1,722,595 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
Augmentation of secondary organics for enhanced pretreatment of thermomechanical pulping wastewater in biological acidogenesis
No full textThermomechanical pulping (TMP) wastewater was used for augmenting readily biodegradable organics in order to enhance microbial hydrolysis by mesophilic and thermophilic acidogens. A biochemical methane potential test with the TMP wastewater revealed that approximately 12-14% of the total chemical oxygen demand was anaerobically biodegradable. Mesophilic and thermophilic acidogens at 35 and 55 degreesC in batch mode were tested to investigate the effects of various concentrations of organic acids and ethanol produced from readily biodegradable organics on the hydrolysis of lignocellulosics. The experiment was designed to have initial glucose concentrations of 5, 15 and 30 g/l. The combined effects of the production of organic acids, ethanol, and enriched acidogenic populations by addition of glucose promoted hydrolysis. Compared to the control with no glucose addition, approximately 5.3 and 6.6 times more fragmentation of lignocellulosics in the wastewater occurred in mesophilic and thermophilic acidogenesis, respectively. Higher efficiencies in the thermophilic trials than those in the mesophilic tests were likely due to the elevated temperature. (C) 2003 Elsevier Science Ltd. All rights reserved.X113sciescopu
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
Selective measurement of non-microbial protein in wastewater by use of Kjeldahl and adenosine 5'-triphosphate analysis
No full textWe developed a procedure employing adenosine 5'-triphosphate (ATP) and total Kjeldahl nitrogen (TKN) measurements to estimate non-microbial protein concentration of dairy-processing wastewater; which also contains acid-producing microorganisms. Two different physiological conditions where maximum rates of acetic and butyric acid production occurred, which were pH 7.1 at 36.2 degrees C (Condition A) and pH 7.3 at 36.2 degrees C (Condition B), respectively, were tested in batch-mode in completely mixed bioreactors. The ratios of microbial nitrogen to ATP concentration were constant at post-lag phases, which were 23.2 mg N/mg ATP and 13.2 mg N/mg ATP for conditions A and B, respectively. Use of these conversion factors provides a simple and reliable way to measure the non-microbial protein concentration in acidogenesis of dairy-processing wastewater.X113sciescopu
Modeling and optimization in anaerobic bioconversion of complex substrates to acetic and butyric acids
No full textCheese-processing wastewater was biologically treated to produce short-chain organic acids in laboratory scale continuously stirred tank reactors. A constant inoculum system was used to mimimize the experimental error due to the use of inconsistent inoculum. The inoculum system was operated with dilute cheese-processing wastewater with 5000 mg soluble chemical oxygen demand/L at pH 6.5 and 35 degrees C at 0.5 days hydraulic retention time. Response surface methodology was successfully applied to determine the optimum physiological conditions where the maximum rates of acetic and butyric acid production occurred. These were pH 7.01 at 36.2 degrees C and pH 7.26 at 36.2 degrees C, respectively. The lack of overall predictability for butyric acid production meant that the response surface was much more complicated than that of acetic acid; therefore, a small change in pH or temperature could cause large variations in the response of butyric acid production. (C) 1997 John Wiley & Sons, Inc.X1123sciescopu
Characterization of and bioproduction of short-chain organic acids from mixed dairy-processing wastewater
No full textMixed wastewater from the cheese-processing industry was characterized and biologically treated to produce short-chain organic acids (i.e., acetic, propionic, butyric, and valeric acids) in laboratory-scale continuously stirred tank reactors. A total of 97.7% of total chemical oxygen demand (TCOD) in this wastewater was due to the presence of lactose, lactate, protein, and fat, which respectively composed 66.6%, 10.6%, 17.2%, and 3.3% of the TCOD. A constant inoculum system, an anaerobic continuously stirred tank reactor (CSTR) with 1.5 L working volume, was used to minimize the experimental error due to the use of inconsistent inoculum. The inoculum system was operated with dilute mixed waste, 5000 mg soluble COD/L at pH 6.5 and 35 degrees C at 0.5 days hydraulic retention time (HRT). Two identical 2.8 L anaerobic CSTRs equipped with temperature and pH controllers wc?re separately used to evaluate system performance. Several different HRTs (0.6 days, washout points) were randomly tried and the organics in the wastewater were converted to these four organic acids at up to 62.4% at pH 7.01, 36.2 degrees C, and 0.45 days HRT.X1119sciescopu
Formation of organic acids and ammonia during acidogenesis of trout-processing wastewater
No full textA set of experiments was carried out to characterize trout-processing wastewater and to investigate biological acidification (acidogenesis) of the wastewater. Based on individual amino acids analysis and stoichiometric calculations, protein was a major organic material which composed 92.9% of chemical oxygen demand (COD) in the wastewater Three concentrations of COD set up in a ratio of 1:4:9 made by dilution of raw wastewater (11.4, 45.7, and 102.7 g COD/L) were tested for acidogenesis in batch mode. Production of acetate, propionate, isobutyrate, butyrate, methylbutyrate, and valerate was monitored. Acetate production was predominant in all treatments, and amounts of acetate and butyrate were proportional only to the initial wastewater strength. The formation of odd-chain organic acids (propionate, methylbutyrate, and valerate) increased with decreasing initial wastewater strength. Based on stoichiometric calculations, total conversions of organics in the wastewater to short-chain organic acids at initial COD concentrations set up in a ratio of 9:4:1 were respectively 52.1%, 74%, and 79.6%.X1112sciescopu
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