Este estudo faz uma análise dos níveis de emissões veiculares relacionados com os problemas de poluição na cidade de São Paulo. Utilizando a metodologia denominada bottom-up, avalia de forma teórica os índices de poluentes que saem pelo tubo de escapamento da maior frota de veículos leves do país. São abordados tópicos relacionados com o dia-a-dia da cidade como crescimento da frota, combustíveis, transporte público, poluição atmosférica e seus efeitos à saúde e ainda a influência atmosférica na região. Foram feitas diversas simulações no decorrer do estudo denominadas de cenários, que são baseadas na simples, porém eficiente, aplicação da metodologia bottom-up que utiliza, para os cálculos, os fatores de emissões de acordo com a evolução das fases do PROCONVE para obter a quantidade de determinados poluentes emitido por ano. Os cenários permitem a substituição dos veículos mais velhos por veículos novos e apresentam resultados positivos para o meio ambiente, dentre eles aqueles que podem ser considerados como alternativas ousadas e outros podem ser vistos como alternativas mais conservadoras, mas todos demostram melhorias significativas para a qualidade do ar na cidade de são Paulo. A evolução das fases citadas trouxeram muitos benefícios ao meio ambiente por meio das novas tecnologias desenvolvidas e embarcadas nos veículos novos e que não deixam de ser a solução para o futuro, onde melhorias nas condições atmosféricas devem ser alcançadas. Questões como políticas públicas e legislações específicas para a substituição dos veículos velhos da rua, não saem da teoria. Na prática o trânsito está cada vez mais caótico, em partes pela quantidade de carros em péssimas condições de uso que ainda circulam e quebram todos os dias, afetando diretamente a qualidade do ar na metrópole paulista. / This study presents an analysis of the levels of vehicles emissions related to the pollution problems in São Paulo City. Using a methodology called bottom-up, this thesis presents a theoretical evaluation on the rates of pollutants coming out the exhaust pipe of the largest light vehicles fleet in Brazil. Issues related to daily city activities such as the fleet growth, fuels, public transportation, air pollution and its effects on the population health and the atmospheric influence in the region as well are presented. Simulations for scenarios drawn were based on a simple but efficient, implementation of bottom-up approach that employs, for calculations, the emission factors according to the changing phases of PROCONVE (the Brazilian National Program for the Pollution Control of Vehicles) for the amount of pollutants emitted per year. The scenarios consider that replacement of older vehicles by new ones is positive for the environment. Some scenarios may be considered as non-conservative alternatives and others can be seen as conservative, but all demonstrate significant improvements to the quality of air in São Paulo City. The evolution of the phases mentioned have brought many benefits to the environment through new technologies developed for new vehicles and represent a solution for the future, when improvements in atmospheric conditions must be met. Issues such as public policies and laws specific to the replacement of old vehicles still have to be improved. In practical means, the traffic is increasingly chaotic, in part by the amount of cars in poor use that still run and break every day, directly affecting the air quality in metropolitan region.

Este estudo faz uma análise dos níveis de emissões veiculares relacionados com os problemas de poluição na cidade de São Paulo. Utilizando a metodologia denominada bottom-up, avalia de forma teórica os índices de poluentes que saem pelo tubo de escapamento da maior frota de veículos leves do país. São abordados tópicos relacionados com o dia-a-dia da cidade como crescimento da frota, combustíveis, transporte público, poluição atmosférica e seus efeitos à saúde e ainda a influência atmosférica na região. Foram feitas diversas simulações no decorrer do estudo denominadas de cenários, que são baseadas na simples, porém eficiente, aplicação da metodologia bottom-up que utiliza, para os cálculos, os fatores de emissões de acordo com a evolução das fases do PROCONVE para obter a quantidade de determinados poluentes emitido por ano. Os cenários permitem a substituição dos veículos mais velhos por veículos novos e apresentam resultados positivos para o meio ambiente, dentre eles aqueles que podem ser considerados como alternativas ousadas e outros podem ser vistos como alternativas mais conservadoras, mas todos demostram melhorias significativas para a qualidade do ar na cidade de são Paulo. A evolução das fases citadas trouxeram muitos benefícios ao meio ambiente por meio das novas tecnologias desenvolvidas e embarcadas nos veículos novos e que não deixam de ser a solução para o futuro, onde melhorias nas condições atmosféricas devem ser alcançadas. Questões como políticas públicas e legislações específicas para a substituição dos veículos velhos da rua, não saem da teoria. Na prática o trânsito está cada vez mais caótico, em partes pela quantidade de carros em péssimas condições de uso que ainda circulam e quebram todos os dias, afetando diretamente a qualidade do ar na metrópole paulista. / This study presents an analysis of the levels of vehicles emissions related to the pollution problems in São Paulo City. Using a methodology called bottom-up, this thesis presents a theoretical evaluation on the rates of pollutants coming out the exhaust pipe of the largest light vehicles fleet in Brazil. Issues related to daily city activities such as the fleet growth, fuels, public transportation, air pollution and its effects on the population health and the atmospheric influence in the region as well are presented. Simulations for scenarios drawn were based on a simple but efficient, implementation of bottom-up approach that employs, for calculations, the emission factors according to the changing phases of PROCONVE (the Brazilian National Program for the Pollution Control of Vehicles) for the amount of pollutants emitted per year. The scenarios consider that replacement of older vehicles by new ones is positive for the environment. Some scenarios may be considered as non-conservative alternatives and others can be seen as conservative, but all demonstrate significant improvements to the quality of air in São Paulo City. The evolution of the phases mentioned have brought many benefits to the environment through new technologies developed for new vehicles and represent a solution for the future, when improvements in atmospheric conditions must be met. Issues such as public policies and laws specific to the replacement of old vehicles still have to be improved. In practical means, the traffic is increasingly chaotic, in part by the amount of cars in poor use that still run and break every day, directly affecting the air quality in metropolitan region.

With the increasingly stringent regulations and laws being put in place worldwide with regards to a cleaner and a safer environment, the modern diesel engine has scope to be improved upon to help meet these new standards set for the betterment of our cities. There are many current modes of alternative transport, with diesel-hydrogen combustion being a transitional solution from fossil fuels to hydrogen powered vehicles. The main objective of this research effort was to investigate the effects of intake air enrichment with hydrogen on the performance, combustion, and emissions of a diesel engine. The secondary aim was to design and optimise accurate engine models which can replicate real world experiments and conditions. This becomes increasingly useful in the modern era of engine testing and development as it allows for more manufacturers to test and optimise new combustion methods, without the need for a physical engine, to meet the ever-tightening emissions legislations. Therefore, the accuracy of the models produced could pave the way for more simulations to be carried out via manufacturers with more confidence. The experimental tests were carried out on a 2.0 litre Ford High Speed Direct Injection (HSDI) diesel engine. the engine was tested at various conditions mimicking light- and medium-duty diesel engines. Hydrogen was used via a bottle with the composition of the gas replicating exhaust gas reformed intake air. The percentage of the hydrogen and the start of injection for diesel were altered for the tests. The simulations were carried out on a replicated four-cylinder 2.0 litre Ford HSDI diesel engine on Ricardo Wave® and a single-cylinder DI diesel engine modelled based on a small Yanmar L70N diesel engine. The experimental operating parameters were used in the simulations to measure the level of accuracy achieved with the models on the software. The experimental results showed that with hydrogen enrichment of the intake air, the CO and smoke emissions were reduced significantly, however NOx emissions were found to have increased at certain conditions. The simulations for the multi-cylinder diesel engine showed great promise with an average of 95% accuracy across the operating conditions and emissions measured. The single-cylinder diesel engine displayed low levels of Total Hydrocarbons (THC), Carbon Monoxide (CO), with a slight increase in Oxides of Nitrogen (NOx) emissions but did show high levels of accuracy against literature and other experimental work based on similar operating conditions. Although there is an abundance of literature currently investigating the effects of hydrogen enrichment of the intake air, the new contributions to knowledge of this research is the comparison between simulated and experimental work of transitional combustion methods such as this. This research is believed to help aid the industry in testing and optimising of simulated engine models for a more reliable manufacturing process.

University, Diss.--København, 2007.

Thesis (Ph. D.)--University of Queensland, 2002. / Includes bibliographical references.

published_or_final_version / Speech and Hearing Sciences / Master / Master of Science in Audiology

Gridded, regional photochemical models use simplified photochemical reaction mechanisms, and two commonly used mechanisms are the [California] Statewide Air Pollution Research Center (SAPRC) mechanism and the Carbon Bond (CB) mechanism. Versions of the mechanisms currently in use include SAPRC99 and the CB-IV version from 1996. For the modeling done of the summer of 2000 in southeast Texas, the SAPRC99 mechanism leads to concentrations of ozone that are 30-45 ppb higher than with CB-IV, and is more sensitive to reductions in NOx emissions. Differences between the mechanisms could have significant consequences for determining the levels of emission reductions that will be required to demonstrate attainment with the National Ambient Air Quality Standard (NAAQS) for ozone, with concentrations averaged over 8 hours. Therefore, various modeling tools, together with chamber experiments were used to diagnose the differences between the mechanisms. These differences are due to differences in both reaction rate parameters/stoichiometry and the condensation methods in the mechanisms. Major reasons for the differences are differences in aromatics and free radicals chemistries, which lead to higher radical concentrations in the SAPRC formulation.

In this study the performance, emission and economic evaluation of using the clove stem oil (CSO)–diesel blended fuels as alternative fuels for diesel engine have been carried out. Experiments were performed to evaluate the impact of the CSO–diesel blended fuels on the engine performance and emissions. The societal life cycle cost (LCC) was chosen as an important indicator for comparing alternative fuel operating modes. The LCC using the pure diesel fuel, 25% CSO and 50% CSO–diesel blended fuels in diesel engine are analysed. These costs include the vehicle first cost, fuel cost and exhaust emissions cost. A complete macroeconomic assessment of the effect of introducing the CSO–diesel blended fuels to the diesel engine is not included in the study. Engine tests show that performance parameters of the CSO–diesel blended fuels do not differ greatly from those of the pure diesel fuel. Slight power losses, combined with an increase in fuel consumption, were experienced with the CSO–diesel blended fuels. This is due to the low heating value of the CSO–diesel blended fuels. Emissions of CO and HC are low for the CSO–diesel blended fuels. NOx emissions were increased remarkably when the engine was fuelled with the 50% CSO–diesel blended fuel operation mode. A remarkable reduction in the exhaust smoke emissions can be achieved when operating on the CSO–diesel blended fuels. Based on the LCC analysis, the CSO–diesel blended fuels would not be competitive with the pure diesel fuel, even though the environmental impact of emission is valued monetarily. This is due to the high price of the CSO.

Abstract Parmotrema austrosinense (Zahlbr.) Hale lichens were collected from the Pretoria central business district (CBD), as well as three sites to the east of Pretoria; the National Botanical Gardens, the CSIR campus and the suburb of Lynnwood, with the aim of utilising these lichens as biomonitors of air quality to determine the effects of the phasing out of leaded petrol and the simultaneous introduction of manganese anti-knock additives to fuel in South Africa. In addition to lichens, roadside dust and soil samples were collected from the CBD and CSIR campus, and all samples were analysed by flame atomic absorption spectrometry after acid digestion. There was no significant difference (95 % confidence) between the Mn content of lichens from all sampling sites (overall average of 97.1 ± 39.1 μg.g-1, n= 28), which was most likely due to an even suspension of Mn-containing particles arising from soil dust. Additional contributions to Mn loading as a result of vehicle emissions were currently not evident. For all non-CBD sites, higher Pb levels were found in lichens which were nearer to busy roads, suggesting an historical impact by vehicular emissions of Pb arising from leaded petrol usage. The Pb concentrations in lichens found in the CBD (average of 181.1 ± 98.0 μg.g-1, n=10) were significantly higher (95 % confidence limits) than those of lichens growing outside of the CBD area (average of 41.5 ± 36.4 μg.g-1, n=18), and the Pb levels were higher than those of Mn, which was contrary to that found in sites outside the CBD.

An analysis of climate change in Nigeria has been carried out. The aim was to investigate the environmental impact of Green house gases. The three zones of the country namely the extreme North, the middle zone and the extreme South have all been separately examined with respect to changes in solar radiation, temperature, precipitation and evaporation. The agricultural productivity for each zone was compiled, and trend plots over time carried out. Correlation tests were done between productivity and climatic changes and it was found that each zonal area reacted differently to changes in climate. The emission of carbon dioxide, methane and the oxides of nitrogen in Nigeria were calculated and trends plotted. A correlation test was also carried out between carbon dioxide emission and temperature change for each zone. The relationship between temperature change and productivity was shown in a regression model. An economic appraisal for Nigeria involving the GDP, pollution and population was examined in terms of the productivity- pollution index. This was also extended to some of the Western countries