1,720,966 research outputs found

    Life cycle cost from consumer side: A comparison between traditional and ecological vehicles

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    The present work investigates the economic feasibility of ecological vehicles. The comparison has been developed between traditional vehicles, gasoline and diesel fueled, and green vehicles powered by electric, hybrid or natural gas motors. Nowadays, the vehicle life cycle cost is an important decision criterion used by consumer to buy a car, due to fuel price increasing. Life cycle cost includes purchase cost, operation cost, but also social cost lead to environmental impact regarding production, use and end-of-life phases. The proposed research focuses life cycle cost from consumer side in order to evaluate the economic feasibility, using ecological solutions for transportation in EU. Different use scenarios are proposed, considering different vehicle sizes and mileages, without considering taxes and any governance incentives. © 2014 IEEE

    Cooling simulation of an EV battery pack to support a retrofit project from lead-acid to li-ion cells

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    A niche of the electric vehicle market is the electric retrofit of existing vehicles. These updates replace internal combustion engines with high efficiency electric motors and high capacity Li-ion batteries. This market is dominated by mostly small and medium size enterprises that provide tailored solutions to customers. These companies seek to reduce their costs and lead times by using virtual prototyping tools and methods in the main design processes. In this context, our work defines a design methodology to support designers in the definition of cooling systems. As a test case, we analyzed the electric retrofit of a small electric car with a lead-acid battery that was updated to Li-ion technology. We focused on a simulation of the cooling of the battery using a thermal analysis based on the physical parameters of the cell and test bench results. The issue is the evaluation of the heat generated by the electrochemical reactions of lithium ion battery cells. A representative battery module was simulated following the methodological approach. The virtual prototyping analysis was divided into two levels: the thermal simulation of a single cell, and the computational fluid dynamics (CFD) analysis of a battery module composed of LiFePO4 prismatic cells. The geometric and fluid dynamic parameters were investigated with a CFD solver to study the cooling performance. A cooling system configuration was proposed and analyzed using the virtual prototyping tools. © 2013 IEEE

    Dealing with LCA modeling for the end of life of mechatronic products

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    This paper discusses end-of-life (EoL) modeling issues in Life Cycle Assessment (LCA), through the application to a domestic cooker hood. Two EoL approaches are applied and discussed, namely the avoided burden and the one recommended by the Product Environmental Footprint (PEF) Guide, presently under testing. While no case studies on PEF application have been published yet, to the best of our knowledge, the scientific community is questioning the robustness and relevance of some methodological aspects, especially the EoL formula. The objective of the work is to provide a case study for supporting the scientific discussion on EoL modeling by: applying the avoided burden approach to the cooker hood EoL; testing the PEF EoL approach on a cooker hood component, the aluminum filter, and compare the results with those obtained from the avoided burden approach; evaluating how both the approaches affect the allocation of burdens/credits associated to recycling. The Global Warming Potential (GWP) and the Abiotic Depletion Potential (ADP) impact categories are investigated. The study points out that the PEF EoL approach delivers higher environmental impacts than the avoided burden one, due to a reduced contribution from the avoided impacts. Overall, the application of the PEF EoL approach is more complex, due to the additional and often not available information needed, such as the recycled content of the materials and the disposal treatments that are avoided when recycled materials are used in the product. Also the structure of the LCA datasets may limit the application of the PEF EoL. © 2015, Gh. Asachi Technical University of Iasi. All rights reserved

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

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    We 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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