1,721,008 research outputs found
Process simulation of a SOFC and double bubbling fluidized bed gasifier power plant
No full textThe development of reliable fuel cells power plant based on renewable fuels stands out as one of the promising energy systems solutions for the future. Indeed fuel cells can increase the efficiency and the cleaning of the electrical energy production from renewable fuels. Process simulations of advanced power plants fed by low cost renewable fuels like biomass waste are a key step to develop renewable resources based on high temperature fuel cells applications. The aim of this work is to predict the component behaviour of a specific power plant mainly composed of a small indirectly heated gasifier and a Solid Oxide Fuel Cell (SOFC) and fed by chestnut coppice, waste available in great quantity in Central Italy, as well as in several other European regions. The plant's thermodynamic behaviour is analysed by means of the process simulator CHEMCAD(C) in which particular models for the SOFC and the gasifier have been developed in FORTRAN by the authors and then interfaced to commercial software. The results of the predictive model are presented and discussed, showing the possibility of an extremely interesting "carbon neutral" small plant configuration with high electrical and global efficiency exclusively based on the use of low cost renewable resources. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved
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
Technologies for smart grids: A brief review
No full textIn electrical power systems smart grid is widely recognized as the new solution that must be developed to manage distributed network tackling the increment of renewable energies. Through monitoring capability, data integration, effective communication, advanced analysis and system control the smart grid can meet the power demand as well as increase total efficiency and reduce consumption and costs. Many different technologies must converge to create a smart grid as a storage systems utilized as an energy buffer, telecommunication systems that can exchange data with sensors and actuators, advanced control systems that monitor the power grid and manage energy flows in real time. This paper reviews the state of the art of present application of these technologies in smart grids. The specific focus of the work is on telecommunication systems to have a monitoring through last smart metering application. The impacts and benefits of real time controls are investigated to improve the power efficiency, security and quality. © 2013 IEEE
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
Deactivation model study of high temperature H2S wet-desulfurization by using ZnO
Full text linkHigh-temperature desulfurization techniques are fundamental for the development of reliable and efficient conversion systems of low-cost fuels and biomass that answer to the nowadays environmental and energy security issues. This is particularly true for biomass gasification coupled to SOFC systems where the sulfur content has to be minimized before being fed to the SOFC. Thus, commercially available zinc oxide has been studied and characterized as a desulfurizing agent in a fixed-bed reactor at high temperatures from 400◦C to 600◦C. The sorbent material was characterized by XRD, BET, SEM, and EDS analyses before and after adsorption. The sorbent’s sorption capacity has been evaluated at different temperatures, as well as the breakthrough curves. Moreover, the kinetic parameters as the initial sorption rate constant k0, the deactivation rate constant kd, and the activation energy have been calculated using the linearized deactivation model. The best performances have been obtained at 550◦C, obtaining a sorption capacity of 5.4 g per 100 g of sorbent and a breakthrough time of 2.7 h. These results can be used to extend ZnO desulfurization techniques to a higher temperature than the ones used today (i.e., 550◦C with respect to 400◦C)
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