Digital Commons Network^™

Anion Exchange Membrane Durability For Electrochemical Co2 Reduction In Membrane Electrode Assembly Cells, Soundarzo Tasnim

LSU Master's Theses

The electrochemical reduction of CO₂ using membrane electrode assembly (MEA) cells has emerged as a promising approach for carbon capture and conversion into valuable products. This study investigates the degradation mechanisms of anion exchange membranes (AEMs) in CO₂ reduction applications, focusing on Sustainion X37-50, PiperION, and FAA-3-50. The research analyzes the impact of chemical and mechanical degradation on membrane performance, highlighting key stability challenges in long-term operation. Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS) were employed to monitor functional group stability and ionic conductivity loss over extended operation. The results indicate that hydroxide-induced degradation leads to nucleophilic …

Exploring The Validity Of Vocabulary Assessments In Racially, Dialectically, And Socioeconomically Diverse Preschool Populations, Lauren Betzer

LSU Master's Theses

Recent research has advocated for interactive assessments of vocabulary over more traditional, static assessments, as interactive assessments are more sensitive to linguistic and cultural diversity. Static vocabulary assessments, such as the Peabody Picture Vocabulary Test (PPVT), probe existing knowledge, while interactive assessments, such as the Quick Interactive Language Screener (QUILS), examines a child’s language in a wholistic manner by assessing previously learned vocabulary knowledge, syntactic knowledge, and processing when learning a new concept. It remains unclear which assessment more accurately captures children's vocabulary knowledge throughout the Deep South—a region characterized by its unique cultural and linguistic environment, which includes the …

Water Exposure Time Distributions Controlled By Freshwater Releases In A Semi-Enclosed Estuary, Caitlin R.R. Turner, Matthew Hiatt

Faculty Publications

Freshwater diversions manage water shortages, salinity, and control floodwater by redirecting river flows; however, their full ecological and hydrological impact remains unknown. This study examines the Lake Pontchartrain Estuary in Louisiana using a hydrodynamic model and Lagrangian particle tracking to assess how diversion operations (open, closed) and tributary discharge levels (low, median, high) influence water exposure time—the cumulative duration water remains in a domain, including re-entry. Exposure time was analyzed based on the time required for 50%, 75%, and 90% of released particles ((Formula presented.), (Formula presented.), and (Formula presented.)) to leave a defined region of interest (ROI). Results show …

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 …

Understanding The Effect Of Chiral Nn Parametrization On Nuclear Shapes From An Ab Initio Perspective, Kevin S. Becker, Kristina D. Launey, Andreas Ekström, Grigor H. Sargsyan, Darin C. Mumma, Tomáš Dytrych, Daniel Langr, Jerry P. Draayer

Faculty Publications

The ab initio symmetry-adapted no-core shell model naturally describes nuclear deformation and collectivity, and is therefore well-suited to studying the dynamics and coexistence of shapes in atomic nuclei. For the first time, we analyze how these features in low-lying states of⁶Li and¹²C are impacted by the underlying realistic nucleon-nucleon interaction. We find that the interaction parametrization has a notable but limited effect on collective shapes in the lowest⁶Li and¹²C states, while collective structures in the excited 2⁺ state of¹²C are significantly more sensitive to the interaction parameters and exhibits …

Gatekeeper Training As A Form Of Suicide Prevention: An Evaluation Of Applied Suicide Intervention Skills Training (Asist), Sarah E. Pardue-Bourgeois

LSU Doctoral Dissertations

Applied Suicide Intervention Skills Training (ASIST) is the most widely used gatekeeper training (McAuliffe & Perry, 2007) and the literature examining its effects shows strong support for self-reported changes in attitudes and knowledge regarding suicide, and confidence to intervene with a person with thoughts of suicide (Gould et al., 2013; Shannonhouse et al., 2017a; Shannonhouse et al., 2017b; Shannonhouse et al., 2019). However, no research currently exists that investigates whether individuals trained in ASIST can provide the suicide-specific intervention skills post-training. Thus, the current study sought to extend the current literature by broadly investigating the following aims. Study aims investigated …

Intersectionality And Experiences With Mental Health Care: Transgender And Gender Diverse Autistic Adults, Megan Callahan

LSU Doctoral Dissertations

Current prevalence rates of autism spectrum disorder (ASD) in transgender and gender diverse (TGD) populations range between 4 and 13% (Thrower et al., 2020). Studies into autistic TGD individuals’ experiences with healthcare have primarily collected qualitative data, identifying themes including barriers to healthcare, invalidation of both autistic and TGD identities, difficulty finding competent providers, limited support and resources, and refusal of care (Cooper et al., 2022; Maroney & Horne, 2022; Hall et al., 2020). N = 3094 self-identified TGD adults completed the 2017 TransLifeline Mental Health Survey, a collaborative effort between the National LGBTQ Task Force and the TransLifeline, which …

Stomach Content And Stable Isotope Analysis Of Invasive Lionfish (Pterois Volitans) In The Florida Keys, Emily E. Shallow, Cassandra N. Glaspie, Michael J. Polito, Mitchell S. Lovell

Faculty Publications

The invasive red lionfish, Pterois volitans, plays a unique role in seagrass and reef ecosystems, where it functions as a top predator and competitor for both food and shelter. Given the ubiquitous distribution of lionfish in the Gulf of Mexico and Caribbean basins, their species provides an excellent opportunity to understand how an invasive predator's diet and primary energy pathways change as a function of size and habitat type. To investigate these patterns, we studied lionfish from a mosaic of deep reef, shallow patch reef, and seagrass bed habitats in the Florida Keys using stomach contents and stable isotope analysis …

High-Significance Detection Of Correlation Between The Unresolved Gamma-Ray Background And The Large-Scale Cosmic Structure, B. Thakore, M. Negro, M. Regis, S. Camera, D. Gruen, N. Fornengo, A. Roodman, A. Porredon, T. Schutt, A. Cuoco, A. Alarcon, A. Amon, K. Bechtol, M. Becker, G. Bernstein, A. Campos, A. Carnero Rosell, M. Carrasco Kind, R. Cawthon, C. Chang, R. Chen, A. Choi, J. Cordero, C. Davis, J. Derose, H. Diehl, S. Dodelson, C. Doux, A. Drlica-Wagner, K. Eckert, J. Elvin-Poole, S. Everett, A. Ferté

Faculty Publications

Our understanding of the γ-ray sky has improved dramatically in the past decade, however, the unresolved γ-ray background (UGRB) still has a potential wealth of information about the faintest γ-ray sources pervading the Universe. Statistical cross-correlations with tracers of cosmic structure can indirectly identify the populations that most characterize the γ-ray background. In this study, we analyze the angular correlation between the γ-ray background and the matter distribution in the Universe as traced by gravitational lensing, leveraging more than a decade of observations from the Fermi-Large Area Telescope (LAT) and 3 years of data from the Dark Energy Survey (DES). …

X-Ray Polarization Of The Magnetar 1e 1841−045, Rachael Stewart, George A. Younes, Alice K. Harding, Zorawar Wadiasingh, Matthew G. Baring, Michela Negro, Tod E. Strohmayer, Wynn C.G. Ho, Mason Ng, Zaven Arzoumanian, Hoa Dinh Thi, Niccolò Di Lalla, Teruaki Enoto, Keith Gendreau, Chin Ping Hu, Alex Van Kooten, Chryssa Kouveliotou, Alexander Mcewen

Faculty Publications

We report on IXPE and NuSTAR observations beginning 40 days after the 2024 outburst onset of magnetar 1E 1841−045, marking the first IXPE observation of a magnetar in an enhanced state. Our spectropolarimetric analysis indicates that both a blackbody (BB) plus double power-law (PL) and a double blackbody plus power-law spectral model fit the phase-averaged intensity data well, with a hard PL tail (Γ = 1.19 and 1.35, respectively) dominating above ≈5 keV. For the former model, we find the soft PL (the dominant component at soft energies) exhibits a polarization degree (PD) of ≈30% while the hard PL displays …

A Polarized View Of The Young Pulsar Wind Nebula 3c 58 With Ixpe, N. Bucciantini, J. Wong, R. W. Romani, F. Xie, C. Y. Ng, S. Silvestri, N. Di Lalla, Y. J. Yang, S. Zhang, P. Slane, W. T. Ye, M. Pilia, N. Omodei, M. Negro

Faculty Publications

Pulsar wind nebulae (PWNe) are among the most efficient particle accelerators in the Universe; however, the physical conditions and magnetic geometry in their inner regions remain poorly understood. X-ray polarization now provides a unique opportunity to investigate the magnetic field structure and turbulence properties close to the sites where high energy particles are accelerated. Here, we report on recent X-ray polarization measurements of the PWN 3C 58 by the International X-ray Polarimeter Explorer (IXPE). 3C 58 is a young system that displays a characteristic jet-torus structure that, unlike those in other PWNe, is observed almost edge-on. This nebula exhibits a …

Quantum Classical Algorithm For The Study Of Phase Transitions In The Hubbard Model Via Dynamical Mean-Field Theory, Anshumitra Baul, Herbert Fotso, Hanna Terletska, Ka Ming Tam, Juana Moreno

Faculty Publications

Modeling many-body quantum systems is widely regarded as one of the most promising applications for near-term noisy quantum computers. However, in the near term, system size limitation will remain a severe barrier for applications in materials science or strongly correlated systems. A promising avenue of research is to combine many-body physics with machine learning for the classification of distinct phases. We present a workflow that synergizes quantum computing, many-body theory, and quantum machine learning (QML) for studying strongly correlated systems. In particular, it can capture a putative quantum phase transition of the stereotypical strongly correlated system, the Hubbard model. Following …

Evaluation Of The Effects Of Various Types Of Inert And Active Fillers On Asphalt Mixture Performance, Mohammad Hadizadeh Pirbasti

LSU Master's Theses

Abstract:

The performance of asphalt mixtures is significantly influenced by the type and characteristics of fillers used as a replacement for filler part of the aggregates’ batching. According to this research investigation the performance along with durability characteristics of asphalt mixtures are evaluated through different inert and active fillers. The fillers used include Fly Ash, Cement, steel slag powder, and additional filler. These fillers incorporate into two types of asphalt mix design of Stone Matrix Asphalt (SMA) and a surface mix. Fillers are categorized according to their reactive properties alongside their physical attributes leading to active fillers strengthening bond formation …

Interfacial Phenomena Of Plastics: From Surface Modifications To Environmental Impacts, Kennedy Guillot

LSU Doctoral Dissertations

Plastic is a ubiquitous part of everyday life since its introduction in the previous century. Global production continues to exponentially increase, establishing plastics as one of the most dominant materials in modern manufacturing. Within the scope of academia, plastic is essential due to its low cost and sterility, particularly for minimizing contamination. Beyond the laboratory, plastic use spans numerous industries, and its use and disposal has since raised many environmental concerns. Once valued for its durability, plastics now pollute the environment in landfills and natural ecosystems. In recent decades, the consequences of this pollution have been investigated, yet the full …

Considering The Ethics Of Conserving American Art: White Nationalism And The Evolving Meanings Of Nineteenth-Century Genre And Landscape Painting, Evan M. Crocker

LSU Master's Theses

This thesis analyzes the stylistic and conceptual qualities of American genre and landscape painting from the antebellum period and how these qualities acted in service to establishing white nationalism before the Civil War. The intricate and calculated system of typing in genre painting presented carefully crafted idealizations of quintessential Americans, defined by their whiteness and maleness. Landscape painters of the early- to mid-nineteenth century endowed their compositions with a sense of wondrous opportunity which justified and upheld westward expansion under Manifest Destiny. At the intersection of genre and landscape practices sits plantation paintings—specifically house portraits—in which the plantation serves as …

Passive Vibration Isolation Systems For Mitigating Rotational Forces In Football Helmet Impacts, Julian Lee

LSU Master's Theses

Helmets have been used for centuries to mitigate head injuries, evolving with advancements in materials and design. They are critical in athletics, construction, and military applications, where shock and vibration isolation play a key role in head protection. Helmet performance is currently rated using the Head Injury Criterion (HIC) and Helmet Performance Score (HPS) metrics. HIC is a metric used in sports and automotive industries which focuses on the probability of injury occurring due to the magnitude and duration of linear acceleration of the head [1]. The HPS metric was created by using a linear combination of HIC and a …

Airfield Pavement Management Framework Using Advanced Modeling Techniques, Heena Dhasmana, Marwa Hassan, Elise Mansour

Publications

Airport authorities constantly collect pavement condition data and utilize life-cycle cost analysis to select construction and maintenance alternatives. The current Federal Aviation Administration (FAA) Advisory Circular 150/5380-7B recommends using Pavement Condition Index (PCI) to assess airfield pavement condition for planning of Maintenance and Rehabilitation (M&R) treatments. However, structural and functional performance might not be fairly represented by solely one indicator, the PCI. The latter might mask the root cause of the pavement deterioration and lead to inadequate M&R recommendations. Furthermore, the regression nature of the existing airfield pavement assessment models is not adequate for establishing pavement performance prediction as a …

Gendered Expectations: Do Voters Reward Women For Supporting Women's Interests?, Nichole M. Bauer, Anna Gunderson, Jeong Hyun Kim, Elizabeth Lane, Belinda Davis, Kathleen Searles

Faculty Publications

Are women legislators punished for not supporting women's substantive policy interests? We test these gendered expectations. We marshal an original content analysis of cable news coverage and two survey experiments testing voters' assessment of hypothetical legislators on the issues of abortion and equal pay. We find that voters rate both women and men legislators positively for supporting women's issues and negatively evaluate legislators of both genders when they do not support women's interests. We also find that women voters negatively evaluate women legislators who act against women's interests at a greater rate than men voters. While we do not find …

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 …

Using T-Sne For Characterizing Glitches In Ligo Detectors, Tabata Aira Ferreira, Gabriela González

Faculty Publications

Glitches are non-Gaussian noise transients originating from environmental and instrumental sources that contaminate data from gravitational wave detectors. Some glitches can even mimic gravitational wave signals from compact object mergers, which are the primary targets of terrestrial observatories. In this study, we present a method to analyze noise transients from the Laser Interferometer Gravitational-Wave Observatory observatories using Q-transform information combined with t-distributed stochastic neighbor embedding. We implement classification techniques, examine the influence of parameters on glitch classification, and conduct a week-long daily analysis to track outlier transients over time.

Memory-Augmented Llm Agent For Predicting Locomotion Modes In Construction Activities, Ehsan Ahmadi

LSU Doctoral Dissertations

The construction industry faces significant challenges, including labor shortages, high physical demands, and safety risks, necessitating advanced assistive technologies like exoskeletons to enhance worker efficiency and reduce injuries. However, effective exoskeleton control in dynamic construction environments requires accurate locomotion prediction, a task complicated by the diversity of activities and reliance on supervised learning methods that struggle to generalize. This study investigates a multimodal approach to locomotion prediction, leveraging speech commands and visual data from smart glasses to enable adaptive and safe human-exoskeleton interaction. The research unfolds in two stages: the first develops a framework to evaluate the zero-shot capability and …

Use Of Margins Around Small Brain Metastasis Improves Specificity Of Evaluation Methods For Stereotactic Radiosurgery Treatment Plans, Purity Kemunto Bundi

LSU Master's Theses

Purpose: To reduce the high false positive rates (FPRs ≥ 46%) from the evaluation of Gamma Knife stereotactic radiosurgery (SRS) treatment plans for small brain metastases. Specifically, we modified two evaluation indices, Treated Volume Ratio (TVR) and Gradient Index (GI), which exhibited FPRs exceeding 84%. A false positive result incorrectly indicates that an acceptable plan, as determined by a medical physicist and a radiation oncologist, is inacceptable.

Methods: This study utilized training and validation datasets from Gamma Knife treatment plans from The University of Texas MD Anderson Cancer Center (MDACC) and Mary Bird Perkins Cancer Center (MBPCC). Data included doses, …

Integration Of Hydrological Simulations Into The Design Process To Assess The Performance Of Green Infrastructure Designs, Clara Jimenez

Design Research

With the growing threat of flooding in coastal and inland communities, it is necessary to migrate nature-based solutions such as green infrastructure. However, one of the challenges that designers face with this strategy lies in the design phase where it is difficult to quantify the performance with traditional design tools. Thus, there is an incentive to incorporate hydrological models within GIS to aid designers in quantifying performance. The goal of this research is to demonstrate that hydrological simulations can be used as a design tool for designers–such as landscape architects & architects– to analyze the feasibility of green infrastructure designs …

The Legacy Of Auguste Franchomme: Pedagogical Analysis And Performance Practice For The “Twelve Caprices Opus 7 For Cello Solo”, Zi-Yun Luo

LSU Doctoral Dissertations

This written document focuses on a personal pedagogical analysis of the Twelve Caprices composed by the French cellist and pedagogue, Auguste Franchomme. His works have served as significant cello studies for young cellists, comparable in importance to the Twelve Caprices by Carlo Alfredo Piatti and the High School of Cello Playing by David Popper. Each of these caprices is written in different key signatures, tempi, include a variety of bowing styles and techniques, express melodies over a wide range of the cello register, and present unique and ubiquitous issues that cellists may encounter in the canon of cello literature.

In …

Reef Fish Movement And Community Assemblages Associated With A Newly Deployed Artificial Reef, Jade M. Carver, Brett J. Falterman, Stephen R. Midway, Christian Walker, Creed C. Branham, Michael A. Dance

Faculty Publications

Artificial reefs provide critical habitat for fish in areas lacking benthic structure, yet our understanding of how artificial reefs function and develop is limited. Here, changes in fish community assemblages were monitored using baited remote underwater video (BRUV) surveys before and after a new artificial reef was deployed in the northern Gulf of Mexico. Movement of red snapper (Lutjanus campechanus) and gray snapper (Lutjanus griseus) between nearby oil and gas platforms (n = 3) and the new artificial reef was examined using acoustic telemetry, and residency was calculated for fish associated with both structure types. Fish community development at the …

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.

Testing For Normality In Regression Models: Mistakes Abound (But May Not Matter), Stephen Midway, J. Wilson White

Faculty Publications

This study examines the misuse of normality tests in linear regression within ecology and biology, focusing on common misconceptions. A bibliometric review found that over 70% of ecology papers and 90% of biology papers incorrectly applied normality tests to raw data instead of model residuals. To assess the impact of this error, we simulated datasets with normal, interval, and skewed distributions across various sample and effect sizes. We compared statistical power between two approaches: testing the whole dataset for normality (incorrect) versus testing model residuals (correct) to determine whether to use a parametric (t-test) or nonparametric (Mann-Whitney U test) method. …

Fishing For Solutions: Compensation For Bycatch Reduction In The Gulf Of Mexico Shrimp Fishery, Daniel W. Harris

LSU Master's Theses

Bycatch, unintentionally caught non-target species, harms the profitability of commercial fishing operations and leads to death and injury of hundreds of thousands of marine animals per year. In the Gulf of Mexico, commercial shrimpers are required to use a bycatch reduction device (BRD). Better BRDs are being tested to further reduce bycatch. Because their use will not be mandatory, it is important to measure shrimper willingness to voluntarily adopt this conservation technology to predict potential fleet participation. This study uses contingent valuation to elicit commercial shrimpers’ willingness to accept compensation for using these new devices.

We employ an incentivized payment …

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 …