1,721,257 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
Effect of non-beta-lactam antibiotics on penicillin-binding protein synthesis of Enterococcus hirae ATCC 9790
No full textFosfomycin, bacitracin and vancomycin in combination with penicillin exhibit a synergic effect against Enterococcus hirae ATCC 9790. This strain, when incubated in presence of the MIC of non-beta-lactam antibiotics, showed an alternated pattern of PBPs. Bacitracin and vancomycin caused a decrease in the density of all PBPs while fosfomycin only reduced that of PBP 6. It is suggested that the observed synergy is a consequence of the inhibition of PBP synthesis by antibiotics which act on the early stages of peptidoglycan synthesis prior to the formation of cross-links
Experimental heat transfer coefficients during refrigerant vaporisation and condensation inside herringbone-type plate heat exchangers with enhanced surfaces
No full textThis paper presents the experimental work carried out to apply ‘‘cross-grooved’’ surfaces to refrigerant vaporisation and condensation inside plate heat exchangers (PHE) with herringbone macro-scale corrugation. This paper also investigates the effect of an increase in the surface roughness of the plate on refrigerant two-phase heat transfer inside PHE. The enhanced surfaces are experimentally evaluated both in vaporisation and condensation tests with refrigerant 22, and compared against a PHE with a smooth surface. The experimental results show that the ‘‘cross-grooved’’ surface is useful both in vaporisation and condensation, whereas the increase in surface roughness is useful only in vaporisation. The ‘‘cross-grooved’’ surface gives an increase in the heat transfer coefficient from 30% to 40% in vaporisation to 60% in condensation with respect to a PHE with a smooth surface. The enhancement in heat transfer coefficient is higher than the simple increase in heat transfer surface area. A fair agreement was found between present experimental data and semi-empirical correlations both for condensation and vaporisation inside PHE
Development of innovative plate heat exchangers for refrigeration applications
No full textThis paper presents the experimental work carried out to apply the enhanced surfaces widely used for intube refrigerant condensation and vaporisation, such as micro-fin and cross-grooved, into plate heat exchangers (PHE). The paper investigates also the effect of an increase in the surface roughness of the plate on the heat transfer performance in refrigerant vaporisation. The enhanced surfaces are experimentally evaluated both in vaporisation and condensation tests and compared against a traditional PHE surface. The experimental facility and the test procedures are fully described. The experimental results show that the increase in surface roughness is useful only in vaporisation, whereas the cross-grooved surface is useful both in vaporisation and condensation. The cross-grooved surface gives an increase in the heat transfer performance from 40% in vaporisation to 50% in condensation with respect to a traditional PHE surfac
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
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