Bulletin of the American Physical Society
19th Annual Meeting of the APS Northwest Section
Volume 63, Number 6
Thursday–Saturday, May 31–June 2 2018; Tacoma, Washington
Session D1: Poster Session |
Hide Abstracts |
Chair: Tsunefumi Tanaka, University of Puget Sound Room: Thomas Hall Tahoma Room |
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D1.00001: Space-Time Contraction Fields as an Alternative to Dark Matter John Huenefeld General Relativity portrays curved space-time around matter analogous to a deformed rubber sheet. Adding an inward dynamic to a GR field provides a basis to propose a space-time contraction field around matter. Contracting space-time will increase orbital velocities at large distances above that of gravity alone. This contraction field, when applied to a model galaxy yields a flat rotation curve consistent with observations and could be an alternative to dark matter. The contraction field will also create gravitational lensing and hold galactic clusters together, explaining many of the observations attributed to dark matter. Cosmologically, space-time contraction fields surrounding galaxies embedded within other regions of expanding space-time can lead to an observed acceleration of universal expansion. As the surrounding space-time expands, the proportion of expanding space-time to that of contracting space-time within the universe will increase, thus the observed expansion rate of the universe may appear to increase. The theoretical contraction field arises from inertial reference frames in freefall around a gravitating mass. An inertial reference frame falling from an infinite distance reveals a dynamic process within the metric where space-time is continuously contracted around matter in a very specific way. [Preview Abstract] |
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D1.00002: Origin of the Jupiter's Electromagnetic Field Hassan Gholibeigian, Kazem Gholibeigian Two permanent phenomena have appeared inside the Jupiter due to the unbalanced gravitational attraction of the planets and Sun on it. The first is dislocation of the core, and the second is bulge of the liquid metallic ocean of hydrogen and helium. Direction of these two phenomena is toward the result of the gravitational fields' vector on the Jupiter. Distance between centers of the Jupiter and its core varies permanently in magnitude and direction. In other words, dislocated core rotates a round per 10 hours around the Jupiter's center, inverse of the Jupiter's rotation, while it is rotating around itself. This dynamic system of the very hot and massive core creates the strongest magnetic and gravitational fields in the solar system. The radius of the core's rotation becomes maximum, when the Jupiter is approaching to the Sun, in its perihelion which its gravitational field becomes 2.71 times more. Therefore, the Jupiter's magnetic field becomes maximum. This dynamic system occurs inside the Sun and planets too. During the Jupiter's perihelion, when the Earth passes between the Sun and Jupiter, the peak of the solar cycles occurs. Because, based on the Solar cycles hypothesis [Kazem {\&} Hassan Gholibeigian, EGU, 2016], main cause of the solar cycles can be the Jupiter. [Preview Abstract] |
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D1.00003: VIGOR: Virtual Interaction with Gravitational waves to Observe Reality Jay Howard, Michael Park, Joey Key A primary obstacle in physics-based outreach and engagement is the difficulty of facilitating intuitive interactions with physically-accurate representations of the relevant phenomena. We have been collaborating with a group at UT-Dallas to help develop a simulation called VIGOR: Virtual Interaction with Gravitational waves to Observe Reality, which can be used in both public and academic spaces to help facilitate understanding of gravitational wave astronomy. At UW Bothell we have engaged a team of undergraduate developers to help us build the application, with a primary goal of moving the app from a tablet-based simulation to a virtual reality environment. We present here a demo of the simulation, along with a sample in-class activity using VIGOR that we have developed. [Preview Abstract] |
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D1.00004: Optical and Thermodynamic Analysis of Organic Solar Cells Using Physical and Computational Simulations Woong Jae Baek, Andrew Kyung An organic solar cell is a type of photovoltaic cell which produces electricity from sunlight by the photovoltaic effect. Conductive organic polymers are used for light absorption and charge the cell. Optical properties and constants of isotropic thin P3HT:PC61BM film systems, such as refractive index, relative permittivity (dielectric constants), wavelength were considered in the calculations of solar energy. Also the geometrical variations such as thickness and width, and material properties were considered to check those dependencies. Poly(3-hexylthiophene) (P3HT) which is a hydrophobic and well stacking semiconducting polymer was used as an electron donator in the current organic electronics simulations. As an electron acceptor, PCBM, a fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester, was used in conjunction with the electron donor materials P3HT. The computational programs such as Avogadro and Chemcraft have been used in an effort to discover the optimal method and to compute the measurements of stability of the solar cell. The Auto Optimize Tool was used for each and every fullerene derivative modeled in this project to determine its optimization energy. The Universal Force Field (UFF) option was selected for all fullerene derivatives modeled. [Preview Abstract] |
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D1.00005: Performance of biocompatible silk-polypyrrole actuators under biologically relevant conditions Jo'Elen Hagler, Ben Peteson, Janelle Leger, Amanda Murphy Biocompatible actuators that are capable of controlled movement and can function under biologically relevant conditions are of significant interest for biomedical applications. Previously, we demonstrated that a composite of silk biopolymer and the conducting polymer poly(pyrrole) (PPy) can be formed into a functional bilayer bending actuator. These silk-PPy composites can generate forces comparable to human muscle (\textgreater 0.1 MPa) making them ideal candidates for interfacing with biological tissues. We explore the performance of these silk-PPy bilayer actuators under biologically relevant conditions including exposure to protein, serum, enzymes, and biologically relevant temperatures. Free-end bending actuation performance, current response, force generation, and mass degradation under these conditions were investigated. We find that the performance of our silk-PPy devices is sensitive to protein serum and enzyme type, as well as the temperature at which the devices are actuated. However, the silk-PPy actuators under all conditions tested here retained the ability to bend, generate forces, and conduct currents at comparable levels to devices tested under standard operating conditions. The results suggest that our silk-PPy actuators are promising candidates for implantation \textit{in vivo }and for interfacing with biological systems. [Preview Abstract] |
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D1.00006: Thermodynamic and Stereo-chemical Analysis of Gadolinium and Iodinated Contrast Agents for Diagnosis of Alzheimer's Disease Yoosong Song, Richard Kyung Gadolinium derivatives have become commonly used for Contrast Agents in medical treatments such as early diagnosis of Alzheimer's disease. The unique magnetic properties of the gadolinium ion allowed it to be used in a variety of ways, especially in MRI scanning. The energy optimization feature of the Avogadro, Chemcraft and Gaussian programs allow evaluation of the molecule’s thermodynamic and biomedical stability and efficiency. In this paper, the thermodynamic and stereo-chemical effectiveness of gadolinium-based molecules as MRI contrast agents was analyzed. The PC61BA-(Gd-DO3A), a functionalized fullerene that is created through synthesis of PC61BA and Gd-DO3A was modeled and analyzed. Also functionalized polymers with highly iodinated molecules were studied. By making efficient use of the computational programs, we were able to study the computational and theoretical aspects of the functionalized Gadolinium molecules and iodinated molecules to determine whether the derivatives are safe and stable contrast agents. The Auto Optimize Tool and Universal Force Field (UFF) options were used for each and every derivatives modeled in this project to determine its optimization energy. [Preview Abstract] |
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D1.00007: Investigating phenotypically aberrant E. Coli subpopulations via high-throughput 1D single-cell confinement Shahla Nemati, Andreas E. Vasdekis Recent advances in single-cell methods have greatly improved our understanding of cellular heterogeneity, namely cell-to-cell phenotypic differences. Here, we focus on a distinct form of cellular heterogeneity pertaining to phenotypically aberrant subpopulations in clonal cultures. These subpopulations often emanate from failures in DNA replication and nucleoid segregation, which in E. coli, our model system, can result in elongated cells with cell-lengths at division of at least two-fold higher than non-aberrant cells. However, our understanding of how these cells emerge, their frequency, and ramifications on culture response remains incomplete. In this paper, we discuss our approach to address this knowledge-gap using microfluidics and time-lapse microscopy. To accomplish this, we employed two different methods. First, we integrated microfluidics with agar gels and allowed cells to grow in a 2D monolayer. Second, we employed micron-scale channels enabling cellular growth strictly in 1D. Comparing these two methods, we found that 1D cell confinement improved throughput by more than three-fold. We will present our preliminary results on the frequency, growth rates, cell-cycle dynamics of aberrant phenotypes using the improved approach. [Preview Abstract] |
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D1.00008: A Study on the Cardio-mechanics to Detect the Behavior of Biofluid in the Transvalvular System Ki Jung Kim, Jaehyuk Lim, Jeong Hwan Lee In this paper, appropriate biofluid dynamic principles of heart mechanisms were applied to understand the effects; Continuity equation, Bernoulli’s Principle, and Gorlin Equation were used to acquire values that measure the degree of change caused by stenosis on the heart. The purpose of this study is to create a web application using computer programing to detect the behavior of biofluid in the transvalvular system. A web application program created in Javascript, has been adapted to the website to aid users to determine if one has cardiovascular disease; specifically aortic stenosis. In addition, the application shows the physical effects of aortic valve stenosis on the human heart, as well as to link the progression of aortic valve stenosis to the homeostatic mechanisms and sensitivity of the heart. In order to support our hypothesis, several biofluid dynamics-based laws and equations were applied in an attempt to computationally and mathematically prove the role that pressure may have on the system, observing for both significant reactions caused by drastic pressure changes and possible correlations with pressure and other fluid dynamic-related properties. [Preview Abstract] |
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D1.00009: A Study of the DNA Mutation Causing Leber Congenital Amaurosis (LCA) Using Gene Editing Program and Molecular Geometry Analysis Justin Namjoo KIm, Andrew Kyung, Yoonjeong Kwon Retinitis pigmentosa (RP) is a genetic eye disorder that causes visual impairment related to retinal degeneration. Symptoms of RP include a gradual functional decrease in night vision and peripheral vision, often leading to “tunnel vision”. It is rare, however, for a patient to experience complete blindness as a result of RP. Leber Congenital Amaurosis (LCA) is another genetic eye disorder that causes visual impairment in the form of light sensitivity. RP and LCA Type 2 (LCA2) genetic eye disorders have both been linked to a mutation in gene RPE65. RPE65 gene mutation has been commonly identified in LCA patients across a number of countries. This paper identifies and analyzes abnormalities in the genetic sequence that lead to mutations in patients with genetic eye disorders. First, a computational study was performed with genetic mutations identified in RP patients, then a computational study was also performed with pathogenic mutations identified in LCA patients, examining sequence abnormalities in their DNA. Finally, sterochemical analysis was performed to examine the thermodynamic stability of the previously proposed RPE65 O-alkyl cleavage mechanism. [Preview Abstract] |
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D1.00010: A Study on Functionalized Cancer Scanning Contrast Agents in Positron Emission Tomography (PET) Jung Hwan Heo, Andrew Kyung In medical imaging, contrast agents play an important role in refining the clarity and contrast of a body part. Higher clarity and contrast allow the physician to clearly differentiate between the body structure and nearby tissue. This enables accurate examination and diagnosis of any abnormality in the body part. Contrast agents are used for medical scans such as the Positron Emission Tomography (PET) scan, a frequently used diagnostic method in modern clinical practice that does not use damaging ionizing radiation. Through electrochemical techniques, researchers have studied the possibility of using aqueous nanoparticles as contrast agents. This paper uses theoretical and computational simulations to examine nanomaterials such as fluorescent functionalized particles and to evaluate the potential of nano-scaled contrast agents to detect tumor cells. The potential of using nano-scaled contrast agents is determined by molecular stability and safety. This paper compares and analyzes the thermodynamic stabilities of various contrast agents, such as derivatives of lanthanide element and metal oxides. The thermodynamic stability is determined by the molecule’s optimized energy, which can be computed through chemical programs and the Density Functional Theory(DFT). [Preview Abstract] |
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D1.00011: Metastability of extreme wide bandgap semiconductor alloys. Dinesh Thapa, Jesse Huso, Marlayna Garza, Matthew McCluskey, Leah Bergman Two types of UV semiconductors were alloyed in varying compositions in order to change their optical properties by-design. Specifically, we combined ZnO with wurtzite structure and a band gap of 3.3 eV with MgO with rocksalt structure and a bandgap of 7.7 eV. By varying the composition of these semiconductors in a sample, one can achieve an alloy that has a band gap between 3.3 eV and 7.7 eV. This alloy system is deposited far from its thermodynamic equilibrium so to achieve a single phase alloy with the wurtzite structure. The key point of our research is the determination of the stability of the alloys. Annealing studies were performed at elevated temperatures up to 900 C to study the phase separation dynamics of the alloys and the impact of temperature on the structural phase separation and on the bandgap characteristics. [Preview Abstract] |
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D1.00012: ZnO coated nanosprings: deposition methods, structural and optical properties Negar Rajabi, Dinesh Thapa, Jesse Huso, David Mcilroy, Leah Bergman This study presents the effect of film thickness on the structural, morphology and optical properties of ZnO coated Si nanosprings on silicon substrates via sol-gel and atomic layer deposition (ALD). The films coated via sol-gel were dipped 13, 17 and 19 times and the average ZnO grain size was calculated by X-ray diffraction (XRD) at 10, 20 and 27 nm respectively. Also, the ALD films were applied with 80, 120 and 160 cycles and the average grain size is 10, 21 and 30 nm respectively. By increasing the thickness (number of depositions) the crystal structure, Photoluminescence (PL) and Raman Spectra of sol-gel and ALD samples improved due to the better crystallity. Field-Emission Scanning Electron Microscopy in our experiment showed the ALD method results in a better quality film related to the sol-gel growth method. [Preview Abstract] |
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D1.00013: Angular Momentum in Continuum and Quantum Mechanics Robert Close Classical angular momentum is usually defined relative to a specific origin as the cross product of the radial vector with linear momentum. This definition is useful for analysis of rigid body motion. However, the local spin density (\textbf{s}) defined by its curl ($\nabla \times {\rm {\bf s}}=2{\rm {\bf p}})$ is more appropriate for analyzing continuous media since it is an intrinsic physical property of the system independent of any choice of coordinate origin. The equation of evolution of spin density is derived from the physical principle that changes not attributable to translation and steady rotation are due to torque. We discuss application to a viscous fluid and ideal elastic solid. A second-order wave equation describing perturbations of an elastic solid may be transformed into a first-order Dirac bispinor equation. The result is a mechanistic interpretation of relativistic quantum mechanics, with stationary matter interpreted as standing waves. We discuss dynamical operators, the Pauli exclusion principle, interaction via potentials, and quantization, including space quantization. The existence of spin angular momentum in elementary particles, consistent with classical wave theory, provides evidence for the solid nature of the vacuum. [Preview Abstract] |
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D1.00014: Visualizing Equations in Physics with 3D Plastic Surfaces Jonathan W. Alfson, Paul J. Emigh, Aaron Wangberg, Robyn Wangberg, Elizabeth Gire Many physics students have difficulty visualizing and representing multivariable functions. While useful representations of these functions exist, there is a demand for additional tools and activities to help students make connections between variables and understand the relationships among those variables. The Raising Physics to the Surface project is developing 3D plastic models (surfaces) of functions found in physical systems, including mechanics, thermodynamics, and electrostatics. We discuss how the surfaces can be used in classroom activities and what benefits or disadvantages are provided by the inclusion of surfaces during instruction. [Preview Abstract] |
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D1.00015: Facile growth of Metal dichalognide nanostrusstures Ji-Hyun Jang, Kwanghyun Kim, Jin-Wook Min We report an easy and industrial friendly chemical vapour deposition (CVD) technique to make various two dimensional transition metal dichalcogenide (TMD) nanostructures (MoSe$_{\mathrm{2}}$, MoTe$_{\mathrm{2}})$. To the best of our knowledge, this is the first report on synthesizing MoTe$_{\mathrm{2}}$ nanosheets using a CVD method. The optimized conditions for making few layer films as well as vertical nanostructures are presented. The morphology, structure and crystallinity of the TMD nanostructures are evaluated by means of SEM, XRD, XPS, spectroscopic ellipsometry, Raman spectroscopy techniques. The optical bandgap of the MoSe$_{\mathrm{2}}$, MoTe$_{\mathrm{2}}$ nanosheets are confirmed to be 1.535 eV and 1.252 eV respectively from the photoluminescence spectroscopy results. [Preview Abstract] |
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D1.00016: A Study on Rocket Mechanics and Dynamics Using Physical and Computational Simulations Hyunseung Cho, Richard Kyung The mechanics of rocket motion involve aerodynamics and mechanics. Launching a rocket initiates movement of the rocket through the air in a manner dependent on speed, direction, and angle. The trajectory of the rocket is also influenced by environmental factors such as pressure, temperature, humidity, and altitude. Varied trajectories result from different forces acting on the rocket, and Newton’s three laws of motion provide a fundamental understanding of the rocket’s motion upon the launch. The magnitude of the drag force is influenced by the rocket’s shape and size, in addition to the viscosity and density of the air. Lift is the force that acts perpendicular to the oncoming flow direction. Also the shape of the cross section of the fin is crucial factor for creating adequate lift force and drag force for different efficiency. In this paper, to predict and manipulate the trajectory of a rocket, knowledge of drag, lift and gravitational forces are employed with the computational simulations. In applying these three major forces acting on the rocket with Newton’s Second Law, equations for motion in two and three dimensions are used. In this study, physics, mechanics, and programming were used to evaluate rocket fin geometry and trajectory curvature of rocket. [Preview Abstract] |
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D1.00017: Study on the Porosity and Water Retention in Soil Using Phase Diagrams and Soil Mechanics David Jaehyun Park, Amanda Kyung Soil mechanics is a study field of soil physics and geo-engineering that describes the arrangement and attachment of soil particles such as clay, silt, and sand. It includes solid mechanics and fluid mechanics but it differs from those study area in the sense that soils consist of a heterogeneous mixture of fluids and particles. The soil particles are grouped into structures known as aggregates. The process of grouping soil particles is initiated through flocculation, which involves the exchangeable ions and affects water retention in the soil. In this case, experimental and direct measurements of unsaturated conductivities are difficult due to many factors involved in this situation. In this paper, since soil structure is a property of soil that relates to the arrangement and attachment of many particles, we showed how the flocculation of the particles to facilitate aggregation occurs. Hydraulic conductivity through different soils was calculated based on water retention data, and also computational simulations and calculations were conducted to find porosities for different soils. Finally, sieve analysis considering the size distribution of gravel and sand particles were performed using computational calculations. [Preview Abstract] |
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D1.00018: Study on the Solar Cell Using Mathematical and Physical Analysis Min Kyu Kim, Richard Kyung Renewable, green energy is an important field of research amidst the 21st century energy crisis. Although many researchers around the world have been consistently looking for new energy sources, there is a lack of research on efficient storage of energy produced from eco-friendly sources. This research considers how to increase the electric field and capacitance through inserting metal oxides and organic materials as dielectrics to use such dielectrics as a substantial tool for sustainable solar cell development. Optical properties of isotropic thin organic materials, such as refractive index, dielectric constants, and wavelength were considered in the calculations of solar energy. In addition, the mathematical equations, geometrical variations, and material properties were considered to check those dependencies on the efficiency of the solar cell. The research focuses on increasing electric properties of solar batteries using different dielectrics, differing the structure of capacitors and combinations of inorganic metal joints and organic carbon links. The goal is to increase the maximum capacity of batteries that can store more energy with better efficiency. [Preview Abstract] |
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D1.00019: Optimization and Sensitivity Analysis of Suspension System in a Vehicle Impact Using Dynamics and Computational Simulations Jun-hyuk Jonathan Lee, Richard Kyung The dynamics analysis in a vehicle impact-absorption uses optimization to predict motion while considering many factors, such as mass, acceleration, and damping, including the overall equations of motion itself. The predictive dynamics model for impact-absorption system is used in order to simulate the movement of the multi-link manipulator such as a car suspension system. Since the car suspensions regulate the body’s motion and health, it is physically and biologically important and fundamental to analyze the reaction forces on the human body and the car elements itself during the impact-absorption process. Presented model is set up as a spring-mass-damper system that is combined with the multi-link system with a two-degree of freedom serial or parallel chain mechanism. In this research, the governing equations of motion are derived using the two-degree of freedom in the car suspension system, considering various factors and conditions. This research also studies the phenomena between the human bodies and car elements accountable for the forces causing injury through mechanical and vibrational analysis. The lumped element, spring-mass systems containing several hypothetical mass components with springs and dashpots are analyzed using computational simulations. [Preview Abstract] |
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D1.00020: A Study on the Activity and Safety of the Organochloride Pesticides Using Theoretical and Computational Analysis Catherine Cho, Richard Kyung Organochloride pesticides are very effective at eliminating pests, especially insects. But many of these chemical products are viewed negatively by environmental activists and consumers because of one well-known and now banned organochloride pesticide: dichloro diphenyl trichoroethane (DDT). The chlorine-carbon bonds are particularly strong, which keeps these chemicals from breaking down quickly or from being soluble in water. The durability of organochloride pesticides' chemical makeup is one of the reasons it is so effective as an insecticide but also potentially harmful – although it protects crops for a long time, it remains in an animal's system. Along with DDT, other organochloride pesticides, such as aldrin, dieldrin, heptachlor, mirex, chlordecone, and chlordane, have been banned by the U.S. Environmental Protection Agency. In this project, we assessed the thermodynamical and stereochemical safety of several types of organochloride pesticide derivatives. A computational chemical software measured the optimized geometries and chemical properties of the modeled structures by using theoretical values and considering the molecules’ atomic properties. [Preview Abstract] |
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D1.00021: Estimating Economic Index Trends Using Statistical and Computational Simulations Chanyeol Kim, Richard Kyung In order to speculate about the future of an economy, it is crucial to understand economic trends. The fundamental relationship between the share price of a company’s stock and its per-share earnings, also known as the P/E ratio, is a good indicator of the trend of the economy. While investors have used the P/E ratio to determine whether to buy or sell a certain stock, relatively less attention has been paid to the significance of the P/E ratio in terms of its ability to reflect the status of the economy. This paper collected about a century’s worth of P/E ratio data and used the Gumbel distribution to analyze the data. Then, the processed data were plotted in a frequency graph in order to visualize the general trend of the data. In addition, the data were plugged into MATLAB, a programming software, and were experimented with multiple fitting models that could offer further insight to the data trend. Using these methods revealed that lower P/E values are more likely to repeatedly occur, while higher P/E values are much less likely to repeatedly occur. [Preview Abstract] |
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D1.00022: Rehabilitation Methodology for Individuals with Disabilities for Their Health and Social Self-Sufficiency Lois Kim, Sun Lee This research aims to provide rehabilitation methodology and service delivery systems improvements, health and functioning improvements, and employment, independent living, family support, and economic and social self-sufficiency promotions for individuals with disabilities. Disability statistics serve two important goals: providing national, state, and local data to policy-makers, service providers, advocates and others for solving issues that people with disabilities face and improving the society's understanding of obstacles to persons with disabilities. Due to the fact that these statistical data are only similar within state borders and that the cause of developmental disabilities is different among people, it is difficult to draft a universal standard for everyone. The resources, at large, are used for those with chronic developmental disabilities, leading to a lack of funding for intellectual and cognitive disabilities. In other words, the distribution of funding is skewed against those of intellectual disabilities, barring them from their chance at living a regular life. In this research, the trends in economy and employment outcomes of individuals with developmental disabilities were studied and analyzed. [Preview Abstract] |
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D1.00023: Fractal Lifetimes {\&} Atomic Battery Bambang Sukartiono For lifetime, it is supposed there that the intensive parameter (return temperature, chemical potential, etc) fluctuates. These fluctuations evolve on a long time scale-Ryazanov-2003. We reviews them to fractal space time whereas distinguishes time continuous or discrete.If it is true that the conclusion depends in particles {\&} parameters involved, we found Filippov, \textit{et.al}: \textbf{Atomic Battery based-on Ordered Dust-plasma structures''} where the ranges of parameters for which the Coulomb crystallization of dusty plasma in atomic battery is expected are determined. It's funny if Cf$^{\mathrm{255\thinspace }}$took in comparison to ``\textbf{small'' }factor from Dittrich-2003: f(EE,EC) $=$ (1 -- $\alpha $ ) EE $+ \quad \alpha $ C $+$ c$_{\mathrm{F}}$/N. As well as the retrieved statement : ``Experiment on the photovoltaic transformation of the energy of fast electrons to electrical energy are carried out''- \textit{ibid} last but not least May 1995's CERN superconductivity in particle accelerators enhances mesocopic spallation reactions for Gunzi Saito {\&} Frackowiak. [Preview Abstract] |
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D1.00024: Pulsar Signal Simulator Jacob Hesse Recent observations of gravitational waves (GW) have opened up a new field of gravitational astronomy. The North American Nanohertz Observatory for Gravitational waves (NANOGrav) collaboration aims to detect and study nanohertz GW using a Pulsar Timing Array made of millisecond pulsars. To help study the signal from these stars, a project called the Pulsar Signal Simulator (PSS) is being built by NANOGrav and is the focus of my research. The simulator is able to calculate a pulsar signal from source to detection. It starts with the initial signal of a pulsar and adds the different effects that alter the signal, before it reaches Earth. The coded in effects include \textit{dispersion},\textit{ scintillation}, and \textit{scattering}. Each of these effects are results of the radio waves from the pulsar traveling through the interstellar medium. My project is to work on a portion of the PSS that takes, as input, the name of a known pulsar and simulates a signal with user-defined changes. I aim to increase efficiency as well as validate simulation output. This project is beneficial to NANOGrav by characterizing the noise in our galactic scale GW detector. Progress in GW astronomy will allow for deeper insight into galaxy evolution, black holes, and the early history of the universe. [Preview Abstract] |
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D1.00025: Effect of Seed Density on Splash Cup Seed Dispersal Patrick Wigger, Rachel Pepper Splash cup plants are plants that utilize a small, mm-sized cup filled with seeds as a method of seed dispersal. The cup uses kinetic energy of an incident raindrop in order to project the seeds away from the plant up to 1 meter. The dispersal distance is important to ensure the offspring are not clustered too tightly to the parent plant. It has previously been found that a cup angle of 40 degrees to the horizontal is optimal for maximum dispersal of water from cups with no seeds. In this study we examine if the 40 degree cup is optimal for cups containing seeds with varying densities. We released uniform water drops above 5.0 mm 3D printed models of splash cups, using 1.0 mm plastic and glass microspheres of varying densities to simulate seeds. We observed the dispersal characteristics of each bead type by measuring the final seed locations after each splash, and by recording high speed video to determine the angle and velocity of the seeds as they exited the cup. [Preview Abstract] |
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D1.00026: Experimental and theoretical approach towards an SPR biosensor based on guided-wave plasmon polariton modes Sarah Clark, MacKenzie Jewell, Valerie Beale, Brad Johnson, Janelle Leger Surface Plasmon Resonance (SPR) is the phenomenon in which an incident electromagnetic wave couples to charge density oscillations on a metal. The resulting excitation, known as a surface plasmon polariton (SPP), will propagate along the metal-dielectric interface to which it is confined. In an SPR biosensor, a protein binding interaction at the metal surface leads to a modification of the refractive index, altering the SPP excitation conditions. Recently, we have designed a structure that supports guided-wave plasmon polariton modes (GW-PPMs), plasmonic excitations that demonstrate increased propagation lengths compared to those of traditional SPPs in certain regions of phase space. Because it has been shown that higher propagation lengths can lead to increased sensitivity in SPR biosensors, employing GW-PPM-supporting structures could potentially lead to advances in the state-of-the-art performance. In order to correlate biosensor performance with propagation lengths, however, a detailed and complete theoretical model needs to be developed that considers the specific experimental conditions utilized for SPR biosensor testing. We will discuss experimental and theoretical progress towards the production of high-performance SPR biosensors based on GW-PPMs. [Preview Abstract] |
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D1.00027: Ultraviolet Raman spectroscopy of epitaxial ScFeO$_{\mathrm{3}}$ films Nicholas Parker, Katelyn Wada, Lauren Garten, Hanjong Paik, Jennifer Andrew, John Perkins, Matt Beard, Darrell Schlom, David Ginley, Dmitri Tenne Scandium ferrite, ScFeO$_{\mathrm{3}}$ is a recently discovered multiferroic, i.e. a material that exhibits coexisting ferroelectric and magnetic ordering. 10 and 100 nm-thick ScFeO$_{\mathrm{3}}$ films grown by molecular-beam epitaxy on (0001) Al$_{\mathrm{2}}$O$_{\mathrm{3}}$ substrates have been studied by variable temperature ultraviolet Raman spectroscopy. ScFeO$_{\mathrm{3}}$ spectra at room temperature are consistent with the polar hexagonal \textit{P6}$_{3}$\textit{cm} structure. The temperature evolution of the Raman spectra of a ScFeO$_{\mathrm{3}}$ film measured in the range 10--1300 K indicate a transition to a non-polar (likely \textit{P6}$_{3}$\textit{/mmc}) phase; fitting of the temperature dependence of the Raman intensities yields a transition temperature of 900\textpm 50 K. Temperature evolution of Raman spectra indicates that there may be another structural transition at higher temperatures, around 1300 K. Raman spectroscopy results are consistent with other characterization data (x-ray diffraction, reflection high energy electron diffraction, terahertz spectroscopy). [Preview Abstract] |
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D1.00028: Social Topics in Physics: A New and Intersectional Physics Course Michael Vignal We created a conference-style course for undergraduate and graduate students with the purpose of increasing knowledge and awareness of social issues in physics and related STEM fields. In our course, titled “Social Topics in Physics,” students meet weekly to discuss readings on social difference and systems of power in the sciences. Our aim was to validate students’ life experiences and contributions to the class. Students were invited to share ideas and recommend articles for the class and to shape the weekly discussions by connecting the readings to their own experiences. Additionally, we tried to focus on intersections of difference and power in a way that promoted curiosity and compassion. This poster details the different resources and considerations that have made this physics course successful. [Preview Abstract] |
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D1.00029: Students' lack of awareness surrounding special-case analysis MacKenzie Lenz, Elizabeth Gire Physics instructors often expect students to reflect on the meaning of and think about the correctness of their answers. One common reflection strategy is to perform a special-case analysis. We define special-case analysis to be an algebraic manipulation of an answer to confirm what will occur in a new situation for which the student has a known answer or a good intuition. We interviewed eleven students in the first term of an introductory physics with calculus course. Six of the students were enrolled in a reformed course that prompted reflection on homework and five were in a non-reformed course without prompted reflection. These interviews were performed with the intent of learning about student's knowledge and implementation of reflection strategies. One prompt was explicitly designed to encourage special-case analysis; when solving this prompt none of these eleven students preformed a special case analysis. When asked latter if they knew what a limiting or special-case was nine students had no recollection of this strategy and two thought it sounded familiar. [Preview Abstract] |
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D1.00030: Student Application of Special-Case Analysis for Physics Sense-Making Kelby Hahn, Paul Emigh, MacKenzie Lenz, Elizabeth Gire Experts often analyze their own answers to physics questions to check that they align with known results or their physical intuition about the situation. We call this strategy for physics sense-making special-case analysis. Analysis of homework from students in a sophomore mechanics class found that this same strategy is employed by students to check their answers this was followed by an in-depth analysis of what students write when they perform a special-case analysis. This analysis includes details from homework prompts where students were explicitly asked to perform a special-case analysis as well as prompts where students were asked to sense-make and chose to use special-case analysis. We found that students use varied reasoning to defend and understand the special-cases they are analyzing. Some reasoning that students use is comparable to expert use of special-case analysis. Students also appeal to alternative lines of reasoning, such as their ``correct mathematics'' and descriptions about the variable behavior to justify the results of their special cases. [Preview Abstract] |
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D1.00031: Periodic and Quasiperiodic Dynamics of Optoelectronic Oscillators with Narrowband Time-Delayed Feedback Yunjia Bao, Lucas Illing Optoelectronic oscillators with delayed feedback are nonlinear systems that can generate high-frequency electric signals of high spectral purity. The nonlinearity, however, limits the ability to produce stable periodic signals that also have large amplitude because transitions into a chaotic state may occur. This study examines the dynamics and bifurcations of the system as the feedback gain and feedback delay are varied. We experimentally explored feedback parameter regions of stable periodic oscillations as well as the region-boundaries where a torus bifurcation leads to quasiperiodic behavior. We develop a theory that provides the periodic solutions and the feedback parameters at which torus bifurcations occur. We find good agreements between experiments, results of numerical simulations, and theory. [Preview Abstract] |
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D1.00032: Experimental Measurements and Analysis of the Effects of Damping on Circular Drums William Miyahira When a drum is struck, its vibration can be characterized as a linear combination of vibrational modes. These modes are comprised of a number of nodal lines and circles (m,n) where the drum does not vibrate. Each mode has a different decay time, with some of the higher frequency modes ringing out longer than others. Many drummers choose to get rid of this ringing by placing commercially sold gels on the perimeter of the drum. This research looked to develop a method of measuring the decay time of each mode when the drum is struck, and how the addition of the gel affected those measurements. Using an electronic speckle-pattern interferometer optical laser setup along with waterfall data measurements from a spectrum analyzer, I was able to determine the relative decay rates of the modes present when a drum is struck. From these measurements, it was found that the (3,1), (4,1), and (5,1) modes tended to ring out.~When a gel was placed on the drum, it was found that the overall decay time of the drum was decreased by over one second, with the most significant changes being found in the (3,1), (4,1), and (5,1) modes. The gel was observed to act as a viscoelastic material, so that some of the energy in the vibration is lost to heat, which causes the decay rates of the modes to increase. In the future, one could use similar techniques to observe other dampening materials, or observe drums with two heads. [Preview Abstract] |
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D1.00033: Lengthened-Width for UI:the shortest River in the WORLD of Tamborasi,Celebes Widastra Hidajatullah Enhances S1-Final Project in UI denotes Moore's Law in Microelectronics evolve 18 to 24 months doublances follows the topic are Thermally Activated Stoner-Wohlfarth Model we propose the iniials of 1999 Nobel Prize in Physics:"A Theory To Reckon With" from Minister of Bina-Marga 1966: HE. Mr. BrigGen-TNI R. HARTAWAN/Herr Hartmann from Goethe Instituut.
We sought "constricted[ make narrows] loop" of hysteresis parameters depict in Lancis &Kent,2003 anf Ecology Industry described by Mauro Reini as "constructal law" through thermoeconomics.Palazzo,2013 offers with thermoeconomics & EXERGY methods.From Jose Morales & Norcedal nevertheless provided 2000 |
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D1.00034: Largest Fortress In The World From Sultanate Buton III to HE. Mr. Ir. Airlangga Hartarto Sastrosoenarto, MMBA Widastra Hidajatullah Nevertheless,the estabilshment of Wolio Fortress in 16th century formered "Multimeso-Fractal Exciton-FUSION/MMfF & the ex-City on-burnt of Great Fire of London, September 4- 1666 a well as 1662 Sultanate of Cirebon occupies by Sunan Girilaya implied by Perang Gerilya 1942-1947 in Netherlands Indie now are Negara Kesatuan Republik INDONESIA/N.K.R.I provided 6801/v/1992 Piagam Tanda Kehormatan Pahlawan-GERILJA dated Oct 5, 1992. Also depict in HerMajesites Mvr. Dr-HC Hj DYAH MEGAwATI SOEKARNOPUTRI to "isoptera" of termites we found whereas for Environmental Magnetism sought by HE. Mr. Dr. AZWAR MANAF,MMet retrieved Industrial Ecology & THERMOECONOMICS. Further, we appreciates largest Fortress in the World of Sultanate BUTON III to HE. Mr. Ir. AIRLANGGA HARTARTO SASTROSOENARTO,MMBA to be the the VicePresident of the Republic INDONESIA 2019-2024 "cari aku di Air.." & "maria" : Latin name of seas are the Perils of Chrap Oil hidden or not questions electret of Calectro D219 denotes in UFO detector HE. Mr. Ir. ROY HADIOSO TALOGO from Toronto, Canada accompanies Wakil Rektor bidang Administrasi Umum, Alumni & Komunikasi ITB 2017-2021.... [Preview Abstract] |
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D1.00035: Nanoindentation Between Isomorphicity to Displacement through Attractor MayBe Widastra Hidajatullah Took the furthers of ``constricted loop'' from Lanci {\&} Kent-2003 we compare ``generic Stoner-Wohlfarth particle'' with ``generic stable deformation'' provided by Mayr involves gauge theory as \textbf{``A Room Temperature Molecular/Organic-based Magnet''}-1991. Defined by \textbf{nanoindentaion'' }dealt with ``load displacement measurement'' we sought ``anisotropic elastic moduli ever inspected of ``isomorphicity of these moduli spaces for general G'' --\textit{ibid}-h 11 coincides such as the moduli of elliptic curves depict in genericSW. Describes if we appreciates biomolecular electronics'' i.e. we adopt autocatalyst as the ability of certain chemicals to enhance we offers for Engel elasticity `` as well as \textit{constant elasticity of substitution''-}Hollis Chenery- so ``anisotropy distribution is extentively \underline {\textbf{iterated }}to fig 5a from Elwenspoek whereas the fig 5b of ``strange attractor'' for ``the attractor maybe a point, a line or a fractal''/Paul Davies-1992. [Preview Abstract] |
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D1.00036: Exactly solvable chaos in an electromechanical oscillator Lucas Illing A novel electromechanical chaotic oscillator is described that admits an exact analytic solution. The oscillator is a hybrid dynamical system with governing equations that include a linear second order ordinary differential equation with negative damping and a discrete switching condition that controls the oscillatory fixed point. The system produces provably chaotic oscillations with a topological structure similar to either the Lorenz butterfly or R\"ossler's folded-band oscillator, depending on the configuration. Exact solutions are written as a linear convolution of a fixed basis pulse and a sequence of discrete symbols. We find close agreement between the exact analytical solutions and the physical oscillations. Waveform return maps for both configurations show equivalence to either a shift map or tent map, proving the chaotic nature of the oscillations. [Preview Abstract] |
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