1,721,003 research outputs found
Volatile components in magmatic and metamorphic processes : fluid and melt inclusion data
No full textIn the paper are summarized the original and published data on the most abundant volatile components of the deep zones of Earth's crust and upper mantle obtained by thermometric and cryometric study of the melt and fluid inclusions in minerals of almost 300 samples of magmatic and metamorphic rocks. A plot temperature (500-1 500 °C) vs. pressure (up to 13 kbar) was made and analyzed. It was shown that the melts of basic and acid composition are drastically different in contents of the main volatile components : CO2 is characteristic for the former and H2O for the latter. Within the range of 500 °C to 1 100 °C in temperature and 6 to 13 kbar in pressure, magmatic melts were not found ; among the rocks are met only metamorphic rocks, and fluids are represented by carbon dioxide, methane and nitrogen.Les données des différents auteurs concernant les éléments volatils présents dans les zones profondes de la croûte et du manteau, déterminées à l'aide des études thermométriques et cryométriques sur les inclusions fluides et vitreuses de 300 échantillons de roches magmatiques et métamorphiques, sont discutées. On établit et analyse les corrélations entre la température d'homogénéisation des inclusions et la pression des fluides. Il est montré que les liquides silicatés de composition acide et basique se distinguent nettement par la nature et la teneur en volatils, les premiers sont riches en H2O, les seconds en CO2. On remarque l'absence de liquides magmatiques dans un domaine de température compris entre 500 °C et 1100 °C et pour des pressions allant de 6 à 13 kbar. Le domaine est occupé par les roches d'origine métamorphique (notamment les granulites) dont les fluides essentiels sont CO2, CH4 et N2.Naumov Vladimir B. Volatile components in magmatic and metamorphic processes : fluid and melt inclusion data. In: Bulletin de Minéralogie, volume 111, 3-4, 1988. Inclusions fluides. IXth symposium on fluid inclusions. University of Oporto – May 1987
Comparison of sCO2, CO2 mixture, and steam Rankine cycles for CSP with components sizing: implications for cost and flexibility
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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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