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Department Library

2006

Stephanie Allred Magleby (Masters Thesis, March 2006, Advisor: William Evenson )

Abstract

This thesis investigates the violation of Bell’s Inequality through the use of nonlocal measurement schemes as encapsulated in a quasi-deterministic toy model. This toy model, called the Q Box, is reminiscent of Mermin’s Box in that it describes a system that appears to be deterministic yet produces the statistics of a quantum type system.1 [1] The workings of the Q Box are detailed both as a thought experiment and as a computer simulation. Nonlocal measurement protocols similar to those which generate a violation of Bell’s Inequality in the Q Box are also applied to Mermin’s Box, with comparable results.

2005

Michael Skeen (Honors Thesis, August 2005, Advisor: William Evenson )

Abstract

2004

Thomas Butler (Senior Thesis, June 2004, Advisor: William Evenson )

Abstract

n/a

2000

Alma Teao Wilson (PhD Dissertation, August 2000, Advisor: William Evenson )

Abstract

To a much greater degree than is ordinarily realized, Boolean logic shapes physics. Boolean logic models the ubiquitous and often implicit part/whole relations of physics. The present work introduces aggregatibility as an extraordinarily selective property of properties. Aggregatibility of a property requires that the values for the parts---any set of parts--- are sufficient information to compute mass, momentum, or parity of whole from the corresponding property evaluated on its parts, and all of these properties can always be embedded in Abelian groups in a way that respects disjoint union in the underlying Boolean algebra. As applications, we prepare an improved set of axioms for probability theory, we explain how entropy differs from aggregatible quantities, and we justify the limited use of dimensionally inhomogeneous physical quantities.

1998

Eric Scott Leishman (Honors Thesis, July 1998, Advisor: William Evenson )

Abstract

1995

Jun Lu (PhD Dissertation, August 1995, Advisor: William Evenson )

Abstract

Several new families of stochastic models of perturbed angular correlation (PAC) due to diffusion of defects in materials have been developed and studied, which include one-dimensional Z1Z2 models, two-dimensional XY(Nf) + S(Ns,θ,∅) models, three-dimensional XYZ(nt)d(ndθ,∅) models, and N-state+Z models, as defined in the text. The analytical perturbation functions for simultaneous static and rapidly fluctuating EFG’s are derived, and comparisons with other proposed stochastic models are given. Analytic perturbation functions can be used to fit experimental data in seconds compared to hours for a full eigen-calculation. The dependence of perturbation functions on the number of states N is discussed. Possible applications are also presented. These models can allow fitting PAC data over a wide range of temperatures and dopant concentrations in a physically meaningful way within the framework of a single model.

1994

Hui Guan (PhD Dissertation, August 1994, Advisor: William Evenson )

Abstract

Using Blume’s stochastic theory and the approach of Winkler and Gerdau, time-dependent effects on perturbed angular correlation (PAC) spectra due to defect motion in solids in the case of I=5/2 electric quadrupole interactions have been calculated. Detailed analysis of several models, namely, N-state+Z (N=3,4,6), XYZ+S(θ,∅), and XYZ(nf)+Z(ns) models are reported here. The influence on the perturbation function G2(t) of the number of fluctuating electric field gradient (EFG) states (N), the relative static EFG strength (y), the orientation of the symmetry axis of the static EFG versus the fluctuating EFG (θ,∅), and the asymmetry of the EFGs (NfNs) are studied. A large non-Hermitian complex matrix (Blume matrix, B) has been solved for each of the above models. It eigenvalues have real parts and imaginary parts corresponding to the damping factors and the frequencies in G2(t), respectively. Damping and static frequencies in G2(t) have been observed in both slow and rapid fluctuation regimes, i.e. suitable for the low and high temperature region, respectively. In the intermediate fluctuation regime, complex behaviors of the dampening factors and frequencies are observed due to the mixing of the fluctuating EFG states. Approximate forms are given for G2(t) in the slow and rapid fluctuation regimes which cover a wide range of temperatures and contain the most interesting physics. These expressions allow one to fit PAC data for a wide range of temperatures and dopant concentrations. An application of the 4-state symmetric model is illustrated with data from a PAC study of ceria.

1974

Martha Ridgway (Masters Thesis, August 1974, Advisor: William Evenson )

Abstract

We have investigated the effect that ferromagnetic domains have on the shape of the peaks in single-crystal neutron-diffraction patterns. We have assumed that the domains are randomly oriented and have used an averaging technique to determine the overall effect of the domain structure. We find the diffraction pattern to be a superposition of a sharp peak due to nuclear scattering and a broadened peak due to magnetic scattering. We apply this technique to ferromagnetic terbium as an example. This investigation, which can be easily extended to other kinds of domains, provides a new method for studying domain structures for small domain sizes which will improve the understanding of the properties of magnetic materials.

Gregory Leigh Warren (PhD Dissertation, January 1974, Advisor: William Evenson )

Abstract

A negative-slope melting curve was calculated for the elements silicon and germanium from first principles. Three adjustable parameters obtained from the theory were chosen to fit the calculated melting point and volumes to experiment at zero pressure resulting in a good fit of the theory to experiment for pressures up to ~25 kilobar. The metallic liquid state of these elements was described using the Mansoori-Canfield variational approach with a hard-sphere reference system. The solid state was described by a system consisting of interacting ions, covalent-bond charges, and electrons. A variational approach was also used to describe the solid state.