1,721,000 research outputs found
Hierarchical oxygen rich-carbon nanorods: Efficient and durable electrode for all-vanadium redox flow batteries
No full textWe describe the fabrication of hierarchical oxygen and nitrogen enriched-carbon electrode materials from zein and polyacrylonitrile by a simple electrospinning technique for durable and high rate all-vanadium redox flow batteries (VRBs). The nitrogen-doped carbon nanorods (NCNR) provide abundant oxygen-rich and nitrogen active sites, and thereby, enhancing the catalytic activity toward both VO2+/VO2+ and V2+/V3+ ion redox reactions by improving ion transfer kinetics and faster electron transfer rate in VRB. With improving electrocatalytic properties, the NCNR decorating carbon felt electrode (NCNR/CF) exhibits excellent battery performance with an impressive specific capacity of 37.3 Ah L−1 than pristine CF (22.8 Ah L−1) and CNR/CF (28.6 Ah L−1) electrodes. The NCNR/CF electrode also shows an outstanding coulombic efficiency (CE, 98.9%) and energy efficiency (EE, 84.3%) compared with the pristine CF (CE, 91.2% and EE, 73.4%) and the CNR/CF (CE, 95.6% and EE, 81.2%) electrodes in the VRB at 40 mA cm−2 current density. Furthermore, the NCNR/CF electrode exhibits 10.9 and 3.1% higher EE as compared to the pristine CF and CNR/CF electrodes, respectively. Therefore, the impressive cyclic rate capability with negligible capacity decay proves the superiority of NCNR as a potential electrode material for all-vanadium redox flow batteries. © 2019 Elsevier B.V.1
KOH/NaOH‐activated carbon
No full textActivated carbons (ACs) are porous carbonaceous materials with high surface-to-volume ratios and improved chemical functionality. The physical and chemical properties of ACs and their performance in various technologies such as energy storage, solar cells, catalysis, and gas adsorption/separation is highly dependent on the carbon precursors and the activation/carbonization methods. Among the carbon precursors, biomass has become the essential precursor for producing ACs because it is renewable, low-cost, and readily available. The carbonization and activation of biomass precursors are usually performed via physical, chemical, mechanical, and electrochemical approaches. So far, many chemical activating agents (acidic, basic, and neutral) have been reported to synthesize ACs from biomass. This is because chemical activation offers the advantages of kinetic-controlled chemical reactions, low-activation temperature, and low cost. In particular, basic KOH and NaOH are widely used for synthesizing biomass-derived ACs, which are used in electrochemical supercapacitors (ESCs) and other potential applications. This chapter comprehensively discusses the general characteristics, methods, advantages, and imitations of ACs prepared from biomass and activated with KOH and NaOH activators by highlighting the fundamentals of ACs. Finally, the application and the performance of ACs produced by KOH and NaOH activation for ESCs application are discussed
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
Immunosensing Microchip Using Fast and Selective Preparation of an Iridium Oxide Nanoparticle-Based Pseudoreference Electrode
No full textIridium oxide (IrO(x)) electrodes have been used as pseudoreference electrodes operating in buffered solutions, but their preparation requires a time-consuming procedure. Here we report a simple, fast, and selective preparation of an IrO(x) pseudoreference electrode based on the deposition of presynthesized IrO(x) nanoparticles. The reference electrode is applied to an immunosensing microchip consisting of a patterned poly(dimethylsiloxane) plate and an indium-tin oxide-micropatterned glass. The sequence of microfabrication is optimized to accomplish better performance. The microchip is operated by capillary-driven microfluidic controls and used for detecting a target mouse IgG. The measured detection limit in the microchip is ca. 10 pg/mL
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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