1,720,954 research outputs found

    Individual Accelerated Lifetime Tests on the Natural Dye - Sensitised Solar Cells to Determine the Impact of Different Degradation Factors and Strategies to Improve Stability

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    In this contribution we report on the impact of individual accelerated tests on dye-sensitised solar cells (DSSCs) degradation. Influence of the different physical factors on the tested cells lifetimes has been demonstrated. An international IEC 61646 standard has been used as a reference for the choice of the individual tests and the instruction for their further execution. The results obtained demonstrate that several exercises prescribed in the standard, such as dark thermal and humidity cycles, outdoor exposure or indoor accelerated light soaking tests can be useful in the assessment of the TCO glass-based DSSCs lifetime. The devices under tests have been sensitised with four different natural dyes, obtained from the typical Mediterranean plants. The DSSCs sensitised with Pistacia lentiscus extract demonstrate an interesting behaviour, related to the decline and retrieve of the generated photocurrent. Finally, some strategies to improve the natural dye based DSSCs lifetime have been proposed

    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

    An Optical Concentrator System to perform a Light-Soaking Indoor Test on Photovoltaic Receivers

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    In this paper the designs, realization and the indoor and outdoor experimental results of a laboratory test facility system for Concentrator Photovoltaic Receivers (CPR) characterization are reported. In particular, the proposed system has been developed in order to perform tests on CPRs characterized by high geometrical concentration factor (Cgeo). The test facility system is devoted to verify and qualify the behavior of CPR from different points of view. The system design has been developed paying particular attention to the test bench used for the evaluation of I-V characteristics of concentrator solar cells under high geometrical concentration factors. The preliminary study activity has been focused on the irradiance level, light source spectral composition, exposition time and operation temperature dependences of CPR characterization process. The main scope of this research activity is to propose in the next future novel tests to qualify the CPR system for a long-time operation (Light-Soaking and/or Hot-spot endurance tests). To execute measurements in a wide range of concentration, an opto-mechanical system for continuous light Solar Simulator coupling has been designed. The realized prototype produces a maximal geometrical concentration factor equal or less than 900x for testing Solar cells of an active area of 1 cm2

    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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