The ring disclination is a topological defect that may be suitable for light polarization inside of a nematic liquid crystal. Due to its stability and chirality, the ring disclination could also allow for theoretical applications to quantum and classical field theories as a model for fundamental particles. In order to...
Nuclear fusion reactors comprise a significant field of study due to their potential to provide a limitless, clean, and sustainable source of energy. The inertial electrostatic confinement fusor is a type of fusion-generating device that accelerates deuterium gas to the conditions required for fusion. The goal of this research was...
Nuclear fusion has the potential to meet the energy needs of our civilization for centuries to come and does not produce harmful greenhouse gasses or produce long-lasting radioactive waste. A fusion reaction can be readily demonstrated in a confinement scheme known as inertial electrostatic confinement (IEC) fusion. In this work,...
Semiconducting materials which can be ambipolarly doped are highly desirable in many electronics applications, including use as solar cell materials. SnZrS₃ is being investigated for the possibility of ambipolar doping, with potential applications as a solar cell absorber layer. This dissertation covers the synthesis of SnZrS₃ and the related compound...
In this work, we systematically explore the effectiveness of optical aberration correction over a wide range of optical depths using the Segmented and Zernike Polynomial bases. We manufacture a set of 16 optical phantom samples consisting of a clear polyester resin substrate embedded with varying concentrations of aluminum oxide (Al₂O₃)...
I examine the strong co-variability between the surface divergence and vorticity and how it varies with latitude in the Pacific Ocean using surface vector winds from reanalysis and satellite scatterometer observations. This analysis was motivated in part by a significant correlation between divergence and vorticity over the global oceans that...
This work demonstrates correlation of microwave signals encoded with 16-bit codes using the parametric interaction of spin waves. Signal processing correlators are devices that compare two signals, such as a reference code and a received code, where the output indicates the similarity between the signals. Correlators are used in communication...
This thesis presents the results from Monte Carlo calculations on classical vector spins in
face-centered-cubic (FCC) lattices. The goal of the study was to understand the effect of
interlayer coupling, dilution of magnetic atoms in the lattice, and symmetry-changing
strain.
Experimental work by T. M. Giebultowicz et al. and J....
In this thesis, I present studies in the field of terahertz [THz] spectroscopy. It covers both the generation and detection of ultra-fast broadband THz pulses, as well as the transmission properties of vertically grown multi-walled carbon nanotube forests [MWCNTs]. We have found that these vertically grown MWCNTs respond strongly to...
Resistive random access memory (RRAM) is a non-volatile memory technology based on resistive switching in a dielectric or semiconductor sandwiched between two different metals. Also known as memristors, these devices are potential candidates for a next-generation replacement for flash memory. In this thesis, bipolar resistive switching is reported for the...
A method for bandgap energy determination using di use re ection is presented and compared to the traditional integrating sphere method. We have found the bandgap energies of ZnO, TiO₂, Cu₂O, Si, SnZrS₃, SnZrSe₃, Sn₂S₃, and BiCuOSe powders with both methods and found they agree within 0.03 eV. We have...
This thesis describes the transport properties observed in thermally treated graphite oxide (GO), which holds promise as an economical route to obtaining graphene. Graphene is a material consisting of a single atomic plane of carbon atoms and was first isolated as recently as 2004. Several isolation techniques have been investigated,...
This research explores the viability and effectiveness of using an inertial navigation system (INS) to control a beamforming array of microstrip patch antennas with the aim of reducing users' exposure to electromagnetic radiation. The system reduces radiated power directed toward a cellular phone user to below 10% of the total...
Low energy design techniques for digital circuits are examined to determine their suitability for use in a digital logic controller for wireless sensor network nodes. Transistor level simulations are used to evaluate the techniques and those demonstrating an energy reduction are used to implement a digital logic controller. The digital...
Cell signaling under external stimulation is a critical mechanism that governs many biological processes such as cell proliferation, cell migration, and cell apoptosis, etc. For multicellular organisms, the ability to synchronize heterogeneous individual cellular responses through intercellular communication is crucial to maintain normal functionality. However, even though the biological pathways...
Physicists solve problems and communicate their work using many external representations, such as equations, words, diagrams, graphs, sketches, pictures, and more. To learn physics, then, students must learn to use external representations. In this dissertation, I present three manuscripts. Each manuscript discusses how upper-division Paradigms in Physics students use multiple...
We present a classical density functional to model the soft, repulsive potential of a Weeks-Chandler-Andersen (WCA) fluid using Soft Fundamental Measure Theory (SFMT) with temperature-dependent parameters inspired by the Barker-Henderson method. Our functional uses soft spheres to model the soft-sphere WCA potential, and gives results that are in good agreement...
Cell division, arguably the most important event during the life cycle of the eukaryotic cell, is achieved through a complicated yet beautiful machinery. The mitotic spindle — a microtubule-based bipolar structure—is the cellular machinery responsible for the correct segregation of the genetic material, chromosomes. The protein-based nanomachines termed molecular motors...
We use Classical Density Functional Theory (cDFT) to predict the freezing of a Weeks-Chandler-Anderson (WCA) fluid, and construct pressure-temperature and temperature-density phase diagrams. A WCA fluid consists of soft spheres that exhibit the repulsive portion of the Lennard-Jones potential widely used to model the interaction of two neutral atoms. Our...
The optical and electronic properties of amorphous oxide thin films depend crucially on chemical composition, and deposition process variations which give rise to sub-gap defect states. Consequently, there is a need for a reliable, high-throughput method to extract sub-gap defect densities of states in amorphous oxide thin films. We present...