Physical Sciences and Mathematics Commons^™

Ai-Based Defect Detection In Aerospace Ultrasonic Signals, Rami Issac Lake

Graduate Research Theses & Dissertations

Ensuring the safety and integrity of materials and structures throughout the manufacturing cycle is a critical concern across various industries, including aerospace, automotive, oiland gas, and civil engineering. Non-Destructive Inspection (NDI) techniques allow for the examination of materials without causing damage or alteration, enabling the early detection of potential issues before materials are utilized in the field. The inspection of fuselage composites presents a particular challenge due to their complex structures, diverse materials, and differences in thickness, making defect detection a challenging yet crucial task. Moreover, defects of various types and causes can emerge across all depths of the material …

On The Ground And From Above: A Multi-Factor Analysis Of The Direct And Indirect Drivers Of Tallgrass Prairie Small Mammal Communities, Erin Rowland-Schaefer

Graduate Research Theses & Dissertations

Tallgrass prairies are among the most globally threatened ecosystems, with only one percent of the historical extent remaining in Illinois. Prairie restoration is an essential strategy to preserve biodiversity and reestablish threatened species. Practitioners use management tools to shift the landscape context of prairie restoration sites, such as prescribed fire and land cover change. Managers can also impact the landscape connectivity and edge proximity of certain areas through the use of mowed driving lanes. The effects of these factors on small mammals, which are central in tallgrass prairie food webs and relevant to human health and restoration success, are not …

The Effects Of Bureaucratic Corruption On The Financial Constraints Of Nigerian Small Businesses, Obinna Franklin Ezeibekwe

Graduate Research Theses & Dissertations

In this paper, I conduct the first empirical analysis to examine the impact of bureaucratic corruption on small business financial constraints in Nigeria. This study is also the first to compare the average treatment effect (ATE) with the local average treatment effect (LATE) framework to account for potential variations in treatment effects for small Nigerian firms with less than 100 employees. Using the bivariate probit method and two binary instruments, I find that corruption significantly increases the likelihood of financial constraints for a typical micro, small, and medium enterprise (MSME) by approximately 64 to 68 percentage points. When I use …

Hunting Types In North American Eocene And Oligocene Carnivores And Implications For Nimravid Extinction, Miguel Andres Castellanos

Graduate Research Theses & Dissertations

The late Eocene and Oligocene is traditionally seen as a time of great climactic shift, with open habitats beginning to appear and forests receding. This time period saw both the diversification and subsequent extinction of North American nimravids. The causes of the extinction of this early sabertooth group in the Arikareean remain unclear. One possibility for their decline is that nimravids were competitively disadvantaged in open habitats relative to contemporary, possibly more cursorial caniform predators. Here I analyze and compare the hunting styles of Eocene and Oligocene predators in correlation with their ecological implications via discriminant function analysis of the …

Modulating Co2 Electrocatalytic Conversion To Organics Pathway By Nanoconfinement Effects And The Catalytic Site Dimension, Jianxin Wang

Graduate Research Theses & Dissertations

This dissertation presents a comprehensive study on the catalyst supports and the size of catalytic active sites. From a microscopic perspective, this research elucidates the implications of the nanoconfinement effects and the size effects of active sites in the electrocatalytic CO2 reduction process. It lays a solid foundation for the future development of superior catalysts.Electrochemical conversion of CO2 into value-added fuels and chemical feedstocks can serve future energy demands by storing renewable energy and reducing anthropogenic emissions of CO2. CO2 reduction reaction (CO2RR) to multi-carbon chemicals have generated growing interest in recent years, stimulated not only by the economic benefit …

Cold Testing Of A Prototype Superconducting Radiofrequency Electron Gun And Ancillary Systems For The Lcls-Ii-He Project, Kaela Michele Villafania

Graduate Research Theses & Dissertations

Argonne National Laboratory is collaborating with Michigan State University (MSU), Helmholtz-Zentrum Dresden-Rossendorf (HZDR), and Stanford Linear Accelerator Center (SLAC) on the design, fabrication, and testing of a prototype superconducting radiofrequency (SRF) gun for the planned LCLS-II-HE upgrade at SLAC. This electron source will enable the generation of higher-brightness beams at a high repetition rate opening the path to expand LCLS-II-HE FEL performances. This thesis focuses on the cold testing of the prototype gun cavity and ancillary structures including the fundamental input-power coupler and tuning system. Numerical simulations are also presented to understand fields inside of the cavity as well as …

Julia Limiting Directions Of Quasiregular Maps, Julie Marie Steranka

Graduate Research Theses & Dissertations

In this dissertation, we study the set of Julia limiting directions of quasiregular maps. The work combines the study of dynamics of quasiregular maps and applications of nonlinear potential theory to quasiregular maps. Our main result shows that the set of Julia limiting directions of a transcendental-type $K$-quasiregular map $f:\R^n\to \R^n$ must contain a component of a certain measure, depending on the dimension $n$, the maximal dilatation $K$, and the order of growth of $f$. In particular, we show that if the order of growth is small enough, then every direction is a Julia limiting direction. The main tool in …

Pathology And Diagnosis In Inflammatory-Related Diseases: Covid-19 And Age-Related Macular Degeneration, Zane Russell Lacasse

Graduate Research Theses & Dissertations

Chronic inflammation and dysfunctional inflammatory responses are believed to be contributing factors to the severity of many diseases. Since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), it has been recognized that levels of inflammatory markers and the severity of coronavirus disease-2019 (COVID-19) cases are closely related. The work within this dissertation begins with establishing an alternative platform for the diagnosis of COVID-19 and explores ways to enhance the diagnostic utility of this platform. An alternative route for COVID-19 diagnosis was explored using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF MS). The platform utilizes a non-invasive sampling technique …

Design And Performance Of Superconducting Switches For Nanowire Detectors In Magnetic Fields, Timothy James Draher

Graduate Research Theses & Dissertations

Superconducting nanowire devices fit a broad spectrum of applications, including particle detection and quantum computing, and their expanding use across various fields highlights their role in the hybridization of superconducting and conventional semiconductor electronics. Despite their potential, the low signal output of these devices raises challenges in scalability and integration, particularly in applications for nuclear and high-energy physics, where resilience in magnetic fields is becoming a critical optimization factor. The superconducting nanowire cryotron (nTron) addresses these issues by providing operational gain and logic switching in superconducting nanowire circuits, demonstrating adaptability to multiple materials. This dissertation focuses on modifying the conventional …

Gas-Phase Mass Spectrometry Studies Of Ternary Metal Carboxylate Complexes, Anthony James Fanizza

Graduate Research Theses & Dissertations

In the wake of climate change from rising CO2 emissions and with peak oil looming, the dive into sustainable fuels and energy is becoming increasingly essential. This dissertation investigates ternary ligand-metal cationic complexes for potential catalytic applications in the decarboxylation of carboxylic acids to produce bioavailable and carbon-neutral fuel sources. By utilizing gas-phase reactivity studies via mass spectrometry, namely, collision-induced dissociation and ion-molecule reactions, mechanisms can be elucidated in a regulated chemical environment. When paired with density functional theory calculations for molecular geometries, chemical interactions, charge densities, and energetics, system efficiencies can be further clarified presenting a more complete mechanistic …

Groundwater Flow And Water Clarity At Cenotes In The Yucatan Peninsula, Laura Rossana Fracica Gonzalez

Graduate Research Theses & Dissertations

Characterizing and predicting groundwater flow in complex karst aquifers poses significant challenges. This study explores the potential application of Acoustic Doppler Current Profiler (ADCP) technology for in-situ groundwater flow measurement within sinkholes (cenotes) in the Yucatan Peninsula, Mexico. Two specific questions are addressed: 1) Can ADCP determine flow within Yucatan Peninsula sinkholes? 2) Are groundwater flow vectors related to water clarity in open cenotes? The geological setting of the Yucatan Platform is characterized by horizontal sedimentary strata with highly permeable limestones and extensive karst features. The research focuses on the Holbox fracture zone, where groundwater flow dynamics remain elusive. The …

Microwave Simulations Of A Beam Position Monitor And Circuit Designs Assisting Its Beam Testing, Marc Jacob Crowell

Graduate Research Theses & Dissertations

Beam position monitors (BPMs) are non-destructive diagnostic devices widely used in particle accelerators. I will first introduce the need for precision beam position measurement in particle accelerators, and then provide an overview of various types of BPMs. For the first part of my work, I focus on the design and simulation of a button-BPM. Microwave and wakefield simulations were performed to characterize the output signals. Such a design could find a potential application at the Argonne Wakefield Accelerator (AWA) at the Argonne National Laboratory. Although no BPMs have been fabricated to this date, a future beam experiment will be needed …

Ms Environmental Biology Capstone Project, Klaudia Sowizral

Regis University Student Publications (comprehensive collection)

Thelephorales fungi are considered important ectomycorrhizal fungi (EMF) in forest ecosystems, yet the patterns of diversity and distribution and the processes that shape them remain poorly understood. This study aims to address this research gap by conducting an exploratory analysis of Thelephorales fungi in soil and litter across various habitat types and environmental characteristics. To do so, we used data collected and synthesized by the Climush project, a multi-year, systematic sampling of macrofungal diversity across North America, that aims to assess sexual (sporocarp and spore trap data) and asexual (soil and endophyte metabarcode data) diversity and distribution in relation to …

The Impacts Of Anthropogenic Activity And Climate Change On The Formation Of Harmful Algal Blooms (Habs) And Its Ecological Consequence, Zhangxi Hu, Aifeng Li, Zhun Li, Margaret R. Mulholland

OES Faculty Publications

No abstract provided.

Crafting Effective Prompts: Leveraging Generative Ai In Libraries, April Sheppard, Kristin Flachsbart

Staff and Faculty Scholarship

Discover how strategic prompt design can help you harness the power of generative artificial intelligence (AI) in your library. Through a series of examples, the presenters will demonstrate the impact that well-crafted prompts can have on the quality and relevance of AI-generated outputs.

Development Of A Collaborative Research Platform For Efficient Data Management And Visualization Of Qubit Control, Devanshu Brahmbhatt

Computer Science and Engineering Theses

This thesis introduces QubiCSV, a pioneering open-source platform for quantum computing field. With an emphasis on collaborative research, QubiCSV addresses the critical need for specialized data management and visualization tools in qubit control. The platform is crafted to overcome the challenges posed by the high costs and complexities associated with quantum experimental setups. It emphasizes efficient utilization of resources through shared ideas, data, and implementation strategies. One of the primary obstacles in quantum computing research has been the ineffective management of extensive calibration data and the inability to visualize complex quantum experiment outcomes effectively. QubiCSV fills this gap by offering …

Weed Seed Wizard Case Study - Grower From Western Australia’S Central Wheatbelt, Department Of Primary Industries And Regional Development, Western Australia

Biosecurity research reports

The Weed Seed Wizard is a national collaborative project that uses paddock management information to predict weed emergence and crop losses now and in the future.

The Weed Seed Wizard is a computer simulation tool that:

• applies to all Australian grain growing areas

• helps growers understand and manage weed seedbanks on their farms

• uses farm management records to simulate how different crop rotations, weed control techniques, irrigation, grazing and harvest management tactics can affect weed numbers, the weed seedbank and yields

• uses farm-specific management and site-specific weather

• is multi-species

See www.dpird.wa.gov.au for further information on Weed Seed Wizard.

This case …

Weed Seed Wizard Case Study - Don't Stop Harvest Weed Management Because It’S A Dry Year, Department Of Primary Industries And Regional Development, Western Australia

Biosecurity research reports

The Weed Seed Wizard is a national collaborative project that uses paddock management information to predict weed emergence and crop losses now and in the future.

The Weed Seed Wizard is a computer simulation tool that:

• applies to all Australian grain growing areas

• helps growers understand and manage weed seedbanks on their farms

• uses farm management records to simulate how different crop rotations, weed control techniques, irrigation, grazing and harvest management tactics can affect weed numbers, the weed seedbank and yields

• uses farm-specific management and site-specific weather

• is multi-species

See www.dpird.wa.gov.au for further information on Weed Seed Wizard.

This case …

Weed Seed Wizard Scenario - Dormancy Shift In Barley Grass In Balaklava, South Australia, Department Of Primary Industries And Regional Development, Western Australia

Biosecurity research reports

The Weed Seed Wizard is a national collaborative project that uses paddock management information to predict weed emergence and crop losses now and in the future.

The Weed Seed Wizard is a computer simulation tool that:

• applies to all Australian grain growing areas

• helps growers understand and manage weed seedbanks on their farms

• uses farm management records to simulate how different crop rotations, weed control techniques, irrigation, grazing and harvest management tactics can affect weed numbers, the weed seedbank and yields

• uses farm-specific management and site-specific weather

• is multi-species

See www.dpird.wa.gov.au for further information on Weed Seed Wizard.

This South …

Weed Seed Wizard Case Study - An Early Harvest Versus A Late Harvest, Department Of Primary Industries And Regional Development, Western Australia

Biosecurity research reports

The Weed Seed Wizard is a national collaborative project that uses paddock management information to predict weed emergence and crop losses now and in the future.

The Weed Seed Wizard is a computer simulation tool that:

• applies to all Australian grain growing areas

• helps growers understand and manage weed seedbanks on their farms

• uses farm management records to simulate how different crop rotations, weed control techniques, irrigation, grazing and harvest management tactics can affect weed numbers, the weed seedbank and yields

• uses farm-specific management and site-specific weather

• is multi-species

See www.dpird.wa.gov.au for further information on Weed Seed Wizard.

This case …

Student Performance In Modern Physics In An Active, Partially-Flipped Classroom, Scott Yarbrough

Physics Dissertations

The effectiveness of the flipped classroom and hybrid-flipped (partially flipped, partially lecture-based) method of instruction has been extensively studied for high school and introductory undergraduate physics courses, and it has been shown to increase student understanding and performance. However, few studies have been done for upper-level undergraduate courses, and even fewer have been done for virtual courses. In Spring 2021 and Fall 2023, a fully virtual, hybrid-flipped Modern Physics course was taught, primarily to a class of primarily juniors and seniors, with some sophomores. All were STEM majors. The same course, with a similar enrolment and demographic of students, was …

Deep Learning Applications On Ionospheric Studies, Yang Pan

Physics Dissertations

Machine learning techniques, particularly deep learning techniques, have been vigorously pursued to tackle space physics problems and achieved some impressive results recently. The growth of deep learning technologies in different domains enables innovative solutions to those problems compared to conventional methods. Filling data gaps in instrumental observations is among the demanding issues, which benefits space physicists to study ionospheric phenomena with complete data coverage. Global total electron content (TEC) and regional ionospheric electron density (Ne) are among important physical parameters in ionospheric studies. Due to the limited coverage of global navigation satellite system (GNSS) ground receivers and sporadic …

Re-Evaluation Of Lethal Radiation Dose In Drosophila Melanogaster Using 350 Kev Electrons, Dariia Hozhenko

All Graduate Theses, Dissertations, and Other Capstone Projects

Radiation dosimetry from a 350 KeV electron beam and its impact on Drosophila melanogaster response serve as the focal points of this study. While previous research has established an LD50 (lethal radiation dose for 50 % of the population) exceeding 452 Gy across mainly all developmental stages, this investigation extends the understanding by examining dose-dependent differences throughout development, from the pupae stage into adulthood. Fruit flies, irradiated at their most sensitive stage, the egg phase, displayed a notable reduction in effective LD50, especially when accounting for long-term effects. Specifically, the LD50 values decreased to approximately 59 Gy for the maximum …

Leveraging Machine Learning & Deep Learning Methodologies To Detect Deepfakes, Aniruddha Tiwari

All Graduate Theses, Dissertations, and Other Capstone Projects

The rapid evolution of deep learning (DL) and machine learning (ML) techniques has facilitated the rise of highly convincing synthetic media, commonly referred to as deepfakes. These manipulative media artifacts, generated through advanced artificial intelligence algorithms, pose significant challenges in distinguishing them from authentic content. Given their potential to be disseminated widely across various online platforms, the imperative for robust detection methodologies becomes apparent. Accordingly, this study explores the efficacy of existing ML/DL-based approaches and aims to compare which type of methodology performs better in identifying deepfake content. In response to the escalating threat posed by deepfakes, previous research efforts …

Listening To The Voices Of America, Kathryn J. Edin, Corey D. Fields, David B. Grusky, Jure Leskovec, Marybeth J. Mattingly, Kristen M. Olson, Charles Varner

Department of Sociology: Faculty Publications

We make the case for building a permanent public-use platform for conducting and analyzing immersive interviews on the everyday lives of Americans. The American Voices Project (AVP)—a widely watched experiment with this new platform—provides important early evidence on its promise. The articles in this issue reveal that, although public-use interview datasets obviously cannot meet all research needs, they do provide new opportunities to study small or hidden populations, new or emerging social problems, reactions to ongoing social crises, submerged values and attitudes, and many other aspects of American life. We conclude that a permanent AVP platform would help build an …

Re-Evaluating Missouri’S Strategic Element Potential: A Geochemical Study Of The Mesoproterozoic Fe-Cu-Co-Ree Deposits In Southeast Missouri, Usa, Brandon James Sullivan

Doctoral Dissertations

"Iron-oxide-copper-gold (IOCG) deposits are poorly understood mineral systems. For example, we do not know why Cu- and Co-rich IOCG deposits typically occur proximal to Fe ore deposits that are notably Cu and Co-poor, such as Iron Oxide Apatite (IOA) deposits. To better understand the formation of IOA and IOCG deposits in Missouri, USA, this PhD thesis examines the genesis of the Kratz Spring IOA and the Boss Central Dome IOCG deposits. This study presents the first constraints on formation conditions and fluid sources in the studied deposits using integrated petrographic, mineral composition, and Fe isotope analyses of oxide minerals. Observations …

Simulating The Spread Of Information Among Non-Playable Characters In Video Games, Summer Ashley Colon

Senior Projects Spring 2024

This project attempts to improve Non-Player Character (NPC) realism in video games by using an Agent-Based Model (ABM) to automate their communication and interactions. To evaluate how information spreads through interacting NPCs in video games, this simulation assumes that the main purpose of NPC societies is to provide a context in which NPCs interact with each other to spread information about player-generated events that change the game state. The goal is to successfully identify possible programming methods to automate NPC behavior and create a more realistic gaming experience for players. The simulation incorporates three archetypal types of characters that are …

Psilocybin And Music: Proposal To Study The Effects Of Music On Efficacy Of Psilocybin-Assisted Therapy For Treatment-Resistant Depression, Giorgi Gzirishvili

Senior Projects Spring 2024

This paper proposes an experiment to investigate the efficacy of psilocybin-assisted therapy for treating treatment-resistant depression (TRD) and assess the modulating effects of music on therapeutic outcomes. Previous studies have consistently incorporated music into psilocybin-assisted therapy for TRD but have not empirically isolated its effects. This research aims to fill this gap by introducing a controlled variable of music to explore its impact on therapy efficacy. I hypothesize that listening to the music playlist created by Johns Hopkins University during therapy sessions will significantly enhance therapeutic outcomes compared to a control group listening to ambient sounds. Participants, adults diagnosed with …

Results On $K$-Covers In The Game Quads, Daniel Melvin Rose-Levine

Senior Projects Spring 2024

This project explores the $k$-cover conjecture for the game Quads. The conjecture states that for all $k\in\mathbb{N}$, there exists a $k$-cover if and only if $k = 2$ or $k = \frac{2^n-2}{6}$ for some odd $n\in\mathbb{N}$ with $n>1$. We show that if $k$ is one of these values, then there exists a $k$-cover. We discuss partial results in the other direction, i.e., that these are the only values of $k$ for which there exists a $k$-cover.

Problems In Graph Theory With Applications To Topology And Modeling Rna, Rayan K. Ibrahim

Theses and Dissertations

In this thesis, we explore four projects. In the first project, we explore $r$-neighbor bootstrap percolation on a graph $G$. We establish upper bounds for the number of vertices required to percolate in the case that $r=2$ for particular classes of graphs. In the second project, we study the structure of graphs with independence number two. We prove a lower bound on the number of edges of such graphs, related to an upper bound on the number of edges in a triangle-saturated graph, and give a sufficient forbidden induced subgraph condition for independence number two graphs. In the third project, …