1,721,149 research outputs found
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
thermal evolution of Carbon supported clusters studied by time resolved X-ray diffraction
No full textDispelling 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
Polymer-hematite nanocomposites: templating effect of commercial ion-exchangers in the growth of size-controlled iron oxide nanoparticles
No full textThe commercially available ion-exchange resin Amberlite IR120 has been used as the stabilizing agent for the preparation of a size controlled nanostructured hematite phase. The employed synthetic approach, based on the loading of Fe3+ by ion exchange and the subsequent treatment with an aqueous base solution, produces a nanocomposite material with
a remarkably high content of oxide nanoparticles (iron content = 18.8 % w/w, corresponding to 24.9 % w/w of Fe2O3). Scanning electron microscopy and energy dispersive X-ray spectroscopy investigation show
that the iron distribution is egg-like and parallels the distribution of the sulfonic groups of the ion-exchanger. Transmission electron microscopy characterization reveals that the size of the ferric oxide nanoparticles in the nanocomposites is narrowly distributed in the 4-6 nm range and that it is the same after the first and the fifth ion-exchange-precipitation cycle. Selected area Electron Diffraction (SAED) analysis of the nanostructured oxide after five ion-exchange-precipitation cycles indicates that it is hematite with a distorted structure
Effects of gold nanoparticles deposition on the photocatalytic activity of titanium dioxide under visible light
No full textThe effects of gold nanoparticles deposited on titanium dioxide on the photocatalytic oxidative degradation of two organic substrates, i.e. formic acid and the azo dye Acid Red 1, and on
the parallel O2 reduction yielding hydrogen peroxide have been investigated under visible light
irradiation. The method employed to reduce Au(III) to metallic gold in the preparation of Au/TiO2 photocatalysts was found to affect their photoactivity, also by modifying the
properties of TiO2. The presence of gold on TiO2 facilitates both the electron transfer to O2 and
the mineralization of formic acid, which mainly proceeds through direct interaction with photoproduced valence band holes. The so-formed highly reductant CO2 intermediate species
may contribute in maintaining gold in metallic form. The controversial results obtained in the photocatalytic degradation of the dye were rationalised by taking into account that with this substrate, which mainly undergoes oxidation through a hydroxyl radical mediated mechanism, the photogenerated holes may partly oxidise gold nanoparticles, which consequently act as recombination centres of photoproduced charge carriers
A neutron diffraction study of mechanically alloyed and in-situ annealed Al75Mo25 powders
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