Physical Sciences and Mathematics Commons^™

Three-Photon Absorption Process In Organic Dyes Enhanced By Surface Plasmon Resonance, Ion Cohanoschi

Electronic Theses and Dissertations

Multi-photon absorption processes have received significant attention from the scientific community during the last decade, mainly because of their potential applications in optical limiting, data storage and biomedical fields. Perhaps, one of the most investigated processes studied so far has been two-photon absorption (2PA). These investigations have resulted in successful applications in all the fields mentioned above. However, 2PA present some limitations in the biomedical field when pumping at typical 2PA wavelengths. In order to overcome these limitations, three-photon absorption (3PA) process has been proposed. However, 3PA in organic molecules has a disadvantage, typical values of σ3' are small (10-81 …

Effects Of Atmospheric Turbulence On The Propagation Of Flattened Gaussian Optical Beams, Doris Cowan

Electronic Theses and Dissertations

In an attempt to mitigate the effects of the atmosphere on the coherence of an optical (laser) beam, interest has recently been shown in changing the beam shape to determine if a different power distribution at the transmitter will reduce the effects of the random fluctuations in the refractive index. Here, a model is developed for the field of a flattened Gaussian beam as it propagates through atmospheric turbulence, and the resulting effects upon the scintillation of the beam and upon beam wander are determined. A comparison of these results is made with the like effects on a standard TEM00 …

High Birefringence And Low Viscosity Liquid Crystals, Chien-Hui Wen

Electronic Theses and Dissertations

In this dissertation, liquid crystal (LC) materials and devices are investigated in order to meet the challenges for photonics and displays applications. We have studied three kinds of liquid crystal materials: positive dielectric anisotropic LCs, negative dielectric anisotropic LCs, and dual- frequency LCs. For the positive dielectric anisotropic LCs, we have developed some high birefringence isothiocyanato tolane LC compounds with birefringence ~0.4, and super high birefringence isothiocyanato biphenyl-bistolane LC compounds with birefringence as high as ~0.7. Moreover, we have studied the photostability of several high birefringence LC compounds, mixtures, and LC alignment layers in order to determine the failure mechanism …

Near-Infrared Observations Of Comet-Asteroid Transition Objects, Julie Elaine Ziffer

Electronic Theses and Dissertations

The primary objective of this research is to characterize the surface composition of five comet-asteroid transition objects via near-infrared spectroscopy. The five targets include two asteroids with Tisserand invariants lower than 3.0 (1373 Cincinnati and 2906 Caltech), one asteroid that is likely an extinct comet (944 Hidalgo), one intermittent activity comet (162P/Siding Spring), and one nearly dormant comet (28P/Neujmin1). Previous research regarding cometary end states and dynamical and physical properties of comets and asteroids provides the foundation for this work. Focusing primarily on the 1-2.5 µm spectral region of the five target objects, this project specifically searches for mineral species …

On The Use Of Gaussian Filter Functions For Adaptive Optics, Merfit Assad

Electronic Theses and Dissertations

For adaptive optic systems, the use of aperture filter functions calculated using various Zernike modes can be useful in removing lower-order aberrations caused by atmospheric turbulence. Traditionally, these filter functions are calculated using the step function depicting a hard aperture that introduces integrals that are sometimes difficult to integrate and must be done numerically. The Gaussian method can be used in place of the conventional method for calculating the aperture filter functions. Evaluation of the Gaussian approximation for modeling a finite receiver aperture can be made by comparison of reduction in phase variance with results achieved using the conventional method. …

Analytical Potential Of Polymerized Liposomes Bound To Lanthanide Ions For Qualitative And Quantitative Analysis Of Proteins, Marina Santos

Electronic Theses and Dissertations

One of the intriguing features of biological systems is the prevalence of highly selective and often very strong interactions among different cellular components. Such interactions play a variety of organizational, mechanical, and physiological roles at the cellular and organism levels. Antigen-antibody complexes are representative examples of highly selective and potent interactions involving proteins. The marked specificity of protein-antibody complexes have led to a wide range of applications in cellular and molecular biology related research. They have become an integral research tool in the present genomic and proteomic era. Unfortunately, the production of selective tools based on antigen-antibody interactions requires cumbersome …

Design And Optimization Of Nano-Optical Elements By Coupling Fabrication To Optical Behavior, Raymond Rumpf

Electronic Theses and Dissertations

Photonic crystals and nanophotonics have received a great deal of attention over the last decade, largely due to improved numerical modeling and advances in fabrication technologies. To this day, fabrication and optical behavior remain decoupled during the design phase and numerous assumptions are made about "perfect" geometry. As research moves from theory to real devices, predicting device behavior based on realistic geometry becomes critical. In this dissertation, a set of numerical tools was developed to model micro and nano fabrication processes. They were combined with equally capable tools to model optical performance of the simulated structures. Using these tools, it …

Predicting Surface Scatter Using A Linear Systems Formulation Of Non-Paraxial Scalar Diffraction, Andrey Krywonos

Electronic Theses and Dissertations

Scattering effects from rough surfaces are non-paraxial diffraction phenomena resulting from random phase variations in the reflected wavefront. The ability to predict these effects is important in a variety of applications including x-ray and EUV imaging, the design of stray light rejection systems, and reflection modeling for rendering realistic scenes and animations of physical objects in computer graphics. Rayleigh-Rice (small perturbation method) and Beckmann-Kirchoff (Kirchhoff approximation) theories are commonly used to predict surface scatter effects. In addition, Harvey and Shack developed a linear systems formulation of surface scatter phenomena in which the scattering behavior is characterized by a surface transfer …

Probing Random Media With Singular Waves, Chaim Schwartz

Electronic Theses and Dissertations

In recent years a resurgence of interest in wave singularities (of which optical vortices are a prominent example), light angular momentum and the relations between them has occurred. Many applications in various areas of linear and non-linear optics have been based on studying effects related to angular momentum and optical vortices. This dissertation examines the use of such wave singularities for studying the light propagation in highly inhomogeneous media and the relationship to angular momentum transfer. Angular momentum carried by light can be, in many cases, divided in two terms. The first one relates to the polarization of light and …

Quantitative High-Angle Annular Dark Field Scanning Transmission To Electron Microscopy For Materials Science, Rumyana Petrova

Electronic Theses and Dissertations

Scanning transmission electron microscopy (STEM) has been widely used for characterization of materials; to identify micro- and nano-structures within a sample and to analyze crystal and defect structures. High-angle annular dark field (HAADF) STEM imaging using atomic number (Z) contrast has proven capable of resolving atomic structures with better than 2 A lateral resolution. In this work, the HAADF STEM imaging mode is used in combination with multislice simulations. This combination is applied to the investigation of the temperature dependence of the intensity collected by the HAADF detector in silicon, and to convergent beam electron diffraction (CBED) to measure the …

Monitoring Pc Hardware Sounds In Linux Systems Using The Daubechies D4 Wavelet., Robert Karns Henry

Electronic Theses and Dissertations

Users of high availability (HA) computing require systems that run continuously, with little or no downtime. Modern PCs address HA needs by monitoring operating system parameters such as voltage, temperature, and hard drive status in order to anticipate possible system failure. However, one modality for PC monitoring that has been underutilized is sound. The application described here uses wavelet theory to analyze sounds produced by PC hard drives during standard operation. When twenty-nine hard drives were tested with the application and the results compared with the drives' Self-Monitoring, Analysis, and Reporting Technology (S.M.A.R.T.) data, the binomial distribution's low p-value of …

Rocket Powered Flight As A Perturbation To The Two-Body Problem., Clayton Jeremiah Clark

Electronic Theses and Dissertations

The two body problem and the rocket equation r̈ + ∊ α ṙ + k/r³r = 0 have been expressed in numerous ways. However, the combination of the rocket equation with the two-body problem has not been studied to any degree of depth due to the intractability of the resulting non-linear, non-homogeneous equations. The goal is to use perturbation techniques to approximate solutions to the combined two-body and rocket equations.

Extensions Of The Cayley-Hamilton Theorem With Applications To Elliptic Operators And Frames., Alberto Mokak Teguia

Electronic Theses and Dissertations

The Cayley-Hamilton Theorem is an important result in the study of linear transformations over finite dimensional vector spaces. In this thesis, we show that the Cayley-Hamilton Theorem can be extended to self-adjoint trace-class operators and to closed self-adjoint operators with trace-class resolvent over a separable Hilbert space. Applications of these results include calculating operators resolvents and finding the inverse of a frame operator.

The Interquartile Range: Theory And Estimation., Dewey Lonzo Whaley

Electronic Theses and Dissertations

The interquartile range (IQR) is used to describe the spread of a distribution. In an introductory statistics course, the IQR might be introduced as simply the “range within which the middle half of the data points lie.” In other words, it is the distance between the two quartiles, IQR = Q₃ - Q₁. We will compute the population IQR, the expected value, and the variance of the sample IQR for various continuous distributions. In addition, a bootstrap confidence interval for the population IQR will be evaluated.

Evaluating The Effectiveness Of A Company's Online Health And Safety Training Program By Assessing Its Employees Perceptions And Knowledge., Jo Nell Maynard Mullins

Electronic Theses and Dissertations

A cross-sectional study was conducted to evaluate a company’s online H & S training program. The ABC Company’s online 8-hr HAZWOPER refresher course is based on current OSHA standard topics required for certification and principles flexible to fit site- or task-specific situations and conditions.

An 18-question survey was used to evaluate employee perceptions of online training compared to traditional classroom training. Perceptions were compared by demographic variables (e.g. gender, position, race, age and longevity with the ABC Company), which suggested that only age had an influence on employee response. Fifty-five percent of the employees surveyed preferred online training as compared …

Cell Toxicology Study Of Rrr-Alpha-Tocopheryl Polyethylene Glycol 1000 Succinate (Tpgs)., Clarisse Sornsay Muenyi

Electronic Theses and Dissertations

This research focused on the cytotoxic properties of RRR-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) in transformed and cancerous cell lines. We used RAW264.7 macrophage and prostate cancer (LNCaP) cell lines in this study. TPGS caused cell death and decreased cell viability in a dose and time dependent manner. Cell death was evaluated fluorimetrically by employing the nucleic acid-binding fluorophore; propidium iodide. A colorimetric 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay was used to evaluate cell viability. Cell death can occur through necrosis or apoptosis. Our results suggested that TPGS triggered apoptotic cell death. Induction of apoptosis, as measured by caspase …

Cell Toxicity And Uptake Of Rrr-Alpha-Tocopheryl Polyethylene Glycol 1000 Succinate (Tpgs) By Various Cell Ines In Vitro., Christelle Komguem Kamga

Electronic Theses and Dissertations

This research focused on investigating and comparing the cytotoxicity and cellular uptake of RRR-alpha-tocopheryl polyethylene glycol succinate (TPGS, with that of alpha-tocopheryl succinate (α-TS). Both TPGS and α-TS are water-soluble forms of vitamin E with important clinical applications. Cytotoxicity assays with RAW 264.7 and LNCaP cells incubated overnight with TPGS or α-TS at concentrations ≥ 12.4 μM suggest that α-TS is more cytotoxic than TPGS. Macrophages were found to be more sensitive than LNCaP cells when treated with similar concentrations of α-TS. For both cell lines, most of the TPGS or α-TS taken up remained esterified after 24 hours. Our …

A Limit Theorem In Cryptography., Kevin Lynch

Electronic Theses and Dissertations

Cryptography is the study of encryptying and decrypting messages and deciphering encrypted messages when the code is unknown. We consider Λ_π(Δx, Δy) which is a count of how many ways a permutation satisfies a certain property. According to Hawkes and O'Connor, the distribution of Λ_π(Δx, Δy) tends to a Poisson distribution with parameter ½ as m → ∞ for all Δx,Δy ∈ (Z/qZ)^m - 0. We give a proof of this theorem using the Stein-Chen method: As q^{m …}

Bicyclic Mixed Triple Systems., Benkam Benedict Bobga

Electronic Theses and Dissertations

In the study of triple systems, one question faced is that of finding for what order a decomposition exists. We state and prove a necessary and sufficient condition for the existence of a bicyclic mixed triple system based on the three possible partial orientations of the 3-cycle with twice as many arcs as edges. We also explore the existence of rotational and reverse mixed triple systems. Our principal proof technique applied is the difference method. Finally, this work contains a result on packing of complete mixed graphs on v vertices, M_v, with isomorphic copies of two …

Potential Energy Surface Around The Tropylium Ion., Kenneth Wayne Bullins

Electronic Theses and Dissertations

The formation of the tropylium ion, C₇H₇⁺, in the mass spectrum of toluene is a chemical process that has been studied extensively in the past. The advances in computational power of personal computers have made the investigation of the pathway to form this ion and its subsequent decomposition feasible at a fairly high level of theory. The calculations that we performed were at the HF/6-31G (d, p) and the B3LYP/6-311++G (2d) levels. This work will show areas of the potential energy surface around the highly symmetric tropylium ion to give a glance of possible mechanisms …

Electrochemical Remedy And Analysis For The Environment Based On The New Polymer-Dna Composite Material., Noor Feuza Hussain

Electronic Theses and Dissertations

In this work a new material, the conducting polymer-DNA composite, has been reported for the first time due to its promise in micro extraction, transfer, and release of cations under controlled potential conditions by using electrochemically assisted solid phase micro extraction (SPME). The Polypyrrole/DNA composite can be formed easily by oxidation of pyrrole monomers in the presence of chromosomal DNA by electropolymerization. Environmental significant pollutants such as Cd, Pb, Hg, Co, Zn, Cu, and Bi metal ions can be extracted from the aqueous solution and are able to be transferred to another medium defined as the release solution where the …

Paired And Total Domination On The Queen's Graph., Paul Asa Burchett

Electronic Theses and Dissertations

The Queen’s domination problem has a long and rich history. The problem can be simply stated as: What is the minimum number of queens that can be placed on a chessboard so that all squares are attacked or occupied by a queen? The problem has been expanded to include not only the standard 8x8 board, but any rectangular m×n sized board. In this thesis, we consider both paired and total domination versions of this renowned problem.