Statistical, Nonlinear, and Soft Matter Physics Commons^™

Developing A Workforce To Build A Star On Earth, Vola Andrianarijaona, Angelina Castillo, Sean Walters

Campus Research Month

This study is meant to help understand why fusion has remained "30 years away" for decades and why that may finally be changing.We see nuclear fusion not merely as a physics phenomenon, but as a complex engineering challenge requiring coordination across different disciplines, including physics, materials science, electrical and mechanical engineering, systems engineering, robotics, and computer science, etc. Indeed, nuclear fusion is not just about "making atoms fuse"—it's about controlling, powering, measuring, and stabilizing one of the most extreme environments humans have ever built. Advances in superconducting magnets, new materials are bringing fusion closer to reality than ever before, and …

Probing The Ising Model’S Thermodynamics Through Restricted Boltzmann Machines, Xiaobei (Emma) Zhang

HMC Senior Theses

This thesis explores the connection between physics and machine learning by using Restricted Boltzmann Machines (RBMs) to study the thermodynamic properties of the Ising model. The Ising model is a simple but realistic model that captures the magnetic behavior of a system, where spins occupy a lattice of sites and different spin configurations correspond to different energies. The model exhibits phase transitions between ferromagnetic and paramagnetic phases as a function of temperature. RBMs are two-layered neural networks that can learn probability distributions over binary spins. The study generates 2D Ising model data at different temperatures using Monte Carlo simulations, including …

The Future Is Now In Twisted Coil Polymer Actuators (Tcpa), Ryan Ronquillo

Electronic Theses and Dissertations

This thesis aimed to fabricate and test twisted coiled polymer actuators (TCPA) to understand the mechanical and thermal aspects of this artificial muscle fiber. The purpose of this thesis was to find a linear relationship using the LVDT sensor, fabricating TCPA fibers, and interpreting the data. The project tested whether nylon/polymer could be used as a better artificial muscle fiber.

This research accomplished three goals: (1) designing and fabricating a system capable of creating supercoiled muscle fibers consistently, (2) calibrating the Linear Variable Differential Transformer (LVDT) and Core, and (3) analyzing/interpreting the data of the Twisted Coiled Polymer Actuators (TCPA) …

One-Dimensional And Two-Dimensional Simulations Of Helical Homopolymers: A Comparative Analysis Of Energy Stabilization And Efficiency​, Nathan Roberts, Matthew Hooks

Scholars Week

The purpose of our work is to analyze the results of a two-dimensional parallel tempering Monte Carlo simulation of a coarse-grained helical homopolymer. The two-dimensional simulation allows Hamiltonian exchanges across both temperature and torsion values, while the one-dimensional simulation exclusively exchanges across temperature values. The genesis of each simulation is defined by a randomly configured polymer; as time progresses, randomly generated movements of monomers decrease the structure’s energy until equilibrium is reached. Equilibrium is determined by finding the absolute minimum of the data series, computing the mean of all remaining data, and finding the intersection between the rolling average and …

Probability Distributions Of The Scalar Potential, Candace Mathews

Legacy Theses & Dissertations (2009 - 2024)

In the study of cosmological inflation, string theory and supersymmetry have motivated a wide range of possible inflationary models. These models can be parameterized by a scalar potential V, which is a function of N scalar fields, and determines cosmological parameters such as the vacuum stability and energy density. In principle, we can determine V through high energy physics, such as string theory. In practice, though we may not know the details of V we might have clues about a distribution of plausible V’s, which we can build statistics on to further analyze. The purpose of this thesis defense is …

The Entropic Dynamics Of Relativistic Quantum Fields In Curved Space-Time, Selman Ipek

Legacy Theses & Dissertations (2009 - 2024)

It has often been the case in history that the laws of physics have been used as the framework for understanding and implementing information processing. The tacit assumption is that the laws of physics are fundamental and that the notion of information is derived from these laws. Here we take the opposite view: the laws of physics are an application of the rules for processing information. The inferential framework of entropic dynamics (ED) has previously been developed by A. Caticha for the purposes of understanding and deriving quantum theory, in much the same way that E.T. Jaynes used the MaxEnt …

The Origins Of Phantom Partials In The Piano, Lauren M. Neldner

Honors Program Theses

Phantom partials are anomalous frequency components identifiable in the sound of the piano and occur at the sum and difference frequencies of two overtones. For several decades they have been identified as crucial components to the sound of the piano and assumed to be generated by the forced longitudinal motion of the string. Recent work has identified that contrary to common belief, most of the power is produced in the non-string components with the most likely source being the wooden structural components. This work presents experimental results for two plausible theories that could explain the origins of phantom partials in …

Morphological Study Of Voids In Ultra-Large Models Of Amorphous Silicon, Durga Prasad Paudel

Dissertations

The microstructure of voids in pure and hydrogen-rich amorphous silicon (a:Si) network was studied in ultra-large models of amorphous silicon, using classical and quantum- mechanical simulations, on the nanometer length scale. The nanostructure, particularly voids of device grade ultra-large models of a:Si was studied, in which observed three-dimensional realistic voids were extended using geometrical approach within the experimental limit of void-volume fractions. In device-grade simulated models, the effect of void morphology; size, shape, number density, and distribution on simulated scattering intensities in small- angle region were investigated. The evolution of voids on annealing below the crystallization temperature …

Practical Chaos: Using Dynamical Systems To Encrypt Audio And Visual Data, Julia Ruiter

Scripps Senior Theses

Although dynamical systems have a multitude of classical uses in physics and applied mathematics, new research in theoretical computer science shows that dynamical systems can also be used as a highly secure method of encrypting data. Properties of Lorenz and similar systems of equations yield chaotic outputs that are good at masking the underlying data both physically and mathematically. This paper aims to show how Lorenz systems may be used to encrypt text and image data, as well as provide a framework for how physical mechanisms may be built using these properties to transmit encrypted wave signals.

Simulating The Electrical Properties Of Random Carbon Nanotube Networks Using A Simple Model Based On Percolation Theory, Roberto Abril Valenzuela

Physics

Carbon nanotubes (CNTs) have been subject to extensive research towards their possible applications in the world of nanoelectronics. The interest in carbon nanotubes originates from their unique variety of properties useful in nanoelectronic devices. One key feature of carbon nanotubes is that the chiral angle at which they are rolled determines whether the tube is metallic or semiconducting. Of main interest to this project are devices containing a thin film of randomly arranged carbon nanotubes, known as carbon nanotube networks. The presence of semiconducting tubes in a CNT network can lead to a switching effect when the film is electro-statically …

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.

The Inferential Design Of Entropy And Its Application To Quantum Measurements, Kevin Vanslette

Legacy Theses & Dissertations (2009 - 2024)

This thesis synthesizes probability and entropic inference with Quantum Mechanics and quantum measurement [1-6]. It is shown that the standard and quantum relative entropies are tools \emph{designed} for the purpose of updating probability distributions and density matrices, respectively [1]. The derivation of the standard and quantum relative entropy are completed in tandem following the same inferential principles and design criteria. This provides the first design derivation of the quantum relative entropy while also reducing the number of required design criteria to two.

Weak-Value Amplification And Optimal Parameter Estimation In The Presence Of Correlated Noise, Josiah Sinclair, Matin Hallaji, Aephraim M. Steinberg, Jeff Tollaksen, Andrew N. Jordan

Mathematics, Physics, and Computer Science Faculty Articles and Research

We analytically and numerically investigate the performance of weak-value amplification (WVA) and related parameter estimation methods in the presence of temporally correlated noise. WVA is a special instance of a general measurement strategy that involves sorting data into separate subsets based on the outcome of a second “partitioning” measurement. Using a simplified correlated noise model that can be analyzed exactly together with optimal statistical estimators, we compare WVA to a conventional measurement method. We find that WVA indeed yields a much lower variance of the parameter of interest than the conventional technique does, optimized in the absence of any partitioning …

Model For The Electrolysis Of Water And Its Use For Optimization, Roger Lascorz, Javier E. Hasbun Dr

Georgia Journal of Science

The goal of this research was to study the optimization of the electrolysis of water both theoretically and experimentally. For accuracy, 3 hr experiments were made with measurements recorded every 15 min. The results show that a better model than the classical one is needed for water electrolysis. A new model that fits experimental data better is proposed. The results of this new model not only predict hydrogen production in electrolysis of water better, but show a way to predict gas production of any liquid as well as what voltage to use to optimize it.

Thermodynamic Effects Of A Local Bell State Projection Interaction In A One-Dimensional Dynamic Spin System, Nickolas H. Pilgram

Physics

No abstract provided.

Impact Testing Of Youth-Level Helmets Versus College-Level Helmets, Nicole Hermann

Industrial Technology and Packaging

With so many studies being conducted on professional football players regarding concussions and other related brain injuries, it’s amazing that such an important demographic has been missed. While NFL players are just as subjected to serious injuries as anyone else or even more so, it is important to remember that these players are outfitted, in most cases, with top-of-the-line equipment -- especially their helmets. If the focus is shifted to a younger demographic, youth football players in middle school and high school, the equipment is far less advanced and in a vast majority of cases, has been previously used by …

Finite Element Analysis In Porous Media For Incompressible Flow Of Contamination From Nuclear Waste, Abbas Al-Bayati, Saad A. Manaa, Ekhlass S. Ahmed

Applications and Applied Mathematics: An International Journal (AAM)

A non-linear parabolic system is used to describe incompressible nuclear waste disposal contamination in porous media, in which both molecular diffusion and dispersion are considered. The Galerkin method is applied for the pressure equation. For the brine, radionuclide and heat, a kind of partial upwind finite element scheme is constructed. Examples are included to demonstrate certain aspects of the theory and illustrate the capabilities of the kind of partial upwind finite element approach.