1,720,988 research outputs found
UV-cured transparent magnetic polymer nanocomposites
No full textMagnetite nanoparticles are synthesized by thermal decomposition of Fe(acac)3 and subsequently coated with a silica shell exploiting a water-in-oil synthetic procedure. The as-produced nanopowder is mixed with a photocurable hyperbranched resin and the polymerization process is studied by means of real-time FTIR (RT-FTIR). Owing to the presence of the silica shell, the photocuring ability of the systems containing core-shell structures is highly improved compared with that of the formulations filled with bare magnetite nanoparticles, allowing the efficient polymerization of a 100 μm-thick film loaded with an unprecedented 8 vol% of magnetic filler
A fast low-temperature micromolding process for hydrophilic microfluidic devices using UV-curable acrylated hyperbranched polymers
No full textA novel UV- curable low- stress hyperbranched polymer ( HBP) micromolding process is presented for the fast and low- temperature fabrication of hydrophilic microfluidic devices. Process, material and surface properties of the acrylated polyether HBP are also characterized and compared to those of polydimethylsiloxane ( PDMS) and cyclic olefin copolymers ( COC). The HBP dispensed on a PDMS master was cured at room temperature using a 3 min UV exposure at the intensity of 22.2 mW cm(-2). Thermal, mechanical and surface properties of the micromolded HBP structures have been characterized and resulted in a glass transition temperature of 55 degrees C, Young's modulus of 770 MPa and hydrophilic surface having a water contact angle of 54 degrees. Micromolding of 33 mu m thick HBP microstructures has been demonstrated. We achieved 14.5 mu m wide vertical walls, 14.7 mu m wide fluidic channels, 24.1 mu m-wide square pillars and 53.4 mu m wide square holes. A microfluidic network device, composed of microfluidic channels and reservoirs, was fabricated and its microfluidic performance has been verified by a fluidic test
Acrylated hyperbranched polymer photoresist for ultra-thick and low-stress high aspect ratio micropatterns
No full textDifferent photocurable acrylates, including two hyperbranched monomers, are compared with an epoxy negative-tone photoresist (SU-8) with respect to their suitability for the fabrication of ultra-thick polymer microstructures in a photolithographic process. To this end, a resolution pattern was used and key parameters, such as the maximum attainable thickness and aspect ratio, the minimum resolution and the processing time were determined. Compared to SU-8, all acrylate materials allowed the fabrication of thicker layers with a fast single layer fabrication procedure. Microstructures with thicknesses of up to 850 mu m, an aspect ratio of up to 7.7, a 5.5-fold reduction in internal stress and a 6-fold reduction in processing time compared to SU-8 were demonstrated using an acrylated hyperbranched polyether. The specific development process of the hyperbranched polymer combined with channel design moreover enabled us to produce a high-performance valve for micro-battery devices
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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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