1,720,956 research outputs found
Reusing Personal Computer Devices - Good or Bad for the Environment?
No full textThe energy saving potential of reusing / reselling personal computer (PC) devices was evaluated relative to the choice of buying new. Contrary to the common belief of reuse leading to energy savings, with the advent of more efficient laptops and liquid crystal displays (LCD), reuse of an old personal computer device can lead to relative energy expenditure. We found that in certain scenarios this expenditure could be as large as 300% of the lifecycle energy inventory for the new device. As a result, it is essential to assess the reuse of personal computer devices more critically, incorporating the different factors that influence the analysis as discussed below.MIT-Singapore AllianceMIT Energy Initiative (MITEI
Appliance remanufacturing and life cycle energy and economic savings
No full textIn this paper we evaluate the energy and economic consequences of appliance remanufacturing relative to purchasing new. The appliances presented in this report constitute major residential appliances: refrigerator, dishwasher, and clothes washer. The results show that, despite savings achieved in production, appliance remanufacturing is a net energy-expending end-of-life alternative. Moreover, we find that economic incentives can be an influential driver for consumers to remanufacture and re-use old appliances.Massachusetts Institute of Technology. Energy InitiativeSingapore-MIT Alliance for Research and Technolog
Remanufacturing and energy savings
Get PDFThesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 205-213).The substantial growth in industrial production, demand for materials, and population has led to an increasing need for sustainable manufacturing processes to mitigate the negative impacts on the environment and meet the needs of future generations. One proposed direction is remanufacturing, which is a process whereby used products having reached their end-of-life, are restored back to useful service-life. Remanufacturing utilizes the energy and embedded value retained in a product upon reaching end-of-life. Remanufacturing can close the loop between disposal and supply chains, extend the service lifetime of products, conserve resources, and help mitigate environmental consequences attributed to landfilling. Moreover, by preserving the geometrical architecture of cores, remanufacturing can reduce the needs for raw material processing and many manufacturing processes, hence, saving energy. A critical issue to consider when evaluating energy savings in remanufacturing is the product use phase: how well does the remanufactured device perform in the use phase compared to a similar new product from an energy standpoint? To answer this question, we utilize Life Cycle Assessments framework. Using this methodology, we quantify cumulative energy demands of a remanufactured product during its lifecycle and compare it to an equivalent new product. We conduct an analysis of lifecycle energy savings of remanufacturing for 19 different products in 8 distinct product case studies (4 product case studies discussed in detail in this thesis).(cont.) By performing lifecycle evaluations we conclude that remanufacturing can be a net energy-saving option for products that have energy requirements dominated by the production phase. Moreover, our energy analysis sheds light on the importance of considering use phase while evaluating the energy savings potential of remanufacturing. We conclude that from a total life cycle perspective, remanufacturing may be a net energy saving as well as a net energy expending end-of-life option. We argue that in investigating energy savings of remanufacturing as an end-of-life option, one should also evaluate large-scale critical factors in order to effectively address the systems challenges associated with remanufacturing. Our retrospective approach signifies the importance of studying critical factors such as technological improvements, policy interventions, economic incentives, and business models in order to draw inferences about energy and economic savings potential of remanufacturing. In addition, we argue that the generalized claims about remanufacturing as the ultimate end-of-life option are not only subject to dynamic global changes, but also restricted by the limitations in the lifecycle environmental methodologies. Lastly, we conclude that the evaluations for product remanufacturing and energy savings are more valuable and justified if conducted on a case-by-case basis.by Avid Boustani.S.M
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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