Physical Sciences and Mathematics Commons^™

Geometry, Growth And Pattern Formation In Thin Elastic Structures, Salem Al-Mosleh

Doctoral Dissertations

Thin shells are abundant in nature and industry, from atomic to planetary scales. The mechanical behavior of a thin shell depends crucially on its geometry and embedding in 3 dimensions (3D). In fact, the behavior of extremely thin shells becomes scale independent and only depends on geometry. That is why the crumpling of graphene will have similarities to the crumpling of paper. In this thesis, we start by discussing the static behavior of thin shells, highlighting the role of asymptotic curves (curves with zero normal curvature) in determining the possible deformations and in controlling the folding patterns. In particular, we …

Indirect Imaging Using Computational Imaging Techniques, Aparna Viswanath

Electrical Engineering Theses and Dissertations

The work describes various methods employed towards solving the problem of indirect imaging. Computational techniques are employed to indirectly decipher information about an object hidden from view of a camera. Notion of virtualizing the source of illumination and detectors on real world rough surfaces was exploited to construct a non line of sight computational imager. Diversity was explored from the stand point of both illumination of the object and imaging of light reflected from the object. To understand the impact of scattering by real world rough surfaces, an instrument was developed that allows characterization of isoplanatic angle for different surface …

Using Strong Laser Fields To Produce Antihydrogen Ions, Christopher Michael Keating

Dissertations and Theses

We provide estimates of both cross section and rate for the stimulated attachment of a second positron into the (1s^{2 1}S^e) state of the H+ ion using Ohmura and Ohmura's (1960 Phys. Rev. 118 154) effective range theory, Reiss's strong field approximation (1980 Phys. Rev. A 22, 1786), and the principle of detailed balancing. Our motivation for producing H+ ion include its potential to be used as an intermediate state in bringing antihydrogen to ultra-cold (sub-mK) temperatures required for a variety of studies, which include both spectroscopy and the probing of the gravitational interaction of …

Three Dimensional Passive Localization For Single Path Arrival With Unknown Starting Conditions, Britt Aguda

University of New Orleans Theses and Dissertations

Introduced in this paper is the time difference of arrival (TDoA) conic approximation method (TCAM), a technique for passive localization in three dimensions with unknown starting conditions. The TDoA of a mutually detected signal across pairs of detectors is used to calculate the relative angle between the signal source and the center point of the separation between the detectors in the pair. The relative angle is calculated from the TDoA using a mathematical model called the TDoA approximation of the zenith angle (TAZA). The TAZA angle defines the opening angle of a conic region of probability that contains the signal …

Granular Convection And Crystallization Of A Two-Dimensional Granular Medium, Donley S. Cormode

Honors Projects

Granular media are everywhere from beaches to factories to your kitchen cabinets. There are a rich array of phenomena to study with granular media. These include granular convection, jamming, and crystallization. The systems tend to be macroscopic, so it is easy to collect data. The supplies are low-cost and easy to obtain. Studying granular media gives researchers the opportunity to explore foundational ideas in fields such as crystallography and condensed matter. This paper describes a simple, low cost apparatus used to study a vertically shaken two-dimensional granular medium of glass beads. This paper will also describe a few preliminary studies …

An Analysis Of Frenkel Defects And Backgrounds Modeling For Supercdms Dark Matter Searches, Matthew Stein

Physics Theses and Dissertations

Years of astrophysical observations suggest that dark matter comprises more than ~80 % of all matter in the universe. Particle physics theories favor a weakly-interacting particle that could be directly detected in terrestrial experiments. The Super Cryogenic Dark Matter Search (SuperCDMS) Collaboration operates world-leading experiments to directly detect dark matter interacting with ordinary matter. The SuperCDMS Soudan experiment searched for weakly interacting massive particles (WIMPs) via their elastic-scattering interactions with nuclei in low-temperature germanium detectors.

During the operation of the SuperCDMS Soudan experiment, ²¹⁰Pb sources were installed to study background rejection of the Ge detectors. Data from these sources …

The Impact Of Ppb W/Z Lhc Data On Ncteq15 Parton Distribution Functions With An Emphasis On Refitting The Ncteq15 Npdf Set, Eric Godat

Physics Theses and Dissertations

As the LHC experiments increase their statistics and reduce their systematics, it is in- creasingly important to reduce the theoretical uncertainties so we can perform precision com- parisons. The parton distribution functions (PDFs) which describe the hadronic structure of protons and nuclei are the critical link between the experimental data and the proposed theoretical models; hence, a better understanding of the PDFs is essential for improved pre- dictions. Nuclear PDFs, in particular, have proven valuable in this regard, especially for flavor differentiation. I introduce ”nCTEQ+LHC,” the first PDF set fit using the nCTEQ formalism to include data from the LHC. …

Investigating Student Understanding Of Vector Calculus In Upper-Division Electricity And Magnetism: Construction And Determination Of Differential Element In Non-Cartesian Coordinate Systems, Benjamin Schermerhorn

Electronic Theses and Dissertations

Differential length, area, and volume elements appear ubiquitously over the course of upper-division electricity and magnetism (E&M), used to sum the effects of or determine expressions for electric or magnetic fields. Given the plethora of tasks with spherical and cylindrical symmetry, non-Cartesian coordinates are commonly used, which include scaling factors as coefficients for the differential terms to account for the curvature of space. Furthermore, the application to vector fields means differential lengths and areas are vector quantities. So far, little of the education research in E&M has explored student understanding and construction of the non-Cartesian differential elements used in applications …

On The Quantization Of Plane Gravitational Waves In Loop Quantum Gravity, Elise Lepage '18

Physics Theses

Gravitational waves are oscillations in the geometry of spacetime caused by the movement of mass or energy. In loop quantum gravity, geometry is quantized so spatial quantities such as area and volume take on discrete values. We worked on quantizing plane gravitational waves, which propagate in one direction and have uniform wavefronts perpendicular to the direction of travel, using the method of canonical quantization on general relativity.

For canonical quantization, a theory is expressed in terms of its canonical variables and constraints on those variables, then the variables and constraints are taken to quantum operators and the states of the …

A Human Powered Micro-Generator For Charging Electronic Devices, John Adam

Senior Theses

A hand-pulled generator has been designed and tested. A preliminary result has been obtained and discussed. This device was created to provide outlet-free charging. Electronic devices are useful when going out into the wilderness. A portable power supply is necessary to keep an electronic device alive. This project created a device that converts human energy into electricity to charge electronic devices. This thesis overviews the device’s design, build, and tests. Two different tests were run to determine that the device is capable of charging the storage battery. The device presented can provide 14 minutes of charging time with one hour …

Increasing The Longevity Of Tungsten Filaments In A Zone Refiner, Byron D. Greenlee

Senior Theses

Zone refining is used for its ability to purify material and grow single crystals. To produce these single crystals, a suspended molten zone, generated by electron bombardment, passes along the polycrystalline stock. During a zone refining run, the filaments that produce the electron bombardment can fail. In this project, the longevity of tungsten filaments in a zone refiner was investigated. A new bombardment geometry was constructed to attempt to increase the longevity of the filaments. The new geometry had a shield machined into it to prevent line-of-sight impurities originating in the molten zone from striking the filaments. It was found …

Effects Of Tension On Resonant Frequencies Of Strings, Blake Burnett

Senior Theses

This project tests and explores resonance of strings. Since all materials and mechanisms are affected by vibrations, it is important to know the frequencies at which resonance occurs. To explore this subject, strings were used as a model material to test the effect tension has on resonance. The fundamental frequencies and the corresponding modes of resonance were used to analyze the data. The results of this experiment show that increasing tension on a string increases its resonance frequency. Understanding the physics behind resonance frequency allows systems to be designed to take advantage of resonance properties, or to avoid resonance where …

The Effects Of Surface Pace In Baseball, Jason Farlow

Senior Theses

A baseball travels across different surfaces at different paces. The goal of this experiment is to find a percentage difference in speeds the ball will reflect off a given surface. The energy lost on the turf surface was far more significant than on dirt surface as the turf lost an average of 26% of its energy as compared to just 16% of the energy on dirt. In the Northwest conference, teams play on four turf-based infields and five dirt-based infields. The results of this study suggest that kinetic friction forces are more significant in reducing ball rebound speed than in …

Thermoelectrics And Thermoelectric Devices, Benjamin T. Erck

Senior Theses

The field of thermoelectrics has many applications, and more are found in everyday systems. From its current studies, it is apparent that improving the figure of merit zT (which defines a good thermoelectric material) is important in the effectiveness of power generation. Another important part of thermoelectrics is the duality of these devices. They can both move heat and generate power, depending on their role in the system. In this thesis research, a process was made to test these thermoelectric relationships for a few Peltier devices in order to understand their efficiencies and what systems they can be applied to.

Measuring The Double Layer Capacitance Of Electrolytes With Varied Concentrations, Geoffrey Rath

Senior Theses

When electric potentials are applied from an electrolytic fluid to a metal, a double layer capacitor, C_dl, develops at the interface. The layer directly at the interface is called the Stern layer and has a thickness equal to roughly the size of the ions in the fluid. The next layer, the diffuse layer, arises from the gathering of like charges in the Stern layer. This layer is the distance needed for ionic charges to return to equilibrium. This distance, called the Debye length, λ, depends on the square root of the electrolyte concentration. To study the properties of …

The Drag Coefficient Of Varying Dimple Patterns, James M. Seeley, Michael S. Crosser

Senior Theses

There are many golf balls on the market today with varying dimple sizes, shapes, and distribution. These proprietary differences are all designed to reduce drag on the balls during flight, allowing golfers to hit the ball farther distances. There are limited published studies comparing how varying the dimples affects the reduction of drag. An experiment was developed in which golf balls were pulled through a water tank to measure the drag force acting on each ball. The water was chosen to allow for testing at slower velocities than the typical necessary speeds to cause turbulence for balls traveling in air. …

The Computational Study Of Fly Swarms & Complexity, Austin Bebee

Senior Theses

A system is considered complex if it is composed of individual parts that abide by their own set of rules, while the system, as a whole, will produce non-deterministic properties. This prevents the behavior of such systems from being accurately predicted. The motivation for studying complexity spurs from the fact that it is a fundamental aspect of innumerable systems. Among complex systems, fly swarms are relatively simple, but even so they are still not well understood. In this research, several computational models were developed to assist with the understanding of fly swarms. These models were primarily analyzed by using the …

Echoes Of The Past: The Effect Of Background Experience On Far Transfer, Graham H. Hummel-Hall

Electronic Theses and Dissertations

Far transfer is the application of knowledge learned in one setting to a problem in a very different setting. This multi-method study looked at far transfer in humans and whether it could be facilitated, inhibited, or remain unaffected by the number of courses or years a student at a university spent learning about the subject matter of the knowledge being transferred. Through quantitative and qualitative analysis of pretest and post-test data from an introductory undergraduate earth science course, I found that students with more physical science background experience more frequently engaged in successful and accurate transfer of physics information to …

Experimentally Investigating Water Aerosol Formation Via Alpha Radiation In A Humid Nitrogen Atmosphere, Megan Payne

Honors Theses

This project aims to verify the formation of water aerosols induced by an ionizing radiation source in a Nitrogen atmosphere with various levels of humidity. This work is part of an effort to characterize the overall signature of ionizing radiation in Earth’s typical atmosphere. By signature, it is meant all the chemical reactions and physical processes that take place between Earth’s atmosphere and the ionizing radiation. This signature can potentially be used to identify a radiation source out in the field. The identification of a radiation source could potentially be used in a variety of defense applications. To characterize this …

Cosmological Distance Measurements With Rotse Supernovae Iip And Observational Systematics On Desi Emission Line Galaxy Clustering, Govinda Dhungana

Physics Theses and Dissertations

Both Supernovae (SNe) and Baryon Acoustic Oscillations (BAO) surveys emerged as complementary probes of the expansion history of the universe in the last few decades. SNe Ia cosmology has reached the systematic limits in the optical surveys. The most frequently occuring SNe Type IIP are emerging as equally rich distance probes for the next generation larger surveys. In this thesis, I highlight the astrophysical observables of these events in the context of ROTSE III SN survey and using the ROTSE SNe IIP sample, I present calibration in the framework of expanding photosphere method (EPM) to use them as cosmological distance …

Efficient Quantum Approximation : Examining The Efficiency Of Select Universal Gate Sets In Approximating 1-Qubit Quantum Gates., Brent A. Mode

College of Arts & Sciences Senior Honors Theses

Quantum computation is of current ubiquitous interest in physics, computer science, and the public interest. In the not-so-distant future, quantum computers will be relatively common pieces of research equipment. Eventually, one can expect an actively quantum computer to be a common feature of life. In this work, I study the approximation efficiency of several common universal quantum gate sets at short sequence lengths using an implementation of the Solovay-Kitaev algorithm. I begin by developing from almost nothing the relevant formal mathematics to rigorously describe what one means by the terms universal gate set and covering efficiency. I then describe some …

The Pope's Rhinoceros And Quantum Mechanics, Michael Gulas

Honors Projects

In this project, I unravel various mathematical milestones and relate them to the human experience. I show and explain the solution to the Tautochrone, a popular variation on the Brachistochrone, which details a major battle between Leibniz and Newton for the title of inventor of Calculus. One way to solve the Tautochrone is using Laplace Transforms; in this project I expound on common functions that get transformed and how those can be used to solve the Tautochrone. I then connect the solution of the Tautochrone to clock making. From this understanding of clocks, I examine mankind’s understanding of time and …

Examining The Response Of The Martian Atmosphere To Increases In Different Portions Of The Electromagnetic Spectrum During Solar Flares, Bradley R. Kumm

Master's Theses and Doctoral Dissertations

This report describes the methods used to examine how the Martian atmosphere responds to increases in different portions of the electromagnetic spectrum during solar flares. On March 24, 2015 the Mars Atmosphere and Volatile Evolution (MAVEN) mission satellite made measurements of the atmosphere and solar irradiance during a solar flare. These measurements were used by the Flare Irradiance Spectral Model (FISM) to generate solar flux values for 59 wavelength bins describing flare event. The solar flux values at different wavelength bins were scaled by different amounts and input into the Mars Global Ionosphere Thermosphere Model (M-GITM) to create 16 distinct …

Understanding, Designing And Building A Hydroelectric Generator, Nicholas Weare Shenberger

Senior Projects Spring 2018

When you hear the word hydropower you automatically jump to using water in order to create power or electricity. However, delving deeper and trying to understand the technology involved in it becomes quite a lot more complicated. To try to comprehend some of the knowledge of how to convert the power of water into electricity, I decided to design and build my own hydroelectric generator. I took the time to research and discover more about the process of building a generator and the specific pieces that come together in order to build one specifically powered by water. After my research, …

Applied Temperament, Geoffrey D. Hershberger

Theses and Dissertations--Music

The following document was created in order to promote intonation consensus in ensembles and to better facilitate learning in educational settings. Non-keyboard instruments provide musicians an opportunity to make nearly infinitesimal adjustments to pitch while performing; this creates difficulties for students and challenges even the most seasoned professionals. Non-keyboard musicians struggle their whole lives to play in tune, and even when one knows exactly where they want to place a pitch, technical difficulties can foul any musician's performance. When performing solo, the musician must choose a tuning system that is suitable for the music being performed, and attempt to realize …

Establishing A Quality Assurance Routine For Digital Imaging, Sulaiman Rana Al

Browse all Theses and Dissertations

In the clinical medical physics field, Quality Assurance (QA) is a fundamental topic to insure patient safety and effective treatment. In recent years, the imaging hardware for diagnostic x-rays has been shifting to fully digital detectors. However, the quality assurance tests for such detectors in the clinical setting is still under development. In the Medical Imaging Department of Kettering Hospital (Kettering, OH), the currently accepted method of performing QA on detectors is to use an extensive set of tests suggested by the manufacturer. This set of tests requires about 90 minutes, which is too long for daily use. The goal …

Two Stream Instability In Graphene, Mitchell Duffer

Williams Honors College, Honors Research Projects

Mitchell Duffer

Major: Physics

Project Sponsor: Ben Yu-Kuang Hu

Number of Project Credits: 2

Two Stream Instability in Graphene

We investigate the unstable modes of the two-stream instability in graphene to determine if they can occur. This instability occurs when a population of electrons streams past another inside graphene. We obtain the unstable modes by numerically determining the zeros of the non-equilibrium graphene dielectric function using MATLAB. The dielectric function used in this study, in contrast to previous studies, includes the effects of the particle-hole excitation continuum (PHEC) that normally quells the evolution of unstable plasmons. MATLAB’s built in zero …

Quantifying Effects Of Using Thermally Thin Fuel Approximations On Modelling Fire Propagation In Woody Fuels, David Blasen, Jesse Johnson, William Jolly, Russell Parsons

Graduate Student Theses, Dissertations, & Professional Papers

In this paper, we quantify the effects of the thermally thin fuel approximations commonly made in numerical models that eliminate temperature gradients within a heated object. This assumption is known to affect the modeled ignition and burn behavior, but there is little research on its impact, particularly in larger fuels or in numerical models including moisture and chemical decomposition of fuels.

We begin by comparing modeled to observed ignition times and burn rates. To constrain variability in the material properties of wood and focus on variability caused by fuels assumed to be thermally thin, we conduct experiments using thermogravimetric analysis …