Physical Sciences and Mathematics Commons^™

Factors Affecting Groundwater Nitrate Concentration In Madinah Area, Saudi Arabia, Majed M. Almutairi

Masters Theses

High levels of nitrate in groundwater are a serious problem in Madinah Area, Saudi Arabia. Identifying factors affecting groundwater nitrate contamination is important for managing groundwater quality. This study examined factors that have significant impacts on the high level of groundwater nitrate in Madinah Area. Factors examined included well-depth and land cover. Relationships between variables were explored using three statistical approaches: the Kruskal-Wallis test and two types of regression (ordinary least squares [OLS] and geographically weighted regression [GWR]).

Nitrate concentration data show that 73% of obtained groundwater samples exceeded the United States Environmental Protection Agency (EPA) maximum contaminant level (MCL) …

Investigation Of Ch4 Adsorption And Activation On Modified Metalloporphyrin Graphene Sheets, Brianna Haase

Masters Theses

Finding a good catalyst for C-H bond breaking is important due to the rise of natural gas and crude oil emissions. From 2000-2006, CH4 emission concentrations stabilized, but in 2007, it sharply started increasing again. For example, atmospheric CH₄ levels were 1886.37 ppb in July 2021 but this rose to 1904.52 ppb in just one year. Precious metal catalysts, such as Ir systems, have been used for C-H bond breaking, but are not sustainability ideal as they are costly to produce and have a significant carbon footprint. Because of this, less expensive 3d metal catalysts have risen in investigative …

Implications Of Intraspecific Variation In Soil Microbes On Solidago Performance, Yazeed Alshammari

Masters Theses

This study explored the implications of intraspecific variation in soil microbes on the performance of Solidago altissima, a North American species that has become invasive across several continents. This research explored how different clones of Solidago altissima were associated with bacterial and fungal soil microbial communities, which influenced plant performance. In a common garden of 24 Solidago altissima clones, I analyzed the relationship between soil microbial communities, foliar chemistry, clone genetic relatedness, and plant performance. My methods included analysis of soil microbial communities (bacterial and fungal), genetic distances among clones to assess relatedness, and measures of plant performance (light …

Mat: Genetic Algorithms Based Multi-Objective Adversarial Attack On Multi-Task Deep Neural Networks, Nikola Andric

Masters Theses

"Vulnerability to adversarial attacks is a recognized deficiency of not only deep neural networks (DNNs) but also multi-task deep neural networks (MT-DNNs) that attracted much attention in the past few years. To the best of our knowledge, all multi-task deep neural network adversarial attacks currently present in the literature are non-targeted attacks that use gradient descent to optimize a single loss function generated by aggregating all loss functions into one. On the contrary, targeted attacks are sometimes preferred since they give more control over the attack. Hence, this paper proposes a novel targeted multi-objective adversarial ATtack (MAT) based on genetic …

Dynamic Discounted Satisficing Based Driver Decision Prediction In Sequential Taxi Requests, Sree Pooja Akula

Masters Theses

"Ridesharing platforms rely on connecting available taxi drivers to potential passengers to maximize their revenue. However, predicting the stopping decision made by every driver, i.e., the final task performed during a given day, is crucial to achieving this goal. Unfortunately, little research has been done on predicting drivers’ stopping decisions, especially when they deviate from expected utility maximization behavior. This research proposes a Dynamic Discounted Satisficing (DDS) heuristic to model and learn the task at which human agents will stop working for that day, assuming that the human agents are taking sequential decisions based on their preference order. We apply …

Meta-Analysis Of Mesenchymal Stem Cell Gene Expression Data From Obese And Non-Obese Patients, Dakota William Shields

Masters Theses

"The prevalence of gene expression microarray datasets in public repositories gives opportunity to analyze biologically interesting datasets without running the laboratory aspect in house. Such experimentation is expensive in terms of finances, time, and expertise, which often results in low numbers of replicates. Meta-analysis techniques attempt to overcome issues due to few biological or technical replicates by combining separate experiments together to increase statistical power. Proper statistical considerations help to offset issues like simultaneous testing of thousands of genes, unintended hybridization, and other noises.

Microarrays contain light intensities from tens of thousands of hybridized probes giving a measure of gene …

Investigation Of Defect Production And Displacement Energies In Wurtzite Aluminum Nitride, Sean Anderson

Masters Theses

"Aluminum Nitride is an active element of sensors that monitor the performance and well-being of the nuclear reactors due to its piezoelectric properties. Yet, the variations of its properties under irradiation are largely unexplored. We report the results of the molecular dynamics simulations of the structural changes in AlN under irradiation via the knock-on atom technique. By creating and evolving the irradiation cascades due to energetic particle interaction with the atom of the crystalline lattice we determine the rate of the defect production as a function of the deposited energy. Further, we determine a displacement energy, a key characteristic that …

Assessing The Knowledge On Sustainability And Barriers To Daily Sustainable Practices Among Faculty And Students In Higher Education: The Case Of Eastern Illinois University, Joel Edem Holison

Masters Theses

The concept of sustainable development gained prominence with the publication of the Brundtland Report, which emphasized economic progress without jeopardizing future generations' well-being. Following that, the Education for Sustainability (EfS) program was created by the United Nations to raise sustainability awareness. However, the transition to sustainable living is fraught with difficulties, including a lack of knowledge, financial constraints, infrastructure gaps, and political ideologies. This study focuses on sustainable practices among Eastern Illinois University (EIU) students and faculty, as well as the barriers to daily sustainable behaviors. As independent variables influencing sustainable practices, the study evaluates sustainability knowledge/awareness, personal financial situation, …

Development Of A Chemical Biology Approach To Uncover The Influence Of Sequence Variations On Ces1 Activity In Live Cells, Samuel James Knebel

Masters Theses

Drug metabolism is the biochemical process of modifying drugs to detoxify and remove them through enzymatic transformations. These biotransformation’s occur primarily in the liver and are critical to understanding how pharmaceutical compounds are chemically altered inside the human body. Human carboxylesterases (CESs) catalyze the hydrolysis of esters, amides, thioesters, and carbamates. CES-mediated hydrolysis plays an important role in the metabolism of many drugs including the first FDA approved antiviral treatment for COVID-19, remdesivir (Veklury), the seizure control medication rufinamide (Banzel), and the flu antiviral drug oseltamivir (Tamiflu). CES activity is known to be influenced by a variety of factors including …

The Application Of Statistical Modeling To Identify Genetic Associations With Mild Traumatic Brain Injury Outcomes, Caroline Schott

Masters Theses

"Traumatic brain injury (TBI) is a growing health concern, with millions of TBI diagnoses in the United States each year. The vast majority of TBI diagnoses are mild traumatic brain injuries (mTBI), which can be challenging to manage due to variation in symptoms and outcomes. Most individuals with mTBI successfully recover quickly, but a small subset has a delayed recovery. Although the factors that contribute to this variation in recovery are not clearly understood, it is possible that genetic differences may play a role. Very few studies have investigated the association between single nucleotide polymorphisms (SNPs) with mTBI outcomes and …

Computer Vision In Adverse Conditions: Small Objects, Low-Resoltuion Images, And Edge Deployment, Raja Sunkara

Masters Theses

"Computer vision based on deep learning is an essential field that plays a significant role in object detection, image classification, semantic segmentation, instance segmentation, and other applications. However, these models face significant challenges in adverse conditions, such as small objects, low-resolution images, and edge deployment. These challenges limit the accuracy and efficiency of computer vision algorithms, making it difficult to obtain reliable results.

The primary objective of this thesis is to assess the performance of deep learning- based computer vision models in challenging conditions and provide viable solutions to overcome the obstacles. The study will specifically address three key challenges, …

“This Isn't Working For Me. Can We Do It A Different Way?" The Lived Experiences Of Geoscience Students With Learning Disabilities, Nina Morris

Masters Theses

The purpose of this exploratory qualitative study is to better understand the lived experiences of geoscience students with learning disabilities in their geoscience classes. Students with learning disabilities bring a unique perspective while also facing unique challenges in post-secondary education. In the literature, there is limited information on what support and teaching strategies are beneficial to this population. Undergraduate and graduate geoscience students who identify as having a learning disability from colleges and universities in the United States were recruited. Six students consented to participate in the study, and each completed a semi-structured interview. Semi-structured interviews were designed to prompt …

Exploring The Effects Of Tree Roots On Infiltration Process, Nazife Onaral

Masters Theses

Effects of the root structures on soil infiltration dynamics are not clearly defined. Imaging the complex tree root structures and movement of water through the root ball is a challenging task to achieve without damaging the trees and roots by conventional methods. Commonly used methods are invasive, labor-intensive, and not easily accessible. Ground Penetrating Radar (GPR) has commonly been used to characterize soil profiles and it can be a reliable tool to map complex root structures with a novel high-resolution circular data collection technique. Electrical resistivity tomography (ERT) is another reliable geophysical method to image infiltration processes by the change …

Running Out Of Oxygen: Revealing The Interannual And Intra-Annual Dynamics Of Bottom Water Hypoxia In A Great Lakes Estuary Using Time-Series Observations, Experiments, And Analyses, Nate M. Dugener

Masters Theses

Bottom water hypoxia, a condition of low dissolved oxygen in the bottom waters, negatively effects lakes and freshwater and marine coastal estuaries globally. As climate change shifts climatological and ecological patterns, hypoxia continues to shift in duration and severity. In Muskegon Lake, Michigan, hypoxia occurs annually, restricting fish habitat, increasing cyanobacteria blooms, and disrupting ecological and socioeconomic prosperity. In the current study, we examined the duration and severity of hypoxia over a 11 years (2011-2021) utilizing data from the Muskegon Lake Observatory buoy (MLO, https://www.gvsu.edu/wri/buoy/). During 2021, we analyzed the dissolved oxygen (DO) concentrations observed by the MLO, conducted biweekly …

Potential Impacts Of Hemlock Woolly Adelgid Infestation On Forest Overstory And Avian Assemblages In West Michigan, Usa, Nathaniel Sq Wagner

Masters Theses

Invasive species threaten the health and resiliency of native ecosystems wherever they are found. The damage caused by invasive species often leads to a cascade that degrades the ecosystem as a whole. In eastern North America, the invasive insect, hemlock woolly adelgid (Adelges tsugae; HWA), threatens the continued existence of eastern hemlock (Tsuga canadensis) and the species that are associated with it. Often considered a foundation species, eastern hemlock influences the structure and composition of eastern forests by lowering soil temperature, subsequently raising soil moisture content. In the absence of hemlock, many forests become dominated by …

Maximising Social Welfare In Selfish Multi-Modal Routing Using Strategic Information Design For Quantal Response Travelers, Sainath Sanga

Masters Theses

"Traditional selfish routing literature quantifies inefficiency in transportation systems with single-attribute costs using price-of-anarchy (PoA), and provides various technical approaches (e.g. marginal cost pricing) to improve PoA of the overall network. Unfortunately, practical transportation systems have dynamic, multi-attribute costs and the state-of-the-art technical approaches proposed in the literature are infeasible for practical deployment. In this paper, we offer a paradigm shift to selfish routing via characterizing idiosyncratic, multiattribute costs at boundedly-rational travelers, as well as improving network efficiency using strategic information design. Specifically, we model the interaction between the system and travelers as a Stackelberg game, where travelers adopt multi-attribute …

Kinetic And Structural Characterization Of Pseudooxynicotine Amine Oxidase From Pseudomonas Putida S16, Vishakha Choudhary

Masters Theses

Our laboratory has previously shown that nicotine oxidoreductase (NicA2), a member of the flavin-containing amine oxidase family, uses a cytochrome c protein (CycN) as its electron acceptor rather than characteristically accepted molecular oxygen. Within the Pseudomonas putida S16 genome, the nicA2 gene forms an operon with cycN and pseudooxynicotine amine oxidase (pnao), another flavin containing amine oxidase enzyme. The first two steps in the nicotine catabolism pathway are catabolized by NicA2 and Pnao. Through redox chemistry, NicA2 converts nicotine to pseudooxynicotine and Pnao converts pseudooxynicotine to 3-succinoylsemialdehyde-pyridine. In this thesis, we characterize the kinetic and structural properties of …

Fertilizer Waste Mistreatment Facilities: Investigating The Barrier That Keep Waste In And Attention Out At Central Florida's Phosphogypsum Stacks., Harsha Devaraj

Masters Theses

This project investigates the physical and narrative barriers constructed by the phosphate mining and processing industry to dissuade public engagement with its phosphogypsum sites in Central Florida, USA. The barriers around PG utilize decades of misinformation, racial geographies, and misrepresentations of scale, origin, and risk to create powerful narratives about how we should imagine and relate to these materials. These barriers hinder sustained public attention to their sites, enabling extractive industries to expand while avoiding oversight and responsibility. Attention to how these barriers around phosphogypsum are constructed allows us to recognize these strategies at work in how we see and …

How Do You Define The Watershed? Individual Representations Of The Blackstone River Watershed And Their Roles In Collaborative Watershed Governance, Casey Merkle

Masters Theses

Key leaders of civic environmental stewardship organizations shape collaborative watershed governance. Individuals perceive and construct the watershed through past experiences, feeling, emotion, values, and practices. It is not well known how these individuals perceive and construct their own representations of the watershed and environmental stewardship practices. This thesis explored individuals past experiences, feelings, emotions, values, and practices in the Blackstone River watershed to a) examine the ways in which key leaders of civic environmental stewardship organizations represent the watershed b) understand how individuals think, feel, and engage in environmental stewardship practices and, c) reveal the congruences and incongruencies of individual …

Genetic Structure Of Urban White-Tailed Deer In West Michigan, Jacob David Brand

Masters Theses

In urban areas, green spaces are used by humans and wildlife. The proximity between them can lead to both positive and negative interactions, which can make managing urban wildlife difficult. Managers are challenged due to conflicts between wildlife population sizes that can be naturally supported versus those that are socially tolerable. White-tailed deer (Odocoileus virginianus) thrive in urban environments because their habitat requirements are met within green spaces and backyard vegetation. Matrilineal groups of urban white-tailed deer live within the same areas, at times forming high densities that can lead to the spread of diseases or environmental pests, including hemlock …

Parallel Resource Defined Fitness Sharing: A Study On Parallel Optimizations For Niching Algorithms, Blayne A. Rogers

Masters Theses

The exploitation of niches by genetic algorithms (GAs) is a computationally expensive, but effective, methodology for solving complex open problems and real-world applications. Niching, differentiated on the modality of sharing, casts problems in terms of the specific resources available. These concepts arise from the broader natural algorithms that encapsulate the ideas and theories used in artificial intelligence. In remediating the computational costs, a study on exploiting niche-defined parallel structures is performed in the contest of the resourcedefined fitness sharing (RFS) algorithm.

Sharing is a natural algorithm paradigm that emulates the use of resources within an environment or population. Defining these …

Autonomous Eco-Driving With Traffic Light And Lead Vehicle Constraints: An Application Of Best Constrained Interpolation, Yara Hazem Mohamed Mahmoud

Masters Theses

Eco-Driving is a critical technology for improving automotive transportation efficiency. It is achieved by modifying the driving trajectory over a particular route to minimize required propulsion energy. Eco-Driving can be approached as an optimal control problem subject to driving constraints such as traffic lights and positions of other vehicles. Best interpolation in a strip is a problem in approximation theory and optimal control. The solution to this problem is a cubic spline. In this research we demonstrate the connection between Eco-Driving and best interpolation in the strip. By exploiting this connection, we are able to generate optimal Eco-Driving trajectories that …

Instructor Selection And Use Of Virtual Field Experiences In College Geoscience Course, Kristen Foley

Masters Theses

Virtual Field Experiences (VFEs) are a growing supplement and gateway to traditional fieldwork in the geosciences. With VFEs becoming more accepted for use in college geoscience courses, how instructors find and choose VFEs for their students is critical to creating greater accessibility and future resources. VFEs that are not easily accessed by instructors may go unused, and the effort put into making them would have been wasted. This phenomenological descriptive study utilized five focus groups of college geoscience instructors in the United States. Each 1-to-1.5-hour focus group session of 3-7 participants took place on video conferencing software, which was recorded …

Pd-Based Photocatalysts For Heck C-C Cross-Coupling Reactions, Suha Ali Alshehri

Masters Theses

Heck C-C cross-coupling reaction has been widely employed in synthetic organic chemistry because of its high efficiency and simplicity, however the conventional Heck C-C cross-coupling reaction conditions involve the use of an expensive toxicant phosphine-ligated palladium complexes, and high temperature. To address these drawbacks, a highly efficient, homogeneous photocatalyst based on BODIPY for the Heck C-C cross-coupling reactions of aryl iodide and methyl acrylate in DMF solvent under inert conditions has been developed. The 4-Py-BDP-Pd, 3-Py-BDP-Pd and, 2-Py-BOD-Pd catalysts were synthesized and purified using column chromatography. The optical properties of products and intermediates were studied by UV/vis absorption and fluorescence …

Applying Intensity-Based Methods To Disentangle Microwave Spectra Of Complex Mixtures: Analysis Of Weakly Bound Clusters Of 1,1-Difluoroethylene/Co2, Hannah Fino

Masters Theses

Microwave spectroscopy is used to study the solvent-solute interactions between molecules of CO₂ and fluoroethylenes by analyzing the formation of weakly-bound clusters in a gaseous mixture. One of the challenges to analyzing microwave spectra obtained for these weakly-bound species is that spectra for individual clusters are mixed together in an original complex spectrum. This prompts development of automated techniques that could separate complex data into subsets of related data to be more easily analyzed.

The techniques developed in this work are founded on intensity-based analyses, following the work of Dr. Robert Field on Extended Cross Correlation (XCC). The XCC …

Particle Swarm Optimization For Critical Experiment Design, Cole Michael Kostelac

Masters Theses

“Critical experiments are used by nuclear data evaluators and criticality safety engineers to validate nuclear data and computational methods. Many of these experiments are designed to maximize the sensitivity to a certain nuclide-reaction pair in an energy range of interest. Traditionally, a parameter sweep is conducted over a set of experimental variables to find a configuration that is critical and maximally sensitive. As additional variables are added, the total number of configurations increases exponentially and quickly becomes prohibitively computationally expensive to calculate, especially using Monte Carlo methods.

This work presents the development of a particle swarm optimization algorithm to design …

Adsorption Of Arsenic Onto River Sediments, Leticia Augusta Dos Santos Ferreira

Masters Theses

“Previous studies have noted the relationship between shallow groundwater rich in sodium (Na) and bicarbonate (HCO₃) and elevated levels of dissolved arsenic. However, most experimental work on arsenic adsorption in the presence of HCO₃ and differing Na/Ca ratios has proven difficult to extrapolate to natural systems because of differences in tested mineral compositions and component concentrations. In this study, I performed a series of adsorption experiments using river sediments to evaluate the influence of HCO₃ and monovalent/divalent cations on the extent of arsenic adsorption onto natural sediment in groundwater.

Batch adsorption (kinetics, equilibrium, and metal loading) …

Several Problems In Nonlinear Schrödinger Equations, Tim Van Hoose

Masters Theses

“We study several different problems related to nonlinear Schrödinger equations….

We prove several new results for the first equation: a modified scattering result for both an averaged version of the equation and the full equation, as well as a set of Strichartz estimates and a blowup result for the 3d cubic problem.

We also present an exposition of the classical work of Bourgain on invariant measures for the second equation in the mass-subcritical regime”--Abstract, page iv.

Man-In-The-Middle Attacks On Mqtt Based Iot Networks, Henry C. Wong

Masters Theses

“The use of Internet-of-Things (IoT) devices has increased a considerable amount in recent years due to decreasing cost and increasing availability of transistors, semiconductor, and other components. Examples can be found in daily life through smart cities, consumer security cameras, agriculture sensors, and more. However, Cyber Security in these IoT devices are often an afterthought making these devices susceptible to easy attacks. This can be due to multiple factors. An IoT device is often in a smaller form factor and must be affordable to buy in large quantities; as a result, IoT devices have less resources than a typical computer. …

Pressure Relief Wells: Analysis Of Subsurface Heterogeneity To Evaluate Relief Well Locations For Mississippi River Levees, Emma Marie Young

Masters Theses

“When designing pressure relief well systems, it is imperative to understand what major geomorphology and heterogenies features are present, such as buried oxbow lakes, especially when the feature is parallel to the source, such as the Mississippi River. When present, there is a notable greater increase in head pressures, especially on the landward tow of the levee. This can cause erosional features that originally thought of to have been protected from by installing pressure relief wells. When comparing the effective hydraulic conductivities of horizontal clay layers and vertical clay layers spanning the length of the model, little to no noticeable …