Digital Commons Network^™

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 …

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 …

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 …

Problem-Solving In The Preparation Of Teachers For Agricultural Education: A Mixed Methods Study Investigating The Effect Of Metacognitive Awareness And Cognitive Ability On Students Enrolled In An Introductory Agricultural Mechanics Course, Whitney Figland

LSU Doctoral Dissertations

Cognitive and metacognitive ability have been identified as a critical factor that influences individuals to successfully problem-solve. However, recent research has indicated that students do not have the necessary 21st-century skills to be successful in the workplace. This issue has been confounded by the lack of school-based agricultural education (SBAE) teachers’ limited knowledge regarding effectively teaching decision-making skills and the use of teaching methods that promote problem-solving. Therefore, this study sought to understand the effect that cognitive and metacognitive ability had on the problem-solving of students who are enrolled in an Introduction to Agricultural Mechanics course at Louisiana State University. …

The Homotopy Cardinality Of The Representation Category, Justin Murray

LSU Doctoral Dissertations

Given a Legendrian knot in (R^3, ker(dz − ydx)) one can assign a combinatorial invariants called ruling polynomials. These invariants have been shown to recover not only a (normalized) count of augmentations but are also closely related to a categorical count of augmentations in the form of the homotopy cardinality of the augmentation category. In this article, we prove that that the homotopy cardinality of the n-dimensional represen- tation category is a multiple of the n-colored ruling polynomial. Along the way, we establish that two n-dimensional representations are equivalent in the representation category if they are “conjugate homotopic”. We also …

Surface And Bulk Properties Of Multi-Component Metal Alloys, Frank A. Mckay Iii

LSU Doctoral Dissertations

While HEAs have been studied extensively for their material properties, their potential as catalysts remains widely unexplored. To explore the feasibility of CoCrFeNi as a catalyst for the hydrogen evolution reaction, the results of X-ray photoelectron spectroscopy (XPS) and high-resolution electron energy loss spectroscopy (HREELS) experiments are compared to electrochemical experiments and theoretical calculations. XPS shows that this surface forms passive oxides with a propensity of Cr > Fe > Co, with no evidence of Ni oxidation. From comparison to calculations, it is shown that the electrochemical activity is enhanced in a partially oxidized state. The lack of Ni oxidation suggests that …

Development Of Accurate Embedded Fracture Models For Naturally Fractured Reservoirs, Harun Ur Rashid

LSU Doctoral Dissertations

Natural fractures play a critical role in the performance of unconventional oil, gas, and geothermal reservoirs due to their prevalent occurrence within these systems. However, modeling these fractures accurately and efficiently is still challenging. This work centers on an extensive analysis of naturally fractured systems and proposes new fracture modeling algorithms that can predict the performance of fractured tight rocks accurately and efficiently. Several researchers have explored various methodologies to accurately and efficiently model fractured reservoirs. Among the approaches that can account for each individual fracture in these reservoirs, the embedded discrete fracture model (EDFM) is one of the most …

Investigating Gulf Coast Aquifer System: Stratigraphy Reconstruction, Inverse Modeling, And Groundwater Stress Assessment, Shuo Yang

LSU Doctoral Dissertations

The Mississippi Embayment aquifer system (MEAS) and the Coastal Lowlands aquifer system (CLAS) provide substantial groundwater resources for human activities in the U.S. Gulf Coastal Plain. However, the overexploitation has led to groundwater depletion in the MEAS and the CLAS, threatening sustainable groundwater use. Such concern highlights the crucial need for an advanced understanding of stratigraphy and groundwater in these aquifer systems, which is essential for effective regional groundwater management. This dissertation presents a comprehensive investigation of MEAS and CLAS in the Louisiana and southwestern Mississippi region, encompassing three fundamental dimensions: stratigraphy reconstruction, groundwater modeling, and groundwater stress assessments. A …

In-Person, Hybrid, Or Remote: Exploring The Effectiveness Of Teacher Practices On Student Performance During The Covid-19 Pandemic, Ashley M. Segalla

LSU Doctoral Dissertations

Schools and universities had to make unexpected changes beginning in Spring 2020 because of the COVID-19 pandemic. In Spring 2021, one university in the southern region of the United States implemented hybrid teaching formats in College Algebra courses, where students attended half of the classes in-person, and the remaining half of classes were attended synchronously and remotely. The purpose of this mixed methods study was to determine if students’ attendance methods (virtual or in-person) impacted their academic performance in the course. Additionally, the study sought to determine how students and the instructor felt student performance was impacted by hybrid attendance. …

Power Grid Resiliency Enhancement Against Flood-Induced Hazards, Mohadese Movahednia

LSU Doctoral Dissertations

Natural disasters, such as floods, may damage power system assets and lead to widespread and long outages. The impact of flood can be alleviated by preventive actions such as installing tiger dams around power substations before the flood. In this regard, it is imperative that critical substations are identified in terms of the connected load and imposed costs to the system. This study presents a resource allocation approach for protecting power substations against flood events a day ahead of the event. First, the required information for the model is extracted. Flood probability distribution functions are used to generate several flood …

Auslander-Reiten Triangles On A Bounded Derived Category Of Constructible Complexes, Vishnu Prasad Sivaprasad

LSU Doctoral Dissertations

In this dissertation, concepts from homological algebra are used to study the existence of Auslander-Reiten triangles.

Auslander-Reiten triangles are closely related to representable functors, and the main theorem characterizes the existence of representable functors in a specific bounded derived category of constructible complexes.

Under certain boundedness conditions, a specific bounded derived category is shown to have Auslander-Reiten triangles.

Incubating Education: The Lived Experiences Of Louisiana Elementary And Middle School Teachers When Piloting A 4-H Stem School Enrichment Curriculum, Crystal Rose Ahrens

LSU Doctoral Dissertations

This study addressed a deficiency in the agricultural literacy of the U.S. population by focusing on the challenges that core subject teachers face when integrating agriculture into their curriculum. Using a phenomenological research approach, this investigation explored the lived experiences of Louisiana teachers who piloted a 4-H STEM curriculum, focusing on the growth in agricultural literacy of the teachers while instructing third and eighth-grade students on the agricultural-based and STEM-focused topic of embryology. Employing a transcendental phenomenological approach, I acknowledged my biases through reflexivity and adhered to ethical considerations, including informed consent and confidentiality. Key findings emerged through four themes …

Attochemistry Regulation Of Charge Migration, Aderonke Folorunso

LSU Doctoral Dissertations

Charge migration (CM) is a coherent attosecond process that involves the movement of localized holes across a molecule. This phenomenon is potentially useful to understand the fundamental principles of photochemistry, such as light harvesting. The first part of this dissertation discusses the molecular modes of attosecond charge migration. In this work, we used first-principles calculations to investigate the modes of charge migration (CM) in halogenated hydrocarbon chains at attosecond timescales. We have simulated the creation of a localized hole on the halogen atom using constrained density functional theory (DFT) and then tracked its subsequent dynamics with time-dependent DFT (TDDFT). Our …

Performative Mixing For Immersive Audio, Brian A. Elizondo

LSU Doctoral Dissertations

Immersive multichannel audio can be produced with specialized setups of loudspeakers, often surrounding the audience. These setups can feature as few as four loudspeakers or more than 300. Performative mixing in these environments requires a bespoke solution offering intuitive gestural control. Beyond the usual faders for gain control, advancements in multichannel sound demand interfaces capable of quickly positioning sounds between channels. The Quad Cartesian Positioner is such a solution in the form of a Eurorack module for surround mixing for use in live or studio performances.

Diffusion/mixing methods for live multichannel immersive music often rely on the repurposing of hardware …

Understanding And Modeling Drivers’ En-Route Diversion Behavior During Congestion, Mohammad Shapouri

LSU Doctoral Dissertations

In the field of transportation, traffic assignment models primarily have been used to forecast driver route preferences, translating their choices into traffic flow patterns across networks. These models are grounded in distinct behavioral theories and strive to explain how drivers navigate routes based on network features and personal tendencies. Using an aggregation approach, conventional traffic assignment models distribute demand among paths, considering utility and attractiveness. Despite their prevalent use in transportation planning and operations, the fundamental behavioral assumptions of these models have rarely been thoroughly explored. This gap is further compounded by their limited consideration of real-time adjustments and choices …

The Structures And Functions Of Offices Of Academic Affairs: A Case Study, Ryan Thomas Landry

LSU Doctoral Dissertations

This study sought to describe how offices of academic affairs (administrative offices supporting provosts) at public, research-intensive universities in the United States are structured and what kind of work these offices do. There is a dearth of scholarly literature on the topic, indicative of an overall lack of knowledge about these organizations. From a practical standpoint, I intended for this study to contribute to the body of knowledge of higher education administration with hopes that it provides helpful insights to administrators as they consider organizational design. Using the theoretical framework of modern organization theory, I employed an embedded case study …

On Virtue Ethics Theory And Elementary Music Education, Joshua Burgos

LSU Doctoral Dissertations

This dissertation uses virtue ethics theory, teacher research method, and self-study to examine how I perceive myself as contributing to cultivating virtuous persons. Virtue ethics theory, teacher research method, and self-study are empirical, using concrete methods of data generation and analysis, and conceptual, relating to studying philosophical research, ideas, and interpretations (Annas, 2007; Check & Schutt, 2012; Kemmis & McTaggart, 1988). The study aimed to discover how virtue is cultivated through music education and improve teaching practice using virtue ethics theory and empirical research to offer insight into how virtue is cultivated. The study was conducted in an elementary school …

Extended Defects And Linear Junctions At The Surfaces Of Topological Insulators, Eklavya Thareja

LSU Doctoral Dissertations

Topological Insulators (TIs) have emerged as promising candidates for spintronics and quantum computing applications. Two properties that underlie these applications are the locking of spin and momentum of the surface electrons and topological protection of surface states. While the existence of gapless surface states is guaranteed by topology, as long as time-reversal symmetry is intact, other properties of the surface states are still tunable. Spin-momentum locking makes these states immune to scattering from non-magnetic point impurities. However, extended defects can scatter the states even with electrostatic potential. We show that a line defect with magnetic and electrostatic potential scattering hosts …

The Effects Of Acute Hyperosmolality On Immune Cell Functions And Nutrient Sensing, Joshua Granger

LSU Doctoral Dissertations

Hyperosmolar hyperglycemic syndrome (HHS) is a life-threating endocrine emergency commonly seen with type 2 diabetes. HHS has been identified to begin when hyperglycemia leads to glucosuria diuresis, which eventually leads to hyperosmotic conditions. However, hyperosmolality has not been considered as an initiator of HHS, although past research would suggest that it can initiate HHS, specifically through systemic inflammation and glucose insensitivity.

The first study examined the impact of exercise induced hypohydration effect on T-cell populations. After healthy participants reached hypohydration they were then rehydrated with water and monitored for 3-hours. Results indicated that rehydration attenuated the efflux of T-cells from …

Electrophertic Deposition And Characterization Of Molybdenum Disulfide On Silicon Substrates, Alex J. Young

LSU Doctoral Dissertations

The electrical characteristics of 2D materials such as high electron mobility and current density are of great interest to various fields from optoelectronics to renewable energy. Researchers have focused their efforts on transition metal dichalcogenides (TMDCs) due to their direct energy band gap. One such TMDC that has garnered much attention is molybdenum disulfide (MoS2). MoS2 has electrical properties comparable to graphene and is a TMDC with characteristics amenable to applications such as solar cells and sensors. Commonly deposited through time-consuming and complex deposition methods such as chemical vapor deposition (CVD), the viability of MoS2 as an electronic material will …

Understanding And Modeling Drivers’ En-Route Diversion Behavior During Congestion, Mohammad Shapouri

LSU Doctoral Dissertations

In the field of transportation, traffic assignment models primarily have been used to forecast driver route preferences, translating their choices into traffic flow patterns across networks. These models are grounded in distinct behavioral theories and strive to explain how drivers navigate routes based on network features and personal tendencies. Using an aggregation approach, conventional traffic assignment models distribute demand among paths, considering utility and attractiveness. Despite their prevalent use in transportation planning and operations, the fundamental behavioral assumptions of these models have rarely been thoroughly explored. This gap is further compounded by their limited consideration of real-time adjustments and choices …

Vibriosis: An Integrated Study Of Ecology, State Policy, And Health Communication, Ruth Akintoye

LSU Doctoral Dissertations

The CDC reports fatalities within one to two days for 20% of victims of a Vibrio vulnificus infection. This flesh-eating bacterium is part of the Vibrio genus, which comprises various pathogenic species responsible for the human illness, Vibriosis, which is estimated at 80,000 annual cases in the US, according to the CDC.

A vibriosis public health concern exists, but there's no mandatory national surveillance system. This study reveals that only 19 states mandate vibriosis reporting, leaving a gap in understanding the incidence of disease from this flesh-eating bacterium.

This research comprises four studies that advance our knowledge of vibriosis through …

Controlling Guest Binding To Transition Metal Hosts Via Redox Stimuli, Jasmine S. Sanford

LSU Doctoral Dissertations

Several metal complexes were investigated as potential hosts to execute controllable host- guest interactions using a redox stimulus. Previously, our group has synthesized new Cu^II m-xylylenebis(pyridyltriazole) (m-xpt) hosts and their redox properties were analyzed. In Chapter 2, we take advantage of the Cu^II host’s ability to perform redox to investigate its interaction with chloride guest ions. This study was executed with two main Cu-xpt hosts: [Cu₂(m- xpt)₂(NO₃)₂](PF₆)₂ and [Cu₂(m-xpt)₂Cl₂]Cl₂. The host-guest interaction was analyzed with additions …

A Mixed Methods Study: The Experiences Of Community College Students With Open Educational Resources (Oers) In Biology Courses, Adronisha T. Frazier

LSU Doctoral Dissertations

Purpose: The purpose of this dissertation study was to explore community college students’ experiences with open educational resources (OERs). These students were enrolled in biology courses during Spring 2020, Fall 2020, and Spring 2021 at a community college in Southeastern Louisiana. Methodology: This study followed a mixed-methods research design to collect and analyze data about student experiences with OERs through a critical realist and neo-positivistic lens and the Technology Affordances Constraint Theory (TACT). Students completed a survey that assessed their satisfaction with OERs. The survey included demographic questions, Likert-scale items, and a qualitative item. An interview protocol was created using …

Work Hard For The Money: Performance-Based Funding In The State Of Louisiana, Victoria C. Lloyd

LSU Doctoral Dissertations

The purpose of this study is to examine in what ways, if any, the introduction of the equity incentive portion of Louisiana’s performance-based funding model impacted the underserved student groups it was designed to support. I employed a quantitative quasi-experimental design for this study by running three outcome variables (Adult Learner Enrollment, First-Time Enrollment for Racially Minoritized Students, and Low-Income Student Enrollment) by sector (two- and four-year public institutions) and employing a differences-in-differences regression with panel data. In my analysis I uncovered two main findings: 1) Louisiana’s equity incentive is showing early signs of success for all three underserved groups …

Design, Synthesis And Post Functionalization Of Bodipy Dyes For Use As Chemo Sensors., Caroline Njeri Ndung'u

LSU Doctoral Dissertations

An overview of BODIPYs history, basic structure, electronic properties is described. Additionally, their attribute of tenability in their photophysical and electronic properties has been discussed. Lastly, their application in the biomedical field as bio imaging, labeling, chemo sensors and photosensitizers are also discussed. In Chapter 2, a library of meso- Pyridyl and meso pyridinium BODIPY dyes was designed, synthesis and comparison on their photophysical, electrochemical and cytotoxic studies done. From this study chlorine atoms at the 2, 6 positions was shown to enhance their relative fluorescence quantum yields in different organic solvents and water. In chapter 3, 8(meso)-pyridyl-BODIPYs with a …

Probing The Consequences Of Irreversibly Trapping Iron In Bacterioferritin Using Chemical And Genetic Approaches--An Omics Study, Leo S. Fontenot Jr.

LSU Doctoral Dissertations

Antibiotic resistant bacteria pose one of the most urgent threats to public health. Pseudomonas aeruginosa is a multi-drug resistant bacterium for which new antibiotics are urgently needed. My research is focused on understanding and validating iron metabolism as a target for antibiotic development by analyzing the metabolic profiles of iron-starved P. aeruginosa cells caused by irreversibly trapping iron in bacterioferritin. Iron is an essential nutrient for bacteria; however, the reactivity of the Fe²⁺ ion and insolubility of the Fe³⁺ ion present significant challenges to bacterial cells. Iron storage proteins oxidize Fe²⁺ using O₂ and H_{2 …}

Machine Learning-Based Tool To Predict The Retroreflectivity Of Pavement Markings Throughout The U.S., Ipshit I. Idris

LSU Doctoral Dissertations

Retroreflectivity plays a crucial role in pavement markings as it enhances nighttime visibility for drivers. Yet, due to budget constraints, many U.S state agencies rarely monitor retroreflectivity of their markings, and instead, restripe markings based on visual inspection or fixed schedule. Addressing this, Federal Highway Administration (FHWA) introduced a new final rule, effective September 6, 2022, that established a new minimum standard for pavement marking retroreflectivity. This rule requires state agencies to implement a method within four years for maintaining pavement marking retroreflectivity at or above minimum levels. The ultimate objective of this study was to assist state agencies comply …

The Effects Of Amira Learning On Literacy Development In Early Childhood Education, Caroline C. Tolentino

LSU Doctoral Dissertations

The aim of the present study was to investigate the effects of an Artificial Intelligence software, Amira Learning, on literacy development in early childhood education. Specifically, the research investigated the impact of Amira Learning software usage, the feedback it provided, and teachers' perspectives on its alignment with the Science of Reading. The study employed quantitative analyses of oral reading fluency outcomes and compared the pretest and posttest scores of the students after the 6-week usage of the software.

Computational Investigations Of Polymer Electrolytes In Aqueous Solutions, Hishara Keshani Gallage Dona

LSU Doctoral Dissertations

Polymer electrolyte membranes, an intriguing category of soft materials, are characterized by polymer backbones tethered with negatively or positively charged functional groups, finding applications from biological macromolecules to electrochemical separations in fuel cells. This dissertation focuses on computational investigations of polymer electrolytes in aqueous solutions using polypeptoids and ion exchange membranes. Polypeptoids, highly tailorable peptidomimetic polymers lacking backbone hydrogen bonding or chirality, were used as model systems. Micelles formed from these polypeptoid polymers exhibited electrostatic repulsion, which competes with charge-sodium interactions, adding complexity to predicting micelle shapes. This research refined the design strategy, enhancing micelle shape and structure through precise …