1,720,995 research outputs found
Conceptual study of a compact accelerator-driven neutron source for radioisotope production, boron neutron capture therapy and fast neutron therapy
No full textThe feasibility of a compact accelerator-driven device for the generation of neutron spectra suitable for isotope production by neutron capture, boron neutron capture therapy and fast neutron therapy, is analyzed by Monte Carlo simulations. The device is essentially an extension of the activator proposed by Rubbia [CERN/LHC/97-04(EET)], in which fast neutrons are diffused and moderated within a properly sized lead block. It is shown that by suitable design of the lead block, as well as of additional elements of moderating and shielding materials, one can generate and exploit neutron fluxes with the spectral features required for the above applications. The linear dimensions of the diffusing-moderating device can be limited to about 1 m. A full-scale device for all the above applications would require a fast neutron source of about 10(14) s(-1), which could be produced by a 1 mA, 30 MeV proton beam impinging on a Be target. The concept could be tested at the Frascati Neutron Generator, a source producing 14 MeV DT fusion neutrons at the rate of 10(11) s(-1) and located in a large shielded room. (C) 2002 Elsevier Science B.V. All rights reserved
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
Positive safety impact of Ignitor design modifications
No full textIgnitor is a proposed compact high-magnetic field tokamak aimed at studying plasma burning conditions in deuterium-tritium plasmas. A design revision of the ignitor project lead to the substitution of the graphite tiles with molybdenum ones. The consequences of this substitution from the radiological risk and environmental impact viewpoints are examined, applying a computational model for tritium inventory estimate and for activation calculation. It turns out that the global tritium inventory in the machine is almost halved by this design modification, due to a practically negligible tritium inventory in Mo. Activation of Mo is higher that that of C, however, it remains moderate. Because of this, some of the most relevant accidental sequences see a reduction of releases and of doses to public, due to radioactive source terms reduction. Graphite substitution with Mo in the first wall has therefore a global positive effect on the machine radiological safety
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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