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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Sensitivity Analysis in Air Quality Models for Particulate Matter

Napelenok, Sergey L. 31 October 2006 (has links)
Fine particulate matter (PM2.5) has been associated with a variety of problems that include adverse health effects, reduction in visibility, damage to buildings and crops, and possible interactions with climate. Although stringent air quality regulations are in place, policy makers need efficient tools to test a wide range of control strategies. Sensitivity analysis provides predictions on how the interdependent concentrations of various PM2.5 components and also gaseous pollutant species will respond to specific combinations of precursor emission reductions. The Community Multiscale Air Quality Model (CMAQ) was outfitted with the Decoupled Direct Method in 3D for calculating sensitivities of particulate matter (DDM-3D/PM). This method was evaluated and applied to high PM2.5 episodes in the Southeast United States. Sensitivities of directly emitted particles as well as those formed in the atmosphere through chemical and physical processing of emissions of gaseous precursors such as SO2, NOx, VOCs, and NH3 were calculated. DDM-3D/PM was further extended to calculate receptor oriented sensitivities or the Area of Influence (AOI). AOI analysis determines the geographical extent of relative air pollutant precursor contributions to pollutant levels at a specific receptor of interest. This method was applied to Atlanta and other major cities in Georgia. The tools developed here (DDM-3D/PM and AOI) provide valuable information to those charged with air quality management.
132

IMPROVING THE CONVERSION OF THE SULFUR DIOXIDE - LIME REACTION BY USING ADDITIVES

Dombek, Priscilla Emily, 1961- January 1986 (has links)
No description available.
133

A multiple accounts approach for analyzing the effectiveness of NOx emissions controls in the GVRD airshed

Smailes, Robert L. 11 1900 (has links)
This thesis presents an analysis of air quality control initiatives in the GVRD. Starting with an examination of deteriorating regional air quality, oxides of nitrogen emissions (NOx), are the focus (as a precursor to ground level ozone.) The research demonstrates that if the status quo is maintained, episodes of ground level ozone will get worse and the effects will be far reaching and expensive. The Greater Vancouver Regional District's Air Quality Management Plan is reviewed, with emphasis on analysis and evaluation of emission reduction strategies. Emission Reduction Measures (ERMs) are various methods of reducing air pollution (including scrubbers on smoke stacks, transportation demand management, alternative fuels and motor vehicle inspection/maintenance programs.) Emission Reduction Measures are viewed as the tools that must be implemented to solve air quality problems. Environmentally, the most desirable solution would be to implement all ERMs. However, factors such as cost effectiveness and social, financial, political and customer service impacts must be considered and the best measures should be implemented first. The best solutions are those that meet as many objectives as possible while causing the least amount of negative impacts on the economy, society, government and the environment. Finding optimal solutions is a task that requires formalization of common sense. Analytical frameworks such as the cost/benefit analysis, decision analysis and the multiple account/objective analysis are considered as potential tools to help "make sense" of the complexity of air quality policy decisions. The intent is to provide useful and readily understandable information to decision makers. The Multiple Account Analysis (as used by The Crown Corporations Secretariat) is applied to an assortment of Emission Reduction Measures to help identify the "best" order for implementation. This method provides results that compare accounts of importance (such as cost effectiveness and emission reduction potential) and presents decision makers with quality information highlighting tradeoffs and preferences. In the scope of this paper, four ERMs are analyzed across accounts and the results presented in a matrix. The AirCare Program appears as the best choice for effective reduction of oxides of nitrogen when compared to alternative fuels, vanpooling and the Burrard thermal generating plant rebuild.
134

The impact of Air Quality Act on businesses in the greater Durban area.

Shongwe, Bhekumuzi Enock. January 2009 (has links)
The introduction and implementation of the Air Quality Act in South Africa has a significant impact in the communities, in the three spheres of government, namely national, provincial and local, and businesses in the country. This study provides an overview of how the businesses in the Greater Durban Area have been impacted by the introduction and implementation of the AQA. The main objective of the study is to ascertain the impact that the AQA has on businesses in the Greater Durban Area. The main focus is on the following areas of impact: operational, structural, strategic, financial and social impact. The main tool used to collect the primary data was a structured questionnaire. However, because of challenges faced in the collection of data the structured interviews were cancelled. Analyses of results are based on the data collected utilizing the questionnaire as well as the reviewed literature in order to establish the extent to which the data is supported by the existing theory. The overall impression created by the results of the sample indicates that the AQA has been well received by all stakeholders; these stakeholders include businesses, government as well as the society. Although the Act as well as other environmental legislation present some challenges to businesses, these legislation are generally fairly well accepted by private enterprise. The study recommends that for further studies, the data collection instruments must include structured and/or unstructured interviews, in order to ascertain where businesses strategically stand on air quality. This will also help in obtaining indications on funds that businesses spend on social development and/or responsibility and on environment as a whole. / Thesis (M.B.A.)-University of KwaZulu-Natal, Westville, 2009.
135

Analysis and prediction of individual vehicle activity for microscopic traffic modeling

Hallmark, Shauna L. 12 1900 (has links)
No description available.
136

Modeling to reduce oil consumption and emissions of greenhouse gases, hydrocarbons, and particulates for the passenger land transport sector of Bangkok

Gruber, Douglas S January 2007 (has links)
Thesis (M.A.)--University of Hawaii at Manoa, 2007. / Includes bibliographical references (leaves 275-282). / x, 282 leaves, bound ill. 29 cm
137

Evaluation of the ambient air quality analysis of HCL, H2S and NH3 from enhanced evaporation spray system ponds on the Highveld of South Africa

Hermandez Peral, Ivan. January 2006 (has links)
Thesis (MSc (Meteorology))-University of Pretoria, 2006. / Includes bibliographical references. Available on the Internet via the World Wide Web.
138

Avaliação do potencial de Tillandsia recurvata (L.) L., Bromeliaceae, como bioindicadora da poluição atmosférica urbana / Evaluation of potential of Tillandsia recurvata (L.) L., Bromeliaceae, as bioindicator of urban air pollution

Piazzetta, Karime Dawidziak 07 December 2015 (has links)
A poluição do ar representa uma ameaça para o meio ambiente e para a saúde pública, e pode ser avaliada por medidas das concentrações ambientais dos poluentes, que permitem verificar se os limites estabelecidos pelos órgãos ambientais estão sendo respeitados. Estas medidas, no entanto, não indicam de imediato quais os impactos ocasionados aos seres vivos. Diante desta problemática, plantas vêm sendo investigadas como potenciais bioindicadoras de poluição atmosférica e, entre elas, se destacam bromélias do gênero Tillandsia que colonizam diversos substratos e obtêm água e nutrientes diretamente da atmosfera. Neste contexto, esta pesquisa avaliou o potencial da bromélia epífita Tillandsia recurvata (L.) L. presente em áreas urbanizadas do município de Curitiba – PR como bioindicadora da poluição atmosférica urbana. Cinco pontos de amostragem foram selecionados e classificados de acordo com o tráfego de veículos. Os pontos P1 e P2 foram classificados como de alto tráfego de veículos por apresentarem fluxo de caminhões e transporte urbano; o ponto P3 foi classificado como de moderado tráfego, pela predominância de veículos particulares e transporte urbano; e os pontos P4 e P5 foram classificados como de baixo tráfego, com circulação apenas de veículos particulares. Foram analisados a abundância de T. recurvata, parâmetros morfofisiológicos (área foliar, área específica foliar, índice de esclerofilia, proporção peso seco/peso fresco, clorofila (a+b), análise da organização estrutural do mesofilo) e o acúmulo de metais (Fe, Cd, Cr, Cu, Pb e Zn). A análise de abundância e os resultados obtidos nas análises de metais apresentaram relação com a intensidade do tráfego de veículos, ordenando os pontos de amostragem em P1 > P2 = P3 > P4 = P5, demonstrando que a abundância de T. recurvata é maior em áreas impactadas pela poluição atmosférica urbana e indicando que T. recurvata absorve e acumula metais, podendo ser empregada no biomonitoramento da poluição atmosférica urbana em áreas impactadas pelo tráfego veicular. Os parâmetros morfofisiológicos analisados evidenciam que, em função das adaptações que T. recurvata possui, a estrutura interna não é impactada significativamente pela poluição atmosférica urbana. A presença das escamas absorvedoras, a via de metabolismo CAM e a capacidade de armazenar água, dentre outras características, evidenciam seu potencial bioindicador em áreas urbanas, principalmente em relação ao acúmulo de metais. / Air pollution can threat the environment and public health, and is assess by pollutant ́s concentration measurements in order to verify whether the limits set by environmental agencies are being respected. However, these measures do not indicate immediately the impacts to living beings. To faced this problem, plants are been investigated as potential bioindicators of air pollution and, among them, stand out bromeliads Tillandsia genus which colonize various substrates,. obtaining water and nutrients from the atmosphere directly. In this context, this research assessed the potential of epiphytic bromeliad Tillandsia recurvata (L.) L. found in urbanized areas of the city of Curitiba - PR as a bioindicator of urban air pollution. According to vehicle traffic, five sample points were selected and classified. Points P1 and P2 were classified as high-traffic vehicle due presenting trucks and urban transport; point P3 was classified as moderate traffic due the predominance of private vehicles and urban transport; and points P4 and P5 were classified as low-traffic, presenting circulation of private vehicles only. There were analyzed the abundance of T. recurvata, morphophysiological parameters (leaf area, leaf specific area, sclerophylly index, percentage dry weight / fresh weight, chlorophyll (a + b), analysis of structural mesophyll organization) and the heavy metals accumulation (Fe, Cd, Cr, Cu, Pb and Zn). The abundance analysis and the results obtained for metals analysis were correlated with the intensity of vehicular traffic, directing the sampling points P1 > P2 = P3 > P4 = P5. This result demonstrate that the abundance of T. recurvata is greater in urban air pollution impacted areas, thus indicating that T. recurvata absorbs and accumulates metals and can be used in biomonitoring of urban air pollution in areas impacted by vehicular traffic. Morphophysiological parameters analyzed shows that the internal plant ́s structure is not significantly impacted by urban air pollution due plant ́s adptations. The presence of absorbing scales, the CAM metabolism pathway and it ́s store water ability, among other features, demonstrate their potential as bio-indicator in urban areas, especially regarding heavy metals accumulation .
139

Avaliação do potencial de Tillandsia recurvata (L.) L., Bromeliaceae, como bioindicadora da poluição atmosférica urbana / Evaluation of potential of Tillandsia recurvata (L.) L., Bromeliaceae, as bioindicator of urban air pollution

Piazzetta, Karime Dawidziak 07 December 2015 (has links)
A poluição do ar representa uma ameaça para o meio ambiente e para a saúde pública, e pode ser avaliada por medidas das concentrações ambientais dos poluentes, que permitem verificar se os limites estabelecidos pelos órgãos ambientais estão sendo respeitados. Estas medidas, no entanto, não indicam de imediato quais os impactos ocasionados aos seres vivos. Diante desta problemática, plantas vêm sendo investigadas como potenciais bioindicadoras de poluição atmosférica e, entre elas, se destacam bromélias do gênero Tillandsia que colonizam diversos substratos e obtêm água e nutrientes diretamente da atmosfera. Neste contexto, esta pesquisa avaliou o potencial da bromélia epífita Tillandsia recurvata (L.) L. presente em áreas urbanizadas do município de Curitiba – PR como bioindicadora da poluição atmosférica urbana. Cinco pontos de amostragem foram selecionados e classificados de acordo com o tráfego de veículos. Os pontos P1 e P2 foram classificados como de alto tráfego de veículos por apresentarem fluxo de caminhões e transporte urbano; o ponto P3 foi classificado como de moderado tráfego, pela predominância de veículos particulares e transporte urbano; e os pontos P4 e P5 foram classificados como de baixo tráfego, com circulação apenas de veículos particulares. Foram analisados a abundância de T. recurvata, parâmetros morfofisiológicos (área foliar, área específica foliar, índice de esclerofilia, proporção peso seco/peso fresco, clorofila (a+b), análise da organização estrutural do mesofilo) e o acúmulo de metais (Fe, Cd, Cr, Cu, Pb e Zn). A análise de abundância e os resultados obtidos nas análises de metais apresentaram relação com a intensidade do tráfego de veículos, ordenando os pontos de amostragem em P1 > P2 = P3 > P4 = P5, demonstrando que a abundância de T. recurvata é maior em áreas impactadas pela poluição atmosférica urbana e indicando que T. recurvata absorve e acumula metais, podendo ser empregada no biomonitoramento da poluição atmosférica urbana em áreas impactadas pelo tráfego veicular. Os parâmetros morfofisiológicos analisados evidenciam que, em função das adaptações que T. recurvata possui, a estrutura interna não é impactada significativamente pela poluição atmosférica urbana. A presença das escamas absorvedoras, a via de metabolismo CAM e a capacidade de armazenar água, dentre outras características, evidenciam seu potencial bioindicador em áreas urbanas, principalmente em relação ao acúmulo de metais. / Air pollution can threat the environment and public health, and is assess by pollutant ́s concentration measurements in order to verify whether the limits set by environmental agencies are being respected. However, these measures do not indicate immediately the impacts to living beings. To faced this problem, plants are been investigated as potential bioindicators of air pollution and, among them, stand out bromeliads Tillandsia genus which colonize various substrates,. obtaining water and nutrients from the atmosphere directly. In this context, this research assessed the potential of epiphytic bromeliad Tillandsia recurvata (L.) L. found in urbanized areas of the city of Curitiba - PR as a bioindicator of urban air pollution. According to vehicle traffic, five sample points were selected and classified. Points P1 and P2 were classified as high-traffic vehicle due presenting trucks and urban transport; point P3 was classified as moderate traffic due the predominance of private vehicles and urban transport; and points P4 and P5 were classified as low-traffic, presenting circulation of private vehicles only. There were analyzed the abundance of T. recurvata, morphophysiological parameters (leaf area, leaf specific area, sclerophylly index, percentage dry weight / fresh weight, chlorophyll (a + b), analysis of structural mesophyll organization) and the heavy metals accumulation (Fe, Cd, Cr, Cu, Pb and Zn). The abundance analysis and the results obtained for metals analysis were correlated with the intensity of vehicular traffic, directing the sampling points P1 > P2 = P3 > P4 = P5. This result demonstrate that the abundance of T. recurvata is greater in urban air pollution impacted areas, thus indicating that T. recurvata absorbs and accumulates metals and can be used in biomonitoring of urban air pollution in areas impacted by vehicular traffic. Morphophysiological parameters analyzed shows that the internal plant ́s structure is not significantly impacted by urban air pollution due plant ́s adptations. The presence of absorbing scales, the CAM metabolism pathway and it ́s store water ability, among other features, demonstrate their potential as bio-indicator in urban areas, especially regarding heavy metals accumulation .
140

A multiple accounts approach for analyzing the effectiveness of NOx emissions controls in the GVRD airshed

Smailes, Robert L. 11 1900 (has links)
This thesis presents an analysis of air quality control initiatives in the GVRD. Starting with an examination of deteriorating regional air quality, oxides of nitrogen emissions (NOx), are the focus (as a precursor to ground level ozone.) The research demonstrates that if the status quo is maintained, episodes of ground level ozone will get worse and the effects will be far reaching and expensive. The Greater Vancouver Regional District's Air Quality Management Plan is reviewed, with emphasis on analysis and evaluation of emission reduction strategies. Emission Reduction Measures (ERMs) are various methods of reducing air pollution (including scrubbers on smoke stacks, transportation demand management, alternative fuels and motor vehicle inspection/maintenance programs.) Emission Reduction Measures are viewed as the tools that must be implemented to solve air quality problems. Environmentally, the most desirable solution would be to implement all ERMs. However, factors such as cost effectiveness and social, financial, political and customer service impacts must be considered and the best measures should be implemented first. The best solutions are those that meet as many objectives as possible while causing the least amount of negative impacts on the economy, society, government and the environment. Finding optimal solutions is a task that requires formalization of common sense. Analytical frameworks such as the cost/benefit analysis, decision analysis and the multiple account/objective analysis are considered as potential tools to help "make sense" of the complexity of air quality policy decisions. The intent is to provide useful and readily understandable information to decision makers. The Multiple Account Analysis (as used by The Crown Corporations Secretariat) is applied to an assortment of Emission Reduction Measures to help identify the "best" order for implementation. This method provides results that compare accounts of importance (such as cost effectiveness and emission reduction potential) and presents decision makers with quality information highlighting tradeoffs and preferences. In the scope of this paper, four ERMs are analyzed across accounts and the results presented in a matrix. The AirCare Program appears as the best choice for effective reduction of oxides of nitrogen when compared to alternative fuels, vanpooling and the Burrard thermal generating plant rebuild. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate

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