1,721,095 research outputs found
Valorization of Biomass Gasification Char as Filler in Polymers and Comparison with Carbon Black
No full textChar, the solid residue produced during biomass gasification, is usually treated as a waste with high environmental and economic costs associated to its disposal. However, char shows remarkable properties that make it suitable for a plethora of different applications. In particular, this study aims at investigating the feasibility of using char as filler in polymers for boosting polymer thermal stability and electrical conductivity, and comparing its performances with carbon black (CB), a more traditional carbonaceous filler. Char residues were collected from a commercial biomass gasifier, thoroughly characterized, and compared with CB. Both materials were used in combination with a styrene-ethylene-butylene-styrene (SEBS) matrix for the production of two different compounds, deeply characterized as well. An addition of 44 wt% of char increases the thermal stability of the compound and its electrical conductivity up to 2 x 10(-3)S cm(-1), without interfering with its structure and mechanical properties. Less CB (20 wt%) was needed for obtaining composites with the same electrical conductivity. The findings of this study pave the way for new valorization routes for large amounts of char in cutting-edge applications and present the opportunity to the polymer manufacturing to use a high-available and low-cost substitute for carbon-based fillers
Valorization of Biomass Gasification Char as Filler in Polymers and Comparison with Carbon Black
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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
Photoluminescence properties of YAG:Ce3+,Pr3+ phosphors synthesized via the Pechini method for white LEDs
No full textWe describe a facile route for synthesize
YAG nanophosphors via Pechini-type sol–gel process
for white light-emitting diodes technology. The wettype
synthesis was followed by a heat treatment at
1,000 C for 4 h. We carried out a study of the
luminescent properties of the YAG:Ce,Pr system
varying the concentration of praseodymium from
0.125 to 2 mol% maintaining the quantity of cerium
constant at 2 mol%. The diffractometric analysis
confirmed the purity of the YAG phase. The luminescent
analysis showed the typical Ce3? emission arising
from the 5d ! 4f transitions overlapped with the
sharper Pr3? emissions in the red region of the
spectrum. The presence of energy transfer phenomenon
was confirmed by PLE spectra of the samples
and the appearance of concentration quenching at
0.5 mol% Pr was observed thanks to the decrease both
of the intensity of praseodymium emission and mean
lifetime
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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