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Full-Text Articles in Physics

Cold Sintering Diisopropylamonium Bromide To Form Organic Ceramic Pellets, Darren Armstrong Oct 2020

Cold Sintering Diisopropylamonium Bromide To Form Organic Ceramic Pellets, Darren Armstrong

Honors Theses

Diisopropylamonium bromide is an organic ferroelectric compound. Standard sample preparation methods either require a powder or a single crystal. Certain measurements cannot be done on powders due to equipment limitations, and single crystals are difficult and time consuming to produce and handle. Cold sintering is a relatively new process that allows the creation of ceramics. The original cold sintering process was adapted to work for diisopropylamonium bromide. This allows the creation of ceramics with a large surface area. These pellets can achieve up to 95% of the theoretical maximum density. While the pellets are currently unsuitable for electric testing at …


Heel Down And Toe-Off Time Measured With Ultrasonic Doppler System And Force Plate Sensor, Sabin Timsina May 2020

Heel Down And Toe-Off Time Measured With Ultrasonic Doppler System And Force Plate Sensor, Sabin Timsina

Honors Theses

Collie Box is a medical device that measures the gait parameters of the person walk- ing in front of it. This device uses the Ultrasonic Doppler system to extract the heel-contact and toe-off times of a person walking within the range of 2-10 meters. These times are used to determine the leg’s swing phase and double stance times. The ultrasonic transducer of 10mm diameter is driven at 40kHz. At the time of the heel-contact and toe-off, foot velocity is zero while the torso part of the human body is still in motion. The wide directivity of 10mm diameter ultrasonic transducer …


Comparison Of The Vibrational Modes Of Thiolated Gold Nanoparticles Undergoing Core-Conversions Via Raman Spectroscopy, William Gregory Cannella Jr. May 2020

Comparison Of The Vibrational Modes Of Thiolated Gold Nanoparticles Undergoing Core-Conversions Via Raman Spectroscopy, William Gregory Cannella Jr.

Honors Theses

In this project, the vibrational characteristics/vibrational modes are explored via Raman Spectroscopy for thiolated-gold nanoparticles. This class of compounds is also known as gold nanoparticles (AuNPs). They remain of great interest in research areas such as catalysis, gold dependent nanoelectronics, drug delivery, and sensing, due to their unique size-dependent optical, chiroptical, and electronic properties. Vibrational spectroscopy of thiolated gold nanoparticles are oftentimes considered nontrivial as the compounds strongly absorb light in the visible region of the electromagnetic spectrum, are generally considered weak scatterers, and give off large amounts of fluorescence. This combined with their black appearance, susceptibility to localized heating, …


Investigatin Actin-Myosin Mechanics To Model Heart Disease Using Fluorescence Microscopy And Optical Trapping, Justin Edward Reynolds May 2020

Investigatin Actin-Myosin Mechanics To Model Heart Disease Using Fluorescence Microscopy And Optical Trapping, Justin Edward Reynolds

Honors Theses

Hypertrophic cardiomyopathy (HCM) is a hereditary disease in which the myocardium becomes hypertrophied, making it more difficult for the heart to pump blood. HCM is commonly caused by a mutation in the β-cardiac myosin II heavy chain. Myosin is a motor protein that facilitates muscle contraction by converting chemical energy from ATP hydrolysis into mechanical work and concomitantly moving along actin filaments. Optical tweezers have been used previously to analyze single myosin biophysical properties; however, myosin does not work as a single unit within the heart. Multiple myosin interacts to displace actin filaments and do not have the same properties …


Perturbation Of Lagrange Points In Effective Potential Simulations, Swapnil Bhatta May 2020

Perturbation Of Lagrange Points In Effective Potential Simulations, Swapnil Bhatta

Honors Theses

Lagrange points are analytically proven to exist at certain positions in a two-body gravitational system, simply as a function of the gravitational force governing the motion of the bodies and the centrifugal potential due to rotation, providing regions of varying effective potentials. In a system involving interactions between the gravitational forces of multiple bodies however, the position of the Lagrange points ought to change. The purpose of this research project is to verify that the change does indeed occur when a new body is introduced, and compute the perturbation in the position of these points given various parameters.


Characterization Of A Trochoidal Electron Monochromator, Jesse Kruse Mar 2020

Characterization Of A Trochoidal Electron Monochromator, Jesse Kruse

Honors Theses

This thesis presents a quantitative study of a trochoidal electron monochromator and attempts to observe the 2p^53p^2 resonance in neon. A detailed description of the experimental apparatus, including the electron beam system, the vacuum system, and the light analysis system, is presented first. Then, we discuss the theory of how the electron beam is monochromatized, how we measured monochomatization, and how we analyze the light being emitted from the collision cell. The light analysis system is capable of accurately measuring the relative Stokes parameters for any polarization of light, and the electron beam system is capable of producing electron beams …


Quantum Defect Measurements For High Angular Momentum Rydberg States Of Potassium, Abraham Hill Jan 2020

Quantum Defect Measurements For High Angular Momentum Rydberg States Of Potassium, Abraham Hill

Honors Theses

We report measurements of the quantum defect for the f-, g-, and h-states of potassium with principal quantum number n between 26 and 29. Ground state potassium atoms in a magneto-optical trap are excited from the 4s state to the 5p state, then from the 5p state to the ndj state using lasers at 405nm and 980nm, respectively. We then measure the millimeter wave frequencies of the ndj to nl transitions. We extract the quantum defects from these frequency measurements in conjunction with the known d-state quantum defects. Experimental challenges with …


Linked-Cluster Expansions For Lattice Spin Models, Yuyi Wan Jan 2020

Linked-Cluster Expansions For Lattice Spin Models, Yuyi Wan

Honors Theses

Similar to various series expansions that are used to approximate mathematical func- tions, the linked-cluster expansion is an approximation method that allows us to approach the actual values of a very large physical system’s different physical quan- tities by systematically studying smaller systems embedded in this larger system. The main concept in linked-cluster expansion, weight, represents the additional con- tribution to a certain physical quantity by increasing the system size by one unit. These weights are used to eventually build up the result on a larger system. In our case, we focus on the partition function, a quantity that can …


Effects Of Energy Resolution And Bin Size On The Measurements Of Nuclear Neutron Distributions Using Coherent Elastic Neutrino-Nucleus Scattering, Hongyong Zhang Jan 2020

Effects Of Energy Resolution And Bin Size On The Measurements Of Nuclear Neutron Distributions Using Coherent Elastic Neutrino-Nucleus Scattering, Hongyong Zhang

Honors Theses

Coherent elastic neutrino-nucleus scattering is a process that involves the neutral-current scattering of a neutrino with an entire nucleus, which probes more bulk properties of the nucleus. Using the Taylor expansion of the form factors and calculation of effective moments that sums over isotopes, we successfully simulate the events for coherent elastic neutrino-nucleus scattering for detectors using Ar and Ge and demonstrate that coherent elastic neutrino-nucleus scattering can determine both the second moment and the fourth moment. Running the Monte Carlo simulation using a detector filled with 10 tonnes of natural germanium, a neutrino flux of 3*10^7 neutrinos per second …


Self-Organization Of Cosmic Elements During Stellar Evolution, Travis Butler Jan 2020

Self-Organization Of Cosmic Elements During Stellar Evolution, Travis Butler

Honors Theses

An open question in science is how complex systems self-organize to produce emergent structures and properties. One aspect is to find the dependence of structure and organization on the size of a system. It has long been known that there is a quality-quantity relationship in natural systems, which is to say that the properties of system depend on its size. More recently, this has been termed the Size-Complexity Rule. In this Thesis paper, we study the average rates of nucleosynthesis and action efficiency of stars with varying initial metallicities and explosion energies from simulations (Nomoto, Tominaga, Umeda, Kobayashi, & Maeda, …