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Beam Theory For Classical And Quantum Nonlinear Optics---Exposing Classical And Quantum Correlations Of Transverse-Spatial Modes, Robert Nicholas Lanning

LSU Doctoral Dissertations

Optics is arguably the most important branch of physics that has ever been studied. It is not only an essential ingredient of many other branches of physics that we study, it governs how we see, how we measure, and how we communicate in the modern world. And as the world continues to change, so do our tools and resources. In a relatively short amount of time, we have progressed from rudimentary tools that shape the world around us, to tools that harness the fundamental laws of nature. Unsurprisingly, the laws of nature governing optics remain paramount. This is because many …

Copper-Nanoparticle Decorated Graphene Thin Films: Applications In Metal-Assisted Etching And Synthesis Of Next-Generation Graphene-Based Nanomaterials, Jaewoo Park

Electronic Thesis and Dissertation Repository

Since 2006, the experimental discovery of graphene, a single-layer of carbon atoms, has spurred tremendous efforts towards new graphene-based materials. In graphene research, there is a recent trend towards next-generation materials in which graphene layers are locally modified in a controlled fashion at the nanoscale and tailored for specific applications. Examples include nanoparticle-decorated graphene thin films with surface potential tailored for nanoelectronics or advanced catalysis, graphene nanoribbons, graphene quantum dots, and the scalable fabrication of tiny pores in graphene, which are suitable to applications requiring ultrathin molecular sieving membranes. This research is focused on the development of new applications of …

Theoretical Studies Of Ultrafast Electron Dynamics In Atoms And Molecules Via High-Order Harmonic Generation, Paul Vincent Abanador

LSU Doctoral Dissertations

The interaction of atoms and molecules with strong laser pulses is of fundamental interest in physics and chemistry. Notably, the process known as high-order harmonic generation (HHG) refers to the production of extreme-ultraviolet (XUV) light, which occurs when an ensemble of atoms or molecules is subjected to a strong infrared laser field. Characterized by an attosecond time scale (1 as = 10^-18 s), the HHG process provides the capability for experimental measurements to capture the ultrafast motion of electrons in these target atoms and molecules. The underlying physical mechanism behind this process naturally leaves imprints in the properties of …

Bipartite Quantum Interactions: Entangling And Information Processing Abilities, Siddhartha Das

LSU Doctoral Dissertations

The aim of this thesis is to advance the theory behind quantum information processing tasks, by deriving fundamental limits on bipartite quantum interactions and dynamics. A bipartite quantum interaction corresponds to an underlying Hamiltonian that governs the physical transformation of a two-body open quantum system. Under such an interaction, the physical transformation of a bipartite quantum system is considered in the presence of a bath, which may be inaccessible to an observer. The goal is to determine entangling abilities of such arbitrary bipartite quantum interactions. Doing so provides fundamental limitations on information processing tasks, including entanglement distillation and secret key …

High Resolution Ion Beam Investigations Of The Mechanisms Of Titanium Anodization, Mitchell A. Brocklebank

Electronic Thesis and Dissertation Repository

The unique behaviour of thin films, and their surfaces and interfaces, significantly impact material and device properties. Probing these structures with ion beams (IB) provides quantitative composition and thicknesses measurements. In this dissertation, the IB techniques of medium energy ion scattering (MEIS), nuclear reaction profiling (NRP) and Rutherford backscattering spectrometry (RBS) are used to analyze energy losses in ultra-thin films, as well as elucidate the mechanisms of anodic film growth.

Accurate stopping cross sections of protons, ε, in the medium energy range (50-170 kV) often show deviations from Bragg’s rule. Here, ε_Ti, ε_Si, and ε_{TiO2 …}

Indirect Imaging Using Computational Imaging Techniques, Aparna Viswanath

Electrical Engineering Theses and Dissertations

The work describes various methods employed towards solving the problem of indirect imaging. Computational techniques are employed to indirectly decipher information about an object hidden from view of a camera. Notion of virtualizing the source of illumination and detectors on real world rough surfaces was exploited to construct a non line of sight computational imager. Diversity was explored from the stand point of both illumination of the object and imaging of light reflected from the object. To understand the impact of scattering by real world rough surfaces, an instrument was developed that allows characterization of isoplanatic angle for different surface …

Experimental Measurements Of Human Cough Airflows From Healthy Subjects And Those Infected With Respiratory Viruses, Nicholas Dudalski

Electronic Thesis and Dissertation Repository

Research concerning person-to-person respiratory virus transmission is required to develop reliable, evidence-based infection prevention and control measures. Experimental studies of human coughs were comprehensively critiqued from the point of view of methodologies, aerodynamics, droplet dispersion and virology. Particle image velocimetry (PIV) and hot-wire anemometry (HWA) measurements were conducted at x=1 m away from the mouth of human subjects to develop a model for cough flow behaviour at greater distances from the mouth than those studied previously. Experiments were conducted for sick subjects who had presented with influenza-like illness, together with a cohort of healthy subjects. Biological aerosol sampling was conducted …

A Fundamental Investigation Into Low Thermal Conductivity P-Type Chalcogenides And Skutterudites With Potential Thermoelectric Applications, Dean Hobbis

USF Tampa Graduate Theses and Dissertations

Sustainable and renewable energy is an incredibly important area in today’s society and investigation into avenues to improve this wide ranging technology are underway in many different fields. Thermoelectric devices possess the ability for the direct solid-state interconversion of heat and electrical power, which not only allows for sustainable refrigeration but also waste heat recovery. One current restriction on the efficiency of thermoelectric devices is the disparity in thermoelectric performance of p-type and n-type materials. Furthermore, a key physical attribute shared by the majority of high performing thermoelectric materials is low thermal conductivity. Thus in this thesis three separate p-type …

Design And Optimization Of A 3-D Plasmonic Huygens Metasurface For Highly-Efficient Flat Optics, Bryan M. Adomanis

Theses and Dissertations

For miniaturization of future USAF unmanned aerial and space systems to become feasible, accompanying sensor components of these systems must also be reduced in size, weight and power (SWaP). Metasurfaces can act as planar equivalents to bulk optics, and thus possess a high potential to meet these low-SWaP requirements. However, functional efficiencies of plasmonic metasurface architectures have been too low for practical application in the infrared (IR) regime. Huygens-like forward-scattering inclusions may provide a solution to this deficiency, but there is no academic consensus on an optimal plasmonic architecture for obtaining efficient phase control at high frequencies. This dissertation asks …

Reconstruction Of The 3d Temperature And Species Concentration Spatial Distribution Of A Jet Engine Exhaust Plume Using An Infrared Fourier Transform Spectrometer Hyperspectral Imager, Mason D. Paulec

Theses and Dissertations

The measurement of combustion byproducts is useful for determining pollution of any fuel burning application, efficiency of combustion, and determining detectability of aircraft exhausts. Both intrusive and non-intrusive techniques have been utilized to measure these quantities. For the majority of the non-intrusive techniques, the absorption and emission spectra of the gases are utilized for measurements. For this research, the use of the Telops Infrared Fourier Transform Spectrometer (IFTS) Hyperspectral Imager (HSI) was explored within the scope of combustion diagnostic methods, as an option for remote measurements of a jet turbine to determine concentration of species and temperature of the combustion …

Probe Of Electroweak Interference Effects In Non-Resonant Inelastic Electron-Proton Scattering, James Franklyn Dowd

Dissertations, Theses, and Masters Projects

The Qweak collaboration at Jefferson Lab made the first direct measurement of the proton's weak charge, Q_W^p, via a measurement of the parity-violating asymmetry in elastic e ⃑p scattering with low four-momentum transfer. to meet the high-precision goals, energy-dependent electroweak radiative corrections were applied to the measured asymmetry. The γZ box, □_γZ, where a photon and a Z-boson are simultaneously exchanged, was the most problematic of these corrections. It could not be calculated through the same perturbative methods as the rest of the corrections. The □_γZ correction depends on theoretical models of the γZ interference structure functions, F_1,2^γZ, for which …

Beryllium And Indium Activation Measurements Of Total Neutron Yield From A Pulsed Photoneutron Source, Kristina K. Brown

Physics & Astronomy ETDs

A pulsed photoneutron source consisting of a beryllium sphere and a 5 MeV endpoint 30 ns bremsstrahlung beam emanating from the Mercury pulsed-power source was assembled and tested in October 2017 at the Naval Research Laboratory (NRL) in Washington, D.C. [1]. The objective of this experiment was to verify the feasibility of using a pulsed power source to create a large number of photoneutrons in a short period of time, leveraging the low photoneutron production threshold of 9Be to maximize neutron production. Several diagnostics were deployed to characterize the source and target, including indium and beryllium activation detectors that measured …

A Network Theoretical Approach To Real-World Problems: Application Of The K-Core Algorithm To Various Systems, Kate Burleson-Lesser

Dissertations, Theses, and Capstone Projects

The study of complex networks is, at its core, an exploration of the mechanisms that control the world in which we live at every scale, from particles no bigger than a grain of sand and amino acids that comprise proteins, to social networks, ecosystems, and even countries. Indeed, we find that, regardless of the physical size of the network's components, we may apply principles of complex network theory, thermodynamics, and statistical mechanics to not only better understand these specific networks, but to formulate theories which may be applied to problems on a more general level. This thesis explores several networks …

Baryons And Interactions In Magnetic Fields, Amol Deshmukh

Dissertations, Theses, and Capstone Projects

The QCD external field problem allows one to probe the rich behavior of strongly interacting systems under external conditions, including the modification of hadron structure and interactions due to external electromagnetic fields. These dynamics, moreover, are likely relevant to describe the physics in the interiors of magnetars and in non-central heavy-ion collisions, for which large magnetic fields upwards of $10^{19}$ Gauss are conceivable. Additionally motivated by lattice QCD calculations in external fields, we study the behavior of single- and two-baryon (specifically, two-nucleon) systems in large magnetic fields. The dependence of single-baryon energies on magnetic fields is explored using chiral dynamics. …

Direct Experimental Evidence Of Toroidal Symmetry In A Lanthanide-Based Molecular Magnet, Qing Zhang

Dissertations, Theses, and Capstone Projects

Molecular magnets (MM) are finite clusters of identical exchange-coupled magnetic systems arranged within a crystalline array such that interactions between neighboring MMs are negligible. Their small size has proven them amenable test beds for the investigation of a wide range of fundamental quantum phenomena such as spin frustration quantum tunneling (QT) of magnetization and Neel vector quantum coherence and Berry phase interference.

Cases where MMs have been found to exhibit quantum wave-functions that evolve coherently are particularly interesting due to their potential for use in quantum information processing. Toroidal magnetic moments, a kind of MM, have fascinating properties that could …

Quantum And Classical Transport Of 2d Electrons In The Presence Of Long And Short Range Disorder, Jesse Kanter

Dissertations, Theses, and Capstone Projects

This work focuses on the study of electron transport of 2-D electron gas systems in relation to both fundamental properties of the systems such as disorder and scattering mechanisms, as well as unique magnetoresistance (MR) effects. A large portion of the discussion is built around the use of an in plane magnetic field to vary the ratio between the Zeeman energy between electrons of different spins and the Landau level spacing, creating a tool to control the quantization of the density of states (DOS).

This tool is first used to isolate Quantum Positive Magnetoresistance (QPMR), which grants insight to the …

Supercharged Models Of Intrinsically Disordered Proteins And Their Utility In Sensing, Peter J. Schnatz

Dissertations, Theses, and Capstone Projects

In this thesis I show that greatly increasing the magnitude of a protein’s net charge using surface supercharging transforms that protein into a ligand-gated or counterion-gated conformational molecular switch. To demonstrate this I first modified the designed helical bundle hemoprotein H4 using simple molecular modeling, creating a highly charged protein which both unfolds reversibly at low ionic strength and undergoes the ligand-induced folding transition commonly observed in signal transduction by intrinsically disordered proteins in biology. Due to the high surface charge density, ligand binding to this protein is allosterically activated by low concentrations of divalent cations and the polyamine spermine. …

Charge State Dynamics And Quantum Sensing With Defects In Diamond, Jacob D. Henshaw

Dissertations, Theses, and Capstone Projects

In recent years, defect centers in wide band gap semiconductors such as diamond, have received significant attention. Defects offer great utility as single photon emitters, nanoscale sensors, and quantum memories and registers for quantum computation. Critical to the utility of these defects, is their charge state.

In this dissertation, experiments surrounding the charge state dynamics and the carrier dynamics are performed and analyzed. Extensive studies of the ionization and recombination processes of defects in diamond, specifically, the Nitrogen Vacancy (NV) center, have been performed. Diffusion of ionized charge carriers has been imaged indirectly through the recapture of said carriers by …

Interdisciplinary Studies Of Complex Network And Machine Learning And Its Applications, Shaojun Luo

Dissertations, Theses, and Capstone Projects

In this dissertation, we introduce the concept of network-based statistical inference methods of two types: network structure inference and variable inference. For network structure inference, we introduce correlation matrix, graphical Lasso, network clustering and identify the influencer in the network. For variable inference, we also introduce from Bayesian network, to Random Markov Field and Ising Model, Boltzmann and Restricted Boltzmann machine and the algorithm of Belief Propagation. Last but not the least, we introduce the most widely used neural network family and its two main types: Convolutional Neural Network and Recurrent Neural Network.

In Chapter 3 we provide an example …

Application Of Spectral Solution And Neural Network Techniques In Plasma Modeling For Electric Propulsion, Joseph R. Whitman

Theses and Dissertations

A solver for Poisson's equation was developed using the Radix-2 FFT method first invented by Carl Friedrich Gauss. Its performance was characterized using simulated data and identical boundary conditions to those found in a Hall Effect Thruster. The characterization showed errors below machine-zero with noise-free data, and above 20% noise-to-signal strength, the error increased linearly with the noise. This solver can be implemented into AFRL's plasma simulator, the Thermophysics Universal Research Framework (TURF) and used to quickly and accurately compute the electric field based on charge distributions. The validity of a machine learning approach and data-based complex system modeling approach …

Evaluation And Quantification Of Diffractive Plenoptic Camera Algorithm Performance, Jack A. Shepherd Iii

Theses and Dissertations

A diffractive plenoptic camera is a novel approach to the traditional plenoptic camera which replaces the main optic with a Fresnel zone plate making the camera sensitive to wavelength instead of range. However, algorithms are necessary to reconstruct the image produced by plenoptic cameras. While many algorithms exist for traditional plenoptic cameras, their ability to create spectral images in a diffractive plenoptic camera is unknown. This paper evaluates digital refocusing, super resolution, and 3D deconvolution through a Richardson-Lucy algorithm as well as a new Gaussian smoothing algorithm. All of the algorithms worked well near the Fresnel zone plate design wavelength, …

Nmr Characterizations Of Candidate Battery Electrolytes, Stephen A. Munoz

Dissertations, Theses, and Capstone Projects

Enormous strides have been made in next-generation power sources to build a more sustainable society. Energy storage has become a limiting factor in our progress, and there are huge environmental and financial incentives to find the next step forward in battery technology. This work discusses NMR methods for characterizing materials for use in battery application, with a special focus on relaxometry and diffusometry. Examples are provided of various recent investigations involving novel candidate electrolyte materials with different collaborators. Works discussed in this thesis include: the characterization of a new disruptive solid polymer electrolyte technology, investigations of the dynamics of super …

The Periglacial Landscape Of Mars: Insight Into The 'Decameter-Scale Rimmed Depressions' In Utopia Planitia, Arya Bina

Electronic Thesis and Dissertation Repository

Currently, Mars appears to be in a ‘frozen’ and ‘dry’ state, with the clear majority of the planet’s surface maintaining year-round sub-zero temperatures. However, the discovery of features consistent with landforms found in periglacial environments on Earth, suggests a climate history for Mars that may have involved freeze and thaw cycles. Such landforms include hummocky, polygonised, scalloped, and pitted terrains, as well as ice-rich deposits and gullies, along the mid- to high-latitude bands, typically with no lower than 20o N/S. The detection of near-surface and surface ice via the Phoenix lander, excavation of ice via recent impact cratering activity as …

Using Strong Laser Fields To Produce Antihydrogen Ions, Christopher Michael Keating

Dissertations and Theses

We provide estimates of both cross section and rate for the stimulated attachment of a second positron into the (1s^{2 1}S^e) state of the H+ ion using Ohmura and Ohmura's (1960 Phys. Rev. 118 154) effective range theory, Reiss's strong field approximation (1980 Phys. Rev. A 22, 1786), and the principle of detailed balancing. Our motivation for producing H+ ion include its potential to be used as an intermediate state in bringing antihydrogen to ultra-cold (sub-mK) temperatures required for a variety of studies, which include both spectroscopy and the probing of the gravitational interaction of …

Techniques For Improved Space Object Detection Performance From Ground-Based Telescope Systems Using Long And Short Exposure Images, David J. Becker

Theses and Dissertations

Space object detection is of great importance in the highly dependent yet competitive and congested space domain. Detection algorithms employed play a crucial role in fulfilling the detection component in the space situational awareness mission to detect, track, characterize and catalog unknown space objects. Many current space detection algorithms use a matched filter or a spatial correlator on long exposure data to make a detection decision at a single pixel point of a spatial image based on the assumption that the data follows a Gaussian distribution. This research focuses on improving current space object detection algorithms and developing new algorithms …

Performance Impact Of Different Lower-Limb Setup Positions In The Backstroke Swimming Start, Gordon E. Barkwell

Electronic Thesis and Dissertation Repository

The performance impact of different knee extension angles in the setup position for a backstroke start was evaluated using an instrumented starting surface. Ten backstroke swimmers completed maximum-effort starts in each of two setup positions: one with the knees flexed, and one with the knees extended. The start handles and touchpad were instrumented with tri-axial force plates. Activity of major hip and knee extensors was measured using surface electromyography. Body position was recorded throughout the start using two high-speed cameras. There was no difference in time to 10 m between the two conditions, indicating there is likely no advantage in …

Topological Recursion And Random Finite Noncommutative Geometries, Shahab Azarfar

Electronic Thesis and Dissertation Repository

In this thesis, we investigate a model for quantum gravity on finite noncommutative spaces using the topological recursion method originated from random matrix theory. More precisely, we consider a particular type of finite noncommutative geometries, in the sense of Connes, called spectral triples of type ${(1,0)} \,$, introduced by Barrett. A random spectral triple of type ${(1,0)}$ has a fixed fermion space, and the moduli space of its Dirac operator ${D=\{ H , \cdot \} \, ,}$ ${H \in {\mathcal{H}_N}}$, encoding all the possible geometries over the fermion space, is the space of Hermitian matrices ${\mathcal{H}_N}$. A distribution of the …

Vibrating-Wire Rheometry, Cameron C. Hopkins

Electronic Thesis and Dissertation Repository

This thesis consists of two projects on the behaviour of a novel vibrating-wire rheometer and a third project studying the gelation dynamics of aqueous solutions of Pluronic F127. In the first study, we use COMSOL to perform two-dimensional simulations of the oscillations of a wire in Newtonian and shear-thinning fluids. Our results show that the resonant behaviour of the wire agrees well with the theory of a wire vibrating in Newtonian fluids. In shear-thinning fluids, we find resonant behaviour similar to that in Newtonian fluids. In addition, we find that the shear-rate and viscosity in the fluid vary significantly in …

Optical And X-Ray Studies Of Compact X-Ray Binaries In Ngc 5904, Vanshree Bhalotia

College of Science and Health Theses and Dissertations

Globular clusters are the oldest objects in the Milky Way, serving as probes of early galactic evolution due to their chemically uncontaminated history. Compact binaries act as an internal energy source through their dynamical interactions, and measuring the types of X-ray binaries within a cluster provides an understanding of its stellar population and dynamics, as stellar collisional frequencies have been correlated to the number of X-ray sources detected in globular clusters. Compact binaries can be found by correlating X-ray positional data with optical imaging data. In this project, optical fluxes of sources from archival HST images of NGC 5904 have …

"Effect Of Zinc And Strontium Dopants On The Structure And Stability Of Hydroxyapatite At High Temperatures", Dylan Correll Smith

College of Science and Health Theses and Dissertations

Hydroxyapatite (HA) is a bioceramic that synthetically mimics human bone. It is commonly used in medical applications as a filler for damaged bone, and in procedures such as dental implants and hip replacements. Doping of HA with elements such as zinc and strontium is known to increase the bioactivity of HA, as well as increase the retention and adsorption of therapeutic molecules for drug delivery. High-temperature, in-situ X-ray diffraction data were measured on 10 at. % zinc-doped, 10 at. % strontium-doped, and undoped HA powders at the Advanced Photon Source at Argonne National Laboratory. This research studied the temporal and …