1,720,973 research outputs found
Corrosion of the zinc negative electrode of zinc–cerium hybrid redox flow batteries in methanesulfonic acid
No full textCorrosion of zinc in aqueous methanesulfonic acid has been evaluated over a wide range of concentrations of acid (0.5–5 mol dm-3), dissolved zinc (0.5–2 mol dm-3), and electrolyte temperature (22–50 °C). The corrosion rate of zinc, in terms of weight loss and the volume of hydrogen evolved, varied with time and it was found to be highly dependent on the surface state and electrolyte conditions. With an initial active layer of zinc present, the corrosion rate rapidly increased following a decline when the proton concentration in the solution decreased to ca. 0.56 mol dm-3. Organic and inorganic inhibitors were added to the electrolyte to suppress the zinc corrosion in 1 mol dm-3methanesulfonic acid. The strong adsorption and blocking effects of cationic organic adsorption inhibitors, such as cetyltrimethyl ammonium bromide and butyltriphenyl phosphonium chloride, led to a significant decrease in zinc corrosion over a 10 h immersion period. With the addition of indium and lead ions inhibitors, the zinc surface showed less activity. Zinc corrosion continued to a smaller extent in the presence of these metallic inhibitors during the first few hours, but the metallic layer of the inhibitors did not cover the surface completely resulting in continued hydrogen evolution and making the inhibitors less effective at longer times
Effect of RVC porosity on the performance of PbO2 composite coatings with titanate nanotubes for the electrochemical oxidation of azo dyes
Full text linkReticulated vitreous carbon (RVC) of different porosities (20, 45, 60, 80, and 100 ppi—pores per inch) has been used as a large surface area substrate for preparing 3D-like PbO2 coatings (RVC/PbO2) as well as composite coatings with hydrothermally synthesized titanate nanotubes (RVC/PbO2/TiNT) by galvanostatic electrodeposition from baths containing lead(II) methanesulfonate and methanesulfonic acid. The effect of the RVC porosity on the coating thickness, the electrocatalytic behaviour and the ability to remove the colour and total organic carbon (TOC) from solutions containing the azo dye Methyl Orange has been systematically assessed. As shown from scanning electron micrographs, the greatest thickness (up to 120 ?m) was obtained using > 60 ppi, but the ?-PbO2 nanocrystallytes mainly grew on the external surface, leaving mostly uncoated inner RVC stripes and ending in planar-like PbO2-based electrodes. In contrast, thinner but perfectly adherent and homogeneous coating of the inner and outer surface was achieved with 20-60 ppi, showing electrodes with an optimal three-dimensionallity. This was especially confirmed by cyclic voltammograms for the composite coatings, as deduced from their highest electroactivity that can be related to enhanced adsorption onto the TiNT clusters and the larger ability to produce active PbO2(radical dotOHOH). The comparative electro-oxidation of 0.25 × 10?3 mol dm?3 Methyl Orange acidic solutions in 0.05 mol dm?3 Na2SO4 at 0.6 A demonstrated that RVC (45 ppi)/PbO2/TiNT was the optimum material. It allowed the quickest decolourisation, reaching 60% in 2.5 min and > 98% at 45 min, and > 55% TOC abatement at 240 min. The anode presented a perfect surface coverage, with no evidence of RVC degradation. The effect of dye concentration and supporting electrolyte nature was studied, revealing a very positive effect of NaCl
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
Decolorization of methyl orange dye at IrO2-SnO2-Sb2O5 coated titanium anodes
No full textA film of iridium and tin dioxides doped with antimony oxide (IrO2-SnO2-Sb2O5) was deposited onto Ti mesh and plate substrates by the Pechini method. The electrode surface morphology and composition were characterized by SEM-EDS. The ternary oxide coating was used for the anodic oxidation of methyl orange (MO) azo dye. Linear sweep voltammetry was used to identify the electrode potentials that favour MO degradation. Batch electrolyses were then carried out at a constant electrode potential of 1.5, 1.75 and 2.0V vs. SHE using either a three-electrode batch cell or a flow reactor. The dye solutions were totally decolorized via reactive oxygen species, such as OH, H2O2 and O3 formed in situ from water oxidation at the Ti/IrO2-SnO2-Sb2O5 surface
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
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