1,720,962 research outputs found
Use of Deep Eutectic Solvents (DESs) for the Preparation of Thermoelectric Materials
No full textGlobal energy consumption was reported at 4.1 x 10²⁰ J (equivalent to 13 terawatts) in 2005, expected to more than triple by the end of the century based on projected population and economic growth. These rapidly increasing energy demands coupled with concerns over climate change as well as depletion of fossil fuel supplies has led to intensive efforts to increase the efficiency of current processes of energy production, conversion and recovery. Thermoelectric materials have in recent years emerged as a potential solution to this problem. Thermoelectric devices use temperature gradients to generate electrical energy due to the potential difference across a cell.
The cell potentials for most materials are generally quite small and so semiconductor materials have to be used to optimise the cell potential. These materials are generally quite difficult to produce and this thesis examines two novel methods of creating semiconductor materials on a conducting surface. Both techniques make use of deep eutectic solvents (DESs), a novel type of solvent formed by mixing a quaternary ammonium salt with a hydrogen bond donor.
This study will focus on simple metal sulfides as they are inexpensive to prepare and could be used for large surface area devices. The first technique oxidises a metal electrochemically in a DES containing sodium sulfide to produce a metal sulfide on the metal surface. The second technique uses powders of the metal sulfide on an electrode surface and by a process of oxidation and reduction it attempts to fuse the powder onto the electrode surface. It is shown that both techniques are successful and a thermoelectric device could be constructed but the layers produced are relatively thin
Use of Deep Eutectic Solvents (DESs) for the Preparation of Thermoelectric Materials
No full textGlobal energy consumption was reported at 4.1 x 10²⁰ J (equivalent to 13 terawatts) in 2005, expected to more than triple by the end of the century based on projected population and economic growth. These rapidly increasing energy demands coupled with concerns over climate change as well as depletion of fossil fuel supplies has led to intensive efforts to increase the efficiency of current processes of energy production, conversion and recovery. Thermoelectric materials have in recent years emerged as a potential solution to this problem. Thermoelectric devices use temperature gradients to generate electrical energy due to the potential difference across a cell.
The cell potentials for most materials are generally quite small and so semiconductor materials have to be used to optimise the cell potential. These materials are generally quite difficult to produce and this thesis examines two novel methods of creating semiconductor materials on a conducting surface. Both techniques make use of deep eutectic solvents (DESs), a novel type of solvent formed by mixing a quaternary ammonium salt with a hydrogen bond donor.
This study will focus on simple metal sulfides as they are inexpensive to prepare and could be used for large surface area devices. The first technique oxidises a metal electrochemically in a DES containing sodium sulfide to produce a metal sulfide on the metal surface. The second technique uses powders of the metal sulfide on an electrode surface and by a process of oxidation and reduction it attempts to fuse the powder onto the electrode surface. It is shown that both techniques are successful and a thermoelectric device could be constructed but the layers produced are relatively thin
sj-docx-1-tva-10.1177_15248380231219256 – Supplemental material for Building A Comprehensive, Longitudinal Dataset to Advance Research on the Efficacy of State-Level Anti-bullying Legislation: 1999 to 2017
No full textSupplemental material, sj-docx-1-tva-10.1177_15248380231219256 for Building A Comprehensive, Longitudinal Dataset to Advance Research on the Efficacy of State-Level Anti-bullying Legislation: 1999 to 2017 by Marizen R. Ramirez, Andrew Ryan, Katherine Lymn, Scott Burris, Amy Cook, Lindsay K. Cloud and Mark L. Hatzenbuehler in Trauma, Violence, & Abuse</p
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
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