Digital Commons Network^™

Enhancing Compton Telescope Imaging With Maximum A Posteriori Estimation A Modified Richardson–Lucy Algorithm For The Compton Spectrometer And Imager, H. Yoneda, T. Siegert, I. Martinez-Castellanos, S. Gallego, C. Karwin, H. Bates, S. E. Boggs, C. Y. Huang, A. Joens, S. Matsumoto, S. Mittal, E. Neights, M. Negro, U. Oberlack, K. Okuma, S. Pike, J. Roberts, F. Rogers, Y. Sheng, T. Takahashi, A. Valluvan, Y. Watanabe, D. Hartmann, C. Kierans, J. Tomsick, A. Zoglauer

Faculty Publications

We present a modified Richardson-Lucy (RL) algorithm tailored for image reconstruction in MeV gamma-ray observations, focusing on its application to the upcoming Compton Spectrometer and Imager (COSI) mission. Our method addresses key challenges in MeV gamma-ray astronomy by incorporating Bayesian priors for sparseness and smoothness while optimizing background components simultaneously. We introduce a novel sparsity term suitable for Poisson-sampled data in addition to a smoothness prior, allowing for flexible reconstruction of both point sources and extended emission. The performance of the algorithm is evaluated using simulated three-month COSI observations of gamma-ray lines of ⁴⁴Ti (1.157 MeV), ²⁶Al (1.809 …

Algebraic Description Of The Triaxially To Axially Rotational Shape Phase Transition, Yu Zhang, Yu Xin Liu, Feng Pan, J. P. Draayer

Faculty Publications

Within the framework of the interacting boson model, we propose a novel algebraic scheme to describe spin-dependent structural evolutions in triaxial nuclei. Our analysis demonstrates that a triaxially to axially rotational shape phase transition can be induced by the high-order correction which is microscopically motivated by the pairing interaction on the γ-unstable rotation. This prescription is further applied to describe the structural evolutions along the yrast sequences of Ba132 and Xe130, providing an exemplary case for demonstrating a unified explanation of both low-energy collective structures and high-spin phenomena in O(6)-like nuclei.

The Frequency Shift And Q Of Disordered Superconducting Rf Cavities, Hikaru Ueki, Mehdi Zarea, J. A. Sauls

Faculty Publications

Niobium superconducting radio-frequency (SRF) cavities for high-energy accelerator applications have been greatly improved in terms of the quality factor Q by techniques such as Nitrogen doping. However, the mechanisms leading to improvement in Q are still not fully understood. Quite recently the SRF group at Fermilab measured anomalies in the frequency shift of N-doped SRF Niobium cavities near the transition temperature. Here we report our theoretical analysis of these results based on the microscopic theory of superconductivity that incorporates anisotropy of the superconducting gap and inhomogeneous disorder in the screening region of the SRF cavities. We are able to account …

Advanced Manufacturing Of Multifunctional Shape Memory Polymer Composites And Self-Healing Systems, John B. Konlan

LSU Doctoral Dissertations

The need for multifunctional light weight structures for engineering applications is on the rise. Multifunctional composites are desired because of their ability to combine multiple functionalities into one structure. The advantages of a high strength-to-weight ratio of multifunctional composites make them desirable and suitable for use in energy-efficient applications. Shape-memory polymers (SMPs) have attracted interest over the past several decades because of their multifunctional nature. They have found use in many applications such as aerospace, satellites, automobiles, textiles, and biomedical devices, where lightweight and multifunctionality are key. The self-healing nature of most SMPs makes them suitable for use in lightweight …

Promoting Social Inclusion Through Sport: A Case Study Of Uyghur Youth In China, Hongxin Li, Yunchao Bai, John Nauright

Faculty Publications

This study examines the role of sports as a means of promoting social inclusion among Uyghur youth in China, drawing upon social inclusion theory. Utilizing a qualitative case study methodology, we explored the perspectives of Uyghur youth athletes to gain insight into the challenges they face in achieving social inclusion without feeling “othered” or excluded. Data analysis followed an inductive grounded theory approach, identifying first‐order concepts, second‐order themes, and aggregate theoretical dimensions. Our findings reveal that social inclusion of Uyghur youth through sports participation is influenced by multiple factors, including language barriers, stereotypes, cultural differences, high expectations, and government policies. …

Unveiling The Interfacial Reconstruction Mechanism Enabling Stable Growth Of The Delafossite Pdcoo2 On Al2o3 And Laalo3, Anna Scheid, Tobias Heil, Y. Eren Suyolcu, Qi Song, Niklas Enderlein, Arnaud P. Nono Tchiomo, Prosper Ngabonziza, Philipp Hansmann, Darrell G. Schlom, Peter A. Van Aken

Faculty Publications

Delafossites, composed of noble metal (A⁺) and strongly correlated sublayers (BO2^-), form natural superlattices with highly anisotropic properties. These properties hold significant promise for various applications, but their exploitation hinges on the successful growth of high-quality thin films on suitable substrates. Unfortunately, the unique lattice geometry of delafossites presents a significant challenge to thin-film fabrication. Different delafossites grow differently, even when deposited on the same substrate, ranging from successful epitaxy to complete growth suppression. These variations often lack a clear correlation to obvious causes like lattice mismatch. Unidentified stabilization mechanisms appear to enable growth in certain …

A Natural Short Sleep Mutation Promotes Longevity Through Mitochondrial Respiration In Drosophila, Pritika Pandey

LSU Doctoral Dissertations

Aging is an irreversible process characterized by progressive physiological decline and an increased risk of metabolic disorders, cognitive impairment, cardiovascular diseases, and neurodegeneration. Disruptions to the circadian clock—whether due to genetic mutations or behavioral factors—accelerate aging and age-related pathologies, highlighting a strong link between circadian regulation and longevity. However, certain individuals harbor a dec2^P384R mutation, which enables natural short sleep without the detrimental effects of chronic sleep deprivation. This suggests that these individuals have evolved adaptations that activate pro-health pathways, allowing them to function optimally with reduced sleep. To investigate the genetic mechanisms underlying these changes, we developed a …

Through The Looking Glass : Diversity Through The Eyes Of A Dress Form, Amara Copeland

LSU Master's Theses

This article aims to look into educational institutions and how they address diversity using curatorial displays. Does fashion and costume curation add to the seclusion of luxury? Looking into this correlation, this study aims to answer these next couple of questions. How does museum curation add to fashion social norms? Is it a subconscious or conscious decision when deciding on a mannequin or dress form? How do museum and fashion curations add to the exclusion of minorities in the world of luxury? What is costume luxury, and who do we say can obtain it?

This research aims to understand the …

Effects Of Nitro-Substitution On The Spectroscopic And Self-Assembly Properties Of Bodipy Dyes, Caroline Gwaro, Caroline Ndung’U, Petia Bobadova-Parvanova, Dylan Goliber, Quynh Do, Ashley R. Walker, Evan Murders, Daniel Lamaster, Frank R. Fronczek, Jayne Garno, Maria Da Graça H. Vicente

Faculty Publications

A series of boron dipyrromethene (BODIPY) dyes were nitrated in high yields using nitronium tetrafluoroborate at positions 2, 3, and 2,6 of the BODIPY core. This method allows for the regioselective nitration of the pyrrolic positions under milder conditions than previously reported methods. The photophysical properties and electronic transitions of these BODIPYs were investigated by using UV-vis spectroscopy, fluorescence spectroscopy, and density-functional theory (DFT) calculations. The introduction of one nitro group dramatically increases the dipole moment of the molecule, induces marked blue shifts in the absorption and emission bands, decreases the molar absorptivity, and increases the Stokes shifts of the …

Advancing Aerial Survey Techniques For Non-Breeding Waterfowl Populations: A Comprehensive Review And Application In Northeastern Louisiana, Victoria L. Drake

LSU Master's Theses

Aerial surveys play a crucial role in monitoring North America's waterfowl populations and habitat conditions, and consistency across geographies and years allows biologists to track trends through time. The goal of this project was to redesign the northeastern portion of the Louisiana wintering waterfowl survey to align with statistically robust transect surveys conducted in neighboring states within the Mississippi Alluvial Valley. To identify the optimal sampling method, we evaluated three transect weighting schemes: stratified random (unweighted), stratified by watershed, and stratified by expert opinion. Approximately 10% of the total sampling area was randomly selected for each survey period, adhering to …

Global Ocean Bottom Temperature Observation Design: Observing System Simulation Experiments For Strategic Deployment Of Smart Subsea Cables, Karen E. Renninger-Rojas

LSU Master's Theses

Deep-ocean observations below 2000 meters remain limited, restricting our ability to model global ocean processes critical to climate prediction. This thesis evaluates the potential of SMART (Science Monitoring and Reliable Telecommunications) subsea cables to address these observational gaps by conducting Observing System Simulation Experiments (OSSEs) and adjoint sensitivity analyses using the MITgcm ocean model and ECCO outputs.

Vertical decorrelation analysis showed that temperature and salinity in key regions decouple from the upper ocean beyond 2000 m. Over 60% of the proposed SMART cable sites exhibited decorrelation depths exceeding Argo’s maximum sampling depth, highlighting their strategic value for deployment.

A comparison …

Animal-Assisted Therapy With Children In Hospitals And Schools: A Systematized Review, Tantine Kendig

LSU Master's Theses

It has been demonstrated that animals can offer humans significant health benefits. Animal-assisted therapy (AAT) is a growing form of therapy used in various settings to enhance the health of children, encompassing both physical and mental wellness. The challenges of hospitalization and the school environment have been shown to pose different challenges for children, such as an increase in anxiety, stress, depression, and others that have the potential to affect their mental, physical, emotional, and social well-being. This study aimed to assess the effectiveness of animal-assisted therapy, specifically dog-assisted therapy, on children in hospital and school settings by conducting a …

Multiparticle Quantum Plasmonics: Fundamentals And Applications, Mingyuan Hong

LSU Doctoral Dissertations

Quantum plasmonics explores the interaction between light and collective charge oscillations at metal-dielectric interfaces, enabling strong light confinement and enhanced quantum effects at the nanoscale. While traditional quantum optics has primarily focused on single-photon systems, an intermediate regime exists between classical and single-photon optics - multiparticle (or multiphoton) quantum optics. In this regime, classical light sources, when analyzed through techniques such as photon-number-resolving (PNR) detection and projective measurement, can reveal nontrivial quantum correlations. This thesis investigates how multiparticle quantum plasmonics harnesses these correlations to control quantum statistical properties, enhance coherence, and enable novel applications in quantum technologies.

In this thesis, …

Impacts Of Extreme Weather Conditions On Coastal Fisheries Near Bayou Teche, Louisiana From 2019–2023, Georgia C. Davis

LSU Master's Theses

The region of Southcentral Louisiana, particularly around Bayou Teche, thrives on its commercial and recreational fisheries. These fisheries are occasionally subject to events like extreme weather that cause sudden and unexpected losses (NOAA Fisheries, 2024a). Between 2019 and 2023, a series of extreme weather events impacted southcentral Louisiana near Bayou Teche. This series of extreme events includes Hurricane Barry (2019), Hurricane Laura (2020), Hurricane Delta (2020), Hurricane Zeta (2020), Hurricane Ida (2021), and a United States Drought Monitor (USDM) D4 drought (2023). This study analyzes the impacts of the extreme weather series on coastal fish observed species richness (SR) in …

Decadal To Millennial-Scale Morphodynamic Evolution Of Microtidal Marshes, Samuel Mason Zapp

LSU Doctoral Dissertations

Tidal marshes are susceptible to rapidly converting to open water due to their low elevations within the tidal frame. A continuous supply of externally supplied mineral sediment and in situ organic material production is necessary to offset elevation losses from relative sea level rise and erosion. Complex feedbacks between hydrodynamics, the erosion, transport, and deposition of sediment, and physical modification of the landscape by the establishment of intertidal vegetation govern the spatial and temporal patterns of elevation response. This dissertation focuses on modeling how these dynamics drive marsh landscape evolution in the past, present, and into the future under changing …

Neuronal Cftr: A Study Of Subcellular Localization And Interactions With Implications For A Role In Synaptic Transmission, Brandon J. Leviskas

LSU Doctoral Dissertations

Protein-protein interactions vary among cell types and the localization of these interactions help to define protein function. The function of cystic fibrosis transmembrane conductance regulator (CFTR) is well established in the context of epithelial tissue due to the debilitating effects of its mutations that cause the disease cystic fibrosis. While in neurons a role has been established in our lab for CFTR in the regulation of cytosolic Cl- in retinal amacrine cells (ACs). This research sets out to learn if CFTR has a synaptic role. Exploring this potential role, localization of CFTR was examined using fluorescent and immunogold labeled transmission …

Ligo Detector Characterization In The First Half Of The Fourth Observing Run, S. Soni, B. K. Berger, D. Davis, F. Di Renzo, A. Effler, T. A. Ferreira, J. Glanzer, E. Goetz, G. González, A. Helmling-Cornell, B. Hughey, R. Huxford, B. Mannix, G. Mo, D. Nandi, A. Neunzert, S. Nichols, K. Pham, A. I. Renzini, R. M.S. Schofield, A. Stuver, M. Trevor, S. Álvarez-López, R. Beda, C. P.L. Berry, S. Bhuiyan, L. Blagg, R. Bruntz, S. Callos, M. Chan, P. Charlton, N. Christensen, G. Connolly

Faculty Publications

Progress in gravitational-wave (GW) astronomy depends upon having sensitive detectors with good data quality. Since the end of the Laser Interferometer Gravitational-Wave Observatory-Virgo-KAGRA third Observing run in March 2020, detector-characterization efforts have lead to increased sensitivity of the detectors, swifter validation of GW candidates and improved tools used for data-quality products. In this article, we discuss these efforts in detail and their impact on our ability to detect and study GWs. These include the multiple instrumental investigations that led to reduction in transient noise, along with the work to improve software tools used to examine the detectors data-quality. We end …

Disorder Enhanced Thermalization In Interacting Many-Particle System, Chakradhar Rangi, Herbert F. Fotso, Hanna Terletska, Juana Moreno, Ka Ming Tam

Faculty Publications

We introduce an extension of the nonequilibrium dynamical mean-field theory to incorporate the effects of static random disorder in the dynamics of a many-particle system by integrating out different disorder configurations resulting in an effective time-dependent density-density interaction. We use this method to study the nonequilibrium transient dynamics of a system described by the Fermi Anderson-Hubbard model following an interaction and disorder quench. The method recovers the solution of the disorder-free case for which the system exhibits qualitatively distinct dynamical behaviors in the weak-coupling (prethermalization) and strong-coupling regimes (collapse-and-revival oscillations). However, we find that weak random disorder promotes thermalization. In …

Disentanglement In Representation Learning: Interpretability In Dimension Reduction With Vae, Minh Hong Vu

LSU Doctoral Dissertations

This research explores both theoretical and practical aspects of disentangled representation learning by extending the VAE framework. We address the core challenge of extracting independent generative factors from observed data while preserving high reconstruction fidelity. To this end, we propose two novel VAE variants: (i) the $\lambda\beta$-VAE, which incorporates an additional $\ell^2$-norm reconstruction loss to improve accuracy, and (ii) the $\gamma\beta$-VAE, which introduces a mutual information regularization term to encourage independence across latent dimensions.

Our theoretical analysis is conducted in a linear Gaussian setting, where we derive optimal solutions for these VAE-based models. We further examine how varying levels of …

Ai-Based Accessibility Widget (Aibaw) Shortcomings For Blind Web Users, Joshua A. Rovira

LSU Master's Theses

With legal, ethical, and financial motivations to make their websites more accessible, many businesses and sites have begun to employ the use of artificial intelligence (AI) based widgets to automatically make necessary modifications to their sites' pages and subdomains. In this work, we conduct a qualitative case study to determine the efficacy of these AI tools as they pertain specifically to blind users. We analyze pages from twelve websites using accessiBe's AI accessibility widget and provide a taxonomy of their violations against the Web Content Accessibility Guidelines (WCAG) 2.1 level AA compliance. We found each website to bear numerous violations …

My Tunisia Encounters: Inspiration For Some Mathematical Ideas, Hui-Hsiung Kuo

Journal of Stochastic Analysis

No abstract provided.

Wind-Resilient Solar: Harnessing Cfd For Enhanced Load Estimation, Aly Mousaad Aly

Faculty Publications

Solar panels are a cornerstone of renewable energy infrastructure, playing a pivotal role in global sustainability efforts. To ensure their resilience and long-term viability, accurate wind load estimations are essential for designing supporting structures, which account for nearly 50% of their total cost. However, traditional building codes lack comprehensive guidance for solar panels, resulting in inconsistent estimations due to discrepancies in scaled wall-bounded wind tunnel testing methodologies. These inaccuracies pose safety risks, increase costs, and hinder adoption. Emerging technologies like computational fluid dynamics (CFD) simulations offer a promising alternative by enabling full-scale analysis under realistic conditions of complete turbulence. This …

The Impact Of Visual Stimuli And The Properties Of Green Walls On Human Well-Being In Built And Immersive Virtual Environments, Alireza Sedghikhanshir

LSU Doctoral Dissertations

The built environment significantly influences human well-being, particularly in the context of stress recovery and cognitive restoration. This dissertation investigates the impact of visual stimuli, particularly green walls, on human responses related to stress, restoration, and thermal comfort. The research is guided by three primary objectives: (1) examining the role of visual stimuli and their properties in promoting stress recovery and restoration, (2) evaluating the potential of Immersive Virtual Environments (IVEs) as tools for delivering and studying restorative environments, and (3) investigating the influence of green walls on indoor environmental conditions.

A series of experimental studies were carried out to …

Intraspecific Variation In Morphological And Biochemical Responses To Salinity And Flooding In Phragmites Australis, Olivia Hurley

LSU Master's Theses

Phragmites australis is a widespread wetland plant species with numerous haplotypes, several of which are highly invasive. In low-lying coastal marshes of Louisiana, the Delta-type (haplotype M1) dominates across a wide range of salinity and flooding environments. This suggests that Phragmites may be highly adaptable to diverse environmental conditions and that there may be a genetic component, as seen in other coastal wetland plant species. While non-native Phragmites haplotypes are targeted for control and removal in many areas, they are considered beneficial for marsh stabilization and contributing to elevation gain in coastal Louisiana, where several areas experience rapid land loss. …

Optimizing Llm X86 Assembly Code Comprehension Through Fine-Tuning, Darrin Michael Lea

LSU Master's Theses

Reverse engineering is a cybersecurity process that focuses on understanding the underlying functionality of software or malware. This is an arduous process that demands large amounts of time and effort from cybersecurity practitioners. Large Language Models (LLMs) offer a potential solution to this problem. LLMs have worked their way into various fields of cybersecurity in recent years, including incident response and malware classification. However, LLMs have historically struggled with low-level code comprehension: a necessary part of reverse engineering. While LLMs can generate code and explain its function on the surface level, they struggle to grasp the wider context. In this …

Unfitted Finite Element Methods For Shape Optimization And Liquid Crystals, Jeremy T. Shahan

LSU Doctoral Dissertations

We present an approach to shape optimization problems that uses an unfitted finite element method (FEM). The domain geometry is represented, and optimized, using a (dis- crete) level set function and we consider objective functionals that are defined over bulk domains. For a discrete objective functional, defined in the unfitted FEM framework, we show that the exact discrete shape derivative essentially matches the shape derivative at the continuous level. In other words, our approach has the benefits of both optimize-then- discretize and discretize-then-optimize approaches.

Specifically, we establish the shape Fréchet differentiability of discrete (unfitted) bulk shape functionals using both the …

Innovative Design Methodology For Durable Open-Graded Friction Course Asphalt Mixtures, Anas Abualia

LSU Doctoral Dissertations

Open-graded friction course (OGFC) is a thin asphalt mixture surface layer with a high percentage of coarse aggregates and high interconnected air voids, which provides improved skid resistance, visibility, and decreased pavement-tire noise. However, construction personnel at DOTD reported that conventional OGFC mixtures have short service life (raveling distress). Further, their structural contribution to the pavement structure is commonly neglected and designed only for functionality purposes.

The objective of this study was to develop a rational mix design methodology to improve the durability of OGFC asphalt mixtures. Specific objectives are to: (1) conduct a rheological and chemical characterization of polymer-, …

“They Love Our Rhythm, But Not Our Blues:” An Examination Of The Relationship Between Hip Hop On Depression, Anxiety, And Self-Care Among African American And Hispanic/Latinx Emerging Adults, Richard W. Wiley Jr.

LSU Doctoral Dissertations

Depression and anxiety are among the most common mental health problems for emerging adults of color in higher education. Specifically, African American/Black and Hispanic/Latinx emerging adults on college campuses have poorer mental health than their White counterparts. Considering the systemic oppression and cultural stressors that impact mental health among African American/Black and Hispanic/Latinx students, Critical Race Theory (CRT) and Emerging Adulthood Theory were theoretical frameworks for this study. The purpose of this study was to examine the relationship between Hip Hop music and depression, anxiety, and intentional use as self-care among African American/Black and Hispanic/Latinx emerging adults who were college …

Modeling And Simulation Of Methane And Co2 Hydrates In Porous Media, Chico Sambo

LSU Doctoral Dissertations

This dissertation presents a comprehensive study on modeling and simulation for
methane hydrate production and CO2 sequestration. The research focuses on pore-
scale and reservoir-scale modeling techniques to understand the dynamics of gas
hydrate dissociation, the associated risks of subsidence, and the potential for CO2
storage in deep-sea environments.
This dissertation begins with an investigation into pore-scale modeling. Specif-
ically, a detailed pore network model was developed to simulate the processes of
methane hydrate dissociation and formation. However, the numerical simulations
revealed that assuming an isothermal process for hydrate formation and dissociation
is not physically realistic. Consequently, the results obtained …

The Influence Of Life Skills, Teammate And Coach Behavior, And The Sport Environment On The Mental Well-Being Of Intercollegiate Athletes, Lauren A. Shute

LSU Doctoral Dissertations

Abstract

Intercollegiate athletics generate significant interest in the United States, where concerns about the health and well-being of student-athletes have gained increased attention in recent years. Student-athletes face the same developmental challenges as their non-athlete college peers, but they also encounter biological, psychological, sociocultural, and spiritual challenges often introduced or exacerbated by their participation in sport. To assist this subgroup of the college student population in managing their various athletic, academic, and personal responsibilities, the National Collegiate Athletic Association (NCAA) has prioritized and implemented life skills programming. Yet, while much has been documented regarding life skills development at the youth …