1,721,022 research outputs found
Application of Electrochemical Reactors for Industrial Waste-water Treatment
No full textThe effectiveness of electrochemical reactors for industrial wastewater treatment has been improved since three-dimensional electrodes have been introduced; in fact, limitations of mass transfer can arise, due to the low concentrations of pollutants which may be involved in the process. Three-dimensional electrodes offer a very high electrode area per unit electrode volume and they can act as turbulence promoters or give rise to high linear electrolyte velocity, resulting in high values of mass transport coefficient. However, careful selection of operative parameters is needed in order to obtain high performance. This paper examines the results obtained in our laboratory on the cathodic reduction of copper at RVC electrodes; in particular the interference of dissolved oxygen is studied during the removal of copper from extremely diluted solutions (C < 10 ppm). Some results are also discussed on the removal of organic pollutants by electrochemical oxidation at three-dimensional anode consisting of a fixed bed of carbon pellets
Characterization of rainwater quality from the Veneto region network data using Multiway Data Analysis
No full text
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
Removal of NO-3 from water by electrochemical reduction in different reactor configurations
No full textA series of cathode materials were investigated to establish their performance towards the electrochemical reduction of nitrate ions in\ud
unbuffered aqueous solutions. In particular, Ti/PdO–Co3 O4 (for simplicity Ti/Pd–Co), nanostructured SS/Pd–Cu (Cu content: 15%, w/w), Ti/Pd–Co loaded with small amounts of electrodeposited Cu (Ti/Pd–Co–Cu) electrodes were prepared and studied by using both cyclic voltammetry and exhaustive electrolysis experiments. Cyclic voltammetry was mainly employed to establish the potentials at which the reduction of NO3 and of one of the intermediate reduction products (NO2) occurred at the different materials, and the effect of copper, employed as a promoter, for the nitrate ion reduction. With this respect a bulk copper working electrode was also investigated. Exhaustive electrolysis were performed under stagnant and stirred conditions in either a single-cell batch or membrane reactor, operating at a constant potential. For the latter reactor, a thick Nafion 117 membrane was used to separate the cathodic from the anodic compartment. The experiments showed that good results, in terms of nitrate removal, were obtained by using the membrane reactor equipped with the Ti/Pd–Co–Cu cathode operating at -0.9 V versus SCE, where the nitrate content was lowered from 200 down to 50 mg/L, which represents the upper limit for drinking water. The performance of the various electrodes in the presence of NaClO\ud
4 as base electrolyte in both compartments of the reactor, or NaCl as base electrolyte in the anodic compartment\ud
only, was also investigated in order to simultaneously remove nitrate and ammonia. The latter, which is the main final product formed in the reduction process, diffused through the Nafion membrane into the anodic compartment where it was oxidized by electrogenerated active chlorine.\ud
For the anodic generation of chlorine the Ti/Pt–Ir material was chosen, due to its previously assessed excellent electrocatalytic properties towards this reaction. The current efficiency of nitrate reduction and energy consumption under different conditions were also evaluated
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
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