1,720,962 research outputs found
Preparation and Properties of Glass-Ceramic Materials obtained by recycling, goethite industrial waste
No full textGres porcelanico: aplicaciones arquitectonicas, procesado ypropiedades fisico - mecanicas [Porcelainized stoneware: architectural, processing and physico-mechanical properties]
Full text linkPorcelainized stoneware is an extremely hard and homogeneous unglazed ceramic material obtained by fast-firing of kaolinitic ceramic bodies containing a large amount of fluxes. The obtained tiles, available in a large variety of colours, shape size and surface finish, are characterized by very low porosity (<0.3wt% expressed as wafer absorption) and are ideal for heavy-traffic areas subject to mechanical and chemical stresses. Porcelainized stoneware tiles offer alternative valid (and in many cases necessary) solutions to the traditional glazed tiles either for interiors or for exteriors both in modem or classic constructions for flooring and covering.Porcelainized stoneware is an extremely hard and homogeneous unglazed ceramic material obtained by fast-firing of kaolinitic ceramic bodies containing a large amount of fluxes. The obtained tiles, available in a large variety of colours, shape size and surface finish, are characterized by very low porosity (<0.3wt% expressed as wafer absorption) and are ideal for heavy-traffic areas subject to mechanical and chemical stresses. Porcelainized stoneware tiles offer alternative valid (and in many cases necessary) solutions to the traditional glazed tiles either for interiors or for exteriors both in modem or classic constructions for flooring and covering.El gres porcelanico es un material ceramico muy duro yhomogeneo, no vidriado en su superficie, obtenido porcoccion rapida de composiciones ricas en caolinita,conteniendo una gran cantidad de fundentes. Las plaquetasde pavimentos que se obtienen son de una variedad muyextensa en aspectos, disenos y colores, caracterizandose,fundamentalmente, por su muy baja porosidad (<0,3wt%,expresado en porcentaje de capacidad de absorcion deagua). Estos material es son ideal es para trafico pesado enareas sujetas a intensas tensiones mecanicas y quimicas. Elgres porcelanico ofrece altemativas vdlidas (y, en muchoscasos, soluciones necesarias) a los pavimentos vidriadostradicionales, en interiores o para usos exteriores, amboscon decoraciones modernas o clasicas para suelos orecubrimientos de paredes
Valorisation of different granite residues in self-compacting mortar
No full textWith the publication, in September 2002, of the European standard EN 12620 titled “Aggregates for concrete”, the chance for concrete producers to work with aggregates of high and certified quality has been definitely assessed. However, for the first time, EN 12620 takes into account that aggregates for cementitious conglomerates must not derive only from natural sources, but also from industrial or recycled materials processing. Accordingly, many researches in the field of valorization and characterization of wastes that could be re-used as aggregates are currently running and the possibility to use residues or industrial by-products as filler for self compacting conglomerates (SCC), instead of traditionally used calcium carbonate, appears particularly attractive. In this paper the feasibility to use Hispanic granite sawing residues as filler for self compacting mortar has been investigated and compared to previous results obtained with granite by-products coming from raw materials treatments for ceramic products. Mechanical properties and microstructure of the new conglomerates is discussed
Properties and applications of high iron content glass-ceramics obtained from recycling of goethite wastes.
No full text
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
Design, obtainment and properties of glasses and glass-ceramics from coal fly ash
No full textGlasses and glass-ceramics were obtained by mixing up to 50 wt% of Italian or Spanish coal fly ash with other wastes (glass cullet and float dolomite). The behaviour of 10 compositions was investigated by thermal (DTA) and mineralogical (XRD) analysis, microstructural (SEM) characterization, mechanical and chemical measurements. It was verified that the contribution of the alkaline-earth elements in the original composition is fundamental to easily obtain glass-ceramics with a fine microstructure which improves the mechanical properties. Otherwise, with a small addition of Ay ash and without dolomite, very stable glassy materials were obtained that did not exhibit any visible etching either in water or in acid media. Therefore, the combined vitrification/devitrification technique is a suitable methodology for the recycling and exploitation of coal fly ash. (C) 1998 Elsevier Science Ltd. All rights reserved
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