1,720,960 research outputs found
Optical simulation of Rondine® PV solar concentrators by two inverse characterization methods
No full textIn this paper we describe two optical characterization methods applied to photovoltaic solar concentrators. Both methods are of the 'inverse' type, where the light source is applied in place of the receiver in order to reverse the path of light inside the concentrator. The first method is the 'inverse illumination method', already known in the literature, whereas the second one is a method obtained by modifying the 'inverse luminescence method', operating with electroluminescent light. Both methods use ideal Lambertian sources for producing the inverse light and can be applied to any type of solar concentrator (photovoltaic or thermodynamic). The optical simulations show their equivalence in obtaining the angular distribution of the transmission efficiency function of Rondine® PV concentrators, but the original inverse illumination method requires a simpler configuration and significantly lower simulation times. © 2012 IOP Publishing Ltd
Photovoltaic concentrators: Entry into solar market
No full textThe development of new technologies in the field of renewable energies is becoming a key issue for economies of the next future. The worldwide exponential growth of photovoltaic installation, recently pushed up in many countries by feed-in tariffs, is giving a boost to the research and development of new solutions in the PV world. Huge investments have recently been made for the installation of plants for production of purified polysilicon as well as for the production of thin film solar cells. A very interesting way for reduction of costs of the photovoltaic energy production, which has the final goal to compete with the fossil fuel sources, is given by the photovoltaic concentrators; this alternative solution consists of replacing the large area of photoactive material, which is the most expensive component of the PV panels, with low cost optical structures with the function of concentrating the light on photovoltaic cell of the small area
Development of a mirror-based LCPV module and test results
No full textThe design and the technical features of a low concentration photovoltaic module based on silicon solar cells are here presented, reporting manufacturing topics and results of experimental tests. The product here described has been developed, taking into account costs, efficiency, reliability, and investments required for its industrial production and for its commercial exploitationThe design of a specific low concentration photovoltaic module is described here, with a report of the results of the first experimental tests of its industrial version. The product is a 20× reflective concentrating photovoltaic module based on silicon solar cells. The optics were designed to mount these modules on 2-axis trackers with angular pointing accuracy of up to about ±4° without significant power loss. The high angular acceptance of the non-imaging optics permits the collection of a high fraction of the circumsolar light impinging on the module's frontal aperture, providing high direct normal irradiance efficiency in real operative conditions. Many technical features of the product are described here, in which features are the result of 5 years of product development in order to improve performance, reliability and cost issues
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
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