1,720,956 research outputs found
Simulation tridimensionnelle de l´écoulement d´un fluide de Bingham dans une conduite à section droite carrée.
No full textLe présent travail consiste en l’étude numérique du transfert thermique en mode de convection forcée, lors de l’écoulement stationnaire d’un fluide non newtonien incompressible obéissant au modèle rhéologique de Bingham. Cet écoulement a lieu dans une dans une conduite de section droite carrée maintenue à température parentale constante et uniforme. L’influence du nombre de Bingham sur les caractéristiques hydrodynamique et thermique a été étudiée. Pour résoudre le système d’équations qui gouvernent le phénomène de convection et qui satisfont aux conditions aux limites retenues, un code de calcul basé sur la méthode des volumes finis et l’algorithme SIMPLER a été utilisé. Ce code a été validé, par la suite, après confrontation de nos résultats à ceux de la littérature. Les surfaces de la conduite chauffées à la même température sont considérées comme l’unique source de chaleur, en d’autres termes, la dissipation visqueuse n’est pas prise en compte dans l’équation de l’énergie. Nous admettons par ailleurs, que les mécanismes de conduction-convection sont les seuls modes de transfert thermique mis en œuvre, à l'exclusion de tout échange par rayonnement. Nous supposons enfin, que la différence entre la température de la paroi et celle du fluide à l’entrée (Tp–T0) est suffisamment faible pour que les propriétés physiques de ce dernier (sa masse volumique , sa viscosité plastique p, sa chaleur spécifique Cp, sa conductivité thermique k et sa contrainte seuil puissent être considérées comme constantes. L’effet du nombre de Bingham traduisant le rapport entre les contraintes d’élasticités et les contraintes visqueuses du fluide, sur les caractéristiques hydrodynamiques et thermiques de l’écoulement a été étudié. Les résultats dévoilent que l’influence du nombre de Bingham s’étend le long de la conduite et donne des valeurs différentes de celle obtenus pour le fluide newtonien, cette influence est beaucoup plus important sur le coefficient de frottement et le développement des profils de vitesse que sur l’évolution longitudinal de Nusselt
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Etude numérique de la convection forcée lors de l'écoulement d'un fluide de Bingham entre deux plans parallèles
Get PDFLe présent travail porte sur l'étude numérique de l'écoulement d'un fluide non newtonien obéissant au modèle rhéologique de Bingham entre deux plans parallèles siège d'un transfert thermique par mode de convection (naturelle, mixte et forcée). Les deux plans sont maintenus à température pariétale constante et uniforme. Les caractéristiques hydrodynamiques et thermiques de l'écoulement seront étudiées
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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