Physical Sciences and Mathematics Commons^™

Development Of Transition Metal-Catalyzed Polymerization Reactions And Their Applications For The Preparation Of Well-Defined Conjugated Polymer Architectures, Carlos Anthony Chavez

LSU Doctoral Dissertations

The synthesis of conjugated polymers and design of complex materials based on them have become increasingly popular as the demand for low-cost efficient and processible optoelectronic and semiconducting devices escalates. While advanced applications of polymeric materials require some degree of sophistication, success can be achieved through careful consideration of polymerization techniques and methodologies. Controlling critical aspects of the polymerization process allows for synthesis of complex macromolecular architectures possessing unique and novel properties that may be worth of further comprehensive investigation. This dissertation primarily focuses on the development and preparation of well-defined hierarchical macromolecular architectures. The foundation of this work encompasses …

Exploring Superconductivity In Chiral Structured Aube, Drew Jared Rebar

LSU Doctoral Dissertations

AuBe is a noncentrosymmetric superconductor with the B20 FeSi-type structure. Noncentrosymmetric superconductors are expected to give rise to unconventional superconductivity due to spin orbit coupling and a mixed spin-singlet, spin-triplet state. The B20 structure of AuBe is particularly interesting since this is one of the only known crystal structures for bulk magnetic skyrmions in materials such as MnSi and Cu2OSeO3. The superconducting state was characterized by specific heat, dc magnetization, ac susceptibility, and resistivity. Specific heat revealed AuBe to host an isotropic gap characteristic of predominantly s-wave spin-singlet pairing in the weak coupling limit. Magnetization and susceptibility measurements revealed a …

Optimized Aperiodic Multilayer Structures For Absorbers And Thermal Emitters, Christopher H. Granier

LSU Doctoral Dissertations

In this dissertation, we begin with a brief introduction to nanophotonics. In particular, we will focus on the theory of computational electricity and magnetism, specifically, the method used for this research, the transfer-matrix method. We will also provide discussions of the principles which motivate the analysis of the multilayer structures: Planck's blackbody distribution, Kirchoff's law, and thermodynamics. Finally, we will provide a brief discussion of computer-based optimization algorithms, specifically NLOPT (a library which provides computational packages for nonlinear optimization) and genetic algorithms. This background information is necessary to understand discussions which occur in later chapters.

Chapter 2 will discuss multilayer …

Single Molecule Electrophoresis And Optical Detection Using Thermoplastic Nanofluidic Devices: An Experimental And Simulation Study, Kumuditha Madushanka Weerakoon Ratnayake

LSU Doctoral Dissertations

Nanofludic devices provide a great platform for single molecular analysis. The unique phenomena in nanoscale gained such interest in investigating the single molecular behavior in nanochannels. Sizes less than 200 nm in one or two-dimensional structures have lead to fascinating observations not accessible in microscale. When a single molecule translocates through a nanotube it interacts with channel walls by adsorption/ desorption, van der Waals interactions and hydrophilic interactions providing a mechanism for separation without any extra additives. Moreover, double layer thickness governed by the background electrolyte plays a vital role. We report single molecular electrophoresis phenomena in nanochannels and nanoslits …

Safety Procedures For Volcanic Activity In The United States And Japan, Ashley Eisenmenger

A with Honors Projects

This paper discusses the volcanic eruption evacuation and safety procedures in the United States, a country where few realize the potential risks and compares them with procedures in Japan, which experiences frequent eruptions.

The Stratal Architecture Of The False River Point Bar (Lower Mississippi River, La), Alexandra Lechnowskyj

LSU Master's Theses

The False River point bar system is located roughly thirty miles north of Baton Rouge, LA. It is an oxbow lake cut off from the Mississippi River, and represents a large-scale modern analogue to the ancient systems of northeastern Alberta, Canada, specifically those of the Athabasca Oils Sands. While previous work has been done regarding the general architecture of a point bar, there is still omplexity associated with larger scale systems, as studies have been mostly based on small and medium-scale examples. Examination of the point bar was done through a combination of coring and geophysical logging, followed by software …

Mitochondria- Targeted Antioxidant Skq1 Reverses Glaucomatous Lesions In Rabbits, Elena N. Iomdina, Inna P. Khoroshilova-Maslova, Olga V. Robustova, Olga A. Averina, Nadezhda A. Kovaleva, Gjumrakch Aliev, V. Prakash Reddy, Andrey A. Zamyatnin, Maxim V. Skulachev, Ivan I. Senin, Vladimir P. Skulachev

Chemistry Faculty Research & Creative Works

Glaucoma is the main cause of irreversible blindness worldwide. This disease is characterized by apoptosis of retinal ganglion cells (RGC) and visual field loss that seems to be related to elevated intraocular pressure (IOP). Several lines of evidences have implicated the crucial role of mitochondrial dysfunction in the pathogenesis of glaucoma. Increased mitochondrial oxidative stress in RGC may underlie or contribute to susceptibility of RGC to apoptosis. In our work we (i) designed a rabbit model of chronic, moderately elevated IOP for studying glaucoma and (ii) demonstrated efficacy of mitochondria- Targeted antioxidant SkQ1 as a tool to reverse several traits …

Initial Evaluations Of A U.S. Navy Rapidly Relocatable Gulf Of Mexico/Caribbean Ocean Forecast System In The Context Of The Deepwater Horizon Oil Spill Disaster, Edward D. Zaron, Patrick J. Fitzpatrick, Scott L. Cross, John M. Harding, Frank L. Bub, Jerry D. Wiggert, Dong S. Ko, Yee Lau, Katharine Woodward, Christopher N.K. Mooers

Civil and Environmental Engineering Faculty Publications and Presentations

In response to the Deepwater Horizon (DwH) oil spill event in 2010, the Naval Oceanographic Office deployed a nowcast-forecast system covering the Gulf of Mexico and adjacent Caribbean Sea that was designated Americas Seas, or AMSEAS, which is documented in this manuscript. The DwH disaster provided a challenge to the application of available ocean-forecast capabilities, and also generated a historically large observational dataset. AMSEAS was evaluated by four complementary efforts, each with somewhat different aims and approaches: a university research consortium within an Integrated Ocean Observing System (IOOS) testbed; a petroleum industry consortium, the Gulf of Mexico 3-D Operational Ocean …

Shape Optimization For Drag Minimization Using The Navier-Stokes Equation, Chukwudi Paul Chukwudozie

LSU Master's Theses

Fluid drag is a force that opposes relative motion between fluid layers or between solids and surrounding fluids. For a stationary solid in a moving fluid, it is the amount of force necessary to keep the object stationary in the moving fluid. In addition to fluid and flow conditions, pressure drag on a solid object is dependent on the size and shape of the object. The aim of this project is to compute the shape of a stationary 2D object of size 3.5 m2 that minimizes drag for different Reynolds numbers. We solve the problem in the context of shape …

Using Fault Kinematics To Evaluate The Relationship Between Cenozoic Fault Activity, Sedimentation Rates And Salt Movement In The Gulf Of Mexico - A Comparison Between Southwest Louisiana And Southeast Louisiana, Abah Philip Omale

LSU Master's Theses

ABSTRACT Fault initiation and reactivation across south Louisiana during the Cenozoic was driven by either clastic sediment progradation mobilizing underlying salt or by sediment progradation inducing tensional bending stresses during lithospheric flexure. Climate and tectonics within the North American continent during the Cenozoic created differences in the source location, amount of sediments transported, as well as the spatial and temporal distribution of sediments transported into the Gulf of Mexico. This study analyzes 140 fault intercepts along 11 regional cross sections containing well log data in south Louisiana. Cumulative throw, incremental throw, and fault slip rates indicate fault activity punctuated by …

Dosimetric Advantages Of Personalized Phantoms For Quality Assurance And Research In Radiation Dose Measurements, Andrew Michael Halloran

LSU Master's Theses

Background: Phantoms have been in use in medical and health physics for decades, serving as a surrogate for human tissue in several different applications. In radiation dose measurements, anthropomorphic phantoms are designed with tissue substitute materials to mimic both the elemental compositions and anatomical structures of the human body. In some cases the performance of anthropomorphic phantoms for personalized measurements is severely limited by the use of reference anatomy in the geometric design. 3D printing could potentially be used to overcome some of these shortcomings by enabling rapid fabrication of personalized phantoms for individual patients based on radiographic imaging data. …

Comparison Of 3d And 4d Cbct For The Localization Of Moving Targets, Runyon Colie Woods

LSU Master's Theses

Purpose: Compare the localization accuracy of 3D cone beam computed tomography (CBCT) and 4D CBCT for a dynamic respiratory phantom, considering cases with and without respiratory variations between planning and treatment. Methods and Materials: A respiratory phantom was imaged using 3D CBCT and 4D CBCT. Measurements of the amplitude of motion in 3D CBCT and 4D CBCT and size of the sphere at its exhale position in 4D CBCT were acquired. The phantom was then misaligned by known distances relative to a reference position. 3D CBCT and 4D CBCT were used to re-align the phantom by comparing localization images to …

Neodymium Isotope Ratios And A Positive Δ13c Excursion: Connecting Oceanographic And Climate Changes Near The M4-M5 Sequence Boundary Of The Late Ordovician, Zachary Wright

LSU Master's Theses

A significant positive carbon isotope excursion first described from the Guttenberg Member of the Decorah Formation in Iowa called the GICE is a defining feature of Late Ordovician chemostratigraphy. It occurs near the M4-M5 sequence boundary of the Late Ordovician and has been correlated across the globe using prominent K-bentonite ash beds and conodont biomarkers. The cause of the GICE has been debated, with some arguing that it represents the initiation of a glacial period in a greenhouse climate 10 Ma before the end Ordovician glaciation and extinction. A variety of cooling signals have been identified across the M4-M5 sequence …

The Influence Of Marine Topography On The Antarctic Ice Sheet, Daniel Michael Mullally Jr

LSU Master's Theses

The primary controls on Antarctic Ice Sheet (AIS) volume and extent include changes in water temperature, precipitation, atmospheric temperature, and sea level. Here we evaluate the influence of a 5th control, the depth of the continental shelf. Shelf depth affects ice sheet mass balance in the marine environment by controlling the flux of ice that can be exported to the marine environment. This is significant because heat exchange between ocean and ice sheet have been demonstrated to be a dominant control on marine ice volume (Pollard and DeConto, 2009). We used the Parallel Ice Sheet Model (PISM) to simulate AIS …

Potential For Geothermal Energy In Northern Louisiana: Analysis Of The Subsurface Environment In Union And Morehouse Parishes, Tessa Shizuko Hermes

LSU Master's Theses

Efforts to mitigate greenhouse gas emissions and reduce dependence on fossil fuels have led to renewed focus on the exploration and development of alternative energy production. One such option is hydrothermal binary geothermal energy production from geothermal reservoirs with temperatures of at least 100 °C at depths no greater than 5 km. In the U.S., such systems have the potential to provide 5,400 % of 2013 total U.S. energy consumption. This study evaluates the potential for geothermal energy systems implementation in Morehouse and Union Parishes, Louisiana, by using publicly available bottom hole temperature (BHT), mud weight (MW), logged formation top …

Effect Of The Herbicide Atrazine On Phytoplankton, Water Quality, And Ecosystem Functions In Louisiana Estuaries, Alexis Victoria Starr

LSU Master's Theses

Pesticides are used primarily for agricultural purposes in the US and while these chemicals provide many benefits, the inherent toxicity of the compounds pose a substantial risk to the environment. These chemicals may enter water bodies in areas with a high proportion of agricultural land use through surface run off, ground water discharge, and erosion, and negatively impact non-target aquatic organisms. As a result, Louisiana’s estuaries may be vulnerable to a variety of compounds, including the herbicide atrazine. Atrazine is used extensively throughout the Midwest and has been known to enter the Mississippi River through surface runoff and ground water …

Magnetic Resonance Elastography Of The Brain Using An Ergonomic Driver: Assessment Of Scan-Rescan Reproducibility, Hatim Chafi

LSU Master's Theses

Magnetic resonance elastography (MRE) allows the visualization of displacement patterns from induced harmonic mechanical waves propagating in tissue. Strain and mechanical properties can be computed from these displacement patterns. Mechanical properties of tissue are affected by various disease processes. MRE has shown brain tumor to differ in stiffness in comparison to normal tissue. MRE is currently being offered as an upgrade on most conventional MRI scanners. However, the actuator supplied by vendors is a drum driver designed primarily for hepatic MRE scan. The goals of the project was to design and build an ergonomic flexible driver for use in MRE …

Fish Biomass And Community Structure Around Standing And Toppled Oil And Gas Platforms In The Northern Gulf Of Mexico Using Hydroacoustic And Video Surveys, Emily Marissa Reynolds

LSU Master's Theses

There has been relatively little study of the efficacy of decommissioned oil and gas platforms as artificial reef habitats for fish assemblages in the northern Gulf of Mexico (GOM). A variety of fish species have been reported on these structures, but the species biomass distribution and community structure has not been studied thoroughly. Hydroacoustic and video surveys were conducted quarterly from June 2013 to June 2014 at three standing and two toppled oil and gas platforms located approximately 130 km off the coast of Louisiana at 90 m depth; to gain information about the spatial biomass distribution and community structure …

Fish Assemblage Response To Environmental Gradients And Altered Dendritic Connectivity In The Red River Basin, Central Louisiana, Catherine Nell Reuter

LSU Master's Theses

Louisiana’s small streams provide critical habitat for diverse ecologically and economically important fish species. However, the relationship between these fish assemblages and habitat variables remains poorly understood. The role of anthropogenic alteration of dendritic stream connectivity is of specific interest and has been shown to significantly influence stream ecology. This study explored the interaction among watershed characteristics, stream connectivity, stream physico-chemistry, and fish assemblages in little-studied Red River basin of central Louisiana as well as how reservoir littoral zones compared to streams, both in terms of fish assemblage and habitat. Fish and habitat were sampled in 21 headwater streams, half …

Oil And Gas Platforms On Ship Shoal, Northern Gulf Of Mexico As Habitat For Reef-Associated Organisms, David Bradley Reeves

LSU Master's Theses

Nearshore Louisiana has experienced substantial changes within the last half-century, including the annual formation of the world’s second largest hypoxic zone and the construction of thousands of oil and gas platforms (rigs). Ship Shoal and its rigs may provide important substrate in nearshore Louisiana because rigs act as de facto artificial reefs and the shoal’s bottom waters were well oxygenated on 43% of days when surrounding areas were hypoxic. From July to September of 2014, fish assemblages and hydrography were compared at shoal rigs, rigs inshore of the shoal, and rigs offshore of the shoal, and stone crab populations were …

String Searching With Ranking Constraints And Uncertainty, Sudip Biswas

LSU Doctoral Dissertations

Strings play an important role in many areas of computer science. Searching pattern in a string or string collection is one of the most classic problems. Different variations of this problem such as document retrieval, ranked document retrieval, dictionary matching has been well studied. Enormous growth of internet, large genomic projects, sensor networks, digital libraries necessitates not just efficient algorithms and data structures for the general string indexing, but indexes for texts with fuzzy information and support for queries with different constraints. This dissertation addresses some of these problems and proposes indexing solutions. One such variation is document retrieval query …

Population Abundance And Transience Of Selected Coastal Plain Crayfishes, Samantha Lott

LSU Master's Theses

Crayfish are important for stability, determining ecosystem structure, and ecosystem functions in freshwater habitats. Louisiana has many endemic species of crayfish, but most are poorly described. This study investigated the populations of some of the lesser known crayfishes in the South Central Plains. Specifically, the goals were to examine movement, movement across anthropogenic barriers, and estimate population size of 10 species reported from the area: Procambarus natchitochae, P. vioscai, P. clarkii, P. acutus, P. zonangulus, P. tulanei, P. kensleyi, Orconectes maletae, O. lancifer, and O. palmeri. In combination with a field team, I sampled twelve wadeable streams with DC backpack …

Planktonic Influence On The Toxicity Of Hewafs (High-Energy Water Attenuated Fractions), Erin Elizabeth Saal

LSU Master's Theses

The Deep Water Horizon oilrig explosion led to the release of 6.8 ± 1.7 x 108 kg or 4.9 million barrels of petroleum hydrocarbons into the Gulf of Mexico. The spill persisted from the end of April to mid July 2010 affecting a significant portion of the Gulf coast. The effects of this spill are being studied in labs across the country, and this thesis investigated high-energy water accommodated fractions (HEWAFs) as a potential tool for use in this effort. Water accommodated fractions (WAFs) are mediums containing only the fraction of petroleum that remains in aqueous phase after a mixing …

Pytracks: A Tool For Visualizing Fish Movement Tracks On Different Scales, Ross Fossum

LSU Master's Theses

A fundamental problem in conservation biology and fisheries management is the ability to make educated decisions based on the data collected. Fish populations and their spatial distributions need to be represented accurately for conversation efforts and management decisions. Methods such as modeling, surveying, and tracking can all be used to collect data on a particular fishery. To include the movement patterns in conservation and management, one needs to work with and process fish tracking data or data exported from fish movement simulation models. This data can often be difficult to process. This topic is becoming increasingly popular as technology to …

A Critique Of A Student-Centered Learning Approach Used In A Geometry Classroom, Alana Blackwell Day

LSU Master's Theses

This thesis offers a framework for identifying effective classroom materials to support student-centered learning. Based on a review of published studies on effective classroom activities, as well as theses by Louisiana Math and Science Teachers Institute (LaMSTI) graduates, we identify promising characteristics. We employed these in five lessons, refined them into questions, and offer in final form for use.

Partial Cosine-Funk Transforms At Poles Of The Cosine-Λ Transform On Grassmann Manifolds, Christopher Adam Cross

LSU Doctoral Dissertations

The cosine-λ transform, denoted C^λ, is a family of integral transforms we can define on the sphere and on the Grassmannian manifolds of p-dimensional subspaces in Kⁿ where K is R, C or the skew field H of quaternions. We treat the Grassmannians as the symmetric spaces SO(n)/S(O(p) × O(q)), SU(n)/S(U(p) × U(q)) and Sp(n)/(Sp(p) × Sp(q)) and we work by analogy with the case of the cosine-λ transform on the sphere, which is also a symmetric space.

The family C^λ extends meromorphically in λ to the complex plane with poles at (among other values) λ …

Writing In The Geometry Classroom, Amy Lynn Rome

LSU Master's Theses

This study sought a time-efficient way to implement writing in ninth-grade Geometry. Students wrote responses to five expository writing prompts spread out over the spring semester of the 2014-2015 school year. Students’ first attempts were graded and returned to them along with feedback in the form of a teacher-written exemplar. Students rewrote assignments to improve their grades. All first and second attempts were collected and evaluated. We found that students were more successful after seeing the exemplar. Moreover, on assignments occurring later in the semester, more students were able to score in the top categories of the writing assignments on …

The Implementation Of Two Cooperative Learning Structures, Rally Coach And Teams-Games-Tournaments, In High School Chemistry Courses, Joanna Miketinas Stewart

LSU Master's Theses

To combat the obstacles that students experience in chemistry, two cooperative learning strategies, Rally Coach and Teams-Games-Tournaments, were implemented in five chemistry courses at East Ascension High School. Rally Coach called for two students to work as a pair and peer tutor to successfully complete practice problems for each lesson. Teams-Games-Tournaments required students to work in groups of four to complete practice problems and compete for team points as a review. Every student experienced both learning strategies. A comparison was made to see which cooperative learning strategy better helped student performance, including comparisons of effects on different student demographics and …

Metacommunity Dynamics And The Biogeography Of Central Louisiana Crayfishes, William Robert Budnick

LSU Master's Theses

The greatest diversity of crayfishes, especially of rare Orconectes species, is found in the central Louisiana watersheds (Red River, Mermentau, Calcasieu, and Vermillion-Teche), and most species are widely distributed among the drainages. The purpose of this research was to lay groundwork for species distribution and metacommunity modelling for crayfishes in this region. To address this goal, two field studies were performed in the summers of 2013 and 2014, as well as an indoor laboratory study. Analyses of broadly distributed species indicated no significant correlations between species abundances and habitat variables nor any significant environmental gradients for those species. Within-drainage variability …

A Rapid And High Content Assay That Measures Cyto-Id-Stained Autophagic Compartments And Estimates Autophagy Flux With Potential Clinical Applications, Sujuan Guo, Yanping Liang, Susan F. Murphy, Angela Huang, Haihong Shen, Deborah F. Kelly, Pablo Sobrado, Zhi Sheng

Chemistry Faculty Research & Creative Works

The lack of a rapid and quantitative autophagy assay has substantially hindered the development and implementation of autophagy-targeting therapies for a variety of human diseases. To address this critical issue, we developed a novel autophagy assay using the newly developed Cyto-ID fluorescence dye. We first verified that the Cyto-ID dye specifically labels autophagic compartments with minimal staining of lysosomes and endosomes. We then developed a new Cyto-ID fluorescence spectrophotometric assay that makes it possible to estimate autophagy flux based on measurements of the Cyto-ID-stained autophagic compartments. By comparing to traditional autophagy approaches, we found that this assay yielded a more …