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Utah State University

2016

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Articles 1 - 30 of 96

Full-Text Articles in Physics

Foundations Of Wave Phenomena, Charles G. Torre Dec 2016

Foundations Of Wave Phenomena, Charles G. Torre

Charles G. Torre

This is an undergraduate text on the mathematical foundations of wave phenomena. Version 8.2.


Foundations Of Wave Phenomena: Complete Version, Charles G. Torre Dec 2016

Foundations Of Wave Phenomena: Complete Version, Charles G. Torre

Foundations of Wave Phenomena

This is the complete version of Foundations of Wave Phenomena. Version 8.3.


Please click here to explore the components of this work.


On The Propagation Of Atmospheric Gravity Waves In A Non-Uniform Wind Field: Introducing A Modified Acoustic-Gravity Wave Equation, Ahmad Talaei Dec 2016

On The Propagation Of Atmospheric Gravity Waves In A Non-Uniform Wind Field: Introducing A Modified Acoustic-Gravity Wave Equation, Ahmad Talaei

All Graduate Plan B and other Reports

Atmospheric gravity waves play fundamental roles in a broad-range of dynamical processes extending throughout the Earth’s neutral atmosphere and ionosphere. In this paper, we present a modified form for the acoustic-gravity wave equation and its dispersion relationships for a compressible and non-stationary atmosphere in hydrostatic balance. Importantly, the solutions have been achieved without the use of the well-known Boussinesq approximation which have been used extensively in previous studies.

We utilize the complete set of governing equations for a compressible atmosphere with non-uniform airflows to determine an equation for vertical velocity of possible atmospheric waves. This intricate wave equation is ...


Dynamical Interactions Between Two Uniformly Magnetized Spheres, Boyd F. Edwards, John M. Edwards Nov 2016

Dynamical Interactions Between Two Uniformly Magnetized Spheres, Boyd F. Edwards, John M. Edwards

All Physics Faculty Publications

Studies of the two-dimensional motion of a magnet sphere in the presence of a second, fixed sphere provide a convenient venue for exploring magnet-magnet interactions, inertia, friction, and rich nonlinear dynamical behavior. These studies exploit the equivalence of these magnetic interactions to the interactions between two equivalent point dipoles. We show that magnet-magnet friction plays a role when magnet spheres are in contact, table friction plays a role at large sphere separations, and eddy currents are always negligible. Web-based simulation and visualization software, called MagPhyx, is provided for education, exploration, and discovery


High Altitude Dependence Of Ionizing Radiation From Cosmic Rays, Zack Gibson, Akihiro Nagata, Midori Morikawa, Takuyuki Sakai, Takahiro Shimizu, Yuta Takahashi, Shusuke Okita, Raul Ramirez, Alexandra Hughlett, Toshihiro Kameda, Jr Dennison Oct 2016

High Altitude Dependence Of Ionizing Radiation From Cosmic Rays, Zack Gibson, Akihiro Nagata, Midori Morikawa, Takuyuki Sakai, Takahiro Shimizu, Yuta Takahashi, Shusuke Okita, Raul Ramirez, Alexandra Hughlett, Toshihiro Kameda, Jr Dennison

Posters

The flux of ionizing radiation from cosmic background sources has been measured as a function of altitude using a compact Geiger counter aboard a high altitude balloon. The payload was developed by researchers from University of Tsukuba and flown under the auspices of the Utah State Get-Away-Special (GAS) team. Dose rate, temperature, pressure, humidity, altitude and position data were acquired during a ~4 hour flight up to an altitude of 32 km in August 2016. The altitude reached by this balloon was more than 5 times the height of that reached by Victor Hess’ experiment in 1912, which later won ...


Space Environment Effects Of Ionizing Radiation On Seed Germination And Growth, Alex Souvall, Takuyuki Sakai, Takahiro Shimizu, Yuta Takahashi, Midori Morikawa, Shusuke Okita, Akihiro Nagata, Toshihiro Kameda, Shaunda Wenger, Jr Dennison Oct 2016

Space Environment Effects Of Ionizing Radiation On Seed Germination And Growth, Alex Souvall, Takuyuki Sakai, Takahiro Shimizu, Yuta Takahashi, Midori Morikawa, Shusuke Okita, Akihiro Nagata, Toshihiro Kameda, Shaunda Wenger, Jr Dennison

Presentations

An initial limited set of tests of germination rate and seed growth in a controlled environment have identified statistically significant differences between control samples and seed flown in a Russian LEO research flight. Most significantly, average seed germination of space borne seeds was 2 days less than the 6 days for the control seeds. Modification of the seed coat leading to enhanced rate of water uptake, as a result of radiation from the space environment or abrasion due to launch vibrations, is hypothesized to cause early germination. High school students will conduct growth tests on seeds exposed to simulated space ...


Plasma Deflection Test Setup For E-Sail Propulsion Concept, Allen Andersen, Jason Vaughn, Todd Schneider, Ken Wright Oct 2016

Plasma Deflection Test Setup For E-Sail Propulsion Concept, Allen Andersen, Jason Vaughn, Todd Schneider, Ken Wright

Presentations

The Electronic Sail or E-Sail is a novel propulsion concept based on momentum exchange between fast solar wind protons and the plasma sheath of long positively charged conductors comprising the E-Sail. The effective sail area increases with decreasing plasma density allowing an E-Sail craft to continue to accelerate at predicted ranges well beyond the capabilities of existing electronic or chemical propulsion spacecraft. While negatively charged conductors in plasmas have been extensively studied and flown, the interaction between plasma and a positively charged conductor is not well studied. We present a plasma deflection test method using a differential ion flux probe ...


Relaxation Of Radiation Effects On The Optical Transmission Of Polymers, Alexandra Hughlett, Tyler Kippen, J. R. Dennison Oct 2016

Relaxation Of Radiation Effects On The Optical Transmission Of Polymers, Alexandra Hughlett, Tyler Kippen, J. R. Dennison

Posters

Changes in optical transmission of polymers over time were studied to determine the factors contributing to relaxation of defect states induced by intense radiation doses. Samples of low density polyethylene (LDPE), polyether ether ketone (PEEK), polypropylene (PP), and polyimide (PI) received doses up to 500 MGy from an 8 MeV electron accelerator. These doses were intended to simulate long-term exposure of common spacecraft materials in geosynchronous orbit. Features and absorption edges in ~250 nm to 1000 nm UV to IR transmission spectra can be related to energies associated with various defects previously observed in these highly disordered materials. Recent work ...


Temperature Dependence Of Electrostatic Breakdown In Highly Disordered Polymers, Tyler Kippen Oct 2016

Temperature Dependence Of Electrostatic Breakdown In Highly Disordered Polymers, Tyler Kippen

Senior Theses and Projects

No abstract provided.


Temperature Dependency Of Electrostatic Breakdown In Ldpe And Peek, Tyler Kippen, Allen Andersen, Jr Dennison Sep 2016

Temperature Dependency Of Electrostatic Breakdown In Ldpe And Peek, Tyler Kippen, Allen Andersen, Jr Dennison

Posters

Electrostatic breakdown is a leading cause of many of the anomalies and failures attributed to spacecraft interactions with the space environment. It is therefore critical to understand how the electrostatic field strength varies due to changing environmental conditions, including temperature and radiation dose. Standard step-up to electrostatic discharge (ESD) tests were performed on two polymers, low density polyethylene (LDPE) and polyetheretherketone (PEEK). Tests were done at room temperature and at other temperatures ranging from ~130 K to ~350 K. Preliminary analysis found that samples tested at a higher temperature had lower average breakdown field strength and a narrower distribution of ...


Predictive Formula For Electron Penetration Depth Of Diverse Materials Over Large Energy Ranges, Anne C. Starley, Gregory Wilson, Lisa Phillipps, Jr Dennison Sep 2016

Predictive Formula For Electron Penetration Depth Of Diverse Materials Over Large Energy Ranges, Anne C. Starley, Gregory Wilson, Lisa Phillipps, Jr Dennison

Posters

No abstract provided.


Dependence Of Electrostatic Field Strength On Voltage Ramp Rate For Spacecraft Materials, Krysta Moser, Allen Andersen, Jr Dennison Sep 2016

Dependence Of Electrostatic Field Strength On Voltage Ramp Rate For Spacecraft Materials, Krysta Moser, Allen Andersen, Jr Dennison

Posters

No abstract provided.


Mineral Physics Modeling Of The Effect Of Water On Crustal Seismic Velocity Ratios, Eric Lyman Sep 2016

Mineral Physics Modeling Of The Effect Of Water On Crustal Seismic Velocity Ratios, Eric Lyman

Physics Capstone Project

This research explores the relationship between the presence of water (H2O) in the make up of rocks and minerals (specifically quartz) at different levels in the crust. The relationships were calculated using Perple_x software to adjust the level of the different chemical and mineral make up of the rock. The densities were calculated using the velocity of primary waves and shear waves as collected by Tony Lowry. There seems to be at least a casual link between water content and quartz content.


Mysterious Mesospheric Bores Over The South Pole, Christina Solorio Sep 2016

Mysterious Mesospheric Bores Over The South Pole, Christina Solorio

Physics Capstone Project

Abstract. During the winter‐time, the South Pole lies at the center of the giant Antarctic polar vortex which isolates it from the rest of the world. Over the past four years, USU has successfully operated an infrared camera at the US Amundsen‐Scott South Pole Station to investigate dynamics of atmospheric gravity waves within the vortex. Gravity waves are generated when a force disturbs an air packet and buoyant and gravitational forces in turn cause it to oscillate. While gravity waves in general are ubiquitous in the atmosphere, propagating well into the mesosphere and lower thermosphere region (~80‐100 ...


Evidence Of The Excitation Of A Ring-Like Gravity Wave In The Mesosphere Over The Andes Lidar Observatory, F. Vargas, G. Swenson, A. Liu, Pierre-Dominique Pautet Aug 2016

Evidence Of The Excitation Of A Ring-Like Gravity Wave In The Mesosphere Over The Andes Lidar Observatory, F. Vargas, G. Swenson, A. Liu, Pierre-Dominique Pautet

All Physics Faculty Publications

On 23 March 2012, our all-sky imager recorded a concentric, ring-like gravity wave pattern. The wave arose within the area covered by images of both OH and O(1S) nightglow emissions taken at the Andes Lidar Observatory (ALO), Chile (30.3ÁS, 70.7ÁW). We have estimated the observed and intrinsic parameters of the event and located the wave source within the lower mesosphere altitude range using a reverse ray tracing method. By the analysis of GOES and LIS satellite images, we have not found evidence of neither convective nor lightning activity nearby ALO, indicating that the source of the ring-like ...


Smartphone Seismology: Data Acquisition Through Consumer Available Devices, Matt Olsen Aug 2016

Smartphone Seismology: Data Acquisition Through Consumer Available Devices, Matt Olsen

Physics Capstone Project

No abstract provided.


Cubesat Space Environments Effects Studied In The Space Survivability Test Chamber, Jr Dennison, Gregory Wilson, Alex Souvall, Ben Russon, Katie Gamaunt Aug 2016

Cubesat Space Environments Effects Studied In The Space Survivability Test Chamber, Jr Dennison, Gregory Wilson, Alex Souvall, Ben Russon, Katie Gamaunt

Posters

CubeSats are particularly susceptible to environmental-induced modifications, which can lead to deleterious or catastrophic consequences. This is increasingly important as small satellites—with minimal shielding due to reduced mass and size constraints and reliance on more compact and sensitive electronics—have longer mission lifetimes and make more diverse, complex and sensitive measurements. The current push to expand deployment of CubeSats beyond LEO, into even more demanding environments where modest relief due to shielding by the Earth’s magnetosphere is absent (such as polar or GEO orbits), can further exacerbate these problems.

Testing of small satellites is therefore critical to avoid ...


Scale Analysis Of Equatorial Plasma Irregularities Derived From Swarm Constellation, Chao Xiong, Claudia Stolle, Hermann Lühr, Jaeheung Park, Bela G. Fejer, Guram N. Kervalishvili Jul 2016

Scale Analysis Of Equatorial Plasma Irregularities Derived From Swarm Constellation, Chao Xiong, Claudia Stolle, Hermann Lühr, Jaeheung Park, Bela G. Fejer, Guram N. Kervalishvili

All Physics Faculty Publications

In this study, we investigated the scale sizes of equatorial plasma irregularities (EPIs) using measurements from the Swarm satellites during its early mission and final constellation phases. We found that with longitudinal separation between Swarm satellites larger than 0.4°, no significant correlation was found any more. This result suggests that EPI structures include plasma density scale sizes less than 44 km in the zonal direction. During the Swarm earlier mission phase, clearly better EPI correlations are obtained in the northern hemisphere, implying more fragmented irregularities in the southern hemisphere where the ambient magnetic field is low. The previously reported ...


Stratospheric Gravity Wave Fluxes And Scales During Deepwave, Ronald B. Smith, Allison D. Nugent, Christopher G. Kruse, David C. Fritts, James D. Doyle, Steven D. Eckermann, Michael J. Taylor, Andreas Dornbrack, M. Uddstrom, William Cooper, Jorgen Jensen, Stuart Beaton Jul 2016

Stratospheric Gravity Wave Fluxes And Scales During Deepwave, Ronald B. Smith, Allison D. Nugent, Christopher G. Kruse, David C. Fritts, James D. Doyle, Steven D. Eckermann, Michael J. Taylor, Andreas Dornbrack, M. Uddstrom, William Cooper, Jorgen Jensen, Stuart Beaton

All Physics Faculty Publications

During the Deep Propagating Gravity Wave Experiment (DEEPWAVE) project in June and July 2014, the Gulfstream V research aircraft flew 97 legs over the Southern Alps of New Zealand and 150 legs over the Tasman Sea and Southern Ocean, mostly in the low stratosphere at 12.1-km altitude. Improved instrument calibration, redundant sensors, longer flight legs, energy flux estimation, and scale analysis revealed several new gravity wave properties. Over the sea, flight-level wave fluxes mostly fell below the detection threshold. Over terrain, disturbances had characteristic mountain wave attributes of positive vertical energy flux (EFz), negative zonal momentum flux, and ...


Obtaining Continuous Observations From The Upper Stratosphere To The Lower Thermosphere Using The Alo-Usu Rayleigh-Scatter Lidar., Jonathan L. Price, Vincent B. Wickwar, Leda Sox, Matthew T. Emerick, Joshua P. Herron, Shayli Elliott, Bryant Ward, Benjamin Lovelady Jun 2016

Obtaining Continuous Observations From The Upper Stratosphere To The Lower Thermosphere Using The Alo-Usu Rayleigh-Scatter Lidar., Jonathan L. Price, Vincent B. Wickwar, Leda Sox, Matthew T. Emerick, Joshua P. Herron, Shayli Elliott, Bryant Ward, Benjamin Lovelady

Posters

The Rayleigh-scatter lidar at the Atmospheric Lidar Observatory at Utah State University (ALO-USU; 41.74° N, 111.81° W) started observations in 1993. In 2012 the original lidar system was upgraded with an array of larger mirrors and two lasers to enable observations of the upper mesosphere and lower thermosphere from 70 km to about 115 km in altitude. (Continued refinement should provide data to above 120 km.) Recently, the original system was reconfigured [Elliott et al., 2016] to again observe the lower mesosphere between 40 km and 90 km. Initial data collected by these two parts of the Rayleigh ...


Searching For Troposphere-Mesosphere Connections Using The Alo-Usu Rayleigh-Scatter Lidar, David K. Moser, Vincent B. Wickwar, Joshua P. Herron Jun 2016

Searching For Troposphere-Mesosphere Connections Using The Alo-Usu Rayleigh-Scatter Lidar, David K. Moser, Vincent B. Wickwar, Joshua P. Herron

Posters

The paucity of whole-atmosphere data introduces significant challenges that hinder the study of atmospheric couplings. The mesosphere in particular is a low-information void between the lower and upper atmosphere, which may prevent us from a complete realization of vertical interactions. The Rayleighscatter lidar at Utah State University’s Atmospheric Lidar Observatory (ALO-USU; 41.74° N, 111.81° W), operated with little interruption from 1993 to 2004, providing a valuable temporal and spatial (45 – 90 km) resource in this realm. When studied alongside a multitude of other atmospheric data sources, possible unforeseen connections or insights may result. In this study, an ...


Seasonal Temperatures From The Upper Mesosphere To The Lower Thermosphere Obtained With The Large, Alo-Usu, Rayleigh Lidar, Vincent B. Wickwar, Leda Sox, Matthew T. Emerick, Joshua P. Herron Jun 2016

Seasonal Temperatures From The Upper Mesosphere To The Lower Thermosphere Obtained With The Large, Alo-Usu, Rayleigh Lidar, Vincent B. Wickwar, Leda Sox, Matthew T. Emerick, Joshua P. Herron

Posters

Observations have been made with the large, Rayleigh-scatter lidar at the Atmospheric Lidar Observatory at Utah State University (ALO-USU; 41.74° N, 111.81° W) from summer 2014 to summer 2015. During this first operational year, the lidar acquired nearly 100 nights of observations between 70 and 115 km altitude, i.e., from the upper mesosphere, through the mesopause, and into the lower thermosphere. This was possible because of the large 4.9 m2 collecting area of the mirrors and the 42 W of 532 nm emission at 30 Hz. These two factors produce a figure of merit, the power-aperture-product ...


Simultaneous, Collocated Rayleigh And Sodium Lidar Temperature Comparison, Leda Sox, Vincent B. Wickwar, Tao Yuan, Neal Criddle Jun 2016

Simultaneous, Collocated Rayleigh And Sodium Lidar Temperature Comparison, Leda Sox, Vincent B. Wickwar, Tao Yuan, Neal Criddle

Posters

There are relatively few instruments that have the capabilities to make near continuous measurements of the mesosphere-lower-thermosphere (MLT) region. Rayleigh-scatter (RS) and resonance lidars, particularly sodium (Na) resonance lidar, have been the two dominant ground-based techniques for acquiring mesosphere and MLT vertical temperature profiles, respectively, for more than two decades. With these measurements, the dynamics and long-term temperature trends of the MLT region can be studied. For the first time, we will present simultaneous, night-time averaged temperatures acquired from the same observational site, on the campus of Utah State University (USU), using these two lidar techniques. This comparison is also ...


Reestablishing Observations Throughout The Mesosphere With The Alo-Usu Rayleigh-Scatter Lidar, Shayli Elliott, Bryant Ward, Benjamin Lovelady, Jessica Gardiner, Lucas Priskos, Matthew T. Emerick, Vincent B. Wickwar Jun 2016

Reestablishing Observations Throughout The Mesosphere With The Alo-Usu Rayleigh-Scatter Lidar, Shayli Elliott, Bryant Ward, Benjamin Lovelady, Jessica Gardiner, Lucas Priskos, Matthew T. Emerick, Vincent B. Wickwar

Posters

In the last few years, the Rayleigh-scatter lidar at the Atmospheric Lidar Observatory at Utah State University (ALO-USU; 41.74° N, 111.81° W) has been upgraded to extend observations from 70 km up to 115 km. This project describes a student project to build and use a complementary Rayleigh-scatter lidar to go from 40 to 90 km, from the upper stratosphere to the upper mesosphere. At the upper end, this new lidar overlaps with the high-altitude lidar. This was done in a period of just over two months. This lidar shares the same lasers, but introduces a 44-cm mirror ...


The Response Of Equatorial Electrojet, Vertical Plasma Drift, And Thermospheric Zonal Wind To Enhanced Solar Wind Input, Chao Xiong, Hermann LüHr, Bela G. Fejer Jun 2016

The Response Of Equatorial Electrojet, Vertical Plasma Drift, And Thermospheric Zonal Wind To Enhanced Solar Wind Input, Chao Xiong, Hermann LüHr, Bela G. Fejer

All Physics Faculty Publications

In this study we used observations from the CHAMP and ROCSAT-1 satellites to investigate the solar wind effects on the equatorial electrojet (EEJ), vertical plasma drift, and thermospheric zonal wind. We show that an abrupt increase in solar wind input has a significant effect on the low-latitude ionosphere-thermosphere system, which can last for more than 24 h. The disturbance EEJ and zonal wind are mainly westward for all local times and show most prominent responses during 07–12 and 00–06 magnetic local time (MLT), respectively. The equatorial disturbance electric field is mainly eastward at night (most prominent for 00 ...


Solar Cycle Variability In Mean Thermospheric Composition And Temperature Induced By Atmospheric Tides, M. Jones Jr., J. M. Forbes, M. E. Hagan Jun 2016

Solar Cycle Variability In Mean Thermospheric Composition And Temperature Induced By Atmospheric Tides, M. Jones Jr., J. M. Forbes, M. E. Hagan

All Physics Faculty Publications

In this paper we demonstrate that dissipation of upward propagating tides produces significant changes in the mean temperature of the thermosphere, ranging from +19æK at solar minimum to _15æK at solar maximum in the equatorial region. Our methodology consists of measuring the differential response of the thermosphere-ionosphere-electrodynamics general circulation model (TIE-GCM) under solar minimum and solar maximum conditions to constant tidal forcing at its 97ækm lower boundary, as specified by the observationally based Climatological Tidal Model of the Thermosphere. Diagnosis of the model reveals that these changes are mainly driven by 5.3æ_m nitric oxide (NO) cooling, which more efficiently ...


Positive And Negative Gps-Tec Ionospheric Storm Effects During The Extreme Space Weather Event Of March 2015 Over The Brazilian Sector, P. R. Fagundes, F. A. Cardoso, B. G. Fejer, K. Venkatsch, B.A. G. Ribeiro, V. G. Pillat Jun 2016

Positive And Negative Gps-Tec Ionospheric Storm Effects During The Extreme Space Weather Event Of March 2015 Over The Brazilian Sector, P. R. Fagundes, F. A. Cardoso, B. G. Fejer, K. Venkatsch, B.A. G. Ribeiro, V. G. Pillat

All Physics Faculty Publications

We studied the response of the ionosphere (F region) in the Brazilian sector during extreme space weather event of 17 March 2015 using a large network of 102 GPS- total electron content (TEC) stations. It is observed that the vertical total electron content (VTEC) was severely disturbed during the storm main and recovery phases. A wavelike oscillation with three peaks was observed in the TEC diurnal variation from equator to low latitudes during the storm main phase on 17_18 March 2015. The latitudinal extent of the wavelike oscillation peaks decreased from the beginning of the main phase toward the recovery ...


Importance Of Grad-Shafranov Re-Solves Towards Accurately Modeling An Iter Equilibrium In Nimrod, Joseph Jepson May 2016

Importance Of Grad-Shafranov Re-Solves Towards Accurately Modeling An Iter Equilibrium In Nimrod, Joseph Jepson

Physics Capstone Project

No abstract provided.


Instrumentation Enhancements For Electron Yield Measurements Of Extremely Low-Conductivity High-Yield Dielectrics, Justin Christensen, Gregory Wilson, Jr Dennison May 2016

Instrumentation Enhancements For Electron Yield Measurements Of Extremely Low-Conductivity High-Yield Dielectrics, Justin Christensen, Gregory Wilson, Jr Dennison

Conference Proceedings

Electron yield, a material dependent property which describes how it will charge under incident electron irradiation of a given energy, is defined as the number of electrons emitted from a material per incident electron. While very important for spacecraft charging modelling, the measurement of electron yield for insulating materials is very challenging because insulators quickly charge up under electron irradiation, thereby modifying the yield measurements.

Improved techniques have been implemented to reduce charging with each yield measurement, as well as to neutralize acquired charge between measurements. The goal is to determine the “intrinsic yield” (yield of uncharged insulator). New analysis ...


Instrumentation Enhancements For Electron Yield Measurements Of Extremely Low-Conductivity High-Yield Dielectrics, Justin Christensen, Gregory Wilson, Jr Dennison May 2016

Instrumentation Enhancements For Electron Yield Measurements Of Extremely Low-Conductivity High-Yield Dielectrics, Justin Christensen, Gregory Wilson, Jr Dennison

Presentations

Electron yield, a material dependent property which describes how it will charge under incident electron irradiation of a given energy, is defined as the number of electrons emitted from a material per incident electron. While very important for spacecraft charging modelling, the measurement of electron yield for insulating materials is very challenging because insulators quickly charge up under electron irradiation, thereby modifying the yield measurements.

Improved techniques have been implemented to reduce charging with each yield measurement, as well as to neutralize acquired charge between measurements. The goal is to determine the “intrinsic yield” (yield of uncharged insulator). New analysis ...