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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

Characterizing Subsurface Textural Properties Using Electromagnetic Induction Mapping and Geostatistics

Abdu, Hiruy 01 May 2009 (has links)
Knowledge of the spatial distribution of soil textural properties at the watershed scale is important for understanding spatial patterns of water movement, and in determining soil moisture storage and soil hydraulic transport properties. Capturing the heterogeneous nature of the subsurface without exhaustive and costly sampling presents a significant challenge. Soil scientists and geologists have adapted geophysical methods that measure a surrogate property related to the vital underlying process. Apparent electrical conductivity (ECa) is such a proxy, providing a measure of charge mobility due to application of an electric field, and is highly correlated to the electrical conductivity of the soil solution, clay percentage, and water content. Electromagnetic induction (EMI) provides the possibility of obtaining high resolution images of ECa across a landscape to identify subtle changes in subsurface properties. The aim of this study was to better characterize subsurface textural properties using EMI mapping and geostatistical analysis techniques. The effect of variable temperature environments on EMI instrumental response, and ECa - depth relationship were first determined. Then a procedure of repeated EMI mapping at varying soil water content was developed and integrated with temporal stability analysis to capture the time invariant properties of spatial soil texture on an agricultural field. In addition, an EMI imaging approach of densely sampling the subsurface of the Reynolds Mountain East watershed was presented using kriging to interpolate, and Sequential Gaussian Simulation to estimate the uncertainty in the maps. Due to the relative time-invariant characteristics of textural properties, it was possible to correlate clay samples collected over three seasons to ECa data of one mapping event. Kriging methods [ordinary kriging (OK), cokriging (CK), and regression kriging (RK)] were then used to integrate various levels of information (clay percentage, ECa, and spatial location) to produce clay percentage prediction maps. Leave-one-out cross-validation showed that the multivariate estimation methods CK and RK, incorporating the better sampled surrogate ECa, were able to improve the RMSE by 7% and 28%, respectively, relative to OK. Electromagnetic induction measurements provide an important exhaustive layer of information that can improve the quality and resolution of soil property maps used in hydrological and environmental research.
132

Estimating the Effectiveness of a Seasonal Gas Tax for Controlling Episodic PM2.5 Concentrations in Cache County, Utah

Moscardini, Leo A. 01 May 2014 (has links)
For several years, residents of Cache County, Utah have suffered from the recurrence of what has come to be known as the winter-inversion, or “red-air-day” season. Each year during this season – which occurs primarily in the months of December, January, and February – particulate matter concentrations measuring two and half micrometers or less (commonly known as PM2.5) rise and languish (for periods of days or even weeks) above federally mandated standards, causing extensive harm to community health and confounding what have thus far been the relatively tepid control efforts undertaken by local and state policymakers. Through time-series regression modeling, we establish a statistical relationship between PM2.5 concentrations and vehicle use in Cache County, and further calculate a gas-price elasticity for the region. Next, we analyze the benefits and costs associated with a potential seasonal gas tax which, if set appropriately and enforced effectively, could decrease vehicle use and thereby lower health costs through concomitant decreases in PM2.5 concentrations. Specifically, we find a relatively strong positive relationship between percentage of vehicle trips reduced and associated reductions in PM2.5concentrations, and a gas price elasticity of approximately -0.31 in what we call a “high price variability environment.” Based upon these results, benefit-cost analysis suggests a potentially positive social net benefit for Cache County associated with imposing a seasonal gas tax to reduce PM2.5 concentrations during the winter-inversion season. Our benefit-cost analysis, which uses quantitative estimation techniques on both sides of the ledger, yields a first-of-its-kind social net benefit estimate for controlling elevated PM2.5 concentrations in Cache County through the imposition of a seasonal gas tax.
133

Perceptions of Agriculture Teachers Toward Including Students with Disabilities

Giffing, Monica D 01 May 2009 (has links)
The inclusion of students with special needs in regular education classrooms has been required by federal law for more than three decades. However, much of the responsibility for successful accommodation of students with disabilities rests upon the shoulders of teachers. Previous research has indicated that successful inclusion of students with special needs is strongly influenced by the attitude of teachers involved. In this study, all secondary agriculture teachers in Utah were surveyed to determine their attitudes and perceptions related to their willingness and ability to include students with special needs in their classrooms and laboratories. Selected personal and professional characteristics were correlated with these attitudes and perceptions. A large majority of teachers responded that they understand the concept of inclusion, are in favor of including students with disabilities, and have had a positive experience teaching students with special needs. However, fewer respondents indicated that they had the skill level to successfully include students with disabilities. Overall, while teachers indicated willingness to include the students with most of the specific types of disabilities, they were less positive in their perceived abilities to successfully accommodate students with some specific categories of special needs.
134

Agriculture, Environmental Restoration and Ecosystem Services: Assessing the Costs of Water Storage on Agricultural Lands in South Florida

Ouellette, Kayla 18 March 2014 (has links)
A large part of the environmental restoration required by the Comprehensive Everglades Restoration Plan calls for more water-storage on lands south of Lake Okeechobee in order to restore the natural water flows of the Everglades watershed. The Everglades Agricultural Area (EAA) can be used for increased water storage in order to relieve coastal estuaries of excess water in the rainy season. This water storage can deliver additional ecosystem services of soil retention and reduced CO2 emissions that could compensate farmers for the cost of water storage by increasing long term farm profitability. The goals of this study were 1) to quantify the environmental and economic trade-offs of different water storage scenarios using water-tolerant sugarcane cultivars, and 2) to quantify the amount of water storage possible in the EAA under different water storage scenarios. A mathematical model was developed to calculate soil depth, soil subsidence, depth to the water table, sugarcane production, farm return, water storage and carbon loss for three different sugarcane cultivars with different water-tolerances. A GIS tool is also developed to estimate the amount of water storage possible in the EAA. The study found that even though water-tolerant sugarcane cultivars experience higher yields and net returns than non-water-tolerant cultivars the water storage costs with these water tolerant cultivars was greater. Raising water tables on farm lands did have the environmental benefits of reduced soil subsidence, extended farm life and increased years of water storage. However total CO2 emissions rise from 14 to 136%. Results of the GIS analysis revealed that water storage capacity for a DWT of 61 cm is 1,404,562 ac-ft, 1,417,400 ac-ft for DWT 45 cm and 1,474,692 ac-ft for DWT 20 cm. The GIS analysis was also able to identify flow ways that could possibly carry water south from Lake Okeechobee and ultimately to the WCAs south of the EAA. These results show that raising water tables in the EAA to deliver the ecosystem service of expanded water storage is overall more costly, but yearly costs are very low. Therefore water storage on farmlands is an affordable interim method of water storage.
135

Institutional factors that influence access of the poor to forest benefits : case studies of community and leasehold forestry regimes in Nepal : a thesis submitted in partial fulfilment of the requirement for the degree of Doctor of Philosophy (PhD) in Rural Development, Massey University, Institute of Natural Resources, Palmerston North, New Zealand

Bajracharya, Bijaya January 2008 (has links)
The community and leasehold forestry regimes (CF and LF regimes) are high priority programmes that are designed by the Nepalese government to conserve forests and reduce poverty through the introduction of formal institutions in terms of legal property rights and governance structures and processes. However, little is known about the mechanisms through which informal and formal institutions influence resource access of the poor under these regimes. By employing a collective case study approach, this research provides some understanding of the mechanisms through which formal and informal institutional factors influence access of the poor to forest resources governed under the CF and LF regimes in Nepal. This study found that informal institutional factors significantly influence the impact of formal institutions irrespective of the regime that was imposed on the Nepalese hill communities. It was revealed that where more than one social group co-exist in a community, discriminatory sociocultural norms (for example patriarchal and caste-based norms), and customary property rights favour one social group over others. As a result, certain social groups have greater access to resources and benefits from the resources than do other social groups. Of particular significance, and not previously reported, the lack of prior experience in collective action of the low castes along with their weak social networks and poor leadership ability is highlighted as being directly linked to their relatively limited access to forest resources. When the Bista system, a specific type of a traditional bridging social network is eroded, the low castes end up with less access due to removal of support from the high castes. This study shows that a more inclusive regime (for example CF regime) is likely to lead to more effective outcomes for the livelihood of the poor as compared to a more exclusive regime (e.g. LF regime). When the powerful are included in the forest user group (FUG), along with the poor, there is less resistance to the shift in property rights and the improved access of the poor to forest benefits that the regimes are intended to achieve. However, it was found that active participation is more determinant of resource access than is a specified set of property rights granted by right of membership in a FUG. Although some FUG governance structures provide a forum where the disadvantaged members of the FUGs have the right to participate in decision making, their participation is constrained by discriminatory sociocultural norms. Further, this study revealed that the decision-making processes dominated by the elites tend to address the needs of the disadvantaged members to only a very limited extent. However, improving capacities has the potential to enhance participation of disadvantaged members in the processes. The research findings suggest that informal institutions must explicitly be considered in the design and implementation of CBNRM regimes in order for them to be successful in improving livelihoods of the poor. The implementing staff need support mechanisms for changing their own attitudes and behaviours to those that are more favourable to the social shift that the regimes are intended to bring about. CBNRM regimes have the potential to improve the livelihoods of the poor, but research must continue on how this can be achieved.
136

Consumer Willingness to Pay for Eco-labeled Refrigerators

Li, Xiaogu 01 May 2011 (has links)
The United States Environmental Protection Agency has used environmental information provision as a policy tool to take advantage of consumer preferences for products that meet higher environmental standards. Such environmental programs include a variety of policies ranging from eco-labeling programs to voluntary environmental agreements between governments and manufacturers. This study analyzes the effects of two such programs - the ENERGY STAR program, an eco-labeling program, and the Climate Leaders program, a voluntary environmental agreement program - on consumer preferences for a household appliance. The study estimates consumer willingness to pay (WTP) for the two programs and examines factors that motivate WTP. A particular interest for the ENERGY STAR program is in determining how the offer of a mail-in rebate affects these preferences. Data used for this study was collected from an online survey conducted in the United States during March and April, 2009. Conditional and random parameter logit models, with product attributes only and with demographic and other individual characteristics as interaction terms, are used to analyze the data. Findings from this study imply that consumers are willing to pay a premium equivalent to a significant portion of the purchase prices for the products approved by either program. Also, it is found that consumers who are more concerned about environmental issues, such as global climate change, and who have confidence in the effects of collective action, are more likely to engage in the purchase of such environmentally friendly products. These results should help government agencies and manufacturers evaluate the effectiveness of environmental information provision programs.
137

Classification Of Ethanol Consumers and Willingness to Pay for Reductions in Greenhouse Gas Emissions Through Purchases of E85

Marra, Adrienne Elizabeth 01 August 2010 (has links)
In recent years, the issues of energy dependency and renewable energy options have gained recognition with not only policy-makers but also mainstream consumers. Understanding consumer beliefs and preferences related to these issues is therefore relevant as innovative renewable energy markets have the potential to change conventional consumer purchasing decisions. This paper investigates the beliefs and behaviors of U.S. consumers related to E85 ethanol from corn and cellulosic feedstocks. Four distinct market segments are created so that the ethanol market can be investigated more in-depth. Overall familiarity with ethanol as an alternative fuel is high; however, individual segments vary on beliefs related to corn and cellulosic ethanol, purchasing Flex-Fuel Vehicles, general concern for the environment, and many other factors. In order to successfully market ethanol to a diverse market, the preferences, beliefs and behaviors of these four distinct segments should be taken into account. While environmental concern has waxed and waned over time, issues like as climate change have come to the forefront of both domestic and international discussion and policy. The role of greenhouse gas emissions in contributing to climate change has been acknowledged. As a major source of emissions, transportation fuels are an obvious source of potential reductions in greenhouse gas emissions. This study segments consumers into four distinct market segments and uses a contingent choice method to determine willingness to pay for reductions in greenhouse gas emissions through purchases of E85 ethanol blends. Overall, willingness to pay is estimated at about 0.18 cents per gallon for each percentage in emissions reductions when compared with gasoline containing no ethanol (E0). Willingness to pay for emissions reductions varies in significance and degree across the four market segments. The diversity between the four segments implies that marketing plans should take into account the heterogeneity of consumers and make efforts to account for their varied needs and preferences.
138

Consumer Willingness to Pay for E85

Skahan, Denise A 01 August 2010 (has links)
Concerns regarding energy security, resource sustainability, and environmental protection have heightened interests in renewable fuels and sparked the research and development of ethanol as a transportation fuel. This study examines consumers’ willingness to pay for ethanol from various potential feedstocks; corn, switchgrass and wood wastes. Data was collected via a survey of fuel consumers across the United States in 2009. Results show that consumers have a preference for E85 (a fuel blend with 85 percent ethanol and 15 percent gasoline) from corn, switchgrass and wood wastes compared to E0 (gasoline) and a preference for E85 from switchgrass and wood wastes, but not corn when compared to E10 (10 percent ethanol and 90 percent gasoline). Also, consumers have a preference for E85 compared to E10 but not compared to E0. Mean WTP for E85 was insignificant across all models, but significant for all other product attributes; percentage of fuel imported, percentage of greenhouse gas emissions reduced, and the proximity of fuel in driving distance. This suggests a WTP for a combination of fuel attributes associated with ethanol rather than just for E85. Results suggest that price and proximity of the fuel have a greater impact on fuel selection than percentage of the fuel imported and reductions in greenhouse gas emissions. Republicans had a positive WTP for E85 compared to E10 and a negative WTP for E85 compared to E0 regardless of feedstock, which may suggest that Republicans actually have no preference for E85; however, these findings may also suggest that Republicans view E85 as a voluntary “policy” whereas E10 is an example of government intrusion in the free market. Thus, they may ultimately have preferences over the manner in which the blend is being introduced to the market. Across all models, those undecided in political affiliation, those previously familiar with ethanol, and those who prefer to devote U.S. farmland to food instead of fuel generally exhibited a lower WTP for E85 while Westerners, those worried about the environment, and those believe that reducing dependence on foreign oil is more important than environmental protection generally had a greater WTP for E85.
139

Food Expenditures away from Home by Type of Meal and by Facility.

Liu, Miaoru 01 August 2011 (has links)
Consumer expenditure on food away from home in the United States has grown substantially in recent decades. Changes in the food service system, increased complexity of family structure, and the food policies made by government agencies have continued to influence the marketing, distribution, retailing, and demand for food products and the food industry. This study explores consumption behavior on food away from home (FAFH) and determines the differentiated impacts of economic and demographic variables on FAFH by type of meal and by type of facility among different household types. Each of the two systems of expenditures is estimated with two alternative econometric procedures to accommodate censoring in the dependent variables: the trivariate Tobit estimator and the multivariate sample selection estimator. Data for this study come from the 2008 and 2009 Consumer Expenditure Surveys, the most recent U.S. national household expenditure surveys conducted by the Bureau of Labor Statistics. Joint statistical significance of error correlations among equations justifies estimation of the sample selection systems. The opposite marginal effects on probabilities and expenditure levels of some variables highlight the advantage of the sample selection system over the Tobit system. Segmentation of the sample by household types is also justified with formal statistical tests. The empirical results indicate that the effects of demographic and socioeconomic factors on FAFH consumption vary by type of meal and by type of facility. Income, work hours, race, education, geographical region, and household composition are important factors. Food stamps have no impact on FAFH for married couples without children and single parenthood has conflicting effects on probabilities and conditional levels of expenditures.
140

Evaluation of Capital Investment and Cash Flows for Alternative Switchgrass Feedstock Supply Chain Configurations

Chen, Jie 01 August 2011 (has links)
Biofuels have been widely recognized as a potential renewable energy source, and the United States’ government has been interested in producing ethanol from lignocellulosic biomass such as switchgrass. To evaluate whether lignocellulosic biomass based biofuels production is economically feasible, this paper estimated the capital investment outlays, operation costs, and net present value for investment in alternative switchgrass feedstock supply chain configurations in East Tennessee a 25 million gallon per year ethanol biorefinery. Two scenarios are analyzed in the study. The conventional hay harvest scenario includes the production, harvest, storage and transportation of biomass feedstocks from the fields to the biorefinery. The preprocessing scenario added preprocessing facilities into the biomass supply chain. According to various harvest, storage, preprocessing, and harvest equipment options, analysis and comparisons were made among different systems. The capital budgeting model developed in this study generated the optimal feedstock supply chain configurations to determine the largest net present value of cash flow from investment. Results of this study shown that with the Biomass Crop Assistance Program (BCAP) incentives, a round bale system using feedstock stored without tarp on pallets using custom hired equipment had the largest positive net present value. By comparison, if all the harvest equipment is purchased rather than custom hired, the stretch wrap baler preprocessing systems, using switchgrass harvested by a chopper with rotary cutter-header, was found to have a cost advantage over conventional hay harvest logistic systems (large round bale and large square bale systems) and pellet preprocessing systems. Assuming most likely values for switchgrass price and production costs, none of the feed stock supply chain configurations evaluated in this study produced a positive net present value when BCAP subsidies were assumed to not be available. However, without the BCAP incentives and based on combination of optimistic assumption, the round bale system using feedstock stored without tarp on pallets using custom hired equipment still has the largest positive net present value. Without the BCAP incentives, no feedstock supply chain configuration using purchased rather than custom hired equipment generated a positive net present value.

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