1,721,052 research outputs found
Glass transition in an epoxy resin induced by temperature, pressure and chemical conversion: a rationale based on configurational entropy
No full textInfluence of the wettability on the electrical response of microporous systems
No full textThe permittivity of different microporous systems, including sintered glass filters, Berea sandstones and reservoir rocks, was measured in the frequency range 10(2)-10(10) Hz. For each system, the natural pore wettability was modified to get two different sets of samples: those strongly oil-wet and those water-wet. The samples were saturated with a hydrocarbon oil and water at different degrees of water content. Dielectric spectra showed a conductivity contribution due to ionic carriers in addition to a Maxwell-Wagner-Sillars relaxation, active up to high frequencies. Because of the dominant role that wettability plays in the electrical response of partially saturated microporous solids, water-wet and oil-wet samples showed remarkable differences in the loss tangent spectra, as well as different times and strengths of the Maxwell-Wagner-Sillars relaxation. The dielectric spectra were analysed by using some standard models for extracting valuable information about the pore wettability. Moreover, the use of impedance measurements for in situ determination of the wettability of reservoir rocks was evaluated
Glass transition of an epoxy resin induced by temperature, pressure and chemical conversion: a rationale based on configurational entropy
No full textA comparative dielectric study is reported on the dynamics of a glass-forming epoxy resin when the glass transition is approached through different paths: cooling, compression, and polymerisation. Deep similarities are observed in dynamic properties. A unified reading of the experimental behaviour of the structural relaxation time of chemically reacting and stable systems close to the glass transition is given in the framework of the Adam-Gibbs theory of configurational entropy
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
Carissimo Serra / Illustrissimo professore (sul carteggio Serra-Croce)
No full textAttraverso il carteggio tra Renato Serra e Benedetto Croce emergono sia il senso di un rapporto personale "vero", a lungo caratterizzato dalla stima e dall'amicizia, sia i termini di un netto dissenso intellettuale, scandito da visioni del mondo, della vita e della cultura (specie della presa della filosofia sulla vita) radicalmente alternative e inconciliabili. Una doppia relazione, personale e intellettuale, destinata a consumarsi, fino alla brusca rottura finale
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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