1,720,997 research outputs found
Investigation on temperature fields in industrial chilling of pork legs for PDO Parma ham production and coupled temperature/microbial growth simulation
No full textIn the present work, temperature distribution within an industrial blast chiller with pork leg for Protected Designation of Origin Parma ham production was studied and the slowest cooling zone and the fastest cooling zone were recognized. Moreover, apparent heat transfer coefficients in both positions were calculated and resulted equal to 27.1 and 15.6 W m−2 °C−1, respectively. A finite element method model by distinguishing the three main components (skin, lean meat and bone) of the leg for the unsteady heat transfer during cooling was developed and validated against industrial chiller data. Good agreement between experimental and simulated data was obtained with RMSE value for thermal centre equal to 0.81 °C. Furthermore, in order to introduce CCP limit in the HACCP plan, a microbial growth model of the most important pathogens in meat was developed starting from the heat transfer model results. Temperature as well as pathogen growth were estimated in the case of different plant breakdowns. Defined CCP limit was represented by reaching 11 °C at 5 mm of depth within 2 h from the beginning of the cooling process, moreover a different cooling program was simulated and established as the alternative one
Synthesis of 6(I)-amino-6(I)-deoxy-2(I-VII)-tetradeca-O-methyl-cyclomaltoheptaose
No full textThe preparation of 6(I)-amino-6(I)-deoxy-2(I-VII),3(I-VII)-tetradeca-O-methyl-cyclomaltoheptaose is reported. Two different routes (A and B), both starting from beta-cyclodextrin (betaCD), have been examined. Route A involved: (i) synthesis of heptakis(6-0-tert-butyldimethylsilyl)-betaCD from betaCD; (ii) permethylation of the secondary hydroxyl groups with methyl iodide and sodium hydride; (iii) desilylation of the primary hydroxyls with ammonium fluoride; (iv) monotosylation at O-6 position of per-(2,3-O-methyl)-betaCD,- (5) nucleophilic replacement of the tosyl group with azide anion; (v) reduction of the azido group by catalytic transfer hydrogenation using hydrazine hydrate in the presence of Pd/C in methanol/water. Route B started from the known 6(I)-monoazido-6(I)-monodeoxy-beta-CD (two steps from beta-CD) and entailed: (i) protection of the remaining primary hydroxyls using tert-butyldimethylsilylchloride (TBDMSCI); (ii) exhaustive methylation of the secondary hydroxyls with methyl iodide and sodium hydride; (iii) removal of the TBDMS protecting groups with ammonium fluoride; (iv) reduction of the azido group as above. Route A was found to be less convenient than Route B due to the inherent difficulty of controlling the monotosylation of per-(2,3-O-methyl)-betaCD
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
Computation fluid dynamics design of a plate fin heat exchanger with different transverse vortex generators for food processing
No full textIn this work, the performance of a plate heat exchanger with rectangular, rhombus, and elliptical vortex generators with 3, 5, and 7 mm width and 3, 6, and 9 mm height were investigated by means of computation fluid dynamics (CFD). Moreover, seven flow rates (from 0.01 to 1 ms−1) were tested and 196 CFD models were obtained. Heat transfer coefficient, pressure drop, Colburn j, and Fanning f factor were considered to evaluate the performance of the heat exchanger. The best heat exchange was obtained for rhombus wings and the highest Colburn j factor was obtained for 7 mm width and 6 mm height. The lowest pressure drop was obtained for 3 mm width and 3 mm height elliptical wings. Regarding surface reduction, the best result for all the geometries was with 5 mm width and 9 mm height, allowing a possible reduction of 25, 26, and 23% for rectangular, rhombus, and elliptical geometry. Practical applications: Plate heat exchangers are extensively used for continuous thermal processing of liquid foods without particles in suspension and with low viscosity. In the last decades, due to the increasing demand of high quality foods and energy saving, increasing the overall heat transfer performances of food processes became crucial for the sector. Computation fluid dynamics (CFD) technique can contribute to understanding food fluid flows inside heat exchangers and in supporting equipment design. Product and process quality can be improved with minimum cost and time investment. In this work CFD was used for studying the performances of a plate heat exchanger with different passive vortex generators presenting different shapes and dimensions. The simulated data allowed identifying the best geometry with the best balance between heat performance improvements and pressure losses. The proposed approach successfully applied to Newtonian fluid could be extended also to non-Newtonian liquid foods and to different plate heat exchanger design
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
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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