Other Physics Commons^™

The Battle Between Impeccable Intonation And Maximized Modulation, Timothy M. True

Musical Offerings

Equal temperament represents a way of completing the musical circle, and systematically compensating for the Pythagorean comma. Pythagoras discovered this acoustical problem around 550 B.C., and since that time music theorists have debated how to deal with it. The problem is that no perfect solution exists—something must be compromised. As musical styles developed, specific factors and harmonic tendencies led to the gradual adoption of equal temperament. Early in music history, theorists preferred systems which kept acoustical purity relatively intact. Pythagorean intonation and just intonation serve as two examples. However, the move from modality to tonality decentralized the melody ...

A Nonlinear Approximate Solution To The Damped Pendulum Derived Using The Method Of Successive Approximations, Justin A. Hill, Javier E. Hasbun 8394092

Georgia Journal of Science

An approximate analytic solution to the damped pendulum is derived using the method of successive approximations to obtain a nonlinear approximation for the system. We take the approximate solution to the undamped pendulum using the method of successive approximations and compare it to the damped pendulum solution when a linear approximation is used. By looking at these two solutions, we can make an educated guess about the form of the general, approximate solution to the nonlinear damped pendulum. By adjusting the initial guesses and the initial conditions, we derive approximate solutions in three ways. Using MATLAB, the approximate solutions are ...

Performance Impact Of Different Lower-Limb Setup Positions In The Backstroke Swimming Start, Gordon E. Barkwell

Electronic Thesis and Dissertation Repository

The performance impact of different knee extension angles in the setup position for a backstroke start was evaluated using an instrumented starting surface. Ten backstroke swimmers completed maximum-effort starts in each of two setup positions: one with the knees flexed, and one with the knees extended. The start handles and touchpad were instrumented with tri-axial force plates. Activity of major hip and knee extensors was measured using surface electromyography. Body position was recorded throughout the start using two high-speed cameras. There was no difference in time to 10 m between the two conditions, indicating there is likely no advantage in ...

Spin Alignment Generated In Inelastic Nuclear Reactions, Daniel Hoff

Arts & Sciences Electronic Theses and Dissertations

The spin alignment of inelastically excited 7Li projectiles, when the target remains in its ground state, was determined through angular-correlation measurements between the breakup fragments of 7Li_ (_ + t). It was found that 7Li_ is largely aligned along the beam axis (longitudinal) in this type of inelastic reaction, regardless of the target. This longitudinal alignment is well described by DWBA calculations, which can be explained by an angular-momentum-excitation-energy mismatch condition. These calculations also explain the longitudinal spin alignment of excited nuclei in several other systems, showing the phenomenon is more general. The experiment involving 7Li was performed at the Texas ...

Verification And Evaluation Of A Passive Intensity Modulation Device For Bolus Electron Conformal Therapy, Elizabeth Noel Hilliard

LSU Master's Theses

Purpose: Bolus electron conformal therapy (BECT) provides effective radiation treatment for superficial cancers and other diseases close to the skin surface, but can have as great as a 30% planning target volume (PTV) dose heterogeneity due to scattering from the irregular proximal bolus surface. Intensity modulated (IM) BECT can improve PTV dose homogeneity, but is not currently available. This study fabricated patient-specific passive intensity modulators and validated their delivering planned dose distributions calculated by a modified pencil beam redefinition algorithm (PBRA).

Methods: Two test-patterns and four patient-specific intensity modulators were designed, fabricated, and tested. Dose plans were generated using a ...

Locality And Nonlocality In The Interaction-Free Measurement, Daniel Rohrlich, Yakir Aharonov, Tomer Landsberger

Mathematics, Physics, and Computer Science Faculty Articles and Research

We present a paradox involving a particle and a mirror. They exchange a nonlocal quantity, modular angular momentum L_z mod 2ћ, but there seems to be no local interaction between them that allows such an exchange. We demonstrate that the particle and mirror do interact locally via a weak local current 〈L_z mod 2ћ〉_w. In this sense, we transform the “interaction-free measurement” of Elitzur and Vaidman, in which two local quantities (the positions of a photon and a bomb in the two arms of a Mach-Zehnder interferometer) interact nonlocally, into a thought experiment in which two nonlocal ...

Scattering Of Few Photon Fields By Two Level Systems In A One Dimensional Geometry, William Konyk

Theses and Dissertations

Recent experimental progress has realized strong, efficient coupling of effective two level systems to waveguides. We study the scattering of multimode photons from such emitters coupled losslessly to the confined geometry of a one dimensional waveguide. We develop novel techniques for describing the scattered state of both single and multi-photon wavepackets and explore how such wavepackets interact with arrays of emitters coupled to a one dimensional waveguide. Finally, we apply these techniques and analyze the capability of two particular systems to act as a quantum conditional logic gate.

Improved Target Coverage Of Spinal Metastases Through The Use Of Flattening Filter Free Beams, Laura Bennett

UT GSBS Dissertations and Theses (Open Access)

Of the patients that are diagnosed with metastatic disease, up to 40% will develop vertebral osseous metastases. These metastases tend to be located in close proximity to the spinal cord itself, making it difficult to achieve the recommended minimum dose of 14 Gy for single fraction SBRT or 21 Gy¹ for three fraction SBRT while maintaining acceptable doses to the cord and cauda equina. This proximity of the target to critical structures has the potential to compromise the efficacy of the radiation treatment plan in favor of reducing normal tissue dose, resulting in poor local control and tumor recurrence ...

The Relationship Between Electrical Conductivity And Magnetically Damped Motion, Kalem Akhtar

The International Student Science Fair 2018

Varying electrical conductivities of different, non-magnetic metals appears to affect the magnitude of magnetically damped motion. To determine the relationship between magnetic damping and conductivity an experiment was designed using different length tubes of aluminium, copper and brass. The tubes had the same diameter and similar wall thickness. A short, cylindrical neodymium magnet was dropped through the tubes of and the time for the magnet to traverse the tube was recorded using a smartphone camera. These times allowed for the terminal velocity to be calculated for each metal length and the average terminal velocity for each metal was determined. This ...

Electricity, Light And Semiconductors, Josephine Zhao

The International Student Science Fair 2018

As technology advanced these days, computers are playing a more and more important role in our daily life; especially in those areas that requires higher technology, for example, aerospace. And as computers keep developing, they tend to be smaller and lighter but much more sufficient. It is the base stone of modern information era. A CPU is the brain of a computer, and as the computers get smaller and smaller, the CPUs are getting smaller and smaller, using semiconductors. Semiconductors have many properties that is extremely useful to human, their conductivity are controlled by their environment, and therefore are adaptable ...

The Relationship Between Electrical Conductivity And Magnetically Damped Motion, Kalem Akhtar

The International Student Science Fair 2018

Varying electrical conductivities of different, non-magnetic metals appears to affect the magnitude of magnetically damped motion. To determine the relationship between magnetic damping and conductivity an experiment was designed using different length tubes of aluminium, copper and brass. The tubes had the same diameter and similar wall thickness. A short, cylindrical neodymium magnet was dropped through the tubes of and the time for the magnet to traverse the tube was recorded using a smartphone camera. These times allowed for the terminal velocity to be calculated for each metal length and the average terminal velocity for each metal was determined. This ...

Light, Electricity And Semiconductors, Josephine Zhao

The International Student Science Fair 2018

No abstract provided.

Lattice Scales From Gradient Flow And Chiral Analysis On The Milc Collaboration's Hisq Ensembles, Nathan Joseph Brown

Arts & Sciences Electronic Theses and Dissertations

The interactions of quarks and gluons form most of the visible matter around us. Yet, extracting precise predictions from the field theory describing them, Quantum Chromodynamics (QCD), is notoriously difficult. By simulating the QCD interaction on a Euclidean space time lattice, the field theory can be regularized non-perturbatively and familiar statistical techniques from classical statistical mechanics can be applied. Then, by systematically improving each component of the process, high precision results can be obtained. Some of the possible components to be improved include the discretization of the continuum action, the determination of the lattice scale(s), the generation of gauge ...

Endorectal Digital Prostate Tomosynthesis, Joseph Robert Steiner

LSU Doctoral Dissertations

Several areas of prostate cancer (PCa) management, such as imaging permanent brachytherapy implants or small, aggressive lesions, benefit from high image resolution. Current PCa imaging methods can have inadequate resolution for imaging these areas. Endorectal digital prostate tomosynthesis (endoDPT), an imaging method that combines an external x-ray source and an endorectal x-ray sensor, can produce three-dimensional images of the prostate region that have high image resolution compared to typical methods. This high resolution may improve PCa management and increase positive outcomes in affected men.

This dissertation presents the initial development of endoDPT, including system design, image quality assessment, and examples ...

Investigating Student Understanding Of Vector Calculus In Upper-Division Electricity And Magnetism: Construction And Determination Of Differential Element In Non-Cartesian Coordinate Systems, Benjamin Schermerhorn

Electronic Theses and Dissertations

Differential length, area, and volume elements appear ubiquitously over the course of upper-division electricity and magnetism (E&M), used to sum the effects of or determine expressions for electric or magnetic fields. Given the plethora of tasks with spherical and cylindrical symmetry, non-Cartesian coordinates are commonly used, which include scaling factors as coefficients for the differential terms to account for the curvature of space. Furthermore, the application to vector fields means differential lengths and areas are vector quantities. So far, little of the education research in E&M has explored student understanding and construction of the non-Cartesian differential elements used in applications of vector calculus. This study contributes to the research base on the learning and teaching of these quantities.

Following course observations of junior-level E&M, targeted investigations were conducted to categorize student understanding of the properties of these differentials as they are constructed in a coordinate system without a physics context and as they are determined within common physics tasks. In general, students did not have a strong understanding of the geometry of non-Cartesian coordinate systems. However, students who were able to construct differential area and volume elements as a product of differential lengths within a given coordinate system were more successful when applying vector calculus. The results of this study were used to develop preliminary instructional resources to aid in the teaching of this material.

Lastly, this dissertation presents a theoretical model developed within the context of this study to describe students’ construction and interpretation of equations. The model joins existing theoretical frameworks: symbolic forms, used to describe students’ representational understanding of the structure of the constructed equation; and conceptual blending, which has been used to describe the ways in which students combine mathematics and physics knowledge when problem solving. In addition to providing a coherent picture for how the students in this study connect contextual information to symbolic representations, this model is broadly applicable as an analytical lens and allows for a detailed reinterpretation of similar analyses using these frameworks.

Vibrational Relaxation Theory For Systems Embedded In Microscopically Specified Reservoirs, Anastasia Aemilia Ierides

Physics & Astronomy ETDs

This dissertation is a study of the theoretical framework of the practical as well as fundamental problem of the process of relaxation to equilibrium of quantum mechanical systems. The fundamental aspect is concerned with the simultaneous occurrence of decoherence and population equilibration. The practical aspect deals with experimental observations of vibrational relaxation of molecules embedded in liquids or solids. The systems include, but are not limited to, the nondegenerate dimer and harmonic oscillator, in one case weak and in the other strong, interaction with a thermal bath. The time dependence of the energy and the temperature dependence of the relaxation ...

Atmospheric Radiation And Tgfs: Unexplained Radiation In Our Skies, Adrian Gallegos

Honors College Research

There is a significant correlation between atmospheric electrification via thunderstorms and the occurrence of large emissions of x-ray and gamma ray radiation known as Terrestrial Gamma Ray Flashes (TGFs). Some physical phenomenon may be explained by either the RREA or Thermal Runaway models, but the scientific community as a whole is still largely at work on the theoretical frameworks.

Quasiprobability Behind The Out-Of-Time-Ordered Correlator, Nicole Yunger Halpern, Brian Swingle, Justin Dressel

Mathematics, Physics, and Computer Science Faculty Articles and Research

Two topics, evolving rapidly in separate fields, were combined recently: the out-of-time-ordered correlator (OTOC) signals quantum-information scrambling in many-body systems. The Kirkwood-Dirac (KD) quasiprobability represents operators in quantum optics. The OTOC was shown to equal a moment of a summed quasiprobability [Yunger Halpern, Phys. Rev. A 95, 012120 (2017)]. That quasiprobability, we argue, is an extension of the KD distribution. We explore the quasiprobability's structure from experimental, numerical, and theoretical perspectives. First, we simplify and analyze Yunger Halpern's weak-measurement and interference protocols for measuring the OTOC and its quasiprobability. We decrease, exponentially in system size, the number of ...

Hyperpolarization Of Silicon Nanoparticles With Tempo Radicals, Jingzhe Hu, Nicholas Whiting, Pratip Bhattacharya

Nicholas Whiting

Examining Students' Representation Choices In University Modeling Instruction, Daryl Mcpadden

FIU Electronic Theses and Dissertations

Representations (such as pictures, diagrams, word descriptions, equations, etc.) are critical tools for learning, problem solving, and communicating in science, particularly in physics where multiple representations often serve as intermediate steps, a means to evaluate a solution, and highlight different aspects a physical phenomenon. This dissertation explores the representation choices made by students in the University Modeling Instruction (MI) courses on problems from across introductory physics content. Modeling Instruction is a two-semester introductory, calculus-based physics sequence that was designed to guide students through the process of building, testing, applying, and refining models. As a part of this modeling cycle, students ...