1,720,979 research outputs found
Creep test facility development and creep analysis of braced composite cross arms in 132 kV transmission tower
Get PDFPreviously, most of cross arms in 132 kV latticed suspension towers made of wood timber cross arms to sustain electrical cables and insulators above the ground. However, wood timber cross arms seemed to degrade and fail after 20 years of service due to creep, natural wood defect and attack from natural enemies. This issue has brought the urgency to replace the previous cross arms with pultruded glass fibre reinforced polymer composite (PGFRPC) cross arms due to better strength, lightweight, and low degradability. To date, no study has been conducted on the evaluation of creep properties of cross arms’ material and structure for long-term service application. Moreover, the creep testing facilities specialising in cross arms are still undeveloped to conduct the creep test for outdoor use. Lastly, no research has been conducted on the enhancement of cross arm structure by retrofitting with additional braced arms to improve creep resistance performance. It is reported on the development and characterization of creep responses of PGFRPC cross arms. Initially, a hybrid TRIZ-Morphological Chart-ANP method was implemented to develop the conceptual design for both multi-operation flexural and cantilever beam creep test rigs. From the product design specifications (PDS), concept designs 3 and 5 were selected as the final design concept for multi-operation flexural and cantilever beam creep test rigs, respectively. For three-point flexural creep analysis, it started with quasi-static flexural test and found out the modulus of elasticity of PGFRP almost the same value as Balau wood. In contrast, the flexural strength of pultruded GFRP increases about 72.97 % compared to Balau wood. This finding further established that PGFRP composite permitted better creep resistance as the creep strain increases about 100% in Balau wood as compared to PGFRP composite. This is due to low creep strain and better stability of transition of elastic to viscoelastic phase. These creep results for both wood and composite cross arms were optimized with Findley model, and two general creep equations was generated. For the cantilever beam creep results, it was illustrated that both wood and composite cross arms exhibited less creep strain after retrofitting with additional braced arms. Furthermore, the creep resistance performance for both braced wood and composite cross arms improved about 15 to 21 % higher. This is due to higher structural integrity and more stable elastic transition to viscoelastic phases. Further numerical analyses demonstrated that the stress-independent material exponent exhibited approximately the same values between right and left arms, and higher elastic, and viscoelastic performance for both braced wood and composite cross arms under long-term creep. To summarise, PGFRPC cross arms have been revealed to have better mechanical strength and creep resistance performances, which is suitable to replace wood cross arms. In addition, the enhancement of PGFRPC cross arms by incorporating bracing system contributes to significant improvement of creep resistance and mechanical performances for the current design
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
Effect of kenaf alkalization treatment on morphological and mechanical properties of epoxy/silica/kenaf composite
No full textThe mechanical performance of silica modified epoxy at various concentration of sodium hydroxide for surface treatment of multi-axial kenaf has been analyzed. Epoxy resin with amine hardener was modified with silica powder at 20 phr and toughened by treated kenaf fiber that immerses in various concentrations of sodium hydroxide (NaOH) ranging from 0% to 9% of weight. The composite was analyzed through differential scanning calorimetry (DSC) to ensure complete curing process. The mechanical properties of the composites were analyzed through flexural test, Charpy impact test and DSC to ensure the complete curing process. DSC analysis results show epoxy sample was completely cured at above 73°C that verifies the curing temperature for preparation for the composite. Hence, 3% NaOH treated composite exhibits the best mechanical properties, with 10.6 kJ/m2 of impact strength, 54.1 MPa of flexural strength and 3.5 GPa of flexural modulus. It is due to the improvement of fiber-matrix compatibility. Analysis by SEM also revealed that a cleaner surface of kenaf fiber treated at 3% NaOH shown cleaner surface, thus, in turn, improve surface interaction between fiber and matrix of the composite. The composites produced in this work has high potential to be used in automotive and domestics appliances
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
