Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Periodic (3)
- Atmospheric gravity waves (2)
- Bouncing modes (2)
- Magnetized (2)
- Na lidar (2)
-
- Spheres (2)
- AMTM (1)
- Aluminum (1)
- Annealing Temperature (1)
- Antartica (1)
- Atmospheric internal waves (1)
- Benzene (1)
- Carbon-nanotube (1)
- Chaotic (1)
- Charge modeling (1)
- Climate change (1)
- Clusters (1)
- Coriolis force (1)
- Database (1)
- Defects (1)
- Diurnal tidal wave (1)
- Einstein Equations (1)
- Electron Temperature (1)
- Electron yield (1)
- Electrons (1)
- Electrophoresis (1)
- Emission Spectrum (1)
- Energy Distribution (1)
- Environment (1)
- Equivalence Problem (1)
Articles 1 - 24 of 24
Full-Text Articles in Physical Sciences and Mathematics
Traveling-Wave Electrophoresis: 1d Model, Austin Green
Traveling-Wave Electrophoresis: 1d Model, Austin Green
Physics Capstone Projects
A 1D model of traveling-wave electrophoresis predicts that molecular diffusion raises the trapping threshold and that other physical properties of the species effect the trapping threshold as well. Small concentrations, below 5μM, raise the trapping threshold for high diffusivity species, resulting in a lower efficiency. Species with a mid-range electrophoretic mobility and diffusivity have their trapping threshold slightly lowered with an increase in concentration, leading to more particles traveling with the wave.
National Security And Climate Change, Madison Moran
National Security And Climate Change, Madison Moran
Physics Capstone Projects
Certain scientific subjects are often divisive or technical, which makes those topics difficult to discuss with audiences outside the scientific sphere. One way of getting around this obstacle is to cater scientific communication to different target audiences to cut through any audience biases. In order to accomplish that, a communicator needs to understand the relationship between audiences’ worldviews, and what they know, feel, and do regarding the subject at hand, and then how that relationship influences the types of media audiences trust and to which they respond positively. The following study investigates the worldviews of a military audience with respect …
New Techniques For Holography From Supergravity, Oscar Varela
New Techniques For Holography From Supergravity, Oscar Varela
Funded Research Records
No abstract provided.
Hodographic Analysis Of Na Lidar Data To Measure Atmospheric Gravity Wave Parameters, Jeffrey Ormsby
Hodographic Analysis Of Na Lidar Data To Measure Atmospheric Gravity Wave Parameters, Jeffrey Ormsby
Physics Capstone Projects
The Utah State University Sodium lidar observatory, hosted in Science and Engineering Research building at Logan campus, measures the winds and temperature near the boundary of eddy diffusion dominated upper atmosphere between 80 and 110-km, where various atmospheric internal waves, especially atmospheric gravity waves (buoyancy waves), play important roles in the dynamics and chemistry. In this study, using a hodographic algorithm, the lidar data were analyzed to extract critical parameters of these gravity waves detected in this region, such as horizontal propagating phase velocity and wavelength. Results were compared with the independent Advanced Atmospheric Temperature Mapper (AMTM) observations, co-located at …
Design, Monitoring And Management Approaches For The Root-Zone In Microgravity, Scott B. Jones
Design, Monitoring And Management Approaches For The Root-Zone In Microgravity, Scott B. Jones
Funded Research Records
No abstract provided.
Spacetime Groups, Ian M. Anderson, Charles G. Torre
Spacetime Groups, Ian M. Anderson, Charles G. Torre
All Physics Faculty Publications
A spacetime group is a connected 4-dimensional Lie group G endowed with a left invariant Lorentz metric h and such that the connected component of the isometry group of h is G itself. The Newman-Penrose formalism is used to give an algebraic classification of spacetime groups, that is, we determine a complete list of inequivalent spacetime Lie algebras, which are pairs, (g, n), with g being a 4-dimensional Lie algebra and n being a Lorentzian inner product on g. A full analysis of the equivalence problem for spacetime Lie algebras is given which leads to a completely …
Fabrication Of Suspended Microbolometers On Soi Wafers, Isaac Maxfield
Fabrication Of Suspended Microbolometers On Soi Wafers, Isaac Maxfield
Physics Capstone Projects
A bolometer is a device to measure radiation energy by converting photon energy into heat on an isolated absorber. We plan to use carbon-nanotube (CNT) based absorber to enhance the photon absorption. The absorber is a few microns in size and is suspended with micron-sized bridges which also support metal lines for electrical measurements.
Determining The Phase Of The Diurnal, Solar Thermal Tidal Wave In The Upper Atmosphere Using Nighttime Na Lidar Measurements, Trevor Harshman
Determining The Phase Of The Diurnal, Solar Thermal Tidal Wave In The Upper Atmosphere Using Nighttime Na Lidar Measurements, Trevor Harshman
Physics Capstone Projects
Solar thermal tidal waves play a critical role in the dynamics of the mesosphere and thermosphere. Obtaining measurements of the diurnal tidal wave above 100 km is difficult. This could be solved using a physics-based empirical model. To derive this model requires knowing the phase at different points along the tidal wave. In this study, I determine the phase at multiple points along the thermal diurnal tidal wave using measurements taken by a fluorescence lidar in the range of 80 to 100 km. A simple calculation of the phase based on the zeroes and extrema of the wave is demonstrated.
Synthesis Of Graphene By Liquid Precursors At Lower Temperatures, Clayton Hansen
Synthesis Of Graphene By Liquid Precursors At Lower Temperatures, Clayton Hansen
Physics Capstone Projects
Benzene, toluene, and xylene can be liquid precursors for graphene and carbon nanotube synthesis. However, the growth mechanisms can have greater variances for different carbon allotropes. In the case of graphene, Cu can be the catalyst for dehydrogenation and provides a weakly-coupled substrate for 2-dimensional graphene nucleation and growth. In the case of carbon nanotubes, Fe nanoparticles are essential to catalyze the C-C bonds breaking and dissolve carbon before the precipitation of a graphene cap over the catalyst particle where a tube forms. Controlling the precursor feed rate is crucial for a successful synthesis. In this research, we developed a …
Material Outgassing Kinetics: The Development Of A Testing Capability, Alex Kirkman
Material Outgassing Kinetics: The Development Of A Testing Capability, Alex Kirkman
Physics Capstone Projects
Contamination due to outgassing of materials can cause the degradation of critical hardware of a spacecraft. Using outgassing rates, kinetic expressions can be developed and used in models to predict the evolution of molecules and migration of contaminants for specific materials. These models could be used in the selection process of materials to help mitigate the amount of contamination of mission critical hardware for the expected life of the spacecraft. By using the ASTM E1559 test standard this can be achieved. This standard uses the quartz crystal microbalance (QCM) collection approach. A temperature-controlled effusion cell, containing the sample material, impinges …
Waves Over Mcmurdo Station, Robert Johnson
Waves Over Mcmurdo Station, Robert Johnson
Physics Capstone Projects
Atmospheric gravity waves (GWs) are generated by gravity acting on weather systems effectively causing them to oscillate. These waves can then propagate upwards into the upper atmosphere, where they are observed as they pass through glowing layers of gas, called airglow, in the upper atmosphere at approximately 87 kilometers altitude. Using Physics and a little bit of chemistry we can observe the properties of these waves with special infrared cameras. Combining the data between images taken at the same time but with different filters, we can determine the temperature amplitudes of the waves, important for improving our understanding of their …
Clustering And Classifying Geophysical Rock Properties Of The San Andreas Fault, Jared Bryan
Clustering And Classifying Geophysical Rock Properties Of The San Andreas Fault, Jared Bryan
Physics Capstone Projects
Borehole geophysical data provide important in situ observations for identifying and characterizing geologic and structural features in the subsurface. We perform an unsupervised classification of geophysical logs from the Sand Andreas Fault Observatory at Depth (SAFOD) borehole in order to define intervals of distinct geophysical properties. We focus on borehole geophysical data collected during Phase 3 drilling operations from 3.0-3.3 km measured depth, which encompasses the active trace of the San Andreas Fault. We use dimensionality reduction to increase the interpretability of the retrieved clusters, and we compare the performance of distance- and density-based clustering techniques. K-means clustering produces highly …
Optical Relaxation Of Defects In Kapton Caused By Irradiation, Ashlan Keeler Swainston
Optical Relaxation Of Defects In Kapton Caused By Irradiation, Ashlan Keeler Swainston
Physics Capstone Projects
Radiation can create atomic-scale defect states in polymers, leading to changes in their optical, electrical and mechanical properties. Recent studies of polymers have shown that these defect states are sensitive to oxygen or air exposure. It is believed that air cause the number of defect states to decrease and the polymers to revert to their original states. However, the time scale of this regression is not known. This experiment quantified the time that it takes one polymer to recover and the extent of said recovery; polymide (PI). In order to study the regression, optical transmission data were taken using a …
Understanding Noether’S Theorem By Visualizing The Lagrangian, Seth Moser
Understanding Noether’S Theorem By Visualizing The Lagrangian, Seth Moser
Physics Capstone Projects
By approaching Lagrangian mechanics from a graphical perspective the implications of Noether’s Theorem can be made easier to understand. Plotting the Lagrangian for classical single particle systems for one coordinate onto a position-velocity phase space along with the corresponding equations of motion can demonstrate how a system is invariant under continuous transforms in that coordinate. This invariance can be shown to be associated with a quantity in the system that’s conserved via Noether’s Theorem. The relationship between the symmetry of the system and conserved quantities can then be extended to fields. Invariance in this case is extended to include invariance …
Evidence For Horizontal Blocking And Reflection Of A Small‐Scale Gravity Wave In The Mesosphere, Neal R. Criddle, Pierre-Dominique Pautet, Tao Yuan, C. Heale, J. Snively, Yucheng Zhao, Michael J. Taylor
Evidence For Horizontal Blocking And Reflection Of A Small‐Scale Gravity Wave In The Mesosphere, Neal R. Criddle, Pierre-Dominique Pautet, Tao Yuan, C. Heale, J. Snively, Yucheng Zhao, Michael J. Taylor
All Physics Faculty Publications
The variations of the horizontal phase velocity of an internal gravity wave, generated by wave “blocking” or “reflection” due to an inhomogeneous wind field, have been predicted theoretically and numerically investigated but had yet to be captured experimentally. In this paper, through a collaborative observation campaign using a sodium (Na) Temperature/Wind lidar and a collocated Advanced Mesospheric Temperature Mapper (AMTM) at Utah State University (USU), we report the first potential evidence of such a unique gravity wave process. The study shows that a small‐scale wave, captured by the AMTM, with initial observed horizontal phase velocity of 37 ± 5 m/s …
Determing The Chaotic Nature Of Periodic Orbits, Bo Johnson
Determing The Chaotic Nature Of Periodic Orbits, Bo Johnson
Physics Capstone Projects
The determination of the long-term behavior of periodic orbits is considered. Different numerical techniques, including the Lyapunov Exponent, the Smaller Alignment Index, and the Generalized Alignment Index are used. Because of the discontinuous nature of the system under consideration, these methods are found to be insufficient and a more simplistic approach is utilized. The simplistic approach determines long-term behavior up to 500 periods of an orbit. It is found that in-phase periodic modes result in the largest amount of stable modes. Future work will look at the common characteristics of the in-phase modes to better understand why they are more …
Giving Students A Better Understanding Of The Concepts Behind The Coriolis Force, Ridge Cole
Giving Students A Better Understanding Of The Concepts Behind The Coriolis Force, Ridge Cole
Physics Capstone Projects
The Coriolis force is a physical phenomenon that has proven difficult for students to understand for centuries. While the mathematical approach to teaching this phenomenon is well known and outlined, the concepts behind this force have proven to be very elusive to students. Through the use of modern technology and new ways of presenting these concepts, we hope to give students a clear understanding of the Coriolis force in the future.
Stormtime Longitudinal Variability In The Ionosphere-Thermosphere System, Ludger Scherliess
Stormtime Longitudinal Variability In The Ionosphere-Thermosphere System, Ludger Scherliess
Funded Research Records
No abstract provided.
Experimental Investigation Of The Secondary And Backscatter Electron Emission From New Spacecraft Surface Materials, Millan F. Diaz-Aguado, John W. Bonnell, Stuart D. Bale, Justin Christensen, Phillip Lundgreen, Jordan Lee, Jr Dennison, Justin Dekany, Brian Wood, Mike Gruntman
Experimental Investigation Of The Secondary And Backscatter Electron Emission From New Spacecraft Surface Materials, Millan F. Diaz-Aguado, John W. Bonnell, Stuart D. Bale, Justin Christensen, Phillip Lundgreen, Jordan Lee, Jr Dennison, Justin Dekany, Brian Wood, Mike Gruntman
Journal Articles
The emission of secondary and backscattered electrons influences spacecraft surface potentials and the surrounding plasma. Modern spacecraft use new materials for which secondary emission properties have been unavailable. In this work, the total electron yield (i.e., the sum of secondary and backscattered electron yields) was measured for niobium-C103 alloy, molybdenum Titanium, Zirconium, Molybdenum (TZM) alloy, tantalum-tungsten alloy, Elgiloy®, graphite lubricant (DAG 213®), and titanium nitride. The surface properties of tungsten were also measured for comparison with past test data. The materials were readied as spacecraft flight materials and temperature-treated ("annealed") to predicted peak flight temperatures. The yield properties for 10 …
Strategies For Determining Electron Yield Material Parameters For Spacecraft Charge Modeling, Phil Lundgreen, John R. Dennison
Strategies For Determining Electron Yield Material Parameters For Spacecraft Charge Modeling, Phil Lundgreen, John R. Dennison
All Physics Faculty Publications
Accurate modeling of spacecraft charging is essential to mitigate well‐known and all‐too‐common deleterious and costly effects on spacecraft resulting from charging induced by interactions with the space plasma environment. This paper addresses how limited availability of electron emission and transport properties of spacecraft materials—in particular, secondary electron yields—and the wide ranges measured for such properties pose a critical issue for modeling spacecraft charging. It describes a materials charging database for electron emission properties under development, which facilitates more accurate spacecraft charge modeling when used in concert with the strategies outlined herein. These data and techniques provide tools for more accurate …
The Development And Validation Of A 'Flux-Corrected Transport' Based Solution Methodology For The Plasmasphere Refilling Problem Following Geomagnetic Storms, Kausik Chatterjee, Robert W. Schunk
The Development And Validation Of A 'Flux-Corrected Transport' Based Solution Methodology For The Plasmasphere Refilling Problem Following Geomagnetic Storms, Kausik Chatterjee, Robert W. Schunk
All Physics Faculty Publications
The refilling of the plasmasphere following geomagnetic storms remains one of the longstanding and interesting problems in ionosphere-magnetosphere coupling research. The objective of this paper is the formulation and development of a one-dimensional (1D) refilling model using the flux-corrected transport method, a numerical method that is extremely well-suited to handling problems with shocks and discontinuities. In this paper, the developed methodology has been validated against exact, analytical benchmarks, and extremely good agreement has been obtained between these analytical benchmarks and numerical results. The ultimate objective of this research is the development of a three-dimensional (3D) multi-ion model for ionosphere-magnetosphere coupling …
Periodic Bouncing Modes For Two Uniformly Magnetized Spheres. I. Trajectories, Boyd F. Edwards, Bo A. Johnson, John M. Edwards
Periodic Bouncing Modes For Two Uniformly Magnetized Spheres. I. Trajectories, Boyd F. Edwards, Bo A. Johnson, John M. Edwards
All Physics Faculty Publications
We consider a uniformly magnetized sphere that moves without friction in a plane in response to the field of a second, identical, fixed sphere, making elastic hard-sphere collisions with this sphere. We seek periodic solutions to the associated nonlinear equations of motion. We find closed-form mathematical solutions for small-amplitude modes and use these to characterize and validate our large-amplitude modes, which we find numerically. Our Runge-Kutta integration approach allows us to find 1243 distinct periodic modes with the free sphere located initially at its stable equilibrium position. Each of these modes bifurcates from the finite-amplitude radial bouncing mode with infinitesimal-amplitude …
Periodic Bouncing Modes For Two Uniformly Magnetized Spheres. Ii. Scaling, Boyd F. Edwards, Bo A. Johnson, John M. Edwards
Periodic Bouncing Modes For Two Uniformly Magnetized Spheres. Ii. Scaling, Boyd F. Edwards, Bo A. Johnson, John M. Edwards
All Physics Faculty Publications
A uniformly magnetized sphere moves without friction in a plane in response to the field of a second, identical, fixed sphere and makes elastic hard-sphere collisions with this sphere. Numerical simulations of the threshold energies and periods of periodic finite-amplitude nonlinear bouncing modes agree with small-amplitude closed-form mathematical results, which are used to identify scaling parameters that govern the entire amplitude range, including power-law scaling at large amplitudes. Scaling parameters are combinations of the bouncing number, the rocking number, the phase, and numerical factors. Discontinuities in the scaling functions are found when viewing the threshold energy and period as separate …
A Semi-Kinetic Model Of Plasmasphere Refilling Following Geomagnetic Storms And Comparison With Hydrodynamic Results, Kausik Chatterjee, Robert W. Schunk
A Semi-Kinetic Model Of Plasmasphere Refilling Following Geomagnetic Storms And Comparison With Hydrodynamic Results, Kausik Chatterjee, Robert W. Schunk
All Physics Faculty Publications
The objective of this paper is the development of a kinetic model for plasmasphere refilling following geomagnetic storms. The kinetic model is based on the ‘particle-in-cell’ method, a method based on the simulation of particle motion and thus well-suited to high altitude, low-density regimes, where the plasma transport equations are not valid. The model was validated with exact, analytical benchmarks, which are provided in this paper. The refilling results obtained from the kinetic model were then compared with results from a recently developed hydrodynamic solution methodology based on the ‘flux-corrected transport’ (FCT) method, and the limitations of hydrodynamic modeling for …