1,720,966 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Eine neue Theorie zur Berechnung der zeitabhängigen Oberflächeneigenschaften bei der Reaktivdestillation
No full textDie Reaktivdestillation kann in die zwei ihre zugrundeliegenden Operationen der Destillation und Reaktion aufgeteilt werden. Betrachtet man die Destillation lassen sich Oberflächeneigenschaften der vorliegenden flüssigen und gasförmigen Phase im Gleichgewicht mittels der Dichtegradiententheorie beschreiben. Die benötigten Gleichgewichtszustände, welche in der Dichtegradiententheorie verwendet werden, erhält man mittels einer Zustandsgleichung (EoS). Hiermit lassen sich Eigenschaften wie die Oberflächenspannung, Konzentrations- beziehungsweise Dichteprofile der Oberfläche und die Dicke der Oberfläche von Reinstoffen und Mischungen bestimmen. Die Variablen der Oberflächeneigenschaften sind in der Destillation durch Temperatur, Zusammensetzung und Dichten der vorliegenden Phasen gegeben. Im Falle der Reaktivdestillation wird das Phasengleichgewicht zusätzlich vom Reaktionsgleichgewicht beziehungsweise der Reaktionskinetik beeinflusst. Die Oberflächeneigenschaften erhalten somit die zusätzliche Variable der Zeit. Für den verwandten Fall der Reaktivextraktion wurde eine neue Theorie entwickelt, um die zeitabhängigen Grenzflächeneigenschaften zu beschreiben. Bisher wurden nur die zeitabhängigen Grenzflächeneigenschaften im inkompressiblen Fall modelliert. Der prinzipielle Unterschied bei der Reaktivextraktion ist, dass das Flüssig-Flüssig Gleichgewicht als inkompressibel betrachtet werden kann und die Modellierung mittels eines GE-Modells ohne Zugang zu den Dichten erfolgen kann. Diese Dissertation behandelt die Erweiterung des Modells vom inkompressiblen auf den kompressiblen Fall, um somit für die Reaktivdestillation die Überlagerung von Phasen- und Reaktionsgleichgewicht zu beschreiben. Das Modell ist in der Lage neben den Gleichgewichtszuständen die Oberflächeneigenschaften in Abhängigkeit der Reaktionskinetik beziehungsweise -Fortschritt zu bestimmen. Als Grundlage der Modellierung dient die Reaktion der Hexylacetatsynthese: 1-Hexanol + Essigsäure ⇄ Hexylacetat + Wasser. Es wird die Perturbed Chain Statistical Associating Fluid Theory (PC-SAFT) beziehungsweise die Associated Reference PC-SAFT (ARPC-SAFT) Zustandsgleichung für Wasser und dessen Mischungen verwendet. Die Parametrisierung der Zustandsgleichung erfolgt ausschließlich durch Anpassung an Reinstoffdaten. Es wird ein binärer Wechselwirkungsparameter verwendet, welcher ausschließlich an Gas-Flüssig Gleichgewichtsdaten der binären Randsysteme angepasst wird. Die Reaktionskinetik wird mit den Aktivitäten, erhalten aus derselben Parametrisierung, an experimentelle Daten der Gleichgewichtsreaktion angepasst. Der Modellansatz ist in der Lage für ein quaternäres reagierendes Systems eine Vorhersage über die zeitlich und örtlich aufgelösten Oberflächeneigenschaften zu machen
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Get PDFWe 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
Phase and Interfacial behavior of the ternary system Toluene / Ethanol / Water
Get PDFEquilibrium data in ternary liquid-liquid systems is necessary for the design of extraction processes. Interfacial tension is an important parameter in mass transfer models, and therefore highly relevant in extraction. Thus, experimental measurements of these parameters are a prerequisite for the development of industrial processes. This work analyzes the interfacial behavior of the water-ethanol-toluene system by experimentally determining equilibrium tie lines and interfacial tensions at 25 °C. A total of five concentration points was analyzed. Each point was measured three times. Concentrations at equilibrium were determined using gas chromatography for ethanol and toluene, and a Karl-Fischer titrator for water content. Interfacial tensions were measured using a spinning drop tensometer. Phase densities and refractive indexes were also measured, all of them at 25 °C. The obtained equilibrium data was found to be inconsistent with previous literature data. This was probably caused by errors in the experimental method. Interfacial tension measurements were consistent with previous experiments, and it was found to decrease with ethanol content, as was expected.Grado en Ingeniería Químic
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe 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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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