Physical Sciences and Mathematics Commons^™

Characterizations Of Some Classes Of Graphs That Are Nearly Series-Parallel, Victoria Fontaine

LSU Doctoral Dissertations

A series-parallel graph can be built from a single-edge graph by a sequence of series and parallel extensions. The class of such graphs coincides with the class of graphs that do not have the complete graph K₄ as a minor. This dissertation considers a class M₁ of graphs that are close to being series-parallel. In particular, every member of the class has the property that one can obtain a series-parallel graph by adding a new edge and contracting it out, or by splitting a vertex into two vertices whose neighbor sets partition the neighbor set of the original …

Multimode Approach To Classical And Quantum Diffraction, Zhihao Xiao

LSU Doctoral Dissertations

I have investigated classical diffraction of optical beams with multimode approach, which is a significant improvement upon the traditional Huygens–Fresnel principle based diffraction theory. I have also investigated quantum diffraction with multimode approach, which describes the behavior of multimode quantum state. Multimode approach to classical and quantum diffraction provides a clear mathematical formalism and is verified by numerical simulations. In addition, I present the work on superconducting qubit and oscillator with time-dependent coupling coefficient, with first order correction with finite qubit energy and schemes based on and π pulses.

Development Of Remote Hydroxylation Via Redox Catalysis And Mild Activation Of Thioglycosides For O-Glycosylation, Kristina Deveaux

LSU Doctoral Dissertations

The focus of this dissertation is the development of a C-H functionalization method using redox catalysis and the synthesis of saccharides using thioglycosides. Chapter 1 is a review of C-H functionalization and visible-light photoredox catalysis. Over the years there have been many significant contributions to the field of C-H functionalization. Select examples have been discussed and a foundation for the method developed in chapter 2 has been outlined. Chapter 2 discusses the development and optimization of a C-H functionalization method. This approach uses the Tz^o directing group and Ir(ppy)₃ to activate a remote C-H bond via 1,6- and …

Electromagnetic Resonant Scattering In Layered Media With Fabrication Errors, Emily Anne Mchenry

LSU Doctoral Dissertations

In certain layered electromagnetic media, one can construct a waveguide that supports a harmonic electromagnetic field at a frequency that is embedded in the continuous spectrum. When the structure is perturbed, this embedded eigenvalue moves into the complex plane and becomes a “complex resonance” frequency. The real and imaginary parts of this complex frequency have physical meaning. They lie behind anomalous scattering behaviors known collectively as “Fano resonance”, and people are interested in tuning them to specific values in optical devices. The mathematics involves spectral theory and analytic perturbation theory and is well understood [16], at least on a theoretical …

Nanopatterns Of Zinc Phthalocyanines, Gold Nanoparticles, And Porphyrins Prepared Using Particle Lithography: Characterization Of Patterning Steps With Scanning Probe Microscopy, Ashley Marie Taylor

LSU Doctoral Dissertations

The growth and self-assembly of molecules on surfaces can be directly visualized at the molecular level using studies which combine nanoscale lithography and high-resolution imaging. Nanopatterning provides a unique and practical approach for direct views of surface changes after the key chemical steps of nanopatterning, providing landmarks and baselines for measuring growth in vertical and lateral dimensions. Controlling the arrangement of materials on surfaces at the nanoscale can be achieved using particle lithography. Arrays of well-defined nanostructures can be prepared with reproducible geometries and arrangement. Results for the preparation of nanopatterns produced with particle lithography are presented using high resolution …

Coupled Plasmon/Molecule Dynamics Near Core-Shell Nanoparticles: Synthesis, Ultrafast Characterization, And Quantum/Classical Modeling, Holden Tyler Smith

LSU Doctoral Dissertations

In this dissertation, the resonance coupling of chromaphoric dyes adsorbed on the surface of plasmonic nanoparticles (NPs) are investigated using a combined theoretical and experi- mental approach. Colloidal gold, gold-silver core-shell, silver-gold core-shell, and gold-silver- gold core-shell-shell NPs are considered. These NPs are thiolated with mercaptosuccinic acid, and malachite green dyes are adsorbed to the surface of the nanoparticle (NP) via elec- trostatic interactions. Second harmonic generation is used to determine the surface to the isotherm of the molecular dyes to the colloidal nanoparticle surface. Adsorption isotherms show that the SHG intensity increases as the concentration of dye increases, reaching …

An Enhanced Bridge Weigh-In-Motion Methodology And A Bayesian Framework For Predicting Extreme Traffic Load Effects Of Bridges, Yang Yu

LSU Doctoral Dissertations

In the past few decades, the rapid growth of traffic volume and weight, and the aging of transportation infrastructures have raised serious concerns over transportation safety. Under these circumstances, vehicle overweight enforcement and bridge condition assessment through structural health monitoring (SHM) have become critical to the protection of the safety of the public and transportation infrastructures. The main objectives of this dissertation are to: (1) develop an enhanced bridge weigh-in-motion (BWIM) methodology that can be integrated into the SHM system for overweight enforcement and monitoring traffic loading; (2) present a Bayesian framework to predict the extreme traffic load effects (LEs) …

Paleoenvironmental Variation And Provenance Records From Neogene Deep Sea Sediment Of The South China Sea, Chang Liu

LSU Doctoral Dissertations

I employed several paleoenvironmental proxies by utilizing deep sea sediment from the largest marginal basin in east Asia, namely the South China Sea (SCS), to reconstruct the long term paleoenvironmental variation in SE Asia since the Neogene. Sediments deposited within the SCS were mainly delivered by several major fluvial systems whose catchment basins cover several geological blocks in SE Asia. By analyzing the sediment’s geochemical and mineralogical characteristics, several indices which are affected by the source of the sedimentary influx, as well as the weathering state could be built and applied to constrain my paleoenvironmental reconstructions

Two deep sea drilling …

When, How, And Why Did The West Antarctic Ice Sheet Retreat In The Ross Sea Since The Last Glacial Maximum Using Foraminiferal And Porewater Geochemistry, Matthew Decesare

LSU Doctoral Dissertations

The Antarctic Ice Sheets (AIS) began to retreat from their Last Glacial Maximum (LGM) position sometime after 19,000 years ago. However, the corrosive waters circulating around Antarctica has prevented the recovery of radiocarbon-dateable material, hindering the development of deglacial chronologies. During Expedition NBP1502B to the eastern Ross Sea, an unprecedented quantity of fossil foraminifera and bivalves were recovered. Radiocarbon-dated specimens have been used to constrain the timing of West-AIS retreat from Whales Deep basin and Ross Bank. Whales Deep samples show that the WAIS retreated from its LGM position on the continental shelf edge by 14,700 ± 400 calibrated radiocarbon …

Self-Assembly Mechanisms Of Organosilanes And Porphyrins Investigated With Scanning Probe Microscopy, Phillip Charles Chambers Ii

LSU Doctoral Dissertations

This dissertation details the development of new fabrication strategies for the preparation of spatially selective surfaces by combining techniques of particle lithography and scanning probe microscopy (SPM). This combination of lithography and nanoscale surface characterization was applied to study the mechanisms of molecular level surface-assembly of organosilanes and porphyrin on surfaces of Si(111). Particle lithography was used to investigate the surface assembly of 4-chloromethylphenyltrichlorosilane (CMPS) within exposed sites of nanoholes in selected solvents and at selected temperatures to gain insight into the details of self-polymerization. Nanopillars of CMPS were generated under selected conditions of solvent and temperature and characterized with …

Assessing Morphodynamics Of The Lower Mississippi River From 1985 To 2015 With Remote Sensing And Gis Techniques, Bo Wang

LSU Doctoral Dissertations

The Lower Mississippi River is one of the most highly engineered rivers in the world. The river is now completely regulated by a combination of levees, artificial cutoffs, bank revetments, and dike fields; however, the river engineering has also complicated the geomorphological response to the sediment brought in the river. This dissertation research examined morphodynamics of the middle portion of the Lower Mississippi River from Vicksburg, Mississippi (river kilometer: 737) to Red River Landing, Louisiana (river kilometer: 486) to elucidate river engineering effects on sediment transport, storage, and distribution. The Old River Control Structure (ORCS) diverts approximately 25% of the …

New Synthetic Reactions Towards Global Chlorination And Enamides Functionalization, Mirza Ardella Saputra

LSU Doctoral Dissertations

This dissertation focuses on two main projects, global chlorination and enamide functionalization, which both encompass in cationic intermediates. Inspired by the desires to find a new chlorination method, global chlorination project is emphasized in chapter one and chapter two, in which chapter one details various known chlorine-containing natural products, including alkyl chlorides and vinyl chlorides. This chapter also describes the previously known protocols to synthesize alkyl chlorides in the attempts of chlorosulfolipids total syntheses, as well as several known reactions to synthesize vinyl chlorides that are both important functional groups in organic synthesis. Chapter two depicts our novel synthetic reaction …

Studying The Reaction 34ar(Alpha,P)37k And Its Impact On Xrb Nucleosynthesis And Observables, Amber C. Lauer

LSU Doctoral Dissertations

Type I X-Ray bursts (XRB’s) are a site of nucleosynthesis for some proton-rich elements up to A=100. These stellar explosions occur on the surface of a neutron star in a Low- Mass X-ray Binary accreting H- and He-rich material. During accretion nuclear burning occurs through stable processes such as the hot CNO (HCNO) cycles, but at some critical accretion condition the the HCNO cycles are bypassed through a breakout reaction. This triggers the thermonuclear runaway of the XRB. During the burst, nucleosynthesis on certain proton-rich nuclei, called (α, p) waiting points, can stall which could stall the energy generation and …

Hierarchical Fusion Based Deep Learning Framework For Lung Nodule Classification, Kazim Sekeroglu

LSU Doctoral Dissertations

Lung cancer is the leading cancer type that causes the mortality in both men and women. Computer aided detection (CAD) and diagnosis systems can play a very important role for helping the physicians in cancer treatments. This dissertation proposes a CAD framework that utilizes a hierarchical fusion based deep learning model for detection of nodules from the stacks of 2D images. In the proposed hierarchical approach, a decision is made at each level individually employing the decisions from the previous level. Further, individual decisions are computed for several perspectives of a volume of interest (VOI). This study explores three different …

Non-Centrosymmetric Superconductivity And Magnetism In The Presence Of Broken Symmetries, Mojammel Alam Khan

LSU Doctoral Dissertations

Non-centrosymmetric (NC) superconducting and magnetic compounds have been synthesized and investigated using magnetic, specific heat, and transport measurements, as well as by neutron scattering and quantum oscillations. The crystal structures of NC compounds are defined by the lack of an inversion center. In NC superconductors, a finite antisymmetric spin orbit coupling originating from broken inversion symmetry results in unconventional Cooper pairing. Instead of a single spin channel, the order parameter is a mixture of spin-singlet and spin-triplet states. For NC magnetic compounds, the antisymmetric and isotropic spin interactions compete, leading to a helical ground state.

We have studied the NC …

Energy-Constrained Quantum Communication And Digital Dynamical Decoupling, Haoyu Qi

LSU Doctoral Dissertations

This is a two-part thesis glued together by an everlasting theme in Quantum Information Science \-- to save the quantum state, or the information stored in it, from unavoidably environment-induced noise. The first part of this thesis studies the ultimate rate of reliably transmitting information, stored in quantum systems, through a noisy evolution. Specifically, we consider communication over optical links, upon which future inter-city quantum communication networks will be built. We show how to treat the infinite-dimensional bosonic system rigorously and establish the theory of energy-constrained private and quantum communication over quantum channels. Our result represents important progress in the …

Influences Of Hurricanes, Floods, And Organic Production On River-Delta Evolution Over Decadal To Centennial Time-Scales, Crawford M. White

LSU Doctoral Dissertations

Episodic overbank flooding and sediment resuspension events (such as cold front passages or tropical cyclones) are recognized as important natural components for wetlands maintaining vertical equilibrium with sea-level. However, the relative importance of these components to an anthropogenically unmodified delta complex remains unclear. This study uses sediment cores to describe the relative importance of these vertical accretion components the Lafourche and Balize Deltas of the Mississippi River. Existing wetlands of the abandoned lower Lafourche receive no direct fluvial sediment, but instead are supported by sediment resuspended by tropical cyclones and cold fronts that pass over them. Wetlands of the modern …

Information Theoretic Study Of Gaussian Graphical Models And Their Applications, Ali Moharrer

LSU Doctoral Dissertations

In many problems we are dealing with characterizing a behavior of a complex stochastic system or its response to a set of particular inputs. Such problems span over several topics such as machine learning, complex networks, e.g., social or communication networks; biology, etc. Probabilistic graphical models (PGMs) are powerful tools that offer a compact modeling of complex systems. They are designed to capture the random behavior, i.e., the joint distribution of the system to the best possible accuracy. Our goal is to study certain algebraic and topological properties of a special class of graphical models, known as Gaussian graphs. First, …

Hydroformylation And Aldehyde-Water Shift Catalysis By Dirhodium Tetraphosphine Complexes, Marshall Douglas Moulis

LSU Doctoral Dissertations

The use of a unique tetraphosphine ligand (et,ph-P4) allows for the chelating of two rhodium centers to perform bimetallic coopertivity in hydroformylation reactions to better the yields the linear aldehyde product. The proposed catalyst is [Rh₂(μ-H)₂(CO)₄(rac-et,ph-P4)]²⁺ and has been studied by in situ FT-IR and NMR. When tested in a polar phasic acetone/water (30 % by vol.), the catalyst forms a monocationic system [Rh₂(μ-H)₂(CO)₄(rac-et,ph-P4)]⁺ that has an initial TOF of 26 min^-1, selectivity of 27:1 L:B, and low byproducts of …

Nanoparticle-Based Drug-Delivery Systems Studied By Second Harmonic Generation, Raju Ram Kumal

LSU Doctoral Dissertations

Second harmonic generation (SHG) is used to study different types of colloidal nanoparticle drug-delivery systems. The surface charge density, electrostatic surface potentials, and ion adsorptions of 50 nm colloidal gold nanoparticle samples coated with mercaptosuccinic acid are determined using SHG measurements under varying NaCl and MgCl₂ concentrations in water. Numerical solutions to the spherical Poisson-Boltzmann equation are fit to the SHG results to account for the nanoparticle surface curvature and ion adsorption to the Stern layer interface, showing excellent agreement with electrophoretic mobility measurements. In another study, nanoparticles of gold, silver and polystyrene are functionalized with microRNA using a …

Moduli Spaces Of Flat Gsp-Bundles, Neal David Livesay

LSU Doctoral Dissertations

A classical problem in the theory of differential equations is the classification of first-order singular differential operators up to gauge equivalence. A related algebro-geometric problem involves the construction of moduli spaces of meromorphic connections. In 2001, P. Boalch constructed well-behaved moduli spaces in the case that each of the singularities are diagonalizable. In a recent series of papers, C. Bremer and D. Sage developed a new approach to the study of the local behavior of meromorphic connections using a geometric variant of fundamental strata, a tool originally introduced by C. Bushnell for the study of p-adic representation theory. Not only …

Revisions To Rainfall Intensity Algorithms In Przm5.0 To Improve Estimates Of Off-Field Runoff, Eroded Sediment And Pesticide Mass, Tammara Levey Estes

LSU Doctoral Dissertations

The Environmental Protection Agency (EPA) model Pesticide Root Zone Model, version 5.0 (PRZM5.0) is used to estimate off-field loadings of pesticide concentrations in runoff and eroded sediment. Climate change has resulted in an increase in rainfall intensity patterns for much of the United States. This change impacts off-field runoff and eroded sediment as well as off-field pesticide loads from agricultural fields. Thus, the PRZM5.0 EPA “lookup” table for runoff curve numbers and the internal algorithm for eroded sediment estimation have become outdated since both temporal and geographical conditions have changed. This research presents (1) a revised method for estimating runoff …

Quaternary River Erosion, Provenance, And Climate Variability In The Nw Himalaya And Vietnam, Tara Nicole Jonell

LSU Doctoral Dissertations

The influence of Quaternary climate variation on sediment generation, storage, and transport in two mountainous Asian river basin was examined in the largest tributary to the upper Indus River in the Himalayan rain shadow, the Zanskar River basin (~15,000 km²), and the smaller, subtropical Song Gianh basin (<3,500 km²) of central Vietnam. Spatial patterns of erosion in the Zanskar River Basin were established to quantify the dominant controls on Quaternary sedimentation in the Himalayan rain shadow on the edge of the Tibetan Plateau. Glacial erosion and precipitation along the High Himalaya together dominate sediment production and transport …

Condition Of Birds In Amazonian Rainforest Fragments And Second-Growth Forests, Angelica Maria Hernandez Palma

LSU Doctoral Dissertations

Deforestation modifies otherwise intact expanses of forest into small, isolated fragments. In addition to fragmentation, deforestation also creates abrupt forest edges and large areas of regenerating vegetation where land is abandoned after clearing. Understanding how changes in the landscape affect the physical condition of birds is crucial for managing populations in human-modified landscapes. Here I use the biomarkers feather growth rate and feather quality (ptilochronology), fluctuating asymmetry (FA), and stress hormones from feathers (CORT), to estimate the physical condition of Amazonian understory birds living in forest fragments, second-growth forests, and continuous forests. Feather CORT revealed how fragmentation disrupts interspecific interactions; …

Resonant Interactions In Strong Field Laser Physics, Seth Jacob Camp

LSU Doctoral Dissertations

We present a theoretical study of the influence of resonant enhancement on high harmonic generation for harmonics near the ionization threshold of helium and argon atoms. This is done by solving the time-dependent Schrodinger equation (TDSE) for the interaction between an atom and a driving laser pulse. By varying parameters of the driving laser pulse, we are able to identify the enhancement of harmonics resulting from multiphoton resonances between the ground state and Stark-shifted excited states of the atom. In this way, spectral and temporal signatures of resonant enhancement are identified and highlighted. We also study trajectory dynamics in HHG. …

Symbolic And Deep Learning Based Data Representation Methods For Activity Recognition And Image Understanding At Pixel Level, Manohar Karki

LSU Doctoral Dissertations

Efficient representation of large amount of data particularly images and video helps in the analysis, processing and overall understanding of the data. In this work, we present two frameworks that encapsulate the information present in such data. At first, we present an automated symbolic framework to recognize particular activities in real time from videos. The framework uses regular expressions for symbolically representing (possibly infinite) sets of motion characteristics obtained from a video. It is a uniform framework that handles trajectory-based and periodic articulated activities and provides polynomial time graph algorithms for fast recognition. The regular expressions representing motion characteristics can …

Effect Of Metal Speciation In Fly Ash On Environmentally Persistent Free Radical Formation, Elisabeth Eileen Cook

LSU Doctoral Dissertations

Waste incineration and Superfund sites lead to the formation of pollutants harmful to both the environment and human health. Environmentally Persistent Free Radicals (EPFRs) are a class of newly discovered radical pollutants known to form on combustion by-products such as fly ash and particulate matter. EPFRs are rapidly gaining attention for their harmful effects on the environment and human health. Previous research has shown the formation of EPFRs through surface-mediated reactions with transition metal-oxides on particulates. The work presented in this dissertation explores the relationship between fly ash composition and EPFR formation. Fly ash production occurs from combustion systems, namely …

Branch And Stem Growth As Affected By Loss Of Leaf Area On Selected Branches In Loblolly Pine, Shannon Dumo Kidombo

LSU Doctoral Dissertations

Leaf area and crown dynamics control how trees grow through their supply of carbohydrates and growth regulators, and their influence on tree mechanical stability. The influence of leaf area and crown dynamics to tree growth was investigated by testing the interdependence between leaf area, branch, and stem growth on young loblolly pine trees. The objectives were to (1) determine the influence of current and previous year’s leaf area on elongation of branches; (2) describe and test a unique way of quantitatively measuring the effect of neighbor branches on net growth of a target branch; (3) quantify the growth impact of …

On Braids, Branched Covers And Transverse Invariants, Jose Hector Ceniceros

LSU Doctoral Dissertations

In this work, we present a brief survey of knot theory supported by contact 3-manifolds. We focus on transverse knots and explore different ways of studying transverse knots. We define a new family of transverse invariants, this is accomplished by considering $n$-fold cyclic branched covers branched along a transverse knot and we then extend the definition of the BRAID invariant $t$ defined in cite{BVV} to the lift of the transverse knot. We call the new invariant the lift of the BRAID invariant and denote it by $t_n$. We then go on to show that $t_n$ satisfies a comultiplication formula and …

Manifestations Of Symmetry In Polynomial Link Invariants, Kyle Istvan

LSU Doctoral Dissertations

The use and detection of symmetry is ubiquitous throughout modern mathematics. In the realm of low-dimensional topology, symmetry plays an increasingly significant role due to the fact that many of the modern invariants being developed are computationally expensive to calculate. If information is known about the symmetries of a link, this can be incorporated to greatly reduce the computation time. This manuscript will consider graphical techniques that are amenable to such methods. First, we discuss an obstruction to links being periodic, developed jointly with Dr. Khaled Qazaqzeh at Kuwait University, using a model developed by Caprau and Tipton. We will …