1,720,988 research outputs found
Stress-corrosion failure mechanisms in soda-lime silica glass
No full textThe present work focuses on stress-corrosion mechanisms in soda-lime silica glass. Four-point beam-bending tests were performed on small specimens, measuring failure time in function of temperature and relative humidity. By using linear elastic fracture mechanics, average velocity of edge flaws propagation was evaluated as a function of stress intensity factor, allowing a comparison with experimental curves from the literature. Experimental results are consistent with the main stress-corrosion theories and with chemical kinetics equation for a general reaction. Also, by using a crack evolution power-law and an equivalence relation for constant stress, we have compared our results with lifetime curves relative to environmental conditions of the tests
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
Enhancing the design bending strength of new and aged glass with a functional coating
No full textAnnealed glass is susceptible to stress corrosion. This stress corrosion phenomenon, also known as static fatigue, embodies a reduction of the tensile strength due to the combined presence of applied tension stress and humidity. As a consequence, the effective strength of annealed glass members in building construction is limited. According to the classical theory developed to account for this phenomenology and to previous experiences published in the literature, stress corrosion can be prevented by avoiding the interaction between water molecules and the silica network. In the present work an innovative polymeric coating cured by UV radiation is applied to the surface of glass specimens to prevent stress corrosion. This coating is suitable to constitute a barrier between humidity and glass surface, thus increasing the reliability of new glass structures and their resistance to long-term loads, due to a compositional profile that maximizes hydrophobicity and water vapor barrier on the air side and adhesive properties on the substrate side. Coating effectiveness is assessed experimentally in terms of load-carrying capacity of coated plates tested under equibiaxial bending conditions with the coaxial double ring setup. New and naturally aged glasses are analyzed. The results evidence an increase of the design bending strength between 60 and 90% with respect to the strength of un-coated glass
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