1,721,271 research outputs found
Optimum Turbomachine Selection for Power Regeneration in Vapor Compression Cool Production Plants
No full textPower Regeneration in Refrigeration Plant concept has been analyzed and has been shown to be capable of saving about
25% power in Cryogenic Plants with the Power Regeneration System (PRS) running under nominal conditions. The innovative component Compressor Expander Group (CEG) based on turbomachinery has been designed and built modifying CETT compressor and expander, both selected for optimum plant performance. Experiments have shown the good response of the turbomachines to run with R404a as working fluid. Power saving up to 12% under PRS derated conditions
(50% loading) has been demonstrated. Such experiments allowed predicting a power saving up to 25% under CEG full load
Energy storage technologies as techno-economic parameters for master-planning and optimal dispatch in smart multi energy systems
No full textSmart multi-energy systems based on distributed polygeneration power plants have gained increasing attention for having shown the capability of significant primary energy savings and reduced CO2 pollutant emissions due to the high renewable energy sources penetration. Compared to the traditional power plants, the large variability in the end-user demands (electricity, heat and cold energy), coupled with the uncertainty in the solar and wind energy availability, require the adoption of energy storage systems for dampening the intermittency problems and for performing peak shaving. In a multi-energy system, energy storage technologies typically exist in the form of electrochemical energy and thermal energy storage. Costs and technological limits of energy storage systems are the key parameters that influence the optimal design and operation of the system. In this paper, by adopting an in-house developed simulation tool (©E-OPT) based on mixed integer quadratic programming, a sensitivity analysis has been carried out for investigating the techno-economic impact of different storage technologies (i.e. lithium-ion, Vanadium redox, ice and phase change material thermal storage) for optimally designing and operating a multi-energy system. Two case studies, characterized by electricity and peak cooling demand of 1600 kWe and 3000 kWc respectively, have been assessed and the results of master-planning and optimal dispatch discussed for two scenarios, grid-connected and island mode. The results show that multi-energy systems which include combined heat and power units, solar PVs and energy storage systems lead to achieve more than 1.1 M savings in net present value and 15% and 25% reduction in CO2 emissions, when compared with traditional power plant generation
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
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
Reseñas. Volumen 13 (2024)
No full textThe following scientific contributions are reviewed in this volume:
- GÓMEZ ROMÁN, Ana María. El Palacio del Conde de Luque en Granada. Despliegue artístico y nobleza ilustrada. Granada: Editorial Universidad de Granada, 2024. ISBN: 978-84-338-7107-7.
- MAZZONI, Stefano: Europa in festa. Lo spettacolo dal Cinquecento all’Ottocento. Firenze, Polistampa, 2024, ISBN: 978-88-596-2143-0. En este volumen se reseñan las siguientes contribuciones científicas:
- GÓMEZ ROMÁN, Ana María. El Palacio del Conde de Luque en Granada. Despliegue artístico y nobleza ilustrada. Granada: Editorial Universidad de Granada, 2024. ISBN: 978-84-338-7107-7.
- MAZZONI, Stefano: Europa in festa. Lo spettacolo dal Cinquecento all’Ottocento. Firenze, Polistampa, 2024, ISBN: 978-88-596-2143-0
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