang, W. Wang, and J. G. Powers, 2008: A Description of the Advanced Research WRF Version 3.Tech. Rep., National Center for Atmospheric Research.

  15. AlphaSpectrum ASPECT analysis code for background correction & peak integration

    SciTech Connect

    Rodgers, John C.

    2005-04-13

    The ASPECT code provides a means for rapid analysis of energy-resolved spectra obtained by multi-channel pulse-height analysis (MCA) during (or after) counting of alpha-emissions from a filter air sample (or other suitably prepared sample) utilizing a solid-state detector, or other detector having sufficient energy resolution indiviual radioisotope peaks indentified in a spectrum are fitted using a peak shape algorithm by non-linear least-square fitting procedures that minimize Chi-square differences between the data and a fitted peak function. The code accomplishes the identification of all significant peaks present in the spectrum with automatic recalibration to the 7.68 Po-214 alpha peak from the Radon-222 decay chain, the subtraction of all radon progeny interference overlaps with lower energy peaks in the energy range of Pu-238, Am-241, Pu-239, and U-234/Th-232, and the integration of the counts in any peak identified for these transuranic radionuclides. The output is therefore in the form of isotope specific net transuranic CPM, DPM or concentration, available in near real-time during air sampling. In this "copyright" version, the assumption is made that the alpha spectra to be analyzed have been stored by unique name in sequential form: "FileName(i)", where "FileName" can be any name and i is the index number of the file saved (e.g., i = 1,2, ..., n). this format is one automatically generated by the alpha Environmental Continuous Air Monitor (ECAM), developed by Los Alamos National Laboratory, and manufactured by Canberra Industries, a Laboratory Industrial Partner for this technology. It is assumed in this version of the code that the alpha spectrum data are stored in a 256 channel spectrum, although a larger num ber of channels could be easily accommodated by small code changes. The ECAM data output format is RADNET compliant (an inidustry standard developed at Los Alamos), and include, in addition to a 256-channel alpha spectrum, data on the count time

  16. Détermination expérimentale de la résistance thermique d'interface d'un dépôt métallique submicronique sur son substrat

    NASA Astrophysics Data System (ADS)

    Hmina, N.; Scudeller, Y.

    1995-06-01

    de la résistance électrique du dépôt. La détection à large bande passante (25 MHz) assure une bonne restitution du signal. Celui-ci est filtré numériquement pour être ensuite analysé. De très faibles résistances, comprises entre 10^{-8} et 10^{-6} m^2 K/W, peuvent être détectées lorsque l'observation des variations de température s'effectue avant la première microseconde. Le principe de la méthode et le dispositif expérimental sont présentés. La sensibilité de la méthode est analysée en détail. Des résultats, obtenus sur des dépôts de 200 à 600 nm de cuivre pulvérisés sur un substrat de verre de Silice, sont présentés. Des résistances d'interfaces de l'ordre de 10^{-7} m^2 K/W ont été identifiées avec une précision d'environ 30 %.

  17. Phyllosilcates in the Knob Fields around Ariadnes Colles on Mars: Stratigraphy, Mineralogy and Morphology

    NASA Astrophysics Data System (ADS)

    Wendt, L.; Bishop, J. L.; Neukum, G.

    2012-04-01

    The region between Terra Cimmeria and Terra Sirenum contains several fields of enigmatic knobs, in-cluding Ariadnes Colles, Atlantis Chaos and Gorgo-num Chaos. They have been mapped as Hesperian or Amazonian units [1,2] and are located within the shoreline of the Eridania Lake, which might have formed Ma'adim Vallis [3]. The knob fields contain Mg/Fe-rich and locally Al-rich phyllosilicates [5,6, this study]. Following the stratigraphic placement by [1,2], the knobs are younger than the Noachian, in a possible disagreement to [4]. The region also features chloride deposits [7] and valley networks younger than the Hesperian ridged plains (Hr unit [1,2]), named Mid-Latitude Valleys (MLV) by [8], and has been proposed as an MSL landing site by [9]. The knob fields have been mapped by [10] as "surface type 4" of a possible airfall deposit informally named "Electris deposit", which covers the Hesperian ridged plains and cratered uplands. A recent study by [6], suggested that the knob fields are not part of, but postdate the "Electris deposit", yet possibly contain reworked "Electris" material. Our geological mapping shows that the knob fields are indeed one morphological expression consistent with the "Electris deposit" model [10]. However, the "Electris" deposit does not stratigraphically overlay the Hesperian ridged plains (Hr unit) and is eroded back to the level of the ridged plains, as proposed by [6,10]. Instead, the "Electris" deposit, including the knob fields, is covered or embayed by the ridged plains, and thus is older. This results in a late Noachian age for the "Electris deposit", in agreement with [11]. This also reconciles the apparent contradiction of the stratigraphy suggested by [1,2,6,10] to [4], as the clays would then indeed have formed in the "phyllosian" period, as "sedimentary clays" of [12]. Wide valley networks cut into the "Electris" deposit and may have filled the Eridania lake. The knob fields and clays within are observed at varying total

  18. A two-phase solid/fluid model for dense granular flows including dilatancy effects

    NASA Astrophysics Data System (ADS)

    Mangeney, Anne; Bouchut, Francois; Fernandez-Nieto, Enrique; Koné, El-Hadj; Narbona-Reina, Gladys

    2016-04-01

    account for this transfer of fluid into and out of the mixture, a two-layer model is proposed with a fluid layer on top of the two-phase mixture layer. Mass and momentum conservation are satisfied for the two phases, and mass and momentum are transferred between the two layers. A thin-layer approximation is used to derive average equations. Special attention is paid to the drag friction terms that are responsible for the transfer of momentum between the two phases and for the appearance of an excess pore pressure with respect to the hydrostatic pressure. We present several numerical tests of two-phase granular flows over sloping topography that are compared to the results of the model proposed by {Pitman and Le} [2005]. In particular, we quantify the role of the fluid and compression/dilatation processes on granular flow velocity field and runout distance. F. Bouchut, E.D. Fernandez-Nieto, A. Mangeney, G. Narbona-Reina, A two-phase shallow debris flow model with energy balance, {ESAIM: Math. Modelling Num. Anal.}, 49, 101-140 (2015). F. Bouchut, E. D. Fernandez-Nieto, A. Mangeney, G. Narbona-Reina, A two-phase two-layer model for fluidized granular flows with dilatancy effects, {J. Fluid Mech.}, submitted (2016). R.M. Iverson, M. Logan, R.G. LaHusen, M. Berti, The perfect debris flow? Aggregated results from 28 large-scale experiments, {J. Geophys. Res.}, 115, F03005 (2010). R. Jackson, The Dynamics of Fluidized Particles, {Cambridges Monographs on Mechanics} (2000). E.B. Pitman, L. Le, A two-fluid model for avalanche and debris flows, {Phil.Trans. R. Soc. A}, 363, 1573-1601 (2005). S. Roux, F. Radjai, Texture-dependent rigid plastic behaviour, {Proceedings: Physics of Dry Granular Media}, September 1997. (eds. H. J. Herrmann et al.). Kluwer. Cargèse, France, 305-311 (1998).

  19. Proposal for revisions of the United Nations Moon Treaty

    NASA Astrophysics Data System (ADS)

    Fernandes, Vera; Abreu, Neyda; Fritz, J.; Knapmeyer, Martin; Smeenk, Lisa; Ten Kate, Inge; Trüninger, Monica

    . More than 30 years have passed since the Moon Treaty (c. 1979) was elaborated, and since then technology and science have evolved leading to the need to change the requirements. As stated in the Moon Treaty, the State par-ties who had signed the Treaty meet every 5 and 10 years to revise the Treaty and suggest the necessary ratifications and amendments. The present version of the Moon Treaty, however, does not demonstrate ratifications that take into consideration environmental protection and preservation. For this, it is here suggested, that both the Antarctica Treaty (c. 1959), and more importantly, the Protocol on Environmental Protection to the Antarctic Treaty (c. 1991) are to be used as references for future documents that will be drawn pertaining the Moon. The Antarctica Treaty is currently one of the world's most successful international agreements and has evolved through time as needs and awareness require. The Protocol on Environmental Protection to the Antarctic Treaty reflects concerns regarding the impact of humans on the fragile environment of that continent. This concern is equally critical as new stages of lunar exploration unfold and the effects of such activity are progressively assessed. The key aspects of the Antarctic Protocol applicable to the Moon Treaty are: (1) a ban on commercial mineral resource activity, (2) careful waste disposal management, and (3) protection of areas of par-ticular scientific, environmental, and historical value. These measures should be implemented to prevent irreparable damage of the pristine lunar environment while permitting scientific, educational, and touristic uses and encouraging continued commitment to exploration of the Moon and other planetary bodies irrespective of exploration being robotic or human. A num-ber of other documents that establish an Environmental Code of Conduct for certain areas within the Antarctic continent (e.g., Management Plan for the Antarctic Specially Managed Area No.2, the McMurdo Dry

  20. A quality control system for digital elevation data

    NASA Astrophysics Data System (ADS)

    Knudsen, Thomas; Kokkendorf, Simon; Flatman, Andrew; Nielsen, Thorbjørn; Rosenkranz, Brigitte; Keller, Kristian

    2015-04-01

    planes of the transformed data. Since the photogrammetrical and the LiDAR derived roof centerline sets are independently derived, a low RMS difference indicates that both data sets are of very high accuracy. The horizontal precision is derived by doing a similar comparison between LiDAR derived roof centerlines in the overlap zone of neighbouring flight strips. Contrary to the vertical and horizontal descriptors, the point classification correctness is neither geometric, nor well defined. In this case we must resolve by introducing a human in the loop and presenting data in a form that is as useful as possible to this human. Hence, the QC system produces maps of suspicious patterns such as Vegetation below buildings Points classified as buildings where no building is registered in the map data base Building polygons from the map data base without any building points Buildings on roads All elements of the QC process is carried out in smaller tiles (typically 1 km × 1 km) and hence trivially parallelizable. Results from the parallel executing processes are collected in a geospatial data base system (PostGIS) and the progress can be analyzed and visualized in a desktop GIS while the processes run. Implementation wise, the system is based on open source components, primarily from the OSGeo stack (GDAL, PostGIS, QGIS, NumPy, SciPy, etc.). The system specific code is also being open sourced. This open source distribution philosophy supports the parallel execution paradigm, since all available hardware can be utilized without any licensing problems. As yet, the system has only been used for QC of the first part of a new Danish elevation model. The experience has, however, been very positive. Especially notable is the utility of doing full spatial coverage tests (rather than scattered sample checks). This means that error detection and error reports are exactly as spatial as the point cloud data they concern. This makes it very easy for both data receiver and data provider, to

  1. Numerical study of the coupling of two identification methods - thermal and electromagnetic - for the reconstruction of inclusions in thick walls

    NASA Astrophysics Data System (ADS)

    Le Touz, Nicolas; Dumoulin, Jean; Soldovieri, Francesco

    2016-04-01

    thermal effusivity ratio much greater than one by reference to the effusivity of the wall. For these types of defects, located at different depths and different thicknesses, it has been shown that the coupling of the two reconstructions led to a reconstruction of better quality that the use of only one of the two methods, either on a qualitative term (the position of the defect and its shape) or quantitative (thermal parameters reconstructed). In particular, the variation of thermal parameters in the vicinity of defects occurs on a much smaller distance when using a priori information, enabling better estimate the discontinuity caused by the presence of the defect. References : [1] Brouns, J., Développement d'outils numériques pour l'audit énergétique des bâtiments, PhD thesis, Université Paris-Est, SIE, 2014 [2] Nassiopoulos, A., Bourquin, F., On-site building walls characterization, Numerical Heat Transfer, Part A : Applications, 63(3) :179 :200, 2013 [3] Soldovieri, F., Solimene, R., Lo Monte, L., M. Bavusi, Loperte, A., Sparse reconstruction from GPR data with applications to radar detection, IEEE transactions on instrumentation and measurement, Vol. 60, 3, 2011 [4] Persico, R., Introduction to Ground Penetrating Radar, IEEE Press, Wiley, 2014

  2. The chaos and order in human ECG under the influence of the external perturbations

    NASA Astrophysics Data System (ADS)

    Ragulskaya, Maria; Valeriy, Pipin

    The results of the many-year telecommunication heliomedical monitoring "Heliomed" show, that space weather and geophysical factor variations serve as a training factor for the adaptation-resistant member of the human population. Here we discuss the specific properties of the human ECG discovered in our experiment. The program "Heliomed" is carried out simultaneously at the different geographical areas that cover the different latitudes. The daily registered param-eters include: the psycho-emotional tests and the 1-st lead ECG, the arterial pressure, the variability cardiac contraction, the electric conduction of bioactive points on skin. The results time series compared with daily values of space weather and geomagnetic parameters. The analysis of ECG signal proceeds as follows. At first step we construct the ECG embedding into 3D phase space using the first 3 Principal Components of the ECG time series. Next, we divide ECG on the separate cycles using the maxima of the ECG's QRS complex. Then, we filter out the non-typical ECG beats by means of the Housdorff distance. Finally, we average the example of the ECG time series along the reference trajectory and study of the dynamical characteristics of the averaged ECG beat. It is found, that the ECG signal embeded in 3D phase space can be considered as a mix of a few states. At the rest, the occurrence of the primary ECG state compare to additional ones is about 8:2. The occurrence of the primary state increases after the stress. The main effect of the external perturbation is observed in structural change of the cardio-cycle and not in the variability of the R-R interval. The num-ber of none-typical cycles increase during an isolated magnetic storm. At the all monitoring centers participating experiment the same type of changes in the cardiac activity parameters is detected to go nearly simultaneously during an isolated magnetic storm. To understand the origin of the standard cardio-cycle changes we use the dynamical

  3. Stardust Interstellar Preliminary Examination

    NASA Astrophysics Data System (ADS)

    Westphal, A.; Stardust Interstellar Preliminary Examation Team: http://www. ssl. berkeley. edu/~westphal/ISPE/

    2011-12-01

    A. J. Westphal, C. Allen, A. Ansari, S. Bajt, R. S. Bastien, H. A. Bechtel, J. Borg, F. E. Brenker, J. Bridges, D. E. Brownlee, M. Burchell, M. Burghammer, A. L. Butterworth, A. M. Davis, P. Cloetens, C. Floss, G. Flynn, D. Frank, Z. Gainsforth, E. Grün, P. R. Heck, J. K. Hillier, P. Hoppe, G. Huss, J. Huth, B. Hvide, A. Kearsley, A. J. King, B. Lai, J. Leitner, L. Lemelle, H. Leroux, R. Lettieri, W. Marchant, L. R. Nittler, R. Ogliore, F. Postberg, M. C. Price, S. A. Sandford, J.-A. Sans Tresseras, T. Schoonjans, S. Schmitz, G. Silversmit, A. Simionovici, V. A. Solé, R. Srama, T. Stephan, V. Sterken, J. Stodolna, R. M. Stroud, S. Sutton, M. Trieloff, P. Tsou, A. Tsuchiyama, T. Tyliszczak, B. Vekemans, L. Vincze, D. Zevin, M. E. Zolensky, >29,000 Stardust@home dusters ISPE author affiliations are at http://www.ssl.berkeley.edu/~westphal/ISPE/. In 2000 and 2002, a ~0.1m2 array of aerogel tiles and alumi-num foils onboard the Stardust spacecraft was exposed to the interstellar dust (ISD) stream for an integrated time of 200 days. The exposure took place in interplanetary space, beyond the orbit of Mars, and thus was free of the ubiquitous orbital debris in low-earth orbit that precludes effective searches for interstellar dust there. Despite the long exposure of the Stardust collector, <<100 ISD particles are expected to have been captured. The particles are thought to be ~1μm or less in size, and the total ISD collection is probably <10-6 by mass of the collection of cometary dust parti-cles captured in the Stardust cometary dust collector from the coma of the Jupiter-family comet Wild 2. Thus, although the first solid sample from the local interstellar medium is clearly of high interest, the diminutive size of the particles and the low numbers of particles present daunting challenges. Nevertheless, six recent developments have made a Preliminary Examination (PE) of this sample practical: (1) rapid automated digital optical scanning microscopy for three

  4. A general spectral method for the numerical simulation of one-dimensional interacting fermions

    NASA Astrophysics Data System (ADS)

    Clason, Christian; von Winckel, Gregory

    2012-08-01

    This software implements a general framework for the direct numerical simulation of systems of interacting fermions in one spatial dimension. The approach is based on a specially adapted nodal spectral Galerkin method, where the basis functions are constructed to obey the antisymmetry relations of fermionic wave functions. An efficient Matlab program for the assembly of the stiffness and potential matrices is presented, which exploits the combinatorial structure of the sparsity pattern arising from this discretization to achieve optimal run-time complexity. This program allows the accurate discretization of systems with multiple fermions subject to arbitrary potentials, e.g., for verifying the accuracy of multi-particle approximations such as Hartree-Fock in the few-particle limit. It can be used for eigenvalue computations or numerical solutions of the time-dependent Schrödinger equation. The new version includes a Python implementation of the presented approach. New version program summaryProgram title: assembleFermiMatrix Catalogue identifier: AEKO_v1_1 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKO_v1_1.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 332 No. of bytes in distributed program, including test data, etc.: 5418 Distribution format: tar.gz Programming language: MATLAB/GNU Octave, Python Computer: Any architecture supported by MATLAB, GNU Octave or Python Operating system: Any supported by MATLAB, GNU Octave or Python RAM: Depends on the data Classification: 4.3, 2.2. External routines: Python 2.7+, NumPy 1.3+, SciPy 0.10+ Catalogue identifier of previous version: AEKO_v1_0 Journal reference of previous version: Comput. Phys. Commun. 183 (2012) 405 Does the new version supersede the previous version?: Yes Nature of problem: The direct numerical

  5. Approche au diagnostic de la maladie cœliaque chez les patients ayant une faible densité minérale osseuse ou des fractures de fragilité

    PubMed Central

    Rios, Lorena P.; Khan, Aliya; Sultan, Muhammad; McAssey, Karen; Fouda, Mona A.; Armstrong, David

    2013-01-01

    Résumé Objectif Présenter aux cliniciens une mise à jour sur le diagnostic de la maladie cœliaque (MC), ainsi que des recommandations sur les indications de procéder au dépistage de la MC chez les patients présentant une faible densité minérale osseuse (DMO) ou des fractures de fragilité. Qualité des données Un groupe de travail multidisciplinaire a élaboré des questions cliniquement pertinentes relativement au diagnostic de la MC servant de fondement à une recherche documentaire dans les bases de données MEDLINE, EMBASE et CENTRAL (de janvier 2000 à janvier 2009) à l’aide des mots clés en anglais celiac disease, osteoporosis, osteopenia, low bone mass et fracture. Les ouvrages scientifiques existants comportent des études de niveaux I et II. Message principal La prévalence estimée de la MC asymptomatique est de 2 % à 3 % chez les personnes qui ont une faible DMO. Par ailleurs, un dépistage ciblé est recommandé pour les patients qui ont des T-scores de −1,0 ou moins à la colonne vertébrale ou aux hanches ou des antécédents de fractures de fragilité associées à des symptômes ou à des problèmes reliés à la MC, des antécédents familiaux de MC ou de bas niveaux de calcium urinaire, une insuffisance en vitamine D et des niveaux à la hausse d’hormones parathyroïdiennes en dépit d’un apport suffisant en calcium et en vitamine D. Le dépistage de la MC devrait se faire pendant que le sujet consomme un régime alimentaire contenant du gluten. On procède au dépistage initial par le dosage d’immunoglobuline (Ig) A antitransglutaminase en utilisant la transglutaminase tissulaire humaine recombinante ou une autre transglutaminase tissulaire, en association avec l’immunofluorescence des IgA anti-endomysium. Une biopsie du duodénum est nécessaire pour confirmer le diagnostic de la MC. Le typage des antigènes des leucocytes humains peut aider à confirmer ou à exclure le diagnostic de la MC dans les cas où la s

  6. Numerical simulation of stratified flows from laboratory experiments to coastal ocean

    NASA Astrophysics Data System (ADS)

    Fraunie, Philippe

    2014-05-01

    behind a cylinder // 2007. Fluid Dyn. V. 42 (1). P. 12-23. 4. Bardakov R. N., Mitkin V. V., Chashechkin Yu. D. Fine structure of a stratified flow near a flat-plate surface // J. Appl. Mech. Tech. Phys. 2007. V. 48(6) P. 840-851. 5. Chashechkin Yu. D., Mitkin V. V. An effect of a lift force on the structure of attached internal waves in a continuously stratified fluid // Dokl. Phys. 2001. V. 46 (6). P. 425-428. 6. Houcine H., Chashechkin Yu.D, Fraunié P., Fernando H.J.S., Gharbi A., Lili T. Numerical modeling of the generation of internal waves by uniform stratified flow over a thin vertical barrier // Int J. Num Methods in Fluids. 2012. V.68(4). P. 451-466. DOI: 10.1002/fld.2513 7. Bodnar T., Benes , Fraunié P., Kozel K.. Application of Compact Finite-Difference Schemes to Simulations of Stably Stratified Fluid Flows. Applied Mathematics and Computation 219 : 3336-3353 2012. doi:10.1016/j.amc.2011.08.058 8. Schaeffer A. Molcard A. Forget P. Fraunié P. Garreau P. Generation mechanisms for mesoscale eddies in the Gulf of Lions: radar observation and modelling. Ocean Dynamics vol 61, 10, pp1587-1609, 2011. DOI.1007/s10236-011-0482-8.

  7. Numerical analysis of internal waves in stratified wake flows

    NASA Astrophysics Data System (ADS)

    Fraunie, Philppe

    2014-05-01

    stratified flow behind a cylinder // 2007. Fluid Dyn. V. 42 (1). P. 12-23. [4] Bardakov R. N., Mitkin V. V., Chashechkin Yu. D. Fine structure of a stratified flow near a flat-plate surface // J. Appl. Mech. Tech. Phys. 2007. V. 48(6) P. 840-851. [5] Chashechkin Yu. D., Mitkin V. V. An effect of a lift force on the structure of attached internal waves in a continuously stratified fluid // Dokl. Phys. 2001. V. 46 (6). P. 425-428. [6] Houcine H., Chashechkin Yu.D, Fraunié P., Fernando H.J.S., Gharbi A., Lili T. Numerical modeling of the generation of internal waves by uniform stratified flow over a thin vertical barrier // Int J. Num Methods in Fluids. 2012. V.68(4). P. 451-466. DOI: 10.1002/fld.2513 [7] Bodnar T., Benes , Fraunié P., Kozel K.. Application of Compact Finite-Difference Schemes to Simulations of Stably Stratified Fluid Flows. Applied Mathematics and Computation 219 : 3336-3353 2012. doi:10.1016/j.amc.2011.08.058

  8. The evolution of groundwater rights and groundwater management in New Mexico and the western United States

    NASA Astrophysics Data System (ADS)

    DuMars, Charles T.; Minier, Jeffrie D.

    été, mais protégés par des principes de lois de propriété. Cinq systèmes de réglementation de base pour les droits sur les eaux souterraines aux États-Unis ont évolué jusqu'à aujourd'hui. Les problèmes posés par les différences hydrologiques entre les eaux souterraines hydrauliquement connectées aux cours d'eau et celles d'aquifères non réalimentés ont été résolus jusqu'à un certain point par quelques cas de jugement. La modélisation numérique et d'autres méthodologies techniques ont également évolué pour évaluer les résultats scientifiques apportés dans différentes conditions hydrologiques, mais ne sont pas à l'abri de critiques. Le rôle courant des aquifères évolue entre celui des possibilités de stockage pour l'eau recyclée et leur utilisation dans ce but peut être même étendue plus loin dans le futur. Les implications politiques des choix relatifs à la gestion simultanée des eaux souterraines et de surface ne doivent pas être exagérées. Comme le montre cet article, la gestion active de l'épuisement futur des nappes qui affecte les systèmes fluviaux est essentielle pour la capacité finale à planifier l'exploitation, la gestion et l'utilisation des ressources en eau d'une manière rationnelle qui coordonne la demande actuelle et future à la réalité de la rareté de l'alimentation. Les exemples utilisés dans cet article démontrent le besoin d'une capacité d'élaboration, non seulement pour développer de bonnes techniques de mesure, ou pour former d'excellents avocats et juges pour écrire de bonnes lois, mais aussi pour que des praticiens gestionnaires de l'eau maintiennent le processus dans un cours rationnel pour éviter une exploitation sans limite des ressources aussi bien qu'un protectionnisme conservateur qui empêche son usage à jamais. Históricamente, los derechos del agua se originaron como un bien público que se transformaron después en derechos individualizados para usar los recursos públicos, de forma

  9. Geochemistry and the understanding of ground-water systems

    NASA Astrophysics Data System (ADS)

    Glynn, Pierre D.; Plummer, L. Niel

    2005-03-01

    techniques, ont aidé à l' élucidation des élucider les mécanismes d'écoulement et de transport dans les systèmes d'eaux souterraines, et à la compréhension des archives informations paléo-environnementales. Les informations hydrochimiques et isotopiques peuvent être utilisées pour interpréter l'origine et le mode de recharge des eaux souterraines, affiner l'estimation des temps de recharge et d' écoulements, déchiffrer les processus de réaction, apporter une meilleure information paléohydrogéologique et calibrer les modèles d'écoulement des eaux souterraines. Beaucoup de progrès ont besoin d'être réalisés pour obtenir des échantillons représentatifs. Des améliorations sont nécessaires dans l'interprétation des informations obtenues, et dans la construction et l'interprétation de modèles numériques utilisant des données hydrochimiques. La meilleure approches arsurément un processus itératif optimisé entre la collection de données de terrain et l'analyse, l'interprétation, et l'application d'outils de modélisation statistique, inverse et direct. Des avancées sont anticipées par les dans le demeine des études microbiologiques, dans la caractérisation des matières organiques naturelles, le marquage isotopique, les mesures de gaz dissous, les réactions cinétiques la compréhension des couplages. Une perspectives thermodynamique pourraient faciliter la comparaison et la compréhension des multiples processus physiques, chimiques et biologiques qui affectent les systèmes hydrogéologiques. La geoquímica ha contribuido significativamente al entendimiento de los sistemas de aguas subterráneas durante los últimos 50 años. Entre los avances históricos puede incluirse el desarrollo del concento de facies hidroquímicas, la aplicación de la teoría de equilibrio, investigación de los procesos oxidación-reducción, y datación con radiocarbono. Otros conceptos, herramientas y técnicas hidroquímicas han ayudado a esclarecer los

  10. Inverse modeling of groundwater flow in the semiarid evaporitic closed basin of Los Monegros, Spain

    NASA Astrophysics Data System (ADS)

    Samper-Calvete, F. J.; García-Vera, M. A.

    ha a été programmée, en partie dans un bassin évaporitique fermé où existent des lacs de playa. Le projet a fait émergé des préoccupations environnementales. L'évaluation des impacts hydrologiques de l'irrigation implique de quantifier correctement l'hydrogéologie de cette région. A partir des informations disponibles, un modèle hydrogéologique conceptuel a étéétabli il identifie deux aquifères principaux interconnectés par drainance au travers d'un imperméable. Un modèle numérique, établi sur la base de ce modèle conceptuel, a été calibré en conditions de régime permanent, en utilisant la méthode d'estimation automatique du maximum de vraisemblance des paramètres (Carrera and Neuman, 1986a). Le modèle calibré reproduit correctement la piézométrie mesurée et est en accord avec les informations concernant l'écoulement des nappes. La résolution du problème inverse a fourni des estimations acceptables des paramètres. On en a conclu que l'anisotropie joue un rôle essentiel dans certaines parties de l'aquifère inférieur. La moyenne géométrique de la conductivité hydraulique est d'environ deux ordres de grandeur plus élevée que la conductivité hydraulique moyenne obtenue par des essais de terrain à l'échelle locale. Cet effet d'échelle sur la conductivité hydraulique est conforme aux résultats obtenus par Neuman (1994) et Sánchez-Vila et al. (1996). Resumen La hidrogeología de zonas endorreicas en zonas evaporíticas ha recibido muy poca atención en el pasado debido fundamentalmente a que en estas zonas las aguas subterráneas tienen una elevada salinidad debido a la alta solubilidad de sus materiales. El interés por la hidrogeología de la zona de Los Monegros en el noreste de España surgió a raiz de la aprobación en 1986 del proyecto de Los Monegros II en la zona central del valle del Ebro que contempla la puesta en regadío de 60,000 ha, algunas de las cuales se encuentran situadas en la zona endorreica de Los

  11. Teaching astronomy mediated by information and communication technologies: a preliminary approach

    NASA Astrophysics Data System (ADS)

    Rosa, R. H. L.; Voelzke, M. R.

    2014-08-01

    O presente trabalho é parte preliminar de um estudo mais amplo em nível de doutorado sobre o ensino de astronomia mediado pelas tecnologias da informação e comunicação, utilizando dispositivos compactos, móveis e pessoais. Este estudo também faz parte do projeto institucional do CEFETMG sobre ambientes diversificados de aprendizagem sob fomento da agência estadual FAPEMIG (Fundação de Amparo à Pesquisa do Estado de Minas Gerais). Esta apresentação aborda o resultado das concepções prévias de estudantes em relação a conhecimentos básicos de astronomia, ligados à percepção e observação direta do céu. Três turmas de estudantes de 1ª série e uma turma de 3ª série do ensino integrado médio técnico da Educação Básica, Técnica e Tecnológica (EBTT) do CEFETMG Campus II - Belo Horizonte/MG foram submetidas a uma avaliação prévia através de questionário estruturado. Este questionário foi elaborado de forma a abordar a percepção dos estudantes em relação aos recursos gráficos (figuras e desenhos) representativos de conhecimentos básicos de astronomia, comuns em livros didáticos. Após a análise dos resultados desta avaliação, organizou-se uma estratégia de intervenção didática em sala de aula sobre o conteúdo de astronomia, utilizando-se de recursos de mediação baseados nas tecnologias da informação e comunicação. Os temas selecionados para esta estratégia didática foram relacionados aos assuntos básicos de astronomia em que ocorreu maior nível de desconhecimento dos estudantes. Os estudantes foram submetidos a avaliação posterior elaborada com os mesmos pressupostos da avaliação prévia. A análise dos resultados foi realizada a partir dos pressupostos da aprendizagem significativa (Ausubel; Novak e Hanesian, 1983). O ensino de astronomia por mediação das tecnologias da informação e comunicação indica uma alternativa preliminar aos trabalhos de campo usuais orientados na prática escolar, tais

  12. Learning about the Sky from the Environment: An Experience Working Along One Year with Students of Elementary Education. (Spanish Title: Aprendiendo sobre EL Cielo Desde el Entorno: Una Experiencia Trabajando Durante un Año Junto a Estudiantes del Primario.) Aprendendo sobre o Céu a Partir do Entorno: Uma Experiência de Trabalho ao Longo de um Ano com Alunos de Ensino Fundamental

    NASA Astrophysics Data System (ADS)

    Longhini, Marcos Daniel; Gomide, Hanny Angeles

    2014-12-01

    percepción limitada que los estudiantes tienen de su alrededor la cual, sin embargo, se expandió debido a las actividades llevadas a cabo, sobre todo en relación con la Luna. Trabajar con medidas sistemáticas revela el manejo cuidadoso de los datos para que sean comprensibles para los estudiantes, así como el trabajo con las sombras para que comprendan primero como se forman estas para después trabajarlas en Astronomía. Por último, llegamos a la conclusión de que el proceso desarrollado consistió en una etapa inicial de una obra que debe ser profundizado en los años posteriores de la formación de estos estudiantes. Projeto de pesquisa desenvolvido com 95 alunos do 6º ano do Ensino Fundamental de uma escola pública estadual de Uberlândia, Minas Gerais. Foi um trabalho contínuo, de fevereiro a dezembro de 2013, o qual levou os alunos a participarem de atividades de observação do entorno, dentre ele, o céu, analisando as mudanças ocorridas. Focamos no estudo das variações de temperaturas, chuvas, duração do dia, variações do tamanho das sombras e mudanças nos aspectos da Lua. Nosso foco de análise centrou-se em discutir os conhecimentos que os referidos alunos tinham acerca dos temas indicados no início e ao término da implementação da proposta. Os resultados mostraram a percepção limitada que os estudantes possuem de seu entorno, todavia, ampliada em função das atividades desenvolvidas, principalmente no que se refere à Lua. O trabalho com medidas sistemáticas revela o cuidado no tratamento dos dados para que eles se tornem compreensíveis aos alunos, assim como o trabalho com as sombras sinaliza para que os alunos primeiramente compreendam como as sombras são formadas para depois trabalhar isso em Astronomia. Por fim, concluímos que o processo vivido constituiu-se em uma etapa inicial de um trabalho que deve ser estimulado para os anos subsequentes da formação desses alunos.

  13. The Shadow of a Gnomon Along a Year: Routine Observations and Teaching of Apparent Motion of the Sun and the Four Seasons. (Spanish Title: La Sombra de un Gnomon lo Largo de un Año: Observaciones de Rutina y la Enseñanza del Movimiento Aparente del Sol y Las Cuatro Estaciones.) A Sombra de um Gnômon ao Longo de um Ano: Observações Rotineiras e o Ensino do Movimento Aparente do Sol E das Quatro Estações

    NASA Astrophysics Data System (ADS)

    Trogello, Anderson Giovani; Danhoni Neves, Marcos Cesar; de Carvalho Rutz da Silva, Sani

    2013-12-01

    , al solsticio de junio, al equinoccio de septiembre y al solsticio de diciembre. Además, se dictaron clases teóricas en la sala de aula. Estos métodos buscaron construir conceptos en torno al movimiento aparente del Sol y la sucesión de las estaciones. Teniendo en cuenta los resultados de las actividades se aplicó una evaluación cuyos datos demuestran la existencia de un aprendizaje deseado por los estudiantes en cuanto a: el reconocimiento de los puntos cardinales, la descripción del movimiento solar aparente y la aparición de las estaciones y su alternancia a partir de observaciones astronómicas visuales sin instrumentos. Muitas concepções alternativas são reconhecidas entre os diversos grupos de estudantes, em especial nos da educação básica. Dentre elas, o movimento aparente do Sol, por mais quotidiano que seja, proporciona variadas interpretações. Deste modo, observar e registrar o movimento dos astros na abóboda celeste é uma tarefa necessária ao ensino de Astronomia. O trabalho que ora se apresenta propõe a apresentação dos resultados da observação do movimento aparente do Sol por intermédio da marcação da sombra de um gnômon vertical por alunos de uma turma do sexto ano do ensino fundamental de uma escola do campo do Paraná. O projeto em si ocorreu em quatro etapas, em datas próximas do equinócio de março, do solstício de junho, do equinócio de setembro e do solstício de dezembro. Além disso, foram desenvolvidas aulas teóricas em sala de aula. Tais métodos buscaram construir conceitos em torno da movimentação aparente do Sol e da alternância das estações do ano. Diante dos resultados provenientes das atividades desenvolvidas foi aplicada uma avaliação e os dados demonstraram um aprendizado desejado dos alunos quanto: ao reconhecimento dos pontos cardeais; à descrição do movimento solar aparente e a ocorrência das estações do ano e sua alternância a partir de observações astronômicas a olho nu.

  14. Astrophysics in Schools: Playing with Observational Data. (Spanish Title: Astrofísica Escolar: Jugando con Datos Observacionales.) Astrofísica Escolar: Brincando com Dados Observacionais

    NASA Astrophysics Data System (ADS)

    Navone, Hugo D.; Scancich, Miriam; Vázquez, Rubén A.

    2011-07-01

    principales dimensiones educativas que emergen del mismo. La propuesta está destinada a alumnos del último año de nivel medio y primeros años de la universidad, y a estudiantes y profesores de Institutos de Formación Docente. Las puestas en práctica realizadas muestran que la propuesta es viable, que moviliza inquietudes en torno a temáticas de Astrofísica y que se fortalece al adquirir un carácter lúdico y cooperativo. A utilização de registros observacionais na construção de seqüências didáticas em Astrofísica Escolar não é algo usual no ensino médio. Tampouco o é uma abordagem de temáticas dentro do contexto da Natureza da Ciência. Agrega-se a estas carências a falta de propostas que estimulem a utilização do computador como um laboratório para estudar a natureza. Os aspectos mencionados expõem a existência de um desajuste entre ciência escolar e ciência avançada, estabelecendo a necessidade de elaborar projetos educativos simples que promovam o diálogo interdisciplinar entre ambos campos do conhecimento. Partindo destes pressupostos, este trabalho apresenta a reformulação escolar do problema abordado por Hubble -a relação entre redshift e distância das galáxias- e se exploram as principais dimensões educativas que emergem do mesmo. A proposta está destinada a alunos do último ano do nível médio, primeiros anos do curso superior e a estudantes e professores de Institutos de Formação Docente. As atividades práticas realizadas mostram que a proposta é viável, que mobiliza inquietudes em torno da temática e da Astrofísica e que se fortalece ao adquirir um caráter lúdico e cooperativo.

  15. Non-linearite et couplages lumiere-matiere en electrodynamique quantique en circuit

    NASA Astrophysics Data System (ADS)

    Bourassa, Jerome

    écanique lagrangienne et la représentation des modes propres d'oscillation. La grande qualité de la méthode réside dans la description analytique détaillée des paramètres de l'hamiltonien du système en fonction de la géométrie et des caractéristiques électromagnétiques du circuit. Non seulement le formalisme développé réconcilie le modèle quantique avec l'électromagnétisme classique et la théorie des circuits, mais va bien au-delà en formulant d'importantes prédictions sur la nature des interactions et l'influence des fluctuations du vide du résonateur sur la dynamique des qubits supraconducteurs. À l'aide d'exemples numériques réalistes et compatibles avec les technologies actuelles, je montre comment de simples optimisations de conception permettraient d'augmenter grandement l'efficacité et la rapidité d'exécution de calculs quantiques avec l'architecture, en plus d'atteindre des régimes de non-linéarité et de couplage lumière-matière inédits. En permettant de mieux comprendre l'interaction lumière-matière dans les circuits et d'optimiser l'architecture afin d'atteindre de nouveaux régimes de couplages, la méthode d'analyse de circuit développée dans cette thèse permettra de tester et raffiner nos connaissances sur l'électrodynamique quantique et la physique quantique. Mots-clés: Information quantique, électrodynamique quantique, supraconductivité, électromagnétisme, qubit supraconducteur, résonateur non linéaire, couplage ultrafort, effet Kerr.

  16. Des Vents et des Jets Astrophysiques

    NASA Astrophysics Data System (ADS)

    Sauty, C.

    well expected result from the theory. Although, collimation may be conical, paraboloidal or cylindrical (Part 4), cylindrical collimation is the more likely to occur. The shape of outflows may then be used as a tool to predict physical conditions on the flows or on their source. L'éjection continue de plasma autour d'objets massifs est un phénomène largement répandu en astrophysique, que ce soit sous la forme du vent solaire, de vents stellaires, de jets d'étoiles en formation, de jets stellaires autour d'objets compacts ou de jets extra-galactiques. Cette zoologie diversifiée fait pourtant l'objet d'un commun effort de modélisation. Le but de cette revue est d'abord de présenter qualitativement le développement, depuis leur origine, des diverses théories de vents (Partie 1) et l'inter disciplinarité dans ce domaine. Il s'agit d'une énumération, plus ou moins exhaustive, des idées proposées pour expliquer l'accélération et la morphologie des vents et des jets, accompagnée d'une présentation sommaire des aspects observationnels. Cette partie s'abstient de tout aspect faisant appel au formalisme mathématique. Ces écoulements peuvent être décrits, au moins partiellement, en résolvant les équations magnétohydrodynamiques, axisymétriques et stationnaires. Ce formalisme, à la base de la plupart des théories, est exposé dans la Partie 2. Il permet d'introduire quantitativement les intégrales premières qu'un tel système possède. Ces dernières sont amenées à jouer un rôle important dans la compréhension des phénomènes d'accélération ou de collimation, en particulier le taux de perte de masse, le taux de perte de moment angulaire ou l'énergie du rotateur magnétique. La difficulté de modélisation réside dans l'existence de points critiques, propres aux équations non linéaires, qu'il faut franchir. La nature physique et la localisation de ces points critiques fait l'objet d'un débat important car ils sont la clef de voute de la r

  17. A computational model of wall shear and residence time of particles conveyed by steady flow in a curved tube

    NASA Astrophysics Data System (ADS)

    Thiriet, M.; Graham, J. M. R.; Issa, R. I.

    1993-01-01

    un profil uniforme de vitesse axiale, pour des valeurs du nombre de Dean 140 leq De leq 430. Un calcul numérique de l'écoulement turbulent a été effectué pour De sim 22 100 avec un profil de vitesse plat en entrée du modèle. La vitesse axiale dépend non seulement de la valeur du nombre de Dean, mais aussi du nombre de Reynolds et de la courbure du tube séparément. Le profil de vitesses est perturbé pour de très faibles courbures. Le tronçon de conduit où les mouvements secondaires sont les plus forts est situé d'autant plus près de l'entrée du coude que la couche limite en entrée est plus épaisse. L'écoulement secondaire se développe sur une région plus étendue du coude et le cisaillement pariétal est plus élevé quand le nombre de Reynolds augmente. Le coude affecte le cisaillement pariétal en amont et en aval. La présence d'un coude dans une conduite fait croître le temps de résidence des particules en suspension par rapport aux valeurs prises dans un tube droit isolé uniquement dans l'élément de conduite droit situé en aval du coude. Quand le nombre de Reynolds augmente, le régime d'écoulement restant laminaire, cette caractéristique disparaît. Elle est cependant observée en écoulement turbulent, le temps de résidence prenant en tout point des valeurs beaucoup plus faibles que celles obtenues en regime laminaire.

  18. Astronomical Perception of the Secondary School's Students in São Paulo's State School in Suzano City. (Spanish Title: Percepción Astronómica de Alumnos de la Enseñanza Media de la Red Estatal de San Pablo en la Ciudad de Suzano.) Percepção Astronômica de um Grupo de Alunos do Ensino Médio da Rede Estadual de São Paulo da Cidade de Suzano

    NASA Astrophysics Data System (ADS)

    França de Oliveira, Edilene; Voelzke, Marcos Rincon; Amaral, Luis Henrique

    2007-12-01

    año y 20,6% tenían la idea de cuales son los objetos celestes más cercanos de la Tierra. En contraposición, 67,6% clasificaron correctamente el Sol como una estrella; 55,9% relacionaron el Big Bang al origen del Universo; solamente 20,6% identificaron un año-luz como unidad de distancia y 32,4% reconocieron una estrella fugaz como meteoro. El presente análisis fue expandido para otros grupos de la Enseñanza Media, no solamente del período nocturno, sino también diurno de la misma escuela. En esta primera fase se nota el pequeño conocimiento de los alumnos sobre eventos astronómicos y principalmente la gran confusión sobre el significado correcto de los términos astronómicos populares. Embora a Astronomia seja uma das ciências mais antigas da humanidade e muitos dos conceitos astronômicos serem populares, observa-se que uma parcela significativa dos estudantes encontra-se à margem dessas informações. O presente trabalho visa analisar o nível de conhecimento básico dos alunos do Ensino Médio da Rede Estadual da cidade de Suzano quanto aos fenômenos astronômicos que os rodeiam. Para tanto foi elaborado um formulário constando de questões de múltipla escolha, aplicado no primeiro ano noturno da Escola Estadual Batista Renzi. Num espaço amostral de 34 alunos constatou-se que apenas 29,4% compreendiam a sucessão dos dias; 20,6% explicaram corretamente as estações do ano e 20,6% tinham idéia de quais são os objetos celestes mais próximos da Terra. Em contraposição, 67,6% classificaram corretamente o Sol como estrela; 55,9% relacionaram o Big Bang à origem do Universo; apenas 20,6% identificaram um ano-luz como unidade de distância e 32,4% reconheceram uma estrela cadente como meteoro. A presente análise foi expandida para mais 310 alunos de outras classes de Ensino Médio, não somente do período noturno, mas também diurno da mesma escola. Nesta primeira fase nota-se o pequeno discernimento dos alunos sobre eventos astronômicos e

  19. Geochemistry and the understanding of ground-water systems

    NASA Astrophysics Data System (ADS)

    Glynn, Pierre D.; Plummer, L. Niel

    2005-03-01

    techniques, ont aidé à l' élucidation des élucider les mécanismes d'écoulement et de transport dans les systèmes d'eaux souterraines, et à la compréhension des archives informations paléo-environnementales. Les informations hydrochimiques et isotopiques peuvent être utilisées pour interpréter l'origine et le mode de recharge des eaux souterraines, affiner l'estimation des temps de recharge et d' écoulements, déchiffrer les processus de réaction, apporter une meilleure information paléohydrogéologique et calibrer les modèles d'écoulement des eaux souterraines. Beaucoup de progrès ont besoin d'être réalisés pour obtenir des échantillons représentatifs. Des améliorations sont nécessaires dans l'interprétation des informations obtenues, et dans la construction et l'interprétation de modèles numériques utilisant des données hydrochimiques. La meilleure approches arsurément un processus itératif optimisé entre la collection de données de terrain et l'analyse, l'interprétation, et l'application d'outils de modélisation statistique, inverse et direct. Des avancées sont anticipées par les dans le demeine des études microbiologiques, dans la caractérisation des matières organiques naturelles, le marquage isotopique, les mesures de gaz dissous, les réactions cinétiques la compréhension des couplages. Une perspectives thermodynamique pourraient faciliter la comparaison et la compréhension des multiples processus physiques, chimiques et biologiques qui affectent les systèmes hydrogéologiques. La geoquímica ha contribuido significativamente al entendimiento de los sistemas de aguas subterráneas durante los últimos 50 años. Entre los avances históricos puede incluirse el desarrollo del concento de facies hidroquímicas, la aplicación de la teoría de equilibrio, investigación de los procesos oxidación-reducción, y datación con radiocarbono. Otros conceptos, herramientas y técnicas hidroquímicas han ayudado a esclarecer los

  20. Mixing and diffusion in intermittent overturning turbulence

    NASA Astrophysics Data System (ADS)

    Redondo, Jose M.; Mahjoub, Otman B.; Gonzalez-Nieto, Pilar L.; Lawry, Andrew

    2014-05-01

    , Oxford 1993 [6] J.M Redondo, J.M. Grau, A. Platonov, G. Garzon, (2008) Rev. Int. Met. Num. Ing. 24, 23. [7] Fraunie P., Berreba S. Chashechkin Y., Velasco D. and Redondo J.M. (2008) LES and laboratory experiments on the decay of grid wakes in strongly stratified flows. Il Nuovo Cimento C 31, 909-930. [8] Redondo J.M. (2002) "Mixing efficiencies of different kinds of turbulent processes and instabilities, Applications to the environment in Turbulent mixing in geophysical flows". Eds. Linden P.F. and Redondo J.M. 131-157. [9] Redondo J.M. (1990). The structure of density interfaces, Ph. D. Thesis, DAMTP University of Cambridge. [10]Redondo J.M. (1987). Effects of ground proximity on dense gas entrainment, Journal of Hazardous Materials, 16, 381-393. [11] Lopez, P., Cano, J.L. and Redondo, J.M.(2008) An experimental model of mixing processes generated by an array of top-heavy turbulent plumes, Il Nuovo Cimento, 31C, 679-698.

  1. Application of the groundwater-balance equation to indicate interbasin and vertical flow in two semi-arid drainage basins, Mexico

    NASA Astrophysics Data System (ADS)

    Carrillo-Rivera, J. J.

    2000-09-01

    coeficiente de almacenamiento (S). En particular, la ecuación de balance de agua subterránea proporciona resultados poco fiables cuando el flujo vertical es ignorado o no puede ser evaluado de forma adecuada. El flujo vertical se identifica por un incremento de temperatura del agua subterránea, que puede llegar a superar la temperatura ambiental en hasta 23 °C. La presencia de fallas regionales y las extracciones pueden favorecer el flujo vertical. Cuando éste es ignorado, aumenta la incertidumbre en la estimación del coeficiente de almacenamiento mediante un balance de agua subterránea. El valor obtenido con este médodo (S=0,19) es característico de acuíferos libres, pero resulta varios órdenes de magnitud mayor que el que sería esperable teniendo en cuenta las condiciones hidrogeológicas. Estos hallazgos son útiles para evaluar si los recursos de agua subterránea están siendo "sobreexplotados". Las conclusiones obtenidas son instructivas de cara a la aplicación de modelos numéricos de flujo transitorio que no consideran el flujo vertical por densidad.

  2. 3D Stratigraphic Modeling of Central Aachen

    NASA Astrophysics Data System (ADS)

    Dong, M.; Neukum, C.; Azzam, R.; Hu, H.

    2010-05-01

    ; no. 6; p. 667-682 2. Martin Ross, Michel Parent and René Lefebvre (2005) 3D geologic framework models for regional hydrogeology and land-use management: a case study from a Quaternary basin of southwestern Quebec, Canada. Hydrogeology Journal, 13:690-707 3. Martin Ross, Richard Martel, René Lefebvre, Michel Parent and Martine M. Savard (2004) Assessing rock aquifer vulnerability using downward advective times from a 3D model of surficial geology: A case study from the St. Lawrence Lowlands, Canada. Geofísica Internacional Vol. 43, Num. 4, pp. 591-602

  3. In silico FRET from simulated dye dynamics

    NASA Astrophysics Data System (ADS)

    Hoefling, Martin; Grubmüller, Helmut

    2013-03-01

    : Python, Cython, C (ANSI C99). Computer: Any (see memory requirements). Operating system: Any OS with CPython distribution (e.g. Linux, MacOSX, Windows). Has the code been vectorised or parallelized?: Yes, in Ref. [2], 4 CPU cores were used. RAM: About 700MB per process for the simulation setup in Ref. [2]. Classification: 16.1, 16.7, 23. External routines: Calculation of Rκ2-trajectories from GROMACS [3] MD trajectories requires the GromPy Python module described in Ref. [4] or a GROMACS 4.6 installation. The md2fret program uses a standard Python interpreter (CPython) v2.6+ and < v3.0 as well as the NumPy module. The analysis examples require the Matplotlib Python module. Nature of problem: Simulation and interpretation of single molecule FRET experiments. Solution method: Combination of force-field based molecular dynamics (MD) simulating the dye dynamics and Monte Carlo sampling to obtain photon statistics of FRET kinetics. Additional comments: !!!!! The distribution file for this program is over 50 Mbytes and therefore is not delivered directly when download or Email is requested. Instead a html file giving details of how the program can be obtained is sent. !!!!! Running time: A single run in Ref. [2] takes about 10 min on a Quad Core Intel Xeon CPU W3520 2.67GHz with 6GB physical RAM References: [1] M. Saito, M. Matsumoto, SIMD-oriented fast Mersenne twister: a 128-bit pseudorandom number generator, in: A. Keller, S. Heinrich, H. Niederreiter (Eds.), Monte Carlo and Quasi-Monte Carlo Methods 2006, Springer; Berlin, Heidelberg, 2008, pp. 607-622. [2] M. Hoefling, N. Lima, D. Hänni, B. Schuler, C. A. M. Seidel, H. Grubmüller, Structural heterogeneity and quantitative FRET efficiency distributions of polyprolines through a hybrid atomistic simulation and Monte Carlo approach, PLoS ONE 6 (5) (2011) e19791. [3] D. V. D. Spoel, E. Lindahl, B. Hess, G. Groenhof, A. E. Mark, H. J. C. Berendsen, GROMACS: fast, flexible, and free., J Comput Chem 26 (16) (2005) 1701

  4. The evolution of groundwater rights and groundwater management in New Mexico and the western United States

    NASA Astrophysics Data System (ADS)

    DuMars, Charles T.; Minier, Jeffrie D.

    été, mais protégés par des principes de lois de propriété. Cinq systèmes de réglementation de base pour les droits sur les eaux souterraines aux États-Unis ont évolué jusqu'à aujourd'hui. Les problèmes posés par les différences hydrologiques entre les eaux souterraines hydrauliquement connectées aux cours d'eau et celles d'aquifères non réalimentés ont été résolus jusqu'à un certain point par quelques cas de jugement. La modélisation numérique et d'autres méthodologies techniques ont également évolué pour évaluer les résultats scientifiques apportés dans différentes conditions hydrologiques, mais ne sont pas à l'abri de critiques. Le rôle courant des aquifères évolue entre celui des possibilités de stockage pour l'eau recyclée et leur utilisation dans ce but peut être même étendue plus loin dans le futur. Les implications politiques des choix relatifs à la gestion simultanée des eaux souterraines et de surface ne doivent pas être exagérées. Comme le montre cet article, la gestion active de l'épuisement futur des nappes qui affecte les systèmes fluviaux est essentielle pour la capacité finale à planifier l'exploitation, la gestion et l'utilisation des ressources en eau d'une manière rationnelle qui coordonne la demande actuelle et future à la réalité de la rareté de l'alimentation. Les exemples utilisés dans cet article démontrent le besoin d'une capacité d'élaboration, non seulement pour développer de bonnes techniques de mesure, ou pour former d'excellents avocats et juges pour écrire de bonnes lois, mais aussi pour que des praticiens gestionnaires de l'eau maintiennent le processus dans un cours rationnel pour éviter une exploitation sans limite des ressources aussi bien qu'un protectionnisme conservateur qui empêche son usage à jamais. Históricamente, los derechos del agua se originaron como un bien público que se transformaron después en derechos individualizados para usar los recursos públicos, de forma

  5. Inverse modeling of groundwater flow in the semiarid evaporitic closed basin of Los Monegros, Spain

    NASA Astrophysics Data System (ADS)

    Samper-Calvete, F. J.; García-Vera, M. A.

    ha a été programmée, en partie dans un bassin évaporitique fermé où existent des lacs de playa. Le projet a fait émergé des préoccupations environnementales. L'évaluation des impacts hydrologiques de l'irrigation implique de quantifier correctement l'hydrogéologie de cette région. A partir des informations disponibles, un modèle hydrogéologique conceptuel a étéétabli il identifie deux aquifères principaux interconnectés par drainance au travers d'un imperméable. Un modèle numérique, établi sur la base de ce modèle conceptuel, a été calibré en conditions de régime permanent, en utilisant la méthode d'estimation automatique du maximum de vraisemblance des paramètres (Carrera and Neuman, 1986a). Le modèle calibré reproduit correctement la piézométrie mesurée et est en accord avec les informations concernant l'écoulement des nappes. La résolution du problème inverse a fourni des estimations acceptables des paramètres. On en a conclu que l'anisotropie joue un rôle essentiel dans certaines parties de l'aquifère inférieur. La moyenne géométrique de la conductivité hydraulique est d'environ deux ordres de grandeur plus élevée que la conductivité hydraulique moyenne obtenue par des essais de terrain à l'échelle locale. Cet effet d'échelle sur la conductivité hydraulique est conforme aux résultats obtenus par Neuman (1994) et Sánchez-Vila et al. (1996). Resumen La hidrogeología de zonas endorreicas en zonas evaporíticas ha recibido muy poca atención en el pasado debido fundamentalmente a que en estas zonas las aguas subterráneas tienen una elevada salinidad debido a la alta solubilidad de sus materiales. El interés por la hidrogeología de la zona de Los Monegros en el noreste de España surgió a raiz de la aprobación en 1986 del proyecto de Los Monegros II en la zona central del valle del Ebro que contempla la puesta en regadío de 60,000 ha, algunas de las cuales se encuentran situadas en la zona endorreica de Los

  6. C++QEDv2 Milestone 10: A C++/Python application-programming framework for simulating open quantum dynamics

    NASA Astrophysics Data System (ADS)

    Sandner, Raimar; Vukics, András

    2014-09-01

    ++ libraries, GNU Scientific Library, Blitz++, FLENS, NumPy, SciPy Catalogue identifier of previous version: AELU_v1_0 Journal reference of previous version: Comput. Phys. Comm. 183 (2012) 1381 Does the new version supersede the previous version?: Yes Nature of problem: Definition of (open) composite quantum systems out of elementary building blocks [2,3]. Manipulation of such systems, with emphasis on dynamical simulations such as Master-equation evolution [4] and Monte Carlo wave-function simulation [5]. Solution method: Master equation, Monte Carlo wave-function method Reasons for new version: The new version is mainly a feature release, but it does correct some problems of the previous version, especially as regards the build system. Summary of revisions: We give an example for a typical Python script implementing the ring-cavity system presented in Sec. 3.3 of Ref. [2]: Restrictions: Total dimensionality of the system. Master equation-few thousands. Monte Carlo wave-function trajectory-several millions. Unusual features: Because of the heavy use of compile-time algorithms, compilation of programs written in the framework may take a long time and much memory (up to several GBs). Additional comments: The framework is not a program, but provides and implements an application-programming interface for developing simulations in the indicated problem domain. We use several C++11 features which limits the range of supported compilers (g++ 4.7, clang++ 3.1) Documentation, http://cppqed.sourceforge.net/ Running time: Depending on the magnitude of the problem, can vary from a few seconds to weeks. References: [1] Entry point: http://cppqed.sf.net [2] A. Vukics, C++QEDv2: The multi-array concept and compile-time algorithms in the definition of composite quantum systems, Comp. Phys. Comm. 183(2012)1381. [3] A. Vukics, H. Ritsch, C++QED: an object-oriented framework for wave-function simulations of cavity QED systems, Eur. Phys. J. D 44 (2007) 585. [4] H. J. Carmichael, An Open

  7. Prediction uncertainty of plume characteristics derived from a small number of measuring points

    NASA Astrophysics Data System (ADS)

    French, H. K.; van der Zee, S. E. A. T. M.; Leijnse, A.

    sensibles à la dimension du panache en fonction de la distance entre les différents points de mesure. Afin de réduire les erreurs de prédiction de la variance, la distance entre les points de mesure doit être inférieure au double de l'écart-type du panache examiné. La dimension totale de l'ensemble doit couvrir une étendue de plusieurs écarts-types du panache pour éviter qu'une partie de la matière échappe à la zone surveillée. Des simulations numériques du panache en dispersion (les calculs de comparaison sont basés sur 9000 nœuds avec 30 points de mesure) montrent que le centre vertical et le centre horizontal de la matière dispersée ont été bien prédits à tous les degrés d'hétérogénéité, de même que pour les variances horizontales. Les variances verticales ont été plus sensibles aux erreurs de prédiction, mais les estimations étaient du même ordre de grandeur que les valeurs réelles. Resumen Un número pequeño de puntos de medida puede producir un sesgo en la caracterización en campo del flujo y transporte de solutos en la zona no saturada. La simulación de transporte advectivo (no difusivo) de un penacho Gaussiano a travs de un conjunto de 30 puntos de medida regularmente distribuidos revelan fluctuaciones temporales regulares de los momentos espaciales del penacho. Una distribución irregular de puntos de medida predijo a su vez fluctuaciones irregulares, más alejadas de la realidad, por lo que se recomienda el uso de esquemas de muestreo regulares. Los momentos espaciales fueron sensibles a la relación entre tamaño del penacho y distancia entre puntos de medida. Para reducir los errores en la predicción de la varianza, la distancia entre puntos de observación debe ser menor que dos veces la desviación estándar del penacho. El tamaño del área muestreada debe cubrir varias desviaciones estándar del penacho para evitar perder parte de la masa. Las simulaciones numricas en un penacho dispersivo, comparando los c

  8. The Practice of Research of a Basic Education Teacher Involving Mental Models of the Phases of the Moon and Eclipses. (Spanish Title: La Práctica de Investigación de un Maestro de Educación BÁsica con El Uso de los Modelos Mentales de Las Fases de la Luna Y Eclipses.) A Prática de Pesquisa de um Professor do Ensino Fundamental Envolvendo Modelos Mentais de Fases da Lua e Eclipses

    NASA Astrophysics Data System (ADS)

    Pessôa Queiroz, Glória; Jubitipan Borges de Sousa, Carlos; Auxiliadora Delgado Machado, Maria

    2009-12-01

    continuada de professores. A participação ativa do professor num grupo de pesquisa na universidade o

  9. Modélisation d'un choc thermique doux d'un verre S.S.C en utilisant l'approche thermomécanique

    NASA Astrophysics Data System (ADS)

    Malou, Z.; Hamidouche, M.; Madjoubi, M. A.; Bousbaa, C.; Bouaouadja, N.

    2005-05-01

    Dans ce travail, nous avons étudié l'endommagement du verre silico-sodo-calcique (trois différentes épaisseurs : 2mm, 4mm, et 8mm) par choc thermique descendant. Nous avons utilisé l'approche thermomécanique en terme de facteur d'intensité de contrainte en se basant sur un calcul numérique. Le choc thermique descendant, est la mise en contact brutal d'un échantillon, préalablement chauffé à une température Ti, avec un milieu dont la température Tf est inférieure à Ti. Le gradient thermique engendré induit des contraintes de tension dans les couches superficielles du corps. Ces contraintes peuvent conduire à la rupture du matériau. Les hypothèses prises en compte lors de la simulation sont comme suit : Le refroidissement des échantillons en verre chauffés à différentes températures, inférieures à sa température de transition, est fait par jet d'air à 20° C pendant 6 secondes. Ce temps est suffisant pour que la température des échantillons atteigne l'ambiante. Le coefficient de transfert de chaleur est de 600 W/°C.m2. Les températures chaudes ont été variées entre 100° C et 450° C. Lors des calculs, nous avons intégré, l'évolutions en fonction de la température des propriétés thermoélastiques du verre. Dans un premier temps, nous avons déterminé les températures et les contraintes transitoires dans l'échantillon à tout instant du choc thermique. Ensuite, nous avons déterminé l'évolution du facteur d'intensité de contrainte (FIC) durant le refroidissement. Enfin, les FIC calculés sont comparés à la ténacité (K1c) du matériau. Cette dernière a été mesurée en utilisant la mécanique linéaire de la rupture. Nous avons vérifié que quand le facteur FIC atteint la valeur de la ténacité dans la zone des défauts critiques, ces derniers se propagent d'une manière brutale causant ainsi la dégradation de l'échantillon. Par cette technique, nous avons directement accès à l'écart de température critique

  10. Some current methods to represent the heterogeneity of natural media in hydrogeology

    NASA Astrophysics Data System (ADS)

    de Marsily, G.; Delay, F.; Teles, V.; Schafmeister, M. T.

    that it will encourage the development of new ideas and approaches. Résumé On sait depuis longtemps que les propriétés des roches en profondeur sont éminemment variables dans l'espace. On sait que cette variabilité est due à la complexité extrême et à la variation au cours du temps des processus responsables de la formation de la croûte terrestre, de la tectonique des plaques à l'érosion, au transport sédimentaire et au dépôt, sans oublier les effets mécaniques, climatiques et de diagenèse. En tant que géologues, nous avons appris a "lire" cette histoire complexe au sein des roches, et à tenter d'extrapoler dans l'espace notre compréhension. En tant que physiciens, nous avons ensuite appris que pour étudier les écoulements dans de tels milieux, nous devions appliquer les concepts de la mécanique des milieux continus. En tant que mathématiciens utilisant des méthodes analytiques pour résoudre les problèmes d'écoulement, nous avons de plus appris que nous devions simplifier cette réalité complexe en un très petit nombre d'unités, tels que les aquifères et les aquitards, dont chacune est décrite par des propriétés équivalentes constantes. Enfin, dans les années récentes, en tant que numériciens, nous avons appris que nous avions désormais la liberté de "discrétiser" cette réalité complexe, et de la décrire comme un ensemble de petites "boîtes" homogènes de milieu continu, chacune d'entre elles pouvant avoir des propriétés différentes. Comment utilisons nous cette liberté nouvellement acquise? En avons-nous réellement besoin? Si la réponse est "oui", comment pouvons nous attribuer des propriétés différentes aux roches des milliers ou même millions de petites "boîtes" dans nos modèles, pour représenter au mieux la réalité, et comment déterminer les intervalles de confiance des propriétés choisies pour chaque roche? En hommage au Professeur Eugène S. Simpson, avec lequel le premier auteur de cet article a eu

  11. Capture-zone design in an aquifer influenced by cyclic fluctuations in hydraulic gradients

    NASA Astrophysics Data System (ADS)

    Zawadzki, Willy; Chorley, Don; Patrick, Guy

    2002-10-01

    alors réalisées sur la base du gradient hydraulique moyen déterminé au moyen de techniques de filtrage sur des mesures continues de la piézométrie. Lorsque la période de la fluctuation cyclique dans le gradient hydraulique est proche de ou supérieure au temps de parcours du contaminant, les variations résultantes de gradient hydraulique ne peuvent plus être ignorées. Dans ces cas-là, des procédures ont été mises au point pour prendre en compte ces fluctuations dans la conception de la zone d'extraction. Celles-ci prennent en considération la caractérisation propre du régime de la nappe, l'évaluation du temps de parcours moyen et de la période des fluctuations cycliques, et des techniques numériques qui permettent de considérer les fluctuations cycliques dans la conception de la zone d'extraction. Resumen. El diseño de un sistema de bombeo y tratamiento de aguas subterráneas para una instalación de manufactura de madera que está próxima al estuario del río Fraser, sometido a la influencia de las mareas, ha requerido el desarrollo de metodologías para tener en cuenta las variaciones cíclicas de los gradientes hidráulicos. El diseño de tales sistemas debe considerar los efectos de las fluctuaciones cíclicas en la captura de contaminantes en fase disuelta. Cuando el período de la fluctuación cíclica es mucho menor que el tiempo de tránsito del contaminante disuelto entre el punto de entrada y el de descarga, se puede ignorar las variaciones del gradiente hidráulico provocadas por dichos ciclos. Las zonas de captura se diseñan entonces en función del gradiente hidráulico promedio, que se determina mediante técnicas de filtrado de medidas continuas del nivel piezométrico. Cuando el período de la fluctuación cíclica del gradiente hidráulico es comparable o mayor que el tiempo de tránsito del contaminante, no puede ignorarse las variaciones resultantes en el gradiente hidráulico. En ese caso, se tiene que desarrollar

  12. Effect of cotrimoxazole prophylaxis on malaria occurrence in HIV-infected patients on antiretroviral therapy in sub-Saharan Africa*

    PubMed Central

    Kasirye, R; Baisley, K; Munderi, P; Grosskurth, H

    2015-01-01

    utilisant des termes pour paludisme, VIH et CTX. Les études répondant aux critères d'inclusion ont été examinées et évaluées pour les biais et les facteurs confusionnels. Résultats Six études (en Ouganda, Kenya, Malawi, Zambie et Zimbabwe) avaient des données pertinentes sur l'effet du CTX sur le paludisme chez les patients sous ART; 4 étaient des études de cohortes d'observation (ECO) et deux des essais contrôlés randomisés (ECR). Deux études étaient sur des enfants et une sur des femmes seulement. La taille des échantillons variait de 265 à 2200 patients. Quatre études ont comparé des patients sous ARV et CTX avec des patients sous ART seul. Deux ECR ont constaté une augmentation significative de cas de paludisme à frottis positifs chez les individus sous ART seul: (IRR= 32,5; IC: 8,6 à 275,0 et HR = 1,5; IC: 3,3 – 2,21) et deux ECO ont rapporté moins d’épisodes de parasitémie chez les individus sous CTX et ART (OR 0,85; IC: 0,65 à 1,11 et de 3,6% contre 2,4% des échantillons, P = 0,14). Une ECO a trouvé une réduction de 76% (IC95%: 63-84%) contre 83% (IC 95% = 74-89%) de l'incidence du paludisme chez les enfants sous CTX et ART que chez ceux sous CTX seul, lorsque les deux groupes étaient comparés à des enfants VIH négatifs. L'autre étude fait état d'une réduction de 64% de l'incidence du paludisme après l'ajout de l’ART au CTX (RR = 0,36, IC95%: 0,18 à 0,74). Les deux ECR n’étaient pas réalisées en aveugle. Seule une étude a rapporté l'adhésion au CTX et à l’ART, et seule 2 études ont effectué des ajustements pour la numération des CD4 initiale. Conclusion Peu d’études ont évalué l'effet du CTX sur le paludisme chez les patien

  13. Résultats du traitement du synovialosarcome des members

    PubMed Central

    Lukulunga, Loubet Unyendje; Moussa, Abdou Kadri; Mahfoud, Mustapha; El Bardouni, Ahmed; Ismail, Farid; Kharmaz, Mohammed; Berrada, Mohamed Saleh; El Yaacoubi, Moradh

    2014-01-01

    (dans certaines situations), radiographie pulmonaire, la TDM pulmonaire et l'IRM. Les dimensions de la masse ont varié de 3 à 30 cm avec une moyenne de 8,25 cm. La TDM thoracique a révélé 5 cas de métastases pulmonaires. La numération formule sanguine réalisée dans le cadre du bilan préopératoire a montré une anémie dans 4 cas. L'examen anatomopathologique a mis en évidence dans 13 cas (67%) de synovialosarcome biphasique et 7 cas de monophasique avec 15 cas de grade III et 5 cas de grade II selon la FNLCC. Nous avons effectué un traitement conservateur dans 12 cas (60%) avec 9 cas de R0 et 3 cas de R1, et radical dans 8 cas (amputation, désarticulation). Cette chirurgie a été associée dans certains cas à la chimiothérapie et ou radiothérapie. Cependant il a été noté quelques complications: 1 cas de collection postopératoire, 1 cas de radionécrose, 5 cas de métastases pulmonaires, 3 cas de récidive tumorale et 3 cas de décès. Les résultats carcinologiques étaient R0 dans 85% (n = 17) et R1 dans 15% (n = 3) et les résultats fonctionnels avec un recul moyen de 3 ans selon MSTS (70%) étaient satisfaisants dans 55% (n = 11). Le synovialosarcome est une tumeur d’évolution imprévisible dont le diagnostic mal aisé. La prise en charge multidisciplinaire doit être précoce afin d'améliorer le pronostic. Le traitement carcinologique est souvent difficile à obtenir au prix de sacrifice d’éléments nobles et la chirurgie réparatrice laborieuse. Le traitement radical permet d'améliorer la qualité de vie du patient associé à la radiothérapie et chimiothérapie adjuvantes. PMID:25574319

  14. The Practice of Research of a Basic Education Teacher Involving Mental Models of the Phases of the Moon and Eclipses. (Spanish Title: La Práctica de Investigación de un Maestro de Educación BÁsica con El Uso de los Modelos Mentales de Las Fases de la Luna Y Eclipses.) A Prática de Pesquisa de um Professor do Ensino Fundamental Envolvendo Modelos Mentais de Fases da Lua e Eclipses

    NASA Astrophysics Data System (ADS)

    Pessôa Queiroz, Glória; Jubitipan Borges de Sousa, Carlos; Auxiliadora Delgado Machado, Maria

    2009-12-01

    continuada de professores. A participação ativa do professor num grupo de pesquisa na universidade o levou à reflexão sobre caminhos didáticos possíveis de serem descritos, analisados e comunicados a outros professores. A construção de uma pedagogia própria, levando em conta os modelos mentais dos alunos sobre temas básicos de Astronomia, e as mudanças promovidas a partir das aulas dadas, trouxeram amplas conseqüências sobre a pedagogia adotada pelo professor. Hoje a prática desse professor incorpora uma nova visão de ciência e formas alternativas de dialogar com os alunos, elementos indispensáveis a um pesquisador em Educação em Ciências.

  15. Groundwater flow and solute transport at the Mourquong saline-water disposal basin, Murray Basin, southeastern Australia

    NASA Astrophysics Data System (ADS)

    Simmons, Craig; Narayan, Kumar; Woods, Juliette; Herczeg, Andrew

    2002-03-01

    salmueras contenidas en la balsa y de los procesos que controlan su migración por medio de (1) análisis de cloruros e isótopos estables del agua (2H/1H y 18O/16O), con el fin de determinar la mezcla entre las aguas subterráneas regionales y las lacustres, y (2) el código numérico SUTRA, que permite modelar flujo de densidad variable y transporte de solutos. Los resultados hidroquímicos indican que el agua evaporada se ha desplazado al menos 100 m hacia el Este y que no hay un movimiento apreciable de la salmuera hacia el río Murray, situado al Sur. Se emplea el modelo para considerar varios escenarios de gestión. La carga de sal hacia el río Murray es mayor en el escenario "más negativo", que incluye irrigación entre la balsa y el propio río. Las condiciones actuales de funcionamiento llevan a un pequeño (si existe) movimiento de la salmuera desde la balsa hasta el río.

  16. Assessment of hydraulic properties of sedimentary and volcanic aquifer systems under arid conditions in the Republic of Djibouti (Horn of Africa)

    NASA Astrophysics Data System (ADS)

    Jalludin, Mohamed; Razack, Moumtaz

    déduire la transmissivité. Concernant les aquifères volcaniques, la transmissivité a également été estimée à l'aide d'une relation empirique reliant la transmissivité et le débit spécifique corrigé des pertes de charge anormales. La transmissivité pour chaque aquifère couvre jusqu'à quatre ordres de grandeur, montrant la forte hétérogénéité de ces milieux. Pour les roches volcaniques, on observe que la transmissivité est d'autant meilleure que la roche est plus jeune. Leur transmissivité a ainsi diminué durant les temps géologiques. La compréhension des propriétés hydrauliques de ces aquifères complexes est à présent bien meilleure, ce qui permet d'envisager une gestion optimale de leurs ressources à l'aide de modèles numériques. La República de Yibuti (23.000 km2, 500.000 habitantes) está situada en el Cuerno de África, donde se han formado diversas unidades volcánicas-basaltos y riolitas-y rocas sedimentarias desde la expansión de los continentes acaecida al inicio de la deriva continental (hace 30 millones de años). La precipitación media anual es inferior a 150 mm. Las rocas volcánicas y sedimentarias, con dimensión inferior a 2.000 km2, constituyen acuíferos locales. Los basaltos estratificados forman un acuífero regional que se extiende a más de 9.000 km2. La multitud de datos existente ha sido almacenada desde los años 1960 en una base de datos. La transmisividad de estos acuíferos ha sido determinada mediante datos de ensayos de bombeo y una relación empírica que usa la capacidad específica corregida con las pérdidas turbulentas en el pozo. La transmisividad de estos acuíferos se comporta como una variable lognormal, hecho importante para los trabajos previstos de modelación con métodos estadísticos. La transmisividad de cada acuífero puede variar hasta en cuatro órdenes de magnitud, manifestando su gran heterogeneidad. Para los materiales volcánicos, la transmisividad es mayor cuanto más joven es

  17. The Analysis and Design of Low Boom Configurations Using CFD and Numerical Optimization Techniques

    NASA Technical Reports Server (NTRS)

    Siclari, Michael J.

    1999-01-01

    computation requires an hour of computational time on a Cray computer, one can see that the use of constrained numerical optimization quickly becomes impractical.Hence, in order to practically couple a numerical design optimization technique with a CFD method, the CFD method must be extremely efficient with running times on the order of only minutes. The CFD Euler code developed under NASA sponsorship and referred to as MIM3D-SB for the most part fulfills these efficiency requirements. Analysis of wing- body configurations can be computed in a matter of a few minutes. The present study will concentrate on the feasibility of the use of this CFD code in conjunction with a numerical design optimization technique for the sonic boom reduction of candidate HSCT configurations. A preliminary supersonic aircraft design system has been established that utilizes the numerical design optimization code NPSOL developed at Stanford University coupled with the supersonic NUM3D-SB CFD code. Many questions still need to be answered in regard to using CFD and numerical optimizers as design tools. There are difficulties related to both the CFD codes and the numerical optimizers. Numerical optimizers can converge to a local minima rather than a global minima. This behavior is largely a function of the initial guess in the design space. The optimizer also is searching for a minimum of the function in terms of its derivative without any regard to the actual function value. Numerically (i.e. CFD) determined gradients can also generate spurious numerical local minima. In addition, for the sonic boom problem, grid fineness will also determine the accuracy of the final design solution. Design optimization methods work well on problems defined by continuous objective functions. The sonic boom signature design problem is not necessarily defined by a continuous objective function. The signature can have a variety of shapes; i.e. from N-wave to multiple shocks. The far-field or ground signature may not

  18. Proposal for revisions of the United Nations Moon Treaty

    NASA Astrophysics Data System (ADS)

    Fernandes, Vera; Abreu, Neyda; Fritz, J.; Knapmeyer, Martin; Smeenk, Lisa; Ten Kate, Inge; Trüninger, Monica

    . More than 30 years have passed since the Moon Treaty (c. 1979) was elaborated, and since then technology and science have evolved leading to the need to change the requirements. As stated in the Moon Treaty, the State par-ties who had signed the Treaty meet every 5 and 10 years to revise the Treaty and suggest the necessary ratifications and amendments. The present version of the Moon Treaty, however, does not demonstrate ratifications that take into consideration environmental protection and preservation. For this, it is here suggested, that both the Antarctica Treaty (c. 1959), and more importantly, the Protocol on Environmental Protection to the Antarctic Treaty (c. 1991) are to be used as references for future documents that will be drawn pertaining the Moon. The Antarctica Treaty is currently one of the world's most successful international agreements and has evolved through time as needs and awareness require. The Protocol on Environmental Protection to the Antarctic Treaty reflects concerns regarding the impact of humans on the fragile environment of that continent. This concern is equally critical as new stages of lunar exploration unfold and the effects of such activity are progressively assessed. The key aspects of the Antarctic Protocol applicable to the Moon Treaty are: (1) a ban on commercial mineral resource activity, (2) careful waste disposal management, and (3) protection of areas of par-ticular scientific, environmental, and historical value. These measures should be implemented to prevent irreparable damage of the pristine lunar environment while permitting scientific, educational, and touristic uses and encouraging continued commitment to exploration of the Moon and other planetary bodies irrespective of exploration being robotic or human. A num-ber of other documents that establish an Environmental Code of Conduct for certain areas within the Antarctic continent (e.g., Management Plan for the Antarctic Specially Managed Area No.2, the McMurdo Dry

  19. The general circulation in the eastern Algerian subbasin inferred from the ELISA experiment

    NASA Astrophysics Data System (ADS)

    Aubertin, E.; Millot, C.; Taupier-Letage, I.; Albérola, C.; Robin, S.; Font, J.

    2003-04-01

    relationships with both the bathymetry and the AE's dynamics are under study Albérola C., S. Rousseau, C. Millot, M. Astraldi, J. Font, J. Garcia-Lafuente, G.P. Gasparini, U. Send and A. Vangriesheim, 1995. Tidal currents in the interior of the Western Mediterranean Sea. Oceanol. Acta, 18, 2, 273-284. Bouzinac C., J. Font and C. Millot, 1999. Hydrology and currents observed in the channel of Sardinia during the PRIMO-1 experiment from November 1993 to October 1994. J. Mar. Systems, 20, 1-4, 333-355. Fuda J.-L., C. Millot, I. Taupier-Letage, U. Send and J.M. Bocognano, 2000. XBT monitoring of a meridian section across the Western Mediterranean Sea. Deep-Sea Res., I 47, 2191-2218. Millot C., 1994. Models and data: a synergetic approach in the western Mediterranean Sea. Erice School Proceedings,"Ocean Processes in Climate Dynamics: Global and Mediterranean Examples", P. Malanotte-Rizzoli and A.R. Robinson eds, 407-425. Millot C., I. Taupier-Letage and M. Benzohra, 1997. Circulation off Algeria inferred from the Médiprod-5 current meters. Deep-Sea Res., 44, 9-10, 1467-1495. Obaton D., C. Millot, G. Chabert D'Hières and I. Taupier-Letage, 2000. The Algerian Current: comparisons between in situ and laboratory measurements. Deep-Sea Res., I 47, 2159-2190. Puillat I., I.Taupier-Letage and C. Millot. Algerian eddies lifetimes can near 3 years, 2002. Journal of Marine Syst., 31, 4, 245-259. Ruiz S., J. Font, M.Emelianov, J. Isern-Fontanet, C. Millot and I. Taupier-Letage, 2002. Deep structure of an open sea eddy in the Algerian Basin. J. Mar. Sys., 33-34, 179-195. Testor P., 2002. Etude lagrangienne de circulations tourbillonnaires de subméso et méso échelle en Méditerranée occidentale sur la base d'observations et de simulations numériques : phénoménologie et interaction avec la circulation générale. Thèse de Doctorat d'Université, Paris 6.

  20. PREFACE: 6th International Conference on Inverse Problems in Engineering: Theory and Practice

    NASA Astrophysics Data System (ADS)

    Bonnet, Marc

    2008-07-01

    . Lionheart (U. Manchester, UK) M. Bertero (U. Genova, Italy) D. Maillet (Nancy-U., France) J. Blum (U. Nice, France) W. Marquardt (RWTH Aachen, Germany) H. D. Bui (Ecole Polytech., France) P. A. Martin (Col. School of Mines, USA) T. Burczynski (Silesian Tech. U., Gliwice, Poland) A. Michalak (U. of Michigan, USA) G. Dassios (U. Patras, Greece) A. Nenarokomov (Moscow Aviation Inst., Russia) D. Delaunay (U. Nantes, France) D. Murio (U. Cincinnati, USA) H. Dinh Nho (Hanoi Inst. Maths, Vietnam) A. J. Nowak (Silesian Tech. U. Gliwice, Poland) A. El Badia (U. Tech. Compiègne, France) H. R. B. Orlande (Federal U. Rio de Janeiro, Brazil) J. Frankel (U. Tennessee, USA) L. Päivärinta (U. Helsinki, Finland) O. Ghattas (Carnegie Mellon U., USA) D. Petit (U. Poitiers, France) B. Guzina (U. Minnesota, USA) L. Pronzato (U. Nice, France) A. Hasanov (Kocaeli U., Turkey) M. Prud'homme (Ecole Polytech. Montréal, Canada) F. Hild (ENS Cachan, France) O. Scherzer (U. Innsbruck, Austria) C.-H. Huang (National Cheng Kung U., Taiwan) V. Shutyaev (Inst. Num. Maths, Russia) M. Ikehata (Gunma U., Japan) A. J. Silva Neto (U. Estado Rio de Janeiro, Brazil) M. Jaoua (Ecole Nat. Ingé. Tunis, Tunisia) V. Steffen Jr (U. Federal Uberlandia, Brazil) Y. Jarny (U. Nantes, France) G. Uhlmann (U. Washington, USA) S. Kabanikhin (Sobolev Inst. Maths., Russia) K. A. Woodbury (U. Alabama, USA) J. Kaipio (U. Kuopio, Finland) A. Yagola (Moscow State U., Russia) Kyung Youn Kim (Cheju National U., South Korea) E. Zuazua (U. Complutense Madrid, Spain) Additional Reviewers H. Ammari (ESPCI and Ecole Polytech., France) Y. Favennec (U. Poitiers, France) S. Avril (Ecole Mines St. Etienne, France) O. Fudym (Ecole Mines Albi, France) G. Bal (U. Columbia, USA) M. Girault (U. Poitiers, France) J.-L. Battaglia (U. Bordeaux, France) F. Hemez (Los Alamos Natl. Lab., USA) F. Bauer (Johannes Kepler U., Linz, Austria) M. Janicki (RICAM, Linz, Austria & T.U. Lodz, Poland) C. Bissieux (U. Reims, France) N. Laraqi (U. Paris X, France

  1. Lagrangian analysis. Modern tool of the dynamics of solids

    NASA Astrophysics Data System (ADS)

    Cagnoux, J.; Chartagnac, P.; Hereil, P.; Perez, M.; Seaman, L.

    la mesure lagrangienne de la vitesse matérielle et de la contrainte, en fonction du temps dans le matériau comprimé par une onde longitudinale plane ou sphérique. La spécificité lagrangienne des mesures requises est assurec par le fait qu'un capteur inclus dans un matériau solide est lié dans le mouvement aux particules du matériau qui l'entourent. Cette métrologie lagrangienne est décrite dans le deuxième chapitre. Les auteurs se sont intéressés aux techniques considérées aujourd'hui comme les plus performantes ; elles se rapportent d'une part à la vitesse matérielle: jauges électromagnétiques, interféromètres Doppler laser de types VISAR et IDL ; d'autre part à la contrainte : jauges piézorésistives (50 Ω et basse impédance) et techniques piézoélectriques (jauges PVF2-capteurs à quartz). Dans chacun des cas les principes de fonctionnement ainsi que les techniques de mise en œuvre sont détaillés. Les auteurs utilisent largement leurs propres résultats pour décrire l'étalonnage de ces moyens métrologiques et comparer leurs performances : étendue de mesure, temps de réponse, précision, durée maximale d'utilisation, surface visée... Ce sont ces performances que devra prendre en compte le mécanicien lorsqu'il devra choisir parmi les différents moyens métrologiques la technique la mieux adaptée à l'analyse lagrangienne qu'il se proposera d'effectuer dans un matériau donné. Les arguments développés à la fin du chapitre 2 devraient lui permettre de guider son choix aussi bien dans le cas du mouvement monodimensionnel plan que dans le cas du mouvement monodimensionnel sphérique. Dans le troisième chapitre la précision de l'analyse lagrangienne est examinée sous l'aspect de l'influence des précisions des méthodes d'analyse numérique d'une part et des techniques expérimentales d'autre part. A partir du traitement de différents cas concrets d'analyse, les auteurs cherchent à sensibiliser le lecteur aux diff

  2. Immunological failure of first-line and switch to second-line antiretroviral therapy among HIV-infected persons in Tanzania: analysis of routinely collected national data

    PubMed Central

    Vanobberghen, Fiona M; Kilama, Bonita; Wringe, Alison; Ramadhani, Angela; Zaba, Basia; Mmbando, Donan; Todd, Jim

    2015-01-01

    benefits of increased coverage. Objectifs Les taux d’échec du traitement de 1ère ligne et les passages au traitement de 2nde ligne sont des indicateurs clés pour les programmes nationaux VIH. Nous avons évalué l’échec immunologique du traitement selon les critères de l’OMS dans le programme national VIH tanzanien. Méthodes Nous avons inclus les adultes entreprenant une thérapie de 1ère ligne entre 2004 et 2011 avec une numération des CD4 prétraitement disponible et un suivi ≥6 mois. Nous avons évalué les rapports en dessous du risque pour l’échec immunologique du traitement et le passage subséquent à la thérapie de 2nde ligne, en utilisant les méthodes de risques concurrents pour tenir compte des décès. Résultats Sur 121.308 adultes, 7% ont connu un échec immunologique du traitement et 2% sont décédés sans observation d’échec immunologique du traitement, sur une médiane de 1,7 ans. La probabilité cumulée d’échec immunologique du traitement sur six ans était de 19,0% (IC95%: 18,5 à 19,7) et 5,1% (4,8 à 5,4) de décès. Les prédicteurs d’échecs immunologiques du traitement comprenaient: l'instauration précoce du traitement (p <0,001), l'initiation dans les établissements de niveau inférieur (SHR = 2,23 [2,03 à 2,45] pour les dispensaires versus les hôpitaux), le sexe masculin (1,27 [1,19 à 1,33]) et l'initiation du traitement à des taux de CD4 faibles ou élevés (par exemple, 1,78 [1,65 à 1,92] et 5,33 [4,65 à 6,10] pour des taux <50 et ≥500 versus des taux compris entre 200 et 349 cellules/mm3, respectivement). Sur 7.382 participants à l'analyse sur le moment du changement de traitement, 6% ont changé de traitement et 5% sont décédés avant le changement. Quatre ans après l’échec immunologique du traitement, la probabilité cumulative du changement de traitement était de 7,3% (6,6 à 8,0) et de 6,8% (6,0 à 7,6) pour les décès. Ceux qui ont connu un échec immunologique dans les dispensaires, les

  3. Toward Open Science at the European Scale: Geospatial Semantic Array Programming for Integrated Environmental Modelling

    NASA Astrophysics Data System (ADS)

    de Rigo, Daniele; Corti, Paolo; Caudullo, Giovanni; McInerney, Daniel; Di Leo, Margherita; San-Miguel-Ayanz, Jesús

    2013-04-01

    Theory. ISBN: 9780954612061 Eaton, J. W., 2012. GNU octave and reproducible research. Journal of Process Control 22 (8), 1433-1438. http://dx.doi.org/10.1016/j.jprocont.2012.04.006 R Development Core Team, 2011. The R reference manual. Network Theory Ltd. Vol. 1, ISBN: 978-1-906966-09-6. Vol. 2, ISBN: 978-1-906966-10-2. Vol. 3, ISBN: 978-1-906966-11-9. Vol. 4, ISBN: 978-1-906966-12-6. Ramey, C., Fox, B., 2006. Bash reference manual : reference documentation for Bash edition 2.5b, for Bash version 2.05b. Network Theory Limited. ISBN: 978-0-9541617-7-4. de Rigo, D., 2012. Semantic array programming for environmental modelling: Application of the mastrave library. In: Seppelt, R., Voinov, A. A., Lange, S., Bankamp, D. (Eds.), International Environmental Modelling and Software Society (iEMSs) 2012 International Congress on Environmental Modelling and Software. Managing Resources of a Limited Planet: Pathways and Visions under Uncertainty, Sixth Biennial Meeting. pp. 1167-1176. http://www.iemss.org/iemss2012/proceedings/D3_1_0715_deRigo.pdf de Rigo, D., 2012. Semantic Array Programming with Mastrave - Introduction to Semantic Computational Modelling. http://mastrave.org/doc/MTV-1.012-1.htm Van Rossum, G., Drake, F.J., 2011. Python Language Ref. Manual, Network Theory Ltd. ISBN: 0954161785. http://www.network-theory.co.uk/docs/pylang/ The Scipy community, 2012. NumPy Reference Guide. SciPy.org. http://docs.scipy.org/doc/numpy/reference/ The Scipy community, 2012. SciPy Reference Guide. SciPy.org. http://docs.scipy.org/doc/scipy/reference/ de Rigo, D., Castelletti, A., Rizzoli, A. E., Soncini-Sessa, R., Weber, E., Jul. 2005. A selective improvement technique for fastening neuro-dynamic programming in water resources network management. In: Zítek, P. (Ed.), Proceedings of the 16th IFAC World Congress. Vol. 16. International Federation of Automatic Control (IFAC), pp. 7-12. http://dx.doi.org/10.3182/20050703-6-CZ-1902.02172 de Rigo, D., Bosco, C., 2011. Architecture of a Pan