1,721,345 research outputs found
Prediction of the crack propagation direction in combined static-cyclic multi-axially loaded cruciform specimens
No full textThe prediction of crack propagation due to arbitrary mission profiles is still open to debate. One of the main difficulties is how to predict the mission crack deflection angle reliably. In the present paper, experimental and numerical crack propagation data from cruciform specimens subject to a static load along one arm and a cyclic load along the other are reported. It is shown that, for missions purely in the tensile range, the dominant step criterion leads to a better prediction of the deflection angle than the dominant cycle criterion. For all other types of missions, the dominant cycle criterion should be used
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
Metallisch dichtende Beschichtungen im Armaturenbau
No full textIn almost all industrial sectors, valves are used for the regulation of various media flows, which is why the valve production is one of the most important economic sectors in Germany. However, the valve market is highly competitive. New types of coatings offer the possibility to increase economic efficiency and competitiveness. In this thesis, two concepts are presented for increasing the economic efficiency and competitiveness through the development of thermally sprayed valve coatings. On the one hand, solid lubricants are integrated into established wear protective coatings that are commonly used in valves, and on the other hand, valve coatings that require less post-processing steps are developed. Valves are usually controlled by an actuator, whereby energy is lost in the form of heat during each switching operation. By integrating graphite and hexagonal boron nitride, friction and wear are reduced compared to conventionally used valve coatings. By the use of powders with a finer particle size distribution, near-net-shape coatings have been developed in which the necessary surface quality is achieved by direct polishing, without the need for the cost-intensive grinding process. Abrasion resistance tests show that the developed coatings have a higher wear resistance than conventionally used valve coatings. In the case of solid lubricant containing coatings this increased resistance is attributed to the reduction of shear stresses due to the solid lubricants and in the case of the fine powder coatings due to the higher cohesion of the coating and the more finely dispersed carbides. Electrochemical corrosion, erosion and cavitation tests show that the integration of solid lubricants reduces these resistances. The reason for this is the low cohesion of the solid lubricants and the additionally introduced paths at which the electrolyte can infiltrate the coating. However, a sufficient resistance can be achieved through a process development and the integration of finer solid lubricants. Due to the dense coating structure, the near-net-shape coatings exhibit a higher resistance to erosion, cavitation and corrosion compared to conventionally used valve coatings under the investigated test conditions. A demonstrator test qualified the most promising solid lubricant containing coating for the use in the valve industry
Seminar Härte am 5. November 2013 in der MPA Darmstadt. Härteprüfverfahren und Normen, Bildanalyse und Modernisierung, Umwertung, tragbare Härteprüfgeräte.
No full textVariations 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
Lifetime and microstructural aspects of new single and double layer EB-PVD thermal barrier coatings
No full textEin mechanismenbasiertes Konzept zur Bewertung der Strukturintegrität keramischer Multilagen-Wärmedämmschichten
Full text linkAppropriate 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
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