1,721,058 research outputs found
Superconducting properties of zinc substitution in Tl-2223 phase
No full textThe effect of partial replacement of copper by zinc in Tl2Ba2Ca2Cu3O10-δ superconductor phase is studied. Superconducting samples of the nominal composition Tl2Ba2Ca2Cu3-xZnx O10-δ with x ranging from 0 to 0.6 are prepared under normal pressure by a one step of solid-state reaction technique. The samples are characterized by using X-ray powder diffraction, scanning electron microscope (SEM) and EDX. The X-ray data indicate that the partial replacement of Cu2+ions by Zn2+ions does not influence the tetragonal structure of the samples, and the lattice parameters a and c vary according to the difference in the ionic radii of Cu and Zn. The superconducting parameters, such as superconducting transition temperature Tc, critical current density Jc and irreversibility field Bir are calculated from electrical resistivity and AC-magnetic susceptibility measurements. © 2007 Elsevier B.V. All rights reserved.Abou-Aly A.I., 2002, INT C RES TRENDS SCI, V91; ADACHI S, 1990, PHYSICA C, V111, P543; Awad R, 2000, PHYSICA C, V341, P685, DOI 10.1016-S0921-4534(00)00650-X; Awad R, 2007, SUPERCOND SCI TECH, V20, P401, DOI 10.1088-0953-2048-20-4-017; Awad R, 2001, PHYSICA B, V307, P72, DOI 10.1016-S0921-4526(01)00971-1; Batista-Leyva AJ, 2003, SUPERCOND SCI TECH, V16, P857, DOI 10.1088-0953-2048-16-8-305; BEAN CP, 1964, REV MOD PHYS, V36, P31, DOI 10.1103-RevModPhys.36.31; BERKLEY DD, 1993, PHYS REV B, V47, P5524, DOI 10.1103-PhysRevB.47.5524; CHEN DX, 1990, PHYSICA C, V167, P317, DOI 10.1016-0921-4534(90)90349-J; Chu SY, 2000, PHYSICA C, V337, P229, DOI 10.1016-S0921-4534(00)00107-6; Fradina IA, 1999, PHYSICA C, V311, P81, DOI 10.1016-S0921-4534(98)00563-2; Glowacki BA, 1997, CRYOGENICS, V37, P609, DOI 10.1016-S0011-2275(97)00053-2; HAZEN RM, 1988, PHYS REV LETT, V60, P1657, DOI 10.1103-PhysRevLett.60.1657; Isber S, 2005, SUPERCOND SCI TECH, V18, P311, DOI 10.1088-0953-2048-18-3-018; Isber S, 2006, J PHYS CONF SER, V43, P450, DOI 10.1088-1742-6596-43-1-112; Kayed TS, 2003, CRYST RES TECHNOL, V38, P946, DOI 10.1002-crat.200310118; Kuhberger M, 2003, PHYSICA C, V390, P263, DOI 10.1016-S0921-4534(03)00706-8; LEE MW, 1995, PHYSICA C, V245, P6, DOI 10.1016-0921-4534(95)00100-X; Mezzetti E, 2000, PHYSICA C, V332, P115, DOI 10.1016-S0921-4534(00)00008-3; MOHAMMED NH, 2005, ARAB INT C REC ADV P, P9; Nishida A, 2003, PHYSICA C, V392, P349, DOI 10.1016-S0921-4534(03)00848-7; Pavard S, 1999, PHYSICA C, V316, P198, DOI 10.1016-S0921-4534(99)00259-2; Ravi S, 2000, PHYSICA C, V330, P58, DOI 10.1016-S0921-4534(99)00611-5; REN ZF, 1991, PHYSICA C, V184, P24, DOI 10.1016-0921-4534(91)91496-Q; RUCKENSTEIN E, 1989, MATER LETT, V8, P421, DOI 10.1016-0167-577X(89)90065-7; Tang H, 1997, PHYSICA C, V282, P2111, DOI 10.1016-S0921-4534(97)01171-4; Triscone G, 1996, PHYSICA C, V264, P233, DOI 10.1016-0921-4534(96)00262-6; VANDERAH TA, 1992, CHEM SUPERCONDUCTOR, P90; WANG YB, 1993, J LOW TEMP PHYS, V15, P169; WESTERHOLT K, 1989, PHYS REV B, V39, P11680, DOI 10.1103-PhysRevB.39.11680; Wisniewski A, 2000, PHYS REV B, V61, P791, DOI 10.1103-PhysRevB.61.791; XU YW, 1990, PHYSICA C, V169, P205, DOI 10.1016-0921-4534(90)90177-G; Yamauchi H, 1998, SUPERCOND SCI TECH, V11, P1006, DOI 10.1088-0953-2048-11-10-022; Yang Li, 1994, Physics Letters A, V18543
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
Superconducting properties of Tl-2223 phase substituted by iron
No full textBulk superconducting samples of type Tl2Ba2Ca 2Cu3-xFexO10-δ; with 0 x 0.4, have been prepared using a single step of solid-state reaction. The prepared samples have been characterized using X-ray powder diffraction (XRD), scanning electron microscope (SEM) and microprobe analysis (MPA). The tetragonal structure of Tl-2223 did not change with the partial replacement of Cu 2+ by Fe3+ ions, whereas the lattice parameters were found to vary as function of Fe-content. The superconducting transition temperature Tc determined from electrical resistivity and ac magnetic susceptibility measurements shows suppression in its value as Fecontent increases. The suppression in Tc was attributed to the magnetic disorder and Cooperpairs breaking. The critical current density Jc and field irreversibility Bir were calculated as function of Fe-content. © 2006 IOP Publishing Ltd.Abou-Aly A. I., 2002, INT C RES TRENDS SCI, P91; Awad R, 2000, PHYSICA C, V341, P685, DOI 10.1016-S0921-4534(00)00650-X; Awad R, 2001, PHYSICA B, V307, P72, DOI 10.1016-S0921-4526(01)00971-1; BEAN CP, 1964, REV MOD PHYS, V36, P31, DOI 10.1103-RevModPhys.36.31; ESKES H, 1988, PHYS REV LETT, V61, P1415, DOI 10.1103-PhysRevLett.61.1415; GOTO T, 1997, PHYSICA C, V263, P8750; Isber S, 2005, SUPERCOND SCI TECH, V18, P311, DOI 10.1088-0953-2048-18-3-018; Koo JH, 2003, J PHYS-CONDENS MAT, V15, pL729, DOI 10.1088-0953-8984-15-46-L03; Li Y, 1999, PHYSICA C, V315, P129, DOI 10.1016-S0921-4534(99)00209-9; SIEGAD MP, 1997, J MATER RES, V12, P1421; WESTERHOLT K, 1989, PHYS REV B, V39, P11680, DOI 10.1103-PhysRevB.39.1168022
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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