1,720,959 research outputs found
MASS-TRANSFER CHARACTERISTICS FOR A ROTATING CUP-LIKE CYLINDER
No full textA numerical study is made of Row and mass transfer characteristics for a cup-like cylinder, which rotates steadily about its own central longitudinal axis. This study simulates the earlier mass transfer experiment of Sparrow and Chaboki, which provided only the averaged value of Sherwood number. Comprehensive numerical solutions have been obtained for the Navier-Stokes equations over an extended range of Reynolds numbers. Numerically-constructed Row visualizations exhibit the structures of three-component velocity and concentration fields. The patterns of meridional flows, which are directly responsible for convective transport, are analyzed. The distributions of azimuthal flow are illustrated. Plots of the local Sherwood number at the inner surface of the cup are given. Physically plausible descriptions are presented of the local mass transfer characteristics for both cases of a transferring base endwall and a non-transferring base endwall. The numerical results of the cavity-average Sherwood number are consistent with the previous experimental data
Numerical simulations of a piston-type flowmeter of high linearity
No full textNumerical simulation is conducted of a new type of piston-cylinder flowmeter with a high degree of linearity. Numerical solutions to the Navier-Stokes equations are obtained by using the geometrical particulars which are close to thereat systems. The computed results demonstrate high degrees of linearity between the flow rate and force exerting on the piston. Numerically-constructed flow patterns and pressure profiles are presented. The effects of the gap size and the thickness of the piston on the linearity of the flowmeter are examined. Explicit impacts of the Reynolds number on the pressure profiles are exhibited. (C) 1997 Elsevier Science Ltd
Buoyant heat transfer in a rotating cup-like cavity
No full textA numerical study is made of buoyant flow and heat transfer in a vertically mounted cup-like cylinder which rotates steadily about the longitudinal axis. The temperature at the cylinder sidewall is lower than that of the surroundings. The relevant nondimensional parameters are identified. The governing Navier-Stokes equations, with the Boussinesq-fluid approximation, are solved numerically. The rotational Reynolds number Re is large, and the cylinder aspect ratio is O(1). The three-component velocity and temperature fields are portrayed. When the base surface is insulated, for the Richardson number Ri greater than or equal to O(1), the meridional flow weakens, the boundary layer-like character in the temperature field diminishes, and the azimuthal flow approaches that of a rigid-body rotation. When the base surface is transferring, the velocity fields are little altered from those of the insulated base, but appreciable differences are seen in the temperature fields. Physical explanations and rationalizations are offered on the basis of numerical results. Detailed profiles of local Nusselt numbers at the solid boundaries are provided. The trends are consistent with the physical reasonings. (C) 2000 Elsevier Science Ltd. All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Variations on the Author
Full text link“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
Full text linkWe 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
Full text linkWe 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
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