1,720,964 research outputs found
The use of foundry waste sand from investment casting in the production of porcelain tiles
No full textIn this study, the effects of different types of investment casting waste sand were investigated in porcelain tile production in place of clay and kaolin. Dry and firing shrinkages, water absorption, dry and firing strengths and densities of porcelain tile bodies were determined. In addition, color measurements, XRD analysis and SEM analyses of the relevant samples were also investigated. A1, A2, A3, B and C porcelain tiles had higher density, firing shrinkage and firing strength values. However, they had lower water absorption, dry shrinkage and dry strength values than those of the reference porcelain tile. Quartz, mullite and albite were found in all the bodies as main phases and, in addition, zircon phase was determined in bodies in which waste sand was incorporated.Necmettin Erbakan University Scientific Research Projects [191451001]This study was supported by Necmettin Erbakan University Scientific Research Projects under project no: 191451001. Our thanks go to the Ceramic Research Center for their technical support on the experimental studies
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Destructive and non-destructive testing of bronze-waste tire-concrete composites
Get PDFIn this study, the effects of finely-milled bronze and waste tire on the mechanical properties of concrete have been investigated. Approximately 2.5% and 5% by weight for each additive (bronze sawdust and waste tire) were added to dry concrete. The open porosity, density, compressive strength values of cured concrete have been determined. In addition, the Schmidt rebound hammer (SRH) and the ultrasonic pulse velocity (UPV) tests, which are non-destructive test methods, were applied. The microstructure and fracture surfaces of these materials were characterized by scanning electron microscopy (SEM). It was observed that the density of pure concrete was 2.35 g/cm3 while the density was 2.19 g/cm3 for a C+5%B+5%T material. Similarly, pure concrete had an almost three times better compressive strength and a two times better SRH value than those of the C+5%B+5%T material. The density and mechanical properties of concrete materials containing bronze and waste tire decreased due to micro crack formations, weak bonding and deep cracks forming especially between the concrete and additives
Mechanical properties and freeze-thaw resistances of bronze-concrete composites
Get PDFStudies in the literature show that the physical and mechanical properties of concrete could be improved by the incorporation of different kinds of industrial waste, including waste tire rubber and tire steel. Recycling of waste is important for economic gain and to curb environmental problems. In this study, finely ground CuAl10Ni bronze is used to improve the physical and mechanical properties, and freeze-thaw resistances of C30 concrete. The density, cold crushing strength, 3-point bending strength, elastic modulus, toughness, and freeze-thaw resistances of concrete are determined. In addition, the Schmidt Rebound Hammer (SRH) and the ultrasonic pulse velocity (UPV) tests, which are non-destructive test methods, are applied. SEM/EDX analyses are also carried out. It is noted that a more compacted structure of concrete is achieved with the addition of bronze sawdust. Then higher density and strength values are obtained for concretes that are produced by bronze addition. In addition, concretes including bronze sawdust generally show higher toughness due to high plastic energy capacities than pure concrete
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
Effect of precision casting sand waste of 4140 steel on the sintering and densification behaviour of chamotte refractories
No full textIn this study, the sintering behaviour and densifications of chamotte refractories that were produced by incorporation of 4140 precision casting sand waste at different ratios are investigated. Thermal properties are examined using thermogravimetry and differential scanning calorimetry thermal analysis methods. Open porosities and densities of refractories have been determined using Archimedes principles according to ASTM C20. The chemical analysis of raw material and phase analysis of refractories, and also chamotte raw material and sintered chamotte material at 1723 K, are obtained by X-ray fluorescence and X-ray diffraction, respectively. In addition, the changes in microstructure are characterized using a scanning electron microscope. According to the results, chamotte refractory that was produced by 10% 4140 precision casting sand waste has the highest density and lowest open porosity due to the smallest grain size after sintering compared with those of pure (C0) refractory and chamotte refractory with the addition of 20% 4140 precision casting sand waste
- …
