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Organic Fouling Mitigation In Forward Osmosis Technology Through The Use Of Oscilatting Alternating Current Electric Fields, Logan Werner

Graduate College Dissertations and Theses

Forward osmosis (FO) is the term given to osmosis in water filtration applications. FO has many advantages to conventional membrane filtration processes. The lack of external pressure needed to force solvent through the membrane is dramatically decreased in FO, resulting in a lower cost of operation compared to reverse osmosis. Lower external pressures also result in decreased fouling on the membrane surface and improved permeate flux. Fouling is one of the foremost challenges within the membrane filtration industry and is one of the biggest contributors to operating costs. While FO results in less fouling than RO, fouling remains a major …

Modeling To Evaluate The Contribution Of The Built Environment On Heat Microenvironments And Analysis Of The Efficiency And Efficacy Of Electric Vehicle Purchase Incentives, Parker King

Graduate College Dissertations and Theses

This dissertation provides an integrated examination of urban heat mitigation strategies and the effectiveness of electric vehicle (EV) purchase incentives, employing innovative methodologies across its four chapters to address pressing environmental and policy challenges. It leverages a unique dataset obtained through extensive mobile sampling, state-of-the-art machine learning techniques, revealed preference data collected through robust survey design, and detailed sociodemographic analyses to offer insights into the dynamics of urban heat islands, sustainable transportation, and policy efficiency.

The first section details the quantifying of micro-environment heat differences pertaining to the influence of the built environment across 10 cities over 20 days, using …

Metagenomic Insights Into The Full-Scale Anaerobic Digestion Of Cow Manure And Pre-Treated Food Waste, Amy Camille Decola

Graduate College Dissertations and Theses

Anaerobic digestion provides many benefits, such as diverting organic waste from landfills, promoting nutrient recovery, reducing greenhouse gas emissions, and producing renewable energy. A complex community of microorganisms is responsible for the anaerobic digestion process that converts organic matter into biogas, a renewable energy source. The start-up phase of an anaerobic digester is considered a crucial point in solidifying the core microbial community that will ensure a stable anaerobic digester. A full-scale anaerobic digester that co-digests cow manure and pre-treated food waste from a hydrolysis tank was studied from start-up through stable performance in order to better understand the dynamics …

Sars-Cov-2 Surveillance And Assessment Of Oscillating Electric Field-Assisted Phosphorus Recovery And Inactivation Of Escherichia Coli In Wastewater, Kamruzzaman Khan

Graduate College Dissertations and Theses

Clean water is one of the most essential substances for life on earth. However, human activities generate wastewater containing nutrients, pathogens, and other pollutants. The wastewater must be treated to specific standards before discharging into a natural body of water. Wastewater treatment is already a challenging task, and it is becoming more challenging due to increased human activities and pollutants of emerging concern. To address these challenges, a unique electric field-assisted method has been developed to complement existing treatment techniques to enhance the efficacy of wastewater treatment. There are two main parts to this work. The first part of the …

Travel Behavior, Responses To Fuel Prices, And Barriers To Change In Small And Rural Communities, Erica Quallen

Graduate College Dissertations and Theses

Travel behavior and the factors which drive it in small and rural communities has been historically understudied in transportation research. By understanding these factors and behaviors, a clearer picture of these regions can be drawn so that meaningful change towards greenhouse gas reductions can be realized. My research aims to examine barriers to making sustainable travel behavior changes such as using multi-modal transportation, reducing overall amounts of travel, or moving to locations closer to necessary services. I do this by first evaluating what “rural” means in terms of existing definitions of the term. The assessment of rural definitions analyzes vehicle …

Exploring Mycorrhizae In Riparian Restoration To Enhance Phosphorus Mitigation And Pollinator Habitat On Unceded Territory, Jessica Ann Rubin

Graduate College Dissertations and Theses

When land degradation imperils freshwater quality, land managers can restore ecosystem functions. The premise of three published/accepted thesis chapters is that mycorrhizae can enhance water quality function of riparian buffers and pollinator habitat through diverse, native polyculture associations.

Where water quality is threatened through excess phosphorus (P) loads from agriculture, riparian buffers are considered Best Management Practices (BMPs). They intercept agricultural nutrients before reaching waterways. However, their seasonal cycles, saturation capacity, and often degraded conditions limit their ability to protect water quality. In particular, riparian buffers can transition from sinks to sources of P when agricultural practices chronically contribute P, …

Characterization Of Effects Of Electric And Acoustic Fields On Fouling During Microfiltration Experiments, Yuxiang Shen

Graduate College Dissertations and Theses

Membrane processes have been a promising purification and separation technique as it can potentially remove any ions, particles, and colloids by size selection. Membrane processes are still limitedly used in the real-world industrial application due to its relatively cost prohibitive maintenance and operation, which is attributed to membrane fouling and concentration polarization under pressurized conditions. To improve the efficiency of membrane filtration, alternatives to the traditional cleaning methods have been investigated to mitigate the fouling and concentration polarization problems. Among the alternatives, application of an external field, e.g., electric field or acoustic field, to the mitigate fouling during membrane filtration …

A Holistic Approach To River Restoration Design And Conservation Planning On The Reach And Basin Scales Using Hydraulic Modeling And Multi-Objective Optimization Tools, Lindsay Courtney Worley

Graduate College Dissertations and Theses

Flooding events around the world cost billions (USD) in damages each year. For decades, engineers have combated flood related damages by implementing flood mitigation controls such as channelization, levees or berms, and armoring. Recent advances in the study of river dynamics, however, have challenged the efficacy of these traditional flood mitigation techniques and pose that these structures are disconnecting channels from their floodplains, increasing flow rates, and contributing to more erosion. The effects of climate change combined with future predictions of increased storm frequency and intensity make it necessary to revise flood hazard mitigation strategies. A more nature-based alternative to …

Development Of Protocols For Determining Deleterious Material Content In Crushed Recycled Glass, Fiona Nutbeam

Graduate College Dissertations and Theses

Glass recycling appears to be a viable way to reduce waste; however, there are many challenges to ensuring the recycled product has an economically and environmentally sustainable end use. Cleaning recycled glass to a standard that allows it to be melted down into new glass is extremely difficult when single-stream recycling is in practice. The recycled glass that is not melted down is processed into different materials, such as processed glass aggregate (PGA). As states implement bans on landfilling recyclable materials (e.g., Act 148 in Vermont), additional uses for PGA are needed. In New England, there are diminishing sources of …

Upcycling Dairy Manure Fine Solids Captured By Dissolved Air Flotation As Part Of A Phosphorus Recovery And Reuse Strategy, Katherine Keith Porterfield

Graduate College Dissertations and Theses

Dissolved air flotation (DAF) has shown potential to substantially improve phosphorus (P) mass balance on dairy farms by capturing P associated with fine solids from liquid manure, enabling new management options. However, at < 25% total solids, further dewatering and other upcycling is necessary to facilitate export of recovered fine solids off farm for use in bagged or bulk products. I generated plant foods using DAF-captured dairy manure fine solids thermally dried to 45% total solids blended with other organic residuals. Dry biomass of tomato and marigold seedlings amended with 6% v/v plant food was six-times greater than the unamended control and not significantly different from a market alternative treatment. Because thermal dewatering can be prohibitively costly, I generated a second batch of plant foods using DAF-captured dairy manure fine solids conditioned with 3, 4.5 and 6% (w/w) quicklime or lime kiln dust (LKD) and dewatered using a benchtop press for comparison with thermally dried fine solids. Tomato seedling biomass was similar for thermally dried and LKD plant foods, but quicklime plant foods had no effect compared to the unamended control. Quicklime and LKD conditioned fine solids contained approximately 30 and 10 times less plant-available P than thermally dried fine solids, respectively—likely due to precipitation of Ca-P minerals. These studies indicate that DAF-captured dairy manure fine solids could be upcycled to bagged horticultural products with substantial agronomic value, however sustainable materials drying remains a key challenge to realizing this potential.

The Effects Of Oxidized Biodiesel Fuel On Fatty Acid Methyl Ester Composition And Particulate Matter Emissions From A Light-Duty Diesel Engine, Jack Elliot Reed

Graduate College Dissertations and Theses

Diesel particulate matter (PM) is classified by the EPA as carcinogenic, with the transportation sector largely responsible these emissions within the United States. Biodiesel (B100) is derived from renewable sources, providing similar chemical composition to diesel fuel and is in the current diesel supply up to 5% across the nation. However, biodiesel has an inherent oxidation issue due to the unique mixture of fatty acid methyl ester (FAME) molecules present in the biodiesel that are not in diesel. Biodiesel oxidation can only be delayed, and the inevitable process results in changes to the original fuel composition that may alter emissions …

Robustness And Accuracy Bounds Of Model-Based Structural Health Monitoring, Nestor Ramon Polanco

Graduate College Dissertations and Theses

The strength and stiffness of structures degrade with time due to a combination of external forces and environmental conditions. A vehicular bridge, an offshore platform, a ship hull, or a wind turbine are examples of structures that for decades must endure cumulative degradation of their mechanical properties due to cyclic loading. Fatigue-induced damage typically starts at the exterior surface of the component unless microscopic or macroscopic imperfections are present in the material's structure. Structural Health Monitoring (SHM) provides a scientific non-destructive framework to estimate the structure's current state and remaining service life. In many model-based structural health monitoring applications, the …

Flood Analysis Of Bridge-Stream Interactions Using Two-Dimensional Models, Rachel Seigel

Graduate College Dissertations and Theses

The 2011 Tropical Storm Irene resulted in considerable property and infrastructure damage in Vermont and neighboring states, including damages to and failure of over 300 bridges and 800 km (500 miles) of roads in Vermont alone, which brought to light the vulnerability of regional transportation infrastructure to extreme flood events. The northeastern United States is experiencing more frequent precipitation events of longer duration (i.e., extreme events). Infrastructure therefore must be able to withstand more frequent flood events of greater magnitude. It is not feasible to analyze and retrofit each structure for the rigorous hydraulic demands of extreme flood events; so …

Geomechanical, Geochemical, And Hydrological Aspects Of Co2 Injection Into Saline Reservoirs, Maziar Foroutan

Graduate College Dissertations and Theses

Carbon dioxide Capturing, and Sequestration (CCS) is a promising technique that helps mitigate the amount of CO2 emitted into the atmosphere. CCS process mainly involves capturing CO2 at the industrial plant, followed by transportation and injection into a suitable geological storage, under supercritical conditions. Saline aquifers are among the best geological storage candidates due to their availability, high storage capacity and injectivity. Despite the CCUS technology promise, several public safety concerns remain to be address, including but not limited to reservoir/wellbore stability and integrity, CO2 leakage, ground deformation (uplift) and induced seismicity.

The injected supercritical CO2 is trapped through different …

A State Estimation Framework For Fatigue Monitoring And Prognosis Of Minimally Instrumented Structural And Biomechanical Systems, Benjamin Leblanc

Graduate College Dissertations and Theses

Fatigue damage is the continuous degradation of a material, primarily due to the formation of microcracks and resulting from the repeated application of stress cycles. Traditionally a fatigue analysis was performed during the structural design stage of a machine or structure; however, more recently there has been increased interest in the monitoring and prognosis of fatigue damage in existing and operating structures. In monitoring, the structure already exists and its mechanical properties can be estimated by processing sensor measurements and non-destructive testing. The traditional approach to fatigue monitoring is to carry out a visual inspection, find macroscopic cracks and then …

Edge-Of-Field Hydrology And Nutrient Fluxes Within Northeastern Agroecosystems: Evaluation Of Alternative Management Practices And Water Quality Models, Cameron Robert Twombly

Graduate College Dissertations and Theses

Agricultural runoff is one of largest contributors of phosphorus (P), nitrogen (N), and sediment affecting freshwater systems in watersheds across the Northeastern U.S., including the Lake Champlain Basin in Vermont. Agricultural cropping systems, such as corn silage and haylands, used for dairy feed production have been shown to impact watershed hydrology and water quality. Agricultural best management practices (BMPs) have the potential to decrease runoff volumes and flow rates and the associated export of nutrients and sediment from agricultural fields. Many states in the Northeastern U.S., including Vermont, are beginning to require farmers to implement water quality BMPs and further …

Sparsity Constrained Inverse Problems - Application To Vibration-Based Structural Health Monitoring, Chandler B. Smith

Graduate College Dissertations and Theses

Vibration-based structural health monitoring (SHM) seeks to detect, quantify, locate, and prognosticate damage by processing vibration signals measured while the structure is operational. The basic premise of vibration-based SHM is that damage will affect the stiffness, mass or energy dissipation properties of the structure and in turn alter its measured dynamic characteristics. In order to make SHM a practical technology it is necessary to perform damage assessment using only a minimum number of permanently installed sensors. Deducing damage at unmeasured regions of the structural domain requires solving an inverse problem that is underdetermined and(or) ill-conditioned. In addition, the effects of …

Performance-Based Seismic Monitoring Of Instrumented Buildings, Milad Roohi

Graduate College Dissertations and Theses

This dissertation develops a new concept for performance-based monitoring (PBM) of instrumented buildings subjected to earthquakes. This concept is achieved by simultaneously combining and advancing existing knowledge from structural mechanics, signal processing, and performance-based earthquake engineering paradigms. The PBM concept consists of 1) optimal sensor placement, 2) dynamic response reconstruction, 3) damage estimation, and 4) loss analysis. Within the proposed concept, the main theoretical contribution is the derivation of a nonlinear model-based observer (NMBO) for state estimation in nonlinear structural systems. The NMBO employs an efficient iterative algorithm to combine a nonlinear model and limited noise-contaminated response measurements to estimate …

Adhesion Of Bituminous And Cementitious Materials Using Particle-Probe Scanning Force Microscopy, Yujie Li

Graduate College Dissertations and Theses

As the most important materials in civil engineering, bituminous and cementitious materials have been used widely in pavements and constructions for many years. Accurate determination of adhesion is important to the bonding properties of bituminous and cementitious materials. In this work, we presented a novel approach to measure the adhesion between binders and aggregate mineral particles at microscopic scale.

Particle probe scanning force microscopes (SFM) were used to study the adhesion between mineral microspheres representing the primary aggregate constituents (Al2O3, SiO2 and CaCO3) and various control (PG 64-22 and PG 58-22) and modified binders. Results showed that these modified SFM …

Acoustic Emission Sensing For Crack Monitoring In Prefabricated And Prestressed Reinforced Concrete Bridge Girders, Robert Lee Worley Ii

Graduate College Dissertations and Theses

Prefabricated and pre-stressed reinforced concrete beams and girders are integral components of many highway structures, including those built by rapid construction techniques. Concerns exist regarding the development of cracks during curing, form removal, detensioning, transport, installation, and operation. Non-destructive, Acoustic Emission (AE) sensing techniques have the potential for detecting and locating cracking in prefabricated, pre-stressed concrete girders used as Prefabricated Bridge Elements and Systems (PBES) used in rapid construction practices as part of a Quality Assurance/Quality Control (QA/QC) program. AE sensing records transient elastic waves produced by the release of stored elastic energy resulting in plastic deformations (i.e., crack nucleation …

Simulating Hydraulic Interdependence Between Bridges Along A River Corridor Under Transient Flood Conditions, Matthew Everett Trueheart

Graduate College Dissertations and Theses

The interactions between rivers, surrounding hydrogeological features, and hydraulic structures such as bridges are not well-established or understood at the network scale, especially under transient conditions. The cascading hydraulic effects of local perturbations up- and downstream of the site of perturbation may have significant, unexpected, and far-reaching consequences, and therefore often cause concern among stakeholders. The up- and downstream hydraulic impacts of a single structural modification may extend much farther than anticipated, especially in extreme events. This work presents a framework and methodology to perform an analysis of interdependent bridge-stream interactions along a river corridor. Such analysis may help prioritize …

Coupled Thermal-Hydrological-Mechanical-Chemical Processes In Geothermal And Shale Energy Developments, Arash Kamali-Asl

Graduate College Dissertations and Theses

Coupled Thermal-Hydrological-Mechanical-Chemical (THMC) processes that exist in the development of different geo-resources (e.g. deep geothermal and shale gas) affect the fracture response (i.e. aperture and permeability), which in turn influences the reservoir production. The main goal of this study was to experimentally evaluate the impact of THMC processes on the response of rock specimens relevant for deep geothermal and shale gas formations. The effects of THMC processes were investigated on: (i) success of the hydraulic fracturing/hydro-shearing mechanism during stimulation stage, and (ii) closure of the created network of fractures during production stage.

The elastic, cyclic, creep, and failure characteristics of …

Quantifying The Seismic Vulnerability Of Bridges In Low To Moderate Seismicity Regions, John Edward Lens

Graduate College Dissertations and Theses

The U.S. Congressional Research Service issued a report for Congress in May 2016, entitled” Earthquake Risk and U.S. Highway Infrastructure: Frequently Asked Questions” which highlighted the absence of a national database on the status of seismic vulnerability of bridges or other infrastructure, and thus no estimate of costs to retrofit vulnerable bridges. Low to moderate seismicity regions exist in each of the continental United States, with over 30 states having mostly or entirely low-to-moderate seismicity. Resources at state transportation agencies and municipalities are focused on higher seismicity regions, creating a gap in quantifying the system-wide seismic vulnerability despite an overall …

Improving Detection And Prediction Of Bridge Scour Damage And Vulnerability Under Extreme Flood Events Using Geomorphic And Watershed Data, Ian Anderson

Graduate College Dissertations and Theses

Bridge scour is the leading cause of bridge damage nationwide. Successfully mitigating bridge scour problems depends on our ability to reliably estimate scour potential, design safe and economical foundation elements that account for scour potential, identify vulnerabilities related to extreme events, and recognize changes to the environmental setting that increase risk at existing bridges.

This study leverages available information, gathered from several statewide resources, and adds watershed metrics to create a comprehensive, georeferenced dataset to identify parameters that correlate to bridges damaged in an extreme flood event. Understanding the underlying relationships between existing bridge condition, fluvial stresses, and geomorphological changes …

Fluvial Processes In Motion: Measuring Bank Erosion And Suspended Sediment Flux Using Advanced Geomatic Methods And Machine Learning, Scott Douglas Hamshaw

Graduate College Dissertations and Theses

Excessive erosion and fine sediment delivery to river corridors and receiving waters degrade aquatic habitat, add to nutrient loading, and impact infrastructure. Understanding the sources and movement of sediment within watersheds is critical for assessing ecosystem health and developing management plans to protect natural and human systems. As our changing climate continues to cause shifts in hydrological regimes (e.g., increased precipitation and streamflow in the northeast U.S.), the development of tools to better understand sediment dynamics takes on even greater importance. In this research, advanced geomatics and machine learning are applied to improve the (1) monitoring of streambank erosion, (2) …

Generating And Measuring Prescribed Levels Of Cohesion In Soil Simulants In Support Of Extraterrestrial Terramechanics Research, Laura Obregon

Graduate College Dissertations and Theses

Scientists have been well aware of the complexity of Martian and lunar regoliths. There are vast unexplored areas on both, the Moon and Mars, as well as uncertainties in our understanding of the physicochemical properties of their regoliths. Lunar and Martian regoliths differ from terrestrial soils in that they appear granular, but are expected to contain some cohesion. As such, cohesion in regolith poses challenges for future space operations, more specifically for landing, settlement, and mobility purposes. The ability to induce prescribed levels of cohesion in regolith simulants and reliably measure it would allow scientists to evaluate space technology limitations …

Smart Classifiers And Bayesian Inference For Evaluating River Sensitivity To Natural And Human Disturbances: A Data Science Approach, Kristen Underwood

Graduate College Dissertations and Theses

Excessive rates of channel adjustment and riverine sediment export represent societal challenges; impacts include: degraded water quality and ecological integrity, erosion hazards to infrastructure, and compromised public safety. The nonlinear nature of sediment erosion and deposition within a watershed and the variable patterns in riverine sediment export over a defined timeframe of interest are governed by many interrelated factors, including geology, climate and hydrology, vegetation, and land use. Human disturbances to the landscape and river networks have further altered these patterns of water and sediment routing.

An enhanced understanding of river sediment sources and dynamics is important for stakeholders, and …

A New Evolutionary Algorithm For Mining Noisy, Epistatic, Geospatial Survey Data Associated With Chagas Disease, John P. Hanley

Graduate College Dissertations and Theses

The scientific community is just beginning to understand some of the profound affects that feature interactions and heterogeneity have on natural systems. Despite the belief that these nonlinear and heterogeneous interactions exist across numerous real-world systems (e.g., from the development of personalized drug therapies to market predictions of consumer behaviors), the tools for analysis have not kept pace. This research was motivated by the desire to mine data from large socioeconomic surveys aimed at identifying the drivers of household infestation by a Triatomine insect that transmits the life-threatening Chagas disease. To decrease the risk of transmission, our colleagues at the …

Application Of Electrokinetics In Subsurface Energy Extraction, Maria Peraki

Graduate College Dissertations and Theses

The world’s growing population results in increased energy needs that cannot yet be fully supported by the renewable sources of energy. These modern conditions and restraints have created the need to further research methods to enhance the recovery of resources previously unavailable due to technical and/or economic reasons and to reduce the environmental impacts of using fossil fuels. In this dissertation, applications of electrokinetic phenomena for the improvement of subsurface energy resource extraction are investigated using experimental and numerical tools.

Electrodialysis is proposed as a method of pre-treatment of the flow-back water produced during fracturing stage of shale gas extraction. …

Assessing The Probability Of Fluid Migration Caused By Hydraulic Fracturing; And Investigating Flow And Transport In Porous Media Using Mri, James Montague

Graduate College Dissertations and Theses

Hydraulic fracturing is used to extract oil and natural gas from low permeability formations. The potential of fluids migrating from depth through adjacent wellbores and through the production wellbore was investigated using statistical modeling and predic-tive classifiers. The probability of a hydraulic fracturing well becoming hydraulically connected to an adjacent well in the Marcellus shale of New York was determined to be between 0.00% and 3.45% at the time of the study. This means that the chance of an in-duced fracture from hydraulic fracturing intersecting an existing well is highly dependent on the area of increased permeability caused by fracturing. …