Digital Commons Network^™

Stability Analysis Of Thermohaline Convection With A Time-Varying Shear Flow Using The Lyapunov Method, Kalin Kochnev

Honors Scholar Theses

This work applies the Lyapunov method to identify instabilities and compute the growth rate of a linear time-varying system. The linear system studied describes cold fresh water on top of hot salty water with a periodically time-varying background shear flow. A time-dependent weighting matrix is employed to construct a Lyapunov function candidate. The resulting linear matrix inequalities are discretized in time using the forward Euler method. As the number of temporal discretization points increases, the growth rate predicted by the Lyapunov method or Floquet theory, used for comparison, will converge to the same value obtained from numerical simulations. Furthermore, the …

Enviromental Dna (Edna) Tools For Invasive Mosquitofish (Gambusia Affinis) Surveillance At The Shoshone Pupfish (Cyprinidon Nevadensis Shoshone) Refugium, Yusuf Olamilekan Umar

UNLV Theses, Dissertations, Professional Papers, and Capstones

Spring-fed aquatic ecosystems of the North American Southwest and U.S. Great Basin hosts a plethora of endemic fish species due to the effects of hydrologic fragmentation that resulted from Pleistocene aridification. Threats to endemic fishes worldwide include human intentional or unintentional release of exotic species into their habitats. Early detection of invasive species, while corrective actions are still possible, is critical for management, yet traditional survey methods are often disruptive to sensitive ecosystems, costly, and limited in sensitivity. The recent development of environmental DNA (eDNA) approaches offers powerful alternatives for invasive species monitoring in aquatic systems. In this study, a …

Assessment Of Fish Community Dynamics, Movement, And Morphology In Relation To Stream Barriers In The Upper Illinois Bayou Watershed, Risa Mccollough

ATU Theses and Dissertations 2021 - Present

Intermittent streams are increasingly recognized as vital components of river networks by supporting dynamic fish communities shaped by variable hydrology and habitat connectivity. They are becoming increasingly vulnerable to fragmentation by anthropogenic activities, namely road crossings, dams, and climate shifts that intensify seasonal drying. In response, I conducted two studies in the Illinois Bayou watershed in Arkansas to assess the effects of fragmentation on fish community dynamics and morphology in intermittent streams.

In the first study, I examined temporal fish community dynamics across two barriers: a natural waterfall in Dare Creek and a low-water crossing in Dry Creek. Simultaneously, I …

Health Implications Of Heavy Metal Contamination In Commercially Available Deodorant And Antiperspirant Products Sold In Benghazi, Libya, Maysson Yaghi, Khaled Elsherif

Al-Bahir

The extensive usage of deodorants and antiperspirants raises concerns about the potential health risks posed by heavy metal content. This study quantified the levels of five heavy metals: Aluminum, Zirconium, Lead, Cadmium, and Chromium in 22 commercial products widely used in Benghazi, Libya, and assessed the associated health risks. Samples, categorized into gel, stick, and roll-on formulations, were analyzed using iCAP TQ ICP-MS. Al and Zr showed the widest concentration ranges, reflecting their intentional use as active ingredients. Al levels ranged from trace amounts (0.032 mg/kg) up to a maximum of 99.10 mg/kg, while Zr was found exclusively in gel …

Toward A Unified Network Flow Framework: From Conservation Principles To Fluid Dynamics Models, Zonghan Zhang

Theses and Dissertations

Network flows govern a wide range of critical systems, from tangible infrastructures like transportation and power grids to replicable processes such as information spread and epidemics. While tangible flows obey conservation laws and physical constraints, replicable flows, like rumors or viruses, can grow, decay, or vanish unpredictably. Despite their increasing interaction in real-world settings, these flow types are typically modeled in isolation, using disconnected mathematical frameworks. This dissertation presents a unified modeling approach that bridges the gap between conserved and replicable flows by embedding principles from fluid dynamics into graph-based propagation models. I introduce physically informed extensions to classical models, …

Assessing Water Quality And Algae In Wetland Reserve Easements In The Alluvial Valleys Of Mississippi And Louisiana, Avery June Wissmueller

Theses and Dissertations

Wetlands in agricultural landscapes play a critical role in improving water quality by retaining and transforming nutrients and pollutants. In the Mississippi Alluvial Valley (MAV), widespread conversion of bottomland hardwood forests to row-crop agriculture has diminished this natural function. The Wetland Reserve Easement (WRE) program restores wetlands on marginal farmland to recover ecosystem services. In this study, I evaluated water quality and algal productivity in WREs compared to natural reference wetlands and crop sites. Restored wetlands showed improved water quality compared to crop sites and were often comparable to or intermediate between reference wetlands. Seasonal variation and hydrologic differences shaped …

Education In The Planetarium: A Practical Approach, Matthew Fyfe

Honors Projects

This project proposes live planetarium programming built within the 5E instructional model. It creates a practical application of this with lesson modules surrounding topics in observational astronomy. Specifically, there are investigations into instrumentation through CCD cameras and data collection and processing through spectroscopy and photometry with light curve folding with activities highlighting each. Each module is broken down into segments corresponding to the learning cycles of the 5E model, and as they are self contained in this way can be used piecemeal in different combinations.

White Nose Syndrome In Bats And Infant Mortality In Georgia, Rhys Medcalfe, Sean Medcalfe, Simon Medcalfe

Journal of the Georgia Public Health Association

Background: White nose syndrome (WNS) is a disease in bats caused by the fungus Pseudogymnoascus destructans that can result in bat mortality rates of over 90%. WNS was discovered in Georgia in 2012 in 3 counties but has continued to spread to 14 counties as of 2023, with P. destructans detected in a further seven. Biodiversity loss has been linked to human health outcomes including infant mortality. Understanding the link between WNS, biodiversity loss, and infant mortality in Georgia is important because Georgia ranks 42^nd out of the 50 states for infant mortality rate.

Methods: Using panel data from …

Engineered Multifunctional Drug-Loaded Dendrimer Nanoparticles For Glaucoma: Triple Mechanism Via Antioxidant Activity, Iron Chelation, And Enhanced Ocular Transport, Burhan Ates, Ashish Trital, Vimalin Jeyalatha Mani, Lei Xu, Jonathan Kenlee, Nuran Ercal, Hu Yang

Chemistry Faculty Research & Creative Works

In this study, we developed multifunctional nanoparticles based on polyamidoamine (PAMAM) dendrimers functionalized with caffeic acid (CA) and poly (ethylene glycol) maleimide (PEGM) for the topical delivery of hydrophobic antiglaucoma drugs brimonidine (BM) and betaxolol (BX). The PAMAM-CA and PAMAM-CA-PEGM conjugates exhibited antioxidant and iron-chelating activities in a dose-dependent manner. BM- and BX-loaded dendrimer nanoparticles produced using a multi-inlet vortex mixer showed uniform spherical morphology (∼80 nm by TEM) and hydrated sizes of ∼135-144 nm by DLS. Both nano formulations demonstrated high cytocompatibility with human corneal epithelial cells and were nonirritant in the HET-CAM assay, with PEGM further improving cytocompatibility. …

Water Circulation Beneath A Hovering Suas For Water Quality Monitoring Applications, Erin E. Hackett, Boone Fleenor, Jensine C. Coggin, Duvall Dickerson-Evans, Nikolaos Vitzilaios, Whitney E. Schuler, Paige K. Williams, Michael L. Myrick

Marine Science

Water quality has traditionally been measured via in situ sensors and satellites. The latter has limited applicability for smaller inland water bodies, while the former requires significant logistics, labor, and expense for routine sampling, and reactive/spurious sampling is often not feasible as a result (e.g., sampling pre-/post-storm). Consequently, small uncrewed aircraft system-based (sUAS-based) sampling has emerged as a potential solution to bridge these sampling gaps and challenges. But sampling from an sUAS is complicated by the need to pump water from depth, rather than suspending a sensor from the sUAS, due to concern over sampling sUAS-impacted waters. Here, we measure …

Exploring The Potential Of Martian Agriculture: Assessing Viability And Nutritional Composition Of Plants Cultivated In Martian Regolith, Abigail Ross

Honors Theses

In addition to sunlight and water, plants can utilize a small number of nutrients from the soil to biosynthesize all the materials that are needed for growth and development. However, plants require an environment where they are able to obtain those nutrients, such as iron, magnesium, potassium, sulfur, and nitrogen. Environmental factors determine the types and accessibility of nutrients available to plants. Plants then take up these nutrients from the soil to aid in biological mechanisms and the synthesis of important molecules needed for growth and development. Ascorbic acid, commonly known as Vitamin C, is a vital molecule that is …

Unsaturated Fatty Acid Oil-Based Microdroplets: A Promising Novel Class Of Microdroplets, Ramiz S. Alejilat

Seton Hall University Dissertations and Theses (ETDs)

Droplet-based microfluidics has rapidly advanced numerous fields, including chemistry, biology, materials science, medicine, food science, and cosmetics. In these systems, fluorocarbon oil combined with fluorinated surfactants is the preferred medium for fluid encapsulation, offering exceptional stability and biocompatibility essential for sensitive biological and chemical processes. However, growing concerns about the environmental and biological risks associated with fluorinated chemicals have prompted a search for alternatives.

This study is the first to explore the use of unsaturated fatty acids derived from emu oil for microdroplet formation. We characterized droplet formation based on flow rates and the presence non-fluorinated surfactant at a certain …

An Analysis Of Face Synthesis Methods And Their Influence On Human Perception, Maha Habib Almaimani

All Dissertations

Synthetic faces (e.g., computer-generated characters) have been increasingly utilized across various fields, including entertainment, healthcare, and education. Perceptual studies are often conducted to understand how synthetic faces are perceived by humans, aiming to enhance both quality and user experience in these domains. Over the years, numerous methods have been developed to create synthetic faces, ranging from traditional techniques such as image composites, Active Appearance Models, and 3D Morphable Models to more recent machine-learning-based frameworks like Generative Adversarial Networks (GANs) and Variational Autoencoders (VAEs).

Despite the growing adoption of synthetic face generation and the variety of algorithms available for their creation, …

Declined Charge: An Attempt At The Horror Game Genre, Fernando Sepulveda Guizar

Computer Science and Software Engineering

Books and movies are a great medium for people to experience new worlds and experiences through a usually passive method. This can be great for stories with a set story and have all the pieces fall into place as the author intended. Video games on the other hand can give players a more active role in the worlds and stories that they experience. Players have direct control over the player character, and their actions have consequences that may or may not persist throughout the entire game, which is not usually the case with movies or books. This is why horror …

The Price Of Priorities: How Human Choices Fuel Climate And Ecological Decline, Keisha Hickman

Biological Sciences Undergraduate Honors Theses

This thesis examines the ways in which human priorities and behaviors contribute to the escalating climate crisis and ecological systems. We will first analyze the role of social media in shaping public discourse on climate change and critically evaluate the priorities of institutions that have the means to assist in wildlife conservation. Both speak to the current behaviors of humankind prioritizing their own entertainment over meaningful efforts to mitigate climate change and preserve biodiversity. We will then shift to exploring the profound impact of human population growth and its associated activities on other species and ecosystems. Finally, the thesis will …

Controlling Selectivity In Electrocatalytic Co2 Reduction With An External Magnetic Field., Nawaraj Karki

Electronic Theses and Dissertations

My dissertation describes how to alter the speciation and concentration of molecules at the electrode-electrolyte interface, and how those alterations affect reactivity and selectivity. This dissertation presents two distinct approaches to control the mass transport of neutral molecules such as carbon dioxide (CO₂) at the electrode-electrolyte interface by using an external magnetic field. The first finding demonstrates that magnetic fields indirectly affect the mass transport of target analytes such as CO₂ molecules by selectively interacting with charged species, such as hydroxide ions (OH^-). Such interaction induces magnetohydrodynamic (MHD) effects, which generate localized hydrodynamic flow and …

Direct And Satellite-Based Quantification Of Greenhouse Gas Fluxes In Small Ponds., Mark Christopher Tierney

Electronic Theses and Dissertations

As evidenced by their historic losses due to anthropogenic activities, wetlands are undervalued ecosystems that provide numerous ecosystem services, from recreational opportunities to carbon (C) storage. However, these wetlands are also the largest natural source of atmospheric methane (CH₄). Additionally, small water bodies (< 10,000 m²) are disproportionately large emitters relative to larger lakes and reservoirs. As construction and restoration efforts proceed, it is crucial to identify wetlands that need restoration and to understand the factors driving both greenhouse gas (GHG) fluxes and the C balance of these systems. This dissertation investigates the drivers of greenhouse gas fluxes …

Bridging Conservation And Disaster Recovery: A Dual Study On Wetland Program Plans Evaluation And Midwest Post Disaster Recovery Assessment, Rao Nargis Jahan

Community and Regional Planning Program: Theses

Wetlands provide essential ecological, social, and economic benefits for our society. In the United States, states and tribes play crucial roles in wetland protection, restoration, and management. However, no research has systematically measured state-level wetland planning efforts towards national conservation goals. This study is the first to comprehensively evaluate how state-level Wetland Program Plans (WPPs) align with national missions, particularly the "no-net-loss" of wetlands goal. Our research assesses the EPA-approved state-level WPPs from 42 out of 50 states in the United States during the period from 2015 to 2024. Using a protocol of 30 indicators across five categories, this study …

Impacts Of Nutrient Addition And Disturbance On Coastal Dune Arthropod Communities And Trophic Interactions, Kayla Beitzel

Graduate Theses and Dissertations (2019 - present)

Coastal dune ecosystems face ongoing threats from human-mediated disturbance and altered resource availability. Because these dunes provide critical habitat for many organisms, including shorebirds, beach mice, and arthropods, changes in disturbance regimes or resource availability can impact plant communities and higher trophic levels by altering plant richness and productivity, which in turn influence arthropod abundance and diversity. To examine how disturbance and nutrient addition affect arthropod communities, we established twenty 5×5 m plots on Dauphin Island, crossing mechanical disturbance with a 10 g m⁻² addition of nitrogen, phosphorus, and potassium, replicated across five experimental blocks. Arthropods were sampled using three …

Greenhouse Gas Accounting For Western Australian Agriculture 2023, Johnny Machon, Christophe D'Abbadie

Climate Science Published Reports

This report presents new modelling of the greenhouse gas emissions attributable to Western Australia’s agricultural industries and provides an overview of sequestration at the state level. The report updates the estimates from previous technical reports by the Department of Primary Industries and Regional Development (DPIRD). It presents not only emissions from agricultural activities in Western Australia (WA) but also from the production of agricultural inputs and energy use. This broader picture of emissions aligns with frameworks for emissions reporting at the business and product level.

Total on-farm and pre-farm emissions are estimated to have been about 12.6–13.3 million tonnes of …

Water Circulation Beneath A Hovering Suas For Water Quality Monitoring Applications, Erin E. Hackett, Boone Fleenor, Jensine C. Coggin, Duvall Dickerson-Evans, Nikolaos Vitzilaios, Whitney E. Schuler, Paige K. Williams, Michael L. Myrick

Faculty Publications

Water quality has traditionally been measured via in situ sensors and satellites. The latter has limited applicability for smaller inland water bodies, while the former requires significant logistics, labor, and expense for routine sampling, and reactive/spurious sampling is often not feasible as a result (e.g., sampling pre-/post-storm). Consequently, small uncrewed aircraft system-based (sUAS-based) sampling has emerged as a potential solution to bridge these sampling gaps and challenges. But sampling from an sUAS is complicated by the need to pump water from depth, rather than suspending a sensor from the sUAS, due to concern over sampling sUAS-impacted waters. Here, we measure …

A Temporal Extension Of Tasselnet With Uncertainty Quantification Using Bayesian Latent Autoregressive Model, Gayara Demini Fernando Muthunama Gonnage

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Manual counting of maize tassels remains a time-consuming and labor-intensive process. Automating tassel counting using maize field images has received significant interest, with researchers exploring methods to streamline this task. Accurate tassel detection can substantially reduce both time and labor costs, offering a practical solution for large-scale agricultural management. Current studies in this area predominantly focus on training object detection algorithms to enhance prediction accuracy and efficiency. Images for this task are often captured in sequences, meaning they capture the exact location of the maize fields over time. However, existing tassel detection and counting methods typically ignore this sequential nature, …

Cattlefever: An Automated Cattle Fever Estimation System, Trong Thang Pham, Ethan Coffman, Beth Kegley, Jeremy G. Powell, Jiangchao Zhao, Ngan Le

Electrical Engineering and Computer Science Faculty Publications and Presentations

Farmers face the critical challenge of monitoring cattle well-being for both ethical and economic success, relying on signals like body temperature and facial expressions to assess their animals' health. However, these indicators have traditionally relied on human observation with manual measurement, which is time-consuming and subjective. Despite this clear need, no automated system currently exists for monitoring cattle body temperature, and available datasets remain limited in scope. To address these challenges, we make two key contributions: (i) We introduce CattleFace-RGBT, a novel RGB-Thermal (RGB-T) Cattle Facial Landmark dataset consisting of 2,300 paired RGB and thermal images (4,600 images in total), …

Process Optimization And Cost Reduction For Cellulose Nanocrystals For Metal Removal From Rendered Fat, Sheikh Abdur Rehman

All Theses

Cellulose nanocrystals (CNCs) coupled with polymers featuring a high density of amine functional groups, such as polyethylenimine (PEI), exhibit significant metal-capturing capabilities. Rendered animal fat has applications in a vast number of industries, with the potential to be used as a feedstock for the biodiesel/renewable diesel industries. Nevertheless, rendered fat samples occasionally contain concentrations of metals/inorganic contaminants above the suitable threshold for use in this application. Thus, a cost-effective solution to remove light metal/inorganic contaminants from rendered fat samples is desirable.

To address this problem, a cellulose nanocrystal coupled with polyethylenimine, i.e., CNC-f-PEI, was developed by previous …

From Inside The Recording Studio, Mckayla J. Adkison

Capstone Projects and Master's Theses

This project documents the historical, technical, and creative significance of recording studios through both industry examples and the design and construction of a personal backyard studio. By examining iconic studios such as Abbey Road and Capitol Records, the paper highlights how technological innovation, acoustic engineering, and architectural design have shaped the evolution of recorded music. These concepts are then applied to the planning and construction of a custom-built recording studio, emphasizing room dimensions, sound isolation techniques, acoustic treatment, lighting, and sustainable design choices. In addition, the project addresses the importance of aesthetics and emotional comfort in creating a space that …

Increasing Soil Health In Zero-Grade, Flood-Irrigated Rice In Eastern Arkansas, Hannah Elizabeth Vickmark

Graduate Theses and Dissertations

In an effort to build and maintain soil health and sequester soil C, many producers and researchers are turning towards regenerative management practices in agricultural systems, such as reduced tillage or no-tillage (NT), the implementation of winter cover crops (CC), and the use of organic or green manures, such as biochar. However, little research is being conducted on the long-term soil health and agronomic benefits of these practices in a flood-irrigated rice (Oryza sativa L.) production system. Three replications of seven treatment combinations were applied to 6.1 x 30.5 m rice plots. Baseline soil health properties were quantified at six …

Emotion Analysis And Neural Language Models For Classification, Andrew Mackey

Graduate Theses and Dissertations

Emotion analysis is a branch of artificial intelligence and natural language processing focused on recognizing emotions hidden throughout various forms of digital data, including text, images, and multi-modal representations. In this dissertation, we present four published and planned works that investigate different methodologies for natural language analysis tasks using deep learning techniques. The first published work we present considers the task of identifying fake news using various text and emotion representations. We demonstrate that emotion representations combined with word embedding techniques can improve the accuracy of fake news classification. Our second published work further investigates the fake news classification task …

Solar Powered Conservation: The Effects Of Solar Photovoltaic Facilities On Avian Community Composition, Michael Christopher Ferrara

Graduate Theses and Dissertations

The expansion of solar photovoltaic energy infrastructure is transforming landscapes worldwide. Increasingly, facilities are planted with native vegetation, yet how vegetation characteristics and landscape variables shape wildlife communities in solar facilities remains poorly understood. Because avian populations have been in decline and are sensitive to habitat changes, understanding how solar facilities influence avian communities is important. In Chapter 1, we used autonomous recording units, local vegetation measurements, and land use and land cover data to quantify how avian community occupancy is influenced by solar cover in solar facilities and comparable reference sites. We used a Bayesian multi-species occupancy model to …

Multiple Aspects Of Environmental Temperature Have Complex Interactions With Avian Parental Behavior To Influence Offspring Outcomes, William H. Kirkpatrick

Graduate Theses and Dissertations

Anthropogenic climate change is projected to shift not only average temperatures across the globe, but also the amount of thermal variation experienced in the natural environment. Exposure to shifts in averages and a wider range of thermal experiences will cause shifts in wildlife behavior. In avian species, behaviors exhibited during reproduction have implications for the well-being of their offspring. Here, I explore specific incubation behaviors in four species: Scaled Quail (Callipepla squamata), Northern Bobwhite Quail (Colinus virginianus), Tree Swallows (Tachycineta bicolor), and Eastern Bluebirds (Sialia sialis). I examined constancy, or the percentage of time on the nest, and off-bout duration, …

Ring-Opening And Monofunctionalization Study On Spiro Cyclic Aminals And N, O-Acetals System Via Nitrogen-Centered Radical Intermediates, Chujun Zhou

Graduate Theses and Dissertations

The nitrogen-centered radical has been drawing increasing attention among researchers. Radical polarity is one of the key factors in studying nitrogen-centered radicals’ reactivity, and the functional groups attached to the nitrogen atom are of vital importance. Among different types of nitrogen-centered radicals, aminium radical and metal aminium radical are electrophilic due to the positive charge on the intermediate. The sulfonamide radical, amidyl radical, and cyanide amine radical are also electrophilic since the nitrogen is adjacent to electron electron-withdrawing group. The neutral amino radical, iminyl radical, masked nitrogen radical are nucleophilic because of the electron-donating groups. After classifying the nitrogen-centered radical, …