1,721,479 research outputs found
Synthesis of binary and ternary semiconductors by means of microwave irradiation
No full textPure CdTe and CuInSe2 are prepared with high yields and short reaction times starting from metal or binary alloy powders and irradiating the mixture with a microwave radiation of a 2.45 GHz of frequency and 1000 W of power under argon atmosphere. It was possible to successfully synthesize extremely pure CuInSe2 single crystalline phase, differently from a multi-phase mixture as expected from the phase diagram Cu2Se-In2Se3. XRD and SEM analyses, performed for the characterization, have confirmed the success of the process
THE EFFECT OF QUENCHING ON THE MECHANICAL-PROPERTIES OF POWDER METALLURGICALLY PRODUCED AL-SIC (PARTICLES) METAL MATRIX COMPOSITES
No full textSeveral factors contribute to the strengthening in particulate metal matrix composites (MMCs); their interdependence makes the elaboration of an exhaustive explanation of the phenomenon difficult. In the present work, a comparison between different powder metallurgically produced MMCs consistency of an aluminium matrix reinforced with SiC particles, both in the as-extruded state and in the quenched state, is carried out. Data concerning two powder metallurgy processes, four average particle sizes and four volume fractions of the reinforcement are analysed and compared with the unreinforced matrix. Such analysis allows a deeper
understanding both about the result of the mismatch in between the thermal expansion coefficients of the matrix and of the reinforcement on dislocation density, and about the Al-SiC solid state reaction. These phenomena act on the strengthening mechanism. Their effect is very specific, because it strongly depends on the SiC particle average size
and volume fraction. So, the difference between the ultimate tensile strengths of the as-extruded composites and the quenched composites can change case by case. Sometimes, the improvement in mechanical properties is excellent. This gives well-grounded encouragement in study and design
of a suitable heat treatment for such MMCs
Frugoni, Una lontana città. Sentimenti e immagini nél Medioevo
No full textLapostolle Christine. Frugoni, Una lontana città. Sentimenti e immagini nél Medioevo. In: Médiévales, n°9, 1985. Langues, sous la direction de François Jacquesson . pp. 141-144
La scrittura dei sentimenti e la speranza
No full textLa tensione bipolare fra sentimenti e negazione dei sentimenti incide sulle diverse forme dell’arte, contribuendo a definire non solo stagioni letterarie, ma a cogliere quell’energia sotterranea che rende autentici gli esiti dell’attività creativa e credibili i percorsi finzionali. Le trasformazioni determinate dai sentimenti, soprattutto nella produzione francese degli ultimi due decenni, rivelano come il confronto fra i sentimenti degli umani e i sentimenti dei personaggi letterari faccia emergere una rinnovata vitalità della scrittura, in cui la narrazione dei sentimenti si fa sentimento della narrazione
Double doping: a method to decrease dislocation densities in LEC InP crystals
No full textIn this paper we shall report on the characteristics of LEC InP double doped with Cd and Te. Unlike (Cd,S)-doped material, (Cd, Te)-doped InP is p-type, with low-carrier concentration. In the following, the results of structural and electrical analysis carried out on several LEC InP crystals co-doped with Cd and Te are presented. The role of multiple doping as a strategy for dislocation reduction will also be discussed
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
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