1,721,277 research outputs found
Lettre de M. F. Berton, M. C. (San-Francisco)
No full textB. A. Lettre de M. F. Berton, M. C. (San-Francisco). In: Le Globe. Revue genevoise de géographie, tome 11, 1872. pp. 147-151
Lettre de M. Francis Berton, M. C. (Californie).
No full textBerton Francis. Lettre de M. Francis Berton, M. C. (Californie).. In: Le Globe. Revue genevoise de géographie, tome 13, 1874. pp. 77-82
Lettre de M. F. Berton, M. C. (San-Francisco)
No full textB. A. Lettre de M. F. Berton, M. C. (San-Francisco). In: Le Globe. Revue genevoise de géographie, tome 11, 1872. pp. 147-151
Influence of Reinforcement Volume Fraction on Fibers Length Reduction in Injection Molding of LGFRT
No full textxLong glass fiber-filled polypropylene composites are widely used in industry because of their low material and production cost combined with excellent mechanical performances and lightness. Mechanical properties of the parts, in particular elastic modulus, strength and impact resistance, strongly depend on the volume fraction of the reinforcement, on the average fiber length and on its distribution and orientation. During the processing of fiber-reinforced thermoplastics, such as in extrusion and injection molding, fibers are subjected to breakage, reducing the average fiber length. The phenomena governing the fiber degradation are very complex to analyze since both materials properties and process parameters play a key role in the fiber fracture mechanisms, which can be divided into three categories of interaction: fiber-fiber interactions, fiber – polymer matrix interactions, and fiber collision with the manufacturing system. The aim of this study is to analyze the influence of the reinforcement volume fraction on the residual fibers length during injection molding. Experimental tests in different process condition were conducted on an injection molding machine, in order to determine the lower degradation induced on the fibers with the increasing of the reinforcement volume fraction. The traditional measurement procedure, that is limited by the field of view of the optical CMM used, was improved in order to measure even the longer fibers. The application of image mosaic techniques allowed to merge different images, bypassing the limit imposed by the instrument
A new procedure for the analysis of fibre breakage after processing of fibre-reinforced thermoplastics
No full textDuring the processing of fibre-reinforced thermoplastics, such as in extrusion and injection moulding, fibre breakage takes place and the average fibre length is reduced. This reduction in length might result in a loss of reinforcement efficiency because the mechanical properties of the composite strongly depend on residual fibre length. For this reason an accurate measure of the fibre length obtained at different process conditions is necessary to relate it with the process parameters. The most used method for determining a fibre length distribution is performed measuring the fibre length by image analysis from micrographs. In the case of thermoplastics reinforced with long fibres, the inability to measure the longer fibres may lead to an underestimation of the average fibre length and thus the correlation between the process parameters and the fibre damage is impaired. In this paper a new procedure is proposed, based on template matching and image mosaic, allowing the measure of fibres of any size. Furthermore this technique allows a researcher to consider all the fibre contained within the specimen. The results obtained with this new procedure is a more accurate estimation of the average fibre length and its distribution even with fibres longer than the available sizes of the micrographs
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
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