Physical Sciences and Mathematics Commons^™

Unit Assessments For High School Geometry, Damayanthi Srimathi Jegart

LSU Master's Theses

Abstract Eight unit tests closely aligned with the Louisiana Comprehensive Curriculum for high school geometry were developed. Five of these were administered, each to the same 115 students spanning all ability and attainment levels in a magnet school in a semi-rural Louisiana district. The results were analyzed to determine the quality of the questions as well as to glean information about student-learning. The test scores were compared to the results of the state-administered end-of-course test for high-school geometry. The main findings were as follows: a) most students do not communicate their reasoning or justification unless directed to do so, and …

Operational Methods For Evolution Equations, Lee Gregory Windsperger

LSU Doctoral Dissertations

This dissertation refines and further develops numerical methods for the inversion of the classical Laplace transform and explores the effectiveness of these methods when applied (a) to an asymptotic generalization of the Laplace transform for generalized functions and (b) to the numerical approximation of solutions of ill-posed evolution equations (e.g. backwards in time problems).

Chapter 1 of the dissertation reviews some of the key features of asymptotic Laplace transform theory and its application to evolution equations. Although some of the statements and results contain slight modifications and improvements, the material presented in Chapter 1 is known …

Depositional Environments Of Upper Meiocene Through Pleistocene Siliciclastic Sediments, Baton Rouge Aquifer System, Southeastern Louisiana, Elizabeth Laurel Chamberlain

LSU Master's Theses

Saltwater encroachment northward into freshwater sands of the Baton Rouge aquifer system, southeast Louisiana, poses a serious environmental threat to the metropolitan water source. The aquifer consists of a 0.6 mile-thick succession of interbedded, unconsolidated south-dipping siliciclastic sandy units and confining mudstones dating from the Upper Miocene through the Pleistocene. The study area is crosscut by the Baton Rouge fault, a west-east trending listric fault that serves as a leaky barrier to saltwater intrusion from the south. A better understanding of the connectivity, morphology and depositional setting of this aquifer system and hydraulic properties of the Baton Rouge fault is …

Hadronic Physics From Extensive Air Showers, Guofeng Yuan

LSU Doctoral Dissertations

Although cosmic rays were discovered exactly one century ago, the most fundamental questions about them are still not answered, especially the origin and composition of ultra-high energy cosmic rays (UHECR). The Pierre Auger Observatory (PAO) is constructed with the goal of solving these mysteries. The PAO uses hybrid design and take advantage of both the air fluorescence and surface array technique. Since its debut in 2004, PAO has published several important scientific results.

The most probable candidate for UHECR composition is proton or iron nucleus. The two candidates do show differences in both fluorescence detector (FD) signal and in the …

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 …

Resonance And Double Negative Behavior In Metamaterials, Yue Chen

LSU Doctoral Dissertations

In this work, a generic class of metamaterials is introduced and is shown to exhibit frequency dependent double negative effective properties. We develop a rigorous method for calculating the frequency intervals where either double negative or double positive effective properties appear and show how these intervals imply the existence of propagating Bloch waves inside sub-wavelength structures. The branches of the dispersion relation associated with Bloch modes are shown to be explicitly determined by the Dirichlet spectrum of the high dielectric phase and the generalized electrostatic spectra of the complement. For numerical purposes, we consider a metamaterial constructed from a sub-wavelength …

Linking Nitrogen Biogeochemistry To Different Stages Of Wetland Soil Development In The Mississippi River Delta, Louisiana, Kelly Marie Henry

LSU Doctoral Dissertations

Extensive wetland loss and nutrient-enhanced eutrophication occur across the Mississippi River delta and include newly emergent landscapes, in the early stages of ecological succession, and older landscape formations, with fully developed ecological communities. Here I tested how the anthropogenic effects of a climate-induced vegetation shift, an oil spill, and nitrate-enrichment regulate the principal environmental factors controlling nutrient biogeochemistry in wetland soils at different stages of development throughout the Mississippi River delta. In the older, transgressing Barataria basin, there was no clear effect of the climate-induced species shift from Spartina alterniflora Loisel to Avicennia germinans L. on soil nutrient chemistry. Observed …

Conformance Testing Of Peer-To-Peer Systems Using Message Traffic Analysis, John Wesley Burris

LSU Doctoral Dissertations

Peer-to-Peer architectures are used by a large number of distributed systems; however, the challenges such as maintaining a reliable and stable peer-to-peer network can make such networks undesirable for distributed systems. Peer-to-peer architectures are designed to be executed on systems with diverse hardware configurations, distant geographic locations, and varied, unpredictable Internet connectivity that make the software testing process difficult. This research defines a method for conformance testing peer-to-peer content distribution systems called “Method for Conformance Testing by Analyzing Message Activity” (MCTAMA). MCTAMA uses a common representation for describing the behavior of nodes during both design and deployment. ATAMA generates, evaluates …

Factors Affecting Short-Term Oxygen Variability In The Northern Gulf Of Mexico Hypoxic Zone, Brenda Leroux Babin

LSU Doctoral Dissertations

Open-water continuous monitoring of DO concentrations at a single station (C6) in the Gulf of Mexico from 1989 to 2008 afforded an excellent opportunity to characterize short-term oxygen variability and to estimate the relative importance of key physical and biological factors controlling the development, persistence, and dissipation of hypoxia. I investigated temporal trends in three aspects of short-term DO variability: respiration rates (i.e., how quickly bottom waters become hypoxic), persistence of hypoxia, and the dissipation of hypoxia (i.e., re-aeration events). I identified the range of respiration rates present at the study site, and showed how these rates vary throughout the …

Identification And Incorporation Of Quantitative Indicators Of Ecosystem Function Into Single-Species Fishery Stock Assessment Models And The Associated Biological Reference Points, Melissa Hedges Monk

LSU Doctoral Dissertations

The move towards an ecosystem approach to fisheries management requires baseline information on the biotic communities and an understanding of the interactions among species. The two objectives of this study were to describe the demersal fish community (DFC) associated with the northwestern Gulf shrimp trawl fishery, and to utilize a multispecies Lotka-Volterra model to examine possible community level effects of fishing. Community level effects include predator-prey interactions and the responses of fish in the same community to fishing pressure. The summer and fall Southeast Area Monitoring and Assessment Program (SEAMAP) bottomfish trawl surveys were used to identify spatial and temporal …

Chemical And Biological Evaluation Of Antibiotic-Based Ionic Liquids And Gumbos Against Pathogenic Bacteria, Marsha Rae Cole

LSU Doctoral Dissertations

The research presented in this dissertation explores a novel pragmatic therapeutic approach for control, prevention, and treatment of infectious disease using Active-Pharmaceutical Ingredient-based Ionic Liquids (API-ILs) and Groups of Uniform Materials Based on Organic Salts (GUMBOS). Accordingly, several antiseptic- and antibiotic-based API-ILs and GUMBOS were synthesized and characterized using a combination of analytical and microbiological techniques. Overall, this research presents an advanced alternative to combination antibiotic therapy by using a novel group of ionic antimicrobial materials that have controlled pharmacokinetics, improved bioavailabilities, reduced toxicities, multi-modal properties, and potent antimicrobial spectrum of activity as a viable alternative to combating bacterial infections. …

Developing A Geospatial Protocol For Coral Epizootiology, Jennifer Anne Lentz

LSU Doctoral Dissertations

This dissertation explores how geographic information systems (GIS) and spatial statistics, specifically the techniques used to map, detect, and spatially analyze disease epidemics, could be used to advance our understanding of coral reef health. Given that different types of spatial analysis, as well as different parameter settings within each analysis, can produce noticeably different results, poor selection or improper use of a given technique would likely lead to inaccurate representations of the spatial distribution and false interpretations of the disease. For this reason, I performed a comprehensive review of the following types of exploratory spatial data analysis (ESDA): mapping and …

Single-Molecule Detection Of Molecular Beacons Generated From Ldr On Thermoplastic Microfluidic Device For Bioanalysis, Zhiyong Peng

LSU Doctoral Dissertations

Current clinical techniques for nucleic acid detection and analysis often involve PCR, lacking adequate specificity or sensitivity to meet the stringent requirements in certain applications. This research aims to develop an innovative molecular assay and the associated hardware to rapidly signal the presence of certain targets using reporter sequence found in their genome without requiring PCR. This assay coupled the sensitivity of single-pair fluorescence resonance energy transfer (spFRET) with the specificity of ligase detection reaction (LDR) to provide near real-time readout of target biomarkers. Heightened concerns on potential bioterrorism threats, such as rapid dissemination of pathogenic bacteria or viruses into …

Nitrogen And Carbon Export To The Gulf Of Mexico By The Atchafalaya River, A Major Distributary Of The Mississippi River, April Elizabeth Bryantmason

LSU Doctoral Dissertations

Summer hypoxia in the Northern Gulf of Mexico has been attributed to large nutrient inputs, especially nitrate-nitrogen, from the Mississippi-Atchafalaya River system. The 2008 Gulf Hypoxia Action Plan calls for river corridor wetland restoration to reduce nitrate loads, but it is largely unknown how effective riverine wetland systems in the lower Mississippi River (MR) are for nitrate removal. This dissertation research examined nitrate and carbon export from the Atchafalaya River (AR) to: (1) determine nitrate processing by a river swamp basin under varied seasons, (2) investigate nitrate retention and processing in the AR during a major flood event, and (3) …

Cluster Based Jamming And Countermeasures For Wireless Sensor Network Mac Protocols, David Trammell

LSU Doctoral Dissertations

A wireless sensor network (WSN) is a collection of wireless nodes, usually with limited computing resources and available energy. The medium access control layer (MAC layer) directly guides the radio hardware and manages access to the radio spectrum in controlled way. A top priority for a WSN MAC protocol is to conserve energy, however tailoring the algorithm for this purpose can create or expose a number of security vulnerabilities. In particular, a regular duty cycle makes a node vulnerable to periodic jamming attacks. This vulnerability limits the use of use of a WSN in applications requiring high levels of security. …

On The Synthesis, Characterization, And Magnetization Of Ln-M-X (Ln = Lanthanide; M = Ti-Cr, Cu, Mo, Pd; X = Al, Ga) Intermetallics, Michael James Kangas

LSU Doctoral Dissertations

The focus of the research presented herein was to grow single crystals of Ln-M-X (Ln = lanthanide; M = Ti-Cr, Cu, Mo, Pd; X = Al, Ga) intermetallic compounds and to characterize their crystal structures and physical properties. Overall, the flux growth technique facilitated a detailed analysis of previously known structure-types (LnM2Al20 (Ln = La, Ce, Pr, Yb; M = Ti, V, Cr), Ln6M4Al43 (Ln = Gd, Yb; M = Cr, Mo), and Yb2Pd3Ga9), as well as the synthesis and characterization of new compounds (LnCrxGa3 (Ln = Ho, Er; x ~ 0.13), YbCr2Al20-xFex (x ~ 0.2), Ln(Cu,Al,Ga)13-x, and Ln2PdGa12 (Ln …

Visualization Of Time-Varying Data From Atomistic Simulations And Computational Fluid Dynamics, Bidur Bohara

LSU Doctoral Dissertations

Time-varying data from simulations of dynamical systems are rich in spatio-temporal information. A key challenge is how to analyze such data for extracting useful information from the data and displaying spatially evolving features in the space-time domain of interest. We develop/implement multiple approaches toward visualization-based analysis of time-varying data obtained from two common types of dynamical simulations: molecular dynamics (MD) and computational fluid dynamics (CFD). We also make application case studies. Parallel first-principles molecular dynamics simulations produce massive amounts of time-varying three-dimensional scattered data representing atomic (molecular) configurations for material system being simulated. Rendering the atomic position-time series along with …

Pmi 5011 Regulates The Ubiquitin Proteasome System In Skeletal Muscle, Heather Christianne Kirk-Ballard

LSU Doctoral Dissertations

Insulin resistance in type 2 diabetes is associated with impaired glucose and protein metabolism in skeletal muscle. The impaired insulin signaling in skeletal muscle affects muscle mass by tilting the balance between skeletal muscle protein synthesis and degradation toward degradation, a process that is primarily regulated by the ubiquitin-proteasome system. Studies have shown that an extensively characterized ethanol extract of Artemisia dracunculus L (Russian Tarragon), termed PMI 5011, enhances insulin signaling in human primary skeletal muscle cells and in a rodent model of insulin resistance. The aim of this project is to determine if the effect of PMI 5011 on …

Chemical Crystallography At The Interface Of Physics, Chemistry, And In Engineering: Structure Determination Of Highly Correlated Extended Solids, Main Group Compounds, Coordination Complexes, And Bioceramics, Gregory Todd Mccandless

LSU Doctoral Dissertations

Multi-disciplinary research is essential to address the major challenges in science, engineering, and medicine. For these three areas, crystallography has played and continues to play a huge role by providing researchers with the means to determine the structure of a compound and relate these to its properties. This dissertation is highly interdisciplinary, focusing on structure determination of complex systems and materials with tailored applications. This work includes the characterization by single crystal and powder X-ray diffraction of intermetallic extended solids, layered metal oxides, inorganic complexes, discrete organic molecules, and bioceramics. These projects range from modeling translational disorder with pseudo-hexagonal symmetry …

The Head And Tail Conjecture For Alternating Knots, Cody Armond

LSU Doctoral Dissertations

The colored Jones polynomial is an invariant of knots and links, which produces a sequence of Laurent polynomials. In this work, we study new power series link invariants, derived from the colored Jones polynomial, called its head and tail. We begin with a brief survey of knot theory and the colored Jones polynomial in particular. In Chapter 3, we use skein theory to prove that for adequate links, the n-th leading coefficient of the N-th colored Jones polynomial stabilizes when viewed as a sequence in N. This property allows us to define the head and tail for adequate links. In …

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 …

Investigation Of Electroosmotic Flow Dynamics And Reproducibility In Capillary Electrophoresis, Funda Kizilkaya

LSU Doctoral Dissertations

The goal of this dissertation is to investigate electroosmotic flow (EOF) and electric field dynamics during capillary electrophoresis (CE) experiments using methods based on periodic photobleaching of fluorophores added to the separation buffer at nanomolar concentrations. The methods provide time resolved EOF and local electric field information during an experiment, which can be applied to fundamental studies to provide better understanding of CE techniques. The potential of the EOF monitoring method to improve CE migration reproducibility was investigated in Chapter 2. The EOF monitoring method and four other methods from the literature were applied to the same electrophoretic separations, and …

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 …

Synthesis, Cellular Studies, And Computational Analysis Of Porphyrin And Bodipy Conjugates With Affinity For Epidermal Growth Factor Receptor, Alecia Michelle Mccall

LSU Doctoral Dissertations

Chapter 1 is a description of the basic fundamental concepts of porphyrins and BODIPYs, (including synthetic methodologies), a general mechanism of the processes of EGFR, and computational concepts that are elaborated upon in future chapters. Chapter 2 is a discussion solely on the porphyrins that were synthesized to be used as fluorophores for EGFR-targeted conjugates, both peptidic and non-peptidic. The porphyrins were primarily synthesized via the Lindsey method as well as by O-alkylation of tetrahydroxy porphyrins. Synthesis of PEG linkages are discussed as well through three methodologies. Chapter 3 is a presentation of the synthesis, characterization, cellular studies, and computational …

Advances In Quantum Optical Metrology And The Establishment Of An Invisible Quantum Tripwire, Steven Blane Mccracken

LSU Doctoral Dissertations

This thesis presents a summary of the foundation and background of the field of quantum optics, and an analysis of some recent discoveries in various fields of which I have aided in furthering investigative research and advancement through publications. Such topics include numerical optimization of generalized quantum states used in phase sensitive quantum metrology, an analysis of object detection through the use of quantum interferometry in the presence of lossy conditions, and the use of the latter technique to propose an invisible quantum tripwire. First is a collaborative effort to numerically optimize quantum optical states for quantum metrological applications. We …

Beta-Diketone And Beta-Ketoenamine Based Molecular Squares, Jackson Kiplagat Cherutoi

LSU Doctoral Dissertations

Abstract This dissertation focuses on synthesis of β-diketone and β-ketoenamine ligands for molecular polygons. Previous work with the bis(β-diketone) m-pbaH2 showed that it can be converted to a copper molecular square, Cu4(m-pba)4, but its use in host-guest reactions was limited by its low solubility in most organic solvents. Accordingly, in the present work, the m-pbhxH2 ligand, with pentyl chains replacing the methyl groups in the β-diketone moieties of m-pbaH2, was successfully prepared beginning with 6-dodecyne. This ligand reacts with Cu2+ to make the molecular square Cu4(m-pbhx)4, which is soluble in a wider range of solvents. Host-guest reactions of Cu4(m-pbhx)4 with …

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 …

Studies Of A Dirhodium Tetraphosphine Catalyst For Hydroformylation And Aldehyde-Water Shift Catalysis, Aaron Rider Barnum

LSU Doctoral Dissertations

Research into the dirhodium tetraphosphine catalyst precursor [rac-Rh2(nbd)2(et,ph-P4)](BF4)2 shows it is capable of forming a highly active and regioselective hydroformylation catalyst in situ when using an acetone or acetone/water solvent. Hydroformylation experiments (using 1-hexene), FT-IR studies, and acid-base studies were performed to better understand the various complexes of the dirhodium catalyst cycle. These studies lead to the newly proposed catalyst mechanism when performed in an acetone/water solution, using the monocationic [rac-Rh2(H)(µ-CO)2(CO) (et,ph-P4)]+ as the proposed active catalyst complex for hydroformylation. For the conversion of 1-hexene to heptanal, it is capable of performing an initial rate of 30 turnovers per min, …

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 …

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 …