1,720,968 research outputs found
Fuel injection parameters study for low exhaust emissions of a common-rail diesel engine fueled with different biodisesels' blend / How Heoy Geok
Get PDFNowadays, the use of diesel engines is increasing rapidly due to their superior fuel economy, higher efficiency and excellent reliability. The energy crisis of fossil fuel depletion, rising price of diesel and environmental degradation have triggered a search for clean, sustainable and alternative fuels for internal combustion engines. Biodiesel is one of the most promising alternative fuels because it is a biodegradable, non-toxic and renewable fuel. This research aims to produce biodiesel from different feedstock such as coconut, calophyllum inophyllum and moringa oleifera oil and tested in a medium-duty four-cylinder diesel engine. In addition, the in-house produced coconut biodiesel was also used in the study of the effects of biodiesel blends, fuel injection timing, split injection schemes, injection dwell angle and mass ratio on the engine performance, emissions and combustion characteristics. At the first stage, a detailed investigation and characterization of key physicochemical properties were carried out. This was followed by the investigation of the effects of the usage of all these biodiesel blends on engine performance, emissions, exhaust particulate matter and combustion under different engine operating conditions. At second stage, parametric studies relating with start of injection timing variation and multiple injection schemes using COB20 and COB50 blends were performed and benchmarked with petroleum diesel fuel as baseline. At the final stage, the impact of two-stage injection dwell angle and mass ratio on engine performance, emissions and combustion characteristics using coconut biodiesel blends were investigated. The results showed that all biodiesel fuels and its blends have physicochemical properties relatively close to those of petroleum diesel. The experimental results also suggested that there are some penalties in engine brake power, brake specific fuel consumption (BSFC), and nitrogen oxide (NOx) blends with the presence of biodiesel fuel in the blend. The second stage experimental results revealed that a remarkably lower NOx level below 100 ppm can be obtained by retard SOI timing for both of the COB20 and COB50 fuel operations and with triple injection scheme. Multiple split injections is a practical strategies to simultaneously decrease NOx and smoke emissions when the SOI timing is fine-tuned and is an ideal alternative to operate with biodiesel fuel. For the last stage experiment, the results showed that exhaust emissions, engine performance and combustion characteristics are substantially affected by types of fuel and SOI timing but slightly influenced by two-stage injection dwell angle. Also, a considerably lower level of NOx below 90 ppm is achievable via late SOI timing for fuel operations conducted using COB20 or COB50 biodiesel blends with injection mass ratio of 25:75. Overall, the results indicated that biodiesel from coconut, calophyllum inophyllum and moringa oleifera oil can be used satisfactorily in the modern high-pressure common-rail diesel engine without modification. Besides, the results revealed that multiple and two-stage fuel injection with different mass ratio and dwell angle are practical strategies to simultaneously decrease NOx and smoke emissions when the SOI timing is fine-tuned and is an ideal alternative to operate with biodiesel fuel
Preparation of papers for IEEE Transactions and Journals (May 2007)
No full textThese instructions give you guidelines for preparing papers for IEEE TRANSACTIONS and JOURNALS. Use this document as a template if you are using Microsoft Word 6.0 or later. Otherwise, use this document as an instruction set. The electronic file of your paper will be formatted further at IEEE. Define all symbols used in the abstract. Do not cite references in the abstract. Do not delete the blank line immediately above the abstractit sets the footnote at the bottom of this column
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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