1,720,957 research outputs found
Mg batteries : improvement of performances by interface engineering
No full textLes batteries basées sur des éléments multivalents représentent une alternative prometteuse aux batteries lithium-ion, offrant des perspectives de densités énergétiques plus élevées et de coûts plus faibles. Les électrodes négatives en magnésium (Mg) métallique se distinguent par leur faible potentiel de réduction, leur grande capacité volumique et l'abondance naturelle du magnésium dans la croûte terrestre. Depuis la conception du premier prototype de batterie rechargeable en Mg en 2000, le développement d'électrolytes adaptés pour former une couche de passivation efficace à la surface du magnésium reste un obstacle majeur pour avoir des systèmes vraiment rechargeables.Cette thèse se concentre sur l'amélioration des performances électrochimiques des anodes en Mg métallique en étudiant les relations entre la composition chimique, la morphologie de la couche de passivation et son comportement électrochimique. Elle examine systématiquement des facteurs tels que les solvants, les substrats, les concentrations en sel, les additifs et les types de sels pour optimiser la couche de passivation dans les batteries en Mg.Les résultats montrent que bien que le type de solvant et le temps d'immersion affectent significativement la composition chimique de la couche de passivation, son épaisseur reste inchangée. De plus, la structure cristalline du substrat, notamment la similarité entre le Ti et le Mg, améliore l'électrodéposition en augmentant les cinétiques de dépôt et en réduisant la surtension de nucléation. La concentration en sel impacte également la couche de passivation, des concentrations plus faibles produisant des interphases riches en produits de décomposition du solvant, tandis que les concentrations plus élevées forment des couches résistantes dominées par les produits de décomposition de l'anion du sel. L'utilisation de Mg(butyl)2 comme additif d'électrolyte contribue également à obtenir des interphases beaucoup plus fines avec moins de produits de décomposition inorganiques et d'anion.En outre, ce travail identifie une "couche de passivation idéale" comme étant fine et contenant à la fois des ions iodure et du bore. L'ajout de BI3 s'est révélé particulièrement efficace pour augmenter l'efficacité coulombique et améliorer les performances de dépôt et de redissolution (plating/stripping) du Mg. La thèse examine également comment le type de sel influence la chimie de surface des dépôts de Mg et, par conséquent, leur comportement électrochimique, notamment à travers l'étude de plusieurs électrolytes de type alkoxyborate de magnésium. Il a été constaté que les couches de passivation contenant une quantité significative de bore dans un environnement organique montrent une haute efficacité coulombique avec des surtensions suffisamment faibles.Dans l'ensemble, ces résultats visent à approfondir notre compréhension des processus de passivation et à contribuer au développement de nouveaux systèmes de stockage électrochimiques de l'énergie à base de Mg.Multivalent batteries present a promising alternative to lithium-ion batteries, offering the potential for higher energy density and lower costs. Metallic magnesium (Mg) negative electrodes stand out due to their low reduction potential, high volumetric capacity and the natural abundance of magnesium in the Earth's crust. Since the first prototype of a rechargeable Mg battery was introduced in 2000, the development of suitable electrolytes to form an effective passivation layer on magnesium 's surface has remained a significant barrier to achieving full rechargeability.This thesis focuses on improving the electrochemical performance of Mg metal anodes by investigating the relationship between the passivation layer's chemical composition, morphology, and electrochemical behavior. It systematically examines factors such as solvents, substrates, salt concentrations, additives, and salt types to optimize the passivation layer in Mg batteries.The findings show that while solvent type and immersion time significantly affect the chemical composition of the passivation layer, its thickness remains unchanged. Additionally, the crystal structure of the substrate, particularly the similarity between Ti and Mg, enhances electrodeposition by increasing plating kinetics and lowering nucleation overpotential. Salt concentration also impacts the passivation layer, with lower concentrations yielding organic-rich interphases and higher concentrations forming resistive, anion-dominated layers. Using Mg(butyl)2 as an electrolyte's additive also contributed to yield much thinner interphases with fewer inorganic and anion decomposition products.Furthermore, this work identifies an "ideal" passivation layer as thin, incorporating both iodide and boron. Adding BI3 proved particularly effective in increasing Coulombic efficiency and improving Mg plating and stripping performance. The thesis also examines how salt type influences Mg deposits' surface chemistry and, consequently, their electrochemical behavior, particularly through a study of several magnesium alkoxyborate electrolytes. It was found that passivation layers with significant boron content in an organic environment achieve high Coulombic efficiency with sufficiently low overpotentials.Overall, these findings aim to expand our understanding of passivation processes and support the development of next-generation Mg-based energy storage systems
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
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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