1,720,962 research outputs found
Short-range mobilization of elements during thermal metamorphism of the Kharlovo gabbro aureole
No full textMass balance and compositional variation in the outer part of the contact aureole shows that mass transfer of the main petrogenetic components was confined to small domains of a few hundredths of mm3 in chlorite-biotite-mica and epidote-plagioclase-titanomagnetite aggregates. The chemical homogeneity of the environment was practically unaffected by the thermal metamorphism. -Author
The origin of arfvedsonite in metabasites from contact aureole of the Kharlovo gabbro intrusion
No full textHornblende and arfvedsonite were formed at T = 525-550 degrees C and P = 1-1.5 kbar in the middle part of the contact aureole of the Kharlovo gabbro massif according to the following reactions:
(1) 0.8 Chl + 0.27 Bt + 0.83 Cal + 1.38 Mag + 1.68 Spn + 1.4 Ab = 1.5 Hbl + 1.58 Ilm + 4.65 H2O + 0.83 CO2
(2) 0.02 Chl + 1.18 Ab + 0.21 Cal + 0.14 Mag = 0.1 Arf + 1.0 Olg + 0.02 H2O + 0.21 CO2
A rare combination of heterogeneous rock composition, PT-parameters and thermal metamorphism of short duration led to the formation of arfvedsonite in metabasites. Arfvedsonite formed under local saturation of pore solution by Si, Na and Fe in a very small volume as a result of a local metasomatic reaction. These reactions were controlled mainly by sodium and silicon leaching during incongruent dissolution of acid plagioclase. Mass balance analysis and the variation of composition and amount of coexisting mineral show that the transfer of the main petrogenetic components was limited to volumes as small as 0.06-0.1 mm(3)
Inverse modeling approach for obtaining kinetic parameters of diffusion-controlled metamorphic reactions in the Kharlovo Contact Aureole (South Siberia, Russia)
No full textA new approach for deriving kinetic parameters of diffusion-controlled metamorphic reactions is described. It is based on comparison of models of temperature field evolution near a cylindrical intrusion and observable chemical changes in biotite at the contact aureole of the Kharlovo massif. Unlike other methods used to construct quantitative models of reactions which produce distinctly expressed zoned microtextures, the proposed approach allows better understanding of the processes occurring in texture-homogeneous rocks, where complete consumption of some reactant mineral phases prevent accurate reconstruction of the metamorphic process. The calculations: yielded estimates of the effective rates of metamorphic reactions (10(-12) s(-1)) and the effective diffusion coefficient (5.29 x 10(-16) cm(2) s(-1)). These values are consistent with experimentally and theoretically derived estimates of solid-state diffusion, including grain-boundary diffusion
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
- …
