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UNT Theses and Dissertations
 Zinc Oxide Nanoparticles for Nonlinear Bioimaging, Cell Detection and Selective Cell Destruction

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Light matter interactions have led to a great part of our current understanding of the universe. When light interacts with matter it affects the properties of both the light and the matter. Visible light, being in the region that the human eye can "see," was one of the first natural phenomenon we used to learn about our universe. The application of fundamental physics research has spilled over into other fields that were traditionally separated from physics, being considered two different sciences. Current physics research has applications in all scientific fields. By taking a more physical approach to problems in fields such as chemistry and biology, we have furthered our knowledge of both. Nanocrystals have many interesting optical properties. Furthermore, the size and properties of nanocrystals has given them applications in materials ranging from solar cells to sunscreens. By understanding and controlling their interactions with systems we can utilize them to increase our knowledge in other fields of science, such as biology. Nanocrystals exhibit optical properties superior to currently used fluorescent dyes. By replacing molecular dyes with nanoparticles we can reduce toxicity, increase resolution and have better cellular targeting abilities. They have also shown to have toxicity to cancer and antibacterial properties. With the understanding of how to target specific cells in vitro as well as in vivo, nanoparticles have the potential to be used as highly cell specific nanodrugs that can aid in the fight against cancer and the more recent fight against antibiotic resistant bacteria. This dissertation includes our work on bioimaging as well as our novel drug delivery system. An explanation of toxicity associated with ZnO nanoparticles and how we can use it and the nonlinear optical properties of ZnO for nanodrugs and nanoprobes is presented. digital.library.unt.edu/ark:/67531/metadc271908/  A New Approach for Transition Metal Free Magnetic Sic: Defect Induced Magnetism After Selfion Implantation
 SiC has become an attractive wide bandgap semiconductor due to its unique physical and electronic properties and is widely used in high temperature, high frequency, high power and radiation resistant applications. SiC has been used as an alternative to Si in harsh environments such as in the oil industry, nuclear power systems, aeronautical, and space applications. SiC is also known for its polytypism and among them 3CSiC, 4HSiC and 6HSiC are the most common polytypes used for research purposes. Among these polytypes 4HSiC is gaining importance due to its easy commercial availability with a large bandgap of 3.26 eV at room temperature. Controlled creation of defects in materials is an approach to modify the electronic properties in a way that new functionality may result. SiC is a promising candidate for defectinduced magnetism on which spintronic devices could be developed. The defects considered are of room temperature stable vacancy types, eliminating the need for magnetic impurities, which easily diffuse at room temperature. Impurity free vacancy type defects can be created by implanting the host atoms of silicon or carbon. The implantation fluence determines the defect density, which is a critical parameter for defect induced magnetism. Therefore, we have studied the influence of low fluence low energy silicon and carbon implantation on the creation of defects in ntype 4HSiC. The characterization of the defects in these implanted samples was performed using the techniques, RBSchanneling and Raman spectroscopy. We have also utilized these characterization techniques to analyze defects created in much deeper layers of the SiC due to implantation of high energy nitrogen ions. The experimentally determined depths of the Si damage peaks due to low energy (60 keV) Si and C ions with low fluences (< 1015 cm2) are consistent with the SRIM2011 simulations. From RBSC Si sublattice measurements for different fluences (1.1×1014 cm2 to 3.2×1014 cm2) of Si implantation in 4HSiC, the Si vacancy density is estimated to range from 1.29×1022 cm3 to 4.57×1022 cm2, corresponding to average vacancy distances of 4.26 Å to 2.79 Å at the damage peak (50±5 nm). Similarly, for C implanted fluences (1.85×1014 cm2 to 1×1015 cm2), the Si vacancy density varies from 1.37×1022 cm3 to 4.22×1022 cm3 with the average vacancy distances from 4.17 Å to 2.87 Å at the damage peak (110±10 nm). From the Raman spectroscopy, the implantationinduced lattice disorders calculated along the caxis (LO mode) and perpendicular to caxis (TO mode) in 4HSiC are found to be similar. Furthermore, the results obtained from SQUID measurements in C implanted ntype 4HSiC sample with fluences ranging from 1×1012 to 1.7×1016 ions/cm2 have been discussed. The implanted samples showed diamagnetism similar to the unimplanted sample. To date, to our best of knowledge, no experimental work has been reported on investigating defect induced magnetism for selfion implantation in ntype 4HSiC. These first reports of experimental results can provide useful information in future studies for a better understanding of selfion implantation in SiCbased DMS. digital.library.unt.edu/ark:/67531/metadc271849/
 Criticality in Cooperative Systems
 Cooperative behavior arises from the interactions of single units that globally produce a complex dynamics in which the system acts as a whole. As an archetype I refer to a flock of birds. As a result of cooperation the whole flock gets special abilities that the single individuals would not have if they were alone. This research work led to the discovery that the function of a flock, and more in general, that of cooperative systems, surprisingly rests on the occurrence of organizational collapses. In this study, I used cooperative systems based on selfpropelled particle models (the flock models) which have been proved to be virtually equivalent to sociological network models mimicking the decision making processes (the decision making model). The critical region is an intermediate condition between a highly disordered state and a strong ordered one. At criticality the waiting times distribution density between two consecutive collapses shows an inverse power law form with an anomalous statistical behavior. The scientific evidences are based on measures of information theory, correlation in time and space, and fluctuation statistical analysis. In order to prove the benefit for a system to live at criticality, I made a flock system interact with another similar system, and then observe the information transmission for different disturbance values. I proved that at criticality the transfer of information gets the maximal efficiency. As last step, the flock model has been shown that, despite its simplicity, is sufficiently a realistic model as proved via the use of 3D simulations and computer animations. digital.library.unt.edu/ark:/67531/metadc271910/
 Theoretical and Experimental Investigations of Peg Based Thermo Sensitive Hydro Microgel
 Poly ethylene glycol (PEG) based microgels were synthesized and investigated. The PEG microgel has the same phase transition as the traditional poly Nisopropylacrylamide (PNIPAM). As a good substitute of PNIPAM, PEG microgel exhibits many advantages: it is easier to control the lower critical solution temperature (LCST) of the microgel by changing the component of copolymers; it has a more solid spherical coreshell structure to have a double thermo sensitivity; it is straightforward to add other sensitivities such as pH, magnetic field or organic functional groups; it readily forms a photonic crystal structure exhibiting Bragg diffraction; and, most importantly, the PEG microgel is biocompatible with human body and has been approved by FDA while PNIPAM has not. PEG microgels with coreshell structure are synthesized with a twostep free radical polymerization and characterized with DLS, SLS and UV–Vis. The dynamic mechanics of melting and recrystallizing of the PEG coreshell microgel are presented and discussed. Photonic crystals of PEG microgels were synthesized and characterized. The crystal can be isolated in a thin film or a bulk column. The phase transition of PEG microgel was simulated with the mean field theory. The enthalpy and entropy of phase transition can be estimated from the best fit to theoretical calculation with experimental data. digital.library.unt.edu/ark:/67531/metadc177187/
 Microwave Cavity Method for Measuring Plasma Properties
 This discussion is concerned primarily with communications blackout during spacecraft entry into a planetary atmosphere. The gas in the shock layer, between shock wave and vehicle surface, ionizes from the intense heating which takes place in the bow shock wave and a viscous region of high gas enthalpy. This ionization may persist throughout the subsequent flow over the vehicle and into the wake, thus completely engulfing the vehicle and its communications elements. The problem will be to simulate a plasma model that will be of interest for hypervelocity reentry vehicles and to provide meaningful expressions for the various plasma parameters of interest (electron density, electron temperature, collision frequency, etc.) in terms of the microwave measurables (amplitude, phase shifts, frequency shifts, polarization, etc.) digital.library.unt.edu/ark:/67531/metadc163950/
 A Vacuum Tube for an Electrostatic Generator
 The purpose of this study has been to construct two accelerating tubes with small beam apertures for the Van de Graaff, modifying the prototype tube designed and tested by Wiley (20), to design and construct a vacuum system for evacuating the tubes, and to determine the characteristics of the tube under operating conditions while installed in the generator. digital.library.unt.edu/ark:/67531/metadc163894/
 The Diurnal Variation of Cosmic Radiation
 The primary purpose of this investigation was to study the diurnal variation of cosmicray intensity. digital.library.unt.edu/ark:/67531/metadc163872/
 Design and Testing of a Positive Ion Accelerator and Necessary Vacuum System
 This thesis is a study of the design and testing of a positive ion accelerator and necessary vacuum system. digital.library.unt.edu/ark:/67531/metadc163830/
 Electrical Conductivity in Thin Films
 This thesis deals with electrical conductivity in thin films. Classical and quantum size effects in conductivity are discussed including some experimental evidence of quantum size effects. The component conductivity along the applied electric field of a thin film in a transverse magnetic field is developed in a density matrix method. digital.library.unt.edu/ark:/67531/metadc164055/
 A Study of the Celestial Gammaray Flux
 This thesis is a study of the celestial gammaray flux. It reviews several of the proposed mechanisms for producing high energy gamma rays and describes several of the attempts to detect their presence. Also included is a short historical review of the spark chamber, along with a qualitative description of its operation. digital.library.unt.edu/ark:/67531/metadc163905/
 The Temperature Dependence of Magnetic Susceptibility of Galvinoxyl
 The twofold purpose of this investigation was to design and construct an apparatus for direct magnetic susceptibility measurements as a function of temperature and to provide the complete susceptibility characterization of the free radical galvinoxyl in the room temperatureliquid nitrogen range. digital.library.unt.edu/ark:/67531/metadc163921/
 Temperature Dependence of the Magnetic Susceptibility of the Organic Free Radical Galvinoxyl
 This thesis examines temperature dependence of magnetic susceptibility of the organic free radical galvinoxyl. digital.library.unt.edu/ark:/67531/metadc163874/
 Nuclear Magnetic Resonance in a Crystalline Stable Free RadicalWurster's Blue Perchlorate
 This thesis investigates the nuclear magnetic resonance in a crystalline stable free radical. digital.library.unt.edu/ark:/67531/metadc163873/
 The Optimum Design of a Broadband Helix for Use in Electron Spin Resonance
 This thesis examines optimum designs for broadband helix to be used in electron spin resonance. digital.library.unt.edu/ark:/67531/metadc163904/
 The Dielectric Constant of Galvinoxyl
 The molecules in many substances are know to undergo at characteristic temperatures a change in their rotational freedom in the solid state, signifying either a change in structure of the material of the onset of limited rotation of the molecule about some symmetry axis. The purpose of this research was to determine from dielectric constant measurements over the 100°K420°K temperature range whether or not the organic free radical galvinoxyl and its diamagnetic parent molecule, dihydroxydiphenylmethane, undergo any such transitions. digital.library.unt.edu/ark:/67531/metadc163926/
 A Microwave Spectrometer for Narrowline Electron Spin Resonance Studies
 This thesis explores the basic theory, design and construction of electron spin resonance spectrometer. digital.library.unt.edu/ark:/67531/metadc163881/
 Antiferromagnetic Ordering in PicrylAminoCarbazyl
 The purpose of the experiment was to investigate other paramagnetic salts to determine whether the W. B. perchlorate type peak was more common than previously suspected. An organic salt, picrylnaminocarbazyl, was chosen. digital.library.unt.edu/ark:/67531/metadc163864/
 Design and Testing of a Corona Column and a Closed Gas Distribution System for a Tandem Van de Graaff Voltage Generator
 The purpose of this study had been to design and test a corona column and an insulating gas distribution system for a small tandem Van de Graaff. The intent of this paper is to describe the gas handling system and to compare experimentally the effects of corona electrode shape on the corona current carried between adjacent sections of the column. digital.library.unt.edu/ark:/67531/metadc163849/
 Gamma Rays Resulting from Neutron Scattering in Cesium
 The purpose of this investigation was to attempt to resolve the energy levels of Cs133 that can be excited by inelastic scattering of 14 Mev neutrons. digital.library.unt.edu/ark:/67531/metadc163901/
 Gamma Ray Distribution from Neutron Excitation in Cesium
 The purpose of this investigation was to analyze the gamma rays resulting from excitation of Cs133 by the inelastic scattering of 14 MeV neutrons and to determine the relative intensity of each gamma ray. digital.library.unt.edu/ark:/67531/metadc163933/
 A Nonequilibrium Approach to Scale Free Networks
 Many processes and systems in nature and society can be characterized as large numbers of discrete elements that are (usually nonuniformly) interrelated. These networks were long thought to be random, but in the late 1990s, Barabási and Albert found that an underlying structure did in fact exist in many natural and technological networks that are now referred to as scale free. Since then, researchers have gained a much deeper understanding of this particular form of complexity, largely by combining graph theory, statistical physics, and advances in computing technology. This dissertation focuses on outofequilibrium dynamic processes as they unfold on these complex networks. Diffusion in networks of noninteracting nodes is shown to be temporally complex, while equilibrium is represented by a stable state with Poissonian fluctuations. Scale free networks achieve equilibrium very quickly compared to regular networks, and the most efficient are those with the lowest inverse power law exponent. Temporally complex diffusion also occurs in networks with interacting nodes under a cooperative decisionmaking model. At a critical value of the cooperation parameter, the most efficient scale free network achieves consensus almost as quickly as the equivalent alltoall network. This finding suggests that the ubiquity of scale free networks in nature is due to Zipf's principle of least effort. It also suggests that an efficient scale free network structure may be optimal for real networks that require high connectivity but are hampered by high link costs. digital.library.unt.edu/ark:/67531/metadc149609/
 Theoretical and Experimental Investigations Concerning Microgels of Varied Spherical Geometries
 Polymer gels have been studied extensively due to their ability to simulate biological tissues and to swell or collapse reversibly in response to external stimuli. This work presents a variety of studies using polyNisopropylacrylamide (PNIPA) hydrogels. The projects have been carried out both in the lab of Dr. Zhibing Hu and in collaboration with others outside of UNT: (1) an analysis of the swelling kinetics of microgel spherical shells prepared using a novel design of microfluidic devices; (2) a comparison of the drugrelease rates between nanoparticle structures having either core or corewithshell (coreshell) designs; (3) an investigation into the thermodynamics of swelling for microgels of exceedingly small size. digital.library.unt.edu/ark:/67531/metadc149680/
 Ultrafast Spectroscopy of Hybrid Ingan/gan Quantum Wells
 Group III nitrides are efficient light emitters. The modification of internal optoelectronic properties of these materials due to strain, external or internal electric field are an area of interest. Insertion of metal nanoparticles (MNPs) (Ag, Au etc) inside the Vshaped inverted hexagonal pits (IHP) of InGaN/GaN quantum wells (QWs) offers the potential of improving the light emission efficiencies. We have observed redshift and blueshift due to the Au MNPs and Ag MNPs respectively. This shift could be due to the electric field created by the MNPs through electrostatic image charge. We have studied the ultrafast carrier dynamics of carriers in hybrid InGaN/GaN QWs. The change in quantum confinement stark effect due to MNPs plays an important role for slow and fast carrier dynamics. We have also observed the image charge effect on the ultrafast differential transmission measurement due to the MNPs. We have studied the nonlinear absorption spectroscopy of these materials. The QWs behave as a discharging of a nanocapacitor for the screening of the piezoelectric field due to the photoexcited carriers. We have separated out screening and excitonic bleaching components from the main differential absorption spectra of InGaN/GaN QWs. digital.library.unt.edu/ark:/67531/metadc149635/
 Variational Wave Function for Sodium
 The practical method of applying the variation principle to the calculation of the energy of an atom demands a trial function which contains variable parameters. The previous work done using this approach was based on the use of some combination of hydrogenic wave functions containing parameters inserted in appropriate places. The present calculation of the energy of the elevenelectron atom has been brought about using this method. digital.library.unt.edu/ark:/67531/metadc130344/
 Operation and Control of a Radiofrequency Ion Source
 This thesis examines the operation and control of a radiofrequency ion source. digital.library.unt.edu/ark:/67531/metadc130340/
 Neutron Density Depression Due to an Oblate Spheroidal Detector
 In this paper, two projects have been undertaken. First, Workman's calculations have been checked to a higher degree of approximation to determine the accuracy of his method. Second, a new set of boundary conditions has been developed for obtaining solutions of the neutron diffusion equation which do not depend on the solution of the equation inside the detector. digital.library.unt.edu/ark:/67531/metadc130362/
 Dynamical Friction Coefficients for Plasmas Exhibiting NonSpherical Electron Velocity Distributions
 This investigation is designed to find the net rate of decrease in the component of velocity parallel to the original direction of motion of a proton moving through an electron gas exhibiting a nonspherical velocity distribution. digital.library.unt.edu/ark:/67531/metadc130480/
 Energy Losses of Protons Projected through a Plasma Due to Collisions with Electrons of the Plasma for a Variety of NonMaxwellian Electron Velocity Distributions
 The purpose of this thesis is to study energy losses suffered by protons in traversing a plasma through collision with the electrons of the plasma. For these electrons a variety of nonMaxwellian velocity distributions are assumed. digital.library.unt.edu/ark:/67531/metadc130468/
 A Computer Analysis of Complex GammaRay Spectra
 The purpose of this investigation was to provide a method for determining the relative intensities of all gamma rays in a particular spectrum, and thereby determine the relative transition probabilities. digital.library.unt.edu/ark:/67531/metadc130612/
 Electron Transport in Bismuth at Liquid Helium Tempratures
 To obtain information on the band structure of bismuth, galvanomagnetic potentials were measured in a single crystal at liquidhelium and liquidnitrogen temperatures. These measurements were analyzed for information on the different carriers, particularly for the existence of a highmobility band of holes. digital.library.unt.edu/ark:/67531/metadc130512/
 Size Effect in the Electrical Conductivity of Bismuth
 If a physical dimension of a metallic specimen is comparable with, or smaller than, the mean free path of the conduction electrons, then the observed electrical conductivity will be less than that of a conventional bulk sample. This phenomenon is called a size effect, and is the result of electron scattering from the specimen surfaces. In the present investigation, measurements were made on electropolished monocrystalline specimens ranging from matchbox geometry to thickfilm geometry in order to obtain further information on the size effect in bismuth at liquid helium temperatures. digital.library.unt.edu/ark:/67531/metadc130880/
 A Precision Angular Correlation Table and Calculation of Geometrical Correction Factors
 In recent years yy angular correlations have been very useful in confirming the spins of excited nuclear states. Angular correlation techniques have also been employed to study the electric and magnetic character of excited nuclear states. With these things in mind, it was decided to design, construct, and test a precision angular correlation table. digital.library.unt.edu/ark:/67531/metadc131220/
 Recombination Rate Coefficient Measurements in the Helium Afterglow
 This thesis describes a method of determining the recombination rate coefficient experimentally, which does not depend on a specific model of the recombination process. With this method established, results are presented for the recombination rate coefficient measurements at 44.6 Torr. digital.library.unt.edu/ark:/67531/metadc131182/
 Temperature Dependence of Line Widths of the Inversion Spectra of Ammonia
 One of the purposes of this work is to investigate modifications that have to be made to a standard sourcemodulation microwave spectrograph so that it can be used to study gases at various temperatures. Another objective in this work is to determine experimentally the function of temperature that describes how the line widths of microwave spectral lines vary with changing temperature. The most important segment of the study is the temperature dependence of the line width since from an accurate knowledge of this temperature dependence one is able to determine what molecular force fields are present and the relative importance of parts of the molecular force field. digital.library.unt.edu/ark:/67531/metadc131126/
 Cross Section for the 165/Ho (n, 2n) 164/Ho Reaction at 15.6 MeV
 It was the purpose of this investigation to bring together the ideas and procedures involved in the measurement of (n, 2n) reaction cross sections. Some of the inherent properties of the material under investigation (Holium) are involved in determining these relationships. digital.library.unt.edu/ark:/67531/metadc131148/
 Measurement of the Atomicoxygen Concentration under Simulated Upper Atmosphere Conditions
 This thesis describes an experimental technique for measuring the atomicoxygen concentration under simulated upper atmosphere conditions. digital.library.unt.edu/ark:/67531/metadc131196/
 Monte Carlo Calculations of Reflected Intensities for Real Spherical Atmospheres
 To calculate the emergent radiation field, a realistic atmospheric model and algorithm must be developed. The radiation field may be characterized by the emergent intensities of scattered light. This is possible only if the algorithm determines these intensities as dependent upon atmospheric and angular parameters. digital.library.unt.edu/ark:/67531/metadc131064/
 Boundary Scattering of Electrons in Thin Cadmium Single Crystals
 In the present investigation, zinc was plated onto a cadmium crystal to determine the effect on the scattering parameter. digital.library.unt.edu/ark:/67531/metadc130996/
 Cs133 (n,2n) CrossSection at 15.6 and 16.1 MeV
 The intent of this investigation is the determination of the values of the Cs133 (n,2n)Cs132 crosssection at neutron energies of 15.6 and 16.1 MeV. Neutrons of this energy are produced with comparative ease by means of the DT reaction, in which deuterons of energy 500 and 750 keV, respectively, are impingent upon a tritium target. digital.library.unt.edu/ark:/67531/metadc131110/
 Size Dependence in the Electrical Conductivity of Bismuth
 In the present investigation, measurements were made at liquidhelium temperatures on singlecrystal bismuth samples which had a stairstep geometry in order to study several thicknesses during one helium run. These samples were also thinned to extend the thickness range of the steps to a thinner region. In addition J.E. Parrott's theory is extended to include a diagonal anisotropic relaxationtime tensor and the effect of holes on the size effect. A discussion of the theory of Parrott, and the extension of Parrott's theory in connection with the experimental results is presented. digital.library.unt.edu/ark:/67531/metadc131132/
 Gurevich Magnetomorphic Oscillations in Single Crystals of Aluminum at Helium Temperatures
 The Sondheimer theory was tested by looking for oscillatory phenomena in a group of single crystals representing a range in dimensions from matchbox geometry to thinfilm geometry. The single crystals were identical with respect to impurity content, strain, orientation, surface condition, and probe placement. digital.library.unt.edu/ark:/67531/metadc130866/
 Magnetomorphic Oscillations in Cadmium Cylinders
 The work presented here is an experimental investigation of the effect of cylindrical geometry on electrical conductivity, in which singlecrystal samples of cadmium at the temperature of liquid helium are used, with the diameter on the order of the electron mean free path. digital.library.unt.edu/ark:/67531/metadc131138/
 A Study and Critique of the Mean Position Concept in Relativistic Wave Mechanics
 The basic concept to be used in studying the question of oneparticle interpretations of relativistic wave equations is that of observables and operator representations that are different from the more usual classically motivated observables and representations. In particular, the concept of a meanposition observable will be used to determine to what extent the oneparticle "problems" can be resolved. digital.library.unt.edu/ark:/67531/metadc130778/
 (N, 2N) Cross Section Measurements in Praseodymium141 as a Function of Neutron Bombarding Energy
 Using the parallel disk method of activation analysis, the (n,2n) reaction cross section in 141Pr was measured as a function of neutron energy in the range 15.4 to 18.4 MeV. The bombarding neutrons were produced from the 3T(d,n)4He reaction, where the deuterons were accelerated by the 3MV Van de Graff generator of the North Texas Regional Physics Laboratory in Denton, Texas. digital.library.unt.edu/ark:/67531/metadc131376/
 A Study of the Decay Levels of 169/Tm69
 The purpose of this investigation was to study the radiations of the 169/Tm nucleus as it deexcites after the electron capture decay of the 169/Yb. Numerous unreported gammas were present in the sample. The origins of these gamma rays were found. digital.library.unt.edu/ark:/67531/metadc131328/
 Vertex Functions in KMesonNucleon Scattering
 The purpose of this study was to investigate some theoretical approaches to the scattering of positive kmesons by nucleons in an attempt to explain the experimental data. In this work the problem has been investigated by the technique of the weak coupling approximation. digital.library.unt.edu/ark:/67531/metadc130726/
 A Correction Factor for the First Born Approximation
 This thesis looks at a Schroedinger equation and the Born approximation. digital.library.unt.edu/ark:/67531/metadc130574/
 Application of the Wigner Formalism to a Slightly Relativistic Quantum Plasma
 A slightly relativistic fermion gas is described by the dynamical theory obtained from the Wigner distribution function. The problem is approached in a selfconsistent manner including the twobody Darwin Hamiltonian. The goal is to find the departures from equilibrium and dispersion relations for wave propagation in the gas. digital.library.unt.edu/ark:/67531/metadc130850/
 Quantized Hydrodynamics
 The object of this paper is to derive Landau's theory of quantized hydrodynamics from the manyparticle Schroedinger equation. Landau's results are obtained, together with an additional term in the Hamiltonian. digital.library.unt.edu/ark:/67531/metadc131535/
 Solutions of the Equations of Radiative Transfer by an Invariant Imbedding Approach
 This thesis is a study of the solutions of the equations of radiative transfer by an invariant imbedding approach. digital.library.unt.edu/ark:/67531/metadc131045/