1,720,960 research outputs found
Strength and morphological behavior of glass-carbon/epoxy hybrid composite plates aging in seawater, engine oil and diesel fuel degradation environment
No full textIn this study, glass/epoxy (GFRP), carbon/epoxy (CFRP) and glass-carbon/epoxy hybrid (GCFRP) composites were aged in seawater, engine oil and diesel fuel degradation environments for 30, 60 and 90 days. The effect of aging environment and time on the structural strength of the composite was examined by applying tensile, three-point bending and low-velocity impact tests to aged composites. Scanning electron microscopy analyses were compared to detect fracture damage occurring in the internal structure of the composites. It was concluded that the degradation environment that most affects the mechanical strength of composites is seawater. Degradation resistance is improved due to the glass/carbon hybridization effect. It has been determined that the glass-carbon hybridization effect in GCFRP composites significantly changes their mechanical strength compared to GFRP and CFRP composites stacked alone. By comparing the glass-carbon hybridization effect in CFRP composites with GFRP and CFRP composites stacked alone, their advantages under different tests are clearly emphasized.Inn niversitesi [1822]; Scientific Research Projects Coordination Unit of Inonu UniversityThe author(s) announced the following financial support for the research of this article: This study was supported by the Scientific Research Projects Coordination Unit of Inonu University (Project ID: 1822)
DRY SLIDING WEAR RESISTANCE OF AGED WOVEN CARBON AND GLASS FIBER-REINFORCED EPOXY MATRIX COMPOSITES IN DIFFERENT DEGRADATION ENVIRONMENTS
Get PDFIn this study, the dry sliding behavior of carbon/epoxy (CFRP) and glass/epoxy (GFRP) composites, aged for 30, 60, and 90 days in artificial seawater, engine oil, and diesel fuel environments, was experimentally tested and compared using the pin-on-disc method. The composites were manufactured using a vacuum-assisted resin transfer molding (VARTM) process, reinforced with RIM 135 epoxy polymer matrix, twill-woven glass fibers, and plain-woven carbon fibers. Wear tests were conducted following the ASTM G99-17 standard. AISI 52100 bearing steel, hardened to 65 HRC, was used as the abrasive disc, and the experiments were performed on a pin-on-disc wear testing device. The dry sliding behavior of the aged composites was examined under 10 N, 20 N, and 30 N loads using the pin-on-disc method. The results indicated that the lowest weight loss occurred in the diesel fuel environment, while the highest weight loss was observed in the engine oil environment. Furthermore, the seawater environment was found to have the least impact on the specific wear rate.Scientific Research Projects Coordination Unit of Inonu University [FDK-2019-1822]The authors gratefully acknowledge that this study was supported by the Scientific Research Projects Coordination Unit of Inonu University (Project ID: FDK-2019-1822)
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
A new approach to the production of partially graded and laminated composite material composed of SiC-reinforced 7039 Al alloy plates at different rates
No full text[Abstract Not Available
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
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
Mechanical behavior of composite pipes joined with non-embedded and embedded adhesive layers
No full textIn this study, the mechanical behavior of composite pipes joined with embedded and non-embedded adhesive layers is investigated. Due to their high resistance, corrosion resistance, repair and lightness, composite materials have been used in industry increasingly. In general, composite pipes are used for the transport of pressurized liquids and gases. Joining processes are performed using many different methods. This study is intended to facilitate the joining process of composite pipes and to increase their applicability. In this study, the development of various bonding methods were investigated using composite pipes and double reinforced structural adhesives. Likewise stress behavior was analyzed. Generally, models with patch and patch quality are found in the literature.In this study by contrast, joining operations will be made easier by means of composite pipe joining models designed using glue without a patch. As a result, time and extra cost savings can be achieved
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