1,721,033 research outputs found
CATalytic–Post Processor (CAT-PP): A new methodology for the CFD-based simulation of highly diluted reactive heterogeneous
No full textScaling-up and -down of conventional ideal lab-scale catalytic reactors often introduces strong non-idealities in the flow field which may drastically affect the expected reactor performances and effectiveness. Computational fluid-dynamic (CFD) analysis is required to assess the extent of such non-idealities. In the case of reactive systems, and in particular in the case of heterogeneous catalytic processes, however, computational efforts are huge and, due to the wide range of space and time scales, may become hardly sustainable when detailed chemical kinetics have to be implemented and solved for transient processes. A specific case, encountered in most of the applications of environmental catalysis, is represented by highly diluted process streams, where reactants and products have concentrations of the order of hundreds of part per million and the reaction duty is extremely low. In this case, the reactor fluid dynamic is not affected by the occurrence of chemical reactions, while the activity of the system can be significantly affected by the reactor hydrodynamics. A new simulation approach, named CATalytic–Post-Processor (CAT-PP), is proposed in this paper to treat those systems. Such approach results in a numerical tool which acquires the flow-field data from non-reactive CFD simulations, performed by a commercial code (ANSYS Fluent) and post-processes them by solving the species transport equations with a detailed kinetic scheme. The potential of the proposed approach is demonstrated through its application to the dynamic analysis of a FTIR-operando reactor-cell loaded with a lean-NOx-trap catalyst. It is shown that CAT-PP allows to effectively simulate a transient diluted catalytic process taking care of the actual reactor hydrodynamics even implementing detailed surface (or gas/solid) kinetic schemes
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
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
EFFECTIVENESS OF DIFFERENT TASK PARADIGMS IN REVEALING BLINDSIGHT
No full textFour patients with hemianopia from posterior cerebral artery infarction were tested for residual unconscious vision ('blindsight') in their anopic hemifield. One task tested for spatial summation between the normal and the abnormal hemifields. A second task tested for temporal interactions between the two hemifields. A third task required a manual localization of the site of a brief flash in the hemianopic side. The last test was administered either in a condition of free gaze during pointing or in a condition in which the gaze was kept fixed throughout all phases of the task. The first two tasks differed from the third not only in the type of visual function, that is, detection vs spatial localization, but also in the response criterion. A forced-choice procedure was adopted in the localization task while in the spatial and temporal interfield interaction tasks a reaction time paradigm that did not require guessing was used. One patient showed unequivocal evidence of blindsight on all tasks, thus excluding the possibility that this blindsight depended on the nature of the response. An interesting dissociation was found in the localization task where 1 patient showed evidence of blindsight when tested under conditions of unrestrained gaze during pointing but not when tested under fixed gaze conditions
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
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