Physical Sciences and Mathematics Commons^™

Effects Of Hydrological Connectivity On Created Marsh Sustainability, Katie Swann

LSU Master's Theses

While efforts are being made to curb the high rate of coastal land loss in Louisiana, and even to restore ecosystem services and functions, it is generally accepted that restoration of these areas and functions is not a one-to-one value. It may take decadal time scales to reach efficient functional processing of nutrients and carbon storage rates, which may never reach true capacity comparable to similar naturally-organized systems. Although it is imperative to preserve these areas, restoration of ecosystem services and biogeochemical processes of coastal wetlands are preferable to future without action scenarios. Effectively directing the use of the limited …

Computational Nanoscale Investigations Of Structure, Dynamics, And Reactivity At Solid–Liquid Interfaces, Golam Azom

LSU Doctoral Dissertations

Interfaces where two or more condensed phases meet govern phenomena central to catalysis, electrochemical energy conversion, separations, and environmental remediation. Their structural heterogeneity and dynamic nature make them challenging to probe experimentally, but computer simulations provide molecular-level insights into processes that remain inaccessible to experiments. This dissertation employs ab initio molecular dynamics (AIMD), classical molecular dynamics, and machine-learned interatomic potentials to investigate the structure, dynamics, and proton transport at graphene oxide (GO)–liquid interfaces.

The first project explores aqueous GO interfaces across a spectrum of oxidation states that extends from highly oxidized sheets to fully reduced graphene. Deep neural network force …

Modeling Nutrient Functions: Strengthening The Reliability And Applicability Of Ecosystem Service Models For Land Use Decision-Making, Mariam Gabriela Valladares Castellanos

LSU Doctoral Dissertations

Effective water quality management requires a clear understanding of both the magnitude and spatial distribution of nutrient retention and export across dynamic landscapes, given their direct implications for drinking water supply, ecosystem integrity, fisheries, and recreational uses. Equally important is anticipating trade-offs from management actions, which can alter ecosystem functioning and the flow of services. Modeling tools provide a means to predict nutrient outcomes, evaluate these trade-offs, and support decision-making; however, their utility is often constrained by persistent challenges, including model uncertainty, limited applicability in data-scarce regions, and insufficient empirical foundations to inform scenario-driven decision-making. This dissertation addresses these gaps …

User Privacy In The Digital Playground: An In-Depth Investigation Of Facebook Instant Games, Sideeq Bello

LSU Master's Theses

Amid growing concerns over data privacy in web and mobile applications, this study aims to assess the privacy mechanisms in instant games on Facebook, a platform with approximately 3.03 billion monthly active users and a substantial repository of personal data. Instant Games have become increasingly popular due to their ease of access and social integration features. Investigating these games can provide insights into privacy mechanisms and practices, thereby informing the development of more fair, compliant, and user privacy-centric gaming experiences. Thus, this study proposes an integrated analytical framework that leverages a combination of descriptive, memory, and network analysis techniques to …

A Bdg Inequality For Stochastic Volterra Integrals, Alexandre Pannier

Journal of Stochastic Analysis

We establish Burkholder-Davis-Gundy-type inequalities for stochastic Volterra integrals with a completely monotone convolution kernel, which may exhibit singular behaviour at the origin. When the supremum is taken over a finite interval, the upper bound depends linearly on the Lγ-norm of the kernel, for any γ > 2. We demonstrate the utility of this inequality in quantifying the pathwise distance between two stochastic Volterra equations with distinct kernels, with a particular emphasis on the multifactor Markovian approximation. For kernels that decay sufficiently fast, we derive an alternative inequality valid over an infinite time interval, providing uniformin- time bounds for mean-reverting stochastic Volterra …

How The Inter-Nucleon Force Shapes Emergent Collectivity And Imparts Uncertainties In Ab Initio Nuclear Observables, Kevin Becker

LSU Doctoral Dissertations

The importance of collective motion in atomic nuclei has been well-established for many decades. Even before the advent of the nuclear shell model and its much-needed answers to surprising empirical phenomena, collectivity and surface deformation have played a vital role in broadening our knowledge. Reconciling the collective and single-particle camps into a unified description required tremendous strides in the application of group theory and advances in high-performance supercomputing, and thanks to these efforts the symmetry-adapted no-core shell model, or SA-NCSM, has developed into a reliable model for the study of deformed light and medium-mass nuclei. State-of-the-art calculations reveal remarkably simple …

Compound-Specific Isotope Records Of Dust Provenance And Hydroclimate In The North Pacific And Marginal Seas Of East Asia: Integrating N-Alkane Δ13c And Δd With Standardized Analytical Frameworks, Julian W. Traphagan

LSU Doctoral Dissertations

This dissertation presents advancements in compound-specific isotope analysis (CSIA) through methodological innovation and paleoclimate reconstruction in Central and East Asia. Utilizing plant wax n-alkanes from International Ocean Discovery Program (IODP) and Ocean Drilling Program (ODP) sediment cores, this research reconstructs atmospheric circulation shifts responding to tectonic evolution and climate transitions since the Late Miocene.

Chapter 1 investigates hydrogen isotope compositions (δD_wax) from IODP U1430 (Sea of Japan), ODP 886, and ODP 1208 (North Pacific) to trace dust provenance and hydroclimate changes since ~13 Ma. Results reveal persistently segmented source-to-sink systems: the Sea of Japan dominated by westerly …

Investigation Of Co-Current And Counter-Current Multiphase Flow In Upstream Drilling And Production Applications, Hazem Fleifel

LSU Doctoral Dissertations

In the domain of upstream Petroleum Engineering, the dynamics of co-current and counter-current multiphase flows present huge challenges, significantly impacting the efficiency of associated processes. This study investigates two specific applications concerning these flow behaviors, involving both laboratory experiments and transient computer simulations. This work investigates two distinct well control and production enhancement processes, involving multiphase flow dynamics: the bullheading kill procedure and liquid-assisted gas lift (LAGL).

The first topic (Topic 1) explores the bullheading process, a type of well control methods, by challenging the traditional understanding that gas removal efficiency increases monotonically with injection pump flow rate. Through 1D …

Designing A Data Collection And Visualization Toolkit For Scalable Tensor Algebra In Quantum Chemistry Applications, Epiya J. Ebiapia

LSU Master's Theses

Large-scale quantum chemistry computations, such as those executed with the Tensor Algebra for Many-body Methods (TAMM) framework, require careful configuration of runtime parameters to achieve high performance and cost efficiency in high-performance computing (HPC) and cloud environments. Without effective performance analysis tools, researchers risk inefficient use of computational resources, leading to longer runtimes and higher costs.

To address this challenge, this thesis presents the design and implementation of a performance profiling and visualization toolkit for TAMM, developed as part of the DOE TEC4 project in collaboration with Pacific Northwest National Laboratory, Microsoft, and Louisiana State University. The toolkit collects detailed …

The Characteristic Function Of The Cube Of A Gaussian Random Variable, Andreas Boukas

Journal of Stochastic Analysis

Using the spectral resolution of the multiplication operator on the Schwartz class of L2(R,C), we compute the characteristic function of the cube of a Gaussian random variable.

Measuring The Impact On Landscape And Sediment Transport Of Climate And Anthropogenic Influence In The Mississippi River Since 2000 Bce, Bailey Wycoff

LSU Master's Theses

Understanding river dynamics is crucial to being able to interpret the geological history preserved in sediment deposited on continental margins, deltas, and alluvial plains. Sediment buffering can be a key control on the sediment flux to the ocean and involves sediment storage and recycling in flood plains. The efficiency of the transport varies depending on climatic and more recently anthropogenic influences. Sediment moving through meandering streams may be temporarily deposited in a point bar on the convex side of a meandering river. Meanders are sometimes cut off, creating an oxbow lake and filled in. The area of study, False River, …

Patterns And Processes Behind Secretive Marshbird Movement, Abundance, And Distribution Across Southeastern Louisiana, Leah Moran

LSU Doctoral Dissertations

Restoration and conservation of coastal Louisiana hinges on understanding the patterns and processes underlying habitat heterogeneity on the landscape and therefore the species that inhabits this region, including secretive marshbirds. Elusive in nature, this guild of birds has evolved under dynamic hydroperiods, and myriad plant communities present within wetlands. Only recently, however, has research focused on the role of hydrologic dynamics and vegetative structure and distribution on abundance, movement and detection of marshbirds, specifically within southeastern Louisiana. This study aimed to quantify the ecological patterns and processes, particularly hydrologic processes and landscape structure, driving breeding secretive marshbird movement, abundance and …

Operator Information Quantities Of Semigroups Associated With Functions Of The Number Operator, Ryo Inayoshi, Kimiaki Saito

Journal of Stochastic Analysis

In this paper, we present recent developments on the operator information quantity acting on white noise functionals. In particular, we give a stochastic expression of the operator information quantity of a semigroup generated by some function of the number operator through a white noise delta distribution centered at an infinite dimensional Ornstein-Uhlenbeck process.

Investigating The Relationships Among Suspended Sediment Concentration, And Marsh Edge Erosion In Barataria Bay, La, Lily Vowels

LSU Master's Theses

Barataria Bay, Louisiana, USA exhibits a unique microtidal, wind-driven hydrodynamic climate where extensive levee infrastructure throughout Louisiana has starved Barataria Bay and similar interdistributary bays of the historic levels of terrigenous sediment import. This has contributed to extreme coastal wetland loss in Louisiana. This project seeks to understand how hydrodynamic and meteorological conditions are linked to sediments’ fate after erosion from the marsh edge. Specifically, this project seeks to differentiate the roles of wave resuspension and marsh edge erosion (MEE) in sediment dynamics in Barataria Bay. An acoustic wave and current profiler (AWAC) was used to capture hydrodynamic conditions, and …

Dose Characterization Of Galactic Cosmic Rays In The Human Brain: A Phits-Based Study With A Segmented Anatomical Phantom, Shanice N. Manning

LSU Master's Theses

Astronauts aboard the International Space Station (ISS) are chronically exposed to a complex space radiation environment composed of galactic cosmic rays (GCR), solar particles, and Earth's trapped radiation. These high-energy particles interact with spacecraft shielding, producing secondary particles that can penetrate inside and deposit energy in sensitive tissues. Although animal studies have been useful in assessing space radiation risks, anatomical and physiological differences limit their applicability to human anatomy especially neuroanatomy. To address this gap, we developed a computational framework to model radiation dose distribution within the human brain using Monte Carlo simulations in Particle and Heavy Ion Transport code …

Quasistatic Peridynamics, Existence Of Unique Solution In The Presence Of Damage, Nuwanthi N. Samarawickrama

LSU Doctoral Dissertations

A mathematical model for damage propagation based on nonlocal potentials is developed within the framework of peridynamics. This model is applied to simulate damage evolution in cyclically loaded structures. By neglecting inertial effects, a well-posed quasistatic formulation for cyclic loading is obtained.\\ The resulting equation is expressed as a nonlocal and nonlinear integral operator that couples damage evolution to the deformation field.\\ This coupling occurs through the product of a damage factor and the derivative of a force potential. The damage factor ranges between zero and one, where one represents undamaged material and zero indicates complete damage.\\ It serves to …

Digital Forensics And Ai: Artifact Analysis And Using Ai In The Forensics Domain, Clinton Joel Walker

LSU Doctoral Dissertations

Digital Forensics (DF) is a field of forensic science focusing on the acquisition, authentication, and analysis of digital evidence while maintaining integrity of that data. DF analysts use forensic tools to parse large volumes of data for investigations and depend on them for identification of pertinent digital evidence in vast amounts of data. Keeping up with innovations and ever-expanding data volumes is a constant challenge for these investigators. The prevalence of Artificial Intelligence (AI) in everyday computing is rapidly expanding, with the use of Machine Learning (ML) and Large Language Models (LLM)s becoming increasingly commonplace. Innovations in technology bring new …

Towards Leveraging Social Media Data For Fostering Collaborations Among Non-Profits, Monazil Chowdhury

LSU Doctoral Dissertations

Nonprofit organizations serve a crucial role in tackling a wide range of significant social, environmental, and economic issues. But it is often hard to get a clear picture of their work because their information is spread out and it is difficult to see how they are collaborating. To address this issue we developed a web-based tool to collect scattered data—from a variety of sources, such as the IRS, social media, and the Census, into one easy-to-use resource. The tool begins by taking IRS records and geocoding each nonprofit’s physical address With its coordinates. It then retrieves census tract information from …

Quantitative Boundary Doubling Estimates For Elliptic Equations, Jack Dalberg

LSU Doctoral Dissertations

We present an approach for obtaining quantitative boundary doubling inequalities for elliptic equations with Neumann boundary conditions. Carleman estimates are used to prove three-ball inequalities, which are then used to prove quantitative doubling inequalities, with bootstrapping from the interior to the boundary. This approach is illustrated by its application to the Laplace eigenvalue problem with homogeneous Neumann boundary conditions, where sharp doubling inequalities are recovered.

When then consider a equation with non homogeneous Neumann boundary conditions. By following the approach, we are able to obtain potentially sharp results. Finally, we are able to get an improvement on previously obtained results …

Gain Threshold Optimization Using Fano Resonance, Alina Oktiabrskaia

LSU Doctoral Dissertations

The study of resonances in electromagnetics plays a critical role in the design of optical systems. This dissertation investigates the interaction between resonance and gain in optical structures to establish a universal principle for achieving ultra-low-threshold lasing. Through the analysis of geometric symmetries, material properties, and coupling mechanisms, this research develops prototype structures applicable to a wide range of optical and electromagnetic systems. A range of models is considered, starting from a simple onedimensional string-resonator system (based on the model of H. Lamb), then advancing to two- and three-dimensional waveguide models, and culminating with a realistic high-contrast model in open …

The Search For Magnetar Giant Flares In Archival Gamma-Ray Burst Data To Constrain Their Rates And Energetics, Aaron Trigg

LSU Doctoral Dissertations

Magnetar giant flares are rare, extremely bright bursts of gamma-rays from highly magnetized neutron stars. These events are difficult to identify because, at extragalactic distances, they can appear similar to other astrophysical phenomena. Only a handful have been confidently identified to date, limiting our understanding of their origin and physical properties. This dissertation focuses on expanding the sample of known events and enabling a more detailed characterization of their observational features. We report on two newly identified examples, GRB 180128A and GRB 231115A, that are consistent with a magnetar origin based on their spectral properties and association with nearby star-forming …

Investigation Of Subcellular Damage And Long-Term Non-Cancerous Cardiovascular Effects Following Whole-Body Photon Irradiation, Nousha Afshari

LSU Doctoral Dissertations

Current radiobiological models focus primarily on nuclear DNA damage and fail to fully explain radiation-induced noncancerous health effects. This dissertation investigates whether non-nuclear subcellular structures contribute to radiation-induced biological damage through experimental biomarker analysis and computational microdosimetry. The central hypothesis posits that whole-body photon irradiation results in subcellular non-nuclear damage, specifically increased circulating mitochondrial DNA concentrations, that correlates with radiation dose and long-term noncancerous effects such as cardiovascular disease.

Specific Aim 1 measured mitochondrial and nuclear DNA concentrations in banked blood samples from 72 Chinese rhesus macaques that previously received whole-body photon irradiation ($0-10$ Gy) from Cobalt-60 or LINAC sources. …

Increasing The Economic And Social Viability Of Carbon Capture Using Biomass Slurry Fracture Injection, Zachary G. Laird

LSU Master's Theses

The climate is changing. This is a fact not a statement, not a theory, and not a falsehood, this is a fact. At the current projections the world’s average temperature is expected to rise by at least 2°C from pre-industrial averages by 2050 (Emissions Pathways to 2100 - Climate Action Tracker, 2024). This temperature rise will be catastrophic for a vast number of communities. What is driving this changing climate? Humans. In particular the carbon emissions caused by human activities. As humans we consume large amounts of meat, causing the need for cattle to increase, generating large amounts …

A Theory Of Fundamental Strata For Twisted Formal Connections, Sorawit Viwanthananut

LSU Doctoral Dissertations

Let $G$ be a complex reductive group. A fundamental stratum for $G$ is a triple $(x,r,\beta)$ where $x$ is a point in the Bruhat-Tits building of $G$, $r$ is a nonnegative real number called depth of the stratum, and $\beta$ is a semistable functional on the Moy-Prasad filtration of $\fg$ associated to $x$ at level $r$. Fundamental strata were first introduced to classify admissible representations of a $p$-adic reductive group. More recently, Bremer and Sage have shown that fundamental strata play an important role in the geometric Langlands program and developed a theory of fundamental strata for $G$-connections. In this …

Strichartz Estimates For Many Particle Dispersive Equations, Tristan Reynoso

LSU Doctoral Dissertations

Dispersive equations are useful for describing a wide variety of phenomena in which solutions disperse through the space as time progresses. These equations show up frequently in physics, especially when studying quantum mechanical and fluid related systems. The single particle variants of equations such as the Schr\"{o}dinger and Wave equations have been studied at great length throughout modern history. Over the last couple decades progress has been made toward extending single particle dispersive equations to cover their many body counterparts. Space-time Strichartz estimates for the homogenous $N$-particle Schr\"{o}dinger equation with small interacting potentials was recently established on both $\mathbb{R}^d$ and …

Source Origins Of Hunter-Harvested Waterfowl In Arkansas And Louisiana, Shannon C. Stemaly

LSU Master's Theses

Understanding variability in breeding origins of harvested waterfowl is important for effective population management and regional conservation. Band-recovery data are often used to estimate harvest derivation and inform resource allocation for cross-seasonal conservation. However, uneven spatial and temporal banding effort across species' breeding ranges may result in an incomplete understanding of summer origins and recruitment, particularly if portions of the breeding range are inaccessible. Analysis of stable-hydrogen isotope ratios in duck feathers (δ²H_f) provides an alternative method for identifying source origins of unmarked populations since environmental deuterium values follow a predictable latitudinal gradient across North …

On Excursions Associated With A Certain Local Time Of Simple Symmetric Random Walks, With Applications, Takahiko Fujita, Naohiro Yoshida

Journal of Stochastic Analysis

In this note, some applications of excursions associated with a certain local time of simple symmetric random walks are presented. Specifically, the excursions are applied to calculate some probability distributions of interest regarding the random walks. Furthermore, a solution of the Skorokhod embedding problem for random walks is obtained through the excursions.

The Jacod-Yor Theorem For Sigma Martingales And The Second Fundamental, Moritz Sohns

Journal of Stochastic Analysis

In this paper, we prove the Jacod-Yor Theorem for sigma martingales, a class of processes that generalize local martingales and play a pivotal role in financial mathematics. While the Jacod-Yor Theorem has been extensively studied for L2-martingales, martingales, and local martingales, no prior version exists for sigma martingales. Our result establishes the connection between sigma martingales and their martingale representation properties, addressing a critical gap in the literature. As an application, we prove the Second Fundamental Theorem of Asset Pricing for markets where price processes are modeled as sigma martingales.

Investigating The Role Of Aerosols In Extreme Precipitation Events Along The Gulf Coast Of The U.S.A., Wenjia Cao

LSU Doctoral Dissertations

Atmospheric aerosols have been found to influence tropical cyclone (TC) and flood event development. In this study, the Weather Research and Forecasting model is applied to investigate specific microphysical impacts and aerosol sensitivity to heavy precipitation and TC events in the U.S. Gulf Coastal area. The Thompson aerosol-aware scheme with regular and adjusted aerosol concentration scenarios is used to quantify precipitation, wind field, horizontal/vertical structures, and track variations, by aerosol mixing ratio. In general, results for the three storms analyzed (the 2016 Baton Rouge, Louisiana, flood event (Chapter 2); Hurricane Harvey in 2017 (Chapter 3); and an idealized storm event …

Estimating The Future Frequency Of Bonnet Carré Spillway Openings, Kayla Thomas

LSU Master's Theses

In the 2010s, the Bonnet Carré Spillway (BCS) in southeastern Louisiana, U.S.A., experienced an unprecedented uptick in openings to mitigate the possibility of flooding, including a record double-opening in 2019. Both the environmental consequences of BCS openings associated with nutrients that run from the Mississippi River into Lake Pontchartrain and the synoptic-scale meteorological conditions that necessitate these openings are poorly understood. With the unexpectedly frequent openings in recent years and the ever-present threat of climate change, it is vital to consider the future shift of synoptic-scale climate patterns and how it can relate to BCS openings. Understanding the potential for …