Pde Model For Protocell Evolution And The Origin Of Chromosomes Via Multilevel Selection, 2023 University of Pennsylvania
Pde Model For Protocell Evolution And The Origin Of Chromosomes Via Multilevel Selection, Daniel B. Cooney, Fernando W. Rossine, Dylan H. Morris, Simon A. Levin
Biology and Medicine Through Mathematics Conference
No abstract provided.
Reaction-Diffusion System On Irregular Boundaries Reproduces Multiple Generations Of Petal Spot Patterns In Monkeyflower Hybrids, 2023 William & Mary
Reaction-Diffusion System On Irregular Boundaries Reproduces Multiple Generations Of Petal Spot Patterns In Monkeyflower Hybrids, Emily Simmons
Biology and Medicine Through Mathematics Conference
No abstract provided.
Helices In Fluids And Their Applications, 2023 James Madison University
Helices In Fluids And Their Applications, Eva M. Strawbridge
Biology and Medicine Through Mathematics Conference
No abstract provided.
Monolithic Multiphysics Simulation Of Hypersonic Aerothermoelasticity Using A Hybridized Discontinuous Galerkin Method, 2023 Mississippi State University
Monolithic Multiphysics Simulation Of Hypersonic Aerothermoelasticity Using A Hybridized Discontinuous Galerkin Method, William Paul England
Theses and Dissertations
This work presents implementation of a hybridized discontinuous Galerkin (DG) method for robust simulation of the hypersonic aerothermoelastic multiphysics system. Simulation of hypersonic vehicles requires accurate resolution of complex multiphysics interactions including the effects of high-speed turbulent flow, extreme heating, and vehicle deformation due to considerable pressure loads and thermal stresses. However, the state-of-the-art procedures for hypersonic aerothermoelasticity are comprised of low-fidelity approaches and partitioned coupling schemes. These approaches preclude robust design and analysis of hypersonic vehicles for a number of reasons. First, low-fidelity approaches limit their application to simple geometries and lack the ability to capture small scale flow …
An Integrated Experimental And Modeling Approach To Design Rotating Algae Biofilm Reactors (Rabrs) Via Optimizing Algae Biofilm Productivity, Nutrient Recovery, And Energy Efficiency, 2023 Utah State University
An Integrated Experimental And Modeling Approach To Design Rotating Algae Biofilm Reactors (Rabrs) Via Optimizing Algae Biofilm Productivity, Nutrient Recovery, And Energy Efficiency, Gerald Benjamin Jones
All Graduate Plan B and other Reports, Spring 1920 to Spring 2023
Microalgae biofilms have been demonstrated to recover nutrients from wastewater and serve as biomass feedstock for bioproducts. However, there is a need to develop a platform to quantitatively describe microalgae biofilm production, which can provide guidance and insights for improving biomass areal productivity and nutrient uptake efficiency. This paper proposes a unified experimental and theoretical framework to investigate algae biofilm growth on a rotating algae biofilm reactor (RABR). The experimental laboratory setups are used to conduct controlled experiments on testing environmental and operational factors for RABRs. We propose a differential-integral equation-based mathematical model for microalgae biofilm cultivation guided by laboratory …
Asymptotic Properties And Separation Rates For Navier-Stokes Flows, 2023 University of Arkansas-Fayetteville
Asymptotic Properties And Separation Rates For Navier-Stokes Flows, Patrick Michael Phelps
Graduate Theses and Dissertations
In this dissertation, we investigate asymptotic properties of local energy solutions to the Navier-Stokes equations and develop an application which controls the separation of non-unique solutions in this class. Specifically, we quantify the rate at which two, possibly unique solutions evolving from the same data may separate pointwise away from a singularity. This is motivated by recent results on non-uniqueness for forced and unforced Navier-Stokes and analytical and numerical evidence suggesting non-uniqueness in the Leray class. Our investigation begins with discretely self-similar solutions known to exist globally in time and to be regular outside a space-time paraboloid. We prove decay …
Advancements In Fluid Simulation Through Enhanced Conservation Schemes, 2023 Clemson University
Advancements In Fluid Simulation Through Enhanced Conservation Schemes, Sean Ingimarson
All Dissertations
To better understand and solve problems involving the natural phenomenon of fluid and air flows, one must understand the Navier-Stokes equations. Branching several different fields including engineering, chemistry, physics, etc., these are among the most important equations in mathematics. However, these equations do not have analytic solutions save for trivial solutions. Hence researchers have striven to make advancements in varieties of numerical models and simulations. With many variations of numerical models of the Navier-Stokes equations, many lose important physical meaningfulness. In particular, many finite element schemes do not conserve energy, momentum, or angular momentum. In this thesis, we will study …
The Magnetic Field Of Protostar-Disk-Outflow Systems, 2023 Western University
The Magnetic Field Of Protostar-Disk-Outflow Systems, Mahmoud Sharkawi
Electronic Thesis and Dissertation Repository
Recent observations of protostellar cores reveal complex magnetic field configurations that are distorted in the innermost disk region. Unlike the prestellar phase, where the magnetic field geometry is simpler with an hourglass configuration, magnetic fields in the protostellar phase are sculpted by the formation of outflows and rapid rotation. This gives rise to a significant azimuthal (or toroidal) component that has not yet been analytically modelled in the literature. Moreover, the onset of outflows, which act as angular momentum transport mechanisms, have received considerable attention in the past few decades. Two mechanisms: 1) the driving by the gradient of a …
Data-Driven Computational Methods For Quasi-Stationary Distribution And Sensitivity Analysis, 2023 University of Massachusetts Amherst
Data-Driven Computational Methods For Quasi-Stationary Distribution And Sensitivity Analysis, Yaping Yuan
Doctoral Dissertations
The goal of the dissertation is to develop the computational methods for quasi-stationary- distributions(QSDs) and the sensitivity analysis of a QSD against the modification of the boundary conditions and against the diffusion approximation.
Many models in various applications are described by Markov chains with absorbing states. For example, any models with mass-action kinetics, such as ecological models, epidemic models, and chemical reaction models, are subject to the population-level randomness called the demographic stochasticity, which may lead to extinction in finite time. There are also many dynamical systems that have interesting short term dynamics but trivial long term dynamics, such as …
Fourth Order Dispersion In Nonlinear Media, 2023 University of Massachusetts Amherst
Fourth Order Dispersion In Nonlinear Media, Georgios Tsolias
Doctoral Dissertations
In recent years, there has been an explosion of interest in media bearing quartic
dispersion. After the experimental realization of so-called pure-quartic solitons, a
significant number of studies followed both for bright and for dark solitonic struc-
tures exploring the properties of not only quartic, but also setic, octic, decic etc.
dispersion, but also examining the competition between, e.g., quadratic and quartic
dispersion among others.
In the first chapter of this Thesis, we consider the interaction of solitary waves in
a model involving the well-known φ4 Klein-Gordon theory, bearing both Laplacian and biharmonic terms with different prefactors. As a …
Continuum Model Of Faceted Ice Crystal Growth In Cirrus Clouds In 1 Dimension, 2023 University of Puget Sound
Continuum Model Of Faceted Ice Crystal Growth In Cirrus Clouds In 1 Dimension, Ella Slattery
Summer Research
Ice crystals in cirrus clouds exhibit stable faceted growth and roughening which affects reflectivity. A numerically stable modelling system of partial differential equations representing the thickness of ice surfaces over time may assist in describing these features. A sinusoidal relationship between total thickness and water vapor deposition on the surface of ice crystals was observed experimentally; the modelling equation for this relationship was applied to the system in order to develop a one variable model. The developed one variable models continue to exhibit numerical instabilities prior to a Fourier Transform. Stable limit cycles of ice growth were observed in the …
Integrable Systems On Symmetric Spaces From A Quadratic Pencil Of Lax Operators, 2023 Technological University Dublin
Integrable Systems On Symmetric Spaces From A Quadratic Pencil Of Lax Operators, Rossen Ivanov
Conference papers
The article surveys the recent results on integrable systems arising from quadratic pencil of Lax operator L, with values in a Hermitian symmetric space. The counterpart operator M in the Lax pair defines positive, negative and rational flows. The results are illustrated with examples from the A.III symmetric space. The modeling aspect of the arising higher order nonlinear Schrödinger equations is briefly discussed.
Effects Of Slip On Highly Viscous Thin-Film Flows Inside Vertical Tubes (Constant Radius, Constricted And Flexible), 2023 Virginia Commonwealth University
Effects Of Slip On Highly Viscous Thin-Film Flows Inside Vertical Tubes (Constant Radius, Constricted And Flexible), Mark S. Schwitzerlett
Theses and Dissertations
Viscous liquid film flows in a tube arise in numerous industrial and biological applications, including the transport of mucus in human airways. Previous modeling studies have typically used no-slip boundary conditions, but in some applications the effects of slip at the boundary may not be negligible. We derive a long-wave model based on lubrication theory which allows for slippage along the boundary. Linear stability analysis verifies the impact of slip-length on the speed, growth rate, and wavelength of the most unstable mode. Nonlinear simulations demonstrate the impact of slip-length on plug formation and wave dynamics. These simulations are conducted for …
The Lagrangian Formulation For Wave Motion With A Shear Current And Surface Tension, 2023 Technological University Dublin
The Lagrangian Formulation For Wave Motion With A Shear Current And Surface Tension, Conor Curtin, Rossen Ivanov
Articles
The Lagrangian formulation for the irrotational wave motion is straightforward and follows from a Lagrangian functional which is the difference between the kinetic and the potential energy of the system. In the case of fluid with constant vorticity, which arises for example when a shear current is present, the separation of the energy into kinetic and potential is not at all obvious and neither is the Lagrangian formulation of the problem. Nevertheless, we use the known Hamiltonian formulation of the problem in this case to obtain the Lagrangian density function, and utilising the Euler-Lagrange equations we proceed to derive some …
Does Faceted Ice Growth Follow A Characteristic Pattern, 2023 University of Puget Sound
Does Faceted Ice Growth Follow A Characteristic Pattern, Spencer Racca-Gwozdzik
Summer Research
Under certain heat conditions, ice crystals can form differently from the snowflakes that generally grow. Instead of attaching on the boundaries of a plane of ice, under these conditions, new water molecules will permeate a quasi-liquid layer above the ice that causes them to attach closer to the center of the plane and build up from there. These ice formations are close to cylindrical with patterns of roughness on the sides and top at the micrometer scale. The growth can be modeled with a system of partial differential equations that is similar to a reaction diffusion system. This project tries …
Foundations Of Wave Phenomena: Complete Version, 2023 Department of Physics, Utah State University
Foundations Of Wave Phenomena: Complete Version, Charles G. Torre
Foundations of Wave Phenomena
This is the complete version of Foundations of Wave Phenomena. Version 8.3.1.
Please click here to explore the components of this work.
Solitons And Their Applications In Physics, 2023 Eastern Washington University
Solitons And Their Applications In Physics, B. A. Yount
EWU Masters Thesis Collection
No abstract provided.
Using Modflow To Assess Groundwater Storage Enhancement Via A Floodplain Infiltration Basin, 2023 Central Washington University
Using Modflow To Assess Groundwater Storage Enhancement Via A Floodplain Infiltration Basin, Lindsay Henning
All Master's Theses
Delaying groundwater discharge into rivers until it is critically needed during baseflow conditions provides promise for lowering elevated stream temperatures and improving habitat for aquatic species. Increasing groundwater storage may accomplish this in locations where excess spring runoff can be captured and allowed to infiltrate into the subsurface for later beneficial use, a process known as Managed Aquifer Recharge (MAR). Here, MAR via an infiltration basin is considered at a site along the Teanaway River in central Washington State. The effects of simulated ephemeral ponds of sizes varying from 554 m3 to 2430 m3 (0.449 acre-feet to 1.97 …
Beginner's Analysis Of Financial Stochastic Process Models, 2023 Harvey Mudd College
Beginner's Analysis Of Financial Stochastic Process Models, David Garcia
HMC Senior Theses
This thesis explores the use of geometric Brownian motion (GBM) as a financial model for predicting stock prices. The model is first introduced and its assumptions and limitations are discussed. Then, it is shown how to simulate GBM in order to predict stock price values. The performance of the GBM model is then evaluated in two different periods of time to determine whether it's accuracy has changed before and after March 23, 2020.
Modeling Self-Diffusiophoretic Janus Particles In Fluid, 2023 Harvey Mudd College
Modeling Self-Diffusiophoretic Janus Particles In Fluid, Kausik Das
HMC Senior Theses
We explore spherical Janus particles in which a chemical reaction occurs on one face, depleting a substrate in the suspending fluid, while no reaction occurs on the other face. The steady state concentration field is governed by Laplace’s equation with mixed boundary conditions. We use the collocation method to obtain numerical solutions to the equation in spherical coordinates. The asymmetry of the reaction gives rise to a slip velocity that causes the particle to move spontaneously in the fluid through a process known as self-diffusiophoresis. Using the Lorentz reciprocal theorem, we obtain the swimming velocity of the particle. We extend …