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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.
151

Essays on environmental and natural resource economics

Stafford, Teresa Michelle 09 November 2010 (has links)
In the first essay, I assess the effect of indoor air quality (IAQ) in school buildings on student test performance and attendance rates. Results indicate that performance on standardized tests significantly improves while attendance rates are unresponsive to improvements in IAQ. The improvement in math scores ranges from 0.102 - 0.189 standard deviations per $500,000 spent on IAQ-related renovations and is 35% - 50% greater than the improvement in reading scores. For the same budget, results suggest that the improvement in math scores following IAQ-related renovations is several times larger than the improvement associated with class size reductions. In the second essay, I examine the responsiveness of the daily labor supply of fishermen to transitory variations in the daily wage using data from the Florida spiny lobster fishery. The applicability of this research is both narrow and general. Understanding this relationship is key to determining the effectiveness of landing fees as a means to regulate fisheries. Tracing out the labor supply curve is also fundamental to labor economics and policy. I find that the wage elasticity of labor supply (participation) is positive and statistically different from zero, with a point estimate of 0.967. This suggests an upward slopping labor supply curve and refutes the notion of reference dependent preferences. In the third essay, I examine the bias associated with ignoring the multi-species aspect of labor supply decisions in spatially explicit bioeconomic fishery models. Using a complete 15-year panel of all fishing trips made by fishermen possessing a Florida spiny lobster license, including non-lobster trips, I show that the simplifying assumption of a dichotomous choice structure at the first node (i.e. participate in the target fishery or not) is not innocuous and that predicted participation rates can change substantially with the addition of another species as an outside alternative in the first decision node. / text
152

Monolayer and multilayer particle resuspension from indoor surfaces : literature review and experimental methodology

Boor, Brandon Emil 14 February 2011 (has links)
Resuspension is an important source of particles in the indoor environment. A variable that may have a significant impact on the fraction of particles removed from indoor surfaces is the type of particle deposit. Particles may be deposited in either a monolayer, where there is minimal particle-to-particle contact, or a multilayer, where there is substantial particle-to-particle contact and interaction. This paper provides a review of theoretical and experimental studies on particle resuspension from monolayer and multilayer particle deposits. In addition, an experimental methodology was developed to determine resuspension from the two types of deposits on indoor surfaces. Seeded samples were exposed to controlled flow conditions in a micro-scale wind tunnel and were analyzed with fluorescence stereomicroscopy. Resuspension was found to occur at significantly lower velocities for multilayer deposits compared to monolayer deposits. / text
153

Indoor air quality in retail stores

Rhodes, Joshua Daniel 07 July 2011 (has links)
Retail stores are understudied given the energy, occupant health, and potential sales impacts associated with poor indoor air quality (IAQ). There is also evidence of elevated pollutants in retail environments. This thesis is an exploration of the indoor air quality of retail stores. The first section of this thesis is a literature review on field investigations of the indoor air quality in retail buildings. Sixteen investigations report different measurements in 17 specific types of retail environments. Measurements vary depending on the specific investigation, but include VOCs, SVOCs, particles, microbiological species, and radon. When reported, indoor to outdoor ratios of almost all pollutants are greater than unity, suggesting the importance of indoor sources in retail environments. The second section of this thesis is an analysis of the whole store net emission factor for different retail environments. From the types of pollutants found in the retail store investigations, VOCs were the only pollutant group studied frequently enough to merit this analysis. The final section is an analysis of the potential for pollutant remediation strategies. Two methods, increasing air change rate and air cleaning, are considered with an analysis of the energy penalties associated with each. / text
154

Urban ecosystems and human health in South Africa : examining the relationships between housing, energy, indoor air quality and respiratory health

Savage, Leah Krystyn 03 October 2007 (has links)
In South Africa one of the strongest influences on domestic indoor air quality is the type of energy used for heating, cooking and other household purposes. Emissions from fuel combustion, along with housing factors, can result in respiratory infections, a leading cause of death in the country. In this study I examine the relationships between energy types, patterns of use, housing conditions such as improper ventilation and overcrowding, indoor air quality and respiratory health in poorer communities of Msunduzi Municipality, South Africa. These variables were examined using an ecohealth perspective through the integration of data concerning individual time-activity budgets, housing materials and structure, energy sources used for heating, cooking and lighting, respiratory symptoms and continuous real time monitoring of indoor air pollutants (particulate matter (PM), carbon dioxide (CO2), carbon monoxide (CO) and sulphur dioxide (SO2)). A total of 20 dwellings, displaying large variability in housing structure and energy patterns, were sampled for 24 hours (hr) over a period of 60 days. The mean 24-hr average indoor concentrations measured were as follows: PM2.5= 16 ± 11 µg/m3, PM10= 78 ± 46 µg/m3, CO= 5 ± 6 ppm and SO2= 0.18 ± 0.27 ppm. Mean indoor concentrations measured were significantly greater than mean outdoor concentrations (p<0.0001 (PM2.5), p=0.017 (PM10), p<0.0001 (CO), p<0.0001 (SO2)). Although PM concentrations increased with the use of increasingly inefficient-burning fuel types (gas < paraffin < wood), no significant differences in the means were found across these fuel types. It is thought that the high degree of variability among dwellings and the small sample size in this study obscured any statistically significant relationships. No significant differences in mean concentrations were found across different housing types either. Indoor exposures were, on average, highest among very young children (ages 0-5) and elders (ages 51+). All age groups reported experiencing high levels of respiratory symptoms, with the elder group (ages 51+) reporting the highest percentages for each symptom. This study will be used to inform local governments and NGOs of local indoor air pollution and exposure risks, so that policy and resources can be allocated accordingly to improve physical environments. / Thesis (Master, Environmental Studies) -- Queen's University, 2007-09-27 08:52:05.443
155

The whole is greater than the sum of its parts : cumulative risk of indoor air pollution and urban vulnerability in Cato Manor.

Binedell, Michelle Louise. January 2003 (has links)
Low-income communities are potentially more vulnerable to physical, social and environmental hazards than wealthier communities. The lack of services associated with these communities (such as water supply, sanitation facilities and electrification) has increased the exposure of households to health hazards. These households also lack the coping mechanisms and resources to deal with the stress that these hazards impose on them. This study is concerned with the potential health hazards imposed from indoor air pollution. Traditional health risk assessments are used to determine the level of risk to human health from a variety of chemical or biological hazards. What these assessments do not include however, is a measure of the vulnerability of the household. The aim of this study therefore, was to develop a methodology for generating a vulnerability index for the inclusion of factors underlying urban poverty and vulnerability into a risk assessment of indoor air pollution. The approach adopted in this study followed an iterative and inductive pathway. Theories on risk assessment and urban vulnerability were explored in order to understand the manner in which risk to human health is assessed and compounded by vulnerability. Secondary data sources as well as a household survey provided information that aided the selection of a number of vulnerability indicators. These indicators were chosen as measures of vulnerability specifically for low-income households in South African settlements. The findings of the research show that there are a number of factors or issues which underlie vulnerability. The issues are related to demographics, livelihoods, physical exposures, externalities, services and general health. This study used a four-tiered selection approach to sift through the issues of vulnerability and to transform the key issues into a set of vulnerability indicators which make up the vulnerability index. / Thesis (M.Sc.)-University of Natal, Durban, 2003.
156

Houses with mould problems : Comparison of two methods for verifying mould growth in buildings

Takkinen, Johanna January 2005 (has links)
During the last ten years, the adverse health effects in upper respiratory system and irritation symptoms have become increasingly evident in residents living in moisture damaged houses with dampness and mould growth. In the mid of 1995, Finnish environmental health authorities faced the problem with an increasing demand for investigations to verify the microbial growth in suspected buildings and thereby taking appropriate control measures to protect the health of occupants. As an extension of an earlier relatively onerous method for quantification of microbial growth on surfaces, the Food Laboratory in Porvoo developed an applied direct streak method (DSM) aiming at a facilitation of the method verifying the presence of mould growth. The method was established in close collaboration with health inspectors. The DSM was compared to the original culture method (CM) and repeatability and reproducibility were good or very good. The DSM is a semi-quantitative method and enables the health inspectors to take surface samples without breaking the building structures and without being restricted to stiff surfaces. The results can demonstrate that the material is damaged by active viable mould growth. The DSM provides a powerful and useful tool for health inspectors to verify mould growth in buildings and it supports them to make decisions that are needed to protect the health of occupants. The cost of DSM is about one fourth of that of the more elaborate CM. The DSM is being increasingly used in Finland. / <p>ISBN 91-7997-123-7</p>
157

A Field Study of Airflow in a High-Rise Multi-Unit Residential Building

Ricketts, Lorne January 2014 (has links)
Airflow into, out of, and within buildings is fundamental to their design and operation as it can affect occupant health and comfort, building durability, and energy consumption. This thesis works to develop the understanding of airflow patterns and pressure regimes in high-rise multi-unit residential buildings which are both unique and complex due to the combination of their height, typical inclusion of operable windows, and compartmentalized layout. Specific attention is directed towards the performance of corridor pressurization based ventilation systems which are used pervasively within industry to ventilate and control contaminant transfer in these buildings. Airflow is caused by pressure differences which for buildings are created by the driving forces of wind, stack effect, and mechanical ventilation systems. These airflows are resisted by the air permeance (i.e. airtightness) of building elements including the exterior enclosure and interior compartmentalizing elements. Using an experimental program at a case study building, this thesis assesses the interaction of these driving forces of airflow with the physical building to create the airflow patterns for a typical high-rise multi-unit residential building. Perflourocarbon tracer (PFT) testing was performed to measure in-service airflows into and out of the suites. This testing found that the air change rates of upper suites are significantly higher than that of lower suites and that most suites receive small fractions of modern ventilation rates or are over ventilated. Airflow measurements of the supply of ventilation air to each corridor indicate that these low flow rates are in part due to leakage of air from the supply duct. The PFT testing also found that significant airflow occurred from the parking garage below the building into the occupied building spaces indicating significant potential for transfer of harmful air contaminants. The air permeance of the exterior enclosure and interior compartmentalizing elements were measured using neutralized fan pressurization and depressurization techniques and found to be within typical ranges. In particular this testing found that only 20% of the flow paths out of the corridor were to the adjacent suites through the suite entrance doors and that flows to the elevator shaft and stairwells could create a significant inefficiency in the ventilation system. A long-term monitoring program was implemented at the case study building primarily to monitor exterior environmental conditions including wind and exterior temperature and to correlate these with measured pressure differences. A strong correlation was found between building pressure and exterior temperature. Nearly 70% of the theoretical stack effect pressure was measured to act across the corridor to suite pressure boundary which creates a significant pressure differences to be overcome by the ventilation system, likely contributing to the uneven distribution of ventilation rates. Both wind and stack effect pressures were found to often be of similar or greater magnitude than mechanically induced pressure differences and thus can overwhelm the ventilation system. Overall, the corridor pressurization based ventilation system at the case study building does not effectively or efficiently ventilate the building and also does not provide sufficient control of air contaminants. As the case study building was found to be relatively representative of a typical multi-unit residential building, the findings from this building can be extended to many other buildings. Effective ventilation and airflow control in multi-unit residential buildings likely requires suite compartmentalization and direct supply of ventilation via ducted or in-suite systems.
158

Emissions and Energy Use Efficiency of Household Biochar Production during Cooking in Kenya

Helander, Hanna, Larsson, Lovisa January 2014 (has links)
This project examines the efficiency of a biochar-producing stove in meeting the needs of households in rural of Kenya. The stove has been tested and evaluated by five household in Embu, Kenya and compared with two other common cooking methods. The main parameters were time consumption, fuel consumption and emissions of carbon monoxide and particulate matter. Usability and energy use efficiency have also been evaluated. Three potential feedstocks have been examined for use in the biochar-producing stove; Grevillea prunings, maize cobs and coconut husks. The biochar-producing stove was well received by the households. It has potential of saving time, it saves fuel and it has a significantly lower level of emissions than other examined stoves. Despite some challenges related to the usability and the handling of the stove, an implementation of the biochar-producing stove can contribute to an alleviation of the women’s burdens, save fuel and contribute to a healthier indoor air climate.
159

An indoor air quality case study : the diagnosis and remediation of Cowgill Hall's IAQ problem /

Hilten, Craig Steven. January 1989 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1989. / Vita. Abstract. Includes bibliographical references (leaves 78-81). Also available via the Internet.
160

Identification of factors affecting contaminant levels and determination of infiltration of ambient contaminants in public transport buses operating on biodiesel and ULSD fuels /

Kadiyala, Akhil. January 2008 (has links)
Thesis (M.S.C.E.)--University of Toledo, 2008. / Typescript. "Submitted as partial fulfillments of the requirements for The Master of Science in Engineering." "A thesis entitled"--at head of title. Bibliography: leaves 81-92.

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