1,720,997 research outputs found
Synthesis and characterizations of amorphous carbon nanotubes / gold particles hybrid materials / Lim Yu Dian
Full text linkCarbon nanotubes (CNT) have attracted great attentions due to its unique properties. However, most works being carried out focus on crystalline CNT. In this work, amorphous CNT (a-CNT) were synthesized successfully via a simple chemical technique at 220 °C in a short period of time. Surface morphological studies revealed that as prepared nanotubes present in agglomerated tubular structures with open ends, having diameter of 51.6 nm. The diameter of a-CNT reduced to 40 nm upon functionalization with nitric acid and further reduced to 10.2 nm as treated with auric chloride solution due to introduction of defective sites by these treatments. Both structural and elemental studies confirmed that the nanotubes were carbon and amorphous. From zeta potential measurement, it was found that nitric acid served as the most effective oxidation agent in functionalizing a-CNT with carboxyl groups compared to citric, sulphuric, and hydrochloric acids. Oxidation of nanotubes increased dispersion stability and ensured the successful hybridization between the a-CNT and gold (Au) nanoparticles. Thermal stability of a-CNT decreases with decorations of gold particles on its surface as per findings in Thermogravimetry Analysis (TGA). Electrical conduction are proven to be improved by surface modification where functionalized a-CNT has lower electrical resistivity than as-synthesized a-CNT, and the electrical resistivity decreases significantly with increasing gold content. As-synthesized and modified a-CNT/Epoxy composites exhibits lower electrical resistivity when cured in room temperature compared to 15 ºC, where exception was found on functionalized a-CNT. Through transference number measurement, gold particles are found to contribute to the overall electrical conduction via electron conduction
Self-Steerable Propulsion of Disk-Like Micro-Craft with Dual Off-Center Nanoengines
No full textThis paper reports a novel disk-like micro-craft with dual off-center nozzle nanoengines, consisting of three different metals: gold, nickel, and platinum. A bubble propulsion mechanism originating from momentum change induced by the detachment of oxygen bubbles is proposed to elaborate the self-steerable propulsion of the disk-like gold-nickel-platinum micro-craft. The as-proposed micro-craft is fabricated by a layer-by-layer deposition method based on the micro-electro-mechanical systems technology. Herein, the self-steerable propulsion of the fabricated micro-craft dispersed in deionized water with different hydrogen peroxide concentrations is characterized. As a consequence, the speed of the micro-craft is increased with the increment of hydrogen peroxide concentration. In addition, the micro-craft can always move forward linearly.
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
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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