1,720,957 research outputs found
Efficacy of high-performance epoxy resin as a binder to replace eco-unfriendly phenolic resins in Cu-free brake pads
No full textThis research explored high-performance epoxy resin (EPR) for the first time as a binder in the formulation of brake pads to overcome the limitations of phenolic resins (short shelf life, harmful emissions, etc.) and compared them to phenolic pads to determine their potential. EPRs offered higher heat resistance, lower density, post-curing free, and longer shelf life. Brake pads (15%, 20%, and 25% epoxy, and 20 vol% phenolic) were assessed for physical, mechanical, thermal, tribological, and noise - vibration (NV) properties. The findings revealed promising tribological and NV performance for epoxy pads, suggesting EPR has the potential to replace phenolic resins in the friction industry
Eco-friendly Polybenzoxazine (PBZ) resins to address the age-old challenge of replacement of phenolic resins in friction materials
No full textPhenol-formaldehyde resins (Ph-Rs) have been invariably used for the last few decades as a binder/matrix in friction materials (FMs) in the industry owing to the ease of processing, excellent balance of brake-performance properties, commercial availability, and cost. However, Ph-Rs pose persistent environmental concerns due to emissions of harmful volatiles during processing (NH3, formaldehyde), apart from the challenge of limited shelf life (∼2–6 months). The present work aimed to address such issues by exploring the potential of five types of in-house synthesized Polybenzoxazines (PBZ) resins to develop brake pads for passenger cars. The composite brake pads' performance (physical, mechanical, and tribological) was compared with those based on Ph-R containing other identical ingredients in the same amount. PBZ-based brake pads exhibited notable advantages compared to PhR-based ones, such as an 8–87% increase in the fade ratio, a 9–41% higher wear resistance, and a 0.5 to 5.4 dBA reduction in noise levels. Interestingly, dimethyl substituted PBZ (PBZ-dma) based brake-pads showed the best tribological (10% lower sensitivity of μ to speed and pressure, 15–87% higher fade ratio, 35% higher wear resistance) and noise vibration performance (lower vibration and sound pressure levels by 2.8% and 0.51 dBA, respectively) apart from its 7% higher thermal stability and thermomechanical properties (∼67% higher storage modulus and 50% higher tanδ). Present work confirms the potential of PBZs (having unlimited shelf life) as the next-generation binders for FMs with superior braking performance and eco-friendliness
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
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
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