1,720,969 research outputs found
In situ interlamellar production of amide-based functional copolymer/clay nanocomposites
No full textFunctional amide-based copolymer/clay nanocomposites were synthesized by in situ radical-initiated interlamellar copolymerization from acrylamide and citraconic anhydride monomers in the presence of organically modified montmorillonite (O-MMT) clay. The structure-property relationships and the effect of O-MMT clay on the properties of the nanocomposites were evaluated using attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, H-1 nuclear magnetic resonance (NMR) spectroscopy and X-ray diffraction (XRD) analysis. The obtained results confirmed the in situ interlamellar production of the nanocomposites by intercalation of comonomers into O-MMT layers from increased basal spacing in the nanocomposites. The chemical structures of the synthesized nanocomposites were also confirmed from the comprehensive analysis of the characteristic bands and peaks of the segments. The effect of three different amounts of O-MMT clay (2, 4, and 6 wt%) loading on the thermal and dynamic mechanical properties was also investigated by thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). All the nanocomposites exhibited improved thermal stability compared to the neat copolymer. These results showed that the nanocomposites containing higher clay content had higher resistance to thermal degradation. The results obtained from this study suggest that these nanocomposites with amide and anhydride functional groups prepared by in situ interlamellar copolymerization may be promising as new high-performance nanomaterials
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
‐Acrylamide) Nanomaterials
No full textIn this work, poly(itaconic anhydride-co-acrylamide) copolymer was synthesized by free radical solution copolymerization and poly(itaconic anhydride-co-acrylamide)/nanoclay nanocomposites were prepared by in situ interlamellar copolymerization with three different loading of nanoclay. Intercalation and formation of nanostructures were clarified by spectroscopic techniques. The interaction/compatibility between nanoclay and the copolymer was verified by following the characteristic bands of nanoclay and functional groups in the ATR-FTIR spectra. The increase in d-spacing between silicate layers in nanocomposites was determined from XRD analysis. The thermal and viscoelastic properties of nanomaterials and the effect of simultaneous addition of nanofiller were evaluated by thermogravimetric and dynamic mechanical analysis. It was observed that nanocomposites reinforced with nanoclay had higher thermal stability than pristine poly(itaconic anhydride-co-acrylamide) and thermal stability increased proportionally with amount of nanoclay loaded. The improvement effect of the incorporated nanoclay on the storage modulus was observed at higher temperature values for the nanocomposite loaded with 4 % nanoclay
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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