1,721,065 research outputs found

    Electromechanical modeling of Nb3Sn superconducting wires subjected to periodic bending strain

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    The transport performance of Nb3 Sn cable-in- conduit conductors (CICCs) depends on the strain distribution along the superconducting filaments determined by the combi- nation of electromagnetic and mechanical forces applied to the strands. Experimental studies on the effect of bending strain were performed at the University of Twente by means of the Test Arrangement for Strain Influence on Strands (TARSIS) facility. The aim of this paper is to verify the agreement between a detailed electromechanical model of the wire and the experimental results obtained in TARSIS. A numerical model of two Nb3Sn internal tin strands was developed, which describes the wire through a distributed parameter nonlinear electrical circuit. The model re- quires a single strand to be discretized into a number of elements, connected by transverse conductances and subjected to a given strain distribution. The strain distribution maps were computed at the École Centrale Paris by means of the MULTIFIL code at different experimental conditions in the TARSIS facility. The simulation results show good agreement with the experimental ones in terms of both critical current and n-value degradation

    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

    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

    Analysis of AC Losses in the ITER Central Solenoid Insert Coil

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    The circle-in-square cable-in-conduit conductor that will be adopted for the 3L module of the ITER Central Solenoid (CS) coil has been recently tested to assess its performance in conditions relevant for the real operation of the magnet. The tests on a ∼43-m-long conductor were performed in the CS Insert Project carried out under the responsibility of the US ITER Domestic Agency, in charge of the CS modules manufacturing. In this paper, we present an evaluation of the ac losses of this conductor aiming at the assessment of the nτ value for the conductor coupling losses. The electromagnetic (EM) and thermal-hydraulic (TH) analysis of these experiments is then performed. A detailed distribution of the coupling losses in the conductor is computed, with the electromagnetic part of the THELMA model. The obtained power density distribution is then input to the TH model (the 4C code) to compute the TH parameters (e.g., the temperature evolution at selected locations along the conductor) during Central Solenoid Model Coil current dumps. The EM/TH model is then validated against experimental data and used to extract relevant information on the conductor ac losses

    Manufacture and Test of the ITER TF Type HTS Current Lead Prototypes

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    High temperature superconducting current leads (HTS-CL) are designed to supply the current to the large superconducting ITER magnets for the operation with reduced heat load to the cryogenic system. The Toroidal field (TF) current leads are the largest with a current capacity of 68 kA each. The Institute of Plasma Physics of the Chinese Academy of Sciences (ASIPP) is responsible for the supply of the current leads based on a design jointly developed with the ITER organization. Before the supply of the TF HTS-CL series, a pair of prototypes was manufactured in 2014 by ASIPP and associated manufacturers according to previously qualified manufacturing procedures. Rigorous quality control measures were developed and applied in preparation for series manufacturing. To verify compliance of the prototypes with the ITER specification, thorough testing was conducted in 2015. The test items under particular scrutiny were: the pressure drop in the counter-flow heat exchanger, the loss of flow accident test after steady state operation at 68 kA current, the so-called overheating time of the HTS module following an induced quench, the electrical resistances of the soldered joints inside the lead assembly (i.e., the low temperature superconducting (LTS) to busbar and the HTS to LTS joints), and the conduction heat load per lead to the 4.5 K end. In this paper, the main manufacturing steps are discussed, and test results are presented and discussed
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