Digital Commons Network^™

Synthesis Of Gold Nanoparticles Via Pulsed Liquid Ablation For Use In The Photodynamic Therapy Of Bacteria, Justice Ben Yosef

Masters Theses & Specialist Projects

With the ever-increasing threat of antibiotic resistant bacteria, alternative treatment methods have been developed including photodynamic therapy (PDT). Within the PDT process, photosensitizers are used to generate reactive oxygen species (ROS) and facilitate the cell termination process. This work lays the conceptual foundation for the functionalization of the photosensitizer methylene blue (MB) with gold nanoparticles (AuNPs) and INF-55 as a potential inhibitor of the AcrAB-TolC efflux pump to enhance the effectivity of the PDT process.

AuNPs were synthesized using pulsed laser ablation in an aqueous citrate solution. Both nanosecond and picosecond pulse durations, as well as both 532 nm and …

Grey Relational Analysis And Canonical Correlation Analysis Of Air Pollution In Three Kentucky Counties, Sarah Hartman

Masters Theses & Specialist Projects

Air pollution is a crucial factor that affects both the environment and public health. Various methods are available for assessing air quality and pollution levels, such as regression models, principal component analysis, and factor analysis tools. However, some of these methods present issues in multicollinearity and the nature of collected data. It is important to recognize that air pollution data is often uncertain, incomplete, and contains limited valid data points. Weather conditions and economic activities are also factors that can affect air pollution. With growing communities in Kentucky (KY), it is essential to address these factors as the state has …

Development Of An Enhanced Sampling Workflow To Accelerate Molecular Docking With Sparse Biophysical Information, Zachary Stichter

Masters Theses & Specialist Projects

Rapid docking of flexible biological macromolecules remains a significant open challenge in protein structure determination. While rigid docking is relatively simple with toolkits such as TagDock, a key obstacle to rapid flexible docking is the complexity and roughness of the free energy surface associated with protein conformational motion (often termed the many-minima problem), meaning conventional molecular dynamics methods do not effectively sample protein conformations near the interaction complex in accessible timescales. Methods such as metadynamics and replica exchange molecular dynamics exist to ameliorate this obstacle, yet these methods use nonphysical biases or random swaps to enhance sampling. In contrast, high …

Towards The Quantification Of Estrone And 17Β-Estradiol Conjugates In Dairy Cattle Urine Sorptive Stir Bar Extraction And Gas Chromatography-Mass Spectometry, S.M. Istiak Ahmed

Masters Theses & Specialist Projects

The global concern regarding the presence of compounds with estrogenic properties in the environment has grown significantly. Endocrine-disrupting compounds (EDCs) are environmental pollutants that disrupt the endocrine systems of both wildlife and humans. Estrogens, with their potent estrogenic effects, are particularly noteworthy among the various substances with endocrine-disrupting properties. They are of concern due to their prevalence in the environment, especially due to dairy waste contamination. These lipophilic compounds can accumulate in livestock fat tissues, potentially entering the human food chain. Sulfated forms of estrone and β- estriol, which exhibit a higher degree of saturation than their non-conjugated counterparts, have …

Liquid Chromatography Mass Spectrometry Method Development For The Determination Of Β–Defensins In Bovine Milk, Elisha Ogbebor

Masters Theses & Specialist Projects

Bovine mastitis is caused by a wide range of pathogens which results in a substantial economic loss for the dairy cattle livestock industry. β-defensins are a part of the innate immune system and act as the first line of defense against mastitis in bovine. β-defensins (~6- 10kDa) are antimicrobial peptides that contain about 28 to 67 amino acids, the presence of six cysteine residues results in their three disulfide bonds and a β-sheet structure. A few β- defensins have been identified in cows based on the site of occurrence and time of expression in tissue, but not in milk. A …

The Socialization Of Social Media: Examining The Impact Of Social Media Use On Interpersonal Skills During Face-To-Face Interaction, Tenille Thomas

Masters Theses & Specialist Projects

Research has well established that the use of social networking sites (SNS) has increased accessibility and connectivity to people with limitless boundaries. SNS have progressively become the preferred source of communication. However, often overlooked is the impact SNS use has on face-to-face interactions, specifically on interpersonal skills. The purpose of this study was to examine the relationship between SNS use and face-to-face interaction. Specifically, this study examines the participant’s ability to recognize and interpret nonverbal cues with increased SNS use. This was a correlational study utilizing a quantitative design of self-reported questionnaires. A total of 178 participants, ranging in age …

Pollutant Forecasting Using Neural Network-Based Temporal Models, Richard Pike

Masters Theses & Specialist Projects

The Jing-Jin-Ji region of China is a highly industrialized and populated area of the country. Its periodic high pollution and smog includes particles smaller than 2.5 μm, known as PM2.5, linked to many respiratory and cardiovascular illnesses. PM2.5 concentration around Jing-Jin-Ji has exceeded China’s urban air quality safety threshold for over 20% of all days in 2017 through 2020.

The quantity of ground weather stations that measure the concentrations of these pollutants, and their valuable data, is unfortunately small. By employing many machine learning strategies, many researchers have focused on interpolating finer spatial grids of PM2.5, or hindcasting PM2.5. However, …

Bioactivity And Structural Properties Of Hydroxyapatite On Ti6a|4v And Si(100) Surfaces By Pulsed Laser Deposition, Salizhan Kylchbekov

Masters Theses & Specialist Projects

Although biomedical implant technology is very advanced, there are still caveats in terms of biocompatibility properties because metals are inert to biological processes such as osseointegration, cell growth, and cell adhesion. This results in statistically significant complications and opens rooms for improvements. Among many techniques to improve this problem, coating the metal surface with biologically functional materials has resulted in the best performances. Hydroxyapatite (HAP), Ca_₁₀(PO_₄)_₆(OH)_₂, is the most stable form of calcium phosphates in human body environment and is functional in key processes such as ion exchange, osteoblast (bone cells) formation, …

Adaptable Object And Animation System For Game Development, Isaiah Turner

Masters Theses & Specialist Projects

In contemporary times, video games have swiftly evolved into a prominent medium, excelling in both entertainment and narrative delivery, positioning themselves as significant rivals to traditional forms such as film and theater. The burgeoning popularity of gaming has led to a surge in aspiring game developers seeking to craft their own creations, driven by both commercial aspirations and personal passion. However, a common challenge faced by these individuals involves the considerable time investment required to acquire essential skills and establish a foundational framework for their projects. Accessible game development engines that offer a diverse range of fundamental features play a …

Landscape/Atmosphere Interactions And Carbon-Dioxide Dynamics In The Great Onyx Groundwater Basin, Mammoth Cave National Park, Kentucky, Meghan Raines

Masters Theses & Specialist Projects

An increase in atmospheric CO2 since the Industrial Revolution has altered rates of global climate change and has motivated a need to better quantify the flux of carbon between Earth’s reservoirs. Attempts to quantify the exchange of atmospheric carbon between sources and sinks have led to an increasing interest in the terrestrial landscape, including the continental carbon sink associated with carbonate-mineral dissolution. This research sought to better inform an understanding of karst landscapes and their relationship with global climate change through carbon cycling. The study utilized high-resolution data collection of pH, temperature, and specific conductance of waters in the Cascade …

Index Bucketing: A Novel Approach To Manipulating Data Structures, Jeffrey Myers

Masters Theses & Specialist Projects

Handling nested data collections in large-scale distributed systems poses considerable challenges in query processing, often resulting in substantial costs and error susceptibility. While substantial efforts have been directed toward overcoming computation hurdles in querying vast data collections within relational databases, scant attention has been devoted to the manipulation and flattening procedures necessary for unnesting these data collections. Flattening operations, integral to unnesting, frequently yield copious duplicate data and entail a loss of information, devoid of mechanisms for reconstructing the original structure. These challenges exacerbate in scenarios involving skewed, nested data with irregular inner data collections. Processing such data demands an …

Topology Optimization For Artificial Neural Networks, Justin Mills

Masters Theses & Specialist Projects

This thesis examines the feasibility of implementing two simple optimization methods, namely the Weights Power method (Hagiwara, 1994) and the Tabu Search method (Gupta & Raza, 2020), within an existing framework. The study centers around the generation of artificial neural networks using these methods, assessing their performance in terms of both accuracy and the capacity to reduce components within the Artificial Neural Network’s (ANN) topology.

The evaluation is conducted on three classification datasets: Air Quality (Shahane, 2021), Diabetes (Soni, 2021), and MNIST (Deng, 2012). The main performance metric used is accuracy, which measures the network's predictive capability for the classification …

Towards Deposition Of Iron & Nickel Onto Cadmium Selenide/Cadmium Sulfide Nanorods, Rajib Nath

Masters Theses & Specialist Projects

Metal-semiconductor hybrids have been studied extensively as photocatalysts for the watersplitting reaction to generate hydrogen gas and oxygen gas to use as a renewable energy source. The semiconductor component converts light into electrochemical energy, while the metal component provides a site for chemical reactions with water. Here, the choice of metal can have a significant impact on the efficiency of the catalyst. Platinum efficiently catalyzes the watersplitting reaction and is therefore commonly used in metal-semiconductor hybrids to generate hydrogen. Platinum is very expensive, which motivates research into improving less costly metals like iron or nickel that do not have nearly …

Hydrological Dynamics Of Surface-Groundwater Interactions Between Major Springs Of Mammoth Cave And The Green River, Kentucky, Usa, Matthew Cecil

Masters Theses & Specialist Projects

Mammoth Cave is an iconic example of the cave and karst systems that underlie over 50% of the United States and provide around 13% of the world’s population with water resources. These environmental features are vulnerable to drought, pollution, and human impacts. The complex hydrological regime of the Mammoth Cave system has been studied in the past, but there are improvements and updates that can be made to the past research. The dynamics of the surface-groundwater system, particularly reversals of the Green River and how it backfloods into the cave, are some examples. Echo River and River Styx Springs provide …

A Predictive Flood Model For Urban Karst Groundwater Systems, Trayson Lawler

Masters Theses & Specialist Projects

Urban karst environments are often plagued by groundwater flooding, which occurs when water rises from the subsurface to the surface through the underlying caves and other karst features. The heterogeneity and interconnectedness of karst systems often makes them very unpredictable, especially during intense storm events; urbanization exacerbates the problem with the addition of many impervious surfaces. Residents in such areas are frequently disturbed and financially burdened by the effects of karst groundwater flooding. The Federal Emergency Management Agency (FEMA) offers limited protection to citizens living near flood-prone areas as they primarily focus on the areas near surface bodies of water. …

A Comparison Of Computational Perfusion Imaging Techniques, Shaharina Shoha

Masters Theses & Specialist Projects

Dynamic contrast agent magnetic resonance perfusion imaging plays a vital role in various medical applications, including tumor grading, distinguishing between tumor types, guiding procedures, and evaluating treatment efficacy. Extracting essential biological parameters, such as cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT), from acquired imaging data is crucial for making critical treatment decisions. However, the accuracy of these parameters can be compromised by the inherent noise and artifacts present in the source images.

This thesis focuses on addressing the challenges associated with parameter estimation in dynamic contrast agent magnetic resonance perfusion imaging. Specifically, we aim …

A Monte Carlo Analysis Of Nonprobability Sampling & Post Hoc Corrections, Julia Hong

Masters Theses & Specialist Projects

Nonprobability samples are often used in place of probability samples because the former are less trouble and less expensive. Unfortunately, it is difficult to determine how well a sample represents population parameters when using nonprobability samples. Researchers attempt to mitigate the disadvantages of nonprobability sampling by performing post hoc corrections, but this adjustment may not successfully undo the effects of nonprobability sampling. To examine these effects, a Monte Carlo simulation was conducted to create a pseudo-population from which samples were drawn. Forty-one conditions were replicated 10,000 times each, with each sample consisting of 100 observations. A post-stratification adjustment was made …

Source Code Plagiarism Detection Using Jplag & Stack Overflow Data, Sudheer Yetthapu

Masters Theses & Specialist Projects

Advancements in computer technology and internet services have led to the availability of vast amounts of information like videos, articles, research papers, and code samples. Free online information will increase the possibility of plagiarism and collusion among students. People can commit plagiarism in both text and code [1], as tools used to detect plagiarism between texts and between codes are distinct. Traditionally plagiarism in code is detected using manual inspection, which is a tedious process and misses to compare code from previous submissions and external sources. To overcome this issue, systems that can automatically detect plagiarism in code were developed …

Carbon Cycling And Critical Zone Dynamics In An Urbanized Karst Groundwater System, Amy Hourigan

Masters Theses & Specialist Projects

Increasing atmospheric CO₂ concentrations are correlated to rising global temperatures. Investigating the cumulative global carbon cycling processes is important to understand and quantify the global carbon cycle. By investigating basic geochemical parameters, EpCO₂, DIC, and δ¹³C_DIC, at four sites along Lost River Cave (LRC), in Bowling Green, Kentucky, concentrations, fluxes and sources of C dissolved in groundwater were determined. Urban karst groundwater systems, compared to more natural karst landscapes, typically exhibit widespread impervious, heat-absorbing surfaces, urban heat island effects, and increased anthropogenic groundwater inputs and localized CO₂ emissions. Carbonate hydrogeochemical …

An Integrated Gis & Flood Vulnerability Index Approach To Evaluating Risk & Environmental Equity In Urban Karst Communities, Chloe Cooper

Masters Theses & Specialist Projects

This study examines how the usage of an integrated GIS (Geographic Information Systems), flood vulnerability assessment, and management approaches can aid in hazard response planning in karst groundwater systems, particularly in urban environments. In order to also better understand the impacts of flood events on socially vulnerable groups, this research was focused on historically excluded communities. Additionally, place-based vulnerabilities were primarily assessed based upon three main factors in the vulnerability framework and how these components intersect: social, environmental conditions, and economic. By understanding which areas of the City of Bowling Green, an iconic urban karst area, are most vulnerable and …

Robust Sensor Design For The Novel Reduced Models Of The Mead-Marcus Sandwich Beam Equation, Ahmet Aydin

Masters Theses & Specialist Projects

Novel space-discretized Finite Differences-based model reductions are proposed for the partial differential equations (PDE) model of a multi-layer Mead-Marcus-type beam with (i) hinged-hinged and (ii) clamped-free boundary conditions. The PDE model describes transverse vibrations for a sandwich beam whose alternating outer elastic layers constrain viscoelastic core layers, which allow transverse shear. The major goal of this project is to design a single boundary sensor, placed at the tip of the beam, to control the overall dynamics on the beam.

For (i), it is first shown that the PDE model is exactly observable by the so-called nonharmonic Fourier series approach. However, …

Evaluation Of Silver Nanoparticles Attached To Methylene Blue As An Antimicrobial Agent And Its Cytotoxicity, Somon Hakimov

Masters Theses & Specialist Projects

Antibiotics resistance is considered as one of the greatest public health challenges of our time. In this work, we have synthesized silver nanoparticles (Ag NPs) using pulsed liquid ablation in different medium of growth and later combined with methylene blue (MB) to evaluate its potential as an effective photodynamic therapy agent. Ag NPs were synthesized by pulsed laser ablation technique in Polyvinylpyrrolidone (PVP), citrate, and Polyvinyl alcohol (PVA). The Ag NPs were characterized using transmission electron microscopy (TEM), UV-Visible (UV-Vis), and photoluminescence (PL) spectra. Next, Ag NPs were coupled with MB and used to deactivate the Gram-negative bacteria, Escherichia coli …

Canary: An Automated Approach To Security Scanning And Remediation, David Wiles

Masters Theses & Specialist Projects

Modern software has a smaller attack surface today than in the past. Memory-safe languages, container runtimes, virtual machines, and a mature web stack all contribute to the relative safety of the web and software in general compared to years ago. Despite this, we still see high-profile bugs, hacks, and outages which affect major companies and widely-used technologies. The extensive work that has gone into hardening virtualization, containerization, and commonly used applications such as Nginx still depends on the end-user to configure correctly to prevent a compromised machine.

In this paper, I introduce a tool, which I call Canary, which can …

Towards The Determination Of Estrone And 17Β-Estradiol In Dairy Cattle Waste Using Solid Phase And Stir Bar Sorptive Extractions With Liquid Chromatography-Mass Spectrometry And Gas Chromatography-Mass Spectrometry, Pallavi Ragi

Masters Theses & Specialist Projects

Steroidal hormones are naturally produced as a part of many physiological processes and are excreted in the urine and feces of animals and humans. Farm animals in concentrated animal feeding operations (CAFOs) are routinely implanted with synthetic and natural hormones to enhance growth and production, contributing significantly to environmental steroid hormone contamination. Every year around 49 tons of estrogens are generated by livestock waste in the United States alone. Due to rainfall and runoff, these steroid hormones reach the environment when animal waste is applied as manure. Studies show that estrogens and other steroidal hormones present in the surface waters …

Real-Time Monitoring Of Paraquat Photodegradation Using Colloidal Gold Surface Enhanced Raman Spectroscopy, Nathan Wilson

Masters Theses & Specialist Projects

Monitoring chemical reactions in aqueous solution is a challenge because most instrumental techniques either are not suited for the rapid timescales, are not sensitive enough to detect products at low concentrations, or do not have sufficient structure-to-spectrum relationships. Raman spectroscopy is a promising method to monitor reactions, as it is fast, dependent on chemical structure, and has little interference from water. However, Raman scattering is generally very weak. Surface-enhanced Raman spectroscopy (SERS) improves the signal strength of Raman spectroscopy by using a metal surface plasmon, or oscillation of the surface’s electrons, to allow for highly selective and sensitive detection and …

Generation & Kinetic Studies Of Porphyrin Chromium-Oxo Intermediates, Iyanu Olumide Ojo

Masters Theses & Specialist Projects

Recent emerging applications of chromium porphyrin complexes are generating increasing interest in oxidation chemistry and catalysis. Its recent application as metal-organic frames in spintronic devices supports the rich electronic system of chromium metal. Through the past decades, first-row transition metalloporphyrins have served as biomimetic oxidation catalysts and models of cytochrome P450 enzymes. However, the oxygen atom transfer mechanism of chromium porphyrin complexes, most especially in sulfide oxidation reactions, has been scarcely investigated.

In this study, high-valent chromium-oxo porphyrin species, namely Cr^IV-oxo and Cr^V-oxo species, with electron-donating tetramesitylporphyrin(TMP) ligand were successfully generated and characterized with UV-vis, ESI-MS, …

Factors Influencing Tree Growth In A Bottomland Hardwood Along The Green River In Kentucky, Caleb Miller

Masters Theses & Specialist Projects

In bottomland hardwood forests, large fluctuations in moisture availability can lead to stress from both flooded and drought conditions. These forests can have a complex species composition with different water use and drought strategies. The bottomlands in which these species co-occur can have a complex spatial distribution of alluvial sediments due to the meandering and migration of river or stream channels, which may impact the hydrology, nutrient dynamics, and productivity. At Western Kentucky University's Green River Preserve, approximately 9 ha of bottomland hardwood forest were planted in 2006. Although these hardwoods have received equal amounts of sunlight, rainfall, and wind, …

Liquid Chromatography With Tandem Mass Spectrometry Method Development For The Determination Of Β–Defensins In Bovine Milk, Symone T. Whalin

Masters Theses & Specialist Projects

Bovine mastitis, caused by a wide array of pathogens, results in a substantial economic loss for the dairy cattle livestock industry. β-defensins are a part of the bovine’s innate immune system and act as the first line of defense against mastitis. Only foundational research has been done on β-defensins’ ability to treat and prevent mastitis. There have been no analytical methods reported in the literature for analyzing β-defensins in bovine milk. This research aims to create an analytical approach to determine β-defensins in bovine milk. It is challenging to determine an analyte in a complex sample matrix, and milk is …

Towards Semiconductor Nanorods With Nickel/Iron Cocatalyst., Kehinde Ayorinde

Masters Theses & Specialist Projects

The adverse effects associated with the utilization of fossil fuels has led to the need to provide an alternative cleaner energy. Photocatalytic hydrogen evolution reaction via water splitting provides a renewable pathway to generating energy. Our photocatalyst system includes a semiconductor component (CdSe/CdS core/shell nanorods) to capture light and an attached metal (cocatalyst) for the hydrogen evolution reaction. Platinum is an effective metal catalyst for this reaction due to strong proton binding energy that easily facilitates the reduction of water to produce hydrogen gas. However, due to the high cost of platinum, there is a need to find a less …

Semantic Completeness Of Intuitionistic Predicate Logic In A Fully Constructive Meta-Theory, Ian Ray

Masters Theses & Specialist Projects

A constructive proof of the semantic completeness of intuitionistic predicate logic is explored using set-generated complete Heyting Algebra. We work in a constructive set theory that avoids impredicative axioms; for this reason the result is not only intuitionistic but fully constructive. We provide background that makes the thesis accessible to the uninitiated.