Bulletin of the American Physical Society
18th Annual Meeting of the APS Northwest Section,
Volume 62, Number 7
Thursday–Saturday, June 1–3, 2017; Forest Grove, Oregon
Session D1: Poster Session I |
Hide Abstracts |
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D1.00001: Neutrosophic Triplet Field used in Physical Applications Florentin Smarandache, Mumtaz Ali Neutrosophic Triplet Field (NTF) is a set endowed with two binary laws (M, *, {\#}), such that: \newline a) (M, *) is a commutative neutrosophic triplet group; which means that: \newline - M is a set of neutrosophic triplets with respect to the law * (i.e. if x belongs to M, then neut(x) and anti(x), defined with respect to the law *, also both belong to M); \newline - the law * is well-defined, associative, and commutative on M (as in the classical sense); \newline b) (M, {\#}) is a neutrosophic triplet group; which means that: \newline - M is a set of neutrosophic triplets with respect to the law {\#} (i.e. if x belongs to M, then neut(x) and anti(x), defined with respect to the law {\#}, also both belong to M); \newline - the law {\#} is well-defined and associative on M (as in the classical sense); c) the law {\#} is distributive with respect to the law * (as in the classical sense). \newline Applications. \newline This new field of neutrosophic triplet structures is important, because it reflects our everyday life [it is not simple imagination!]. \newline The neutrosophic triplets are based on real triads: (friend, neutral, enemy), (positive particle, neutral particle, negative particle), (yes, undecided, no), (pro, neutral, against), and in general \textit{(\textless A\textgreater , \textless neutA\textgreater , \textless antiA\textgreater )} as in neutrosophy. ~ [Preview Abstract] |
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D1.00002: Neutrosophic Triplet Ring and its Applications Florentin Smarandache, Mumtaz Ali Neutrosophic Triplet Ring (NTR) is a set endowed with two binary laws (M, *, {\#}), such that: \newline a) (M, *) is a commutative neutrosophic triplet group; which means that: \newline - M is a set of neutrosophic triplets with respect to the law * (i.e. if x belongs to M, then neut(x) and anti(x), defined with respect to the law *, also belong to M); \newline - the law * is well-defined, associative, and commutative on M (as in the classical sense); \newline b) (M, {\#}) is a set such that the law {\#} on M is well-defined and associative (as in the classical sense); \newline c) the law {\#} is distributive with respect to the law * (as in the classical sense). [Preview Abstract] |
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D1.00003: Retardation effects in induced atomic dipole-dipole interactions Jeffrey McGuirk, Sean Graham We present mean-field calculations of azimuthally averaged retarded dipole-dipole interactions in a Bose-Einstein condensate induced by a laser, at both long and short wavelengths. Our calculations demonstrate that dipole-dipole interactions become significantly stronger at shorter wavelengths, by as much as 30-fold, due to retardation effects. This enhancement, along with the inclusion of the dynamic polarizability, indicate a method of inducing long-range interatomic interactions in neutral atom condensates at significantly lower intensities than previously realized. [Preview Abstract] |
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D1.00004: Primary Pressure Standard with Cold Atoms Pinrui Shen, Kais Jooya, James Booth, Kirk Madison We developed a method of using an ultra-cold ensemble of atoms confined in a trap as an atomic primary pressure standard. This primary standard uses a 3D MOT to trap $^{87}$ Rb and then transfers them into a quadrupole magnetic trap where atoms could collide with background gas atoms in a shallower trap, resulting in loss of the atoms. The measured loss rate is proportional to the density of the background gas particles and to a velocity-averaged collision cross-section. The advantages of this cold atom standard (CAS) are that it is based on immutable atomic properties, can be used to measure the pressure of any species - in contrast with existing pressure standards which only measures either Argon or Nitrogen, and it transduces loss rate into pressure. The CAS is currently being tested against a NIST-calibrated ionization gauge using both Argon and Nitrogen over the pressure range (10$^{-6}$ - 10$^{-9}$) Torr. The gauge factor for Argon is found to be 1.25 and the Nitrogen measurements have allowed the long-range Vanderwals coefficient for N$_{2}$ - Ar elastic collisions to be determined, which allows us for it to be used as a standard. We also studied the Majorana losses in this quadrupole magnetic trap and reduced its effect to improve the accuracy of the CAS. [Preview Abstract] |
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D1.00005: Binary gas mixture in a high speed channel Dr. Sahadev Pradhan The viscous, compressible flow in a 2D wall-bounded channel, with bottom wall moving in? the positive $x-$direction, simulated using the direct simulation Monte Carlo (DSMC) method,? has been used as a test bed for examining different aspects of flow phenomenon and separation performance of a binary gas mixture at Mach number \textit{Ma }$=$\textit{ (U\textunderscore w / }$\backslash $\textit{sqrt(}$\gamma $\textit{ k\textunderscore B T\textunderscore w /m)?) }in the range\textit{0.1 \textless Ma \textless 30}, and Knudsen number \textit{Kn }$=$\textit{ 1/(}$\backslash $\textit{sqrt(2) }$\pi $\textit{ d\textasciicircum 2 n\textunderscore d H)}in the range? \textit{.1 \textless Kn \textless 10}. The generalized? analytical model is formulated which includes the fifth order differential equation for the? boundary layer at the channel wall in terms of master potential ($\chi )$, which is derived? from the equations of motion in a 2D rectangular $(x - y)$coordinate. The starting point? of the analytical model is the Navier-Stokes, mass, momentum and energy conservation? equations in the $(x - y)$coordinate, where $x$and $y$are the streamwise? and wall-normal directions, respectively. The linearization approximation is used ((Pradhan {\&} Kumaran\textit{, J. Fluid Mech -}); (Kumaran {\&} Pradhan, \textit{J. Fluid Mech -})), where the equations of motion are truncated at linear order in the velocity and pressure perturbations to the base flow, which is anisothermal compressible Couette flow. Additional assumptions in the? analytical model include high aspect ratio \textit{(L \textgreater \textgreater H)}, constant temperature in the base state (isothermal condition), and low? Reynolds number (laminar flow). The analytical solutionsare compared with direct simulation Monte Carlo (DSMC) simulations and found good agreement (with a difference of less than 10{\%}), provided the boundary conditions are accurately incorporated in the analytical solution. [Preview Abstract] |
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D1.00006: DSMC Simulations of High Mach Number Taylor-Couette Flow Dr. Sahadev Pradhan The main focus of this work is to characterise the Taylor-Couette flow of an ideal gas between two coaxial cylinders at Mach number \textit{Ma }$=$\textit{ (U\textunderscore w / }$\backslash $\textit{sqrt\textbraceleft kb T\textunderscore w / m\textbraceright )}in the range 0.01 \textless Ma \textless , and Knudsen number \textit{Kn }$=$\textit{ (1 / (}$\backslash $\textit{sqrt\textbraceleft 2\textbraceright }$\backslash $\textit{pi d\textasciicircum 2 n\textunderscore d (r\textunderscore 2 - r\textunderscore 1))) }in the range 0.001 \textless Kn \textless , using two-dimensional (2D) direct simulation Monte Carlo (DSMC) simulations. Here, \textit{r\textunderscore 1}and \textit{r\textunderscore 2}are the radius of inner and outer cylinder respectively, \textit{U\textunderscore w}is the circumferential wall velocity of the inner cylinder, \textit{T\textunderscore w}is the isothermal wall temperature, \textit{n\textunderscore d}is the number density of the gas molecules, $m$and $d$ are the molecular mass and diameter, and \textit{kb}is the Boltzmann constant. The cylindrical surfaces are specified as being diffusely reflecting with the thermal accommodation coefficient equal to one. In the present analysis of high Mach number compressible Taylor-Couette flow using DSMC method, wall slip in the temperature and the velocities are found to be significant. Slip occurs because the temperature/velocity of the molecules incident on the wall could be very different from that of the wall, even though the temperature/velocity of the reflected molecules is equal to that of the wall. Due to the high surface speed of the inner cylinder, significant heating of the gas is taking place. The gas temperature increases until the heat transfer to the surface equals the work done in moving the surface. The highest temperature is obtained near the moving surface of the inner cylinder at a radius of about (1.26 r\textunderscore 1). [Preview Abstract] |
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D1.00007: DSMC simulations of leading edge flat-plate boundary layer flows at high Mach number Dr. Sahadev Pradhan The flow over a 2D leading-edge flat plate is studied at Mach number \textit{Ma }$= (U_{inf}/ \backslash $\textit{sqrt\textbraceleft k}$_{B}T_{inf}$\textit{/ m\textbraceright ) }in the range \textit{\textless Ma \textless 10}, and at Reynolds number number \textit{Re }$= (L_{T} U_{inf}$\textit{ rho}$_{inf\thinspace }$\textit{)/ mu}$_{inf\thinspace }$ equal to 10$^{\mathrm{\thinspace \thinspace }}$using two-dimensional (2D) direct simulation Monte Carlo (DSMC) simulations to understand the flow phenomena of the leading-edge flat plate boundary layer at high Mach number. Here, $L_{T}$is the characteristic dimension, $U_{inf}$and $T_{inf}$are the free stream velocity and temperature, \textit{rho}$_{inf}$ is the free stream density, $m$is the molecular mass, \textit{mu}$_{inf\thinspace }$is the molecular viscosity based on the free stream temperature $T_{inf},$and $k_{B}$is the Boltzmann constant. The variation of streamwise velocity, temperature, number-density, and mean free path along the wall normal direction away from the plate surface is studied. The qualitative nature of the streamwise velocity at high Mach number is similar to those in the incompressible limit (parabolic profile). However, there are important differences. The amplitudes of the streamwise velocity increase as the Mach number increases and turned into a more flatter profile near the wall. There is significant velocity and temperature slip ((Pradhan and Kumaran, J. Fluid Mech-2011); (Kumaran and Pradhan, J. Fluid Mech-2014)) at the surface of the plate, and the slip increases as the Mach number is increased. It is interesting to note that for the highest Mach numbers considered here, the streamwise velocity at the wall exceeds the sound speed, and the flow is supersonic throughout the flow domain. [Preview Abstract] |
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D1.00008: Thin film deposition using rarefied gas jet Dr. Sahadev Pradhan The rarefied gas jet of aluminium is studied at Mach number \textit{Ma }$=$\textit{ (U\textunderscore j / }$\backslash $\textit{sqrt\textbraceleft kb T\textunderscore j / m\textbraceright )}in the range \textit{.01 \textless Ma \textless 2}, and Knudsen number \textit{Kn }$=$\textit{ (1 / (}$\backslash $\textit{sqrt\textbraceleft 2\textbraceright }$\backslash $\textit{pi d\textasciicircum 2 n\textunderscore d H)} in the range \textit{.01 \textless Kn \textless 15}, using two-dimensional (2D) direct simulation Monte Carlo (DSMC) simulations, to understand the flow phenomena and deposition mechanisms in a physical vapor deposition (PVD) process for the development of the highly oriented pure metallic aluminum thin film with uniform thickness and strong adhesion on the surface of the substrate in the form of ionic plasma, so that the substrate can be protected from corrosion and oxidation and thereby enhance the lifetime and safety, and to introduce the desired surface properties for a given application. Here, $H$is the characteristic dimension, \textit{U\textunderscore j}and \textit{T\textunderscore j}are the jet velocity and temperature, \textit{n\textunderscore d}is the number density of the jet, $m$and $d$ are the molecular mass and diameter, and \textit{kb}is the Boltzmann constant. An important finding is that the capture width (cross-section of the gas jet deposited on the substrate) is symmetric around the centerline of the substrate, and decreases with increased Mach number due to an increase in the momentum of the gas molecules. DSMC simulation results reveals that at low Knudsen number \textit{((Kn }$=$\textit{ 0.01);}shorter mean free paths), the atoms experience more collisions, which direct them toward the substrate. However, the atoms also move with lower momentum at low Mach number$,$which allows scattering collisions to rapidly direct the atoms to the substrate. [Preview Abstract] |
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D1.00009: Composite reinforced metallic cylinder for high speed rotation Dr. Sahadev Pradhan The objective of the present study is to design and development of the composite reinforced thin metallic cylinder to increase the peripheral speed significantly and thereby improve the separation performance in a centrifugal gas separation processes through proper optimization of the internal parameters. According to Dirac equation (Cohen (1951)), the maximum separative work for a centrifugal gas separation process increase with 4th power of the peripheral speed. Therefore, it has been intended to reinforce the metallic cylinder with composites (carbon fibers: T-700 and T- 1000 grade with suitable epoxy resin) to increase the stiffness and hoop stress so that the peripheral speed can be increased significantly, and thereby enhance the separative output. Here, we have developed the mathematical model to investigate the elastic stresses of a laminated cylinder subjected to mechanical, thermal and thermo-mechanical loading. A detailed analysis is carried out to underline the basic hypothesis of each formulation. Further, we evaluate the steady state creep response of the rotating cylinder and analyze the stresses and strain rates in the cylinder. [Preview Abstract] |
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D1.00010: Analysis of high-speed rotating flow inside gas centrifuge casing Dr. Sahadev Pradhan The generalized analytical model for the radial boundary layer inside the gas centrifuge casing in which the inner cylinder is rotating at a constant angular velocity $\Omega $\textit{\textunderscore i} while the outer one is stationary, is formulated for studying the secondary gas flow field due to wall thermal forcing, inflow/outflow of light gas along the boundaries, as well as due to the combination of the above two external forcing. The analytical model includes the sixth order differential equation for the radial boundary layer at the cylindrical curved surface in terms of master potential ($\chi )$, which is derived from the equations of motion in an axisymmetric $(r - z)$ plane. The linearization approximation is used, where the equations of motion are truncated at linear order in the velocity and pressure disturbances to the base flow, which is a solid-body rotation. Additional approximations in the analytical model include constant temperature in the base state (isothermal compressible Couette flow), high aspect ratio (length is large compared to the annular gap), high Reynolds number, but there is no limitation on the Mach number. The discrete eigenvalues and eigenfunctions of the linear operators (sixth-order in the radial direction for the generalized analytical equation) are obtained. The solutions for the secondary flow is determined in terms of these eigenvalues and eigenfunctions. These solutions are compared with direct simulation Monte Carlo (DSMC) simulations and found excellent agreement (with a difference of less than 15{\%}) between the predictions of the analytical model and the DSMC simulations, provided the boundary conditions in the analytical model are accurately specified. [Preview Abstract] |
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D1.00011: Applications of Classical Spin Angular Momentum Robert Close The recent discovery of a classical interpretation of spin angular momentum has potential applications in mechanical engineering, fluid dynamics, and particle physics. Spin density is the field whose curl is equal to twice the momentum density. It is related to the usual angular momentum density by integration by parts. Helmholtz decomposition may be used to uniquely determine spin density from momentum density. Analysis of motion in terms of spin and torque densities has the advantage that compressible and incompressible velocity fields are explicitly separated. This is useful for separating compression and shear waves in solids. The equation relating spin and torque densities in incompressible viscous fluids is likewise simpler than the Navier-Stokes equation. The description of spin density in an ideal elastic solid has the same energy, momentum, and angular momentum operators as relativistic quantum mechanics. Interference of different Dirac wave functions gives rise to the Pauli exclusion principle, interaction potentials, and space quantization. These results lend credence to the idea that the vacuum can be modeled as an elastic solid, offering a simple paradigm for the understanding of quantum mechanics and gravity. [Preview Abstract] |
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D1.00012: Using Wavelets to Remove Unwanted Noise from RTS Signals Benjamin Hendrickson, Ralf Widenhorn, Morley Blouke, Denis Heidtmann, Erik Bodegom We propose a novel method to remove white and (1/f) noise from discrete 1-D signals. This method, which was developed for the analysis of random telegraph signal (RTS) noise, utilizes the discrete wavelet transform (DWT) and simple arithmetic to construct a noise free approximate representation of the original signal. There are two central aspects to the method, amplitude and time. The DWT creates a details vector that tracks the amplitude of the changes of the original signal sample to sample, similar in application to the derivative. These changes are then measured against the Universal Threshold (UT). If a change in the signal is larger than the UT the change is kept, if not, the change is set to zero. This ensures that large sudden changes are preserved, while small differences are disregarded. We also employ a temporal screen to disregard transient events that may have resulted from measurement error or unexpected single events such as cosmic rays. Our method is notable since it is completely arithmetic and time based, making it far more intuitive than many analytical techniques. [Preview Abstract] |
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D1.00013: ABSTRACT WITHDRAWN |
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D1.00014: stats++ : An Open-Source Statistical Software Package Jeevake Attapattu, Praveer Tiwari, Jeffrey McMahon We present stats++ (http://statsxx.com/), an open-source statistical software package. stats++ is advanced, comprehensive statistical software for: data collection and processing, statistics, machine learning, and optimization, with open C++ source code. Included is also a detailed wiki, for stats++ and data science (in general), and online discussion forums. stats++ can be used effectively and efficiently, even with little prior experience. Applications in computational physics are presented; in particular, machine-learned wavefunctions (quantum mechanics) and gravitational waveforms (general relativity). [Preview Abstract] |
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D1.00015: Quantum Phases of ${}^{4}$He in Reduced Dimensions Thomas Badman, Jeffrey McMahon When close to absolute zero, the large quantum motion of helium causes it to display exotic properties. Depending on the environment that the atoms are in, phases and transitions between them emerge in interesting ways. In this presentation, we present results from computer simulations of helium in reduced dimensions; in particular, when adsorbed to graphene and graphite. We use the numerically-exact diffusion Monte Carlo method, though address several contemporary issues regarding approximations and convergence. Interesting results include commensurate solid phases with stabilities that do not agree with previous work, the possibility of supersolidity, and anisotropic superfluidity that may be stabilized by straining the substrate. [Preview Abstract] |
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D1.00016: Metallic Hydrogen: A Liquid Superconductor? Craig Tenney, Zachary Croft, Jeffery McMahon High- and room-temperature superconductivity and metallic hydrogen have been singled out as two of the top three problems in all of physics. Both of these involve dense hydrogen. It is expected that at high pressures, hydrogen becomes metallic, and a superconductor. Recent calculations predict that the critical temperature is above room temperature; and thus that of melting. This suggests that hydrogen may remain superconducting in the liquid phase. In this presentation, we investigate this possibility. Results from first-principles simulations are presented and discussed. Our results show that the critical temperature remains high in the liquid phase, and above that of melting. Metallic hydrogen is therefore expected to be a liquid superconductor. These results significantly improve our understanding of fundamental interactions in condensed matter. [Preview Abstract] |
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D1.00017: Machine-Learned Template Bank for Gravitational Waves Praveer Tiwari, Jeffrey M. McMahon Last year, the Laser Interferometer Gravitational-Wave Observatory (LIGO) detected, for the first time, a gravitational wave. Such are useful, because they can can give a lot of information about their source, which would otherwise be impossible to get from other astronomical detectors. One way of extracting this information is a method called matched filtering. This involves first creating a template bank of gravitational waveforms, for different source parameters. That detected is then compared with, and matched to those from this bank. One problem with this way of generating the templates is that the equations of general relativity must be numerically solved, which can take several weeks to get an accurate waveform (and only for a single set of parameters). In this presentation, we discuss an approach based on machine learning, whereby an artificial neural network is trained to learn numerical waveforms for a wide parameter range. The machine can then be used calculate waveforms that are arbitrarily close to the numerical ones, even for parameters not included in the training. With this approach, we are creating a numerically-exact template bank for gravitational waves. [Preview Abstract] |
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D1.00018: Self Gravitation of Differentially Rotating Resolved Stars in Protosteller Systems Attila Varga, Kathryn Hadley, James Imamura In protostellar systems, where a disk of hot gas surrounds a young protostar, gravitational coupling between the star and the disk can arise, resulting in modes driven by the star. A comparison between point-mass stars and resolved stars in linear hydrodynamic simulations can be made in an attempt to examine the coupling of different modes in the systems. Concurrent research has used a star to disk mass ratio 5-1, here we use a 1-1 ratio. In point star systems, orbital coupling is seen between the point mass and the disk. This is compared to a differentially rotating resolved star, where the star can couple rotationally through the quadrupole of the flattened star. We examine the instabilities in the disk and star where bar like modes will form for spherical stars. We find that by increasing the flatness of the star and approaching the dynamic threshold for bar like modes, the star will strongly couple and change the modes in the disk. For the most spherical stars, the disk coupling matches the point star. This behavior can be quantified by comparing eigenvalues of the systems, and qualitatively analyzed by comparing phase plots of constant phase loci for the star and disk where a qualitative difference is seen. Plots showed smooth winding arms distinct from bar modes. [Preview Abstract] |
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D1.00019: Gravitational Coupling of Uniformly Rotating Resolved Stars in Star-Disk Systems. Willis Rogers, Kathryn Hadley, James Imamura Using linear hydrodynamics equations we modeled protostellar star-disk systems with resolved stars to determine the effect of gravitational coupling on the evolution of the star and the disk. We wanted to see if stars with low ratios of kinetic energy to gravitational potential energy, with star to disk mass ratio of 1:1, behave similarly to models of higher mass ratios. Stars were modeled as slowly rotating spheroids in uniform rotation (UR). For the systems modeled, the star in UR did not have an appreciable effect on the evolution of its associated disk. Gravitational coupling of the star and disk was found to be weak. The modeled disks show similar mode growth rates and frequencies when the star was represented as a point mass, and as a resolved mass in UR. Single armed modes in the disk displace the center of mass of the star, this suggests the star’s orbital motion is being driven by angular momentum coupling. Stars in UR had weak multipole moments compared to the monopole, similar to the point star case. The multipole increases with flatness of the star, differentially rotating stars which can be flatter could support stronger gravitational coupling. Models with higher mass ratios show similar multipole properties with shorter growth times and larger frequencies. [Preview Abstract] |
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D1.00020: The effect of radiative cooling on clump formation in self-gravitating disks William Dumas, Jim Imamura, Kathryn Hadley, Rebecka Tumblin, Erik Keever One pathway to the formation of multiple stellar systems is the fragmentation of a rotationally supported disk formed after initial gravitational collapse of a rotating interstellar cloud. Recent observations of the system Barnard 5 (Pineda et al. 2015) consisting of a protostar and four condensations, and the triple protostar system L1448 IRS3B (Tobin et al. 2016) point to the important role that gravitational instability likely plays in the formation of multiple stellar objects. We investigate the effect of radiative cooling on massive self-gravitating disks surrounding a central stellar point mass ranging from 0.1 to 0.4 of the disk mass. Linear analysis shows that in the absence of cooling the growth of instability is dominated by modes related to the Jeans instability named J-modes (Hadley et al. 2014). Calculations are performed using the hydrodynamics code CHYMERA. Equilibrium models are evolved using a parameterized cooling function with cooling rates that lead to constant cooling time scales from 0.5 to 10 times the orbital period at density maximum in the disk. In contrast to most published studies of fragmentation of disks into clumps, we find that fragmentation is found even for the weakly cooled models. Models with higher star to disk mass ratio develop more clumps. [Preview Abstract] |
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D1.00021: When Will I Ever Use This? Providing a Unifying Theme in the Electronics Laboratory Through Fluid Mechanics Experiments Daniel Borrero We discuss the transformation of a junior-level instrumentation laboratory from a sequence of cookbook labs to a semester-long, project-based course. In the original course, students conducted a series of activities covering the usual electronics topics (amplifiers, filters, oscillators, logic gates, etc.) and learned basic LabVIEW programming for data acquisition and analysis. Students often see these topics as disconnected and not immediately related to ``real'' lab work. To provide a unifying theme, we restructured the course around the design and construction of a simple fluid dynamics experiment called a Taylor-Couette system where fluid is sheared between rotating coaxial cylinders, leading to a variety of interesting phenomena. The electronics labs were reworked to guide students from fundamental electronics through the design and construction of a stepper motor driver to drive the cylinders. Some of the legacy labs were replaced with a module on computer-aided design (CAD) in which students designed parts for the apparatus, which they then built in the departmental machine shop. Signal processing topics like spectral analysis were introduced in the context of time-series analysis of video data acquired from flow visualization. The course culminated with a capstone project in which students conducted experiments of their own design on a variety of topics in rheology and nonlinear dynamics. [Preview Abstract] |
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D1.00022: Arduino-based Electronics in a Junior-level Advanced Laboratory Course Michaela Kleinert, Daniel Borrero-Echeverry We discuss our experience working with Arduino microcontrollers to develop a project-based alternative to the traditional analog electronics module of our junior-level advanced laboratory course. This module has two parts. During the first part, students carry out tutorial exercises to learn about the basic structure of Arduino programming, as well as a variety of sensors (thermistors, photoresistors, ultrasonic position sensors, etc.), user inputs (switches, potentiometers, etc.), and output devices (LED displays, servo motors, etc.). They also learn how to interface the Arduino with a computer for use as a data-logger. In the second part of the module, students devise, build, and test an electronics project of their own design. Arduinos are an ideal platform for this type of project-based learning due to their low cost, which allows students to experiment without fear of damaging expensive equipment. Examples of student projects include a lightning detector, a Morse code translator, and a variety of interactive games. We present preliminary results from attitudinal surveys administered pre- and post-instruction, which suggest students are more confident in their electronics and programming skills after completing the module. We also discuss ideas for future implementations of the course. [Preview Abstract] |
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D1.00023: Experimental and Analytic Analysis on Double Parabolic Solar Reflectors Yun Jin Jeong, Jae Won LiM Although solar energy is currently an abundant and widely used renewable energy source around the world, one of its biggest drawback is its low efficiency in converting sunlight into usable energy. Thus, increasing the efficiency of the panels is the biggest concern that must be addressed in order to develop solar energy as a source that can replace fossil fuels in the coming future. Solar energy is converted from sunlight into electricity, thermal energy, and other types of energy. One of the most common ways to harness solar energy is through solar panels, reflectors, and concentrators, which are equipped with solar cells or photovoltaic cells. To find the optimal environment for maximizing efficiency of solar energy production, this research conducts experiments that test new combinations of reflectors . The reflector components on the system are altered to achieve highest efficiency. The first proposed reflector has primary and secondary parabolic reflectors, and the second proposed reflector has double parabolic reflectors with Fresnel Lens. By changing the location of Fresnel Lens, the foci of the two parabolic reflectors are calculated and the amount of electricity is measured by a voltmeter. [Preview Abstract] |
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D1.00024: Virtual Human Joint Modeling and Predictive Dynamic Analysis Using Computational Simulation Jae Young Lee, Richard Kyung In modern society, virtual human modeling and simulation has been an attraction for researchers. The new findings have influenced new designs and products in numerous fields. Predictive dynamics are used to create virtual simulations required to describe certain human motions and make physics related predictions. In this paper, human joint motions have been captured and analyzed using physical and computational simulation. This research virtually constructs a method that evaluates the effect of motion of human joint under a specific external loading. To test the method, two degrees of freedom serial chain mechanism with mass, damper, and spring constant have been used. Multibody system dynamics, embodying theories based on classical and analytical mechanics, are applied to interconnected mechanical systems. Since the use of dynamics of the mechanical human motions is an obstacle, simplification of the body joints has been made. Also, to further understand and solve this obstacle, numerical and vector computations are used. Predictive dynamics are describes as a second order ODE(Ordinary Differential Equations) solving the present algorithm. The mass of the system adheres to a spring and damper, and the system response with initial conditions has been calculated. [Preview Abstract] |
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D1.00025: Development of Noise Reduction Algorithm Using Physical and Computational Analysis Dongkyun Kim, Richard Kyung Most sounds are comprised of a complex mixture of vibrations. An intricate combinations of high frequencies and low frequencies make up the integrated sound of spectrum. In this paper, computational mathematics and physics knowledge were employed to carry out the spectral analysis and to create an algorithm for removal of noise from a sound sample. First, the wave forms and the spectrums of sound file were analyzed to check its energy and the level of fuzzy tones in their harmonics. Because the entire plot of the frequency is tool lengthy and noisy to model with the Fast Fourier Transform (FFT) function in Matlab, analysis on the first few periods of the sound sample was carried out. Once the correct curve fitting for the decay of the peaks of the sound amplitude had been determined, creating an accurate computer generated denoised model of the sound was as simple as multiplying the modeled Fourier series by the curve fitted model using an algorithm. [Preview Abstract] |
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D1.00026: Mechanical and Computational Analysis of Engine Torque and Dynamic Properties Ji Won Jung, Richard Kyung Recently, the demand for the development of dynamic properties of internal combustion engine is continuously rising in order to find a new and efficient engine model. This research presents mathematical and computational analysis for a motion of a non-offset piston connected to a crank through a connecting rod in internal combustion engine This paper shows how the engine torque and other dynamic properties are found, and also shows the outcomes as different graphs. The force resulting from the pressure in the cylinder was calculated using factors such as the area of the piston, the indicated cylinder pressure, and the atmospheric pressure. Also the inertial forces of moving parts are considered in the calculation the total force, because it was necessary to know the effect of moving mass as well. Torque was found after checking the force acting in the axial direction of the cylinder, and the force acting on the connecting rod axis was found in terms of connecting the rod angle. To obtain the torque of an engine, a coding was written using the Matlab software. [Preview Abstract] |
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D1.00027: Estimating Natural Disaster Trends Using Statistical and Computational Simulations Seung Min Cho, Richard Kyung In order to combat the heightened natural disasters, data stations were expanded, allowing experts to closely monitor the intensity and breadth of the disasters. Among the many disasters, floods are the most common natural disaster, causing natural disaster fatalities worldwide. Modeling natural disasters in a specific area and carrying out data analysis can be a difficult task when the pattern is complicated. It is not easy for researchers to extract the patterns from the analytical process in order to characterize the natural disaster. The objectives of this research are to describe the impact of flood events on human populations and to identify risk factors associated with these outcomes using statistical and computational simulations. In this paper, several functions, such as regression analysis using least square method, are used to find trends and proper curves that describe the natural disasters. Developing a better outcome that would decrease the deviation or minimize the total sum of the squares of the residuals, it is statistically possible to describe if the pattern of a sample data exists for a certain period, or if this technology is a reliable way to design new environmental experiments. [Preview Abstract] |
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D1.00028: Physical and Biochemical Mechanics of the Dental Bacteria Biofilm and Polyphenols as Plaque Inhibitors Yong Woong Lee, Yejin KIm, Jae Won Lim The cause of periodontitis is different from other diseases caused by single pathogenic microorganisms. Accumulation of different types of bacteria that forms dental plague or dental film causes the periodontal disease. Microbial molecules and oral fluids make their way into enamel by slowly diffusing through a pellicle. Adaptive changes and interactions of the microorganisms in this complex make them resistant to antimicrobial agents. In this research, molecular mechanisms of bacterial adhesion in the dental bacteria biofilm were biophysically studied. To figure out how the microorganisms such as Streptococcus mutans are able to adhere to the acquired pellicles, biochemical examination of the plaque site occurred by bacterial accumulation on teeth was carried out. In the present paper, computational modeling was employed to find the electrostatic and hydrophobic interaction of a component of bacterial protein's side chain and a component of the acquired pellicle. In addition, polyphenols, which inhibit the formation of plaque caused by the Streptococcus mutans, were computationally modeled and biochemically analyzed to find their bond properties and enthalpy of formations. [Preview Abstract] |
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