Engineering Commons^™

Enhancing Concrete Sustainability With Self-Healing Technologies, Al Shimaa Abdullatif

Theses and Dissertations

Thanks to its strength, durability and affordability, Portland cement concrete is the most commonly used building material worldwide. However, concrete cracking is inevitable due to numerous factors including shrinkage, exposure to external chemicals, internals reactions, excessive loads, to name but a few. Self-healing is a promising technique that can enable concrete to autogenously heal cracks and alleviate much of the damage. Such healing can without a doubt extend the service life with less need for external repair works therefore it contributes to sustainability. Over the years, several means of self-healing agents have been explored including bio-based procedures and the incorporation …

Quantitative Evaluation Of Baseflow Separation Methods Using An Integrated Hydrologic Model: A Case Study In A Snow-Dominated Watershed, Jihad Othman

All Graduate Reports and Creative Projects, Fall 2023 to Present

Baseflow, commonly referred to as the groundwater contribution to streamflow, constitutes approximately 50% of streamflow in mountainous regions of the Western United States. Accurately quantifying the amount of baseflow is critical for water management and decision-making, as it significantly impacts stream water quality, low flow availability, and ecosystem health. Traditionally, baseflow has been estimated using conceptual and automated baseflow separation methods, which are known to be both arbitrary and ambiguous, posing a challenge to validate them. In this study, we developed an integrated hydrologic model that seamlessly integrated the exchange between surface and subsurface flows to physically quantify the baseflow …

Assessment Of Future Streamflow In The Colorado River Basin With Some Implications For Water Management, Homa Salehabadi

All Graduate Theses and Dissertations, Fall 2023 to Present

Long-range water supply planning in many river basins, such as the Colorado, requires assessing plausible future streamflow scenarios. Given nature's randomness and climate change, it is important to evaluate water resources system behavior under a wide range of plausible conditions. The research described in this dissertation examined various future streamflow scenarios in the Colorado River Basin to provide essential inputs needed for planning in the uncertain future. First, the research examined historical severe droughts in the basin and created three sets, or ensembles, of plausible future streamflow time series by resampling these past droughts. These ensembles are thus consistent with …

Sand Aggregation By Methanotrophic Bacteria And Marine Microbial Hydrocarbon Degradation Under Differing Biogeochemistries, Ann-Marie G. Harik

Doctoral Dissertations

Methanotrophic bacteria, bacteria that can metabolize methane, are ubiquitous, EPS-producing, and capable of degrading hundreds of contaminants (Hazen, 2010). This dissertation looks at the possibility of using methanotrophic bacteria in sand surface aggregation and oil spill responses. Sand aggregation practices are widely used from infrastructure improvements to reversing desertification. In chapter 2, two selected methanotrophic cultures had their growth curves measured and their extracellular polymeric substances (EPS) production estimated. This second chapter tested and rejected two null hypotheses; the first null hypothesis was that there is no difference in EPS production rates over a culture’s growth curve, showing that the …

Evaluation Of Bioengineered Bank Stabilization Methods For Use In Stormwater Mitigation Programs, Jaimie Ellen Dieker Armitage

Masters Theses

Streambank erosion has become an escalating concern due to climate change and increased land development. This erosion adversely affects human populations and aquatic ecosystems, yet there are limited incentives to stabilize eroding shorelines. Traditionally, shorelines have been protected using hard armoring techniques with materials such as rock or concrete. While these methods are effective, there are growing shifts towards bioengineered or vegetated methods of shoreline stabilization. Recently, the Tennessee Department of Environment and Conservation (TDEC) approved bioengineered bank stabilization as an acceptable stormwater mitigation technique due to its water infiltration benefits. This research, conducted in Knoxville, TN, aims to enhance …

Degradation Products And Microbial Communities Associated With The Conversion Of Five Long-Chain Fatty Acids Relevant For Anaerobic Co-Digestion Of Fog With Sludge, Claire Funk

All Theses

Anaerobic digestion is a technology that allows wastewater treatment plants to convert sludge to energy by recovering the biogas produced during the breakdown of proteins, carbohydrates, and lipids. Furthermore, adding fats, oils, and greases (FOG) through co-digestion with wastewater sludge can increase energy production as lipids have a higher methane yield than proteins and carbohydrates. However, adding FOG can also lead to operational problems in the digester due to the potential accumulation of certain long-chain fatty acids (LCFAs). Current research is limiting in the degradation pathways of prominent LCFAs in FOG and the microbial communities responsible for their degradation

The …

Hydrogen Isotope Exchange On Diffusion Pump Oils, Carson G. Allen

All Theses

The extent of isotopic exchange of deuterium and tritium with protium atoms in hydrocarbon pump oil was investigated as a means to quantify the chemical stability of a mineral oil, a silicone oil, and a polyphenyl ether oil as candidates for implementation in a diffusion pump. In its target application at a fusion power plant, a chemically stable and radiation hard oil offers substantial reductions in tritium inventory, electrical consumption, and operational pump expenses over alternate solutions for vacuum induction. Select oils were introduced to deuterium and tritium isotopes in a high temperature environment, analogous to an operating vacuum pump. …

Extraction Of Neutron-Gamma Irradiated Diffusion Pump Oils, Cooper L. Tillman

All Theses

This work successfully demonstrates solvent extraction methods for separation of oil from the by-products when two commercially available vacuum pump oils were exposed to an intense neutron and gamma-ray radiation environment. Nuclear fusion power at a commercial scale has accelerated the need for radiation resistant vacuum technology, such as oil-based diffusion pumps. Polyphenyl ether and aromatic silicone oils were irradiated at the Rhode Island Nuclear Science Center (RINSC) up to MGy absorbed doses with neutron and gamma-ray radiation. Solvent extractions were performed using hexane and isopropanol to characterize the oil extraction as a function of total absorbed dose. The by-products …

Towards Developing A Watershed Assessment Framework Using Geomorphic-Based Hydrologic And Hydraulic Modeling, Matthew J. Tolson

Masters Theses

Urban hydromodification has created a need for an urban watershed assessment framework involving environmental rehabilitation practices to prioritize long-term and cost-effective enhancement strategies. This study sought to develop a watershed-scale model using Personal Computer Storm Water Management Model (PCSWMM) and field reconnaissance to be included in the planning phase of future watershed assessment frameworks. Typical modeling efforts for urban watershed stormwater management plans do not consider fluvial geomorphology during model development. To create an effective stormwater management and stream restoration watershed plan, this study sought to determine the level of model development necessary to prioritize watershed enhancement activities and explore …

Development Of Satellite-Assisted Forecasting System For Vibrio Vulnificus Prevalence In Coastal Waters, Saber Aradpour

LSU Doctoral Dissertations

Vibrio vulnificus is a halophilic gamma proteobacterium that is autochthonous to coastal waters and is responsible for 50% of seafood-related deaths in the United States. This study presents a series of nowcasting and forecasting models for predicting vibrio vulnificus abundance in oysters by identifying the long-range dependence of vibrio vulnificus abundance on antecedent environmental conditions and detecting the environmental conditions using satellite remote sensing technology. It was discovered that vibrio vulnificus abundance exhibits a long-range dependence on antecedent environmental conditions which can be characterized by seven independent environmental predictors (stressors) including sea surface temperature (SST), water level (WL), sea surface …

Refinement Of A Regional Storm Surge Mesh For High-Resolution Topographic Representation Of Volusia County, Morgan Harbin

Doctoral Dissertations and Master's Theses

In 2022, Volusia and Flagler Counties of northeast central Florida were impacted indirectly by consecutive Hurricanes Ian and Nicole; the destabilization of dunes and armoring infrastructure caused by Ian left the region susceptible to Hurricane Nicole, which caused unprecedented coastal damage to dunes and seawalls. The extent of damage that occurred within Volusia and Flagler Counties during the 2022 hurricane season, the underrepresentation of this region within sustainability and resilience research, and the ecological, social, and economic value of the geography provide just cause for scientific inquiry of the area’s coastal dynamics. This thesis specifically describes an investigation of Hurricane …

Advancing Understanding Of Opinions, Perceptions, And Knowledge In Underrepresented Communities In The El Paso Region To Promote Electric Vehicles And Electrified Infrastructure Use To Reduce Environmental Impacts, Liliana Lozada-Medellin

Open Access Theses & Dissertations

As the transportation and automotive industries continue growing, environmental and human health impacts remain a growing concern for planners, policy-makers, constructors, and the public as well (Krause et al., 2013; Larson et al., 2014). Although Electric Vehicles (EVs) are entering the market as a green technology solution to counteract greenhouse gas (GHG) emissions from internal combustion engine vehicles (ICEVs), there are still barriers that need to be overcome for widespread diffusion and adoption as the best solution. These include disseminating basic information about the technology for public awareness, considering equity concerns, and ensuring equitable access to infrastructure for all (L. …

Closing The Phosphorus Loop With Green Infrastructure: Removal And Recovery Using Amended Soils And 3d-Printed Material, Colin Wilson

Dissertations (1934 -)

Phosphorus (P) is a life-essential element aiding the deterioration of water quality. Stormwater runoff transports nonpoint source P pollution to waterbodies, contributing to excessive P loading which may result in eutrophication. Green infrastructure (GI) is implemented to solve stormwater runoff pollution, but the P removal performance of these systems is variable. Moreover, P is arguably being unsustainably mined for fertilizer production and animal feed supplements to support demand from increasing global populations. This dissertation explored advancing the circular P economy utilizing additive manufacturing and GI soil amendments to remove and recover P from stormwater runoff. Laboratory-scale batch experiments were used …

Flood Hazard And Vulnerability Mapping Using Deep Learning And Earth Observation Data, Nafiseh Ghasemian Sorboni

Electronic Thesis and Dissertation Repository

Urban flood risk assessment is critical for safeguarding lives and infrastructure amid frequent floods. Recent advances in Earth Observation (EO) data enable the creation of flood risk maps with enhanced spatial and temporal resolutions. While traditional Machine Learning (ML) algorithms lack optimal feature selection, Deep Learning (DL) algorithms excel in extracting complex patterns from EO data. This dissertation delves into the estimation of flood hazard and vulnerability within urban environments through DL algorithms and EO data. Several innovative methodologies were proposed: 1) A Convolutional Siamese Network (CSN) was devised for urban flood mapping using SAR satellite imagery. This method employed …

Differentiating Dynamic System Outcomes In Cam Photosynthesis Through Sonification, Duncan Turley

Civil and Environmental Engineering Undergraduate Honors Theses

Sonification is a powerful tool that is harnessed by modern engineers to represent information through audio, and is beginning to be used to interpret more complex data sets. Sonification can be used to facilitate the listeners' ability to grasp microscopic or complex changes in the state of a system. This study uses the assigning of sound patterns to model outputs that indicate chaotic or non-chaotic systems in Crassulacean acid metabolism photosynthesis. Using sound allows the interpretation of chaotic data without the more time intensive processes typically used, such as of Fast Fourier Transformations. Based on past research, it is known …

Modeling The Effectiveness Of Bioremediation On Methyl Tertiary-Butyl Ether In Groundwater, Logan Bundy

Master's Theses

Methyl tertiary-butyl ether (MTBE) and its degraded form tertiary-butyl alcohol (TBA) are both known carcinogens that have contaminated groundwater aquifers across the United States. MTBE is a synthesized compound, once widely used as an additive in gasoline to increase oxygenation. Because of its popularity, MTBE was released into the environment primarily through fuel combustion and leaking underground storage tanks. These two compounds are known to be recalcitrant to most conventional physico-chemical treatment methods. Previous studies have suggested that bioremediation is effective at degrading MTBE and TBA in contaminated groundwater. Bioremediation involves the injection of oxygen, nutrients, and pre-adapted bacterial cultures …

Evaluation Of Factors Influencing The Delivery Of Septic System Wastewater Effluent To Tributaries, Evan Angus

Electronic Thesis and Dissertation Repository

There is concern that septic systems may contribute nutrients, fecal pathogens, and emerging contaminants to tributaries, and thereby impair surface water quality. The objective of this thesis was to quantify the percentage of septic effluent reaching multiple streams and to evaluate whether this percentage varies based on the stream flow conditions and the physical and socioeconomic characteristics of a subwatershed. This was addressed by broad-scale sampling in 46 subwatersheds in the Lake Erie and Lake Simcoe Basins, Ontario, with data analyzed using statistical models. It was found that the percentage of septic effluent reaching subwatershed outlets, based on acesulfame stream …

Coupling Treatment Technologies With Bioelectrochemical Systems To Optimize Resource Recovery From Wastewater, Matthew Stephen Ferby

McKelvey School of Engineering Theses & Dissertations

Wastewater is a common waste produced from municipal, agricultural, and industrial processes. As the world’s population increases, the amount of wastewater produced globally is expected to reach approximately 450 billion m3 in the next two decades. Issues surrounding water, food, and energy accessibility will also become more imminent as the population grows. Interestingly, wastewater is an unconventional source of resources including water, nutrients (e.g., NH4+ and PO43-), and energy. However, conventional wastewater treatment processes focus primarily on the removal of containments rather than the recovery of resources. Bioelectrochemical systems (BES) have the ability to recover resources from wastewater. These engineered …

Past And Future Predictions Of Climate Change And Urbanization Effects On The Carbon, Nitrogen, And Water Dynamics In Northeastern Forest Ecosystems, Linghui Meng

Dissertations - ALL

Human activities have significantly influenced the structure and function of forest ecosystems in the northeastern US. Urbanization directly reduces forest area and alters forest functions. Forest growth, health, and function can also be affected by climate change, atmospheric carbon dioxide (CO2) concentrations, and air pollution including ground-level ozone (O3) and atmospheric nitrogen (N) deposition. Critical questions for research and environmental management are: How will urbanization, climate change, and air pollution interact to influence the function of forest ecosystems, and how will changes in these environmental drivers alter the function of forests in the future? In this dissertation, I simulate the …

Investigating The Effects Of Suspended Algal Content, Dissolved Oxygen, And Temperature On A High-Frequency Acoustic Attenuation System In A Controlled Laboratory Environment, Noah Watson

Honors Theses

The Single Frequency Acoustic Attenuation System (SFAAS) has been developed at the National Center for Physical Acoustics (NCPA). This system uses acoustic methods to monitor fine suspended sediment concentration in streams. Site-specific calibrations are necessary for this system, and previous research has indicated that algal concentration or dissolved oxygen concentration of water may affect collected data. Temperature, dissolved oxygen concentration, and fluorescence, used as a proxy for algal concentration, were monitored during this system’s use, and calibrations were derived to account for the effect of each of these variables on acoustic measurements. It has been shown that temperature has a …

Effect Of Waste Covid-19 Masks On Compaction Characteristics Of Silty-Clay Soil, Sydney K. Lawson

Honors College Theses

The present study aims to explore the effect of adding shredded waste Covid-19 masks to silty-clay soil on the soil’s compaction characteristics for beneficial use in embankment, the subgrade of roadways, or backfill. This was accomplished by using two different types of masks: blue surgical masks and KN95 masks. Both mask types were hand shredded into half-inch sections using safety-scissors. The maximum dry density (MDD) and optimum moisture content (OMC) are the two most important compaction characteristics, and they were determined by the Standard Proctor Compaction Test (ASTM D698 / AASHTO T99). The change of both the MDD and OMC …

Ammonia Recovery From Digester Centrate With Electrochemical Membrane Systems: Mechanism, Performance, And Application, Fubin Liu

McKelvey School of Engineering Theses & Dissertations

Nitrogen plays an indispensable role in living organisms and thus is a key element for agricultural production. Ammonia (NH3), as an important part in nitrogen cycle, can be synthesized by nitrogen fixing bacteria and the Haber-Bosch process, the latter of which requires an extensive energy input. Wastewaters can contain a large amount of nitrogen compounds because of kitchen and toilet wastes being discharged to sewage. The concentration of ammonia nitrogen (NH4+-N) can be hundreds mg per liter in some wastewaters like anaerobic digester (AD) centrate. However, both Haber-Bosch process and conventional wastewater ammonia treatment process are energy intensive, which making …

Land-Sea Connection Of Microplastic Fiber Pollution In Frenchman Bay, Maine, Grace A. Johnson

Electronic Theses and Dissertations

Global plastic production has been increasing over the past 50 years and is causing an increase in plastic waste entering the oceans. Plastic in the ocean is broken down into microplastics by a variety of physical, chemical, and biological processes. This study investigates the extent and potential sources of microplastic fiber pollution in Frenchman Bay, Maine, a coastal bay with complex geomorphology, numerous estuaries and many small tributaries that bring freshwater into it. Frenchman Bay is an important factor in Maine’s economy through its impact on tourism and commercial fishing. It is also a semi-sheltered coastal bay with some freshwater …

Physical And Stochiometric Controls On Nutrient Uptake And Ecosystem Respiration In Contrasting Sites, Jancoba K. Dorley

Civil Engineering ETDs

Meteorological, hydrological, and biogeochemical processes naturally control stream ecosystems. These processes define the frequency and distribution of precipitation and the supply and demand of solutes and particles to support aquatic food chains through space and time. Studies have also found that stream ecosystems are also controlled by anthropogenic activities, which occur on a much shorter timescale. These anthropogenic activities affect stream ecosystems' structure and function from local to planetary changes to the environment. It is essential for scientists and engineers to understand the relationships between naturally occurring processes and those created by human activities for a better interpretation of stream …

Urban Ecohydrology And The Watershed Microbial Continuum, Victoria C. Rexhausen

Doctoral Dissertations

A rapidly urbanizing world is adding unprecedented stress to water resources. Urbanization results in high rates of stream impairment, including but not limited to ecological stress, pollution, and flooding. A fully integrated and holistic perspective is necessary for effective remediation strategies for these wicked problems. This monitoring study from a heterogeneous urban watershed investigated the geospatial and seasonal interactions between urban hydrology and biological processes using stable isotope compositions, anions, and microbial.

This research found that nitrate concentrations in an urban watershed were ecologically driven. NO₃^- concentrations ranged from 0.4 to 12.7 mg/L throughout the watershed. Nitrate concentrations …

Integrated Approaches In Wastewater Surveillance Of Sars-Cov-2: Monitoring, Persistence, Sampling Optimization, And Impacts On Microbial Community Structure, Ye Li

Doctoral Dissertations

Wastewater-based epidemiology (WBE) serves as a crucial tool for monitoring SARS-CoV-2 prevalence on university campuses, yet concerns persist regarding its effectiveness as an early warning system for COVID-19 outbreaks. This study aimed to address these concerns through a comprehensive field trial conducted at the University of Tennessee, Knoxville. We investigated correlations between SARS-CoV-2 concentrations, both with and without normalization using Pepper Mild Mottle Virus (PMMoV), and various parameters. Significant positive correlations were observed between SARS-CoV-2 concentrations and active cases in the weeks prior to, during, and following the monitoring period, unaffected by PMMoV normalization. Concurrently, the persistence of SARS-CoV-2 RNA …

Sulfonated Polyethersulfone Membranes For Electrodialysis Desalination And The Influence Of Solvent Evaporation On Current Efficiency, Salinity Reduction, And Permselectivity, Li Chen

Open Access Theses & Dissertations

The high cost of ion exchange membranes significantly limits the public application of electrodialysis. The research of novel, inexpensive ion exchange membranes is essential to developing and applying electrodialysis desalination technology. This research focuses on fabricating cation exchange membranes with polyethersulfone (PES) and sulfonated PES (sPES) for water treatment. N-Methyl-2-Pyrrolidone (NMP) was used as an organic solvent to dissolve PES. After different solvent evaporation times were optimized from 0 hr to 24 hr, those membranes were formed through the phase inversion technique. The performance results show that the PES membranes performed the best when the solvent evaporated at 3 hr, …

Tracking Perfluoroalkyl Substances From Wastewater Influent To Its Accumulation In Vegetables And Forage Grass, Simon Kozik

All Graduate Theses and Dissertations, Fall 2023 to Present

Per and poly-fluorinated alkyl substances (PFAS) are a class of chemicals that are persistent in the environment. PFAS was found in wastewater, which can be used after wastewater treatment for irrigation water, and in the biosolids that can be mixed with soils to provide nutrients and generally improve soil quality. This study found when wastewater was used it increases the level of PFAS in vegetables and forage grass. PFAS concentrations were tracked from the influent of the wastewater treatment plant to the effluent, to the irrigation water, to the soil, and finally into the vegetable and forage grass grown on …

Development And Evaluation Of An Arsenic Transport Model For The Maurice River Watershed, Christina Eddleman

All Theses

For many Superfund sites across the United States, arsenic is one of the most common contaminants of concern that must be cleaned up to protect human and environmental health. Past research and health studies have documented the harmful effects of inorganic arsenic on humans and the environment but selecting an appropriate remediation plan depends on several site-specific factors at each Superfund site. To assist in determining an appropriate remediation plan, sediment and contaminant transport models have been used to simulate the transport of arsenic and other contaminants of concern at contaminated sites to, e.g., make relative comparisons of the efficacy …

Bay Water Level Influences On Inundation And Morphological Changes Of A Semi-Connected Barrier Island During A Hurricane, Sydney D. Goodman

<strong> Theses and Dissertations </strong>

This research aims to identify flooding and erosion changes along a semi-connected barrier island system due to varying bay water levels during storm conditions. The numerical model XBeach is used to simulate Hurricane Michael conditions and the resulting inundation and morphological change near Tyndall Air Force Base (Tyndall AFB). The installation is located 12 miles southeast of Panama City Beach along the panhandle of Florida and is vulnerable to flooding due to its proximity to the Gulf of Mexico (GoM), Saint Andrew Sound and Saint Andrew Bay. A land bridge connects the barrier island to the mainland of Tyndall AFB …