Physical Sciences and Mathematics Commons^™

Biological Applications Of Extraordinary Electroconductance And Photovoltaic Effects In Inverse Extraordinary Optoconductance, Lauren C. Tran

Arts & Sciences Electronic Theses and Dissertations

The Extraordinary Electroconductance (EEC) sensor has been previously demonstrated to have an electric field sensitivity of 3.05V/cm in a mesoscopic-scale structure fabricated at the center of a parallel plate capacitor. In this thesis, we demonstrate the first successful application of EEC sensors as electrochemical detectors of protein binding and biological molecule concentration. Using the avidin derivative, captavidin, in complex with the vitamin biotin, the change in four-point measured resistance with fluid protein concentration of bare EEC sensors was shown to increase by a factor of four in the presence of biomolecular binding as compared to baseline. Calculations for approximate field …

Assessing Optic Neuritis In A Mouse Model Of Multiple Sclerosis With Diffusion Mr Imaging, Chia-Wen Chiang

Arts & Sciences Electronic Theses and Dissertations

Optic neuritis (ON) is an early manifestation in patients of multiple sclerosis (MS), typically resulting in visual dysfunction. The inflammatory demyelination of the optic nerve in ON closely resembles pathologies of the rest of central nervous system (CNS) white matter in MS. Since accumulated axonal degeneration in MS was considered as the potential cause leading to permanent disability, correlating optic nerve pathology and visual function in ON could be a model system to investigate the relationship between functional outcome and neuropathology. It may also present a new way to reflect the disease progression in MS. Various MR techniques have been …

Several Problems Concerning Multivariate Functions And Associated Operators, Kelly Ann Bickel

All Theses and Dissertations (ETDs)

This dissertation examines two distinct problems about multivariate functions and their associated operators. It first discusses the structure of Agler decompositions, which give useful ways to represent two-variable Schur functions on the bidisk using positive kernels. An elementary proof of the existence of Agler decompositions is provided, which uses special shift-invariant subspaces of the Hardy space. These shift-invariant subspaces are specific cases of Hilbert spaces that can be defined from Agler decompositions and their properties are analyzed. More specific results are obtained for certain classes of polynomials and rational inner functions.

Secondly, this dissertation examines differentiation of matrix-valued functions. Specifically, …

Molecular Design And Photophysical Characterization Of Synthetic Bacteriochlorins For Solar Energy Conversion And Photodynamic Therapy, Eunkyung Yang

All Theses and Dissertations (ETDs)

The design, photophysical characteristics and some potential applications of synthetic bacteriochlorins are discussed. Bacteriochlorins: e.g., bacteriochlorophylls) are tetrapyrrole macrocycles with two reduced pyrrole rings, whereas chlorins: e.g., chlorophylls) and porphyrins: e.g., hemes) have one and zero reduced pyrrole rings. Molecular design characteristics are revealed by understanding the effects of substituent types and patterns and the central metal ion on the photophysical properties and electronic structure. These effects are elucidated via studies of the optical absorption and emission spectra and excited-state decay pathways, and analysis of the molecular-orbital characteristics within the four-orbital model. The studies also encompass analysis of the properties …

Icy Satellite Tectonic, Geodynamic And Mass Wasting Surface Features: Constraints On Interior Processes And Evolution, Kelsi Nab Singer

All Theses and Dissertations (ETDs)

Empirical data collected from mapping campaigns combined with modeling of geologic processes improves our understanding of planetary geology. Many planet- or satellite-scale processes cannot be reproduced in labs, thus analyzing surface features provides insights to confirm, discount, or improve models. I present the methods used to map and characterize the morphometry of several types of geologic features found on three icy satellites of Jupiter and Saturn, and the resulting data. Trends in the data provide insight into feature formation, and to both surface and interior processes occurring in icy satellites. Topics include: i) linear features and despinning stresses on Iapetus, …

Limit Theorems For Random Billiard Models, Timothy Chumley

All Theses and Dissertations (ETDs)

The central objects of study in this dissertation are random billiard systems. These are Markov chain systems with general state spaces derived from deterministic billiard systems by selecting one or more dynamical variables and replacing them with random variables with fixed probability distributions. In particular, we study two specific model systems; one which models gas diffusion through cylindrical channels whose walls have a microscopic structure, and another which models a minimalistic heat engine. The main results for the gas diffusion model, a series of probabilistic limit theorems, allow us to express transport characteristics such as mean exit times of the …

High Pressure Studies Of Superconductivity, Narelle Jayne Hillier

All Theses and Dissertations (ETDs)

Superconductivity has been studied extensively since it was first discovered over 100 years ago. High pressure studies, in particular, have been vital in furthering our understanding of the superconducting state. Pressure allows researchers to enhance the properties of existing superconductors, to find new superconductors, and to test the validity of theoretical models. This thesis presents a series of high pressure measurements performed in both He-gas and diamond anvil cell systems on various superconductors and on materials in which pressure-induced superconductivity has been predicted. Under pressure the alkali metals undergo a radical departure from the nearly-free electron model. In Li this …

On The (Co)Homology Of Non-Commutative Toroidal Orbifold, Safdar Quddus

All Theses and Dissertations (ETDs)

Noncommutative torus algebra was studied in the early 80's as a fundamental example of noncommutative geometry. Connes calculated its cyclic and Hochschild cohomology. In this thesis, we study noncommutative toroidal orbifolds generated by actions of finite subgroups of S L(2,) on a noncommutative torus algebra.

In the first part, we calculate the Hochschild and cyclic homology of Γ for all finite subgroups Γ S L(2,). In the second part we analyse the cohomology of these algebras and compute the Chern-Connes pairing between the elements of and explicit cocycles discovered in our calculations. In the third part we discuss some …

Thermophysical And Structural Measurements Of Liquid Metallic Alloys Using Electrostatic Levitation, James Christopher Bendert

All Theses and Dissertations (ETDs)

In the study of the glass transition, the properties of high temperature liquids in their equilibrium and supercooled states may provide clues to the question of why certain compositions form glasses more easily than others. In metallic alloys such measurements are difficult due to the high reactivity and high melting temperatures of these liquids. Levitation methods provide a solution this problem by isolating liquid alloys from their environments. Here, the techniques of data acquisition and analysis for thermophysical property measurements under electrostatic levitation are presented, with demonstrative examples from select compositions from the Cu-Zr system. The development of techniques and …

Tracial Rokhlin Property And Non-Commutative Dimensions, Qingyun Wang

All Theses and Dissertations (ETDs)

This dissertation focuses on finite group actions with the tracial Rokhlin property and the structure of the corresponding crossed products. It consists of two major parts. For the first part, we study several different aspects of finite group actions with certain versions of the Rokhlin property. We are able to give an explicit characterization of product-type actions with the tracial Rokhlin property or strict Rokhlin property. We also show that, in good circumstances, the actions with the tracial Rokhlin property are generic.

In the second portion of this dissertation, we introduce the weak tracial Rokhlin property for actions on non-simple …

Energetics And Dynamics In Quantum Confined Semiconductor Nanostructures, Jessica Hoy

All Theses and Dissertations (ETDs)

The ability to tune the band-gap energies of semiconductor quantum dots, nanoplatelets, and quantum wires, their significant absorption cross sections, and high photoluminescence quantum yields make these nanostructures promising moieties for use in optoelectronic devices, solar concentrators, chemical sensors, and biological labels. The variable dynamics of the electron-hole pairs that occur within semiconductor nanostructures, however, can complicate the utility of these devices. The variability of the dynamics is born from the different paths accessible for the charge carriers to undergo. In this work, three pathways are proposed to be of primary consequence, namely, electronic intraband relaxation, coupling to surface-mediated processes, …

Actomyosin Contractility In Nonmuscle Cells, Nilushi Lakmali Dasanayake

All Theses and Dissertations (ETDs)

Forces and stresses generated by the action of myosin minifilaments are analyzed via simulation of their motion in idealized computer-generated random, isotropic actin networks and actin bundles. The networks and bundles are generated as random collections of actin filaments in two dimensions with constrained orientations, crosslinked and attached to fixed walls: four walls for isotropic networks, two for bundles). Myosin minifilaments are placed on actin filament pairs and allowed to move and deform the network so that it exerts forces on the walls.

The stresses are overwhelmingly contractile in both cases, because minifilament equilibrium positions having contractile stress have lower …

Determination Of Average Loss Lifetimes For Near‐Earth Electrons In Solar Storms, John Blears

Undergraduate Theses—Unrestricted

The rate of electron wave‐particle scattering in the near‐Earth magnetosphere is investigated using multiple simulations of solar storms from solar cycle 23 (1996‐2005). Simulations are created using the Hot Electron and Ion Drift Integrator (HEIDI) model, which analyzes the drifts of keV‐energy electrons through the inner magnetosphere and identifies the precipitation of these particles into the upper atmosphere. The loss lifetime formulation used by HEIDI, which represents the rate at which the keV‐energy of the electrons is extinguished, predicts unreasonably large loss lifetimes deep in the inner magnetosphere. This discrepancy between the values used by the HEIDI model and those …

Rapid, Efficient And Versatile Strategies For Functionally Sophisticated Polymers And Nanoparticles: Degradable Polyphosphoesters And Anisotropic Distribution Of Chemical Functionalities, Shiyi Zhang

All Theses and Dissertations (ETDs)

The overall emphasis of this dissertation research included two kinds of asymmetrically-functionalized nanoparticles with anisotropic distributions of chemical functionalities, three degradable polymers synthesized by organocatalyzed ring-opening polymerizations, and two polyphosphoester-based nanoparticle systems for various biomedical applications.

Inspired by the many hierarchical assembly processes that afford complex materials in Nature, the construction of asymmetrically-functionalized nanoparticles with efficient surface chemistries and the directional organization of those building blocks into complex structures have attracted much attention. The first method generated a Janus-faced polymer nanoparticle that presented two orthogonally click-reactive surface chemistries, thiol and azido. This robust method involved reactive functional group transfer by …

Aliquot Cycles For Elliptic Curves With Complex Multiplication, Thomas Morrell

Undergraduate Theses—Unrestricted

We review the history of elliptic curves and show that it is possible to form a group law using the points on an elliptic curve over some field L. We review various methods for computing the order of this group when L is finite, including the complex multiplication method. We then define and examine the properties of elliptic pairs, lists, and cycles, which are related to the notions of amicable pairs and aliquot cycles for elliptic curves, defined by Silverman and Stange. We then use the properties of elliptic pairs to prove that aliquot cycles of length greater than …

Use Of Self-Assembled Monolayers To Tailor Surface Properties: From Lubrication To Neuronal Development, Natalie Ann Lafranzo

All Theses and Dissertations (ETDs)

The subsequent work describes advances in modifying the chemical properties of various substrates to tailor the surface properties for specific applications. This is achieved by making use of a molecular assembly known as self-assembled monolayers, or SAMs. SAMs are composed of tightly packed organic molecules that form a well-ordered structure on a substrate. Typically, the head group of the monomer is covalently anchored to the substrate, and monolayer order and self-assembly is achieved through van der Waals interactions between the long alkyl chains of the monomer's tail group. Monolayers containing head groups consisting of thiols, siloxanes, and phosphonates have been …

Superfluidity In Neutron Stars, Samuel J. Witte

Undergraduate Theses—Unrestricted

Nucleon pairing is studied with specific considerations directed toward the possible influence on neutron star cooling. We present an in-depth analysis of BCS theory using realistic nuclear potentials and consider the impact short-range correlations can have on the gap. Gap calculations are incorporated into neutron star cooling simulations and the significance of the 3P2 −3F2 channel in various hadronic cooling models is closely examined. An analysis of the 1S0 gap in neutron matter suggests short-range correlations can drastically alter the magnitude, density range, and temperature dependence of the gap. While the newly constructed 1S0 gap does not significantly alter the …

Learning With Single View Co-Training And Marginalized Dropout, Minmin Chen

All Theses and Dissertations (ETDs)

The generalization properties of most existing machine learning techniques are predicated on the assumptions that 1) a sufficiently large quantity of training data is available; 2) the training and testing data come from some common distribution. Although these assumptions are often met in practice, there are also many scenarios in which training data from the relevant distribution is insufficient. We focus on making use of additional data, which is readily available or can be obtained easily but comes from a different distribution than the testing data, to aid learning.

We present five learning scenarios, depending on how the distribution we …

Effective 1d Language For Fractional Quantum Hall States, John Flavin

Arts & Sciences Electronic Theses and Dissertations

In the theory of the fractional quantum Hall effect, much attention is paid to the correspondence between fractional quantum Hall wave functions and conformal blocks in certain rational conformal field theories (CFT). This correspondence is powerful, enabling the calculation of the fractional statistics of a state that would be difficult if not impossible to calculate directly from the wave functions. But it is, in general, conjectural, remaining without microscopic justification in many cases of interest, and involves heavy mathematical machinery. We detail an alternative method to calculate Abelian and non-Abelian fractional statistics, the coherent state method. The method relies on …

Bayesian Bidimensional Regression And Its Extension, Haeri Lee

All Theses and Dissertations (ETDs)

No abstract provided.

Functional, Degradable Polyester Materials Synthesized From Poly(Epsilon-Caprolactone-Co-2-Oxepane-1,5-Dione): An Investigation Into The Derivatization, Self Assembly, And Degradation Behavior Of Poly(Epsilon-Caprolactone)-Based Materials, Rhiannon K. Iha

Arts & Sciences Electronic Theses and Dissertations

Biocompatible, degradable polymers possessing a high degree of complexity are an extremely desirable target for many applications. In order to further develop the range and utility of materials made from aliphatic polyesters, poly(epsilon-caprolactone-co-2-oxepane-1,5-dione) (P(CL-co-OPD)) was used as a polymeric precursor for the construction of a series of functional polyester-based materials. By taking advantage of the electrophilic ketone moieties characteristic of the OPD repeat unit, small molecule and polymer grafts were attached to the PCL backbone through the formation of both hydrazone and ketoxime ether linkages. This work has focused on both the synthesis and characterization of functional, degradable polyesters, including …

Discovery And Identification Of New Dna Photoproducts And Investigation Of The Redox Mechanism Of Human Apurinic/Apyrimidinic Endonuclease 1 (Hape1) Protein, Dian Su

All Theses and Dissertations (ETDs)

Exposure of cells to ultraviolet light results in the formation of DNA photoproducts, many of which have been linked to skin cancer. The majority of these photoproducts arise from a photoreaction between two pyrimidines. Irradiation of double stranded B form DNA under physiological conditions mainly produces adjacent dimers. Nonadjacent photodimers of both intrastrand and interstrand types are much rarer. Intrastrand-type nonadjacent dimers form when one or more nucleotides between two pyrimidines become extrahelical owing to the formation of single strand DNA or a slipped structure. This allows the two pyrimidines to photodimerize in a colinear arrangement, as if the intervening …

Hardy And Lipschitz Spaces On Unit Spheres, Leonardo Colzani

Arts & Sciences Electronic Theses and Dissertations

The main objective of this work is to develop a theory of Hardy spaces on the surface (SIGMA)(,N) of the unit ball B(,N+1) in (//R)('N+1), analogous to the maximal and atomic theory of Hardy spaces on (//R)('N), and to characterize the duals of these spaces as spaces of Lipschitz functions.