1,720,956 research outputs found
Spin-density-wave behaviour of the (Cr100-xAlx)95Mo5 alloy system
No full textProceedings of South African Institute of Physics (SAIP), 2011. The 56th annual conference of the South African Institute of Physics,Electrical resistivity, Seebeck coefficient and specific heat measurements on a
(Cr100-xAlx)95Mo5, 0 8.1 at.% Al alloy system are reported. The results indicate two
possible quantum critical points in the magnetic phase diagram of this system. One is an
incommensurate spin-density-wave ? paramagnetic quantum critical point situated at
1.5 at.% Al and the other a paramagnetic ? commensurate spin-density-wave critical point
at 5 at.% Al. We forward experimental evidence that this system harbours two
spin-density-wave related quantum critical points which presents an unusually rich case study
for magnetic quantum criticality of the itinerant kind.,South African National Research Foundatio
Magnetic properties of the (Cr -xAlx) V alloy system
No full textProceedings of the South African Institute of Physics (SAIP), 2013. The 58th annual conference of the South African Institute of Physics,Electrical resistivity (?), Seebeck coefficient (S) and magnetic susceptibility (?)
measurements as a function of temperature on the (Cr -xAlx) V alloy system, with 0 < x
are reported. N?el temperatures (TN) obtained from all these measurements decrease with Al
concentration, disappearing near x ? 1.5, again reappearing for x ? . ?(T) and S(T) for
samples with x ? 6.1 show weak anomalies making the determination of TN difficult. However,
these anomalies are sharply defined in ?(T), proving that it is an important tool in probing
antiferromagnetic in this system. The present results show that the addition of just 1 at.% V to
the Cr -xAlx alloy system suppresses antiferromagnetism in the concentration range
5 ? x ? . This behaviour is similar to that observed for the (Cr -xAlx) 5Mo5 alloy system
Magnetic susceptibility studies of the (Cr98.4Al1.6)100-x Mox alloy System
No full textProceedings of the South African Institute of Physics (SAIP), 2014. The 59th annual conference of the South African Institute of Physics.,The magnetic susceptibility as a function of temperature, ??(??), on a spin-densitywave
antiferromagnetic (Cr98.4Al1.6)100-xMox alloy system in the concentration range 0 ? x ? 8.8
is reported in order to investigate the possibility of quantum critical behaviour in this alloy
system. N?el temperatures, TN, obtained from ??(??) measurements decrease with Mo
concentration and sharply tend towards 0 K at a critical concentration xc ? 4.5.
Antiferromagnetism is suppressed to below 4 K in alloys with x ? 4.5. Alloys in the
concentration range 0 ? x ? 3.0 depict an upturn in the ??(??) curves just above the N?el
temperature. The upturn is attributed to local magnetic moments formed around the impurity
atoms. The magnetic phase diagram of the alloy system points towards the existence of a
quantum critical point at the critical concentration x = xc. The suggestion of quantum critical
behaviour in this alloy system from previous electrical resistivity(??), Seebeck coefficient (??)
and specific heat (??p) measurements is corroborated in this study.,South African National Research Foundatio
Spin-density-wave effects and quantum critical behaviour of the (Cr98.4Al1.6)100-xMox, (Cr100-yAly)95Mo5 and (Cr100-zAlz)99V1 alloy systems
No full textAbstract: Please refer to full text to view abstractPh.D. (Physics
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
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