Digital Commons Network^™

Infrared And X-Ray Spectroscopic Studies Of The Copper(Ii) Oxide Mediated Reactions Of Chlorinated Aromatic Precursors To Pcdd/F, Steven L. Alderman

LSU Doctoral Dissertations

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) are toxic compounds produced in combustion systems such as incinerators, and their emissions are an important environmental issue. Chlorinated phenols and benzenes form PCDD/F through heterogeneous reactions following adsorption onto fly-ash surfaces. Current research implicates transition metals in promoting formation of phenoxyl radicals that react to form PCDD/F, although this has not been studied extensively. This objective of this work is to better understand PCDD/F formation from chlorinated aromatic precursors. Using 2 chlorophenol as a model PCDD/F precursor and silica as a fly-ash surrogate, time-dependent chemisorption of 2 chlorophenol onto silica was studied in situ …

Macroinvertebrate Community Of Ecology Of Lowland, Subtropical Streams In Louisiana, Michael Douglas Kaller

LSU Doctoral Dissertations

Freshwater ecosystems, particularly streams and rivers, have been the subject of prodigious research. Unfortunately, in comparison to neighboring regions, the Gulf of Mexico coastal plain has not received as much attention. Therefore, I collected data on the macroinvertebrates of these streams to begin the understanding of the relationships between community structure and environmental characteristics. In contrast to the hypothesized ancestral streams of these macroinvertebrates, coastal plain streams are commonly devoid of rocks leaving only woody debris as usable hard substrates and are typically lower in dissolved oxygen. I examined habitat selection by colonization of woody debris with large and small …

Synthesis Of Symmetric And Asymmetric Water-Soluble Porphyrin Derivatives, Caroline Owendi Ongayi

LSU Doctoral Dissertations

Novel symmetric and asymmetric water-soluble tetrabenzoporphyrin are synthesized in relatively good yields. These compounds are synthesized by the condensation of butanopyrrole with several aldehydes that contain masked water solubilizing groups followed by metal insertion, oxidation and demetallation and deprotection of the masked solubilizing groups. The biological evaluation (in vitro and in vivo) studies are described in addition to the photophysical evaluations of the corresponding compounds. A novel versatile route to the syntheses of novel free-bases and metallo-benzoylbiliverdin is discussed. The treatment of metal free-dodecasubstituted porphyrin with sodium nitrite and trifluoroacetic acid at room temperature in the presence of oxygen affords …

Effects Of Body Size On Goose Behavior: Lesser Snow Goose And Ross's Goose, Jon Einar Jonsson

LSU Doctoral Dissertations

Body size is highly variable among geese, both at intra- and interspecific levels. Interspecific variation in several behaviors has been attributed to differences in body size in geese: incubation constancy, tendency to maintain family units, and time spent foraging. Body size has important physiological implications for birds, mostly because mass-specific metabolic rate is greater for birds of smaller mass. The Body-size Hypothesis predicts that smaller species deplete their energy reserves at relatively faster rates than do larger species. Hypotheses and conclusions concerning effects of body size on waterfowl behavior often are based on comparisons of species that confront different climates, …

Teacher Beliefs And Practices Survey: Operationalizing The 1997 Naeyc Guidelines, Kyung-Ran Kim

LSU Doctoral Dissertations

This study examined the psychometric properties of a revised measurement, the Teacher Beliefs and Practices Survey, devised for teachers of 3- to 5-year-old children. The measure was designed to reflect the concepts of DAP (developmentally appropriate practices) as presented in the revised 1997 NAEYC guidelines and consisted of 2 scales. Three hundred seventy five surveys completed by public kindergarten teachers in Southeast Louisiana were utilized in the study. Reliability was examined using internal consistency method. Cronbach¡¯s ¥á was .858 for the Beliefs Scale and .787 for the Instructional Activities Scale. Validity of the measure was examined in its content, criterion, …

Wavelet Sets With And Without Groups And Multiresolution Analysis, Mihaela Dobrescu

LSU Doctoral Dissertations

In this dissertation we study a special kind of wavelets, the so-called minimally supported frequency wavelets and the associated wavelet sets. Most of the examples of wavelet sets are for dilation sets which are groups. In this work we construct wavelet sets for which the dilation set, D, is of the form D=MN, where the product is direct, and so D is not necessarily group. In the second part of this dissertation we construct multiwavelets associated with MRA's and we generalize the rotations in the dilation sets to Coxeter groups.

Active Security Mechanisms For Wireless Sensor Networks And Energy Optimization For Passive Security Routing, Lydia Ray

LSU Doctoral Dissertations

Wireless sensor networks consisting of numerous tiny low power autonomous sensor nodes provide us with the remarkable ability to remotely view and interact with the previously unobservable physical world. However, incorporating computation intensive security measures in sensor networks with limited resources is a challenging research issue. The objective of our thesis is to explore different security aspects of sensor networks and provide novel solutions for significant problems. We classify security mechanisms into two categories - active category and passive category. The problem of providing a secure communication infrastructure among randomly deployed sensor nodes requires active security measurements. Key pre-distribution is …

Stm And Arpes Studies Of Epitaxial Multilayer Ag On Cu(110) And Ni(110), Weichang Zhao

LSU Doctoral Dissertations

Ag nanostructures of multilayer coverages (< 30 monolayers) epitaxially self-assembled on Cu(110) and Ni(110) have been explored by scanning tunneling microscopy (STM), angle-resolved photoelectron emission spectroscopy (ARPES), and low energy electron diffraction (LEED). We have studied varied nanostructure morphologies self-assembled depending on different deposition/annealing processes and coverages, their atomic structures, growth behaviors and mechanisms, and the electronic structures of nanowires. At nominal coverages of 1.2 ML < ¦È < ~10 ML, there are two epitaxial structures on Cu(110) and Ni(110). One is a Ag(110) multilayer film, which has a superstructure with lateral periodic units of eight and three/four substrate lattice constants along [¯110] and along [001] respectively. Another is that of Ag(110) nanowires surrounded by pseudohexagonal Ag(111) monolayer. The Ag(110) nanowires are triangular in cross section. The two side surfaces are faceted and the long axis is atomically straight along [¯110]. Typical lengths are within the range of 100 ~ 5000 Å, widths 70 ~ 300 Å, side slopes 10 ~ 30º, and heights 5 ~ 60 Å. The Ag nanowires present extraordinary anisotropy with observed aspect ratios (length:width) of up to 20:1. The Ag(110) nanowires are in-registry with the substrate along [001], but not along [¯110]. At coverages of ~ 10 ML < ¦È < ~25 ML, there also exist two different nanostructures, the nanowires and a Ag(110) atomically-flat film with some pits as deep as down to the substrate and a one-dimensional quasiperiodic superstructure along [001]. There are two basic separations of the superstructural stripes: one is three lattices wide (~11 Å) and the other is two lattices wide (~7 Å). Both of nanostructures are stable at temperature up to at least 200 ¡ãC and not inter-transformable. The growth of the nanowires is driven by the elastic strain mechanism, but the growth of the atomically-flat film is driven by electronic growth mechanism originated from the electron quantum confinement in the vertical direction of the film. The ARPES of the nanowires shows dispersion in the vertical and the [¯110] directions, but no dispersion in the [001] direction because of the limited width (~ 200 Å).

Host-Parasite Cophylogeny And Rates Of Evolution In Two Rodent-Louse Assemblages, Jessica E. Light

LSU Doctoral Dissertations

Studies of cophylogeny greatly increase understanding of associations between hosts and their parasites. This study uses molecular data to test the hypothesis that members of two rodent families (Geomyidae and Heteromyidae) and their associated lice (Geomydoecus and Fahrenholzia, respectively) show a statistically significant pattern of cophylogeny. Both host groups are generally solitary organisms and both louse groups are obligate ectoparasites, often exhibiting extreme degrees of host specificity. This intimate and potentially long-term association likely has resulted in coevolutionary adaptations and counter adaptations on the part of both symbiotic partners. Phylogenetic analysis of chewing lice (Geomydoecus) reveals two major clades corresponding …

An Investigation Of Selected Academic And Nonacademic Predictor Variables Of Academic Performance Of Student-Athletes At Louisiana State University, Derek Jerone Morgan

LSU Doctoral Dissertations

This study investigated the effects of selected predictor variables of academic achievement on the academic performance of student-athletes at Louisiana State University. This study attempted to identify cognitive and noncognitive variables that might explain the variance in the cumulative college grade point average (GPA)among student-athletes at LSU enrolled during the 2003-04 academic year. Cognitive variables included ACT composite score, high school GPA, and cumulative college GPA. Noncognitive variables included positive self-concept, support of academic plans, and community involvement. In addition, data were collected for two sport variables--type of sport participation (revenue and non-revenue generating sports) and time spent on sport …

A Historical Approach To Training The Vocal Registers: Can Ancient Practice Foster Contemporary Results?, Taylor Lee Ferranti

LSU Doctoral Dissertations

A review of the extant vocal literature containing the writings of Tosi, Mancini, and Garcí­a, shows that the topic of vocal registration appeared to be at the core of their training procedures. The essence of their vocal instruction centered around how the registers coordinated, separated, and developed to form the functional basis of a sound technique. However, of all the topics that encompass historical pedagogy, none will confound the diligent voice teacher more than the topic of vocal registers. For this reason, contemporary pedagogy has developed certain methodologies that appear to be at odds with the historical approach to training …

The Spectral Conforming Model And Its Applications, Jaeho Shim

LSU Doctoral Dissertations

It has been observed that finite element or finite difference model of order can approximate with fair accuracy less than one-third of the eigenvalues of the underlying continuous system corresponding to the low spectrum. The new discrete model, namely the spectral conforming model, is developed to predict the eigenvalues of continuous systems in both the low and high spectra. The spectral conforming models are developed using an inverse vibration method. The classical vibration problem is the direct method. In the direct approach, the characteristic behaviors of the system, i.e. frequency response, natural frequency, and steady state response are analyzed and …

Material Length Scales In Gradient-Dependent Plasticity/Damage And Size Effects: Theory And Computation, Rashid Kamel Abu Al-Rub

LSU Doctoral Dissertations

Structural materials display a strong size-dependence when deformed non-uniformly into the inelastic range: smaller is stronger. This effect has important implications for an increasing number of applications in structural failure, electronics, functional coatings, composites, micro-electro-mechanical systems (MEMS), nanostructured materials, micro/nanometer fabrication technologies, etc. The mechanical behavior of these applications cannot be characterized by classical (local) continuum theories because they incorporate no ‘material length scales’ and consequently predict no size effects. On the other hand, it is still not possible to perform quantum and atomistic simulations on realistic time and structures. It is therefore necessary to develop a scale-dependent continuum theory …

Constructive Habituation As An Educational Approach To Process-Object Reification In Mathematics, Alonzo F. Peterson

LSU Doctoral Dissertations

Sfard and Thompson (1994) state that what matters most is that educators develop ways of thinking, teaching, and learning mathematics. This study introduced constructive habituation, a new strategy developed to aid both students and teachers in the thinking, teaching, and learning of mathematics. Constructive habituation attempts to unite constructivist teaching methods aimed at supporting students’ conceptual understanding of content and habituationist teaching method aimed at establishing routine responses to routine tasks. This study is exploratory in nature, designed to investigate if constructive habituation is a more effective means than a traditional teaching method in helping students reach process-object reification as …

Microelectrophoresis System Utilizing Conductivity Detection Analyzing Biological Molecues, Michelle Galloway

LSU Doctoral Dissertations

Microfabrication technology has proven to be a valuable tool for creating polymer-based devices utilized in chemical and biochemical assays. Although, reducing the size of the device allows for short analysis times and reduces the reagent demand to ultrasmall volumes (< 1 nanoliter), a resulting consequence is the constraint placed on the limits of detection associated with the detector hardware required for readout. To overcome such constraints, laser-induced fluorescence (LIF) is often employed as a detection method as it provides low detection limits, which approach the single molecule level. Unfortunately, most LIF systems do not offer the benefits of miniaturization, with the detector components (i.e. laser, optics, filters) often times requiring a much larger footprint compared to the device. Another readout strategy that has shown promise for these devices is conductivity detection. Detection can be accomplished using either conventional-size or microfabricated electrodes, which can be integrated on the device. Although conductivity has been commonly used to detect inorganic or small organic species, the potential for detection of biological species has received little attention. In this work, an integrated conductivity detector was developed for the analysis of amino acids, peptides, proteins, and oligonucleotides (double-stranded DNA). Using the detector, mass detection sensitivities in the range of 10^-18 - 10^-21 moles were achieved. To increase the throughput of the system a state-of-the-art, multichannel device with a conductivity array detector was devised. This device, which consists of a 16-channel fluidic network and a printed circuit board, is geared toward automating three-processing steps onto a single fluidic platform including purification, preconcentration and detection for downstream parallel processing.

The Radon-Gauss Transform, Vochita Mihai

LSU Doctoral Dissertations

Gaussian measure is constructed for any given hyperplane in an infinite dimensional Hilbert space, and this is used to define a generalization of the Radon transform to the infinite dimensional setting, using Gauss measure instead of Lebesgue measure. An inversion formula is obtained and a support theorem proved.

Electronic Structural Investigations Of Bi- And Polymetallic Complexes Using Quantum Mechanical Methods, Zakiya Sheni Wilson

LSU Doctoral Dissertations

Understanding the dynamics influencing chemical reactivity is essential for properly exploiting matter into more useful purposes. In that manner, computational chemistry is a tool frequently used to study chemical properties at the most intimate level, i.e. the single molecule.

With this work, we probe the chemistry governing a variety of multi-faceted bi- and polymetallic compounds. To date our research consists of four major projects: bimetallic rhodium-catalyzed hydroformylation and aldehyde-water shift hydrocarboxylation catalysis; a novel linear M-H-M interaction in a bridged bis(dialkylphosphino)methane complex of nickel; and CeBe₁₃, a heavy fermion conductor. Computational investigations on these systems allow us to …

Quantification Of Marine Sediment Properties From Planar And Volumetric Pore Geometries, Allen Hagerman Reed

LSU Doctoral Dissertations

Pore geometry and topology are important determinants of sediment physical properties, such as porosity and permeability. They also influence processes that occur in the sediment, such as acoustic propagation, attenuation, and dispersion, single- and multi-phase fluid flow, and hydrodynamic dispersion. This study uses images to evaluate pore geometry and topology of ooid (subspherical particles) and siliclastic (angular quartz) sand that was collected from the marine environment south of Bimni Bahamas and Ft. Walton Beach, FL, respectively. Image analysis techniques and predictive tools enable insight into the relationships among sediment pore geometry, topology, and physical properties for these differently shaped sands. …

The Syntheses Of Novel Indicators And Materials For Chiral Separation, Rolanda Johnson

LSU Doctoral Dissertations

The colorimetric properties of resorcinarene solutions had not been fully investigated since von Baeyer's initial synthesis. We find that the solutions containing resorcinarene macrocycles develop color upon heating or standing. In the presence of saccharides, these solutions exhibit significant color changes which are readily observable by visual inspection. We determined that the solution color is due to macrocycle ring opening and oxidation. The optical responses to saccharides are due to complexation of the sugar with the acyclic chromophores. We have applied these mechanistic insights towards the challenging problems of the visual detection of saccharides and other important biologically analytes. In …

Optimization Of A Skewed Logistic Distribution With Respect To The Kolmogorov-Smirnov Test, James Charles Finney

LSU Doctoral Dissertations

The four-parameter kappa distribution (Hosking 1994) was analyzed with respect to the various possible shapes of the probability density function. The general form for the cumulative distribution function when both h and k are non-zero is: F(x) = { 1 - h [ 1 - k ( x - ξ ) / α ]^1/k }^1/h. The parameters h and k work together to define the function's shape, ξ affects location, and α is the scale parameter. A method of selecting parameters to minimize the Kolmogorov-Smirnov test statistic, D, was developed. The technique was first described for the …

Address Optimizations For Embedded Processors, Sai Pinnepalli

LSU Doctoral Dissertations

Embedded processors that are common in electronic devices perform a limited set of tasks compared to general-purpose processor systems. They have limited resources which have to be efficiently used. Optimal utilization of program memory needs a reduction in code size which can be achieved by eliminating unnecessary address computations i.e., generate optimal offset assignment that utilizes built-in addressing modes. Single offset assignment (SOA) solutions, used for processors with one address register; start with the access sequence of variables to determine the optimal assignment. This research uses the basic block to commutatively transform statements to alter the access sequence. Edges in …

A Qualitative Exploration Of Students' Experiences With Tutorial Learning, Angela Alexander

LSU Doctoral Dissertations

The purpose of this study is to explore how students perceive their tutorial learning experiences at the collegiate level in a campus-based center and to explore the personality preferences of the students who participate in tutoring, according to the Myers-Briggs Type Indicator (MBTI). The study is designed to address tutoring from the perspective of the tutee’s experiences and to allow them to tell their story of how tutoring impacted their academic experience. The following research questions guide this study: 1. What are students’ perceptions of their tutorial learning experiences? 2. Are students’ perceptions of their tutorial learning experiences related to …

Integrating A Technology-Enriched Curriculum: Ethno-Case Study, Juliette D. Angers

LSU Doctoral Dissertations

The purpose of this qualitative study was to provide an examination of beliefs, context factors, and practices of exemplary teachers that lead to a technology-enriched curriculum. Three middle school teachers participated. Using both direct and participant observation the Spradley model was followed with three rounds of observations: (1) descriptive, (2) focused, and (3) selective. Interviews were conducted with open-ended questions and documents were collected from the parish website. This research provides: (1) up-to-date information on what and how educational technology is used today; and (2) information which gives other educators an understanding of what beliefs and context factors influence teachers …

Pattern-Based Model Transformation: A Metamodel-Based Approach To Model Evolution, Sheena Judson Miller

LSU Doctoral Dissertations

Software systems continue to grow in complexity at a rapid pace, creating systems that are complex to build and evolve. The problems that accompany changes in requirements, system upgrades, and error correction produce a desire for software evolution methods that increase the efficiency and effectiveness of adapting complex software to changes. As software systems evolve, design models must be modified to accommodate the required changes. Techniques that control the changes to models in a systematic manner are a key to model evolution. A process that improves the ability to effectively modify a design, thereby enhancing design qualities, supports the need …

Leaf Litter Processing By Macrodetritivores In Natural And Restored Neotropical Mangrove Forests, Gary Eugene Raulerson

LSU Doctoral Dissertations

Knowledge of mangrove litter dynamics is crucial to an understanding of the energetic links between mangrove ecosystems and nearby estuaries and coastal waters. Previous research into the role played by macrodetritivores in Neotropical mangrove litter processing has been contradictory. This study used leaf tethering to examine the effects of macrodetritivores on initial rates of mangrove litter degradation in South Florida, USA. Leaf litter dynamics experiments were run in both natural and restored mangrove forests to assess functionality of the restoration projects. Although less important than in some other parts of the world (e.g., the Indo-Pacific), macrodetritivores played a significant role …

Cost Effective And Sequential Methods For Teaching Educational Paraprofessionals To Implement Behavior Management Strategies In Preschool Classrooms, Natalie Jan Slider

LSU Doctoral Dissertations

This study examined the efficacy of cost effective and sequential training methods for teaching educational paraprofessionals to implement behavior management strategies in preschool classrooms. Investigation of the effects of increasingly complex and time consuming methods of training on both paraprofessional and student behaviors were evaluated. Training methods employed included written take-home manuals and summary cards, modeling videotapes, and performance feedback. Training materials included three behavior management strategies (e.g., instruction-giving, praise, and time out) that have shown to have extensive support in the empirical literature (Brophy, 1981; Budd, Riner, & Brockman, 1983; Flanagan, Adams, & Forehand, 1979; O’Dell, Krug, Patterson, & …

Dynamic Performance Of Bridges And Vehicles Under Strong Wind, Suren Chen

LSU Doctoral Dissertations

The record of span length for flexible bridges has been broken with the development of modern materials and construction techniques. With the increase of bridge span, the dynamic response of the bridge becomes more significant under external wind action and traffic loads. The present research targets specifically on dynamic performance of bridges as well as the transportation under strong wind. The dissertation studied the coupled vibration features of bridges under strong wind. The current research proposed the modal coupling assessment technique for bridges. A closed-form spectral solution and a practical methodology are provided to predict coupled multimode vibration without actually …

Applications Of The Titanium Catalyzed Cyclocarbonylation Towards Natural Product Syntheses, Jongtae Yang

LSU Doctoral Dissertations

Recently an efficient methodology, a hetero Pauson-Khand reaction, based on titanium-catalyzed cyclocarbonylation of tethered enals for the general preparation of ¥ã-butyrolactone rings, which are typically embedded in polycyclic systems of many natural products was reported. To demonstrate this new strategy, the total syntheses of the natural products asteriscanolide and ginkgolide were investigated. The first part of this work is dedicated to synthetic efforts toward the total synthesis of asteriscanolide. Approaches highlighted by the [2,3]-Wittig rearrangement, the thermal silyloxy-Cope rearrangement, and a titanium-catalyzed cyclocarbonylation, which is the pivotal step to afford the ¥ã-butyrolactone ring. This study firmly established the utility of …

Students With A Ged In Four-Year Institutions: The Voices Of Persisters, Luria Shaw Stubblefield

LSU Doctoral Dissertations

This study examined the persistence of students with a GED in four-year institutions. Qualitative research methods were employed to better understand the experiences of GED recipients relative to their progress towards baccalaureate degrees. The theoretical framework for this study was symbolic interactionism. Data were collected in two phases. After a pilot study, Phase I data collection consisted of two focus group interviews with three participants each from two institutions in Louisiana. For Phase II, 10 GED recipients at each university were engaged in semi-structured, in-depth interviews, photography, photo elicitation interviews, and document analysis of students’records. The data were analyzed using …

Modeling The Effects Of Rainfall Intensity And Deep Chiseling On Infiltration And Runoff Within Drainmod For Alluvial Soils, Daniel Nyabiba Moriasi

LSU Doctoral Dissertations

Accurate hydrologic models are needed to aid engineers and researchers design, install and evaluate efficient and cost-effective agricultural water management systems to reduce risks associated with food production, and to reduce soil erosion and water pollution. One model used for the alluvial soils of Louisiana is DRAINMOD. This model does not accurately predict infiltration and runoff for the crusting-prone alluvial soils of Louisiana. The main goal of this study was to modify the current DRAINMOD model to incorporate the effects of rainfall intensity and deep chiseling to improve its estimation of infiltration and surface runoff. The second goal was to …