1,722,634 research outputs found
Informe preliminar del crucero Unanue 7108
No full text25 p.Presenta información recogida en el crucero oceanográfico 7108 realizado a bordo del B.A.P. Unanue, el cual tuvo como propósito realizar observaciones sobre los aspectos físicos, químico y de la fertidilidad de las aguas costeras, a fin de conocer las condiciones actuales del ambiente marino en el período invernal de 1971. La duración fue de 16 días (del 16 de agosto al 02 de setiembre de 1971), con paradas intermedias en el Callao, Los Órganos y Paita y con un recorrido total de 3012 millas náuticas que cubrió el área que comprende entre las latitudes 4°S - 18°S hasta una distancia máxima de 150 millas de la costa peruana
Microstructural evolution during homogenization of aluminum alloy AA 7108.
No full textComponentes extrudados da liga de alumínio AA 7108 pertencente ao sistema Al-Zn-Mg são frequentemente utilizados na área de transporte. No presente trabalho, a microestrutura da liga 7108 foi estudada nas seguintes condições: bruta de solidificação, após homogeneização e após extrusão. Foram utilizadas as seguintes técnicas complementares de caracterização microestrutural: microscopia óptica, microscopia eletrônica de varredura (MEV), microanálise por dispersão de energia acoplada ao MEV, difração de raios X, medidas de dureza Vickers e de condutividade elétrica. Após solidificação, a liga apresentou estrutura dendrítica, microssegregação e compostos intermetálicos. Após tratamento de homogeneização por cerca de 10 horas a 486ºC, ocorreu dissolução quase completa das partículas de intermetálicos e diminuição da microssegregação. Foi detectada também a presença da fase Al3(Zr,Ti), que não se dissolveu durante tratamento térmico de homogeneização de até 20 horas de duração. Durante a extrusão ocorreu recristalização com significativo refino de grão, além de formação de zona periférica de grãos grosseiros. A técnica de difração de raios X utilizando o método proposto por Williamsonn e Hall mostrou eficaz e promissora para acompanhar a homogeneização.Extruded components of the aluminum alloy AA 7108 belonging to the Al-Zn-Mg system are often used in the transport area. In the present work, the microstructure of alloy 7108 was studied in the following conditions: after solidification, after homogenization heat treatment and after extrusion. The following complementary techniques of microstructural characterization were used: optical microscopy, scanning electron microscopy (SEM), energy dispersive microanalysis coupled to SEM, X-ray diffraction, Vickers hardness measurements and electrical conductivity. After solidification, the alloy presented dendritic structure, microssegregation and intermetallic compounds. After homogenization heat treatment for about 10 hours at 486 °C, almost complete dissolution of the intermetallic particles occurred and decreased microssegregation. The presence of Al3(Zr, Ti) phase was also detected, which did not dissolve during the homogenization heat treatment of up to 20 hours. During extrusion, recrystallization occurred with significant grain refining, in addition to formation of peripheral coarse grains zone. The technique of X-ray diffraction using the method proposed by Williamsonn and Hall showed effective and promising to accompany the homogenization
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
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