Dissertations / Theses: 'Fuel emissions'

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Sukjit, Ekarong. "Synergistic effects of alcohol-based renewable fuels : fuel properties and emissions." Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/4674/.

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Biodiesel is known to improve the fuel properties of alcohol-diesel blends. However biodiesel is obtained from different feedstock and consequently the composition can be different, with varying fatty acid profiles resulting in different physical and chemical properties and a different response when blended with alcohol-diesel blends. To understand the effect of molecular structure of biodiesel on fuel properties and emissions, the most representative individual fatty acid methyl esters were added to alcohol-diesel blends. The results show that 15% of all methyl esters was enough to avoid phase separation of alcohol-diesel blends and keep the wear scar diameter of the blends below the limitation required by lubricity standards. Short carbon chain length and saturated methyl ester are recommended to improve emissions of alcohol-diesel blends. A comparison between two different alcohols used in the engine tests highlighted that butanol blends were more effective in reducing carbonaceous gas emissions and particulate matter emissions than ethanol blends. Further research on the effect of molecular structure of biodiesel on alcohol-diesel blends was conducted to understand influence of hydroxylated biodiesel which is derived from castor oil. The existence of hydroxyl group in biodiesel considerably improves the lubricity of alcohol-diesel blends. It was also shown to be beneficial in terms of engine-out emissions such as enhancing soot oxidation and reducing activation energy to oxidise soot emissions. To counteract the likely increase in gaseous carbonaceous emissions with alcohol blends, the addition of hydrogen to replace part of the carbon within the liquid fuel was studied. The incorporation of hydrogen and alcohol blends indicates that there was a dramatic reduction in carbon dioxide, unburnt hydrocarbons and particulate matter emissions.

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Winborn, Lorne Derek. "The cold operation of SI engines and the significance of fuel losses, oil dilution and mixture gas/fuel ratio." Thesis, University of Nottingham, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366597.

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3

Flora, Giacomo. "Fuel Structure Effects on Surrogate Alternative Jet Fuel Emission." University of Dayton / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1450286398.

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Creery, Niall James. "Inlet manifold fuel film study." Thesis, Queen's University Belfast, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343081.

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Tzillah, Aisha. "The Emissions of Criteria Air Pollutants from Biodiesel Fuel Usage." University of Cincinnati / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1258667095.

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Romo, Millares Cesar Alfredo. "Mathematical modelling of fuel NO emissions from PF burners." Thesis, Imperial College London, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282876.

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Xiao, Zhiying. "Influence of fuel composition on diesel combustion and emissions." Thesis, Brunel University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285096.

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8

Lake, Timothy Hugh. "Gasoline combustion systems for improved fuel economy and emissions." Thesis, University of Brighton, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302289.

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This document is the statement of independent and original contribution to knowledge represented by the published works in partial fulfilment of the requirements of the University of Brighton for the degree of Doctor of Philosophy (by publication). The thesis reviews the impact of research work conducted between 1992 and 1998 on various concepts to improve the economy and emissions of gasoline engines in order to address environmental and legislative pressures. The research has a common theme, examining the dilution of the intake charge (with either recycled exhaust gas [EGR], excess air, or the two in combination) in both conventional port injected [MPI] and direct injection [G-DI] combustion systems. After establishing the current status of gasoline engine technology before the programme of research was started, the thesis concentrates on seven major pieces of research between 1992 and 1996. These explored a subsequently patented method of applying recycled exhaust gas to conventional port injected gasoline engines to improve their economy and emissions whilst staying compatible with three-way catalyst systems. Nine other studies are reviewed which took place between 1992 and 1999 covering other methods of improving gasoline engines, specifically direct injection and two-stroke operation. Together, all the studies provide a treatise on methods to improve the gasoline engine and the thesis allows a view from a broader perspective than was possible at the time each study was conducted. In particular, the review identifies a range of strategies that use elements of the research that can be used to improve economy and emissions. Four major categories of systems researched include: conventional stoichiometric MPI engines developed to tolerate high EGR rates [CCVS]; two-stroke G-DI engines; G-DI engines operating stoichiometrically with high EGR rates; and G-DI engines operating with high dilution from both excess air and EGR. The findings of the studies illustrate that although good fuel economy improvements and emissions can be obtained with EGR dilution of stoichiometric engines, the highest fuel economy improvements require lean deNOx aftertreatment [LNA] and these, in turn, require new aftertreatment technologies and preferably new fuel specifications. The development of suitable LNA and the cost of implementation of these approaches represents one of the main barriers to improving gasoline engine fuel economy and emissions.

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Kurji, Hayder. "Fuel flexibility with low emissions for gas turbine engines." Thesis, Cardiff University, 2017. http://orca.cf.ac.uk/104977/.

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This work examined the performance of swirl burners using different injection strategies for various substitute fuels. The research procedure involved various stages; firstly, an assessment study between two liquid fuels, a pure biodiesel and saturated biodiesel, compared to kerosene. Atomization forms were obtained, and a combustion test campaign was initiated using a generic swirl burner. Emissions and power outputs were measured at gas turbine relevant equivalence ratios. Excess oxygen and atomization trends in the biodiesel seem to be playing a significant role in the creation of emissions and flame stability when compared to kerosene. Secondly, an experimental study on the combustion of methane-carbon dioxide mixtures was achieved. Gas mixtures were examined by using different injection strategies with and without swirl and with and without central injection. A smaller 20-kW swirl burner was used to analyse stability and emissions performance by using these blends and to study the impact of CO2 addition. The burner configuration comprised a centre body with an annular, premixed gas/air jet introduced through five, 60° swirl vanes. CO2 dilution reduced flame stability and operability range. The introduction of CO2 decreases temperatures in the combustion zone thus producing a lessening in emissions of nitrous oxides across all equivalence ratios. Regarding injection regimes, the external purely premixed injection system has lower NOx and CO. Addition of CO2 increases the lean blowout limit of all blends. In the last section, a new burner was finally employed to carry out trials using multi-phase injection, where, experimental work investigated the performance of a swirl burner using various mixtures of CO2/CH4 blends with either diesel or biodiesel derived from cooking oil. The swirl burner was employed to analyse gas turbine combustion features under atmospheric conditions to quantify flame stability and emissions by using these fuels. The results revealed that the use of biodiesel and CO2/CH4 blends mixtures led to lower CO production. Results showed that a notable reduction of ~50% in NOx was obtained at all conditions for the biodiesel blends.

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Landsberg, Gary B. (Gary Bryan) 1975. "Liquid fuel hydrocarbon emissions mechanisms in spark-ignition engines." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/89274.

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Chu, Van Thuy. "Measurement and assessment of ship emissions." Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/126390/3/Thuy%20Chu%20Van%20Thesis.pdf.

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This project developed an in-vessel emission measurement system and emission evaluation protocol to aid air quality modellers, government regulators and industry. The work enables characterisation of emissions emitted in different ships using heavy fuel oil and operating under a full range of conditions such as at-berth, manoeuvring and ocean-going. Results from the project will improve the quality of input data to air quality modellers who assess the impact of ship emissions on coastal and port areas.

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Dhaliwal, Baljit. "Alternative fuel effects on vehicle emissions and indoor air quality." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0011/MQ60113.pdf.

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Al-Khayat, Thamir A. H. "Dispersion of radioactive emissions from a nuclear fuel fabrication plant." Thesis, Lancaster University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.236387.

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Clark, Kevin David. "Toxic metal and NOx emissions from pulverised solid fuel combustion." Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.413705.

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Nicklin, Timothy J. "Automation of vehicle testing for fuel economy and emissions optimisation." Thesis, Brunel University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.488732.

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Dorbian, Christopher S. (Christopher Salvatore). "Estimating the environmental benefits of aviation fuel and emissions reductions." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/59668.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2010.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 99-103).
With commercial aviation continuing to grow and environmental policymaking activity intensifying, it is becoming increasingly necessary to assess the environmental impact of measures that result in changes in aviation fuel bum levels. For estimating air quality and climate impacts, it is important to employ a multi-gas approach that accounts for the effects of all emitted species, not just carbon dioxide (CO₂). The main objective of this thesis is to develop a simplified framework for monetizing the CO₂ and non-CO₂ co-benefits of aviation fuel and emissions reductions. The approach is based on two main pieces, both of which are derived using the Aviation environmental Portfolio Management Tool (APMT). First, the air quality marginal damage cost of a unit of fuel is estimated using an air quality response surface model. Second, a simplified probabilistic impulse response function model for climate is employed to derive a non-CO₂/CO₂ impact ratio that can be multiplied by a social cost of carbon to estimate the additional benefits of fuel bum reductions from aviation beyond those associated with CO2 alone. The sensitivity of the non-CO₂/CO₂ climate ratio to metric choice, scientific assumptions, background scenarios, and other policymaker choices is explored. Notably, it is found that given the large uncertainties in short-lived effects, the choice of metric is not particularly influential on the overall ratio value (that is, similar results-within the range of uncertainty-are found for the different metrics considered). This thesis also validates the use of the climate ratios and air quality marginal damages through two sample applications. The first study explores the impact of various aviation growth scenarios and demonstrates the applicability of this framework to a multi-year analysis. The second study concerns the introduction of an advanced aircraft concept into the present-day aviation fleet and demonstrates the ability of the climate ratios to capture scientific and valuation-based uncertainties. In both cases, the derived ratios and air quality damage costs are found to be a good surrogate for a full impact analysis in APMT, relative to the overall uncertainty in estimating impacts.
by Christopher S. Dorbian.
S.M.

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Rezai, Armon, and der Ploeg Frederick Van. "Cumulative Emissions, Unburnable Fossil Fuel and the Optimal Carbon Tax." WU Vienna University of Economics and Business, 2016. http://epub.wu.ac.at/4795/1/EcolEcon_WorkingPaper_2016_8.pdf.

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A new IAM is used to calculate the optimal tradeoff between, on the one hand,locking up fossil fuel and curbing global warming, and, on the other hand,sacrificing consumption now and in the near future. This IAM uses the Oxford carbon cycle, which differs from DICE, FUND and PAGE in that cumulative emissions are the key driving force of changes in temperature. We highlight how time impatience, intergenerational inequality aversion and expected trend growth affect the time paths of the optimal global carbon tax and the optimal amount of fossil fuel reserves to leave untapped. We also compare these with the adverse and deleterious global warming trajectories that occur if no policy actions are taken. (authors' abstract)
Series: Ecological Economic Papers

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Шапочка, Микола Костянтинович, Николай Константинович Шапочка, Mykola Kostiantynovych Shapochka, Олександр Вікторович Лямцев, Александр Викторович Лямцев, and Oleksandr Viktorovych Liamtsev. "Optimization of fuel consumption and decrease of transport vehicles emissions." Thesis, Вид-во СумДУ, 2010. http://essuir.sumdu.edu.ua/handle/123456789/8278.

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Torrão, Guilhermina Cândida Antas. "Effect of vehicle characteristics on safety, fuel use and emissions." Doctoral thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/12644.

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Engenharia Mecânica
Nos últimos anos, o número de vítimas de acidentes de tráfego por milhões de habitantes em Portugal tem sido mais elevado do que a média da União Europeia. Ao nível nacional torna-se premente uma melhor compreensão dos dados de acidentes e sobre o efeito do veículo na gravidade do mesmo. O objetivo principal desta investigação consistiu no desenvolvimento de modelos de previsão da gravidade do acidente, para o caso de um único veículo envolvido e para caso de uma colisão, envolvendo dois veículos. Além disso, esta investigação compreendeu o desenvolvimento de uma análise integrada para avaliar o desempenho do veículo em termos de segurança, eficiência energética e emissões de poluentes. Os dados de acidentes foram recolhidos junto da Guarda Nacional Republicana Portuguesa, na área metropolitana do Porto para o período de 2006-2010. Um total de 1,374 acidentes foram recolhidos, 500 acidentes envolvendo um único veículo e 874 colisões. Para a análise da segurança, foram utilizados modelos de regressão logística. Para os acidentes envolvendo um único veículo, o efeito das características do veículo no risco de feridos graves e/ou mortos (variável resposta definida como binária) foi explorado. Para as colisões envolvendo dois veículos foram criadas duas variáveis binárias adicionais: uma para prever a probabilidade de feridos graves e/ou mortos num dos veículos (designado como veículo V1) e outra para prever a probabilidade de feridos graves e/ou mortos no outro veículo envolvido (designado como veículo V2). Para ultrapassar o desafio e limitações relativas ao tamanho da amostra e desigualdade entre os casos analisados (apenas 5.1% de acidentes graves), foi desenvolvida uma metodologia com base numa estratégia de reamostragem e foram utilizadas 10 amostras geradas de forma aleatória e estratificada para a validação dos modelos. Durante a fase de modelação, foi analisado o efeito das características do veículo, como o peso, a cilindrada, a distância entre eixos e a idade do veículo. Para a análise do consumo de combustível e das emissões, foi aplicada a metodologia CORINAIR. Posteriormente, os dados das emissões foram modelados de forma a serem ajustados a regressões lineares. Finalmente, foi desenvolvido um indicador de análise integrada (denominado “SEG”) que proporciona um método de classificação para avaliar o desempenho do veículo ao nível da segurança rodoviária, consumos e emissões de poluentes.Face aos resultados obtidos, para os acidentes envolvendo um único veículo, o modelo de previsão do risco de gravidade identificou a idade e a cilindrada do veículo como estatisticamente significativas para a previsão de ocorrência de feridos graves e/ou mortos, ao nível de significância de 5%. A exatidão do modelo foi de 58.0% (desvio padrão (D.P.) 3.1). Para as colisões envolvendo dois veículos, ao prever a probabilidade de feridos graves e/ou mortos no veículo V1, a cilindrada do veículo oposto (veículo V2) aumentou o risco para os ocupantes do veículo V1, ao nível de significância de 10%. O modelo para prever o risco de gravidade no veículo V1 revelou um bom desempenho, com uma exatidão de 61.2% (D.P. 2.4). Ao prever a probabilidade de feridos graves e/ou mortos no veículo V2, a cilindrada do veículo V1 aumentou o risco para os ocupantes do veículo V2, ao nível de significância de 5%. O modelo para prever o risco de gravidade no veículo V2 também revelou um desempenho satisfatório, com uma exatidão de 40.5% (D.P. 2.1). Os resultados do indicador integrado SEG revelaram que os veículos mais recentes apresentam uma melhor classificação para os três domínios: segurança, consumo e emissões. Esta investigação demonstra que não existe conflito entre a componente da segurança, a eficiência energética e emissões relativamente ao desempenho dos veículos.
During the last years, the number of fatalities per million inhabitants in Portugal has always been higher than the average in the European Union. Therefore, at national level, there is a need for a more effective understanding of crash data and vehicles effects on crash severity. This research examined the effects of vehicle characteristics on severity risk, fuel use and emissions. The main goal of this research was to develop models for crash severity prediction in single vehicle-crashes and two-vehicle collisions. Furthermore, this research aimed at developing an integrated analysis to evaluate vehicle’s safety, fuel efficiency and emission performances. Crash data were collected from the Portuguese Police Republican National Guard records for the Porto metropolitan area, for the period 2006-2010. A total of 1,374 crashes were collected, 500 single-vehicle crashes and 874 two-vehicle collisions. For the safety analysis, logistic regressions were used. For single-vehicle crashes, the effect of vehicle characteristics to predict the probability of a serious injury and/or killed in vehicle occupants (designed as binary target) was explored. For two-vehicle collisions, additional binary targets were designed: one target to predict the probability of a serious injury and/or killed in vehicle V1) and another target to predict the probability of a serious injury and/or killed in vehicle V2). To overcome the challenge imposed by sample size and high imbalanced data (only 5.1% were severe crashes), research methodology was developed based on a resampling strategy and 10 stratified random samples were used for validation. During the modeling stage, the effect of vehicle characteristics, such as weight, engine size, wheelbase and age of vehicle were analyzed. For the vehicle’s fuel efficiency and emissions analysis, pollutants were estimated using CORINAIR methodology. Following, emissions data were fit into linear regression models. Finally, an integrated analysis indicator (entitled “SEG”) that provides rating classification for the evaluation of vehicle’s safety, fuel efficiency and emission performances, was developed. Regarding these results, for single-vehicle crashes, injury severity prediction model identified age of the vehicle and engine size as statistically significant, at 5% level. Model performance accuracy rate was 58.0% (S.D. 3.1). For two-vehicle collisions, when predicting injury severity in vehicle V1, the engine size of the opponent vehicle (vehicle V2) increased the risk for the occupants of the subject vehicle (vehicle V1), at 10% level. Injury severity prediction model for vehicle V1 revealed a good performance with a mean prediction accuracy rate of 61.2% (S.D. 2.4). When predicting injury severity for the other vehicle involved (vehicle V2), the engine size of the opponent vehicle (vehicle V1) increased the risk for the occupants of vehicle V2, at 5% level. Injury severity prediction model for vehicle V2 achieved a mean prediction accuracy rate of 40.5% (S.D. 2.1). The results of the integrated analysis indicator, SEG, revealed that recent vehicle achieved better rating simultaneously for all the three domains: safety, fuel efficiency and emissions performances. Newer vehicles showed a better overall safety rating, were more fuel efficient (less CO2 emissions) and reduced emissions (more environmental friendly). This research relevance showed that there is no trade-off between safety, fuel efficiency and emissions.

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van, der Ploeg Frederick, and Armon Rezai. "Cumulative emissions, unburnable fossil fuel, and the optimal carbon tax." Elsevier, 2017. http://dx.doi.org/10.1016/j.techfore.2016.10.016.

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A stylised analytical framework is used to show how the global carbon tax and the amount of untapped fossil fuel can be calculated from a simple rule given estimates of society's rate of time impatience and intergenerational inequality aversion, the extraction cost technology, the rate of technical progress in renewable energy and the future trend rate of economic growth. The predictions of the simple framework are tested in a calibrated numerical and more complex version of the integrated assessment model (IAM). This IAM makes use of the Oxford carbon cycle of Allen et al. (2009), which differs from DICE, FUND and PAGE in that cumulative emissions are the key driving force of changes in temperature. We highlight the importance of the speed and direction of technological change for the energy transition and how time impatience, intergenerational inequality aversion and expected trend growth affect the time paths of the optimal global carbon tax and the optimal amount of fossil fuel reserves to leave untapped. We also compare these with the adverse global warming trajectories that occur if no policy actions are taken.

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21

Brooks, Thomas D. "Split-main fuel injection strategies for diesel engines and their influence on emissions and fuel consumption." Thesis, University of Nottingham, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417186.

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Bernardes, Pedrozo Vinícius. "An experimental study of ethanol-diesel dual-fuel combustion for high efficiency and clean heavy-duty engines." Thesis, Brunel University, 2017. http://bura.brunel.ac.uk/handle/2438/15850.

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Higher atmospheric concentration of greenhouse gases (GHG) such as carbon dioxide and methane has contributed to an increase in Earth's mean surface air temperature and caused climate changes. This largely reflects the increase in global energy consumption, which is heavily dependent on oil, natural gas, and coal. If not controlled, the combustion of these fossil fuels can also produce high levels of nitrogen oxides (NOx) and soot emissions, which adversely affect the air quality. New and extremely challenging fuel efficiency and exhaust emissions regulations are driving the development and optimisation of powertrain technologies as well as the use of low carbon fuels to cost-effectively meet stringent requirements and minimise the transport sector's GHG emissions. In this framework, the dual-fuel combustion has been shown as an effective means to maximise the utilisation of renewable liquid fuels such as ethanol in conventional diesel engines while reducing the levels of NOx and soot emissions. This research has developed strategies to optimise the use of ethanol as a substitute for diesel fuel and improve the effectiveness of dual-fuel combustion in terms of emissions, efficiency, and engine operational cost. Experimental investigations were performed on a single cylinder heavy-duty diesel engine equipped with a high pressure common rail injection system, cooled external exhaust gas recirculation, and a variable valve actuation system. A port fuel injection system was designed and installed, enabling dual-fuel operation with ethanol energy fractions up to 0.83. At low engine loads, in-cylinder control strategies such as the use of a higher residual gas fraction via an intake valve re-opening increased the combustion efficiency (from 87.7% to 95.9%) and the exhaust gas temperature (from 468 K to 531 K). A trade-off between operational cost and NOx reduction capability was assessed at medium loads, where the dual-fuel engine performance was less likely to be affected by combustion inefficiencies and in-cylinder pressure limitations. At high load conditions, a Miller cycle strategy via late intake valve closing decreased the in-cylinder gas temperature during the compression stroke, delaying the autoignition of the ethanol fuel and reducing the levels of in-cylinder pressure rise rate. This allowed for the use of high ethanol energy fractions of up to 0.79. Finally, the overall benefits and limitations of optimised ethanol-diesel dual-fuel combustion were compared against those of conventional diesel combustion. Higher net indicated efficiency (by up to 4.4%) combined with reductions in NOx (by up to 90%) and GHG (by up to 57%) emissions can help generate a viable business case of dual-fuel combustion as a technology for future high efficiency and clean heavy-duty engines.

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Udell, Thomas Gregory. "Reducing emissions of older vehicles through fuel system conversion to natural gas." Thesis, Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/19896.

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Prabhakar, Niranjani. "Measuring the cost-effectiveness of idle reduction technologies in heavy-duty trucks." Thesis, Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/54481.

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The main objective of idle reduction devices is to reduce the amount of energy wasted by idling trucks, decrease exhaust emissions and save in fuel use and maintenance costs and vehicle life extension. To achieve reductions emissions from vehicle idling in heavy-duty trucks, strategies and actions have been employed through the use of various technologies, namely auxiliary power units (APUs), direct-fire heaters (DFHs), truck stop electrification (TSE) and advanced truck stop electrification (ATSE). Little quantitative data exists on the amount of emissions that are emitted by heavy-duty trucks during idling. In general, diesel engines emit less CO and hydrocarbons (HC) when compared to gasoline engines since fuel-lean mixtures tend to reduce CO and HC emissions. The purpose of this study is to conduct a systematic review that illustrates the status of data present in literature for costs and emissions reduced for APUs, DFHs, TSEs and ATSEs. From the review process, a cost calculator was devised from the synthesis of literature data to measure cost-effectiveness of these technologies in dollars per year per ton per year of emissions reduced over a 30 year investment period. Data on capital costs, maintenance and operational costs, and fuel costs were reported in order to calculate net present values, payback periods and fuel savings from each technology. Given the relevant data available from various studies that compute the efficiency of competing technologies, TSEs were the most cost-effective for the investor and the truck owner in regards to NOx emissions reduction. Cost-effectiveness measured for investors at $1,707.57 and $1,473.27 per ton of NOx reduced, and $16,799.91, $22,261.44, and $20,583.79 per ton of NOx reduced for truck owners. The calculator also served as a tool to illustrate insufficient data currently present in the body of literature. Limited quantitative data and unknown variability of costs as a function of time over the 30-year investment period was used to assess best practices. Thus, policymakers and other stakeholders can benefit from this review in order to conduct future studies that would enlighten greater understanding of data points from specifications of the operating context and devise more robust models for the sake of comparing these technologies based on impact and risk

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Tira, Hendry Sakke. "Impact of alternative fuels and hydrogen-enriched gaseous fuel on combustion and emissions in diesel engines." Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/4376/.

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The utilisation of alternative fuels, specifically gaseous fuel, in diesel engines has some disadvantages such as reduced engine thermal efficiency and increased exhaust gas emissions, although showing good results in reducing soot and NOX, simultaneously. Therefore, the effect of the hydrogen – enriched gaseous fuel in the dual fuelled combustion process was studied as a mean of improving further the combustion process and control emissions. The hydrogen addition was very effective in overcoming the penalty of the biogas or LPG-diesel dual fuelled engine operation. With the presence of hydrogen the oxidation rate of combustion product was improved thus reducing emissions (HC, CO and PM except NOX) whilst the engine thermal efficiency was also improved. The implementation of exhaust gas recirculation (EGR) and advanced injection timing showed great potential for dual fuelled engine. The utilisation of EGR at high LPG concentration further improved soot – NOX trade-off through low in-cylinder temperatures and reduced amount of liquid fuel used for combustion. Moreover, the properties of the injected diesel fuels as a pilot fuel have been shown to significantly affect the combustion process, rate of heat release, and emissions formation and oxidation. Oxygenated fuel like RME contributed to the reduction of emissions, except NOX, while a high cetane number fuel like GTL showed better tolerance to EGR addition and soot – NOX trade-off.

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Arter, Micah. "The effects of diesel fuel density on fuel consumption measurements of portable in-use emissions measurement systems." Morgantown, W. Va. : [West Virginia University Libraries], 2007. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5509.

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Thesis (M.S.)--West Virginia University, 2007.
Title from document title page. Document formatted into pages; contains vii, 91 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 60-62).

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Ryste, Julianne Mari. "Screening LCA of GHG emissions related to LNG as ship fuel." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for marin teknikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18643.

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In view of the increasingly popular climate change debate worldwide, maritime transport is under pressure to create sustainable solutions for a cleaner future.One of these solutions is using liquefied natural gas (LNG) as ship fuel. LNG has a higher hydrogen-to-carbon ratio compared with oil-based fuels, which results in lower specific CO2 emissions (kg CO2/kg fuel). Other benefits of LNG are the total elimination of SOx emissions and particulate matter, and 85-90 % reductions in NOx emissions. DNV has estimated a net global warming benefit of 15 % with the use of LNG. However there is still a need to map the greenhouse gas emissions throughout the life cycle of LNG. This thesis is a Screening Life Cycle Assessment of LNG as fuel, with the main objective to carry out a life cycle analysis of the process “Bunkering of LNG”. Screening is a simplified LCA which aims at identifying the important parts of a life cycle, or so-called hotspots. Bunkering of LNG and the bunkering facility have been chosen as the hotspots in this analysis for their uniqueness. The processes related to bunkering have not been analysed at this level of detail in published literature. The LCA software GaBi Educational has been used to implement the bunkering model and analyse the life cycle inventory results. Processes related to energy use, manufacturing and direct emissions were included in the GaBi model. The CML 2001 method was used to assess the Global Warming Potential (GWP). This is the main characterisation factor of the environmental issue climate change, which was in focus in this analysis.The impact assessment showed that emissions related to manufacturing are the greatest contributors to the GWP, with a total GWP of 75 917 [kg CO2-Equiv]. Energy use contributes the least, with only 0,36 ‰ of the total impact, which is considered negligible. Direct emissions stand for 7 777 [kg CO2-Equiv] and is the only area of the bunkering life cycle where emissions can be considerably reduced. In fact, all direct emissions can be omitted by the use of BOG recovery strategies, such as vapour return. The conclusion drawn is that the emissions associated with bunkering of LNG is perhaps not the main issue. A more pressing issue at the moment is the low fuelling possibilities for LNG. If LNG is to become the fuel of the future, fuelling must be made more accessible and available.

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Potluri, Srinivas. "Combustion emissions from conventional boiler firing coal and tire derived fuel." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-10102009-020130/.

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Knirsch, Ulrich. "Reducing car fleet emissions through fuel technology / policy alternatives for Sweeden." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/36621.

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Runyon, Jon. "Gas turbine fuel flexibility : pressurized swirl flame stability, thermoacoustics, and emissions." Thesis, Cardiff University, 2017. http://orca.cf.ac.uk/100686/.

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Power generation gas turbine manufacturers and operators are tasked increasingly with expanding operational flexibility due to volatility in global gaseous fuel supplies and increased renewable power generation capacity. Natural gas containing high levels of higher hydrocarbons (e.g. ethane and propane) is typical of liquefied natural gas and shale gas, two natural gas sources impacting gas turbine operations, particularly looking forward in the United Kingdom. In addition, hydrogen-blending into existing natural gas infrastructure represents a potential energy storage opportunity from excess renewable power generation, with associated combustion impacts not fully appreciated. This thesis aims to address the specific operational problems associated with the use of variable gaseous fuel compositions in gas turbine combustion through a combination of experimental and numerical techniques, with a focus on natural gas blends containing increased levels of higher hydrocarbons and hydrogen. Parametric experimental combustion studies of the selected fuel blends are conducted in a new fully premixed generic swirl burner at elevated ambient conditions of temperature and pressure to provide representative geometry and flow characteristics typical of a can-type industrial gas turbine combustor. New non-intrusive diagnostic facilities have been designed and installed at Cardiff University’s Gas Turbine Research Centre specifically for the characterization of the influence of fuel composition, burner geometry, and operating parameters on flame stability, flame structure, thermoacoustic response, and environmental emissions. Experimental measurements are supported through the use of numerical chemical kinetics and acoustic modelling. Results from this thesis provide an experimental validation database for chemical kinetic reactor network and CFD modelling efforts. In addition, it informs gas turbine manufacturers on potential burner design modifications for future fuel flexibility and provide enhanced empirical tools to power generation gas turbine operators for increased operational stability, reduced environmental impact, and increased utilization.

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Liu, Helen 1972. "Fuel component effects on hydrocarbon emissions from a spark-ignition engine." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/50465.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1998.
Includes bibliographical references (p. 59-60).
A fuel component perturbation experiment was performed in order to determine the sensitivity of the engine-out emission levels of two olefins, 2-methylpropene (2MP) and 1,3-butadiene, to selected fuel components. In this experiment, a base fuel was perturbed with the following four major fuel components: MTBE, toluene, m,p-xylene, and iso-octane. For each of these components, new fuel mixtures were blended by increasing the percent volume of that particular component by three different increments. A spark-ignition engine was run at steady-state using these different fuel blends plus a baseline fuel with no perturbation. Samples were collected and analyzed using gas chromatography methods. Different hydrocarbon exhaust species were identified and quantified, and trends in any of these species were noted. The final results do indicate increasing trends in 2MP from the MTBE- and iso-octane- perturbed fuel blends. The sensitivity factor for the fuel MTBE/exhaust 2MP relationship was found to be approximately 3.582 x 10-5 g 2MP/(g fuel X % vol MTBE) using normalized data and 3.598 x 10-5 g 2MP/(g fuel X % Vol MTBE) using data corrected by an offset factor. For the iso-octane fuel mixture, the sensitivity was 3.287 x 10-5 g 2MP/(g fuel X % vol iso-oct) using normalized data and 3.500 x 10-5 g 2MP/(g fuel X % vol iso-oct) using data corrected by an offset factor. Perturbing the fuel with the aromatics did not have any noticeable effects on the exhaust hydrocarbon species. However, the exhaust samples from these fuel blends were also used in determining the MTBE and iso-octane sensitivities. By increasing the aromatic percent volumes, the percent volumes of MTBE and iso-octane in the fuel mixtures decreased. Neither MTBE, toluene, m-pxylene, nor iso-octane had any noticeable effect on the levels of 1,3-butadiene in the exhaust.
by Helen Liu.
S.M.

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Lodi, Chiara, Antti Seitsonen, Elena Paffumi, Gennaro Michele De, Thomas Huld, and Stefano Malfettani. "Reducing CO2 emissions of conventional fuel cars by vehicle photovoltaic roofs." Elsevier, 2018. https://publish.fid-move.qucosa.de/id/qucosa%3A73237.

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The European Union has adopted a range of policies aiming at reducing greenhouse gas emissions from road transport, including setting binding targets for tailpipe CO2 emissions for new light-duty fleets. The legislative framework for implementing such targets allows taking into account the CO2 savings from innovative technologies that cannot be adequately quantified by the standard test cycle CO2 measurement. This paper presents a methodology to define the average productivity of vehicle-mounted photovoltaic roofs and to quantify the resulting CO2 benefits for conventional combustion engine-powered passenger cars in the European Union. The method relies on the analysis of a large dataset of vehicles activity data, i.e. urban driving patterns acquired with GPS systems, combined with an assessment of the shading effect from physical obstacles and indoor parking. The results show that on average the vehicle photovoltaic roof receives 58% of the available solar radiation in real-world conditions, making it possible to reduce CO2 emissions from passenger cars in a range from 1% to 3%, assuming a storage capacity of 20% of the 12 V battery dedicated to solar energy. This methodology can be applied to other vehicles types, such as light and heavy-duty, as well as to different powertrain configurations, such as hybrid and full electric.

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Padalkar, Rahul Rajaram. "Global Commercial Aircraft Fuel Burn and Emissions Forecast: 2016 to 2040." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/79661.

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This thesis discusses enhancements to the Global Demand Model (GDM). The model addresses the need to predict: a) number of flights Worldwide by Origin-Destination (OD) airport pair, b) the number of seats (surrogate of demand) by OD airport pair, c) the fleet evolution over time, d) fuel consumption by OD pair and aircraft type, and emissions by OD pair and aircraft type. The model has developed an airline fleet assignment module to predict changes to the airline fleet in the future. Specifically, the model has the capability to examine the fuel and emission benefits of next generation N+1 aircraft and advanced NASA's N+2 aircraft are adopted in the future.
Master of Science

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Garcia, Pardo Diego. "Piston bowl combustion simulation - From fuel spray calibration to emissions minimization." Thesis, KTH, Mekanik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-203950.

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The current pollution policies in all European and American countries are forcing the industry to movetowards a more efficient and environmentally friendly engines. On the other hand, customers requiremaintaining the power and fuel consumption. Lowering mainly nitrous oxides (NOx) and carbon particles(Soot) is therefore a challenging task with a very strong impact on mainly the automotive andaeronautical market.The purpose of the current work is to research the pollution production of automotive diesel enginesand optimize the fuel injection and piston geometry to lower the emissions. The interaction betweenfuel and air as well as the combustion are the two main physical and chemical processes governing thepollutants formation. Converged-CFD will be the CFD tool employed during the analysis of the previousproblems.The fuel-air interaction is related to jet break up, vaporization and turbulence. The strong dependenceon the surrounding flow field of the previous processes require the equations to be solved numericallywithin a CFD code. The fuel is to be placed in a combustion chamber (piston) where the spray will affectthe surrounding flow field and ultimately the combustion process.In order to accurately represent the nature of the processes, the current work is divided into two mainchapters. Spray modelling and Combustion Modelling. The first will help to accurately model the discretephase (fuel spray) and the vapour entrainment. The second chapter, combustion modelling willretrieve the knowledge gain in the first part to accurately represent the fuel injection in the chamber aswell as the combustion process to ultimately model the pollutants emissions.Finally, a piston bowl optimization will be performed using the previous analysed models and give theindustry a measure of the potential improvement by just adjusting the fuel injection or by modifyingthe piston bowl geometry.

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Marlowe, Christopher L. "Development of computational tools for modeling engine fuel economy and emissions." Morgantown, W. Va. : [West Virginia University Libraries], 2009. http://hdl.handle.net/10450/10469.

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Thesis (M.S.)--West Virginia University, 2009.
Title from document title page. Document formatted into pages; contains viii, 84 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 65-66).

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Mazlan, Nurul Musfirah. "Assessing/Optimising Bio-fuel Combustion Technologies for Reducing Civil Aircraft Emissions." Thesis, Cranfield University, 2012. http://dspace.lib.cranfield.ac.uk/handle/1826/7941.

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Gas turbines are extensively used in aviation because of their advantageous volume as weight characteristics. The objective of this project proposed was to look at advanced propulsion systems and the close coupling of the airframe with advanced prime mover cycles. The investigation encompassed a comparative assessment of traditional and novel prime mover options including the design, off-design, degraded performance of the engine and the environmental and economic analysis of the system. The originality of the work lies in the technical and economic optimisation of gas turbine based on current and novel cycles for a novel airframes application in a wide range of climatic conditions. The study has been designed mainly to develop a methodology for evaluating and optimising biofuel combustion technology in addressing the concerns related to over-dependence on crude oil (Jet-A) and the increase in pollution emissions. The main contributions of this work to existing knowledge are as follows: (i) development of a so-called greener-based methodology for assessing the potential of biofuels in reducing the dependency on conventional fuel and the amount of pollution emission generated, (ii) prediction of fuel spray characteristics as one of the major controlling factors regarding emissions, (iii) evaluation of engine performance and emission through the adaptation of a fuel’s properties into the in-house computer tools, (iv) development of optimisation work to obtain a trade-off between engine performance and emissions, and (v) development of CFD work to explore the practical issues related to the engine emission combustion modelling. Several tasks have been proposed. The first task concerns the comparative study of droplet lifetime and spray penetration of biofuels with Jet-A. In this task, the properties of the selected biofuels are implemented into the equations related to the evaporation process. Jatropha Bio-synthetic Paraffinic Kerosine (JSPK), Camelina Bio-synthetic Paraffinic Kerosine (CSPK), Rapeseed Methyl Ester (RME) and Ethanol are used and are evaluated as pure fuel. Additionally, the mixture of 50% JSPK with 50% Jet-A are used to examine the effects ofblend fuel. Results revealed the effects of fuel volatility, density and viscosity on droplet lifetime and spray penetration. It is concluded that low volatile fuel has longer droplet lifetime while highly dense and viscous fuel penetrates longer. Regarding to the blending fuel, an increase in the percentage of JSPK in the blend reduces the droplet lifetime and length of the spray penetration. An assessment of the effect of JSPK and CSPK on engine performance and emissions also has been proposed. The evaluation is conducted for the civil aircraft engine flying at cruise and at constant mass flow condition. At both conditions results revealed relative increases in thrust as the percentage of biofuel in the mixture was increased, whilst a reduction in fuel flow during cruise was noted. The increase in engine thrust at both conditions was observed due to high LHV and heat capacity, while the reduction in fuel flow was found to correspond to the low density of the fuel. Regarding the engine emissions, reduction in NOx and CO was noted as the composition of biofuels in the mixture increased. This reduction is due to factors such as flame temperature, boiling temperature, density and volatility of the fuel. While at constant mass flow condition, increases in CO were noted due to the influence of low flame temperature which leads to the incompletion of oxidation of carbon atoms. Additionally, trade-off between engine thrust, NOx, and CO through the application of multi-objective genetic algorithm for the test case related to the fuel design has been proposed. The aim involves designing an optimal percentage of the biofuel/Jet-A mixture for maximum engine thrust and minimum engine emissions. The Pareto front obtained and the characteristics of the optimal fuel designs are examined. Definitive trades between the thrust and CO emissions and between thrust and NOx emissions are shown while little trade-off between NOx and CO emissions is noted. Furthermore, the practical issues related to the engine emissions combustion modelling have been evaluated. The effect of assumptions considered in HEPHAESTUS on the predicted temperature profile and NOx generation were explored. Finally, the future works regarding this research field are identified and discussed.

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Cambridge, Shevonn Nathaniel. "The effect of compression ratio on emissions from an alcohol-fueled engine." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-09122009-040220/.

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Carson, Christopher Edward. "An investigation of stratified charging of two-stroke engines." Thesis, Queen's University Belfast, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241331.

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Hedman, Björn. "Dioxin emissions from small-scale combustion of bio-fuel and household waste." Doctoral thesis, Umeå University, Chemistry, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-593.

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Denna avhandling behandlar rökgasutsläpp av persistenta organiska föroreningar, framförallt dioxiner, vid förbränning av fasta biobränslen och torrt hushållsavfall i relativt små anläggningar (5-600 kW) utan avancerad rökgasreningsteknik.

Samförbränning av avfall och biobränsle i effektiva mindre biobränslepannor testades som en alternativ strategi till den vanligen förekommande storskaliga hanteringen och förbränningen fast hushållsavfall. Medan storskalig förbränning av avfall ger investeringsmässiga fördelar med rökgasreningsteknik etc. kan små lokala anläggningar ha transportmässiga fördelar och möjligheter till utnyttjande av lokala biobränsletillgångar. Källsorterat, torrt, brännbart hushållsavfall insamlades från hushåll i glesbygd och samförbrändes i brikettform med energigräset rörflen i 150-600 kW biobränslepannor. Endast undantagsvis understeg dioxinemissionerna gällande gränsvärden för avfallsförbränning och nivåerna av väteklorid i rökgas översteg gränsvärdena flerfaldigt. Det bedömdes att någon form av extra rökgasrening är nödvändig för att säkerställa nivågränserna. Dioxiner hittades också i det eldade avfallet, framförallt i textilfraktionen. Dioxinmängderna i rökgaserna var oftast lägre än i det ingående bränslet.

Intermittent pelletseldning gav oväntat höga utsläpp av dioxiner med en emissionsfaktor på 28 ng(WHO-TEQ)/kg. Vedeldning i en modern miljömärkt villapanna gav betydligt lägre utsläpp av dioxiner än eldning i en gammal kombipanna och eldning med full lufttillförsel, som kan jämföras med användning av ackumulatortank, resulterade i upp till 90% minskning av utsläpp av dioxiner jämfört med eldning med reducerat lufttillskott (’pyreldning’). Eldning av plastavfall i en vedpanna gav höga utsläpp av dioxiner.

Okontrollerad förbränning av trädgårdsavfall och hushålls avfall i tunna eller som öppen eld ’bakgårdsbränning’, gav stora variationer i utsläppsnivåer som bara delvis kunde kopplas till avfallsinnehåll. Resultaten visar att denna typ av förbränning kan vara en betydande källa till dioxiner i miljön, och ett emissionsfaktorintervall på 4-72 ng (WHO-TEQ)/kg föreslås för bedömningar av utsläpp från backgårdsbränning av avfall med låga eller måttliga klorhalter.

En sammanfattande slutsats av alla försök är att dioxin utsläpp beror på komplicerade samband mellan bränsleinnehåll och förbränningsbetingelser. Bränslen med mycket höga klorhalter av ger oftast högre utsläpp av dioxiner än bränslen med låga klorhalter medan små skillnader döljs av variationer i förbränningsbetingelser.

This thesis deals with emissions of persistent organic pollutants, primarily dioxins, from the combustion of solid biofuels and dry combustible household waste in relatively small facilities, 5-600 kW, without advanced air pollution controls.

Co-combustion of waste and biofuel in effective small boilers was tested as an alternative to prevailing large-scale management and combustion strategies for handling municipal solid waste. This approach includes no advanced air pollution control systems, but offers two advantages: limiting transport and providing scope to use local biofuel resources. Source-sorted, dry, combustible household waste was collected from households in a sparsely populated area and co-combusted as briquettes together with reed canary-grass in 150-600 kW biofuel boilers. Most trials showed difficulties to meet regulative limits for the emissions of dioxins valid for incineration of MSW and the regulated limits for emissions of hydrochloric acid were exceeded manifold. It was concluded that additional flue-gas cleaning will be needed to ensure that emissions are sufficiently low. Dioxins were also found in the waste, especially in the textile fraction. The mass of dioxins in the flue-gas emissions was generally lower than the mass in the fuel input.

Intermittent combustion of wood pellets in a residential boiler resulted in an unexpectedly high dioxin emissions factor of 28 ng (WHO-TEQ)/kg fuel. Combustion of wood in a modern environmentally certified boiler yielded considerably lower dioxin emissions than combustion in an old boiler, and combustion with a full air supply, i.e. with use of heat storage tank, resulted in up to 90% reductions in dioxin emission factors compared to combustion with reduced air supply. Combustion of plastic waste in a residential wood boiler resulted in high emissions of dioxins.

Tests of uncontrolled combustion of garden and household waste in barrels or open fires, ‘backyard burnings’, resulted in emissions with large variations that could only be partly correlated to the waste constituents. The results imply that this may be an important source of dioxins in the environment and an emission factor range of 4-72 ng (WHO-TEQ)/kg is suggested for estimating emissions from backyard burnings of lightly and moderately chlorine-contaminated waste.

A summarized conclusion from all of the experiments is that predicting emission levels from waste contents is not straightforward (except that fuels with very high chlorine levels will usually result in high levels of dioxins in flue-gas emissions). Moderate differences in chlorine levels will usually be masked by the effect of variations in combustion conditions.

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40

Yousif, Safwan Yousif Ahmed. "Modelling of toxic heavy metal partitioning and emissions from solid fuel combusters." Thesis, Imperial College London, 2000. http://hdl.handle.net/10044/1/7428.

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Roy, Vincent. "Effect of exhaust gas recirculation on fuel consumption and nitrogen oxides emissions." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ63554.pdf.

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42

Hedman, Björn. "Dioxin emissions from small-scale combustion of bio-fuel and household waste /." Umeå : Department of Chemistry, Umeå University, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-593.

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Rockey, Helen Anne. "The environmental control and clean technology of fuel emissions and crystallisation processes." Thesis, Brunel University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.394707.

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Brophy, Kieran. "Development of atmospheric inversions to evaluate fossil fuel CO2 emissions in California." Thesis, Imperial College London, 2018. http://hdl.handle.net/10044/1/64778.

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The aim of this thesis is to explore the use of atmospheric inversions to quantify emissions of fossil fuel CO2 (ffCO2) for the U.S. state of California and assess its implications for the monitoring and verification of emissions. California is of particular interest to atmospheric inversion studies of ffCO2 due to a combination of its ambitious emissions reduction legislation and high density greenhouse gas measurement network. First I examine uncertainties associated with inventories of ffCO2 emissions that inform prior uncertainty in the inversion. Next I investigate potential errors and uncertainties related to the spatial and temporal representation of ffCO2 emissions, and modelled atmospheric transport. To do this I perform simulation experiments based on a network of groundbased observations of CO2 concentration and radiocarbon in CO2, a tracer of ffCO2, by combining prior emissions and transport models, currently used in many atmospheric studies. Finally, as nearly all national and sub national climate change mitigation policies target economic sector specific emissions reductions, I investigate the development of a novel inversion approach that optimizes emissions by sector. My results show that although an atmospheric inversion of ffCO2 in California can reduce a hypothetical bias in the magnitude of prior emissions estimates, uncertainties in ffCO2 estimates arising from the choice of prior emissions or atmospheric transport model are on the order of 15% or less of state-total emissions for the ground-based network in California we consider. The need for temporal variations to be included in prior emissions is highlighted along with continuing efforts to evaluate and improve the representation of atmospheric transport for regional ffCO2 inversions. I conclude that further work on establishing relationships between emissions sectors and trace gases is required for the successful monitoring of sector specific ffCO2 emissions.

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Turner, Dale Michael. "The combustion and emissions performance of fuel blends in modern combustion systems." Thesis, University of Birmingham, 2010. http://etheses.bham.ac.uk//id/eprint/1165/.

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The combustion and emissions performance of fuel blends in modern combustion systems has been investigated with the intention of reducing emissions, improving efficiency and assessing the suitability of future automotive fuels. The combustion systems used in this study include Homogeneous Charge Compression Ignition (HCCI) and Direct Injection Spark Ignition (DISI). By adding a small quantity (10%) of diesel to gasoline, the HCCI combustion of this ‗Dieseline‘ mixture shows a 4% increase in the maximum and a 16% reduction in the minimum loads (IMEP) achievable. The NOX emissions are reduced, with greater than 30% savings seen for high engine loads. The addition of bio-fuels (ethanol and 2,5 di-methylfuran) to gasoline in HCCI combustion resulted in reduced ignitability giving rise to a 0.25 bar IMEP reduction of the maximum load. A 70% increase in NOX emissions is seen at an engine load of 3.5 bar IMEP. The addition of ethanol and to a lesser extent 2,5 di-methylfuran (DMF) to gasoline in DISI combustion shows increased combustion efficiency. The NOX emissions are reduced with ethanol, but are increased with the addition of DMF. At wide open throttle the bio-fuels show up to a 3 percentage point increase in efficiency through the use of more favourable spark timings brought about by the increased octane ratings and enthalpies of vaporisation. The PM emissions from DISI combustion can be reduced by up to 58% (mass) with the addition of ethanol. The soluble organic fraction forms a significant part of the total PM, particularly for the higher ethanol blends at wide open throttle. The addition of DMF however increases the total PM by up to 70% (mass) through the incomplete combustion of the ring structure.

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Acar, Joseph 1977. "Effect of engine operating parameters and fuel characteristics on diesel engine emissions." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/30319.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2005.
Includes bibliographical references (leaf 32).
To examine the effects of using synthetic Fischer-Tropsch (FT) diesel fuel in a modern compression ignition engine, experiments were conducted on a MY 2002 Cummins 5.9 L diesel engine outfitted with high pressure, common rail fuel injection, a variable geometry turbo charger, cooled EGR and a fully configurable engine management computer. Additionally, the effect of varied injection timing and EGR rates were studied to examine how the engine can be optimized for FT fuel. The test fuels included two standard diesel fuels, one with 400 PPM sulfur content and the other 15 PPM sulfur. The experimental fuels were Syntroleum Corporation's S-1 fuel, as well as blends of 25% S-1 with a balance of 15 or 400 PPM D2. Tests were conducted with three engine operating conditions: 1682 RPM, 474 kPa BMEP; 2011 RPM, 1000 kPa BMEP; 2011 RPM, 1400 kPa BMEP. It was found that FT fuel reduced NOx emissions 19% in low load tests, but alone had little effect in higher load tests. FT fuel reduced particulate matter (PM) emissions in almost all test case, on the order of 25 to 75%. Retarding injection timing and increasing EGR both reduce NOx emissions. In the case of standard fuels, these reduction come at the expense of increased PM. However, FT fuel reduced this effect and allows for more retarded timing and further increased EGR rates to control NO. Blended fuels, containing 25% FT, by volume, and a balance of 15 PPM or 400 PPM fuel, were found to provide most of the benefit of straight FT fuel. The FT/15 blend reduced PM 40% and the FT/400 blend reduced PM 60%.
by Joseph Acar.
S.M.

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McConnachie, D. (Dominic Alistair). "Climate policy and the airline industry : emissions trading and renewable jet fuel." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/72902.

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Thesis (S.M. in Technology and Policy)-- Massachusetts Institute of Technology, Engineering Systems Division, Technology and Policy Program, 2012.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 81-89).
In this thesis, I assess the impact of the current EU Emissions Trading Scheme and a hypothetical renewable jet fuel mandate on US airlines. I find that both the EU Scheme up until 2020 and a renewable jet fuel mandate of 1 bn gallons per year from 2018 to 2022 would have a small impact on US airlines and emissions, and operations would continue to grow by -3% p.a. I find that if carriers pass on all additional costs to consumers in the EU Scheme, including the opportunity costs associated with free allowances, windfall gains may be substantial at about $2.6bn because under current allocation rules, airlines would only have to purchase about a third of the required allowances. However, an increase in the proportion of allowances auctioned would reduce windfall gains and profits for US airlines would decline. If airlines pass on only allowance expenses airlines do not receive windfall gains. Out-of-sector abatement is estimated at about a third of airline emissions for the North Atlantic routes, compared to the estimated 1.6% in-sector emissions reductions due largely to reductions in demand under the EU Scheme. Under proposed EU legislation, airlines can use renewable jet fuel instead of purchasing emissions allowances. I find that the current allowance price would make it cheaper for airlines to purchase renewable jet fuel only under conditions where the renewable fuel price premium is 10 cents per gallon or less. I find that a renewable jet fuel mandate of 1bn gallons per year for US commercial aviation (about 4% of the total fuel use) with renewable jet fuel price premium of $1.50 would increase airline fuel costs by ~2% and reduce greenhouse gas emissions by between 2% and 4%. Emissions would continue to grow and reach approximate 2018 levels by 2022. I use the social cost of carbon, with a baseline value of $100/tCO₂e, to calculate the societal cost-effective price premium of renewable jet. I find that fuels can have a price premium of between 40c and $1.30 per gallon, depending on life cycle greenhouse gas reduction. Renewable jet fuels examined in this thesis, including the only commercially available fuel, currently have price premiums of more than $2 per gallon and a calculated greenhouse gas abatement cost of more than $250/tCO₂e. This thesis shows that the emerging renewable jet fuel industry needs to reduce costs to achieve greenhouse gas abatement costs, and therefore societal benefits, comparable to the social cost of carbon or EU allowance costs. It also shows that for the fuels examined with currently estimated prices, the EU Scheme, and the now defunct Waxman-Markey Bill would be lower cost options of greenhouse gas abatement for airlines than a renewable fuel mandate, and in any case would not preclude the use of renewable fuels should they be produced with lower price premiums.
by Dominic A. T. McConnachie.
S.M.in Technology and Policy

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Picazo, Christine Pilar L. (Christine Pilar Lopez). "Comparison of energy efficiency, emissions, and costs of internal combustion and fuel cell vehicles operating on various fuels." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/9562.

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Thesis (S.M.)--Massachusetts Institute of Technology, Sloan School of Management, Technology and Policy Program, 1999.
Includes bibliographical references (p. 113-117).
This thesis aims to evaluate a new transportation technology (fuel cells) against a proven technology (internal combustion engine). Technology is ever evolving, and the new must be an improvement upon the old; otherwise, there is no sense in adopting the new and unproven technology. For the commercialization of the fuel cell vehicle to be successful, it has to be competitive with the internal combustion vehicle in terms of policy parameters which influence the automobile's development and diffusion. These parameters are performance, environmental effects, and economics. A meaningful comparison considers these parameters. Thus the criteria chosen for the comparison are indicators of the parameters-energy efficiency, emissions, and cost to the consumer. A variety of fuels are chosen for each type of vehicle, and the full fuel cycle energy efficiency and emissions resulting from the extraction, production and consumption of these fuels are considered. This results in a comparison that takes into account the entire system associated with the use of fuels in a vehicle. The energy efficiency and emissions are estimated using a simple Reference Case, and a number of previous studies. The cost to the consumer for each type of vehicle is estimated using previous cost studies. Both the initial cost and the operating costs are included in the analysis. The results of the analysis indicate that, considering the full fuel cycle, fuel cell vehicles are more energy efficient and emit fewer pollutants than internal combustion vehicles. However, the difference between the two are dampened by the inefficiencies and emissions associated with the extraction and production of the fuel. Even if fuel cell vehicles are mass-produced, they are still more expensive than conventional vehicles. Thus there is a tradeoff between improved efficiency and environmental performance, and cost. Fuel cell vehicles may possibly cost less than conventional automobiles if they last longer, and are priced on a per kilometer basis. Despite the higher cost, consumers may be willing to pay a premium for improved performance. Moreover, other considerations not within the scope of this thesis, such as other performance parameters and a vehicle support network, must be taken into account.
by Christine Pilar L. Picazo.
S.M.

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Ferrarotti, Marco. "Experimental and numerical investigation of fuel flexibility and pollutant emissions in novel combustion technologies using renewable synthetic fuels." Doctoral thesis, Universite Libre de Bruxelles, 2020. https://dipot.ulb.ac.be/dspace/bitstream/2013/312265/6/contraMF.pdf.

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By 2050, Europe needs to have drastically decoupled its economic growth from its emissions of CO2. This is a direct response to the compelling evidence from the increasing risks of climate change brought about by the anthropogenic Greenhouse Gas (GHG) emissions and pollutant emissions (NOx). A replacement of significant percent of fossil fuels with renewable energy sources will be needed. However, energy production from most renewable energy sources, is typically intermittent and unpredictable. This requires a reliable mid-long term energy storage to synchronize production and demand. The Power-to-Fuel option or chemical storage can be the key for a sustainable energy system. Indeed, converting the excess of renewable energy into second generation fuels will unlock a long-term and high-density energy storage, ensuring also a reduction of the carbon footprint. These ”green” non-conventional fuels are blends of CH4, H2, CO and NH3. However, to achieve Power-to fuel, the development of an efficient combustion technology, coupled with virtually zero pollutant emissions, stable working conditions with different load and fuel and significant energy saving is required. In the last years, a so-called MILD or flameless combustion has drawn attention for its ability of meeting the mentioned targets. However, the studies available in literature are conducted on Jet in hot co-flow-like systems or they face conventional fuels, such as natural gas or methane. The examples using non-conventional fuels are scarce and limited to few operating conditions. In this framework, this PhD thesis focuses on a threefold aspect. Experimental campaigns investigated fuel flexibility of flameless combustion in the ULB furnace. A progressive addition of hydrogen in methane enhanced combustion features, reducing the ignition delay time and increasing the reactivity of the system, possibly losing its flameless behavior. Indeed, a threshold of 25% H2 was defined for reaching flameless/MILD conditions, characterized by still low pollutant emissions and temperature peak. This is in line with the goal of introducing “green” hydrogen into the natural gas pipeline (up to 20%) to reduce CO2 emissions. Further experimental campaigns tested the role of the injection geometry (varying the air injector ID) and fuel lance length to reduce NO emissions and retrieve flameless/MILD conditions for high hydrogen content. Finally, ammonia/hydrogen blends were tested. Results suggests that stoichiometry has a major impact on NO emissions. An optimal window, minimizing both NO and NH3-slip emissions was defined using an equivalence ratio of 0.9. To qualitatively describe the observed trends, a simplified reactors network was considered. The analysis highlighted the most important reactions correlated to NO formation and the reason of the NO reduction at stoichiometry condition. On the other side an affordable and reliable numerical model was optimized and tested in the Adelaide Jet in Hot Co-flow burner. The latter is a simplified burner capable of mimicking MILD combustion conditions. A set of RANS simulations were run using the Partially Stirred Reactor (PaSR) approach, investigating different mixing model formulations: a static, a fractal-based and a dynamic formulation, based on the resolution of transport equations for scalar variance and dissipation rate. A study about the role of combustion models and kinetic mechanisms on the prediction of NO formation was also conducted. Finally, an analysis of the choice of a Heat Release Rate (HRR) marker for MILD (HM1 flame) and not MILD (HM3 flame) conditions was carried out. Once having awareness of the capability of the proposed numerical model, simulations were conducted to define the key aspects in simulating a flameless furnace, varying the composition of the fuel, considering methane/hydrogen and ammonia/hydrogen blends. In particular, for the latter case, existing kinetic schemes showed a major over-estimation of NO emissions, reason why an optimization study was conducted in a simplified reactor (well stirred reactor) using a Latin Hypercube Sampling. Finally, the first-of-its-kind digital twin based on CFD simulations for a furnace operating in flameless combustion conditions was created. A reduced- order model (ROM) based on the combination of Proper Orthogonal Decomposition (POD) and Kriging was developed for the prediction of spatial fields (i.e. temperature) as well as pollutant in the exhausts.
D’ici 2050, l’Europe devra découpler sa croissance économique de ses émissions de CO2. Il s’agit d’une réponse nécessaire au changement climatique et à la pollution de l’air induits par les émissions atmosphérique de gaz à effet de serre (GES) et de polluants (NOx). Un remplacement d’un pourcentage significatif des combustibles fossiles par des sources d’énergie renouvelables sera nécessaire. Cependant, la production d’énergie à partir des sources renouvelables est généralement intermittente et imprévisible. Cela nécessite un stockage d’énergie fiable à moyen et long terme, pour synchroniser la production et la demande d’énergie. L’option Power-to-Fuel, ou stockage chimique, peut être la clé d’un système énergétique durable. En effet, la conversion de l’excès d’énergie renouvelable en carburants de deuxième génération permettra de débloquer un stockage d’énergie à long terme et à haute densité, en assurant également une réduction de l’empreinte carbone. Ces carburants non conventionnels « verts » sont des mélanges de CH4, H2, CO et NH3. Cependant, pour exploiter le potentiel du Power-to-Fuel, il est nécessaire de développer une technologie de combustion efficace, avec des émissions de polluants pratiquement nulles, assurant des conditions de travail stables avec une charge et des carburants différents et des économies d’énergie significatives. Au cours des dernières années, une combustion dite « MILD », ou sans flamme, a attiré l’attention pour sa capacité à atteindre les objectifs mentionnés. Cependant, les études disponibles dans la littérature sont menées sur des systèmes de laboratoire (jet in hot co-flow) et avec des carburants conventionnels comme le gaz naturel ou le méthane. Les exemples utilisant des carburants non conventionnels sont rares et limités à quelques conditions de fonctionnement.Dans ce cadre, cette thèse de doctorat se concentre sur un triple aspect.Des campagnes expérimentales ont étudié la flexibilité du combustible dans un four sans flamme installé à l'ULB. L’ajout progressif d’hydrogène dans le méthane permet d’améliorer les caractéristiques de combustion, en réduisant le délai d’allumage et augmentant la réactivité du système, ce qui, par contre, cause un éloignement du système des conditions sans flamme. En effet, un seuil supérieur de 25% H2 a été identifié pour les mélanges méthane/hydrogène, pour travailler dans des conditions sans flammes (MILD), caractérisées par une faible augmentation de température et des émissions de polluants amoindries .Cela est conforme à l’objectif d’introduire de l’hydrogène « vert » dans le gazoduc (jusqu’à 20%) afin de réduire les émissions de CO2. D’autres campagnes expérimentales se sont focalisées sur le rôle de la géométrie d’injection (variation du diamètre de l’injecteur d’air) et de la longueur de la lance du carburant pour réduire les émissions des oxydes d’azote et récupérer les conditions sans flamme/MILD pour une teneur élevée en hydrogène. Enfin, des mélanges ammoniac/hydrogène ont été testés. Les résultats suggèrent que la stœchiométrie a un impact majeur sur les émissions d’oxydes d’azote. Une fenêtre optimale minimisant les émissions de NO et d’ammoniac imbrulées a été définie en utilisant un rapport d'équivalence de 0,9. Pour tracer qualitativement les tendances observées, un réseau de réacteurs simplifié a été construit. L’analyse a mis en évidence les réactions les plus importantes pour la formation des NOx et elle a permis de justifier la réduction des oxydes d’azote à l’état stœchiométrique.De l’autre côté, un modèle numérique robuste et fiable a été optimisé et testé pour le brûleur Jet in Hot Co-flow de l’Université d’Adelaide. Ce dernier est un brûleur simplifié capable de simuler les conditions de combustion MILD/sans flamme. Un ensemble de simulations RANS ont été effectuées à l’aide de l’approche du réacteur partiellement agité (Partially Stirred Reactor – PaSR - en anglais), en examinant les différentes formulations de modèles de mélange :une formulation statique, fractale et dynamique, basée sur la résolution des équations de transfert pour la variance scalaire et le taux de dissipation. Une étude sur le rôle des modèles de combustion et des mécanismes cinétiques dans la prédiction de la formation des oxydes d’azote a également été réalisée. Enfin, une analyse sur le choix d’un marqueur de taux de dégagement de chaleur (Heat Release Rate – HRR – en anglais) pour les conditions MILD et non MILD a été réalisée. Après validation, les modèles développés ont été utilisés pour définir les aspects clés de la simulation d’un four sans flamme, en variant la composition du combustible, pour des mélanges méthane/hydrogène et ammoniac/hydrogène. En particulier, pour ce dernier cas, les schémas cinétiques existants ont montré une surestimation importante des émissions d’oxydes d’azote, raison pour laquelle une étude d’optimisation a été menée dans un réacteur simplifié.Enfin, le premier jumeau numérique en son genre, basé sur des Simulations numériques de Dynamique de Fluides (CFD – Computational Fluid Dynamics en anglais) pour un four fonctionnant dans des conditions de combustion sans flamme, a été créé. Un modèle à ordre réduit (ROM – Reduced Order Model en anglais) basé sur la combinaison de la Décomposition Orthogonale aux valeurs Propres (POD) et du Kriging a été développé pour la prédiction des variables d’intérêt (température et espèces chimiques majeures) ainsi que des polluants dans les fumées.
Doctorat en Sciences de l'ingénieur et technologie
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George, Sam. "Investigation of lubricant oil consumption and its contribution to particulate matter emissions." Morgantown, W. Va. : [West Virginia University Libraries], 2008. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=6004.

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Thesis (Ph. D.)--West Virginia University, 2008.
Title from document title page. Document formatted into pages; contains xii, 152 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 111-119).

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