1,721,242 research outputs found
Liquid impact erosion mechanism and theoretical impact stress analysis in TiN-coated steam turbine blade materials
No full textCoating of TiN film was done by reactive magnetron sputter ion plating to improve the liquid impact erosion resistance of steam turbine blade materials, 12Cr steel and Stellite 6B, for nuclear power plant application. TiN-coated blade materials were initially deformed with depressions due to plastic deformation of the ductile substrate. The increase in the curvature in the depressions induced stress concentration with increasing number of impacts, followed by circumferential fracture of the TiN coating due to the circular propagation of cracks. The liquid impact erosion resistance of the blade materials was greatly improved by TiN coating done with the optimum ion plating condition. Damage decreased with increasing TiN coating thickness. According to the theoretical analysis of stresses generated by liquid impact, TiN coating alleviated the impact stress of 12Cr steel and Stellite 6B due to stress attenuation and stress wave reactions such as reflection and transmission at the coating-substrate interface
Investigation of liquid impact erosion for 12Cr steel and Stellite 6B
No full textA study has been made on the liquid impact erosion mechanisms of 12Cr steel and Stellite 6B (Co-28Cr) currently used as steam turbine blade materials. 12Cr steel underwent the transition from ductile to brittle deformation behavior during liquid impacts. Damage started with the formation of isolated hollows. The increase in density and the overlapping of these hollows resulted in surface undulations with repeated impacts. The cumulative liquid impacts produced a work hardened surface, followed by the material loss due to crack formation and propagation. The deformation in Stellite 6B was especially governed by its microstructure. The carbide precipitates were selectively eroded while the precipitate-matrix interface and the precipitate interior acted as initiating sites for cracks. The damage of the cobalt matrix, where the mechanical twins were formed, was much lower than that of the carbide precipitates. (C) 1998 Elsevier Science B.V. All rights reserved
Adhesion and wear properties of TiN films deposited on martensitic stainless steel and Stellite by reactive magnetron sputter ion plating
No full textTiN films were deposited onto the turbine blade materials, AISI 403 martensitic stainless steel and Stellite 6B, using reactive magnetron sputter ion plating. The hardness of the TiN film increases with the residual compressive stress and has a maximum value of 3400 kg/mm(2) at the substrate bias of about -75 V. In the scratch adhesion test, the critical loads for cohesive failure and adhesive failure are sensitively covered by the film hardness. The wear rate decreases with increasing hardness and has a minimum Value at about -75 V. The ion plated TiN has a superior wear resistance than the bare Stellite 6B and AISI 403 martensitic stainless steel. (C) 1998 Elsevier Science B.V
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
Endoplasmic reticulum stress is associated with alpha-synucleinopathy in transgenic mice model.
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