1,720,954 research outputs found
Use of Waste Plastics in Asphalt Mixes: Addressing the Variability of Source
Get PDFUse of waste plastics in asphalt mixtures suffers from a serious problem of significant variability with global sources; preventing proper guidelines for field applications. The aim of this study is to address the variability in source of waste plastic and its impact on asphalt mixture design. The study was designed to provide a selection criterion to evaluate the suitability of waste polyethylene (PE) for asphalt pavements. PE obtained from five sources was used as a replacement for asphalt binder. Dry mixing of plastics with asphalt and aggregate was performed at the dosage levels of 3%, 6%, and 9%. The changes in asphalt mixture volumetrics were correlated to plastic properties such as density(ρ), viscosity (η), melting point (Tm), and Degree of Crystallinity (Xc), apart from source. Construction Densification Index and Traffic Densification Index were also calculated for the workability of PE mixtures. From the calorimeter analysis, the thermal characteristics concluded that even though five PEs irrespective of sources could be categorized as PE, the plastics differed significantly in terms of melting enthalpies with varied Xc and η. The volumetric analysis of plastic modified mixtures conveyed that PE with Xc (65%) and η (\u3e5594 Pa.sec at 165°C) resulted in reduced workability of the mixtures. Such plastics were identified to have filler tendency rather than a binding material in the asphalt mixtures. Finally, PE with Xc value of 65.56% at a dosage of 6% is found to be optimum for designing PE modified mixture, irrespective of source. Overall, the study recommends to address PE in terms of core properties such as Xc and η rather than source or supplier to reduce variability and better understand its suitability in asphalt mixtures
Performance Assessment of Microencapsulated Phase Change Materials with Low to High Thermoregulation Range in Asphalt Binder
Get PDFAsphalt pavements face significant challenges due to low temperature cracking and rutting caused by extreme temperature fluctuations and traffic loading. These issues result in higher maintenance costs and reduced service life of the pavements. To address this, researchers explored the use of Microencapsulated Phase Change Materials (MPCMs) to induce thermoregulation in asphalt pavements. However, the existing research focused on high-temperature performance of binders, highlighting the need of research on evaluating the low-temperature performance. Therefore, the study aims to evaluate the impact of incorporating MPCMs on low to high temperature performance of binders. Three types of MPCMs were incorporated into asphalt binder with melting points of 6°C (MPCM6D), 28°C (MPCM28D) and 37°C (MPCM37D) at varying dosages (5%, 10%, and 20%) using a low shear mixture. The thermoregulation property and performance of binders were studied. Differential scanning calorimeter analysis was conducted to verify thermoregulation properties and assess the survival of capsules during blending. The low temperature cracking resistance was evaluated by measuring creep stiffness and creep rate using Bending Beam Rheometer (BBR). The behavior within and outside MPCMs thermoregulation range was assessed by examining complex shear modulus (G*) change rate through temperature sweep test. The results showed that enthalpy change increased with increase in MPCMs dosage, indicating effective thermoregulation and capsule survival. Due to steady state test conditions, BBR could not able to capture the low temperature performance of MPCM binders. The temperature sweep test indicated that G* change rate was not constant, illustrating that near the melting points, MPCMs could thermoregulate stiffness of binder. In conclusion, outside the thermoregulation range, all MPCMs positively impacted rutting resistance while compromising fatigue and low-temperature cracking attributable to physical interaction of MPCMs with binder. Within the thermoregulation range, MPCM6D and MPCM 28D effectively enhanced low and intermediate temperature cracking resistance whereas MPCM37D enhanced rutting resistance
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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