1,721,076 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
Versatile plug flow catalytic cell for in situ transmission∕fluorescence x-ray absorption fine structure measurements
No full textA novel flow-through catalytic cell has been developed for in situ x-ray absorption spectroscopy (XAS) experiments on heterogeneous catalysts under working conditions and in the presence of a liquid and a gas phase. The apparatus allows to carry out XAS measurements in both the transmission and fluorescence modes, at moderate temperature (from RT to 50-80 ◦C) and low-medium gas pressure (up to 7-8 bars). The materials employed are compatible with several chemicals such as those involved in the direct synthesis of hydrogen peroxide (O2, H2, H2O2, methanol). The versatile design of the cell allows to fit it to different experimental setups in synchrotron radiation beamlines. It was used successfully for the first time to test nanostructured Pd catalysts during the direct synthesis of hydrogen peroxide (H2O2) in methanol solution from dihydrogen and dioxygen
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
Spin Polarization of the Photoelectrons and Photon Polarization of X-Ray Absorption: Spectroscopy and Magnetometry
No full textWe introduce here how to perform spectroscopies that are sensitive to the spin polarization of the electron states, via the direct measure of the P vector of a (photo)electron beam in a suitable experimental set-up and how to perform photoemission/photoabsorption experiments that, by exploiting the polarization of the exciting photon beam, are directly sensitive to the spin order in the initial state revealing, for example, the magnetization state of solids and surfaces or the effects of spin-orbit interaction in the surface electronic structure
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
Synchrotron radiation XRPD study on the early hydration of cements
Full text linkSynchrotron radiation X-ray powder diffraction has been used to monitor the evolution of hydrous phases during the first hours of the hydration process on synthetic clinker phases and on commercial cements. In order to collect data as soon as water is added to the system, the hydration of the paste was achieved using a remote controlled system. The data were quantitatively analysed via full-profile Rietveld method. The results of quantitative analysis (phase composition) and the lattice parameters determination are very useful to obtain detailed information on the structural evolution of the hydrous phases, in particular during the early stages of the hydration processes
Microstructural analysis of RuO2-basede thick-film resistors
No full textThis paper presents results of a microstructural analysis on RuO2-based Thick Film Resistors performed by X.ray diffraction and absorption spectroscopy. The study concerns four different types of RuO2-based TFRS, prepared changing the substrate, the glass of matrix and the vehicle but keeping the RUO2 powder fixed. In addition each type has been fired at different temperatures, ranging from 450 deg. C up to 1000 deg. C . The collected data clearly indicated that changes in resistivity are directly related to structural modification of the glass matrix and a consistent interaction with the alumina substrate exists. On the contrary firing temperature and substrates have minor effects on RuO2 conductive phase
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