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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.
271

Renewable Energy Across the 50 United States and Related Factors

Christenson, Cynthia Brit 25 January 2013 (has links)
Renewable energy production replaces diminishing non-renewable energy sources including fossil fuels. Major sources of renewable energy include biofuels, geothermal, hydroelectric, solar thermal and photovoltaic, wind, wood, and biomass. Greater use of renewable energy sources can fill gaps in energy as non-renewable sources are depleted, provide more energy independence at a state and national level, and help address climate change by reducing greenhouse gas emissions from combustion of fossil fuels. The research objectives of this thesis are two-fold. First, which U.S. states are leaders in renewable energy production? Second, what factors may account for variation among U.S. states in levels of renewable energy production? The five state leaders in production of renewable energy are Washington, California, Iowa, New York, and Texas. Potential influences on renewable energy production include these factors: total energy importation or exportation by state, education level of residents, retail electricity cost, gross state product, poverty level, total population, along with indicators of political and religious ideology including Republican presidential voting, belief in God, and renewable energy potential. A Pearson correlation analysis was conducted to identify multi-collinearity between the independent variables and a factor analysis was used to explore possible associations between all variables. Finally, linear regression analysis is conducted to identify those independent variables significantly associated with the dependent variable, renewable energy production levels for each state. Factors found to be associated with higher renewable energy production are a larger state economy as measured by higher gross state product (GSP) and greater renewable energy potential. The analysis yields insights into the conditions under which U.S. states are more likely to produce higher levels of renewable energy, relevant information for state and federal planning for increased energy independence and greenhouse gas reduction.
272

An Assessment of Livelihood Security in International Community-based Wildlife Conservation Projects

Perez-Watkins, Monica Antonia 13 February 2013 (has links)
Strategies for human livelihood security and wildlife conservation often conflict, especially in rural and impoverished areas where wildlife and their habitats are important sources of livelihood. Community-based conservation approaches to wildlife conservation seek to remedy this conflict. Still, problems persist and alternative forms of livelihood are often not generated or accounted for in community-based projects. Therefore, it is important to understand the extent to which and specific ways livelihood security are incorporated into community-based wildlife conservation projects. This thesis uses qualitative methods to examine the extent to which livelihood security is incorporated into community-based wildlife conservation projects. Specifically, I assess whether and how well various subcomponents of livelihood security, which I identify as income, non-monetized benefits and access rights, representative participatory management, and food security, are incorporated into projects from developing regions around the world. My content analysis and rating of the quality of evidence of 27 published case studies revealed that various subcomponents of livelihood security are often incorporated into community-based wildlife conservation projects, though the subcomponents are often only weakly or moderately incorporated and sometimes are not incorporated at all. Among the four subcomponents of livelihood security, representative participatory management is incorporated into the projects to the greatest extent and food security is incorporated the least. Although case studies might mention livelihood security, in one-quarter of such instances, no evidence was provided that a particular subcomponent was actually incorporated into the project. Still, livelihood security was found to be incorporated to a moderate or strong extent in slightly more than one-third of instances. Recommendations to better incorporate livelihood security into wildlife conservation projects are provided for project facilitators, including non-governmental organizations, funders, and government agencies.
273

Measuring City Commitment to Climate Change Mitigation

Clinton, Kelsey Wefer 04 May 2012 (has links)
An increasing number of cities are focusing on sustainability and climate change mitigation by joining groups such the International Council for Local Environmental Initiatives (ICLEI). ICLEI uses a five-step milestone process to help cities achieve their mitigation goals. These milestones include conducting a greenhouse gas inventory, setting reduction targets, creating a Climate Action Plan, and implementing and monitoring that plan. Prior studies have examined factors that may influence a citys decision to join ICLEI, but few have looked at how committed the cities are to sustainability and to ICLEI itself after joining the organization. The purpose of this study is to uncover why some member cities show a greater commitment to the ICLEI program than others. Commitment to climate change mitigation was measured by the number of ICLEI program milestones achieved by 257 member cities. Fifteen independent variables covering socioeconomic conditions, local residents attitudes, climate stress, and location were included in a principal components analysis, chi-square test, and multiple regression analysis to identify key factors that may explain variation in level of commitment to climate change mitigation. The results show that the number of years a city has been an ICLEI member has a positive effect on milestone attainment, while the levels of car dependency and hazardous air pollutants have negative effects. In other words, member cities with higher levels of hazardous air pollution and greater dependence on automobiles had achieved fewer ICLEI milestones than cities with lower levels of climate stress. These findings are useful not only in evaluating the effectiveness of ICLEI, but in yielding better understanding of the varied environmental, cultural and socioeconomic contexts of member cities. The insights have implications for ICLEI and other similar organizations that may need to target member cities facing more significant challenges in meeting program goals with additional technical assistance and support to help them achieve meaningful local climate change mitigation.
274

The Ecological Impact of the Deepwater Horizon Oil Spill on Vibrio Parahaemolyticus Type III Secretion System and the Vibrio Community

Stephens, Erica L. 30 April 2012 (has links)
Vibrio spp are gram-negative, halophilic bacteria that naturally occur in both shallow coastal waters and parts of the deepest oceans and are a known human pathogen. There have not been extensive studies that analyze an oil spill as an environmental stressor to vibrios. If there were to be an increase in the pathogenicity of vibrios it would be a cause for human health concern. The purpose of the two studies presented was to determine changes in the pathogenicity of V. parahaemolyticus pathogenicity and the vibrio community, with respect to V. cholera, V. parahaemolyticus, and V. vulnificus. The results showed that there was an insignificant change in V. parahaemolyticus pathogenicity, and there was not a significant trend in the species composition of the vibrio community when interacting with oil. Even though the results did not show statistically significant or consistent trends of both studies, the study was an innovative evaluation of the vibrio community and various oil concentration effects thereon.
275

Composition and Physiological Characteristics of the University Lake Ecosystem Phytoplankton Community: Impacts of Seasonal and Episodic Events

Norris, Brianne Elizabeth 19 June 2012 (has links)
This research determined the changes in phytoplankton community composition in a shallow subtropical lake, influenced by urban surroundings. Specifically this research focused on the effects of seasonal progression and episodic events on the changing inorganic nutrient dynamics and the effects those dynamics had on the phytoplankton community composition and productivity. This research quantified gross primary production and respiration to determine if seasonality or episodic events were acting as forcing functions of the phytoplankton community composition. Water samples were collected weekly at three sites on the lakes perimeter, as well as following episodic events, to monitor nitrate (NO3), phosphate (PO4-3), ammonium (NH4), and silicate (Si) concentrations, and diagnostic pigment concentrations. Gross primary production and respiration was measured following a four-hour incubation period. Results show that seasonality was not significant in affecting the inorganic nutrient concentrations, but episodic events were significant in influencing the concentrations of NO3 and PO4-3. Gross primary production existed at a mean rate of 3.45 gram carbon/gram chlorophyll a/ hour (g C/g chl/hr), and the median respiration rate was 0.66 g C/g chl/hr. Primary production and respiration were not significantly affected by seasonal progression, but gross assimilation of oxygen was significantly increased following episodic events, and increases were dependent on the presence of phosphate and ammonium. The phytoplankton community composition was determined to be 51% chlorophyceae, 30% cyanobacteria, 10% diatoms, and 3.4% cryptophyceae, Chlorophytes and diatoms significantly affected by seasonality and episodic events, but only at particular test sites, and the cyanobacteria and diatom populations experience a negative linear growth relationship with one another. The changes in community composition were the result of both seasonality and episodic events, and fluctuations of ammonium and phosphates, while productivity was influenced solely by the occurrence of episodic events. Low biodiversity within the phytoplankton community exists in this lake as a result of urban runoff and eutrophication.
276

THE CONTEXT OF PUBLIC ACCEPTANCE OF HYDRAULIC FRACTURING: IS LOUISIANA UNIQUE?

White, Crawford 16 July 2012 (has links)
Hydraulic fracturing has received increased attention over the past decade. The rapid adoption of this technique coupled with accurate directional horizontal drilling has unlocked several US shale formations. Amid the possibility of 100% domestically sourced natural gas, public perception varies and opponents question the long-term risks and repercussions of the technique. This thesis will provide context to some of the variation seen in the public perception of hydraulic fracturing among three states: Louisiana, Pennsylvania, and Texas. Two surveys of Louisiana stakeholders were conducted in order to rank the state in terms of acceptance amongst previously conducted surveys of its two peers. Results show that of the three states, Louisianans have accepted hydraulic fracturing the most and Pennsylvanians the least. Factors have been identified that may explain differences in acceptance among these states. These include well densities, potentially affected populations, previous environmental contamination experiences, variations among state regulatory response, and the personal histories and experiences of each states populations. Louisianas unique history with oil and gas, high exposure to energy development, and vital role in the United States energy market may all be contributing factors for the acceptance of hydraulic fracturing and horizontal drilling of shale as reasonable practices. Meanwhile, the increased frequency of fracking accidents and negative portrayal in documentaries may both contribute to Pennsylvanias low rate of acceptance.
277

An Analysis of the Allocation of FEMA Public Assistance Funds Along the U. S. Gulf Coast Following Hurricanes Katrina, Rita, and Wilma

Golden, Pamela Camille 18 April 2013 (has links)
Due to the effects of global climate change, natural disasters such as hurricanes are increasing in terms of both intensity and frequency. During the record-breaking hurricane season of 2005, Hurricanes Katrina, Rita, and Wilma struck the U. S. Gulf Coast, affecting areas from Texas to Florida and causing billions of dollars in damage. This study examines the allocation of FEMA Public Assistance across the affected Gulf of Mexico states, what factors account for variation in in assistance allocation, what are the priorities for recovery among county leaders and what obstacles they have encountered since 2005. This study includes 136 counties and seven independent variables. The analysis includes bivariate correlation and multiple regression analysis, and a brief survey that was sent out to the Emergency Management Agency Director in each county of the study area. The results show that the level of damage and amount of poverty within a county were strong predictors of Public Assistance allocation. Debris Removal and Infrastructure projects were the highest overall priority for communities and the most common obstacle faced by the local government was difficulty in getting a firm commitment from FEMA regarding the eligibility of a project. These results have important implications for future disaster management that will face ever-evolving risks.
278

Inductively Coupled Plasma Optical Emission Spectroscopy Analysis of Heavy Metal Concentrations in Gulf Menhaden (Brevoortia patronus) Populations in the Northern Gulf of Mexico from 2011 to 2012

Rockett, Hannah Paula 03 July 2013 (has links)
In 2010, the Deepwater Horizon (DWH) oil spill, released 4.9 million barrels of oil into the Gulf of Mexico, creating the largest marine oil spill in the history of the U.S. petroleum industry. Trace metals, including those from crude oil, were dispersed in the water column and bound to suspended particulates. As obligate filter-feeding omnivores and a predominate fishery in the Gulf of Mexico, Gulf menhaden (Brevoortia patronus) are susceptible to trace metal accumulation. Samples of menhaden were collected at two locations in coastal Louisiana, Grand Isle (GI) and Vermillion Bay (VB), with VB serving as the non-impacted DWH oil spill site and GI as the impacted DWH oil spill site. The analysis of trace metals was performed using inductively coupled plasma-optic emission spectroscopy (ICP-OES) methods. Eleven metals (As, Ba, Cd, Co, Cr, Cu, Fe, Ni, Pb, Zn, V) were chosen and observed by four variables: place (VB or GI), size (small or large), month (July, August or September), and year (2011 or 2012) and the interactions between the variables. Metal concentrations in the current study followed the sequence: Fe > Zn > Ba > As > V > Cr > Cu > Ni > Pb > Co > Cd. Results showed that in 2011, VB had statistically higher concentrations than GI for 9 of the 11 metals. Elevated discharge rates during the Mississippi River Flood of 2011 produced a dilution effect, decreasing the concentration of trace metals in the water column at GI. Size was also significant, with small fish having statistically higher concentrations for 8 of the 11 metals. In fish, younger/smaller fish have higher metabolic activities than older/larger fish, which leads to a higher metal accumulation in smaller fish. Arsenic was the only metal that had higher concentrations in 2011 and in large fish. Differences in arsenic trends may be attributed to the DWH oil spill, which may have caused reduced adsorption of arsenic by the mineral goethite and increased concentrations of arsenic in the water. Iron and zinc in the current study exceeded the FAO/WHO maximum permissible limit.
279

Community Resilience to Coastal Hazards: An Analysis of Two Geographical Scales in Louisiana

Li, Chi 12 July 2013 (has links)
Quantifying resilience is difficulties due to the different definitions of resilience, the interchangeable uses with two other terms vulnerability and adaptability, as well as the lack of consensus on what indicators should be selected to quantifying resilience. This thesis research studied the community resilience in Louisiana by applying the Resilience Inference Measurement (RIM) model at two geographic levels: county level and zip code level. The RIM model accesses resilience by using three dimensions (exposure, damage, and recovery) and two abilities (vulnerability and adaptability). The types of coastal hazards included in this study were: coastal, flooding, hurricane/tropical storm, tornado, and severe storm/thunder storm. The study time period was 2000 to 2010. K-means clustering analysis was used to derive the resilience groups. Discriminant analysis was applied to validate the resilience rankings by using a set of indicator variables. At the county level, discriminant analysis yielded a remarkably high 93.8% classification accuracy when population growth rate in 2000-2010 was used as a recovering indicator and 28 adaptability variables were used to characterize the counties. The accuracy at the zip-code level decreased to 80.2% when population growth rate was used as a recovering indicator. In general, the findings at two different scales are consistent; counties and zip codes with higher socioeconomic status and more resources were found to be more resilient. Interestingly, the three most potent indicators revealed at both scales were the same, which are median rent, median value of owner-occupied housing units and housing density. These findings support the use of the RIM model to further explore adaptability indicators and the underlying process leading to resilience.
280

Polysulfone ultrafiltration membranes impregnated with silver nanoparticles show improved biofouling resistance and virus removal

January 2009 (has links)
Biofouling and virus penetration are two significant obstacles in water treatment membrane filtration. Biofouling reduces membrane permeability, increases energy costs, and decreases the lifetime of membranes. In order to effectively remove viruses, nanofiltration or reverse osmosis (both high energy filtration schemes) must be used. Thus, there is an urgent demand for low pressure membranes with anti-biofouling and anti-viral properties. The antibacterial properties of silver are well-known, and silver nanoparticles (nAg) are now incorporated into a wide variety of consumer products for microbial control. In this study, nAg incorporated into polysulfone ultrafiltration membranes (nAg-PSf) exhibited antimicrobial properties towards a variety of bacteria, including Escherichia coli K12 and Pseudomonas mendocina KR1, and enhanced the removal of MS2 bacteriophage. Nanosilver incorporation also increased membrane hydrophilicity, reducing the potential for other types of membrane fouling. Thus, the incorporation of nAg into polysulfone ultrafiltration membranes increases both membrane efficiency and effectiveness.

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