Other Physics Commons^™

Using Differential Equations To Model A Cockatoo On A Spinning Wheel As Part Of The Scudem V Modeling Challenge, Miles Pophal, Chenming Zhen, Henry Bae

Rose-Hulman Undergraduate Mathematics Journal

For the SCUDEM V 2020 virtual challenge, we received an outstanding distinction for modeling a bird perched on a bicycle wheel utilizing the appropriate physical equations of rotational motion. Our model includes both theoretical calculations and numerical results from applying the Heaviside function for the swing motion of the bird. We provide a discussion on: our model and its numerical results, the overall limitations and future work of the model we constructed, and the experience we had participating in SCUDEM V 2020.

Waves And Oscillations In A Sunspot: Observations And Modeling Of Noaa Ar 12470, Yi Chai

Dissertations

Waves and oscillations are important solar phenomena not only because they can propagate and dissipate energy in the chromosphere, but also because they carry information about the structure of the atmosphere in which they propagate. Among these phenomena, the one of the most interesting ones occurs in the sunspot umbra. In this area, continuously propagating magnetohydrodynamic (MHD) waves generated from below the photosphere create the famous 3-minute sunspot umbral oscillations that affect the line profile of spectral lines due to temperature, density, and velocity changes of the plasma in the region. In the past decades, numerous observations and models have …

Nondestructive Evaluation Of 3d Printed, Extruded, And Natural Polymer Structures Using Terahertz Spectroscopy And Imaging, Alexander T. Clark

Dissertations

Terahertz (THz) spectroscopy and imaging are considered for the nondestructive evaluation (NDE) of various three-dimensional (3D) printed, extruded, and natural polymer structures. THz radiation is the prime candidate for many NDE challenges due to the added benefits of safety, increased contrast and depth resolution, and optical characteristic visualization when compared to other techniques. THz imaging, using a wide bandwidth pulse-based system, can evaluate the external and internal structure of most nonconductive and nonpolar materials without any permanent effects. NDE images can be created based on THz pulse attributes or a material’s spectroscopic characteristics such as refractive index, attenuation coefficient, or …

Periodic Fast Multipole Method, Ruqi Pei

Dissertations

Applications in electrostatics, magnetostatics, fluid mechanics, and elasticity often involve sources contained in a unit cell C, centered at the origin, on which periodic boundary condition are imposed. The free-space Green’s functions for many classical partial differential equations (PDE), such as the modified Helmholtz equation, are well-known. Among the existing schemes for imposing the periodicity, three common approaches are: direct discretization of the governing PDE including boundary conditions to yield a large sparse linear system of equations, spectral methods which solve the governing PDE using Fourier analysis, and the method of images based on tiling the plane with copies of …

Developing A Natural Language Processing Approach For Analyzing Student Ideas In Calculus-Based Introductory Physics, Jon M. Geiger, Lisa M. Goodhew, Tor Ole B. Odden

Honors Projects

Research characterizing common student ideas about particular physics topics has made a significant impact on university-level physics teaching by providing knowledge that supports instructors to target their instruction and by informing curriculum development. This work utilizes a Natural Language Processing algorithm (Latent Dirichlet Allocation, or LDA) to categorize student ideas, with the goal of significantly expediting the process of categorizing student ideas. We preliminarily test the LDA approach by applying the algorithm to a collection of introductory physics student responses to a conceptual question about circuits, specifically attending to whether it is useful for characterizing conceptual resources, or student ideas …

In-Phantom Film Measurements Of Two Treatment Planning Systems For Single-Fraction Spine Sbrt, Michael J. Taylor

LSU Master's Theses

Purpose: Treatment planning accuracy for spine stereotactic body radiation therapy (SBRT) varies depending on the dose calculation algorithm utilized in the treatment planning system (TPS). This project compared the end-to-end accuracy between spine SBRT plans calculated in a convolution-superposition based TPS (TPS_CS) and Monte Carlo based TPS (TPS_MC) with radiochromic film measurements. The hypothesis was that TPS_MC would calculate the dose gradient in the critical region between the vertebral body and the spinal cord more accurately than TPS_CS.

Methods: Single-fraction spine SBRT treatments following RTOG 0631 and local institutional guidelines were planned in …

Transistion Metal Chalcogenides And Phosphides For Energy Storage And Conversion Through Water Splitting, Kelsey Thompson

Electronic Theses & Dissertations

In contemporary society, there are many different ways that energy is used in daily life. From applications that require a high energy density to long-term storage in a stable manner, the requirements for energy usage are diverse. Therefore, the greater the number of uses a designed material exhibits, the more practical it may be for wide-scale manufacture. Two areas of particular interest for energy applications are fuel cells (to generate energy) and supercapacitors (to store energy). To provide cheaper and more durable alternatives for energy storage, electrodes containing CoMoO₄, NiMoO₄, CoMoS₄, NiMoS₄, …

Acoustic Waves In The Upper Atmosphere, Geoffrey Blayne Schulthess

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Atmospheric waves can be generated by tropospheric sources such as earthquakes and explosions, causing significant disturbances in the upper atmosphere and ionosphere, where radio wave communications take place. For this analysis, they will be separated into two sub-groups called acoustic waves and gravity waves. Because each of these waves have unique frequency ranges, they can be observed and measured in order to determine their source type and location. Past studies attempted to build the connections between these waves with severe storms and earthquakes, which have improved our understanding of their complexity. Because of the complex nature of these waves, simplified …

The Impact Of Sea-Level Rise In Numerically Modeled Landfalling Hurricanes: Katrina And The Gulf Coast., Serenity Nadirah Mercuri

Electronic Theses and Dissertations

With climate change, landfalling hurricanes become an increasing threat to coastal regions. However, the interactions between the coastal landscape and landfalling hurricanes are often overlooked when addressing sea-level rise outside of inundation and independent of sea surface temperature. This study analyzed the potential impacts regarding structure and intensity as a result of sea-level rise in the Gulf of Mexico using the WRF-ARW numerical model coupled with a 1D ocean model. Analysis showed that 10 m windspeed from landfall forward was higher in modified coastlines, and minimum sea-level pressure post-landfall was consistently lower for modified runs where storms maintain a higher …

Hepatocellular Carcinoma Image-Guided Intervention: Quantitative Characterization Of Reagents For Thermochemical Ablation, Emily A. Thompson

Dissertations and Theses (Open Access)

Thermochemical ablation (TCA) is a minimally invasive therapy under development for hepatocellular carcinoma, a leading cause of cancer death worldwide. TCA utilizes acid-base chemistry delivered simultaneously to induce local ablation when administered. When delivered via a mixing catheter placed directly into the tumor, acid (e.g., AcOH) and base (e.g., NaOH) react to completion at the catheter tip, producing the acetate salt, water, and releasing heat (Δ>50°C) in sufficient quantities to induce lethal osmotic and thermal stress in tumor cells. However, these two reagents are not distinguishable from tissues with noninvasive imaging modalities, which makes monitoring the delivery of TCA …

Dust-Gas Dynamics Driven By The Streaming Instability With Various Pressure Gradients, Stanley Antedio Baronett

UNLV Theses, Dissertations, Professional Papers, and Capstones

The radial pressure gradient (RPG), along the midplane of gaseous protoplanetary disks (PPD) – planetary nurseries – poses a severe obstacle to planet formation. Micron-sized dust grains, embedded in the disc, must quickly grow to kilometer-sized planetesimals – the building blocks of planets – before fatally drifting inwards, by RPG-induced gas drag, into a central host star. However, the RPG simultaneously powers one of the most robust processes to overcome this radial-drift barrier: the streaming instability (SI). Spontaneously triggered, the SI aerodynamically concentrates drifting dust via drag-induced, coupled interactions and feedback with the surrounding gas. In particular, the non-linear phase …

Dispersion In High Temperature Superconductors, Lazar Novakovic

Undergraduate Research Symposium Podium Presentations

Superconductors are used in many different industries: Efficient power transmission, Maglev train, MRIs

Can Rigorous Metaphorical Thinking Improve Learning Outcomes?, Arian Dovald

Campus Research Month

Theoretical metaphors are a novel way of analyzing theories in physics. Thinking of physical models as theoretical metaphors clarifies the role of language in scientific modeling. They show how theories make connections between concepts, language, and math. I propose a study to measure the effect on learning outcomes of explicit instruction on theoretical metaphors.

Student-Developed Laboratory Activities Using Rolling Object On An Inclined Plane To Improve Student Learning, Qing Shao, Joseph Ametepe

Georgia Journal of Science

This work presents an alternative method of teaching undergraduate introductory physics laboratory. Students are presented with an experimental scenario “Rolling object on an inclined plane” and guided to develop their own laboratory activities in a studio-style setting. The overall goal of this alternative approach is to shift part of the learning responsibility to students. Through guided self-developed activities, students establish the connections between different physics concepts. Such a shift makes students active participants in the classroom, allows them to explore ideas independently, and discover through doing the exploring. Furthermore, the pedagogy is aimed at (i) motivating and actively engaging students …

Lattice Optics Optimization For Recirculatory Energy Recovery Linacs With Multi-Objective Optimization, Isurumali Neththikumara, Todd Satogata, Alex Bogacz, Ryan Bodenstein, Arthur Vandenhoeke

College of Sciences Posters

Beamline optics design for recirculatory linear accelerators requires special attention to suppress beam instabilities arising due to collective effects. The impact of these collective effects becomes more pronounced with the addition of energy recovery (ER) capability. Jefferson Lab’s multi-pass, multi-GeV ER proposal for the CEBAF accelerator, ER@CEBAF, is a 10- pass ER demonstration with low beam current. Tighter control of the beam parameters at lower energies is necessary to avoid beam break-up (BBU) instabilities, even with a small beam current. Optics optimizations require balancing both beta excursions at high-energy passes and overfocusing at low-energy passes. Here, we discuss an optics …

Comparative Analysis Of Trends In American Physics Education, Adam Tyler Crank

Honors Capstone Projects and Theses

No abstract provided.

A Unified Spproach To Schrödinger Evolution Of Superoscillations And Supershifts, Yakir Aharonov, Jussi Behrndt, Fabrizio Colombo, Peter Schlosser

Mathematics, Physics, and Computer Science Faculty Articles and Research

Superoscillating functions and supershifts appear naturally in weak measurements in physics. Their evolution as initial conditions in the time-dependent Schrödinger equation is an important and challenging problem in quantum mechanics and mathematical analysis. The concept that encodes the persistence of superoscillations during the evolution is the (more general) supershift property of the solution. In this paper, we give a unified approach to determine the supershift property for the solution of the time-dependent one-dimensional Schrödinger equation. The main advantage and novelty of our results is that they only require suitable estimates and regularity assumptions on the Green’s function, but not its …

Kemar Hats Head Orientation Directivity, Samuel D. Bellows, Timothy W. Leishman

Directivity

This directivity data set for a KEMAR head head-and-torso simulator (HATS) includes head orientations in 14 directions in 5° steps starting from 0° to 40° and then in 10° steps from 40° to 90°. The full spherical measurements followed at an a = 0.97 m radius with the mouth aperture at the spherical center. The sampling density and distribution followed the AES 5° dual-equiangular sampling standard, omitting the south pole (θ = 180°). Thus, each spherical directivity assessment included 36 polar-angle θ samples and 72 azimuthal-angle ϕ samples. The presented data include 22 1/3-octave bands, ranging from 80 Hz …

Isolated Objects And Their Evolution: A Derivation Of The Propagator’S Path Integral For Spinless Elementary Particles, Domenico Napoletani, Daniele Carlo Struppa

Mathematics, Physics, and Computer Science Faculty Articles and Research

We formalize the notion of isolated objects (units), and we build a consistent theory to describe their evolution and interaction. We further introduce a notion of indistinguishability of distinct spacetime paths of a unit, for which the evolution of the state variables of the unit is the same, and a generalization of the equivalence principle based on indistinguishability. Under a time reversal condition on the whole set of indistinguishable paths of a unit, we show that the quantization of motion of spinless elementary particles in a general potential field can be derived in this framework, in the limiting …

A Virtual Physics Laboratory For Remote/Online Learning, Themistoklis Chronis

Summer Community of Scholars (RCEU and HCR) Project Proposals

No abstract provided.

The Meaning Of Dark, Light And Shadows: Inferences In Art, Materiality And Cultural Practices, Frank Prendergast

Book/Book Chapter

Our visual awareness relies on light acting on the eye to perceive materiality and colour. Medieval thought wrestled to articulate and comprehend its nature. The notebooks of Leonardo Da Vinci, for example, included his descriptions to define light and make comparisons so as to differentiate between light and shadow. His focus was on the illumination of surfaces from the perspective of a painter, seeing shadows as ‘the diminution of light by the intervention of an opaque body’ and ‘the counterpart of luminous rays’. In his mind, a shadow ‘stood between light and darkness’, with darkness being ‘the absence of light’. …

Lepton Flavor Violation And Effective Field Theories, Renae Conlin

Wayne State University Dissertations

The Standard Model is believed to be a low energy effective theory of some completetheory at higher energies. This is already evidenced in the observation of neutrino oscillations. Standard Model processes conserve the lepton flavor quantum numbers. Adding massive neutrinos to the Standard Model, the branching ratios of lepton flavor violating processes are found to be incredibly small. For example, a process μ → eγ has a branching ratio order ∼ 10^−54. These tiny branching ratios of lepton flavor violating processes indicate that they are especially clean areas to look for beyond the Standard Model physics. Any observed flavor violation …

Investigating The Impacts Of Microgravity On Methanotrophic Bacteria Metabolism For Methane Gas Oxidation, Daisy Li, Elena Zhu, Stella Ristic '25, Joshua Suarez

Distinguished Student Work

An abundance of waste methane gas is produced on the International Space Station (ISS) as a result of the Sabatier Reaction, a part of the Environmental Control and Life Support System (ECLSS). In order to manage this organic waste, this experiment seeks to understand how microgravity impacts the methane-oxidizing metabolism of methanotrophic bacteria, namely Methylorubrum podarium. As methanotrophs have never been studied in space, this investigation may unlock a novel understanding of their behavior in microgravity, leading to promising future applications such as improved life support systems in deep space. In this experiment, cameras will capture snapshots of the bacterial …

A Modulated Structure Derived From The Xa-Type Mn2Rusn Heusler Compound, Xingzhong Li, Wen-Yong Zhang, Ralph Skomski, David J. Sellmyer

Nebraska Center for Materials and Nanoscience: Faculty Publications

A modulated structure derived from the inverse Heusler phase (the XA-type and the disordered variant L2₁B-type) has been observed in rapidly quenched Mn2RuSn ribbons. The powder X-ray diffraction pattern of the quenched ribbons can be indexed as an L2₁B-type structure. Electron diffraction patterns of the new structure mostly resemble those of the XA-type (and the disordered variant L2₁B-type) structure and additional reflections with denser spacing indicate a long periodicity. Orthogonal domains of the modulated structure were revealed by a selected-area electron diffraction pattern and the corresponding dark-field transmission electron microscopy images. The structure was …

Localization Effects And Anomalous Hall Conductivity In A Disordered 3d Ferromagnet, Paul M. Shand, Y. Moua, G. Baker, Shah R. Valloppilly, Pavel V. Lukashev, Parashu Kharel

Nebraska Center for Materials and Nanoscience: Faculty Publications

We have prepared the Heusler alloy CoFeV_0.5Mn_0.5Si in bulk form via arc melting. CoFeV_0.5Mn_0.5Si is ferromagnetic with a Curie temperature of 657 K. The longitudinal resistivity exhibits a minimum at 150 K, which is attributable to competition between quantum interference corrections at low temperatures and inelastic scattering at higher temperatures. The magnetoresistance (MR) is positive and nearly linear at low temperatures and becomes negative at temperatures close to room temperature. The positive MR in the quantum correction regime is evidence of the presence of the enhanced electron interaction as a contributor to …

Development Of Novel Intracavitary Intensity Modulated Brachytherapy Applicators For Optimizing The Target Coverage In Gynecologic Malignancies, Monte Carlo Simulation Dosimetry, Moeen Meftahi

Theses and Dissertations

Gynecologic brachytherapy (GYN-BT) is essential for treating cervical and endometrial cancers, the most prevalent female reproductive cancers. This technique enables high radiation doses to a target with rapid dose fall-off to protect adjacent healthy organs. This dissertation aims to address some of the limitations of intracavitary GYN-BT using an intensity modulated brachytherapy (IMBT) technique and Monte Carlo (MC) simulations.

First, a novel non-invasive shielded vaginal cylinder (VC) applicator was designed to provide optimized radiation coverage for the target volume at vaginal apex, site of most recurrences without BT, for endometrial cancer BT. Physical limitations of current applicators and their resulting …

Comparing Twins Ion Temperature Maps With Mms, Ampere, And Themis Observations During July 26, 2017 Reconnection Event, Isabella M. Householder

Honors Theses and Capstones

The solar wind releases a constant stream of ionized particles into space which causes complex behaviors to occur within Earth’s magnetosphere. These disruptions can initiate magnetic reconnection and cause flow reversal of ions in the magnetotail. Two flow reversal events were locally detected by the Magnetospheric Multiscale Mission (MMS) on July 26, 2017 at 0700 UT and 0730 UT. The Two Wide-Angle Imaging Neutral-Atom Spectrometers (TWINS) provide a global measurement of heated signatures of the magnetic field and detected an increase in ion temperature during these reconnection events without the presence of a geomagnetic storm. Active Magnetosphere and Planetary Electrodynamics …

Development Of A Fluxgate Magnetometer Model, Eleonora Olsmats

Honors Theses and Capstones

As a part of the UNH SWFO-L1 mission to monitor space weather and the sun’s behavior, the fluxgate magnetometer is an important component to measure external magnetic fields. The basic principle of a fluxgate magnetometer is to detect changes in the ambient magnetic field by inducing a magnetic field in a ferromagnetic material via a drive winding. Each magnetometer is unique due to the ferromagnetic properties of the core material which can be seen in the hysteresis loop which is a relationship between the magnetic field strength (H) and the induced magnetic field (B). Measuring the hysteresis of a fluxgate …

Attempts To Measure Nanosecond Resolved Electronic Dynamics Of Charge Density Wave Phase Transition In 1t-Tas2, Ben Campbell

Honors Theses and Capstones

Scanning tunneling microscopes allow for atomic spatial resolution but the resulting images are necessarily time-averaged and fast dynamics are lost. Pump-probe spectroscopy is a common optical technique used to measure ultrafast electronic dynamics but the integration of optical pump-probe spectroscopy into an STM requires specialized knowledge and equipment. Alternatively, an all-electronic pump-probe spectroscopy technique has recently been developed for use with an STM that replaces the laser pulses of optical pump-probe with voltage pulses. In this paper, I implemented an all-electronic pump-probe scheme into an existing scanning tunneling microscope using an arbitrary waveform generator and a lock-in amplifier. I developed …

Location And Calibration Of Lightning Pulses From Lofar Radiation Measurements, Nicholas R. Demers

Honors Theses and Capstones

Lightning has the power to shock and awe as an incredible force of nature, yet so many phenomena surrounding lightning are still not well-understood. In fact, the very physics regarding what actually sparks a lightning strike remain poorly defined. In an effort to understand how lightning initiation is achieved, data collected from the Low Frequency Array in the Netherlands were calibrated and interferometry performed to map the flash in 4D space. The calibration process itself is explored, from choosing lightning sources to calibrate, to the various stages of calibration leading to a fully calibrated flash ready for interferometric analysis. Using …