1,720,956 research outputs found
Controlling Epitaxial GaAs[subscript x]P[subscript 1-x]/Si[subscript 1-y]Ge[subscript y] Heterovalent Interfaces
No full textHigh quality epitaxial growth of GaAsP on SiGe templates would allow access to materials and band gaps that would enable novel, high performance devices on Si. However, GaAsP/SiGe interface engineering has proved to be very complex. In this paper, we explore the effects of strain at the heterovalent interface between GaAsP and SiGe alloys on the overall defect morphology.United States. Army Research Office (Grant W911NF-09-1-0222
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Integration of GaAsP alloys on SiGe virtual substrates for Si-based dual-junction solar cells
No full textThesis: Ph. D., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (pages 117-122).Integration of III-V compound semiconductors with silicon is an area that has generated a lot of interest because III-V materials and Si are best suited for different types of devices. Monolithic integration enables the best material to be chosen for each application, enabling new functionalities with the potential of additional miniaturization on a system level. Integration of GaAsP alloys on Si substrates would enable the creation of high efficiency dual-junction solar cells on low cost and light weight Si wafers and would also enable a path for yellow and green light emission devices on a Si platform. Our work focused on the materials integration problems for multiple pathways to integrate GaAsP alloys on Si substrates. We first addressed the direct integration of GaAsP alloys on Si substrates. Our results showed that despite the low lattice-mismatch conditions at the P-rich end of the GaAsP alloy spectrum, it was difficult to achieve thin films low defect density. We proceeded to focus on the integration of GaAsP alloys on Si via the use of SiGe compositionally graded layers. Through a combination of methods we addressed problems related to antiphase disorder and lattice mismatch between GaAsP and SiGe materials system. We demonstrated the epitaxial growth lattice-matched GaAsP on Si₀.₈₈Ge₀.₁₂, Si₀.₅Ge₀.₅, Si₀.₄Ge₀.₆ and Si₀.₃Ge₀.₇ virtual substrates with excellent interface properties. Our studies showed the effects of initiation conditions and intentional strain at the GaAsP/SiGe heterovalent interface. We have established strain-engineering methods at the GaAsP/SiGe heterovalent interface to prevent dislocation loop nucleation and expansion. We were able to attain GaAsP films on Si with a threading dislocation density as low as 1.2x10⁶/cm² . Our GaAsP/SiGe heterovalent interface research advanced the understanding of such structures. We developed methods to fabricate optimized GaAsP tunnel junction film, which would be necessary for any current-matched dual junction solar cell design. Prototype dual-junction GaAsP/Si solar cell test devices showed good preliminary performance characteristics and offer great promise for future devices integrated with the newly developed high quality GaAsP/Si virtual substrates.by Prithu Sharma.Ph. D
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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