1,720,955 research outputs found
High-temperature electrical conductivity of FeTiO3 and ilmenite.
No full textResistivity measurements have been carried out on FeTiO3 and the mineral ilmenite to characterize these materials in terms of oxygen exchange in the gas phase. These measurements were obtained in the temperature range 400-1273 K and in the oxygen partial pressure range 0.5-101.3 Pa. The activation energies of conductivity were found in the range 0.10 +/- 0.01-0.40 +/- 0.01 eV for FeTiO3, and 0.13 +/- 0.01-0.21 +/- 0.01 eV for ilmenite, independent of the oxygen fugacity. FeTiO3, which behaves as p-type semiconductor, shows a sigma proportional to(P-o2)(1/n) experimental dependence with n = +4, supporting an oxygen-exchange process based mainly on the formation of singly negative metal vacancies. Under the same conditions, the resistivity measurements carried out on ilmenite indicated that the sample conductivity was independent of the oxygen partial pressure. This is to be expected if the concentrations of electrons and electron defects are much larger than those of the ionic defects. In this case, the disorder of electrons is not influenced by small deviations from ideal stoichiometry
MUTUAL CONVERSION OF (BIPB)(2)SR2CAN-1CUNOX HTSCS WITH N=1, 2, 3 - TEMPERATURE AND OXYGEN PARTIAL-PRESSURE DEPENDENCE
No full textThe transformation of the 2223 (n = 3) phase in the 2201 (n = 1) phase by heating the sample in Ar atmosphere was studied. The subsequent cycling of the sample temperature and the oxygen enrichment of the gas phase convert the 2201 (n = 1) phase in the 2223 (n = 3) phase in the presence of the 2212 (n = 2) and Ca2PbO4 compound. The in situ resistivity measurements, T-c values and XRD carried out on the sample confirm these phase changes. The experiment indicates that this process is oxygen dependent at low oxygen partial pressure
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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