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 20 of 28 for “"NOx emission"”.
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Mechanistic Investigation of FCC CO/NOx Emission Control Additives
… released from this unit in the form of NOx and NH3. Among the different technologies currently employed to control these pollutants, the use of catalytic additives is the most attractive one, as it is simple, cost-effective, and applicable to existing FCC units without the need for …
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Two-Phase Anaerobic Digestion to Reduce the NOx Emission Potential of Biogas
… power production, but in air basins with strict emissions limits, biogas combustion is difficult to implement due to the high costs of controlling NOx emissions. NOx production can be minimized by blending H<sub>2</sub> gas with CH<sub>4</sub> at a volume ratio of 15:85 …
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Performance simulation and control design for diesel engine NOx emission reduction technologies
Fuel efficiency and emission reductions are the two consistent drivers for internal combustion engine development for both on-highway and off-road vehicles. Advanced combustion technologies are proposed for the improvement of fuel consumption and reduction of harmful gas production inside the …
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Applied and Fundamental Studies of LNT-SCR Dual-layer Monolithic Catalysts for Lean NOx Emission Control
… stringent both greenhouse gas (GHG) and tailpipe NOx emission standards have driven the continuous improvement of commercial deNOx technologies, NOx reduction & storage (NSR, also referred to as lean NOx trap (LNT)) and selective catalytic reduction (SCR) technologies. This dissertation conducts …
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Effects Of Transport Properties And Flame Unsteadiness On Nitrogen Oxides Emissions From Laminar Hydrogen Jet Diffusion Flames
… role in maximum flame temperature and affect NOx emission from jet diffusion flame. The fuel Lewis number is varied by increasing/decreasing the mole fraction of diluents in the fuel stream. Therefore, maximum flame temperatures and then NOx emission levels were expected to differ for Ar- and …
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Examination of the high load limit of an HCCI engine
… examines constrains imposed by nitric oxide (NOx) 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 …
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Unraveling the fingerprints of NOx using stable isotopes: Implications for NOx source partitioning and oxidation chemistry
… composition (δ15N & δ18O) of nitrogen oxides (NOx )may be a useful tool for constraining NOx emission sources as well as for understanding the atmospheric oxidation pathways responsible for its removal if various NOx sources and sink processes exhibit characteristic isotopic compositions …
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Influence of recent Asian SO₂ and Asian NOx̳ emissions change (2001 to 2010) on particulate matter : shifts in Asian sulfate enhancement over US surface, major production pathway, and lifetime
… of recent (2001 to 2010) growth in Asian NOx and Asian SO 2 emission on transpacific transport of Asian particulate matter, especially sulfate, by quantifying and analyzing the details of chemistry and its sequential influence on transpacific transport during spring and summer. From 2001 …
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Simulation of Combustion and Thermal-flow Inside a Pyroscrubber
… of unburned volatiles, solid carbon, ashes, or emissions (e.g. CO, NOx and SOx) in the flue gas finally discharged. To maximize the energy recovery and reduce pollutant emission from the pyroscrubber, 3-D computational models are developed using FLUENT to simulate the combustion and thermal-flow …
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An improved method of investigation of combustion parameters in a natural gas fuelled SI engine with EGR and H2 as additives
… A new method to predict the trends of MFB and emissions, based on the online analysis of cylinder pressure is introduced. A diagnostic method to study the heat release rate in a natural gas fuelled engine has been developed for future use. Natural gas fuelled vehicles are environmentally …
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Model-based active control of thermoacoustic instability in continuous combustion processes
… maintaining performance objectives such as low NOx emission and high efficiency. This thesis considers the physics behind the thermoacoustic instability and utilizes a model based on the physics to understand the problem and design an active controller to suppress the instability. A …
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Modeling and Simulation of Coupled LNT – SCR Catalytic System under Anaerobic and Aerobic Operating Conditions
… metal loading in the LNT while keeping the NOx emission below a specified level. We present a mathematical model of this system using hydrogen as the reductant. Simulations are used to determine the influence of the architecture of the LNT-SCR bricks, non-uniform precious metal loading in …
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Methodology for characterization of representativeness uncertainty in performance indicator measurements of thermal and nuclear power plants
… using a Photomodeler (Case Study 3) and the NOx emission measurement from a Combined Cycle Gas Turbine (Case Study 4). In Case Study 1, the non-parametric bootstrap method was used to quantify sampling, iterative and discretization uncertainties thus demonstrating its applicability to CFD …
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Uncertainties in estimates of the oxidative capacity of the urban atmosphere : a modeling and measurement approach
Mobile emissions represent a significant fraction of the total anthropogenic emissions burden in megacities and have a deleterious effect on air quality at local and regional scales. Due to the significant sources of uncertainties involved during the estimation of mobile emissions, an adequate …
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Micro-physical modeling of aircraft exhaust plumes and condensation Trails
… current and future impacts on the environment. Emissions from aircraft engines are a significant contributor to atmospheric NOx driving climate change, air quality impacts and other environmental concerns. To quantify these effects, global chemistry-transport models are frequently used. However, …
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Air quality analysis of nitrogen oxides and relationships with ozone pollution
… in high enough concentrations. Nitrogen oxides (NOx), especially nitrogen dioxide (NO₂), are increasingly of concern due to the environmental and health problems they cause. This reviews the recent literature on the reasons and impacts of NOx pollution as well as ozone pollution related to NOx …
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Effect of start injection toward combustion, performances and emision characteristic of B20 biodiesel fuel
… of biodiesel fuel. The performance and exhaust emission have been tested with blended B10 biodiesel (10% POME and 90% pure diesel) and compared with B20 biodiesel (20% POME and 80% pure diesel). The engine was tested under full load steady-state conditions at 1800rpm to 3400rpm with variable …
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The effect of fuel injection pressure and in cylinder temperature on igniton delay, combustion performance and emission
… process that strongly affects the exhaust emissions. This study investigated effects of ambient temperature,Ti and injection pressure, Pinj on the heat release process during ignition delay periods. Rapid compression machine (RCM) was used to simulate actual phenomenon inside the combustion …
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Performances of a Spark Ignition (SI) engine fuelled with Liquefied Petroleum Gas (LPG) using Liquid Sequential Injection (LSI) technique
… more power in SI engines and to reduce exhaust emissions. An experimental work was conducted on a 1.6 Liters, 4-cylinder engine from a Proton Gen 2 (S4PH), equipped with gasoline Multi Point Port Injection (MPI) system. The engine was retrofitted with LPG Liquid Sequential Injection (LSI) and a …
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New insights into understanding urban traffic emissions using novel mobile air quality measurements in the Breathe London pilot study
… measurements to better understand urban traffic emissions. As part of the Breathe London project, two Google Street View Cars (based at the National Physical Laboratory) were fitted with air quality monitoring instrumentation and were driven across London over approximately a one year period. …
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