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Molybdenum Alkylidyne Complexes With Phenoxide Ligands For Alkyne Metathesis, Marvin L. Stewart Jr

LSU Doctoral Dissertations

Abstract

Alkyne metathesis is a powerful synthetic tool, which provides easy access to complex organic molecules in a single-step. It is a dynamic covalent reaction that scrambles alkynes, carbon-carbon triple bonds (C≡C). Molybdenum- or tungsten-alkylidyne (Mo≡C, W≡C) complexes are typically used as catalyst to cleave and reform alkyne bonds. Our goal has been to gain a deeper understanding of the intrinsic differences between functional ligands by the development of novel phenoxide ligands.

In chapter 2 we explore the detailed synthesis of novel phenoxide podand ligands in an effort to identify their mo-alkylidyne complexes. We were able to synthesize a variety …

The Lowest Discriminant Ideal Of Cayley-Hamilton Hopf Algebras, Zhongkai Mi

LSU Doctoral Dissertations

Discriminant ideals are defined for an algebra R with central subalgebra C and trace tr : R → C. They are indexed by positive integers and more general than discriminants. Usually R is required to be a finite module over C. Unlike the abundace of work on discriminants, there is hardly any literature on discriminant ideals. The levels of discriminant ideals relate to the sums of squares of dimensions of irreducible modules over maximal ideals of C containing these discriminant ideals. We study the lowest level when R is a Cayley-Hamilton Hopf algebra, i.e. C is also a Hopf subalgebra, …

Ammonium Chemotaxis In Chlamydomonas Reinhardtii, Gabela Nelson

LSU Doctoral Dissertations

Analysis of ammonium chemotaxis in Chlamydomonas reinhardtii is largely hindered, compared to that of phototaxis, despite equal importance on flagellated microalgal physiology. A major contribution of this shortfall is the lack of proper assay method. We developed a simple Petri dish assay method in which light is homogenously exposed while patterns of the cellular migration are tracked with a function of time. Using the method, new findings were revealed. First, this research presented that a strain lacking the eyespot organelle required for light gradient-sensing exhibits similar chemotactic behavior compared to a wild-type strain, suggesting Chlamydomonas sense an ammonium gradient not …

A Feasibility Study Of Drilling Fluid Slippage For Wellbore Displacement, John Johnson

LSU Master's Theses

In the ideal plug-flow mode viscoplastic drilling fluids display uniform frontal velocity due to wall slippage (at very low flowrate limited by the fluid’s yield strength). The flow rate could be increased by raising the yield strength that would make the fluid best candidate for frontal displacement. Based on this concept the study qualifies wall slippage effect for wellbore displacement. Using a conceptual model of fluid motion between two parallel plates defines maximum velocity as a function of shearing rate and yield stress. Conversion to coaxial geometry gives practical formulas for fluid testing with rotational viscometer. A new analysis of …

Research On 3d Printing Resin Exposure Properties And Its Application On Centrifugal Microfluidic Platform Based On Fluorescence Detection, Zheng Qiao

LSU Doctoral Dissertations

This dissertation encapsulates significant advancements in the field of SLA 3D printing and centrifugal microfluidics. Central to the research is the development of a novel mathematical model for predicting trapped resin thickness in SLA 3D printing, a groundbreaking contribution that addresses a critical aspect of printing intricate structures. This model, the first to establish a mathematical relationship for resin thickness, is rooted in a comprehensive study of the resin curing process. The research leverages the concept of 'critical dosage' for resin curing, leading to a more refined and theoretically grounded approach for calculating curing thickness. Experimentation further validates the model, …

“Everything Is Not What It Seems”: Discovering Public Relations In Business Sectors In Vietnam, Ba-Anh-Tu Truong

LSU Master's Theses

Vietnam is a shining star in emerging markets, with an annual economic growth rate of 6-7%. Its abundant labor supply, stable political climate, and geographic proximity to major global supply chains make it an ideal candidate for manufacturer planning in advanced economies such as the United States, Europe, Australia, Japan, China, and Korea. Investing in public relations and communication management, especially understanding the Vietnamese market, effectively prepares multinational corporations for future business expansion. This mission is difficult for academia and industrial professionals since Vietnam is a “silent country” in public relations research. To fill the gap, this thesis employs the …

All-Optical Probes Of Particle-Like Charge Migration Dynamics, Kyle A. Hamer

LSU Doctoral Dissertations

Particle-like charge migration (CM) is the coherent, back-and-forth motion of a positively-charged electron hole along the backbone of a molecule following a sudden ionization. CM in small molecules generally occurs on an Angstrom (10^-10 m) spatial scale and an attosecond (10^-18 s) timescale. I use time-dependent density-functional theory (TDDFT) to simulate CM modes in organic molecules, and to explore all-optical probes of this attosecond electron dynamics using high-harmonic spectroscopy (HHS). By leveraging my results from previous studies of two-center interferences in carbon dichalcogens, in which I separated the harmonic signal into contributions from individual Kohn-Sham orbitals, I first …

Post-Modeling Adjustments And Delivered Dose Verification Of The 6fff Beam Model Commissioned For The Monaco Treatment Planning System, Grant C. Debevec

LSU Master's Theses

External beam radiation therapy has been shown to be an effective treatment method for tumors and abnormalities of the spine and vertebral region. Treating the spine using a stereotactic body radiation therapy (SBRT) technique can reduce toxicity to the spinal cord. The 6 MV flattening filter free (6FFF) beam model is currently used to plan and calculate dose for SBRT treatment plans, and the treatment plans are delivered using a linear accelerator (LINAC).

The commissioned beam model represents an invariant component of a LINAC. For volumetric modulated arc therapy (VMAT) treatment plans, the multileaf collimator (MLC) positions are changing throughout …

Phonic Faces As An Intervention To Improve Decoding Skills Of Children With Persistantly Poor Decoding Abilities, Kayla Therese Martin

LSU Master's Theses

Background: Orthographic rules, phonological awareness, and the ability to process morphemes and phonemes from speech and language begins with verbal speech and the child unknowingly recognizes words from his or her environment as early as the senses can process their surroundings. Some children have difficulty integrating these processes to learn how to read. As Ehri (1979) mentions the importance of establishing mental processes, such as amalgamation and phonological recoding, are essential as a basis for establishing reading fundamentals. Decoding occurs through a complex integration of phonological and orthographic knowledge (Ehri 1992). Early readers typically have well-established amalgams for spoken words …

Spatial Behavior Of Hospital Visits By Hand, Foot, And Mouth Disease Patients In Nanchang, China, Zeliu Zheng

LSU Doctoral Dissertations

Hand foot mouth disease (HFMD) is one of the widespread transmissible diseases that target preschool children, especially in urban regions in East Asia. Understanding the travel patterns of the HFMD patients helps us understand how the spatial behaviors of patients vary across space and what are the underlying forces. It is essential for understanding the healthcare market and planning for resource allocation. Foremost, health behavior and outcome change significantly across geographic regions of various urbanicities (i.e., degrees of urbanization) due to the uneven distribution of healthcare resource. In addition, health studies in the U.S. often use hospital service areas (HSAs) …

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 …

Spatial Mapping Of The Benthic Community And How It Is Used To Research Effects Of Dredging In Louisiana's Lake Borgne., Meghan Johnson

LSU Master's Theses

Benthic communities are vitally important for healthy aquatic ecosystems across Louisiana’s coast. Specifically in Lake Borgne, ecologically important species of fish like the Gulf Sturgeon (Acipenser oxyrinchus desotoi) rely on benthic macrofauna as their main food source. The purpose of this study was to determine the spatial landscape of biodiversity and abundance of the benthic macrofauna community in Lake Borgne. Environmental conditions played a key role in community structure during the study period (fall 2021 through summer 2023) with a major drought occurring in 2023. In 2023, the decline in the abundance of most benthic invertebrates and in …

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 …

Reducibility Of Schrödinger Operators On Multilayer Graphs, Jorge Villalobos Alvarado

LSU Doctoral Dissertations

A local defect in an atomic structure can engender embedded eigenvalues when the associated Schrödinger operator is either block reducible or Fermi reducible, and having multilayer structures appears to be typically necessary for obtaining such types of reducibility. Discrete and quantum graph models are commonly used in this context as they often capture the relevant features of the physical system in consideration.

This dissertation lays out the framework for studying different types of multilayer discrete and quantum graphs that enjoy block or Fermi reducibility. Schrödinger operators with both electric and magnetic potentials are considered. We go on to construct a …

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 …

“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 …

Introducing Chinese Folk Songs Through Arrangements For Trombone & Piano And Chamber Music, Tianyu Xue

LSU Doctoral Dissertations

The scarcity of trombone in traditional Chinese music reflects the limited exposure and education for the trombone in China. Additionally, Chinese folk songs have minimal presence on the global stage. This project will bridge this gap by developing a series of trombone pieces that incorporate Chinese musical elements, explicitly focusing on elevating Chinese folk songs through trombone performance. This initiative offers an opportunity for trombonists worldwide to delve into the richness of Chinese folk music. The core of this work involves selecting Chinese folk songs that represent diverse historical contexts, regional characteristics, and emotional content and then arranging them for …

Unveiling The Idiomatic And Performance Inspirations: A Comparative Study Of The Red Violin Caprices By John Corigliano., Johan Alexander Pepper

LSU Doctoral Dissertations

John Corigliano's composition for "The Red Violin," a 1998 film by Don McKellar and François Girard, presents a multifaceted exploration of thematic material and performance challenges. This dissertation investigates Corigliano's creation of the "Red Violin" Caprices, examining their origins in the film's soundtrack and their transformation into solo works. Corigliano's intention to showcase the artistry of violinist Joshua Bell through these caprices underscores their technical and musical complexity. The Caprices, replete with references to the Baroque era and various virtuosic works, demand a high level of virtuosity from performers. Drawing on a sequence of seven chords and Anna’s Theme from …

The Use Of Duddingtonia Flagrans Aged In Mineral For Gastrointestinal Parasitic Nematode Control In Small Ruminants, Elisa M. Preston

LSU Master's Theses

Gastrointestinal nematodes (GIN) are a major constraint to small ruminant health and production throughout the world. Haemonchus contortus commonly known as the “barber pole worm” is a major concern for producers and veterinarians because of the severe anemia, and other clinical symptoms these worms cause. For decades, anthelmintics have been used to control the GIN burden small ruminants face. Katahdin (n=36) and Hampshire sheep (n=12) were used in a randomized block design experiment over a 30-day period. The objective of this study was to evaluate the effectiveness of Duddingtonia flagrans spores, the active ingredient in a commercial product, Bioworma® (International …

Addition And Subtraction: Coral Reproduction And Disease In A Changing Ocean, Ashley Rossin

LSU Doctoral Dissertations

Marine diseases are changing the landscapes of coral reefs particularly throughout the Western Atlantic. Stony coral tissue loss disease (SCTLD) swept through this region impacting at least 22 stony coral species. White plague (WP) is a more ephemeral disease, but still has a significant impact on coral reef health and perseverance, especially under a changing ocean. While these impacts are seen on the reef-scale, we can zoom into the tissue-level to identify disease markers for both diseases and identify their differences. This has ramifications for disease intervention, as well as mitigation strategies. Despite continuous disease outbreaks, healthy corals persist and …

Subroups 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.

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 …

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 …

Round Ii: Exploring The Experiences Of Black, First-Generation Graduate And Professional Students At Historically Black Colleges And Universities (Hbcus), Derrick D. Lathan

LSU Doctoral Dissertations

This phenomenological study explores the experiences of Black, first-generation (first-gen) students pursuing advanced degrees at historically Black colleges and universities (HBCUs), following the COVID-19 pandemic and racial justice movements like Black Lives Matter. Additionally, this study examines the present-day motivations to pursue advanced degrees, particularly the benefits of doing so at an HBCU. The main research question guiding this study is: What are the experiences of Black, first-gen graduate and professional students at historically Black colleges and universities (HBCUs)? The sub-questions are:

1. How do Black, first-gen graduate and professional students describe being a first-gen student?
2. What barriers and supports impact …

Decoding Affective Information From Neuronal Populations In The Human Hippocampus, Alexander N. Lawriw

LSU Master's Theses

The hippocampus is understood to play a key role in the formation of episodic memories. Prominent theories suggest this is made possible through use of sparse encoding schemes, in which a small number of neurons encode each episodic event using a distinct pattern of neuronal activity. However, more recent computational models suggest that the hippocampus may also be capable of representing semantic structure, a notion previously thought to be exclusive to the neocortex. In our previous line of work, we trained multivariate classifiers to predict the semantic content, specifically affect, of computer-generated faces given spiking data taken from individual neurons …

Effects Of Iconic Gestures On Word Pair Learning In Autistic And Non-Autistic Adults, Caprielle G. Priola

LSU Master's Theses

Previous studies have demonstrated that simultaneous speech and iconic gestures enhance learning and memory for listeners. Additionally, metacognitive awareness, which can be measured through judgements of learning (JOLs), has also been shown to impact learning and memory. However, it has not been established that these benefits apply to all learners. Existing studies on gesture processing and metacognitive abilities in autistic adults yield mixed findings. The present study aims to investigate the impact of co-speech iconic gestures on word pair recall and perceived learning (JOLs) in autistic and non-autistic adults.

Forty non-autistic adults and 40 autistic adults participated in an online …

Geospatial Analysis Of Historical Tropical Cyclone Intensity And Rainfall In Georgia, United States, Reilly T. Corkran

LSU Master's Theses

Tropical cyclones, characterized by their high wind speeds and heavy rainfall, cause widespread devastation, affecting millions of people and leading to economic losses worldwide. Tropical cyclone-specific research in Georgia is scarce, likely due to the coast’s minimal geographical extent and the relative infrequency of direct landfalls. Research on Georgia tropical cyclones does not account for storms that make landfall in Florida and continue north, northeast, or northwest. In 2018, Hurricane Michael generated $4.7 billion in property, agriculture, and forestry damages across southwest Georgia as a Category 3 hurricane. With an increasing population, property development, and agriculture sector sensitive to tropical …

Investigating Drivers Of High Wetland Loss Rates In Brackish Marshes Of The Mississippi River Delta, Natalie M. Matherne

LSU Master's Theses

Coastal wetlands provide numerous ecological services, but high rates of wetland loss have been seen, especially within the Mississippi River Delta. The erodibility of the marsh, which depends on its strength, can be affected by waterlogging-impacted factors. This study focused on investigating factors influencing soil shear strength in brackish to intermediate salinity marshes along the northern Gulf of Mexico coast using a comparative field study and a controlled greenhouse experiment to test the hypothesis that soil waterlogging reduces soil strength. I predict species-specific responses such that marshes dominated by the Sporobolus pumilus (formerly, Spartina patens), which is less flood …

Different Error Patterns Of /L/ In Children And Speech-Language Pathologists' Perception And Treatment, Grace E. Lemoine

LSU Master's Theses

Children often simplify target speech sounds using phonological processes, or common developmental error patterns. However, some children produce less common error patterns that differ from common errors. In the current study, less common errors involving /l/ sounds were studied as the phoneme /l/ is a sound that is subject to frequent misarticulations in young children and perceptual confusion among listeners. The current study focused on less common errors because studies have suggested that atypical errors can indicate weak phonological representations and poor phonological awareness skills, which can have long-term effects on children’s literacy skills. Therefore, the aim of the current …

Speech And Language Errors In An 8-Year-Old Spanish-English Bilingual Speaker: A Case Study, Alaniss Heredia

LSU Master's Theses

Despite the growing population of Spanish-English bilingual speakers with developmental language disorders and speech sound disorders (SSD) in the United States, there is limited research on assessment for this population. Research suggests that the linguistic environment in which the Spanish-English bilingual speakers are brought up should be considered when assessing and treating this population since the Spanish-English bilingual population is diverse. One result of such environments is differences in degrees of language exposure. For example, a child can be exposed to two languages but have more exposure in one than the other. This might lead to better proficiency in one …