Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 11 of 11 for “"three-way catalyst"”.
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Experimental and numerical study of the behavior of three-way catalytic converters under different engine operation conditions
The thesis reports the studies on how the three-way catalytic converters behave under different operation conditions. The main focus of the work is in the oxygen storage capacity of the three-way catalyst. Rich-to-lean air/fuel ratio step-change experiments were carried out to quantify the oxygen …
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Closed-Loop Combustion Control of a Multi Cylinder HCCI Engine using Variable Compression Ratio and Fast Thermal Management
… current Spark Ignited (SI) engine equipped with three-way catalyst offers low emissions, but has low efficiency at part load, which results in unnecessarily high CO2 emissions. The Compression Ignited (CI) engines have higher efficiency and hence lower CO2 emissions, but suffer from higher …
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CO and Hydrocarbon Oxidation on PD/Ceria-Zirconia/Alumina Three-Way Catalysts
… impact of automotive emissions. Over the years, three-way catalysts (TWCs) have been developed and widely implemented to control and reduce tailpipe emissions of carbon monoxide (CO), hydrocarbons (HCs), and nitrogen oxides (NOx) by converting these harmful and undesirable species to CO2, H2O, …
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Examination of the high load limit of an HCCI engine
… emission and by the need to maintain a minimum catalyst temperature on HCCI operation. Then the nature of the approach to high load limit was examined for three fuels with very different behavior.An engine simulation was used to examine constrains imposed by NOx emission and by catalyst …
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Ash impacts on gasoline particulate filter performance and service life
… shown to increase the light-off temperature of three-way catalyst coatings in GPF.
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Characterization of the composition and toxicity of particulate matter emissions from advanced heavy-duty natural gas engines
… agencies. Also, the ammonia emissions from three-way catalyst equipped heavy-duty natural gas engines could be a major contributor to the formation of secondary PM in the atmosphere.;This CARB funded study focuses primarily on characterizing the toxicity of the volatile fraction of PM from …
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Evaluation of advanced air-fuel ratio control strategies and their effects on three-way catalysts in a stoichiometric, spark ignited, natural gas engine
… expected to decrease further in the future. A three-way catalyst (TWC) is a cost-effective exhaust after treatment system can be used to reduce pollutant emissions through a series of reactions that are catalyzed by special conditions within the catalyst. Using TWCs, emissions can be …
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Feed-Forward Air-Fuel Ratio Control during Transient Operation of an Alternative Fueled Engine
… from stoichiometric combustion, allowing the three-way catalyst to operate in its most efficient range. The research detailed in this thesis shows the effectiveness of using a model-based approach to air-fuel ratio control and the importance of adaptive algorithms for day-to-day changes in …
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Diluted Operation of a Heavy-Duty Natural Gas Engine - Aiming at Improved Effciency, Emission and Maximum Load
… high fuel prices, high technology costs (e.g. catalysts, fuel injection systems) and unsustainably in supplying fuel are enough reasons to convenience engine developers to explore alternative technologies or fuels. Using natural gas/biogas can be a very good alternative due to the attractive …
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Octane requirement increase arising from the use of lead free fuel
… in CO and HC's with the employment of a three-way catalyst is also discussed. All tests were carried out on a Fiat 127A engine at wide open throttle and standard timing setting. A Froude dynamometer was used to vary engine speed. With the introduction of lead-free petrol, interest in …
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The development of ceria-based catalysts for automotive after-treatment applications
… for the development of cost-effective industrial catalysts and is, therefore, the focal material for this work.<br/><br/>Modern internal combustion engine technology is being directed towards lean burn operation, involving higher air-fuel ratios in order to improve thermal efficiency. In turn, the …