1,721,460 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
Determination of formaldehyde content in leather: Standard EN ISO 17226, revision and possible improvements
No full textThe retanning process is the main application of formaldehyde in the tanning industry since formaldehyde participates in two groups of synthetic organic tanning agents: syntans and resins. Resins can be hydrolysed with the result that formaldehyde is released. Thus, formaldehyde in leather can be free or from hydrolysis of resins. Due to the carcinogenic character of formaldehyde, its presence in leather should be avoided or should be below allowable limits. The EN ISO 17226 Standard is the Official Standard for the determination of formaldehyde content in leather, which, in the authors’ opinion, presents certain ambiguities in the wording of some operations included in their analysis methods and, some of these operations, are susceptible of improvement. Therefore, a revision of the EN ISO 17226 Standard (Parts 1 and) 2 is carried out in this work and, in particular, of the extraction phase of formaldehyde present in leather (possible use of alternative surfactant and shaking method); reaction time between the extracted formaldehyde with the dinitrophenylhydrazine solution (Part 1 of the Standard) and stability of the acetylacetone solution (Part 2 of the Standard).Peer ReviewedPostprint (published version
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
Determination of formaldehyde content in leather: Standard EN ISO 17226, revision and possible improvements
No full textThe retanning process is the main application of formaldehyde in the tanning industry since formaldehyde participates in two groups of synthetic organic tanning agents: syntans and resins. Resins can be hydrolysed with the result that formaldehyde is released. Thus, formaldehyde in leather can be free or from hydrolysis of resins. Due to the carcinogenic character of formaldehyde, its presence in leather should be avoided or should be below allowable limits. The EN ISO 17226 Standard is the Official Standard for the determination of formaldehyde content in leather, which, in the authors’ opinion, presents certain ambiguities in the wording of some operations included in their analysis methods and, some of these operations, are susceptible of improvement. Therefore, a revision of the EN ISO 17226 Standard (Parts 1 and) 2 is carried out in this work and, in particular, of the extraction phase of formaldehyde present in leather (possible use of alternative surfactant and shaking method); reaction time between the extracted formaldehyde with the dinitrophenylhydrazine solution (Part 1 of the Standard) and stability of the acetylacetone solution (Part 2 of the Standard).Peer Reviewe
Determination of formaldehyde content in leather: Standard EN ISO 17226, revision and possible improvements
No full textThe retanning process is the main application of formaldehyde in the tanning industry since formaldehyde participates in two groups of synthetic organic tanning agents: syntans and resins. Resins can be hydrolysed with the result that formaldehyde is released. Thus, formaldehyde in leather can be free or from hydrolysis of resins. Due to the carcinogenic character of formaldehyde, its presence in leather should be avoided or should be below allowable limits. The EN ISO 17226 Standard is the Official Standard for the determination of formaldehyde content in leather, which, in the authors’ opinion, presents certain ambiguities in the wording of some operations included in their analysis methods and, some of these operations, are susceptible of improvement. Therefore, a revision of the EN ISO 17226 Standard (Parts 1 and) 2 is carried out in this work and, in particular, of the extraction phase of formaldehyde present in leather (possible use of alternative surfactant and shaking method); reaction time between the extracted formaldehyde with the dinitrophenylhydrazine solution (Part 1 of the Standard) and stability of the acetylacetone solution (Part 2 of the Standard).Peer ReviewedPostprint (published version
Influence of the chromatographic conditions of the EN ISO 17226-1 Standard "determination of formaldehyde content in leather. Part 1. Quantification by hplc" on the robustness of the method
No full textGiven the carcinogenic character of formaldehyde, it should be reliably determined in any substrate. The EN ISO 17226 Standard is the Official Method to quantify formaldehyde in leather using either the chromatographic or the colorimetric methods. In cases of discrepancy between results, according to the ISO Organization, preference should be given to the chromatographic method (EN ISO 17226-1 Standard) instead of the colorimetric one (EN ISO 17226-2 Standard). The EN ISO 17226-1 Standard recommends chromatographic conditions of column, mobile phase composition and flow rate. The paper studies the influence of changes in flow rate, composition of the mobile phase and separating columns recommended by the EN ISO 17226-1 Standard for the determination of formaldehyde content in leather. It has been made relevant that small variations in the flow rate and differences in mobile phase compositions ranging from 35/65 to 45/55 Water/Acetonitrile does not significantly affect the results of formaldehyde concentration. As regards the different separating columns, non-significant differences between them were observed. However, considering the effectiveness and the retention time of the separating columns, the solid-core particle (Cortecs®C18) column can be recommended because it has in excess the capacity to separate the formaldehyde peak from that of the residual DNPH reagent in less than 2 minutes which is lower than those of the other columns tested. Consequently, the productivity of the analytical laboratories is improved. © 2019 American Leather Chemists Association. All rights reserved.Peer reviewe
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
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