1,721,020 research outputs found
Tailoring oxygen evolution performances of carbon nitride systems fabricated by electrophoresis through Ag and Au plasma functionalization
No full textThe strategic interest in the production of green hydrogen by sunlight-activated water splitting has stimulated significant efforts aimed at the implementation of active and cost-effective catalysts for the oxygen evolution reaction (OER), the overall process bottleneck. Herein, we report on an original fabrication route to OER electrocatalysts based on graphitic carbon nitride. In particular, the target systems were deposited on conductive glass substrates via a simple electrophoretic technique and functionalized with highly dispersed noble metals (Au, Ag or Au + Ag) in low amounts by radio frequency (RF)-sputtering under mild conditions. An advanced material characterization revealed the possibility of tailoring carbon nitride morphology as a function of the used precursor and of achieving a homogeneous spatial distribution of the functionalizing metals. The latter ranged from atomically dispersed (silver), to low-sized nanoaggregates (gold) or partially alloyed core–shell nanoparticles (gold+silver), with an intimate metal-nitride interfacial contact. Functional tests evidenced a remarkable sensitivity to Vis light even at low applied potentials, and photoelectrocatalytic performances directly dependent on the nature of metal species and on the features of the underlying carbon nitride deposit. These evidences, rationalized mainly on the basis of Schottky junctions and the possible concurrence of surface plasmon resonance (SPR), candidate the proposed strategy as a versatile route to cheap and efficient OER electrocatalysts for energy conversion
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
The Efficient Coupling between MgAlTi Layered Double Hydroxides and Graphitic Carbon Nitride Boosts Vis Light-Assisted Photocatalytic NOx Removal
Get PDFAtmospheric pollution has been recognized as a primary global emergency, especially in large cities and industrial areas. Among the most common harmful pollutants, nitrogen oxides (NOx) are responsible for a plethora of adverse effects, and their effective elimination from air has become an imperative task. In this regard, photocatalysis stands as an attractive technology for NOx degradation, provided that low-cost and efficient visible -light photocatalysts are developed. In this regard, the construction of heterojunctions between energy band-matched semiconductors is an effective strategy to boost the ultimate material photoactivity. In the present study, green heterocomposites based on MgAlTi layered double hydroxides (LDHs) and graphitic carbon nitride (gCN) are prepared using an amenable and cost-effective route. A proper modulation of the system characteristics, as demonstrated by a comprehensive investigation, enabled to obtain very attractive DeNO(x) performances thanks to the efficient construction of MgAlTi/gCN heterojunctions with tailored features. The formation of the target heterocomposites significantly enhances the visible light photoactivity of the pristine LDH, boosting nitrogen monoxide transformation to nitrites/nitrates with a remarkable recycling stability. Overall, the presently reported results open the door to a profitable system exploitation for air purification under real-world conditions, with considerable impact on both human wellbeing and environmental protection
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
Plasma-Assisted Synthesis of Co3O4-Based Electrocatalysts on Ni Foam Substrates for the Oxygen Evolution Reaction
Get PDFElectrocatalytic oxygen evolution reaction (OER) plays a key role in sustainable energy conversion and storage, but is severely hampered by the lack of efficient catalysts, whose development remains a critical and challenging issue. Herein, it is reported for the first time that pure and Fe2O3-containing Co3O4-based OER electrocatalysts are grown on highly porous Ni foams by plasma enhanced-chemical vapor deposition and/or radiofrequency sputtering. Thanks to the inherent advantages of cold plasma synthesis routes, Ni foam supports are efficiently infiltrated by Co3O4 nanostructures and eventually nanosized Fe2O3, allowing a fine-tuning of their mutual content, nano-organization, and oxygen defectivity. For Co3O4-Fe2O3 systems, these issues enable current densities up to ≈120 mA cm−2 at 1.79 V versus the reversible hydrogen electrode, an overpotential of ≈350 mV at 10 mA cm−2 and a Tafel slope as low as 60 mV dec−1, favorably comparing with literature values for most cobalt-based OER catalysts reported so far. Such features, accompanied by a good time stability, represent an important goal for eventual practical applications and candidate the proposed fabrication route as a valuable tool for the design of efficient electrocatalysts with precisely engineered properties and based on naturally abundant transition elements
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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