1,720,975 research outputs found

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

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    We 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

    Author Index

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    Influence of Magnetic Field on the Kinetics of Ho(III) Solvent Extraction Using D2EHPA: A Comprehensive Study

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    The kinetics of Ho(III) extraction using di(2-ethylhexyl)phosphoric acid (D2EHPA) under the influence magnetic field are examined. The methodology for kinetics research is based on spectrophotometric techniques. Initial experiments without a magnetic field assess the influence of Ho(III) concentration (0.00625-0.1 m), pH (1-6), D2EHPA concentration (0.1-2 m), and temperatures (5-35 °C). Subsequent tests (5-35 °C) determine the influence of the magnetic field. Experimental considerations are supplemented with numerical simulations of the magnetic field affecting the extraction system. A white precipitate formed at the phase boundary is characterized using X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) techniques. Post-extraction solutions are analyzed with nuclear magnetic resonance (NMR) spectroscopy to investigate the structure and magnetic properties of the D2EHPA-Ho(III) complex. The conducted research indicate that magnetic fields notably enhance kinetics of extraction above 25 °C, suggesting a possible change in the extraction mechanism

    SEparation of rare earth metals ions in a static magnetic field

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    Rare earth metals are recovered through hydrometallurgical processes. The most difficult stage is the separation from the REE ion mixture allowing pure metals extraction. The used methods are based on subtle differences in chemical properties between individual REE ions. The present work determines efficiency of the separation of aqueous solutions of rare earth metals basing on the differences in physical properties (magnetic moment). The distribution of ions in the solution takes place in a steady magnetic field generated by a set of neodymium magnets. The following parameters affecting the method efficiency are analyzed: time, solution pH, concentration of individual REE ions, complexing additives, as well as the experiment duration and location of stationary magnets in relation to the liquid

    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We 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

    Separation of Ho3+ in Static Magnetic Field

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    The rare earths elements (REE) belong to the group of critical metals and they are achieving more and more interest due to their special properties. However, there occur some problems connected with their production. The most difficult phase is separation of REE. It includes a necessity to intensify currently applied processes and looking for new solutions. The present work introduces an idea to use differences in physical properties of the REE ions to get them separated. In the experimental part of the work some efforts were undertaken to analyse results presenting changes of holmium ions concentration under an influence of the magnetic field gradient. There was determined the gradient of magnetic field and concentration of Ho3+ ions depending on initial concentration of the solution and time. A simulation of changing the concentration of holmium ions in the solution under an influence of the magnetic field gradient was performed to compare the mathematical model with the obtained results
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