1,720,974 research outputs found
An extended thermodynamics description of stationary heat transfer in binary gas mixtures confined in radial symmetric bounded domains
No full textIn this paper, we describe the stationary heat transfer problem in non-reacting gas mixtures confined between two coaxial cylinders or two concentric spheres kept at different temperatures. For the description of this phenomenon, we refer to the extended thermodynamics 13-moments single temperature system and we compare its predictions with those obtained by the classical Navier–Stokes–Fourier–Fick approximations.
In contrast with the classical theory, we show that extended thermodynamics takes over also thermodiffusion
effects, predicts boundary layers for the common temperature and non-vanishing stress tensors. Furthermore, we compare the results with those already obtained in the planar case, in order to point out the effects of the radial dependence
Heat transfer in gas mixtures: Advantages of an extended thermodynamics approach
No full textIn this work we analyze and compare different approaches to the heat transfer problem in gas mixtures. Our aim is to show that for rarefied gases far from equilibrium the extended thermodynamics description is capable to reproduce some features observed by kinetic theory, that cannot be described by the Navier–Stokes–Fourier–Fick approximations. In this framework, we consider the case of a binary inert gas mixture confined between two infinite parallel plates kept at different temperatures
On a Multi-Temperature Mixture Model for Flame Structure
No full textWe present a multi-temperature mixture model for the description of a stationary one-dimensional flame and compare it with classical and extended thermodynamics equations for a single temperature
Some 2D heat transfer problems in metals described by a linearized extended thermodynamics model
Full text linkWe describe qualitatively some 2D stationary problems for metal electrons in the
presence of a temperature gradient and a magnetic field. To this aim we refer to a linearized
Extended Thermodynamics model that allows a semianalytical construction of the solutions.
The results are in agreement with the thermomagnetic effects already known in the literatu
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
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