Degradation Effects Of Ionizing Radiation On Commercially Available Spacecraft Components, 2016 Utah State University
Degradation Effects Of Ionizing Radiation On Commercially Available Spacecraft Components, Alex Souvall
Senior Theses and Projects
No abstract provided.
Controlled Generation Of Comb-Like Electron Beams In Plasma Channels For Polychromatic Inverse Thomson Gamma-Ray Sources, 2016 University of Nebraska-Lincoln
Controlled Generation Of Comb-Like Electron Beams In Plasma Channels For Polychromatic Inverse Thomson Gamma-Ray Sources, Serge Y. Kalmykov, X. Davoine, I Ghebregziabher, R Lehe, A F. Lifschitz, B A. Shadwick
Serge Youri Kalmykov
Brane Brick Models, Toric Calabi-Yau 4-Folds And 2d (0,2) Quivers, 2016 CUNY City College
Brane Brick Models, Toric Calabi-Yau 4-Folds And 2d (0,2) Quivers, Sebastian Franco, Sangmin Lee, Rak-Kyeong Seong
Publications and Research
We introduce brane brick models, a novel type of Type IIA brane congurations consisting of D4-branes ending on an NS5-brane. Brane brick models are T-dual to D1-branes over singular toric Calabi-Yau 4-folds. They fully encode the innite class of 2d (generically) N = (0; 2) gauge theories on the worldvolume of the D1-branes and streamline their connection to the probed geometries. For this purpose, we also introduce new combinatorial procedures for deriving the Calabi-Yau associated to a given gauge theory and vice versa.
New Flexible Channels For Room Temperature Tunneling Field Effect Transistors, 2016 Michigan Technological University
New Flexible Channels For Room Temperature Tunneling Field Effect Transistors, Boyi Hao, Anjana Asthana, Paniz Khanmohammadi, Paul Bergstrom, Douglas R. Banyai, Madhusudan A. Savaikar, John A. Jaszczak, Yoke Khin Yap
Department of Physics Publications
Tunneling field effect transistors (TFETs) have been proposed to overcome the fundamental issues of Si based transistors, such as short channel effect, finite leakage current, and high contact resistance. Unfortunately, most if not all TFETs are operational only at cryogenic temperatures. Here we report that iron (Fe) quantum dots functionalized boron nitride nanotubes (QDs-BNNTs) can be used as the flexible tunneling channels of TFETs at room temperatures. The electrical insulating BNNTs are used as the one-dimensional (1D) substrates to confine the uniform formation of Fe QDs on their surface as the flexible tunneling channel. Consistent semiconductor-like transport behaviors under various …
Ultrafast Saturation Of Electronic-Resonance-Enhanced Coherent Anti-Stokes Raman Scattering And Comparison For Pulse Durations In The Nanosecond To Femtosecond Regime, 2016 Wright State University - Main Campus
Ultrafast Saturation Of Electronic-Resonance-Enhanced Coherent Anti-Stokes Raman Scattering And Comparison For Pulse Durations In The Nanosecond To Femtosecond Regime, Anil K. Patnaik, Sukesh Roy, James R. Gord
Physics Faculty Publications
The saturation threshold of a probe pulse in an ultrafast electronic-resonance-enhanced (ERE) coherent anti-Stokes Raman spectroscopy (CARS) configuration is calculated. We demonstrate that while the underdamping condition is a sufficient condition for saturation of ERE-CARS with the long-pulse excitations, a transient gain must be achieved to saturate the ERE-CARS signal for the ultrafast probe regime. We identify that the area under the probe pulse can be used as a definitive parameter to determine the criterion for a saturation threshold for ultrafast ERE-CARS. From a simplified analytical solution and a detailed numerical calculation based on density-matrix equations, the saturation threshold of …
Off The Lip Conference - Transdisciplinary Approaches To Cognitive Innovation. Conference Proceedings, 2016 University of Plymouth
Off The Lip Conference - Transdisciplinary Approaches To Cognitive Innovation. Conference Proceedings, Sue Denham, Michael Punt, Edith Doove, Martha Blassnigg, Raluca Briazu, Kathryn Francis, Agi Haynes, Guy Edmonds, Adam Benjamin, Matthew Emmett, Iris Garrelfs, Christopher B. Germann, Joanna Griffin, Diane Humphrey, Bryanna Lucyk, Christie Purchase, Rachel Sansone, Emily Baxter, Amy Ione, Frank Loesche, Abigail Jackson, Alexis Kirke, Eduardo Miranda, Luke Rendell, Simon Ingram, Yutaka Nakamura, Gi Taek Ryoo, Eugenia Stamboliev, Michael Straeubig, Chun-Wei Hsu, Pinar Oztop, Mihaela Taranu, Sundar Sarukkai, James Sweeting, Minami Hirayama
Off the Lip Conference - Transdisciplinary Approaches to Cognitive Innovation
The promise of cognitive innovation as a collaborative project in the sciences, arts and humanities is that we can approach creativity as a bootstrapping cognitive process in which the energies that shape the poem are necessarily indistinguishable from those that shape the poet. For the purposes of this conference the exploration of the idea of cognitive innovation concerns an understanding of creativity that is not exclusively concerned with conscious human thought and action but also as intrinsic to our cognitive development. As a consequence, we see the possibility for cognitive innovation to provide a theoretical and practical platform from which …
Exploring The Weak Mach Reflection Regime, 2016 Brigham Young University
Exploring The Weak Mach Reflection Regime, Kevin Leete, Dr. Kent Gee
Journal of Undergraduate Research
When a shock wave reflects off a rigid surface with certain combinations of incident shock strength and angle, a Mach reflection can occur. This is when portions of the incident and reflected waves merge to create a stronger shock called a Mach stem that travels parallel to the reflecting surface. This phenomenon has been studied extensively for two extreme cases: large outdoor explosions and small, laboratory experiments of weak shocks. The purpose of this project was to design and execute an outdoor experiment where this phenomenon could be observed by microphones as well as high speed video imaging to detect …
Optically Detected Magnetic Resonance Of Silicon Vacancies In Sic: Predicting Resonance Of Cylindrical Cavities, 2016 Brigham Young University
Optically Detected Magnetic Resonance Of Silicon Vacancies In Sic: Predicting Resonance Of Cylindrical Cavities, Kyle Miller, John Colton
Journal of Undergraduate Research
Optically Detected Magnetic Resonance is one method of performing Electron Spin Resonance (ESR) on a material. ESR is used to determine the electron spin lifetime of a material, an important parameter for use in quantum computing. Resonant cavities are conducting containers that are frequently used in ESR to create a strong magnetic field near the sample. As such it is valuable to design a resonant cavity and predict its resonant frequency. Cylindrical cavities modified with dielectric resonators (DRs) are viable for such experiments.
First-Order Superfluid To Valence-Bond Solid Phase Transitions In Easy-Plane Su(N) Magnets For Small N, 2016 University of Kentucky
First-Order Superfluid To Valence-Bond Solid Phase Transitions In Easy-Plane Su(N) Magnets For Small N, Jonathan D'Emidio, Ribhu K. Kaul
Physics and Astronomy Faculty Publications
We consider the easy-plane limit of bipartite SU(N) Heisenberg Hamiltonians, which have a fundamental representation on one sublattice and the conjugate to fundamental on the other sublattice. For N = 2 the easy plane limit of the SU(2) Heisenberg model is the well-known quantum XY model of a lattice superfluid. We introduce a logical method to generalize the quantum XY model to arbitrary N, which keeps the Hamiltonian sign-free. We show that these quantum Hamiltonians have a world-line representation as the statistical mechanics of certain tightly packed loop models of N colors in which neighboring loops are …
High Resolution Shock Capturing On Gpus, 2016 Brigham Young University
High Resolution Shock Capturing On Gpus, Forrest Glines, David Neilsen
Journal of Undergraduate Research
This research project concerns the development simulation code to confirm neutron star mergers as the progenitors of Short Hard Gamma Ray Bursts. Short Hard Gamma Ray Bursts (SHGBs) are short (less than 2 second) high energy bursts that we observe with satellites. Their exact cause has not yet been confirmed, but they are believed to be created by the merging of either two neutron stars or a neutron star falling into a black hole. Neutron stars are ultra dense, highly magnetic, and compact stars at the end of their evolution. In a binary system the stars lose angular momentum to …
Ν = 1/2 Landau Level: Half-Empty Versus Half-Full, 2016 University of Kentucky
Ν = 1/2 Landau Level: Half-Empty Versus Half-Full, Ganpathy Murthy, R. Shankar
Physics and Astronomy Faculty Publications
We show here that an extension of the Hamiltonian theory developed by us over the years furnishes a composite fermion (CF) description of the ν = 1/2 state that is particle-hole (PH) symmetric, has a charge density that obeys the magnetic translation algebra of the lowest Landau level (LLL), and exhibits cherished ideas from highly successful wave functions, such as a neutral quasiparticle with a certain dipole moment related to its momentum. We also a provide an extension away from ν = 1/2, which has the features from ν = 1/2 and implements the PH transformation on the LLL as …
Porous Cantilevers As Chemical Sensors, 2016 Brigham Young University
Porous Cantilevers As Chemical Sensors, Steven Noyce, Robert Davis
Journal of Undergraduate Research
Many chemical sensing methods rely on the binding mechanism of the analyte to create a measurable response, making it difficult to create new sensors quickly, but resonant sensors require only that an analyte be bound and rely on the resulting change in mass to obtain a measurement. Solid resonant microcantilevers, or small vibrating fixed-free beams, are a type of resonant sensor that have shown extremely high sensitivities in vacuum environments. The sensitivity of these cantilevers, however, decreases greatly in fluid environments such as air or water due to fluid damping. We propose that porous microcantilever sensors offers both a ten …
Phase Matching In Laser Generated Harmonics, 2016 Brigham Young University
Phase Matching In Laser Generated Harmonics, David Squires, Justin Peatross
Journal of Undergraduate Research
In this mentored research project, we investigated how intense laser light is scattered by samples of gas. In particular, we measured light scattered in non-phase-matched directions perpendicular to the laser beam.
According to classical phase matching, the intensity of light scattered from a sample depends on whether the sample is best approximated as a continuous medium or a collection of discrete emitters (Figure 1). In the former case, as the angle between the phase-matching direction and the radiated harmonic approaches π/2 radians, the intensity of that radiated harmonic light approaches 0. In the latter case, the light intensity reaches …
Determining The Size Of A Light Source Using The Hanbury Brown And Twiss Effect, 2016 Brigham Young University
Determining The Size Of A Light Source Using The Hanbury Brown And Twiss Effect, Adam Kingsley, Dallin Durfee
Journal of Undergraduate Research
In 1956, Hanbury Brown and Twiss (HBT) published a paper1 on a method of determining the angular size of a star by comparing the intensities gathered from two detectors. They used this effect by using two photomultiplier tubes and by increasing the distance between them, saw a drop in the correlation between the currents. Because the correlations are made by the interference at the detectors but only the intensity is measured, the effect is sometimes referred to as intensity interferometry.
The idea arose to use the HBT effect to teach undergraduates various principles of light in a lab setting. …
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 begins …
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.
Collapse Of A Degenerate Fermi Gas, 2016 Universita di Firenze and Istituto Nazionale
Collapse Of A Degenerate Fermi Gas, Giovanni Modugno, Giacomo Roati, Francesco Riboli, Francesca Ferlaino, Robert Brecha, Massimo Inguscio
Robert J. Brecha
A degenerate gas of identical fermions is brought to collapse by the interaction with a Bose-Einstein condensate. We used an atomic mixture of fermionic potassium-40 and bosonic rubidium-87, in which the strong interspecies attraction leads to an instability above a critical number of particles. The observed phenomenon suggests a direction for manipulating fermion-fermion interactions on the route to superfluidity.
Cost Optimization With Solar And Conventional Energy Production, Energy Storage, And Real Time Pricing, 2016 University of Dayton
Cost Optimization With Solar And Conventional Energy Production, Energy Storage, And Real Time Pricing, Ata Raziei, Kevin Hallinan, Robert Brecha
Robert J. Brecha
Research is presented that investigates the potential for solar power generation with battery energy storage for reducing the effective cost of energy delivered to residential customers if real time pricing is present. A linear optimization approach is developed based upon a two-step process. In step one, given a specified solar array area and battery capacity, the optimal means to meet loads based upon grid power, solar power, and/or battery power is determined. This analysis considers an expected lifespan of the solar panel. With these results established, in the next step, the capital costs for the solar arrays and batteries are …
Dipolar Oscillations In A Quantum Degenerate Fermi–Bose Atomic Mixture, 2016 Universita di Firenze and Istituto Nazionale
Dipolar Oscillations In A Quantum Degenerate Fermi–Bose Atomic Mixture, Francesca Ferlaino, Robert Brecha, Peter Hannaford, Francesco Riboli, Giacomo Roati, Giovanni Modugno, Massimo Inguscio
Robert J. Brecha
We study the dynamics of coupled dipolar oscillations in a Fermi–Bose mixture of 40K and 87Rb atoms. This low-energy collective mode is strongly affected by the interspecies interactions. Measurements are performed in the classical and quantum degenerate regimes and reveal the crucial role of the statistical properties of the mixture. At the onset of quantum degeneracy, we investigate the role of Pauli blocking and superfluidity for K and Rb atoms, respectively, resulting in a change in the collisional interactions.