1,720,967 research outputs found
Thermoelectric power of (Cu<sub>0.5</sub>Tl<sub>0.5</sub>)-1223 superconducting phase added with BaSnO3 nanoparticles
Get PDFIn this study, we report the thermoelectric power (TEP) measurements of Cu0.5Tl0.5Ba2Ca2Cu3O10-δ added with BaSnO3 nanoparticles. BaSnO3 nanoparticles were prepared by chemical co-precipitation method, while (BaSnO3)x/(CuT1)-1223 superconducting samples with 0.00 ≤ x ≤ 1.50 wt% were prepared using the solid-state reaction method. The standard four-probe technique was applied to measure DC electrical resistivity in the temperature range from 300 to 77 K. Superconducting transition temperature (Tc) increases up to 117.5 for x = 0.25 wt.% and then it decreases with further x addition. The TEP coefficient was measured as a function of temperature in a wide temperature range from ∼77 K (liquid nitrogen temperature) up to 280 K using a standard differential technique. The behavior of the obtained TEP coefficient is suit with high-Tc copper-oxide superconductors. The results were investigated according to two-band model with an extra linear term. Several parameters such as the pseudo-gap temperature (T*), Fermi energy (EF) and Fermi temperature (TF) values were calculated and discussed in terms of nanoparticles BaSnO3 addition.1 online resource : illustration
Surface Functionalized Medium Entropy Alloys for Electrochemical Hydrogen Production
No full textA Doctor of Philosophy Dissertation in Materials Science and Engineering by Shahbaz Ahmad entitled, “Surface Functionalized Medium Entropy Alloys for Electrochemical Hydrogen Production”, submitted in October 2024. Dissertation advisors are Dr. Mehmet Egilmez and Dr. Ali S. Alnaser. Soft copy is available (Dissertation, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).This thesis explores non-precious metal-based electrocatalysts, focusing on medium and high entropy alloys (HEAs) like CoCrNi, CoNiV, and CoNi(Cr/V) for the hydrogen and oxygen evolution reactions (HER and OER). These multi-principal element alloys utilize cost-effective transition metals, known for their robustness, corrosion resistance, and structural stability, and are systematically synthesized and characterized here. Analysis confirmed a stable, single-phase face-centered cubic (FCC) crystal structure in these alloys, while electrochemical testing showed that CoNi(Cr/V) achieved a notable overpotential of 50 mV at 10 mA/cm² and a Tafel slope of 48 mV/dec, highlighting its excellent catalytic performance for HER. To expand on this work, equiatomic thin films of NiCoCr, NiCoV, and NiCo(Cr/V) were created via magnetron sputtering. As bifunctional electrocatalysts, these films exhibited remarkable activity for alkaline water splitting, with the NiCo(Cr/V) film performing comparably to platinum-based catalysts (Pt/C) and showing resilience in both acidic and alkaline conditions. These properties make the NiCo(Cr/V) system a promising candidate for sustainable energy applications. Further, laser structuring applied to NiCo(Cr/V) thin films enhanced the electrochemical performance, with the laser-structured LS-NiCo(Cr/V) samples showing improved HER and OER metrics compared to unstructured samples. This finding highlights the value of laser processing in refining both surface properties and electrocatalytic function in medium entropy alloys.In summary, this research showcases the potential of multi-principal element alloys and surface structuring methods for cost-effective, high-performance electrocatalysts in water splitting applications. These innovations enhance the understanding of electrocatalytic mechanisms and pave the way for practical, sustainable hydrogen production solutions, supporting a shift toward cleaner and economically viable energy systems.College of Arts and SciencesMultidisciplinary ProgramsPhD in Materials Science and Engineering (PhD-MSE
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
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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