Other Physics Commons^™

A Simple And Inexpensive Optical Technique To Help Students Visualize Mode Shapes, Thomas R. Moore, Ashley E. Cannaday, Sarah A. Zietlow

Student-Faculty Collaborative Research Publications

An imaging technique is introduced that is suitable for visualizing the mode shapes of vibrating structures in an educational setting. The method produces images similar to those obtained using electronic speckle pattern interferometry (ESPI) but it can be implemented for less than 1=10 the cost of a commercial ESPI system, and the apparatus is simple enough that it can be constructed by undergraduate students. This technique allows for real-time visualization of the normal modes and detection shapes of harmonically vibrating structures, including those with shapes that make generating Chladni patterns with sand or powder impossible. The theory of operation and …

Normal Modes Of The Indian Elephant Bell, Robert Perrin, Luke Chalmers, Daniel Elford, Gerry M. Swallowe, Thomas R. Moore

Faculty Publications

The geometrical structure of the Indian elephant bell is presented and the requirements on its normal modes from group representation theory are described. These are in good agreement with the results of a finiteelement model (FEM) for a specific 16-tine case. The spectrum consists of a sequence of families of modes lying on saturation curves and so is completely different from those of conventional bells. Physical explanations for the occurrence of these families are presented in terms of the tines behaving as a closed loop of coupled cantilevers with constraints from the dome. Each family is found to consist of …

Review Of Ultrasound Elastography Quality Control And Training Test Phantoms, S. Cournane, Andrew Fagan, Jacinta Browne

Articles

While the rapid development of ultrasound elastography techniques in recent decades has sparked its prompt implementation in the clinical setting adding new diagnostic information to conventional imaging techniques, questions still remain as to its full potential and efficacy in the hospital environment. A limited number of technical studies have objectively assessed the full capabilities of the different elastography approaches, perhaps due, in part, to the scarcity of suitable tissue-mimicking materials and appropriately designed phantoms available. Few commercially-available elastography phantoms possess the necessary test target characteristics or mechanical properties observed clinically, or indeed reflect the lesion-to-background elasticity ratio encountered during clinical …

Terahertz Wireless Communication, Ke Su

Dissertations

The goal of this thesis is to explore Terahertz (THz) wireless communication technology. More specifically the objective is to develop and characterize several THz communication systems and study the effect of atmosphere propagation through fog droplets and dust particles on THz communications.

For demonstration, a THz continuous wave (CW) photomixing system is designed. Terahertz signals are phase encoded with both analog ramp signals and pseudorandom binary data, transmitted over a short distance, and detected. The limitation of transmission bandwidth, low single to noise ratio, vibration effects are also analyzed. In order to study and compare propagation features of THz links …

Non-Destructive Evaluation Of Agglomerated Cork Products Using Thz Spectroscopy And Imaging, Han Zhang

Theses

Terahertz spectroscopy from 0.15 to 0.3 THz is used to classify agglomerated cork products. Position dependent scattering of radiation allows one to image the internal structure of cork products. Previous studies have focused on natural (solid) cork stoppers. In this study, the feasibility of classifying agglomerated cork structures using THz imaging and spectroscopy is investigated. Both THz images and spectra are used to classify the agglomerated cork samples. Classification of the samples used three methods: visible examination of the THz images, statistical analysis of the pixel intensities, and a polynomial regression of the THz spectral data averaged over all pixels. …

Qpced2.0: A Computer Program For The Processing And Quantification Of Polycrystalline Electron Diffraction Patterns, Xingzhong Li

Nebraska Center for Materials and Nanoscience: Faculty Publications

The processing and quantification of electron diffraction patterns have become vital in advanced electron crystallographic analysis work. A computer program, QPCED2.0, has been developed for the handling of selected-area electron diffraction patterns for polycrystalline materials. QPCED2.0 can be used to enhance the visibility of electron diffraction patterns, to convert electron diffraction patterns into intensity profiles, and to retrieve precisely the lattice d spacings and the integral intensities of the diffraction rings. The design and implementation of QPCED2.0 are elucidated and application examples are given.

"The Objective Of This Experiment Is To Try To Reach A Coupling Efficiency Of 1% Through A Small Pinhole, Using An Led As A Source...", Gregory E. Drubka

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Response To Griffiths, Matthew S. Leifer

Mathematics, Physics, and Computer Science Faculty Articles and Research

"First of all, I would like to thank Prof. Griffith for his comments. The exchange has reminded me of the series of letters that appeared in Physics Today following the publication of an article by Chandralekha Singh, Mario Belloni, and Wolfgang Christian on improving the teaching of undergraduate quantum mechanics (see http://ptonline.aip.org/ journals/doc/PHTOAD-ft/vol_60/iss_3/8_1.shtml). In those responses, both Griffiths and Travis Norsen argued that students’ understanding of quantum mechanics would be vastly improved if they were taught more about the foundations of quantum theory, and I wholeheartedly agree with that sentiment. The thing is, Griffiths argued vociferously that this should be …

A Locking-Free Hp Dpg Method For Linear Elasticity With Symmetric Stresses, Jamie Bramwell, Leszek Demkowicz, Jay Gopalakrishnan, Weifeng Qiu

Mathematics and Statistics Faculty Publications and Presentations

We present two new methods for linear elasticity that simultaneously yield stress and displacement approximations of optimal accuracy in both the mesh size h and polynomial degree p. This is achieved within the recently developed discontinuous Petrov- Galerkin (DPG) framework. In this framework, both the stress and the displacement ap- proximations are discontinuous across element interfaces. We study locking-free convergence properties and the interrelationships between the two DPG methods.

Question 1: Google And Pac-Man; Question 2: Magnetic Levitation, Larry Weinstein

Physics Faculty Publications

On the 30th anniversary of the introduction of the video game Pac-Man, Google created a miniature version of the game and placed it as its logo on its home page. How much total time was wasted in the United States playing this game?

(Thanks to Daniel Drill of Old Dominion University for suggesting the question.)

Animal tissue is diamagnetic. How large a magnetic field gradient is needed to levitate frogs or people?

Create A Matlab Simulation Of Laser Pulses Propagating Through Optical Fibers While Being Affected By Dispersion And Non-Linear Effects Using The Ssprop As A Foundation, Trevor Werline

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Review Of The Mathematical Language Of Quantum Theory: From Uncertainty To Entanglement, Matthew S. Leifer

Mathematics, Physics, and Computer Science Faculty Articles and Research

A book review of The Mathematical Language of Quantum Theory: From Uncertainty to Entanglement by Teiko Heinosaari and Mario Ziman.

Transverse Measurements Of Polarization In Optically Pumped Rb Vapor Cells, J. M. Dreiling, E. B. Norrgard, D. Tupa, Timothy J. Gay

Timothy J. Gay Publications

We have developed a simple heuristic method for determining the polarization of an optically pumped alkalimetal vapor. A linearly polarized probe beam traverses a vapor cell perpendicular to the pump-beam propagation direction, and the transmitted beam intensity is monitored for orthogonal linear polarizations. As the probe beam is scanned in frequency across the D₁ transition, its linear-polarization-dependent transmission can be used as a measure of the atomic orientation of the vapor. We analyze these transmission differences and their dependence on the alkali-metal number density in the vapor.

Pbr, Epr, And All That Jazz, Matthew S. Leifer

Mathematics, Physics, and Computer Science Faculty Articles and Research

"In the past couple of months, the quantum foundations world has been abuzz about a new preprint entitled "The Quantum State Cannot be Interpreted Statistically" by Matt Pusey, Jon Barrett and Terry Rudolph (henceforth known as PBR). Since I wrote a blog post explaining the result, I have been inundated with more correspondence from scientists and more requests for comment from science journalists than at any other point in my career. Reaction to the result amongst quantum researchers has been mixed, with many people reacting negatively to the title, which can be misinterpreted as an attack on the Born rule. …

Review Of Elegance And Enigma: The Quantum Interviews, Matthew S. Leifer

Mathematics, Physics, and Computer Science Faculty Articles and Research

A review of Elegance and Enigma: The Quantum Interviews, edited by Maximilian Schlosshauer.

Fast Super-Resolution With Affine Motion Using An Adaptive Wiener Filter And Its Application To Airborne Imaging, Russell C. Hardie, Kenneth J. Barnard, Raúl Ordóñez

Electrical and Computer Engineering Faculty Publications

Fast nonuniform interpolation based super-resolution (SR) has traditionally been limited to applications with translational interframe motion. This is in part because such methods are based on an underlying assumption that the warping and blurring components in the observation model commute. For translational motion this is the case, but it is not true in general. This presents a problem for applications such as airborne imaging where translation may be insufficient. Here we present a new Fourier domain analysis to show that, for many image systems, an affine warping model with limited zoom and shear approximately commutes with the point spread function …

The Singular Perturbation In The Analysis Of Mode I Fracture Based Upon A New Multiscale Theory, Kai-Bin Fu

Applications and Applied Mathematics: An International Journal (AAM)

A theory of fracture is presented that is based upon an extension of continuum mechanics to the nanoscale fracture through the incorporation of long-range intermolecular forces which correct bulk material descriptions near interfaces. To be consistent with the literature, constant surface energies are assigned to interfaces. In the analysis of mode I fracture for quasi-brittle material, it is observed that the incorporation of these long-range intermolecular forces predicts sharp fracture tip rather than blunt and avoids stress singularity. The details of the singular perturbation employed in this analysis are also presented.

Reflection Of Waves In Transversely Isotropic Thermoelastic Solid, Raj R. Gupta

Applications and Applied Mathematics: An International Journal (AAM)

The main objective of the present paper is to study the propagation of waves in the transversely isotropic medium in the context of thermoelasticity with GN theory of type-II and III. By imposing the boundary conditions on the components of displacement, stresses and temperature distribution, wave equation have been solved. Numerically simulated results have been plotted graphically with respect to frequency to evince the effect of anisotropy. Keywords: Thermoelasticity, transversely isotropic, reflection, plane wave AMS 2010 No.: 74JXX, 74F, 74B, 80A. 1. Introduction In last three decades, non-classical theories involving finite speed of heat transportation in elastic solids have been …

A New Algorithm For Solving Shortest Path Problem On A Network With Imprecise Edge Weight, Amit Kumar, Manjot Kumar

Applications and Applied Mathematics: An International Journal (AAM)

Nayeem and Pal (Shortest path problem on a network with imprecise edge weight, Fuzzy Optimization and Decision Making 4, 293-312, 2005) proposed a new algorithm for solving shortest path problem on a network with imprecise edge weight. In this paper the shortcomings of the existing algorithm, (Nayeem and Pal, 2005) are pointed out and to overcome these shortcomings a new algorithm is proposed. To show the advantages of the proposed algorithm over existing algorithm the numerical examples presented in (Nayeem and Pal, 2005) are solved using the proposed algorithm and obtained results are discussed.

Quantitative Comparison Of Late Effects Following Photon Versus Proton External-Beam Radiation Therapies: To Ward An Evidence-Based Approach To Selecting A Treatment Modality, Rui Zhang

Dissertations and Theses (Open Access)

Radiation therapy has been used as an effective treatment for malignancies in pediatric patients. However, in many cases, the side effects of radiation diminish these patients’ quality of life. In order to develop strategies to minimize radiogenic complications, one must first quantitatively estimate pediatric patients’ relative risk for radiogenic late effects, which has not become feasible till recently because of the calculational complexity. The goals of this work were to calculate the dose delivered to tissues and organs in pediatric patients during contemporary photon and proton radiotherapies; to estimate the corresponding risk of radiogenic second cancer and cardiac toxicity based …