1,720,977 research outputs found
Rheological Modelling of the Bitumen from Reclaimed Asphalt with Rejuvenation and Re-ageing
No full textHot recycling of reclaimed asphalt (RA) in new asphalt concrete (AC) allows achieving large environmental and economic benefits. However, the aged bitumen in RA has a stiff and brittle behaviour, which may lead the AC to premature fatigue, thermal and reflection cracking. In the last years, many researches aimed at studying the effect of ageing on bitumen rheological properties to model the mechanical behaviour of RA. However, how these properties changes in the AC including hot-recycled RA and rejuvenator during its service life is still an object of investigation. The present paper aims at analysing the evolution of the rheological behaviour of the bitumen extracted from RA with rejuvenation (40/60 blending of virgin and RA bitumen, with addition of a rejuvenator) and re-ageing (simulating the service life of the hot recycled AC). RTFOT and PAV devices were used to reproduce bitumen ageing in the laboratory and DSR allowed determining the complex modulus of the binders. The ageing and rejuvenating effects were characterised through the variation of the 2S2P1D model parameters and apparent molecular weight distribution (AMWD). Results proved the efficacy of the rejuvenation process in reducing stiffness and raising the viscous properties of the RA bitumen. After long-term re-ageing (RTFOT + PAV), the rejuvenated RA bitumen showed comparable rheological behaviour with respect to the bitumen initially recovered from RA. However, AMWD analysis showed that the rejuvenator did not adequately disrupt the asphaltene clusters in the aged bitumen
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
A dissipated energy comparison to evaluate fatigue resistance using 2PB
Get PDFFlexural fatigue due to repeated traffic loading is a process of cumulative damage and one of the main failure modes of flexible pavement structures. Typically, micro-cracks originate at the bottom of an asphalt concrete layer due to horizontal tensile strains. Micro-cracking starts to propagate towards the upper layers under repeated loading which can lead to pavement failure.
Different approaches are usually used to characterise fatigue resistance in asphalt mixtures including the phenomenological approach, the fracture mechanics approach and the dissipated energy approach. This paper presents a comparison of fatigue resistance calculated for different dissipated energy models using 2 Point Bending (2PB) at IFSTTAR in Nantes. 2PB tests have been undertaken under different loading and environmental conditions in order to evaluate the properties of the mixtures (stiffness, dissipated energy, fatigue life and healing effect)
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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