Physical Sciences and Mathematics Commons^™

Environmental Fate Of Rna Interference Biopesticides, Ke Zhang

McKelvey School of Engineering Theses & Dissertations

Emerging agricultural biotechnology uses RNA interference (RNAi) to protect crops from pests. RNAi is a cellular mechanism in which double-stranded RNA (dsRNA) directs the degradation of the homologous messenger RNA (mRNA), leading to gene silencing and preventing the synthesis of essential proteins. As applied to agriculture, dsRNA biopesticides have been developed that can trigger RNAi inside of the pest tissues to cause reduced pest growth and/or increased pest mortality. When dsRNA biopesticides are released to receiving environments (e.g., agricultural soils and surface water), they pose potential ecological risks to non-target organisms. This dissertation aims to advance the understanding of the …

Dynamics Of Spatiotemporal Heterogeneities In Particulate Intercalation Electrodes, Shubham Agrawal

McKelvey School of Engineering Theses & Dissertations

Electrochemical energy systems rely on particulate porous electrodes to store or convert energies. While the three-dimensional porous structures of the electrodes were introduced to maximize the interfacial area for better overall performance of the system, spatiotemporal heterogeneities arising from materials thermodynamics localize the charge transfer processes onto a limited portion of the available interfaces. These reaction heterogeneities may cause local hot and cold spots, and early battery failures. This dissertation focuses on the following three aspects of the dynamic reaction heterogeneities in the particulate cathodes and anodes in the lithium-ion batteries: (i) the real-time evolution of reaction heterogeneities in graphite …

The Phylogeography Of Rare Central Tennessee Glade Endemics Trifolium Calcaricum And Viola Egglestonii, Rachel Ann Lyman

Arts & Sciences Electronic Theses and Dissertations

Endemic species are range-restricted to a particular type of habitat and generally occur in a few small populations. Often endemic species are threatened or endangered due to their geographic isolation and limited habitat breadth. Despite the fact that understanding factors that may have shaped the evolutionary history of a species with a narrow distribution can provide important insights for their management and conservation, little is known about the historical forces that gave rise to many endemic species. Endemic species can arise because of factors such as variation in climate, geographic barriers, and habitat specificity, or the combination of several of …

Sustainable Bioproduction By Rhodopseudomonas Palustris Tie-1 Through Metabolic Engineering, Wei Bai

McKelvey School of Engineering Theses & Dissertations

The heavy reliance of the petroleum industry for raw material and the rising atmospheric CO2 caused by this reliance have driven the research and development of sustainable alternatives. Microbial production of chemicals, such as fuel and plastic, has been viewed as a feasible method. The wide selection of substrates by microbes enables them to produce chemicals using naturally abundant material or industrial waste, such as CO2, making the production sustainable. Compared to the model organisms such as Escherichia coli, Saccharomyces cerevisiae, many non-model organisms have a broader selection for carbon, electron, and nitrogen sources, making them great candidates for sustainable …

Landesque Capital And Community Organization In A Maya Economic Center: A Case Study At Salinas De Los Nueve Cerros, Guatemala, Alexander Ernesto Rivas

Arts & Sciences Electronic Theses and Dissertations

Many ancient Maya lowland cities developed water-rich landscapes that met the multiple needs of growing populations. The development of landesque capital, in which permanent changes in infrastructure, water procurement, and agricultural productivity are best understood at sites with a long history of occupation. Salinas de los Nueve Cerros was an ancient Maya center that was occupied for approximately 2000 years, surviving the ‘Maya Collapse.’ This site, located in the Maya lowlands, had ties to both highland and lowland communities through its primacy in exporting salt. However, what is not yet understood is whether the commercial population of Nueve Cerros practiced …

Testing Assumptions On The Relationship Between Humans And Their Environment: Case Studies From Cahokia Mounds, Illinois, Caitlin Gail Rankin

Arts & Sciences Electronic Theses and Dissertations

Many archaeologists argue that studying past human response to climate change can be helpful in informing future strategies to adapt to modern effects of climate change; however, archaeological research is rarely utilized in climate change policy. Much of archaeological research involves forming hypotheses to explain observations of past phenomena. However, the advancement of knowledge requires a back and forth between hypothesis forming and hypothesis testing. I argue that a lack of engagement in hypothesis testing has stalled the advancement in archaeological knowledge on the relationship between humans and their environment. Ultimately, it is this stall in the advancement of knowledge …

Toward Improved Understanding Of Black And Brown Carbon Radiative Impacts Over South Asia, Apoorva Pandey

McKelvey School of Engineering Theses & Dissertations

Atmospheric aerosols directly affect the Earth’s radiative budget by absorbing and scattering solar radiation. Carbonaceous aerosols constitute 20-90% of the global aerosol mass burden and are recognized by the Intergovernmental Panel on Climate Change as important drivers of direct radiative forcing (DRF). Aerosol radiative impacts have been implicated in regional atmospheric warming in South Asia: changing Indian monsoon patterns, and accelerating melting of the Himalayan glaciers. There are systematic global discrepancies between estimates of aerosol absorption optical depths derived from observations and those from climate models. Over South Asia, models predict six times lower aerosol absorption than ground-based observations, leading …

Metabolic Engineering Of Cyanobacteria For Production Of Chemicals, Po-Cheng Lin

McKelvey School of Engineering Theses & Dissertations

Concerns over the impact of climate change caused by CO2 emission have driven the research and development of renewable energies. Microbial production of chemicals is being viewed as a feasible approach to reduce the use of fossil fuels and minimize the impact of climate change. With recent advances in synthetic biology, microorganisms can be engineered to synthesize petroleum-based chemicals and plant-derived compounds. Cyanobacteria are photosynthetic prokaryotes that use only sunlight, CO2, and trace minerals for growth. Compared to other microbial hosts, cyanobacteria are attractive platforms for sustainable bioproduction, because they can directly convert CO2 into products. However, the major challenge …

Metabolic Engineering Of Cyanobacteria For Production Of Chemicals, Po-Cheng Lin

McKelvey School of Engineering Theses & Dissertations

Concerns over the impact of climate change caused by CO2 emission have driven the research and development of renewable energies. Microbial production of chemicals is being viewed as a feasible approach to reduce the use of fossil fuels and minimize the impact of climate change. With recent advances in synthetic biology, microorganisms can be engineered to synthesize petroleum-based chemicals and plant-derived compounds. Cyanobacteria are photosynthetic prokaryotes that use only sunlight, CO2, and trace minerals for growth. Compared to other microbial hosts, cyanobacteria are attractive platforms for sustainable bioproduction, because they can directly convert CO2 into products. However, the major challenge …

Self-Assembly Of Conducting Polymer Nano- And Microstructures For Energy Storage, Luciano Matteo Santino

Arts & Sciences Electronic Theses and Dissertations

Plastics are materials composed of many long chains of molecules with repeating subunits; strong interactions between neighboring molecules lead to the material used throughout the world. Plastics are commonly thought to be insulating, in stark contrast to the conductivity of metals. However, certain polymer structures were discovered to exhibit semiconducting properties, the subject of the Nobel Prize in Chemistry in 2000. Conducting polymers have a unique molecular structure with an electronically conjugated backbone, allowing electrons to freely travel both across the chain and in between chains. This work focuses on controlling the kinetics of the reaction between the vapors of …

Understanding The Meaning Of Microbialites As Geobiological Archives, Scott Randall Beeler

Arts & Sciences Electronic Theses and Dissertations

Microbialites, sedimentary structures formed from the interaction of microorganisms with their environment, provide one of the oldest and most complete records of life on Earth, making them an invaluable tool in the field of geobiology. However, much of the information that could be gained from microbialites remains obscured due to our incomplete understanding of how variability in the microbial, geochemical, and physical processes driving their formation affect their morphological and geochemical characteristics. Modern environments of active microbialite formation provide the opportunity to study the relationship between variability in these environmental processes and the resultant mineral product and can act as …

Wish You Were Here, Janie Stamm, Janie I. Stamm

Graduate School of Art Theses

The State of Florida is under threat from the effects of climate change. Rising sea levels are creeping up on to Florida’s coast, eroding the beaches and encroaching on heavily populated cities. Over my lifetime I will watch the water spill over the streets of my home town. I will watch the water flood the Everglades, pushing saltwater into freshwater habitats. I will watch the water begin to drown the state, taking Florida’s many little known histories along with it. This thesis serves as a document of Floridian life during the Anthropocene.

Within this thesis, I tell the story of …

Towards Engineering Advanced Nanomaterials: Elucidating Fundamental Particle Behavior In Water And Critical Sorption Dynamics, Changwoo Kim

McKelvey School of Engineering Theses & Dissertations

As advanced nanomaterials, inorganic-organic nano composites have received great interest as potential platform (nano) structures for sensor, catalyst, sorbent, and environmental applications. Here, my Ph.D. research has focused on the design, synthesis, and characterization of advanced water-stable engineered metal-oxide nanoparticles functionalized by organic frames for environmental applications. For the environmental applications, I have evaluated particleoptimized sorption processes for the remediation and separation of arsenic, chromium, and uranium under environmentally relevant conditions. More specifically, I have explored the critical role of organic coating on sorption mechanisms and performances using engineered iron oxide -based, manganese oxide -based, and manganese ferrite -based (core) …

Preventing Extinction Of At-Risk Plant Species In A Complex World, Holly Lee Bernardo

Arts & Sciences Electronic Theses and Dissertations

Earthճ current biodiversity crisis is now considered a true mass extinction event, with species level extinction rates well above background rates and population level extinction rates orders of magnitude more common that species extinctions. There are many threats driving this loss of biodiversity. How each threat impacts the viability of a species is highly context dependent, but all are anthropogenic in origin and so as the human population continues to increase, so too will the pressure of these threats on our natural systems. Ultimately, how much a threat decreases the viability of a species depends on how that threat influences …

Fundamental Controls On The Reactivity Of Aluminum Oxide And Hydroxide Surfaces: Contributions Of Surface Site Coordination States And Interfacial Water Structure, Tingying Xu

Arts & Sciences Electronic Theses and Dissertations

Chemical reactions at mineral-water interfaces are of great importance in many geological and environmental processes. Essential to many of these is adsorption because it directly controls contaminant fate and nutrient availability, promotes the nucleation and growth of minerals, initiates surface redox reactions, and plays a crucial role in carbon cycling and sequestration. These reactions occur at mineral surface sites having multiple possible coordination states that interact with both adsorbates and water. While general ion adsorption mechanisms and surface charging behaviors are well established, the roles of individual surface functional group types and water in affecting the structure and reactivity of …

Wild Primates In Documentary Films: Biodiversity, Behavior, And Pedagogical Applications, Crystal Marie Riley Koenig

Arts & Sciences Electronic Theses and Dissertations

The representation of wild primates in the nature documentary genre could have important implications for conservation and education. However, no prior research has looked at the content of this genre or its use in education. To fill this gap, the current research included a content analysis of all available documentaries focused on wild primates (n = 210) and a survey of 219 college-level anthropology instructors, with an emphasis on determining how primate biodiversity was portrayed, whether primate behavior was realistically depicted in documentaries, whether mistakes and inaccuracies were common, and how college instructors use primate documentaries as resources in their …

Dying Worlds: Environment, Ecology, And Empire In British Literature 1878-1919, Susanna Williams

Arts & Sciences Electronic Theses and Dissertations

This dissertation argues that models of approaching environmental crisis in late-nineteenth- and early-twentieth-century British literature have been obscured by a false, mid-twentieth century, American-centered genealogy of environmentalism. As Victorian scientists made discoveries about deep time, entropy, and tidal drag, scientific and popular writers in the following decades came to terms with ideas about an earth made unfit for human existence and humans’ imminent extinction. Writers grappled with feelings of loss and grief, and they felt disoriented by time scales and energetic processes that were beyond the scope of a single human life. This overwhelming information required them to take a …

Can Prescribed Fire Reduce Tick Parasitism Of Birds?, Leslie A. Sterling, Kim Medley, Katie Westby, Solný Adalsteinsson

Undergraduate Research Symposium Posters

Tick-borne diseases spread through enzootic transmission cycles that often involve ticks parasitizing bird hosts. Some avian species are competent reservoirs, amplifying the pathogens that cause tick-borne illnesses in humans. Prescribed burns in forests have the potential to reduce tick-borne disease risk if they limit interactions between ticks and infectious wildlife hosts. Although prescribed burns are increasingly being used for a variety of habitat management purposes, little is known about how they affect tick-host interactions. We hypothesize that if prescribed fires reduce tick abundance, then birds in burned forest plots will host fewer ticks than birds in unburned forest plots. Experimental …

Abiotic- And Biotic-Formation Of Manganese Oxides And Their Fate In Environmental Systems, Haesung Jung

McKelvey School of Engineering Theses & Dissertations

Manganese (hydr)oxide (Mn (hydr)oxide) minerals are ubiquitous in aquatic and terrestrial environments. These minerals have high surface areas and are highly sorptive and redox active. From decades of accumulated knowledge about natural redox cycling, we have found that Mn (hydr)oxides play critical roles as electron donors and acceptors in elemental geochemical cycling and biological metabolisms in nature. Thus, Mn (hydr)oxides have garnered increasing interest to understand natural systems. Considering the variety of redox reactions with Mn (hydr)oxides in nature, it is also expected that there should be diverse pathways to form Mn (hydr)oxides through abiotic and biotic processes. Previous studies …

Participation In Governance And Well-Being In The Yukon Flats, Jessica Charlene Black

Arts & Sciences Electronic Theses and Dissertations

This dissertation explains the relationship between participation in governance and well-being in the Yukon Flats. To garner a deeper understanding of this relationship, definitions of governance and well-being are sought from the participants, thus providing holistic, Indigenous definitions of these concepts. Both formal and informal governance are also explored to understand the important institutions that underpin these larger relationships. Lastly, this dissertation investigates the relationship between participation in traditional hunting, fishing, and gathering and well-being in the Yukon Flats. Qualitative methods, including semi-structured interviews, observations, and photographs are all used to document these relationships. Applied thematic analysis is used due …

Studies In Pressurized Oxy-Combustion: Process Development And Control Of Radiative Heat Transfer, Akshay Gopan

McKelvey School of Engineering Theses & Dissertations

Fossil fuels supply over 80% of the world’s primary energy and more than two-thirds of the world’s electricity. Of this, coal alone accounts for over 41% of the electricity supplied globally. Though coal is globally well-distributed and can provide stable and reliable energy on demand, it emits a large amount of carbon dioxide—a greenhouse gas responsible for global warming. Serious concerns over the implication of the increased global temperature have prompted the investigation into low carbon energy alternatives. The idea of capturing the carbon dioxide emitted from the combustion sources is considered as one of the viable alternatives. This would …

Understanding Household, Network, And Organizational Drivers Of Adoption Of Cleaner Cooking Fuels In Rural India, Praveen Kumar

Arts & Sciences Electronic Theses and Dissertations

Adoption of evidence-based cleaner cooking systems such as Liquefied Petroleum Gas (LPG) is a crucial first step in eventually providing a sustainable solution for household air pollution. To promote adoption of LPG in below poverty line households, we require evidence-based implementation strategies. For these strategies to be feasible and scalable, they need to be grounded in a thorough understanding of the household, network, and organizational level drivers of LPG adoption. However, systematic research on adoption of LPG by poor communities is still lacking.

The overall objective of the study was to develop a better understanding about new insights on the …

How Do Environmental Changes And Shared Cultural Experiences Impact The Health Of Indigenous Peoples In South Louisiana?, Shanondora M. Billiot

Arts & Sciences Electronic Theses and Dissertations

Global environmental change is an ongoing and complex social problem that will continue to permeate all spheres of life on earth (Moran, 2010). Not all communities experience social and economic consequences of environmental change at the same level (Adger, 2006a; Cutter, Boruff, & Shirley, 2003; Gillespie, 2010; Nicholls et al., 2007; Vogel, Moser, Kasperson, & Dabelko, 2007). The variability of vulnerability, or potential for exposure or harm, stems from proximity to fragile ecosystems as well as social and economic differences across communities (Boruff, Emrich, & Cutter, 2005). Additionally, environmental changes are projected to have adverse impacts on marginalized populations through …

Environmentalism And The Music Of Sir Peter Maxwell Davies, Karen Olson

Arts & Sciences Electronic Theses and Dissertations

Music critics and scholars frequently present British composer Sir Peter Maxwell Davies (1934-2016) as a green composer, but little work has been done to determine the kinds of environmentalism his music supports. This dissertation focuses on the relationship between Davies’s music and British environmentalism, both as protest music and as government policy. Drawing on such diverse fields as philosophy of the environment, British political history, and environmental aesthetics, I examine how Davies’s music responded to the political climate of its times, and how its reception changed as certain environmental models, such as sustainable development, gained political relevance. Over the course …

Coexistence Of Confamilial, Folivorous Indriids, Propithecus Diadema And Indri Indri, At Betampona Strict Nature Reserve, Madagascar, Lana Kerker Oliver

Arts & Sciences Electronic Theses and Dissertations

In this dissertation, I examine how two confamilial and ecologically similar indriids, indri (Indri indri), and diademed sifakas (Propithecus diadema) maintain coexistence in Betampona Nature Reserve (BNR), an eastern lowland rainforest in Madagascar. These two species occur sympatrically throughout much of their species ranges and are similarly-sized folivorous primates. As anatomic folivores, they present an opportunity to investigate how niche differentiation and resource partitioning allow two sympatric primate species with similar feeding patterns to coexist. I examined coexistence strategies and the general behavioral ecology of each species by examining their activity patterns, dietary profiles, home range use, and daily path …

The Evolution Of Igneous Rocks On The Moon: Insights From Lunar Meteorites And Apollo 12, Sarah Valencia

Arts & Sciences Electronic Theses and Dissertations

Lunar samples are the “ground truth” that anchor our knowledge of lunar geology. Lunar rocks present many challenges in that they are often brecciated (composed of multiple rock types), and their location of formation on the Moon is not always known. The brecciated nature of lunar samples also has advantages – multiple lithologies that have a related petrogenetic history can occur in the same sample, allowing us to trace the petrogenetic history of evolving magmatic systems. In this dissertation, I examine two evolved magmatic systems, using samples from the Northwest Africa (NWA) 773 clan of lunar meteorites and Apollo 12 …

Sub 2 Nm Particle Characterization In Systems With Aerosol Formation And Growth, Yang Wang

McKelvey School of Engineering Theses & Dissertations

Aerosol science and technology enable continual advances in material synthesis and atmospheric pollutant control. Among these advances, one important frontier is characterizing the initial stages of particle formation by real time measurement of particles below 2 nm in size. Sub 2 nm particles play important roles by acting as seeds for particle growth, ultimately determining the final properties of the generated particles. Tailoring nanoparticle properties requires a thorough understanding and precise control of the particle formation processes, which in turn requires characterizing nanoparticle formation from the initial stages. The knowledge on particle formation in early stages can also be applied …

Who Is Morally Responsible For Microfiber Pollution?, Luka Cai

Undergraduate Research Symposium Posters

Microplastic fiber pollution (MFP) is the persistence of microfibers (fibrous plastic particles less than 5mm in diameter and length) in the environment in levels sufficient to harm aquatic/marine ecosystems, primarily caused by the laundering of polyester garments. MFP is a compelling issue because it causes harm to natural habitats, animals, and human beings, harm that moral agents need to be held accountable for. I define moral responsibility as an agent’s accountability for an act which they voluntarily committed/contributed to. Causal responsibility is the relationship between an agent and an outcome of the agent’s act. I theorize that an agent’s moral …

Calcium Carbonate Formation In Energy-Related Subsurface Environments And Engineered Systems, Qingyun Li

McKelvey School of Engineering Theses & Dissertations

Geologic CO2 sequestration (GCS) in subsurface saline aquifers is a promising strategy to mitigate climate change caused by increasing anthropogenic CO2 emissions from energy production. At GCS sites, interactions between fluids and geomedia are important because they can affect CO2 trapping efficiency and the safety of CO2 storage. These interactions include the dissolution and precipitation of minerals. One of the most important minerals is calcium carbonate, because it can permanently trap CO2.

In this work, Portland cement was used as a model geomedium to investigate the chemical reactions, mechanical alterations, transport of reactive fluids, and the interplay of all these …

Nanostructured Thin Film Synthesis By Aerosol Chemical Vapor Deposition For Energy Storage Applications, Tandeep Singh Chadha

McKelvey School of Engineering Theses & Dissertations

Renewable energy sources offer a viable solution to the growing energy demand while mitigating concerns for greenhouse gas emissions and climate change. This has led to a tremendous momentum towards solar and wind-based energy harvesting technologies driving efficiencies higher and costs lower. However, the intermittent nature of these energy sources necessitates energy storage technologies, which remain the Achilles heel in meeting the renewable energy goals. This dissertation focusses on two approaches for addressing the needs of energy storage: first, targeting direct solar to fuel conversion via photoelectrochemical water-splitting and second, improving the performance of current rechargeable batteries by developing new …