1,721,022 research outputs found
Innovazioni nello scavo meccanizzato in roccia
No full textNel corso degli anni l’evoluzione ed il perfezionamento dello scavo meccanizzato, sia per scopi estrattivi sia civili, sono stati oggetto di crescente attenzione. In ambienti di tipo hard rock, la tradizionale tecnica di scavo mediante Drill & Blast, ancora ampiamente impiegata per gallerie di breve o media lunghezza, è stata progressivamente sostituita, per gallerie di lunghezza notevole (mediamente superiore a 1 km), dallo scavo meccanico a piena sezione mediante Tunnel Boring Machine (TBM), a fronte di notevoli vantaggi soprattutto in termini di tempi e sicurezza in fase di realizzazione. Il successo di tale tecnica è fortemente influenzato dalle caratteristiche dell’opera da realizzare e dalle proprietà del materiale oggetto dello scavo. Nei decenni passati sono stati raggiunti numerosi progressi circa l’ottimizzazione dello scavo con TBM in condizioni ideali, storicamente associate ad ammassi rocciosi con caratteristiche omogenee e ricorrenti lungo il tracciato della galleria. La sfida attuale riguarda la messa a punto di macchine sempre più “flessibili”, in grado di essere impiegate efficacemente anche in ammassi rocciosi eterogenei.
Il presente studio ha lo scopo di illustrare le recenti innovazioni nel campo delle hard rock TBM. Sono analizzate le diverse tipologie di macchine impiegabili in differenti configurazioni e condizioni di scavo, evidenziando gli aspetti critici per la progettazione e realizzazione di macchine innovative, con particolare riferimento agli scavi in aree montane, in genere caratterizzati da notevoli lunghezze del tracciato e da elevate coperture.
Sono infine riportati esempi di recente impiego di TBM per la realizzazione di gallerie in condizioni geotecniche difficili
Green fuel production by coupling plastic waste oxy-combustion and PtG technologies. Economic, energy, exergy and CO2-cycle analysis
No full textThis study deals with the simulation of a waste to energy plant, with the implementation of a power to gas unit that converts the CO2 produced by the incineration of the municipal solid waste in methane. The simulation study was supported by the environmental, i.e. CO2-cycle analysis, economic and exergetic analysis. Three plant configurations were considered, in which the difference between the use of combustion air and pure oxygen as oxidant was analyzed. The work shows that a WtE plant implemented with a PtG unit is able to produce up to 1317 Nm3/h of methane with 940 kg/h of plastic waste feed, with a fuel cost for the base scenario of 5 $/MWh. Finally, in this work the energy and exergy analysis were carried on different scenarios resulting in a maximum value for energy and exergy efficiency of 36% and 26.4%, respectively
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
Strategie e problemi relativi all’intervento dello psicologo clinico in un Centro di Foniatria
No full textDispelling 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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