1,721,117 research outputs found
Organic Rankine Cycle (ORC) Power Systems: Technologies and Applications
No full textOrganic Rankine Cycle (ORC) Power Systems: Technologies and Applications provides a systematic and detailed description of organic Rankine cycle technologies and the way they are increasingly of interest for cost-effective sustainable energy generation. Popular applications include cogeneration from biomass and electricity generation from geothermal reservoirs and concentrating solar power installations, as well as waste heat recovery from gas turbines, internal combustion engines and medium- and low-temperature industrial processes. With hundreds of ORC power systems already in operation and the market growing at a fast pace, this is an active and engaging area of scientific research and technical development.
The book is structured in three main parts: (i) Introduction to ORC Power Systems, Design and Optimization, (ii) ORC Plant Components, and (iii) Fields of Application.
Provides a thorough introduction to ORC power systems
Contains detailed chapters on ORC plant components
Includes a section focusing on ORC design and optimization
Reviews key applications of ORC technologies, including cogeneration from biomass, electricity generation from geothermal reservoirs and concentrating solar power installations, waste heat recovery from gas turbines, internal combustion engines and medium- and low-temperature industrial processes
Various chapters are authored by well-known specialists from Academia and ORC manufacturer
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
Definition of a general performance map for single stage radial inflow turbines and analysis of the impact of expander performance on the optimal ORC design in on-board waste heat recovery applications
Full text linkSmall-scale Organic Rankine Cycles (ORCs) represent a promising technology for on-board waste heat recovery (WHR) from internal combustion engines (ICEs) especially in innovative long-haul trucks transport applications. Despite market leader companies have already proved its effectiveness, detailed system design procedures are scarcely available in the open literature and proposed solutions are often more simplified with respect to current industrial state-of-art. The present work describes a methodology to include within the ORC design and optimization procedure an efficiency map of the turbo-expander, retrieved exploiting a reduced-order method developed in-house. The proposed approach allows therefore to design the thermodynamic cycle considering a realistic performance of the expander and to retrieve the best cycle architectures and turbine geometry depending on heat source characteristics and active constraints. First the turbine performance is defined in general terms and investigation of its applicability to different fluids and to expansions characterized by various degrees of non-ideality is provided. Then, the methodology is applied to different WHR applications highlighting for several potential working fluids the impact of adopting turbine performance maps within the cycle optimization procedure rather than assuming constant efficiency values. Results show that the cycle configuration and the main design parameters are strongly affected by the plant size and the working fluid selection, and that the adoption of a turbine performance map is particularly valuable when dealing with small size power plants adopting high density fluids. In particular, the assumption of constant turbine efficiency may lead to the definition of thermodynamic cycles extremely far from the optimal ones (e.g. adoption of supercritical cycles rather than subcritical ones) that in turn can result in an unfeasible design of the turboexpander. Moreover, this assumption may also lead to an incorrect comparison between different candidate working fluids lacking in identify those more suitable for a specific plant size. Both those limits can be solved with the adoption of the expander performance map proposed in this work. Final results show that on board WHR ORC can reach an efficiency of at least 20% in a relatively large range of internal combustion engine size. On the contrary, the choice of the best working fluid is affected by engine size and chosen hot sources: for small available thermal power the use of complex and flammable hydrocarbons (cyclopentane, cyclohexane, toluene) is the most efficient choice while the use of low GWP non-flammable halogenated hydrocarbons (R1233zd and R245fa) becomes promising only for relatively large available thermal power
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
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
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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