Physics Commons^™

Computational Exploration Of Vortex Nucleation In Type Ii Superconductors Using A Finite Element Method In Ginzburg-Landau Theory, Alden Roy Pack

Theses and Dissertations

Using a finite element method, we numerically solve the time-dependent Ginzburg-Landau equations of superconductivity to explore vortex nucleation in type II superconductors. We consider a cylindrical geometry and simulate the transition from a superconducting state to a mixed state. Using saddle-node bifurcation theory we evaluate the superheating field for a cylinder. We explore how surface roughness and thermal fluctuations influence vortex nucleation. This allows us to simulate material inhomogeneities that may lead to instabilities in superconducting resonant frequency cavities used in particle accelerators.

Computational Exploration Of Vortex Nucleation In Type Ii Superconductors Using A Finite Element Method In Ginzburg-Landau Theory, Alden Roy Pack

Theses and Dissertations

Using a finite element method, we numerically solve the time-dependent Ginzburg-Landau equations of superconductivity to explore vortex nucleation in type II superconductors. We consider a cylindrical geometry and simulate the transition from a superconducting state to a mixed state. Using saddle-node bifurcation theory we evaluate the superheating field for a cylinder. We explore how surface roughness and thermal fluctuations influence vortex nucleation. This allows us to simulate material inhomogeneities that may lead to instabilities in superconducting resonant frequency cavities used in particle accelerators.

Bare Aluminum Oxidation, R. Steven Turley

Faculty Publications

This paper computes the oxidation rate of bare evaporated aluminum thin films under high vacuum conditions and exposed to air.

Characterization Of Military Aircraft Jet Noise Using Wavepacket Analysis And Other Array Processing Methods, Blaine M. Harker

Theses and Dissertations

Sound generation and radiation properties are studied of full-scale tactical jet engine noise. This is motivated by the high sound exposure levels from jet noise, particularly for tactical engines. Acoustic source reconstruction methods are implemented computationally on existing jet noise data. A comparative study is performed using numerical simulations to understand the capabilities of more advanced beamforming methods to successfully estimate the source properties of a distributed, partially correlated source distribution. The properties and limitations of each beamforming method are described. Having validated the methods, beamforming with regularization”via the Hybrid Method”is implemented on linear array measurements near an installed tactical …

Characterization Of Military Aircraft Jet Noise Using Wavepacket Analysis And Other Array Processing Methods, Blaine M. Harker

Theses and Dissertations

Sound generation and radiation properties are studied of full-scale tactical jet engine noise. This is motivated by the high sound exposure levels from jet noise, particularly for tactical engines. Acoustic source reconstruction methods are implemented computationally on existing jet noise data. A comparative study is performed using numerical simulations to understand the capabilities of more advanced beamforming methods to successfully estimate the source properties of a distributed, partially correlated source distribution. The properties and limitations of each beamforming method are described. Having validated the methods, beamforming with regularization—via the Hybrid Method—is implemented on linear array measurements near an installed tactical …

An Exploration Of Crum’S And Algebraic Crum Detection, Shae Machlus, Branton Campbell

Student Works

1. The cooperative rigid unit modes (CRUM's) of cubic perovskite were investigated at non-special k-points using ISODISTORT and Shared Shifts Mathematica code. CRUM's were generated by the T₄ irrep on the T line which confirms previously published results.
2. The solution space of the MtM CRUM detection method was determined and compared to that of the M method. Analysis by example and by theory showed the solution spaces of both methods are identical. MtM was realized to be effectively M with a lower tolerance. An improved row reduction routine is being developed that uses an adaptable ratio-driven tolerance instead of …

Reflectance Of Xuv Light On A Two Dimensional Conducting Rough Surface, Chelsea Thangavelu

Student Works

A Fortran program is set up to solve for the reflectance of XUV light from a rough two dimensional surface, resembling experimental mirrors used to reflect XUV light. Because the roughness of the surface is on the order of magnitude of the wavelength of XUV light, our approach requires a Greene's Function instead of using traditional geometrical optics or physical optics. Our Fortran program calculates the impedance (Z) matrix which requires integration over Greene's Function at non-singular points. The Z matrix helps solve for the induced surface current J(x') at non-singular points. At singular points, the program implements a series …

Exploring The Solvability Of The Jaynes-Cummings And Jaynes-Cummings-Like Models: Implementing Quantum Control, Austen Couvertier

Student Works

In this paper we aim to explore the dynamics and overall solvability of the Jaynes-Cummings \& Jaynes-Cummings-Like models. As a lens to understand these dynamics, we focused on cases where the parameters of the system were made time-dependent. All previous work on solving the dynamics of the Jaynes-Cummings models has relied heavily on the use of differential methods and setting the parameters as time-independent constants which were zero or one. To account for this, we utilized the Wei-Norman method which allowed us to analytical solve the time-dependent Hamiltonian. Through the use of this method, we can understand the more general …

Developing A Location Detector Using Acoustical Energy Quantities, Jacey Young

Student Works

In this paper, development through the use of LabVIEW for an acoustical energy quantity detector is discussed. This detector uses the quantity of sound intensity to locate the direction of a sound source in three dimensional space with relation to the center of a spherical microphone probe placed directly under a web camera. The direction and the magnitude of the sound intensity are then used to generate an arrow pointing in the direction of the sound source and position it on top the web camera's image of the surrounding area. These quantities are then also used to highlight an area …

2d Surface Creation Using Intel Mkl, R. Steven Turley

Faculty Publications

This document illustrates how to use the Intel Math Kernel Library (MKL) to create surfaces with a given cut-off spatial frequency and rms surface height. They closely mimic typical surfaces our group has measured using atomic force microscopy (AFM).

Circular Integration Region, R. Steven Turley

Faculty Publications

This report explains how to transform a singular integration over the an arc of a circle into an integration over a unit square using various coordinate transformations include a Duffy transformation. Fortran code illustrating the algorithms is included along with unit test validations.

Using Page Method In The Two Point Method To Determine Sound Power, Christopher Reynolds

Student Works

Sound power is the energy emitted by a sound source per unit time. It is commonly used by industries to determine the noise (unwanted sound) of machinery. There are multiple recognized standards for determining the sound power of a source. The requirements for the ISO3741 standard are tedious and strict but can produce a low standard of deviation in the results. There is another method, the Two Point method, which less strict than the standards but the standard of deviation in the results vary. This paper discusses the performance of the PAGE method employed in the Two Point method to …

Magnetic Domain Morphology In [Co(4a)/Pt(7a] Thin Film, Jeremy Metzner

Student Works

A collection of results for multi-layered thin films and their magnetic domains.

Three Ways To Stabilize An Injection Lock, Ethan Welch, Dallin Durfee, Jarom Jackson

Student Works

An injection locked laser can jump out of lock if its current or temperature drifts. By monitoring the spectra or the amplitude of the injection locked laser, we have been able to detect drifts and apply feedback to prevent injection lock from breaking.

Using Frequency Noise Feedback To Satabilize Extended Cavity Diode Lasers For Use In Atomic Physics, Mckinley Pugh, Dallin Durfee

Journal of Undergraduate Research

Diode lasers in particular are useful in atomic physics because they are durable, compact, and relatively inexpensive. Unfortunately diode lasers also have linewidths that are much wider than atomic transitions. One common method to narrow the linewidth of diode lasers is to add a reflection grating outside the laser, creating an extended cavity diode laser (ECDL). While ECDLs are effective at narrowing the linewidth, they also introduce so many variables that affect the wavelength of the laser that small changes in the laser’s environment can cause the laser to mode hop, or jump to an entirely different wavelength.

Characterizing The Design Space Of Oscillatory Biological Networks, Leanne Lunsford, Denise Stephens, Eric Hintz

Journal of Undergraduate Research

Characterizing the relevant parameters of a design space in order to satisfy a specific behavior criterion is an important problem throughout all of science and engineering. In this project we proposed to apply model reduction to the case of biological oscillations involving Michaelis-Menten reactions. By removing irrelevant parameters from a fully connected network we were able to reduce a known problem in systems biology to a more general model. Furthermore, significant progress has been made in applying Manifold Boundary Approximation Method (MBAM) to oscillatory models in systems biology.

Fabrication Of Dye Sensitized Solar Cells Using Native And Non-Native Nanocrystals In Ferritin As The Dye, Alessandro Perego, John Colton

Journal of Undergraduate Research

Dye-sensitized solar cells (DSSCs) present a valuable and sustainable alternative to silicon solar cells. These cells present numerous advantages compered to inorganic photovoltaic systems, such as ability of absorb more sunlight per surface area than standard silicon-based solar panels, DSSCs are also able to work even in low-light conditions such as non-direct sunlight and cloudy skies. Finally, they are economical, easy to manufacture and constructed from abundant and stable resource materials. This makes DSSCs an attractive replacement for current photovoltaic technology. Ferritin (FTN) is a 12 nm diameter spherical protein with an 8 nm hollow interior, which naturally contains iron …

Reverse-Engineering Gene Networks That Can Remember Using The Manifold Boundary Approximation Method, Andrew White, Mark Transtrum

Journal of Undergraduate Research

Observable biological behaviors result from the interactions of microscopic elements, which form complex systems that we can model mathematically. Ideally, mechanistic models should predict a biological system’s behavior without misrepresenting the system’s biochemistry. The method of model reduction known as the Manifold Boundary Approximation Method (MBAM) [2, 3] can help us identify which parts of a model are relevant for explaining a particular behavior. This project applies MBAM to gene transcription networks that exhibit a behavior known as “memory,” the ability to retain cellular decisions to activate or silence genes. We hypothesize that MBAM can help us model the behaviors …