1,720,958 research outputs found
Cationic UV Curing of Bioderived Epoxy Furan-Based Coatings: Tailoring the Final Properties by in Situ Formation of Hybrid Network and Addition of Monofunctional Monomer
Get PDFBiobased monomers are becoming essential to develop green products to substitute for petroleum-based materials. In this study, biobased monomers, such as furfuryl alcohol and 2,5-furandimethanol, are successfully functionalized with epoxy functional groups producing glycidyl furfuryl alcohol (GFA) and diglycidyl furfuryl alcohol (DGFA), respectively. Herein, DGFA is investigated as an innovative cationic UV-curable monomer for coating applications. An easy tailoring of the properties of the final UV-cured coatings is demonstrated by varying the ratio of DGFA:GFA or creating a hybrid coating by using tetraethyl orthosilicate (TEOS) as a precursor of silica to form an inorganic network. Real-time Fourier transform infrared spectroscopy is used to monitor the cationic photopolymerization of DGFA formulations. Finally, glass transition, contact angle, thermal stability, and mechanical properties are investigated as a function of TEOS and GFA content in DGFA formulations. The thermal mechanical behavior is studied by dynamic mechanical thermal analysis. The thermal properties of the networks are analyzed by dynamic scanning calorimetry and thermogravimetric analysis
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
Etherification of Bio-Based Furanic Compounds via Continuous Flow
Get PDFThe ultimate goal of biorefinery is to move away from a fossil-based industry aiming to a more sustainable one centered on the use of renewable feedstocks. It is well known that numerous bio-based platform chemicals can be obtained from biomass. Among them, 5-hydroxymethylfurfural (HMF) and 2,5-bis(hydroxymethyl)furan (FDCA) – achieved by HMF hydrogenation – are two of the most studied representatives. The etherification of these molecules with different alcohols yields 5-(alkoxymethyl)furfurals (AMFs) and 2,5-bis(alkoxymethyl) furans (BAMFs) respectively, both demonstrating potential application as fuel additives. In addition, HMF, when subjected to self-etherification, leads to 5,5′-[oxybis(methylene)]bis-2-furfural (OBMF), another bio-based monomer of growing interest. In this work, a comprehensive investigation on the etherification of HMF and 2,-5-bis(hydroxymethyl)furan (BHMF) promoted by a commercially available ion exchange resin – Purolite CT275DR – is conducted using a continuous flow apparatus. The reaction conditions are optimized for the etherification of BHMF with ethanol and then extended to achieve a library of BAMFs. In addition, HMF etherification and self-etherification are studied. HMF self-etherification to form OBMF is conducted using dimethyl carbonate in the presence of both heterogeneous and homogeneous acid catalysts. Finally green metrics are calculated for the etherification of BHMF with ethanol and the values are compared to previously published procedures
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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