1,721,007 research outputs found

    On the mechanical behaviour of BFRP to aluminum AA6086 mixed joints

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    The aim of this work is to analyze the possibility to join aluminum alloy AA6086 and composite laminates reinforced with basalt fibers, an innovative material which use is growing in several applications as an alternative to glass fibers. To this goal, three joining techniques were investigated: mechanical by Self Piercing Riveting (in the next called SPR), adhesive by co-curing technique and mixed in which the joining techniques (i.e. adhesive and mechanical) were combined. Two manufacturing technologies (i.e. hand lay-up and vacuum bagging) were used both to produce composite substrates and to realize co-curing adhesion between the substrates to be joined. Mixed joints were realized by inserting the rivets in co-cured joints after 48 h than the initial phase of the curing process (i.e. the phase of mixing the resin with own hardener). Overall, six lots of joints were realized (two for each joining technique). All joints were characterized by performing single lap joint tests. The mechanical results were analyzed through a two way analysis of variance. The experimental results show that adhesive joints, realized by vacuum bagging method, show average failure load 22.9% higher and standard deviation 70.6% lower than those realized by hand lay-up, respectively. This means that the vacuum bagging technology allows to increase the adhesion strength of the interface between metal sheet and Basalt Fiber Reinforced Polymer (in the next BFRP), allowing the above failure load growth. Furthermore the failure mechanisms change from adhesive mode to partially cohesive one for the adhesive joints realized by hand lay-up and vacuum bagging, respectively. By comparing mixed joints, different results are obtained: i.e. the hand lay-up joints show both higher average failure load (+42.9%) and standard deviation (+208.3%) than those realized by vacuum bagging. The poor performances of the mixed joints realized by vacuum bagging can be considered due to the excessive value of the chosen riveting load. Statistically, two variables were investigated: i.e. joining technology (i.e. mechanical, adhesive and mixed) and manufacturing process (i.e. hand lay-up and vacuum bagging). These can influence the properties of the joints. In particular, the joining technology results a significant factor. Moreover, an interaction between the two variables exists

    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

    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

    Segmentation of MR brain images with bias artifact

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    Brain MR Images corrupted by RF- Inhomogeneity (bias artifact) exhibit brightness variations across the image. As a consequence, a standard Fuzzy C-Means (fern) segmentation algorithm may fail. In this work we show a new general-purpose bias removing algorithm, which can be used as a pre-processing step for a fern segmentation. We also compare our experimental results with the ones achieved by using E2 D - H U M filter, showing an improvement in brain segmentation and bias removal

    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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