1,721,257 research outputs found
Exhaust emissions and mutagenic effects of diesel fuel, biodiesel and biodiesel blends
No full textThe replacement of petroleum-derived fuels by renewable biogenic fuels has become of worldwide interest with the environmental effects being scientifically investigated. Biodiesel has been proven to be a suitable alternative to petrodiesel and blending up to 20% biodiesel with petrodiesel is policy promoted in the USA and the EU. To investigate the influence of blends on the exhaust emissions and possible health effects, we performed a series of studies with several engines (Euro 0, III and IV) using blends of rapeseed-derived biodiesel and petrodiesel. Regulated and non-regulated exhaust compounds were measured and their mutagenic effects were determined using the Bacterial Reverse Mutation Assay (Ames-Test) according to OECD Guideline 471. Exhaust emissions of blends were approximately linearly dependent on the blend composition, particularly when considering regulated emissions. However, a negative effect of blends was observed with respect to mutagenicity of the exhaust emissions. In detail, an increase of the mutagenic potential was found for blends with the maximum observed for B20. From this point of view, B20 must be considered as a critical blend when petrodiesel and biodiesel are used as binary mixtures. (C) 2012 Elsevier Ltd. All rights reserved
Comparison of exhaust emissions and their mutagenicity from the combustion of biodiesel, vegetable oil, gas-to-liquid and petrodiesel fuels
No full textEfforts are under way to reduce diesel engine emissions (DEE) and their content of carcinogenic and mutagenic polycyclic aromatic hydrocarbons (PAH). Previously, we observed reduced PAH emissions and DEE mutagenicity caused by reformulated or newly developed fuels. The use of rapeseed oil as diesel engine fuel is growing in German transportation businesses and agriculture. We now compared the mutagenic effects of DEE from rapeseed oil (RSO), rapeseed methyl ester (RME, biodiesel), natural gas-derived synthetic fuel (gas-to-liquid, GTL), and a reference petrodiesel fuel (DF) generated by a heavy-duty truck diesel engine using the European Stationary Cycle. Mutagenicity of the particle extracts and the condensates was tested using the Salmonella typhimurium mammalian microsome assay with strains TA98 and TA100. The RSO particle extracts increased the mutagenic effects by factors of 9.7 up to 17 in strain TA98 and of 5.4 up to 6.4 in strain TA100 compared with the reference DF. The RSO condensates caused up to three times stronger mutagenicity than the reference fuel. RME extracts had a moderate but significantly higher mutagenic response in assays of TA98 with metabolic activation and TA100 without metabolic activation. GTL samples did not differ significantly from DF. Regulated emissions (hydrocarbons, carbon monoxide, nitrogen oxides (NO.), and particulate matter) remained below the limits except for an increase in NO, exhaust emissions of up to 15% from the tested biofuels. Published by Elsevier Ltd
Abschlussbericht zum Forschungsvorhaben "Bestimmung der Emissionen und der Partikelgrößenverteilung (Feinstaub) im Abgas eines modernen Euro-4-Nutzfahrzeugmotors mit SCR-Abgasreinigung im Betrieb mit Biodiesel"
No full textVergleich des Modellverhaltens eines strukturierten mathematischen Modells mit dem neuronaler Netze
No full textSchlussbericht zum Forschungsvorhaben "Prüfstandsuntersuchungen zu Kraftstoffmischungen aus Diesel und Bioethanol (DBE): Abschlussbericht des IMS - Lehrstuhl für Kolbenmaschinen ; Teilbericht zum Unterauftrag der FAL ; Förderkennzeichen: 22005605
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Research project final report "Comparison of shell middle distillate, premium diesel fuel and fossil diesel fuel with rapeseed oil methyl ester"
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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
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