1,721,157 research outputs found
Trattamento di modifica del Si in leghe Al-Si da fonderia: facciamo il punto
No full textIn questo articolo viene riassunto lo stato dell'arte in materia di trattamenti
Mechanical Properties and Structural Analysis of Coatings and Engineered Surfaces
No full textThe performance improvement in engineering components during operation is a challenging issue and surface engineering methods have been attracting considerable interest in both research and industrial fields [...
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
Efficiency in the correction of Class II division 1 malocclusions with prominent upper incisors and increased overjet: A comparison between two methods
No full textBACKGROUND: The aim of the present study was to evaluate the efficiency and effectiveness of high-pull traction on a Stephenson plate as well as cervical headgear treatments in Class II Division 1 growing subjects with prominent upper teeth and an increased overjet. METHODS: A prospective study was undertaken, involving participants who underwent maxillary correction of Class II malocclusions. Twenty-three patients (Stephenson plate group, SPG, mean age 10.4±0.9 years) were treated and compared with 24 subjects treated with headgear (HGG, mean age 9.6±1.2 years). Lateral cephalograms were analysed using Jarabak and Pancherz analysis. Shapiro-Wilk's and Student's t tests were applied. RESULTS: The SPG showed significant decreases in the overjet (-4.1 versus -0.8 mm) and molar relationship (-6.1 versus -1.5 mm). A significant upper-incisor correction was found in SPG (1/SpP -10.3° versus + 2.2°). SNA (-1.4 versus 0.3°) and WITS (-1 versus 0.3 mm) were reduced in SPG, showing a partial maxillary restraint. In SPG, the overjet correction (4.1 mm) was mainly due to the dental component (65.9%) and occurred almost completely in the maxilla (92.7%); the molar relationships improvement of 6.1 mm was mainly dental (77%); in HGG, the reduction of the overjet was limited (-0.8 mm), and the skeletal maxillary contribution was negligible. CONCLUSIONS: The high-pull traction on the Stephenson plate was more efficient and effective than HG in the treatment of Class II dentoskeletal malocclusions with prominent upper teeth and a severe overjet; the overjet reduction was obtained at approximately 6 months, contributing to the substantial Class II correction
Microstructural and erosive wear characteristics of a high chromium cast iron
No full textSurface material loss due to erosive wear is responsible for the increased cost of main-tenance and downtime in industries. Hence, hardfacing is one of the most valuable and effective techniques employed to improve the wear resistance of heavy-duty components. The present paper investigates the microstructural and erosive wear characteristics of a hypereutectic high-chromium cast iron, considering the erosion resistance, resulting from the impact of micro-sized particles, of both as-received and heat-treated conditions. Micro-sized particles involve the erosion-resistant characteristics of carbide and matrix, contemporary. Due to this, the enhancement of the matrix strength could improve the mechanical support to withstand cracking deformation and spalling. Ac-cordingly, the effect of a destabilization heat treatment on the microstructure was firstly investigated by hardness tests, X-ray diffraction analyses, optical and scanning electron microscopy. Specifically designed erosive tests were carried out using a raw meal powder at an impingement angle of 90◦ . The resulting superior wear resistance of the heat-treated samples was relayed on the improved matrix microstructure: consistent with the observed eroded surfaces, the reduced matrix/carbides hardness difference of the heat-treated material is pivotal in enhancing the erosion resistance of the hardfacing. The present results contribute to a better understanding of the microstructure–property relationships concerning the erosive wear resistance
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