1,720,959 research outputs found
Energy analysis of a pasta factory and application of cogeneration
No full textThe energy production factor has become increasingly important following the trend within energy markets toward ever greater margins for optimisation. In the light of this fact, energy analysis provides a useful tool for determining the consumption of individual process phases in order to devise comprehensive intervention strategies aimed at more rational energy usage.
The application of cogeneration to food-production processes is likewise of great interest, due to the opportunity it affords for improving the overall energy performance of facilities. The present study is concerned with the application of the above technologies to a pasta factory, beginning with a thorough energy analysis of the existing installation to select the most appropriate type of cogeneration system, and the development of a project to accommodate its anticipated future expansion in years to come.
The factory in question consists of a line for the production of short dried pasta shapes having a capacity of 2,000 kg/h. Production runs continuously from Monday to Friday, and the process requires both electrical and thermal energy (in the form of superheated water at 130°C).
Thermal analysis
For the thermal analysis, mass and energy balances were determined by measuring the moisture and temperature of product exiting the individual loads within the drying process, and using the values for temperature and humidity of the machines recorded by the supervision system by means of capacitive/resistive sensors. The factory produces forty-seven different types of short dried pasta shapes, which can be roughly classified into two groups according to their specific volume: "short pasta" and "soup pasta". The experimental analysis was conducted on the above two groups as well as on "bowtie" and "protein-enriched corkscrew" pasta shapes which, due to their lower throughput and special recipes, are better able to highlight any differences in thermal demand.
Next, the thermal demand for each of the above four types of pasta was determined and, based upon the contribution of each group to the total annual output of the factory, a weighted average of the thermal requirements of the individual process loads was computed, and found to be 288.7 kcal/kg.
Electrical analysis
For the electrical analysis, the various loads within the plant were identified and suitable reduction coefficients estimated, partly on the basis of experience and partly based on graphs obtained from tests with current probes on the electrical panels. These graphs indicated that during certain work cycles the load does not always absorb maximum power, and so these cycles were monitored to better understand the functioning of the individual machines. The results of the electrical analysis were used to estimate the contribution of each load to the total consumption, and hence identify the process phases that incurred the highest electrical expenditure. The average monthly consumption was found to be 123,793 kWh which, for a monthly pasta output of 665,448 kg, again estimated using a weighted average, gave an overall specific energy consumption of 0.186 kWh/kg.
Application of cogeneration
After determining the overall energy consumption of the pasta factory in its present state, the feasibility of installing a cogeneration plant was evaluated, with the pasta factory divided into 4 production lines having a total capacity of 7,000 kg/h, and assuming 7,000 working h/year.
On the basis of the assumptions made and the results of a market survey, the system chosen was a natural gas-fuelled reciprocating Otto cycle engine with 1,105 kWe rated power, connected in parallel to the electricity supply grid, and an auxiliary boiler. The cogenerator was slightly undersized to ensure it would always operate at full load, for maximum efficiency.
An economic analysis and profitability analysis were carried out to ascertain that the savings accrued over the life time of the system could reimburse the investment cost. The Pay-Back Period (PBP) was found to be 29 months, and the resultant Net Present Value (NPV) indicates that the project is viable, with the annual revenues sufficient to both pay back the interest and recover the initial outlay before the end of the useful life of the investment
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
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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