1,721,138 research outputs found

    Fracture Mechanics Approach to compare Laser Sintered parts and Injection Mouldings of Nylon-12

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    In comparison to equivalent parts made by injection moulding, components manufactured by laser sintering are often perceived to offer inferior mechanical properties, yet the evidence for this is rarely based upon systematic research studies. In this paper, attempts have been made to conduct a fundamental study of the fracture behaviour of both injection moulded and laser sintered parts, based upon a modification of a standard technique used to determine linear elastic fracture mechanics parameters. The influence of specimen thickness (in the range 2–10 mm) was also included in the experimental plan, which concentrated upon the testing of single-edge notch bending (SENB) beam specimens. Force-displacement characteristics demonstrated significant plastic deformation in nylon (PA12) specimens, so that the J-integral method was used to obtain quantitative fracture parameters, including the energy requirements for crack growth. Comparisons of this parameter showed thickness-dependent ‘geometry-sensitive’ data for each set of samples. For the injection moulded SENB specimens, energy absorption decreased with increasing thickness, a result attributed to the influence of plane-strain-dominated conditions. In contrast, laser sintered samples exhibited increased toughness as specimen thickness increased towards 10 mm; this could not be explained by density or particle melting data and may be interpreted by changes in molecular structure that occur during the additive manufacturing process

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

    Singing for Lung Health: service evaluation of the British Lung Foundation programme.

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    AIMS: Singing for Lung Health (SLH) is a novel intervention for individuals with respiratory disease. Qualitative results suggest benefits to physical, mental and emotional health. Limited data also suggest objective improvements in measures of quality of life with SLH are achievable. It is not known how effective the SLH groups supported by the British Lung Foundation (BLF) in the UK are. The objective was to understand the clinical impact SLH has on individuals with respiratory disease. METHODS: The BLF conducted a questionnaire survey of singers with respiratory disease from new SLH groups set up in 2016-2017. Questionnaires were administered prior to participants' first session and after 12 weeks of singing. Health-related quality of life, patient activation, anxiety and breathlessness outcomes were included. Healthcare resource utilisation including general practitioner (GP) visits, hospitalisations and frequency of inhaler use were recorded. RESULTS: A total of 228 singers participated from 26 SLH groups in the UK. Participants were 70.7 (10.1) years old, 156 (68.4%) were female and 114 (47.5%) had chronic obstructive pulmonary disease (COPD). In all, 113 (49.5%) participants provided 12-week data. There were significant improvements in COPD Assessment Test (CAT) score (Mean = -1.4, CI: (-0.25 to -2.48) (  p = .017)). Furthermore, 45% of singers reported reduced GP visits (  p ≤ .001) and 18% reported reduced hospital admissions (  p = .01). However, there were no significant improvements in general quality of life, anxiety, patient activation, breathlessness or inhaler use. Baseline characteristics were not significantly different between people who completed the 12-week evaluation and those who did not. CONCLUSIONS: This service evaluation found that participants in SLH groups report improvement in respiratory health-related quality of life and a reduction in healthcare utilisation. SLH has potential economic and health benefits. Therefore, to confirm these findings, these endpoints should be evaluated further in large-scale randomised controlled trials (RCTs)

    Variations on the Author

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    “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

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    We 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

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    We 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

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We 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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