1,720,960 research outputs found
Achieving superior grain refinement and mechanical properties in vanadium through high-pressure torsion and subsequent short-term annealing
Get PDFCommercial purity vanadium with an initial grain size of ~27 ?m and a Vickers microhardness of Hv?85 was processed by high-pressure torsion (HPT) under a pressure of 6.0 GPa at room temperature through 1/2 to 10 turns. After processing through 10 turns, some samples were immediately subjected to a short-term annealing (15 min) at different temperatures from 773 to 1173 K. The microstructures developed in HPT and in HPT plus post-HPT annealing were characterized by electron backscatter diffraction (EBSD). Processing by HPT for 10 turns gave a refined grain size of ~410 nm and an increased hardness of Hv?240. Post-HPT annealing demonstrated that the ultrafine grained vanadium has good thermal stability up to at least 873 K. Tensile testing at room temperature gave an ultimate tensile strength of ~920 MPa after 10 turns of HPT with an elongation of ~29%. These results show HPT processing produces superior mechanical properties in vanadium by comparison with processing by ECAP or ECAP plus cryorolling
Silicides and dopants interaction study for advanced technologies in microelectronic : study of the interaction of NiPt-based silicides and the phosphorus
No full textDans le but d’intégrer des technologies CMOS avec des cellules mémoires, une seule étape de siliciuration de tous les contacts permettrait de diminuer les couts et de faciliter l’intégration. La formation de siliciure simultanément au niveau des sources, drains et grilles avec du NiPt(10 at.%) est nécessaire pour la technologie FD-SOI parce que cette dernière induit des spécifications exigeantes en ce qui concerne la siliciuration. En effet, le siliciure formé avec le procédé Salicide se doit d’être très fin et stable pour contenir le phénomène de diffusion anormale du Ni qui pourrait être à l’origine de fuites de la jonction. De plus, la réduction des dimensions des cellules mémoires nécessite l’incorporation de dopants d’une manière alternative à l’implantation ionique. L’introduction de dopage au phosphore de manière in-situ pendant le dépôt de silicium nécessite la compréhension de l’interaction du siliciure et des dopants. Dans cette étude, différents types de dopage sont étudiés dans des substrats mono et poly-cristallins afin de correspondre aux multiples types de silicium qui sont présents dans les technologies et qui nécessitent une siliciuration. La redistribution du phosphore entraînée par la formation du siliciure est étudiée et discutée à l’aide de caractérisations par sonde atomique tomographique et spectrométrie de masse à ionisation secondaire à temps de vol. De plus, la réaction à l’état solide est étudiée à l’aide de diffraction par rayons-X afin de comprendre l’impact des dopants sur la séquence de phases. Finalement, la redistribution des dopants observée expérimentalement est étayée par des simulations basées sur un modèle par éléments finisFor the purpose of co-integrating the CMOS technology with memory cells, a unique step of silicidation of all the contacts would decrease costs and ease the integration. The simultaneous silicide formation on the source, drain and gate contacts with NiPt(10 at.%) is required for the FD-SOI technology because the latter induces challenging specifications for the silicidation. As a matter of fact, the silicide formed with the Salicide process must be very thin and stable to contain the NiSi piping phenomenon that could lead to junction leakage. Meanwhile, new integration roads and the reduction of the dimensions of the memory cells arise the need of other ways of dopant incorporation as a substitute to ionic implantation. The introduction of phosphorus by in-situ doping during the deposition of silicon requires the understanding of the interaction of silicide and dopants with this configuration. In this study the metallization of phosphorus doped Si is presented. Different doping types are investigated with mono and poly-crystalline substrates in order to match the various silicon layers needing a silicidation and present in the technologies. The phosphorus redistribution occurring during silicide formation is studied and discussed thanks to Atom Probe Tomography and Time-of-Flight Secondary Ion Mass Spectrometry analyses. Moreover, the solid-state reaction is studied thanks to X-Ray diffraction to understand the dopants’ impact on the phase sequence. Finally, the dopant redistribution is analyzed thanks to modelin
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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