1,720,956 research outputs found
Linking the thermal, morphological and electrical properties of thermoplastic polymer composites containing an organoclay
No full textNew material discovery to meet a list of property specifications is both slow and costly, whereas combining known materials to achieve a composite displaying a variety of properties from the constituent parts is widely regarded to be more effective. Blending polymers together with the incorporation of a nano-clay to form a nanocomposite alters the thermal, mechanical and electrical properties in particular.This thesis investigates the ability to form composites and their resulting thermal, morphological and electrical properties. Within each material system, results of varying the relative ratio of their constituents will be investigated and a comment made on the compatibility of the constituents. The hypothesis being that, in each case, a link between these properties can be established such that understanding the interdependency can better inform future material development. The polymeric materials investigated include polyethylene, polypropylene, polystyrene and copolymers of ethylene and vinyl acetate
The dielectric effect of xylene on an organoclay-containing composite
No full textThe influence of a non-polar solvent, xylene, on the electrical properties of a system containing polypropylene, a copolymer of ethylene and vinyl acetate and an organoclay has been considered, since the production of such materials may often involve exposure to a solvent. Although, in isolation, neither the organoclay nor the xylene has a marked effect on the dielectric response of the system, when combined, synergistic effects can be seen. We interpret this in terms of solvent-mediated relaxation of amphiphilic compatibilizer moieties introduced into the organoclay to aid processability. These local relaxation processes appear adversely to affect the AC breakdown strength of the system, which is recoverable upon the removal of xylene from the material.</p
A comparative analysis of different dielectric fluids for cable sealing ends
No full textA growing interest is observed in research to explore biodegradable alternative fluids as liquid insulation in high voltage equipment, due to their dielectric strength, environmental friendliness and enhanced fire safety. The present report deals with comparing the performance of possible alternative oils with silicone oil, which is typically used in the cable sealing ends. A detailed study of various physicochemical aspects and the impact of moisture ingress on these properties of mineral oil, natural and synthetic ester oil, and silicone oil is conducted. This work aims to identify the best liquid dielectric suitable for its application for cable terminations
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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