1,721,088 research outputs found
Industrial scale production of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)
No full textLarge scale production of poly(3-hydroxy-butyrate-co-3-hydroxyhexanoate) [P(3HB-co-3HHx)] by Aeromonas hydrophila 4AK4 was examined in a 20,000 1 fermentor. Cells were first grown using glucose as a carbon source, and polyhydroxyalkanoate (PHA) biosynthesis was triggered by the addition of lauric acid under conditions of limited nitrogen or phosphorus. When cells first grown in a medium containing 50 g glucose 1(-1) were further cultivated after the addition of 50 g lauric acid 1(-1) under phosphorus limitation, a final cell concentration, PHA concentration and PHA content of 50 g 1(-1), 25 g 1(-1), and 50 wt%, respectively, were obtained in 46 h, equivalent to PHA productivity of 0.54 g 1(-1) h(-1). The copolymer produced was found to be a random copolymer, and the 3HHx fraction was 11 mol%.This work was supported by Procter &
Gamble. We thank many researchers at the Jiangmen Biotechnology
Institute (Guangdong, China) for their invaluable contribution
to this work. We also thank Dr. Phillip R Green (Procter & Gamble,
USA) for NMR and DSC analyses of PHA
H4 exponential finite-difference scheme for convective diffusion-equations
No full textPerturbations are applied to the convective coefficients and source term of a convection-diffusion equation so that second-order corrections may be applied to a second-order exponential scheme. The basic Structure of the equations in the resulting fourth-order scheme is identical to that for the second order. Furthermore, the calculations are quite simple as the second-order corrections may be obtained in a single pass using a second-order scheme. For one to three dimensions, the fourth-order exponential scheme is unconditionally stable. As examples, the method is applied to Burgers' and other fluid mechanics problems. Compared with schemes normally used, the accuracies are found to be good and the method is applicable to regions with large gradients
A perturbational h4 exponential finite-difference scheme for the convective diffusion equation
No full textA perturbational h4 compact exponential finite difference scheme with diagonally dominant coefficient matrix and upwind effect is developed for the convective diffusion equation. Perturbations of second order are exerted on the convective coefficients and source term of an h2 exponential finite difference scheme proposed in this paper based on a transformation to eliminate the upwind effect of the convective diffusion equation. Four numerical examples including one- to three-dimensional model equations of fluid flow and a problem of natural convective heat transfer are given to illustrate the excellent behavior of the present exponential schemes, the h4 accuracy of the perturbational scheme is verified using double precision arithmetic
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
Exergy analysis for resource conversion of the Chinese Society 1993 under the material product system
No full textThe resource exergy conversion in Chinese society in 1993 under the material product system (MPS) was investigated. Major resources that entered the society were divided into subgroups and analyzed in detail. The end use was broken down into ten end-use sectors: the forestry industry, food industry, iron and steel industry, nonferrous metal industry, chemical industry, textile industry, transportation, households, commerce, other industry. The total exergy input was 62.9 EJ, which was 53.3 GJ/cap. The total exergy output contained 11.66 EJ or 9.88 GJ/cap, which was 19% of the total exergy input. One RMB (Chinese Renminbi) yuan ($ 0.17) corresponded to 3.37 MJ resource exergy output. (C) 2005 Elsevier Ltd. All rights reserved.ThermodynamicsEnergy & FuelsSCI(E)EI0ARTICLE8-91115-11503
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
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