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Utah State University

2009

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Articles 1 - 30 of 74

Full-Text Articles in Physics

Reduction And Characterization Of Error In Low Current Measurements, Justin Dekany, Jr Dennison, Alec Sim Oct 2009

Reduction And Characterization Of Error In Low Current Measurements, Justin Dekany, Jr Dennison, Alec Sim

Presentations

No abstract provided.


Intra-Annual Comparison Of Mesospheric Gravity Waves Over Halley And Rothera Stations, Antarctica, Jonathan Pugmire, Michael J. Taylor, K. Nielsen, A. Wall, J. Thompson, P. D. Pautet Oct 2009

Intra-Annual Comparison Of Mesospheric Gravity Waves Over Halley And Rothera Stations, Antarctica, Jonathan Pugmire, Michael J. Taylor, K. Nielsen, A. Wall, J. Thompson, P. D. Pautet

Graduate Student Posters

No abstract provided.


Temperature Dependence Of Electrostatic Breakdown Of Polymeric Insulators, Charles Sim, Jr Dennison Oct 2009

Temperature Dependence Of Electrostatic Breakdown Of Polymeric Insulators, Charles Sim, Jr Dennison

Presentations

No abstract provided.


Project: F.U.N.B.O.E. (Follow-Up Nucleate Boiling On-Flight Experiment), Getaway Special Team 2009 Oct 2009

Project: F.U.N.B.O.E. (Follow-Up Nucleate Boiling On-Flight Experiment), Getaway Special Team 2009

Education and Outreach

No abstract provided.


Third Grade Lesson Plan: Where Does Heat Come From?, Getaway Special Team 2009 Oct 2009

Third Grade Lesson Plan: Where Does Heat Come From?, Getaway Special Team 2009

Education and Outreach

No abstract provided.


Sixth Grade Lesson Plan: Heat Moves, Getaway Special Team 2009 Oct 2009

Sixth Grade Lesson Plan: Heat Moves, Getaway Special Team 2009

Education and Outreach

No abstract provided.


Fifth Grade Lesson Plan: Solid, Liquid, And Gas, Getaway Special Team 2009 Oct 2009

Fifth Grade Lesson Plan: Solid, Liquid, And Gas, Getaway Special Team 2009

Education and Outreach

No abstract provided.


Self-Similar Nested Sequences On A Chaotic Attractor For Travelingwave Electrophoresis, Boyd F. Edwards Sep 2009

Self-Similar Nested Sequences On A Chaotic Attractor For Travelingwave Electrophoresis, Boyd F. Edwards

All Physics Faculty Publications

Oscillating electric potentials are applied to interdigitated arrays of cylindrical electrodes above and below a stationary conducting viscous fluid. The phases of these potentials are chosen to produce a longitudinal traveling wave that traps high-mobility ions and partially traps intermediate-mobility ions in periodic and narrowband chaotic attractors with average velocities that are commensurate with the wave speed. Stable periodic attractors have periods up to 101 times the wave period. Incommensurate broadband chaotic attractors are described by one-dimensional iterated contact-angle return maps, which feature self-similar nested sequences that converge geometrically at unstable trapped orbits. Sequences of singular angles and sequences of ...


Analysis And Modeling Of Ducted And Evanescent Gravity Waves Observed In The Hawaiian Airglow, D. B. Simkhada, J. B. Snively, Michael J. Taylor, S. J. Franke Aug 2009

Analysis And Modeling Of Ducted And Evanescent Gravity Waves Observed In The Hawaiian Airglow, D. B. Simkhada, J. B. Snively, Michael J. Taylor, S. J. Franke

All Physics Faculty Publications

Short-period gravity waves of especially-small horizontal scale have been observed in the Maui, Hawaii airglow. Typical small-scale gravity wave events have been investigated, and intrinsic wave propagation characteristics have been calculated from simultaneous meteor radar wind measurements. Here we report specific cases where wave structure is significantly determined by the local wind structure, and where wave characteristics are consistent with ducted or evanescent waves throughout the mesopause region. Two of the documented events, exhibiting similar airglow signatures but dramatically different propagation conditions, are selected for simple numerical modeling case studies. First, a Doppler-ducted wave trapped within relatively weak wind flow ...


The Effect Of Negative Energy Shells On Schwarzschild Spacetime And Their Penrose Diagrams, Jeffrey Hazboun, Tevian Dray Jul 2009

The Effect Of Negative Energy Shells On Schwarzschild Spacetime And Their Penrose Diagrams, Jeffrey Hazboun, Tevian Dray

Presentations

No abstract provided.


The Effect Of Negative-Energy Shells On The Schwarzschild Black Hole, Jeffrey Hazboun, Tevian Dray Jul 2009

The Effect Of Negative-Energy Shells On The Schwarzschild Black Hole, Jeffrey Hazboun, Tevian Dray

Faculty publications

We construct Penrose diagrams for Schwarzschild spacetimes joined by massless shells of matter, in the process correcting minor flaws in the similar diagrams drawn by Dray and ’t Hooft (Commun Math Phys 99:613–625, 1985), and confirming their result that such shells generate a horizon shift. We then consider shells with negative energy density, showing that the horizon shift in this case allows for travel between the heretofore causally separated exterior regions of the Schwarzschild geometry. These drawing techniques are then used to investigate the properties of successive shells, joining multiple Schwarzschild regions. Again, the presence of negative-energy shells ...


Flight Experiments On The Effects Of Contamination On Electron Emission Of Materials, Jr Dennison, Joshua L. Hodges, Jeff Duce, Amberly Evans Jun 2009

Flight Experiments On The Effects Of Contamination On Electron Emission Of Materials, Jr Dennison, Joshua L. Hodges, Jeff Duce, Amberly Evans

All Physics Faculty Publications

We report on a study of the effects of prolonged exposure to the space environment and of chargeenhanced contamination on the electron emission and resistivity of spacecraft materials. The State of Utah Space Environment & Contamination Study (SUSpECS) was deployed on the International Space Station (ISS) in March 2008 onboard the MISSE-6 payload during STS-123. The Materials International Space Station Experiment (MISSE-6) program is designed to characterize the performance of candidate new space materials over the course of its ~17 month exposure to the LEO environment, with a target return date of August 2009 on STS-127. Approximately 165 samples are mounted ...


Electron Densities In The Lower Thermosphere From Guvi 135.6 Nm Tomographic Inversions In Support Of Spreadfex, F. Kamalabadi, J. Comberiate, Michael J. Taylor, Pierre-Dominique Pautet Jun 2009

Electron Densities In The Lower Thermosphere From Guvi 135.6 Nm Tomographic Inversions In Support Of Spreadfex, F. Kamalabadi, J. Comberiate, Michael J. Taylor, Pierre-Dominique Pautet

All Physics Faculty Publications

The SpreadFEx campaign was conducted with the goal of investigating potential neutral atmospheric dynamics influences in seeding plasma instabilities and bubbles extending to higher altitudes from September to November 2005, with primary measurements in Brazil. In this paper, we present the results of space-based UV and ground-based optical observations in support of this campaign. Specifically, we present multi-dimensional electron density images obtained tomographically from the 135.6 nm emissions measured by the GUVI instrument aboard the TIMED satellite that result from radiative recombination of O+ and compare those with the corresponding 630.0 nm OI images recorded in the Brazilian ...


The First Frontier: High Altitude Ballooning As A Platform For Student Research Experiences In Science And Engineering, Shane L. Larson, John C. Armstrong, William A. Hiscock Jun 2009

The First Frontier: High Altitude Ballooning As A Platform For Student Research Experiences In Science And Engineering, Shane L. Larson, John C. Armstrong, William A. Hiscock

All Physics Faculty Publications

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High altitude balloon platforms are ideal for providing hands-on research experiences for students in physics, atmospheric science, engineering, and other aerospace-related disciplines. We describe a basic high altitude balloon platform that can be constructed and operated by undergraduate students. The existing HARBOR and BOREALIS programs are used to illustrate some possible science and engineering research projects that students can pursue as part of a high-altitude flight program.


Simultaneous Observations Of Equatorial F-Region Plasma Depletions Over Brazil During The Spread-F Experiment (Spreadfex), Pierre-Dominique Pautet, Michael J. Taylor, N. P. Chapagain, H. Takahashi, A. F. Medeiros, F. T. São Sabbas, D. C. Fritts Jun 2009

Simultaneous Observations Of Equatorial F-Region Plasma Depletions Over Brazil During The Spread-F Experiment (Spreadfex), Pierre-Dominique Pautet, Michael J. Taylor, N. P. Chapagain, H. Takahashi, A. F. Medeiros, F. T. São Sabbas, D. C. Fritts

All Physics Faculty Publications

From September to November 2005, the NASA Living with a Star program supported the Spread-F Experiment campaign (SpreadFEx) in Brazil to study the effects of convectively generated gravity waves on the ionosphere and their role in seeding Rayleigh-Taylor instabilities, and associated equatorial plasma bubbles. Several US and Brazilian institutes deployed a broad range of instruments (all-sky imagers, digisondes, photometers, meteor/VHF radars, GPS receivers) covering a large area of Brazil. The campaign was divided in two observational phases centered on the September and October new moon periods. During these periods, an Utah State University (USU) all-sky CCD imager operated at ...


Mesospheric Atmospheric Gravity Wave Properties Derived From Rayleigh-Scatter Lidar Observations Above Logan, Utah, Durga Kafle May 2009

Mesospheric Atmospheric Gravity Wave Properties Derived From Rayleigh-Scatter Lidar Observations Above Logan, Utah, Durga Kafle

Posters

Approximately 900 nights of observations with a Rayleigh-scatter lidar at Utah State University’s Atmospheric Lidar Observatory (41.7°N, 111.8°W, 1.47 km above sea level), spanning the 11-year period from late 1993 through 2004, have been reduced to derive nighttime temperature and relative density profiles between 45 and 90 km. Of these, 150 profiles that extend to 90 km or above were used in this work, which is based mainly on relative density data with 3-km altitude resolution and 1-hour temporal resolution. This is, we believe, the first comprehensive study of monochromatic gravity waves using Rayleigh-Scatter ...


Electrostatic Discharge In Spacecraft Materials, Jennifer Roth, Jr Dennison, Ryan C. Hoffman, David Peak May 2009

Electrostatic Discharge In Spacecraft Materials, Jennifer Roth, Jr Dennison, Ryan C. Hoffman, David Peak

Senior Theses and Projects

Understanding the characteristics of electron beam bombardment that induce electrostatic discharge (ESD) of insulating materials is crucial to constructing an electrically stable spacecraft. A measurement system has been designed to determine the beam energy and charge flux densities at which typical spacecraft materials intended for the James Webb Space Telescope (JWST) undergo ESD. Because discharge events occur over time intervals ranging from nanoseconds to minutes, multiple detection methods were employed as charge was accumulated on a sample surface; these methods included monitoring of sample current and optical emissions from the sample surface. Each sample was also examined with optical microscopy ...


Analysis Of Total Electron Content (Tec) Variations In The Low- And Middle-Latitude Ionosphere, Ja Soon Shim May 2009

Analysis Of Total Electron Content (Tec) Variations In The Low- And Middle-Latitude Ionosphere, Ja Soon Shim

All Graduate Theses and Dissertations

Detailed study of the spatial correlations of day-to-day ionospheric TEC variations on a global scale was performed for four 30-day-long periods in 2004 (January, March/April, June/July, September/October) using observations from more than 1000 ground-based GPS receivers. In order to obtain the spatial correlations, initially, the day-to-day variability was calculated by first mapping the observed slant TEC values for each 5-minute GPS ground receiver-satellite pair to the vertical and then differencing it with its corresponding value from the previous day. This resulted

in more than 150 million values of day-to-day change in TEC (delta TEC). Next, statistics were ...


On The Applicability Of Genetic Algorithms To Fast Solar Spectropolarimetric Inversions For Vector Magnetography, Brian J. Harker May 2009

On The Applicability Of Genetic Algorithms To Fast Solar Spectropolarimetric Inversions For Vector Magnetography, Brian J. Harker

All Graduate Theses and Dissertations

The measurement of vector magnetic fields on the sun is one of the most important diagnostic tools for characterizing solar activity. The ubiquitous solar wind is guided into interplanetary space by open magnetic field lines in the upper solar atmosphere. Highly-energetic solar flares and Coronal Mass Ejections (CMEs) are triggered in lower layers of the solar atmosphere by the driving forces at the visible ``surface'' of the sun, the photosphere. The driving forces there tangle and interweave the vector magnetic fields, ultimately leading to an unstable field topology with large excess magnetic energy, and this excess energy is suddenly and ...


Novel Growth Of Ingaas/Gaas Nanostructures By Molecular Beam Epitaxy, Dong Jun Kim May 2009

Novel Growth Of Ingaas/Gaas Nanostructures By Molecular Beam Epitaxy, Dong Jun Kim

All Graduate Theses and Dissertations

This dissertation presents an extensive study of the epitaxial growth mechanism by a novel growth method. This novel growth method was developed at Utah State University and is a modification of the Stranski-Krastanov (S-K) growth mode. Our new growth method consists of a two-step process, low temperature growth and high temperature annealing. During low temperature growth, diffusion is minimized, resulting in the deposition of a pseudomorphic epilayer. During high temperature annealing, diffusion is induced from the pseudomorphic epilayer, resulting in the transformation of the epilayer into nanostructures. Benefits of this novel growth method are a significantly smaller segregation and suppressed ...


Algebraic Computing Tools In General Relativity: Energy-Momentum Tensors And Exact Solutions To The Einstein Field Equations, Sydney Joanne Chamberlin May 2009

Algebraic Computing Tools In General Relativity: Energy-Momentum Tensors And Exact Solutions To The Einstein Field Equations, Sydney Joanne Chamberlin

Undergraduate Honors Capstone Projects

Maple is a mathematical software program containing packages of tools that may be used in making difficult computations. The Tensor sub-package of Maple's Differential Geometry package is a collection of commands used for making tensor computations on manifolds. We present a series of new tools for the Tensor package. Included with these tools are new commands to compute objects of geometric and physical interest -energy-momentum tensors, matter field equations, the Bel-Robinson tensor, etc. -along with tools to compute the geometric properties of these objects. Additionally, an electronic database of exact solutions to the Einstein field equations has been created ...


Polar Mesospheric Clouds: A Satellite And Ground-Based Comparison, Jodie Barker-Tvedtnes May 2009

Polar Mesospheric Clouds: A Satellite And Ground-Based Comparison, Jodie Barker-Tvedtnes

Undergraduate Honors Capstone Projects

Polar Mesospheric Clouds (PMCs) are tenuous ice clouds that form near the cold (<150K) summer mesopause region (80-85 km). From the ground, these clouds are seen during twilight hours as Noctilucent or “night shining” Clouds (NLCs) and are typically seen from latitudes from 50° to 65°. Observations by the Solar Backscatter Ultraviolet (SBUV) instruments on the NOAA satellites have shown that the occurrence and brightness of NLCs have been increasing over the last three decades prompting speculation concerning their possible role in climate change. Recently the Aeronomy of Ice in the Mesosphere (AIM) satellite was launched (April 2007) and is the first satellite dedicated to the study of NLCs. In this report, we compare SBUV and AIM PMC observations with ground-based image data collected during two campaigns from Edmonton, Canada (June 30-July 17, 2007) and Delta Junction, Alaska (July 29-August 17, 2007). Four nights of data are discussed where coincident measurements were obtained by AIM, SBUV/2 and ground-based imagers. The results show good spatial or temporal agreement, but rarely both, and illustrate the importance of coordinated measurements for better understanding the geographic and local time variability of PMCs. Initial studies using data from the Ozone Monitoring Instrument (OMI) on the AURA satellite are also presented.


Electrostatic Discharge In Spacecraft Materials, Jennifer Albretsen Roth May 2009

Electrostatic Discharge In Spacecraft Materials, Jennifer Albretsen Roth

Undergraduate Honors Capstone Projects

Understanding the characteristics of electron beam bombardment that induce electrostatic discharge (ESD) of insulating materials is crucial to constructing an electrically stable spacecraft. A measurement system has been designed to determine the beam energy and charge flux densities at which typical spacecraft materials intended for the James Webb Space Telescope (JWST) undergo ESD. Because discharge events occur over time intervals ranging from nanoseconds to minutes, multiple detection methods were employed as charge was accumulated on a sample surface; these methods included monitoring of sample current and optical emissions from the sample surface. Each sample was also examined with optical microscopy ...


Rayleigh-Lidar Determinations Of The Vertical Wavelength Of Mesospheric Gravity Wave, Joe R. Slansky, Durga N. Kafle, Vincent B. Wickwar Apr 2009

Rayleigh-Lidar Determinations Of The Vertical Wavelength Of Mesospheric Gravity Wave, Joe R. Slansky, Durga N. Kafle, Vincent B. Wickwar

Posters

Atmospheric structures have been observed in the Rayleigh lidar data acquired between 1993 and 2004 at Utah State University (USU). The observations pertain to the density and temperature in the mesosphere between 45 and 90 km altitude. The structures referred to arise from monochromatic Atmospheric Gravity Waves (AGWs). Previous analysis of these data have searched for and found a spectrum with a peak in the vertical wavelength 12–16 km. It has been suggested by other researchers using other types of data that there may be another peak in the spectrum at shorter wavelengths. For this study the lidar data ...


Rayleigh-Lidar Observations Of Mesospheric Instabilities, Gabriel C. Taylor, Durga N. Kafle, Vincent B. Wickwar Apr 2009

Rayleigh-Lidar Observations Of Mesospheric Instabilities, Gabriel C. Taylor, Durga N. Kafle, Vincent B. Wickwar

Posters

From 1993 to 2004 the Utah State University Rayleigh lidar, known as the USU green laser, collected 900 nights of data from the mesosphere (45-90 km). From these observations profiles of relative neutral densities and absolute temperatures were derived. Usually, the atmosphere is horizontally stratified with a balance between gravitational and pressure forces. When this balance is perturbed, it leads to the generation of buoyancy or “gravity” waves. An example of these is clear air turbulence, which can have dramatic effects on airplanes. As these waves propagate upward, the decrease in atmospheric density and conservation of energy combine to give ...


First Observation Of An Undular Mesospheric Bore In A Doppler Duct, J. Fechine, C. M. Wrasse, H. Takahashi, A. F. Medeiros, P. P. Batista, B. R. Clemesha, L. M. Lima, D. C. Fritts, B. Laughman, Michael J. Taylor, Pierre-Dominique Pautet, M. G. Mlynczak, J. M. Russell Apr 2009

First Observation Of An Undular Mesospheric Bore In A Doppler Duct, J. Fechine, C. M. Wrasse, H. Takahashi, A. F. Medeiros, P. P. Batista, B. R. Clemesha, L. M. Lima, D. C. Fritts, B. Laughman, Michael J. Taylor, Pierre-Dominique Pautet, M. G. Mlynczak, J. M. Russell

All Physics Faculty Publications

On 1 October 2005, during the SpreadFEx campaign, a distinct mesospheric bore was observed over S˜ao Jo˜ao do Cariri (7.4 S, 36.5 W), Brazil by using airglow allsky imagers. The event appeared both in the OI5577 and OH emissions, forming a well extended wave front which was followed by short waves from behind. Simultaneous wind and temperature data obtained by the meteor radar and the TIMED/SABER satellite instrument revealed that the bore event occurred during the Doppler ducting condition in the emission layers.


Core-Level Spectroscopy Of The Pd/W(110) Interface: Evidence Of Long-Range Pd-Island—Winteractions At Submonolayer Coverages, D. Mark Riffe, N. D. Shinn, B. Kim, K. J. Kim, T. H. Kang Apr 2009

Core-Level Spectroscopy Of The Pd/W(110) Interface: Evidence Of Long-Range Pd-Island—Winteractions At Submonolayer Coverages, D. Mark Riffe, N. D. Shinn, B. Kim, K. J. Kim, T. H. Kang

All Physics Faculty Publications

We have measured W 4f7/2 core-level photoemission spectra from W(1 1 0) in the presence of Pd overlayers for coverages up to ∼1 pseudomorphic monolayer (ML). At coverages close to 0.05 ML a striking change in the W core-level spectrum is observed, which we interpret as indicating a long-range lateral effect of 2D Pd islands upon the W electronic structure in both the first and second W layers. As the coverage increases the long-range effect weakens and finally vanishes near 0.85 ML. Above this coverage the W spectra are typical for a W-based bimetallic ...


Simultaneous Observation Of Ionospheric Plasma Bubbles And Mesospheric Gravity Waves During The Spreadfex Campaign, H. Takahashi, Michael J. Taylor, Pierre-Dominique Pautet, A. F. Medeiros, D. Gobbi, C. M. Wrasse, J. Fechine, M. A. Abdu, I. S. Batista, E. R. De Paula, J. A.H. Sobral, D. Aruda, D. C. Fritts Apr 2009

Simultaneous Observation Of Ionospheric Plasma Bubbles And Mesospheric Gravity Waves During The Spreadfex Campaign, H. Takahashi, Michael J. Taylor, Pierre-Dominique Pautet, A. F. Medeiros, D. Gobbi, C. M. Wrasse, J. Fechine, M. A. Abdu, I. S. Batista, E. R. De Paula, J. A.H. Sobral, D. Aruda, D. C. Fritts

All Physics Faculty Publications

During the Spread F Experiment campaign, under NASA Living with a Star (LWS) program, carried out in the South American Magnetic Equator region from 22 September to 8 November 2005, two airglow CCD imagers, located at Cariri (7.4° S, 36.5° W, geomag. 11° S) and near Brasilia (14.8° S, 47.6° W, geomag. 10° S) were operated simultaneously and measured the equatorial ionospheric bubbles and their time evolution by monitoring the airglow OI 6300 intensity depletions. Simultaneous observation of the mesospheric OH wave structures made it possible to investigate the relationship between the bubble formation in the ...


Space Research Projects For The International Space Station, Kyle Hodgson Mar 2009

Space Research Projects For The International Space Station, Kyle Hodgson

Posters

Space Italian Dressing Experimental Setup (SIDES) examines the dynamics of fluid segregation between fluids of differing densities. While in space the fluids will not undergo buoyant or convective forces, thus isolating the affects of separation due to density and molecular forces. The experiment will serve as an outreach experiment in addition to gleaning scientific data; mixtures are a topic of study in the 5th grade curriculum.

The objective of International Paper Airplanes in Space (IPAS) is to excite children about space research by giving them a chance to take part in it. IPAS includes collecting paper airplanes made by elementary-school ...


Microgravity Experiments For The Iss, Justin Koeln, Jan Sojka Mar 2009

Microgravity Experiments For The Iss, Justin Koeln, Jan Sojka

Posters

The Get Away Special (GAS) team is a microgravity research team known for leading Utah State University to the impressive distinction of flying more experiments in space than any other university in the world. The following experiments were designed by the GAS team after receiving the opportunity to develop and experiment to be performed by a Space Flight Participant aboard the International Space Station (ISS).