1,721,187 research outputs found
Kenneth R. Seddon – A Rock Star of Ionic Liquids
Get PDFAt the beginning of 2018, the world of science lost one of its most unique and influential people. Professor Kenneth R. Seddon was a pioneering chemist, who dedicated his life to the study and promotion of ionic liquids as a broad chemical platform
Improved synthesis of tadalafil using dimethyl carbonate and ionic liquids
No full textAn improved synthesis of tadalafil, a drug for the treatment of male erectile dysfunction, involves the use of safer solvents and reagents as well as a reduced number of steps
“Sweet” ionic liquid gels: materials for sweetening of fuels
No full textThe search for new materials to be used in desulfurisation (sweetening) of fuels is one of the main topics of current research. In this paper, we explored the possibility of using supramolecular gels obtained from the gelation of ionic liquid binary mixtures. Indeed, some ionic liquids are generally known as efficient extraction phases for desulfurisation of fuels. In rare cases, one of their main drawbacks is their partial solubility in the fuel, leading to contamination. Then, their immobilisation due to the formation of a gelatinous network may be a challenge. Ionic liquid gels were obtained by mixing certain [NTf2]−-based ionic liquids (solvents) with the ones of gluconate-based ionic liquids (gelators). Our gelators are derived from renewable sugars, which possess the marked ability to form hydrogen bonds highly favouring gel formation. In this work, for the first time, ionic liquid gels were used to adsorb typical sulfur compounds omnipresent in fuels. Aromatic sulfur contaminants like thiophene, benzothiophene and dibenzothiophene were selected as model compounds. Our ionogels proved to be efficient adsorption phases, particularly in the removal of benzo- and dibenzothiophenes usually claimed to be refractory compounds for both extraction and oxidative desulfurisation processes. The adsorption efficiency was barely affected by volume, but significantly depended on the fuel concentration
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
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