1,721,545 research outputs found
Turbulence during H- and L-mode plasmas in the scrape-off layer of the ASDEX Upgrade tokamak
No full textWe present evidence showing that the statistical properties of turbulence in the scrape-off layer (SOL) are not modified in a high-confinement mode (H-mode) inbetween edge-localized modes (ELMs) with respect to a low confinement mode (L-mode). The plasma being in the upper-single null magnetic configuration, the reciprocating probe around the bottom X-point is used to characterize in the same discharge the low and the high-field SOL. In H-mode inbetween ELMs, the average value and the standard deviation of the ion saturation current are found very close to values in L-mode. The normalized standard deviation is found to have the same values as in L-mode independently of the probe position. The probability distribution function is found similar in the two regimes reflecting the fact that the two transport processes, diffusion and convection, are not modified with respect to each other. The power spectra were also found similar, indicating the same distribution of the turbulence intensity among the scales in L- and H-modes. The plasma profiles in the SOL, determined using the lithium beam diagnostic, were found to have the same shape as a function of the radial position also reflecting the non-modification of the transport properties in L- and H-modes. © 2008 IOP Publishing Ltd.Antar GY, 2007, PHYS PLASMAS, V14, DOI 10.1063-1.2424886; Antar GY, 2003, PHYS PLASMAS, V10, P419, DOI 10.1063-1.1536166; Antar GY, 2001, PHYS REV LETT, V87, DOI 10.1103-PhysRevLett.87.065001; Antar GY, 2005, PHYS PLASMAS, V12, DOI 10.1063-1.1953592; Antar GY, 2003, PHYS PLASMAS, V10, P3629, DOI 10.1063-1.1599855; BIGLARI H, 1989, PHYS FLUIDS B-PLASMA, V1, P109, DOI 10.1063-1.859206; Carter TA, 2006, PHYS PLASMAS, V13, DOI 10.1063-1.2158929; Garcia OE, 2005, PHYS PLASMAS, V12, DOI 10.1063-1.2044487; Gruber O, 2001, NUCL FUSION, V41, P1369, DOI 10.1088-0029-5515-41-10-306; Kirk A, 2005, PLASMA PHYS CONTR F, V47, P995, DOI 10.1088-0741-3335-47-7-003; Krasheninnikov SI, 2001, PHYS LETT A, V283, P368, DOI 10.1016-S0375-9601(01)00252-3; Krasheninnikov SI, 2005, PHYS PLASMAS, V12, DOI 10.1063-1.1940061; Kurzan B, 2005, PHYS REV LETT, V95, DOI 10.1103-PhysRevLett.95.145001; Kurzan B, 2007, PLASMA PHYS CONTR F, V49, P825, DOI 10.1088-0741-3335-49-6-010; Moyer RA, 1999, PLASMA PHYS CONTR F, V41, P243, DOI 10.1088-0741-3335-41-2-007; Pigarov AY, 2002, PHYS PLASMAS, V9, P1287, DOI 10.1063-1.1459059; Rudakov DL, 2002, PLASMA PHYS CONTR F, V44, P717, DOI 10.1088-0741-3335-44-6-308; Rudakov DL, 2005, NUCL FUSION, V45, P1589, DOI 10.1088-0029-5515-45-12-014; Tsalas M, 2005, J NUCL MATER, V337, P751, DOI 10.1016-j.jnucmat.2004.09.027; van Milligen BP, 2005, PHYS PLASMAS, V12, DOI 10.1063-1.1884615; WAGNER F, 1982, PHYS REV LETT, V49, P1408, DOI 10.1103-PhysRevLett.49.1408; Xu YH, 2005, PLASMA PHYS CONTR F, V47, P1841, DOI 10.1088-0741-3335-47-10-01438
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
The stability of charged-particle motion in sheared magnetic reversals
Full text linkWe consider the motion of charged particles in a static magnetic reversal with a shear component, which has application for the stability of current sheets, such as in the Earth's geotail and in solar flares. We examine how the topology of the phase space changes as a function of the shear component by. At zero by, the phase space may be characterized by regions of stochastic and regular orbits (KAM surfaces). Numerically, we find that as we vary by, the position of the periodic orbit at the centre of the KAM surfaces changes. We use multiple-timescale perturbation theory to predict this variation analytically. We also find that for some values of by, all the KAM surfaces are destroyed owing to a resonance effect between two timescales, making the phase space globally chaotic. By investigating the stability of the solutions in the vicinity of the fixed point, we are able to predict for what values of by this happens and when the KAM surfaces reappear
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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