Photonic Crystals With Alternate Arrays Of Rods And Holes In A Low Dielectric-Index Material, 2016 Graduate Center, City University of New York
Photonic Crystals With Alternate Arrays Of Rods And Holes In A Low Dielectric-Index Material, Dimitar L. Dimitrov
All Graduate Works by Year: Dissertations, Theses, and Capstone Projects
This thesis theoretically deals with the propagation of electromagnetic waves (light beams) in periodically modulated dielectric material structures based on Maxwell’s equations. We are interested in novel light propagation characteristics in these man-made dielectric material structures for practical applications, especially on optical communications and computations. Since the wavelength range of light is on the same order of magnitude as the modulation periods of dielectric materials, an analogy of the light propagation in dielectric-constant modulated structures with the electron transport in solid-state crystals is used throughout my thesis by using a term “photonic crystals (PhCs)” referring to these dielectric structures ...
Targeting Residential Energy Reduction For City Utilities Using Historical Electrical Utility Data And Readily Available Building Data, Kevin P. Hallinan, J. Kelly Kissock, Robert J. Brecha, Austin Mitchell
Energy use data for the eight-year period 2003–2010 was analyzed for over 1200 single family residences in Village of Yellow Springs, Ohio. Electricity, natural gas, residential building, and weather databases are merged to permit determination of the energy intensity of each home in the village. The energy use intensity for each home is disaggregated into weather independent and weather dependent electric and natural gas use. This use is compared to typical baseline, cooling, and heating energy use for the region. From this comparison, priority homes are identified for energy reduction investment. Collective potential low cost energy reduction is estimated ...
Prioritizing Investment In Residential Energy Efficiency And Renewable Energy: A Case Study For The U.S. Midwest, Robert J. Brecha, Austin Mitchell, Kevin P. Hallinan, J. Kelly Kissock
Residential building energy use is an important contributor to greenhouse gas emissions and in the United States represents about 20% of total energy consumption. A number of previous macro-scale studies of residential energy consumption and energy-efficiency improvements are mainly concerned with national or international aggregate potential savings. In this paper we look into the details of how a collection of specific homes in one region might reduce energy consumption and carbon emissions, with particular attention given to some practical limits to what can be achieved by upgrading the existing residential building stock. Using a simple model of residential, single-family home ...
Cost-Availability Curves For Hierarchical Implementation Of Residential Energy-Efficiency Measures, 2016 University of Dayton
Cost-Availability Curves For Hierarchical Implementation Of Residential Energy-Efficiency Measures, Roman Villoria-Siegert, Philip Brodrick, Kevin P. Hallinan, Robert J. Brecha
Historical residential electricity data and natural gas consumption data were collected for, respectively, 1,200 and 178 residences in a small town in the USA. These data were merged with local building and weather databases, and energy consumption models were developed for each residence, revealing substantial variation in heating and cooling intensity. After estimating approximate physical building characteristics, energy profiles for each residence were calculated, and savings from adoption of the most cost-effective energy-efficiency measures for each residence were estimated. Effectively, we wish to leverage commonly available data sets to infer characteristics of building envelopes and equipment, without the need ...
A Locking-Free Hp Dpg Method For Linear Elasticity With Symmetric Stresses, 2016 University of Texas at Austin
A Locking-Free Hp Dpg Method For Linear Elasticity With Symmetric Stresses, Jamie Bramwell, Leszek Demkowicz, Jay Gopalakrishnan, Weifeng Qiu
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.
Model For The Electrolysis Of Water And Its Use For Optimization, 2016 Georgia Institute of Technology
Model For The Electrolysis Of Water And Its Use For Optimization, Roger Lascorz, Javier E. Hasbun Dr
Georgia Journal of Science
The goal of this research was to study the optimization of the electrolysis of water both theoretically and experimentally. For accuracy, 3 hr experiments were made with measurements recorded every 15 min. The results show that a better model than the classical one is needed for water electrolysis. A new model that fits experimental data better is proposed. The results of this new model not only predict hydrogen production in electrolysis of water better, but show a way to predict gas production of any liquid as well as what voltage to use to optimize it.
Investigation Of A Solar Air Heater's Conversion Efficiency And Output Power As A Function Of The Grid Number, Nicole Elizabeth Fronsdahl
Honors Theses By Year
A Solar Air Heater (SAH) is a device that converts solar energy into thermal energy. Solar irradiance enters the SAH through a glazing and heats an absorbing material|in our case several blackened, corrugated aluminum mesh grids. The grids transfer their thermal energy to the passing air. This paper theoretically and experimentally investigates the optimal number of grids to maximize efficiency and minimize the return on investment for our single pass wire mesh grid SAH. A higher number of grids increases the absorption and output temperature, yet also increases ow resistance in the device. Our experimental and theoretical investigation finds ...
Automated Sea State Classification From Parameterization Of Survey Observations And Wave-Generated Displacement Data, 2016 University of New Orleans, New Orleans
Automated Sea State Classification From Parameterization Of Survey Observations And Wave-Generated Displacement Data, Jason A. Teichman
University of New Orleans Theses and Dissertations
Sea state is a subjective quantity whose accuracy depends on an observer’s ability to translate local wind waves into numerical scales. It provides an analytical tool for estimating the impact of the sea on data quality and operational safety. Tasks dependent on the characteristics of local sea surface conditions often require accurate and immediate assessment. An attempt to automate sea state classification using eleven years of ship motion and sea state observation data is made using parametric modeling of distribution-based confidence and tolerance intervals and a probabilistic model using sea state frequencies. Models utilizing distribution intervals are not able ...
The Millikan Oil Drop Experiment: A Simulation Suitable For Classroom Use, 2016 University of West Georgia
The Millikan Oil Drop Experiment: A Simulation Suitable For Classroom Use, Benjamin Hogan, Javier E. Hasbun
Georgia Journal of Science
Due to advancements in computing techniques it has become possible to extend the accessibility of physics experiments across the physics curriculum by means of computational simulations. The widespread availability of computers in modern classrooms provides virtual access to hands-on physics, chemistry, and biology experiments, among others. Here, specifically, we consider Robert Millikan’s famous oil drop experiment. This experiment requires equipment that can be dangerous and expensive. A more practical approach is achieved via a computer simulation, a useful and a universally available alternative. The goal is to encourage scientific thinking, literacy, and innovation while promoting a free network of ...
A Cylindrically Symmetric “Micro-Mott” Electron Polarimeter, 2016 University of Nebraska - Lincoln
A Cylindrically Symmetric “Micro-Mott” Electron Polarimeter, Nathan B. Clayburn, Evan M. Brunkow, S. J. Burtwistle, George H. Rutherford, Timothy J. Gay
Timothy J. Gay Publications
A small, novel, cylindrically symmetric Mott electron polarimeter is described. The effective Sherman function, Seff , or analyzing power, for 20 kV Au target bias with a 1.3 keV energy loss window is 0.16 ± 0.01, where uncertainty in the measurement is due primarily to uncertainty in the incident electron polarization. For an energy loss window of 0.5 keV, Seff reaches its maximum value of 0.24 ± 0.02. The device’s maximum efficiency, I/Io, defined as the detected count rate divided by the incident particle rate, is 3.7 ± 0.2 ...
Particle Image Velocimetry Design & Installation, 2016 University of Arkansas, Fayetteville
Particle Image Velocimetry Design & Installation, Zach Ritchie
Mechanical Engineering Undergraduate Honors Theses
This work will mainly focus on the design, construction, and installation of the Particle Image Velocimetry (PIV) system in the Chemical Hazards Research Center wind tunnel. The PIV system utilizes a Class IV (double pulsed) laser, optics to produce a light sheet, timing circuitry, and a high-resolution camera (with buffered output) to measure a system’s velocity (two-dimensional) field by determining the displacement of particles over the time between laser pulses. For maximum mobility and functionality, the PIV system was installed in the center of the tunnel on a moveable cart with the laser and camera mounted to an adjustable ...
The Singing Cymbal: Is It Really Photon Momentum?, 2016 Department of Physics, Rollins College
The Singing Cymbal: Is It Really Photon Momentum?, Thomas R. Moore, Samantha Collin, Nikki Etchenique
Student-Faculty Collaborative Research
A simple demonstration that is occasionally used in the classroom to show that light carries momentum involves making an orchestral cymbal audibly ring using light from a common photoflash. A metal plate or a piece of foil can also be used, however, it appears that many people use a cymbal because the sound is easily heard at a reasonable distance. It is such an impressive example of the effects attributable to photon momentum that it is posted on the CERN website for educational under the name “singing cymbal.” Although it is an impressive demonstration, a series of simple classroom experiments ...
Corrosion In A Molten Salt Environment, 2016 College of William and Mary
Corrosion In A Molten Salt Environment, Samuel Peter Paiewonsky Girdzis
College of William & Mary Undergraduate Honors Theses
Molten salt can be used to transfer and store energy, but presents challenges in terms of corrosion. In this research, we investigate the early stages of corrosion on stainless steel exposed to molten nitrate salts. Specifically, we are interested in the initial attack on grains and grain boundaries, including the effects of internal stress and/or a weakened passivation layer. We have developed procedures for exposing stainless steel coupons to a mixture of molten sodium nitrate and potassium nitrate at 565$\celsius$. Following exposure to molten salt, samples are analyzed using field emission scanning electron microscopy (FE-SEM) and energy-dispersive X-ray ...
Spatio-Spectral Sampling And Color Filter Array Design, 2016 University of Dayton
Spatio-Spectral Sampling And Color Filter Array Design, Keigo Hirakawa, Patrick Wolfe
Owing to the growing ubiquity of digital image acquisition and display, several factors must be considered when developing systems to meet future color image processing needs, including improved quality, increased throughput, and greater cost-effectiveness. In consumer still-camera and video applications, color images are typically obtained via a spatial subsampling procedure implemented as a color filter array (CFA), a physical construction whereby only a single component of the color space is measured at each pixel location. Substantial work in both industry and academia has been dedicated to post-processing this acquired raw image data as part of the so-called image processing pipeline ...
Reply To “Comment On Gravitational Slingshot,” By C. L. Cook [Am. J. Phys. 73 (4), 363 (2005)], 2016 Loyola University Chicago
Reply To “Comment On Gravitational Slingshot,” By C. L. Cook [Am. J. Phys. 73 (4), 363 (2005)], Asim Gangopadhyaya, Asim Gangopadhyaya, Robert Cacioppo, John Dykla
No abstract provided.
Kl−Ks Mass Difference And Supersymmetric Left-Right-Symmetric Theories, 2016 Loyola University Chicago
Kl−Ks Mass Difference And Supersymmetric Left-Right-Symmetric Theories, Asim Gangopadhyaya
The supersymmetric contributions to the KL−KS mass difference makes the previously obtained bounds on the right-handed scale (MR>1.6 TeV) much weaker. This raises the interesting possibility that the left-right model could be tested as an alternative to SUL(2)⊗U(1) at low energies. Also we find that to demand that the supersymmetric contribution to the KL−KS mass difference be less than 3.5×10−15 GeV requires that scalar-quark masses be more than 400 GeV.
Bicrystallography In Two Dimensions: A Graphical Procedure And Comparison Of Its Results To Experiments, 2016 Portland State University
Bicrystallography In Two Dimensions: A Graphical Procedure And Comparison Of Its Results To Experiments, Andrew Maas, Peter Moeck
Three dimensional (3D) bicrystallography describes ideal structures of grain boundaries comprehensively at the atomic level as a function of the five macroscopic and two of the four microscopic parameters [1,2]. Free energy minimization of these structures leads to the real structure of these topologically distinct regions within crystals. These minimizations may either reduce the symmetries of ideal bicrystals or leave them intact. Since the symmetries of physical properties need to be compatible (by the Shubnikov-Curie and Curie-Minnigerode-Neumann principles ) with the symmetries of the atomic arrangements from which they arise, bicrystallography allows for predictions about which phenomena can occur ...
Revisiting Hafemeister’S ‘Science And Society’ Tests, 2016 University of Dayton
Revisiting Hafemeister’S ‘Science And Society’ Tests, Robert Brecha, Rex Berney, Bruce Craver
Robert J. Brecha
We revisit a series of papers on science and society issues by David Hafemeister in the 1970s and 1980s. The emphasis in the present work is on world oil production limits and some consequences of various possible scenarios for the near future. Some of the data and scenarios used by Hafemeister are updated for U.S. oil production in the past two decades and extended to an analysis of a peak in world oil production in the future. We discuss some simple scenarios for future energy use patterns and look at the consequence of these scenarios as world oil production ...
Emissions Scenarios In The Face Of Fossil-Fuel Peaking, 2016 University of Dayton
Emissions Scenarios In The Face Of Fossil-Fuel Peaking, Robert Brecha
Robert J. Brecha
Emissions scenarios used by the Intergovernmental Panel on Climate Change (IPCC) are based on detailed energy system models in which demographics, technology and economics are used to generate projections of future world energy consumption, and therefore, of greenhouse gas emissions. We propose in this paper that it is useful to look at a qualitative model of the energy system, backed by data from short- and medium-term trends, to gain a sense of carbon emission bounds. Here we look at what may be considered a lower bound for 21st century emissions given two assumptions: first, that extractable fossil-fuel resources follow the ...
Bose-Einstein Condensation Of Potassium Atoms By Sympathetic Cooling, 2016 Universita di Firenze and Istituto Nazionale
Bose-Einstein Condensation Of Potassium Atoms By Sympathetic Cooling, Giovanni Modugno, Gabriele Ferrari, Giacomo Roati, Robert Brecha, A. Simoni, Massimo Inguscio
Robert J. Brecha
We report on the Bose-Einstein condensation of potassium atoms, whereby quantum degeneracy is achieved by sympathetic cooling with evaporatively cooled rubidium. Because of the rapid thermalization of the two different atoms, the efficiency of the cooling process is high. The ability to achieve condensation by sympathetic cooling with a different species may provide a route to the production of degenerate systems with a larger choice of components.