1,720,974 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
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
Mineralogy and physicochemical properties of smectite clays from Bana and Sabga (Cameroon). Potential use in bleaching process of edible vegetable oil
Get PDFIn this study, clay samples were collected in the localities of Bana and Sabga, in the regions of the west and north-west Cameroon, respectively. The purpose of this study was to determine their mineralogical composition, their physico-chemical properties and to assess their potential use in the bleaching process of palm oil, which is the main edible vegetable oil produced and refined in Cameroon.
The results obtained from the analyses (XRD, FTIR, DTA / TGA and SEM) revealed that montmorillonite is the main clay mineral in these materials. It is associated with kaolinite and mica. Non-clay minerals such as quartz, anatase, cristobalite, K-feldspar and heulandite are also identified in variable quantities. Chemical analyses of the major elements show that the clays from Bana and Sabga consist mainly of the follow oxides such as SiO2, Al2O3 and Fe2O3. Bana clays have a cation exchange capacity (CEC) between 50 and 60 meq/100 g and a specific surface area between 50 and 60 m2/ g. Sabga clays have a lower capacity cation exchange (38- 46 meq/100 g) and a wider range of specific surface area (33-90 m2 / g). The characterization of the natural clays allowed to select of one sample by locality for sulfuric acid treatment.
The acid treatment of these materials led to structural, morphological and textural changes. Analysis by X-ray diffraction showed a progressive decrease in the intensity of the (001) reflection of montmorillonite and a shift of its basal d001-value. Treatment with more acid concentration causes an increase in the surface area of the obtained products and a decrease in cation exchange capacity.
The assessment of the bleaching power of natural and acid-activated Bana clay in palm oil decolorization shows that the activated clay has a high bleaching capacity (~ 87%) compared to the natural clay (~ 55%). palm oil Bleaching by these clay materials does not deteriorate the bleached oil. These materials can thus be used as bleaching earths in the refining oil process
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
MINERALOGIE ET PROPRIETES PHYSICO-CHIMIQUES DES SMECTITES DE BANA ET SABGA (CAMEROUN).Utilisation dans la décoloration d'une huile végétale
No full textIn this study, clay samples were collected in the localities of Bana and Sabga, in the regions of the west and north-west Cameroon, respectively. The purpose of this study was to determine their mineralogical composition, their physico-chemical properties and to assess their potential use in the bleaching process of palm oil, which is the main edible vegetable oil produced and refined in Cameroon. The results obtained from the analyses (XRD, FTIR, DTA / TGA and SEM) revealed that montmorillonite is the main clay mineral in these materials. It is associated with kaolinite and mica. Non-clay minerals such as quartz, anatase, cristobalite, K-feldspar and heulandite are also identified in variable quantities. Chemical analyses of the major elements show that the clays from Bana and Sabga consist mainly of the follow oxides such as SiO2, Al2O3 and Fe2O3. Bana clays have a cation exchange capacity (CEC) between 50 and 60 meq/100 g and a specific surface area between 50 and 60 m2/ g. Sabga clays have a lower capacity cation exchange (38- 46 meq/100 g) and a wider range of specific surface area (33-90 m2 / g). The characterization of the natural clays allowed to select of one sample by locality for sulfuric acid treatment.The acid treatment of these materials led to structural, morphological and textural changes. Analysis by X-ray diffraction showed a progressive decrease in the intensity of the (001) reflection of montmorillonite and a shift of its basal d001-value. Treatment with more acid concentration causes an increase in the surface area of the obtained products and a decrease in cation exchange capacity.The assessment of the bleaching power of natural and acid-activated Bana clay in palm oil decolorization shows that the activated clay has a high bleaching capacity (~ 87%) compared to the natural clay (~ 55%). palm oil Bleaching by these clay materials does not deteriorate the bleached oil. These materials can thus be used as bleaching earths in the refining oil process./Dans cette étude, des échantillons d’argiles ont été collectés dans les localités de Bana et Sabga, respectivement dans les régions de l’Ouest et Nord-ouest Cameroun. Le but de cette étude était de déterminer leurs compositions minéralogiques, leurs propriétés physico-chimiques et d’évaluer leur potentielle utilisation dans la décoloration de l’huile de palme, qui représente la principale huile végétale comestible produite et raffinée au Cameroun. Les résultats obtenus à partir des analyses classiques (DRX, FTIR, ATD/ATG et MEB) ont révélé que la montmorillonite est le minéral de base dans ces matériaux. Elle est associée à la kaolinite et au mica. Sont aussi identifiés en quantités variable les minéraux non-argileux tels que le quartz, l’anatase, la cristobalite, les feldspaths potassiques et l’heulandite. Les analyses chimiques des éléments majeurs montrent que les argiles de Bana et Sabga sont constituées principalement des oxydes SiO2, Al2O3 et Fe2O3. Les argiles de Bana possèdent une capacité d’échange cationique (CEC) variant entre 50 et 60 méq/100 g et une surface spécifique comprise entre 50 et 60 m2/g. Les argiles de Sabga présentent une capacité d’échange cationique plus faible (38 à 46 méq/100g) et une plus large gamme de surface spécifique (33 à 90 m2/g). Le bilan minéralogique des argiles étudiées a permis de sélectionner dans chaque localité un échantillon pour un traitement à l’acide sulfurique.Le traitement acide de ces matériaux a conduit à des modifications structurales, morphologiques et texturales. Les analyses par la diffraction de rayon X montrent une diminution progressive de l’intensité de la réfection (001) de la montmorillonite et un déplacement de sa distance basale (d001). Le traitement par des acides de plus en plus concentrés provoque une augmentation de la surface spécifique des produits obtenus et une diminution de leur capacité d’échange cationique.L’évaluation du pouvoir décolorant de l’argile de Bana riche en smectite et présentant une évolution significative en termes de propriétés physiques et texturales suite à l’activation montre que l’argile activée présente une forte capacité de décoloration (~87 %) par rapport à l’argile naturelle (~55 %). La décoloration de l’huile de palme par ces matériaux, activés ou non, ne provoque aucune dégradation à l’huile traitée. Ces matériaux peuvent donc être valorisés comme terres décolorantes dans le processus de raffinage des huiles
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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