1,721,000 research outputs found
Analisi numerica dell’accoppiamento di materiali a cambiamento di fase a scambiatori geotermici
No full textL’impiego di materiali a cambiamento di fase (PCMs) è una soluzione diffusamente utilizzata per l’accumulo di energia termica, nell’ambito dello sfruttamento di risorse rinnovabili caratterizzate da una certa discontinuità della disponibilità energetica. Un’ulteriore possibilità di utilizzo è rappresentata dallo smorzamento della richiesta termica istantanea degli impianti di climatizzazione a pompa di calore, in particolare quelle geotermiche (GSHPs). In questo lavoro, un modello numerico agli elementi finiti è utilizzato per risolvere lo scambio termico nel terreno e valutare le prestazioni di scambiatori geotermici a installazione orizzontale (HGHEs) accoppiati all’utilizzo di materiali a cambiamento di fase. L’installazione proposta prevede che i PCMs siano miscelati direttamente con il materiale di riempimento delle trincee per l’alloggiamento di HGHEs, o in alternativa alloggiati in appositi contenitori posti a contatto con la superficie dello scambiatore. I risultati ottenuti mostrano che l'uso dei PCMs in accoppiamento a HGHEs è in grado di soddisfare parzialmente i picchi di richiesta per riscaldamento delle pompe di calore, smorzando le sollecitazioni termiche all’interfaccia scambiatore/terreno. Di conseguenza, i valori di picco della temperatura del fluido termovettore ne risultano ridotti e pertanto, è possibile raggiungere migliori rendimenti (COP) per le pompe di calore. Inoltre, l’utilizzo di PCMs rende possibile lo stoccaggio stagionale di energia termica per impianti con scambiatori geotermici orizzontali
Vertical Greening Systems and Urban Heat Island related aspects: outcomes of a research project
No full textVegetation in architecture can be assumed as a proper design strategy aimed at improving climate in cities and towns. Vertical Greening Systems (VGSs) and green roof are both building systems introduced extensively in recent times in architecture design. The interest about such systems is remarkable and it is often due to both their physics and environmental performances. A variety of ecological benefits can be ascribed to VGSs, i.e. heat island effect mitigation, noise abatement, heating and cooling energy demand reduction, absorption of particulate matters as well as of VOC, enhancement of biodiversity. Furthermore a noteworthy contribution is given towards those aspects related to extreme weather events affecting nowadays European cities, such as heat-waves and urban flooding. Within an industrial research project, focused on the design, manufacture and performance assessment of a VGS, a number of environmental issues were tackled in. The study was aimed, on one hand, identifying a methodology to select materials to be used in the module assembly and, on the other hand, at testing its performance during actual operating use. In this paper results are presented concerning the aspects related to UHI at the mere building envelope scale, as the assessment of the CO2 equivalent emissions due to manufacturing processes, the analysis of VGS thermal behavior and of its potential in reducing the wall external surface temperatures. These experimental results will constitute the starting point for a research activity aimed at evaluating, through the use of simulation tools, the UHI mitigation at building and urban scal
Apparent Temperature Index on different types of urban surface covers within a city park of Florence
No full textGoing 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
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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