1,720,960 research outputs found
Supertargeting-based hierarchic evaluation for setting paths in relaxation of retrofitted Heat Exchanger Networks
No full textThe application of pinch analysis to the retrofit of existing heat exchanger networks is a complex task, which can be hardly standardised due to the large number of unquantifiable design considerations. Top-down and bottom-up approaches have been usually pursued, respectively oriented
to relax a Maximum Energy Recovery (MER) configuration and to improve the existing network by removing network pinches. In this paper the bottom-up approach is critically examined, considering a well known case study represented by an aromatics plant; a MER design is also obtained and evaluated, to represent a target for process improvement. The final objective of researches in this sector is the identification of preferential routes for the improvement of the existing network. In this paper several retrofit routes are investigated, identifying six solutions that lead to a small number of topology changes. For each solution, a detailed thermal analysis provided the size, the number of
shells and the temperature profiles associated with the operation of any heat exchanger; the solutions were relaxed to reduce the number of new units and the relaxed configurations were also evaluated.
An analysis of the payback time associated with any retrofit option let us recognize that preferential routes could be identified by a preliminary evaluation of marginal costs
"Thermal penalty factors" accounting for site topological characteristics in pinch design of Heat Exchanger Networks
No full textPinch analysis allows to determine targets and solutions for minimum energy requirements
in process plants, basing on innovative tools like composite curves and table problem formulation, which ultimately allow generating an optimized heat exchanger network design. On another hand, this
technique does not account directly for a number of factors which could play a primary role for the practical feasibility of the network. What if, for instance, once identified an optimal lay-out, we realize
that some matches are hardly feasible in practice? Could we adapt the conventional pinch approach to keep into account site topological features since the preliminary design phase? In this paper the authors attempt answering these questions by introducing “Thermal Penalty Factors”, to be calculated for any match by accounting for the capital cost needed to realize it. Appropriate expressions for these penalty factors (in kW) are firstly obtained; successively, these factors are integrated into the composite curves, so as to enable the analyst to account for them since the design phase. A simple case study is adopted to highlight the potential of thermal penalty factors in contributing to achieve
more reliable targets
Italia e Turchia tra Europa e Medio Oriente (1969-1993)
No full textQuesto lavoro indaga sulle relazioni bilaterali italo-turche negli anni Settanta e Ottanta del Novecento. Il colpo di Stato del settembre 1980 in Turchia ebbe conseguenze negative sui rapporti tra Ankara e la Comunità Europea, ma non sulle relazioni bilaterali con Roma, considerata l’importanza strategica del paese anatolico. Una posizione di convergenza si ebbe anche sulla decisione di non sostenere le sanzioni contro il leader libico Gheddafi, volute dal presidente degli Stati Uniti, Ronald Reagan. Tra la fine degli anni Ottanta e l’inizio degli anni Novanta, si cercarono nuove possibilità di collaborazione tra Italia e Turchia, sia in vista della creazione di un asse mediterraneo, con l’obiettivo di bilanciare l’asse dell’Europa centrale e settentrionale dopo l’unificazione della Germania, sia in funzione della protezione dalla pressione demografica proveniente dalla sponda meridionale del Mediterraneo, percepita come una minaccia
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
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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