1,721,352 research outputs found
Doping-induced disorder and conductivity anisotropy in the spin density wave state of iron pnictides
No full textWe examine the role of doped impurity atoms on the conductivity anisotropy of the spin-density wave state in
iron pnictides. The conductivity is calculated in a self-consistent spin-density wave state with random impurities
in a two-orbital model. We find that the increase in impurity concentration leads to an increased suppression of
conductivity in both the antiferromagnetic and ferromagnetic directions. However, the conductivity anisotropy is
larger in comparison to the Drude-weight anisotropy in the hole-doped regions. The difference between the two
is explained in terms of the anisotropic scattering by the impurities. We demonstrate the effect of the anisotropic
impurity scattering by calculating the modulation in the density of states introduced by a single impurity. It is also
shown that an increase in the Drude-weight anisotropy with changing carrier concentration, which results mainly
from the reconstructed band characteristics, may be directly linked to a similar anisotropy in the density-of-states
modulation caused by the impurity atom.11Nsciescopu
Design of inflatable lunar structure
No full textNASA and other space agencies are now looking to create a lunar settlement for the continued exploration of Moon and beyond. The most challenging aspect of a lunar settlement is its construction, and the weight and size of building materials brought from Earth. In-Situ Resource Utilization (ISRU) and inflatable structures are considered to be the most preferred way for the fabrication of a lunar settlement because they minimize weight and size. The use and performance of inflatables and flexible structures in space applications have been increased in the recent past due to the technological advancements in materials technology. So, we propose the concept of two-tier semi-rigid inflatable structure where the base is built with the help of autonomous robots using ISRU, and the main inflatable structure is manufactured on Earth and inflated on the lunar surface. Also, magnesium is proposed as the base material as it is the most abundantly available structural-strength material in lunar environment, and it is relatively easy to machine. A hemispherical inflatable structure placed on top of a cylindrical base with regolith shielding around the structure is considered as a possible lunar design as well as the test prototype. A static analysis is first conducted on the proposed design using ANSYS, and the stress values are order-of-magnitude verified with simple calculations that prove the possibility of the material and model. Also, an order-of-magnitude analysis is conducted on meteoroid impact loads where we estimate the maximum size of meteoroid that our structure can sustain. As future work, we suggest the framework known as Performance Based Engineering. We had spent some time attempting to use this framework for a simplified lunar structural analysis. However, large data gaps precluded significant progress. But we include it as one of our future research topics.M.S.Includes bibliographical referencesby Dheeraj Kumar Kaj
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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