Digital Commons Network^™

Finite Monodromy And Artin Representations, Emma Lien

LSU Doctoral Dissertations

Artin representations, which are complex representations of finite Galois groups, appear in many contexts in number theory. The Langlands program predicts that Galois representations like these should arise from automorphic representations and many examples of this correspondence have been found such as in the proof of Fermat's Last Theorem. This dissertation aims to make an analysis of explicitly computable examples of Artin representations from both sides of this correspondence. On the automorphic side, certain weight 1 modular forms have been shown to be related to Artin representations and an explicit analysis of their Fourier coefficients allows us to identify the …

The Theory Of X-Ray And Neutron Interferometry Using A Modulated Phase Grating, Hunter C. Meyer

LSU Master's Theses

Grating interferometry exploits wave interference to simultaneously image multiple physical properties of an object and can be performed using X-rays or neutrons. The modulated phase grating interferometer (MPGI) is a recently developed interferometry system that allows for the simultaneous acquisition of attenuation, differential-phase contrast, and dark-field images, which highlight X-ray or neutron absorption, refraction, and small angle scatter, respectively. This interferometry system uses a single grating, with a relatively high period envelope function, to produce interference fringes that can be directly resolved by standard high resolution detectors. The grating is sampled at a relatively low pitch, to meet coherence requirements …

Estimating Crustal Thickness In Northwest Louisiana Using The Receiver Function Method, Delton Samuel

LSU Master's Theses

I aim to constrain the crustal thickness of the Sabine Block in the Sabine Uplift region of northwest Louisiana, using the frequency domain receiver function deconvolution technique followed by H-κ stacking. The passive margin on the southern edge of the North American continent experienced an active tectonic history, including the spreading events that led to the formation of the Gulf of Mexico. A previous study proposed the Sabine Block is a residual fragment of Proterozoic orogenic origin; however, its full extent and geometry are up for debate. It is now overlain by thick sedimentary sequences ranging from ~4-6 km deposited …

Computational Modeling Of Nanoscale Interaction Of Plasmonic Materials With 2d Materials For Sensing Applications, Maria Iftesum

LSU Master's Theses

Plasmonics is a new and exciting field that has the potential to advance many different types of technology, from information processing and energy harvesting to sensing and imaging. The broad field of plasmonic materials and their potential to improve the functionality of cutting-edge technologies are examined in this thesis.

The thesis explores the synthesis, characterization, and manipulation of plasmonic materials after providing an overview of the basic ideas behind plasmonics. Their distinct plasmonic properties and possible uses are clarified by a thorough investigation of a variety of materials, including noble metals, two-dimensional materials, metal oxides and hybrid structures.

A thorough …

Quantification Of Belowground Biomass And Sediment Accretion In Mangroves Of Different Coastal Environmental Settings Of The Costa Rican Pacific Coast, Denise M. Poveda

LSU Master's Theses

The adaptation of intertidal ecosystems such as mangroves to anticipated accelerated relative sea level rise is dependent on net increase of sediment surface elevations and forest migration inland. Ecosystem models developed to simulate trajectories of ecosystem adaptations have determined that rates of soil formation are most sensitive to surface sediment (organic and inorganic) deposition and subsurface organic production by mangrove roots. Mangrove belowground biomass contributes to soil organic matter accumulation, while mangrove litter has minor contribution due to export and annual decay. In addition to belowground biomass production, inorganic sediment loading is also key contribution to soil formation and accretion. …

Profiling Of Voltage-Gated Sodium Channel Subtype Expression And Resulting Susceptibility To Targeted Osmotic Lysis In Cancer, Spencer Gerard Lemoine

LSU Doctoral Dissertations

Cancer is a disease characterized by a wide array of dysregulated cellular function, activity, and growth. At times, specific dysregulations associated with cancer can be exploited as avenues of potential treatment. The sodium handling mechanisms and their associated proteins in cancer have received closer attention recently closely as such a potential mechanism to exploit for treating advanced cancer. Some novel treatments aim to inhibit the expression or activity of these sodium handling proteins in an attempt to prevent the cancer from advancing or becoming more aggressive; however, such approaches have had limited success. Targeted osmotic lysis (TOL) is a new …

The Modular Generalized Springer Correspondence For The Symplectic Group, Joseph Dorta

LSU Doctoral Dissertations

The Modular Generalized Springer Correspondence (MGSC), as developed by Achar, Juteau, Henderson, and Riche, stands as a significant extension of the early groundwork laid by Lusztig's Springer Correspondence in characteristic zero which provided crucial insights into the representation theory of finite groups of Lie type. Building upon Lusztig's work, a generalized version of the Springer Correspondence was later formulated to encompass broader contexts.

In the realm of modular representation theory, Juteau's efforts gave rise to the Modular Springer Correspondence, offering a framework to explore the interplay between algebraic geometry and representation theory in positive characteristic. Achar, Juteau, Henderson, and Riche …

Subgroups Of Coxeter Groups And Stallings Foldings, Jake A. Murphy

LSU Doctoral Dissertations

For each finitely generated subgroup of a Coxeter group, we define a cell complex called a completion. We show that these completions characterizes the index and normality of the subgroup. We construct a completion corresponding to the intersection of two subgroups and use this construction to characterize malnormality of subgroups of right-angled Coxeter groups. Finally, we show that if a completion of a subgroup is finite, then the subgroup is quasiconvex. Using this, we show that certain reflection subgroups of a Coxeter are quasiconvex.

“Redención”: Testimonios Of Latinas Who Chose To Leave The Higher Education Industry, Delia P. Madrid-Nothdurft

LSU Doctoral Dissertations

Using the methodological framework of testimonio, this study was an exploration of the experiences of former higher education professionals who identify as women in the Latinx community. Grounded in Latino Critical Theory (LatCrit) and Critical Race Feminism (CRF), this research aims to highlight the narratives of Latina professionals who have separated from the higher education sector. The study is informed by the conceptual framework of Chicana feminist perspective, which contextualizes the analysis of these experiences within a socio-cultural context. Using semi-structured interviews, participants shared their testimonios, providing rich accounts of their journeys and challenges within higher education. Through thematic …

Analytic Wavefront Sets Of Spherical Distributions On The De Sitter Space, Iswarya Sitiraju

LSU Doctoral Dissertations

In this work, we determine the wavefront set of certain eigendistributions of the Laplace-Beltrami operator on the de Sitter space. Let G′ = O_1,n(R) be the Lorentz group, and let H′ = O_1,n−1(R) ⊂ G′ be its subset. The de Sitter space dSⁿ is a one-sheeted hyperboloid in R^1,n isomorphic to G′/H′. A spherical distribution is an H′-invariant eigendistribution of the Laplace-Beltrami operator on dSⁿ. The space of spherical distributions with eigenvalue λ, denoted by D_λ^H'(dSⁿ), has dimension 2. We construct a basis for the space of …

Applied Depositional Geosystems Of The Coos Bay Basin, Oregon: Organic Geochemistry, Maturation, Paleoenvironmental Reconstruction And Biostratigraphy Of The Coaledo Delta During The Middle Eocene Climatic Optimum (Meco), Allison K. Barbato

LSU Doctoral Dissertations

The Coos Bay Basin on the southwestern coast of Oregon is a forearc basin that contains exceptionally preserved Eocene to Miocene, tidal to wave-dominated, shallow deltaic to deep marine sediments of the Coaledo Delta. Coastal depositional environments are known to host source, reservoir, and seal rocks. Climate, topographic relief, and geographical position all play an important role in regional vegetation development and oceanic setting. This study assesses 84 outcrop and 12 core samples from Coos Bay for their organic geochemical characteristics and microfossil assemblage to provide source rock characterization information, organofacies descriptions, environmental reconstructions, and age control.

Results indicate the …

Unavoidable Topological Minors Of Large Or Infinite 3-Connected Rooted Graphs, Phuc A. Nguyen

LSU Doctoral Dissertations

The goal of this thesis is to determine the unavoidable topological minors of large and infinite $ 3 $-connected rooted graphs, where a rooted graph is a graph $ G $ together with a specified subset $ X $ of $ V(G) $ or $ E(G) $. We have two results for finite graphs. First, every $ 3 $-connected finite graph $ G $ with a sufficiently large $ X \subseteq E(G) $ must contain a topological minor $ K_{3, n}, W_n $, or $ V_n $, using many edges of $ X $, where $ W_n $ is a …

Thermal Frontal Polymerization – Applications In Coatings And Composites, Maria Martinez

LSU Doctoral Dissertations

Thermal frontal polymerization has long been used as a method to cure composites and coatings. However, this is the first time these applications have been used without the use of a catalyst, for the case of composites and coatings.

Chapter 2 discusses how to optimize cure-on-demand, thin layer coatings, using frontal polymerization. Previously, for the use of curing thin layer coating using thermal FP, it was known to just make the formulation viscous enough, as this would prevent premature quenching caused by heat loss. It was discovered that for a given layer thickness, a minimum viscosity and initiator concentration were …

Two New Catalysts For Oxidation Of Water To Oxygen, Takia Sultana

LSU Master's Theses

If fuels, such as hydrogen or methanol, are to be produced from renewable energy (solar or wind) in the future, efficient catalysts will be needed, not only for fuel production reactions but for the essential simultaneous oxidation of water to O₂. Ruthenium complexes are among the more promising water oxidation catalysts (WOCs). Two new isomeric ruthenium WOCs have been prepared based on the benzylpyridyltriazole ligand (Figure 3); trans-py-[Ru(tpy)(bpt)(H₂O)]²⁺ (trans-py-1) and trans-trz-[Ru(tpy)(bpt)(H₂O)]²⁺ (trans-trz-1) (tpy = 2,2’:6’,2’’-terpyridine, bpt = benzylpyridyltriazole). Ceric ammonium nitrate [(CAN)/Ce(IV)] oxidants were …

Improving Implicit Communication In Remote Collaboration Through Augmented Reality And Digital Twins, Nicholas Levergne

LSU Master's Theses

Large scale digital twinning projects are beginning to emerge across the tech industry. Within these projects is a desire to integrate augmented reality capabilities into industrial workflows. However, research on augmented reality technology for remote collaboration lacks ecologically valid studies of real world scenarios. Additionally, prior remote collaboration literature is focused on white-collar applications instead of blue-collar field work. Prior AR collaboration software is similarly limited, with most software allowing mixed camera views and annotation that requires participants to be stationary. This thesis introduces SpectAR, an augmented reality and desktop remote collaboration software suite developed in Unreal Engine 5.1.1. SpectAR …

Effects Of Music Instruction For 3-4-Year-Old Children On Cognitive Development And Spatial Skills, Veronica Perez Espinosa

LSU Master's Theses

The impact of music instruction on child cognitive development has been examined by researchers in many contexts, but not as often in very young children. The purpose of the present study was to investigate the effects of music instruction on the spatial and cognitive skills of preschool children ages 3-4. Participants in the study were 68 three- to four-year-old students who received weekly music instruction at a private school in South Louisiana. Of the 68 participants, and using a quasi-experimental design, 30 students in three intact classes were randomly assigned to receive a movement song treatment and the other 38 …

Field Evaluation Of Experimental Maize Hybrids For Resistance To The Fall Armyworm (Lepidoptera: Noctuidae) In A Warm Temperate Climate, Xinzhi Ni, Alisa Huffaker, Eric A. Schmelz, Wenwei Xu, W. Paul Williams, Baozhu Guo, Xianchun Li, Fangneng Huang

Faculty Publications

The polyphagous fall armyworm (FAW), Spodoptera frugiperda, has become an invasive pest worldwide in recent years. To develop maize germplasm with multiple pest resistance and understand genetic inheritance, 12 experimental hybrids (six pairs of reciprocal crosses) with diverse genetic backgrounds and four commercial checks were examined for FAW resistance in 2013 and 2014. The experiment utilized a randomized complete block design with four replications as the block factor. FAW injury on maize plants was assessed at 7 and 14 d after the artificial infestation at the V6 stage, and predatory arthropod taxa and abundance on maize seedlings were recorded 7 …

Preferential Hydrologic States And Tipping Characteristics Of Global Surface Soil Moisture, Vinit Sehgal, Binayak P. Mohanty

Faculty Publications

A dynamic transition in soil hydrologic states through meteorological variability and terrestrial feedback governs soil-vegetation-climate (SVC) interactions, constrained by critical soil moisture (SM) thresholds. However, observational and scaling constraints limit critical SM threshold estimation at the remote-sensing (RS) footprint scale. Using global surface SM (θRS) from NASA’s Soil Moisture Active Passive (SMAP) satellite, we characterize the seasonal preferential hydrologic states of θRS and derive three tipping characteristics to estimate the intensity (Mean Tipping Depth, (Formula presented.)), frequency (Tipping Count, η), and duration (Mean Tipped Time, (Formula presented.)) of the excursion of θRS from wet- to dry-average conditions. The preferential state …

A Joint Fermi-Gbm And Swift-Bat Analysis Of Gravitational-Wave Candidates From The Third Gravitational-Wave Observing Run, C. Fletcher, J. Wood, R. Hamburg, P. Veres, C. M. Hui, E. Bissaldi, M. S. Briggs, E. Burns, W. H. Cleveland, M. M. Giles, A. Goldstein, B. A. Hristov, D. Kocevski, S. Lesage, B. Mailyan, C. Malacaria, S. Poolakkil, A. Von Kienlin, C. A. Wilson-Hodge, M. Crnogorčević, J. Delaunay, A. Tohuvavohu, R. Caputo, S. B. Cenko, S. Laha, T. Parsotan, R. Abbott, H. Abe, F. Acernese, K. Ackley, N. Adhikari, R. X. Adhikari, V. K. Adkins

Faculty Publications

We present Fermi Gamma-ray Burst Monitor (Fermi-GBM) and Swift Burst Alert Telescope (Swift-BAT) searches for gamma-ray/X-ray counterparts to gravitational-wave (GW) candidate events identified during the third observing run of the Advanced LIGO and Advanced Virgo detectors. Using Fermi-GBM onboard triggers and subthreshold gamma-ray burst (GRB) candidates found in the Fermi-GBM ground analyses, the Targeted Search and the Untargeted Search, we investigate whether there are any coincident GRBs associated with the GWs. We also search the Swift-BAT rate data around the GW times to determine whether a GRB counterpart is present. No counterparts are found. Using both the Fermi-GBM Targeted Search …

Homology Growth, Hyperbolization, And Fibering, Grigori Avramidi, Boris Okun, Kevin Schreve

Faculty Publications

We introduce a hyperbolic reflection group trick which builds closed aspherical manifolds out of compact ones and preserves hyperbolicity, residual finiteness, and—for almost all primes p—-homology growth above the middle dimension. We use this trick, embedding theory and manifold topology to construct Gromov hyperbolic 7-manifolds that do not virtually fiber over a circle out of graph products of large finite groups.

Teenage Blues: Predictors Of Depression Among Adolescents In Nigeria, Adefunke Dadematthews, Chukwuemeka Nzeakah, Lucky Onofa, Oluwagbemiga Dadematthews, Temitope Ogundare

Faculty Publications

Background Depressive disorders, with a prevalence of 15-21%, are among the most common disorders in children and adolescents, and increases the risk of suicide, the second leading cause of death in children aged 10 to 19. Aim To determine the prevalence and correlates of depressive disorders among senior students attending secondary schools in Abeokuta. Method The study was conducted in five schools randomly selected from a representative sample and was carried out in 2 phases. In the first phase, students were selected via systematic random sampling and given consent forms and GHQ-12 to administer to the parents. In the second …

Quantitative Comparison Of Tddft-Calculated High Harmonic Generation Yields In Ringshaped Organic Molecules, Stephanie Armond

Honors Capstones

No abstract provided.

Modeling And Numerical Analysis Of The Cholesteric Landau-De Gennes Model, Andrew L. Hicks

LSU Doctoral Dissertations

This thesis gives an analysis of modeling and numerical issues in the Landau-de Gennes (LdG) model of nematic liquid crystals (LCs) with cholesteric effects. We derive various time-step restrictions for a (weighted) $L^2$ gradient flow scheme to be energy decreasing. Furthermore, we prove a mesh size restriction, for finite element discretizations, that is critical to avoid spurious numerical artifacts in discrete minimizers that is not well-known in the LC literature, particularly when simulating cholesteric LCs that exhibit ``twist''. Furthermore, we perform a computational exploration of the model and present several numerical simulations in 3-D, on both slab geometries and spherical …

Interactive Effects Of Co2, Temperature, And Nitrate Limitation On The Growth And Physiology Of Marine Cyanobacterium Synechococcus Sp. Ccmp 1334, Alyssa K. Sharbaugh

LSU Master's Theses

The marine cyanobacterium Synechococcus sp. CCMP 1334 was grown in a continuous culture system on a 12:12 h light:dark cycle at all combinations of low and high pCO2 (400 and 1000 ppmv, respectively), nitrate availability (nitrate-limited and nutrient-replete conditions), and temperatures of 21°C, 24°C, 28°C, 32°C, and 35°C. The maximum median nutrient-replete growth rate was ~1.15 d−1 at 32 –35°C. Median growth rates at 1000 ppmv pCO2 were higher than those at 400 ppmv at all temperatures, but most of the differences were statistically insignificant. Carbon:nitrogen ratios were independent of pCO2 at a fixed relative growth rate but decreased with …

Role Of Electronegativity In Environmentally Persistent Free Radicals (Epfrs) Formation On Zno, Syed Monjur Ahmed, Reuben A. Oumnov, Orhan Kizilkaya, Randall W. Hall, Phillip T. Sprunger, Robert L. Cook

Faculty Publications

Environmentally persistent free radicals (EPFRs), a group of emerging pollutants, have significantly longer lifetimes than typical free radicals. EPFRs form by the adsorption of organic precursors on a transition metal oxide (TMO) surface involving electron charge transfer between the organic and TMO. In this paper, dihalogenated benzenes were incorporated to study the role of electronegativity in the electron transfer process to obtain a fundamental knowledge of EPFR formation mechanism on ZnO. Upon chemisorption on ZnO nanoparticles at 250 °C, electron paramagnetic resonance (EPR) confirms the formation of oxygen adjacent carbon-centered organic free radicals with concentrations between 10¹⁶ and 10 …

17O-Excess In Tropical Cyclones Reflects Local Rain Re-Evaporation More Than Moisture Source Conditions, Chijun Sun, Timothy Shanahan, Shaoneng He, Adriana Bailey, Jesse Nusbaumer, Jun Hu, Aubrey Hillman, Erika Ornouski, Jacob Warner, Kristine Delong

Faculty Publications

17O-excess is a relatively new water isotope parameter that could potentially provide useful information about the hydrological cycle. Previous works focusing on 17O-excess in polar regions suggest that it primarily tracks moisture source relative humidity, but little is known about how to interpret 17O-excess data in lower latitudes. Here we present quasi-hourly triple oxygen isotope data of precipitation collected from two tropical cyclones in Texas and Louisiana in 2020 to understand the impacts of environmental and meteorological processes on the 17O-excess of low-to mid-latitude precipitation. We find that at both hourly timescales and the event scale, 17O-excess is strongly correlated …

Sensor Analytics For Subsea Pipeline And Cable Inspection: A Review, Connor R. Vincent

LSU Master's Theses

Submarine pipelines and cables are vital for transmitting physical and digital resources across bodies of water, necessitating regular inspection to assess maintenance needs. The safety of subsea pipelines and cables is paramount for sustaining industries such as telecommunications, power transmission, water supply, waste management, and oil and gas. Incidents like those involving the Nord Stream subsea pipeline and the SEA-ME-WE 4 subsea communications cable exemplify the severe economic and environmental consequences of damage to these critical infrastructures. Existing inspection methods often fail to meet accuracy requirements, emphasizing the need for advancements in inspection technologies. This comprehensive survey covers the sensors …

An Analysis And Ontology Of Teaching Methods In Cybersecurity Education, Sarah Buckley

LSU Master's Theses

The growing cybersecurity workforce gap underscores the urgent need to address deficiencies in cybersecurity education: the current education system is not producing competent cybersecurity professionals, and current efforts are not informing the non-technical general public of basic cybersecurity practices. We argue that this gap is compounded by a fundamental disconnect between cybersecurity education literature and established education theory. Our research addresses this issue by examining the alignment of cybersecurity education literature concerning educational methods and tools with education literature.

In our research, we endeavor to bridge this gap by critically analyzing the alignment of cybersecurity education literature with education theory. …

Investigation Of Gas Dynamics In Water And Oil-Based Muds Using Das, Dts, And Dss Measurements, Temitayo S. Adeyemi

LSU Master's Theses

Reliable prediction of gas migration velocity, void fraction, and length of gas-affected region in water and oil-based muds is essential for effective planning, control, and optimization of drilling operations. However, there is a gap in our understanding of gas behavior and dynamics in water and oil-based muds. This is a consequence of the use of experimental systems that are not representative of field-scale conditions. This study seeks to bridge the gap via the well-scale deployment of distributed fiber-optic sensors for real-time monitoring of gas behavior and dynamics in water and oil-based mud. The aforementioned parameters were estimated in real-time using …

Characterizing And Mitigating Transient Noise In Ligo Observatories For Gravitational Wave Detection, Jane Glanzer

LSU Doctoral Dissertations

The existence of gravitational waves is predicted by Albert Einstein's Theory of General Relativity. Commonly referred to as "ripples in spacetime", these waves are generated by some of the most violent and energetic processes in the universe. Despite their theoretical prediction over a century ago, it wasn't until 2015 that the Advanced LIGO (aLIGO) interferometers in Hanford, WA and Livingston, LA directly detected gravitational waves for the first time, confirming Einstein's theory and ushering in a new era of astrophysics.

Detecting gravitational waves requires incredible precision. Because of the extreme sensitivity required, it is possible for the gravitational wave data …