1,721,068 research outputs found
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
Élaboration d'une nouvelle architecture pour anodes en silicium poreux dans les batteries lithium-ion, intégrant une approche économique et écologique via l'utilisation de silicium grade solaire
Get PDFLe silicium est l’un des matériaux d’anode les plus prometteurs pour les batteries Li-ion, notamment pour répondre à la demande croissante de stockage d’énergie sous forme de microbatteries pour les appareils mobiles et autonomes. Cependant, le développement de telles batteries est entravé par des défaillances mécaniques et électrochimiques résultant de l’expansion massive du volume du Si et de la croissance continue de l’interphase de l’électrolyte solide (SEI). Cette thèse se consacre à l'amélioration des batteries lithium-ion en se focalisant sur les anodes en silicium. L'objectif principal est le développement d'une nouvelle architecture d'anode, baptisée "panel sandwich like", visant à atténuer l'expansion volumique du silicium et la croissance de la SEI. Appliquée sur une puce, cette structure offre des performances électrochimiques exceptionnelles, avec des capacités surfaciques élevées jusqu'à 10 mAh/cm² et une durée de vie prolongée jusqu'à 1000 cycles. En parallèle, la thèse explore le potentiel du silicium de grade solaire comme alternative économique. Ces travaux ouvrent des perspectives novatrices pour le stockage d'énergie, soutenant la transition mondiale vers les énergies renouvelables.
La contribution significative de cette recherche repose sur la proposition d'une solution économique et technologique pour surmonter les défis du silicium en tant que matériau anodique. La structure "panel sandwich like" simplifie la fabrication des batteries tout en offrant des performances électrochimiques exceptionnelles. En outre, l'exploration du silicium de grade solaire représente une avancée novatrice, ouvrant la voie à des anodes plus abordables. En conclusion, cette thèse jette les bases pour des recherches futures, notamment l'application potentielle de la structure "panel sandwich like" sur différents types de silicium et l'optimisation continue des formulations d'anodes. Ces développements offrent des opportunités d'innovation et de croissance continue dans le domaine du stockage d'énergie, soutenant ainsi la transition mondiale vers les énergies renouvelablesAbstract: Silicon is one of the most promising anode materials for Li-ion batteries, especially to meet the growing demand for energy storage in the form of microbatteries for mobile and autonomous devices. However, the development of such batteries is hindered by mechanical and electrochemical failures resulting from massive Si volume expansion and continuous growth of the solid electrolyte interphase. This thesis is dedicated to advancing lithium-ion batteries by focusing on silicon anodes. The primary objective is the development of a novel anode architecture, termed "panel sandwich like," aiming to mitigate silicon's volumetric expansion and the growth of the solid electrolyte interphase (SEI). Applied on a chip, this structure exhibits outstanding electrochemical performance, with high areal capacities up to 10 mAh/cm² and an extended cycle life of up to 1000 cycles. Concurrently, the thesis explores the potential of solar-grade silicon as an economical alternative. These findings open innovative perspectives for energy storage, supporting the global transition to renewable energies. The significant contribution of this research lies in proposing an economical and technological solution to overcome challenges associated with silicon as an anode material. The "panel sandwich like" structure simplifies battery manufacturing while delivering exceptional electrochemical performance. Additionally, the exploration of solar-grade silicon represents an innovative breakthrough, paving the way for more affordable anodes. In conclusion, this thesis lays the groundwork for future research, including the potential application of the "panel sandwich like" structure to different silicon types and ongoing optimization of anode formulations. These developments offer opportunities for innovation and continuous growth in the field of energy storage, supporting the global transition to renewable energies
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
Influence of interface energy on high-pressure phase transitions : study of functional oxides nanoparticles
No full textLa modification des diagrammes de phase sous pression dans les nanomatériaux en comparaison de matériaux massifs est généralement reliée de façon univoque à l'énergie de surface. L'objectif de ce travail a consisté à étudier l'influence de l'énergie d'interface, définie par l'état de surface (défauts cristallins et chimie de surface) et l'énergie de surface, sur le comportement à haute pression de différents nanomatériaux pour lesquels un effet de taille est fréquemment rapporté. Le contrôle et la caractérisation de l'état de surface de nanoparticules d'Y2O3 nous ont permis de montrer que l'amorphisation sous pression rapportée dans la littérature n'est pas uniquement due à la réduction de la taille de grain mais nécessite une densité de défauts initiale, généralement non contrôlée. Une forte dépendance en taille de la pression de transition dans ZnO est avancée dans la littérature. L'étude sous pression de différents échantillons nanométriques de ZnO (issus de diverses voies de synthèse) a été effectuée par spectroscopie Raman et diffraction de rayons X. La qualité cristalline de ces derniers a été estimée par Photoluminescence, XPS, Raman et IR. Tandis que les échantillons présentant une forte densité de défauts conduisent à une augmentation de la pression de transition, le comportement d'un échantillon "sans défauts" ne diffère que peu de celui de ZnO massif. Différentes approches et extensions de modèles thermodynamiques sont proposées: modèles de Gibbs, Landau et Ginzburg-Landau. Ces derniers ouvrent la voie à la définition d'un protocole expérimental permettant d'obtenir des données fiables pour étudier les transitions de phase de nanomatériaux sous pressionThe modification of phase diagrams under pressure into nanosized materials in comparison with bulk ones is usually attributed to surface energy. The goal of this work has consisted into studying the influence of interface energy, which includes both the surface state (crystalline defects and surface chemistry) and surface energy, on the high-pressure behavior of several nanomaterials for which size effects has been reported. The control and characterization of the surface state for Y2O3 nanoparticles has enabled us to show that the pressure induced amorphization reported into literature is not only linked to size reduction but require an initial density of defects A strong size dependence of ZnO transition pressure is claimed into literature. The high-pressure study of different ZnO nanometric samples (obtained through several ways of synthesis) has been performed by Raman spectroscopy and X-ray diffraction. The crystalline quality of our samples has been investigated by photoluminescence, XPS, Raman and IR. Whereas samples exhibiting a high density of defects lead to an increase of pressure transition, the behaviour of “defect free” nanoparticles is rather equivalent to bulk one. Several approaches and extensions of thermodynamic models are submitted: model of Gibbs, Landau and Ginzburg-Landau. Those models open the way to the definition of an experimental protocol which allow to obtain reliable data in order to study phase transitions of nanomaterials under pressur
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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