1,720,989 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
Study of sulfosuccinate and extended sulfated sodium surfactants on the Malaysian crude/water properties for ASP application in limestone
No full textAmong the successful methods in enhanced oil recovery (EOR) is the chemical EOR. The surfactant-based chemical techniques are highly recommended. However, some drawbacks remained unsolved such as surfactant selection and application in the reservoirs. Surfactants are particularly applied in sandstone reservoirs, so paving the path to expand the implementation to limestone reservoirs is required. Recently, alkaline surfactant polymer (ASP) was suggested for limestone reservoirs in Malaysia. However, limited studies discussed the effect of surfactant screening on the process. Thus, this study investigates the influence of sulfosuccinate and extended sulfated sodium surfactants in improving ASP performance. The evaluation considered the interfacial tension, wettability and recovery factor. The approach used was two-stage experiments of surfactant analysis and ASP core flooding. The first step used the drop Kruss spinning drop tensiometer, and data physics equipment drop shape analyzer to analyze the IFT and the contact angle. The second stage included the limestone sandpack preparation and characterization, followed by ASP flooding. The results showed that single surfactant has low IFT between 0.005 and 0.05 mN/m, while significantly, the synergy of surfactant mixtures has ultra-low IFT of 0.0006–0.001 mN/m. The contact angle results showed a drastic alteration of 65–81% reduction. The cationic surfactants achieved complete water-wet on limestone. The sandpack preparation confirmed acceptable uniformity by the histogram identification. The oil recovery proved additional recovery between 22 and 40%. The results of this research are a step forward to attain the technical feasibility of ASP in limestone reservoirs
Utilizing Ultrasonic Waves in the Investigation of Contact Stresses, Areas, and Embedment of Spheres in Manufactured Materials Replicating Proppants and Brittle Rocks
Full text linkPeer reviewe
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
UTILIZING ULTRASONIC WAVES IN THE INVESTIGATION OF CONTACT STRESSES, AREAS, AND EMBEDMENT OF SPHERES IN MANUFACTURED MATERIALS REPLICATING PROPPANTS AND BRITTLE ROCKS
Full text linkIn the oil and gas industry, hydraulic fracturing (HF) is a common application to create additional permeability in unconventional reservoirs. Using proppant in HF requires understanding the interactions with rocks such as shale, and the mechanical
aspects of their contacts. However, these studies are limited in literature and inconclusive. Therefore, the current research aims
to apply a novel method, mainly ultrasound, to investigate the proppant embedment phenomena for different rocks. The study
used proppant materials that are susceptible to fractures (glass) and others that are hard and do not break (steel). Additionally,
the materials used to represent brittle shale rocks (polycarbonate and phenolic) were based on the ratio of elastic modulus
to yield strength (E/Y). A combination of experimental and numerical modeling was used to investigate the contact stresses,
deformation, and vertical displacement. The results showed that the relation between the stresses and ultrasound reflection
coefficient follows a power-law equation, which validated the method application. From the experiments, plastic deformation
was encountered in phenolic surfaces despite the corresponding contacted material. Also, the phenolic stresses showed a
difference compared to polycarbonate for both high and low loads, which is explained by the high attenuation coefficient of
phenolic that limited the quality of the reflected signal. The extent of vertical displacements surrounding the contact zone
was greater for the polycarbonate materials due to the lower E/Y, while the phenolic material was limited to smaller areas not
exceeding 50% of polycarbonate for all tested load conditions. Therefore, the study confirms that part of the contact energy
in phenolic material was dissipated in the plastic deformation, indicating greater proppant embedment, and leading to a loss
in fracture conductivity for rocks of higher E/
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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