1,720,976 research outputs found
Prediction of Friction and Wear Behavior of Ternary Polycarbonate-Poly(Butylene Terephthalate)/Multiwalled Carbon Nanotubes Polymer Nanocomposites Using Feature Engineering Assisted Machine Learning Algorithms
No full textIn the present work, polycarbonate-poly(butylene terephthalate)/multiwalled carbon nanotubes (PC-PBT/MWCNT) nanocomposites were produced via melt-compounding, extrusion, and molding techniques with nanofiller wt. fractions of 0, 1, 3, 5, and 7 wt %. Nanofiller induced microstructural, mechanical and dry sliding wear property changes were evaluated, and coefficients of friction (COF) and specific wear rate (SWR) responses were predicted by employing machine learning (ML) models with and without feature engineering (FE) integration. One wt % nanofiller addition resulted in 52%, 41%, and 119% increase in tensile modulus, flexural modulus, and impact strength of neat samples, respectively. Nanofiller addition also resulted in up to 52% and 41% enhancement in tensile and flexural moduli, and up to 91% and 22% reduction in SWR and COF values. The lowest COF and SWR were recorded as 0.231 for 1 wt % MWCNT under 10 N and 4.48 (x10-15) m3/Nm for 0.5 wt % MWCNT under 5 N, respectively. Wear data and worn surface analysis results indicate that COF is directly affected by a transfer-film-formation mechanism at the contact interface, whereas SWR is sensitive to a variety of other factors including contact mechanics features. FE-assisted K-Star model demonstrated the highest prediction accuracy (R 2 = 0.96), whereas the highest accuracy without FE was achieved by Lasso model (R 2 = 0.87). The improved accuracy of FE-assisted models is ascribed to their higher robustness against inconsistencies in the data sets.T?rkiye Bilimsel ve Teknolojik Arastirma Kurumu [TUBITAK 1002-A, 123M666, TUBITAK]This research was supported by the TUBITAK 1002-A project (grant no. 123M666). The author gratefully acknowledges the financial support provided by TUBITAK
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
Elevated Temperature Wear Behavior of FeCr Slag Coating as an Alternative Coating Material for Caster Rolls
No full textThe aim of this study is to show that ferrochrome (FeCr) slag, an industrial waste material, can be used as an alternative protective coating material in service conditions for the caster roll surfaces used in the continuous casting line of steelmaking. Atmospheric plasma spray (APS) method was utilized in coating processes. Considering the working conditions of continuous casting production line, the Thermal Barrier Coating (TBC) system was used as a basis for deposition processes. For production of the TBC system, the commercial NiCoCrAlY (Amdry, 45 + 5 mu m) coating powder was initially deposited as metallic bond coat layer onto the surface of AISI 316L substrate, and then FeCr slag layer was successfully deposited as the top coating layer. After the deposition of FeCr slag powder, the resulting coating layer was found to have low porosity with a homogeneous microstructure. Dry sliding wear tests were performed under different loads (7N, 10N and 13N) and temperatures (200, 400 and 600 degrees C) using a ball-on-disc test rig with heating unit. At low loads (7N, 10N) and temperatures (200, 400 degrees C), predominantly spallation type abrasion was observed, while at high load and temperatures (13N, 600 degrees C), the formation of tribolayer and delamination were the dominant wear mechanisms on the surface of FeCr slag coatings. According to the test results, it can be said that FeCr slag powder is a suitable candidate as a protective coating material against adhesive wear at elevated temperatures for caster rolls.TUBITAK (The Scientific and Technological Research Council of Turkey) [113M178]This study was financially supported by TUBITAK (The Scientific and Technological Research Council of Turkey) with project no. 113M178
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
TORSION OF A CIRCULAR ANISOTROPIC BEAM WITH TWO LINEAR CRACKS WEAKENED WITH A CIRCULAR CAVITY
No full textVarious components made of anisotropic materials (plast-mass, glass material, etc.) have been widely used in the production of modern mechanisms and machinery. Precise calculation of these elements, constituting the design, holds great importance. In general, fracture and distribution are essential issues in safety calculations. In this study, torsion of a beam with an S oblast having outer and inner constraints as L-2 and L-1 circles with R-2 and R-1 radii, respectively, is investigated
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