Physics Commons^™

Energy Conservation In Large Buildings, A. Rosenfeld, David W. Hafemeister

Anatoly Rozenfeld

As energy prices rise, newly energy aware designers use better tools and technology to create energy efficient buildings. Thus the U.S. office stock (average age 20 years) uses 250 kBTU/ft2 of resource energy, but the guzzler of 1972 uses 500 (up × 2), and the 1986 ASHRAE standards call for 100–125 (less than 25% of their 1972 ancestors). Surprisingly, the first real cost of these efficient buildings has not risen since 1972. Scaling laws are used to calculate heat gains and losses of buildings to obtain the ΔT(free) which can be as large as 15–30 °C (30–60 °F) for large …

Local Pt Invariance And Supersymmetric Parametric Oscillators, Ramy El-Ganainy, Konstantinos G. Makris, Demetrios N. Christodoulides

Ramy El-Ganainy

We introduce the concept of local parity-time symmetric (PT) invariance in optical waveguides (or cavity) structures. Starting from a Lagrangian formalism, we establish the connection between light dynamics in these configurations and the seemingly different physics of “supersymmetric” parametric oscillators. Using this powerful tool, we present analytical solutions for optical beam propagation in local PT-invariant coupled systems and we show that the intensity tunneling between the two channels critically depends on the initial conditions. For unbalanced inputs, symmetric as well as asymmetric power evolution can be observed depending on the excitation channel. On the other hand, under certain physical conditions, …

Progress On: “Coherent Terahertz Acoustic Phonon Scattering: Novel Diagnostic For Erosion In Plasma Thruster Discharge Chamber Walls", Thomas E. Wilson, Iain D. Boyd

Physics Faculty Research

The study is based on the success in obtaining the first experimental evidence for the direct excitation of coherent nanosecond-pulsed high-frequency acoustic phonons in semiconducting doping superstructures by electromagnetic fields of the same frequency. Acoustic phonons are detected by a superconducting bolometer, with nanosecond resolution, at the appropriate time-of-flight across a (100) silicon substrate for ballistic longitudinal phonons when a silicon delta-doped doping superlattice is illuminated with grating-coupled nanosecond-pulsed 246-GHz laser radiation with an approximate power density of 1 kW/mm². The absorbed phonon power density in the bolometer detector is estimated to be 10 μW/mm², in …

Topics In Field Theory, Alexander Patrushev

Electronic Thesis and Dissertation Repository

This thesis consists of different projects in classical and quantum field theory on a curved background which are connected by a common usage of theoretical ideas as well as cal- culation techniques. The introduction clarifies such connections. In the second chapter we apply the Dirac constraint formalism to the second and first order 1 + 1 dimensional gravitational action coupled to a scalar field. The third chapter is devoted to a calculation of the one loop effective action for a spinor field coupled to a constant background chiral vector field. In the fourth chapter we find a new expression for …

Mapping Nuclear Fallout Using The Weather Research & Forecasting (Wrf) Model, Joseph C. Schofield

Theses and Dissertations

There are many models that attempt to predict transport & dispersion (T&D) of particulate matter in the sensible atmosphere. The majority of these existing models are unable to incorporate atmospheric processes such wet deposition through scavenging and cloud condensation nuclei (CCN) formation. To this end, the numerical weather prediction (NWP) model known as the Weather Research & Forecasting with Chemistry (WRF/Chem) Model is studied to determine its suitability as a potential tool for predicting particulate T&D following an atmospheric nuclear detonation. This is done by modifying relevant modules, originally designed to predict the settling of volcanic ash, such that a …

Light Scattering Study Of Elongated Particles: From Inorganic Nanorice To Polypeptide Micelles, Philip Dee

Undergraduate Research Posters 2012

Utilizing the powerful experimental technique of Dynamic Light Scattering (DLS) for size characterization of anisotropic particles can be extremely misleading. Unfortunately, this point is often not realized by researchers who strive for particle sizing of nanoparticles in suspensions. We present a consistent analysis of DDLS results on FeOOH nanorice and outline the potential difficulties and challenges of DDLS application for polypeptide micelles.

Extending Newton’S Apsidal Theorem: Effective Angular Momentum, Cameron J. Tuckerman

Undergraduate Research Posters 2012

Apsidal Shift, or the angular displacement of the orbital apses, is an important quantity in the study of the orbits of planets, starts, and other celestial bodies. The apparent lack of shift of our nearby planets is that on which Sir Isaac Newton based his assumption of the inverse-square relationship in Universal Gravity. We are able to find excellent approximations for the Apsidal Shift and use our results to generalize Newton's Apsidal Theorem.

Pumping Up The [N I] Nebular Lines, Gary J. Ferland, W. J. Henney, C. R. O'Dell, R. L. Porter, P. A. M. Vanhoof, R. J. R. Williams

Physics and Astronomy Faculty Publications

The optical [N I] doublet near 5200 Å is anomalously strong in a variety of emission-line objects. We compute a detailed photoionization model and use it to show that pumping by far-ultraviolet (FUV) stellar radiation previously posited as a general explanation applies to the Orion Nebula (M42) and its companion M43; but, it is unlikely to explain planetary nebulae and supernova remnants. Our models establish that the observed nearly constant equivalent width of [N I] with respect to the dust-scattered stellar continuum depends primarily on three factors: the FUV to visual-band flux ratio of the stellar population, the optical properties …

Quantum Corrections To The Gravitational Interaction Of Massless Particles, Thomas J. Blackburn Jr.

Open Access Dissertations

Donoghue's effective field theory of quantum gravity is extended to include the interaction of massless particles. The collinear divergences which accompany massless particles are examined first in the context of QED and then in quantum gravity. A result of Weinberg is extended to show how these divergences vanish in the case of gravity. The scattering cross section for hypothetical massless scalar particles is computed first, because it is simpler, and the results are then extended to photons. Some terms in the cross section are shown to correspond to the Aichelburg-Sexl metric surrounding a massless particle and to quantum corrections to …

Swelling And Folding As Mechanisms Of 3d Shape Formation In Thin Elastic Sheets, Marcelo A. Dias

Open Access Dissertations

We work with two different mechanisms to generate geometric frustration on thin elastic sheets; isotropic differential growth and folding. We describe how controlled growth and prescribing folding patterns are useful tools for designing three-dimensional objects from information printed in two dimensions. The first mechanism is inspired by the possibility to control shapes by swelling polymer films, where we propose a solution for the problem of shape formation by asking the question, ``what 2D metric should be prescribed to achieve a given 3D shape?'', namely the reverse problem. We choose two different types of initial configurations of sheets, disk-like with one …

Searches For Gravitational Waves From Binary Black Hole Coalescences With Ground-Based Laser Interferometers Across A Wide Parameter Space, Satyanarayan Ray Pitambar Mohapatra

Open Access Dissertations

This is an exciting time for Gravitational Wave (GW) theory and observations. From a theoretical standpoint, the grand-challenge problem of the full evolution of a Binary Black Hole (BBH) system has been solved numerically, and a variety of source simulations are made available steadfastly. On the observational side, the first generation of state-of-the-art GW detectors, LIGO and Virgo, have achieved their design goal, collected data and provided astrophysically meaningful limits. The second generation of detectors are expected to start running by 2015. Inspired by this zeitgeist, this thesis focuses on the detection of potential GW signatures from the coalescence of …

Parity Violation In Neutron Deuteron Scattering In Pionless Effective Field Theory, Jared James Vanasse

Open Access Dissertations

In this dissertation the parity violating neutron deuteron scattering amplitudes are calculated using pionless effective field theory to leading order. The five low energy parity violating constants present in pionless effective field theory are estimated by matching onto the "best" values for the parameters of the model by Desplanques, Donoghue, and Holstein (DDH). Using these estimates and the calculated amplitudes, predictions for the spin rotation of a neutron through a deuteron target are given with a value of 1.8×10-8 rad cm-1. Also given are the longitudinal analyzing power in neutron deuteron scattering with a polarized neutron yielding 2.2×10-8, and a …

Crystal Field And Zeeman Splittings For Energy Levels Of Nd3+ In Hexagonal Aln, John B. Gruber, Gary W. Burdick, Ulrich Vetter, Brandon Mitchell, Volkmar Dierolf, Hans Hofsass

Faculty Publications

The crystal-field and Zeeman splittings of the energy levels of Nd3+(4f3) 2S+1LJ in hexagonal phase AlN have been investigated. The multiplet manifolds of Nd3+(4f3) analyzed include the ground state, 4I9/2, and excited states 4I11/2, 4I13/2, 4F3/2, 4F5/2, 2H(2)9/2, 4F7/2, 4S3/2, 4G5/2, and 2G7/2. Experimental energy levels were obtained from analyses of the 12 K cathodoluminescence spectra from Nd3+-implanted films of AlN, and from the 15 K photoluminescence excitation spectra and the site-selective combined excitation-emission spectra (CEES) recently reported for in situ Nd-doped hexagonal AlN grown by plasma-assisted molecular beam epitaxy (PA-MBE). CEES results identify a main site and two minority …

Ads/Cft In String Theory And M-Theory, Daniel R. Gulotta '03

Doctoral Dissertations

The AdS/CFT correspondence is a powerful tool that can help shed light on the relationship between geometry and field theory.

The first part of this thesis will focus on the construction of theories dual to Type IIB string theory on AdS₅ x Y⁵, where Y⁵ is a toric Sasaki-Einstein manifold. This thesis will introduce a consistency condition called "proper ordering" and demonstrate that it is equivalent to several other previously known consistency conditions. It will then give an efficient algorithm that produces a consistent field theory for any toric Sasaki-Einstein Y⁵.

The second part …

Search For A Fermiophobic Higgs Boson In Pp Collisions At S√=7 Tev, The Cms Collaboration, S. Chatrchyan, V. Khachatryan, Marc M. Baarmand, B. Dorney, Marcus Hohlmann, Himali Kalakhety, Igor Vodopiyanov

Aerospace, Physics, and Space Science Faculty Publications

Combined results are reported from searches for a fermiophobic Higgs boson in the γγ, WW, and ZZ decay modes in proton-proton collisions at s=7" role="presentation" style="box-sizing: inherit; display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; text-wrap: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">s√=7�=7 TeV. The explored Higgs boson mass range is 110–300 GeV. The data sample corresponds to an integrated luminosity of 4.9–5.1 fb⁻¹. A fermiophobic Higgs boson is excluded at 95% confidence level in the mass range 110–194 GeV, and at 99% …

Hordó Kollektor 3.0, Pal R. Molnar

Pal R. Molnar

Napjainkban egyre többen telepítenek napkollektorokat, a használati melegvíz ellátására, illetve fűtés rásegítésre. Ezen kollektorok hatásfoka széles határok között váltakozik.

Tensile-Strained Growth On Low-Index Gaas, Paul J. Simmonds, Minjoo Larry Lee

Paul J. Simmonds

We present a comparative study of the growth of tensile-strained GaP on the four low-index surfaces of GaAs: (001), (110), (111)A, and (111)B. For each surface orientation we outline the growth conditions required for smooth GaAshomoepitaxy. We are able to predict the resulting surface morphology when GaP is deposited onto these four GaAssurfaces by considering the influence of surface orientation on tensile strain relief. GaP deposited on GaAs(001) forms extremely smooth, planar layers. In contrast, the elastic relief of tensile strain on both GaAs(110) and GaAs(111)A leads to the three-dimensional self-assembly of GaP into dislocation-free nanostructures. Similarities between tensile and …

High-Frequency Rapid B-Mode Ultrasound Imaging For Real-Time Monitoring Of Lesion Formation And Gas Body Activity During High-Intensity Focused Ultrasound Ablation, Madhu Sudhan Reddy Gudur, Ronald Kumon, Yun Zhou, Cheri X. Deng

Physics Publications

Abstract:

The goal of this study was to examine the ability of high-frame-rate, high-resolution imaging to monitor tissue necrosis and gas-body activities formed during high-intensity focused ultrasound (HIFU) application. Ex vivo porcine cardiac tissue specimens (n = 24) were treated with HIFU exposure (4.33 MHz, 77 to 130 Hz pulse repetition frequency (PRF), 25 to 50% duty cycle, 0.2 to 1 s, 2600 W/cm2). RF data from Bmode ultrasound imaging were obtained before, during, and after HIFU exposure at a frame rate ranging from 77 to 130 Hz using an ultrasound imaging system with a center frequency of 55 MHz. …

Improved He I Emissivities In The Case B Approximation, R. L. Porter, Gary J. Ferland, P. J. Storey, M. J. Detisch

Physics and Astronomy Faculty Publications

We update our prior work on the case B collisional-recombination spectrum of He i to incorporate ab initio photoionization cross-sections. This large set of accurate, self-consistent cross-sections represents a significant improvement in He i emissivity calculations because it largely obviates the piecemeal nature that has marked all modern works. A second, more recent set of ab initio cross-sections is also available, but we show that those are less consistent with bound-bound transition probabilities than our adopted set. We compare our new effective recombination coefficients with our prior work and our new emissivities with those by other researchers, and we conclude …

Fast Super-Resolution Using An Adaptive Wiener Filter With Robustness To Local Motion, Russell C. Hardie, Kenneth J. Barnard

Electrical and Computer Engineering Faculty Publications

We present a new adaptive Wiener filter (AWF) super-resolution (SR) algorithm that employs a global background motion model but is also robust to limited local motion. The AWF relies on registration to populate a common high resolution (HR) grid with samples from several frames. A weighted sum of local samples is then used to perform nonuniform interpolation and image restoration simultaneously. To achieve accurate subpixel registration, we employ a global background motion model with relatively few parameters that can be estimated accurately. However, local motion may be present that includes moving objects, motion parallax, or other deviations from the background …