1,720,961 research outputs found
Al2O3-platelet reinforced glass matrix composites from a mixture of wastes
No full textWastes consisting of mining residues from feldspar excavation, lime from fume abatement systems of the glass industry and panel glass from dismantled cathode ray tubes have been converted into an opaque fluorine-containing glass, featuring the precipitation of CaF2 crystals just upon cooling. Fine glass powders were added with Al2O3 platelets (from 5% to 15% by vol.) and viscous flow pressureless sintered at 800°C for 1h, leading to dense glass matrix composites. Due the overall mechanical properties, approaching those available for glass-ceramics, coupled with a simple and economical manufacturing procedure, the obtained products could find applications in the building industry and constitute a promising way for the absorption of the investigated wastes
Sintered glass-ceramics from mixtures of wastes
No full textPanel glass from dismantled cathode ray tubes, mining residues from feldspar excavation and lime from fume abatement systems of the glass industry have been employed as raw materials for several glass compositions. The prepared glasses were ground into fine powders and subjected to sintering treatments at low temperatures (880-930°C), with concurrent crystallization, thus obtaining sintered glass-ceramics. The mechanical properties (for example, bending strength exceeding 100 MPa) and the aesthetic appearance of the materials, together with the simplicity of the manufacturing method, are promising for applications in the building industry
La valorizzazione delle risorse turistiche venete
No full texta cura della Giunta Regionale del Venet
Sintered glass-ceramics from mixtures of waste materials
No full textPanel glass from dismantled cathode ray tubes, mining residues from feldspar excavation and lime from fume abatement systems of the glass industry have been employed as raw materials for several glass compositions. The prepared glasses were ground into fine powders and subjected to sintering treatments at low temperatures (880-930°C), with concurrent crystallization, thus obtaining sintered glass-ceramics. The mechanical properties (for example, bending strength exceeding 100 MPa) and the aesthetic appearance of the materials are thought to be promising for applications in the building industry
Sintered sanidine glass-ceramics from industrial wastes
No full textGlass obtained from melting a mixture of industrial wastes (panel glass from dismantled cathode ray tubes, mining residues from feldspar excavation and lime from fume abatement systems of the glass industry) has been employed for the production of sanidine based glass-ceramics. The glass-ceramics were developed by a sintering treatment with concurrent crystallization, from fine powders (<37 μm), at a relatively low temperature (880°C). The enhanced nucleating activity of glass surfaces likely promoted the formation of sanidine, hardly found in glass-ceramics, as the main crystal phase. Due to the achieved mechanical properties (bending strength of about 120 MPa, Vickers’ microhardness exceeding 7 GPa) and aesthetic appearance, resulting from a compact and homogeneous microstructure, the obtained sanidine glass-ceramics may find applications as construction materials
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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