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Full-Text Articles in Physics

Non-Destructive Thickness Uniformity Measurement Of Photosensitive Gelatin Film, Clayton Halper Apr 2024

Non-Destructive Thickness Uniformity Measurement Of Photosensitive Gelatin Film, Clayton Halper

Physics Capstone Projects

Volume phase holographic gratings (VPHG’s) depend on dichromate gelatin of which uniform thickness is vital. The photosensitive nature of the film makes current thin film measurement devices not viable for production means. This project attempts to create a non-destructive measurement of photosensitive gelatin film used in VPHG production. Application of thin film interference at chosen wavelengths enable analysis of uniformity by comparison between the thin film inference patterns at different wavelengths. An initial proof of concept was established and a path towards a production ready device is outlined.

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Dynamics And Scaling Of Particle Streaks In High-Reynolds-Number Turbulent Boundary Layers, Tim Berk, Filippo Coletti Nov 2023

Dynamics And Scaling Of Particle Streaks In High-Reynolds-Number Turbulent Boundary Layers, Tim Berk, Filippo Coletti

Mechanical and Aerospace Engineering Faculty Publications

Inertial particles in wall-bounded turbulence are known to form streaks, but experimental evidence and predictive understanding of this phenomenon is lacking, especially in regimes relevant to atmospheric flows. We carry out wind tunnel measurements to investigate this process, characterizing the transport of microscopic particles suspended in turbulent boundary layers. The friction Reynolds number Re𝜏 = O(104) allows for significant scale separation and the emergence of large-scale motions, while the range of viscous Stokes number St+ = 18–870 is relevant to the transport of dust and fine sand in the atmospheric surface layer. We …

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Nalidarturbopauseshear, Titus Yuan Aug 2023

Nalidarturbopauseshear, Titus Yuan

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The USU Na lidar has been upgraded to be able to measure temperature and winds in the lower thermosphere up to ~ 115 km routinely. The new capability, coupled with the existing nightglow instruments at USU, enables the investigation of the extreme large wind and shears in this region and their correlation to the atmospheric gravity waves activities in the upper mesosphere.

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A Simple Method For Determining Shallow Charge Distributions In Dielectrics Via Pulsed Electroacoustic Measurements, Zachary Gibson, J. R. Dennison Aug 2023

A Simple Method For Determining Shallow Charge Distributions In Dielectrics Via Pulsed Electroacoustic Measurements, Zachary Gibson, J. R. Dennison

Journal Articles

The understanding of charge dynamics in dielectric materials is paramount in mitigating electrostatic discharge events for spacecraft. The most critical spacecraft charging events are found to result from incident electrons in the energy range of 10 keV to 50 keV. The charge embedded in dielectric materials in this energy range are deposited a distance into the material on the order of a few to tens of microns. One way to measure and understand the deposited charge is via pulsed electroacoustic measurements (PEA). However, the typical PEA spatial resolution of ~ 10 μm is not sufficient to resolve or discern charge …

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Radon In Utah Homes, Madison Mackay May 2023

Radon In Utah Homes, Madison Mackay

Physics Capstone Projects

Radon gas can be found nearly everywhere. It is formed by the decay of radium, which is found in rocks, soil, plants, and animals. Radon gas can become trapped in buildings and is dangerous at high levels. It is particularly known to be high in many areas of the state of Utah. It is important for the average citizen in Utah to understand more about radon and what levels they may be exposed to. An experiment was done to try an alternate, faster method of testing for radon gas. This experiment was performed in several different locations in Utah. While …

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Preparation, Characterization And Electron Yield Analysis On Highly Insulating Granular Particles, Heather Allen May 2023

Preparation, Characterization And Electron Yield Analysis On Highly Insulating Granular Particles, Heather Allen

Physics Capstone Projects

This study focuses on obtaining reliable electron yield measurements of highly insulating granular particles of various shape, size, and composition. Measurements of this kind have long been considered too difficult to collect on granular samples due to experimental complexities leading to a critical knowledge gap in the fundamental electrostatic behaviors of dust. A significant portion of this study was spent on preparing and characterizing granular samples before any type of measurement took place. Particles of varying sizes ranging from ~1 μm to ~100 μm, shapes including cubical, spherical, and angular, and composition including NaCl, MgO, Al2O3 and …

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Engineering Lab Building Telescope Manual, Aidan L. Tueller May 2023

Engineering Lab Building Telescope Manual, Aidan L. Tueller

Physics Capstone Projects

In partnership with Dr. Jan Sojka, head of the Physics Department, a plan was created to make the telescope on top of the Engineering Lab building operational again for either staff, students, classes, or labs to use. The telescope was purchased through funds by Utah NASA Space Grant Consortium. This paper will contain basic information about how to operate the telescope and use its equipment. There is an online manual from Meade that is much longer but goes into much more detail about individual pieces and specific parts of the telescope.

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Metasurfaces For Holography, Scott Howell May 2023

Metasurfaces For Holography, Scott Howell

Physics Capstone Projects

Holography uses the interference of light waves to store information about an object, which can then be seen from different angles to create a partial 3D view. A simple experiment can be done using a laser diode, photographic plate, and a set of dice to create a holographic image. The holographic film is thin and can only hold a single image. Reflection holography can create a 3D diffraction pattern and allows more information to be packed into a single medium. Computer generated holograms can be designed to create holograms without a real object to be used in augmented reality. High …

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The Kp Index And Behavior Of Quiet Periods, Collette Walbeck Apr 2023

The Kp Index And Behavior Of Quiet Periods, Collette Walbeck

Physics Capstone Projects

The Kp-index quantifies the electromagnetic effects in the Earth’s atmosphere and is used in a variety of scientific fields. Higher Kp values tend to be the focus in these fields as they relate to high solar activity and geomagnetic storms. This study aimed to examine the significance, if any, of lower Kp indices. A simple data analysis was performed on continuous sequences of low Kp values, deemed Quiet Periods. Both the daily average of the values and the full set of Kp data were used. A decaying exponential relationship was discovered between the length of these periods and their frequencies …

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High Frequency Radio Communication, Tyler Larsen Apr 2023

High Frequency Radio Communication, Tyler Larsen

Physics Capstone Projects

High frequency radio communication has been the most reliable form of communication for many decades. Over that period, we have learned and experienced times of enhanced signals along with complete radio blackouts. The purpose of this research is to collect and analyze radio signal data to see the evidence of various reasons as to why these phenomena occur. A radio antenna was set up at USU campus to retrieve the signals from beacon networks across the globe that transmit signals every 15 minutes. By tracking a few of these signals we can locate the times of discrepancies in the signals …

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Effectiveness Of Multilayer Graded-Z Forms Of Radiation Shielding, Brinley Packer Apr 2023

Effectiveness Of Multilayer Graded-Z Forms Of Radiation Shielding, Brinley Packer

Physics Capstone Projects

This study explored how different forms of radiation shielding were more or less effective than standard single-layer shielding. Beta and gamma radiation sources were used and measured using a Geiger counter to determine how well the various forms of shielding protect against the radiation. The shielding effectiveness of standard homogeneous materials (e.g., graphite, carbon/epoxy composites, aluminum, and lead) of various thicknesses for different radiation sources was measured to provide standards for comparison. Once a basis of effective shielding was established, the study can go into greater depth into how to use shielding materials to be more effective, to better shield …

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For The Dissertation: A Classification Of Tensors In Ecsk Theory, Joshua James Leiter, Charles G. Torre Apr 2023

For The Dissertation: A Classification Of Tensors In Ecsk Theory, Joshua James Leiter, Charles G. Torre

Physics Student Research

This dissertation presents a Petrov/Plebanski/Segre/Algebraic (PPSA) classification scheme for both the curvature and torsion tensors in Einstein-Cartan-Sciama-Kibble theory (ECSK); additionally the work includes a software package in Maple with computational and PPSA classification tools. Six different solutions are classified using the new software tools developed. We also present a new boundary term for ECSK-NMC scalar theory to ensure Dirichlet boundary conditions. New work completed includes the decomposition of an arbitrary 4th rank tensor under SO (p, q), equivalent SL (2, C) irreducible spinor decompositions of arbitrary 3rd and 4th rank tensors. We provide new proofs that the corresponding spinors are …

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Mesopause Region Temperature And Na Number Density Between 1990 And 2017, Tao Yuan, Chiao-Yao She Apr 2023

Mesopause Region Temperature And Na Number Density Between 1990 And 2017, Tao Yuan, Chiao-Yao She

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The Colorado State University (CSU) Na lidar performed nocturnal mesopause region Na density and temperature observations between March 1990 and March 2010 at Fort Collins, CO (41.6N, 105W). The lidar was relocated to Utah State University (USU) campus and has continued its regular observation at Logan, Utah (42N, 112W) since September 2010.

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Relevancy Of Pulsed Electroacoustic Measurements For Investigating Spacecraft Charging, Zachary Gibson, J. R. Dennison Feb 2023

Relevancy Of Pulsed Electroacoustic Measurements For Investigating Spacecraft Charging, Zachary Gibson, J. R. Dennison

Journal Articles

The magnitude and spatial distribution of charge embedded in dielectric materials and the evolution of the charge distributions with time are paramount for the understanding and mitigation of spacecraft charging. Spacecraft materials are charged primarily by incident fluxes of low-energy electrons, with electron fluxes in the 10–50 keV range often responsible for the most deleterious arcing effects. While the pulsed electroacoustic (PEA) method can provide sensitive nondestructive measurements of the internal charge distribution in insulating materials, it has often been limited for spacecraft charging applications by typical spatial resolutions of ≤ 10 μm , with a 10- μm …

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Space Environment Effects On The Electron Yields Of Ldef Thermal Control Coatings, Trace Taylor, Matthew Robertson, Heather Allen, Jr Dennison, Michael Guy, Emily Willis Feb 2023

Space Environment Effects On The Electron Yields Of Ldef Thermal Control Coatings, Trace Taylor, Matthew Robertson, Heather Allen, Jr Dennison, Michael Guy, Emily Willis

Journal Articles

Space-environment-induced degradation of white thermal control coatings from the Long Duration Exposure Facility (LDEF) was investigated. Much of the exterior of the LDEF was painted with a white thermal control coating, Aeroglaze A276; and most of the interior was coated with a black thermal control coating, Aeroglaze Z306. Outgassing from these coatings and other LDEF materials interacted with the white surface when exposed to sunlight after volatile materials condensed on the LDEF surfaces. Surface morphology was characterized by optical and scanning electron microscopies. Fourier-transform infrared spectroscopy and energy-dispersive x-ray spectroscopy were used to identify the chemical compounds and elements present …

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Comparison Of Pulsed Electroacoustic Measurements And Af-Numit3 Modeling Of Polymers Irradiated With Monoenergetic Electrons, Zachary Gibson, J. R. Dennison, Brian Beecken, Ryan Hoffmann Feb 2023

Comparison Of Pulsed Electroacoustic Measurements And Af-Numit3 Modeling Of Polymers Irradiated With Monoenergetic Electrons, Zachary Gibson, J. R. Dennison, Brian Beecken, Ryan Hoffmann

Journal Articles

Successful spacecraft design and charging mitigation techniques require precise and accurate knowledge of charge deposition profiles. This paper compares models of charge deposition and transport using a venerable deep dielectric charging code, AF-NUMIT3, with direct measurements of charge profiles via pulsed electroacoustic (PEA) measurements. Eight different simulations were performed for comparison to PEA experiments of samples irradiated by 50 or 80 keV monoenergetic electrons in vacuum and at room temperature. Two materials, polyether-ether ketone (PEEK) and polytetrafluoroethylene (PTFE), were chosen for their very low conductivities so that minimal charge migration would occur between irradiation and PEA measurements. PEEK was found …

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Characterizing The Charging Properties Of Lunar Dust Is Critical To Returning To The Moon, Heather Allen Jan 2023

Characterizing The Charging Properties Of Lunar Dust Is Critical To Returning To The Moon, Heather Allen

Research on Capitol Hill

Reliable electron yield (EY) measurements of highly insulating granular particles have long been considered too difficult to collect due the many experimental complexities that arise from the nature of the granular materials. This has led to a critical knowledge gap for both engineering strategies and basic science issues essential for myriad important space applications. This talk will emphasize the preliminary EY measurements of highly insulating granular samples we have collected, including a range of sasmples with typical particle size ranging from ~1 μm to ~100 μm, samples with cubical, spherical and highly angular particle shapes, studies of highly angular Al2O3 …

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Grinding Cocoa Changes Chocolate Properties, Joseph Cooney Jan 2023

Grinding Cocoa Changes Chocolate Properties, Joseph Cooney

Research on Capitol Hill

This research studies how the viscoelastic properties of chocolate change through the 72-hour grinding process of chocolate manufacturing. Utah State University's Aggie Chocolate Factory produces chocolate from single-origin sources, each of which has a unique flavor, and thus a unique chemistry. This research explores the effects of grinding time on the viscoelasticity of each of these origins' chocolate types, including dark, sweet dark chocolate, and milk chocolate. Chocolate is a non-Newtonian fluid and therefore the Casson model (eq. 1) was used to obtain values for viscosity and yield stress, τ^(1/2)=τ_0^(1/2)+(η_PL y' )^(1/2) (1) Where τ is the shear stress measured …

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Effects Of Exposure To Atmospheric Humidity On Breakdown Field Strength Measurements Of Polymers, Megan Loveland Dewaal Dec 2022

Effects Of Exposure To Atmospheric Humidity On Breakdown Field Strength Measurements Of Polymers, Megan Loveland Dewaal

Physics Capstone Projects

This study investigates the effects of absorbed water introduced via exposure to atmospheric humidity on electrostatic breakdown field strength measurements of polymers. Conducting breakdown tests under sample conditions appropriate for different applications is essential. If the breakdown field strength is overestimated for an application, an insulator may be used inappropriately in high electric fields where they are more likely to break down. Comparisons are made between: sets of pristine samples, samples that underwent a thorough vacuum bake out to remove absorbed water, and samples subject to subsequent incremental prolonged atmospheric exposure. These investigated the effects of absorbed water and determined …

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Spacecraft Charging Test Considerations For Composite Materials, Allen Andersen, Wousik Kim, J. R. Dennison, Brian Wood, Todd A. Schneider, Jason Vaughn, Kenneth H. Wright Jr., Nelson W. Green, Eric Suh, Joel Schwartz, Abdul-Majeed Azad Dec 2022

Spacecraft Charging Test Considerations For Composite Materials, Allen Andersen, Wousik Kim, J. R. Dennison, Brian Wood, Todd A. Schneider, Jason Vaughn, Kenneth H. Wright Jr., Nelson W. Green, Eric Suh, Joel Schwartz, Abdul-Majeed Azad

Journal Articles

Composite materials present a growing challenge for spacecraft charging assessments. We review some recent lessons learned for charging tests of composite materials using both parallel-plate and electron beam test geometries. We also discuss examples of materials that exhibit significant variations between samples, despite them all having the same trade name.

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Inertial Motion On The Earth's Spheroidal Surface, Boyd F. Edwards, Cade Pankey, John M. Edwards Nov 2022

Inertial Motion On The Earth's Spheroidal Surface, Boyd F. Edwards, Cade Pankey, John M. Edwards

All Physics Faculty Publications

As seen by an observer in the rotating frame, the earth’s small spheroidal deformations neutralize the centrifugal force, leaving only the smaller Coriolis force to govern the “inertial” motion of objects that move on its surface, assumed smooth and frictionless. Previous studies of inertial motion employ weakly spheroidal equations of motion that ignore the influence of the centrifugal force and yet treat the earth as a sphere. The latitude dependence of these equations renders them strongly nonlinear. We derive and justify these equations and use them to identify, classify, name, describe, and illustrate all possible classes of inertial motion, including …

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Round Robin Tests Of Electron Irradiated Polymers Via Pulsed Electroacoustic Measurements, Zachary Gibson, J. R. Dennison, Virginie Griseri Oct 2022

Round Robin Tests Of Electron Irradiated Polymers Via Pulsed Electroacoustic Measurements, Zachary Gibson, J. R. Dennison, Virginie Griseri

Physics Student Research

Charge accumulation and migration can be studied using the pulsed electroacoustic (PEA) method to directly measure internal charge distributions in dielectric materials. This study aims to compare measurements using PEA systems constructed in labs at Utah State University and Université Paul Sabatier to establish confidence in comparing PEA results between different PEA systems. While there is good agreement in data measured for pristine samples with DC bias applied and no charge embedded, there are discrepancies in the data when measuring irradiated samples with embedded charge. The overall characteristics of charge distributions measured with both systems is clearly the same, but …

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Pulsed Electroacoustic Measurements Of Polymers Irradiated With Low Energy Monoenergetic Electrons, Zachary Gibson, Jr Dennison Sep 2022

Pulsed Electroacoustic Measurements Of Polymers Irradiated With Low Energy Monoenergetic Electrons, Zachary Gibson, Jr Dennison

Physics Student Research

Understanding the dynamics and accumulation of embedded charge in dielectric materials is paramount for many applications from HVDC power transmission to spacecraft charging. The pulsed electroacoustic (PEA) method allows for nondestructive measurements of embedded charge distributions in dielectrics. The spatial resolution of PEA measurements are typically ~10 μm. However, some of the most deleterious spacecraft charging events result from electron fluxes with 10 keV to 50 keV energies, resulting in electron ranges of 1's to 10's of μm. Due to the resolution of the PEA method and the superposition of the interfacial charge with the deposited charge distribution, it is …

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Uncertainties Of The Pulsed Electroacoustic Method: Peak Positions Of Embedded Charge Distributions, Zachary Gibson, J. R. Dennison Jul 2022

Uncertainties Of The Pulsed Electroacoustic Method: Peak Positions Of Embedded Charge Distributions, Zachary Gibson, J. R. Dennison

Physics Student Research

The pulsed electroacoustic (PEA) method allows for nondestructive measurements of internal charge distributions in dielectric materials. These measurements have been paramount in understanding and mitigating charge accumulation, aging, and electrostatic discharge in materials for various applications. This study aims to examine more closely the uncertainties of pulsed electroacoustic measurements. The first few moments of a charge distribution are directly related to the magnitude, peak position, full-width-at-half-maximum, and skewness. The uncertainty in the magnitude of the charge distribution is often quite large, but the peak position can be determined with a precision of <1 μm. This has been demonstrated in our lab with repeated PEA measurements of polyether-etherketone (PEEK) with internal charge present. This precision is further validated with measurements of PEEK irradiated with differing doses of 50 keV incident electrons, resulting in peak positions that differ by only a few μm. A final test is given by measurements monitoring the slow migration of the charge distributions in these irradiated samples over several months. The measured shifts in the peak position of the charge distributions are ≤1 μm. Though the spatial resolutions of PEA measurements are typically ~10 μm, as defined by the full- width-at-half-maximum of the leading interfacial peak, the precision of the peak position can be more than an order of magnitude greater. The statistical analysis of the repeated measurements to determine uncertainties, as well as the validation measurements, demonstrate the high precision determination of the peak position of embedded charge distributions.

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What Is A Photon? Foundations Of Quantum Field Theory, Charles G. Torre Jun 2022

What Is A Photon? Foundations Of Quantum Field Theory, Charles G. Torre

All Physics Faculty Publications

This is a brief, informal, and relatively low-level course on the foundations of quantum field theory. The prerequisites are undergraduate courses in quantum mechanics and electromagnetism.

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Normal-Mode Oscillations For The Circular And Dipolar States Of A Filled Hexagonal Magnetic Dipole Cluster, Peter T. Haugen, Andrew D. P. Smith, Boyd F. Edwards Jun 2022

Normal-Mode Oscillations For The Circular And Dipolar States Of A Filled Hexagonal Magnetic Dipole Cluster, Peter T. Haugen, Andrew D. P. Smith, Boyd F. Edwards

All Physics Faculty Publications

We analyze the rotational dynamics of six magnetic dipoles of identical strength at the vertices of a regular hexagon with a variable-strength dipole in the center. The seven dipoles spin freely about fixed axes that are perpendicular to the plane of the hexagon, with their dipole moments directed parallel to the plane. Equilibrium dipole orientations are calculated as a function of the relative strength of the central dipole. Small-amplitude perturbations about these equilibrium states are calculated in the absence of friction and are compared with analytical results in the limit of zero and infinite central dipole strength. Normal modes and …

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Large Earthquakes' Effect On The Ionosphere, Aaron Houston May 2022

Large Earthquakes' Effect On The Ionosphere, Aaron Houston

Physics Capstone Projects

The ionosphere is a part of the Earth’s atmosphere that stretches from 80 – 600 kilometers. Gases in this area are ionized which creates a range of free electrons that make up the plasma of the ionosphere. A group of these electrons is known as Total Electron Content (TEC), which is responsible for signal delays between satellites in orbit and their GPS receivers on the surface. Using this delay, the TEC in a specific region can be calculated. This helps in GPS error analysis. During the earthquake in Japan on March 11, 2011, there was allegedly a noticeable jump in …

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Improving The Efficiency Of The Preconditioning Of Iterative Solutions To The Kinetic Equation, D. Caleb Price May 2022

Improving The Efficiency Of The Preconditioning Of Iterative Solutions To The Kinetic Equation, D. Caleb Price

Physics Capstone Projects

To achieve the reality of fusion, a greater understanding of plasma is required. The kinetic equation can be evolved simultaneously alongside the fluid equations to solve for kinetic closures. NIMROD performs this with numerical solvers where the General Minimum Residual (GMRES) solver becomes more efficient with a preconditioning matrix as input. Using a GPU-enabled library, the efficiency of GPU offloading to the preconditioning step was tested. A significant decrease in the factoring time of preconditioning matrix was observed. This suggests that the allocation of GPUs is worth investigating for NIMROD’s own benefit, but also anyone seeking to improve the efficiency …

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Seasonal Variations In Global Ionospheric Total Electron Content, Jason Knudsen May 2022

Seasonal Variations In Global Ionospheric Total Electron Content, Jason Knudsen

Physics Capstone Projects

As the Sun ionizes atoms and molecules in the Earth’s ionosphere, the region of atmosphere above approximately 100 km in altitude, the created ionization in this region affects many of the systems that we rely on in daily life. This includes cellular service, GPS navigation, weather forecasting, and credit card data. A good measure for the level of ionization in the ionosphere is total electron content (TEC), which is the number of electrons in a square column above a given geographic location. The TEC over a geographic location influences the propagation of radio waves that traverse that section of the …

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Characteristics Of Mesospheric Temperature And Gravity Waves Over Chile In 2020-2021, Damien M. Devitt, Kenneth Zia May 2022

Characteristics Of Mesospheric Temperature And Gravity Waves Over Chile In 2020-2021, Damien M. Devitt, Kenneth Zia

Physics Capstone Projects

Gravity waves (GWs) are often confused with gravitational waves in the fabric of space time. However, there is a clear distinction between them. Gravity wave is a term used by the atmospheric research field to describe perturbations in the atmosphere. Gravity pulls the perturbations down and causes oscillations, these present in the form of waves. The best visualization is to think of ripples on a pond, as the ripple reaches its peak gravity pulls the ripple down and creates an oscillating effect.

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