1,720,957 research outputs found
Development of Calibration Strategies for Gasoline Direct Injection Engines within the Scope of Sustainable Mobility
Full text linkAl fine di limitare i contributi al riscaldamento globale dovuto alla combustione di combustibili fossili, i principali paesi del mondo hanno fissato nuovi obiettivi sulla riduzione del consumo di carburante dei veicoli e delle emissioni di CO2 dallo scarico. Man mano che gli standard sulle emissioni di CO2 in tutto il mondo diventano più rigorosi, il motore turbocompresso a iniezione diretta di benzina (GDI) ridimensionato fornisce una piattaforma matura per ottenere un migliore risparmio di carburante. Per questo motivo, si prevede che il motore GDI acquisirà quote crescenti di mercato nei prossimi anni. L'iniezione di liquido nel cilindro, sebbene vantaggiosa nella maggior parte dei regimi di funzionamento del motore, crea emissioni durante le fasi di avviamento a freddo e di minimo rapido a freddo. L'avviamento a freddo del motore è responsabile di una quota sproporzionata di idrocarburi (HC), monossido di carbonio (CO), ossidi di azoto (NOx) e particolato (PM) emessi durante il ciclo di certificazione. La comprensione delle fonti degli inquinanti in questa fase è necessaria per l'ulteriore penetrazione nel mercato di GDI sotto il vincolo di standard di emissione più rigorosi. Questa tesi si propone di esaminare i processi di formazione dei principali inquinanti in varie condizioni in un motore GDI e la sensibilità delle emissioni inquinanti a differenti strategie di calibrazione. A tal fine è stata effettuata un'analisi dettagliata dei principali parametri di combustione del motore. I risultati mostrano che i processi di formazione degli inquinanti sono fortemente dipendenti dalla formazione della miscela e dallo storico di temperatura e pressione del processo di combustione, quindi particolare attenzione deve essere riservata alla calibrazione del motore.In order to limit the contributions to global warming due to burning of fossil fuels, major countries across the world have set new targets on reducing vehicular fuel consumption and tailpipe CO2 emissions. As the CO2 emission standards around the world become more stringent, the turbocharged downsized gasoline direct injection (GDI) engine provides a mature platform to achieve better fuel economy. For this reason, it is expected that the GDI engine will capture increasing shares of the market during the coming years. The in-cylinder liquid injection, though advantageous in most engine operation regimes, creates emissions during the cold crank-start and cold fast-idle phases. The engine cold-start is responsible for a disproportionate share of the hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NOx) and particulate matter (PM) emitted over the certification cycle. Understanding the sources of the pollutants during this stage is necessary for the further market penetration of GDI under the constraint of tighter emission standards. This thesis aims to examine the formation processes of the principal pollutants during various conditions in a GDI engine, and the sensitivity of the pollutant emissions to different calibration strategies. To this end, a detailed analysis was carried out with regard to the main engine combustion parameters. The results show that the pollutant formation processes are strongly dependent on the mixture formation and on the temperature and pressure history of the combustion process, so particular attention must be reserved to the engine calibration
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
Assessing patients' involvement in decision making using the Italian version of option instrument during obstertric consultation
No full textAuthor-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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