Physical Sciences and Mathematics Commons^™

Bioremediation Of Petroleum Hydrocarbons In Coastal Sediments, Charbel Abou Khalil

Dissertations

The biodegradation of dispersed crude oil in the ocean is relatively rapid (a half-life of a few weeks). However, it is often much slower on shorelines, usually attributed to low moisture content, nutrient limitation, and higher oil concentrations in beaches than in dispersed plumes. Another factor may be the increased salinity of the upper intertidal and supratidal zones since these parts of the beach are potentially subject to prolonged evaporation and only intermittent inundation. Therefore, two laboratory experiments are conducted to investigate whether such an increase in porewater salinity results in additional inhibitory effects on oil biodegradation in seashores.

In …

Anthropogenic Effects On Tidal Distortion In A Tidal River, Matthew D. Fischer

Electronic Theses and Dissertations

Tidal rivers are landward portions of estuarine systems constituting the union between coastal, tidally controlled settings and rivers, where fluvial processes dominate. In these reaches, river discharge (mean flow) and tides are the two most important mechanisms in controlling geophysical flows. The processes governing water levels and current amplitudes in tidal rivers are highly nonlinear and modulated by external forcings- thus requiring sophisticated techniques for accurate prediction and forecasting. Physical oceanographers and estuarine physicists tend to limit their study area to the maximum extent of the horizontal tide (salinity intrusion), not the most landward point influenced by tidal water levels. …

Use Of Machine Learning And Natural Language Processing To Enhance Traffic Safety Analysis, Md Abu Sayed

Theses and Dissertations

Despite significant advances in vehicle technologies, safety data collection and analysis, and engineering advancements, tens of thousands of Americans die every year in motor vehicle crashes. Alarmingly, the trend of fatal and serious injury crashes appears to be heading in the wrong direction. In 2021, the actual rate of fatalities exceeded the predicted rate. This worrisome trend prompts and necessitates the development of advanced and holistic approaches to determining the causes of a crash (particularly fatal and major injuries). These approaches range from analyzing problems from multiple perspectives, utilizing available data sources, and employing the most suitable tools and technologies …

Sulfonated Styrene Grafted Sebs/Abs Made By Additive Manufacturing For Ion Exchange Applications, Avianna Elaine Gallegos

Open Access Theses & Dissertations

An interpenetrating polymer network (IPN) for cation exchange applications was synthesized from a blend of styrene-ethylene/butylene-styrene (SEBS) and acrylonitrile butadiene styrene (ABS), which was 3D printed, grafted with crosslinked polystyrene (PS), and sulfonated. A method for styrene grafting was applied to reduce the damage to polymer phases caused by the sulfonation reaction. Styrene and divinylbenzene monomers were introduced to the IPN and induced with heat treatment to polymerize in situ. The graft copolymerization reaction was enhanced with varying quantities of benzoyl peroxide as a chemical initiator. The samples were subsequently sulfonated with chlorosulfonic acid in dichloroethane and functionalized for ion …

Identification Of Factors Contributing To Traffic Crashes By Analysis Of Text Narratives, Cristian D. Arteaga-Sanchez

UNLV Theses, Dissertations, Professional Papers, and Capstones

The fatalities, injuries, and property damage that result from traffic crashes impose a significant burden on society. Current research and practice in traffic safety rely on analysis of quantitative data from crash reports to understand crash severity contributors and develop countermeasures. Despite advances from this effort, quantitative crash data suffers from drawbacks, such as the limited ability to capture all the information relevant to the crashes and the potential errors introduced during data collection. Crash narratives can help address these limitations, as they contain detailed descriptions of the context and sequence of events of the crash. However, the unstructured nature …

A Case Study In Design, Construction, And Operation Of A Meromictic Solar Pond In Texas, Usa, Bianca Paola Meneses Brassea

Open Access Theses & Dissertations

Over the last four decades, meromictic solar ponds have been the subject of limnological studies and engineering research. A case of practical interest is the salinity gradient solar pond (SGSP). SGSP science and technologies have been systemically advanced in El Paso, Texas. This dissertation aims to share lessons learned in designing, constructing, and operating the El Paso Solar Pond, a NaCl-based solar pond that achieved high-temperature performance over two decades, commencing in 1984. Many of the practical lessons learned have not been published and are thus not readily available in archival journals, and this contribution provides a remedy. The value …

Identifying Particulate Matter Spatial Variation In The El Paso Del Norte Region Using Land-Use Regression Modeling And Data Obtained From A Network Of Low-Cost Sensors, Leonardo Demetrio Vazquez-Raygoza

Open Access Theses & Dissertations

The emergence and rise in popularity of low-cost sensors for atmospheric observation aresetting a new precedent in identifying emission hotspots and providing high-resolution spatial and temporal data. Furthermore, low-cost sensors are becoming popular among institutions and the public, allowing community scientists to become more involved in air quality monitoring. However, concerns about the accuracy and precision of low-cost sensors have been questioned. Most recent research has focused on the utility of real-time monitoring and calibration requirements for these sensors. A low-cost monitoring project has deployed sensors in the El Paso del Norte region in low and high annual average daily …

Water Hardness Removal By Electrochemical Precipitation In A Continuous Flow Condition Using Conductive Concrete As Cathode, Tahsin Tareque

Theses and Dissertations

This study focuses on the electrochemical precipitation (EP) process to reduce excess water hardness from the Lower Rio Grande Valley (LRGV) tap water using electrically conductive concrete as cathode in a continuous flow condition. LRGV tap water is extremely hard with hardness more than 350 mg/L as CaCO3. Humans can pleasantly consume water with hardness less than 150 mg/l as CaCO3 according to World Health Organization (WHO). Hard water is also known to cause mechanical problems to boilers and heat exchangers. In this process, electricity is passed through electrodes submerged in electrolyte, which causes an alkaline environment around the cathode …

Sustainability And Health Impacts Of Pulse Crops In The United States Using Life Cycle Assessment, Prathamesh A. Bandekar

Graduate Theses and Dissertations

Environmental sustainability and human health impact of pulses produced and consumed in the United States was assessed using life cycle assessment (LCA). The study included three objectives 1) to estimate environmental impact of current production and consumption practices in the United States using attributional LCA; 2) to estimate environmental and human health impact of iso-caloric diets containing varying amounts of pulses using Hybrid-LCA and Combined Nutritional and Environmental-LCA (CONE-LCA); and 3) to estimate environmental impact of increased demand for pulses using consequential LCA. Scope of the study varied for each objective with system boundary encompassing cradle-to-grave activities for objective 1 …

Ligand-Promoted Dissolution Of Uranyl Phosphate Across Scales, Brennan Ferguson

All Dissertations

The formation of uranyl phosphate precipitate is a remediation strategy because the low solubility of uranyl phosphate minerals, like chernikovite, limits the mobility of uranium in contaminated soils. However, organic ligands can complex with aqueous metal cations to form more soluble species. For example, citrate is a commonly occurring organic ligand produced by plants and microbes that increases the solubility of uranium and therefore the dissolution of uranyl phosphate minerals in the uranyl phosphate-citrate system. This effect is an important control on the mobility of uranium in organic-rich, and near-surface vegetated environments. Nevertheless, key aspects of the citrate-uranyl phosphate system …

Mysteerio: Multi-Regional Environmentally Extended Input-Output Model For United States, Yash Srivastava

All Theses

This research work titled My State Environmentally Extended Regional Input-Output (MYSTEERIO) is based on the concept of multi-regional environmentally extended input-output (MREEIO), which is a combination of lifecycle thinking and economics principles. Numerous studies have highlighted the advantages of using this methodology to determine the environmental impacts associated with economic activities for a region. However, no prior attempt has been made to conduct a state-level analysis for the US. This research work thus tries to estimate the impacts embodied due to the consumption of goods and services at the state level by using the MREEIO principles. Extensive coverage of the …

Quantifying A 21-Year Surface Water And Groundwater Interaction In A Ridge And Valley Lake Environment Using A Highly Constrained Modeling Approach, Richard T. Bowers Jr.

USF Tampa Graduate Theses and Dissertations

Karst lakes are ubiquitous in ridge terrain settings in limestone aquifer coastal plain environments. In west-central Florida, these lakes are frequently connected to the Upper Floridan aquifer and have unique aquifer recharge characteristics. They have been selectively studied because they commonly have no or very limited surface water discharge and limited drainage areas, have appreciable surface water and groundwater interaction and leak to the deep aquifer. An innovative modeling approach was developed to collectively understand and more precisely quantify this vertical leakage, both from a lake-specific and regional water budget standpoint, for a 21-year study period (2000-2020). A unique, calibrated …

Geology-Based Shear-Wave Velocity Model Of Reference Site Conditions In South Carolina For Seismic Site Response Analysis, Camilius Amevorku

All Dissertations

Assessing earthquake hazard in the State of South Carolina is important because it is one of the most seismically active regions of the eastern United States and has experienced earthquakes of damaging levels in the historical past. Examples of these damaging seismic events are the 1886 Charleston earthquake (M 6.7 to 7.5) and the 1913 Union County earthquake (M 4.5 to 5.5).

Small-strain shear-wave velocity (V_S) is an important parameter in performing site response analysis. The deep nature of the top of reference firm rock (i.e., V_S ≥ 760 m/s or B-C boundary) due to …

Cascadia Subduction Zone Earthquake Vertical Ground Acceleration Investigation And Potential Impact On Bridges In The Pacific Northwest, Rachel Caroline Bassil

Civil and Environmental Engineering Master's Project Reports

The effects of vertical ground accelerations during subduction zone earthquakes currently are not sufficiently understood. There are numerous case studies and evidence that effects of vertical ground accelerations can significantly impact the performance of bridges during a seismic event, but most previous research has been focused on shallow crustal earthquakes. Current bridge design codes provide little guidance for accounting for vertical ground accelerations in seismic design, in part because additional information is needed about the characteristics of vertical ground motions during Cascadia Subduction Zone (CSZ) earthquakes in the Pacific Northwest.

For this study, recorded seismic data from recent subduction zone …

Fate Of Metals In Presence Of Minerals And Mineral-Organic Assemblages, Neha Sharma

McKelvey School of Engineering Theses & Dissertations

Metals can enter aquatic systems from natural and anthropogenic processes associated with weathering, sediment re-suspension, industrial activities, and atmospheric deposition. Metals pose health and environmental risks at high concentrations due to their potential toxicity and bioaccumulation, but many trace metals also serve as essential micronutrients for biogeochemical processes in natural aquatic systems. Biogeochemical processes such as methanogenesis, denitrification, and mercury methylation require transition metals such as nickel (Ni), cobalt (Co), copper (Cu), and molybdenum (Mo) for completion. These biogeochemical processes can be substantial contributors of greenhouse gases, such as methane (CH4) and nitrous oxide (N2O), into the atmosphere. The behavior, …

Development Of Deep Shear Wave Velocity Profiles And An Approach To Generate Site Signature Consistent Pseudo Shear Wave Velocity Profiles In The Mississippi Embayment, Ashraf Kamal Himel

Graduate Theses and Dissertations

This dissertation details the development of a surface wave method (SWM) technique to generate deep shear wave velocity profiles (VS profiles), applying this technique at 24 sites across the Mississippi embayment and developing an approach to generate pseudo site signature consistent VS profiles from velocity functions and fundamental frequency. In the presented SWM technique, active and passive source surface wave measurements are inverted along with fundamental frequency to develop a site signature consistent VS profile. Multiple transformation methods, including MSPAC, HRFK and FK are used to resolve experimental dispersion data from surface wave measurements. SWM VS profile at the Central …

Application Of A 14c-Assay To Assess Methanotrophic Biodegradation Of Tce In Low Ph Groundwater, Evan Groome

All Theses

Current biological strategies for remediating trichloroethylene (TCE) in low pH aquifers (i.e., pH14C-TCE assay was developed to determine pseudo first-order rate constants for the degradation of TCE in microcosms containing soil and groundwater from the Boeing Michigan Aeronautical Research Center (BOMARC) superfund site, where the pH ranges from 4.1 to 4.9. The ¹⁴C-TCE assay was also adapted to calculate soil-normalized rate constants for data from this site, as well as data that Szwast²¹ collected from the Beltsville Agricultural Research Center (BARC). In addition to natural attenuation, biostimulation through amendments of methane and nutrients were also assessed. This treatment …

Tree Ring Reconstructions Of Streamflow For The Lower Rio Grande Valley Of Texas, Adedolapo Mutiyat Adeyanju

Theses and Dissertations

The Rio Grande River is a major water source for people living within the USA-Mexico border. The Rio Grande River has its headwaters in the San Juan Mountains in Colorado and the Sierra Madre Occidental in Mexico before flowing into Texas through El-Paso. The water supply issues facing the Lower Rio Grande Basin (LRGB) are extremely complex from international restrictions to severe climate change. The river shares its flow between the U.S.A and Mexico based on the provisions of the 1944 treaty between the U.S.A and Mexico. The LRGB flow is regulated by releases from Falcon and Amistad Reservoirs managed …

Wetland Soil Development Along Salinity And Hydrogeomorphic Gradients In Active And Inactive Deltaic Basins Of Coastal Louisiana, Amanda Fontenot

LSU Master's Theses

Coastal wetlands provide an abundance of ecosystem services that benefit society, such as essential habitat for commercial species, storm protection, nutrient cycling, and carbon storage. Louisiana faces rapid rates of relative sea level rise (natural subsidence and eustatic sea levels) that threaten wetland survival, which are amplified by a reduction of riverine sediment input. An important determining factor of marsh survival is the formation of wetland platform elevation, known as vertical accretion, which is determined by several processes including sediment deposition & erosion, below ground biomass (BGB) productivity, decomposition of organic matter, shallow & deep subsidence, and soil compaction. Feldspar …

Learning From Machines: Insights In Forest Transpiration Using Machine Learning Methods, Morgan Tholl

Dissertations and Theses

Machine learning has been used as a tool to model transpiration for individual sites, but few models are capable of generalizing to new locations without calibration to site data. Using the global SAPFLUXNET database, 95 tree sap flow data sites were grouped using three clustering strategies: by biome, by tree functional type, and through use of a k-means unsupervised clustering algorithm. Two supervised machine learning algorithms, a random forest algorithm and a neural network algorithm, were used to build machine learning models that predicted transpiration for each cluster. The performance and feature importance in each model were analyzed and compared …

Development Of Software Tools For Efficient And Sustainable Process Development And Improvement, Jake P. Stengel

Theses and Dissertations

Infrastructure is a key component in the well-being of our society that leads to its growth, development, and productive operations. A well-built infrastructure allows the community to be more competitive and promotes economic advancement. In 2021, the ASCE (American Society of Civil Engineers) ranked the American infrastructure as substandard, with an overall grade of C-. The overall ranking suffers when key infrastructure categories are not maintained according to the needs of the population. Therefore, there is a need to consider alternative methods to improve our infrastructure and make it more sustainable to enhance the overall grade. One of the challenges …

Remote Sensing Of High Latitude Rivers: Approaches, Insights, And Future Ramifications, Merritt E. Harlan

Doctoral Dissertations

High latitude rivers across the pan-Arctic domain are changing due to changes in climate and positive Arctic feedback loops. Understanding and contextualizing these changes is challenging due to a lack of data and methods for estimating and modeling river discharge, and mapping rivers. Remote sensing, and the availability of satellite imagery can provide ways to overcome these challenges. Through combining various forms of fieldwork, modeling, deep learning, and remote sensing, we contribute methodologies and knowledge to three key challenges associated with better understanding high latitude rivers. In the first chapter, we combine field data that can be rapidly deployed with …

Effects Of Experimental Scale On The Adsorption Of Two Pharmaceutical Drugs Detected In Municipal Wastewater Effluent, Michael Moore

Master's Theses

Pharmaceutical drugs are being produced and consumed in increasing quantities every year and are poorly treated by conventional wastewater treatment processes, leading to increasing detection of such compounds in surface water, groundwater, and municipal drinking water. Soil aquifer treatment (SAT) is a promising method for treating these emerging compounds through combined adsorption and degradation of target compounds in soil. This thesis examines the consistency of results from typical studies like adsorption isotherms and soil columns utilized in analysis of SAT performance, across varying experimental scales. The adsorption behavior of two pharmaceuticals was investigated as a function of experimental scale and …

Understanding Ch4 Emissions From Compostables: An Exploration Of Local Ch4 Emissions From Landfilled Compostables And The Efficacy Of Emission Mitigation Via Anaerobic Biogas Digestion, Jordan-Yoosuf Aljbour

University Honors Theses

Methane (CH₄) is the second most abundant anthropogenic greenhouse gas within the atmosphere, comprising ~16% of the total anthropogenic greenhouse gas composition on Earth. It has an ~12-year lifetime relative to its eventual oxidation via reaction with tropospheric hydroxyl radicals (OH), and has a 100-year indirect global warming potential (GWP) approximately ranging between 28-36 [Environmental Protection Agency, 2021]. In recent years, the observed average global concentration of atmospheric CH₄ has increased by ~11.0% from 2020 (~15.3 ppb) to 2021 (~17.0 ppb) [Dlugokencky et al., 1994; National Oceanic and Atmospheric Administration, 2022]. With …

Planning Methodology For Alternative Intersection Design And Selection, Liran Chen

Dissertations

The recent publication of the 6th Edition of the Highway Capacity Manual included a chapter on Ramp Terminals and Alternative Intersections that introduces various alternative intersection designs and assesses the performance of Median U-turn, Restricted crossing U-turn and Displaced left-turn intersections. Missing from the literature is an alternative intersection selection tool for identifying whether an alternative intersection would be successful under local conditions. With limited information of organized alternative intersection research, most planners must rely heavily on their personal judgement while selecting the most suitable intersection designs. As appealing as alternative intersections are, there is no comprehensive methodology for planners …

A Self-Learning Intersection Control System For Connected And Automated Vehicles, Ardeshir Mirbakhsh

Dissertations

This study proposes a Decentralized Sparse Coordination Learning System (DSCLS) based on Deep Reinforcement Learning (DRL) to control intersections under the Connected and Automated Vehicles (CAVs) environment. In this approach, roadway sections are divided into small areas; vehicles try to reserve their desired area ahead of time, based on having a common desired area with other CAVs; the vehicles would be in an independent or coordinated state. Individual CAVs are set accountable for decision-making at each step in both coordinated and independent states. In the training process, CAVs learn to minimize the overall delay at the intersection. Due to the …

Reactive Iron Mineral Coatings In Redox Transition Zones Of A Site With Historical Contamination: Abiotic Attenuation, Xin Yin

Dissertations

Reactive iron mineral coatings are found throughout reduction-oxidation (redox) transition zones and play a significant role in contaminant transformation processes. In this study, an 18.3-meter core is collected, subsampled, and preserved under anoxic conditions to maintain its original redox state. Screening analyses are conducted at sampling increments of 5.08 cm in depth for the following: elemental concentrations with X-ray fluorescence (XRF), sediment pH, sediment oxidation-reduction potential (ORP), total volatile organic carbon (TVOC) in the sample headspace, and abundant bacteria (16S rRNA sequencing). Using the Fe and S gradients correlated with microbial data, five RTZs are delineated. To characterize iron mineral …

A Circular Economy Approach To Improve E-Waste Recycling In California: Economic Potential And Policy Options, Kripa Shah

Master's Projects and Capstones

The higher consumption rates of electronic devices along with their short life cycles and few repair options poses a huge challenge for E-waste industries to manage them effectively. E-waste comprises of hazardous materials and toxic constituents that can affect the environment and public health through improper disposal. However, they also contain few valuable materials that, if recovered, can reduce the dependence on virgin raw materials. Circular economy has the potential to utilize these valuable materials and gain environment and socio-economic benefits. The research explains how the adoption of a circular economy approach can help improve the E-waste recycling in California …

Impact Of Climate Oscillations/Indices On Hydrological Variables In The Mississippi River Valley Alluvial Aquifer., Meena Raju

Theses and Dissertations

The Mississippi River Valley Alluvial Aquifer (MRVAA) is one of the most productive agricultural regions in the United States. The main objectives of this research are to identify long term trends and change points in hydrological variables (streamflow and rainfall), to assess the relationship between hydrological variables, and to evaluate the influence of global climate indices on hydrological variables. Non-parametric tests, MMK and Pettitt’s tests were used to analyze trend and change points. PCC and Streamflow elasticity analysis were used to analyze the relationship between streamflow and rainfall and the sensitivity of streamflow to rainfall changes. PCC and MLR analysis …

Characterization Of Water Flow And Solute Transport Driven By Preferential Flow In Soil Vadose Zone, Abdullah Al Mamun

All Dissertations

The vadose zone acts as a buffer zone between the ground surface and the aquifers underneath and controls the transmission of infiltrating water and contaminants, for example, pesticides and chemical spills. Therefore, understanding the flow and transport processes that dominate the vadose zone is important. Macropores are ubiquitous and particularly found in abundance in the vadose zone. These macropores facilitate preferential flow, through which water travels rapidly deep into the soil, bypassing most of the porous matrix. Preferential flow and transport have environmental significance as their processes impact hydrology, ecology, agriculture, subsurface contamination, and waste management sectors. Thus, the overall …