1,721,090 research outputs found
The role of solid oxide fuel cells in future ship energy systems
No full textWith rising concerns about emissions from shipping, fuel cells are expected to take an important role in ship propulsion. In particular, solid oxide fuel cells (SOFC) offer high efficiency with the possibility of combined heat and power production. In this paper, we investigate energy, cost, and emission savings on ships resulting from the use of SOFCs using an optimization-based approach. A global sensitivity analysis was used to investigate the effects of the high uncertainty of problem parameters. This setup is applied to two case studies: a cruise ship and a tanker. The results show that SOFCs could provide a reduction in ship greenhouse gas emissions by up to 34% and that when using natural gas as fuel, SOFCs are the most cost-optimal solution that allows a significant reduction in GHG emissions. A wider adoption of SOFCs would also lead to a decrease of other pollutant emissions. The sensitivity analysis shows that the lifetime of the stack is the most impacting uncertain parameter, followed by fuel prices and by the investment cost of the SOFC stack. The study highlights that, in a future of stricter constraints on greenhouse gas emissions and where the SOFC technology will be fully industrialized, SOFCs will be able to play an important role in bridging shipping towards decarbonization
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
3D design and optimization of heat exchanger network for solid oxide fuel cell-gas turbine in hybrid electric vehicles
No full textThe development of electric vehicles is considered as one of the sustainable way in the automotive industry to reduce greenhouse gases emissions and to allow transportation sector to comply with environmental targets required in present and future years. Due to the limited range of autonomy of the electric vehicles and the induced cost and environmental impacts of large capacity batteries, hybrid electric vehicles have been deeply investigated and developed over the last years. In this study, a Solid Oxide Fuel Cell combined with Gas Turbines (SOFC-GT) is used as a range extender in hybrid electric vehicle. The SOFC-GT system increases the autonomy of the electric vehicle and has high electric efficiency of 77%. In this work, the Heat Exchanger Network (HEN) to recover thermal energy in the SOFC-GT system has been studied. The HEN has to meet the targets of limited volume and mass to be compatible with the installation on the hybrid vehicle. This study is basically divided into three steps. In the first step, the HEN synthesis is performed with a mathematical model developed in AMPL, stating the optimal matches between hot and cold streams. In the second step, a model is developed to size the heat exchangers with the LMTD method. In the final step, an optimization problem is solved to minimize the volume or mass of the HEN, by sizing the heat exchangers with a global view of HEN, considering their assembly in a limited space and defining the paths of flow streams. Finally, some heat exchangers have been printed using plastic with a SLA 3D printer, with presentation purpos
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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