1,721,349 research outputs found
Methane electrochemical oxidation at low temperature on Rh single atom/NiO/V2O5 nanocomposite
No full textThe direct conversion of methane is still a challenge. Here, an enhanced catalyst for direct and selective oxidation of methane at low temperature was prepared by exploiting Rh single atoms, dispersed in a mixed oxides nanocomposite (based on NiO and V2O5). We found that the prepared nanocatalyst can catalyze the selective oxidation of CH4 efficiently to methanol. The maximum methanol production was 5.2 μmol/hcm2 (0.65 mol h−1 g−1) with a current efficiency of 91 %. A negligible production of CO2 (current efficiency of 6%) was the only other product. The methanol molar fraction kept stable for at least 500 min, at 100 mA, and T = 100 °C. The comparative analysis with the literature results highlights the high efficiency of our catalyst in selectively promoting methanol production with high yields and stability, providing a novel pathway for the production of efficient catalysts based on the exploitation of single-atoms dispersed on useful surfaces
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
Study of pumpkin drying through magnetic resonance imaging
Full text linkNuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI) techniques are widely used in food science, mainly because they are non-invasive techniques. MRI, as a non-destructive technique, allows the study of intact samples and without any preparation of the samples before analysis. In food processing, the monitoring of distribution and water content is a consolidated analysis technique, frequently used on the market in order to preserve appropriate nutritional and health characteristics of food according to quality standards. In a food matrix, the variation of the water content is related to the changes in the internal structure and in the physico-chemical properties that occur during the transformation process. In this study MRI technique is used to evaluate the variation of the water content as a function of the drying time. Pumpkin samples are analyzed at four different drying temperatures of 50, 60, 65, and 70°C. The transverse relaxation time, T2, is used to assess the hydration level of the samples by comparing the information extracted from MR images with the drying kinetics measured by gravimetric method. Moreover, T2 maps are used to correlate the change in water distribution with the change in T2 values. The results show that the global weight loss curves obtained with the standard gravimetric method and with the MRI data are in excellent agreement. This work indicates that monitoring changes in the T2 profile of food (i.e., pumpkin) is a useful method for evaluating moisture profiles and changes induced on the sample during the drying process
Magnetic resonance imaging during the templated synthesis of mesoporous TiO2 supporting Pt nanoparticles for MOR
No full textMesoporous TiO2 was prepared, inside "Taurasi" grape skins. The peel impregnation was followed by magnetic resonance imaging, to monitor the transport process in the natural template and the interaction of the solute with the templating structure. Moreover, the prepared mesoporous structure was used to support ultra-small platinum nanoparticles (USNPs), allowing high dispersion and maximizing active metals utilization. USNPs characterization was performed by means of high-resolution analytical transmission electron microscopy, CO-Diffuse Reflectance Infrared Fourier Transform spectroscopy, and X-ray photoelectron spectroscopy. Low Pt loaded TiO2 was then tested in methanol oxidation reactions, showing an excellent behavior: negligible onset potentials (0.06 V) and very high If/Ib ratio (3.85). The results obtained in this work evidence the outstanding performances of the synthesized nano-electrocatalysts
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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