1,720,975 research outputs found
Derivative resolution in the spectrophotometric assay of pharmaceuticals. Note IV - Analysis of mixtures of 1,4-benzodiazepine compounds
No full textSCADA data analysis for long-term wind turbine performance assessment: A case study
No full textThe long-term analysis of wind turbine performance is a complex task, because the extracted power has a multivariate dependence on ambient conditions and working parameters, which in general changes during the machine lifetime due to aging effects and-or technology optimization. For this reason, the aim of this study is developing appropriate techniques based on SCADA data analysis. A real-world test case is discussed: a decade (2011–2020) of data has been analyzed for seven 2-MW wind turbines owned by ENGIE Italia, which underwent a control optimization in 2018. Four wind turbines in the long run display even a positive drift, which is due to the control upgrade; two have a slight performance decline with age which is compatible with literature estimates; one wind turbine has a noticeable worsening in time, which is exacerbated rather than compensated by the control optimization. It is therefore argued that the long-term performance trend depends on the history of each wind turbine and the resulting scenario is complex. The control optimization provides the expected improvement on six wind turbines out of seven, but leads to a worsening on the worst wind turbine: therefore, the health status of each machine should be monitored before altering the operation
Thin layer chromatography in pharmaceutical quality control. Assay of inosiplex in different pharmaceutical forms
No full textThe authors describe an HPTLC concentration zone method developed for the quality control of Inosiplex in different pharmaceutical forms. The plates were found to have good operating capacity in terms of specificity, accuracy, reliability and reproducibility with respect to the three molecular components of the active principle. The coefficients of variation of inosine and p-aminobenzoic acid are between 0.5 and 0.7. The method was also satisfactory for the quality control of 1-(dimethylamino)-2-propanol. Also if evidentiation is performed directly on the eluted spot, the coefficients of variation are between 1.2 and 1.6 for the three pharmaceutical forms
Thin layer densitometry in the quantitative assay of drugs. Note V - Assay of the reserpine and chlorthalidone in the presence of the potential impurities of their solid pharmaceutical forms
No full textDensitometric detection of compounds separated by thin layer was applied to the assay of a mixture of reserpine and chlorthalidone and their possible impurities. The method of analysis gave satisfactory results in the quality control of pharmaceutical preparations. Good results were obtained in urine tests for the detection of chlorthalidone, reserpine and methylreserpate. The times for the development of fluorescence in reserpine and methyl reserpate directly in the chromatographic plate, are also described
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
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