Physical Sciences and Mathematics Commons^™

A Source-To-Sink Analysis Of The Pantanal Basin (Brazil): Implications For Weathering, Erosion, And Landscape Evolution In The World's Largest Wetland, Edward L. Lo

Theses and Dissertations--Earth and Environmental Sciences

Large back-bulge retro-arc basins have limited information about the sediment composition, yet they comprise important parts of the stratigraphic rock record. The exorheic Pantanal Basin is the world's largest continental wetland that regulates many valuable ecosystem services (water storage, nutrient cycling, agriculture, ranching, tourism, and transportation). This dissertation is composed of three studies that utilize a suite of tools to examine the most fundamental basin-wide source-to-sink sediment processes and controls that affect the characteristics and distribution of modern sediments.

The first paper consists of a metadata analysis of 76 shallow tropical floodplain lakes in the literature with bathymetric data and …

Estimating Bedrock Shear Wave Velocity At Vsap, Paducah, Kentucky, Using Ambient Noise, Russel Rogers

Theses and Dissertations--Earth and Environmental Sciences

Due to the nature of the Mississippi Embayment region and its vicinity to the New Madrid Seismic Zone, earthquake ground-motion site effects are potential hazards and quantifying the associated hazard is a necessary step for public safety. Measuring the V_s contrast between bedrock and overlying soil layers is necessary for site effect evaluation. Various methodologies for investigating shear wave velocity (V_s) profiles have been implemented in the Mississippi Embayment. However, these previous studies provided a wide range of bedrock Vs. In this study, microtremor array measurements, utilizing ambient background noise, were used to provide an additional estimate …

Reasoning About The Conant Gasket, M. Douglas Mcilroy

Computer Science Technical Reports

Previously conjectured properties of the Conant gasket, a particular non-periodic tiling of the non-negative integer grid, are proved using new recurrences. A slabwise periodicity property is identified and proved. Further fractal properties are conjectured.

Convection Allowing Simulations Of Hail In Historical And Future Climate Epochs, Jillian Rose Goodin

Graduate Research Theses & Dissertations

This thesis investigates the potential impact of anthropogenic climate change on hail frequency and intensity, which poses a significant threat to life and property, accounting for annual insured losses of around $30 billion in the U.S. This approach uses convection-allowing dynamically-downscaled regional climate simulations using input data from NCAR's bias-corrected Community Earth System Model to simulate historical and projected future climate regimes under two greenhouse gas emission scenarios. A column maximum diameter hail diagnostic is simulated by the Weather Research and Forecasting regional climate model to identify instances of hail days and size to quantify changes in large hail frequency …

Vanadium Partitioning Between Magnetite, Hematite, And A Hydrothermal Fluid: Implications For Iocg And Ioa Deposits, Jeremy Raymond Nederbo

Graduate Research Theses & Dissertations

Iron oxide-copper-gold (IOCG) and iron oxide-apatite (IOA) deposits are major sources of iron contained within magnetite and/or hematite as well as copper contained within copper-iron sulfides and gold as a native metal. Their formations have been attributed to magmatic, hydrothermal, or a mixture of magmatic-hydrothermal processes. Vanadium can readily substitute into magnetite via ion exchange due to similar atomic radii and charges as iron and has thus been hypothesized to be an effective tracer of hydrothermal or magmatic inputs. To evaluate the mobility of vanadium in a magnetite-hematite-fluid system, experiments on the partitioning of vanadium between magnetite, hematite and a …

Computational Studies Of The Effects Of Substitutions On Silatranes And Ring Strain Energies, As Well As Determination Of Aromaticity And Complexation In Polypnictogen Analogues Of The Cyclooctatetraenyl Dianion, Alexander Stuart Pixler

Graduate Research Theses & Dissertations

The work in this dissertation computationally examines four areas involving variations on archetype molecules and how they affect reactivity and physical properties. Studies in Chapters 2 and 3 assess substituent effects on cyclic systems, while those in Chapters 4 and 5 explore both partial and complete substitution of ring component atoms as well as the chemical implications of the substitution.The effect of substituents on molecular reactivity is a critical concept that affects every branch of chemistry. Previous work within our group showed that 1-hydridosilatrane was an effective and selective reducing agent for a variety of compounds. Fully 3,3,7,7,10,10-substituted silatranes have …

Investigating Changes In Permeability Caused By The Transport And Retention Of Microplastics In Saturated Sand Columns, Iliansherry Santiago

Graduate Research Theses & Dissertations

Microplastics (MPs), plastic particles present and continuously moving in our environment, represent a contaminant of global concern to the scientific community and society. MPs are particles less than 5 mm and are ubiquitous in our surroundings and the environment. MPs have been detected in oceans, soils, freshwater, drinking water and groundwater. MPs are considered contaminants of emerging concern (CEC), as they contain toxic components and serve as carriers for other contaminants that may affect the ecology and human health. Limited laboratory and field experiments demonstrate that MPs are transported and retained in porous media of a groundwater aquifer. A research …

An Experimental Investigation Of Gold Incorporated Into Bornite, Intermediate Solid Solution (Iss), And Pyrrhotite: Implications For Porphyry Ore Deposits, Carli Lynn Schmidt

Graduate Research Theses & Dissertations

Magmatic-hydrothermal ore deposits contain metals sourced from a melt and transported to shallower levels by a magmatic volatile phase (MVP) where they can be deposited as native elements or structurally bound in sulfide or oxide minerals. Porphyry ore deposits are a major subclass of such and contain plentiful concentrations of societally significant metals including copper and gold. These deposits include the Grasberg porphyry Cu-Au-(Mo) deposit in Indonesia, the Bingham Canyon porphyry Cu-Mo-Au deposit in Utah, USA, and the Far Southeast porphyry Cu-Au deposit in the Philippines. In these systems gold is often found associated with bornite, intermediate solid solution (ISS, …

Diagram Affordances And Their Impact On Students’ Answers About Rivers And Groundwater, Daniel R. Curtis

Graduate Research Theses & Dissertations

Diagrams are important tools for conveying information in geoscience education. Choosing what imagery to use and assessing its effectiveness is not straightforward. A diagram needs sufficient affordances (i.e., details, dimension) for the viewers to comprehend the intended message without adding too many details that will confuse and distract the viewer. Prior research suggests that the viewer’s knowledge and experience impact how diagram affordances are interpreted. Understanding this interaction between knowledge, context, and diagram affordance is critical for education and assessment.To investigate how changes in affordances affect student interpretation of images, we surveyed undergraduate students (N = 201) in introductory Earth …

Materials And Electrochemical Interfaces For High Energy Density Sodium Metal Batteries, Olusola John Dahunsi

Graduate Research Theses & Dissertations

Batteries with low-cost, high energy and safe features density are now widely demanded.This dissertation systematically and comprehensively studies the materials and electrochemical interfaces of sodium (Na) metallic anodes and metal-free anodes for high energy density sodium metal batteries (SMB) to meet energy storage demands. This dissertation is divided into two sections, with the first section focusing on the modifications made to pristine metallic sodium anodes using 1.6 at % tin (Sn) to create Na-Sn alloy anodes. The results confirm that the Na-Sn anode features interconnected Na15Sn4 backbones that support sodium structurally, enhance Na+/Na redox kinetics, and facilitate dendrite-free Na plating …

Grey To Green: The Impact Of Environmental Policy On Us Crime Rates, Kassandra Gonzalez

Graduate Research Theses & Dissertations

This study explores the social implications of climate change and environmental degradation on deviant and criminal behavior. This study employs general strain theory to examine the effectiveness of city-level climate change mitigation actions in reducing crime rates. Through a systematic approach, this study reviews literature on environmental harms and community strain and explores the impact of local pro-environmental policies on crime reduction. Focusing on the United States, UCR crime rate reports and UN-guided Sustainable Development Goal data are analyzed at the US county level. The findings suggest that sustainable practices, especially those related to local infrastructure and community engagement, could …

The Future Of Extreme Windstorms In The United States: Insights From Convection-Permitting Simulations, Kristie Kaminski

Graduate Research Theses & Dissertations

A derecho is a long-lived, convectively induced, extratropical windstorm that produces severe wind gusts and an affiliated damage swath across an extensive area. This peril can generate billions of dollars in losses and poses a significant risk to life, infrastructure, and wind-sensitive industries. While the response of severe convective storms to anthropogenic climate change has received much attention in the literature, research assessing the genitors of derechos—mesoscale convective systems—has focused on understanding potential changes in the United States hydroclimate, not their severe wind potential. To date, there has been no research investigating spatiotemporal changes to derecho activity in the context …

Historical And Potential Future Climate Of Extreme Daily Precipitation Over The Contiguous United States Using Convection-Permitting Simulations, Sylvia Stinnett

Graduate Research Theses & Dissertations

The impacts of anthropogenic climate change will be felt most strongly through changes in hazards such as extreme precipitation. The potential for extreme precipitation changes—both increases and decreases—may have significant societal impacts (e.g., agriculture production, loss of life and property). However, limited research has quantified future projected changes in extreme precipitation due to computational limitations and considerable time expenditure for convection-permitting simulations of substantial duration.This project sought to analyze changes in extreme daily precipitation—defined as the 99th percentile daily accumulated value—due to climate change in the contiguous United States (CONUS) using a dynamically downscaled and convection-permitting regional climate modeling framework. …

Evaluating Ai Sentiment Analysis, Aakriti Shah

Honors Program Theses

This paper presents a comparative analysis of human and AI performance on a sentiment analysis task involving the coding of qualitative data from community program transcripts. The results demonstrate promising but imperfect agreement between two AI models, Claude and Bing, versus three human annotators and one expert annotator using the Community Capitals framework categories. While both models achieved fair alignment with human judgment, confusion patterns emerged involving metaphorical language and text overlapping multiple categories. The findings provide a case study for benchmarking conversational AI systems against human baselines to reveal limitations and target improvements. Key gaps center around distinguishing between …

A Machine Learning Approach To Deepfake Detection, Delaney Conrad

All Undergraduate Theses and Capstone Projects

The ability to manipulate videos has been around for decades but a process that once would take time, money, and professionals, can now be created by anyone due to the rapid advancement of deepfake technology. Deepfakes use deep learning artificial intelligence to make fake digital content, typically in the form of swapping a person’s face in a video or image. This technology could easily threaten and manipulate individuals, corporations, and political organizations, so it is essential to find methods for detecting deepfakes. As the technology for creating deepfakes continues to improve, these manipulated videos are becoming increasingly undetectable. It is …

Graphs Without A 2c3-Minor And Bicircular Matroids Without A U3,6-Minor, Daniel Slilaty

Mathematics and Statistics Faculty Publications

In this note we characterize all graphs without a 2C3-minor. A consequence of this result is a characterization of the bicircular matroids with no U3,6-minor.

Odd Solutions To Systems Of Inequalities Coming From Regular Chain Groups, Daniel Slilaty

Mathematics and Statistics Faculty Publications

Hoffman’s theorem on feasible circulations and Ghouila-Houry’s theorem on feasible tensions are classical results of graph theory. Camion generalized these results to systems of inequalities over regular chain groups. An analogue of Camion’s result is proved in which solutions can be forced to be odd valued. The obtained result also generalizes the results of Pretzel and Youngs as well as Slilaty. It is also shown how Ghouila-Houry’s result can be used to give a new proof of the graph- coloring theorem of Minty and Vitaver.

Spatially Resolved Imaging Of The Inner Fomalhaut Disk Using Jwst/Miri, András Gáspár, Schuyler Grace Wolff, George H. Rieke, Jarron M. Leisenring, Jane Morrison, Kate Y.L. Su, Kimberly Ward-Duong, Jonathan Aguilar, Marie Ygouf, Charles Beichman, Jorge Llop-Sayson, Geoffrey Bryden

Astronomy: Faculty Publications

Planetary debris disks around other stars are analogous to the asteroid and Kuiper belts in the Solar System. Their structure reveals the configuration of small bodies and provides hints for the presence of planets. The nearby star Fomalhaut hosts one of the most prominent debris disks, resolved by the Hubble Space Telescope, Spitzer, Herschel and the Atacama Large Millimeter Array. Images of this system at mid-infrared wavelengths using JWST/MIRI not only show the narrow Kuiper belt-analogue outer ring, but also that (1) what was thought from indirect evidence to be an asteroid-analogue structure is instead broad, extending outward into the …

Effective Strategies To Sustain Small African American Food Service Businesses Beyond 5 Years, Alvin West

Walden Dissertations and Doctoral Studies

AbstractAfrican American small food service business owners contribute to national and local economies; however, only 45% of them sustain their businesses beyond 5 years. African American small food service business owners are concerned with the lack of effective business strategy implementation, as it is the number one predictor of actual business failure. Grounded in the general systems theory, the purpose of this qualitative multiple case study was to explore strategies African American small food service business owners used to sustain their businesses beyond 5 years. The participants were seven African American small food service business owners in the southeastern United …

Delineating A Stream Network At Gale Crater, Mars, On Arcgis Pro: A Geographic Information Systems Approach, Elpidio Guzman De La Cruz

West Chester University Master’s Theses

The northwestern region of the Gale crater experienced flooding in the past. Delineation of stream networks for the northwestern region of Gale Crater, Mars employing geographic information systems (GIS) techniques is applied. The stream network produced by the algorithm in the study traverses the clay unit in Gediz Vallis, and visual HiRISE imagery analysis correlates with a topologic cross section of an inverted river channel of 750 meters wide and 90 meters deep. HiRISE imagery analysis further confirms a sulfate and clay stratigraphic unit in a stream 125 meters wide and 25 meters deep. Lastly, data smoothing procedures in the …

Climate Security Insights From The Covid-19 Response, Mark P. Nevitt

Faculty Articles

The climate change crisis and COVID-19 crisis are both complex collective action problems. Neither the coronavirus nor greenhouse gas (GHG) emissions respect political borders. Both impose an opportunity cost that penalizes inaction. They are also increasingly understood as nontraditional, novel security threats. Indeed, COVID-19’s human cost is staggering, with American lives lost vastly exceeding those lost in recent armed conflicts. And climate change is both a threat accelerant and a catalyst for conflict—a characterization reinforced in several climate-security reports. To counter COVID-19, the President embraced martial language, stating that he will employ a “wartime footing” to “defeat the virus.” Perhaps …

Applications For Functional Data Analysis, Kacy D. Kane

Graduate Research Theses & Dissertations

Functional Data Analysis is often used in the study of data that exists over a continuum, such as time. There are two datasets that will be considered here. For the first study we have a dataset on the efficacy of a lobectomy in reduction or elimination of epileptic seizures in patients. After an initial analysis of the dataset from a multinomial model perspective, we found that there were outliers in our dataset. From there, we considered a Multinomial Mixture Model to aid in the detection of outliers. In our second dataset we are considering a social robotics dataset where the …

Introduction: Imagined And Real Ai, Michael Paulus

SPU Works

The increasing role and power of artificial intelligence in our lives and world require us to imagine and shape a desirable future with this technology. Since visions of AI often draw from Christian apocalyptic narratives, current discussions about technological hopes and fears present an opportunity for a deeper engagement with Christian eschatological resources. This book argues that the apocalyptic imagination can transform how we think about and use AI, helping us discover ways artificial agency may help us create a better world.

Improving Developers' Understanding Of Regex Denial Of Service Tools Through Anti-Patterns And Fix Strategies, Sk Adnan Hassan, Zainab Aamir, Dongyoon Lee, James C. Davis, Francisco Servant

Department of Electrical and Computer Engineering Faculty Publications

Regular expressions are used for diverse purposes, including input validation and firewalls. Unfortunately, they can also lead to a security vulnerability called ReDoS (Regular Expression Denial of Service), caused by a super-linear worst-case execution time during regex matching. Due to the severity and prevalence of ReDoS, past work proposed automatic tools to detect and fix regexes. Although these tools were evaluated in automatic experiments, their usability has not yet been studied; usability has not been a focus of prior work. Our insight is that the usability of existing tools to detect and fix regexes will improve if we complement them …

An Empirical Study Of Pre-Trained Model Reuse In The Hugging Face Deep Learning Model Registry, Wenxin Jiang, Nicholas Synovic, Matt Hyatt, Taylor R. Schorlemmer, Rohan Sethi, Yung-Hsiang Lu, George K. Thiruvathukal, James C. Davis

Department of Electrical and Computer Engineering Faculty Publications

Deep Neural Networks (DNNs) are being adopted as components in software systems. Creating and specializing DNNs from scratch has grown increasingly difficult as state-of-the-art architectures grow more complex. Following the path of traditional software engineering, machine learning engineers have begun to reuse large-scale pre-trained models (PTMs) and fine-tune these models for downstream tasks. Prior works have studied reuse practices for traditional software packages to guide software engineers towards better package maintenance and dependency management. We lack a similar foundation of knowledge to guide behaviors in pre-trained model ecosystems.

In this work, we present the first empirical investigation of PTM reuse. …

Arginine-178 Is An Essential Residue For Itpa Function, Nicholas E. Burgis, Caitlin April, Kandise Vanwormer

Chemistry and Biochemistry Faculty Publications

The inosine triphosphate pyrophosphatase (ITPA) enzyme plays a critical cellular role by removing noncanonical nucleoside triphosphates from nucleotide pools. One of the first pathological ITPA mutants identified is R178C (rs746930990), which causes a fatal infantile encephalopathy, termed developmental and epileptic encephalopathy 35 (DEE 35). The accumulation of noncanonical nucleotides such as inosine triphosphate (ITP), is suspected to affect RNA and/or interfere with normal nucleotide function, leading to development of DEE 35. Molecular dynamics simulations have shown that the very rare R178C mutation does not significantly perturb the overall structure of the protein, but results in a high level of structural …

Pakistan, India And The Indus River Basin, Muquadas Ilyas

Dissertations and Theses

Water is a fundamental need of all living things. The right to clean water is classified as a human right under United Nations Resolution 64/292.As such it is the responsibility of governments to ensure its citizens are not deprived of this essential resource. In doing so, effective water management is crucial to provide clean water that is accessible to everyone regardless of any challenges such as geographical constraints or political disputes. This thesis explores the water management efforts of Pakistan and India. These countries are facing a water crisis, whereby numerous citizens have died due to dehydration and diseases contracted …

Field Tests Of A Uav-Compatible Spectrometer To Evaluate Its Suitability For Detailed Soil Radon Potential Mapping, Alexandria Briahnne Thomas

Theses and Dissertations--Earth and Environmental Sciences

As part of ongoing research on radionuclide mapping and radon hazard characterization, field tests were performed to evaluate the suitability and limitations of a UAV-compatible gamma spectrometer. To date, this data set includes completed stationary data collection, mobile ground collection, multi-level UAV flights over a known material transition, as well as redundant ground and multi-level UAV data collection over a relatively uniform area. Total counts were used as a measure of soil radionuclide levels for our data collected above background. Although our test sites were in regions underlain by bedrock with high indoor radon levels, uranium counts were barely above …

Mitigating Supply Chain Disruptions In Retail Discount Department Stores, Anthony T. Patton

Walden Dissertations and Doctoral Studies

Supply chain disruptions can have adverse effects on business outcomes. Retail industry supply chain leaders are concerned with supply chain disruptions because supply chain disruptions can lead to dissatisfied customers and loss of profits. Grounded in game theory, the purpose of this multiple case study was to explore strategies four retail industry supply chain leaders in Northern Illinois and Northwest Indiana implemented to mitigate the effects of supply chain disruptions. Data were collected using semistructured virtual interviews with four retail industry supply chain leaders and a review of company documents. Through thematic analysis, four themes emerged: (a) choosing appropriate inventory …

Diversification Strategies Business Managers Use To Improve Profitability, Kayode Itiola

Walden Dissertations and Doctoral Studies

A lack of diversification strategies can negatively impact business profitability. Business managers of small and medium-sized enterprises who implement appropriate diversification strategies can improve business profitability, ensuring the firm’s sustainability. Grounded in the modern portfolio theory, the purpose of this qualitative single case study was to explore diversification strategies business managers use to improve profitability. The participants were five business managers who successfully used diversification strategies to enhance business profitability. Sources for data collection were semi-structured interviews, company archival documents, and field notes. Data were analyzed using thematic analysis. Four themes emerged: concentric diversification strategy, horizontal diversification strategy, customer needs …