1,721,234 research outputs found
Hybrid hollow silica nanospheres for separation chemistry Influence of synthesis parameters
No full textInternational audienceNowadays, separation of chemical elements is an important stake for many applications. Although liquid-liquid extraction represents the most applied method at industrial scale, it involves many economic and environmental constraints related to the use of large quantities of solvents. There is therefore a growing interest for alternatives as solid-liquid separation and flotation processes which however, require re-designing the actual industrial installations and present limited performances, in terms of extraction capacity and selectivity.This project proposes to evaluate a new approach allowing to maintain the existing separation installations, by replacing the organic phases of liquid-liquid extraction processes, with a porous liquid. Porous liquids were discovered in 2014 by the Oak Ridge Corporation. They are solid materials made up with hollow nanoparticles of silica, that present the particularity to become liquid when grafted with ionic functions. To date, these materials have only been tested for gas separation. Being at the exact junction between liquid-liquid and solid-liquid extraction processes, porous liquids would allow exploiting the advantages of the two processes. Therefore, we propose to form new porous liquids based on various synthesis methods and to test them for extraction at both solid and liquid state. Various synthesis parameters were investigated to control and understand the morphology of the nanospheres as well as their effect on their future extraction properties. Size, shape and homogeneity of the particles could be changed and controlled. To complete this understanding, a Small Angle X-ray Scattering (SAXS) analysis (Fig.1) was done completed by Transmission Electron Microscop
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
Comparison of usual electrode materials in a n,n-trimethylbutylammnium bis (trifluoromethanesulfonyl) imide ionic liquid
Full text linkInternational audienceIonic liquids (ILs) have been studied for two decades as electrolytes for various electrochemical experiments and more specifically for separation and electrodeposition of metals or semiconductors. Among the numerous anions synthesized to design ILs, the bis(trifluoromethanesulfonyl)imide (NTf) anion is commonly used for its electrochemical stability and hydrophobicity. In particular, the combination of short-chained quaternary ammonium cations and the NTf anion gives hydrophobic ILs that have large electrochemical windows (5,0 to 6,0 V) and reasonably low viscosities (20 - 150 mPa.s.) Thus, this family of ILs has become a very common one for electrochemical studies. However, fundamental understanding on the phenomena occurring at the electrode/electrolyte interface in these ILs is still needed in order to select the right electrode material for a given application.The use of electrochemical techniques requires electrodes that are inert in the working potential range. Thus, the present work focusses on a study and comparison of the behavior of three common electrode materials (glassy carbon, platinum and gold) in N-Trimethyl-N-butylammonium bis(trifluoromethanesulfonyl)imide ([N][NTf]). These three materials are commonly considered as totally inert on the electrochemical window of [N][NTf] (-3,0 to +2,7 V vs Fc/Fc), with current densities in the mA range. However, when trying to observe and interpret signals in the uA range, extensive study of phenomena occurring at the electrode/IL interface has to be completed 4,5. Thanks to transient electrochemistry, and by studying the influences of water concentration and acidity in the IL, we could get a better understanding of the different phenomena occurring at the electrode/electrolyte interface. The relative role of the anion was also investigated
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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