1,720,982 research outputs found
Study of the biochemical methane production of winter wheat: influence of growth stage and storage practice
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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
Assessment of process control parameters in the biochemical methane potential of sunflower oil cake
No full textA laboratory-scale study was conducted on the batch anaerobic digestion of sunflower oil cake (SuOC), solid waste derived from the extraction process of sunflower oil. A multi-reactor system was used to compare methane production from this waste at inoculum to substrate ratios (ISRs) of 3.0, 2.0, 1.5, 1.0, 0.8 and 0.5 (expressed as volatile solids (VS) basis). The tests were carried out at mesophilic temperature (35 °C) and run against a control of inoculum without substrate. The results obtained in the biochemical methane potential (BMP) tests showed that the ultimate methane yield (YM,ult) decreased considerably from 227±23 to 107±11 ml CH4 at standard temperature and pressure (STP) conditions g?1 VSadded when the ISR decreased from 3.0 to 0.5, showing a clear influence of the ISR on the methane yield coefficient. The biodegradability (BD) of the waste also decreased from 86% to 41% when the ISR varied from 3.0 to 0.5. A net total ammonia nitrogen (TAN) yield of 39.2 mg N g?1 VSadded was obtained, and this value was not influenced by the ISRs assayed, which demonstrated the appropriate operation of the hydrolytic–acidogenic stage of the overall digestion process. A clear imbalance of the methanogenic process was observed at the lowest ISRs studied (0.5 and 0.8) due to a considerable increase in CODs and TVFA in the digestates. The profile of VFA was also influenced by the ISR, typical of the proteinaceous substrate
Assessment of kinetic parameters for the mesophilic anaerobic biodegradation of two-phase olive pomace
No full textA kinetic study of the anaerobic biodegradation of two-phase olive pomace (TPOP) was carried out using a laboratory-scale stirred tank reactor. The reactor was operated at 35°C. The influent contained between 20% and 100% TPOP, representing in terms of total chemical oxygen demand (TCOD) 34.5–187.9 g TCOD l?1. The hydraulic retention times (HRTs) were set between 40.0 and 8.3 d. It was found that the increase of influent substrate concentration favoured the process failure reducing the pH and increasing the ratio of the total volatile fatty acid (TVFA) to alkalinity. This ratio was found to be proportional to the substrate concentration (S), as follows: TVFA/alkalinity=0.04(S). The kinetic model of Andrews was used to describe the relation between anaerobic biodegradation of TCOD and Volatile Solids (VS) and the formation of methane. The values of the kinetic constants for TCOD removal were determined to be 28 g TCOD l?1 d?1, 27 g TCOD l?1 and 352 g TCOD l?1, respectively, for maximum substrate utilization rates (RSmax), saturation constant (KS) and inhibition constant (Ki). Process inhibition started at substrate concentrations of around 20 g TCOD l?1. For VS biodegradation the kinetic constant values, RSmax, KS and Ki, were 45g VS l?1d?1, 37 and 36 g VS l?1, respectively. Inhibition started at VS concentration of around 18 g l?1. The rates of TCOD removal were lower than those observed for VS removal and inhibition of VS removal occurred at a lower concentration compared to that for TCOD. The QM(max), KS and Ki constants for methane production were approximately 3.1 l CH4 l?1 reactor d?1, 8.7 g TCOD l?1 and 272 g TCOD l?1, respectively. Inhibition of methane formation started at a substrate concentration of around 17 g TCOD l?1. TCOD and VS removal rates were higher than the rate of methane formation and these differences increased when the substrate concentration increased. This fact was underlined by the decrease of pH, the increase of TVFA/alkalinity ratio and the reduction of methane production rate
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
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
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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