Digital Commons Network^™

Surface-Initiated Polymerization As A Novel Strategy Towards Preparation Of Organic Semiconducting Polymer Thin Films, Euiyong Hwang

LSU Doctoral Dissertations

Organic semiconducting polymer thin films are core materials for organic electronics that are conventionally prepared by solution processing techniques. Despite having the advantage of easy and fast thin film manufacturing, solution techniques have intrinsic drawbacks, such as disordered and poor molecular organization in the film (often resulting in poor device performance), as well as insufficient stabilities of the films and resulting devices. To improve this situation, we designed a novel “bottom-up” fabrication of surface-immobilized organic semiconducting thin films through in situ polymerization. This new strategy will allow high degree of control over molecular organization which therefore results in improved free …

A Comprehensive Study Of Dust Formation And Evolution In Core Collape Supernovae, Jennifer Erin Andrews

LSU Doctoral Dissertations

Detection of large amounts of dust in high redshift galaxies suggests that core collapse supernovae (CCSNe) may play a critical role in the dust budget of galaxies in the early universe, when galaxies are only a few hundred million years old. At an age of only 1Gyr, asymptotic giant branch (AGB) stars may not have had the time to become significant dust contributors, leaving CCSNe as an alternative explanation since they quickly evolve and return their material to the surrounding interstellar medium. For the past three years, I have been observing the CCSNe 2007it and 2007od with Gemini, Hubble Space …

Economics Of U.S. Government Debt Accumulation, Carlos Ignacio Garcia Jimenez

LSU Doctoral Dissertations

The United States of America is an indebted nation in the early years of the new millennium, changing from $469 billion in 1973 to $14 trillion in 2010, as spending is justified on the basis that it promotes GDP growth which in turn increases societal benefits. Despite the benefits of debt, its effectiveness and the transmission mechanisms of fiscal policy are still on debate. Consequently, the economic effects of U.S. government debt accumulation are studied in three empirical research articles.

The dissertation is composed of five chapters. The first chapter is an introduction wherein the problem statement, the purpose, objectives …

Characterization Of Photon Counting Czt Detectors For Medical X-Ray Imaging And Spectroscopy, Shannon Fritz

LSU Doctoral Dissertations

Purpose: The purpose of this research was to characterize a photon counting cadmium zinc telluride (CZT) detector for medical x-ray imaging and spectroscopy purposes. The overall aim was to characterize CZT detector properties and to develop modifications and correction methods to address the limiting factors, making the detector clinically viable. Methods: Hole trapping issues were investigated through simulation and experiments with a large area single pixel CZT detector under three different irradiation geometries: edge-on, surface-on, and tilted angle irradiation. Characteristic x-ray escape was simulated using Monte Carlo methods and compared to measurements with a small pixel CZT imaging detector. Monoenergetic …

Damage Detection And Identification In Fiber Reinforced Plastic Structural Members And Field Bridges Using Acoustic Emission Technique, Archana Nair

LSU Doctoral Dissertations

With the increased use of fiber reinforced polymer (FRP) based structural systems for rehabilitation of existing and construction of new bridges there is a requirement for identification of critical components of these structural systems and the determination of critical damage thresholds in them. Of the many available non-destructive techniques (NDT), acoustic emission (AE) monitoring had been identified as one of the most popular techniques applicable for damage discrimination in composites. The current study aimed at using patterns in AE data for the identification of damage modes exhibited by composite structural systems. The extensive experimental program involved testing of two structural …

The Relationship Between Music And Visual Arts Formal Study And Academic Achievement On The Eighth-Grade Louisiana Educational Assessment Program (Leap) Test, Richard Allen Baker Jr.

LSU Doctoral Dissertations

The purpose of this study was to examine the policy implications allowing administrators to exempt a student from required arts instruction if the student obtained unsatisfactory scores on the high-stake state mandated tests in English and mathematics. This study examined English language arts and math test scores for 37,222 eighth grade students enrolled in music and/or visual arts classes and those students not enrolled in arts courses. There were more than 12,000 students who were eligible, but not enrolled in arts courses. Methodology consisted of comparing the mean scores of students receiving music and visual arts instruction with the mean …

A C0 Interior Penalty Method For The Von Kármán Equations, Armin Karl Reiser

LSU Doctoral Dissertations

In this dissertation we develop a C⁰ interior penalty method for the von Kármán equations for nonlinear elastic plates. We begin with a brief survey on frequently used finite element methods for the von Kármán equations. After addressing some topics from functional analysis in the preliminaries, we present existence, uniqueness and regularity results for the solutions of the von Kármán equations in Chapter 3. In the next chapter we review the C⁰ interior penalty method for the biharmonic problem. Motivated by these results, we propose a C⁰ interior penalty method for the linearized von Kármán equations in …

Proteomic Analysis Of The Blood Of Alligator Mississippiensis, Lancia Nadinia Fallen Darville-Bowleg

LSU Doctoral Dissertations

My research focus was to investigate alligator blood using mass spectrometry-based proteomics methods to understand their innate immune systems. The first goal was to sequence peptides and proteins from the blood serum and leukocytes using tandem mass spectrometry and de novo sequencing. The second goal was to determine the function of these biological molecules and their relationship to the immune system. One- and two-dimensional gel electrophoresis was used to separate proteins from alligator leukocytes, which were enzymatically digested. The peptides were measured using reversed phase nano-high performance liquid chromatography coupled with tandem mass spectrometry (nano-HPLC-MS/MS) followed with de novo sequencing. …

Structural And Electronic Properties Of Noble Metals On Metal Oxide Surfaces, Fei Wang

LSU Doctoral Dissertations

Noble metals on metal oxide surfaces play crucial roles in many catalysis applications. Due to extreme complexity of the interfaces and catalytic reaction processes, basic science studies of model systems are needed to guide the construction and optimization of new industrial catalysts. We have employed ultra-high vacuum techniques to investigate the morphology, electronic structure, and surface reactivations of clean metal-oxide/metal nanocluster interfaces in ideal conditions. The systems we chose are Ag/TiO2, a popular photocatalyst, and Cu/ZnO, recently a hot candidate for liquid fuel production. The main characterization techniques that we have employed include Scanning Tunneling Microscopy (STM), Photoemission Spectroscopy (PES), …

The Effects Of A Freshwater Diversion Of Nekton Species Biomass Distributions, Food Web Pathways, And Community Structure In A Louisiana Estuary, Kim De Mutsert

LSU Doctoral Dissertations

A current method to restore Louisiana’s estuaries includes reintroducing freshwater and sediments to wetlands that are hydrologically isolated from the Mississippi River due to the construction of levees. In this dissertation, I examined effects of the second largest freshwater diversion in Louisiana, the Caernarvon Freshwater Diversion (CFD), on estuarine nekton in Breton Sound. Before focusing on Breton Sound, I examined the status of nekton communities in the northern Gulf of Mexico (GOM), and Louisiana wetlands in particular, using the mean trophic level index (MTLI). I demonstrated that commercial targeting caused the previously reported low and declining MTLI from the GOM. …

Factor That Influence The Critical Thinking Skills Of Public School Teachers In A Parish In Southwest Louisiana, Dale Beglis Schanz

LSU Doctoral Dissertations

The purpose of this study is to determine the influence of selected personal and professional demographic characteristics on the critical thinking abilities of teachers in a parish in Southwest Louisiana. The study is a correlational design using a descriptive survey technique with questions for the data collection. The examiner looked at attribute independent variables – characteristics that a subject has before a study begins such as gender, age, race, highest level of education completed, and years of teaching experience. Three hundred and twenty-four teachers in twelve public schools (three high schools, four middle schools, and five elementary schools) participated in …

Retention And Transport Of Mercury And Nickel In Soils, Lixia Liao

LSU Doctoral Dissertations

Nickel (Ni) is one of many trace metals widely distributed in the environment. High concentrations of Ni in soils and aquifers have been observed worldwide, causing several potential human health impacts. Better understanding of Ni transport in soils and aquifers is necessary to assess and remediate insitu environmental contamination. The movement of Ni in soils and aquifers is highly dependent on adsorption-desorption reactions in the solid phase. In this study, kinetic batch, sequential extractions, and miscible displacement experiments were conducted to investigate the effect of several of environmental factors including soil type, reaction time and competing ions, on the fate …

Studies Of Nanoparticles From A Group Of Uniform Materials Based On Organic Salts (Gumbos), Aaron Tesfai

LSU Doctoral Dissertations

Tesfai, Aaron, B.S., B.A., University of Missouri, Columbia, 2003 Doctor of Philosophy, Spring Commencement 2010 Major: Chemistry Studies of Nanoparticles from a Group of Uniform Materials Based on Organic Salts (GUMBOS) Dissertation directed by Professor Isiah M. Warner Pages in dissertation, 101. Words in abstract, 271. Ionic liquids (ILs) are defined as organic salts composed of ions with melting points at or below 100 °C. ILs have gained considerable attention because of their desirable properties such as low volatility, high thermal stability, and tunability. GUMBOS are an emergent class of organic salts, many of which are ionic liquids (ILs). However, …

Choosing Between Remote I/O Versus Staging In Distributed Environments, Ibrahim Hakki Suslu

LSU Doctoral Dissertations

Today, scientifi_x000C_c applications and experiments have become increasingly complex and more demanding in terms of their computational and data requirements. The amount of data generated and used has grown at a very rapid rate. As tens or hundreds of terabytes of data for a single application is very common today; petabytes and even exabytes of data will be very common in a few years. One of the major challenges in distributed computing environments is how to access these large datasets remotely over the network. Data staging and remote I/O are the most widely used data access methods for distributed applications. …

Upland Nesting Waterfowl Population Responses To Predator Reduction In North Dakota, Matthew R. Pieron

LSU Doctoral Dissertations

Population growth for mallards (Anas platyrhynchos), and presumably other upland nesting ducks, in the Prairie Pothole Region is most sensitive to nest success, and nest success is most strongly influenced by predation. I evaluated the efficacy of reducing predator populations to improve nest success and increase local breeding populations of upland nesting ducks on township-sized (93.2 km2) management units in eastern North Dakota, USA, during 2005−2008. I also examined potential territorial limitations on local population growth for mallards. Trappers annually removed an average of 245 predators per trapped site. I monitored 7,489 nests on 7 trapped and 5 nontrapped sites, …

University Admissions Officers' Perceptions Of Student Performance Within The International Baccalaureate Diploma Program, Emily Trabona Tarver

LSU Doctoral Dissertations

This qualitative study sought to provide a general perception of admissions offices of secondary institutions have toward the Diploma Program through a grounded theory approach. The first goal of the study investigated the nature of credit awards for a student’s high school academic performance. Specific attention was paid to the processes institutions use for determining credit awards, policies associated with credit awards, and perceptions related credit awards. The second goal investigated admissions policies, processes, and perceptions associated with credit awards and the DP specifically. Finally, the third goal sought to illustrate the development and/or changes in the perceptions and actions …

A Conductor's Analysis Of Theodore Morrison's War And Reconciliation, Alissa Ann Mercurio Rowe

LSU Doctoral Dissertations

Theodore Morrison (b. 1938) was involved with music at a very young age as singer, organist, and choirmaster. As his musical career prospered he grew as a teacher, conductor, and composer. His compositional output includes several large works for chorus, soloists and orchestra, and a substantial body of shorter works. The smaller works encompass an overture for wind ensemble, chamber pieces for woodwinds and strings, a sonata and a set of variations for organ, several works for chorus and organ, an a cappella mass, three song cycles, and numerous choral pieces and songs. This document presents a brief biographical introduction …

Subgroups Of The Torelli Group, Leah R. Childers

LSU Doctoral Dissertations

Let Mod(Sg) be the mapping class group of an orientable surface of genus g, Sg. The action of Mod(Sg) on the homology of Sg induces the well-known symplectic representation:

Mod(Sg) ---> Sp(2g, Z).
The kernel of this representation is called the Torelli group, I(Sg).

We will study two subgroups of I(Sg). First we will look at the subgroup generated by all SIP-maps, SIP(Sg). We will show SIP(Sg) is not I(Sg) and is in fact an infinite index subgroup of I(Sg). We will also classify which SIP-maps are in the kernel of the Johnson homomorphism and Birman-Craggs-Johnson homomorphism.

Then we will …

Cross-Talk-Free Dual-Color Fluorescence Cross-Correlation Spectroscopy For High-Throughtput Screening, Wonbae Lee

LSU Doctoral Dissertations

High throughput processing of chemical/biochemical information is critical in many areas, such as genome sequencing, drug discovery and clinical diagnostics. Integral to collecting information at high rates with the necessary throughput is the development of systems that can not only monitor the results with high precision and accuracy, but also prepare and process samples prior to the analytical measurement. To achieve the required throughput, we have conducted work directed toward developing a system that provides detection sensitivity at the single-molecule detection (SMD) level. The research was first focused on the development of a sensitive strategy for the detection of proteins …

Analysis And Modeling Of Hurricane Impacts On A Coastal Louisiana Lake Bottom, Angelina Freeman

LSU Doctoral Dissertations

Tropical cyclone impacts on wetland, terrestrial, and shelf systems have been previously studied and reasonably delineated, but little is known about the response of coastal lakes to storm events. For the first time, tropical cyclone impacts on a shallow coastal lake in the Louisiana coastal plain have been studied using direct lines of evidence and numerical modeling. Using side-scan sonar, CHIRP subbottom and echo sounder bathymetric profiles, the lake bottom and shallow subsurface of Sister Lake was imaged pre- and post-Hurricanes Katrina and Rita to provide a geologic framework for assessing the effects of these storms. Box cores were collected …

A Four-Cysteine Zinc Finger In Carboxyltransferase Structurally Links The Functions Of Enzymatic Activity And Negative Feedback Regulation Of Translation, Glen D. Meades

LSU Doctoral Dissertations

Acetyl-CoA carboxylase is the first and committed step of de novo fatty acid synthesis in all organisms. In Escherichia coli, the enzyme is expressed as separate proteins for the three functional components: a biotin carboxylase, a biotin carboxyl carrier protein, and a carboxyltransferase. The carboxyltransferase enzyme has an α2β2 heterotetrameric quaternary arrangement. The crystal structure of the β subunit revealed a zinc-binding domain, a feature common among nucleic acid-binding proteins. Carboxyltransferase preferentially binds mRNA coding for its two subunits over other nucleic acids, suggesting a means by which the enzyme can regulate its own expression. In the first study, the …

Lattice Boltzmann Modeling For Shallow Water Equations Using High Performance Computing, Kevin Tubbs

LSU Doctoral Dissertations

The aim of this dissertation project is to extend the standard Lattice Boltzmann method (LBM) for shallow water flows in order to deal with three dimensional flow fields. The shallow water and mass transport equations have wide applications in ocean, coastal, and hydraulic engineering, which can benefit from the advantages of the LBM. The LBM has recently become an attractive numerical method to solve various fluid dynamics phenomena; however, it has not been extensively applied to modeling shallow water flow and mass transport. Only a few works can be found on improving the LBM for mass transport in shallow water …

Experimental And Numerical Analysis Of Fuel Cells, Abul Bashar Mahmud Hasan

LSU Doctoral Dissertations

Fuel Cells are attractive power source for use in electronic applications. Physical phenomena (water generation, saturation effect in fuel cell, poisoning, and thermal stress) are studied that governs the operation of a Proton Exchange Membrane Fuel Cell (PEMFC) and Solid Oxide Fuel cell (SOFC). Additionally, experimental studies and numerical simulations on PEMFC gas flow channel, the determination of the impact of the single channel fuel cell are presented. Furthermore, preliminary study is done for the application of APS (Air Plasma Spray) to SOFC and adhesion of anode and cathode with electrolytes for the determination of parameters involved in manufacturing the …

Chemistry Of Rhenium(I) Tricarbonyl Complexes Of Biomedical Relevance, Theshini Perera

LSU Doctoral Dissertations

fac-[Re^I(CO)₃L]ⁿ complexes serve as models for short-lived fac-[^99mTc^I(CO)₃L] imaging tracers. Dangling groups on L, needed to achieve desirable biodistribution, complicate the NMR spectra, which are not readily understood. In fac-[Re^I(CO)₃L]⁺ with less complicated L, NH groups (exo-NH) projecting toward the L face sometimes showed an upfield shift attributable to steric shielding of the exo-NH group from the solvent by the chelate rings. To investigate whether exo-NH groups in six-membered rings exhibit the same effect and whether the …

Analysis Of Teacher Efficacy And Perspectives About Literacy Implementation In Selected Elementary Schools, Joy Rene' Abernathy-Dyer

LSU Doctoral Dissertations

Each teacher has a set of beliefs and knowledge as it relates to teaching and learning. In this study, we examine “How do the ways in which teachers perceive mandated literacy implementation impact their classroom instruction?” Therefore, the purpose of this study is to explore some of the issues that attempts to change teachers’ instructional practices in the classroom and seeks to reveal some of the issues that influence as well as hinder instructional reform within that setting. This qualitative case study uses observations, interviews and questionnaires to highlight teacher efficacy from four first grade teachers and classrooms through the …

Popular Sovereignty, Slavery In The Territories, And The South, 1785-1860, Robert Christopher Childers

LSU Doctoral Dissertations

The doctrine of popular sovereignty emerged as a potential solution to the crisis over slavery in the territories because it removed the issue from the halls of Congress. Most historians have focused on its development and implementation beginning in the late 1840s and culminating with passage of the Kansas-Nebraska Act in 1854, but have not recognized its significance in earlier debates over slavery. Popular sovereignty, which took various forms and received different definitions, appeared as a potential solution to the problem of slavery extension as early as the first decade of the nineteenth century when settlers in the Louisiana Purchase …

Studies Of Hydrophobic Organic Pollutant Interactions With Cyclodextrin: Implication For Groundwater Remediation, Heng Gao

LSU Doctoral Dissertations

Henry’s Law constants of several common, subsurface hydrophobic organic pollutants (HOPs) including trichloroethylene (TCE), perchloroethylene (PCE) and benzene, toluene, ethylbenzene and o-xylene (BTEX), were measured over a range of temperatures (35, 45, 55 and 65°C) and cyclodextrin (CD) concentrations (0, 10, 20, 50 and 100 g L-1). In aqueous CD solutions, Henry’s constant values decrease by a power law relationship with increasing CD concentration due to an apparent solubility enhancement caused by HOP partitioning to the hydrophobic cavity of CD molecules. The temperature dependence of air-water partitioning under the influence of CD was well described by the van’t Hoff equation …

A Study Of Communication In Baby Boomers' Romantic Relationships And The Effects Of Their Children's Communication About The Relationships, Lois B. Nemetz

LSU Doctoral Dissertations

This study contributes to our knowledge of life-span communication by examining the communication of the Baby Boomer generation (born 1946-1964) as they re-enter the dating scene. Although Baby Boomers' early years of dating (the 1960's, 1970's, and 1980's) occurred in a time of new-found freedom, especially in sexual relationships, the experience of dating several decades later brings many complications due to aging and children. The intent of this study was not to generalize that all Baby Boomers would express the views stated in this study, but to show the complexity of this generation, and to present a theoretical framework for …

Study Of Microstructure Effect On The Thermal Properties Of Yttria-Stabilized-Zirconia Thermal Barrier Coatings Made By Atmospheric Plasma Spray And Pressing Machine, Monica Bohorquez De Silva

LSU Doctoral Dissertations

Thermal barrier coatings (TBCs) are used in gas turbine engines to achieve a higher working temperature and thus lead to better efficiency. Yttria-Stabilized-Zirconia (YSZ), a material with low thermal conductivity, is commonly used as the top coat layer to provide the thermal barrier effect. In this dissertation the thermo-physical properties of a variety of TBCs samples made out of different fabrication techniques were investigated and compared. The first set of samples was fabricated using a pressing machine device to fabricate 0.5 inch diameter disk shaped YSZ-Al2O3 samples. The YSZ-Al2O3 powder mixture was made of 0, 1, 2, 3, 4 and …

A Study Of The Elongation Of Fibrils Of The Alzheimer's Amyloid Beta Protein With A Coarse-Grained Force Field, Ana Rojas

LSU Doctoral Dissertations

Alzheimer’s disease (AD) is a brain disorder named after the German psychiatrist Alois Alzheimer, who first described the disease in 1906. AD is a form of dementia, characterized by impairment of memory and other intellectual abilities, caused by the loss of neurons and synapses (the structures that permit communication between neurons) in certain regions of the brain. Although the mechanism by which neurons are affected is not yet well understood, research points to a small protein, the beta-amyloid peptide (Abeta), as the first suspect. Ab chains are present in the brains of healthy individuals, but in AD patients, they associate …