1,720,954 research outputs found
Surface Analysis of Erosion Resistance of Recycled PA 3200 GF Powders Produced by Selective Laser Sintering
No full textThis paper evaluates solid particle erosion (SPE) performance of samples produced via selective laser sintering (SLS) using fully recycled PA 3200 GF material, following ASTM G76-95 standards. For this purpose, six samples (30303 mm3) were printed at 0 degrees, 45 degrees, and 90 degrees in x-y and x-z planes with a 100-mu m layer thickness. SPE tests examined erosion at distinct impact angles (30 degrees, 45 degrees, 60 degrees, 90 degrees) and pressures (1, 2, 3 bars). Results showed higher particle velocities reduced erosion resistance, where 45 degrees x-y plane samples demonstrated superior resistance (erosion rates: 0.050, 0.100, 0.220 mg/g under 1, 2, 3 bars, respectively). The 30 degrees impact angle caused maximum erosion, while 90 degrees had the least. Samples positioned horizontally in the x-y plane were most sensitive to impact angles, with 10 higher erosion sensitivity than others. The study highlights how printing direction significantly affects SPE performance in SLS
Solid Particle Erosion Wear Behaviors Of Recycled Pa 3200 Gf Powders Produced By Selective Laser Sintering Method In Different Abrasive Environmental Conditions
No full textInstitute of Electrical and Electronics Engineers Inc.Additive manufacturing methods have been widely used in applications for material preference in our daily lives, especially by enabling the production of complex geometry materials with precise tolerances. The purpose of being preferred in industrial applications is to produce alternative materials thanks to the Selective Laser Sintering (SLS) production system, which offers additive manufacturing. For this reason, in order to adapt the SLS system to the test samples, samples of 25x25x3mm3 were produced from recycled PA 3200 GF powders to form a layer thickness of 100 μm.As a result of the impact of solid particles (especially aerospace systems, energy conversion plants, jet engines, helicopter rotor blades, etc.) with different properties on the material surface at certain velocity and angles, undesirable deformations occur on the material surface. In addition, this type of wear has a critical importance in the world economy. With this convergence, erosion wear tests were carried out in accordance with the international standard ASTM G76-95, prioritizing that material for the aerospace industry can be exposed to this type of wear thanks to the use of samples produced by additive manufacturing and containing recycling powders.In order to carry out solid particle erosion wear tests, especially for sand and dust effect, for the use of samples produced by SLS method and with a change in printing direction in different environmental conditions, taking into account the particle impact angle of 30°, 60° and 90°, under the influence of abrasive particles with Al2O3, SiO2 and C20 properties and experiments were carried out by modeling the operating conditions of 34 m/s impact velocity. Regardless of the printing direction effect, it was concluded that the highest erosion rate of the test materials in all groups occurred at the impact angle of 30°. Erodent properties also showed a dominant effect on the erosion wear mechanism. Moreover, the tangential and vertical efficiency of the abrasive particle impact have a significant effect on erosion wear. © 2022 IEEE
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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