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A Molecular Dynamics Study Of Polymer Chains In Shear Flows And Nanocomposites, Venkat Bala
A Molecular Dynamics Study Of Polymer Chains In Shear Flows And Nanocomposites, Venkat Bala
Electronic Thesis and Dissertation Repository
In this work we study single chain polymers in shear flows and nanocomposite polymer melts extensively through the use of large scale molecular dynamics simulations through LAMMPS. In the single polymer chain shear flow study, we use the Lattice Boltzmann method to simulate fluid dynamics and also include thermal noise as per the \emph{fluctuation-dissipation} theorem in the system. When simulating the nanocomposite polymer melts, we simply use a Langevin thermostat to mimic a heat bath. In the single polymer in shear flow study we investigated the margination of a single chain towards solid surfaces and how strongly the shear flow …
Acoustic Waves In The Upper Atmosphere, Geoffrey Blayne Schulthess
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 …
Dust-Gas Dynamics Driven By The Streaming Instability With Various Pressure Gradients, Stanley Antedio Baronett
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 …
Whistler Waves: Modeling And Observations, Daniel Williams
Whistler Waves: Modeling And Observations, Daniel Williams
Doctoral Dissertations and Master's Theses
The thesis presents the results of all the research from the published and in publication process research in the Journal of Geophysical Research [1]. This research focuses on whistler wave ducting events in the equatorial magnetosphere. High-density ducts are the main focus of whistler study in both studies as they are commonly observed by the Van Allen Probe satellites. A three-step procedure based on the analysis of the whistler wave dispersion relation and numerical simulations of the electron magnetohydrodynamics model. We use this model to identify the parallel and perpendicular wave numbers of the “most trapped” wave in an attempt …
First-Principles-Based Modeling Of Energy Converting Properties Of Conventional And Emerging Ferroelectrics, Maggie Kingsland
First-Principles-Based Modeling Of Energy Converting Properties Of Conventional And Emerging Ferroelectrics, Maggie Kingsland
USF Tampa Graduate Theses and Dissertations
Ferroelectric materials are a type of multifunctional material that exhibit spontaneous polarization reversable by the application of an electric field. They are used in many technologies such as ferroelectric RAM (FeRAM), piezoelectric devices, RFID chips, and capacitors. However, the most commonly used ferroelectrics are often made with rare, expensive elements and are not environmentally friendly. For example, many prototypical ferroelectrics contain elements such as lead, zirconium, and titanium. As technology grows more advanced, there is a need to discover or manufacture cheaper ferroelectrics and to make them less impactful on human health and the earth as a whole. We set …
Cosmogenically-Induced Backgrounds In Legend, Clay Douglas Barton
Cosmogenically-Induced Backgrounds In Legend, Clay Douglas Barton
Dissertations and Theses
Neutrinoless double-beta decay (0νββ) is a hypothetical nuclear decay mode. 0νββ searches are a high priority in nuclear physics. Discovery would ascertain the nature of the neutrino as the first known fundamental Majorana particle, and have far-reaching implications for physics beyond the Standard Model, including a lower bound on the effective neutrino mass scale, first direct evidence of a lepton number violating process, and insight into the matter-antimatter asymmetry in the universe. The next-generation LEGEND (Large Enriched Germanium Experiment for Neutrinoless ββ Decay) project will search for neutrinoless double-beta decay of 76Ge. LEGEND builds on infrastructure and technical expertise of …
A Review Of Monte Carlo Methods And Their Application In Medical Physics For Simulating Radiation Transport, Joe Shields
A Review Of Monte Carlo Methods And Their Application In Medical Physics For Simulating Radiation Transport, Joe Shields
Honors Theses and Capstones
Monte Carlo methods are used to calculate statistical behavior through the use of random number generators and probability density functions. They have been used extensively in medical physics for research in radiotherapy, designing technology, dosimetry, and advanced clinical applications. This paper provides a background on Monte Carlo methods and a review of radiation therapy physics and dosimetry. Additionally, there is a discussion of the different ways Monte Carlo methods are used in medical physics as well as a review of current research related to Monte Carlo methods. The final portion of this paper contains my own Monte Carlo simulation using …
Machine Learning-Driven Surrogate Models For Electrolytes, Tong Gao
Machine Learning-Driven Surrogate Models For Electrolytes, Tong Gao
Dissertations, Master's Theses and Master's Reports
We have developed a lattice Monte Carlo (MC) simulation based on the diffusion-limited aggregation model that accounts for the effect of the physical properties of ionic liquids (ILs) on lithium dendrite growth. Our simulations show that the size asymmetry between the cation and anion, the dielectric constant, and the volume fraction of ILs are critical factors to significantly suppress the dendrite growth, primarily due to substantial changes in electric-field screening. Specifically, the volume fraction of ILs has the optimal value for dendrite suppression. The present simulation method indicates potential challenges for the model extension to macroscopic systems. Therefore, we also …