Physics Commons^™

Hovering Potato ~ Activity Plan, Admin Stem For Success

STEM for Success Showcase

This experiment is a great example of chemistry. This experiment relies heavily on density and diffusion.

• Water is less dense than half of a potato. Therefore, the potato sinks.

• Sugar water is more dense than half of a potato. Therefore, the potato floats.

By slowly adding water to sugar water, two layers are formed which allows the potato to hover in between. Slowly adding the water allows for diffusion to occur at a minimum.

Simulation Of Coherent Remission In Planar Disordered Medium, Pablo Jara-Palacios, Ho Chun Lin, Chia Wei Hsu, Hui Cao, Alexey Yamilov

Physics Faculty Research & Creative Works

Waves remitted from a scattering medium carry information that can be used for non-invasive imaging and sensing. Such techniques are usually limited by a low photon budget. Recent progress in optical wavefront shaping has enabled coherent control with an order-of-magnitude enhancement of remission [1]. This experimental study necessitated increasingly demanding numerical simulations. Extending this line of research requires more sophisticated computational techniques capable of simulating multiple instances of even larger systems. Here, we demonstrate that remission geometry can be efficiently simulated using a novel open-source software package [2] Maxwell's Equations Solver with Thousands of Inputs (MESTI). To verify its numerical …

Nanoscale Hybrid Electrolytes With Viscosity Controlled Using Ionic Stimulus For Electrochemical Energy Conversion And Storage, Sara T. Hamilton, Tony G. Feric, Sahana Bhattacharyya, Nelly M. Cantillo, Steven G. Greenbaum, Thomas A. Zawodzinski, Ah-Hyung Alissa Park

Publications and Research

As renewable energy is rapidly integrated into the grid, the challenge has become storing intermittent renewable electricity. Technologies including flow batteries and CO 2 conversion to dense energy carriers are promising storage options for renewable electricity. To achieve this technological advancement, the development of next generation electrolyte materials that can increase the energy density of flow batteries and combine CO 2 capture and conversion is desired. Liquid-like nanoparticle organic hybrid materials (NOHMs) composed of an inorganic core with a tethered polymeric canopy (e.g., polyetheramine (HPE)) have a capability to bind chemical species of interest including CO 2 and redox-active species. …

Single-Molecule Localization Microscopy Of 3d Orientation And Anisotropic Wobble Using A Polarized Vortex Point Spread Function, Tianben Ding, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

Within condensed matter, single fluorophores are sensitive probes of their chemical environments, but it is difficult to use their limited photon budget to image precisely their positions, 3D orientations, and rotational diffusion simultaneously. We demonstrate the polarized vortex point spread function (PSF) for measuring these parameters, including characterizing the anisotropy of a molecule’s wobble, simultaneously from a single image. Even when imaging dim emitters (∼500 photons detected), the polarized vortex PSF can obtain 12 nm localization precision, 4°–8° orientation precision, and 26° wobble precision. We use the vortex PSF to measure the emission anisotropy of fluorescent beads, the wobble dynamics …

Establishing Independent Tunability Of The Mechanical And Transport Properties Of Polymer Gels, Lucas Rankin

Master’s Theses

Polymer gels can be used in the fabrication of materials for filtering liquid and gaseous media, solid-state electrolytes, and transdermal medical patches. This diverse range of applications primarily relies on the transport and mechanical properties of polymer gels. Both sets of properties have shown excellent tunability, but typically in a coupled fashion. Establishing the independent tunability of the transport and mechanical properties of polymer gels (using simple, cost-effective methods) is paramount if polymer gels are to be used to their full potential. Specifically, block copolymer gels self-assemble into organized nanoscale networks within the gel solvent, which allows for facile control …

Study Of Diffusion, Solubility And Electrophysical Properties Of Scandium, Praseodymium And Europium In Silicon, Sirojiddin Z. Zainabidinov, Dilshad E. Nazyrov, Valentina P. Usacheva

Scientific Bulletin. Physical and Mathematical Research

The purpose of the present work was a comprehensive study of the diffusion, solubility and electrophysical properties of scandium (Sc), praseodymium (Pr) and europium (Eu) impurities in silicon. On the surface of the KEP-15 a layer of radioactive isotopes was sprayed: ⁴⁶Sc, ¹⁴³Pr₂O₃, or ¹⁵²Eu₂O₃. The duration of diffusion annealing varied depending on the diffusion temperature of 5 to 72 hours. Autoradiography, measurements of conductivity and Hall's effect, an isothermal relaxation of capacity and current, a research of diffusion, solubility and electrophysical properties of Sc, Pr and Eu in …

On Demand Nanoscale Phase Manipulation Of Vanadium Dioxide By Scanning Probe Lithography, Dustin Schrecongost

Graduate Theses, Dissertations, and Problem Reports

This dissertation focuses on nanoscale phase manipulations of Vanadium Dioxide. Nanoscale control of material properties is a current obstacle for the next generation of optoelectronic and photonic devices. Vanadium Dioxide is a strongly correlated material with an insulator-metal phase transition at approximately 345 K that generates dramatic electronic and optical property changes. However, the development of industry device application based on this phenomenon has been limited thus far due to the macroscopic scale and the volatile nature of the phase transition. In this work these limitations are assessed and circumvented.

A home-built, variable temperature, scanning near-field optical microscope was engineered …

Polymeric Impulsive Actuation Mechanisms: Development, Characterization, And Modeling, Yongjin Kim

Doctoral Dissertations

Recent advances in the field of biomedical and life-sciences are increasingly demanding more life-like actuation with higher degrees of freedom in motion at small scales. Many researchers have developed various solutions to satisfy these emerging requirements. In many cases, new solutions are made possible with the development of novel polymeric actuators. Advances in polymeric actuation not only addressed problems concerning low degree of freedom in motion, large system size, and bio-incompatibility associated with conventional actuators, but also led to the discovery of novel applications, which were previously unattainable with conventional engineered systems. This dissertation focuses on developing novel actuation mechanisms …

Probability Density Of The Fractional Langevin Equation With Reflecting Walls, Thomas Vojta, Sarah Skinner, Ralf Metzler

Physics Faculty Research & Creative Works

We investigate anomalous diffusion processes governed by the fractional Langevin equation and confined to a finite or semi-infinite interval by reflecting potential barriers. As the random and damping forces in the fractional Langevin equation fulfill the appropriate fluctuation-dissipation relation, the probability density on a finite interval converges for long times towards the expected uniform distribution prescribed by thermal equilibrium. In contrast, on a semi-infinite interval with a reflecting wall at the origin, the probability density shows pronounced deviations from the Gaussian behavior observed for normal diffusion. If the correlations of the random force are persistent (positive), particles accumulate at the …

Quantifying Complex Systems Via Computational Fly Swarms, Troy Taylor

Senior Theses

Complexity is prevalent both in natural and in human-made systems, yet is not well understood quantitatively. Qualitatively, complexity describes a phenomena in which a system composed of individual pieces, each having simple interactions with one another, results in interesting bulk properties that would otherwise not exist. One example of a complex biological system is the bird flock, in particular, a starling murmuration. Starlings are known to move in the direction of their neighbors and avoid collisions with fellow starlings, but as a result of these simple movement choices, the flock as a whole tends to exhibit fluid-like movements and form …

Viscosities, Diffusion Coefficients, And Mixing Times Of Intrinsic Fluorescent Organic Molecules In Brown Limonene Secondary Organic Aerosol And Tests Of The Stokes–Einstein Equation, Dagny A. Ullmann, Mallory L. Hinks, Adrian M. Maclean, Christopher Butenhoff, James W. Grayson, Kelley Barsanti, Jose L. Jimenez, Sergey A. Nizkorodov, Saeid Kamal, Allan K. Bertram

Physics Faculty Publications and Presentations

Viscosities and diffusion rates of organics within secondary organic aerosol (SOA) remain uncertain. Using the bead-mobility technique, we measured viscosities as a function of water activity (a_w) of SOA generated by the ozonolysis of limonene followed by browning by exposure to NH₃ (referred to as brown limonene SOA or brown LSOA). These measurements together with viscosity measurements reported in the literature show that the viscosity of brown LSOA increases by 3–5 orders of magnitude as the aw decreases from 0.9 to approximately 0.05. In addition, we measured diffusion coefficients of intrinsic fluorescent organic molecules within brown …

Diffusion Of Gold Nanoparticles Within Polymer Solutions And Gels, Kavindya Kumari Senanayake R W H

Wayne State University Dissertations

Soft matter is a subfield of condensed matter physics including systems, such as polymers, colloidal dispersions, liquid crystals, surfactants. Understanding their interaction and dynamics is essential for many interdisciplinary fields of study as well as important for technological advancements. We used gold nanoparticles (AuNPs) to investigate the length-scale dependent dynamics in dilute, semidilute, entangled polymer solutions and gels. Two-photon fluctuation correlation spectroscopy (FCS) technique was used to investigate the translation diffusion coefficient of AuNPs. For polymer solutions, we found that existing hydrodynamic and obstruction models are inadequate to describe the size dependence of the particle diffusion coefficient. Within entangled Poly …

Imaging The Three-Dimensional Orientation And Rotational Mobility Of Fluorescent Emitters Using The Tri-Spot Point Spread Function, Oumeng Zhang, Jin Lu, Tianben Ding, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

Fluorescence photons emitted by single molecules contain rich information regarding their rotational motions, but adapting single-molecule localization microscopy (SMLM) to measure their orientations and rotational mobilities with high precision remains a challenge. Inspired by dipole radiation patterns, we design and implement a Tri-spot point spread function (PSF) that simultaneously measures the three-dimensional orientation and the rotational mobility of dipole-like emitters across a large field of view. We show that the orientation measurements done using the Tri-spot PSF are sufficiently accurate to correct the anisotropy-based localization bias, from 30 nm to 7 nm, in SMLM. We further characterize the emission anisotropy …

The Computational Study Of Fly Swarms & Complexity, Austin Bebee

Senior Theses

A system is considered complex if it is composed of individual parts that abide by their own set of rules, while the system, as a whole, will produce non-deterministic properties. This prevents the behavior of such systems from being accurately predicted. The motivation for studying complexity spurs from the fact that it is a fundamental aspect of innumerable systems. Among complex systems, fly swarms are relatively simple, but even so they are still not well understood. In this research, several computational models were developed to assist with the understanding of fly swarms. These models were primarily analyzed by using the …

The Advection-Diffusion Equation And The Enhanced Dissipation Effect For Flows Generated By Hamiltonians, Michael Kumaresan

Dissertations, Theses, and Capstone Projects

We study the Cauchy problem for the advection-diffusion equation when the diffusive parameter is vanishingly small. We consider two cases - when the underlying flow is a shear flow, and when the underlying flow is generated by a Hamiltonian. For the former, we examine the problem on a bounded domain in two spatial variables with Dirichlet boundary conditions. After quantizing the system via the Fourier transform in the first spatial variable, we establish the enhanced-dissipation effect for each mode. For the latter, we allow for non-degenerate critical points and represent the orbits by points on a Reeb graph, with vertices …

Fractional Brownian Motion With A Reflecting Wall, Alexander H. O. Wada, Thomas Vojta

Physics Faculty Research & Creative Works

Fractional Brownian motion, a stochastic process with long-time correlations between its increments, is a prototypical model for anomalous diffusion. We analyze fractional Brownian motion in the presence of a reflecting wall by means of Monte Carlo simulations. Whereas the mean-square displacement of the particle shows the expected anomalous diffusion behavior (x²) ~ t^α, the interplay between the geometric confinement and the long-time memory leads to a highly non-Gaussian probability density function with a power-law singularity at the barrier. In the superdiffusive case α > 1, the particles accumulate at the barrier leading to a divergence of the …

Investigation Of Iron Oxide Nanocolloidal Suspension Diffusion Using A Direct Imaging Method, Ashley E. Rice, Ana Oprisan

Journal of the South Carolina Academy of Science

We performed a set of experiments using a direct imaging method to investigate the diffusion process of iron oxide, Fe₂O₃, nanoparticles. We studied concentration fluctuations that move against the concentration gradient and induce disturbances in the interface between the iron oxide suspension and water in the sample cell. Using this imaging method in combination with the differential dynamic algorithm for image processing, we are able to extract information about the power, size, and lifetime of the fluctuations. We performed this experiment both in the presence and in the absence of a 4.2 mT magnetic field. We …

Analysis Of Residence Time In The Measurement Of Radon Activity By Passive Diffusion In An Open Volume: A Micro-Statistical Approach, Mark P. Silverman

Faculty Scholarship

Residence time in a flow measurement of radioactivity is the time spent by a pre-determined quantity of radioactive sample in the flow cell. In a recent report of the measurement of indoor radon by passive diffusion in an open volume (i.e. no flow cell or control volume), the concept of residence time was generalized to apply to measurement conditions with random, rather than directed, flow. The generalization, leading to a quantity r ∆t , involved use of a) a phenomenological alpha-particle range function to calculate the effective detection volume, and b) a phenomenological description of diffusion by Fick’s law to …

Brownian Motion Of Solitons In A Bose-Einstein Condensate, Lauren M. Aycock, Hilary M. Hurst, Dimitry K. Efimkin, Dina Genkina, Hsin-I Lu, Victor M. Galitski, I. B. Spielman

Faculty Research, Scholarly, and Creative Activity

We observed and controlled the Brownian motion of solitons. We launched solitonic excitations in highly elongated ⁸⁷ Rb Bose-Einstein condensates (BECs) and showed that a dilute background of impurity atoms in a different internal state dramatically affects the soliton. With no impurities and in one-dimension (1D), these solitons would have an infinite lifetime, a consequence of integrability. In our experiment, the added impurities scatter off the much larger soliton, contributing to its Brownian motion and decreasing its lifetime. We describe the soliton's diffusive behavior using a quasi-1D scattering theory of impurity atoms interacting with a soliton, giving diffusion coefficients consistent …

Using Underground Radon To Detect Inactive Geological Faults, Germán Rodríguez Ortiz

Open Access Theses & Dissertations

This Thesis presents the results of an investigation of the concentration of radon in soil around a fault in the East Franklin Mountains in the El Paso area in West Texas. The connection between underground radon exhalations near active faults has been known for decades, but possible similar increases of underground radon levels around inactive faults have not been studied as thoroughly. Arguing that the dilatancy-diffusion model used to explain the phenomenon near active faults does not apply to the case of inactive faults, a hypoThesis is formulated under which increased levels of underground radon must be present near inactive …

Towards A Prediction Of Landscape Evolution From Chemical Weathering And Soil Production, Eric Alan Jackson

Browse all Theses and Dissertations

The time evolution of a periodic landscape under the influence of chemical weathering and physical erosion is computed. The model used incorporates weathering and soil production as a flux limited reaction controlled by groundwater flow. Scaling of the flow rate is obtained from a percolation theoretic treatment. The erosion of the soil material produced by this process is modeled by the diffusion of elevation, as consistent with downslope soil transport proportional to the tangent of the angle of the topography, and application of the equation of continuity to surface soil transport. Three initial topographies are examined over a periods of …

Single Particle Tracking: Analysis Techniques For Live Cell Nanoscopy., Peter K. Relich

Physics & Astronomy ETDs

Single molecule experiments are a set of experiments designed specifically to study the properties of individual molecules. It has only been in the last three decades where single molecule experiments have been applied to the life sciences; where they have been successfully implemented in systems biology for probing the behaviors of sub-cellular mechanisms. The advent and growth of super-resolution techniques in single molecule experiments has made the fundamental behaviors of light and the associated nano-probes a necessary concern among life scientists wishing to advance the state of human knowledge in biology. This dissertation disseminates some of the practices learned in …

Effects Of Time And Diffusion Phase-Lags In A Thick Circular Plate Due To A Ring Load With Axisymmetric Heat Supply, R. Kumar, N. Sharma, P. Lata

Applications and Applied Mathematics: An International Journal (AAM)

The purpose of this paper is to depict the effect of time, thermal, and diffusion phase lags due to axisymmetric heat supply in a ring. The problem is discussed within the context of DPLT and DPLD models. The upper and lower surfaces of the ring are traction-free and subjected to an axisymmetric heat supply. The solution is found by using Laplace and Hankel transform techniques. The analytical expressions of displacements, stresses and chemical potential, temperature and mass concentration are computed in transformed domain. Numerical inversion technique has been applied to obtain the results in the physical domain. Numerically simulated results …

Method To Measure Indoor Radon Concentration In An Open Volume With Geiger-Mueller Counters: Analysis From First Principles, Mark P. Silverman

Faculty Scholarship

A simple method employing a pair of pancake-style Geiger-Mueller (GM) counters for quantitative measurement of radon activity concentration (activity per unit volume) is described and demonstrated. The use of two GM counters, together with the basic theory derived in this paper, permit the detection of alpha particles from decay of 222Rn and progeny ( 218 Po , 214 Po ) and the conversion of the alpha count rate into a radon concentration. A unique feature of this method, in comparison with standard methodologies to measure radon concentration, is the absence of a fixed control volume. Advantages afforded by the reported …

Method To Measure Indoor Radon Concentration In An Open Volume With Geiger-Mueller Counters: Analysis From First Principles, Mark P. Silverman

Faculty Scholarship

A simple method employing a pair of pancake-style Geiger-Mueller (GM) counters for quantitative measurement of radon activity concentration (activity per unit volume) is described and demonstrated. The use of two GM counters, together with the basic theory derived in this paper, permit the detection of alpha particles from decay of 222Rn and progeny ( 218Po , 214 Po ) and the conversion of the alpha count rate into a radon concentration. A unique feature of this method, in comparison with standard methodologies to measure radon concentration, is the absence of a fixed control volume. Advantages afforded by the reported GM …

Classical Transport In Disordered Systems, Antonios Papaioannou

Dissertations, Theses, and Capstone Projects

This thesis reports on the manifestation of structural disorder on molecular transport and it consists of two parts. Part I discusses the relations between classical transport and the underlying structural complexity of the system. Both types of molecular diffusion, namely Gaussian and non-Gaussian are presented and the relevant time regimes are discussed. In addition the concept of structural universality is introduced and connected with the diffusion metrics. One of the most robust techniques for measuring molecular mean square displacements is magnetic resonance. This method requires encoding and subsequently reading out after an experimentally controlled time, a phase ϕ to the …

Tunable Controlled Release Of Molecular Species From Halloysite Nanotubes, Divya Narayan Elumalai

Doctoral Dissertations

Encouraged by potential applications in rust coatings, self-healing composites, selective delivery of drugs, and catalysis, the transport of molecular species through Halloysite nanotubes (HNTs), specifically the storage and controlled release of these molecules, has attracted strong interest in recent years. HNTs are a naturally occurring biocompatible nanomaterial that are abundantly and readily available. They are alumosilicate based tubular clay nanotubes with an inner lumen of 15 nm and a length of 600-900 nm. The size of the inner lumen of HNTs may be adjusted by etching. The lumen can be loaded with functional agents like antioxidants, anticorrosion agents, flame-retardant agents, …

Understanding Electrical Conduction In Lithium Ion Batteries Through Multi-Scale Modeling, Jie Pan

Theses and Dissertations--Chemical and Materials Engineering

Silicon (Si) has been considered as a promising negative electrode material for lithium ion batteries (LIBs) because of its high theoretical capacity, low discharge voltage, and low cost. However, the utilization of Si electrode has been hampered by problems such as slow ionic transport, large stress/strain generation, and unstable solid electrolyte interphase (SEI). These problems severely influence the performance and cycle life of Si electrodes. In general, ionic conduction determines the rate performance of the electrode, while electron leakage through the SEI causes electrolyte decomposition and, thus, causes capacity loss. The goal of this thesis research is to design Si …

Hydrodynamic Analogues Of Hamiltonian Systems, Francisco J. Jauffred

Graduate Masters Theses

A one-dimensional Hamiltonian system can be modeled and understood as a two-dimensional incompressible fluid in phase space. In this sense, the chaotic behavior of one-dimensional time dependent Hamiltonians corresponds to the mixing of two-dimensional fluids. Amey (2012) studied the characteristic values of one such system and found a scaling law governing them. We explain this scaling law as a diffusion process occurring in an elliptical region with very low eccentricity. We prove that for such a scaling law to occur, it is necessary for a vorticity field to be present. Furthermore, we show that a conformal mapping of an incompressible …

Gelatin Diffusion Experiment, Jennifer Welborn

Nanotechnology Teacher Summer Institutes

In this activity, nanotech participants will:

- See how food dyes and gelatin are used to model the delivery of nanoscale medicines to cells in the human body - Measure diffusion distances of 3 different colors of food dye by: Eye, photo image on a computer, ADI software (Analyzing Digital Images) Some useful websites:

• http://www.echalk.co.uk/Science/biologyContent.htm Life Processes and Cells
• http://workbench.concord.org/database/activities/321.html Molecular Workbench Database. Diffusion, osmosis, ...