Physical Sciences and Mathematics Commons^™

Atomic Force Microscope Conductivity Measurements Of Single Ferritin Molecules, Degao Xu

Theses and Dissertations

Conductive Atomic Force Microscope (c-AFM) was used to measure the conductivity of single horse spleen ferritin (HoSF) and azotobacter vinelandii bacterial ferritin (AvBF) molecules deposited on flat gold surfaces. A 500 micron diameter gold ball was also used as a contact probe to measure the conductivity of a thin film of ferritin molecules. The average current measured for holo HoSF was 13 and 5 times larger than that measured for apo HoSF as measured by c-AFM at 1V and gold ball at 2V and respectively, which indicates that the core of ferritin is more conductive than the protein shell and …

Geometric Acoustic Modeling Of The Lds Conference Center, Heather Smith

Theses and Dissertations

This thesis discusses the process of modeling a 21,000 seat fan-shaped auditorium using methods of geometric acoustics. Two commercial geometric acoustics software packages were used in the research: CATT-Acoustic™ 8.0 and EASE™ 4.1. The process first included creating preliminary models of the hall using published absorption coefficients for its surfaces and approximate scattering coefficients based on current best-known techniques. A detailed analysis determined the minimum numbers of rays needed in both packages to produce reliable results with these coefficient values. It was found that 100,000 rays were needed for CATT™ and 500,000 rays were needed for EASE™. Analysis was also …

Analysis And Comparison Of Three Acoustic Energy Density Probes, Lance Lester Locey

Theses and Dissertations

Traditional methods for the investigation of sound fields generally rely on a microphone to convert sound pressure into an electrical signal which can be recorded, displayed, and so forth. The squared sound pressure is directly related to potential energy density. Consequently, the measurement of sound pressure alone does not inherently provide insight into the total energy density of the sound field. Specifically, no information about the kinetic energy density of the sound field is available from this measurement alone. However, it is possible to use two microphones to estimate particle velocity. The squared particle velocity magnitude is directly related to …

On The Variability Of The Fine Structure Constant, Jason Lott Evans

Theses and Dissertations

This thesis addresses the issue of the time variability of the fine structure constant, alpha. Recent claims of a varying alpha are set against the established standards of quantum electrodynamical theory and experiments. A study of the feasibility of extracting data on the time dependence of alpha using particles in Penning traps is compared to the results obtained by existing methods, including those using astrophysical data and those obtained in atomic clock experiments. Suggestions are made on the nature of trapped particles and the trapping fields.

Patterning Polymer Thin Films: Lithographically Induced Self Assembly And Spinodal Dewetting, Regina C. Carns

Pomona Senior Theses

In an age in which the microchip is ubiquitous, the rewards for novel methods of microfabrification are great, and the vast possibilities of nanotechnology lie just a little ahead. Various methods of microlithography offer differing benefits, and even as older techniques such as optical lithography are being refined beyond what were once considered their upper limits of resolution, new techniques show great promise for going even further once they reach their technological maturity. Recent developments in optical lithography may allow it to break the 100-nm limit even without resorting to x-rays.

Neutron Star Electromagnetic Field Structure, Hugh O. Thurman Iii

Physics Theses & Dissertations

This dissertation investigates the neutron star magnetic field from generation to radiation production. We have investigated the spontaneous magnetization process to explain the magnetic field generation. This magnetization is then applied to determine the electromagnetic field structure of the neutron star. As an application of these two calculations, we briefly investigate several radiation mechanisms that are closely related to stellar magnetic fields.

Neutron star magnetic field generation is studied through the spontaneous magnetization process. This process was studied in the non-relativistic, ultra-relativistic, and rigorous relativistic dispersion regimes for the neutrons. Both analytical and numerical approaches show that a phase transition …

Active Minimization Of Acoustic Energy Density In A Mock Tractor Cab, Benjamin Mahonri Faber

Theses and Dissertations

An active noise control (ANC) system has been applied to the problem of attenuating low-frequency tonal noise inside small enclosures. The intended target application of the system was the reduction of the engine firing frequency inside heavy equipment cabins. The ANC system was based on a version of the filtered-x LMS adaptive algorithm, modified for the minimization of acoustic energy density (ED), rather than the more traditional minimization of squared acoustic pressure (SP). Three loudspeakers produced control signals within a mock cabin composed of a steel frame with plywood sides and a Plexiglas® front. An energy density sensor, capable of …

Derivation Of Moving-Coil Loudspeaker Parameters Using Plane Wave Tube Techniques, Brian Eric Anderson

Theses and Dissertations

Small-signal moving-coil loudspeaker driver parameters are traditionally derived through electrical impedance measurement techniques. These parameters are commonly called Thiele/Small parameters, after Neville Thiele and Richard Small who are credited with developing industry-standard loudspeaker modeling techniques. However, because loudspeaker drivers are electro-mechano-acoustical transducers, it should be possible to measure their parameters in physical domains other than the electrical domain. A method of measuring loudspeaker parameters from the acoustical domain will be developed. The technique uses a plane wave tube to measure acoustical properties of a baffled driver under test. Quantities such as the transmission loss through the driver are measured for …

Senior Thesis Work, Corey Jansen

Presidential Scholars Theses (1990 – 2006)

In closing, it is important to remember, as stated earlier, that no one can prove exactly what it was that the authors of Genesis were trying to get across to us. It is valid to note, however, that the stories they were trying to get across were intended for and more properly understood by the people at that time and place. While they form the basis of many of our beliefs in Christianity, they weren't written with the realization that thousands of years later there would be great scientific discoveries that would teach us more about the world and about …

Novel N-Body Orbits For Constrained Potentials Including The Unusual Figure Eight Three Body Orbit, Jan M. Dudzik

Masters Theses

Recently new n-body planar orbits have been discovered which are known as choreographies. These orbits correspond to small n, generally n<20, and exhibit unexpected patterns with respect to given initial conditions. Here we shall examine numerical solutions to the three-body problem and the restricted three-body problem for three body potentials that are the sum of three two-body potentials. Then for an everywhere attractive three body potential with non-collinear and collision-less orbits with a strictly monotone decreasing potential function there exist bound states that are not chaotic that are choreographies. For the right initial conditions these orbits can be mapped numerically and visualized. We will display a number of these cases corresponding to the three body problem, restricted three body problem, the chaotic restricted three body problem and the new figure eight bound state choreography for the Kazalov potential orbits to exhibit some of their special features and to take note of a number of open questions dealing with simple orbital problems.