1,721,018 research outputs found
Water of functionalized microfibrillated cellulose as foaming agent for the elaboration of poly(lactic acid) biocomposites
No full textThis article presents a study on the foam processing of sustainable biocomposites made of polyl(actic acid) (PLA) and functionalized microfibrillated cellulose (MFC) using water as a foaming agent. MFC contains moisture and can be used as a water carrying agent in a 'green' foaming process. The quantity of water, that is, of foaming agent, was adjusted by chemically modifying the fibrils, changing their surface hydroxyl groups, and thus tailoring their hygroscopicity. Functionalized carboxymethylated and acetylated MFC were processed with PLA in a two-step microextruder and various foams were produced. The thermal behavior of the MFC was fully investigated to determine the amount of available foaming agent. Densities and morphologies of resulting foams were correlated to processing temperatures and to water contents ranging from 3.7 to 98 wt%. A low processing temperature and MFC water content of 9 wt% provided uniform foams with the lowest densities. However, too high water content showed poor foaming efficiency and high densities. The obtained foams were compared with foam processed with a chemical foaming agent, used alone or in combination with the MFC.LTC[Boissard, Carole I. R.; Bourban, Pierre-Etienne; Manson, Jan-Anders E.] Ecole Polytech Fed Lausanne, Lab Technol Composites & Polymeres, CH-1015 Lausanne, Switzerland. Manson, JAE (reprint author), Ecole Polytech Fed Lausanne, Lab Technol Composites & Polymeres, Stn 12, CH-1015 Lausanne, Switzerland [email protected] Document Delivery No.: 795TMCited Reference Count: 52Boissard, Carole I. R. Bourban, Pierre-Etienne Tingaut, Philippe Zimmermann, Tanja Manson, Jan-Anders E.European CommissionThis study was supported by the European Commission under the FP7 project SUSTAINCOMP.Sage publications ltdLondo
Thermal and dynamic mechanical properties of blends of bitumen with metallocene catalyzed polyolefins
Get PDFA high penetration grade bitumen has been blended with up to 50 wt% of two different grades of metallocene catalyzed linear low density polyethylene (m-LLDPE) in order to investigate the potential of these and similar copolymers as a substitute for styrene butadiene styrene triblock copolymers in polymer-modified bitumens (PMB). A continuous polymer-rich phase was observed at m-LLDPE contents as low as 5-10 wt%, along with a significant decrease in the effective glass transition temperature of the PMBs with increasing polymer concentration, suggesting benefits for low temperature flexibility. The m-LLDPE-based PMBs also showed relatively low dynamic shear viscosities up to high polymer contents in the range of temperature and shear rate corresponding to typical PMB processing conditions. However, the presence of bitumen in the m-LLDPE-rich phase led to a significant reduction in the melting points of the m-LLDPE, and softening of the PMBs at temperatures as low as 40-50 degrees C, depending on the composition and the melting point of the pure polymer. PMBs based on the m-LLDPE with the higher melting point remained fully elastic in this temperature range, but at the expense of increased crystallinity and a higher glass transition temperature, which limit improvements in low temperature flexibility. On the other hand, the potentially broad composition and property windows associated with m-LLDPEs suggest considerable scope for the fine tuning of PMB properties by using combinations of different m-LLDPEs and/or other polyolefins as a means to optimize performance.LTC[Spadaro, Chiara; Plummer, Christopher J. G.; Manson, Jan-Anders E.] Ecole Polytech Fed Lausanne, Lab Technol Composites & Polymeres LTC, Stn 12, CH-1015 Lausanne, Switzerland. Plummer, CJG (reprint author), Ecole Polytech Fed Lausanne, Lab Technol Composites & Polymeres LTC, Stn 12, CH-1015 Lausanne, Switzerland [email protected] Document Delivery No.: 824CSCited Reference Count: 39Spadaro, Chiara Plummer, Christopher J. G. Manson, Jan-Anders E.Swiss Innovation Promotion Association (KTI/CTI)The authors wish to acknowledge the financial support of the Swiss Innovation Promotion Association (KTI/CTI).SpringerNew yorkNational Licence
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
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