Physical Sciences and Mathematics Commons^™

Developing A Framework For Determining The Contribution Of Transportation Project To Sustainable Development, Karim Ahmed Abdel Warith

Open Access Dissertations

In the past few years, stakeholders in the transportation industry have been concerned with sustainability. However, transportation decision makers have had difficulty incorporating sustainability into transportation infrastructure decisions. This is mainly attributed to the vagueness of the term. Incorporating sustainability into transportation decision making has been a desire put forth by engineers for that past 10 years. However, with no apparent method of defining sustainability, designers and decision makers have not been able to fulfill this desire.

This investigation attempts to define sustainability in a comprehensive and quantitative manner. The research proposes a new methodology that relies on the objective …

The City In Mind: Environmental Literacy And Adaptation In Nineteenth-Century British Literature, Adam Edward Watkins

Open Access Dissertations

This dissertation argues that a new paradigm of selfhood emerged in nineteenth-century British literature, one that recognized the individual will and environmental influence not as antithetical but as dialectical forces in the formation of the self. The concept of an externally negotiated subject challenges both the inward and socially determined conceptions of self that have dominated the relevant criticism. Informed by empiricist, associationist, and evolutionary theories of the mind, the portrayals of subject-formation in this study highlight the radical changes occurring in the human environment in nineteenth-century, which catalyzed the conception of a malleable yet self-forming subject. Along with the …

Solar Cell Temperature Dependent Efficiency And Very High Temperature Efficiency Limits, John Robert Wilcox

Open Access Dissertations

Clean renewable solar energy is and will continue to be a critically important source of electrical energy. Solar energy has the potential of meeting all of the world's energy needs, and has seen substantial growth in recent years. Solar cells can convert sun light directly into electrical energy, and much progress has been made in making them less expensive and more efficient. Solar cells are often characterized and modeled at 25 °C, which is significantly lower than their peak operating temperature. In some thermal concentrating systems, solar cells operate above 300 °C. Since increasing the temperature drastically affects the terminal …

Quantifying Crop Yield, Bioenergy Production And Greenhouse Gas Emissions From Cropland And Marginal Land Using A Model-Data Fusion Approach, Zhangcai Qin

Open Access Dissertations

Bioenergy is becoming increasingly attractive to many countries, but has sparked an intensive debate regarding energy, economy, society and environment. Biofuels provide alternative energy to conventional fossil fuels. However, the environmental impact of producing and using biofuel is a major concern to our society. This study is dedicated to quantifying and evaluating biofuel production and potential climate change mitigation due to potential large-scale bioenergy expansion in the conterminous United States, using model-data fusion approaches.

Biofuel made from conventional (e.g., maize (Zea mays L.)) and cellulosic crops (e.g., switchgrass (Panicum virgatum L.) and Miscanthus (Miscanthus × giganteus)) …

Energy Systems Analysis For A Solar Economy, Dharik Sanchan Mallapragada

Open Access Dissertations

The use of solar energy for human needs faces challenges owing to its relatively low energy intensity and intermittent availability, coupled with the constrained availability of renewable carbon and land resources. This study uses systems analysis tools to identify carbon and energy efficient transformations of solar energy for different purposes, including transportation fuels and grid-scale energy storage. These efforts have been complemented with a feasibility analysis of existing fossil-energy and other hybrid pathways.

In an era of limited fossil resources, liquid fuels from sustainably available (SA) biomass could meet the energy needs of the transportation sector. We present a method …

An Experimental Investigation Of Wind Turbine Aerodynamic Interaction, Brandon Lee Ennis

Open Access Dissertations

Wind turbines have become a viable component in the overall energy makeup of the United States due to improved economics where energy prices have risen and production costs dropped. For a fixed cost, the effectiveness of a wind turbine financially is highly related to its performance. Considering the size of current wind farms, a minor performance improvement will result in large additional sums of revenue. A problem that has received attention with wind farms is that while the fixed costs of the development do get spread out further to reduce the installed cost of each wind turbine, the wind turbines …

An Analysis Of The Impact Of Storage Temperature, Moisture Content & Duration Upon The Chemical Components & Bioprocessing Of Lignocellulosic Biomass, Arun Athmanathan

Open Access Dissertations

The successful utilization of lignocellulosic biomass as a feedstock for fuels and chemicals necessitates storage for 2-6 months. It is correspondingly important to understand the impact of storage parameters - moisture concentration, temperature and duration - on biomass quality.

As aerobic storage is the most viable large-scale solution, aerobic storage experiments were carried out with three projected bioenergy feedstocks - sweet sorghum (Sorghum bicolor) bagasse, corn (Zea mays) stover and switchgrass (Panicum virgatum). Stored samples of each were examined for dry matter loss and composition change to develop a material balance around carbohydrates and lignin.

A mean dry matter loss …

Technology Agnostic Analysis And Design For Improved Performance, Variability, And Reliability In Thin Film Photovoltaics, Sourabh Dongaonkar

Open Access Dissertations

Thin film photovoltaics (TFPV) offer low cost alternatives to conventional crystalline Silicon (c-Si) PV, and can enable novel applications of PV technology. Their large scale adoption however, requires significant improvements in process yield, and operational reliability. In order to address these challenges, comprehensive understanding of factors affecting panel yield, and predictive models of performance reliability are needed. This has proved to be especially challenging for TFPV for two reasons in particular. First, TFPV technologies encompass a wide variety of materials, processes, and structures, which fragments the research effort. Moreover, the monolithic manufacturing of TFPV modules differs significantly from that of …

Understanding The Links Between Human Health And Climate Change: Agricultural Productivity And Allergenic Pollen Production Of Timothy Grass(Phleum Pratense L.) Under Future Predicted Levels Of Carbon Dioxide And Ozone, Jennifer M. Albertine

Open Access Dissertations

The prevalence of allergic disease is expected to increase with climate change. Grasses, which have highly allergenic pollen, are widely distributed across the globe. Changes in production and allergen content of grass pollen have not been specifically investigated. We tested the effects of elevated carbon dioxide and ozone on growth, pollen and allergen production of Timothy grass (Phleum pratense L.). Timothy is also used as an agricultural forage crop so changes in plant productivity can also affect humans indirectly. Plants were fumigated in eight chambers at two concentrations of ozone (O₃; 30 and 80 ppb) and carbon dioxide …

Ecohydrologic Impacts Of Climate And Land Use Changes On Watershed Systems: A Multi-Scale Assessment For Policy, Paul A. Ekness

Open Access Dissertations

Maintaining flows and quality of water resources is critical to support ecosystem services and consumptive needs. Understanding impacts of changes in climate and land use on ecohydrologic processes in a watershed is vital to sustaining water resources for multiple uses. This study completes a continental and regional scale assessment using statistical and simulation modeling to investigate ecohydrologic impacts within watershed systems.

Watersheds across the continental United States have diverse hydrogeomorphic characters, mean temperatures, soil moistures, precipitation and evaporation patterns that influence runoff processes. Changes in climate affect runoff by impacting available soil moisture, evaporation, precipitation and vegetative patterns. A one …

Transition Network: Exploring Intersections Between Culture, The Climate Crisis, And A Digital Network In A Community - Driven Global Social Movement, Emily Polk

Open Access Dissertations

The core aim of this research is to explore the communication processes of the Transition movement, a community-led global social movement as it adapted in a local context. The Transition movement facilitates community-led responses to the current global financial and climate crisis via the Transition Network, an online network that began in 2006, and is comprised of more than 2000 initiatives in 35 countries that have used the Transition model to start projects that use small-scale solutions to achieve greater sustainability. This research uses qualitative ethnographic methods and a theoretical framework based on actor network theory to better understand how …

Resilient Environmental Governance: Protecting Changing Ecosystems Through Multilevel Governance, Casey Stevens

Open Access Dissertations

International governance is increasingly defined by multilevel governance; with short-term projects, transnational cooperation between different groups, and unclear institutional space. In this situation, a key issue is the resilience of governance arrangements or the ability of governance arrangements to respond to political and ecological shocks to the system. Using international biodiversity governance, this study explores the question: What social and political processes produce resilient governance?

This study argues that the key to understanding resilient governance is the network structure within and outside of the governance arrangement. Modular network structures are able to generate ideas from multiple sources, able to solve …

Uncertainty In Climatic Change Impacts On Multiscale Watershed Systems, Olga V. Tsvetkova

Open Access Dissertations

Uncertainty in climate change plays a major role in watershed systems. The increase in variability and intensity in temperature and precipitation affects hydrologic cycle in spatial and temporal dimensions. Predicting uncertainty in climate change impacts on watershed systems can help to understand future climate-induced risk on watershed systems and is essential for designing policies for mitigation and adaptation. Modeling the temporal patterns of uncertainties is assessed in the New England region for temperature and precipitation patterns over a long term. The regional uncertainty is modeled using Python scripting and GIS to analyze spatial patterns of climate change uncertainties over space …

Fate Of 17Α-Estradiol, 17Β-Estradiol, And Estrone In Agricultural Soils And Sediments, Michael L. Mashtare Jr

Open Access Dissertations

The shift to concentrated animal production facilities and increasing rural-urban migration has increased the localized land application of nearly 1 billion tons of manure and biosolids annually. Although these applications provide nutrients and contribute to soil tilth, they also serve as a source for an estimated 49 tons of the natural manure-borne estrogens, 17α-estradiol (17α-E2), 17β-estradiol (17β-E2), and estrone (E1). While these estrogens are critical to endocrine systems, the low concentrations observed in the environment can disrupt endocrine function in non-target organisms, e.g., altering secondary sex characteristics which can lead to changes in wildlife communities.

Research presented here focuses on …

Fisher Population Ecology On The Hoopa Valley Indian Reservation, Northwestern California, Sean Michael Matthews

Open Access Dissertations

I studied aspects of fisher (Martes pennanti) population ecology on the Hoopa Valley Indian Reservation in northern California to fill critical information gaps relative to timber management and its effect on the status of fishers, a candidate for listing under the U.S. Endangered Species Act. A decline in mark-resight density estimates of fishers from 1998 (52/100 km2; 95% CI = 43-64) to 2005 (14/100 km2; 13-16) was likely due to changes in prey habitat suitability, increased predation pressure, and/or disease. The decline was also indicated by catch-per-unit effort indices, but not by camera station or track-plate station indices. Colleagues and …

Finding Blame For Environmental Outcomes: A Cognitive Style Approach To Understanding Stakeholder Attributions, Attitudes, And Values, Christopher Thomas Hawkins

Open Access Dissertations

This study sought to connect two bodies of knowledge--integrative complexity and attribution theory. Integrative complexity is a term that indicates the simplicity vs. complexity of a person's mental frame and perceptual skill. A person who perceives nuance and subtle differences typically scores higher on an integrative complexity measure. Attribution theories are concerned with how individuals perceive causation for various events. The limited research into the linkages between perceived causation for an event and how complexly a person thinks about the domain of that event, coupled with the dearth of attribution research in the natural resource management literature, inspired this research. …

The Effect Of Risk, Time Preference, And Poverty On The Impacts Of Forest Tenure Reform In China, Karen Anne Sullivan

Open Access Dissertations

Forest degradation has steadily increased throughout much of the world. The cause of this continued degradation is complex and multifaceted but there is a growing realization that a key cause, especially in developing countries, is insecure rights to ownership and use of forest resources. This realization coupled with a call for pro-poor forestry policy has stimulated the recent trend in forest policy toward strengthening property rights for forest resources by transferring property rights from the state to communities and individuals, giving them defined rights to manage and extract forest resources. However, a big puzzle remains unsolved—such reforms on property rights …