1,720,957 research outputs found
PERFORMANCE ENHANCEMENT OF VAPOUR COMPRESSION REFRIGERATION SYSTEMS USING NANOPARTICLES: AN EXPERIMENTAL STUDY
No full textIn recent years, the development and characterization of new refrigerants with higher energetic efficiency have gained considerable interest [1], with a particular emphasis on the energetic performance of suitable replacements. Nanofluids have been proposed as possible alternative due to their role in enhancing the thermophysical proprieties of traditional refrigerants [2]. The comprehensive review in [2] suggests that thermal conductivity of nanofluid increases with temperature and volume concentration but it is dependent on nanoparticle size distribution; specific heat is also increased if nanoparticles are added to the refrigerant. As consequence, the improved heat transfer coefficients lead to COP improvements for the same cooling capacity. Recently, the addition of nanoparticles to the compressor oil from a refrigerator has been found to reduce the friction coefficient up to 90% [3]; this suggests that nanoparticles migrating to the lubricant oil can also contribute to improve efficiency and reliability of the system. Findings from the literature are however contradictory at times [2]; it is therefore necessary to further explore the benefits of using nanoparticles dispersed in refrigerants. The present work focuses on a quantitative analysis of the performance enhancement for a vapour-compression refrigeration system due to addition of aluminium oxide (Al2O3) nanoparticle to a commercially available refrigerant, tetrafluoroethane (R134a)
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
Il Progetto “Mentori per la didattica” dell’Università di Palermo dopo sei anni dalla nascita e le iniziative future
No full textL’Ateneo di Palermo sta portando avanti diverse iniziative di miglioramento della qualità della didattica. In particolare, il progetto “Mentori per la didattica” nasce nel 2013 su iniziativa di alcuni docenti di ingegneria con l’obiettivo di migliorare la qualità della didattica dei partecipanti grazie a due strumenti chiave: l’aiuto dei mentori e una serie di incontri di riflessione e approfondimento. Ogni docente (mentee) che aderisce al progetto ha due mentori che hanno il compito di aiutarlo a migliorare la qualità della sua didattica. Inoltre, egli stesso svolge il ruolo di mentore a favore di altri due colleghi, cosicché ciascuno è mentore e mentee allo stesso tempo. I mentori assistono ad alcune lezioni del mentee, incontrano gli studenti e raccolgono il loro parere sul corso e, infine, incontrano il mentee per individuare insieme delle strategie di miglioramento. I mentori non sono interessati ai contenuti della disciplina ma alle modalità di erogazione della lezione. Di conseguenza, non devono essere esperti della disciplina insegnata dal mentee. Il programma prevede anche una serie di incontri che servono per fornire strumenti operativi nonché spunti di riflessione sul tema dell’insegnamento e contribuiscono a realizzare una maggiore consapevolezza del ruolo di docente. Il successo riscosso tra i partecipanti ha fatto sì che, nel corso degli anni, il numero di docenti coinvolti sia aumentato, fino a superare gli ottanta nel 2018, grazie al passaparola, estendendosi a tutte le aree del sapere. Il programma è stato molto apprezzato dai partecipanti e dagli studenti ed ha ricevuto un positivo apprezzamento nella relazione della CEV, relativa alla visita in loco per l’accreditamento periodico dell’Università degli Studi di Palermo. Negli ultimi anni è stata anche prevista la figura dei mentori senior che si occupano di assistere e guidare l’attività dei mentori più giovani. Nella presentazione il progetto sarà illustrato con particolare riferimento ai risultati ottenuti negli anni. Inoltre, saranno presentate altre iniziative future dell’Ateneo di Palermo sul miglioramento della qualità della didattica inclusi dei percorsi di formazione per i neoassunti e per i coordinatori dei CdS e la creazione di un apposita struttura che si occuperà di implementare e coordinare le riflessioni sulle innovazioni metodologiche e tecnologiche e di organizzare i cicli di seminari sopra citati
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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