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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 20 of 26 for “"catalytic converter"”.
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Life Cycle Analysis of a Ceramic Three-Way Catalytic Converter
… analysis compares the environmental impacts of catalytic converters and the effects of not using these devices. To environmentally evaluate the catalytic converter, the emissions during extraction, processing, use of the product are considered. All relevant materials and energy supplies are …
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Comparison of performance and emission characteristics between ceramic and metallic catalytic converter
Catalytic converters have been widely used on vehicles and have already been proved for many years to be the most effective technical solution to reduce exhaust emissions from gasoline engines where ceramic and metallic catalytic converters are the most common types of catalytic converter used. …
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Dynamic Incompressible Navier-Stokes Model of Catalytic Converter in 1-D Including Fundamental Oxidation Reaction Rate Expressions
… past, they might not work with new versions of catalytic converters and the architectures being proposed. In particular, classical models neglect viscosity, conductivity and diffusion in the bulk gas phase. However, in low flow rate regenerative catalysts, these terms might become important. In …
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Ultrasonic and electroplating approach for washcoat of γ-alumina and nickel oxide (nio) catalyst on fecral substrate for catalytic converter
… of pollutants from exhaust system by Three-Way Catalytic Converter (CATCO). Metallic material potential to replace the ceramic material, therefore FeCrAl substrate used as metallic material and γ-Al2O3 as washcoat material and NiO catalyst. This study propose ultrasonic and electroplating …
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Waste heat recovery in automobile engines : potential solutions and benefits
… heat energy from the exhaust through the catalytic converter with a Stirling engine was examined due to its practicality. A novel approach for combining a Stirling engine and a catalytic converter that would be effective was designed. The power output and efficiency of the Stirling Engine …
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Analysis of various fuels in DISI and PFI engines : separating mixing effects from crevice and quench layer effects
… in the exhaust during cold start, when the catalytic converter is further away from the engine. The time the catalytic converter takes to heat to an optimum efficiency is longer. UBHC can also accumulate in the cylinder chambers and can be caused by quenching effects or poor mixing. A system …
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Impact of retarded spark timing on engine combustion, hydrocarbon emissions, and fast catalyst light-off
… gas was tracked from cylinder-exit to the catalytic converter inlet using a variety of experimental techniques. Time-resolved exhaust port and exhaust runner hydrocarbon concentrations were converted to an exhaust HC mass flow rate and compared to time-averaged downstream HC levels. …
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Preparation and Characterization of Palladium Catalysts
… currently available, such as the three way catalytic converter (TWC), have low activity below 400 °C in the catalytic process. Palladium catalysts were prepared by alternative methods including: preparation by wet impregnation or incipient wetness, drying by room temperature or air-oven, and …
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Vehicular Ammonia Emissions in Baltimore, Maryland
… by a reaction of NOx with H2 in the three-way catalytic converter. Ammonia emissions were measured using a mass balance on the Fort McHenry Tunnel, Baltimore, Maryland. Atmospheric concentrations of gas-phase and particulate-phase ammonium were measured during 2003-2004 using denuders and …
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First-principles density functional theory study of sulfur oxide chemistry on transition metal surfaces
… by our chemical kinetics study focusing on the catalytic oxidation of SO2 under oxygen rich conditions. This is the key process that hampers the implementation of the next-generation automotive catalytic converter. The revealed Langmuir-Hinshelwood mechanism demonstrates the essential catalytic …
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The effect of complexes on combustion
… to be formed. Also by placing a catalyst converter in the exhaust system partial oxidation products may be converted to more desirable final products. Finally, in this research the net catalytic effect of using an additive treated fuel and a blank ceramic monolith to trap the metal in the …
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The autoignition characteristics of turbocharged spark ignition engines with exhaust gas recirculation
… extracts exhaust gases from upstream of the catalytic converter and another which extracts gases from downstream - in order to determine if the changes in composition that occur across the catalyst affect the autoignition abatement characteristics of the recirculated exhaust. This testing …
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Recovery of Precious Metals from Secondary Sources
… oxidants, for the recovery of Pd and Pt from catalytic converters and of Au from electronics using non-toxic reagents. The synthesis of dione and dithione ligands (1,4-dimethyl-2,3-piperazinedione, 1,4-dimethyl- 2,3-perhydrodiazepinedione, 1,4-dimethyl- 2,3-piperazinedithione, and …
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The acoustic modelling of dissipative elements in automotive exhausts
… testing of both dissipative silencers and catalytic converters is reported here, although dissipative silencers are of primary interest. The models examined are formulated with a view to introducing them into commercial software aimed at the acoustic design of automotive exhaust systems.The …
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Effects of secondary air injection during cold start of SI engines
… to maximize the simultaneous benefit of reducing converter-in emissions and improving catalyst lightoff performance during cold start. An experimental study was performed to develop a more fundamental understanding of the effects of SAI on exhaust gas emissions and catalyst light-off …
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The catalytic reduction of emissions from a natural gas fueled spark ignited engine
… One possible emissions reduction strategy is the catalytic aftertreatment of the engine-out exhaust for stoichiometric operation. The focus of this work was to develop a catalytic converter test facility, to evaluate the operational and emissions characteristics of a converted natural gas engine, …
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Spatio-Temporal Dynamics of Reaction Zones in Catalytic Monolith Reactors
Catalytic monolith reactors are widely used in exhaust after-treatment systems. Unlike traditional chemical reactors which are commonly operated around certain steady-states, monolith reactors are almost always in transient states due to the nature of their applications. In this work, we studied …
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Low-dimensional Models for Real-time Simulation of Internal Combustion Engines and Catalytic After-treatment Systems
… propose a low-dimensional model of the three-way catalytic converter (TWC) for control and diagnostics. Traditionally, the TWC is controlled via an inner-loop and outer-loop strategy using a downstream and upstream oxygen sensor. With this control structure, we rely on the oxygen sensor voltage to …
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Computer data acquisition, control, and analysis for the University of Tennessee at Chattanooga's internal combustion engine labratory
… rate of the supplementary air supplied to the catalytic converter is controlled using an OMEGA mass flow controller. This controller receives a voltage signal from the computer to determine the flow rate being supplied.Switching of the three solenoid valves that are used to choose the location …
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GMP „Quo vadis?“ Entwicklung eines spezifischen Bewertungstools „GMP-DAKS-Σ“ für die qualitative und quantitative Analyse von GMP-Systemen in onkologisch herstellenden Apotheken
… into quantitative results by means of a catalytic converter with subsequent comparison and processing using Six Sigma. Explorative data analysis by means of GMP-DAKS-Σ evaluation revealed that measurable improvements of the pharmaceutical quality management systems were achieved in the …
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