1,720,977 research outputs found
Electrochemical oxidation of 3-methylpyridine at a boron-doped diamond electrode: Application to electroorganic synthesis and wastewater treatment
No full textThe electrochemical oxidation of 3-methylpyridine (3-MP) at synthetic boron-doped diamond thin film electrode (BDD) has been studied in acid media by cyclic voltammetry and bulk electrolysis. The results have shown that in the potential region of water stability they can occur direct electron transfer reactions on BDD surface that results in electrode fouling due to the formation of a polymeric film on its surface. While during electrolyses in the potential region of water decomposition, indirect oxidation reactions can take place by electrogenerated active intermediates, probably hydroxyl radicals that can avoid electrode fouling.
Depending on the values of applied current density, it is possible to obtain the partial oxidation of 3-MP to nicotinic acid or the complete combustion of 3-MP to CO2
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
Electrochemical oxidation of phenol at boron-doped diamond electrode. application to electro-organic synthesis and wastewater treatment
No full textElectrochemical oxidation of water on synthetic boron-doped diamond thin film anodes
No full textElectrolysis in aqueous 1 M HClO4 and 1 M H2SO4 solutions has been carried out under galvanostatic conditions using boron-doped diamond electrodes (BDD). Analyses of the oxidation products have shown that in 1 M HClO4 the main reaction is oxygen evolution, while in H2SO4 the main reaction is the formation of H2S2O8. In both electrolytes small amounts of O3 and H2O2 are formed. Finally, a simplified mechanism involving hydroxyl radicals formed by water discharge has been proposed for water oxidation on boron-doped diamond anode
Electrochemical Oxidation of 4-Chlorophenol for wastewater treatment. Definition of Anode Activity Parameter
No full textThe electrochemical behavior of lead dioxide and synthetic boron-doped diamond thin film electrodes ~BDDs! has been studied in acid media containing 4-chlorophenol 4-CP by bulk electrolysis under different experimental conditions. In order to quantify the electrochemical activity of a given electrode, for the electrochemical oxidation of organic compounds ~4-CP!, the current efficiency of the anodic oxidation has been normalized taking into consideration mass-transport limitations. The normalized current efficiency ~f! has been defined as the ratio between the current efficiency of the investigated anode to the current efficiency of an ideal anode which has a very fast oxidation rate, resulting in a complete combustion of organics to carbon dioxide. The results have shown that even if the complete combustion of 4-chlorophenol has been achieved at both lead dioxide and boron-doped diamond anodes, the latter give higher f. The difference in reactivity of the electrogenerated hydroxyl radicals on the anode surface, has been proposed to explain the high f values obtained using boron-doped diamond anodes
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