1,720,982 research outputs found
The application of high temperature superconducting materials to power switches
No full textSuperconducting switches may nd application in superconducting magnet systems that
require energy extraction. Such superconducting switches could be bypass-switches that
are operated in conjunction with a parallel resistor or dump-switches where all of the
energy is dissipated in the switch itself. Bypass-switches are more suited to higher energy
circuits as a portion of the energy can be dissipated in the external dump resistor. Dump-switches
require less material and triggering energy as a lower switch resistance is needed
to achieve the required total dump resistance.Both superconducting bypass-switches and superconducting dump-switches can be thermally
activated. Switching times that are comparable to those obtained with mechanical
bypass-switch systems can be achieved using a co-wound heater that is powered by a capacitor
discharge. Switches that have fast thermal diffusion times through the insulation
can be modelled as a lumped system whereas those with slow thermal diffusion times were
modelled with the full heat diffusion equation.Superconducting switches can be formed of either high temperature superconductors
(HTS) or low temperature superconductors (LTS). Switches based on HTS materials allow
operation at higher temperatures where the cost of cooling is less. Extracting the magnet
energy and depositing the heater energy at higher temperatures will also reduce the load on
the overall cryogenic system during switching and energy extraction. For magnet circuits
that are based on high temperature superconductors the switch must also be formed of
HTS material. Due to the approximately T3 dependence of specific heat capacity, switches
that operate at higher temperatures have slower heat diffusion times and require higher
triggering energies than those operating at low temperature. HTS based dump-switches
and HTS based bypass-switches were tested in liquid nitrogen to show that the required
switching time could be achieved at these high temperatures.The design and optimisation of superconducting switches that were formed of various
superconducting materials were performed for example magnet circuits to provide reference
designs of switches. These example circuits were based on selected Large Hadron Collider
600 A circuits that had a stored energy of 5.5 kJ. Superconducting switches may also nd
application in magnet circuits with higher transport currents and higher energies. The
scaling and suitability of the reference designs to higher energy circuits was also described
Power switches utilizing superconducting material for accelerator magnets
No full textPower switches that utilize superconducting material find application in superconducting systems. They can be used for the protection of magnets as a replacement for warm DC breakers, as well as for the replacement of cold diodes. This paper presents a comparison of switches made of various superconducting materials having transport currents of up to 600 A and switching times of the order of milliseconds. The switches operate in the temperature range 4.2-77 K and utilize stainless steel clad YBCO tape and MgB2 tape with a nickel, copper, and iron matrix. Results from simulations and tests are reported
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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