Digital Commons Network^™

Investigations Into The Role Of Natural Organic Matter As An Interface Between Aquatic Organisms And Environmental Pollutants, Caroline Lillian Schneider

LSU Doctoral Dissertations

The impact of the continuous pollution of freshwater environments by multiple pollutants has not been well-studied. The goal of this research was to evaluate the toxicity of several modern pollutants in a model environment. The prokaryotic, unicellular blue-green algae Synechocystis WT6803 and the eukaryotic, multicellular Utterbackia imbecillis mussel larvae were studied along with Suwannee River natural organic matter (NOM). The toxicity response of the blue-green algae Synechocystis sp. was measured through changes in growth rates. The inorganic pollutant silver nanoparticles (0.044 μM) were toxic. Gold nanoparticles did not affect the growth rate. The addition of 15 mg/L NOM partially inhibited …

A Permutational Triadic Approach To Jazz Harmony And The Chord/Scale Relationship, John Bishop

LSU Doctoral Dissertations

This study provides an original triadic theory that combines existing jazz theory, in particular the chord/scale relationship, and mathematical permutation group theory to analyze repertoire, act as a pedagogical tool, and provide a system to create new music. Permutations are defined as group actions on sets, and the sets used here are the constituent consonant triads derived from certain scales. Group structures provide a model by which to understand the relationships held between the triadic set elements as defined by the generating functions. The findings are both descriptive and prescriptive, as triadic permutations offer new insights into existing repertoire. Further, …

Direction Of Mistuning, Magnitude Of Cent Deviation, And Timbre As Factors In Musicians' Pitch Discrimination In Simultaneous And Sequential Listening Conditions, Norman Alan Clark

LSU Doctoral Dissertations

The main purpose of this study was to investigate high school and college wind instrumentalists’ pitch discrimination when judging pitch pairs separated by 0, 5, 7.5, and 10 cents. Participants listened via headphones to a pre-recorded two section perception test; each section (one sequential and one simultaneous) containing 56 tone pairs. Each pair consisted of an in-tune reference tone followed by a test tone of the same pitch (B-flat4 or E4), which was either identical in tuning or altered to one of six mistunings. Tones also varied in timbre (square or sawtooth wave) with the reference and test tones being …

Syntheses And Characterization Of Water-Soluble Phythalocyanines For Diagnosis And Treatment Of Cancer, Benson Getenga Ongarora

LSU Doctoral Dissertations

Ongarora, Benson Getenga, B.S., Moi University, 2005 Doctor of Philosophy, Fall Commencement, 2012 Major: Chemistry Syntheses and Characterization of Water-Soluble Phthalocyanines for Diagnosis and Treatment of Cancer Dissertation directed by Professor M.Graҫa H. Vicente Pages in dissertation, xi. Words in abstract, 251. ABSTRACT Chapter 1 describes the general properties of phthalocyanines, synthesis of metallo-phthalocyanines, their photophysical features and their uses. The concepts of PDT and targeted therapeutics are also introduced. Chapter 2 describes the syntheses, characterization, photophysical studies and biological evaluation of cationic phthalocyanines. The trimethylaminophenoxy substituted phthalocyanines were synthesized through statistical condensation method, which gave a statistical mixture of …

Development Of Innovative Stationary Phases For Chiral And Protein Separations In Open Tubular Capillary Electrochromatography, Leonard Moore, Jr.

LSU Doctoral Dissertations

Protein biomarkers in bodily fluids can lead to an indication of the onset of a disease. Due to low abundance of the biomarker at early stages of the disease and other protein interferences, detection may be challenging. Therefore, in order to achieve more selective protein separations, the development of a novel stationary phase has been investigated. Moreover, novel methods to apply polysaccharides as stationary phases were developed for protein separations as well as chiral separations. The initial discussions in this dissertation commences with the use of novel zwitterionic lysine-based molecular micelles as a coating for open tubular capillary electrochromatography (OT-CEC) …

An Investigation Into Urban Elementary Teachers' Educational Beliefs In Regards To Teaching Writing: Comparing Experiences And Self-Reported Beliefs To Teacher Practices, Shalanda Stanley

LSU Doctoral Dissertations

This six week study investigated six urban elementary teachers’ educational beliefs in regards to teaching writing, comparing their personal histories as writers with their self-reported beliefs on writing and teaching writing, with that of their teacher practices. A further analysis examined how closely aligned their teacher practices were to research-validated practices. During this ethnographic case study, three questions were explored. These questions were: (a) How do teachers’ personal histories with writing inform their beliefs regarding writing in general, as well as their beliefs on teaching writing?, (b) How do teachers’ educational beliefs in regards to teaching writing inform their instructional …

Detection And Characterization Of Environmentally Persistent Free Radicals (Epfrs) In Soils And Sediments From Superfund Sites, Albert Leo N. Dela Cruz

LSU Doctoral Dissertations

Environmentally persistent free radicals (EPFRs) from combustion-generated PM have been demonstrated to form via reactions of molecular precursors with redox-active transition metals at 150-500C thermal reactions in a few seconds reaction times. While ambient temperatures are much lower, soils/sediments contain similar transition metals, and reaction times of contaminants in soils/sediments are years, rather than seconds. This questions whether EPFRs could be formed at ambient temperatures in soils/sediments from Superfund sites that are contaminated with hazardous materials. Superfund soils contaminated with PCP from Georgia and Montana, and sediments contaminated with PAHs from Washington. Using EPR spectroscopy, EPFR concentrations and structural assignments …

Three Essays On Technology Adoption And The Roles Of Off-Farm Labor, Human Capital, And Risk In Contemporary Us Agriculture, Hiroki Uematsu

LSU Doctoral Dissertations

Agriculture can be defined as the domestication and farming of plant and animal species to produce food and fiber products. Our society is fundamentally dependent on agriculture as it is the primary source of nutrients essential to human activities. Historically, the introduction of agriculture and technological development thereafter drastically changed the way human civilization has evolved into what it is today. New technologies allow farmers to produce more outputs with fewer inputs. Saved resources from agricultural production, such as land, labor and time, were used elsewhere to produce other goods and services that enrich the quality of our life. The …

Semantically-Aware Data Discovery And Placement In Collaborative Computing Environments, Xinqi Wang

LSU Doctoral Dissertations

As the size of scientific datasets and the demand for interdisciplinary collaboration grow in modern science, it becomes imperative that better ways of discovering and placing datasets generated across multiple disciplines be developed to facilitate interdisciplinary scientific research.

For discovering relevant data out of large-scale interdisciplinary datasets. The development and integration of cross-domain metadata is critical as metadata serves as the key guideline for organizing data. To develop and integrate cross-domain metadata management systems in interdisciplinary collaborative computing environment, three key issues need to be addressed: the development of a cross-domain metadata schema; the implementation of a metadata management system …

Greenhouse Gas Emissions And Nutrients Dynamics In Restored Wetlands Of The Mississippi River Basin, Christopher Lundberg

LSU Doctoral Dissertations

Greenhouse gases were sampled during spring and summer months in 2010 and 2011 at two sites in the Mississippi River Basin: a riparian forested wetland under restored flood pulsing near Memphis, TN and a coastal estuarine marsh complex impacted by a river diversion at Caernarvon, LA. Mean methane fluxes at Caernarvon (-0.09 g CH4-C m-2 d-1) were lower than those at Memphis (0.53 g CH4-C m-2 d-1), and did not differ between seasons. Nitrous oxide fluxes were generally below detection limits. Fluxes were uncorrelated with water depth, soil temperature, and ambient air temperature, though sampling occurred over a narrow range …

Field Investigation Of Wave And Surge Attenuation In Salt Marsh Vegetation And Wave Climate In A Shallow Estuary, Ranjit S. Jadhav

LSU Doctoral Dissertations

This research investigates and quantifies the effectiveness of salt marsh vegetation in reducing storm-induced waves and surge, and the potential for wetland erosion due to wave action, using field measurements on the Louisiana coast. To quantify wave attenuation and wave energy dissipation by vegetation (Spartina alterniflora), wave data were measured along a transect using pressure transducers during two tropical storms. Measurements showed that incident waves attenuated exponentially over the vegetation. The linear spatial wave height reduction rate increased from 1.5% to 4% /m as incident wave height decreased. The bulk drag coefficient estimated from the field measurements decreased with increasing …

Design And Analysis Of Cloaked Fluorophores For Rapid Detection And Visualization Of Cancer Cells Containing Nad(P)H:Quinone Oxidoreductase-1, William Silvers

LSU Doctoral Dissertations

The development of fluorogenic substrates for real-time tumor cell detection has led to a vastly expanding field for personal oncology. Fluorophores have been studied as appendages to larger scaffolds leading to accumulation of these dyes in tumor cells or their surrounding environment, taking advantage of tumor anatomy. A new class of fluorophores has been developed in which the dye is an active participant in the mechanism of cancer cell detection. These dyes have been conjugated such that their fluorescence has been eliminated or altered and will undergo a change to reveal their fluorescent signal upon activation by a mechanism that …

Phenotypic And Niche Evolution In The Antbirds (Aves: Thamnophilidae), Gustavo Adolfo Bravo

LSU Doctoral Dissertations

A pervasive goal in evolutionary biology has been to address why some clades are richer in species or phenotypic diversity than others. The Thamnophilidae is a large family of insectivorous passerine birds that provides great opportunities to study variation in species and phenotypic diversity. It comprises ca. 220 species that are mostly restricted to the lowlands and lower montane forests of the Neotropics. Its species are diverse in body size and shape, and the family exhibits high species richness, especially in Amazonian forests, where as many as 40 species may co-occur. Therefore, the fundamental research goal of my dissertation is …

What Does The ¹⁴C Method For Estimating Photosynthetic Rates In The Ocean Really Measure?, Shaofeng Pei

LSU Doctoral Dissertations

The ¹⁴C method has been used extensively by both limnologists and oceanographers to measure photosynthetic rates in aquatic systems, and the large database of ¹⁴C measurements that now exists is the ground truth with which satellite algorithms for estimating marine photosynthetic rates on a basin and global scale have been calibrated. However, disconcerting uncertainties still remain with respect to whether and under what circumstances the ¹⁴C method provides an estimate of net or gross photosynthesis, or something in between. My study combined batch and continuous culture studies to clarify this ambiguous issue. The batch culture work with …

Habitat Use, Movements, And Ecology Of Female Mottled Ducks On The Gulf Coast Of Louisiana And Texas, Bruce Edward Davis

LSU Doctoral Dissertations

Mottled ducks (Anas fulvigula) are the most abundant breeding waterfowl in the coastal marshes of Louisiana and Texas. Mottled ducks are non-migratory and heavily dependent on coastal marsh habitats; they must satisfy all of their annual resource needs from within the Gulf Coast region. Coastal marsh habitats are being rapidly lost or degraded in Louisiana and Texas. The hydrology of many coastal marsh habitats has been altered by anthropogenic activity and natural factors. Parameters related to Mottled Duck habitat use and movements in this altered environment are poorly understood, and managers need information on vital rates of Mottled Ducks in …

Gis-Based Urban Land Use Characterization And Population Modeling With Subpixel Information Measured From Remote Sensing Data, Quan Tang

LSU Doctoral Dissertations

This dissertation provides deeper understanding on the application of Vegetation-Impervious Surface-Soil (V-I-S) model in the urban land use characterization and population modeling, focusing on New Orleans area. Previous research on the V-I-S model used in urban land use classification emphasized on the accuracy improvement while ignoring the discussion of the stability of classifiers. I developed an evaluation framework by using randomization techniques and decision tree method to assess and compare the performance of classifiers and input features. The proposed evaluation framework is applied to demonstrate the superiority of V-I-S fractions and LST for urban land use classification. It could also …

Lipid Production From A Louisiana Native Chlorella Vulgaris/Leptolyngbya Sp. Co-Culture For Biofuel Applications, Rong Bai

LSU Doctoral Dissertations

Over the last several decades, microalgae have garnered great interest for biofuel production mainly due to the high lipid productivity and minimum land competition with food crops. In this research, a Louisiana native Chlorella vulgaris/Leptolyngbya sp. co-culture was selected for lipid production. The goal of this work is to improve the lipid productivity and lipid composition of this co-culture via optimizing irradiance and nitrogen levels, lipid extraction method and modeling of pilot photobioreactor (HISTAR). Effects of irradiance and nitrate nitrogen levels on total lipid yield, neutral lipid portion, and fatty acid profile of non-aerated and aerated co-cultures were investigated in …

Optimal Actuation In Active Vibration Control Using Pole-Placement, Carla Ann Guzzardo

LSU Doctoral Dissertations

The purpose of this study was to find and demonstrate a method of optimal actuation in a mechanical system to control its vibration response. The overall aim is to develop an active vibration control method with a minimum control effort, allowing the smallest actuators and lowest control input. Mechanical systems were approximated by discrete masses connected with springs and dampers. Both numerical and analytical methods were used to determine the optimum force selection vector, or input vector, to accomplish the pole placement, finding the optimal location of actuators and their relative gain so that the control effort is minimized. The …

Studies On A Dirhodium Tetraphosphine Hydroformylation Catalyst, Darina Polakova

LSU Doctoral Dissertations

The dirhodium tetraphosphine catalyst [Rh2(nbd)2(rac-et,ph-P4)](BF4)2 was investigated in acetone and water/acetone in order to explain better hydroformylation results in the latter solvent. In-situ NMR spectroscopy showed slower degradation in water/acetone. Less tendency to form penta/hexacarbonyl complexes in water/acetone was shown by 31P{1H} NMR and FT-IR. A pH decrease and hydroformylation studies in presence of a base indicated formation of a monocationic monohydride species. A new reaction mechanism was suggested that takes into account the observed differences from the acetone solvent system. The presence of water enabled production of hydride species when the dirhodium catalyst was exposed to CO gas. We …

Deductive Formal Verification Of Embedded Systems, Zheng Lu

LSU Doctoral Dissertations

We combine static analysis techniques with model-based deductive verification using SMT solvers to provide a framework that, given an analysis aspect of the source code, automatically generates an analyzer capable of inferring information about that aspect.

The analyzer is generated by translating the collecting semantics of a program to a formula in first order logic over multiple underlying theories. We import the semantics of the API invocations as first order logic assertions. These assertions constitute the models used by the analyzer. Logical specification of the desired program behavior is incorporated as a first order logic formula. An SMT-LIB solver treats …

Using Behavior Screening Data To Predict Scores On Statewide Assessments, Jeffrey Steven Chenier

LSU Doctoral Dissertations

Federal and state initiatives (No Child Left Behind, 2001) require schools and districts to set high standards for student growth and achievement. Currently, student growth and progress are measured in Louisiana via statewide achievement tests. In 4th and 8th grades these assessments are considered to be ‘high-stakes’, as promotion and retention decisions are made based on how well students perform on these assessments. Making day-to-day decisions based on one assessment per year is not best practice (Jenkins, Deno, & Markin, 1979); therefore, screening instruments known as curriculum based measures (CBMs) were devised and tailored for school-based implementation. CBMs of academic …

The Effects Of Hydrologic Modifications On Floodplain Forest Tree Recruitment And Growth In The Mississippi River Alluvial Valley, Usa, Hugo Gee

LSU Doctoral Dissertations

Floodplains forests are productive and diverse ecosystems characterized by frequent riverine flooding. Levees and dams have eliminated or altered riverine flooding which can potentially affect floodplain tree recruitment and growth. Increased light availability from canopy disturbances may increase photosynthesis given sufficient soil moisture, but information on the combined effect of canopy disturbances and hydrologic modifications on tree recruitment and growth is lacking. I used dendrochronological techniques to reconstruct tree recruitment, growth (Quercus lyrata, Fraxinus pennsylvanica), and canopy disturbance patterns over a 90-year period at several floodplains in the Mississippi River Alluvial Valley, USA: an unleveed site below dams and two …

Recurrent Novae And Type Ia Supernova Progenitors, Ashley Sara Pagnotta

LSU Doctoral Dissertations

We investigated two types of stellar explosions, recurrent novae (RNe) and Type Ia supernovae (SNe Ia). SNe Ia are the most useful distance markers in astrophysics, but we do not know the identity of their progenitor systems. RNe are good progenitor candidates that consist of a white dwarf (WD) that accretes material from a companion star. The material builds on the surface of the WD until a runaway thermonuclear eruption is triggered, which ejects the accreted material and causes the system to brighten dramatically. We studied the demographics of the nova population and concluded that approximately 25% of classical novae …

Magnetic Compensation In The Bimetallic Oxalates And The Cerium Volume Collapse, Peter Leo Reis

LSU Doctoral Dissertations

In this thesis the author reports his collaborative efforts on two distinct areas of research that has been conducted. The first part of the thesis pertains to the author and his collaborators research on a particular class of organic magnets called the bimetallic oxalates. The main theme of this research was to predict magnetic compensation (magnetization reversal) in unsynthesized bimetallic oxalate structures, motivated by experiments which showed that Fe(II)Fe(III) exhibited magnetic compensation. In addition it was known that a large amount of anisotropy was present in the bimetallic oxalate structure which resulted from the intermediate oxalate molecules between the transition …

C0 Interior Penalty Methods For Cahn-Hilliard Equations, Shiyuan Gu

LSU Doctoral Dissertations

In this work we study C0 interior penalty methods for Cahn-Hilliard equations. In Chapter 1 we introduce Cahn-Hilliard equations and the time discretization that leads to linear fourth order boundary value problems. In Chapter 2 we review related fundamentals of finite element methods and multigrid methods. In Chapter 3 we formulate the discrete problems for linear fourth order boundary value problems with the boundary conditions of the Cahn-Hilliard type, which are called C0 interior penalty methods, and we carry out the convergence analysis. In Chapter 4 we consider multigrid methods for the C0 interior penalty methods. We present two smoothing …

Study On Permanent Magnet Transverse Flux Machine, Oleksandr Dobzhanskyi

LSU Doctoral Dissertations

This dissertation is concentrated mainly on the newest PMTF machine topology proposed and patented by Jacek F. Gieras in March 4, 2010. Such a topology (topology of 2010) is an object of this dissertation. A prototype that was built with 3D Finite Element Method (FEM) modeling of PMTF generator proves that the generator that was built on the basis of topology of 2010 has several significant disadvantages among which the greatest impact have high leakage flux losses. Applying FEM modeling, various steps to improve machine performance have been undertaken. Results obtained from modeling show, that keeping the same diameter and …

Stability Problems In Constrained Pendulum Systems And Time-Delayed Systems, Prashanth Ramachandran

LSU Doctoral Dissertations

In this dissertation, we study the boundary of stability of a class of linear mechanical systems as a function of a parameter. We consider two different systems under this class: a constrained double pendulum connected by a rigid rod and a state-feedback-controlled mechanical system with time delay. In the first system, the destabilizing parameter is the distance between the supports of the two pendulums. In the second system, the destabilizing parameter is the time delay. In the constrained double pendulum system, linear perturbation analysis is used to determine the natural frequency of the system. Our analysis reveals a zone of …

Synthesis And Characterization Of Red And Near-Infrared Bodipy-Based Fluorophores For Various Biological Applications, Timsy Kaur Uppal

LSU Doctoral Dissertations

ABSTRACT 4,4-Difluoro-3a,4a-diaza-s-indacene, better known as BODIPY® dyes, have attracted considerable attention due to their intriguing physicochemical and spectral properties, including high absorption coefficient, fluorescence quantum yield and good photochemical stability. Despite the recent progress achieved in this field, the synthesis of BODIPY derivatives that absorb and emit in the red- and NIR-region of the electromagnetic spectrum and their application to biomolecular targets, represents a long-standing challenge in BODIPY chemistry. This research work is therefore focused on the synthesis and characterization of red and NIR-emissive BODIPY-based fluorophores for various bioanalytical and biomedical applications. Chapter 1 of this dissertation represents a concise …

Continuum And Crystal Strain Gradient Plasticity With Energetic And Dissipative Length Scales, Danial Faghihi Shahrestani

LSU Doctoral Dissertations

This work, standing as an attempt to understand and mathematically model the small scale materials thermal and mechanical responses by the aid of Materials Science fundamentals, Continuum Solid Mechanics, Misro-scale experimental observations, and Numerical methods. Since conventional continuum plasticity and heat transfer theories, based on the local thermodynamic equilibrium, do not account for the microstructural characteristics of materials, they cannot be used to adequately address the observed mechanical and thermal response of the micro-scale metallic structures. Some of these cases, which are considered in this dissertation, include the dependency of thin films strength on the width of the sample and …

A Multifaceted Phenomenon Of Hydrophobic Effects: Insights Learned From Nucleation Algorithm Based Computer Simulation Approach, Hyunmi Kim

LSU Doctoral Dissertations

We have applied our new approach, a combination of the AVUS-HR nucleation algorithm and a thermodynamic cycle, to the studies of hydrophobicity-related researches. Due to the multifaceted characteristics of hydrophobicity, it is essential to acquire knowledge in various environments where hydrophobic relevant events occur for comprehensive understanding of this process. In this regards, we have chosen two relatively unstudied hydrophobic subjects for application of our new methodology. For the first subject, hydrophobic association behaviors of a methane pair confined into a nanometer sized hydrophobic cavity have been investigated. Our new approach demonstrates that the association behavior between two methane molecules …