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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.
251

Classification of air pollution regimes in the Missouri region

Weber, Eric E. Lupo, Anthony R. January 2009 (has links)
Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 23, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Thesis advisor: Dr. Anthony R. Lupo. Includes bibliographical references.
252

Impact of climate-responsive controls and land usage on regional climate and air quality

Trail, Marcus Alexander 08 June 2015 (has links)
Impacts of Climate-responsive Controls and Land Usage on Regional Climate and Air Quality Marcus A. Trail 201 pages Directed by Dr. Armistead G. Russell Regional air quality impacts public health, visibility and ecosystem health, and is significantly affected by changes in climate, land use and pollutant emissions. Predictions of regional air quality responses to such changes can help inform policy makers in the development of effective approaches to both reduce greenhouse gases and improve air quality. However, major sources of uncertainty exist in predicting future air quality including limitations in the tools used to project future emissions, land use changes and uncertainties associated with predicting future climate. Recently, technical advances in downscaling global climate simulations to regional scales, and, the development of bottom-up operational tools used to forecast emissions have enhanced our ability to account for the complex interactions between population, socio-economic development, technological change, and federal and regional environmental policies. The results show that emissions reductions strategies will continue to play a vital role in improving air quality over the U.S. while CO2 emission reduction policies can have mixed positive and negative impacts on air quality. However, additional costs will be necessary to reach air quality goals due to climate change because deeper emission reductions will be required to compensate for a warmer climate, even if current efforts are predicted to show improvement. The results of this study also show that regional climate and O3 and aerosol concentrations are highly sensitive to reforestation and cropland conversion in the Southeast and these land use changes should be considered in air quality management plans.
253

Advancements in concrete material sustainability : supplementary cementitious material development and pollutant interaction

Taylor Lange, Sarah Clare 16 September 2013 (has links)
Calcined clay and fly ash supplementary cementitious materials (SCMs) used in cement based materials were examined for their chemical and mechanical performance, as well as their pollutant interaction. This dissertation addresses three primary research questions, namely: (i) can zincite additions facilitate the use of calcined clay as SCMs by compensating for reductions in early-age mechanical performance or by compensating for their reduced pozzolanic reactivity, (ii) can cement renders, containing metakaolin calcined clays, be engineered for passive carbon dioxide and ozone removal, and (iii) how do the specific activity and emanation fractions of concrete constituents, including fly ash and metakaolin, as well as assembled concretes impact concrete radon emanation and indoor radon concentrations? The first question relates directly to the development of new, sustainable material options, which can replace a portion of cement in a concrete mixture. Results from the experiments with zincite showed that the treatment method removed the dilution effect that occurs when using less reactive materials to substitute a portion of portland cement, but did not considerably influence mechanical properties. Therefore, zincite additions are not a good means of enhancing the utilization of non-kaolinite clays in concrete. As an integrated system, the latter two questions of this dissertation investigate the interaction between airborne pollutants and the cement based materials containing SCMs. The use of SCMs in render and concrete systems resulted in different pollutant uptake and exhalation behavior, relative to non-SCM control systems. For pollutant uptake, render systems containing metakaolin increased the carbon dioxide ingress while decreasing the ozone uptake. For radon exhalation rates, modeling results demonstrated that concretes without fly ash have a higher probability of containing less total radium and lower radon exhalation rates, when compared to samples with fly ash, assuming an emanation fraction of 5%, as suggested in the literature. Experimental results demonstrated that metakaolin, fly ash and control concretes had emanation fractions of 7%, 9% and 13%, respectively, confirming that (i) an assumed fraction of 5% would underpredict indoor radon concentrations and potential health consequences, and (ii) SCMs can reduce the total concrete emanation fraction. This dissertation demonstrates how the use of sustainable material selections, such as calcined clays and fly ashes, not only influences the microstructure and mechanical performance of the cement based materials, but also alters the interaction of the material with its surrounding environment. / text
254

Pollutant control strategies for acceptable indoor air quality and energy efficiency in retail buildings

Zaatari, Marwa 24 February 2014 (has links)
Indoor air is associated with substantial health risks and is estimated to be responsible for the loss of over 4.7 million healthy life years (years lost due to morbidity and mortality) annually in the U.S. The highest indoor air-related health benefits can be expected from policies and strategies that efficiently target pollutants having the greatest contribution to the burden of disease. This burden is caused by indoor sources as well as by outdoor pollutants transported to the indoors. The diversity of pollutants, pollutant sources, and the resulting health effects challenge the comparison of the impacts of different control strategies on energy consumption and indoor air quality. To address this challenge, this work presents a quantitative framework for reaching the optimal energy cost for the maximum achieved exposure benefits, specifically for retail buildings and their understudied energy, economic, and health risk influence. The main objectives of this dissertation are to 1) determine pollutants of concern in retail buildings that contribute the greatest to the burden of disease, and 2) determine energy-efficient, exposure-based control strategies for different retail types and locations. The research in this dissertation is divided into four specific aims that fulfill these two objectives. The first specific aim (Specific aim 1.a) addresses Objective 1 by applying available disease impact models on pollutant concentrations taken from 15 literature studies (150 stores, a total of 34 pollutants). Of those pollutants, there was little data reported on particulate matter (PM) concentrations and none on emission rates for PM, limiting our understanding of exposure to this pollutant. The second specific aim (Specific aim 1.b) also addresses Objective 1 by characterizing particulate matter (PM) concentrations, emission rates, and fate of ambient and indoor-generated particles in retail buildings. The tasks of this specific aim consisted of particulate matter and ventilation measurements in 14 retail buildings. Among the findings of Objective 1, PM2.5 and acrolein are the main contaminants of concern for which control methods should be prioritized, contributing to 160 disability-adjusted life years (DALYs; years lost due to premature mortality and disability) per 100,000 persons annually. Employees in grocery stores mainly drove this burden. An efficient indoor exposure reduction strategy should take into account all mechanisms that influence pollutant concentrations: indoor and outdoor sources (highlighting the importance of retail type and location), infiltration, ventilation, and filtration. The remaining specific aims address Objective 2 by investigating the energy and air quality impact of two commonly used exposure control scenarios, ventilation (Specific aim 2.a) and filtration (Specific aim 2.b). The tasks of Specific aim 2.a consisted of modeling the impact of multiple ventilation strategies on contaminants of concern for six major U.S. cities and two retail types. The tasks for Specific aim 2.b consisted of conducting field measurements on 15 rooftop units to determine the fan energy impacts of filter pressure drop. These results are used in combination with a large dataset of 75 filters commonly installed in commercial buildings to estimate the energy consequences of filtration. Results for Objective 2 are presented from the quantitative comparison of the impact on energy usage and DALYs lost of three main approaches: (1) adjusting ventilation only; (2) adjusting filtration only; and (3) adjusting ventilation and filtration together. All approaches were able to provide substantial reductions in the health risks (19-26% decrease in DALYs lost); the magnitude of the reductions depended on the ventilation/filtration scenario, the retail type, and the city. The magnitude of energy cost to achieve the maximum health benefits depended on the city and the retail type (for example for a 10,000 m2 grocery store, the energy cost ranged from $1,100 for the annual cost of filtration energy in Los Angeles to $24,000 for the annual cost of ventilation in Austin). The uncertainties of the estimates driving these findings are discussed throughout the results section. The finding that emerges from this analysis is the pollutant exposure control ventilation (PECV) strategy. This strategy is superior to the ventilation rate procedure (VRP; ASHRAE Standard 62.1-2010) and the indoor air quality procedure (IAQP; ASHRAE Standard 62.1-2010) as it decides on a range of ventilation rates by weighing the exposures of contaminants of concern found in retail buildings. Then, among the range of ventilation rates identified, the PECV recommends the optimal ventilation rate that leads to energy usage savings in the climate considered. Overall, the work presented here prioritizes specific contaminants of concern in retail buildings and proposes an exposure-based, energy-efficient control strategy for different retail types and locations. Policy makers, engineers, and building owners can use these results to decide amongst appropriate control strategies that will lead to minimum energy consumption and, at the same time, will not compromise occupant health. This work can be repeated for different types of buildings, notably for residences, schools, and offices where abundant information is available on both pollutant concentrations and ventilation rates, but where information is lacking on how to optimize the control strategies for better indoor air quality. / text
255

Assessing and controlling concentrations of volatile organic compounds in the retail environment

Nirlo, Éléna Laure 07 July 2014 (has links)
Retail buildings have potential for both short-term (customer) and long-term (occupational) exposure to indoor pollutants. A multitude of sources of volatile organic compounds (VOCs) are common to the retail environment. Volatile organic compounds can be odorous, irritating or carcinogenic. Through a field investigation and modeling study, this dissertation investigates exposure to, and control of, VOCs in retail buildings. Fourteen U.S. retail stores were tested one to four times each over a period of a year, for a total of twenty-four test visits. Over a hundred parameters were investigated to characterize each of the buildings, including ventilation system parameters, and airborne pollutants both indoors and outdoors. Concentrations of VOCs were simultaneously measured using five different methods: Summa canisters, sorbent tubes, 2,4-dinitrophenylhydrazine (DNPH) tubes, a photoionization detector (PID), and a colorimetric real-time formaldehyde monitor (FMM). The resulting dataset was analyzed to evaluate underlying trends in the concentrations and speciation of VOCs, identify influencing factors, and determine contaminants of concern. A parametric framework based on a time-averaged mass balance was then developed to compare strategies to reduce formaldehyde concentrations in retail stores. Mitigation of exposure to formaldehyde through air cleaning (filtration), emission control (humidity control), and targeted dilution (local ventilation) were assessed. Results of the field study suggested that formaldehyde was the most important contaminant of concern in the retail stores investigated, as all 14 stores exceeded the most conservative health guideline for formaldehyde (OEHHA TWA REL = 7.3 ppb) during at least one sampling event. Formaldehyde monitors were strongly correlated with DNPH tube results. The FMM showed promising characteristics, supporting further consideration as real-time indicators to control ventilation and/or environmental parameters. The vast majority of the remaining VOCs were present at low concentrations, but episodic activities such as cooking and cleaning led to relatively high indoor concentrations for ethanol, acetaldehyde, and terpenoids. Results of the modeling effort demonstrated that local ventilation caused the most uniform improvements to indoor formaldehyde concentrations across building characteristics, but humidity control appeared to have a very limited impact. Filtration used under specific conditions could lead to larger decreases in formaldehyde concentrations than all other strategies investigated, and was the least energy-intensive. / text
256

An analysis of the roadside air quality improvement policy in Hong Kong

Lai, Ho-yan, 黎可欣 January 2011 (has links)
published_or_final_version / Politics and Public Administration / Master / Master of Public Administration
257

Inter-pollutant and reactivity-weighted air pollutant emission trading in Texas

Wang, Linlin 28 August 2008 (has links)
Not available / text
258

Luftqualität in Sachsen: Jahresbericht

21 August 2015 (has links) (PDF)
Der Jahresbericht gibt Auskunft über die Luftqualität im Freistaat Sachsen, insbesondere für Luftschadstoffe mit gesetzlich festgelegten Grenz- bzw. Zielwerten wie Schwefeldioxid, Stickstoffdioxid, Feinstaub, Blei, Benzol und Ozon. Die meteorologischen Bedingungen wirkten sich 2014 im Mittel positiv auf die Schadstoffbelastung der Luft aus. Dennoch gab es an zwei verkehrsnahen Messstellen in Dresden und Chemnitz Grenzwertüberschreitungen bei Stickstoffdioxid. Der 24-Stunden-Grenzwert der Partikelkonzentration (PM10) wurde 2014 an verkehrsnahen Messstellen in Dresden, Chemnitz und Leipzig verletzt. Ozon-Zielwerte zum Schutz der menschlichen Gesundheit und der Vegetation wurden in den Höhenlagen des Erzgebirgskamms nicht eingehalten. Die Konzentrationen der Luftschadstoffe Schwefeldioxid, Feinstaub PM2,5, Benzol und Blei lagen auf dem Niveau der Vorjahre und sind unkritisch. Die Zielwerte für die PM10-Inhaltsstoffe wurden eingehalten.
259

Neighborhood scale air quality modeling in Corpus Christi using AERMOD and CALPUFF

Kim, Hyun Suk 14 February 2011 (has links)
Ambient monitoring and air quality modeling of air toxics concentrations at the neighborhood-scale level is a key element for human exposure and health risk assessments. Since 2005, The University of Texas at Austin (UT) has operated a dense ambient monitoring network that includes both hourly automated gas chromatographs as well as threshold triggered canister samples and meteorological data in the Corpus Christi area. Although Corpus Christi is in attainment with the National Ambient Air Quality Standards for both ozone and fine particulate matter, its significant petroleum refining complex has resulted in concerns about exposure to air toxics. The seven site network, incorporating both the industrial and residential areas in Corpus Christi, provided a unique opportunity to further the development and understanding of air quality modeling for toxic air pollutants at the neighborhood-scale level. Two air dispersion models, AERMOD and CALPUFF, were used to predict air concentrations of benzene for one of the UT operated monitoring sites (Oak Park monitoring site: C634) and the predictions were compared to the observed benzene concentration data at the Oak Park monitoring site to evaluate model performance. AERMOD and CALPUFF were also used to predict benzene concentrations in populated areas and at sensitive receptor locations such as schools and hospitals. Both AERMOD and CALPUFF were able to reproduce the early morning high benzene concentration and the northern wind effect except under strong NNE wind conditions, where the observed data indicated elevated high benzene concentration which AERMOD and CALPUFF failed to predict. These under-predictions could be due to the NNE strong wind condition at that time of these occurrences or could be attributed to different types of emissions other than the point sources emissions from the 2005 TCEQ Photochemical Modeling inventory, such as mobile sources or accidental emission events. These preliminary analyses could be expanded by modeling longer periods, by including other emission sources and by inter-comparisons with observed data from other CCNAT monitoring sites. In addition, fundamentally different modeling approaches (eulerian, rather than lagrangian) could be considered. / text
260

Evaluating the air quality impacts of NO[subscript x] emission trading

Nobel, Carolyn Eve 30 March 2011 (has links)
Not available / text

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