1,720,960 research outputs found
La trigenerazione per riqualificare il sistema energetico dell'Università
No full textPresso il Comprensorio Principale dell’Università di Trieste sono in fase di ultimazione dei complessi lavori di ristrutturazione del sistema di teleriscaldamento, inquadrabili in un più ampio progetto di riqualificazione dell’intero sistema energetico, promosso e coordinato nell’ambito dell’attività di Energy Management condotta dallo scrivente.
L’intervento si propone come obiettivi primari il potenziamento della capacità di generazione e distribuzione del calore, l’integrazione dei sistemi termico ed elettrico, il risparmio energetico, la salvaguardia ambientale e la sicurezza sul luogo di lavoro.
Sul piano distributivo si segnala la realizzazione di una rete di distribuzione del calore completamente rinnovata e potenziata, articolata su tre distinti circuiti ad acqua calda, in grado di vettoriare l’intera potenza termica installata in centrale termica (12 MW equamente ripartita su tre caldaie ad acqua calda) a copertura dell’intero fabbisogno della cittadella universitaria (circa 8 MW) con ampio margine di riserva. Un aspetto qualificante del nuovo sistema di distribuzione del calore è rappresentato dall’adozione di coibentazioni a cella chiusa che, insensibili alle problematiche di stillicidio, permettono l’eventuale circolazione di acqua refrigerata, quale indispensabile premessa per il ricorso alla produzione centralizzata del freddo in regime di trigenerazione.
In termini di sicurezza sul luogo di lavoro, si sottolinea la completa e definitiva soluzione del problema amianto, completamente rimosso dai rivestimenti coibenti delle vecchie tubazioni, mentre sul fronte della salvaguarda ambientale è evidente la valenza del ricorso al metano in sostituzione dell’olio combustibile denso, resa possibile dal potenziamento della rete cittadina con la realizzazione di una nuova linea in media pressione (5 bar) da 200 mm per una lunghezza di circa 500 m. Da ultimo si richiamano le ovvie e positive ricadute dell’adozione di severi parametri di isolamento termico nella coibentazione delle nuove linee di distribuzione nonché i risparmi economici conseguenti all’uso del gas rispetto all’olio combustibile.
Se dunque gli interventi in fase di ultimazione sono di evidente interesse nei riguardi degli obiettivi in precedenza evidenziati, ulteriori e maggiori benefici potrebbero scaturire con la piena realizzazione dell’integrazione dei sistemi termico ed elettrico, mediante l’adozione di un sistema di trigenerazione.
Tale proposta trae origine dalla considerazione dalla concentrazione in un’area circoscritta di una molteplicità di utenze termiche ed elettriche interconnesse in un sistema energetico totalmente rinnovato e già predisposto per la produzione combinata di energia elettrica e calore, in grado di abbattere significativamente i costi di realizzazione di un sistema trigenerativo.
Alla luce di quanto sopra esposto è sembrato utile condurre uno studio di fattibilità tecnica ed economica di un impianto di trigenerazione, quale utile elemento decisionale nella definizione di una strategia di razionalizzazione energetica e di contenimento dei costi.
I risultati cui si perviene, particolarmente incoraggianti anche in considerazione delle ipotesi cautelative assunte a base di progetto, delineano dei risparmi annui di circa € 460.000 con un tempo di recupero dell’investimento di circa 3 anni, con interessanti e positive ripercussioni nei riguardi della decongestione del sistema di distribuzione dell’energia elettrica, allo stato attuale ormai saturo
Investigating the effect of laser power modulation in transient states during fusion cutting of 10 mm thick AISI304
Full text linkIn fusion laser cutting of intricate geometries, the processing speed often varies significantly from its nominal value due to inherent machine dynamics. These variations can lead to excessive energetic input and drifts from the reference cut quality. To address defect formation during transient conditions, a conventional approach involves power reduction to compensate for speed variations. This help prevent thermal imbalances and material overheating issues, ultimately preserving the final cut’s quality. An alternative solution is based on pulsed wave emission, providing dynamic and precise control over the thermal energy delivered to the workpiece. In this work, pulsed wave emission was employed to ensure process stability during transient conditions for fusion cutting of 10mm AISI304. A 6kW fiber laser was utilized alongside a coaxial camera-based monitoring setup to observe the melt dynamics. Results demonstrate that power modulation effectively reduces defect formation, and process emission images can be exploited to identify successful cuts
Effects of laser cutting on the chemical composition and phase transformation capacity in Cu-Al-Mn shape memory alloy sheets
No full textApplication of laser cutting operations on thin sheets of Cu-Al-Mn shape memory alloys can be used for shaping, or for producing different types of holes and hole patterns within the SMA sheets. In this paper, the authors evaluate the effects of laser cutting under different process parameters on the phase and chemical composition in Cu-Al-Mn sheet samples. The effects are observed using optical and scanning electron microscopy (OM and SEM), energy-dispersive x-ray spectroscopy (EDS), and differential scanning calorimetry (DSC)
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
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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