1,721,034 research outputs found
Calculation of the density and thermal expansion coefficient of silicate liquids
No full textIt is shown that density data foraluminum free silicate melts are compatible with composition independent partial molar volumes for the constituent oxides (V1) for silica mole fractions ranging from .35 to .9. The coefficients of thermal expansion of these liquids are virtually temperature independent and can be expressed as linear functions of composition, for which we have derived a set of constants (a,-). Partial molar volumes and a, values for 17 different oxides are calculated, using a data base containing more than 1,200 density observations on aluminum free melts. These results and those reported by Bottinga et al. (1982) make it possible to calculate the density and coefficient of thermal expansion of alumino silicate melts with an accuracy comparable to that of the input data in the temperature interval 1,000 to 2,000 °C.Pour les oxydes, un ensemble de volumes partiels molaires indépendants de la composition est compatible avec les mesures de volume (V) faites sur les liquides silicatés exempts d'aluminium dont la teneur en silice varie de 35 à 90 moles %. Les coefficients d'expansion thermique (a) de ces liquides sont virtuellement indépendants de la température et peuvent être exprimés comme des fonctions additives de la composition. Les constantes nécessaires au calcul de V et de a ont été calculées pour 17 oxydes, à partir de plus de 1 200 mesures de densité. Ces résultats et ceux de Bottinga et al. (1982) rendent possible le calcul de V et de a des liquides silicatés et alumino-silicatés avec une précision comparable à celle des mesures, entre 1 000 et 2 000 °C.Bottinga Yan, Richet Pascal, Weill Daniel F. Calculation of the density and thermal expansion coefficient of silicate liquids. In: Bulletin de Minéralogie, volume 106, 1-2, 1983. Silicates liquides
Application of a percolation model to supercooled liquids with a tetrahedral structure
No full textThe unusual properties of liquid water are explained by a percolation model which emphasizes the geometrical aspects of the tetrahedral structure of this liquid. Statistics over the molecular distribution give predictions about the thermodynamic properties and their dependence on temperature, pressure and concentration of impurities. The model can be generalized to other liquids with analogous structures, such as liquid silica and silicates.Les propriétés inusuelles de l'eau sont expliquées par un modèle de percolation qui souligne le rôle des aspects géométriques de la structure de ce liquide. Un traitement statistique de la distribution moléculaire permet de prédire les propriétés thermodynamiques de l'eau, et leur dépendance vis-à-vis de la température, de la pression et des teneurs en impuretés. Ce modèle peut être généralisé à d'autres liquides de structure analogue, tels que la silice et les silicates fondus.Teixeira José, Stanley Harry Eugene, Bottinga Yan, Richet Pascal. Application of a percolation model to supercooled liquids with a tetrahedral structure. In: Bulletin de Minéralogie, volume 106, 1-2, 1983. Silicates liquides
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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